Her2 targeting cyclic peptides and conjugates thereof

Abstract

Described herein are cyclic peptides targeting human epidermal growth factor receptor 2 (HER2), and their incorporation into compounds for radioligand imaging and therapies, as well as methods and / or uses of such compounds for the imaging, treatment and / or prevention of HER2-implicated diseases and disorders (e.g., cancer).

Description

[0001] 763537: NIT-59597PC (PAT059597-FF) HER2 TARGETING CYCLIC PEPTIDES AND CONJUGATES THEREOF CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application Serial No.63 / 637,572 5 filed April 23, 2024 and U.S. Provisional Application Serial No.63 / 760,270 filed February 19, 2025, which are hereby incorporated herein by reference in their entirety. SEQUENCE LISTING The instant application contains a Sequence Listing which has been submitted herewith in 10 ST.26 XML format and is hereby incorporated by reference in its entirety. Said ST.26 XML copy, created on April 17, 2025, is named 763537_NIT-59597PC_ST26_SEQUENCE_LISTING and is 529,390 bytes in size. BACKGROUND 15 Since the discovery of the human epidermal growth factor receptor 2 (HER2) as an oncogenic driver in a subset of breast cancers and the development of HER2 targeted therapies, the prognosis of HER2 amplified breast cancer has significantly improved (Meric- Bernstram, F. et al., Clin Cancer Res.25(7):2033-2041, 2019). Several monoclonal antibodies and tyrosine kinase inhibitors (TKIs) led to success in the HER2 amplified and / or 20 overexpressed setting (Kunte et al., Cancer.126(19):4278-42882020), which make up approximately 20% of all breast cancers. However, for the roughly 50% of breast cancers with low levels of HER2 expression and lack of amplification, development of these multiple classes of agents has proven unsuccessful (Tarantino, P. et al., J Clin Oncol.38(17):1951- 1962, 2020; Fehrenbacher, L. et al., J Clin Oncol. 38(5) :444-453, 2020; Eiger, D. et al.25 Cancers (Basel).13(5):1015, 2020). This is thought to be due to lack of antigen engagement in the case of the monoclonal antibodies and TKIs, dose-limiting toxicities caused by the payload itself, and / or on-target activity in normal tissues in the case of the antibody-drug conjugates. In addition to an overall lower antigen density in HER2-low tumors, a high degree of heterogeneity for HER2 expression between individual cells of a given lesion is 30 widely accepted as another challenge (Ocaña, A. et al. Breast Cancer Res.2020, Jan 31;22(1):15, Marchio, C. et al. Semin Cancer Biol.2021 Jul;72:123-135). Several next generation HER2-directed antibody-drug conjugates are currently under clinical investigation (Kreutzfeldt et al. Am J Cancer Res. 2020 Apr 1;10(4):1045-1067).ENHERTU, an ADC coupling a topoisomerase I inhibitor to trastuzumab with a cleavable 1 763537: NIT-59597PC (PAT059597-FF) linker, has shown single agent antitumor activity in patients with HER low breast cancer. Currently, HER2 directed treatments in breast cancer are not indicated in patients with HER2 low disease. These patients do not benefit from targeted treatments and are usually treated with chemotherapy combinations. ENHERTU is currently being assessed in a randomized 5 trial in HER2 low (defined as immunohistochemistry (IHC) 2+ / in situ hybridization (ISH)- or IHC 1+ ISH- or untested) versus investigator choice of chemotherapy (Keam, SJ. Drugs. 2020 Apr; 80(5):501-508., Modi, S. et al. N Engl J Med.2020 Feb 13;382(7):610-621). Further, low level and heterogeneous expression of HER2 has posed an obstacle to extending current HER2-directed treatments to more patients. 10 Accordingly, there is a need for targeting agents having both high and specific affinity for HER2 and radiotherapeutic conjugates thereof. SUMMARY Provided herein are cyclic peptides that target human epidermal growth factor 15 receptor 2 (HER2), compounds incorporating such cyclic peptides, which are suitable for radiolabeling, corresponding pharmaceutical compositions, and methods and / or uses of the HER2-targeting compounds (also referred to as HER2-targeting ligands) for the imaging and treatment of HER2-implicated cancers. In particular, the present disclosure provides compounds, or pharmaceutically 20 acceptable salts or solvates thereof, comprising: a) at least one cyclized peptide that binds to human epidermal growth factor receptor 2 (HER2) with a dissociation constant (KD) of about 1000 nM or less as measured by surface plasmon resonance (SPR) at a temperature of 25 °C; and b) at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug. 25 In an aspect, provided herein is a compound, or a pharmaceutically acceptable salt or solvate thereof, comprising: a) at least one cyclized peptide , wherein 2 763537: NIT-59597PC (PAT059597-FF) , wherein A1-A9are as defined herein; and b) at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug, wherein the cyclized peptide conjugated to the at least one imaging agent, 5 chelating agent, radionuclide, or cytotoxic drug via any one of A1-A9, optionally through a linker. In some embodiments, the compounds are HER2-targeting compounds of formula (I), (Ia), (Ib), or (Ic): , 10 3 763537: NIT-59597PC (PAT059597-FF) , or a pharmaceutically acceptable salt or solvate thereof, wherein 5 P is a cyclic HER2-targeting peptide as defined above; L1is, independently at each occurrence, a bond or a linker; M is, independently at each occurrence, an imaging agent, a chelating agent, or a radionuclide, wherein the chelating agent is optionally radiolabeled with a radionuclide; 10 n is 1, 2, 3, or 4; and o is 1, 2, 3, or 4, wherein any of P, L1, or M is optionally substituted with an albumin binder, a biotin tag, or one or more polyethylene glycol (PEG) chains. In certain embodiments, the HER2-targeting compounds are radiolabeled with a 15 diagnostic or therapeutic radionuclide. Such radiolabeled compounds can be referred to a HER2-targeting radioligands, HER2-targeting radiotherapeutics, HER2-targeting radioimaging agents, or HER2-targeting radiopharmaceuticals. The present disclosure further provides pharmaceutical compositions comprising the HER2-targeting compounds described herein, or a pharmaceutically acceptable salt or solvate 20 thereof, and a pharmaceutically acceptable carrier. The present disclosure further provides a combination comprising the HER2-targeting compounds described herein, or a pharmaceutically acceptable salt or solvate thereof, and one or more therapeutically active agents. The present disclosure further provides a method of imaging HER2-related diseases 25 and disorders, comprising administering to a subject in need thereof a diagnostically effective amount of a HER2-targeting ligand and / or a HER2-targeting radioligand, or a pharmaceutically acceptable salt or solvate thereof, or a pharmaceutical composition described herein. The present disclosure further provides a method of treating and / or preventing HER2- 30 related diseases and disorders, comprising administering to a subject in need thereof a therapeutically effective amount of a HER2-targeting ligand and / or a HER2-targeting 4 763537: NIT-59597PC (PAT059597-FF) radioligand, or a pharmaceutically acceptable salt or solvate thereof, or a pharmaceutical composition described herein. BRIEF DESCRIPTION OF THE DRAWINGS 5FIG. 1 shows the results of the biodistribution studies performed with Example H1.FIG. 2 shows the results of the biodistribution studies performed with Example H2.FIG.3 is a graph of the effects of administration of Example H1 and Example H2 on HCC1187 Breast Cancer CDX Tumor growth. FIG.4 is a graph of the effects of administration of Example H2 on ST313 Breast10 Cancer PDX Tumor growth.FIG.5 is a graph of the effects of administration of Example J1 and Example J2 on NSCLC PDX Tumor growth. FIG.6 is a graph of the effects of administration of Example J2 on ST3932 Breast Cancer PDX Tumor growth.15 DETAILED DESCRIPTION Provided herein are cyclic peptides that target human epidermal growth factor receptor 2 (HER2), compounds incorporating such cyclic peptides, which are suitable for radiolabeling, corresponding pharmaceutical compositions, and methods and / or uses of the 20 HER2-targeting compounds (also referred to as HER2-targeting ligands) for the imaging and treatment of HER2-implicated disease, such as, e.g., cancer. Accordingly, described herein are HER2-targeting compounds (or alternatively, HER2-targeting ligands) comprising: a) at least one cyclized peptide , wherein 5 763537: NIT-59597PC (PAT059597-FF) , wherein A1-A9are as defined herein; and b) at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug, wherein the cyclized peptide conjugated to the at least one imaging agent, 5 chelating agent, radionuclide, or cytotoxic drug via any one of A1-A9, optionally through a linker. The HER2-targeting compounds can be, inter alia, a compound of formula (I), (Ia), (Ib), (Ic), or (Id): , 10 , , 6 763537: NIT-59597PC (PAT059597-FF) , 5 or a pharmaceutically acceptable salt or solvate thereof, where P is a cyclic HER2-targeting peptide; M is, independently at each occurrence, selected from an imaging agent, a chelating agent optionally chelated to a radionuclide, a radionuclide, and a cytotoxic drug; L1is a bond or a linker adapted to form a chemical bond between P and M; and n and o are each independently 1, 2, 3, or 4. 10 The compounds disclosed herein, including the compounds of Formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof, exhibit strong binding to HER2, i.e., exhibit a dissociation constant (KD) for human HER2 of about 1000 nM or less as measured by surface plasmon resonance (SPR) at a temperature of 25° C. Compounds of Formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable 15 salt or solvate thereof, also exhibit prolonged tumor retention time. Accordingly, described herein are methods of targeting HER2, imaging HER2- expression, and treating HER2-related disease, with a compound of any of Formulae (I), (Ia), (Ib), (Ic), or (Id) or a pharmaceutically acceptable salt or solvate thereof. The details of the disclosure are set forth in the accompanying description below. 20 Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, illustrative methods and materials are now described. Other features, objects, and advantages of the disclosure will be apparent from the description and from the claims. In the specification and the claims, the singular forms also include the plural unless the context clearly dictates otherwise. Unless defined otherwise, all 25 technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. All patents and publications cited in this specification are incorporated herein by reference in their entireties. It is further appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a 7 763537: NIT-59597PC (PAT059597-FF) single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable sub-combination. 5 Definitions Unless specific definitions are provided, the nomenclature used in connection with, and the procedures and techniques of, analytical chemistry, synthetic organic chemistry, and medicinal and pharmaceutical chemistry described herein are those well-known and commonly used in the art. Standard techniques may be used for chemical synthesis, and 10 chemical analysis. Certain such techniques and procedures may be found for example in “Remington's Pharmaceutical Sciences,” Mack Publishing Co., Easton, Pa., 21st edition, 2005, which is hereby incorporated by reference for any purpose. Where permitted, all patents, applications, published applications and other publications and other data referred to throughout in the disclosure are incorporated by reference herein in their entirety. 15 Unless otherwise indicated, the following terms have the following meanings: The terms “peptide,” “polypeptide,” and “protein” are used interchangeably herein and typically refer to a molecule comprising a chain of two or more amino acids (e.g., L- amino acids, D-amino acids, modified or derivatized amino acids, amino acid analogs, amino acid mimetics, etc.). 20 Unless otherwise indicated, naturally occurring L-amino acids and D-amino acids are both represented by either conventional three-letter, or capitalized one-letter, amino acid designations of Table 1. In some embodiments, naturally occurring L-amino acids are represented by either conventional three-letter, or capitalized one-letter, amino acid designations of Table 1. In some embodiments, D-amino acids, are represented by lower-case 25 one-letter amino acid designations corresponding to one-letter designations of Table 1, i.e., g, a, l, m, f, w, k, q, e, s, p, v, i, c, y, h, r, n, d, and t. Table 1. Naturally occurring amino acids G Glycine Gly P Proline Pro A Alanine Ala V Valine Val L Leucine Leu I Isoleucine Ile M Methionine Met C Cysteine Cys F Phenylalanine Phe Y Tyrosine Tyr 8 763537: NIT-59597PC (PAT059597-FF) WTryptophan Trp H Histidine HisK Lysine Lys R Arginine Arg Q Glutamine Gln N Asparagine Asn E Glutamic Acid Glu D Aspartic Acid Asp S Serine Ser T Threonine Thr The term “L-amino acid,” as used herein, refers to the “L” isomeric form of an amino acid, and conversely the term “D-amino acid” refers to the “D” isomeric form of an amino acid (e.g., (D)Asp or D-Asp; (D)Phe or D-Phe). Amino acid residues in the D isomeric form 5 can be substituted for any L-amino acid residue, as long as the desired function is retained by the peptide. D-amino acids may be indicated as customary in lower case when referred to using single-letter abbreviations. For example, D-arginine can be represented as “arg” or “r.” Alternatively, a lower case “d” in front of an amino acid can be used to indicate that it is of the D isomeric form, for example D-lysine can be represented by dK. 10 In the case of less common or non-naturally occurring amino acids, unless they are referred to by their full name (e.g., sarcosine, ornithine, etc.), frequently employed three- or four-character codes are employed for residues thereof, including, Beta-Ala, b-Ala, or bA (β- alanine), Sar or Sarc (sarcosine, i.e., N-methylglycine), Aib (α-aminoisobutyric acid), Dab (2,4-diaminobutanoic acid), Dap (2,3-diaminopropanoic acid), γ-Glu (γ-glutamic acid), Gaba 15 (γ-aminobutanoic acid), β-Pro (pyrrolidine-3-carboxylic acid), and Abu (2-aminobutyric acid). Further, non-limiting examples of non-naturally occurring amino acids that may appear, e.g., in the compounds disclosed herein including those of Formulae (I), (Ia), (Ib), (Ic) or (Id) appear in Table 2 below. 20 Table 2. Non-limiting list of non-naturally occurring amino acids that may be incorporated into the HER2-targeting cyclic peptides of the present disclosure. 9 763537: NIT-59597PC (PAT059597-FF) 10 763537: NIT-59597PC (PAT059597-FF) 11 763537: NIT-59597PC (PAT059597-FF) 12 763537: NIT-59597PC (PAT059597-FF) 13 763537: NIT-59597PC (PAT059597-FF) 14 763537: NIT-59597PC (PAT059597-FF) 15 763537: NIT-59597PC (PAT059597-FF) 16 763537: NIT-59597PC (PAT059597-FF) 17 763537: NIT-59597PC (PAT059597-FF) 18 763537: NIT-59597PC (PAT059597-FF) Amino acids of the D-isomeric form may be located at any of the positions in the HER2-targeting compounds disclosed herein (e.g., any of A1-A10appearing in the compounds of Formulae (I), (Ia), (Ib), (Ic), (Id), or (I-i)). 5 Peptides may be naturally occurring, synthetically produced, or recombinantly expressed. Peptides may also comprise additional groups modifying the amino acid chain, for example, functional groups added via post-modification. Examples of post-modifications include, but are not limited to, acetylation, alkylation (including, methylation), biotinylation, glutamylation, glycylation, glycosylation, isoprenylation, lipoylation, 10 phosphopantetheinylation, phosphorylation, selenation, and C-terminal amidation. The term 19 763537: NIT-59597PC (PAT059597-FF) peptide also includes peptides comprising modifications of the amino terminus and / or the carboxy terminus. The term peptide also includes modifications, such as, but not limited to, those described above, of amino acids falling between the amino and carboxy termini. The skilled artisan will recognize that the peptide sequences disclosed herein in some 5 cases are depicted having the left end of the sequence being the N-terminus of the peptide and the right end of the sequence being the C-terminus of the peptide, or in other cases are depicted having the left end of the sequence being the C-terminus of the peptide and the right end of the sequence being the N-terminus of the peptide. The context of the use of the sequence will make such directionality clear. Among sequences disclosed herein are 10 sequences incorporating either an “-OH” moiety or an “-NH2” moiety at the carboxy terminus (C-terminus) of the sequence. In such cases, and unless otherwise indicated, an “-OH” or an “-NH2” moiety at the C-terminus of the sequence indicates a hydroxy group or an amino group, corresponding to the presence of a carboxylic acid (COOH) or an amido (CONH2) group at the C-terminus, respectively. In each sequence of the disclosure, a C-terminal “-OH” 15 moiety may be substituted for a C-terminal “-NH2” moiety, and vice-versa. The phrase “amino acid,” “amino acid residue,” or “residue” as used herein refers to an amino acid, a modified or derivatized amino acid, an amino acid analog, or an amino acid mimetic that is incorporated into a peptide by an amide bond or an amide bond mimetic. Unless indicated otherwise the names of naturally occurring and non-naturally 20 occurring amino acid residues used herein follow the naming conventions suggested by the IUPAC Commission on the Nomenclature of Organic Chemistry and the IUPAC-IUB Commission on Biochemical Nomenclature as set out in “Nomenclature of α-Amino Acids (Recommendations, 1974)” Biochemistry, 14(2), (1975). To the extent that the names and abbreviations of amino acids and aminoacyl residues employed in this specification and 25 appended claims differ from those suggestions, they will be made clear to the reader. One of skill in the art will appreciate that certain amino acids and other chemical moieties are modified when bound to another molecule. For example, an amino acid side chain may be modified when it is derivatized (e.g., with a substituent) or forms an intramolecular bridge with another amino acid side chain, e.g., one or more hydrogens may 30 be removed or replaced by the bond. In some embodiments, amino acid residues in the disclosed cyclic peptides may exist in the zwitterionic form. As will be appreciated by one of skill in the art, a zwitterion is a molecule that contains both a positive charge and a negative charge, resulting in an overall neutral charge. For example, an amino acid in the zwitterion form includes a carboxylate ion 20 763537: NIT-59597PC (PAT059597-FF) (negative charge) and an ammonium ion (positive charge). Zwitterionic amino acids may exist at neutral pH. As used herein, “about” means within ±10% of a value. The phrase “pharmaceutically acceptable” as employed herein refers to those 5 compounds, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio. As used herein, “pharmaceutically acceptable salts” means physiologically and 10 pharmaceutically acceptable salts of the compounds disclosed herein, i.e., salts that retain the desired biological activity of the compounds and do not impart undesired toxicological effects thereto. The term “pharmaceutically acceptable salt” or “salt” includes a salt prepared from pharmaceutically acceptable non-toxic acids or bases, including inorganic or organic acids and bases. “Pharmaceutically acceptable salts” of the compounds disclosed herein may 15 be prepared by methods well-known in the art. For a review of pharmaceutically acceptable salts, see Stahl and Wermuth, Handbook of Pharmaceutical Salts: Properties, Selection and Use (Wiley-VCH, Weinheim, Germany, 2002). As used herein, the term “solvate” means a physical association of a compound disclosed herein with one or more solvent molecules. This physical association involves 20 varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances, the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolable solvates. In general, such solvents selected for the purpose of the disclosure do not interfere with the biological activity of the solute. Non- 25 limiting examples of suitable solvates include hydrates, ethanolates, methanolates, and the like. As used herein, the term “hydrate” means a solvate wherein the solvent molecule(s) is / are water. In an embodiment, the solvate is a hydrate. As used herein, the term “stereoisomer” means a molecule that has the same 30 molecular formula and sequence of bonded atoms but differs in the three-dimensional orientations of its atoms in space. The term “tautomer” means two or more interconvertible compounds resulting from at least one formal migration of a hydrogen atom and at least one change in valency (e.g., a single bond to a double bond, a triple bond to a single bond, or vice versa). The exact ratio of 21 763537: NIT-59597PC (PAT059597-FF) the tautomers depends on several factors, including temperature, solvent, and pH. Tautomerizations (i.e., the reaction providing a tautomeric pair) may be catalyzed by acid or base. Exemplary tautomerizations include keto-to-enol, amide-to-imide, lactam-to-lactim, enamine-to-imine, and enamine-to-(a different enamine) tautomerizations. 5 As used herein, the term “treat,” “treatment,” or “treating” means decrease, suppress, attenuate, diminish, arrest, or stabilize the development or progression of a disorder or disease. As used herein, the term “prevent” or “prevention” means no disorder or disease development if none had occurred, or no further disorder or disease development if there had 10 already been development of the disorder or disease. Also contemplated is the ability to prevent some or all of the symptoms associated with the disorder or disease. The term “pharmaceutical composition” is defined herein to refer to a mixture (e.g., a solution or an emulsion) containing at least one active ingredient or therapeutic agent to be administered to a subject, e.g., a human, in order to prevent or treat a particular disease or 15 condition affecting the subject. The term “a therapeutically effective amount” of a compound (i.e., a compound of Formula (I), or a pharmaceutically acceptable salt thereof) of the present disclosure refers to an amount of the compound of the present disclosure that will elicit the biological or medical response of a subject (patient or subject), for example, reduction or inhibition of enzymatic, 20 protein, or cellular activity, or ameliorate symptoms, alleviate conditions, slow or delay disease progression. The therapeutically effective dosage of a compound, the pharmaceutical composition, or the combinations thereof, can be dependent on the body weight, age, sex, and individual condition, the disorder or disease or the severity thereof being treated. A physician, clinician or veterinarian of ordinary skill can readily determine the effective amount of each 25 of the active ingredients necessary to prevent, treat or inhibit the progress of the disorder or disease. The term “detectably effective amount” of a compound (i.e., a compound of Formula (I) or a pharmaceutically acceptable salt thereof) as used herein refers to an amount of the compound of the present disclosure sufficient to provide an acceptable image using 30 equipment that is available in a clinical setting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly or conventionally understood by one of ordinary skill in the art. In the chemical arts a dash at the front or end of a chemical group is a matter of convenience; chemical groups may be depicted with or without one or more dashes without losing their 22 763537: NIT-59597PC (PAT059597-FF) ordinary meaning. A wavy line drawn through a line in a structure indicates a point of attachment of a group. A dashed line indicates an optional bond. A prefix such as “Cu-v” or (Cu-Cv) indicates that the following group has from u to v carbon atoms. For example, “C1-6- alkyl” and “C1-C6alkyl” both indicate that the alkyl group has from 1 to 6 carbon atoms. 5 The term “alkyl” is a straight or branched saturated hydrocarbon. For example, an alkyl group can have 1 to 10 carbon atoms (i.e., C1-10-alkyl), 1 to 8 carbon atoms (i.e., C1-8- alkyl), 1 to 5 carbon atoms (i.e., C1-5-alkyl), 1 to 4 carbon atoms (i.e., C1-4-alkyl), or 1 to 3 carbon atoms (i.e., C1-3-alkyl). Examples of alkyl groups include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), isopropyl 10 (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-bu, n-butyl, -CH2CH2CH2CH3), 2-butyl (s-bu, s-butyl, -CH(CH3)CH2CH3), tert-butyl (t-bu, t-butyl, -CH(CH3)3), 1-pentyl (n-pentyl, - CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3) CH2CH2CH3), neopentyl (-CH2C(CH3)3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), heptyl (-(CH2)6CH3), octyl (-(CH2)7CH3), 2,2,4-trimethylpentyl (-CH2C(CH3)2CH2CH(CH3)2), nonyl (-(CH2)8CH3), 15 decyl (-(CH2)9CH3), undecyl (-(CH2)10CH3), and dodecyl (-(CH2)11CH3). In an embodiment, alkyl refers to C1-6-alkyl. In another embodiment, alkyl refers to C1-4alkyl. In another embodiment, alkyl refers to C1-3alkyl. The term “alkylene” refers to a bivalent alkyl group. For example, an alkylene group can have 1 to 10 carbon atoms (i.e., (C1-10alkylene), 1 to 5 carbon atoms (i.e., (C1-5alkylene), 20 1 to 2 carbon atoms (i.e., (C1-2alkylene), or 1 carbon atom (i.e., C1-alkylene). Examples of alkylene groups include, but are not limited to, methylene (-CH2-), ethylene (-CH2CH2-), n- propylene (-CH2CH2CH2-), n-butylene (-CH2CH2CH2CH2-), etc. The term “aryl,” employed alone or in combination with other terms, means, unless otherwise stated, a carbocyclic aromatic system containing one or more rings (typically one, 25 two or three rings), wherein such rings may be attached together in a pendent manner, such as a biphenyl, or may be fused, such as naphthalene. Examples of aryl groups include phenyl, anthracyl, biphenyl, and naphthyl. In some embodiments, aryl groups have from six to sixteen carbon atoms (e.g., C6-16-aryl). In some embodiments, aryl groups have from six to twelve carbon atoms (e.g., C6-12-aryl). In some embodiments, aryl groups have six carbon 30 atoms (e.g., C6-aryl, which may also be referred to as phenyl). The term “halo” or “halogen” refers to bromo (-Br), chloro (-Cl), fluoro (-F), or iodo (-I). In an embodiment, halo refers to fluoro. The term “haloalkyl” refers to a straight- or branched-chain alkyl group having from 1 to 12 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms in the 23 763537: NIT-59597PC (PAT059597-FF) chain optionally substituting one or more H with halo. Examples of “haloalkyl” groups include trifluoromethyl (CF3), difluoromethyl (CF2H), monofluoromethyl (CH2F), pentafluoroethyl (CF2CF3), tetrafluoroethyl (CHFCF3), monofluoroethyl (CH2CH2F), trifluoroethyl (CH2CF3), tetrafluorotrifluoromethylethyl (CF(CF3)2), and groups that in light 5 of the ordinary skill in the art and the teachings provided herein would be considered equivalent to any one of the foregoing examples. In an embodiment, haloalkyl refers to C(1- 6)haloalkyl. In another embodiment, haloalkyl refers to C(1-4)haloalkyl. In another embodiment, alkyl refers to C(1-3)haloalkyl. The term “cycloalkyl” refers to a saturated or partially unsaturated all carbon ring10 system having 3 to 8 carbon atoms (i.e., C3-8cycloalkyl), or 3 to 6 carbon atoms (i.e., C3-6cycloalkyl), wherein the cycloalkyl ring system has a single ring or multiple rings, e.g., in a spirocyclic or bicyclic form. Exemplary cycloalkyls include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Some cycloalkyl groups may exist as spirocycloalkyls, wherein two cycloalkyl rings are fused 15 through a single carbon atom; for example and without limitation, an example of a spiropentyl group is ; for example and without limitation, examples of spirohexylgroups include , , ; for example and without limitation examples of cycloheptyl groups include , , , ; for example and without limitation examples of cyclooctyl groups include ,20 The terms “heterocycle,” “heterocyclyl,” and “heterocycloalkyl” each refer to a saturated or partially unsaturated ring system that has at least one atom other than carbon in the ring system, wherein the atom is selected from the group consisting of oxygen, nitrogen 25 and sulfur. The heterocyclyl group may, for example, consist of a single ring or multiple rings (e.g., in the form of a spirocyclic or bicyclic ring system). Exemplary heterocycles include, 24 763537: NIT-59597PC (PAT059597-FF) but are not limited to oxetanyl, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, tetrahydropyranyl, tetrahydrofuranyl, and thiomorpholinyl. As used herein, the term “heteroaryl” or “heteroaromatic,” employed alone or in combination with other terms, refers to a heterocycle having aromatic character. Heteroaryl 5 substituents may be defined by the number of carbon atoms, e.g., C1-9-heteroaryl indicates the number of carbon atoms contained in the heteroaryl group without including the number of heteroatoms. For example, a C1-9-heteroaryl will include an additional one to four heteroatoms. Alternatively, heteroaryl substituents may be defined by the number of atoms in the heteroaryl core, e.g., 5-6 membered heteroaryl indicates the number of carbon and 10 heteroatoms contained in the heteroaryl core. As used herein, heteroaryl includes polycyclic ring systems wherein at least one ring has aromatic character and thus, may include one or more rings that are partially saturated. Non-limiting examples of heteroaryls include pyridyl, pyrazinyl, pyrimidinyl (including, e.g., 2- and 4-pyrimidinyl), pyridazinyl, thienyl, furyl, pyrrolyl (including, e.g., 2-pyrrolyl), imidazolyl, thiazolyl, oxazolyl, pyrazolyl (including, e.g., 15 3- and 5-pyrazolyl), isothiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,3,4-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,3,4-thiadiazolyl and 1,3,4-oxadiazolyl. When two terms are combined, such as, for example, “alkylaryl” and “alkylheteroaryl,” it is intended that the elements defined by those terms are covalently attached, and that such covalent attachment may occur at any site of each element. For 20 example, C1-6-alkyl(5 to 6 membered heteroaryl) indicates a C1-6-alkyl that is covalently attached to a 5 to 6 membered heteroaryl. In some embodiments, the 5 to 6 membered heteroaryl may be covalently attached to the C1-6-alkyl at the C1 or C6 carbon, thereby providing a linear alkylheteroaryl group. In some embodiments, the 5 to 6 membered heteroatom is covalently attached to the C1-6-alkyl at any one of C2, C3, C4, and C5 carbon 25 atoms, thereby providing a branched alkylheteroaryl group. Likewise, the C1-6-alkyl may be attached to any atom of the 5 to 6 membered heteroaryl. Further, a substituent defined using combined terms, e.g., “alkylaryl” and “alkylheteroaryl,” may be connected to the compound via any atom of either of the elements defined by the combined terms. For example, an “alkylaryl” or “alkylheteroaryl” substituent may be connected to the compound via the alkyl 30 group or the aryl / heteroaryl group. In various embodiments, an “alkylaryl” or “alkylheteroaryl” substituent is connected to the compound via the alkyl group. In various other embodiments, the “alkylaryl” or “alkylheteroaryl” substituent is connected to the compound via the aryl or heteroaryl group. 25 763537: NIT-59597PC (PAT059597-FF) The term “independently selected” is used herein to indicate that, for a variable which occurs in more than one location in a genus, the identity of the variable is determined separately in each instance. For example, if Rxappears as a substituent on two different atoms, the two instances of Rxmay be the same moiety, or different moieties. The same is 5 true if a single atom is substituted with more than one instance of Rx. The identity of Rxin each instance is determined independently of the identity of the other(s). In non-limiting embodiments, when a substituent is designated in the form: , then it is to be understood that substituent R can occur p number of times on the ring, and R 10 can be a different moiety at each occurrence. It is understood that each R may replace any hydrogen atom attached to a ring atom, including one or both of the (CH2)nhydrogen atoms. Further, in the above example, should the variable Q be defined to include hydrogen atoms, such as when Q is CH2, NH, etc., any floating substituent such as R in the above example, can replace a hydrogen atom of the Q variable as well as a hydrogen atom in any other non- 15 variable component of the ring. The terms “connected to” and “conjugated to” as used herein may be used interchangeably and are meant to indicate that two independent constituents are joined together such as by one or more covalent bonds. In some embodiments, the cyclized peptide is conjugated to or connected to a chelating agent via a covalent bond. 20 The terms “chelated to” and “complexed to” as used herein may be used interchangeably and are meant to indicate that two independent constituents are joined together such as by one or more non-covalent bonds, e.g., coordination bonds. The term “radiolabeled” as used herein means that a non-radioactive compound is labeled with a radioisotope. Radiolabeling can be achieved, e.g., via chelation or 25 complexation of a chelator with an appropriate radionuclide. Radiolabeling can also refer to chemically substituting one group on a compound for a radionuclide, such as, e.g., in the case of18F. Furthermore, it is intended that within the scope of the present invention, any element, in particular when mentioned in relation to a peptide of the disclosure, or pharmaceutically 30 acceptable salt thereof, shall comprise all isotopes and isotopic mixtures of said element, either naturally occurring or synthetically produced, either with natural abundance or in an 26 763537: NIT-59597PC (PAT059597-FF) isotopically enriched form. For example, a reference to hydrogen includes within its scope 1H,2H (i.e., deuterium or D), and3H (i.e., tritium or T). In some embodiments, the compounds described herein include a2H (i.e., deuterium) isotope. By way of example, the group denoted -C(1-6)alkyl includes not only -CH3, but also CD3; not only CH2CH3, but also 5 CD2CD3, etc. Similarly, references to carbon and oxygen include within their scope respectively12C,13C and14C and15O and16O and17O and18O. The isotopes may be radioactive or non-radioactive. As used herein, the term “carrier” or “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, surfactants, antioxidants, preservatives (e.g., 10 antibacterial agents, antifungal agents), isotonic agents, absorption delaying agents, salts, preservatives, drugs, stabilizers (i.e., a pharmaceutically acceptable stabilizer), binders, excipients, disintegration agents, lubricants, sweetening agents, flavoring agents, dyes, and the like and combinations thereof, as would be known to those skilled in the art (see, for example, Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, pp. 15 1289-1329). Except insofar as any conventional carrier is incompatible with the active ingredient, its use in the imaging, therapeutic, or pharmaceutical compositions is contemplated. Unless otherwise specified, conventional definitions of terms control and conventional stable atom valences are presumed and achieved in all formulas and groups. 20 The articles “a” and “an” are used in this disclosure to refer to one or more than one (e.g., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element. HER2-Targeting Compounds 25 The present disclosure provides HER2-targeting compounds, or pharmaceutically acceptable salts or solvates thereof, comprising: a) at least one cyclized peptide that binds to human epidermal growth factor receptor 2 (HER2) with a dissociation constant (KD) of about 1000 nM or less as measured by surface plasmon resonance (SPR) at a temperature of 25 °C; and 30 b) at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug. In an embodiment, the KDis about 200 nM or less. In another embodiment, the cyclized peptide comprises seven to fifteen amino acids and / or amino acid derivatives. 27 763537: NIT-59597PC (PAT059597-FF) In yet another embodiment, the cyclized peptide comprises at least two consecutive amino acids or amino acid derivatives independently selected from tryptophan and tryptophan derivatives. In an aspect, provided herein is a compound, or a pharmaceutically acceptable salt or 5 solvate thereof, comprising: a) at least one cyclized peptide , wherein , wherein A1-A9are as defined herein; and b) at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug, wherein at least one cyclized peptide conjugated to the at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug via any one of A1-A9, optionally through a linker. In some embodiments, the HER2-targeting compound is a compound of formula (I), (Ia), (Ib), or (Ic): 28 763537: NIT-59597PC (PAT059597-FF) (Ia), or (Ic), or a pharmaceutically acceptable salt or solvate thereof, wherein: P is a cyclic HER2-targeting peptide as defined above; L1is, independently at each occurrence, a bond or a linker; M is, independently at each occurrence, an imaging agent, a chelating agent, or a radionuclide, wherein the chelating agent is optionally radiolabeled with a radionuclide; n is 1, 2, 3, or 4; and o is 1, 2, 3, or 4, wherein any of P, L1, or M are optionally substituted with an albumin binder, a biotin tag, or one or more polyethylene glycol (PEG) chains. In some embodiments, L1is a bond. In some embodiments, L1is a linker. In some embodiments of the compounds of compound formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof, M is, independently at each occurrence, an imaging agent, a chelating agent, or a radionuclide, wherein the chelating 5 agent is optionally radiolabeled with a radionuclide. In further embodiments, at least one M is a chelating agent, wherein the chelating agent is radiolabeled with a radionuclide. In further embodiments, at least one M is an imaging agent. In some embodiments, at least one M is a radionuclide. In some embodiments of the compounds of compound formula (I), (Ia), (Ib), (Ic), or 10 (Id), or a pharmaceutically acceptable salt or solvate thereof, n is 1, 2, 3, or 4. In further embodiments, n is 1, 2, or 3. In further embodiments, n is 1 or 2. In further embodiments, n is 1. In further embodiments, n is 2. In further embodiments, n is 3. In further embodiments, n is 4. 29 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the compound of formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof, o is 1, 2, 3, or 4. In further embodiments, o is 1, 2, or 3. In further embodiments, o is 1 or 2. In further embodiments, o is 1. In further embodiments, o is 2. In further embodiments, o is 3. In further embodiments, o is 4. 5 In some embodiments of the compound of formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof, the compound is substituted with an albumin binder. In further embodiments, P is substituted with an albumin binder. In further embodiments, L1is substituted with an albumin binder. In further embodiments, M is substituted with an albumin binder. In some embodiments, none of P, L1, and M are 10 substituted with an albumin binder (i.e., the compound of formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof is not substituted with an albumin binder). In some embodiments, the HER2-targeting compound is a compound of formula (I): , 15 or a pharmaceutically acceptable salt or solvate thereof. In some embodiments, the HER2-targeting compound is a compound of formula (Ib): , 20 or a pharmaceutically acceptable salt or solvate thereof. Cyclic Peptide (P) and incorporation into, e.g., compounds of Formulae (I), (Ia), (Ib), (Ic), and (Id) In some aspects, the present disclosure provides a cyclic peptide (P) that is capable of 25 binding to human epidermal growth factor receptor 2 (HER2), as well as compounds comprising said cyclic peptide (P). In an embodiment, P binds to human epidermal growth factor receptor 2 (HER2) with a dissociation constant (KD) of about 1000 nM or less as measured by surface plasmon resonance (SPR) at a temperature of 25 °C. 30 763537: NIT-59597PC (PAT059597-FF) In another embodiment, the KDis about 200 nM or less. In yet another embodiment, P comprises seven to fifteen amino acids and / or amino acid derivatives. In still another embodiment, P comprises at least two consecutive amino acids or 5 amino acid derivatives independently selected from tryptophan and tryptophan derivatives. In one or more embodiments, P has the structure: , wherein: R1ais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -N(H)- C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, - N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, -N(C1-6-alkyl)2, phenyl, and 5-6 membered heteroaryl of R1aare optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl-C(O)OH, - C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6-alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; 31 763537: NIT-59597PC (PAT059597-FF) selected from C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl of are optionally substituted with 1 or 2 substituents independently selected from halo, -OH, -NH2, and C1-6- alkyl; R1aais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -N(H)- C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, - N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, -N(C1-6-alkyl)2, phenyl, and 5-6 membered heteroaryl of R1aare optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl-C(O)OH, - C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6-alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, C(O)NC1-6-alkyl, NHC(O), N(C1-6-alkyl)C(O), O, and S; a is 1, 2, 3, or 4; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, 2, or 3; and *2 indicates the point of attachment to A2and *9 indicates the point of attachment to A9; A2is , wherein: R2ais selected from H and C1-6-alkyl; R2bis selected from H, C1-6-alkyl, and halo; R2cis selected from halo, C1-6-alkyl, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, phenyl, and 5-6 membered heteroaryl of R2care optionally 32 763537: NIT-59597PC (PAT059597-FF) substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, - C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6- alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; and *3 indicates the point of attachment to A3and *1 indicates the point of attachment to A1; A3is , wherein: R3ais selected from H and C1-6-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-phenyl, - C1-6-alkyl-N(H)-phenyl, -C1-6-alkyl-N(H)-C(O)-phenyl, -C1-6-alkyl-N(H)-C1-6-alkyl-phenyl, - C1-6-alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl- N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl- C(O)NH-C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-N(H)-phenyl, -C1-6-alkyl-N(H)-C(O)- phenyl, -C1-6-alkyl-N(H)-C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heterocycloalkyl), - C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl) of R3care optionally substituted with 1, 2, 3, 4, 5, or 6 substituents independently selected from - CN, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, - NHC(O)C1-6-alkyl, -OH, and -OC1-6-alkyl; and wherein *4 indicates the point of attachment to A4and *2 indicates the point of attachment to A2; A4is , wherein: 33 763537: NIT-59597PC (PAT059597-FF) R4ais selected from H, C1-6-alkyl, and -CH2-phenyl, wherein the C1-6-alkyl and -CH2- phenyl of R4aare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, -C1-6- alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)OH, and -C1-6-alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R4bare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -C(O)NH2, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -OC1-6- alkyl, and C1-6-alkyl; and wherein *5 indicates the point of attachment to A5and *3 indicates the point of attachment to A3; A5is , wherein: R5ais selected from H, C1-6-alkyl, and -CH2-phenyl, wherein the C1-6-alkyl and -CH2- phenyl of R5aare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R5bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5c, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl- C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R5cis selected from H, C1-6-alkyl, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -OH, -OC1-6- alkyl, C1-6-haloalkyl, C1-6-alkyl-C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; and wherein *6 indicates the point of attachment to A6and *4 indicates the point of attachment to A4; A6is 34 763537: NIT-59597PC (PAT059597-FF) , wherein: R6ais selected from H and C1-6-alkyl; R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 5-10 membered heteroaryl, wherein the C1-6-alkyl and 5-10 membered heteroaryl of R6care each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, -C(O)OH, -NH2, - NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, -OC(O)-C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), and -N(H)-C(O)-N(C1-6-alkyl)2; and wherein *5 indicates the point of attachment to A5and *7 indicates the point of attachment to A7; A7is , wherein: R7ais selected from H and C1-6-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 5-10 membered heteroaryl, wherein the C1-6-alkyl and 5-10 membered heteroaryl are each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, -C(O)OH, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)- C(O)-N(H)(C1-6-alkyl), and -N(H)-C(O)-N(C1-6-alkyl)2; and wherein *8 indicates the point of attachment to A8and *6 indicates the point of attachment to A6; A8is , 35 763537: NIT-59597PC (PAT059597-FF) wherein: R8ais selected from H and C1-6-alkyl; R8bis selected from H, C1-6-alkyl, C3-8-cycloalkyl, 5-7 membered heterocycloalkyl ring, and 5-10 membered heteroaryl, wherein the C1-6-alkyl, C3-8-cycloalkyl, 5-7 membered heterocycloalkyl ring, and 5-10 membered heteroaryl of R8bare optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, - C(O)OH, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, and -OC1-6-alkyl; and wherein *9 indicates the point of attachment to A9and *7 indicates the point of attachment to A7; A9is , wherein: Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; R9ais selected from H and C1-6-alkyl; d is 1, 2, or 3; and z’ and z’’ are each independently 0 or 1; and wherein *8 indicates the point of attachment to A8and *1 indicates the point of attachment to A1; and A10is , wherein: Y10is selected from OH and N(R10g)(R10h); R10a, R10c, R10e, R10g, and R10hare each independently selected from H and C1-6-alkyl; R10bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10i, -C1-6-alkyl-O-C(O)R10i, and -C1-6-alkyl-NH-C(O)R10i, 36 763537: NIT-59597PC (PAT059597-FF) wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10bare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10aand R10b, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10j, -C1-6-alkyl-O-C(O)R10j, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10dare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10k, -C1-6-alkyl-O-C(O)R10k, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10eand R10f, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, C3-7 cycloalkyl, 5-6 membered heteroaryl, and 3-7 membered heterocycloalkyl, wherein the C3-7cycloalkyl, 5-6 membered heteroaryl, and 3-7 membered heterocycloalkyl of R10i, R10j, and R10kare each optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, C1-6-alkyl, - C(O)OH, -C(O)NH2, and C1-6-alkyl-C(O)NH2; e and f are each independently 0 or 1; and wherein *9 indicates the point of attachment to A9. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is 37 763537: NIT-59597PC (PAT059597-FF) , wherein: R1ais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, and –N(C1-6-alkyl)2 of R1aare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -C(O)NH2,-C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6- alkyl-C(O)OH, -C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6- alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; is selected from C3-8-cycloalkyl and phenyl, wherein the C3-8-cycloalkyl and phenyl of are optionally substituted with 1 or 2 substituents independently selected from C1-6-alkyl, halo, -OH, and -NH2; R1aais selected from H, C1-6-alkyl, -NH2, -NHC1-6-alkyl, and –N(C1-6-alkyl)2; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, NHC(O), O, and S; a is 1, 2, 3, or 4; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, 2, or 3; *2 indicates the point of attachment to A2and *9 indicates the point of attachment to A9; A2is , wherein: R2ais selected from H and C1-3-alkyl; R2bis selected from H, C1-6-alkyl, and halo; 38 763537: NIT-59597PC (PAT059597-FF) R2cis selected from C1-6-alkyl, phenyl, and 5-6 membered heteroaryl, wherein the phenyl and 5-6 membered heteroaryl of R2care optionally substituted with 1, 2, or 3,substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -NHC1-6-alkyl, – N(C1-6-alkyl)2, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; *3 indicates the point of attachment to A3and *1 indicates the point of attachment to A1; A3is , wherein: R3ais selected from H and C1-3-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl- N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6- alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), - C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl) of R3care optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -NHC(O)C1-6-alkyl, -OH, and -OC1-6-alkyl; wherein *4 indicates the point of attachment to A4and *2 indicates the point of attachment to A2; A4is , wherein: 39 763537: NIT-59597PC (PAT059597-FF) R4ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R4ais optionally substituted with 1 or 2 substituents independently selected from -NH2, -NHC1-6-alkyl, –N(C1- 6-alkyl)2, -OH, and -OC1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, -C1-6- alkyl-pyridyl, -C1-7-alkyl-C(O)OH, and -C1-6-alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1- 6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, and -C1-6-alkyl-pyridyl, of R4bare optionally substituted with 1 or 2 substituents independently selected from halo, -C(O)NH2, -NH2, -NHC1-6-alkyl, – N(C1-6-alkyl)2, -OH, and -OC1-6-alkyl; wherein *5 indicates the point of attachment to A5and *3 indicates the point of attachment to A3; A5is , wherein: R5ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R5ais optionally substituted with 1 or 2 substituents independently selected from -NH2, -NHC1-6-alkyl, –N(C1- 6-alkyl)2, and -OH; R5bis selected from H, C1-6-alkyl, -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and - C1-6-alkyl-NH-C(O)R5c, wherein the C1-6-alkyl, -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1 or 2 substituents independently selected from -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R5cis selected from H, C1-6-alkyl, -NH2, -OH, -OC1-6-alkyl, C1-6-haloalkyl, C1-6-alkyl- C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; wherein *6 indicates the point of attachment to A6and *4 indicates the point of attachment to A4; A6is , wherein: R6ais selected from H and C1-3-alkyl; 40 763537: NIT-59597PC (PAT059597-FF) R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 7-10 membered heteroaryl, wherein the C1-6-alkyl and 7-10 membered heteroaryl of R6care each optionally substituted with 1, 2, or 3 substituents independently selected from C1-6-alkyl, -CN, halo, -NH2, -NHC1-6-alkyl, –N(C1-6- alkyl)2, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl; wherein *5 indicates the point of attachment to A5and *7 indicates the point of attachment to A7; A7is , wherein: R7ais selected from H and C1-3-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 7-10 membered heteroaryl, wherein the C1-6-alkyl and 7-10 membered heteroaryl are each optionally substituted with 1, 2, or 3 substituents independently selected from -CN, halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; wherein *8 indicates the point of attachment to A8and *6 indicates the point of attachment to A6; A8is , wherein: R8ais selected from H and C1-3-alkyl; R8bis selected from H, C1-6-alkyl, C3-6-cycloalkyl, 5-6 membered heteroaryl, wherein the C1-6-alkyl, C3-6-cycloalkyl and 5- 6 membered heteroaryl of R8bare optionally substituted with 1, 2, or 3 substituents independently selected from -CN, halo, -NH2, -NHC1-6-alkyl, – N(C1-6-alkyl)2, and -OH; wherein *9 indicates the point of attachment to A9and *7 indicates the point of attachment to A7; A9is 41 763537: NIT-59597PC (PAT059597-FF) , wherein: Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; R9ais selected from H and C1-3-alkyl; d is 1, 2, or 3; z’ and z’’ are each independently 0 or 1; A10is , wherein: Y10is selected from OH and N(R10g)(R10h); R10a, R10c, and R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10i, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10bare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)OH, -C1-6-alkyl-C(O)OH, and -C(O)NH2; alternatively, R10aand R10b, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10dare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)OH, -C1-6-alkyl-C(O)OH, and -C(O)NH2; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; 42 763537: NIT-59597PC (PAT059597-FF) R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, - N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl-C(O)OH, and -C(O)NH2; alternatively, R10eand R10f, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, 5- 6 membered heterocycloalkyl, and 5-6 membered heteroaryl, wherein the 5- 6 membered heterocycloalkyl, and 5- 6 membered heteroaryl of R10i, R10j, and R10kare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6- alkyl, -N(C1-6-alkyl)2, -N3, -OH, C1-6-alkyl, and C1-6-alkyl-C(O)OH; e and f are each independently 0 or 1; and wherein *9 indicates the point of attachment to A9. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is , wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, and – N(C1-6-alkyl)2of R1aare optionally substituted with 1 or 2 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl- C(O)OH, -C(O)C1-6-alkyl-NH2, 5-membered heteroaryl, -OH, and -NH2; is selected from C5-7-cycloalkyl and phenyl, wherein the C5-7-cycloalkyl and phenyl of are optionally substituted with 1 substituent selected from C1-6-alkyl, halo, -OH, and -NH2; R1aais selected from H, C1-6-alkyl, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; 43 763537: NIT-59597PC (PAT059597-FF) Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, NHC(O), O, and S; a is 1, 2, or 3; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, or 2; *2 indicates the point of attachment to A2and *9 indicates the point of attachment to A9; A2is , wherein: R2ais selected from H and C1-3-alkyl; R2bis selected from H, C1-6-alkyl, and halo; R2cis selected from C1-6-alkyl, phenyl, and 6-membered heteroaryl, wherein the phenyl and 6-membered heteroaryl of R2care optionally substituted with 1 or 2 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-NH2, - N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; and *3 indicates the point of attachment to A3and *1 indicates the point of attachment to A1; A3is , wherein: R3ais selected from H and C1-3-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-(6- membered heterocycloalkyl), -C1-6-alkyl-N(H)-(6-membered heterocycloalkyl), -C1-6-alkyl- N(H)-C(O)-(6-membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(6-membered 44 763537: NIT-59597PC (PAT059597-FF) heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-(6- membered heterocycloalkyl), -C1-6-alkyl-N(H)-(6-membered heterocycloalkyl), -C1-6-alkyl- N(H)-C(O)-(6-membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(6-membered heterocycloalkyl) of R3care optionally substituted with 12, 3, 4, or 5 substituents independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, -NHC(O)C1-6- alkyl, -OH, and -OC1-6-alkyl; and wherein *4 indicates the point of attachment to A4and *2 indicates the point of attachment to A2; A4is , wherein: R4ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R4ais optionally substituted with 1 substituent selected from -NH2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-pyridyl, and -C1-6- alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-pyridyl of R4bare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, - OH, and -OC1-6-alkyl; and wherein *5 indicates the point of attachment to A5and *3 indicates the point of attachment to A3; A5is , wherein: R5ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R5ais optionally substituted with 1 substituent selected from -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R5bis selected from H, C1-6-alkyl, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH- C(O)R5c, wherein the C1-6-alkyl, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1 or 2 substituents independently selected from -NH2, - NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; 45 763537: NIT-59597PC (PAT059597-FF) R5cis selected from H, C1-6-alkyl, -NH2, -OH, -OC1-6-alkyl, C1-6-haloalkyl, C1-6-alkyl- C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; and wherein *6 indicates the point of attachment to A6and *4 indicates the point of attachment to A4; A6is , wherein: R6ais selected from H and C1-3-alkyl; R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 8-9 membered heteroaryl, wherein the C1-6-alkyl and 8-9 membered heteroaryl of R6care each optionally substituted with 1 or 2 substituents independently selected from C1-6-alkyl, -CN, halo, -NH2, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl; and wherein *5 indicates the point of attachment to A5and *7 indicates the point of attachment to A7; A7is , wherein: R7ais selected from H and C1-3-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 8-9 membered heteroaryl, wherein the C1-6-alkyl and 8-9 membered heteroaryl are each optionally substituted with 1 or 2 substituents independently selected from -CN, halo, -NH2, and -OH; and wherein *8 indicates the point of attachment to A8and *6 indicates the point of attachment to A6; A8is 46 763537: NIT-59597PC (PAT059597-FF) , wherein: R8ais selected from H and C1-3-alkyl; R8bis selected from H, C1-6-alkyl, and C3-6-cycloalkyl, wherein the C1-6-alkyl and C3-6-cycloalkyl of R8bare optionally substituted with 1 or 2 substituents independently selected from -CN, halo, -NH2, and -OH; and wherein *9 indicates the point of attachment to A9and *7 indicates the point of attachment to A7; A9is , wherein: Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; R9ais selected from H and C1-3-alkyl; d is 1 or 2; and wherein *8 indicates the point of attachment to A8and *1 indicates the point of attachment to A1; and A10is , wherein: Y10is selected from OH and N(R10g)(R10h); R10a, R10c, and R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; 47 763537: NIT-59597PC (PAT059597-FF) R10bis selected from H, C1-3-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10i, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10bare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10dare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, - N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, 6-membered heterocycloalkyl, and 6-membered heteroaryl, wherein the 6-membered heterocycloalkyl, and 6-membered heteroaryl of R10i, R10j, and R10kare each optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -OH, C1-6-alkyl, and C1-6-alkyl-C(O)OH; e and f are each independently 0 or 1; and wherein *9 indicates the point of attachment to A9. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is a moiety of formula (A1-I), formula (A1-II), formula (A1-III), or formula (A1- IV): (A1-II), 48 763537: NIT-59597PC (PAT059597-FF) (A1-IV). In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is substituted with one PEG chain. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is substituted with a PEG chain, wherein A1and the PEG chain, together, have the structure of formula (A1-P): (A1-P), wherein: XPis selected from CH2, N(RP), and O; YPis selected from H, -OH, -OC1-6-alkyl, and -N(RP)2; each RPis independently selected from H and C1-6-alkyl; a is 1, 2, or 3; n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; and r’ is 0, 1, 2, 3, or 4. 49 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is selected from: 50 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is selected from: . 51 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A1is selected from: . 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A2is a moiety of formula (A2-I): 52 763537: NIT-59597PC (PAT059597-FF) (A2-I), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, and -NH2; and g is 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A2is in the L configuration. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A2is a moiety of formula (A2-Ia): wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2. 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A2is selected from: 53 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A3is a moiety of formula (A3-I) or formula (A3-II): (A3-II), wherein: Y3is selected from a bond and NH; each Y3ais selected from NH and CH2, provided that at least one Y3ais NH; R3ais selected from H and C1-3-alkyl; each R3aais independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, - NH2, -NHC(O)C1-6-alkyl, and -OC1-6-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, -C(O)NHC1-6-alkyl, and -OC1-6-alkyl, wherein the -C(O)NHC1-6-alkyl of R3abis optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo and -OH; h is 1, 2, 3, 4, 5, or 6; i is 0, 1, or 2; and j is 1, 2, 3, 4, 5, or 6. 54 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A3is in the L configuration. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A3is a moiety of formula (A3-I) or formula (A3-IIa): (A3-IIa), wherein: Y3is selected from a bond and NH; each Y3ais selected from NH and CH2, provided that at least one Y3ais NH; R3ais selected from H and C1-3-alkyl; each R3aais independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, - NH2, -NHC(O)C1-6-alkyl, and -OC1-6-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, -C(O)NHC1-6-alkyl, and -OC1-6-alkyl, wherein the -C(O)NHC1-6-alkyl of R3abis optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo and -OH; h is 1, 2, 3, 4, 5, or 6; i is 0, 1, or 2; and j is 1, 2, 3, 4, 5, or 6. 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): 55 763537: NIT-59597PC (PAT059597-FF) A3is a moiety of formula (A3-IIa): (A3-IIa), wherein: R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; and j is 1, 2, 3, 4, 5, or 6. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A3is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A3is selected from: 56 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A4is a moiety of formula (A4-I) or formula (A4-II): or (A4-II), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; R4abis selected from H, halo, -NH2, -OH, -OC1-6-alkyl, and -O-phenyl; k is 1, 2, 3, 4, 5, or 6; l is 0, 1, or 2; and m is 1, 2, 3, 4, 5, or 6. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A4is selected from: 57 763537: NIT-59597PC (PAT059597-FF) . In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A4is selected from: 58 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A4is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A5is a moiety of formula (A5-I), formula (A5-II), or formula (A5-III): (A5-II), or 59 763537: NIT-59597PC (PAT059597-FF) wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5aais selected from H, -OH, and -OC1-6-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; R5acis selected from H, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; and p’ and q’ are each independently 1, 2, 3, 4, 5, or 6. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A5is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): 60 763537: NIT-59597PC (PAT059597-FF) A5is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): R6cis selected from C1-6-alkyl and 9-membered heteroaryl, wherein the C1-6-alkyl and 9-membered heteroaryl of R6care each optionally substituted with 1 or 2 substituents independently selected from C1-6-alkyl, -CN, halo, -NH2, -OH, -OC1-6-alkyl, and -OC(O)-C1- 6-alkyl. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): the 9-membered heteroaryl of R6cis a bicyclic 9-membered heteroaryl. 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A6is a moiety of formula (A6-I), formula (A6-II), or formula (A6-III): (A6-II), or 61 763537: NIT-59597PC (PAT059597-FF) wherein: Y6is selected from NH and CH2; Y6aand Y6’are each independently selected from N and CH, provided that at least one of Y6and Y6ais selected from N and NH and provided that at least one of Y6’and Y6ais N; R6ais selected from H and C1-3-alkyl; each R6aais selected from C1-6-alkyl, -CN, halo, -NH2, -OH, -OC1-6-alkyl, and - OC(O)-C1-6-alkyl; and o’ and p are each independently 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A6is a moiety of formula (A6-Ia), formula (A6-IIa), or formula (A6-IIIa): (A6-IIa), or 62 763537: NIT-59597PC (PAT059597-FF) (A6-IIIa) wherein: R6ais selected from H and C1-3-alkyl; each R6acis selected from C1-6-alkyl, halo, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl; and o’ and p are each independently 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A6is selected from: , In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A6is selected from: 63 763537: NIT-59597PC (PAT059597-FF) . In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): R7cis selected from C1-6-alkyl and 9-membered heteroaryl, wherein the C1-6-alkyl and 9-membered heteroaryl of R7care each optionally substituted with 1 or 2 substituents independently selected from -CN, halo, -NH2, and -OH; In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): the 9-membered heteroaryl of R7cis a bicyclic 9-membered heteroaryl. 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A7is a moiety of formula (A7-I) or formula (A7-II): (A7-II), wherein: Y7is selected from NH and CH2; Y7aand Y7’are each independently selected from N and CH, provided that at least one of Y7and Y7ais selected from N and NH and provided that at least one of Y7’and Y7ais N; R7ais selected from H and C1-3-alkyl; 64 763537: NIT-59597PC (PAT059597-FF) each R7aais selected from C1-3-alkyl, -CN, halo, -NH2, and -OH; and q and r are each independently 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A7is in the L configuration. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A7is a moiety of formula (A7-Iaa): wherein: Y7is selected from NH and CH2; Y7ais selected from N and CH, provided that at least one of Y7and Y7ais selected from N and NH; R7ais selected from H and C1-3-alkyl; each R7aais selected from C1-3-alkyl, -CN, halo, -NH2, and -OH; and q is 0, 1, or 2. 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A7is a moiety of formula (A7-Ia) or formula (A7-IIa): 65 763537: NIT-59597PC (PAT059597-FF) (A7-IIa), wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from C1-3-alkyl, halo, -NH2, and -OH; and q and r are each independently 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A7is a moiety of formula (A7-Iaaa): wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from C1-3-alkyl, halo, -NH2, and -OH; and q is 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A7is selected from: 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): 66 763537: NIT-59597PC (PAT059597-FF) A7is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A8is a moiety of formula (A8-I) or formula (A8-II): (A8-II), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; R8abis selected from H, -CN, halo, -NH2, and -OH; t is 1 or 2; u is 0, 1, or 2; and v is 0, 1, 2, 3, or 4. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A8is selected from: 67 763537: NIT-59597PC (PAT059597-FF) . In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A8is selected from: 5 . In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A9is a moiety of formula (A9-I) or formula (A9-II): wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and d is 1 or 2. 68 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A9is selected from: In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A9is selected from: . 5 In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is a moiety of formula (A10-I), formula (A10-II), formula (A10-III), or formula (A10-IV): (A10-I), 69 763537: NIT-59597PC (PAT059597-FF) (A10-IV). In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is a moiety of formula (A10-Ia) or formula (A10-Ib): or (A10-Ia), wherein: R10ais selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; 70 763537: NIT-59597PC (PAT059597-FF) each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; R10abis selected from H, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; w and y are each independently 1, 2, 3, 4, 5, or 6; and x is 0, 1, or 2. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is a moiety of formula (A10-IIa), formula (A10-IIb), or formula (A10-IIc): (A10-IIc), wherein: each Y10ais independently selected from N, NH, and CH2, provided that at least one Y10ais selected from N and NH; 71 763537: NIT-59597PC (PAT059597-FF) R10aand R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10fis selected from H and C1-6-alkyl, wherein the C1-6-alkyl of R10fis optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, and - OC1-6-alkyl; R10aa, R10ab, and R10acare each independently selected from C1-6-alkyl, halo, -NH2, - N3, -OH, and -OC1-6-alkyl; each R10adis independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, -OC1-6- alkyl, -C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; y, y’, y’’, and y’’’ are each independently 0, 1, or 2; and z, z’, z’’, and z’’’ are each independently 1, 2, 3, 4, 5, or 6. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is a moiety of formula (A10-IIIa): (A10-IIIa), wherein: R10ais selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10aais selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; a’ is 0, 1, or 2; and b’ is 1, 2, 3, 4, 5, or 6. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is a moiety of formula (A10-IVa): 72 763537: NIT-59597PC (PAT059597-FF) (A10-IVa), wherein: each Y10bis independently selected from N, NH, and CH2, provided that at least one Y10bis selected from N and NH; R10a, R10c, and R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10aais selected from C1-6-alkyl, halo, -NH2, -N3, -OH, -OC1-6-alkyl; each R10adis independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, -OC1-6- alkyl, -C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; R10aeis selected from H, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; c’ and f’ are each independently 0, 1, or 2; and d’, e’, and v’ are each independently 1, 2, 3, 4, 5, or 6. In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is selected from: , 73 763537: NIT-59597PC (PAT059597-FF) In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P): A10is selected from: 74 763537: NIT-59597PC (PAT059597-FF) . In some embodiments of the cyclic peptide (P), or compounds comprising cyclic peptide (P), A10is substituted with one biotin tag. In certain embodiments, the cyclic peptide (P) is of Formula (P-I): *α–A1-Tyr-Ser-A4-A5-(W(5OH))-Trp-A8-(NMeDap)*β-A10–, wherein 5*αindicates the point of attachment of A1to NMeDap; *βindicates the point of attachment of NMeDap to A1, wherein A1and NMeDap are attached so Formula (P-I) is a cyclized (cyclic) peptide (P); A1is: NAc-hE, hE, NAc-E, H-GlutarA, or NAc-Asp, each of which is optionally substituted with a PEG chain; 10 A4is NMehF, NMeAhp, NMeAoc, or NMehF(3Cl); A5is: MeKAc, NMeS, NMe-K(TFA), MeK(COCH2OH), or MeK(COEtOH); A8is: CproG or AlloT; A10is NMeF(4F), NMeAoc, or NMeAhp; and A10is bound to L1, wherein L1is a bond or a linker (e.g., Orn or Lys), wherein L115 is bound to M, and M is an imaging agent, chelating agent, radionuclide, or cytotoxic drug (e.g., M is a chelator optionally radiolabeled with a radionuclide). In certain further embodiments, the cyclic peptide (P) of Formula (P-I) is of Formula (P-I-A): *α–A1-Tyr-Ser-A4-A5-(W(5OH))-Trp-A8-(NMeDap)*β-A10–, wherein 20*αindicates the point of attachment of A1to NMeDap; *βindicates the point of attachment of NMeDap to A1, wherein A1and NMeDap are attached so Formula (P-I-A) is a cyclized peptide (P); 75 763537: NIT-59597PC (PAT059597-FF) A1is: NAc-hE, hE, or NAc-E, each of which is optionally substituted with a PEG chain (e.g., mPEG12); A4is NMehF or NMehF(3Cl); A5is: MeKAc or NMeS; 5 A8is: CproG or AlloT; A10is NMeF(4F); and A10is bound to L1, wherein L1is a bond or a linker (e.g., Orn or Lys), wherein L1is bound to M, and M is a chelator (e.g., a chelator of Tables 3-7) optionally radiolabeled with a radionuclide (e.g.,177Lu,161Tb,90Y,67Cu,131I,225Ac,212Pb,211At, or227Th). 10 In certain further embodiments, the cyclic peptide (P) of Formula (P-I) is of Formula (P-I-A-i): *α–A1-Tyr-Ser-(NMehF)-A5-(W(5OH))-Trp-A8-(NMeDap)*β-(NMeF(4F))–, wherein *αindicates the point of attachment of A1to NMeDap; *βindicates the point of attachment of NMeDap to A1, wherein A1and NMeDap are 15 attached so Formula (P-I-A-i) is a cyclized peptide (P); A1is: NAc-hE or mPEG12-hE, wherein mPEG12-hE has the following structure: , wherein *2 indicates the point of attachment to A2and *9 indicates the point of attachment to A9; A5is: MeKAc or NMeS; A8is: CproG or AlloT; and NMeF(4F) is bound to L1, wherein L1is a bond or Lys, wherein L1is bound to M, and M is a chelator selected from DOTA, NOTA, DOTAGA, and NODAGA, wherein M is 76 763537: NIT-59597PC (PAT059597-FF) optionally radiolabeled with a radionuclide (e.g.,177Lu,161Tb,90Y,67Cu,225Ac,212Pb,211At, or227Th); wherein NMeF(4F), L1, and M together have a structure selected from 5 *9 indicates the point of attachment to A9, wherein M is optionally radiolabeled with a radionuclide. 77 763537: NIT-59597PC (PAT059597-FF) In certain embodiments, the cyclic peptide (P) is a cyclic peptide selected from any one of Examples A1 to A77, or a pharmaceutically acceptable salt, solvate, stereoisomer, or tautomer thereof. In certain embodiments, the cyclic peptide (P) is a cyclic peptide selected from any 5 one of Examples A1 to A77, or a pharmaceutically acceptable salt, solvate, stereoisomer, or tautomer thereof. In certain embodiments, a compound of the present disclosure (e.g., ligand, for example, radioligand) is a compound of the table of Example III, or a pharmaceutically acceptable salt, solvate, stereoisomer, or tautomer thereof. 10 Albumin Binders The HER2-targeting cyclic peptide (P), or the compound comprising a cyclic peptide (P), of the present disclosure may further comprise an albumin binder. For example, an albumin binder may be attached to the cyclic peptide via a side chain of any one of A1-A10. In one or more embodiments, an albumin binder is connected to the cyclic peptide via a side 15 chain of A2. Any compound, peptide, polypeptide, or other moiety known in the art as being capable of binding albumin, i.e., having albumin binding affinity, may be connected to the cyclic peptide (or any of the compounds comprising said cyclic peptide) of the instant disclosure as an albumin binder. Addition of an albumin binder to the cyclic peptide may 20 prolong the bioavailability of the disclosed HER2-targeting compounds, thereby enhancing tumor uptake. Exemplary albumin binders are described in Zorzi et al. Non-covalent albumin-binding ligands for extending the circulating half-life of small biotherapeutics. Med. Chem. Comm.2019 Jun 6;10(7):1068-1081, Brandt et al. Mini-review: Targeted radiopharmaceuticals incorporating reversible, low molecular weight albumin binders. Nucl. 25 Med. Biol.2019 Mar;70:46-52, and Lau et al. Bench to Bedside: Albumin Binders for Improved Cancer Radioligand Therapies. Bioconjug. Chem.2019 Mar 20;30(3):487-502. 10.1021 / acs.bioconjchem.8b00919. Epub 2019 Jan 23. PMID: 30616340, which are each incorporated herein by reference in its entirety. In one or more embodiments, the cyclic peptide, or any of the compounds disclosed 30 herein comprising said cyclic peptide, is substituted with an albumin binder selected from fatty acids and derivatives thereof. Such fatty acids and derivatives thereof include, e.g., 78 763537: NIT-59597PC (PAT059597-FF) 5 . 10 In one or more embodiments, the cyclic peptide, or any of the compounds disclosed herein comprising said cyclic peptide, is substituted with an albumin binder selected from: 79 763537: NIT-59597PC (PAT059597-FF) 5 . In various embodiments, the albumin binder is 4-(p-iodophenyl)butyric acid or a derivative thereof, such as, for example: 80 763537: NIT-59597PC (PAT059597-FF) . In some embodiments, the albumin binder is: . In some embodiments, the albumin binder is: 5 . In some embodiments, the albumin binder is Evans blue, or a derivative thereof. In some embodiments, the albumin binder is: . In some embodiments when the cyclic peptide, or compound comprising said cyclic 10 peptide, is substituted with an albumin binder cyclic peptide, said cyclic peptide, is a compound that is Example G1, or a pharmaceutically acceptable salt or solvate thereof. L1(e.g., of compounds of formulae (I), (Ia), (Ib), (Ic), and ) The compounds disclosed herein (e.g., compounds of Formulae (I), (Ia), (Ib), (Ic), and 15 (Id) comprise L1between P and M. In some embodiments, L1is a bond (i.e., a bond between P and M). In some embodiments, L1is a linker. As used herein, the term “linker” means a structural component that connects two parts of a compound. Linkers can comprise an atom such as oxygen or sulfur, a unit such as NR, C(O), C(O)NH, SO, SO2, SO2NH or a chain of atoms, such as substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, 20 substituted or unsubstituted alkynyl, arylalkyl, arylalkenyl, arylalkynyl, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, heterocyclylalkyl, heterocyclylalkenyl, 81 763537: NIT-59597PC (PAT059597-FF) heterocyclylalkynyl, aryl, heteroaryl, heterocyclyl, cycloalkyl, cycloalkenyl, alkylarylalkyl, alkylarylalkenyl, alkylarylalkynyl, alkenylarylalkyl, alkenylarylalkenyl, alkenylarylalkynyl, alkynylarylalkyl, alkynylarylalkenyl, alkynylarylalkynyl, alkylheteroarylalkyl, alkylheteroarylalkenyl, alkylheteroarylalkynyl, alkenylheteroarylalkyl, 5 alkenylheteroarylalkenyl, alkenylheteroarylalkynyl, alkynylheteroarylalkyl, alkynylheteroarylalkenyl, alkynylheteroarylalkynyl, alkylheterocyclylalkyl, alkylheterocyclylalkenyl, alkylheterocyclylalkynyl, alkenylheterocyclylalkyl, alkenylheterocyclylalkenyl, alkenylheterocyclylalkynyl, alkynylheterocyclylalkyl, alkynylheterocyclylalkenyl, alkynylheterocyclylalkynyl, alkylaryl, alkenylaryl, alkynylaryl, 10 alkylheteroaryl, alkenylheteroaryl, or alkynylheteroaryl. In any of these structural components, one or more methylene groups can be interrupted by O, S, S(O), SO2, N(R’), C(O), substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclic; where R’ is hydrogen, acyl, aliphatic or substituted aliphatic. In some embodiments, the linker L is one to about twenty-four atoms, one to about twelve 15 atoms, one to about eight atoms, one to about six atoms, or four to six atoms. The linker may be attached to any amino acid site of the cyclic peptide (P) to form a linkage between P and M. For example, the linker may be attached to the HER2-targeting compound via any one of A1-A10. In some embodiments, the linker is attached to a side chain of any one of A1-A10. In other embodiments, the linker is attached to a backbone nitrogen of 20 any one of A1-A10. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A1. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A2. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A3. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A4. In some embodiments, the linker is attached to the side chain or backbone 25 nitrogen of A5. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A6. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A7. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A8. In some embodiments, the linker is attached to the side chain or backbone nitrogen of A9. In some embodiments, the linker is attached to the side chain or backbone 30 nitrogen of A10. Analogously, the linker may be attached to any site capable of forming a covalent attachment on the chelator to form a linkage between P and M. For example, the linker may be attached to the chelator via a heteroatom, the functional group of a functionalized heteroatom, or an alkyl, cycloalkyl, or aryl group separating the heteroatoms of the chelator. 82 763537: NIT-59597PC (PAT059597-FF) In some embodiments, the linker is attached to a heteroatom of the chelator. In other embodiments, the linker is attached to the functional group of a functionalized heteroatom of the chelator. In yet other embodiments, the linker is attached to an alkyl, cycloalkyl, aryl, or heteroaryl group separating the heteroatoms of the chelator. In some embodiments, the linker 5 is attached to an alkyl group separating the heteroatoms of the chelator. In some embodiments, the linker is attached to a cycloalkyl group separating the heteroatoms of the chelator. In some embodiments, the linker is attached to an aryl group separating the heteroatoms of the chelator. In some embodiments, the linker is a covalent bond. Alternatively, in some 10 embodiments, the linker is a divalent moiety other than a covalent bond. In embodiments in which the linker is a divalent moiety other than a bond, the linker comprises one or more functional groups capable of forming a covalent attachment with the cyclic peptide (P) or chelator (M). Suitable functional groups include, but are not limited to, amine, azide, amide, carboxylic acid, hydroxy, alkoxy, nitrile, alkene, and alkyne functional groups. 15 L1may be any linker known in the art. In some embodiments, the linker includes a group such as, for example, an amino acid, or derivative thereof, CH2, CH2CH2, cycloalkylene, alkylene, arylene, alkylarylene, heteroarylene, heterocycloalkylene, (CR4R5)pO(CR4R5)q, (CR4R5)pN(CR4R5)q, (CR4R5)pS(CR4R5)q, wherein cycloalkylene, alkylene, arylene, alkylarylene, heteroarylene, and heterocycloalkylene are optionally20 substituted with 1, 2, or 3 substituents independently selected from halo, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C1-6haloalkyl, halosulfanyl, CN, NO2, N3, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, C(=NRg)NRcRd, NRcC(=NRg)NRcRd, P(Rf)2, P(ORe)2, P(O)ReRf, P(O)OReORf, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, 25 wherein R4and R5are independently selected from H, halo, OH, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, alkoxyalkyl, cyanoalkyl, heterocycloalkyl, cycloalkyl, C1-6 haloalkyl, CN, and NO2;Ra, Rb, Rc, and Rdare independently selected from H, C1-10alkyl, C1-6haloalkyl, C2-6alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl,30 cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-10alkyl, C1-6haloalkyl, C2-6alkenyl, C2-6alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with 1, 2, or 3 substituents independently selected from -OH, -CN, amino, halo, C1-6 alkyl, C1-6 alkoxy, C1-6 haloalkyl, and C1-6haloalkoxy 83 763537: NIT-59597PC (PAT059597-FF) Re, Rf, and Rgare each independently selected from the group consisting of H and C1-10 alkyl; p is 0, 1, 2, 3, 4, 5, or 6; and q is 0, 1, 2, 3, 4, 5, or 6. 5 In various embodiments, at least one L1is bound to any –NH2 or any C(O) of the cyclized peptide. In various embodiments, at least one L1is bound to any –NH2or C(O) of A1, A3, or A10. In various embodiments, at least one L1is bound to any –NH2 or any C(O) of A1or A10. In various embodiments, L1is a linker of formula (L1-I) or formula (L1-II): wherein: XLis selected from CH2, N(RL), and O; YLis selected from H, -OH, -OC1-6-alkyl, and -N(RL)2; each RLis independently selected from H and C1-6-alkyl; h’ and j’ are each independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; g’ and k’ are each independently 0, 1, 2, 3, or 4; i’ is 0, 1, 2, 3, 4, 5, or 6; and wherein *P indicates the point of attachment to a C(O) on A1or A10and **P indicates the point of attachment to a –NH2 on A1or A10. In various embodiments, A10and L1, together, have the structure: 84 763537: NIT-59597PC (PAT059597-FF) . In various embodiments, A10and L1, together, have the structure: , wherein: l’ is 1, 2, 3, 4, 5, or 6. In various embodiments, A1and L1, together, have the structure: . In various embodiments, L1is a bond. 5 85 763537: NIT-59597PC (PAT059597-FF) M (e.g., of compounds of formulae (I), (Ia), (Ib), (Ic), and (Id)) As disclosed herein, M can be an imaging agent, a chelating agent optionally radiolabeled with a radionuclide, or a radionuclide. In some embodiments, M is an imaging agent. In some embodiments, M is a chelator. In some embodiments, M is a chelator 5 radiolabeled with a radionuclide. In some embodiments, M is a radionuclide. Any M may be connected to the cyclic peptide via any L1described above (whether L1is a linker or a bond). The skilled artisan would be able to determine suitable combinations of M and L1based on the present disclosure, or suitable substitution of the cyclic peptide directly with M in the case where L1is a bond. 10 Imaging Agents In one or more embodiments of the HER2-targeting compounds described herein, M is an imaging agent. HER2-targeting compounds that include an imaging agent may be useful for in vitro and / or in vivo visualization of HER2-related disease progression or response after 15 receiving the instantly disclosed compounds. In some embodiments, the imaging agent is a non-radioactive (or non-radionuclide) imaging agent. In some embodiments, the imaging agent is a fluorescent imaging agent. Suitable imaging agents that may be connected to the cyclic peptide include Cy dyes, Culfo Cy dyes, Alexa Fluor dyes, Dylight dyes, FluoProbes dyes, Seta dyes, IRIS dyes, and 20 other dyes that can be used interchangeably with Cy dyes in most biochemical imaging applications. For example, the compounds of the instant disclosure may be connected to imaging, but not limited to, Cy2, Cy3, Cy3.5, Cy5, Cy5.5, Cy7, Cy7.5, Sulfo Cy2, Sulfo Cy3, Sulfo Cy3.5, Sulfo Cy5, Sulfo Cy5.5, Sulfo Cy7, Sulfo Cy7.5, Alexa Fluor 350, Alexa Fluor 405, Alexa Fluor 430, Alexa Fluor 488, Alexa Fluor 500, Alexa Fluor 514, Alexa Fluor 532, 25 Alexa Fluor 546, Alexa Fluor 555, Alexa Fluor 568, Alexa Fluor 594, Alexa Fluor 610, Dylight 350, Dylight 405, Dylight 488, Dylight 550, Dylight 594, Dylight 633, Dylight 650, Dylight 680, Fluorprobes 390, Fluorprobes 488, Fluorprobes 532, Fluorprobes 547H, Fluorprobes 594, Fluorprobes 647H, Fluorprobes 682, Seta 375 NHS, Seta 400 NHS, Seta 405 NHS, Seta 475 Maleimide, Seta 470 NHS, Seta 555 Azide, Seta 555 DBCO, Seta 55530 NHS, Seta 632 Maleimide, Seta 632 NHS, Seta 633 Azide, Seat 633 NHS, Seta 635 pH di- NHS, Seta 640 pH di-NHS, Seta 646, Maleimide, Seta 646 NHS, Seta 650 Azide, Seta 650 Maleimide, IRIS 2, IRIS 3, IRIS, 3.5, IRIS 5, IRIS 5.5, IRIS 7, IRIS 2 NHS Active, IRIS 3 NHS Active, IRIS 3.5 NHS Active, IRIS 5 NHS Active, IRIS 5.5 NHS Active, and IRIS 7 NHS Active. 86 763537: NIT-59597PC (PAT059597-FF) Additional exemplary imaging agents that may be incorporated into a compound of the present disclosure includes those described in Elmes, R. Bioreductive fluorsecent imaging agents: applications in tumor hypoxia. Chem. Commun.2016, 52, 8935, and Schouw et al. Targeted optical fluorescence imaging: a meta-narrative review and future perspectives. Eur. 5 J. Nucl. Med. Mol. Imaging.2021 Dec;48(13):4272-4292. In some embodiments, the imaging agent is selected from Cy2, Cy3, Cy3.5, Cy5, Cy5.5, Cy7, Cy7.5, Sulfo Cy2, Sulfo Cy3, Sulfo Cy3.5, Sulfo Cy5, Sulfo Cy5.5, Sulfo Cy7, and Sulfo Cy7.5. In some embodiments, the imaging agent is selected from Cy3, Cy3.5, Cy5, Cy5.5, Cy7, Sulfo Cy3, Sulfo Cy3.5, Sulfo Cy5, Sulfo Cy5.5, and Sulfo Cy7. In some 10 embodiments, the imaging agent is selected from Cy3, Cy3.5, Cy5, Cy5.5, Sulfo Cy3, Sulfo Cy3.5, Sulfo Cy5, and Sulfo Cy5.5. In some embodiments, the imaging agent is selected from Cy5, Cy5.5, Sulfo Cy5, and Sulfo Cy5.5. In some embodiments, the imaging agent is Cy5 or Sulfo Cy5. In some embodiments, the HER2-targeting compounds of the present disclosure are 15 bound to Sulfo Cy5: . In some embodiments, M is an imaging agent attached to L1, and L1is a linker attached to a side chain of an amino acid of the cyclic peptide (P). In further embodiments, M is an imaging agent, and L1is a linker attached to a side chain NH2 of an amino acid of the 20 cyclic peptide. In still further embodiments, M is an imagining agent and L1is a linker attached to a side chain NH2of A1or A10of the cyclic peptide. In yet further embodiments, M is an imagining agent and L1is a bond or a linker attached to a lysine side chain or a β- alanine side chain of the cyclic peptide, wherein the lysine or β-alanine is at position A1or A10. In some embodiments, L1is a linker of formula (L1-II), and A1, L1, and M, together, have the structure: 87 763537: NIT-59597PC (PAT059597-FF) , wherein: XLis selected from CH2, N(RL), and O; RLis selected from H and C1-6-alkyl; a is 1, 2, 3, or 4; j’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; k’ is 0, 1, 2, 3, or 4; *2 indicates the point of attachment to A2; and *9 indicates the point of attachment to A9. In some embodiments, L1is a linker of formula (L1-II), and A10, L1, and M, together, have the structure: 88 763537: NIT-59597PC (PAT059597-FF) , wherein: XLis selected from CH2, N(RL), and O; RLis selected from H and C1-6-alkyl; R10aand R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10mis selected from H and C1-3-alkyl; R10aais selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; a is 1, 2, 3, or 4; j’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; k’ is 0, 1, 2, 3, or 4; m’ is 1, 2, 3, 4, 5, or 6; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and *9 indicates the point of attachment to A9. In some embodiments, the HER2-targeting compounds of the present disclosure are bound to: 89 763537: NIT-59597PC (PAT059597-FF) In certain embodiments of HER2-targeting compounds of the present disclosure, L1is a bond and M is an imaging agent attached to a side chain of A10, where M, L1, and A10, 5 together, have the structure: , 90 763537: NIT-59597PC (PAT059597-FF) wherein *9 indicates the point of attachment to A9, and wherein the variables are defined elsewhere herein. In certain embodiments of HER2-targeting compounds of the present disclosure, M is an imaging agent and L1is a linker of formula (L1-I) attached to a side chain A10, where M, 5 L1, and A10, together, have the structure: , wherein *9 indicates the point of attachment to A9, and wherein the variables are defined elsewhere herein. 10 In certain embodiments of HER2-targeting compounds of the present disclosure, L1is a bond and M is an imaging agent attached to a side chain of A1, where M, L1, and A1, together, have the structure: 91 763537: NIT-59597PC (PAT059597-FF) , wherein *2 indicates the point of attachment to A2, *9 indicates the point of attachment to A9, and wherein the variables are defined elsewhere herein. In some embodiments, the compounds disclosed herein comprise both a radionuclide, 5 which may be suitable for imaging (i.e., diagnostically active) or therapy, and a non- radioactive imaging agent. In some embodiments, M is an imaging agent attached to L1, and L1is a linker attached to a side chain of an amino acid of the cyclic peptide (P). In further embodiments, M is an imaging agent, and L1is a bond or a linker attached to a side chain NH2of an amino 10 acid of cyclic peptide P. In yet further embodiments, M is an imagining agent and L1is a bond or a linker attached to a lysine side chain or a β-alanine side chain of the cyclic peptide, wherein the lysine or β-alanine is at position A1or A10. In some embodiments, M, L1, and A10, together, have one of the following structures: , 92 763537: NIT-59597PC (PAT059597-FF) wherein *10 indicates the point of attachment to A10. In some embodiments, M, L1, and A10, together, have one of the following structures: wherein *9 indicates the point of attachment to A9, and wherein the variables are 5 defined elsewhere herein. Chelators In one or more embodiments of the HER2-targeting compounds described herein, M is a chelator. As used herein, the terms “chelator,” “chelating ligand,” and “chelating agent” 10 are interchangeable and typically refer to chemical moieties, agents, compounds, or molecules able to form a complex containing one or more coordinate bonds with a metal ion. The chelators described herein may form a complex with any metal element or metal ion known in the art (e.g. any element of ion of alkali metals, alkaline earth metals, transition metals, inner transition metals (lanthanides, actinides), metalloids, or poor metals, said metals 15 being present alone or in connection with another element, e.g. an ion of a metal in connection with a halogen, e.g. a metal-halogenide) to coordinate to a chelating agent. In some embodiments, the chelator is a nuclide chelator. In some embodiments, the chelator is a radionuclide chelator. Chelators that form a complex with a metal ion, such as a radionuclide, may be 20 referred to herein as radiolabeled chelators. In some embodiments, a chelator complexed or coordinated to a metal ion is depicted with single bonds between heteroatoms of the chelator 93 763537: NIT-59597PC (PAT059597-FF) and the metal ion or is depicted with dashed bonds between the heteroatoms of the chelator and the metal ion. In some embodiments, the chelator forms a complex with a metal ion and with one or more additional molecules, e.g., a water molecule. 5 When the chelator is chelated or complexed to a radionuclide, it can be said that the chelator is radiolabeled. In some embodiments of the compounds described herein, M is a chelator, and the resulting conjugate of the cyclic peptide with a chelator and optionally a linker can be radiolabeled with a radionuclide. In some embodiments, chelating agents suitable for coordinating to metal ions may 10 have a cyclic or acyclic structure. In some embodiments, chelating agents suitable for coordinating to metal ions may have a cyclic or linear structure. In some embodiments, the chelator is a cyclic chelator. As used herein, the term “cyclic chelator” means any chelator having a heterocyclic ring in which two or more of the ring heteroatoms form a coordinate covalent bond to a metal ion, such as, for example, a 15 radionuclide. In an embodiment, the heterocyclic ring has at least two heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur. In another embodiment, the heterocyclic ring is a macrocycle having between 7 and 30 ring atoms. In yet another embodiment, the heterocyclic ring is a macrocycle having between 7 and 20 ring atoms. In still another embodiment, the heterocyclic ring is a macrocycle having between 7 and 15 ring 20 atoms. In an embodiment, the cyclic chelator is DOTA. In some embodiments, the chelator is an acyclic chelator. As used herein, the term “acyclic chelator” means any chelator having an open chain that contains heteroatoms in which two or more of the heteroatoms form a coordinate covalent bond to a metal ion, such as, for example, a radionuclide. An acyclic chelator may comprise cycloalkyl, heterocyclic, 25 aryl, and heteroaryl rings, or a combination thereof. However, when the acyclic chelator comprises heterocyclic and / or heteroaryl rings, no more than one heteroatom of each ring participates in the coordinate covalent bond with the metal ion. In an embodiment, the acyclic chelator is a linear chelator, such as, for example, H2dedpa, BFO, DFO, and mertiatide. In another embodiment, the acyclic chelator is a branched chelator, such as, for example, 30 EDTA, DTPA, Pip-DTPA, ECC, ECD, and citric acid. Suitable cyclic chelators may have a heterocyclic core, such as, for example, a crown ether or an aza-crown ether. In an embodiment, the heterocyclic core is an aza-crown ether. In another embodiment, the heterocyclic core comprises nitrogen and oxygen heteroatoms. In yet another embodiment, the heterocyclic core is a crown ether. 94 763537: NIT-59597PC (PAT059597-FF) Chelators in accordance with the present disclosure may have a heterocyclic core comprising from 2 to 10 heteroatoms. For example, the chelator may have a heterocyclic core comprising 2, 3, 4, 5, 6, 7, 8, 9, or 10 heteroatoms. In some embodiments, heterocyclic core comprises from 2 to 8 heteroatoms, from 3 to 8 heteroatoms, from 2 to 6 heteroatoms or from 5 3 to 6 heteroatoms. In an embodiment, the heterocyclic core comprises 3 heteroatoms. In another embodiment, the heterocyclic core comprises 4 heteroatoms. In another embodiment, the heterocyclic core comprises 5 heteroatoms. In yet another embodiment, the heterocyclic core comprises 6 heteroatoms. In some embodiments, one or more heteroatoms of the core structure is 10 functionalized. For example, heteroatoms of the cyclic core may be functionalized with one or more of H, OH, C(O)ORx,CRx2C(O)Rx, (CRx)nC(O)ORx, (CRx)nC(O)NH2, (CRx)nC(O)NHRx, (CRx)nC(O)NRx2, CRx2P(O)(ORx)2, (CRx)nP(O)(ORx)2, P(O)(ORx)2, alkyl, aryl, cylcoalkyl, heterocycloalkyl, alkylaryl, alkylheteroaryl, and heteroaryl wherein alkyl, aryl, heteroaryl, heterocycloalkyl, alkylaryl, alkylheteroaryl, and cycloalkyl are optionally 15 substituted with one or more H, OH, ORx, CN, SCN, C(O)ORx, C(O)NRx, P(O)(ORx)2, N3, NRx2, SRx, halo, alkyl, haloalkyl, aryl, heteroaryl, benzyl, where alkyl, haloalkyl, aryl, heteroaryl, and benzyl are optionally substituted with one or more Rx, and each Rxis independently selected from H, OH, CN, SCN, NH2, CH2C(O)OH, C(O)OH, halo, alkyl, haloalkyl, alkylaryl, heteroaryl, cycloalkyl, heterocycloalkyl, and P(O)(OH)2 and n is 0, 1, 2, 20 3, 4, or 5. In some embodiments, the heterocyclic core of the chelator comprises heteroatoms separated by alkylene groups, such as, for example, methylene, ethylene, or propylene groups. In some embodiments, the heteroatoms of the heterocyclic core are separated by ethylene groups. In some embodiments, the heteroatoms of the heterocyclic core are 25 separated by methylene groups. The alkylene groups separating the heteroatoms of the core structure may be substituted or unsubstituted. In some embodiments, one or more alkylene groups of the heterocyclic core are substituted with one or more H, OH, C(O)ORx,CRx2C(O)ORx, CRx2P(O)(ORx)2, P(O)(ORx)2, alkyl, aryl, cylcoalkyl, heterocycloalkyl, alkylaryl, alkylheteroaryl, and heteroaryl wherein alkyl, aryl, heteroaryl, 30 heterocycloalkyl, alkylaryl, alkylheteroaryl, and cycloalkyl are optionally substituted with one or more H, OH, ORx, CN, SCN, C(O)ORx, C(O)NRx, P(O)(ORx)2, N3, NRx2, SRx, halo, alkyl, haloalkyl, aryl, heteroaryl, benzyl, where alkyl, haloalkyl, aryl, heteroaryl, and benzyl are optionally substituted with one or more Rx, and each Rxis independently selected from H, 95 763537: NIT-59597PC (PAT059597-FF) OH, CN, SCN, NH2, CH2C(O)OH, C(O)OH, halo, alkyl, alkoxy, haloalkyl, alkylaryl, heteroaryl, cycloalkyl, heterocycloalkyl, P(O)(OH)2, and SH. In an embodiment, the cyclic chelator comprises a 1,4,7,10-tetraazacyclododecane core or a residue thereof, such as, for example, the structures shown in Table 3 or residues 5 thereof, below. 96

[0002] )F F-795950T A P(C P79595-TIN:735367erocP e n M a T ceO doD dolcycazaart et-01,7,4,1ahtiwsrotaleh C cilcyC AS yrA A alTA3T p O O O m D D D exE.3elbaT

[0003] )F F-795950TA P(C P79595-TIN:735367A P2O D-eM roA G A A P T T O O D D

[0004] )F F-795950T A P(C P79595-TIN:735367A P E D- C A S T C OND--A n T B- OPND- 1CASO3-epO M D

[0005] )F F-795950T A P(C P79595-TIN:735367 aA(ot)anS M A AdeConD TrrolO OefM CcyD DerTcaza 0ir0t1-7,4,1asesirpmocrotalehccilcyceht,tnemidAobT4meE S CrD PehtonanI .woleb,45

[0006] )F F-795950T A P(C P79595-TIN:735367P erA ocR1eT N 0n1anonolcycazairt- 7,4,1ahtiwsrotaleh C cilcyCyralp A meT3xO S E.N N 4elbaT

[0007] )F F-795950T A P(C P79595-TIN:735367A T E N- C A T O N A -n GBA - D N CA2O S O N -pN

[0008] )F F-795950T A P(C P79595-TIN:735367A TS E N- C P A2P T OP O O O N N N 763537: NIT-59597PC (PAT059597-FF) In some embodiments, the cyclic chelator comprises a bridged heterocyclic core. In some embodiments, the cyclic chelator comprises a fused heterocyclic core. For example, in one or more embodiments, the heterocyclic core (of the cyclic chelator) may be fused to a heteroaryl or heterocycloalkyl ring, such that the two cycles share a heteroatom. Suitable 5 heteroaryl and heterocycloalkyl rings that may be fused to the heterocyclic core (of the cyclic chelator) include, but are not limited to pyridine, pyrimidine, furan, tetrahydropyran, pyran, dioxane, and oxazole, imidazole, and pyrrole. Chelators comprising a fused or bridged core structure, as well as various other suitable heterocyclic cores, include, but are not limited to, the structures shown in Table 5, 10 below. 104

[0009] )F F-795950T A P(C P79595-TIN:735367 3m2 5L H01srotaleh C cilcyCyralp mexElan oitiAd2d O A A.D-TI5 B R elC T baT

[0010] )F F-795950T A P(C P79595-TIN:735367ap orcam- n B- N CS-p A TAE2E T T

[0011] )F F-795950TA P(C P79595-TIN:735367AP E P- n B- N CS-p A P A T T E C T P

[0012] )F F-795950T A P(C P79595-TIN:735367801

[0013] )F F-795950T A P(C P79595-TIN:735367A T Z T A A9A D01A T Z A 2 A N L C

[0014] )F F-795950T A P(C P79595-TIN:7353672apsib2 H 5 AeTniZdiA p Asib

[0015] )F F-795950T A P(C P79595-TIN:735367 e nigah01 p o C c0r3aB1S D11L A X 2 -aE p T-orBcaC m 763537: NIT-59597PC (PAT059597-FF) In some embodiments, the chelator is an acyclic or linear chelator. Suitable linear chelating ligands may comprise a series of functionalized amines separated by alkylene, arylene, cycloalkyl, heteroaryl, heterocycloalkyl groups, or a combination thereof. In some embodiments, the acyclic chelator comprises 2, 3, or 4 functionalized amines. For example, 5 in some embodiments the linear chelator comprises 2, 3, or 4 amines functionalized with one or more of H, OH, C(O)ORx,CRx2C(O)ORx, CRx2P(O)(ORx)2, P(O)(ORx)2, alkyl, aryl, cylcoalkyl, heterocycloalkyl, alkylaryl, alkylheteroaryl, and heteroaryl wherein alkyl, aryl, heteroaryl, heterocycloalkyl, alkylaryl, alkylheteroaryl, and cycloalkyl are optionally substituted with one or more H, OH, ORx, CN, SCN, C(O)ORx, C(O)NRx, P(O)(ORx)2, N3, 10 NRx2, SR, halo, alkyl, haloalkyl, aryl, heteroaryl, benzyl, where alkyl, haloalkyl, aryl, heteroaryl, and benzyl are optionally substituted with one or more Rx, and each Rxis independently selected from H, OH, CN, SCN, NH2, CH2COOH, C(O)OH, halo, alkyl, haloalkyl, alkylaryl, heteroaryl, cycloalkyl, heterocycloalkyl, and P(O)(OH)2. In some embodiments, the acyclic chelator comprises a series of functionalized 15 amines separated by alkylene groups, such as, for example, methylene, ethylene, and propylene groups. The alkylene groups separating the functionalized amines may be substituted or unsubstituted. In some embodiments, one or more of the alkylene groups separating the functionalized amines are substituted with one or more of H, OH, C(O)ORx,CRx2C(O)ORx, CRx2P(O)(ORx)2, P(O)(ORx)2, alkyl, aryl, cylcoalkyl, 20 heterocycloalkyl, alkylaryl, alkylheteroaryl, and heteroaryl wherein alkyl, aryl, heteroaryl, heterocycloalkyl, alkylaryl, alkylheteroaryl, and cycloalkyl are optionally substituted with one or more H, OH, ORx, CN, SO3-, SCN, C(O)ORx, C(O)NRx, P(O)(ORx)2, N3, NRx2, SRx, halo, alkyl, haloalkyl, aryl, heteroaryl, benzyl, where alkyl, haloalkyl, aryl, heteroaryl, and benzyl are optionally substituted with one or more Rx, and each Rxis independently selected 25 from H, OH, CN, SO3-, SCN, NH2, CH2C(O)OH, C(O)OH, halo, alkyl, haloalkyl, alkylaryl, heteroaryl, cycloalkyl, heterocycloalkyl, and P(O)(OH)2. In an embodiment, the linear chelator comprises a series of functionalized amines separated by methylene groups. In another embodiment, the acyclic or linear chelator comprises a series of functionalized amines separated by ethylene groups, such as, for 30 example, the structures provided in Table 6, below. 112

[0016] )F F-795950T A P(C P79595-TIN:735367 D -B- M N 4 CS3B1-p11srotaleh CcilcycAyralp mexP E.A M 6 T T elD D b E E a T

[0017] )F F-795950T A P(C P79595-TIN:735367 APueT n44D H11D D E E B B H H S

[0018] )F F-795950T A P(C P79595-TIN:735367 nep P bb A M S6 H H T T H T T 763537: NIT-59597PC (PAT059597-FF) The acyclic chelator may comprise a variety of heteroatoms, such as, for example, nitrogen, oxygen, and sulfur heteroatoms. In some embodiments, the acyclic chelator comprises nitrogen heteroatoms. In some embodiments, the acyclic chelator comprises nitrogen and oxygen heteroatoms. In some embodiments, the acyclic chelator comprises 5 nitrogen and sulfur heteroatoms. One or more of the heteroatoms of the acyclic or linear chelator may be functionalized. For example, in some embodiments the acyclic or linear chelator comprises one or more heteroatoms functionalized with phosphoric acid, carboxylic acid, substituted or unsubstituted aryl, substituted or unsubstituted phenyl, substituted or unsubstituted 10 heteroaryl, amide, and substituted or unsubstituted alkyl groups. Substituted aryl, benzyl, heteroaryl, and alkyl functionalized amines may be substituted with one or more hydroxyl, carboxyl, alkyl, carbonyl, cyano, phosphoryl, alkoxy, and aryl groups. One or more heteroatoms of an acyclic chelator may be from a heteroarene, such as, for example, pyridine, pyrrole, thiophene, and furan. One or more heteroatoms of an acyclic 15 chelator may be from a carbonyl functionality, such as, for example, an amide, an ester, an acid, and a thioester. In some embodiments, two or more, but not all, of the heteroatoms in the acyclic core may be connected via a heterocyclyl structure. In some embodiments, the linear chelator comprises a series of heteroatoms separated by a combination of alkylene and arylene groups. In some embodiments, the linear chelator 20 comprises a series of functionalized amines separated by a combination of alkylene and cycloalkyl groups. Alkylene, arylene, and cycloalkyl groups separating the heteroatoms of a linear chelator may be substituted or unsubstituted. Further suitable acyclic chelating ligands include, but are not limited to, the structures shown in Table 7, below. 116

[0019] )F F-795950T A P(C P79595-TIN:735367 s rotaleh CcilcycAyralA P p T m D ex-”EAl-aX n oiH tiC- d A n d PBA.T - D - N 7 lpiC e S-bpaP T

[0020] )F F-795950TA P(C P79595-TIN:735367 8 11A P A T T A G B E

[0021] )F F-795950TA P(C P79595-TIN:735367 ap SdSe6d2 B H

[0022] )F F-795950TA P(C P79595-TIN:735367 21ap ded- n B- ap NaCtSc-o4 p H

[0023] )F F-795950T A P(C P79595-TIN:735367 a patco- n B- N A C C S O S -pF E B R

[0024] )F F-795950TA P(C P79595-TIN:735367 xoh X a HxpyCo2 h2 P H H

[0025] )F F-795950T A P(C P79595-TIN:735367 A A S T P M O D B 3 21editaitCIreN Y m H 763537: NIT-59597PC (PAT059597-FF) Beyond the chelators provided in Tables 3-7, this application covers structurally modified chelators (e.g., containing different or additional substituents, replacement of chelating atoms, etc.) provided that the structurally modified chelators have the same properties as those listed above. 5 Additional chelators that may be incorporated in HER2-targeting compounds of the present disclosure are described in Holik, et al. “The Chemical Scaffold of Theranostic Radiopharmaceuticals: Radionuclide, Bifunctional Chelator, and Pharmacokinetics Modifying Linker.” Molecules 27.10 (2022): 3062 and Kostelnik, et al. “Radioactive main group and rare earth metals for imaging and therapy.” Chemical Reviews 119.2 (2018): 902- 10 956, both of which are incorporated by reference in their entireties. In some embodiments of the HER2-targeting compounds described herein, the compound comprises at least one chelator (e.g., at least one M), and the chelator is selected from DOTA, DOTAGA, NODAGA, AAZTA, NOTA, and p-SCN-Bn-DOTA. In further embodiments, the chelator is selected from DOTA, DOTAGA, NODAGA, and AAZTA. In 15 still further embodiments, the chelator is selected from DOTA, DOTAGA, and NODAGA. In certain embodiments, the chelator is DOTA. In certain embodiments, the chelator is NODAGA. In certain embodiments, the chelator is DOTAGA. In various embodiments, M is a cyclic chelating agent. In further embodiments, M is a cyclic chelating agent selected from: , , , 124 763537: NIT-59597PC (PAT059597-FF) , 125 763537: NIT-59597PC (PAT059597-FF) wherein *L1indicates the point of attachment to L1and wherein the cyclic chelating agent is optionally radiolabeled with a radionuclide. In further embodiments, M is a cyclic chelating agent selected from: , wherein *L1indicates the point of attachment to L1and wherein the cyclic chelating agent is optionally radiolabeled with a radionuclide. In some embodiments the chelator or chelator residue includes any additional bridging atom or bridging moiety for attaching the chelator to L1 or the cyclic peptide P. In a nonlimiting example, bridging atoms or bridging moieties include N, O, S, C(O), or combinations thereof. 5 The chelator may be covalently attached to L1or the cyclic peptide (P) via an attachment at any site on the chelator. For example, a covalent attachment may be formed between a functional group of a functionalized heteroatom, a heteroatom, or an alkyl, aryl, or cycloalkyl group separating the heteroatoms of the chelator to a suitable site on the linker or cyclic peptide. 10 In an embodiment, when the chelator (e.g., M) is substituted by a carboxy (-COOH) functional group, that functional group can serve as a handle for covalent attachment to L1or the cyclic peptide (P). In embodiments, the carboxy-L1or carboxy-P attachment point is an amide (-C(O)N(R)-) moiety. In non-limiting embodiments, the language “M is bound to the - (CH2CH2O)z- via an amide bond,” covers, for example, 126 763537: NIT-59597PC (PAT059597-FF) 5 In one or more embodiments of the HER2-targeting compounds described herein (e.g., a compound of formula (I), (Ia), (Ib), (Ic) and (Id), or a pharmaceutically acceptable salt or solvate thereof), the chelator is attached to L1, which is connected to a side chain of any amino acid of the cyclic peptide. In certain embodiments, the chelator is attached to L1, which is connected to a side chain of A1, A3, or A10. In certain embodiments, the chelator is attached 10 to L1, which is connected to a side chain of A1. In some embodiments, L1is a bond, and A1, L1, and M, together, have the structure: , wherein M is optionally radiolabeled with a radionuclide. 127 763537: NIT-59597PC (PAT059597-FF) In some embodiments, L1is a linker of formula (L1-II), and A1, L1, and M, together, have the structure: , wherein M is optionally radiolabeled with a radionuclide. In some embodiments, L1is a bond, and A10, L1, and M, together, have the structure: , wherein: R10mis selected from H and C1-3-alkyl; and m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide. When the chelator is covalently conjugated to L1or the cyclic peptide, a chemical substitution or reaction occurs to allow for covalent attachment to the linker or the cyclic peptide. The covalent attachment may be formed via any chemical substitution or reaction 128 763537: NIT-59597PC (PAT059597-FF) known in the art suitable for forming the given attachment. In some embodiments, one or more bonds to a hydrogen atom of the chelator are replaced by a bond to the linker or the cyclic peptide. In some embodiments, a ^-bond, for example, of a double or triple bond, between two atoms is replaced by a bond from one of the two atoms to the linker or the cyclic 5 peptide, wherein the other of the two atoms includes a new bond, for example, to a hydrogen (such as a reaction of an amine with an isocyanate (-NCS) to yield a thiourea bond or a reaction of maleimide and a thiol to produce a thioether bond). In some embodiments, a carboxylic acid or activated carboxylic acid is reacted with an amine of the cyclic peptide or linker to form an amide bond. Accordingly, one of skill in the art would recognize the various 10 ways in which a chelator can be covalently attached to the linker or the cyclic peptide of any of the formulae presented herein. Radionuclides In some embodiments of the HER2-targeting compounds described herein, M is a 15 radionuclide. In some embodiments of the HER2-targeting compounds described herein, M is chelator radiolabeled with a radionuclide. Accordingly, in various embodiments, the HER2- targeting compounds may be radiolabeled with a diagnostically and / or therapeutically active radionuclide, thus providing a platform for imaging and radiotherapy targeting HER2. As used herein “radionuclide” (which also may be referred to those skilled in the art as 20 radioactive atoms, radioactive elements, radioactive isotopes, or radioisotopes) is any unstable form of a chemical element that releases radiation. In some embodiments, the radionuclide releases or emits β-particles. In some embodiments, the radionuclide releases or emits α-particles. In some embodiments, the radionuclide releases or emits β-particles and α- particles. 25 The HER2-targeting compounds of the present disclosure may be radiolabeled with a radionuclide at any site of the HER2-targeting peptide. For example, in embodiments in which the HER2-targeting peptide is conjugated directly to a radionuclide, the radionuclide may by covalently attached to the HER2 targeting peptide. In other embodiments in which the HER2-targeting peptide is conjugated directly to a radionuclide, such conjugation may 30 rely on ionic interactions, thereby forming a peptide-radionuclide salt. In some embodiments, when the HER2-targeting peptide is conjugated to a chelator, the HER2-targeting peptide may be radiolabeled via chelation of the radionuclide to the chelator. Chelation of a radionuclide to a chelator may be depicted using solid single bonds, dashed single bonds, or a 129 763537: NIT-59597PC (PAT059597-FF) combination thereof. For example, the chelation of68Ga to DOTA can be depicted below with solid single bonds or dashed single bonds. In some embodiments, the charge may also be indicated. For example, when a radionuclide is chelated to a chelating agent, each of the groups chelating the radionuclide may have a negative charge and the radionuclide being 5 chelated may have an opposing positive charge. Such bonds and charges may be depicted herein as follows: . In the case of225Ac, such bonds and charges may be illustrated (non-limiting) as follows: 10 . The radionuclide may be a therapeutic radionuclide, diagnostic radionuclide, or both. Suitable radionuclides include, but are not limited to, auger-electron emitting radionuclides, β-emitting (beta or beta-minus-emitting) radionuclides, and α-emitting (alpha-emitting) radionuclides. The selection of the type of radionuclide may depend on the use of the HER2- 15 targeting compound. As will be appreciated by the skilled artisan, several factors may be considered when selecting a radionuclide for use in a HER2-targeting compound, such as, for example, the half-life, the linear energy transfer, the imaging capabilities, and the emission range in tissue. For example, b-emitting radionuclides typically have a longer emission range in tissue (e.g., 1–5 mm) and emit photons in an energy range that is easily imaged, and as 20 such, they may be selected for use in a HER2-targeting compound being used for therapeutic, diagnostic, or theragnostic purposes. On the other hand, ^-emitting radionuclides have a shorter emission range in tissue (e.g., 50-100 mm) and a high potency due to the amount of 130 763537: NIT-59597PC (PAT059597-FF) energy deposited per path length traveled (i.e., linear energy transfer), which is approximately 400 times greater than that of electrons. Thus, ^-emitting radionuclides may be selected for therapeutic uses in which high potency of the radionuclide is desired. Accordingly, in some embodiments, the radionuclide is an α-emitting radionuclide. In 5 other embodiments, the radionuclide is a β-emitting radionuclide. In yet other embodiments, the radionuclide is an auger-electron emitting radionuclide. The radionuclide may be a therapeutic radionuclide, an imaging radionuclide, or both. Accordingly, suitable radionuclides may have a decay energy sufficient for therapeutic and / or diagnostic use. In some embodiments, the decay energy of the radionuclide ranges from 10 about 10 keV to about 6,000 keV. In some embodiments, the decay energy of the radionuclide is between 100 and 1,000 keV. Exemplary radionuclides that may be used to radiolabel the present HER2-targeting compounds are described in Sgouros et al. “Radiopharmaceutical therapy in cancer: clinical advances and challenges.” Nature reviews Drug discovery 19.9 (2020): 589-608, which is incorporated herein by reference in its 15 entirety. In some embodiments, the radionuclide is selected from the group consisting of111In, 186Re,188Re,86Y,90Y,89Zr,51Cr,52Mn,51Mn,177Lu,169Yb,175Yb,105Rh,166Dy,166Dy,166Ho, 153Sm,149Pm,151Pm,172Tm,121Sn,117mSn,212Bi,213Bi,142Pr,143Pr,198Au,199Au,123I,124I,125I, 20131I,75Br,76Br,77Br,80Br,82Br,18F,149Tb,152Tb,155Tb,161Tb,43Sc,44Sc,47Sc,212Pb,211At, 223Ra,227Th,226Th,82Rb,32P,76As,89Zr,111Ag,165Er,225Ac, and227Ac. In some embodiments, the radionuclide is111In,99mTc,67Ga,68Ga,203Pb,64Cu,86Y,89Zr,123I,124I,125I,18F,76Br,77Br, 152Tb,155Tb,44Sc,43Sc,67Cu,188Re,90Y,177Lu,213Bi,131I,47Sc,225Ac,212Pb,211At, or227Th. In some embodiments, the radionuclide is66Ga,67Ga,68Ga,64Cu,177Lu, or225Ac. In some 25 embodiments, the radionuclide is111In,99mTc,68Ga,64Cu,89Zr,123I,124I,18F,90Y,177Lu,131I, 225Ac,211At, or227Th. In some embodiments, the radionuclide is177Lu,161Tb,90Y,67Cu,131I,225Ac,212Pb, 211At, or227Th. In certain embodiments, the radionuclide is177Lu. In certain embodiments, the 30 radionuclide is225Ac. In certain embodiments, the radionuclide is161Tb. In certain embodiments, the radionuclide is68Ga. In other embodiments, the radionuclide is111In. In some embodiments, the radionuclide is a radiohalogen, e.g.,18F,75Br,76Br,77Br, 80Br,80mBr,82Br,123I,124I,125I,131I and211At. In some embodiments, the radiohalogen is18F. 131 763537: NIT-59597PC (PAT059597-FF) When the radionuclide is a radiohalogen, the term radiohalogen includes complexes that make the radiohalogen suitable for covalent attachment to the linker or the cyclic peptide or for chelation or complex formation with the chelator. Such complexes contemplated under the term radiohalogen include Si-18F, B-18F, and Al-18F. 5 In some embodiments, the radiohalogen is connected directly to the cyclic peptide or the linker. For example,131I and18F (or any other radiohalogen) can be substituted at any position of the linker or the cyclic peptide suitable for substitution with a halo group. In some embodiments, the radiohalogen is18F. In some embodiments of the cyclic peptide (P), or compound comprising cyclic peptide (P): A10is selected from: 10 , , , 132 763537: NIT-59597PC (PAT059597-FF) . In some embodiments, when a radiohalogen is connected directly to the cyclic peptide or the linker, the chelator is absent. 5 In some embodiments, when the radiohalogen is18F, it may be attached to L1via a prosthetic group and L1 is a linker attached to a side chain of an amino acid of the cyclic peptide (P). In a further embodiment, M (when18F) and L1(wherein L1is a bond or linker) together have the structure: 10In some embodiments, M, L1, and A10, together, have one of the following structures: 133 763537: NIT-59597PC (PAT059597-FF) wherein *9 indicates the point of attachment to A9, and wherein the variables are defined elsewhere herein. Alternatively, in some embodiments, the radiohalogen forms a complex with the chelator. For example, a radiohalogen complex such as, for example, Si-18F, B-18F, and Al- 518F may chelate to a chelator of the presently described HER2-targeting compounds. One of ordinary skill in the art would understand that various radiohalide ions and metal or nonmetal elements may be combined to form a radiohalogen complex. Any such radiohalogen complex may be chelated to a chelator of the HER2-targeting compounds. In some embodiments, Si- 18F is chelated to a chelator. In some embodiments, B-18F is chelated to a chelator. In some 10 embodiments, Al-18F is chelated to a chelator. The HER2-targeting compound of the present disclosure may be radiolabeled with one radionuclide or to more than one radionuclide. In some embodiments, the HER2- targeting compound is radiolabeled with one radionuclide. In some embodiments, the HER2- targeting compound is radiolabeled with more than one radionuclide. For example, the 15 HER2-targeting compound made be radiolabeled with one radionuclide via complexation to the chelator and to another radionuclide via a direct covalent attachment to the linker, cyclic peptide, or the chelator. In some embodiments, a first radionuclide is chelated to the chelator and a second radionuclide is covalently attached to the cyclic peptide. In other embodiments, a first radionuclide is chelated to the chelator and a second radionuclide is covalently attached 20 to the linker. In yet other embodiments, a first radionuclide is chelated to the chelator and a second radionuclide is covalently attached to the chelator. In embodiments in which the HER2-targeting compound is radiolabeled with more than one radionuclide, each of the radionuclides may be the same or different. In some embodiments, two of the same radionuclides are used to radiolabel the HER2-targeting 25 compound of the present disclosure. In some embodiments, two different radionuclides are used to radiolabel the HER2-targeting compound of the present disclosure. In some embodiments, the HER2-targeting compound is radiolabeled with a diagnostic radionuclide and a therapeutic radionuclide. In some embodiments, the HER2-targeting compound is radiolabeled with a radiohalogen and a radionuclide other than a radiohalogen. In some 30 embodiments, the HER2-targeting compound is radiolabeled with a first radiohalogen and a second radiohalogen, where the first radiohalogen is different from the second radiohalogen. In some embodiments, the radionuclide is a therapeutically active radionuclide. Suitable therapeutically active radionuclides include, but are not limited to,67Cu,186Re, 188Re,90Y,177Lu,161Tb,153Sm,213Bi,131I,149Tb,47Sc,225Ac,212Pb,211At,223Ra,227Th, and 134 763537: NIT-59597PC (PAT059597-FF) 226Th. In some embodiments, the radionuclide is a therapeutically active radionuclide selected from67Cu,188Re,90Y,177Lu,213Bi,131I,47Sc,225Ac,212Pb,211At, and227Th. In particular embodiments, the radionuclide is a therapeutically active radionuclide selected from90Y, 177Lu,131I,225Ac,211At, and227Th. In a particular embodiment, the therapeutically active 5 radionuclide is177Lu. In a particular embodiment, the therapeutically active radionuclide is 225Ac. Alternatively, in some embodiments, the radionuclide is a diagnostically active radionuclide (a radionuclide suitable for imaging as, e.g., by PET). Suitable diagnostically active radionuclides include, but are not limited to,111In,99mTc,94mTc,67Ga,68Ga,203Pb, 1064Cu,86Y,89Zr,51Mn,52Mn,123I,124I,125I,18F,76Br,77Br,152Tb,155Tb,44Sc,43Sc, and201Tl. In some embodiments, the radionuclide is a diagnostically active radionuclide selected from 111In,99mTc,67Ga,68Ga,203Pb,64Cu,86Y,89Zr,123I,124I,125I,18F,76Br,77Br,152Tb,155Tb,44Sc, and43Sc. In particular embodiments, the radionuclide is a diagnostically active radionuclide selected from111In,99mTc,68Ga,64Cu,89Zr,123I,124I, and18F. In a particular embodiment, the 15 diagnostically active radionuclide is68Ga. In another particular embodiment, the diagnostically active radionuclide is18F. In another particular embodiment, the diagnostically active radionuclide is64Cu. In another particular embodiment, the diagnostically active radionuclide is111In. In some embodiments, the radionuclide coordinated to or covalently attached to the 20 HER2-targeting compound described herein is stable in vivo. Stable radionuclides may have a half-life that allows for therapeutic and / or diagnostic medical use. For example, the radionuclide may have a half-life from about 10 minutes to about 50 days. In some embodiments, the radionuclide has a half-life between 1 hour and 20 days. In some embodiments, the radionuclide has a half-life between 1 day and 10 days. 25 In some embodiments, the radionuclide is detectable by positron emission spectroscopy (PET), positron emission tomography and computerized tomography (PET / CT), or single photon emission computed tomography (SPECT). In some embodiments, the radionuclide is covalently attached directly to the cyclic peptide or the linker of the HER2-targeting compound. In some embodiments, the 30 radionuclide is coordinated to the chelating ligand of the HER2-targeting compound. Various radionuclides may be complexed to various chelators disclosed herein. One of ordinary skill in the art would recognize the appropriate selection of chelator and radionuclide for any use or method contemplated by the instant disclosure. 135 763537: NIT-59597PC (PAT059597-FF) Additional Embodiments of Formulae (I), (Ia), (Ib), (Ic) and (Id) As previously described, the HER2-targeting compounds of the present disclosure may be compounds of formula (I), (Ia), (Ib), (Ic) or (Id): , 5 , , 10 , or pharmaceutically acceptable salts or solvates thereof, wherein P, L1and M are as previously described and n and o are each independently 1, 2, 3, or 4. It is conceived herein that the HER2-targeting compound may include 1, 2, 3, or 4 P, 15 P-L1moieties, M, or M-L1moieties. In some embodiments, the HER2-targeting compound includes 1, 2, 3, or 4 cyclic peptides, 1, 2, or 3, cyclic peptides, or 1 or 2 cyclic peptides. In some embodiments, the HER2-targeting compound includes 1, 2, 3, or 4 P-L1moieties, 1, 2, or 3, P-L1moieties, or 1 or 2 P-L1moieties. In some embodiments, the HER2-targeting compound includes 1, 2, 3, or 4 M moieties, 1, 2, or 3, M moieties, or 1 or 2 M moieties. In 20 some embodiments, the HER2-targeting compound includes 1, 2, 3, or 4 m-L1moieties, 1, 2, or 3, M-L1moieties, or 1 or 2 M-L1moieties. In embodiments in which the HER2-targeting peptide includes at least two cyclic peptides, each cyclic peptide can be the same or different. In embodiments in which the 136 763537: NIT-59597PC (PAT059597-FF) HER2-targeting peptide includes at least two P-L1moieties, each cyclic peptide and each L1may be independently selected and can be the same or different. In embodiments in which the HER2-targeting peptide includes at least two M moieties, each M moiety can be the same or different. In embodiments in which the HER2-targeting peptide includes at least two M-L15 moieties, each M moiety and each L1may be independently selected and can be the same or different. In some embodiments, the compounds of formulae (I), (Ia), (Ib), and (Ic) are compounds of formulae (I-i), (Ia-i), (Ib-i) and (Ic-i): , 10 , 137 763537: NIT-59597PC (PAT059597-FF) , (Ic-i), 5 wherein A1-A9are as defined elsewhere herein, L1is, independently at each occurrence, selected from the group consisting of a bond and a linker; M is, independently at each occurrence, selected from the group consisting of an imaging agent, a chelating agent, and a radionuclide the chelating agent is optionally 10 radiolabeled with a radionuclide; n is 1, 2, 3, or 4; o is 1, 2, 3, or 4; and wherein any of A1-A9and L1is optionally substituted with an albumin binder. In certain embodiments, the compound of formula (Ia) or formula (Ia-i), or a pharmaceutically 15 acceptable salt or solvate thereof, is Example D6. In certain embodiments, the HER2-targeting compound is compound of formula (I): 138 763537: NIT-59597PC (PAT059597-FF) or a pharmaceutically acceptable salt or solvate thereof, wherein is 1. For example, in some embodiments, the compound of formula (I) is a compound of formula (Id): 5 or a pharmaceutically acceptable salt or solvate thereof, wherein: 10 P is a cyclic (HER2-targeting) peptide; L1is a bond or linker; and M is a chelating agent optionally radiolabeled with a radionuclide; and wherein the cyclic peptide, linker, chelating agent, and radionuclide are as disclosed elsewhere herein. 15 In some embodiments of the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, M is a chelator optionally radiolabeled with a radionuclide, wherein the chelator is selected from DOTA, DOTAGA, NODAGA, AAZTA, NOTA, and p- SCN-Bn-DOTA. In some embodiments of the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, M is a chelator optionally radiolabeled 20 with a radionuclide, wherein the chelator is selected from DOTA, DOTAGA, and NODAGA. In some embodiments of the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, M is a chelator optionally radiolabeled with a radionuclide, wherein the chelator is DOTA. In some embodiments of the compound of formula (Id), or a pharmaceutically 25 acceptable salt or solvate thereof, M is a chelator that is not radiolabeled with a radionuclide. Alternatively, in some embodiments of the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, M is a chelator that is radiolabeled with a radionuclide. In some embodiments, the compound of formula (Id) is a compound of formula (Id-i): 139 763537: NIT-59597PC (PAT059597-FF) , or a pharmaceutically acceptable salt or solvate thereof, wherein A1-A9are as defined elsewhere herein, and L1is connected to the cyclic 5 HER2-targeting peptide via a side chain of any one of A1-A10(wherein A10is included in the definition of A9). In some embodiments, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-ii): , 10 or a pharmaceutically acceptable salt or solvate thereof, wherein L1is connected to the cyclic HER2-targeting peptide via a side chain of A10. In some embodiments of the compound of formula (Id-ii), or a pharmaceutically acceptable salt or solvate thereof, L1is connected to the cyclic HER2-targeting peptide via a side chain 15 NH2of A10. In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, has the following definitions: A1is a moiety of formula (A1-I): 140 763537: NIT-59597PC (PAT059597-FF) (A1-I), wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; a is 1, 2, or 3; and b, c, and x’ are each independently 0 or 1; or A1is substituted with a PEG chain, wherein A1and the PEG chain, together, have the structure of formula (A1-P): (A1-P), wherein: XPis selected from CH2, N(RP), and O; YPis selected from H, -OH, -OC1-6-alkyl, and -N(RP)2; each RPis independently selected from H and C1-6-alkyl; a is 1, 2, or 3; n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; and r’ is 0, 1, 2, 3, or 4; A2is a moiety of formula (A2-I): 141 763537: NIT-59597PC (PAT059597-FF) (A2-I), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2; A3is a moiety of formula (A3-I) or formula (A3-II): (A3-II), wherein: R3ais selected from H and C1-3-alkyl; each R3aais independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, - NH2, -NHC(O)C1-6-alkyl, and -OC1-6-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; Y3is selected from a bond and NH; 142 763537: NIT-59597PC (PAT059597-FF) each Y3ais selected from NH and CH2, provided that at least one Y3ais NH; h is 1, 2, 3, 4, 5, or 6; i is 0, 1, or 2; and j is 1, 2, 3, 4, 5, or 6; A4is a moiety of formula (A4-I): (A4-I), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; k is 1, 2, 3, 4, 5, or 6; and l is 0, 1, or 2; A5is a moiety of formula (A5-I) or formula (A5-II): (A5-II), 143 763537: NIT-59597PC (PAT059597-FF) wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5aais selected from H, -OH, and -OC1-6-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2 and -OH; and p’ and q’ are each independently 1, 2, 3, 4, 5, or 6; A6is a moiety of formula (A6-Ia): wherein: R6ais selected from H and C1-3-alkyl; R6acis selected from OH, C1-6-alkyl, and -C(O)-C1-6-alkyl; and o’ is 0, 1, or 2; A7is a moiety of formula (A7-Ia): wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from -CN, halo, -NH2, and -OH; and q is 0, 1, or 2; A8is a moiety of formula (A8-I) or formula (A8-II): 144 763537: NIT-59597PC (PAT059597-FF) (A8-II), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; R8abis selected from H, -CN, halo, -NH2, and -OH; t is 1 or 2; u is 0, 1, or 2; and v is 0, 1, 2, 3, or 4; and A9is a moiety of formula (A9-I): (A9-I), wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and A10, L1, and M, together, have the structure: 145 763537: NIT-59597PC (PAT059597-FF) , wherein: R10a, R10e, and R10mare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and m’ is 1, 2, 3, 4, 5, or 6, wherein L1is a bond or a linker as defined elsewhere herein, and wherein M is a chelator optionally radiolabeled with a radionuclide. In an embodiment, A1is a moiety of formula (A1-I), A3is a moiety of formula (A3- II), A5is a moiety of formula (A5-II), and A8is a moiety of formula (A8-I): (A3-II), 146 763537: NIT-59597PC (PAT059597-FF) (A8-I), wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y5is selected from O and NH; a is 1, 2, or 3; b, c, and x’ are each independently 0 or 1; j is 1, 2, 3, 4, 5, or 6; t is 1 or 2; u is 0, 1, or 2; and 147 763537: NIT-59597PC (PAT059597-FF) p’ is 1, 2, 3, 4, 5, or 6. In another embodiment, A1is a moiety of formula (A1-I), A3is a moiety of formula (A3-II), A5is a moiety of formula (A5-II), and A8is a moiety of formula (A8-II): (A8-II), wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; 148 763537: NIT-59597PC (PAT059597-FF) R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2 and -OH; R8ais selected from H and C1-3-alkyl; R8abis selected from H, -CN, halo, -NH2, and -OH; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y5is selected from O and NH; a is 1, 2, or 3; b, c, and x’ are each independently 0 or 1; j is 1, 2, 3, 4, 5, or 6; v is 0, 1, 2, 3, or 4; and p’ is 1, 2, 3, 4, 5, or 6. In yet another embodiment, A1is a moiety of formula (A1-P), A3is a moiety of formula (A3-II), A5is a moiety of formula (A5-II), and A8is a moiety of formula (A8-I): (A5-II), and 149 763537: NIT-59597PC (PAT059597-FF) (A8-I), wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y5is selected from O and NH; a is 1, 2, or 3; b, c, and x’ are each independently 0 or 1; j is 1, 2, 3, 4, 5, or 6; t is 1 or 2; u is 0, 1, or 2; and p’ is 1, 2, 3, 4, 5, or 6. In still another embodiment, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia): 150 763537: NIT-59597PC (PAT059597-FF) (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, wherein: 5 L1is a bond or a linker as defined elsewhere herein; and M is a chelator optionally radiolabeled with a radionuclide, wherein M is bound to L1via an amide bond; R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; R2a, R3a, R4a, R5a, R6a, R7a, R8a, and R9aare each independently selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2 and -OH; a is 1, 2, or 3; and b and x’ are each independently 0 or 1. In an embodiment, M is radiolabeled with111In. 10 In an embodiment, M is radiolabeled with225Ac. 151 763537: NIT-59597PC (PAT059597-FF) In an embodiment, M is radiolabeled with68Ga. In an embodiment, M is radiolabeled with177Lu. In an embodiment, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iib): (Id-iib), 5 or a pharmaceutically acceptable salt or solvate thereof, wherein: L1is a linker as defined elsewhere herein; and M is a chelator optionally radiolabeled with a radionuclide, wherein M is bound to L1via an amide bond; R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; R2a, R3a, R4a, R5a, R6a, R7a, R8a, and R9aare each independently selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; 152 763537: NIT-59597PC (PAT059597-FF) a is 1, 2, or 3; and b and x’ are each independently 0 or 1. In an embodiment, M is radiolabeled with68Ga or177Lu. In another embodiment, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iic): (Id-iic), 5 or a pharmaceutically acceptable salt or solvate thereof, wherein: L1is a linker as defined elsewhere herein; and M is a chelator optionally radiolabeled with a radionuclide, wherein M is bound to L1via an amide bond; XPis selected from CH2, N(RP), and O; YPis selected from H, -OH, -OC1-6-alkyl, and -N(RP)2; each RPis independently selected from H and C1-6-alkyl; R2a, R3a, R4a, R5a, R6a, R7a, R8a, and R9aare each independently selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; 153 763537: NIT-59597PC (PAT059597-FF) a is 1, 2, or 3; n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; and r’ is 0, 1, 2, 3, or 4. In an embodiment, M is radiolabeled with68Ga or177Lu. In an embodiment of formula (Id-iia) and formula (Id-iib), or a pharmaceutically acceptable salt or solvate thereof, R1ais selected from H, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6-alkyl, and –N(C1-6- alkyl)2, wherein the -N(H)-C(O)-C1-6-alkyl of R1ais optionally substituted with 1 substituent selected from -C(O)OH, -C(O)C1-6-alkyl, and -C(O)C1-6-alkyl-OH, 5-membered heteroaryl; Y1is selected from a bond, O, and S; and R5abis selected from H, C1-6-alkyl, and C1-6-haloalkyl, wherein the C1-6-alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2 and -OH. In an embodiment of formula (Id-iic), or a pharmaceutically acceptable salt or solvate thereof, R5abis selected from H, C1-6-alkyl, and C1-6-haloalkyl, wherein the C1-6-alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; XPis O; YPis -OC1-6-alkyl; and n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. In an embodiment of formula (Id-iia), formula (Id-iib), and formula (Id-iic), or a pharmaceutically acceptable salt or solvate thereof, L1is a bond. In another embodiment of formula (Id-iia), formula (Id-iib), and formula (Id-iic), or a pharmaceutically acceptable salt or solvate thereof, M is selected from DOTA, DOTAGA, NODAGA, AAZTA, NOTA, and p-SCN-Bn-DOTA, wherein M is bound to L1via an amide bond. In yet another embodiment of formula (Id-iia), formula (Id-iib), and formula (Id-iic), or a pharmaceutically acceptable salt or solvate thereof, M is DOTA, wherein M is bound to L1via an amide bond. In an embodiment, M is radiolabeled with68Ga or177Lu. In an embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-i): 154 763537: NIT-59597PC (PAT059597-FF) (Id-iia-i (SEQ ID NO: 40)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-i) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In yet another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-ii): (Id-iia-ii (SEQ ID NO: 36)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-ii) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. 155 763537: NIT-59597PC (PAT059597-FF) In still another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-iii): (Id-iia-iii (SEQ ID NO: 102)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-iii) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In an embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-iv): 156 763537: NIT-59597PC (PAT059597-FF) (Id-iia-iv (SEQ ID NO: 103)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-iv) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-v): 157 763537: NIT-59597PC (PAT059597-FF) (Id-iia-v (SEQ ID NO: 104)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-v) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In yet another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-vi): (Id-iia-vi), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an 5 embodiment, the compound of formula (Id-iia-vi) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In still another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-vii): 158 763537: NIT-59597PC (PAT059597-FF) (Id-iia-vii (SEQ ID NO: 105)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-vii) is radiolabeled with a radionuclide. In an embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-viii): (Id-iia-viii (SEQ ID NO: 106)), 159 763537: NIT-59597PC (PAT059597-FF) which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-viii) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In yet another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-ix): (Id-iia-ix (SEQ ID NO: 107)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an 5 embodiment, the compound of formula (Id-iia-ix) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In yet another embodiment of formula (Id-iia), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iia-x): 160 763537: NIT-59597PC (PAT059597-FF) (Id-iia-x (SEQ ID NO: 44)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iia-x) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In an embodiment of formula (Id-iib), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iib-i): (Id-iib-i (SEQ ID NO: 41)), 161 763537: NIT-59597PC (PAT059597-FF) which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iib-i) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In another embodiment of formula (Id-iib), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iib-ii): (Id-iib-ii (SEQ ID NO: 42)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an 5 embodiment, the compound of formula (Id-iib-ii) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In an embodiment of formula (Id-iib), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iib-iii): 162 763537: NIT-59597PC (PAT059597-FF) (Id-iib-iii (SEQ ID NO: 108)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iib-iii) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In another embodiment of formula (Id-iib), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iib-iv): (Id-iib-iv (SEQ ID NO: 109)), 163 763537: NIT-59597PC (PAT059597-FF) which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iib-iv) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In an embodiment of formula (Id-iic), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iic-i): (Id-iic-i (SEQ ID NO: 45)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an 5 embodiment, the compound of formula (Id-iic-i) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. In another embodiment of formula (Id-iic), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iic-ii): 164 763537: NIT-59597PC (PAT059597-FF) (Id-iic-ii (SEQ ID NO: 37)), which is optionally radiolabeled with a radionuclide defined elsewhere herein. In an embodiment, the compound of formula (Id-iic-ii) is radiolabeled with a radionuclide. In a further embodiment, the radionuclide is68Ga,111In,177Lu, or225Ac. Compounds Comprising PEG chain and / or DOTA Chelator In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), 5 e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, is optionally substituted with one PEG chain. In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, is substituted with one PEG chain. In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, the PEG chain is bound to A1. 10 In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, has the following definitions: A1is substituted with a PEG chain, wherein A1and the PEG chain, together, have the structure of formula (A1-P): 165 763537: NIT-59597PC (PAT059597-FF) (A1-P), wherein: XPis selected from CH2, N(RP), and O; YPis selected from H, -OH, -OC1-6-alkyl, and -N(RP)2; each RPis independently selected from H and C1-6-alkyl; a is 1, 2, or 3; n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; and r’ is 0, 1, 2, 3, or 4; A2is a moiety of formula (A2-I): (A2-I), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2; A3is a moiety of formula (A3-II): (A3-II), 166 763537: NIT-59597PC (PAT059597-FF) wherein: R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; and j is 1, 2, 3, 4, 5, or 6; A4is a moiety of formula (A4-I): (A4-I), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; k is 1, 2, 3, 4, 5, or 6; and l is 0, 1, or 2; A5is a moiety of formula (A5-II): (A5-II), wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; 167 763537: NIT-59597PC (PAT059597-FF) p’ is 1, 2, 3, 4, 5, or 6; A6is a moiety of formula (A6-Ia): wherein: R6ais selected from H and C1-3-alkyl; R6acis selected from H, C1-6-alkyl, and -C(O)-C1-6-alkyl; and o’ is 0, 1, or 2; A7is a moiety of formula (A7-Ia): wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from halo, -NH2, and -OH; and q is 0, 1, or 2; A8is a moiety of formula (A8-I): (A8-I), wherein: R8ais selected from H and C1-3-alkyl; 168 763537: NIT-59597PC (PAT059597-FF) R8aais selected from -CN, halo, -NH2, and -OH; t is 1 or 2; and u is 0, 1, or 2; A9is a moiety of formula (A9-I): (A9-I), wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and A10, L1, and M, together, have the structure: , wherein: R10a, R10e, and R10mare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; 169 763537: NIT-59597PC (PAT059597-FF) each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide. In an embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id- i), (Id-ii), and (Id-iic)), or a pharmaceutically acceptable salt or solvate thereof, XPis O; YPis -OC1-6-alkyl; and n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, has the following definitions: A1is a moiety of formula (A1-I): (A1-I), wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; and a is 1, 2, or 3; A2is a moiety of formula (A2-I): (A2-I), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; 170 763537: NIT-59597PC (PAT059597-FF) each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2; A3is a moiety of formula (A3-II): (A3-II), wherein: R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; and j is 1, 2, 3, 4, 5, or 6; A4is a moiety of formula (A4-I): (A4-I), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; k is 1, 2, 3, 4, 5, or 6; and l is 0, 1, or 2; A5is a moiety of formula (A5-II): 171 763537: NIT-59597PC (PAT059597-FF) (A5-II), wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; p’ is 1, 2, 3, 4, 5, or 6; A6is a moiety of formula (A6-Ia): wherein: R6ais selected from H and C1-3-alkyl; R6acis selected from OH, C1-6-alkyl, and -C(O)-C1-6-alkyl; and o’ is 0, 1, or 2; A7is a moiety of formula (A7-Ia): 172 763537: NIT-59597PC (PAT059597-FF) wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from -CN, halo, -NH2, and -OH; and q is 0, 1, or 2; A8is a moiety of formula (A8-I): (A8-I), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; t is 1 or 2; and u is 0, 1, or 2; A9is a moiety of formula (A9-I): (A9-I), wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and A10, L1, and M, together, have the structure: 173 763537: NIT-59597PC (PAT059597-FF) , wherein: R10a, R10e, and R10mare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide. In some embodiments of the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof: A2, A3, and A7are each in the L configuration. In some embodiments, the compound of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, has 5 the following definitions: A1is a moiety of formula (A1-I): (A1-I), 174 763537: NIT-59597PC (PAT059597-FF) wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; and a is 1, 2, or 3; A2is a moiety of formula (A2-Ia): (A2-Ia), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2; A3is a moiety of formula (A3-IIa): (A3-IIa), wherein: R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; and j is 1, 2, 3, 4, 5, or 6; A4is a moiety of formula (A4-I): 175 763537: NIT-59597PC (PAT059597-FF) (A4-I), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; k is 1, 2, 3, 4, 5, or 6; and l is 0, 1, or 2; A5is a moiety of formula (A5-II): (A5-II), wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2 and -OH; p’ is 1, 2, 3, 4, 5, or 6; A6is a moiety of formula (A6-Ia): 176 763537: NIT-59597PC (PAT059597-FF) wherein: R6ais selected from H and C1-3-alkyl; R6acis selected from OH, C1-6-alkyl, and -C(O)-C1-6-alkyl; and o’ is 0, 1, or 2; A7is a moiety of formula (A7-Iaaa): wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from -CN, halo, -NH2, and -OH; and q is 0, 1, or 2; A8is a moiety of formula (A8-I): (A8-I), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; 177 763537: NIT-59597PC (PAT059597-FF) t is 1 or 2; and u is 0, 1, or 2; A9is a moiety of formula (A9-I): (A9-I), wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and A10, L1, and M, together, have the structure: , wherein: R10a, R10e, and R10mare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; 178 763537: NIT-59597PC (PAT059597-FF) each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide. In an embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, at least one Y2is CH. In another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, each R2aais independently selected from halo, -OH, and -NH2. In yet another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, R3abis selected from H, -OH, -C(O)OH, -C(O)NH2, and -NH2. In still another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, at least one Y4is CH and wherein l is 0 or 1. In an embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, R5bis selected from -C1-6-alkyl-O-C(O)R5cand -C1-6-alkyl-NH-C(O)R5cand wherein R5cis selected from C1-6-alkyl and -OC1-6-alkyl. In another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, o’ is 0 or 1. In yet another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, q is 0 or 1. In still another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, t is 1 and wherein u is 0 or 1. In an embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, Y9is selected from NH and NC1-6-alkyl. 179 763537: NIT-59597PC (PAT059597-FF) In another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, each R10aais independently selected from halo, -NH2, -N3, and -OH. In yet another embodiment of formula (Id) (and subgenera of formula (Id), e.g., formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, the cyclic peptide, P, is selected from Examples A1-A74 and E1-E3. In yet another embodiment of formula (Id) (and subgenera of formula (Id), e.g., 5 formulae (Id-i) and (Id-ii)), or a pharmaceutically acceptable salt or solvate thereof, the cyclic peptide, P, is selected from Examples A75-A77, E4, and E5. In certain embodiments, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound selected from Examples B1-B7, C1-C3, C5- C30, and D1-D5, F1-F4, G1, H1-H4, I1, and I2. 10 In certain embodiments, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound selected from Examples B9-B13, C31-C37, D6, D7, J1, and J2. In some embodiments, the compound of formula (Ib) is a compound of formula (ib- ii): 15 (ib-ii) or a pharmaceutically acceptable salt or solvate thereof, wherein: RNis H or C1-6-alkyl; 20 x1 and y1, independently, at each occurrence, are 0, 1, 2, 3, 4, 5, or 6; z1, independently at each occurrence, is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; each P is independently a cyclic (HER2-targeting) peptide; and 180 763537: NIT-59597PC (PAT059597-FF) M is a chelating agent optionally radiolabeled with a radionuclide; and wherein the cyclic peptide, chelating agent, and radionuclide are as disclosed elsewhere herein. In an embodiment, M is radiolabeled with68Ga or177Lu. In another embodiment, M is radiolabeled with111In or225Ac. 5 In some embodiments of the compound of formulae (Ib), (Ib-i), and (Ib-ii), or a pharmaceutically acceptable salt or solvate thereof, is a compound selected from Examples B8 and C4. Compounds Comprising Albumin Binders 10 The compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, may further comprise an albumin binding moiety attached to any of P, L1or M. The albumin binder may be as disclosed elsewhere herein. In some embodiments, an albumin binding moiety is attached to the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, via a side chain of any of A1-A10of the cyclic peptide. In some 15 embodiments, an albumin binding moiety is attached to the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, via a functional group on L1. In some embodiments, an albumin binding moiety is attached to the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, via a functional group on M. For example, the compound of formula (Id), may be a compound of formula (Id-iii), (Id-iv), or 20 (Id-v): 25 (Id-iv) 181 763537: NIT-59597PC (PAT059597-FF) , (Id-v) wherein AB is an albumin binder as disclosed elsewhere herein. In some embodiments of formulae (Id-iii), (Id-iv), and (Id-v), or a pharmaceutically acceptable salt or 5 solvate thereof, M is a chelator that is not radiolabeled with a radionuclide. In embodiments of formulae (Id-iii), (Id-iv), and (Id-v), or a pharmaceutically acceptable salt or solvate thereof, M is a chelator that is radiolabeled with a radionuclide. In various embodiments, the compound of formula (Id), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Id-iii), or a pharmaceutically 10 acceptable salt or solvate thereof. In certain embodiments, the compound of formula (Id-iii), or a pharmaceutically acceptable salt or solvate thereof, is a compound that is Example G1. In certain embodiments, the HER2-targeting compound is a compound of formula (I): 15 or a pharmaceutically acceptable salt or solvate thereof, where n is 2, and each L1is the same or different and each M is different. For example, in some embodiments, the compound of (I), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Ie): 20 or a pharmaceutically acceptable salt or solvate thereof, wherein: P is a cyclic HER2-targeting peptide; MIis an imaging agent; 25 MCis a chelator, optionally radiolabeled with a radionuclide; L1Iis a bond or linker, connecting the imaging agent to P; and L1Cis a bond or linker connecting the chelator to P; 182 763537: NIT-59597PC (PAT059597-FF) wherein L1Iand L1Care the same or different, and wherein the cyclic HER2-targeting peptide, imaging agent, chelator, radionuclide, and linker are as disclosed elsewhere herein. In embodiments of the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, MIis an imaging agent as previously described and MCis a chelator 5 radiolabeled with a radionuclide. In some embodiments of the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, MC is a chelator radiolabeled with a therapeutically active radionuclide. In some embodiments of the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, MC is a chelator radiolabeled with a diagnostically active radionuclide. In further embodiments of the compound of formula (Ie), 10 or a pharmaceutically acceptable salt or solvate thereof, the chelator is DOTA, and the radionuclide is177Lu or68Ga. In still further embodiments of the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, the imaging agent is Sulfo Cy5. In certain embodiments, the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, is a compound that is Example D6. 15 The compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, may further comprise an albumin binder as described above. In some embodiments, when the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, comprises an albumin binder, the albumin binder is attached to the compound via a side chain of any one of A1-A10of the cyclic peptide. In some embodiments, when the compound of 20 formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, comprises an albumin binder, the albumin binder is attached to the compound via a functional group on L1I. In some embodiments, when the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, comprises an albumin binder, the albumin binder is attached to the compound via a functional group on L1C. In some embodiments, when the compound of formula (Ie), or 25 a pharmaceutically acceptable salt or solvate thereof, comprises an albumin binder, the albumin binder is attached to the compound via a functional group on MI. In some embodiments, when the compound of formula (Ie), or a pharmaceutically acceptable salt or solvate thereof, comprises an albumin binder, the albumin binder is attached to the compound via a functional group on MC. 30 In some embodiments, the compound of formula (I), is a compound of formula (If): 183 763537: NIT-59597PC (PAT059597-FF) or a pharmaceutically acceptable salt or solvate thereof, wherein: P is a cyclic HER2-targeting peptide; MC1is a chelator optionally radiolabeled with a radionuclide; 5 MC2is a chelator optionally radiolabeled with a radionuclide; and each L1Cis independently selected from a bond and a linker, and wherein the cyclic HER2-targeting peptide and each chelator, radionuclide, and linker is as previously described. In some embodiments of the compound of Formula (If), or a pharmaceutically 10 acceptable salt or solvate thereof, MC1and MC2are the same. In some embodiments of the compound of Formula (If), or a pharmaceutically acceptable salt or solvate thereof, MC1and MC2are different. In some embodiments of the compound of Formula (If), each L1Cis the same. In some embodiments of the compound of Formula (If), or a pharmaceutically acceptable salt or solvate thereof, each L1Cis different. 15 The compound of formula (If), or a pharmaceutically acceptable salt or solvate thereof, may further comprise an albumin binder as described elsewhere herein. In some embodiments, the compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, is a compound of formula (Ig): 20 or a pharmaceutically acceptable salt or solvate thereof, wherein: P is a cyclic HER2-targeting peptide; MRis a radionuclide; 25 MCis a chelator optionally radiolabeled with a radionuclide; L1Ris a bond or a linker; and L1Cis a bond or a linker, wherein the cyclic HER2-targeting peptide, radionuclide, chelator, and linker are as previously described. 30 In certain embodiments of formula (Ig), or a pharmaceutically acceptable salt or solvate thereof, MRis a radiohalogen and L1Ris a bond. In some embodiments of formula (Ig), or a pharmaceutically acceptable salt or solvate thereof, when MRis a radiohalogen and 184 763537: NIT-59597PC (PAT059597-FF) L1Ris a bond, then MCis a chelator radiolabeled with a radionuclide other than a radiohalogen, and L1Cis a linker. The compound of formula (Ig) may further comprise an albumin binder as described elsewhere herein. 5 In certain embodiments, the HER2-targeting compound is a compound of formula (Ib) or (Ic): 10 or a pharmaceutically acceptable salt or solvate thereof, wherein o is 2, each L1is the same or different and each P is different. For example, in some embodiments, the compound of formula (Ib) is a compound of formula (Ih): 15 (Ih), or a pharmaceutically acceptable salt or solvate thereof, wherein: each P is independently a cyclic HER2-targeting peptide; L1is a bond or a linker; and 20 M is an imaging agent, a chelator optionally radiolabeled with a radionuclide, or a radionuclide, and wherein the HER2-targeting cyclic peptides, linker, imaging agent, chelator, and radionuclide are as described elsewhere herein. In some embodiments of the compound of formula (Ih), or a pharmaceutically acceptable salt or solvate thereof, each P is the same. In some embodiments of the compound 185 763537: NIT-59597PC (PAT059597-FF) of formula (Ih), or a pharmaceutically acceptable salt or solvate thereof, each P is different. Each HER2-targeting cyclic peptide of the compound of formula (Ih) may be different by one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, six or more amino acids, seven or more amino acids, 5 eight or more amino acids, or nine or more amino acids. In some embodiments, the HER2- targeting cyclic peptides of the compound of formula (Ih) are different by no more than one amino acid, no more than two amino acids, no more than three amino acids, or no more than four amino acids. In various embodiments of the compound of formula (Ih), or a pharmaceutically 10 acceptable salt or solvate thereof, the compound further comprises an albumin binder (as described elsewhere herein). In some embodiments, the compound of formula (Ic) is a compound of formula (Ii): , (Ii), 15 or a pharmaceutically acceptable salt or solvate thereof, wherein: each P is independently a cyclic HER2-targeting peptide; each L1is selected from a bond and a linker; and M is an imaging agent, a chelator optionally radiolabeled with a radionuclide, or a 20 radionuclide, and wherein the HER2-targeting cyclic peptides, linker, imaging agent, chelator, and radionuclide are as described elsewhere herein. In some embodiments of the compound of formula (Ii), or a pharmaceutically acceptable salt or solvate thereof, each P is the same. In some embodiments of the compound of formula (Ii), or a pharmaceutically acceptable salt or solvate thereof, each P is different. In 25 some embodiments of the compound of Formula (Ih), or a pharmaceutically acceptable salt or 186 763537: NIT-59597PC (PAT059597-FF) solvate thereof, each L1is the same. In some embodiments of the compound of Formula (Ii), or a pharmaceutically acceptable salt or solvate thereof, each L1is different. Each HER2-targeting cyclic peptide of the compound of formula (Ii) may be different by one or more amino acids, two or more amino acids, three or more amino acids, four or 5 more amino acids, five or more amino acids, six or more amino acids, seven or more amino acids, eight or more amino acids, or nine or more amino acids. In some embodiments, the HER2-targeting cyclic peptides of the compound of formula (Ii) are different by no more than one amino acid, no more than two amino acids, no more than three amino acids, or no more than four amino acids. 10 In various embodiments of the compound of formula (Ii), the compound further comprises an albumin binder. The albumin binder may be as described elsewhere herein. In any of formulae (Id)-(Ii), and any other combination of P, L1, and M encompassed by the present disclosure, the cyclic peptide may be further connected to various moieties that may increase or supplement the activity of the disclosed HER2-targeting compounds. 15 Moieties that may be connected to any of the compounds described above include, but are not limited to, albumin binders, additional HER2-targeting agents, additional imaging agents, and cytotoxic drugs. Methods of Synthesis 20 The compounds described herein may be synthesized by many techniques that are known to those skilled in the art. In some aspects, the present disclosure provides a method of chemically synthesizing a radioligand peptide of the present disclosure. In some embodiments, a portion of the peptide is recombinantly synthesized, rather than chemically synthesized. In some embodiments, methods of producing a radioligand peptide include 25 cyclizing the peptide portion after all the constituents have been attached. In other embodiments, methods of producing a radioligand peptide include cyclizing the peptide prior to attachment of all the constituents to one another. In particular embodiments, cyclization is accomplished via any of the various methods described herein. In some embodiments, the peptide is first synthesized and then covalently attached to 30 the linker. The chelator may be attached to the linker before or after attachment of the peptide. For example, in some embodiments, the peptide is attached to the linker to form a linker-peptide intermediate that is then attached to the chelator. In other embodiments, the chelator is attached to the linker to form a linker-chelator intermediate that is then attached to the peptide. 187 763537: NIT-59597PC (PAT059597-FF) In some embodiments, one or more of the amino acid residues or amino acid are covalently attached to one another and then attached to the linker at an intermediate oligomer stage before attaching additional amino acids and cyclization to form a peptide of the disclosure. In such embodiments, the intermediate oligomer may comprise the linker and a 5 fragment of the peptide sequence or the linker, the chelator, and a fragment of the peptide sequence. As will be appreciated by one of ordinary skill in the art, the fragment of the peptide sequence may have a sequence length any number of amino acids shorter than the length of the complete peptide sequence. For example, if the peptide sequence is 10 residues long, then a fragment of that sequence may be 1, 2, 3, 4, 5, 6, 7, 8, or 9 residues long. 10 Illustrative synthetic methods are described in the Examples. Pharmaceutical Compositions and Dosing The present disclosure further provides a pharmaceutical composition comprising HER2-targeting radioligand described herein. In particular, a pharmaceutical composition of 15 the present disclosure includes one or more radioligand peptides disclosed herein and a pharmaceutically acceptable carrier, diluent, or excipient. The pharmaceutically acceptable carrier, diluent or excipient may be a solid, semi-solid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type. The pharmaceutical compositions may be administered parenterally. The term 20 “parenteral” as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous, intradermal and intraarticular injection and infusion. Accordingly, in certain embodiments, the compositions are formulated for delivery by any of these routes of administration. A pharmaceutical composition may be formulated for and administered by parenteral administration. In particular, a pharmaceutical 25 composition of the present disclosure may be formulated for and administered by intravenous administration. Radioligands of the present disclosure may be prepared and / or formulated as pharmaceutically acceptable salts and / or other forms thereof or when appropriate in neutral form. Pharmaceutically acceptable salts are non-toxic salts of a neutral form of a compound 30 that possess the desired pharmacological activity of the neutral form. These salts may be derived from inorganic or organic acids or bases. For example, a compound that contains a basic nitrogen may be prepared as a pharmaceutically acceptable salt by contacting the compound with an inorganic or organic acid. Non-limiting examples of pharmaceutically 188 763537: NIT-59597PC (PAT059597-FF) acceptable salts can be found in Remington: The Science and Practice of Pharmacy, 21st Edition, Lippincott Wiliams and Wilkins, Philadelphia, Pa., 2006. In certain aspects, pharmaceutical compositions for parenteral injection comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, 5 suspensions or emulsions, or sterile powders, for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), carboxymethylcellulose and suitable mixtures thereof, β-cyclodextrin, vegetable oils (such as olive oil), and injectable organic 10 esters such as ethyl oleate. Proper fluidity may be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. These compositions may also contain additives such as preservatives, wetting agents, emulsifying agents, chelating agents, buffering agents, and dispersing agents. 15 In some embodiments, the pharmaceutical composition comprises a chelating agent to sequester internally deposited radionuclides. Any of the chelating agents listed in Tables 3-7 above may be included in pharmaceutical compositions comprising the HER2-targeting radioligand. In various embodiments, the pharmaceutical composition comprises DTPA. Additional exemplary chelating agents that may be included in pharmaceutical compositions 20 of the present disclosure are described in Holik, et al. "The Chemical Scaffold of Theranostic Radiopharmaceuticals: Radionuclide, Bifunctional Chelator, and Pharmacokinetics Modifying Linker." Molecules 27.10 (2022): 3062 and Kostelnik, Thomas I., and Chris Orvig. "Radioactive main group and rare earth metals for imaging and therapy." Chemical Reviews 119.2 (2018): 902-956, both of which are incorporated by reference in their 25 entireties. In some embodiments, the pharmaceutical composition comprises one or more buffering agents to maintain a pH of about 3 to 5. Suitable buffering agents include, but are not limited to acetate, citrate, Tris, lactate, and tartrate, and the acid forms thereof. Pharmaceutical compositions including the HER2-targeting radioligand of the instant 30 disclosure may further comprise a stabilizer, such as, for example, a free radical scavenger, in order to prevent autoradiolysis of the inventive radioligand. Suitable stabilizers for inclusion in the disclosed pharmaceutical compositions include, but are not limited to, 2,5- dihydroxybenzoic acid or salts thereof, ascorbic acid or salts thereof, gentisic acid or salts thereof, methionine, histidine, melatonine, N-acetylmethionine, ethanol, an amino acid 189 763537: NIT-59597PC (PAT059597-FF) infusion solution, or any combination thereof. In some embodiments, the pharmaceutical composition includes a gentisic acid stabilizer. In some embodiments, the pharmaceutical composition includes an ascorbic acid stabilizer. In some embodiments, the pharmaceutical composition include stabilizer including gentisic acid and ascorbic acid. 5 In some embodiments, injectable compositions including a HER2-targeting radioligand are administered by infusion. For example, a composition of the present disclosure may be administered to a subject by an infusion ranging from about 1 to about 120 minutes in duration. In some embodiments, a composition of the present disclosure may be administered to a subject by an infusion ranging from about 1 to about 60 minutes in 10 duration. In some embodiments, a composition of the present disclosure may be administered to a subject by an infusion ranging from about 1 to about 30 minutes in duration. In some embodiments, a composition of the present disclosure may be administered to a subject by an infusion ranging from about 1 to about 20 minutes in duration. In some embodiments, a composition of the present disclosure may be administered to a subject by an infusion ranging 15 from about 1 to about 10 minutes in duration. In some embodiments, a composition of the present disclosure may be administered to a subject by an infusion ranging from about 5 to about 10 minutes in duration. In some embodiments, the pH of the disclosed pharmaceutical compositions ranges from about 3 to about 11. The pH of the compositions may, for example, range from about 3 20 to about 7 or from about 3 to about 5. The total daily usage of the HER2-targeting ligands (e.g., HER2-targeting radioligands) and compositions of the present disclosure can be decided by the attending physician within the scope of reasonable medical judgment. The specific therapeutically effective dose level for any particular subject will depend upon a variety of factors including: 25 a) the disorder being treated and the severity of the disorder; b) activity of the specific compound employed; c) the specific composition employed; d) the age, body weight, general health, sex and diet of the patient; e) the time route, and mechanism of administration; f) the rate of excretion of the specific compound employed; g) the duration of the treatment (including the number of cycles in a treatment); h) administration of combination partners 30 (e.g., chemotherapies and / or imaging agents), and like factors well known in the medical arts. Provided herein are radiopharmaceuticals or radioligands targeting HER2. In particular embodiments, the dosing of a HER2-targeting radioligands of the present disclosure to be administered to a human or other mammal host in single or divided doses may be referred to as administered activity to be delivered to the subject (e.g., human or other 190 763537: NIT-59597PC (PAT059597-FF) mammal host). Administered activity of radiopharmaceuticals is given in units of radioactive disintegrations per unit time (SI units Becquerels (BQ), imperial units Curies(Ci)). The total dose will vary depending on the purpose, i.e., for imaging and / or therapy, and the number of cycles of administration. Dosing may also be based on energy deposited per unit of mass, i.e., 5 the absorbed dose, usually given in J / kg or Gy). The dosing of the radio-labeled compounds will also be determined by the particular radionuclide, and whether said radionuclide is a β-emitter (can also be referred to in the art as a beta-minus emitter) (e.g.,90Y,131I,153Sm, or177Lu) or an α-emitter (e.g.,211At,212Pb,212Bi, 223Ra,225Ac, or227Th). 10 In some embodiments, the total dose (over the course of a treatment regimen) of the HER2-targeting ligand radiolabeled with a β-emitter such as, e.g.,177Lu, is from about 1 GBq to about 200 GBq. In some embodiments, the HER2-targeting radioligand comprising a β- emitter is administered in a total dose to deliver from 10 to 60 GBq of radiation. In some embodiments, the HER2-targeting radioligand comprising a β-emitter is administered in a15 total dose to deliver from 20 to 80 GBq of radiation. In some embodiments, the HER2- targeting radioligand comprising a β-emitter is administered in a total dose to deliver from 40 to 100 GBq of radiation. In some embodiments, the HER2-targeting radioligand comprising the β-emitter is administered in a single dose (once within a 24-hour period) to deliver from about 1 to about 20 GBq of radiation. In some embodiments, the HER2-targeting radioligand 20 comprising the β-emitter is administered in a single dose (once within a 24-hour period) to deliver from about 1 to about 15 GBq of radiation. In some embodiments, the HER2- targeting radioligand comprising the β-emitter is administered in a single dose (once within a 24-hour period) to deliver from about 1 to about 10 GBq of radiation. In some embodiments, the total dose (over the course of a treatment regimen) of the 25 HER2-targeting ligand radiolabeled with an ^-emitter, e.g.,225Ac, is from about 1 MBq to about 100 MBq. In some embodiments, the HER2-targeting radioligand comprising an ^- emitter is administered in a total dose of from about 10 to about 60 MBq of radiation. In some embodiments, the HER2-targeting radioligand comprising an ^-emitter is administered in a total dose of from about 20 to about 80 MBq of radiation. In some embodiments, the 30 HER2-targeting radioligand comprising the ^-emitter is administered in a single dose (once within a 24-hour period) to deliver from about 1 to about 40 MBq of radiation. In some embodiments, the HER2-targeting radioligand comprising the ^-emitter is administered in a single dose (once within a 24-hour period) to deliver from about 5 to about 40 MBq of 191 763537: NIT-59597PC (PAT059597-FF) radiation. In some embodiments, the HER2-targeting radioligand comprising the ^-emitter is administered in a single dose (once within a 24-hour period) to deliver from about 5 to about 25 MBq of radiation. 5 Combination Therapies Also provided herein are combinations (e.g., combination therapies) comprising at least one HER2-targeting ligand of the present disclosure and one or more other therapeutically active agents. The disclosed pharmaceutical combinations may be used in the treatment or prevention of HER2-related diseases, such as, for example, cancer. The HER2- 10 targeting ligand of the present disclosure, when radiolabeled with a suitable imaging and / or therapeutic radionuclide, may be used in the treatment of a cancer wherein the subject is also receiving standard of care treatment or other chemotherapies approved for the treatment of the cancer. Suitable pharmaceutical combinations may include a HER2-targeting compound described herein and one or more immune checkpoint inhibitors, such as, for example, PD-1 15 and PD-L1 inhibitors, CTLA-4 inhibitors, and LAG-3 inhibitors; selected estrogen receptor modulators; cyclin-dependent kinase (CDK) inhibitors, such as, e.g., CDK4 and CDK6 inhibitors; steroidal and nonsteroidal aromatase inhibitors; hormone receptor antagonists and inhibitors; antineoplastic agents; antimitotic agents; mTOR kinase inhibitors; antimetabolites; antifolates; DNA intercalators; tyrosine kinase inhibitors; and / or nonsteroidal anti- 20 inflammatory drugs (NSAIDs). Methods of Treatment The present disclosure also provides a method of treating one or more HER2-related diseases or disorders in a subject in need thereof, the method comprising administering a 25 therapeutically effective amount of a HER2 targeting ligand / therapeutic or radioligand therapeutic described herein to the subject. The HER2 targeting ligands or compounds of the present disclosure may be administered to a subject having any HER2-related disease or disorder, including, but not limited to: proliferation diseases, such as, for example, cancer. In certain embodiments, the HER2-related disease or disorder is cancer. 30 In an aspect, provided herein is a method treating cancer in a subject in need thereof comprising administering a therapeutically effective amount of, e.g., a compound of any of Formulae (I), (Ia), (Ib), (Ic), (Id) and (I-i) particularly a radiolabeled compound of any of Formulae (I), (Ia), (Ib), (Ic), (Id) and (I-i). In an embodiment, the cancer expresses HER2. 192 763537: NIT-59597PC (PAT059597-FF) In some aspects, the HER2-targeting therapeutic (e.g., a HER2-targeting radioligand therapeutic), or pharmaceutical composition thereof, is used as a curative or adjuvant cancer treatment. In other aspects, the HER2-targeting therapeutic (e.g., a HER2-targeting radioligand therapeutic), or pharmaceutical composition thereof, is used as a palliative 5 treatment. Methods of palliative treatment using the disclosed radioligands include local disease control and / or symptomatic relief. The HER2-targeting therapeutics or ligands (e.g., a HER2-targeting radioligand therapeutic) described herein may be used as the primary therapy for treatment of HER2- related disease or disorders, such as cancer. Alternatively, the HER2-targeting therapeutics or 10 ligands (e.g., a HER2-targeting radioligand therapeutic) of the instant disclosure may be the secondary, tertiary, or final therapy for a HER2-related disease or disorder. The HER2-targeting compounds of the instant disclosure may be used in methods of treating cancers such as, for example, biliary tract cancer, bladder cancer (including, e.g., urothelial carcinoma), brain cancer (including, e.g., glioblastoma and brain metastases from 15 another cancer type), breast cancer (including, e.g., triple-negative breast cancer (TNBC), HER2-positive breast cancer, and HR+ breast cancer), cervical cancer, cholangiocarcinoma, colorectal cancer, endocrine cancer, endometrial cancer, epithelial cancer, esophageal cancer (including, e.g., gastroesophageal junction cancer, which can also be referred to as gastroesophageal junction adenocarcinoma), gastric cancer, head and / or neck cancer, 20 hepatocellular carcinoma, lung cancer (including, e.g., non-small cell lung cancer (NSCLC)), melanoma, mesothelioma, nasopharyngeal cancer, neuroendocrine tumor, ovarian cancer, pancreatic cancer (including, e.g., pancreatic ductal adenocarcinoma (PDAC)), prostate cancer, rectal cancer, salivary gland cancer, sarcoma, small intestine cancer, testicular cancer, thyroid cancer, and / or uterine cancer. 25 In some embodiments, HER2-targeting radioligand therapeutics (HER2-targeting radiopharmaceuticals or HER2-targeting radiotherapies) of the instant disclosure are used in a method of treating a carcinoma arising from epithelial tissue. In some embodiments, HER2-targeting radioligand therapeutics (HER2-targeting radiopharmaceuticals or HER2-targeting radiotherapies) of the instant disclosure are used in a 30 method of treating a biliary tract cancer, bladder cancer (including, e.g., urothelial carcinoma), brain cancer (including, e.g., glioblastoma and brain metastases from another cancer type), breast cancer (including, e.g., triple-negative breast cancer (TNBC), HER2- positive breast cancer, and HR+ breast cancer), cervical cancer, cholangiocarcinoma, colorectal cancer, endocrine cancer, endometrial cancer, epithelial cancer, esophageal cancer 193 763537: NIT-59597PC (PAT059597-FF) (including, e.g., gastroesophageal junction cancer, which can also be referred to as gastroesophageal junction adenocarcinoma), gastric cancer, head and / or neck cancer, hepatocellular carcinoma, lung cancer (including, e.g., non-small cell lung cancer (NSCLC)), melanoma, mesothelioma, nasopharyngeal cancer, neuroendocrine tumor, ovarian cancer, 5 pancreatic cancer (including, e.g., pancreatic ductal adenocarcinoma (PDAC)), prostate cancer, rectal cancer, salivary gland cancer, sarcoma, small intestine cancer, testicular cancer, thyroid cancer, and / or uterine cancer. In particular embodiments, the HER2-targeting radioligand therapeutics are used in a method of treating bladder cancer, breast cancer, colorectal cancer, gastric cancer, 10 gastroesophageal junction cancer, non-small cell lung cancer, or pancreatic ductal adenocarcinoma (PDAC). In particular embodiments, the HER2-targeting radioligand therapeutics are used in a method of treating biliary tract cancer, bladder cancer, cervical cancer, endometrial cancer, ovarian cancer, or pancreatic cancer. 15 In particular embodiments, the HER2-targeting radioligand therapeutics are used in a method of treating breast cancer, non-small cell lung cancer, gastric cancer, or gastroesophageal junction cancer. In an embodiment, HER2-targeting radioligand therapeutics of the present disclosure are used in methods of treating cancer. In certain embodiments, the cancer is a solid tumor. In 20 certain embodiments, the cancer is characterized by HER2 over-expression (i.e., the cancer is HER2 positive). In certain embodiments, the cancer is characterized by HER2 expression. In certain embodiments, the cancer is characterized as HER2-low (i.e., the cancer is HER2- negative). In certain embodiments, the cancer is classified as IHC 3+. In certain embodiments, 25 the cancer is classified as IHC 2+. In certain embodiments, the cancer is classified as IHC 1+. In certain embodiments, the cancer is classified as IHC 0. HER2 testing guidelines are described in, e.g., Wolff, A. C., Somerfield, M. R., Dowsett, M. & et, a., 2023. Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: ASCO-College of American Pathologists Guideline Update. Journal of Clinical 30 Oncology, 41(22), pp.3867-3872. In certain embodiments, the HER2 expression is measured by either IHC (Immunohistochemistry) or administration of a HER2-targeted radioimaging agent (such as, e.g., those disclosed herein). In certain embodiments, the cancer is breast cancer and the breast cancer is characterized as HER2-positive (HER2+). In certain 194 763537: NIT-59597PC (PAT059597-FF) embodiments, the breast cancer is characterized as HR+, HER2-low (HER2- or HER2- positive). In certain embodiments, the cancer is breast cancer and the breast cancer is characterized as HER2-low. In certain embodiments, the breast cancer is characterized as 5 HR+, HER2-low (HER2- or HER2-negative). In certain embodiments, the breast cancer is characterized as HR-, HER2-low (HER2- or HER2-negative). In certain embodiments, the cancer is non-small cell lung cancer and the non-small cell lung cancer is characterized by HER2 expression. In certain embodiments, the non-small cell lung cancer is characterized as HER2+ (HER2 ≥1+ or HER2-positive). In certain 10 embodiments, the non-small cell lung cancer is characterized as IHC ≥1+. In certain embodiments, the cancer is gastric cancer and the gastric cancer is characterized by HER2 expression. In certain embodiments, the cancer is gastric cancer and the gastric cancer is characterized as HER2-positive. In certain embodiments, the cancer is gastroesophageal junction cancer and the 15 gastroesophageal junction cancer is characterized by HER2 expression. In certain embodiments, the cancer is gastroesophageal junction cancer and the gastroesophageal junction cancer is characterized as HER2-positive. In certain embodiments, the cancer is bladder cancer and the bladder cancer is characterized by HER2 expression. In certain embodiments, the cancer is bladder cancer and 20 the bladder cancer is characterized as HER2-positive. In some embodiments, methods of treating HER2-related diseases and disorders include co-administration of a disclosed radioligand with an additional therapy. In particular, when the HER2-related disease or disorder is cancer, methods may include combining a HER2-targeting radioligand therapeutic with one or more anti-cancer therapies (i.e., an anti- 25 cancer therapeutic agent or a chemotherapeutic). Any known anticancer therapy may be combined with the radioligand of the present disclosure in order to provide curative, adjuvant, or palliative treatment to a subject in need thereof. For example, suitable anticancer therapies that may be combined with the presently disclosed radioligand therapeutic include, but are not limited to, surgery, anticancer drugs, PARP inhibitors, inhibitors of signaling 30 pathways and mechanisms leading to repair of DNA single and double strand breaks, such as nuclear factor-kappa B signaling, immunomodulators, immune checkpoint inhibitors, antibodies capable of inducing antibody-dependent cellular cytotoxicity, T-cell or NK cell engagers, and cellular therapies using expanded autologous or allogeneic cells. One of ordinary skill in the art would be capable of discerning a suitable anticancer therapy to be 195 763537: NIT-59597PC (PAT059597-FF) used in combination with the radioligand therapeutic depending on a number of factors including, cancer type, stage, and location, as well as the general health and physical characteristics of the patient, e.g., weight, age, sex, etc. The additional anticancer therapy may be administered concurrent with, prior to, or 5 after administration of the HER2-targeting radioligand therapeutic. In some embodiments, the administration schedule involves administering the different agents in an alternating fashion, such as alternating days, weeks, or months. In other embodiments, the compounds may be delivered before and during, or during and after, or before and after treatment with one or more other anticancer therapies. In some embodiments, more than one additional anticancer 10 therapy is administered to a subject. For example, the subject may receive the presently described HER2-targeting radioligand therapeutic, in combination with surgery and at least one other anticancer drug. Alternatively, the compound may be administered in combination with more than one additional anticancer drug or therapy. In any of the foregoing methods, administration of the HER2-targeting radioligand 15 therapeutic to the subject may be conducted parenterally, in particular, intravenously, but other routes of administration are not excluded. Other routes of administration include, but are not limited to, subcutaneous, intramuscular, intraperitoneal, transdermal, topical, buccal, or oral routes. In certain embodiments, the radioligand therapeutic may be administered as close to the disease site as possible, such as in the diseases tissue, surrounding tissue, or 20 nearby blood vessels. The HER2-targeting radioligand therapeutic may be dosed according to the total radiation to be administered to the subject in need thereof, and as described herein. In some embodiments, the HER2-targeting radioligand therapeutic is administered on alternate days, weeks, or months. For example, HER2-targeting radioligand therapeutic 25 described herein may be administered once every two days, or every three days, or every four days, or every five days, or every six days, or every week, or every month. The HER2- targeting radioligands described herein may be administered once every two weeks, or every three weeks, or every four weeks, or every five weeks, or every six weeks, or every seven weeks, or every eight weeks, or every nine weeks, or every ten weeks, or every eleven weeks, 30 or every twelve weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 2 weeks to 10 weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 2 weeks to 6 weeks. In some embodiments, the HER2- targeting radioligand is administered once about every 2 weeks to 4 weeks. In some 196 763537: NIT-59597PC (PAT059597-FF) embodiments, the HER2-targeting radioligand is administered once about every 3 weeks to 10 weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 3 weeks to 6 weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 3 weeks to 4 weeks. In some embodiments, the HER2- 5 targeting radioligand is administered once about every 4 weeks to 6 weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 5 weeks to 6 weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 6 weeks to 8 weeks. In some embodiments, the HER2-targeting radioligand is administered once about every 6 weeks to 7 weeks. 10 In some embodiments, the present disclosure provides a method of treating a subject afflicted with a disease or disorder using the HER2-targeting therapeutics described herein, wherein the treatment is radionuclide therapy. Radionuclide therapy is based on different forms of radiation emitted by a radionuclide, including, but not limited to, radiation of photons, radiation of electrons, such as, for example, ^-particles and auger-electrons, 15 radiation of protons, radiation of neutrons, radiation of positrons, radiation of ^-particles or an ion beam. Accordingly, depending on the kind of particle or radiation emitted by the radionuclide, radionuclide therapy can be distinguished as photon radionuclide therapy, electron radionuclide therapy (e.g., ^-particle radionuclide therapy), proton radionuclide therapy, neutron radionuclide therapy, positron radionuclide therapy, ^-particle radionuclide 20 therapy, or ion beam radionuclide therapy. Methods of the present disclosure that utilize radionuclide therapy for treatment of a subject may rely on any one or more of these forms of radiotherapy. In particular, the HER2-targeting radioligand therapeutic of the present disclosure may be used to provide any one or more of the above forms of radionuclide therapy to a subject in need thereof. In certain embodiments, ^-emitting radionuclide therapy 25 may be useful. In certain other embodiments, ^-emitting radionuclide therapy may be useful. In some embodiments, methods may include the use of certain techniques or systems commonly used in a clinical setting to accelerate and / or increase the effectiveness of the radiation therapy. For example, as oxygen is known in the art to be a potent radiosensitizer by readily forming free radicals, the presently described radioligand may be used in conjunction 30 with high-pressure oxygen tanks, blood substitutes having increased oxygen content, and hypoxic cell radiosensitizers in some cases. The compounds disclosed herein, including the compounds of Formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof, exhibit strong binding to 197 763537: NIT-59597PC (PAT059597-FF) human and / or mouse HER2, i.e., exhibit a dissociation constant (KD) of about 1000 nM, about 500 nM, or about 200 nM or less as measured by surface plasmon resonance (SPR) at a temperature of 25° C (see, e.g., the method described particularly in Section 11.1 and corresponding KDvalues in Table 11.1). 5 In some embodiments, any one of the compounds as disclosed herein exhibit a KD between about 1000 nM and about 0.001 nM as measured by SPR at a temperature of 25° C. In some embodiments, any one of the compounds as disclosed herein exhibit a KDbetween about 500 nM and about 0.001 nM as measured by SPR at a temperature of 25° C. In some embodiments, any one of the compounds as disclosed herein exhibit a KD between about 200 10 nM and about 0.001 nM as measured by SPR at a temperature of 25° C. The compounds disclosed herein, including the compounds of Formula (I), (Ia), (Ib), (Ic), or (Id), or a pharmaceutically acceptable salt or solvate thereof, also exhibit high potency against HER2 (inhibit human and / or mouse HER2 enzymatic activity), i.e., exhibit an IC50for human HER2 of about 1000 nM or less, about 500 nM or less, or about 200 nM or 15 less as measured by an Enzymatic HER2 competition assay (see, e.g., the method described particularly in Section 11.1 and corresponding IC50 values in Table 11.1). In some embodiments, any one of the compounds as disclosed herein exhibit an IC50for human HER2 between about 1000 nM and about 0.001 nM as measured by an Enzymatic HER2 competition assay. In some embodiments, any one of the compounds as disclosed 20 herein exhibit an IC50for human HER2 between about 500 nM and about 0.001 nM as measured by an Enzymatic HER2 competition assay. In some embodiments, any one of the compounds as disclosed herein exhibit an IC50 for human HER2 between about 200 nM and about 0.001 nM as measured by an Enzymatic HER2 competition assay. In some embodiments, any one of the compounds disclosed herein are selective for 25 HER2 over Herstatin and other members of the ErbB family (such as, e.g., EGFR, HER3, and HER4). Methods of Imaging Also provided herein is a method of imaging a disease or disorder associated with 30 human epidermal growth factor receptor 2 using the disclosed HER2-targeting radioligands. In some aspects, the method includes administering a detectably effective amount (an amount effective for imaging) of a radioligand (i.e., a radioimaging agent) of the present disclosure, or a pharmaceutical composition thereof, to a subject. 198 763537: NIT-59597PC (PAT059597-FF) In some embodiments, the method includes imaging one or more cells, tissues, or organs, including, but not limited to, kidney tissue, prostate tissue, brain tissue, vascular tissue, and tumor tissue. The HER2-targeting compounds described herein are suitable for imaging any 5 physiological process or feature in which HER2 is involved, such as for identifying areas of tissues or targets which exhibit or express high concentrations (e.g., over-expression) of HER2. Exemplary physiological processes in which HER2 is involved include, but are not limited to, proliferation diseases, tissue remodeling and / or chronic inflammation, and endocrinological disorders. 10 Provided herein is a method of identifying a subject suitable for treatment with a HER2- targeting radioligand therapeutic comprising administering to the subject a HER2- targeting radioimaging agent and imaging the subject (by, e.g., PET or PET / CT) to determine whether the subject has HER2 expressing cancer. In certain embodiments, the HER2- targeting radioimaging agent comprises a HER2-targeting compound disclosed herein 15 radiolabeled with a radionuclide suitable for radioimaging (e.g., by PET and / or PET / CT and / or SPECT / CT), such as, for example,111In,68Ga or18F. In certain embodiments, the HER2-targeting radioligand therapeutic comprises a HER2-targeting compound disclosed herein radiolabeled with a radionuclide suitable for therapy, such as, for example,177Lu, 225Ac, or161Tb. In some embodiments, the method includes imaging one or more cells, 20 tissues, or organs implicated in a proliferation disease. In some embodiments, the proliferation disease is cancer. For example, one or more cells, tissues, or organs suitable for imaging with the radioligand peptides described herein may be implicated in cancers such as, for example, breast cancer, colorectal cancer, epithelial cancer, ovarian cancer, prostate cancer, pancreatic cancer, kidney cancer, lung cancer, melanoma, fibrosarcoma, bone and 25 connective tissue sarcomas, renal cell carcinoma, giant cell carcinoma, squamous cell carcinoma, and adenocarcinoma. In some embodiments, the method includes imaging one or more cells, tissues, or organs implicated in tissue remodeling and / or chronic inflammation, including, but not limited to, fibrotic disease, wound healing, keloid formation, osteoarthritis, rheumatoid 30 arthritis, and relating disorders involving cartilage degradation. In some aspects, methods of imaging one or more cells, tissues, or organs with HER2- targeting radioligands of the present disclosure further include detecting and / or assessing a disease or disorder in the subject. Detecting and / or assessing a disease or disorder may be useful in diagnosis, prognosis, and prediction of a disease or disorder in the subject. For 199 763537: NIT-59597PC (PAT059597-FF) example, HER2-targeting radioligands disclosed herein may be used to diagnose a disease or disorder afflicting the subject, to determine the subject’s risk of developing a disease or disorder, to assess the evolution of a disease or disorder in the subject, or to predict a subject’s response to a certain therapy given to treat the disease or disorder. 5 In some embodiments, the HER2-targeting radioligands are detectable by positron emission tomography (PET) or single photon emission computed tomography (SPECT). In some embodiments, the HER2-targeting radioligands are detectable by scintigraphy. The HER2-targeting radioligand or a pharmaceutical composition thereof may be administered to the subject for imaging purposes via parenteral administration, but other 10 routes of administration are not excluded. Other routes of administration include, but are not limited to, subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal, or oral routes. The amount of a radioligand described herein, or a pharmaceutically acceptable salt or composition thereof to be administered to a subject may be determined by a person of skill in the art taking into account the disease or condition being treated, including its locale, and 15 factors including age, weight, sex, and the like. Theragnostic Methods The present disclosure further provides a method to both image and treat or prevent a disease or disorder associated with human epidermal growth factor receptor 2 using the 20 disclosed HER2-targeting ligands and radioligands. As used herein, a method of imaging and treating a disease or disorder may be referred to as a theragnostic method. In some embodiments, the theragnostic method includes administering a diagnostically effective and therapeutically effective dose of a HER2-targeting compound described herein to a subject in need thereof. In some embodiments, a HER2-targeting25 compound may be used to image one or more tissues, cells, or organs implicated in a HER2- related disease and to treat the HER2-related disease in those tissues, cells, or organs. In particular, a theragnostic method may be used for both imaging and treatment of cancer in a subject in need thereof. In some embodiments, one HER2-targeting compound is used in the theragnostic 30 method described herein (i.e., the same HER2-targeting radioligand is used in both imaging and therapeutic methods). Accordingly, in some embodiments, the HER2-targeting compound is both diagnostically and therapeutically active. The HER2-targeting compound used in a theragnostic method may be complexed to one radionuclide that is diagnostically and therapeutically active, or more than one 200 763537: NIT-59597PC (PAT059597-FF) radionuclide where at least one of the more than one radionuclides is diagnostically active and at least one of the more than one radionuclide is therapeutically active. In some embodiments, the diagnostically active radionuclide is a radiohalogen and the therapeutically radionuclide is a radionuclide other than a radiohalogen. In other embodiments, the 5 therapeutically and diagnostically active radionuclides are radiohalogens. In yet other embodiments, the therapeutically and diagnostically active radionuclides are radionuclides other than radiohalogens. Alternatively, in some embodiments, more than one HER2-targeting compounds are used in a theragnostic method descried herein. In such embodiments, a diagnostically active 10 HER2-targeting radioligand is used first to diagnose or image the disease or disorder and a therapeutically active HER2-targeting radioligand is subsequently used to treat the disease or disorder. For example, when the HER2-related disease or disorder is cancer, a diagnostically active HER2-targeting radioligand may initially be used to identify and localize the primary tumor mass, and to determine potential local and distant metastasis, and after 15 imaging / diagnosis, a therapeutically active HER2-targeting radioligand (comprising a therapeutically active radionuclide) may be administered as described previously to treat the tumor. When more than one HER2-targeting compounds are used in a theragnostic method, each HER2-targeting compound may be complexed to one or more than one radionuclide. In 20 some embodiments, a diagnostically active HER2-targeting compound is complexed to one diagnostically active radionuclide. In some embodiments, a diagnostically active HER2- targeting compound is complexed to more than one diagnostically active radionuclide. In some embodiments, a therapeutically active HER2-targeting compound is complexed to one therapeutically active radionuclide. In some embodiments, a therapeutically active HER2- 25 targeting compound is complexed to more than one therapeutically active radionuclide. In some embodiments of the theragnostic method described herein, the diagnostic / imaging agent is a HER2-targeting imaging agent described in the art, and the therapeutic agent is a radiolabeled compound described herein (e.g., a radiolabeled compound of any one of Formulae (I), (Ia), (Ib), (Ic), (Id), and (I-i)). In other embodiments of the 30 theragnostic method described herein, the diagnostic / imaging agent is a radiolabeled compound described herein (e.g., a radiolabeled compound of any one of Formulae (I), (Ia), (Ib), (Ic), (Id), and (I-i)) and the therapeutic agent is a HER2-targeting therapeutic agent described in the art. 201 763537: NIT-59597PC (PAT059597-FF) The dosage and administration schedule of a HER2-targeting compound used for theragnostic purposes may be the same as the dosage and administration schedules described above, e.g., a diagnostically active HER2-targeting compound used in a theragnostic method may be dosed and administered as described for a method of imaging and therapeutically 5 active HER2-targeting compound used in a theragnostic method may be dosed and administered as described above for a method of treatment. A therapeutically and diagnostically active HER2-targeting compound may be dosed and administered according to either of the above methods. The dose and administration of a radioligand described herein, or a pharmaceutically acceptable salt or composition thereof to be administered to a subject 10 may be determined by a person of skill in the art taking into account the disease or condition being diagnosed and treated, including its locale, and factors including age, weight, sex, and the like. Kits 15 The present disclosure also includes pharmaceutical kits useful, for example, in the imaging, diagnosis, or treatment of a HER2-related disease or disorder (such as, e.g., cancer) which include one or more containers containing a pharmaceutical composition comprising a therapeutically effective amount of a HER2-targeting ligand and / or radioligand of the disclosure. Such kits can further include one or more various kit components such as, for 20 example, containers with one or more pharmaceutically acceptable carriers, additional containers (e.g., those suitable for handling radioactive waste), and / or instructions, inserts, or labels, indicating quantities of components to be administered, guidelines for administration, and / or guidelines for mixing the components. 25 Equivalents and Scope The disclosure is further illustrated by the following examples and synthesis schemes, which are not to be construed as limiting this disclosure in scope or spirit to the specific procedures herein described. It is to be understood that the examples are provided to illustrate certain embodiments and that no limitation to the scope of the disclosure is intended thereby. 30 It is to be further understood that resort may be had to various other embodiments, modifications, and equivalents thereof which may suggest themselves to those skilled in the art without departing from the spirit of the present disclosure and / or scope of the appended claims. 202 763537: NIT-59597PC (PAT059597-FF) EXAMPLES Example I. Synthesis and Characterization of Cyclic Peptides and Compounds Comprising Them 1Abbreviations and general procedures5 1.1 Abbreviations 203 763537: NIT-59597PC (PAT059597-FF) 204 763537: NIT-59597PC (PAT059597-FF) 1.2 General proceduresUnless otherwise noted, reagents and solvents were used as received from commercial suppliers. Proton nuclear magnetic resonance (NMR) spectra were obtained on a Varian 5 spectrometer at 400 MHz or a Bruker spectrometer at 400 MHz or 600 MHz. Chemical shifts are given in ppm (δ) and coupling constants, J, are reported in Hertz. Tetramethylsilane (TMS) or the solvent peak was used as an internal standard. Only the protons visible in1H NMR were listed. Signals hidden under the solvent peaks were not included. The linear peptides were assembled by Fmoc-based solid phase peptide synthesis using typically peptide 10 synthesizers, namely the Liberty Blue and Liberty Prime from CEM or by manual coupling 205 763537: NIT-59597PC (PAT059597-FF) (see Section 1.3). The syntheses were done at RT or with heating starting from Fmoc-Rink Amide ProTide resin, Fmoc-Rink Amide AM resin, Fmoc-Sieber resin or Fmoc-Lys(Boc)- Wang resin (see Section 10.1, Table 10.1). Fmoc-protected amino acids with appropriateprotecting groups on side chains were used (commercially available or synthesized as 5 described, see Section 10.2, Table 10.2). In some instances, other amino acids or building blocks were used (see Section 10.3, Table 10.3). Amino acids were coupled using a variety of coupling reagents such as HATU, PyAOP, DIC / Oxyma Pure® and, depending on the requirements, a base such as DIPEA. Fmoc was typically removed using 4-methylpiperidine, piperidine or pyrrolidine. Cleavage of the fully protected peptides from the resin was 10 achieved with a mixture of TFA / DCM (e.g.1% TFA in DCM). The linear peptides were cyclized directly or in some instances purified prior to cyclization. The amide bond cyclization was typically performed in DMF or DCM using HATU / 2,6-lutidine. Other conditions used for cyclization were e.g. PyAOP / Et3N, or PyAOP / DIPEA in DCM or T3P / DIPEA in DMF. Thioether macrocyclization was typically performed in ACN / water 15 using a base (e.g. DIPEA or Et3N). Disulfide macrocyclization was typically performed in DMSO / water (1 / 4). Concomitant removal of the protecting groups and cleavage from the resin was achieved by using mixtures of TFA / H2O / DODT / TIS (e.g.92.5 / 2.5 / 2.5 / 2.5). Selective removal of the allyl and alloc protecting groups was achieved using catalytic amounts of Pd(PPh3)4) in the presence of a scavenger (e.g. phenylsilane, triethylsilane or 1,3- 20 Dimethylbarbituric acid) in a solvent (e.g., DCM). Chelator coupling was performed using chelator reagents such as DOTA-NHS ester, NODAGA-NHS ester, NOTA-NHS ester, (R)- DOTAGA-anhydride, p-SCN-Bn-DOTA or tBu-protected AAZTA5, in the presence of a base (e.g., DIPEA), and if required coupling reagents such as HATU and HOAt. Labelling with natural175Lu,natGa,139La or AlnatF was performed in various buffers (e.g. ammonium 25 acetate or sodium acetate buffers) at pH 3.5-6.0 at 80 °C – 100 °C, in the presence or absence of DMF. The final products and intermediates were purified by the preparative reversed-phase HPLC methods described in Section 1.4. The products and intermediates were analyzed by the analytical methods described in 30 Section 1.5 and Section 1.6. 206 763537: NIT-59597PC (PAT059597-FF) 1.3 SPPS Methods1.3.1 SPPS using automated peptide synthesizerThe resin was swollen in the solvent (e.g., DMF or DCM) and then loaded onto the peptide synthesizer (e.g. Liberty Blue™ or Liberty PRIME™ from CEM Inc.) for the SPPS. 5 Fmoc was typically removed using 4-methylpiperidine, piperidine or pyrrolidine. Coupling was accomplished by addition of the Fmoc-amino acid, DIC and Oxyma Pure® or Oxyma Pure® + DIPEA. The coupling and deprotection steps were repeated until the desired polypeptide was obtained. Sometimes the SPPS sequence was interrupted after a cycle and a Fmoc deprotection was performed (e.g. before a manual coupling). After the final coupling 10 was completed, the resin was washed with an appropriate solvent (e.g. DMF, DCM) to provide the protected peptide on resin. The specific conditions used for the automated SPPS are described in the experimental sections below. 1.3.2 SPPS by manual couplingThe resin was swollen in the solvent (e.g., DMF or DCM). The Fmoc amino acid was 15 coupled using a variety of coupling reagents such as HATU, PyAOP, DIC / Oxyma Pure® and depending on the requirements a base such as DIPEA or Et3N. After a pre-activation time the solution was added to the resin. The reaction was shaken at RT upon completion of the reaction. The solution was drained, and the resin washed with an appropriate solvent (e.g. DMF, DCM). Fmoc was typically removed using 4-methylpiperidine, piperidine or 20 pyrrolidine. The specific conditions used for the manual SPPS are described in the experimental sections. 1.4 Preparative HPLC purification methodsThe final products and intermediates were purified by preparative reversed-phase 25 HPLC, using columns of different sizes and with varying flow rates, depending on the amount of material to be purified. The following columns were used: ^XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 100 mm^ XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm30 ^ XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 19 mm x 150 mm^ XBridge® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 150 mm^ XBridge® C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 150 mm^ XBridge® C18, OBD™ Prep Column, 130Å, 5 µm, 50 mm x 250 mm207 763537: NIT-59597PC (PAT059597-FF) ^XBridge® C18, OBD™ Prep Column, 130Å, 5 µm, 50 mm x 150 mm^ XBridge® C18, OBD™ Prep Column, 130Å, 5 µm, 19 mm x 150 mm^ Kinetex® EVO C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 150 mm5 The following mobile phases were used: ^Eluent A: Water + 0.1% TFA and eluent B: ACN^ Eluent A: Water + 0.1% TFA and eluent B: ACN + 0.1% TFA^ Eluent A: Water + 1% AcOH and eluent B: ACN + 1% AcOH^ Eluent A: Water + 0.08% NH4HCO3 and eluent B: ACN10 Gradients were designed based on the specific requirements of the separation problem. Pure products were lyophilized from ACN / H2O and obtained, depending on the used eluents, as a free base or the corresponding salt (e.g. trifluoroacetate, acetate). 1.5 Analytical methods (Peptides)15 1.5.1 LCMS method AP-1Waters Acquity UPLC-MS system / QTof MS (ESI): Eluent A: Water + 0.05% TFA; Eluent B: ACN + 0.04% TFA; Column temperature: 80 °C; Flow: 0.5 mL / min; Column: Acquity UPLC CSH C18, 1.7 µm, 2.1 x 100 mm; Gradient: hold 5% B for 0.2 min; from 5 to 98% B in 9.2 min; hold 98% B for 0.4 min.20 1.5.2 LCMS method AP-2Waters Acquity UPLC-MS system / QTof MS (ESI): Eluent A: Water + 0.05% TFA; Eluent B: ACN + 0.04% TFA; Column temperature: 80 °C; Flow: 0.5 mL / min; Column: Acquity UPLC CSH C18, 1.7 µm, 2.1 x 100 mm; Gradient: hold 0% for 0.3 min; from 0 to 40% B in 8.7 min; from 40 to 98% B in 0.5 min.25 1.5.3 LCMS method AP-3Shimadzu LC / MS system / Single Quadrupole (ESI): Eluent A: Water + 0.025% TFA; Eluent B: ACN + 0.025% TFA; Column temperature: 60 °C; Flow: 0.5 mL / min; Column: Kinetex EVO C182.6 um, 2.1 mm x 150 mm, 100Å (with a guard cartridge 2.1 mm ID); Gradient: hold 0% B for 0.3 min; from 20 to 60% B in 7.15 min; from 60 to 95% B in 30 0.3 min; hold 95% for 1.55 min; from 95 to 20% B in 0.01 min; hold 20% for 3.49 min. hold 20% for 3.49 min. 208 763537: NIT-59597PC (PAT059597-FF) 1.6 Analytical methods (Building Blocks)1.6.1 LCMS method AB-1Waters Acquity UPLC-MS system / MS (ESI): Eluent A: Water + 4.76% isopropanol + 0.05% formic acid + 3.75 mM ammonium acetate; Eluent B: isopropanol + 0.05% formic 5 acid; Column temperature: 80 °C; Flow: 1.0 mL / min; Column: CORTECS C18+, 2.1 x 50 mm, 2.7 μm; Gradient: 1% to 50% B in 1.4 min; 50 to 98% B in 0.3 min. 1.6.2 LCMS method AB-2Waters Acquity UPLC-MS system / MS (ESI): Eluent A: Water + 0.025% TFA; Eluent B: ACN + 0.025% TFA; Column temperature: 60 °C; Flow: 1.0 mL / min; Column: 10 ACQUITY UPLC BEH C18 Column 1.7 µm 2.1 x 100 mm; Gradient: 5% to 95% B in 5.56 min; 95% B for 1.66 min. 1.6.3 LCMS method AB-3Agilent 1260 HPLC system / MS (ESI): Eluent A: Water + 0.1% TFA; Eluent B: 15 ACN + 0.1% TFA; Column temperature: 40 °C; Flow: 1.2 mL / min; Column: Poroshell 120 EC-C18, 2.7 µm 4.6 x 50 mm; Gradient: 5% to 95% B in 5 min; 95% B for 2 min. 2Assembly of cyclic peptides (“A” Examples)2.1 Examples synthesized using Rink Amide resin R1 or R220 2.1.1 Synthesis of (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-acetamido-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl- 12-((5-hydroxy-1H-indol-3-yl)methyl)-15,21-bis(hydroxymethyl)-24-((6- hydroxypyridin-3-yl)methyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,30- nonaoxo-18-phenethyl-1,4,7,10,13,16,19,22,25-nonaazacyclotriacontane-3-25 carboxamide (Example A1) 209 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.1. Synthesis of Example A1 Step 1. A1-1 5 Step 1-1: The assembly of the linear peptide was done on the CEM Liberty Prime Synthesizer using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.5 M solution DMF, 1 mL, 5 eq.), DIC (2 M solution in DMF, 0.5 mL, 10 eq.), Oxyma Pure® (0.25 M solution in DMF, 2 mL, 5 eq.), addition by synthesizer. Fmoc removal was 10 performed using a solution of pyrrolidine (25% in DMF, 0.75 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 40 sec at 110 °C / Coupling: 1 x 2 min at 105 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 2 min at 105 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and 15 DCM (5x). The amino acids and coupling methods are summarized in Table 2.1. 210 763537: NIT-59597PC (PAT059597-FF) Table 2.1. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 5 Step 1-2: To the resin from Step 1-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (5 mL) and the resin was shaken at RT for 2 hr. The crude peptide was precipitated with cold diethyl ether (40 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried 10 at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: SunFire C18 OBD™ Prep Column, 100Å, 5 µm, 30 mm x 150 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A1-1 (28.5 mg, 16 µmol, 20% yield, TFA salt) as a white solid. LCMS Method AP-1, tR= 3.43 min, [M+H]+= 1480.7. 15 Step 2. Example A1 A1-1 (28.5 mg, 1 eq., 17.9 μmol TFA salt) was dissolved in DMF (3 mL). Then HATU (8.15 mg, 1.2 eq., 21.4 μmol), followed by DIPEA (6.93 mg, 9.3 μL, 3 eq., 53.6 μmol) were added. The reaction mixture was stirred at RT for 3 hr, then quenched with 20 ACN / water (1 / 1). The quenched reaction mixture was directly purified, and the product was isolated by preparative RP HPLC (Column: SunFire C18 OBD™ Prep Column, 100Å, 5 µm, 30 mm x 100 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were 211 763537: NIT-59597PC (PAT059597-FF) combined and lyophilized to afford Example A1 (5.3 mg, 3.4 µmol, 19% yield) as a white solid. LCMS Method AP-1, tR = 4.25 min, [M+H]+= 1462.7. The compounds in Table 2.2 were synthesized in analogy to Example A1. 5 Table 2.2. Examples synthesized in analogy to Example A1 (Scheme 2.1.1). 212 763537: NIT-59597PC (PAT059597-FF) 213 763537: NIT-59597PC (PAT059597-FF) 214 763537: NIT-59597PC (PAT059597-FF) 215 763537: NIT-59597PC (PAT059597-FF) 216 763537: NIT-59597PC (PAT059597-FF) 217 763537: NIT-59597PC (PAT059597-FF) 218 763537: NIT-59597PC (PAT059597-FF) 219 763537: NIT-59597PC (PAT059597-FF) 220 763537: NIT-59597PC (PAT059597-FF) 221 763537: NIT-59597PC (PAT059597-FF) 222 763537: NIT-59597PC (PAT059597-FF) 223 763537: NIT-59597PC (PAT059597-FF) 224 763537: NIT-59597PC (PAT059597-FF) A 2.1.2 Synthesis of (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-acetamido-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl- 12-((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-15,21-5 bis(hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,30-nonaoxo-18- phenethyl-1,4,7,10,13,16,19,22,25-nonaazacyclotriacontane-3-carboxamide (Example A25 (A25-2 disclosed as SEQ ID NO: 110 and A25 disclosed as SEQ ID NO: 6)) 225 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.2. Synthesis of Example A25 5 Step 1. A25-1 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 2.5 mL, 5 eq.), DIC (1 M solution in DMF, 1 mL, 10 eq.), Oxyma Pure® (1 M solution 10 in DMF + 0.1 M DIPEA, 0.5 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (5% in DMF, 4 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 4 min at 90 °C 226 763537: NIT-59597PC (PAT059597-FF) Method B Fmoc removal: 2 x 1 min at 90 °C / Coupling: 2 x 4 min at 90 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.3. 5 Table 2.3. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. Step 2. A25-2 10 Step 2-1: The resin from Step 1 (calculated with 100 µmol) was suspended with DCM (2 mL) and treated with phenylsilane (216 mg, 249 μL, 20 eq., 2 mmol). The suspension was shaken at RT for 10 min while purged with argon. A clear solution of Pd(PPh3)4 (11.56 mg, 0.1 eq., 10.0 μmol) in DCM (1 mL) was added at RT. The reaction was agitated with argon for 20 min. The resin was drained, washed with DMA (3x) and DCM (5x), and the procedure 15 was repeated twice. The resin was drained and washed with DMA (3x) and DCM (5x). Step 2-2: To the resin from Step 2-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (4 mL) and the resin was shaken at RT for 1 hr. The crude peptide was precipitated with cold diethyl ether / heptane (1 / 1) (45 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The product was washed with 20 another portion of cold diethyl ether / heptane (1 / 1) (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and 227 763537: NIT-59597PC (PAT059597-FF) eluent B: ACN). Pure fractions were combined and lyophilized to afford A25-2 (41 mg, 26 µmol, 25% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 3.63 min, [M+H]+= 1479.6. 5 Step 3. Example A25 A25-2 (41 mg, 1 eq., 26 μmol, TFA salt) was dissolved in DMF (4 mL). Then HATU (14.7 mg, 1.5 eq., 39 μmol), followed by DIPEA (9.98 mg, 13 μL, 3 eq., 77 μmol) were added. The reaction mixture was stirred at RT for 2 hr. The reaction mixture was directly purified, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide 10 CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A25 (8 mg, 5.2 µmol, 20% yield) as a white solid. LCMS Method AP-1, tR = 4.53 min, [M+H]+= 1461.7. The compounds in Table 2.4 were synthesized in analogy to Example A25. 15 Table 2.4. Examples synthesized in analogy to Example A25 (Scheme 2.1.2). 228 763537: NIT-59597PC (PAT059597-FF) 229 763537: NIT-59597PC (PAT059597-FF) 230 763537: NIT-59597PC (PAT059597-FF) 2.1.3 Synthesis of (6S,9S,12S,15S,18S,21S,24S,27S,30S)-12-((1H-indol-3-yl)methyl)-30-amino-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-9-cyclopropyl-15- ((5-hydroxy-1H-indol-3-yl)methyl)-27-(4-hydroxybenzyl)-18,24-5 bis(hydroxymethyl)-N,7,19,22-tetramethyl-3,8,11,14,17,20,23,26,29-nonaoxo-21- phenethyl-4,7,10,13,16,19,22,25,28-nonaaza-1(1,3)- benzenacyclohentriacontaphane-6-carboxamide TFA salt (Example A31) 231 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.3. Synthesis of Example A31 Step 1. A31-1 5 Step 1-1: The assembly of the linear peptide was done on the CEM Liberty Prime Synthesizer using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.5 M solution DMF, 1 mL, 5 eq.), DIC (2 M solution in DMF, 0.5 mL, 10 eq.), Oxyma Pure® (0.25 M solution in DMF, 2 mL, 5 eq.), addition by synthesizer. Fmoc removal was 10 performed using a solution of pyrrolidine (25% in DMF, 0.75 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 40 sec at 110 °C / Coupling: 1 x 2 min at 105 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 2 min at 105 °C Method C Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 105 °C 15 Method D Fmoc removal: 2 x 10 min at RT / Coupling: 1 x 2 min at 105 °C 232 763537: NIT-59597PC (PAT059597-FF) After the assembly of the linear peptide, the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.5. Table 2.5. 5aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. Step 1-2: To the resin from Step 1-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (5 mL) and the resin was shaken at RT for 2 hr. The crude peptide was 10 precipitated with cold diethyl ether (40 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent 15 A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A31-1 (43.9 mg, 25.3 µmol, 30% yield, TFA salt) as a white solid. LCMS Method AP- 1, tR= 4.98 min, [M+H]+= 1736.8. Step 2. Example A31 20 Step 2-1: A31-1 (24 mg, 1 eq., 19 μmol TFA salt) was dissolved in DMF (3 mL). Then HATU (7.4 mg, 1.5 eq., 19 μmol), followed by DIPEA (5 mg, 6.8 μL, 3 eq., 39 μmol) were added. The reaction mixture was stirred at RT for 2 hr. 233 763537: NIT-59597PC (PAT059597-FF) Step 2-2: The reaction mixture from Step 2-1 was directly treated with pyrrolidine (25 % in DMF) (92 mg, 110 μL, 25 eq., 320 μmol) and shaken at RT for 30 min, then quenched with ACN / water (1 / 1). The quenched reaction mixture was directly purified by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm 5 x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A31 (5.1 mg, 3 µmol, 23% yield, TFA salt) as a white solid. LCMS Method AP-1, tR= 3.93 min, [M+H]+= 1495.7. The compounds in Table 2.6 were synthesized in analogy to Example A31. 10 Table 2.6. Examples synthesized in analogy to Example A31 (Scheme 2.1.3). 234 763537: NIT-59597PC (PAT059597-FF) 235 763537: NIT-59597PC (PAT059597-FF) 2.1.4 Synthesis of (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-amino-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl-12- ((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-15,21- bis(hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,30-nonaoxo-18- 5 phenethyl-1,4,7,10,13,16,19,22,25-nonaazacyclotriacontane-3-carboxamide TFA salt (Example A35 (A35-2 disclosed as SEQ ID NO: 111 and A35 disclosed as SEQ ID NO: 12)) 10 Scheme 2.1.4. Synthesis of Example A35 Step 1. A35-1 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The 236 763537: NIT-59597PC (PAT059597-FF) couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 2.5 mL, 5 eq.), DIC (1 M solution in DMF, 1 mL, 10 eq.), Oxyma Pure® (1 M solution in DMF + 0.1 M DIPEA, 0.5 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (5% in DMF, 4 mL), addition by synthesizer. 5 The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 4 min at 90 °C Method B Fmoc removal: 2 x 1 min at 90 °C / Coupling: 2 x 4 min at 90 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.7. 10 Table 2.7. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 15 Step 2. A35-2 Step 2-1: The resin from Step 1 (calculated with 100 µmol) was suspended with DCM (5 mL). Then Pd(PPh3)4 (34.7 mg, 0.3 eq., 30 μmol) followed by 1,3-Dimethylbarbituric acid (78 mg, 5 eq., 500 mmol) were added. The reaction was agitated with argon for 16 hr. The resin was drained and washed with DCM (10x), DMF (5x) and DCM (5x). 20 Step 2-2: To the resin from Step 2-1 (calculated with 100 µmol) was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (4 mL) and the resin was shaken at RT for 3 hr. The crude peptide was precipitated with cold diethyl ether / heptane (1 / 1) (45 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether / heptane (1 / 1) (30 mL). The suspension was 237 763537: NIT-59597PC (PAT059597-FF) centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A35-2 (26 mg, 12 5 µmol, 12% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 4.65 min, [M+H]+= 1659.7. Step 3. Example A35 Step 3-1: A35-2 (13 mg, 1 eq., 7.33 μmol, TFA salt) was dissolved in DMF (1 mL). 10 Then HATU (4.18 mg, 1.5 eq., 10.99 μmol), followed by DIPEA (2.84 mg, 3.8 μL, 3 eq., 22 μmol) were added. The reaction mixture was stirred at RT for 16 hr. Step 3-2: The reaction mixture from Step 3-1 was directly treated with pyrrolidine (5 % in DMF) (300 μL, 25 eq., 182.7 μmol) and shaken at RT for 30 min, then quenched with ACN / water (1 / 1). The product was isolated by preparative RP HPLC (Column: XSelect® 15 Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and Eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A35 (4.3 mg, 2.58 µmol, 35% yield, TFA salt) as a white solid. LCMS Method AP- 1, tR= 3.78 min, [M+H]+= 1419.7. The compounds in Table 2.8 were synthesized in analogy to Example A35. 20 Table 2.8. Examples synthesized in analogy to Example A35 (Scheme 2.1.4). 238 763537: NIT-59597PC (PAT059597-FF) 239 763537: NIT-59597PC (PAT059597-FF) tR = 3.90 min [M+H]+= 1433.7 A39 (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-N-((S)-1- amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-27-(aminomethyl)-6- cyclopropyl-12-((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)- 15,21-bis(hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,30- nonaoxo-18-phenethyl-1,4,7,10,13,16,19,22,25-nonaazacyclotriacontane-3- 240 763537: NIT-59597PC (PAT059597-FF) 2.1.5 Synthesis of (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-acetamido-15-(4-acetamidobutyl)-N-((S)-1-(((S)-1-amino-6-azido-1-oxohexan-2- yl)amino)-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl-12-((5-hydroxy- 5 1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-21-(hydroxymethyl)-N,4,16,19- tetramethyl-5,8,11,14,17,20,23,26,31-nonaoxo-18-phenethyl- 1,4,7,10,13,16,19,22,25-nonaazacyclohentriacontane-3-carboxamide (Example A74) and (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-acetamido-15-(4-acetamidobutyl)-6-cyclopropyl-N-((S)-1-(((S)-1,6-diamino-1-10 oxohexan-2-yl)amino)-3-(4-fluorophenyl)-1-oxopropan-2-yl)-12-((5-hydroxy-1H- indol-3-yl)methyl)-24-(4-hydroxybenzyl)-21-(hydroxymethyl)-N,4,16,19- tetramethyl-5,8,11,14,17,20,23,26,31-nonaoxo-18-phenethyl- 1,4,7,10,13,16,19,22,25-nonaazacyclohentriacontane-3-carboxamide TFA salt (Example A40 (A40 disclosed as SEQ ID NO: 14)) 15 241 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.5. Synthesis of Example A74 and Example A40 Step 1. A40-1 5 Step 1-1: The assembly of the linear peptide was done on the CEM Liberty Prime Synthesizer using commercial Rink amide AM resin R2 (loading 0.63 mmol / g, 794 mg, 0.500 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.5 M solution DMF, 4 mL, 4 eq.), DIC (4 M solution in DMF, 1 mL, 8 eq.), Oxyma Pure® (0.25 M solution in DMF, 8 mL, 4 eq.), addition by synthesizer. Fmoc removal was 10 performed using a solution of pyrrolidine (25% in DMF, 2.5 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 110 °C / Coupling: 1 x 4 min at 105 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 105 °C 242 763537: NIT-59597PC (PAT059597-FF) After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.9. Table 2.9. 5aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. Step 1-2: To the resin from Step 1-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (20 mL) and the resin was shaken at RT for 3 hr. The crude peptide was 10 precipitated with cold heptane / MTBE (1 / 1) (180 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold heptane / MTBE (160 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm 15 x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A40-1 (194 mg, 93.0 μmol, 19% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 4.07 min, [M+H]+= 1731.0. Step 2. Example A7420 Step 2-1: A40-1 (194 mg, 1 eq., 0.105 mmol, TFA salt) was dissolved in DMF / DCM (1 / 10) (165 mL). Then 2,6-lutidine (281.7 mg, 305 μL, 25 eq., 2.629 mmol) was added. A 243 763537: NIT-59597PC (PAT059597-FF) solution of HATU (43.98 mg, 1.1 eq., 0.116 mmol) in DMF (1 mL) was added dropwise. The reaction mixture was stirred at RT for 1 hr, then concentrated at 30 °C in vacuo to remove the DCM and part of DMF. The residue was precipitated with cold MTBE (100 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with 5 another portion of cold MTBE (100 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A74 (93.5 mg, 0.054 mmol, 51%10 yield) as a white solid. LCMS Method AP-1, tR= 4.96 min, [M+H]+= 1713.8. Step 3. Example A40 Example A74 (127 mg, 1 eq., 74.14 μmol) (two batches of A74 synthesized through different campaigns were combined) was dissolved in DMF (2.00 mL), then TCEP (85.0 mg, 15 4 eq., 296.6 μmol, HCl salt) and DIPEA (57.5 mg, 77.5 μL, 6 eq., 444.8 μmol) were added. The reaction mixture was shaken at RT for 1.5 hr. The reaction mixture was precipitated with cold MTBE (40 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 20 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A40 (121.5 mg, 67 µmol, 90% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 3.98 min, [M+H]+= 1687.9. The compounds in Table 2.10 were synthesized in analogy to Example A40. 25 244 763537: NIT-59597PC (PAT059597-FF) Table 2.10. Examples synthesized in analogy to Example A40 (Scheme 2.1.5). 245 763537: NIT-59597PC (PAT059597-FF) Method AP-1 tR= 5.29 min A44 [M+H]+= 2242.2 (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-15-(4- acetamidobutyl)-N-((S)-1-(((S)-1-amino-6-azido-1-oxohexan-2-yl)amino)-3-(4- 246 763537: NIT-59597PC (PAT059597-FF) 247 763537: NIT-59597PC (PAT059597-FF) 248 763537: NIT-59597PC (PAT059597-FF) A (S ID 3 2.1.6 Synthesis of (6S,9S,12S,15S,18S,21S,24S,27S,30S)-12-((1H-indol-3-yl)methyl)-30-acetamido-18-(4-acetamidobutyl)-N-((S)-1-(((S)-1-amino-6-azido-1-oxohexan-2- yl)amino)-3-(4-fluorophenyl)-1-oxopropan-2-yl)-9-cyclopropyl-15-((5-hydroxy-5 1H-indol-3-yl)methyl)-27-(4-hydroxybenzyl)-24-(hydroxymethyl)-N,7,19,22- tetramethyl-3,8,11,14,17,20,23,26,29-nonaoxo-21-phenethyl-1-oxa- 4,7,10,13,16,19,22,25,28-nonaazacyclohentriacontane-6-carboxamide (Example A49 (A49-2 disclosed as SEQ ID NO: 112)) 249 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.6. Synthesis of Example A49 5 Step 1. A49-1 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer and by manual coupling using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 2.5 mL, 5 eq.), DIC (1 M solution in DMF, 1 mL, 10 eq.), Oxyma 10 Pure® (1 M solution in DMF + 0.1 M DIPEA, 0.5 mL, 5 eq.), addition by synthesizer. Fmoc 250 763537: NIT-59597PC (PAT059597-FF) removal was performed using a solution of pyrrolidine (5% in DMF, 4 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 2 min at 90 °C 5 Method B Fmoc removal: 2 x 1 min at 90 °C / Coupling: 2 x 2 min at 90 °C Fmoc deprotection (after Synthesis cycle 10) was performed using 5% pyrrolidine in DMF (4 mL), addition by synthesizer, 1 x 1 min at 90 °C. Method C (Manual Coupling) The resin was treated with a pre-activated solution of BB2 (63.8 mg, 1.5 eq., 150 10 µmol), HATU (68.4 mg, 1.8 eq., 180 µmol) and DIPEA (64.6 mg, 87.1 µL, 5 eq., 500 µmol) in DMF (4 mL) and mixed at RT for 16 hr. After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.11. 15 Table 2.11. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. Step 2. A49-2 Step 2-1: The resin from Step 1 (calculated with 100 µmol) was suspended with DCM 20 (3 mL) and treated with phenylsilane (216 mg, 248 μL, 20 eq., 2 mmol). The suspension was shaken at RT for 10 min while purged with argon. A clear solution of Pd(PPh3)4 (11.6 mg, 0.1 eq., 10.0 μmol) in DCM (1 mL) was added at RT. The reaction was agitated with argon 251 763537: NIT-59597PC (PAT059597-FF) for 30 min. The resin was drained, washed with DMA (3x) and DCM (5x), and the procedure was repeated twice. The resin was drained and washed with DMA (3x) and DCM (5x). Step 2-2: To the resin from Step 2-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (4 mL) and the resin was shaken at RT for 3 hr. The crude peptide was 5 precipitated with cold diethyl ether / heptane (1 / 1) (45 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether / heptane (1 / 1) (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, 10 OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A49-2 (33 mg, 15 µmol, 15% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 4.98 min, [M+H]+= 1913.9. 15 Step 3. A49-3 Step 3-1: A49-2 (33 mg, 1 eq., 16.28 μmol, TFA salt) was dissolved in DMF (8 mL). Then HATU (6.8 mg, 1.1 eq., 17.91 μmol), followed by DIPEA (16.83 mg, 22.7 μL, 8 eq., 130.2 μmol) were added. The reaction mixture was stirred at RT for 1 hr. Step 3-2: The reaction mixture from Step 3-1 was directly treated with pyrrolidine (5 20 % in DMF) (300 μL, 11 eq., 183 μmol) and shaken at RT for 30 min. The reaction mixture was directly purified and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A49-3 (13 mg, 5.6 µmol, 34% yield, TFA salt) as a white solid. LCMS Method AP-1, 25 tR = 4.32 min, [M+H]+= 1672.8. Step 4. Example A49 A49-3 (13 mg, 1 eq., 7.771 μmol, TFA salt) was dissolved in DMF (4.5 mL). Then HATU (4.4 mg, 1.5 eq., 11.66 μmol) and acetic acid (0.2 M in DMF) (50.51 μL, 1.3 eq., 10.1 30 μmol), followed by DIPEA (10.04 mg, 13.5 μL, 10 eq., 77.71 μmol) were added. The reaction mixture was stirred at RT for 1.5 hr. The reaction mixture was directly purified, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A49 (4.5 252 763537: NIT-59597PC (PAT059597-FF) mg, 2.2 µmol, 28% yield) as a white solid. LCMS Method AP-1, tR= 4.93 min, [M+H]+= 1715.8. 2.1.7 Synthesis of (3R,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-5 acetamido-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl- 12-((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-15,21- bis(hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,30-nonaoxo-18- phenethyl-1-thia-4,7,10,13,16,19,22,25,29-nonaazacyclohentriacontane-3- carboxamide (Example A50) 10 Scheme 2.1.7. Synthesis of Example A50 Step 1. A50-1 15 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer using Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 2.5 mL, 5 eq.), DIC (1 M solution in DMF, 1 mL, 10 eq.), Oxyma Pure® (1 M solution in DMF + 0.1 M DIPEA, 0.5 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a 20 solution of pyrrolidine (5% in DMF, 4 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. 253 763537: NIT-59597PC (PAT059597-FF) Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 4 min at 90 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 90 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.12. 5 Table 2.12. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 10 Step 2. Example A50 Step 2-1: The resin from Step 1 (calculated with 100 µmol) was suspended with DCM (4 mL) and treated with phenylsilane (216 mg, 248 μL, 20 eq., 2 mmol). The suspension was shaken at RT for 5 min while purged with argon. Then Pd(PPh3)4 (11.6 mg, 0.1 eq., 10.0 μmol) was added at RT. The reaction was agitated with argon at RT for 30 min. The reaction 15 was agitated with argon for 30 min. The resin was drained, washed with DMA (3x) and DCM (5x), and the procedure was repeated once. The resin was drained and washed with DMF (5x) and DCM (5x). Step 2-2: The resin from Step 2-1 was suspended with DMF (5 mL). Then chloroacetic acid (14.2 mg, 9 μL, 1.5 eq., 150 μmol), HATU (60.8 mg, 1.6 eq., 160 μmol) 20 and DIPEA (51.7 mg, 69.7 μL, 4 eq., 400 μmol) were added. The reaction mixture was stirred at RT for 3 hr. The resin was drained and washed with DMF (5x) and DCM (5x). Step 2-3: To the resin from Step 2-2 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (5 mL) and the resin was shaken at RT for 1.5 hr. The crude peptide was 254 763537: NIT-59597PC (PAT059597-FF) precipitated with cold diethyl ether (40 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo and purified by preparative RP HPLC 5 (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). The pure fraction was directly used for the next Step. Step 2-4: The product fraction from Step 2-3 was diluted with ACN / water (1 / 1) (20 mL) and DIPEA (38.8 mg, 52.3 μL, 3 eq., 300 μmol) was added. The reaction mixture was 10 stirred at RT for 1 hr, then directly lyophilized to afford the crude peptide. The product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A50 (10 mg, 5.8 µmol, 6% yield) as a white solid. LCMS Method AP-1, tR= 4.53 min, [M+H]+= 1493.5. 15 The compounds in Table 2.13 were synthesized in analogy to Example A50. 255 763537: NIT-59597PC (PAT059597-FF) Table 2.13. Examples synthesized in analogy to Example A50 (Scheme 2.1.7). 2.1.8 Synthesis of (3R,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-amino-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl-12- 5 ((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-15,21- bis(hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26-octaoxo-18- phenethyl-1-thia-4,7,10,13,16,19,22,25-octaazacyclohentriacont-29-yne-3- carboxamide TFA salt (Example A52) 10 256 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.8. Synthesis of Example A52 Step 1. A52-1 5 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer using Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 2.5 mL, 5 eq.), DIC (1 M solution in DMF, 1 mL, 10 eq.), Oxyma Pure® (1 M solution in DMF + 0.1 M DIPEA, 0.5 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a 10 solution of pyrrolidine (5% in DMF, 4 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 4 min at 90 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 90 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and 15 DCM (5x). The amino acids and coupling methods are summarized in Table 2.14. 257 763537: NIT-59597PC (PAT059597-FF) Table 2.14. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 5 Step 2. A52-2 Step 2-1: To the resin from Step 1 (calculated with 100 µmol) was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (5 mL) and the resin was shaken at RT for 2 hr. The crude peptide was precipitated with cold diethyl ether (40 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The product was washed with 10 another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo and purified by preparative RP HPLC (Column: SunFire C18 OBD™ Prep Column, 100Å, 5 µm, 30 mm x 100 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were directly used for the next Step. 15 Step 2-2: The combined product fractions from Step 2-1 were diluted with ACN / water (1 / 1) (10 mL) and Et3N (30.4 mg, 41.8 μL, 3 eq., 300 μmol) was added. The reaction mixture was stirred at RT for 1 hr, then directly lyophilized to afford the crude peptide. The product was isolated by preparative RP HPLC (Column: SunFire C18 OBD™ Prep Column, 100Å, 5 µm, 30 mm x 100 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were 20 combined and lyophilized to afford A52-2 (7.3 mg, 4.0 µmol, 4% yield) as a white solid. LCMS Method AP-1, tR = 5.97 min, [M+H]+= 1655.7. 258 763537: NIT-59597PC (PAT059597-FF) Step 3. Example A52 A52-2 (7.3 mg, 1 eq., 4.4 µmol) was dissolved in DMF (2 mL) and pyrrolidine (25 % in DMF) (31 mg, 36 μL, 25 eq., 110 μmol) was added. The reaction mixture was stirred at RT for 1.5 hr, then quenched with ACN / water (1 / 1). The quenched reaction mixture was directly 5 purified by preparative RP (Column: SunFire C18 OBD™ Prep Column, 100Å, 5 µm, 30 mm x 100 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A52 (3.3 mg, 2 µmol, 46% yield, TFA salt) as a white solid. LCMS Method AP-1, tR= 3.93 min, [M+H]+= 1432.6.10 2.1.9 Synthesis of (3R,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-amino-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-6-cyclopropyl-12- ((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-15,21- bis(hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,30-nonaoxo-18- phenethyl-1-thia-4,7,10,13,16,19,22,25,29-nonaazacyclohentriacontane-3-15 carboxamide TFA salt (Example A53) Scheme 2.1.9. Synthesis of Example A53 20 259 763537: NIT-59597PC (PAT059597-FF) Step 1. A53-1 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer using Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 2.5 mL, 5 5 eq.), DIC (1 M solution in DMF, 1 mL, 10 eq.), Oxyma Pure® (1 M solution in DMF + 0.1 M DIPEA, 0.5 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (5% in DMF, 4 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 4 min at 90 °C 10 Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 90 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.15. Table 2.15. 15aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. Step 2. Example A53 Step 2-1: The resin from Step 1 (calculated with 100 µmol) was suspended with DCM 20 (4 mL) and treated with phenylsilane (216 mg, 248 μL, 20 eq., 2 mmol). The suspension was shaken at RT for 5 min while purged with argon. Then Pd(PPh3)4 (11.6 mg, 0.1 eq., 10.0 μmol) was added at RT. The reaction was agitated with argon at RT for 30 min. The resin 260 763537: NIT-59597PC (PAT059597-FF) was drained, washed with DMF (3x) and DCM (3x), and the procedure was repeated once. The resin was drained and washed with DMF (5x) and DCM (5x). Step 2-2: The resin from Step 2-1 was suspended with DMF (5 mL). Then chloroacetic acid (14.2 mg, 9 μL, 1.5 eq., 150 μmol), HATU (60.8 mg, 1.6 eq., 160 μmol) 5 and DIPEA (51.7 mg, 69.7 μL, 4 eq., 400 μmol) were added. The reaction mixture was stirred at RT for 3 hr. The resin was drained and washed with DMF (5x) and DCM (5x). Step 2-3: To the resin from Step 2-2 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (5 mL) and the resin was shaken at RT for 1.5 hr. The crude peptide was precipitated with cold diethyl ether (40 mL) giving a precipitate. The suspension was 10 centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo and purified by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). The pure fraction was directly used for the 15 next Step. Step 2-4: The product fraction from Step 2-3 was diluted with ACN / water (1 / 1) (20 mL) and DIPEA (25.9 mg, 34.8 μL, 2 eq., 200 μmol) was added. The reaction mixture was stirred at RT for 1 hr, then directly lyophilized to afford the crude peptide. Step 2-5: The crude peptide from Step 2-4 was dissolved in DMF (2 mL) and 20 pyrrolidine (25 % in DMF) (90 mg, 100 μL, 3 eq., 300 μmol) was added. The reaction mixture was stirred at RT for 30 min, then quenched with ACN / water (1 / 1). The quenched reaction mixture was directly purified by preparative RP (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A53 (2.3 25 mg, 1.4 µmol, 1% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 3.84 min, [M+2H]2+= 726.3. 261 763537: NIT-59597PC (PAT059597-FF) 2.1.10 Synthesis of (4R,7S,10S,13S,16S,19S,22S,25S,28R)-10-((1H-indol-3-yl)methyl)-28-amino-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)-7-cyclopropyl-13- ((5-hydroxy-1H-indol-3-yl)methyl)-25-(4-hydroxybenzyl)-16,22- bis(hydroxymethyl)-N,5,17,20-tetramethyl-6,9,12,15,18,21,24,27-octaoxo-19- 5 phenethyl-1,2-dithia-5,8,11,14,17,20,23,26-octaazacyclononacosane-4- carboxamide TFA salt (Example A54 (A54-1 disclosed as SEQ ID NO: 113 and A54 disclosed as SEQ ID NO: 19)) 10 Scheme 2.1.10. Synthesis of Example A54 262 763537: NIT-59597PC (PAT059597-FF) Step 1. A54-1 Step 1-1: The assembly of the linear peptide was done on the CEM Liberty Prime Synthesizer using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.5 5 M solution DMF, 1 mL, 5 eq.), DIC (2 M solution in DMF, 0.5 mL, 10 eq.), Oxyma Pure® (0.25 M solution in DMF, 2 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (25% in DMF, 0.75 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 40 sec at 110 °C / Coupling: 1 x 2 min at 105 °C 10 Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 2 min at 105 °C Method C Fmoc removal: 1 x 40 sec at 110 °C / Coupling: 2 x 1 min at 105 °C Method D Fmoc removal: 2 x 10 min at RT / Coupling: 1 x 2 min at 105 °C After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.16. 15 Table 2.16. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 20 Step 1-2: To the resin from Step 1-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (5 mL) and the resin was shaken at RT for 1 hr. The crude peptide was precipitated with cold diethyl ether (35 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The cleavage procedure was 263 763537: NIT-59597PC (PAT059597-FF) repeated once. The combined crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: SunFire C18 OBD™ Prep Column, 100Å, 5 µm, 30 mm x 100 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A54-1 (20.1 mg, 14.1 µmol, 20% yield, TFA salt) as a 5 white solid. LCMS Method AP-1, tR = 4.01 min, [M+H]+= 1428.6. Step 2. Example A54 A54-1 (20.1 mg, 1 eq., 14.1 μmol TFA salt) was dissolved in DMSO / water (1 / 4) (7.5 mL). The reaction mixture was stirred at RT for 3 days. The reaction mixture was lyophilized 10 to afford the crude peptide and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A54 (6.2 mg, 3.7 µmol, 26% yield, TFA salt) as a white solid. LCMS Method AP-1, tR= 3.89 min, [M+H]+= 1426.6. 15 The compounds in Table 2.17 were synthesized in analogy to Example A54. Table 2.17. Examples synthesized in analogy to Example A54 (Scheme 2.1.10). 264 763537: NIT-59597PC (PAT059597-FF) 265 763537: NIT-59597PC (PAT059597-FF) 2.1.11 Synthesis of (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-15-(4-acetamidobutyl)-27-amino-N-((S)-1-amino-3-(4-fluorophenyl)-1-oxopropan-2-yl)- 6-cyclopropyl-12-((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-21- (hydroxymethyl)-N,4,16,19-tetramethyl-5,8,11,14,17,20,23,26,31-nonaoxo-18- 5 phenethyl-1,4,7,10,13,16,19,22,25-nonaazacyclohentriacontane-3-carboxamide TFA salt (Example A58) and (3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3- yl)methyl)-15-(4-acetamidobutyl)-N-((S)-1-amino-3-(4-fluorophenyl)-1- oxopropan-2-yl)-27-(1-amino-3,6,9,12,15,18,21,24,27,30-decaoxatritriacontan-33- amido)-6-cyclopropyl-12-((5-hydroxy-1H-indol-3-yl)methyl)-24-(4-10 hydroxybenzyl)-21-(hydroxymethyl)-N,4,16,19-tetramethyl- 5,8,11,14,17,20,23,26,31-nonaoxo-18-phenethyl-1,4,7,10,13,16,19,22,25- nonaazacyclohentriacontane-3-carboxamide TFA salt (Example A59) 266 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.11. Synthesis of Example A58 and Example A59 Step 1. Example A58 Step 1-1: The assembly of the linear peptide was done on the CEM Liberty Prime 5 Synthesizer and by manual coupling using commercial Rink amide resin R1 (loading 0.58 mmol / g, 172 mg, 0.100 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.5 M solution DMF, 1 mL, 5 eq.), DIC (2 M solution in DMF, 0.5 mL, 10 eq.), Oxyma Pure® (0.25 M solution in DMF, 2 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (25% in DMF, 0.75 mL), addition by 10 synthesizer. The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 40 sec at 110 °C / Coupling: 1 x 2 min at 105 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 2 min at 105 °C Fmoc deprotection (after Synthesis cycle 5) was performed using 25% pyrrolidine in 15 DMF (0.75 mL), addition by synthesizer, 1 x 40 sec at 110 °C. Method C (Manual coupling) The resin was treated with a pre-activated solution of Fmoc-L-N-Me-Lys(Ac)-OH (50.9 mg, 1.2 eq., 120 µmol), HATU (57.0 mg, 1.5 eq., 150 µmol) and DIPEA (38.8 mg, 52.3 µL, 3 eq., 300 µmol) in DMF (4 mL) and mixed at RT for 5 hr. 20 After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.18. 267 763537: NIT-59597PC (PAT059597-FF) Table 2.18. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 5 Step 1-2: To the resin from Step 1-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (3 mL) and the resin was shaken at RT for 1.5 hr. The crude peptide was precipitated with cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold diethyl ether (20 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried 10 at RT under vacuo. Step 1-3: The crude peptide from Step 1-2 (calculated with 100 µmol) was dissolved in DMF (3 mL). Then HATU (45.6 mg, 1.2 eq., 120 μmol), followed by DIPEA (51.7 mg, 69.7 μL, 4 eq., 400 μmol) were added. The reaction mixture was stirred at RT for 1 hr. Step 1-4: The reaction mixture from Step 1-3 was directly treated with pyrrolidine (25 15 % in DMF) (427 mg, 493 μL, 15 eq., 1500 μmol) and stirred at RT for 30 min, then quenched with ACN / water (1 / 1). The quenched reaction mixture was directly purified by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A58 (15.4 mg, 6.6 µmol, 6.6% yield, TFA salt) as a white 20 solid. LCMS Method AP-1, tR= 3.85 min, [M+H]+= 1516.7. Step 2. Example A59 Step 2-1 To a clear solution of Example A58 (15.4 mg, 1 eq., 9.44 μmol, TFA salt) and Fmoc-PEG10-OH (8.52 mg, 1.2 eq., 11.33 µmol) in DMF (3 mL) was added HATU (5.4268 763537: NIT-59597PC (PAT059597-FF) mg, 1.5 eq., 14.17 µmol) and DIPEA (4.88 mg, 6.6 µL, 4 eq., 37.77 µmol). The reaction mixture was stirred at RT for 2 hr. Step 2-2: The reaction mixture from Step 2-1 was directly treated with pyrrolidine (25% solution in DMF) (62 µL, 20 eq., 188.9 µmol) and stirred at RT for 25 min. The 5 reaction mixture was quenched with ACN / water (1 / 1). The quenched reaction mixture was directly purified, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A59 (6 mg, 2.4 µmol, 26% yield, TFA salt) as a white solid. LCMS Method AP-1, 10 tR= 4.14 min, [M+H]+= 2029.0. The following examples (for structures, see Table 2.19) were synthesized in analogy to Step 2 of Example A59: Example A76 was synthesized from Example A40. Example A77 was synthesized from Example A45. 15 269

[0026] )F F-795950T A P(C P7S95 M 95- CTLIN:735367.)11.1.2eme ehcmSa(N95elA p elm paxmEa / xer (- E u(-poteehftc9-3 lco4y mou)Sc alc2 rtp S72-l,y- ro6-te ytcaet S4S2m)l,ay -z-a291, aot S by1 r2a4c- 6 n-n1,on-go,Sla8 9 at4, 51 3- noN-2,n,S oca 5 ni a)l2r2tyh,9n1i,Sma-ettier1,mde211-ta y61zi,sS)Szaxo,31,e9,2htS4idrd06,S-0yh 1,n,yS9 4ss3,(- 7,(3((43142,1elp. )m o DI 4axN 6.7 3xA Q:E E .9ESO ( N 1.2elbaT

[0027] )F F-795950T A P(C P79595-TIN:735367 -o-di,9,m m6)l 1s31,A a,F72t3y-62e-co3-,3T ea- x lo2,di7 oi2ddn02-- i-,7ma)1S47,H1,xo23 1-4,3S- yx 1b,rac4)2l,yor 11 -3Sn d ,8-e1e y2h,ph-,5-lnaSo tn8r5(1o,u(-yhSlf2 teoc51-1mai,4-latrtn S(-ypn2134or eeph-o,S-lpyolc9l1c,y9, oyc 6c1aS6m,aSb -,9za3r 6-) ,an(acly4,NonD)77I 53A Q:E S O ( N 763537: NIT-59597PC (PAT059597-FF) 2.1.12 Synthesis of 3-(((3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-15-(4-acetamidobutyl)-6-cyclopropyl-3-(((S)-1-(((S)-1,6-diamino-1-oxohexan-2- yl)amino)-3-(4-fluorophenyl)-1-oxopropan-2-yl)(methyl)carbamoyl)-12-((5- hydroxy-1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-21-(hydroxymethyl)- 5 4,16,19-trimethyl-5,8,11,14,17,20,23,26,31-nonaoxo-18-phenethyl- 1,4,7,10,13,16,19,22,25-nonaazacyclohentriacontan-27-yl)amino)-3-oxopropanoic acid TFA salt (Example A60 (A60 disclosed as SEQ ID NO: 21)) 10 272 763537: NIT-59597PC (PAT059597-FF) Scheme 2.1.12. Synthesis of Example A60 5 273 763537: NIT-59597PC (PAT059597-FF) Step 1. A60-1 Step 1-1: The assembly of the linear peptide was done on the CEM Liberty Prime Synthesizer and by manual coupling using commercial Rink amide AM resin R2 (loading 0.63 mmol / g, 1.587 g, 1.000 mmol, SPPS performed in 2 batches of 0.500 mmol scale). The 5 couplings were carried out using the following solutions: Fmoc-amino acid (0.5 M solution DMF, 4 mL, 4 eq.), DIC (4 M solution in DMF, 1 mL, 8 eq.), Oxyma Pure® (0.25 M solution in DMF, 8 mL, 4 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (25% in DMF, 2.5 mL), addition by synthesizer. The amino acids were coupled with a set of different methods. 10 Method A Fmoc removal: 1 x 1 min at 110 °C / Coupling: 1 x 4 min at 105 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 105 °C Fmoc deprotection (after Synthesis cycle 10) was performed using 25% pyrrolidine in DMF (2.5 mL), addition by synthesizer, 1 x 1 min at 110 °C. Method C (Manual Coupling) 15 The resin was treated with a pre-activated solution of Fmoc-L-Homo-Glu(OtBu)-OH (659.3 mg, 1.5 eq., 1.5 mmol), HATU (608.4 mg, 1.6 eq., 1.6 mmol) and DIPEA (646.3 mg, 871 µL, 5 eq., 5.0 mmol) in DMF (20 mL) and mixed at RT for 2 hr. After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.20. 20 Table 2.20. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 274 763537: NIT-59597PC (PAT059597-FF) Step 1-2: To the resin from Step 1-1 was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (40 mL) and the resin was shaken at RT for 3.5 hr. The crude peptide was precipitated with cold heptane / MTBE (1 / 1) (450 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold 5 heptane / MTBE (400 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.08% NH4HCO3and eluent B: ACN). Pure fractions were combined and lyophilized to afford A60-1 (465 mg, 0.24 mmol, 24% yield, TFA salt) as a10 white solid. LCMS Method AP-1, tR= 4.98 min, [M+H]+= 1911.7. Step 2. A60-2 To a solution of A60-1 (465 mg, 1 eq., 0.243 mmol, TFA salt) in DMF / DCM (1 / 10) (320 mL) at RT was added 2,6-lutidine (651.8 mg, 705 μL, 25 eq., 6.083 mmol). A solution 15 of HATU (101.8 mg, 1.1 eq., 0.267 mmol) in DMF (1 mL) was then added dropwise. The reaction mixture was stirred at RT for 40 min and then concentrated at 35 °C in vacuo to remove the DCM and partially the DMF. The residue was precipitated with cold MTBE (100 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold MTBE (40 mL). The suspension was centrifuged, and the 20 solvent was decanted to afford the crude peptide. The product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A60-2 (298 mg, 0.16 mmol, 64% yield) as a white solid. LCMS Method AP-1, tR= 5.97 min, [M+H]+= 1893.9. 25 Step 3. A60-3 To a solution of A60-2 (101.0 mg, 1 eq., 53.35 µmol) in DMF (2 mL) was added pyrrolidine (25% solution in DMF) (151.8 mg, 175 µL, 10 eq., 533.5 µmol) and the reaction mixture was stirred at RT for 20 min. The reaction mixture was precipitated with cold MTBE 30 (45 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined 275 763537: NIT-59597PC (PAT059597-FF) and lyophilized to afford A60-3 (85.2 mg, 47 µmol, 89% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 4.21 min, [M+H]+= 1670.8. Step 4. A60-4 5 To a clear solution of A60-3 (85.2 mg, 1 eq., 47.73 μmol, TFA salt) at RT was added a solution of mono-tert-butyl malonate (CAS 40052-13-9, 11.47 mg, 11.0 µL, 1.5 eq., 71.60 µmol), HATU (23.59 mg, 1.3 eq., 62.05 µmol) and DIPEA (30.85 mg, 41.6 µL, 5 eq., 238.7 µmol) in DMF (0.5 mL) (pre-activated at RT for 5 min). The reaction mixture was stirred at RT for 16 hr. A solution of mono-tert-butyl malonate (CAS 40052-13-9, 114.7 mg, 110 µL,10 15 eq., 716 µmol), HATU (235.9 mg, 13 eq., 620.5 µmol) and DIPEA (123.4 mg, 166 µL, 20 eq., 954.7 µmol) in DMF (1.0 mL) (pre-activated at RT for 5 min) was then added and the reaction mixture was stirred at RT for another 2 hr. The reaction mixture was precipitated with cold MTBE (45 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was 15 isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford A60-4 (40 mg, 22 µmol, 46% yield) as a white solid. LCMS Method AP-1, tR= 5.41 min, [M+H]+= 1813.9. 20 Step 5. Example A60 Step 5-1: A60-4 (40.0 mg, 1 eq., 22.06 μmol) was dissolved in TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (1 mL) and stirred at RT for 1 hr. The reaction mixture was precipitated with cold heptane / MTBE (1 / 1) (45 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold heptane / MTBE (40 mL). The 25 suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo. Step 5-2: The crude peptide from Step 5-1 was dissolved in DMF (1.00 mL), thenTCEP (25.3 mg, 4 eq., 88.25 μmol, HCl salt) and DIPEA (17.11 mg, 23.1 μL, 6 eq., 132.4 μmol) were added. The reaction mixture was shaken at RT for 2 hr. The reaction mixture was 30 precipitated with cold heptane / MTBE (1 / 1) (45 mL). The suspension was centrifuged, and the solvent was decanted. The product was washed with another portion of cold heptane / MTBE (40 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 276 763537: NIT-59597PC (PAT059597-FF) mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A60 (16 mg, 8.5 µmol, 39% yield, TFA salt) as a white solid. LCMS Method AP-1, tR = 3.91 min, [M+H]+= 1731.8. 52.2 Examples synthesized using Lys-Wang resin R42.2.1 Synthesis of ((S)-2-((3S,6S,9S,12S,15S,18S,21S,24S,27S)-9-((1H-indol-3-yl)methyl)-27-acetamido-15-(4-acetamidobutyl)-6-cyclopropyl-12-((5-hydroxy- 1H-indol-3-yl)methyl)-24-(4-hydroxybenzyl)-21-(hydroxymethyl)-N,4,16,19- tetramethyl-5,8,11,14,17,20,23,26,31-nonaoxo-18-phenethyl-10 1,4,7,10,13,16,19,22,25-nonaazacyclohentriacontane-3-carboxamido)-3-(4- fluorophenyl)propanoyl)-L-lysine TFA salt (Example A61 (A61 disclosed as SEQ ID NO: 22)) 15 Scheme 2.2.1. Synthesis of Example A61 Step 1. A61-1 The assembly of the linear peptide was done on the CEM Liberty Prime Synthesizer and by manual coupling using commercial Fmoc-Lys(Boc) preloaded Wang resin R4 (loading 0.61 mmol / g, 164 mg, 0.100 mmol). The couplings were carried out using the 277 763537: NIT-59597PC (PAT059597-FF) following solutions: Fmoc-amino acid (0.5 M solution DMF, 1 mL, 5 eq.), DIC (2 M solution in DMF, 0.5 mL, 10 eq.), Oxyma Pure® (0.25 M solution in DMF, 2 mL, 5 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (25% in DMF, 0.75 mL), addition by synthesizer. 5 The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 40 sec at 110 °C / Coupling: 1 x 2 min at 105 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 2 min at 105 °C Method C Fmoc removal: 2 x 10 min at RT / Coupling: 1 x 2 min at 105 °C Fmoc deprotection (after Synthesis cycle 3) was performed using 25% pyrrolidine in 10 DMF (0.75 mL), addition by synthesizer, 1 x 40 sec at 110 °C. Method D (Manual coupling) The resin was treated with a pre-activated solution of Fmoc-L-CyclopropylGly-OH (37.1 mg, 1.1 eq., 110 µmol), HATU (57.0 mg, 1.5 eq., 150 µmol) and DIPEA (38.8 mg, 52.3 µL, 3 eq., 300 µmol) in DMF (4 mL) and mixed at RT for 4 hr. 15 After the assembly of the linear peptide the resin was washed with DMF (5x) and DCM (5x). The amino acids and coupling methods are summarized in Table 2.21. Table 2.21. aRefers to the corresponding amino acid residue of cyclic peptide, P, as found, e.g., in Formulae 20 (I), (Ia), (Ib), (Ic), (Id), or in the Table of Example III. 278 763537: NIT-59597PC (PAT059597-FF) Step 2. A61 Step 2-1: The resin from Step 1 (calculated with 100 µmol) was suspended with DCM (5 mL) and treated with phenylsilane (216 mg, 248 μL, 20 eq., 2 mmol). The suspension was shaken at RT for 5 min while purged with argon. Then Pd(PPh3)4(23.1 mg, 0.2 eq., 20.0 5 μmol) was added at RT. The reaction was agitated with argon at RT for 1.5 hr. The resin was drained and washed with DMF (3x) and DCM (5x). Step 2-2: The resin from Step 2-1 (calculated with 100 µmol) was suspended with DMF (10 mL). Then HATU (57 mg, 1.5 eq., 150 μmol), followed by DIPEA (38.8 mg, 52.3 μL, 3 eq., 300 μmol) were added. The reaction mixture was stirred at RT for 1 hr. The resin 10 was drained and washed with DMF (3x) and DCM (5x). Step 2-3: To the resin from Step 2-2 (calculated with 100 µmol) was added TFA / H2O / DODT / TIS (92.5 / 2.5 / 2.5 / 2.5) (4 mL) and the resin was shaken at RT for 2 hr. The crude peptide was precipitated with cold diethyl ether (40 mL) giving a precipitate. The suspension was centrifuged, and the solvent was decanted. The product was washed with 15 another portion of cold diethyl ether (30 mL). The suspension was centrifuged, and the solvent was decanted. The crude peptide was dried at RT under vacuo, and the product was isolated by preparative RP HPLC (Column: XSelect® Peptide CSH C18, OBD™ Prep Column, 130Å, 5 µm, 30 mm x 250 mm; Eluent A: H2O + 0.1% TFA and eluent B: ACN). Pure fractions were combined and lyophilized to afford Example A61 (10 mg, 2.4 µmol, 20 2.4% yield, TFA salt) as a white solid. LCMS Method AP-1, tR= 3.84 min, [M+H]+= 1687.8. 2.3 Examples synthesized using Sieber Rink Amide Resin R32.3.1 Synthesis of (3S,6S,9S,12S,15S,18S,21S,24S)-9-((1H-indol-3-yl)methyl)-15-(4-25 acetamidobutyl)-6-cyclopropyl-N-((S)-1-(((S)-1,6-diamino-1-oxohexan-2- yl)amino)-3-(4-fluorophenyl)-1-oxopropan-2-yl)-12-((5-hydroxy-1H-indol-3- yl)methyl)-24-(4-hydroxybenzyl)-21-(hydroxymethyl)-N,4,16,19-tetramethyl- 5,8,11,14,17,20,23,26,31-nonaoxo-18-phenethyl-1,4,7,10,13,16,19,22,25- nonaazacyclohentriacontane-3-carboxamide TFA salt (Example A62 (A6230 disclosed as SEQ ID NO: 23)) 279

[0028] A62-1

[0029] 1. Adipic acid-NHS ester, DIPEA

[0030] DMF, RT, 2 hr

[0031] 2. Pd(PPh3)4, PhSiH3DCM, RT, 2 hr

[0032] 3. 1% TFA in DCM, RT, 6 x 30 min

[0033] Step 2

[0034] A62-3 763537: NIT-59597PC (PAT059597-FF) Scheme 2.3.1. Synthesis of Example A62 Step 1. A62-1 The assembly of the linear peptide was done on the CEM Liberty Blue Synthesizer 5 using commercial Sieber Amide Resin R3 (loading 0.65 mmol / g, 385 mg, 0.250 mmol). The couplings were carried out using the following solutions: Fmoc-amino acid (0.2 M solution DMF, 5 mL, 4 eq.), DIC (1 M solution in DMF, 2 mL, 8 eq.), Oxyma Pure® (1 M solution in DMF + 0.1 M DIPEA, 1 mL, 4 eq.), addition by synthesizer. Fmoc removal was performed using a solution of pyrrolidine (5% in DMF, 10 mL), addition by synthesizer. 10 The amino acids were coupled with a set of different methods. Method A Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 4 min at 90 °C Method B Fmoc removal: 2 x 10 min at RT / Coupling: 2 x 4 min at 90 °C Method C Fmoc removal: 1 x 1 min at 90 °C / Coupling: 1 x 2 min at 90 °C Method D Fmoc removal: 1 x 10 min at RT / Coupling: 1 x 6 min at 50 °C 15 Fmoc deprotection (after Synthesis cycle 10) was performed using 5% pyrrolidine in DMF (10 mL), addition by synthesizer, 1 x 1 min at 90 °C. After the assembly of the linear peptide the resin was washed with DMF (...

Claims

1. 763537: NIT-59597PC (PAT059597-FF) CLAIMS 1. A compound, or a pharmaceutically acceptable salt or solvate thereof, comprising , wherein: R1ais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -N(H)- C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, - N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, -N(C1-6-alkyl)2, phenyl, and 5-6 membered heteroaryl of R1aare optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl-C(O)OH, - C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6-alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; 469 763537: NIT-59597PC (PAT059597-FF) selected from C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl of are optionally substituted with 1 or 2 substituents independently selected from halo, -OH, -NH2, and C1-6- alkyl; R1aais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -N(H)- C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, - N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, -N(C1-6-alkyl)2, phenyl, and 5-6 membered heteroaryl of R1aare optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl-C(O)OH, - C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6-alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, C(O)NC1-6-alkyl, NHC(O), N(C1-6-alkyl)C(O), O, and S; a is 1, 2, 3, or 4; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, 2, or 3; and *2 indicates the point of attachment to A2and *9 indicates the point of attachment to A9; A2is , wherein: R2ais selected from H and C1-6-alkyl; R2bis selected from H, C1-6-alkyl, and halo; R2cis selected from halo, C1-6-alkyl, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, phenyl, and 5-6 membered heteroaryl of R2care optionally 470 763537: NIT-59597PC (PAT059597-FF) substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, - C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6- alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; and *3 indicates the point of attachment to A3and *1 indicates the point of attachment to A1; A3is , wherein: R3ais selected from H and C1-6-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-phenyl, - C1-6-alkyl-N(H)-phenyl, -C1-6-alkyl-N(H)-C(O)-phenyl, -C1-6-alkyl-N(H)-C1-6-alkyl-phenyl, - C1-6-alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl- N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl- C(O)NH-C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-N(H)-phenyl, -C1-6-alkyl-N(H)-C(O)- phenyl, -C1-6-alkyl-N(H)-C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heterocycloalkyl), - C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl) of R3care optionally substituted with 1, 2, 3, 4, 5, or 6 substituents independently selected from - CN, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, - NHC(O)C1-6-alkyl, -OH, and -OC1-6-alkyl; and wherein *4 indicates the point of attachment to A4and *2 indicates the point of attachment to A2; A4is , wherein: 471 763537: NIT-59597PC (PAT059597-FF) R4ais selected from H, C1-6-alkyl, and -CH2-phenyl, wherein the C1-6-alkyl and -CH2- phenyl of R4aare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, -C1-6- alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)OH, and -C1-6-alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R4bare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -C(O)NH2, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -OC1-6- alkyl, and C1-6-alkyl; and wherein *5 indicates the point of attachment to A5and *3 indicates the point of attachment to A3; A5is , wherein: R5ais selected from H, C1-6-alkyl, and -CH2-phenyl, wherein the C1-6-alkyl and -CH2- phenyl of R5aare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R5bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5c, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl- C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R5cis selected from H, C1-6-alkyl, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -OH, -OC1-6- alkyl, C1-6-haloalkyl, C1-6-alkyl-C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; and wherein *6 indicates the point of attachment to A6and *4 indicates the point of attachment to A4; A6is 472 763537: NIT-59597PC (PAT059597-FF) , wherein: R6ais selected from H and C1-6-alkyl; R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 5-10 membered heteroaryl, wherein the C1-6-alkyl and 5-10 membered heteroaryl of R6care each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, -C(O)OH, -NH2, - NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, -OC(O)-C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), and -N(H)-C(O)-N(C1-6-alkyl)2; and wherein *5 indicates the point of attachment to A5and *7 indicates the point of attachment to A7; A7is , wherein: R7ais selected from H and C1-6-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 5-10 membered heteroaryl, wherein the C1-6-alkyl and 5-10 membered heteroaryl are each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, -C(O)OH, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)- C(O)-N(H)(C1-6-alkyl), and -N(H)-C(O)-N(C1-6-alkyl)2; and wherein *8 indicates the point of attachment to A8and *6 indicates the point of attachment to A6; A8is 473 763537: NIT-59597PC (PAT059597-FF) , wherein: R8ais selected from H and C1-6-alkyl; R8bis selected from H, C1-6-alkyl, C3-8-cycloalkyl, 5-7 membered heterocycloalkyl ring, and 5-10 membered heteroaryl, wherein the C1-6-alkyl, C3-8-cycloalkyl, 5-7 membered heterocycloalkyl ring, and 5-10 membered heteroaryl of R8bare optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, - C(O)OH, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, and -OC1-6-alkyl; and wherein *9 indicates the point of attachment to A9and *7 indicates the point of attachment to A7; A9is , wherein: Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; R9ais selected from H and C1-6-alkyl; d is 1, 2, or 3; and z’ and z’’ are each independently 0 or 1; and wherein *8 indicates the point of attachment to A8and *1 indicates the point of attachment to A1; and A10is , 474 763537: NIT-59597PC (PAT059597-FF) wherein: Y10is selected from OH and N(R10g)(R10h); R10a, R10c, R10e, R10g, and R10hare each independently selected from H and C1-6-alkyl; R10bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10i, -C1-6-alkyl-O-C(O)R10i, and -C1-6-alkyl-NH-C(O)R10i, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10bare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10aand R10b, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10j, -C1-6-alkyl-O-C(O)R10j, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10dare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10k, -C1-6-alkyl-O-C(O)R10k, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10eand R10f, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, C3-7cycloalkyl, 5-6 membered heteroaryl, and 3-7 membered heterocycloalkyl, wherein the C3-7 cycloalkyl, 5-6 membered heteroaryl, and 3-7 membered heterocycloalkyl of R10i, R10j, and R10kare each optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, C1-6-alkyl, - C(O)OH, -C(O)NH2, and C1-6-alkyl-C(O)NH2; e and f are each independently 0 or 1; and 475 763537: NIT-59597PC (PAT059597-FF) wherein *9 indicates the point of attachment to A9; and b) at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug, wherein at least one cyclized peptide conjugated to the at least one imaging agent, chelating agent, radionuclide, or cytotoxic drug via any one of A1-A10, optionally through a linker.

2. The compound of claim 1, or a pharmaceutically acceptable salt or solvate thereof, which is a compound of formula (I), (Ia), (Ib), or (Ic): or (Ic), or a pharmaceutically acceptable salt or solvate thereof, wherein: L1is, independently at each occurrence, a bond or a linker; M is, independently at each occurrence, an imaging agent, a chelating agent, or a radionuclide, wherein the chelating agent is optionally radiolabeled with a radionuclide; n is 1, 2, 3, or 4; and 476 763537: NIT-59597PC (PAT059597-FF) o is 1, 2, 3, or 4, wherein any of P, L1, or M are optionally substituted with an albumin binder, a biotin tag, or one or more polyethylene glycol (PEG) chains.

3. The compound of claim 1 or 2, or a pharmaceutically acceptable salt or solvate thereof, wherein the compound of formula (I) is a compound of formula (I-i): (I-i), or a pharmaceutically acceptable salt or solvate thereof, wherein: L1is, independently at each occurrence, selected from a bond and a linker; M is, independently at each occurrence, selected from an imaging agent, a chelating agent, and a radionuclide, wherein the chelating agent is optionally radiolabeled with a radionuclide; n is 1, 2, 3, or 4; and wherein any of A1-A10and L1are optionally substituted with an albumin binder or one or more PEG chains.

4. The compound of any one of claims 1-3, or a pharmaceutically acceptable salt or solvate, thereof, wherein: R1ais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, and –N(C1-6-alkyl)2 of R1aare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -C(O)NH2,-C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6- 477 763537: NIT-59597PC (PAT059597-FF) alkyl-C(O)OH, -C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6- alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; is selected from C3-8-cycloalkyl and phenyl, wherein the C3-8-cycloalkyl and phenyl of are optionally substituted with 1 or 2 substituents independently selected from C1-6-alkyl, halo, -OH, and -NH2; R1aais selected from H, C1-6-alkyl, -NH2, -NHC1-6-alkyl, and –N(C1-6-alkyl)2; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, NHC(O), O, and S; a is 1, 2, 3, or 4; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, 2, or 3; R2ais selected from H and C1-3-alkyl; R2bis selected from H, C1-6-alkyl, and halo; R2cis selected from C1-6-alkyl, phenyl, and 5-6 membered heteroaryl, wherein the phenyl and 5-6 membered heteroaryl of R2care optionally substituted with 1, 2, or 3,substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -NHC1-6-alkyl, – N(C1-6-alkyl)2, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; R3ais selected from H and C1-3-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl- N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6- alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), - C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl) of R3care optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -NHC(O)C1-6-alkyl, -OH, and -OC1-6-alkyl; 478 763537: NIT-59597PC (PAT059597-FF) R4ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R4ais optionally substituted with 1 or 2 substituents independently selected from -NH2, -NHC1-6-alkyl, –N(C1- 6-alkyl)2, -OH, and -OC1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, -C1-6- alkyl-pyridyl, -C1-7-alkyl-C(O)OH, and -C1-6-alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1- 6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, and -C1-6-alkyl-pyridyl, of R4bare optionally substituted with 1 or 2 substituents independently selected from halo, -C(O)NH2, -NH2, -NHC1-6-alkyl, – N(C1-6-alkyl)2, -OH, and -OC1-6-alkyl; R5ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R5ais optionally substituted with 1 or 2 substituents independently selected from -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R5bis selected from H, C1-6-alkyl, -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and - C1-6-alkyl-NH-C(O)R5c, wherein the C1-6-alkyl, -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1 or 2 substituents independently selected from -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R5cis selected from H, C1-6-alkyl, -NH2, -OH, -OC1-6-alkyl, C1-6-haloalkyl, C1-6-alkyl- C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; R6ais selected from H and C1-3-alkyl; R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 7-10 membered heteroaryl, wherein the C1-6-alkyl and 7-10 membered heteroaryl of R6care each optionally substituted with 1, 2, or 3 substituents independently selected from C1-6-alkyl, -CN, halo, -NH2, -NHC1-6-alkyl, –N(C1-6- alkyl)2, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl; R7ais selected from H and C1-3-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 7-10 membered heteroaryl, wherein the C1-6-alkyl and 7-10 membered heteroaryl are each optionally substituted with 1, 2, or 3 substituents independently selected from -CN, halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R8ais selected from H and C1-3-alkyl; R8bis selected from H, C1-6-alkyl, C3-6-cycloalkyl, 5-6 membered heteroaryl, wherein the C1-6-alkyl, C3-6-cycloalkyl and 5- 6 membered heteroaryl of R8bare optionally substituted with 1, 2, or 3 substituents independently selected from -CN, halo, -NH2, -NHC1-6-alkyl, – N(C1-6-alkyl)2, and -OH; Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; 479 763537: NIT-59597PC (PAT059597-FF) R9ais selected from H and C1-3-alkyl; d is 1, 2, or 3; z’ and z’’ are each independently 0 or 1; Y10is selected from OH and N(R10g)(R10h); R10a, R10c, and R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10i, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10bare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)OH, -C1-6-alkyl-C(O)OH, and -C(O)NH2; alternatively, R10aand R10b, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10dare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)OH, -C1-6-alkyl-C(O)OH, and -C(O)NH2; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, - N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl-C(O)OH, and -C(O)NH2; alternatively, R10eand R10f, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, 5- 6 membered heterocycloalkyl, and 5-6 membered heteroaryl, wherein the 5- 6 membered heterocycloalkyl, and 5- 6 membered heteroaryl of R10i, R10j, and R10kare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6- alkyl, -N(C1-6-alkyl)2, -N3, -OH, C1-6-alkyl, and C1-6-alkyl-C(O)OH; and e and f are each independently 0 or 1.

5. The compound of any one of claims 1-4, or a pharmaceutically acceptable salt or solvate thereof, wherein: 480 763537: NIT-59597PC (PAT059597-FF) R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, and – N(C1-6-alkyl)2 of R1aare optionally substituted with 1 or 2 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl- C(O)OH, -C(O)C1-6-alkyl-NH2, 5-membered heteroaryl, -OH, and -NH2; is selected from C5-7-cycloalkyl and phenyl, wherein the C5-7-cycloalkyl and phenyl of are optionally substituted with 1 substituent selected from C1-6-alkyl, halo, -OH, and -NH2; R1aais selected from H, C1-6-alkyl, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, NHC(O), O, and S; a is 1, 2, or 3; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, or 2; R2ais selected from H and C1-3-alkyl; R2bis selected from H, C1-6-alkyl, and halo; R2cis selected from C1-6-alkyl, phenyl, and 6-membered heteroaryl, wherein the phenyl and 6-membered heteroaryl of R2care optionally substituted with 1 or 2 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-NH2, - N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; R3ais selected from H and C1-3-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-(6- membered heterocycloalkyl), -C1-6-alkyl-N(H)-(6-membered heterocycloalkyl), -C1-6-alkyl- N(H)-C(O)-(6-membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(6-membered heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-(6-membered heterocycloalkyl), -C1-6-alkyl-N(H)-(6-membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)- (6-membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(6-membered heterocycloalkyl) of R3care optionally substituted with 12, 3, 4, or 5 substituents 481 763537: NIT-59597PC (PAT059597-FF) independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, -NHC(O)C1-6- alkyl, -OH, and -OC1-6-alkyl; R4ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R4ais optionally substituted with 1 substituent selected from -NH2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-pyridyl, and -C1-6- alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-pyridyl of R4bare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, - OH, and -OC1-6-alkyl; R5ais selected from H and C1-3-alkyl, wherein the C1-3-alkyl of R5ais optionally substituted with 1 substituent selected from -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R5bis selected from H, C1-6-alkyl, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH- C(O)R5c, wherein the C1-6-alkyl, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1 or 2 substituents independently selected from -NH2, - NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; R5cis selected from H, C1-6-alkyl, -NH2, -OH, -OC1-6-alkyl, C1-6-haloalkyl, C1-6-alkyl- C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; R6ais selected from H and C1-3-alkyl; R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 8-9 membered heteroaryl, wherein the C1-6-alkyl and 8-9 membered heteroaryl of R6care each optionally substituted with 1 or 2 substituents independently selected from C1-6-alkyl, -CN, halo, -NH2, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl; R7ais selected from H and C1-3-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 8-9 membered heteroaryl, wherein the C1-6-alkyl and 8-9 membered heteroaryl are each optionally substituted with 1 or 2 substituents independently selected from -CN, halo, -NH2, and -OH; R8ais selected from H and C1-3-alkyl; R8bis selected from H, C1-6-alkyl, and C3-6-cycloalkyl, wherein the C1-6-alkyl and C3-6-cycloalkyl of R8bare optionally substituted with 1 or 2 substituents independently selected from -CN, halo, -NH2, and -OH; Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; R9ais selected from H and C1-3-alkyl; d is 1 or 2; 482 763537: NIT-59597PC (PAT059597-FF) Y10is selected from OH and N(R10g)(R10h); R10a, R10c, and R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10bis selected from H, C1-3-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10i, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10bare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl and -C1-6-alkyl-phenyl of R10dare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, - C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, - N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, 6-membered heterocycloalkyl, and 6-membered heteroaryl, wherein the 6-membered heterocycloalkyl, and 6-membered heteroaryl of R10i, R10j, and R10kare each optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -OH, C1-6-alkyl, and C1-6-alkyl-C(O)OH; and e and f are each independently 0 or 1.

6. The compound of any one of claims 1-5, or a pharmaceutically acceptable salt or solvate thereof, wherein: A1is a moiety of formula (A1-I), formula (A1-II), formula (A1-III), or formula (A1- IV): (A1-I), 483 763537: NIT-59597PC (PAT059597-FF) (A1-IV).

7. The compound of any one of claims 1-6, or a pharmaceutically acceptable salt or solvate thereof, wherein A1is selected from: , , 484 763537: NIT-59597PC (PAT059597-FF) .

8. The compound of any one of claims 1-7, or a pharmaceutically acceptable salt or solvate thereof, wherein: A2is a moiety of formula (A2-I): (A2-I), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, and -NH2; and g is 0, 1, or 2. 485 763537: NIT-59597PC (PAT059597-FF) 9. The compound of any one of claims 1-8, or a pharmaceutically acceptable salt or solvate thereof, wherein A2is selected from:

10. The compound of any one of claims 1-9, or a pharmaceutically acceptable salt or solvate, thereof, wherein: A3is a moiety of formula (A3-I) or formula (A3-II): (A3-II), wherein: Y3is selected from a bond and NH; each Y3ais selected from NH and CH2, provided that at least one Y3ais NH; R3ais selected from H and C1-3-alkyl; each R3aais independently selected from -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, - NH2, -NHC(O)C1-6-alkyl, and -OC1-6-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, -C(O)NHC1-6-alkyl, and -OC1-6-alkyl, wherein the -C(O)NHC1-6-alkyl of R3abis optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo and -OH; 486 763537: NIT-59597PC (PAT059597-FF) h is 1, 2, 3, 4, 5, or 6; i is 0, 1, or 2; and j is 1, 2, 3, 4, 5, or 6.

11. The compound of any one of claims 1-10, or a pharmaceutically acceptable salt or solvate thereof, wherein A3is selected from:

12. The compound of any one of claims 1-11, or a pharmaceutically acceptable salt or solvate thereof, wherein: A4is a moiety of formula (A4-I) or formula (A4-II): (A4-I), 487 763537: NIT-59597PC (PAT059597-FF) or (A4-II), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; R4abis selected from H, halo, -NH2, -OH, -OC1-6-alkyl, and -O-phenyl; k is 1, 2, 3, 4, 5, or 6; l is 0, 1, or 2; and m is 1, 2, 3, 4, 5, or 6.

13. The compound of any one of claims 1-12, or a pharmaceutically acceptable salt or solvate thereof, wherein A4is selected from: , 488 763537: NIT-59597PC (PAT059597-FF) .

14. The compound of any one of claims 1-13, or a pharmaceutically acceptable salt or solvate thereof, wherein: A5is a moiety of formula (A5-I), formula (A5-II), or formula (A5-III): 489 763537: NIT-59597PC (PAT059597-FF) (A5-III), wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5aais selected from H, -OH, and -OC1-6-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; R5acis selected from H, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -OH; and p’ and q’ are each independently 1, 2, 3, 4, 5, or 6.

15. The compound of any one of claims 1-14, or a pharmaceutically acceptable salt or 16. The compound of any one of claims 1-15, or a pharmaceutically acceptable salt orsolvate thereof, wherein R6cis selected from C1-6-alkyl and 9-membered heteroaryl, wherein the C1-6-alkyl and 9-membered heteroaryl of R6care each optionally substituted with 1 or 2 substituents independently selected from C1-6-alkyl, -CN, halo, -NH2, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl. 490 763537: NIT-59597PC (PAT059597-FF) 17. The compound of claim 16, or a pharmaceutically acceptable salt or solvate thereof, wherein the 9-membered heteroaryl of R6cis a bicyclic 9-membered heteroaryl.

18. The compound of any one of claims 1-17, or a pharmaceutically acceptable salt or solvate thereof, wherein: A6is a moiety of formula (A6-I), formula (A6-II), or formula (A6-III): wherein: Y6is selected from NH and CH2; Y6aand Y6’are each independently selected from N and CH, provided that at least one of Y6and Y6ais selected from N and NH and provided that at least one of Y6’and Y6ais N; R6ais selected from H and C1-3-alkyl; each R6aais selected from C1-6-alkyl, -CN, halo, -NH2, -OH, -OC1-6-alkyl, and - OC(O)-C1-6-alkyl; and 491 763537: NIT-59597PC (PAT059597-FF) o’ and p are each independently 0, 1, or 2.

19. The compound of any one of claims 1-18, or a pharmaceutically acceptable salt or solvate thereof, wherein: A6is a moiety of formula (A6-Ia), formula (A6-IIa), or formula (A6-IIIa): (A6-IIIa) wherein: R6ais selected from H and C1-3-alkyl; each R6acis selected from C1-6-alkyl, halo, -OH, -OC1-6-alkyl, and -OC(O)-C1-6-alkyl; and o’ and p are each independently 0, 1, or 2.

20. The compound of any one of claims 1-19, or a pharmaceutically acceptable salt or solvate thereof, wherein A6is selected from: 492 763537: NIT-59597PC (PAT059597-FF) 21. The compound of any one of claims 1-20, or a pharmaceutically acceptable salt or solvate thereof, wherein R7cis selected from C1-6-alkyl and 9-membered heteroaryl, wherein the C1-6-alkyl and 9-membered heteroaryl of R7care each optionally substituted with 1 or 2 substituents independently selected from -CN, halo, -NH2, and -OH.

22. The compound of claim 21, or a pharmaceutically acceptable salt or solvate thereof, wherein the 9-membered heteroaryl of R7cis a bicyclic 9-membered heteroaryl.

23. The compound of any one of claims 1-22, or a pharmaceutically acceptable salt or solvate thereof, wherein: A7is a moiety of formula (A7-I) or formula (A7-II): (A7-I), or 493 763537: NIT-59597PC (PAT059597-FF) (A7-II), wherein: Y7is selected from NH and CH2; Y7aand Y7’are each independently selected from N and CH, provided that at least one of Y7and Y7ais selected from N and NH and provided that at least one of Y7’and Y7ais N; R7ais selected from H and C1-3-alkyl; each R7aais selected from C1-3-alkyl, -CN, halo, -NH2, and -OH; and q and r are each independently 0, 1, or 2.

24. The compound of any one of claims 1-23, or a pharmaceutically acceptable salt or solvate thereof, wherein: A7is a moiety of formula (A7-Ia) or formula (A7-IIa): (A7-IIa), wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from C1-3-alkyl, halo, -NH2, and -OH; and q and r are each independently 0, 1, or 2. 494 763537: NIT-59597PC (PAT059597-FF) 25. The compound of any one of claims 1-24, or a pharmaceutically acceptable salt or solvate thereof, wherein A7is selected from:

26. The compound of any one of claims 1-25, or a pharmaceutically acceptable salt or solvate thereof, wherein: A8is a moiety of formula (A8-I) or formula (A8-II): (A8-II), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; R8abis selected from H, -CN, halo, -NH2, and -OH; t is 1 or 2; u is 0, 1, or 2; and v is 0, 1, 2, 3, or 4. 495 763537: NIT-59597PC (PAT059597-FF) 27. The compound of any one of claims 1-26, or a pharmaceutically acceptable salt or solvate thereof, wherein A8is selected from: .

28. The compound of any one of claims 1-27, or a pharmaceutically acceptable salt or solvate thereof, wherein: A9is a moiety of formula (A9-I) or formula (A9-II): (A9-II), wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and d is 1 or 2. 496 763537: NIT-59597PC (PAT059597-FF) 29. The compound of any one of claims 1-28, or a pharmaceutically acceptable salt or solvate thereof, wherein A9is selected from: , 30. The compound of any one of claims 1-29, or a pharmaceutically acceptable salt or solvate thereof, wherein: A10is a moiety of formula (A10-I), formula (A10-II), formula (A10-III), or formula (A10-IV): 497 763537: NIT-59597PC (PAT059597-FF) (A10-IV).

31. The compound of any one of claims 1-30, or a pharmaceutically acceptable salt or solvate thereof, wherein: A10is a moiety of formula (A10-Ia) or formula (A10-Ib): or (A10-Ia), wherein: R10ais selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1- 6-alkyl; R10abis selected from H, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; w and y are each independently 1, 2, 3, 4, 5, or 6; and x is 0, 1, or 2.

32. The compound of any one of claims 1-31, or a pharmaceutically acceptable salt or solvate thereof, wherein: A10is a moiety of formula (A10-IIa), formula (A10-IIb), or formula (A10-IIc): 498 763537: NIT-59597PC (PAT059597-FF) (A10-IIc), wherein: each Y10ais independently selected from N, NH, and CH2, provided that at least one Y10ais selected from N and NH; R10aand R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10fis selected from H and C1-6-alkyl, wherein the C1-6-alkyl of R10fis optionally substituted with 1 or 2 substituents independently selected from halo, -NH2, -N3, -OH, and - OC1-6-alkyl; 499 763537: NIT-59597PC (PAT059597-FF) R10aa, R10ab, and R10acare each independently selected from C1-6-alkyl, halo, -NH2, - N3, -OH, and -OC1-6-alkyl; each R10adis independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, -OC1-6- alkyl, -C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; y, y’, y’’, and y’’’ are each independently 0, 1, or 2; and z, z’, z’’, and z’’’ are each independently 1, 2, 3, 4, 5, or 6.

33. The compound of any one of claims 1-32, or a pharmaceutically acceptable salt or solvate thereof, wherein: A10is a moiety of formula (A10-IIIa): (A10-IIIa), wherein: R10ais selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10aais selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; a’ is 0, 1, or 2; and b’ is 1, 2, 3, 4, 5, or 6.

34. The compound of any one of claims 1-33, or a pharmaceutically acceptable salt or solvate thereof, wherein: A10is a moiety of formula (A10-IVa): 500 763537: NIT-59597PC (PAT059597-FF) (A10-IVa), wherein: each Y10bis independently selected from N, NH, and CH2, provided that at least one Y10bis selected from N and NH; R10a, R10c, and R10eare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; R10aais selected from C1-6-alkyl, halo, -NH2, -N3, -OH, -OC1-6-alkyl; each R10adis independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, -OC1-6- alkyl, -C(O)NH2, -C(O)OH, and -C1-6-alkyl-C(O)OH; R10aeis selected from H, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; c’ and f’ are each independently 0, 1, or 2; and d’, e’, and v’ are each independently 1, 2, 3, 4, 5, or 6.

35. The compound of any one of claims 1-34, or a pharmaceutically acceptable salt or solvate thereof, wherein A10is selected from: 501 763537: NIT-59597PC (PAT059597-FF) 502 763537: NIT-59597PC (PAT059597-FF) 36. The compound of any one of claims 2-35, or a pharmaceutically acceptable salt or solvate thereof, wherein the compound is a compound of formula (I).

37. The compound of any one of claims 2-36, or a pharmaceutically acceptable salt or solvate thereof, wherein at least one L1is bound to any –NH2 or any C(O) of the cyclized peptide.

38. The compound of any one of claims 2-37, or a pharmaceutically acceptable salt or solvate thereof, wherein at least one L1is bound to any –NH2 or C(O) of A1, A3, or A10.

39. The compound of any one of claims 2-38, or a pharmaceutically acceptable salt or solvate thereof, wherein at least one L1is bound to any –NH2 or any C(O) of A1or A10.

40. The compound of any one of claims 2-39, or a pharmaceutically acceptable salt or solvate thereof, wherein: L1is a linker of formula (L1-I) or formula (L1-II): (L1-II), wherein: XLis selected from CH2, N(RL), and O; YLis selected from H, -OH, -OC1-6-alkyl, and -N(RL)2; each RLis independently selected from H and C1-6-alkyl; h’ and j’ are each independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; g’ and k’ are each independently 0, 1, 2, 3, or 4; i’ is 0, 1, 2, 3, 4, 5, or 6; and 503 763537: NIT-59597PC (PAT059597-FF) wherein *P indicates the point of attachment to a C(O) on A1or A10and **P indicates the point of attachment to a –NH2 on A1or A10.

41. The compound of any one of claims 2-40, or a pharmaceutically acceptable salt or solvate thereof, wherein A10and L1, together, have the structure: .

42. The compound of any one of claims 2-41, or a pharmaceutically acceptable salt or solvate thereof, wherein A10and L1, together, have the structure: , wherein: l’ is 1, 2, 3, 4, 5, or 6.

43. The compound of any one of claims 2-42, or a pharmaceutically acceptable salt or solvate thereof, wherein A1and L1, together, have the structure: 504 763537: NIT-59597PC (PAT059597-FF) .

44. The compound of any one of claims 2-43, or a pharmaceutically acceptable salt or solvate thereof, wherein M is a cyclic chelating agent.

45. The compound of any one of claims 2-44, or a pharmaceutically acceptable salt or solvate thereof, wherein M is a cyclic chelating agent selected from: , 505 763537: NIT-59597PC (PAT059597-FF) , wherein *L1indicates the point of attachment to L1and wherein the cyclic chelating agent is optionally radiolabeled with a radionuclide.

46. The compound of any one of claims 2-45, or a pharmaceutically acceptable salt or solvate thereof, wherein M is a cyclic chelating agent selected from: 506 763537: NIT-59597PC (PAT059597-FF) , wherein *L1indicates the point of attachment to L1and wherein the cyclic chelating agent is optionally radiolabeled with a radionuclide.

47. The compound of any one of claims 2-39, or a pharmaceutically acceptable salt or solvate thereof, wherein L1is a bond.

48. The compound of any one of claims 2-39 and 47, or a pharmaceutically acceptable salt or solvate thereof, wherein L1is a bond, and wherein A1, L1, and M, together, have the structure: , wherein M is optionally radiolabeled with a radionuclide. 507 763537: NIT-59597PC (PAT059597-FF) 49. The compound of any one of claims 2-46, or a pharmaceutically acceptable salt or solvate thereof, wherein L1is a linker of formula (L1-II), and A1, L1, and M, together, have the structure: , wherein M is optionally radiolabeled with a radionuclide.

50. The compound of any one of claims 2-39 and 47, or a pharmaceutically acceptable salt or solvate thereof, wherein L1is a bond, and A10, L1, and M, together, have the structure: , wherein: R10mis selected from H and C1-3-alkyl; and 508 763537: NIT-59597PC (PAT059597-FF) m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide.

51. The compound of any one of claims 2-50, or a pharmaceutically acceptable salt or solvate thereof, wherein the compound of formula (I) is optionally substituted with one PEG chain.

52. The compound of claim 51, or a pharmaceutically acceptable salt or solvate thereof, wherein the PEG chain is bound to A1.

53. The compound of any one of claims 2-52, or a pharmaceutically acceptable salt or solvate thereof, wherein the compound has a structure of formula (I), wherein: A1is substituted with a PEG chain, wherein A1and the PEG chain, together, have the structure of formula (A1-P): (A1-P), wherein: XPis selected from CH2, N(RP), and O; YPis selected from H, -OH, -OC1-6-alkyl, and -N(RP)2; each RPis independently selected from H and C1-6-alkyl; a is 1, 2, or 3; n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; and r’ is 0, 1, 2, 3, or 4; A2is a moiety of formula (A2-I): 509 763537: NIT-59597PC (PAT059597-FF) wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2; A3is a moiety of formula (A3-II): (A3-II), wherein: R3ais selected from H and C1-3-alkyl; R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; and j is 1, 2, 3, 4, 5, or 6; A4is a moiety of formula (A4-I): (A4-I), wherein: 510 763537: NIT-59597PC (PAT059597-FF) each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; k is 1, 2, 3, 4, 5, or 6; and l is 0, 1, or 2; A5is a moiety of formula (A5-II): (A5-II), wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2and -OH; p’ is 1, 2, 3, 4, 5, or 6; A6is a moiety of formula (A6-Ia): (A6-Ia), wherein: R6ais selected from H and C1-3-alkyl; R6acis selected from H, C1-6-alkyl, and -C(O)-C1-6-alkyl; and o’ is 0, 1, or 2; A7is a moiety of formula (A7-Ia): 511 763537: NIT-59597PC (PAT059597-FF) (A7-Ia), wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from halo, -NH2, and -OH; and q is 0, 1, or 2; A8is a moiety of formula (A8-I): (A8-I), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; t is 1 or 2; and u is 0, 1, or 2; A9is a moiety of formula (A9-I): (A9-I), wherein: 512 763537: NIT-59597PC (PAT059597-FF) Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and A10, L1, and M, together, have the structure: , wherein: R10a, R10e, and R10mare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide.

54. The compound of claim 53, or a pharmaceutically acceptable salt or solvate thereof, wherein XPis O; YPis -OC1-6-alkyl; and n’ is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

55. The compound of any one of claims 2-51, or a pharmaceutically acceptable salt or solvate thereof, wherein the compound has a structure of formula (I), wherein: A1is a moiety of formula (A1-I): 513 763537: NIT-59597PC (PAT059597-FF) (A1-I), wherein: R1ais selected from H, C1-6-alkyl, halo, -NH2, -N(H)-C(O)-(C1-6-alkyl), -NHC1-6- alkyl, and –N(C1-6-alkyl)2, wherein the C1-6-alkyl and -N(H)-C(O)-C1-6-alkyl of R1aare optionally substituted with 1 substituent selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6- alkyl, -C(O)C1-6-alkyl-OH, and 5-membered heteroaryl; and a is 1, 2, or 3; A2is a moiety of formula (A2-I): (A2-I), wherein: each Y2is independently selected from N and CH; R2ais selected from H and C1-3-alkyl; each R2aais independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -OH, and -NH2; and g is 0, 1, or 2; A3is a moiety of formula (A3-II): (A3-II), wherein: R3ais selected from H and C1-3-alkyl; 514 763537: NIT-59597PC (PAT059597-FF) R3abis selected from H, -OH, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, -NH2, - NHC(O)C1-6-alkyl, and -OC1-6-alkyl; and j is 1, 2, 3, 4, 5, or 6; A4is a moiety of formula (A4-I): (A4-I), wherein: each Y4is independently selected from N and CH; R4ais selected from H and C1-3-alkyl; each R4aais independently selected from C1-6-alkyl, halo, -NH2, -OH, and -OC1-6- alkyl; k is 1, 2, 3, 4, 5, or 6; and l is 0, 1, or 2; A5is a moiety of formula (A5-II): (A5-II), wherein: Y5is selected from O and NH; R5ais selected from H and C1-3-alkyl; R5abis selected from H, C1-6-alkyl, -NH2, -OH, and C1-6-haloalkyl, wherein the C1-6- alkyl of R5abis optionally substituted with 1 substituent independently selected from -NH2 and -OH; p’ is 1, 2, 3, 4, 5, or 6; A6is a moiety of formula (A6-Ia): 515 763537: NIT-59597PC (PAT059597-FF) wherein: R6ais selected from H and C1-3-alkyl; R6acis selected from OH, C1-6-alkyl, and -C(O)-C1-6-alkyl; and o’ is 0, 1, or 2; A7is a moiety of formula (A7-Ia): wherein: R7ais selected from H and C1-3-alkyl; each R7aais selected from -CN, halo, -NH2, and -OH; and q is 0, 1, or 2; A8is a moiety of formula (A8-I): (A8-I), wherein: R8ais selected from H and C1-3-alkyl; R8aais selected from -CN, halo, -NH2, and -OH; t is 1 or 2; and 516 763537: NIT-59597PC (PAT059597-FF) u is 0, 1, or 2; A9is a moiety of formula (A9-I): (A9-I), wherein: Y9is selected from C(O), NH, NC1-6-alkyl, and S; R9ais selected from H and C1-3-alkyl; and s’ is 1 or 2; and A10, L1, and M, together, have the structure: , wherein: R10a, R10e, and R10mare each independently selected from H and C1-3-alkyl; R10gand R10hare each independently selected from H and C1-6-alkyl; each R10aais independently selected from C1-6-alkyl, halo, -NH2, -N3, -OH, and -OC1-6-alkyl; y is 0, 1, or 2; z is 1, 2, 3, 4, 5, or 6; and 517 763537: NIT-59597PC (PAT059597-FF) m’ is 1, 2, 3, 4, 5, or 6, wherein M is optionally radiolabeled with a radionuclide.

56. A compound which is: (SEQ ID NO: 36), or a pharmaceutically acceptable salt or solvate thereof, which is optionally radiolabeled with a radionuclide. 518 763537: NIT-59597PC (PAT059597-FF) (SEQ ID NO: 37), or a pharmaceutically acceptable salt or solvate thereof, which is optionally radiolabeled with a radionuclide.

58. A compound of any one of claims 1-57 which is radiolabeled with a radionuclide.

59. A compound as selected from B1-B8, C1-C30, D1-D6, E1-E3, F1-F4, and G1, or a pharmaceutically acceptable salt or solvate thereof, which is optionally radiolabeled with a radionuclide.

60. The compound of claim 58 or 59, wherein the radionuclide is selected from111In,99mTc,94mTc,66Ga,67Ga,68Ga,52Fe,169Er,72As,97Ru,203Pb,61Cu,62Cu,64Cu,67Cu,89Sr,186Re,188Re,86Y,90Y,89Zr,51Cr,52Mn,51Mn,177Lu,169Yb,175Yb,105Rh,166Dy,166Dy,166Ho,153Sm,149Pm,151Pm,172Tm,121Sn,117mSn,212Bi,213Bi,142Pr,143Pr,198Au,199Au,123I,124I,125I,131I,75Br,76Br,77Br,80Br,82Br,18F,149Tb,152Tb,155Tb,161Tb,43Sc,44Sc,47Sc,212Pb,211At,223Ra,227Th,226Th,82Rb,32P,76As,89Zr,111Ag,165Er,225Ac, and227Ac.

61. A pharmaceutical composition comprising a compound of any one of claims 1-60, or a pharmaceutically acceptable salt or solvate thereof, and one or more pharmaceutically acceptable carriers.

62. A pharmaceutical composition comprising a compound of any one of claims 1-60, or a pharmaceutically acceptable salt or solvate thereof, and one or more pharmaceutically acceptable stabilizers.

63. A combination comprising a compound according to any one of claims 1-60, or a pharmaceutically acceptable salt or solvate thereof, and one or more therapeutically active agents.

64. A compound according to any one of claims 1-60, or a pharmaceutically acceptable salt or solvate thereof, for use as an imaging agent. 519 763537: NIT-59597PC (PAT059597-FF) 65. A method of imaging cancer in a subject, comprising administering to the subject a compound according to any one of claims 1-60, or a pharmaceutically acceptable salt or solvate thereof, or a pharmaceutical composition according to claim 60 or 61.

66. A compound according to any one of claims 1-59, or a pharmaceutically acceptable salt or solvate thereof, for use in the treatment of cancer in a subject.

67. Use of a compound according to any one of claims 1-59, or a pharmaceutically acceptable salt or solvate thereof, in the manufacture of a medicament for the treatment of cancer in a subject.

68. A method of treating cancer in a subject, comprising administering to the subject a therapeutically effective amount of a compound according to any one of claims 1-59 or a pharmaceutical composition according to claim 61 or 62.

69. The compound of claim 66, the use of claim 67, or the method of claim 68, wherein the cancer is selected from biliary tract cancer, bladder cancer (including, e.g., urothelial carcinoma), brain cancer (including, e.g., glioblastoma and brain metastases from another cancer type), breast cancer (including, e.g., triple-negative breast cancer (TNBC), HER2- positive breast cancer, and HR+ breast cancer), cervical cancer, cholangiocarcinoma, colorectal cancer, endocrine cancer, endometrial cancer, epithelial cancer, esophageal cancer (including, e.g., gastroesophageal junction cancer, which can also be referred to as gastroesophageal junction adenocarcinoma) gastric cancer, head and / or neck cancer, hepatocellular carcinoma, lung cancer (including, e.g., non-small cell lung cancer (NSCLC)), melanoma, mesothelioma, nasopharyngeal cancer, neuroendocrine tumor, ovarian cancer, pancreatic cancer (including, e.g., pancreatic ductal adenocarcinoma (PDAC)), prostate cancer, rectal cancer, salivary gland cancer, sarcoma, small intestine cancer, testicular cancer, thyroid cancer, and / or uterine cancer..

70. The compound of claim 66, the use of claim 67, or the method of claim 68, wherein the cancer is breast cancer, gastric cancer, non-small cell lung cancer, bladder cancer, or gastroesophageal junction cancer. 520 763537: NIT-59597PC (PAT059597-FF) 71. The compound of claim 66, 69 or 70, the use of claim 67, 69, or 70, or the method of claim 68, 69, or 70, wherein the cancer expresses human epidermal growth factor receptor 2 (HER2).

72. The method of any one of claims 65 and 68-71, further comprising administering to the subject an additional therapeutic agent.

73. A cyclized peptide (P): , or a pharmaceutically acceptable salt or solvate thereof, wherein: A1is , wherein: R1ais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -N(H)- C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, - N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, -N(C1-6-alkyl)2, phenyl, and 5-6 membered heteroaryl of R1aare optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl-C(O)OH, - C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6-alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; 521 763537: NIT-59597PC (PAT059597-FF) selected from C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl of are optionally substituted with 1 or 2 substituents independently selected from halo, -OH, -NH2, and C1-6- alkyl; R1aais selected from H, C1-6-alkyl, OH, halo, -NH2, -N(H)-C(O)-C1-6-alkyl, -N(H)- C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, - N(H)-C(O)-C1-6-alkyl, -NHC1-6-alkyl, -N(C1-6-alkyl)2, phenyl, and 5-6 membered heteroaryl of R1aare optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, -C(O)OH, -C(O)C1-6-alkyl, -C(O)C1-6-alkyl-OH, -C(O)C1-6-alkyl-C(O)OH, - C(O)C1-6-alkyl-NH2, -C(O)C1-6-alkyl-NHC1-6-alkyl, -C(O)C1-6-alkyl-N(C1-6-alkyl)2, 5-6 membered heteroaryl, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; Y1is selected from a bond, C≡C, NH, NC1-6-alkyl, O, and S; Y1ais selected from C(O), NH, NC1-6-alkyl, C(O)NH, C(O)NC1-6-alkyl, NHC(O), N(C1-6-alkyl)C(O), O, and S; a is 1, 2, 3, or 4; b, c, t’, and x’ are each independently 0 or 1; u’ is 0, 1, 2, or 3; and *2 indicates the point of attachment to A2and *9 indicates the point of attachment to A9; A2is , wherein: R2ais selected from H and C1-6-alkyl; R2bis selected from H, C1-6-alkyl, and halo; R2cis selected from halo, C1-6-alkyl, C3-8-cycloalkyl, phenyl, and 5-6 membered heteroaryl, wherein the C1-6-alkyl, phenyl, and 5-6 membered heteroaryl of R2care optionally 522 763537: NIT-59597PC (PAT059597-FF) substituted with 1, 2, 3, or 4 substituents independently selected from halo, -C(O)NH2, - C(O)OH, -C(O)C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6- alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -NHC1-6-alkyl, –N(C1-6-alkyl)2, and -NH2; R2dis selected from H, C1-6-alkyl, and halo; and *3 indicates the point of attachment to A3and *1 indicates the point of attachment to A1; A3is , wherein: R3ais selected from H and C1-6-alkyl; R3bis selected from H and C1-6-alkyl; R3cis selected from C1-6-alkyl, -C1-6-alkyl-C(O)NH-C1-6-alkyl, -C1-6-alkyl-phenyl, - C1-6-alkyl-N(H)-phenyl, -C1-6-alkyl-N(H)-C(O)-phenyl, -C1-6-alkyl-N(H)-C1-6-alkyl-phenyl, - C1-6-alkyl-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl- N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl), wherein the C1-6-alkyl, -C1-6-alkyl- C(O)NH-C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-N(H)-phenyl, -C1-6-alkyl-N(H)-C(O)- phenyl, -C1-6-alkyl-N(H)-C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heterocycloalkyl), - C1-6-alkyl-N(H)-(5-6 membered heterocycloalkyl), -C1-6-alkyl-N(H)-C(O)-(5-6 membered heterocycloalkyl), and -C1-6-alkyl-N(H)-C1-6-alkyl-(5-6 membered heterocycloalkyl) of R3care optionally substituted with 1, 2, 3, 4, 5, or 6 substituents independently selected from - CN, -C(O)OH, -C1-6-alkyl-C(O)OH, -C(O)NH2, halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, - NHC(O)C1-6-alkyl, -OH, and -OC1-6-alkyl; and wherein *4 indicates the point of attachment to A4and *2 indicates the point of attachment to A2; A4is , wherein: 523 763537: NIT-59597PC (PAT059597-FF) R4ais selected from H, C1-6-alkyl, and -CH2-phenyl, wherein the C1-6-alkyl and -CH2- phenyl of R4aare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R4bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, -C1-6- alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)OH, and -C1-6-alkyl-NH-C(O)OH, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-O-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R4bare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -C(O)NH2, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), -N(H)-C(O)-N(C1-6-alkyl)2, -OH, -OC1-6- alkyl, and C1-6-alkyl; and wherein *5 indicates the point of attachment to A5and *3 indicates the point of attachment to A3; A5is , wherein: R5ais selected from H, C1-6-alkyl, and -CH2-phenyl, wherein the C1-6-alkyl and -CH2- phenyl of R5aare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R5bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5c, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl- C(O)R5c, -C1-6-alkyl-O-C(O)R5c, and -C1-6-alkyl-NH-C(O)R5cof R5bare each optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, and C1-6-alkyl; R5cis selected from H, C1-6-alkyl, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -OH, -OC1-6- alkyl, C1-6-haloalkyl, C1-6-alkyl-C(O)OH, and C1-6-alkyl-C(O)OC1-6-alkyl; and wherein *6 indicates the point of attachment to A6and *4 indicates the point of attachment to A4; A6is 524 763537: NIT-59597PC (PAT059597-FF) , wherein: R6ais selected from H and C1-6-alkyl; R6bis selected from H and C1-6-alkyl; R6cis selected from C1-6-alkyl and 5-10 membered heteroaryl, wherein the C1-6-alkyl and 5-10 membered heteroaryl of R6care each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, -C(O)OH, -NH2, - NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, -OC(O)-C1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)-C(O)-N(H)(C1-6-alkyl), and -N(H)-C(O)-N(C1-6-alkyl)2; and wherein *5 indicates the point of attachment to A5and *7 indicates the point of attachment to A7; A7is , wherein: R7ais selected from H and C1-6-alkyl; R7bis selected from H and C1-6-alkyl; R7cis selected from C1-6-alkyl and 5-10 membered heteroaryl, wherein the C1-6-alkyl and 5-10 membered heteroaryl are each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, -C(O)OH, -NH2, -NHC1-6- alkyl, –N(C1-6-alkyl)2, -OH, -OC1-6-alkyl, -N(H)-C(O)-C1-6-alkyl, -N(H)-C(O)-NH2, -N(H)- C(O)-N(H)(C1-6-alkyl), and -N(H)-C(O)-N(C1-6-alkyl)2; and wherein *8 indicates the point of attachment to A8and *6 indicates the point of attachment to A6; A8is , 525 763537: NIT-59597PC (PAT059597-FF) wherein: R8ais selected from H and C1-6-alkyl; R8bis selected from H, C1-6-alkyl, C3-8-cycloalkyl, 5-7 membered heterocycloalkyl ring, and 5-10 membered heteroaryl, wherein the C1-6-alkyl, C3-8-cycloalkyl, 5-7 membered heterocycloalkyl ring, and 5-10 membered heteroaryl of R8bare optionally substituted with 1, 2, 3, or 4 substituents independently selected from C1-6-alkyl, -CN, halo, -C(O)NH2, - C(O)OH, -NH2, -NHC1-6-alkyl, –N(C1-6-alkyl)2, -OH, and -OC1-6-alkyl; and wherein *9 indicates the point of attachment to A9and *7 indicates the point of attachment to A7; A9is , wherein: Y9is selected from a bond, C(O), NH, NC1-6-alkyl, O, and S; R9ais selected from H and C1-6-alkyl; d is 1, 2, or 3; and z’ and z’’ are each independently 0 or 1; and wherein *8 indicates the point of attachment to A8and *1 indicates the point of attachment to A1; and A10is , wherein: Y10is selected from OH and N(R10g)(R10h); R10a, R10c, R10e, R10g, and R10hare each independently selected from H and C1-6-alkyl; R10bis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10i, -C1-6-alkyl-O-C(O)R10i, and -C1-6-alkyl-NH-C(O)R10i, 526 763537: NIT-59597PC (PAT059597-FF) wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10bare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10aand R10b, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10dis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10j, -C1-6-alkyl-O-C(O)R10j, and -C1-6-alkyl-NH-C(O)R10j, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10dare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10cand R10d, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10fis selected from H, C1-6-alkyl, -C1-6-alkyl-phenyl, -C1-6-alkyl-(5-6 membered heteroaryl), -C1-7-alkyl-C(O)R10k, -C1-6-alkyl-O-C(O)R10k, and -C1-6-alkyl-NH-C(O)R10k, wherein the C1-6-alkyl, -C1-6-alkyl-phenyl, and -C1-6-alkyl-(5-6 membered heteroaryl) of R10fare optionally substituted with 1, 2, or 3 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, -C(O)OH, -C1-6-alkyl- C(O)OH, and -C(O)NH2; alternatively, R10eand R10f, together with the atoms to which they are attached, form a 5-7 membered heterocycloalkyl ring; R10i, R10j, and R10kare each independently selected from H, C1-6-alkyl, C3-7 cycloalkyl, 5-6 membered heteroaryl, and 3-7 membered heterocycloalkyl, wherein the C3-7cycloalkyl, 5-6 membered heteroaryl, and 3-7 membered heterocycloalkyl of R10i, R10j, and R10kare each optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, -NH2, -NHC1-6-alkyl, -N(C1-6-alkyl)2, -N3, -OH, -OC1-6-alkyl, C1-6-alkyl, C1-6-alkyl, - C(O)OH, -C(O)NH2, and C1-6-alkyl-C(O)NH2; e and f are each independently 0 or 1; and wherein *9 indicates the point of attachment to A9.

74. The cyclized peptide of claim 73, wherein the cyclized peptide is selected from Examples A1-A74. 527

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