Antibody-drug conjugates using MATES technology to deliver cytotoxic agents

Abstract

Among other things, the present disclosure provides techniques for site-specific conjugation of various moieties of interest to targeted agents. In some embodiments, the present disclosure utilizes target-binding moieties to provide high conjugation efficiency and selectivity. In some embodiments, the provided techniques are useful for preparing antibody conjugates.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 190,703, filed May 19, 2021, which is incorporated herein by reference in its entirety. [Background technology]

[0002] Antibody-drug conjugates are useful for a variety of purposes, including, for example, as diagnostic reagents, therapeutic agents (e.g., antigen-targeted therapeutic agents), etc. Existing drug-antibody conjugation technologies can suffer from various challenges. For example, the reaction of conjugating a moiety of interest (e.g., a detection moiety, a drug moiety, etc.) to a target molecule (e.g., the antibody of an antibody-drug conjugate) can be inefficient and / or have low selectivity (e.g., conjugation at various positions of the target molecule (e.g., various amino acid residues of an antibody)), and the composition of the product conjugate is often highly heterogeneous, comprising several individual conjugate types, each independently having a unique copy number of the moiety of interest, conjugation position (e.g., different amino acid residues of a protein), etc.

[0003] Approved antibody-drug conjugates for delivering cytotoxic drugs to cancer cells include ADCETRIS (brentuximab vedotin) and PADCEV (enfortumab vedotin), both of which are useful for delivering monomethyl auristatin E (MMAE). Current drug-antibody conjugation techniques include conjugation via lysine residues, conjugation via reduced interchain disulfide bonds, and conjugation via engineered cysteine ​​residues (Figure 1). Each of these techniques has drawbacks. Conjugation via lysine generates a wide range of drug-antibody ratios (DARs), with each lysine labeled with a statistical probability. This results in millions of possible drug-antibody conjugates. Specifying a high DAR can lead to CMC issues such as aggregation. Some species readily release the conjugated drug, potentially causing toxicity. Conjugation via reduced interchain disulfide bonds also produces a variety of antibody conjugate species. Drug binding can reverse over time, releasing free drug. Existing techniques for conjugation via engineered cysteines have involved extensive antibody engineering or manipulation.

[0004] There is a need for antibody conjugates with predictable DAR and conjugation sites that do not "leak" the conjugated drug and do not require extensive antibody engineering. The present disclosure meets that need and has additional advantages. Summary of the Invention

[0005] The present disclosure provides bifunctional molecules that include monomethyl auristatin E (MMAE) and are capable of forming antibody-drug conjugates, with conjugation occurring at finite and predictable sites on the antibody.

[0006] In some embodiments, the production of a conjugate involves multiple steps, including various reactions such as reduction, oxidation, hydrolysis, etc., which may result in undesired transformations, for example, at one or more positions of the targeting drug moiety (e.g., one or more residues, and / or one or more modifications (e.g., glycans) of the antibody moiety. Such undesired transformations may further reduce the efficiency and / or increase heterogeneity of the product conjugate composition, complicate the characterization, evaluation, and / or purification process, and increase product costs.

[0007] In some embodiments, the present disclosure provides conjugation techniques for conjugating various moieties of interest to targets (e.g., proteins). In some embodiments, the provided techniques provide directed conjugation, in that the moiety of interest is selectively conjugated at a specific location on the target (e.g., a protein such as an antibody). In some embodiments, the provided techniques utilize fewer steps. In some embodiments, the provided techniques utilize mild reaction conditions. In some embodiments, the provided techniques do not include reaction conditions such as reduction, oxidation, and / or hydrolysis. In some embodiments, the provided techniques are substantially free of cleavage from the conjugate molecule comprising the targeting agent moiety and the moiety of interest (e.g., do not include cleavage of groups from the targeting agent moiety, the moiety of interest, and / or the linker moiety). In some embodiments, the moiety of interest is a detectable moiety (e.g., FITC). In some embodiments, the moiety of interest is a drug moiety (e.g., various drug moieties utilized in antibody-drug conjugates). In some embodiments, the moiety of interest is a protein moiety (e.g., an antibody drug conjugated to another antibody drug (as a targeting agent moiety)). In some embodiments, the moiety of interest is or includes a reactive group, hi some embodiments, the moiety of interest is or includes a reactive group such that other moieties of interest can be further incorporated via reaction at the reactive group.

[0008] The techniques of the present disclosure may provide various advantages: in some embodiments, the present disclosure provides improved efficiency and / or selectivity, reduced levels of heterogeneity, and / or reduced undesired conversions (e.g., by avoiding certain reaction conditions (e.g., reduction, oxidation, hydrolysis, etc.) through fewer reaction steps (in some embodiments, only one)).

[0009] In some embodiments, the present disclosure provides that an agent comprising a moiety of interest is conjugated at a specific position of a targeting agent moiety. In some embodiments, the present disclosure provides compositions with increased homogeneity compared to compositions from a reference technique (e.g., a technique that does not use a target-binding moiety (e.g., LG) as described in the provided methods).

[0010] In some embodiments, the present disclosure provides a technology, e.g., mAb Therapeutic Enhancer (MATE™) technology, that provides efficient site-specific chemical conjugation to "off-the-shelf" therapeutic antibody drugs (e.g., various mAbs) and can enable the development of various bispecific therapeutic drugs. Among other things, the technology of the present disclosure (e.g., MATE technology) provides chemical engineering of antibody drugs (e.g., various existing antibodies) without the need to create new DNA vectors or genetic engineering of master cell lines. In some embodiments, advantages of the provided technology include 1) site-specific conjugation specificity and / or 2) no need for genetic engineering compared to certain existing methods that 1) lack site-specific conjugation specificity by indiscriminately binding / conjugating to available amino acid residues and / or 2) require genetic engineering to create the conjugate tag. A schematic diagram of the MATES technology is shown in Figures 2 and 3. [Brief explanation of the drawings]

[0011] [Figure 1] Diagram of existing drug-antibody technologies. A. Conjugation via lysine residues. B. Conjugation via reduced interchain disulfide bonds. C. Conjugation via engineered cysteine ​​residues. [Figure 2]Schematic diagram of the MATES technology. A reactive target-binding moiety, a reactive group, is connected via a linker to an MOI that specifically binds to the target (antibody). The reactive group binds to an antibody lysine residue, releasing the target-binding moiety. [Figure 3] Chemical diagram of a reactive targeting moiety that specifically binds to an antibody after the reactive group on the antibody reacts with an antibody heavy chain lysine. The reactive target binding moiety includes a cyclic peptide target binding moiety, a fluorophenyl reactive moiety, a PEG linker, and a peptide MOI. [Figure 4] Standard curves for residual payload analysis for compound 1101 (FIG. 4A), residual reagent analysis for compound 1101 (FIG. 4B), and residual uABT analysis (FIG. 4C). [Figure 5] HPLC traces and peak areas for compound 1101 payload analysis. Successive traces are shown for payloads from 10 μM (largest peak), 5 μM, 2 μM, and 1 μM. [Figure 6] HPLC traces and peak areas for compound 1101 residual reagent analysis. Successive traces are shown for payloads from 10 μM (highest peak), 5 μM, 2 μM, and 1 μM. [Figure 7] HPLC traces for uABT analysis. Successive traces are shown for payloads from 14 μM (highest peak), 7 μM, 3.5 μM, 1.75 μM, and 0.7 μM. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1.Definition The compounds of the present disclosure include those compounds generally described herein and are further exemplified by the classes, subclasses, and species disclosed herein. As used herein, the following definitions apply unless otherwise indicated. For purposes of this disclosure, chemical elements are identified according to the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75th Ed. In addition, the general principles of organic chemistry are described in "Organic Chemistry", Thomas Sorrell, University Science Books, Sausalito: 1999, and "March's Advanced Organic Chemistry", 5th Ed., Ed.: Smith, MB and March, J., John Wiley & Sons, New York: 2001.

[0013] As used herein, unless otherwise clear from the context, (i) the terms "a" or "an" may be understood to mean "at least one," (ii) the term "or" may be understood to mean "and / or," (iii) the terms "comprising," "comprise," "including" (whether or not used in conjunction with "limited to"), and "include" (whether or not used in conjunction with "limited to") may be understood to encompass the itemized elements or steps, whether presented by themselves or with one or more additional elements or steps, and (iv) the open-ended transitional phrase "comprising" (and other open-ended transitional phrases, e.g., "comprise," "including," and "include") may be understood to encompass the intermediate and close-ended transitional phrases "consisting essentially of" and "consisting of" (v) the term "another" may be understood to mean at least an additional / second one or more; (v) the terms "about" and "approximately" may be understood to allow for standard deviation, as understood by one of ordinary skill in the art; and (vi) when ranges are provided, the endpoints are included. Unless otherwise specified, the compounds described herein may be provided and / or utilized in the form of salts, particularly pharmaceutically acceptable salts.

[0014] Agent: The term "agent" may be used to refer to any chemical compound or entity, including, for example, a polypeptide, a nucleic acid, a sugar, a lipid, a small molecule, a metal, or a combination or complex thereof. In appropriate circumstances, as will be clear from the context to one of skill in the art, the term may be used to refer to an entity that is or includes a cell or organism, or a fragment, extract, or component thereof. Alternatively, or additionally, as the context will make clear, the term may be used to refer to a natural product, in that the natural product is found in and / or obtained from a natural product. In some cases, also as will be clear from the context, the term may be used to refer to one or more entities that are artificial, in that they are designed, engineered, and / or produced by the action of the hand of man and / or are not found in nature. In some embodiments, an agent may be utilized in an isolated or pure form, and in some embodiments, an agent may be utilized in a crude form. In some embodiments, potential agents may be provided as a collection or library that can be screened, for example, to identify or characterize active agents therein. In some cases, the term "agent" may refer to a compound or entity that is or comprises a polymer, and in some cases, the term "agent" may refer to a compound or entity that comprises one or more polymer moieties. In some embodiments, the term "agent" may refer to a compound or entity that is not a polymer and / or is substantially free of polymers and / or is substantially free of one or more specific polymer moieties. In some embodiments, the term may refer to a compound or entity that lacks or is substantially free of any polymer moieties. In some embodiments, an agent is a compound (e.g., a small molecule, protein, nucleic acid, etc.). In some embodiments, an agent is a monovalent, divalent, or polyvalent portion of a compound (e.g., by removing one (for a monovalent moiety) or more (for a divalent or polyvalent moiety) hydrogen atoms and / or other monovalent groups from the compound).

[0015] Aliphatic: "Aliphatic" means a linear (i.e., unbranched) or branched, substituted or unsubstituted hydrocarbon chain that is fully saturated or contains one or more units of unsaturation, or a substituted or unsubstituted monocyclic, bicyclic, or polycyclic hydrocarbon ring that is fully saturated or contains one or more units of unsaturation (but is not aromatic), or a combination thereof. In some embodiments, an aliphatic group contains 1-50 aliphatic carbon atoms. In some embodiments, an aliphatic group contains 1-20 aliphatic carbon atoms. In other embodiments, an aliphatic group contains 1-10 aliphatic carbon atoms. In other embodiments, an aliphatic group contains 1-9 aliphatic carbon atoms. In other embodiments, an aliphatic group contains 1-8 aliphatic carbon atoms. In other embodiments, an aliphatic group contains 1-7 aliphatic carbon atoms. In other embodiments, an aliphatic group contains 1-6 aliphatic carbon atoms. In still other embodiments, aliphatic groups contain 1-5 aliphatic carbon atoms, and in yet other embodiments, aliphatic groups contain 1, 2, 3, or 4 aliphatic carbon atoms. Suitable aliphatic groups include, but are not limited to, linear or branched, substituted or unsubstituted alkyl, alkenyl, alkynyl groups, and hybrids thereof, such as (cycloalkyl)alkyl, (cycloalkenyl)alkyl, or (cycloalkyl)alkenyl.

[0016] Alkenyl: "Alkenyl" means an aliphatic group, as defined herein, having one or more double bonds.

[0017] Alkyl: "Alkyl" is given its ordinary meaning in the art and may include saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl-substituted cycloalkyl groups, and cycloalkyl-substituted alkyl groups. In some embodiments, an alkyl has 1-100 carbon atoms. In certain embodiments, a straight-chain or branched-chain alkyl has about 1-20 carbon atoms in its backbone (e.g., C1-C for a straight chain). 20 , C2 to C for branched chains 20), alternatively having about 1-10 carbon atoms. In some embodiments, cycloalkyl rings have from about 3-10 carbon atoms in their ring structure, and such rings may be monocyclic, bicyclic or polycyclic, alternatively having about 5, 6 or 7 carbons in the ring structure. In some embodiments, alkyl groups can be lower alkyl groups, which lower alkyl groups have from 1-4 carbon atoms (e.g., C1-C4 for a straight chain lower alkyl).

[0018] Alkynyl: "Alkynyl" is an aliphatic group, as defined herein, having one or more triple bonds.

[0019] Aryl: "Aryl," used alone or as part of a larger moiety such as "aralkyl," "aralkoxy," or "aryloxyalkyl," refers to a monocyclic, bicyclic, or polycyclic ring system having a total of 5 to 30 ring members, wherein at least one ring in the system is aromatic. In some embodiments, an aryl group is a monocyclic, bicyclic, or polycyclic ring system having a total of 5 to 14 ring members, wherein at least one ring in the system is aromatic, and each ring in the system contains 3 to 7 ring members. In some embodiments, an aryl group is a biaryl group. The term "aryl" may be used interchangeably with the term "aryl ring." In certain embodiments of the present disclosure, "aryl" refers to an aromatic ring system, including, but not limited to, phenyl, biphenyl, naphthyl, binaphthyl, anthracyl, and the like, which may bear one or more substituents. Also included within the scope of the term "aryl" as used herein are groups in which an aromatic ring is fused to one or more non-aromatic rings, such as indanyl, phthalimidyl, naphthymidyl, phenanthridinyl, or tetrahydronaphthyl.

[0020] Antibody: The term "antibody" refers to a polypeptide that contains sufficient canonical immunoglobulin sequence elements to confer specific binding to a particular target antigen. As is known in the art, naturally occurring intact antibodies are approximately 150 kD tetrameric entities composed of two identical heavy chain polypeptides (about 50 kD each) and two identical light chain polypeptides (about 25 kD each) that associate with each other in what is commonly referred to as a "Y-shaped" structure. Each heavy chain is composed of at least four domains (each about 110 amino acids long): an amino-terminal variable (VH) domain (located at the tip of the Y structure), followed by three constant domains: CH1, CH2, and a carboxy-terminal CH3 domain (located at the base of the stem of the Y). A short region known as the "switch" connects the heavy chain variable and constant regions. A "hinge" connects the CH2 and CH3 domains to the rest of the antibody. Two disulfide bonds within this hinge region connect the two heavy chain polypeptides to each other within an intact antibody. Each light chain is composed of two domains, an amino-terminal variable (VL) domain followed by a carboxy-terminal constant (CL) domain, separated from each other by another "switch." An intact antibody tetramer is composed of two heavy-light chain dimers, where the heavy and light chains are linked to each other by a single disulfide bond and two other disulfide bonds connect the heavy chain hinge regions to each other, thereby connecting the dimers to form a tetramer. Naturally produced antibodies are also typically glycosylated on the CH2 domain. Each domain in a natural antibody has a structure characterized by an "immunoglobulin fold" formed from two beta sheets (e.g., a three-, four-, or five-stranded sheet) packed against each other in a compressed antiparallel beta barrel. Each variable domain contains three hypervariable loops known as "complement-determining regions" (CDR1, CDR2, and CDR3) and four somewhat invariant "framework" regions (FR1, FR2, FR3, and FR4). When a native antibody folds, the FR regions form beta sheets that provide the structural framework for the domain, and the CDR loop regions from both the heavy and light chains come together in three-dimensional space to create a single hypervariable antigen-binding site located at the tip of a Y-structure.The Fc region of a naturally occurring antibody binds to elements of the complement system and to receptors on effector cells, including, for example, effector cells that mediate cytotoxicity. As is known in the art, the affinity and / or other binding attributes of the Fc region for an Fc receptor can be modulated by glycosylation or other modifications. In some embodiments, antibodies produced and / or utilized in accordance with the present disclosure comprise a glycosylated Fc domain, including Fc domains in which such glycosylation has been modified or engineered. For purposes of the present disclosure, in certain embodiments, any polypeptide or complex of polypeptides comprising a sufficient immunoglobulin domain sequence as found in a natural antibody may be referred to and / or used as an "antibody," regardless of whether such polypeptide is produced naturally (e.g., by an organism in response to an antigen) or produced by recombinant engineering, chemical synthesis, or other artificial systems or methods. In some embodiments, antibodies are polyclonal; in some embodiments, antibodies are monoclonal. In some embodiments, antibodies have constant region sequences characteristic of murine, rabbit, primate, or human antibodies. In some embodiments, antibody sequence elements are humanized, primatized, chimeric, etc., as known in the art. Furthermore, the term "antibody," as used herein, can, in appropriate embodiments (unless otherwise specified or clear from context), refer to any of the constructs or formats known or developed in the art for utilizing the structural and functional characteristics of antibodies in alternative presentations.For example, in some embodiments, antibodies utilized in accordance with the present disclosure include, but are not limited to, intact IgA, IgG, IgE, or IgM antibodies; bispecific or multispecific antibodies (e.g., Zybodies®, Ulrich Brinkmann & Roland E. Kontermann (2017) The making of bispecific antibodies); antibodies, mAbs, 9:2, 182-212, doi:10.1080 / 19420862.2016.1268307); antibody fragments, such as Fab fragments, Fab' fragments, F(ab')2 fragments, Fd' fragments, Fd fragments, and isolated CDRs, or sets thereof; single chain Fv; polypeptide-Fc fusions; single domain antibodies (e.g., shark single domain antibodies, e.g., IgNAR or fragments thereof); camelid antibodies; masked antibodies (e.g., Probodies®); small modular immunopharmaceuticals ("SMIP™"); single chain or tandem diabodies The antibody may be in a form selected from: di(TandAb®); VHH; Anticalin®; Nanobody®; minibody; BiTE®; ankyrin repeat protein or DARPIN®; Avimers®; DART; TCR-like antibody; Adnectin®; Affilin®; Trans-body®; Affibody®; TrimerX®; MicroProtein; Fynomer®, Centyrin®; KALBITOR®; CovX-Bodies; and CrossMab. In some embodiments, the antibody may have an enhanced Fc domain. In some embodiments, the antibody may comprise one or more non-native naturally occurring amino acid residues. In some embodiments, the antibody may lack covalent modifications (e.g., glycan attachment) that it would have if produced naturally. In some embodiments, the antibody is a defucosylated antibody. In some embodiments, the antibody is conjugated to another entity.In some embodiments, the antibody may comprise a covalent modification (e.g., the attachment of a glycan, a payload (e.g., a detectable moiety, a therapeutic moiety, a catalytic moiety, etc.), or other pendant group (e.g., polyethylene glycol, etc.).

[0021] Equivalent: The term "equivalent" refers to two or more agents, entities, circumstances, sets of conditions, etc. that may not be identical to one another, but are sufficiently similar to permit comparisons between them, such that one of skill in the art would understand that conclusions can be reasonably drawn based on observed differences or similarities. In some embodiments, comparable sets of conditions, circumstances, individuals, or populations are characterized by multiple substantially identical characteristics and one or a few altered characteristics. One of skill in the art would understand what degree of identity is necessary in any given situation for two or more such agents, entities, circumstances, sets of conditions, etc. to be considered comparable in context. For example, one of skill in the art would understand that sets of circumstances, individuals, or populations are comparable to one another when they are characterized by a sufficient number and type of substantially identical characteristics to warrant a reasonable conclusion that differences in results obtained or phenomena observed under different sets of circumstances, individuals, or populations are caused by, or indicate, variations in those characteristics that vary.

[0022] Alicyclic: The terms "alicyclic," "carbocyclic," "carbocyclyl," "carbocyclic radical," and "carbocycle" are used interchangeably and, unless otherwise specified, refer to a saturated or partially unsaturated, but non-aromatic, cyclic aliphatic monocyclic, bicyclic, or polycyclic ring system described herein having 3 to 30 ring members. Alicyclic groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cycloheptyl, cycloheptenyl, cyclooctyl, cyclooctenyl, norbornyl, adamantyl, and cyclooctadienyl. In some embodiments, an alicyclic group has 3 to 6 carbons. In some embodiments, an alicyclic group is saturated and is a cycloalkyl. The term "alicyclic" may also include an aliphatic ring fused to one or more aromatic or non-aromatic rings, such as decahydronaphthyl or tetrahydronaphthyl. In some embodiments, an alicyclic group is bicyclic. In some embodiments, an alicyclic group is tricyclic. In some embodiments, an alicyclic group is polycyclic. In some embodiments, an "alicyclic" refers to a C3-C6 monocyclic hydrocarbon having a single point of attachment to the rest of the molecule, or a C8-C6 monocyclic hydrocarbon having a single point of attachment to the rest of the molecule, which is fully saturated or contains one or more units of unsaturation, but is not aromatic. 10 Bicyclic or polycyclic hydrocarbons, or C9-C, which are fully saturated or contain one or more units of unsaturation but are not aromatic, with a single point of attachment to the rest of the molecule 16 Refers to polycyclic hydrocarbons.

[0023] Haloalkyl and haloalkoxy: The term "haloalkyl" refers to a C alkoxy group substituted with one or more halogen atoms. 1~4 It refers to a straight-chain or branched alkyl group, examples of which are trifluoromethyl, difluoromethyl, and dichloromethyl. The term "haloalkoxy" refers to a haloalkyl group attached to the group it substitutes via an -O- bond. Examples include trifluoromethoxy and difluoromethoxy.

[0024] Heteroaliphatic: The term "heteroaliphatic" is given its ordinary meaning in the art and refers to an aliphatic group, as described herein, in which one or more carbon atoms are independently replaced with one or more heteroatoms (e.g., oxygen, nitrogen, sulfur, silicon, phosphorus, etc.). In some embodiments, one or more units selected from C, CH, CH, and CH are independently replaced with one or more heteroatoms (including oxidized and / or substituted forms thereof). In some embodiments, a heteroaliphatic group is a heteroalkyl. In some embodiments, a heteroaliphatic group is a heteroalkenyl.

[0025] Heteroalkyl: The term "heteroalkyl" is given its ordinary meaning in the art and refers to an alkyl group, as described herein, in which one or more carbon atoms are independently replaced with one or more heteroatoms (e.g., oxygen, nitrogen, sulfur, silicon, phosphorus, etc.). Examples of heteroalkyl groups include, but are not limited to, alkoxy, poly(ethylene glycol)-, alkyl-substituted amino, tetrahydrofuranyl, piperidinyl, morpholinyl, and the like.

[0026] Heteroaryl: The term "heteroaryl," when used alone or as part of a larger moiety (e.g., "heteroaralkyl" or "heteroaralkoxy"), refers to a monocyclic, bicyclic, or polycyclic ring system having a total of 5 to 30 ring members, in which at least one ring in the system is aromatic and at least one aromatic ring atom is a heteroatom. In some embodiments, heteroaryl groups are groups having 5 to 10 ring atoms (i.e., monocyclic, bicyclic, or polycyclic), and in some embodiments, 5, 6, 9, or 10 ring atoms. In some embodiments, heteroaryl groups have 6, 10, or 14 pi electrons shared in the cyclic array, and have 1 to 5 heteroatoms in addition to the carbon atoms. Heteroaryl groups include, but are not limited to, thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, and pteridinyl. In some embodiments, heteroaryl is a heteroaryl group such as bipyridyl. As used herein, the term "heteroaryl" also includes groups in which a heteroaromatic ring is fused to one or more aryl, alicyclic, or heterocyclyl rings, and the radical or point of attachment is on the heteroaromatic ring. Non-limiting examples include indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzothiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and pyrido[2,3-b]-1,4-oxazin-3(4H)-one. Heteroaryl groups can be monocyclic, bicyclic, or polycyclic. The term "heteroaryl" may be used interchangeably with the terms "heteroaryl ring," "heteroaryl group," or "heteroaromatic," any of which include optionally substituted rings.The term "heteroaralkyl" refers to an alkyl group substituted with a heteroaryl group, wherein the alkyl and heteroaryl portions independently are optionally substituted.

[0027] Heteroatom: The term "heteroatom" means an atom that is not carbon or hydrogen. In some embodiments, the heteroatom is boron, oxygen, sulfur, nitrogen, phosphorus, or silicon (various forms of such atoms, such as oxidized forms (e.g., nitrogen, sulfur, phosphorus, or silicon), quaternized forms of basic nitrogens, or heterocyclic rings (e.g., N in 3,4-dihydro-2H-pyrrolyl), NH (in pyrrolidinyl), or NR + (including substitutable nitrogen in N-substituted pyrrolidinyl). In some embodiments, the heteroatom is oxygen, sulfur, or nitrogen.

[0028] Heterocycle: As used herein, the terms "heterocycle," "heterocyclyl," "heterocyclic radical," and "heterocyclic ring" are used interchangeably and refer to a monocyclic, bicyclic, or polycyclic ring moiety (e.g., a 3- to 30-membered ring) that is saturated or partially unsaturated and has one or more heteroatom ring atoms. In some embodiments, a heterocyclyl group is a stable 5- to 7-membered monocyclic or 7- to 10-membered bicyclic heterocyclic moiety that is either saturated or partially unsaturated and has, in addition to carbon atoms, one or more, preferably 1 to 4, heteroatoms as defined above. When used in reference to a ring atom of a heterocycle, the term "nitrogen" includes substituted nitrogen. As an example, in a saturated or partially unsaturated ring having 0 to 3 heteroatoms selected from oxygen, sulfur, and nitrogen, the nitrogen can be N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl), or +It may be NR (as in N-substituted pyrrolidinyl). A heterocyclic ring can be attached to its pendant group at any heteroatom or carbon atom that results in a stable structure, and any of the ring atoms can be optionally substituted. Examples of such saturated or partially unsaturated heterocyclic radicals include, but are not limited to, tetrahydrofuranyl, tetrahydrothienyl, pyrrolidinyl, piperidinyl, pyrrolinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and quinuclidinyl. The terms "heterocycle," "heterocyclyl," "heterocyclyl ring," "heterocyclic group," "heterocyclic moiety," and "heterocyclic radical" are used interchangeably herein and also include groups in which a heterocyclyl ring is fused to one or more aryl, heteroaryl, or alicyclic rings, such as indolinyl, 3H-indolyl, chromanyl, phenanthridinyl, or tetrahydroquinolinyl. Heterocyclyl groups can be monocyclic, bicyclic, or polycyclic. The term "heterocyclylalkyl" refers to an alkyl group substituted by a heterocyclyl group, where the alkyl and heterocyclyl portions are independently optionally substituted.

[0029] Optionally substituted: As described herein, compounds of the present disclosure may contain optionally substituted and / or substituted moieties. In general, the term "substituted," whether preceded by the term "optionally," means that one or more hydrogens of the specified moiety are replaced with a suitable substituent. Unless otherwise indicated, an "optionally substituted" group may have a suitable substituent at each substitutable position of the group, and if more than one position in any given structure may be substituted with more than one substituent selected from a specified group, the substituents may be the same or different at all positions. In some embodiments, an optionally substituted group is unsubstituted. Combinations of substituents envisioned by the present disclosure are preferably those that result in the formation of stable or chemically feasible compounds. The term "stable," as used herein, refers to compounds that are substantially unchanged when subjected to conditions that allow for their production, detection, and, in certain embodiments, their recovery, purification, and use for one or more purposes disclosed herein. Specific substituents are described below.

[0030] Suitable monovalent substituents on a substitutable atom (e.g., a suitable carbon atom) are independently halogen, —(CH) 0~4 R°, -(CH2) 0~4 OR°, -O(CH2) 0~4 R°, -O-(CH2) 0~4 C(O)OR°, -(CH2) 0~4 CH(OR°)2, -(CH2) 0~4 Ph (which may be substituted with R), -(CH) 0~4 O(CH2) 0~1 Ph (which may be substituted with R°), -CH=CHPh (which may be substituted with R°), -(CH) 0~4 O(CH2) 0~1 -pyridyl (which may be substituted with R), -NO2, -CN, -N3, -(CH2) 0~4 N(R°)2, -(CH2) 0~4 N(R°)C(O)R°, -N(R°)C(S)R°, -(CH2) 0~4N(R°)C(O)NR°2, -N(R°)C(S)NR°2, -(CH2) 0~4 N(R°)C(O)OR°, -N(R°)N(R°)C(O)R°, -N(R°)N(R°)C(O)NR°2, -N(R°)N(R°)C(O)OR°, -(CH2) 0~4 C(O)R°, -C(S)R°, -(CH2) 0~4 C(O)OR°, -(CH2) 0~4 C(O)SR°, -(CH2) 0~4 C(O)OSiR°3, -(CH2) 0~4 OC(O)R°, -OC(O)(CH2) 0~4 SR°, -SC(S)SR°, -(CH2) 0~4 SC(O)R°, -(CH2) 0~4 C(O)NR°2, -C(S)NR°2, -C(S)SR°, -(CH2) 0~4 OC(O)NR°2, -C(O)N(OR°)R°, -C(O)C(O)R°, -C(O)CH2C(O)R°, -C(NOR°)R°, -(CH2) 0~4 SSR°, -(CH2) 0~4 S(O)2R°, -(CH2) 0~4 S(O)2OR°, -(CH2) 0~4 OS(O)2R°, -S(O)2NR°2, -(CH2) 0~4 S(O)R°, -N(R°)S(O)2NR°2, -N(R°)S(O)2R°, -N(OR°)R°, -C(NH)NR°2, -Si(R°)3, -OSi(R°)3, -B(R°)2, -OB(R°)2, -OB(OR°)2, -P(R°)2, -P(OR°)2, -P(R°)(OR°), -OP(R°)2, -OP(OR°)2, -OP(R°)(OR°), -P(O)(R°)2, -P(O)(OR°)2, -OP(O)(R°)2, -OP(O)(OR°)2, -OP(O)(OR°)(SR°), -SP(O)(R°)2, -SP(O)(OR°)2, -N(R°)P(O)(R°)2, -N(R°)P(O)(OR°)2, -P(R°)2[B(R°)3], -P(OR°)2[B(R°)3], -OP(R°)2[B(R°)3], -OP(OR°)2[B(R°)3], -(C 1~4 linear or branched alkylene)O-N(R°)2, or -(C1~4 linear or branched alkylene)C(O)ON(R°), where each R° may be optionally substituted as defined herein and independently represents hydrogen, C 1~20 Aliphatic, C having 1 to 5 heteroatoms independently selected from nitrogen, oxygen, sulfur, silicon, and phosphorus 1~20 Heteroaliphatic, -CH2-(C 6~14 aryl), -O(CH2) 0~1 (C 6~14 aryl), -CH2- (a 5-14 membered heteroaryl ring), a 5-20 membered monocyclic, bicyclic, or polycyclic saturated, partially unsaturated, or aryl ring having 0-5 heteroatoms independently selected from nitrogen, oxygen, sulfur, silicon, and phosphorus, or, notwithstanding the above definitions, two independent occurrences of R° together with their intervening atoms form a 5-20 membered monocyclic, bicyclic, or polycyclic saturated, partially unsaturated, or aryl ring having 0-5 heteroatoms independently selected from nitrogen, oxygen, sulfur, silicon, and phosphorus, which may be substituted as defined below.

[0031] Suitable monovalent substituents on R° (or the ring formed by two independent occurrences of R° together with their intervening atoms) are independently halogen, —(CH2), 0~2 R ● ,-(Halo R ● ), -(CH2) 0~2 OH, -(CH2) 0~2 OR ● , -(CH2) 0~2 CH(OR ● )2, -O(HaloR ● ), -CN, -N3, -(CH2) 0~2 C(O)R ● , -(CH2) 0~2 C(O)OH, -(CH2) 0~2 C(O)OR ● , -(CH2) 0~2 SR ● , -(CH2) 0~2 SH, -(CH2) 0~2 NH2, -(CH2) 0~2 NHR ● , -(CH2) 0~2 NR● 2, -NO2, -SiR ● 3. -OSiR ● 3. -C(O)SR ● , -(C 1~4 Linear or branched alkylene)C(O)OR ● , or -SSR ● and each R ● is unsubstituted or, if preceded by "halo", is substituted only with one or more halogens, and independently represents C 1~4 Aliphatic, -CH2Ph, -O(CH2) 0~1 and a 5-6 membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur. Suitable divalent substituents on a saturated carbon atom of R° include =0 and =S.

[0032] For example, suitable divalent substituents on suitable carbon atoms are, independently, the following: =O, =S, =NNR * 2, =NNHC(O)R * , =NNHC(O)OR * , =NNHS(O)2R * , =NR * , =NOR * , -O(C(R * 2)) 2~3 O- or -S(C(R * 2)) 2-3 S-, where R * Each independent occurrence of may be substituted as defined below with hydrogen, C 1~6 A vicinal substitutable carbon atom of an "optionally substituted" group is selected from aliphatic and unsubstituted 5-6 membered saturated, partially unsaturated, or aryl rings having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur. Preferred divalent substituents attached to a vicinal substitutable carbon of an "optionally substituted" group include -O(CR * 2) 2~3 O-, wherein R * Each independent occurrence of may be substituted as defined below with hydrogen, C 1~6It is selected from aliphatic and unsubstituted 5-6 membered saturated, partially unsaturated, or aryl rings having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

[0033] R * Suitable substituents on the aliphatic group are independently halogen, —R ● ,-(Halo R ● ), -OH, -OR ● , -O(HaloR ● ), -CN, -C(O)OH, -C(O)OR ● , -NH2, -NHR ● , -NR ● 2, or -NO2, and each R ● is unsubstituted or, if preceded by "halo", is substituted only with one or more halogens, and independently represents C 1~4 Aliphatic, -CH2Ph, -O(CH2) 0~1 Ph, or a 5-6 membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

[0034] In some embodiments, suitable substituents on a substitutable nitrogen are independently —R † , -NR † 2. -C(O)R † , -C(O)OR † , -C(O)C(O)R † , -C(O)CHC(O)R † , -S(O)2R † , -S(O)NR † 2. -C(S)NR † 2. -C(NH)NR † 2, or -N(R † )S(O)2R † and each R † are independently hydrogen, C which may be substituted as defined below 1~6 an aliphatic, unsubstituted -OPh, or an unsubstituted 5-6 membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, or two independent R †occurrences of, taken together with their intervening atoms, form an unsubstituted 3-12 membered saturated, partially unsaturated, or aryl monocyclic or bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

[0035] R † Suitable substituents on the aliphatic group are independently halogen, —R ● ,-(Halo R ● ), -OH, -OR ● , -O(HaloR ● ), -CN, -C(O)OH, -C(O)OR ● , -NH2, -NHR ● , -NR ● 2, or -NO2, and each R ● is unsubstituted or, if preceded by "halo", is substituted only with one or more halogens, and independently represents C 1~4 Aliphatic, -CH2Ph, -O(CH2) 0~1 Ph, or a 5-6 membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

[0036] Partially unsaturated: As used herein, the term "partially unsaturated" refers to a ring moiety that includes at least one double or triple bond. The term "partially unsaturated" is intended to encompass rings with multiple sites of unsaturation, but is not intended to include aryl or heteroaryl moieties, as defined herein.

[0037] Pharmaceutical composition: As used herein, the term "pharmaceutical composition" refers to an active agent formulated with one or more pharmaceutically acceptable carriers. In some embodiments, the active agent is present in a unit dose suitable for administration in a treatment regimen that, when administered to a relevant population, exhibits a statistically significant probability of achieving a predetermined therapeutic effect. In some embodiments, a pharmaceutical composition may be specially formulated for administration in solid or liquid form, including those adapted for oral administration (e.g., drenches (aqueous or non-aqueous solutions or suspensions), tablets (e.g., buccal, sublingual, and those intended for systemic absorption), boluses, powders, granules, pastes for application to the tongue, parenteral administration (e.g., as a sterile solution or suspension, or sustained-release formulation, e.g., by subcutaneous, intramuscular, intravenous, or epidural injection), topical application (e.g., as a cream, ointment, or controlled-release patch or spray applied to the skin, lungs, or oral cavity), vaginal or rectal (e.g., as a pessary, cream, or foam), sublingual, intraocular, transdermal, or intranasal, pulmonary, and other mucosal surfaces.

[0038] Pharmaceutically acceptable: As used herein, the phrase "pharmaceutically acceptable" refers to compounds, materials, compositions, and / or dosage forms that 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.

[0039] Pharmaceutically acceptable carrier: As used herein, the term "pharmaceutically acceptable carrier" refers to a pharmaceutically acceptable material, composition, or vehicle, such as a liquid or solid filler, diluent, excipient, or solvent encapsulant, that is involved in carrying or transporting a compound of interest from one organ or part of the body to another. Each carrier must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not harmful to the subject. Some examples of materials that can function as pharmaceutically acceptable carriers include sugars (e.g., lactose, glucose, and sucrose), starches (e.g., corn starch and potato starch), cellulose and its derivatives (e.g., sodium carboxymethylcellulose, ethylcellulose, and cellulose acetate), powdered tragacanth, malt, gelatin, talc, excipients (e.g., cocoa butter and suppository wax), oils (e.g., peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil), glycols (e.g., propylene glycol), polyols (e.g., glycerin, sorbitol, mannitol, and polyethylene glycol), esters (e.g., ethyl oleate and ethyl laurate), agar, buffers (e.g., magnesium hydroxide and aluminum hydroxide), alginic acid, pyrogen-free water, isotonic saline, Ringer's solution, ethyl alcohol, pH buffer solutions, polyesters, polycarbonates, and / or polyanhydrides, as well as other non-toxic, compatible substances used in pharmaceutical formulations.

[0040] Pharmaceutically acceptable salt: The term "pharmaceutically acceptable salt" as used herein refers to a salt of such a compound that is suitable for use in a pharmaceutical context, i.e., a salt that is suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic reaction, etc., within the scope of sound medical judgment and commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, lists of pharmaceutically acceptable salts can be found in, for example, G. Steffen Paulekuhn, et al., Journal of Medicinal Chemistry 2007, 50, 6665 and Handbook of Pharmaceutical Salts: Properties, Selection and Use, P. Heinrich Stahl and Camille G. Wermuth Editors, Wiley-VCH, 2002.

[0041] In some embodiments, pharmaceutically acceptable salts include, but are not limited to, non-toxic acid addition salts of amino groups formed with inorganic acids (e.g., hydrochloric, hydrobromic, phosphoric, sulfuric, and perchloric), or organic acids (e.g., acetic, maleic, tartaric, citric, succinic, or malonic), or by using other methods used in the art (e.g., ion exchange). In some embodiments, pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactate, or the like. Examples of suitable salts include, but are not limited to, bionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate, and the like. In some embodiments, provided compounds contain one or more acidic groups, and the pharmaceutically acceptable salt is an alkali metal salt, alkaline earth metal salt, or ammonium salt (e.g., an ammonium salt of N(R)3, where each R is independently defined and described in this disclosure). Representative alkali metal or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. In some embodiments, the pharmaceutically acceptable salt is a sodium salt. In some embodiments, the pharmaceutically acceptable salt is a potassium salt. In some embodiments, the pharmaceutically acceptable salt is a calcium salt.In some embodiments, pharmaceutically acceptable salts include non-toxic ammonium, quaternary ammonium, and amine cations, formed using counterions such as halides, hydroxides, carboxylates, sulfates, phosphates, nitrates, alkyls having 1 to 6 carbon atoms, sulfonates, and arylsulfonates, as appropriate. In some embodiments, provided compounds contain more than one acid group. In some embodiments, pharmaceutically acceptable salts of such compounds, or salts in general, contain two or more cations, which may be the same or different. In some embodiments, in pharmaceutically acceptable salts (or salts in general), all ionizable hydrogens of acidic groups (e.g., in aqueous solutions having a pKa of about 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2 or less, where the pKa is in some embodiments about 7 or less, in some embodiments about 6 or less, in some embodiments about 5 or less, in some embodiments about 4 or less, and in some embodiments about 3 or less) are replaced with cations.

[0042] Protecting Group: The term "protecting group" is well known in the art and is described in Protecting Groups in Organic Synthesis, T.W. Greene and P.G.M. Butts, 3 rdedition, John Wiley & Sons, 1999, which is incorporated herein by reference in its entirety, and also includes protecting groups specifically adapted for nucleoside and nucleotide chemistry, as described in Current Protocols in Nucleic Acid Chemistry, edited by Serge L. Beaucage et al. 06 / 2012, which is incorporated herein by reference in its entirety, Chapter 2. Suitable amino protecting groups include methyl carbamate, ethyl carbamate, 9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethyl carbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate, 2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methyl carbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc), 2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate (Teoc), 2-methyl- ... -phenylethyl carbamate (hZ), 1-(1-adamantyl)-1-methylethyl carbamate (Adpoc), 1,1-dimethyl-2-haloethyl carbamate, 1,1-dimethyl-2,2-dibromoethyl carbamate (DB-t-BOC), 1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC), 1-methyl-1-(4-biphenylyl)ethyl carbamate (Bpoc), 1-(3,5-di-t-butylphenyl)-1-methylethyl carbamate (t-Bumeoc), 2-(2'-,4'-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethyl carbamate, t-butyl carbamate (BOC), 1-adamantyl carbamate (Adoc), vinyl carbamate (Voc), allyl carbamate (Alloc), 1-isopropyl allyl carbamate (Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc), 8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyl dithiocarbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz), p- Nitobenzyl carbamate, p-bromobenzyl carbamate, p-chlorobenzyl carbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzyl carbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate, 2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate, 2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3-dithianyl)]methyl carbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc), 2,4-dimethylthio Phenyl carbamate (Bmpc), 2-phosphonioethyl carbamate (Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc), 1,1-dimethyl-2-cyanoethyl carbamate, m-chloro-p-acyloxybenzyl carbamate, p-(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate, 2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenyl carbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl Carbamates, 3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methyl carbamate, phenothiazinyl-(10)-carbonyl derivatives, N'-p-toluenesulfonylaminocarbonyl derivatives, N'-phenylaminothiocarbonyl derivatives, t-amyl carbamate, S-benzylthiocarbamate, p-cyanobenzyl carbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentyl carbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate, 2,2-Dimethoxycarbonylvinylcarbamate, o-(N,N-dimethylcarboxamido)benzyl carbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate, 1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate, 2-furanylmethyl carbamate, 2-iodoethyl carbamate, isoborin carbamate, isobutyl carbamate, isonicotinyl carbamate, p-(p'-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate, 1-methyl 1-methyl-1-cyclohexyl carbamate, 1-methyl-1-cyclopropylmethyl carbamate, 1-methyl-1-(3,5-dimethoxyphenyl)ethyl carbamate, 1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1-methyl-1-phenylethyl carbamate, 1-methyl-1-(4-pyridyl)ethyl carbamate, phenyl carbamate, p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate, 4-(trimethylammonium)benzyl carbamate, 2,4,6-trimethylbenzyl Carbamates, formamide, acetamide, chloroacetamide, trichloroacetamide, trifluoroacetamide, phenylacetamide, 3-phenylpropanamide, picolinamide, 3-pyridylcarboxamide, N-benzoylphenylalanyl derivatives, benzamide, p-phenylbenzamide, o-nitrophenylacetamide, o-nitrophenoxyacetamide, acetoacetamide, (N'-dithiobenzyloxycarbonylamino)acetamide, 3-(p-hydroxyphenyl)propanamide, 3-(o-nitrophenoxy)acetamide o-(o-phenyl)propanamide, 2-methyl-2-(o-nitrophenoxy)propanamide, 2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide, 3-methyl-3-nitrobutanamide, o-nitrocinnamide, N-acetylmethionine derivatives, o-nitrobenzamide, o-(benzoyloxymethyl)benzamide, 4,5-diphenyl-3-oxazolin-2-one, N-phthalimide, N-dithiasuccinimide (Dts), N-2,3-diphenylmaleimide, N-2,5-dimethylpyrrole, N-1,1,4,4-Tetramethyldisilylazacyclopentane adduct (STABASE), 5-substituted 1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted 1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1-substituted 3,5-dinitro-4-pyridone, N-methylamine, N-allylamine, N-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3-acetoxypropylamine, N-(1-isopropyl-4-nitro-2-oxo-3-pyrrolin-3-yl)amine, tetra ... Ammonium salts, N-benzylamine, N-di(4-methoxyphenyl)methylamine, N-5-dibenzosuberylamine, N-triphenylmethylamine (Tr), N-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr), N-9-phenylfluorenylamine (PhF), N-2,7-dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm), N-2-picolylamino N'-oxide, N-1,1-dimethylthiomethyleneamine, N-benzylideneamine, Np-methionine N-hydroxybenzylideneamine, N-diphenylmethyleneamine, N-[(2-pyridyl)mesityl]methyleneamine, N-(N',N'-dimethylaminomethylene)amine, N,N'-isopropylidenediamine, Np-nitrobenzylideneamine, N-salicylideneamine, N-5-chlorosalicylideneamine, N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine, N-cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine, N-borane derivatives, N-diphenyl Borinic acid derivatives, N-[phenyl(pentacarbonylchromium or tungsten)carbonyl]amine, N-copper chelate, N-zinc chelate, N-nitroamine, N-nitrosamine, amine N-oxide, diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt), diphenylthiophosphinamide (Ppt), dialkyl phosphoramidate, dibenzyl phosphoramidate, diphenyl phosphoramidate, benzenesulfenamide, o-nitrobenzenesulfenamide (Nps), 2,4-Dinitrobenzenesulfenamide, pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide, triphenylmethylsulfenamide, 3-nitropyridine sulfenamide (Npys), p-toluenesulfonamide (Ts), benzenesulfonamide, 2,3,6-trimethyl-4-methoxybenzenesulfonamide (Mtr), 2,4,6-trimethoxybenzenesulfonamide (Mtb), 2,6-dimethyl-4-methoxybenzenesulfonamide (Pme), 2,3,5,6-tetramethyl-4-methoxybenzenesulfonamide (Mte) , 4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide (Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds), 2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide (Ms), β-trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide, 4-(4',8'-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS), benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

[0043] Suitable protected carboxylic acids further include, but are not limited to, silyl-protected, alkyl-protected, alkenyl-protected, aryl-protected, and arylalkyl-protected carboxylic acids. Examples of suitable silyl groups include trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, triisopropylsilyl, and the like. Examples of suitable alkyl groups include methyl, benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, trityl, t-butyl, and tetrahydropyran-2-yl. Examples of suitable alkenyl groups include allyl. Examples of suitable aryl groups include optionally substituted phenyl, biphenyl, or naphthyl. Examples of suitable arylalkyl groups include optionally substituted benzyl (e.g., p-methoxybenzyl (MPM), 3,4-dimethoxybenzyl, O-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl), and 2- and 4-picolyl.

[0044] Suitable hydroxyl protecting groups include methyl, methoxylmethyl (MOM), methylthiomethyl (MTM), t-butylthiomethyl, (phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM), p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM), guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM), siloxymethyl, 2-methoxyethoxymethyl ( MEM), 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR), tetrahydropyranyl (THP), 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl (MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranyl S,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]phenyl ]-4-Methoxypiperidin-4-yl (CTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl, 1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl, 2,2,2-trimethyl- methylethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl, t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl, benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl, p-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl N-oxide, diphenylmethyl, p,p'-Dinitrobenzhydryl, 5-dibenzosuberyl, triphenylmethyl, α-naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl, tri(p-methoxyphenyl)methyl, 4-(4'-bromophenacyloxyphenyl)diphenylmethyl, 4,4',4''-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4',4''-tris(levulinoyloxyphenyl)methyl, 4,4',4''-tris(benzoyloxyphenyl)methyl methyl, 3-(imidazol-1-yl)bis(4',4''-dimethoxyphenyl)methyl, 1,1-bis(4-methoxyphenyl)-1'-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, 1,3-benzodithiolan-2-yl, benzisothiazolyl S,S-dioxide, trimethylsilyl (TMS), triethylsilyl (TES), triisopropylsilyl (TIPS), dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl silyl (DEIPS), dimethylthexylsilyl, t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl, diphenylmethylsilyl (DPMS), t-butylmethoxyphenylsilyl (TBMPS), formate, benzoylformate, acetate, chloroacetate, dichloroacetate, trichloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, phenoxyacetate Acetate, p-chlorophenoxyacetate, 3-phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate (levulinoyl dithioacetal), pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), alkyl methyl carbonate, 9-fluorenylmethyl carbonate (Fmoc), alkyl ethyl carbonate, alkyl 2,2,2-Trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate (TMSEC), 2-(phenylsulfonyl)ethyl carbonate (Psec), 2-(triphenylphosphonio)ethyl carbonate (Peoc), alkyl isobutyl carbonate, alkyl vinyl carbonate, alkyl allyl carbonate, alkyl p-nitrophenyl carbonate, alkyl benzyl carbonate, alkyl p-methoxybenzyl carbonate, alkyl 3,4-dimethoxybenzyl carbonate, alkyl o-nitrobenzyl carbonate, alkyl p-nitrobenzyl carbonate, alkyl S-benzylthiocarbonate, 4-ethoxy-1-naphthyl carbonate, methyl dithiocarbonate, 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate, 2-formyl Benzene sulfonate, 2-(methylthiomethoxy)ethyl, 4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate, 2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate, isobutyrate, monosuccino ester, (E)-2-methyl-2-butenoate, o-(methoxycarbonyl)benzoate, α-naphthoate, nitrate, alkyl N,N,N',N'-tetramethylphosphorodiamidate, alkyl N-phenylcarbamate, borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate, sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate (Ts). When 1,2-diol or 1,3-diol is protected, the protecting group may be methylene acetal, ethylidene acetal, 1-t-butylethylidene ketal, 1-phenylethylidene ketal, (4-methoxyphenyl)ethylidene acetal, 2,2,2-trichloroethylidene acetal, acetonide, cyclopentylidene ketal, cyclohexylidene ketal, cycloheptylidene ketal, benzylidene acetal, p-methoxybenzylidene acetal, 2,4-Dimethoxybenzylidene ketal, 3,4-dimethoxybenzylidene acetal, 2-nitrobenzylidene acetal, methoxymethylene acetal, ethoxymethylene acetal, dimethoxymethylene orthoester, 1-methoxyethylidene orthoester, 1-ethoxyethylidene orthoester, 1,2-dimethoxyethylidene orthoester, α-methoxybenzylidene orthoester, 1-(N,N-dimethylamino) Examples include ethylidene derivatives, α-(N,N'-dimethylamino)benzylidene derivatives, 2-oxacyclopentylidene orthoesters, di-t-butylsilylene groups (DTBS), 1,3-(1,1,3,3-tetraisopropyldisiloxanylidene) derivatives (TIPDS), tetra-t-butoxydisiloxane-1,3-diylidene derivatives (TBDS), cyclic carbonates, cyclic boronates, ethyl boronate, and phenyl boronate.

[0045] In some embodiments, the hydroxyl protecting group is acetyl, t-butyl, t-butoxymethyl, methoxymethyl, tetrahydropyranyl, 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 2-trimethylsilylethyl, p-chlorophenyl, 2,4-dinitrophenyl, benzyl, benzoyl, p-phenylbenzoyl, 2,6-dichlorobenzyl, diphenylmethyl, p-nitrobenzyl, triphenylmethyl(trityl), 4,4′-dimethoxytrityl, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenyl Silyl, triphenylsilyl, triisopropylsilyl, benzoylformate, chloroacetyl, trichloroacetyl, trifluoroacetyl, pivaloyl, 9-fluorenylmethyl carbonate, mesylate, tosylate, triflate, trityl, monomethoxytrityl (MMTr), 4,4'-dimethoxytrityl (DMTr) and 4,4',4''-trimethoxytrityl (TMTr), 2-cyanoethyl (CE or Cne), 2-(trimethylsilyl)ethyl (TSE), 2-(2-nitrophenyl)ethyl, 2-(4-cyanophenyl)ethyl 2-(4-nitrophenyl)ethyl (NPE), 2-(4-nitrophenylsulfonyl)ethyl, 3,5-dichlorophenyl, 2,4-dimethylphenyl, 2-nitrophenyl, 4-nitrophenyl, 2,4,6-trimethylphenyl, 2-(2-nitrophenyl)ethyl, butylthiocarbonyl, 4,4′,4″-tris(benzoyloxy)trityl, diphenylcarbamoyl, levulinyl, 2-(dibromomethyl)benzoyl(phenylxanthin-9-yl (pixyl), or 9-(p-methoxyphenyl)xanthin-9-yl (MOX). In some embodiments, each of the hydroxyl protecting groups is independently selected from acetyl, benzyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, and 4,4′-dimethoxytrityl. In some embodiments, the hydroxyl protecting group is selected from the group consisting of trityl, monomethoxytrityl, and 4,4′-dimethoxytrityl groups.In some embodiments, the phosphorus-linked protecting group is a group that is attached to the phosphorus bond (e.g., internucleotide bond) throughout oligonucleotide synthesis. In some embodiments, the protecting group is attached to the sulfur atom of a phosphorothioate group. In some embodiments, the protecting group is attached to the oxygen atom of an internucleotide phosphorothioate bond. In some embodiments, the protecting group is attached to the oxygen atom of an internucleotide phosphate bond. In some embodiments, the protecting group is 2-cyanoethyl (CE or Cne), 2-trimethylsilylethyl, 2-nitroethyl, 2-sulfonylethyl, methyl, benzyl, o-nitrobenzyl, 2-(p-nitrophenyl)ethyl (NPE or Npe), 2-phenylethyl, 3-(N-tert-butylcarboxamido)-1-propyl, 4-oxopentyl, 4-methylthio-1-butyl, 2-cyano-1,1-dimethylethyl, 4-N-methylaminobutyl, 3-(2-pyridyl)-1-propyl, 2-[N-methyl-N-(2-pyridyl)]aminoethyl, 2-(N-formyl,N-methyl)aminoethyl, or 4-[N-methyl-N-(2,2,2-trifluoroacetyl)amino]butyl.

[0046] Subject: As used herein, the term "subject" refers to any organism to which a compound or composition is administered in accordance with the present disclosure, e.g., for experimental, diagnostic, prophylactic, and / or therapeutic purposes. Typical subjects include animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and humans, insects, parasites, etc.) and plants. In some embodiments, the subject is a human. In some embodiments, the subject may be suffering from and / or susceptible to a disease, disorder, and / or condition.

[0047] Substantially: As used herein, the term "substantially" refers to the qualitative state of indicating the total or nearly total extent or degree of a desired characteristic or property. Those skilled in the art will understand that biological and chemical phenomena rarely, if ever, reach and / or progress to perfection or achieve or avoid absolute results. Thus, the term "substantially" is used herein to capture the potential lack of perfection inherent in many biological and / or chemical phenomena.

[0048] Therapeutic Agent: In general, the term "therapeutic agent" refers to any agent that, when administered to a subject, induces a desired effect (e.g., a desired biological, clinical, or pharmacological effect). In some embodiments, an agent is considered a therapeutic agent if it demonstrates a statistically significant effect across an appropriate population. In some embodiments, the appropriate population is a population of subjects suffering from and / or susceptible to a disease, disorder, or condition. In some embodiments, the appropriate population is a population of model organisms. In some embodiments, the appropriate population may be defined by one or more criteria, such as age group, sex, genetic background, pre-existing clinical condition, exposure to previous therapy, etc. In some embodiments, a therapeutic agent is a substance that, when administered to a subject in an effective amount, alleviates, ameliorates, relieves, inhibits, prevents, delays the onset of, reduces the severity of, and / or reduces the occurrence of one or more symptoms or characteristics of the disease, disorder, and / or condition of the subject. In some embodiments, a "therapeutic agent" is a drug that has been, or needs to be, approved by a government agency before it can be commercially available for administration to humans. In some embodiments, a "therapeutic agent" is a drug that requires a prescription for administration to humans. In some embodiments, the therapeutic agent is a compound described herein.

[0049] Therapeutically effective amount: The term "therapeutically effective amount" refers to an amount of a substance (e.g., a therapeutic agent, composition, and / or formulation) that, when administered as part of a treatment regimen, elicits a desired biological response. In some embodiments, a therapeutically effective amount of a substance is an amount sufficient to treat, diagnose, prevent, and / or delay the onset of a disease, disorder, and / or condition when administered to a subject suffering from or susceptible to the disease, disorder, and / or condition. As will be understood by one of skill in the art, the effective amount of a substance can vary depending on factors such as the desired biological endpoint, the substance being delivered, and the target cell or tissue. For example, an effective amount of a compound in a formulation for treating a disease, disorder, and / or condition is an amount that alleviates, ameliorates, reduces, inhibits, prevents, delays the onset of, reduces the severity of, and / or reduces the occurrence of one or more symptoms or characteristics of the disease, disorder, and / or condition. In some embodiments, a therapeutically effective amount is administered in a single dose; in some embodiments, multiple unit doses are required to deliver a therapeutically effective amount.

[0050] Treat: The terms "treat," "treatment," or "treating" refer to any method used to partially or completely alleviate, ameliorate, reduce, suppress, prevent, delay onset, reduce severity, and / or reduce the occurrence of one or more symptoms or characteristics of a disease, disorder, and / or condition. Treatment may be administered to a subject who does not show signs of the disease, disorder, and / or condition. In some embodiments, treatment may be administered to a subject who shows only early signs of the disease, disorder, and / or condition, for example, to reduce the risk of developing pathology associated with the disease, disorder, and / or condition.

[0051] Unsaturated: The term "unsaturated," as used herein, means that a moiety has one or more units of unsaturation.

[0052] Unless otherwise stated, structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure, e.g., R and S configurations, Z and E double bond isomers, and Z and E conformers for each asymmetric center. Accordingly, single stereochemical isomers as well as enantiomeric, diastereomeric, and geometric (or conformational) mixtures of the present compounds are within the scope of the disclosure. Unless otherwise stated, all tautomeric forms of the compounds are within the scope of the disclosure. Additionally, unless otherwise stated, structures depicted herein are also meant to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, replacement of hydrogen by deuterium or tritium, or 13 C or 14 Compounds having the inventive structure including the replacement of a carbon with a C-enriched carbon are within the scope of this disclosure. Such compounds are useful, for example, as analytical tools, as probes in biological assays, or as therapeutic agents according to this disclosure.

[0053] 2. Description of Exemplary Embodiments: As described herein, in some embodiments, the present disclosure provides techniques that can conjugate moieties of interest to targets with high efficiency, high selectivity, and / or reduced lateral conversion (e.g., due to the number of chemical reactions and / or conditions / types of chemical reactions). In some embodiments, the present disclosure provides useful reagents and methods for conjugation, resulting in product compositions with enhanced homogeneity (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20-fold or more increase in modification / conjugation at one or more desired sites of the target agent, and and / or 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20-fold or more reduction in modification / conjugation at one or more undesired sites of the targeted agent), purity, and / or reduced undesired modifications (e.g., to specific protein residues as a result of side effects). In some embodiments, the present disclosure provides a compound of formula RI or a salt thereof, as described herein. In some embodiments, a compound of formula RI or a salt thereof is useful for introducing a moiety of interest into a target in a single reaction step. In some embodiments, the present disclosure provides an agent of formula PI or P-II, or a salt thereof. In some embodiments, the product composition comprises multiple agents having a structure of formula PI or P-II, or a salt thereof, and the product composition has a higher level of uniformity of the agents as compared to a reference product composition (e.g., a product composition from a process in which a compound of formula RI, or a salt thereof, is replaced with a compound having the same structure as the compound of formula RI, or a salt thereof, except that each target binding moiety is replaced with -H).

[0054] In some embodiments, the present disclosure provides a method, comprising: 1) A targeting agent, e.g., an antibody, a first group comprising a target binding moiety that binds to a targeting agent; a reactive group; and a moiety of interest that is or contains MMAE; optionally, contacting with a reaction partner comprising one or more linker moieties; 2) A drug, a targeting drug moiety; and a moiety of interest that is or contains MMAE; Optionally, forming an agent comprising one or more linker moieties. Monomethyl auristatin E (MMAE), CAS registration number 474645-27-7, has the following chemical formula: [ka] It is a compound having (MMAE).

[0055] In the disclosed methods, the target binding moiety specifically binds to the targeting agent, and the reactive group reacts with a specific site on the targeting agent, e.g., a specific lysine residue on the targeting agent antibody, such that the agent formed by the method comprises the targeting agent having MMAE attached to the specific site, optionally via a linker.

[0056] In some embodiments, the reactive group is located between the first group and the moiety of interest and is connected to the first group and the moiety of interest independently, and optionally via a linker moiety. In some embodiments, the reactive partner is a compound of formula RI or a salt thereof. In some embodiments, the first group is or includes an LG group described herein. In some embodiments, the first group is or includes an LG group described herein.

[0057] In some embodiments, the present disclosure provides a compound having a structure of formula RI: LG-RG-L RM -MOI (RI) or a salt thereof, wherein: LG is a group comprising a target binding moiety that binds to a targeting agent; RG is a reactive group, LRM is the linker, The MOI provides a compound or salt thereof that is the moiety of interest, including monomethyl auristatin E (MMAE).

[0058] In some embodiments, the present disclosure provides a compound having a structure of formula RI: LG-RG-L RM -MOI (RI) or a salt thereof, wherein: LG is R LG -L LG and R LG teeth, [ka] , R c -(Xaa)z-, a nucleic acid moiety, or a small molecule moiety; each Xaa is independently a residue of an amino acid or amino acid analog; t is 0 to 50; z is 1 to 50; Each R c independently, -L a -R', Each L a are independently a covalent bond or C1 to C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by -C(R')2-, -Cy-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, or -C(O)O-; Each -Cy- is independently an optionally substituted divalent monocyclic, bicyclic, or polycyclic group, and each monocyclic ring is independently C 3~20 Alicyclic ring, C 6~20an aryl ring, a 5- to 20-membered heteroaryl ring having 1 to 10 heteroatoms, and a 3- to 20-membered heterocyclyl ring having 1 to 10 heteroatoms; L LG -L LG1 -, -L LG1 -L LG2 -, -L LG1 -L LG2 -L LG3 - or -L LG1 -L LG2 -L LG3 -L LG4 - and RG is -L RG1 -L RG2 -, -L LG4 -L RG1 -L RG2 -, -L LG3 -L LG4 -L RG1 -L RG2 -, -L LG2 -L LG3 -L LG4 -L RG1 -L RG2 - and L LG1 , L LG2 , L LG3 , L LG4 , L RG1 , L RG2 , and L RM each is independently L; Each L is independently a covalent bond or a divalent optionally substituted straight-chain or branched C alkyl group containing one or more aliphatic moieties, aryl moieties, heteroaliphatic moieties each independently having 1 to 20 heteroatoms, heteroaromatic moieties each independently having 1 to 20 heteroatoms, or any combination of any one or more of such moieties. 1~100 is a group, wherein one or more methylene units of the group are optionally and independently selected from C 1~6 Alkylene, C 1~6 Alkenylene, divalent C with 1 to 5 heteroatoms 1~6Heteroaliphatic group, -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')- , -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S- , -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P(S)(SR')-, -P( S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n ]- (wherein n is 1 to 20), each R' is independently -R, -C(O)R, -COR, or -SOR; Each R is independently —H or C 1~30 Aliphatic, C with 1-10 heteroatoms 1~30 Heteroaliphatic, C 6~30 Aryl, C 6~30 Arylaliphatic, C with 1-10 heteroatoms 6~30 an optionally substituted group selected from arylheteroaliphatic, 5-30 membered heteroaryl having 1-10 heteroatoms, and 3-30 membered heterocyclyl having 1-10 heteroatoms; or two R groups, optionally and independently, together form a covalent bond; or two or more R groups on the same atom optionally and independently combine with said atom to form an optionally substituted 3-30 membered monocyclic, bicyclic, or polycyclic ring having, in addition to said atom, 0-10 heteroatoms; or two or more R groups on two or more atoms optionally and independently, together with their intervening atoms, form an optionally substituted 3-30 membered monocyclic, bicyclic, or polycyclic ring having, in addition to the intervening atoms, 0-10 heteroatoms; The MOI provides a compound or salt thereof that is the moiety of interest, including monomethyl auristatin E (MMAE).

[0059] In some embodiments, the present disclosure provides a method, comprising: 1) a targeting agent and a reactive partner having a structure of formula RI; LG-RG-L RM -MOI (RI) or a salt thereof (wherein LG is a group comprising a target binding domain that binds to a targeted agent; RG is a reactive group, L RM is the linker, the MOI being MMAE or a moiety of interest comprising same; 2) a drug having the structure of formula PI; PL PM -MOI (PI) or a salt thereof (wherein P is a targeting drug moiety; L PM is the linker, the MOI being MMAE or a moiety of interest comprising same.

[0060] In some embodiments, the targeting agent is an antibody. In some embodiments, the targeting agent is an IgG antibody. For example, the antibody can be an anti-CD30 monoclonal antibody such as brentuximab, or an anti-nectin-4 antibody such as enfortumab. In some embodiments, the target is a protein, and the moiety of interest is conjugated to one or more lysine residues. In some embodiments, the agent of formula PI or a salt thereof is an agent of formula P-II or a salt thereof.

[0061] In some embodiments, the present disclosure provides a drug having the structure of P-II. PNL PM -MOI (P-II) 1. A method for preparing a compound of formula PN is a protein drug moiety containing a lysine residue, L PM is the linker, MOI is the fraction of objective The method comprises: PN and a reaction partner having the structure of formula RI, LG-RG-L RM -MOI (RI) or a salt thereof (wherein LG is a group containing a protein-binding domain that binds to PN; RG is a reactive group, L RM is the linker, The MOI is MMAE or a moiety of interest comprising same.

[0062] In some embodiments, as exemplified herein, the contacting is carried out under conditions and for a time sufficient for the lysine residue N to react and form a bond with an atom of RG, releasing LG.

[0063] target After reading this disclosure, one skilled in the art will understand that the techniques provided herein are useful for conjugating a variety of targeting agents to many types of moieties of interest. In some embodiments, the techniques provided are particularly useful for conjugating protein agents to various moieties of interest. In some embodiments, the targeting agent is or includes a nucleic acid.

[0064] In some embodiments, the targeting agent is or comprises a protein drug. In some embodiments, the targeting agent is a protein drug. In some embodiments, the targeting agent is a naturally occurring protein in a cell, tissue, organ, or organism. In some embodiments, the targeting agent is an endogenous protein. In some embodiments, the targeting agent is an exogenous protein. In some embodiments, the targeting agent is a manufactured protein, e.g., a protein produced using various biotechnologies. In some embodiments, the targeting agent is an antibody drug. In some embodiments, the targeting agent is an antibody useful as a therapeutic agent. A variety of such antibodies are known in the art and can be utilized as targeting agents. In some embodiments, the antibody is a monoclonal antibody. In some embodiments, the antibody is a polyclonal antibody. In some embodiments, the antibody is an IgG antibody. In some embodiments, the antibody is IVIG (in some embodiments, pooled from healthy donors). In some embodiments, the protein comprises an Fc region. In some embodiments, the antibody comprises an Fc region. In some embodiments, the Fc region comprises a single heavy chain or fragment thereof. In some embodiments, the Fc region comprises two heavy chains or fragments thereof. In some embodiments, the antibody is a human antibody. In some embodiments, the antibody is a chimeric antibody. In some embodiments, the antibody is a humanized antibody. In some embodiments, the antibody is a murine antibody.

[0065] In some embodiments, when characterizing polyclonal antibody or IVIG agents, digestion, e.g., enzymatic digestion using IdeZ, IdeS, etc., is performed either before, during, or after conjugation, resulting in the removal of specific regions of the antibody (e.g., the Fab) and providing a composition with improved homogeneity for characterization (e.g., by MS).

[0066] In some embodiments, the antibody is a therapeutic antibody, for example, an FDA-approved antibody for therapeutic use. In some embodiments, the therapeutic antibody is useful for treating cancer. In some embodiments, the antibody is selected from the group consisting of adalimumab, alemtuzumab, atezolizumab, avelumab, basiliximab, brentuximab, enfortumab, ipilimumab, cetuximab, daratumumab, dinutuximab, elotuzumab, ibritumomab tiuxetan, imgatuzumab, infliximab, necitumumab, obinutuzumab, ofatumumab, pertuzumab, reslizumab, rituximab, trastuzumab, mogamulizumab, AMP-224, FS-102, GSK-2857916, ARGX-111, ARGX-110, AFM-13, APN- 301, BI-836826, BI-836858, enoblitzumab, otlertuzumab, veltuzumab, KHK-4083, BIW-8962, ALT-803, carotuximab, epratuzumab, inebilizumab, isatuximab, margetuximab, MOR-208, ocaratuzumab, talatuzumab, tremelimumab, benralizumab, lumiliximab, MOR-208, ifibatuzumab, GSK2831781, SEA-CD40, KHK-2823, or BI836858. In some embodiments, the antibody is siltuximab, daclizumab, palivizumab, omalizumab, efalizumab, bevacizumab, natalizumab, tocilizumab, eculizumab, vedolizumab, pembrolizumab, mepolizumab, ixekizumab, panitumumab, golimumab, ustekinumab, canakinumab, denosumab, belimumab, raxibacumab, ramucirumab, nivolumab, secukinumab, evolocumab, alirocumab, brodalumab, or olaratumab. In some embodiments, the antibody is brentuximab or enfortumab. In some embodiments, the antibody is cetuximab. In some embodiments, provided compounds or drugs comprising an antibody drug moiety are useful for treating a condition, disorder, or disease that can be treated by an antibody drug.

[0067] Antibodies may be prepared in accordance with the present disclosure by several techniques. In some embodiments, antibodies may have an engineered structure compared to native immunoglobulins. In some embodiments, antibodies may include specific tags for purification, identification, characterization, etc. In some embodiments, antibodies may contain fragments (e.g., CDRs and / or Fc, etc.) and may not contain the entire immunoglobulin. One of skill in the art will understand that when antibody sites are cited in the present disclosure (e.g., K246, K248, K288, K290, K317, etc., human antibodies according to EU numbering unless otherwise indicated), the amino acid residue may not be at the exact numbered site, but may be present at the site corresponding to that numbered site, e.g., according to EU numbering, and / or sequence homology (e.g., homologs in the same or different species).

[0068] As will be appreciated by those skilled in the art, among other things, the provided techniques can provide for directed conjugation with natural targets (e.g., natural antibodies). In some embodiments, the targeting agent is or comprises a natural antibody drug. In some embodiments, the targeting agent is or comprises an engineered antibody drug. In some embodiments, the targeting agent (e.g., an antibody) does not comprise an engineered non-natural amino acid residue.

[0069] Partner Compounds In some embodiments, the present disclosure provides compounds comprising a first group each independently comprising a target-binding moiety that binds to an antibody drug, a reactive group, a moiety of interest, and optionally one or more linker moieties connecting such groups / moieties. In some embodiments, such compounds are useful as reaction partners for conjugating a moiety of interest to a target. In some embodiments, the present disclosure provides compounds for conjugating a moiety of interest to a target, e.g., various proteins. In some embodiments, the provided compounds each comprise a moiety of interest, a reactive group, a target-binding moiety, and optionally one or more moieties (linkers) connecting such moieties. In some embodiments, the target-binding moiety is part of a leaving group that is released upon contacting such a compound with a target and reacting the reactive group of the compound with a reactive group of the target (e.g., -NH2 of a Lys residue in a target protein). As demonstrated herein, among other things, the provided compounds can provide improved conjugation efficiency, high selectivity, and fewer steps (in some cases, a single step) for the conjugation product. In some embodiments, the provided compounds have a structure of formula RI: LG-RG-L RM -MOI (RI) or a salt thereof, wherein: LG is a group comprising a target binding moiety that binds to a targeting agent; RG is a reactive group, L RM is the linker, The MOI is or is a moiety of interest that includes MMAE.

[0070] In some embodiments, the first group is LG.

[0071] In some embodiments, LG is or comprises a target binding moiety capable of binding to a targeting agent, and optionally a linker moiety.

[0072] As used in this disclosure, a moiety generally refers to a portion of a molecule, e.g., the moiety in an ester RCOOR', where the alcohol moiety is RO-. In some embodiments, a portion of a compound (e.g., a targeted agent, a protein agent, an antibody agent, etc.) retains one or more or all of the desired structural features, properties, functions, and / or activities of the compound. For example, in some embodiments, a target binding moiety can bind to a target as its corresponding target binding compound, optionally in an equivalent manner; in some embodiments, a targeted agent moiety maintains one or more desired structural features, properties, functions, and / or properties equivalent to its corresponding targeted agent compound; and in some embodiments, an antibody agent moiety maintains one or more desired structural features, properties, functions, and / or properties equivalent to its corresponding antibody agent compound (e.g., three-dimensional structure, antigen specificity, antigen binding ability, and / or immunological function, etc.). In some embodiments, a moiety of a compound (e.g., a targeted drug moiety, a protein drug moiety, an antibody drug moiety, etc.) is a monovalent (in the case of a monovalent moiety), divalent (in the case of a divalent moiety), or polyvalent (in the case of a polyvalent moiety) radical of a compound, e.g., a targeted drug compound (in the case of a targeted drug moiety), a protein drug compound (in the case of a protein drug moiety), an antibody drug compound (in the case of an antibody drug moiety), etc. In some embodiments, a monovalent radical is formed by removing a monovalent moiety (e.g., another monovalent group such as hydrogen, halogen, alkyl, aryl, etc.) from a compound. In some embodiments, a divalent or polyvalent radical is formed by removing one or more monovalent (e.g., a monovalent group such as hydrogen, halogen, alkyl, aryl, etc.), divalent, and / or polyvalent moieties from a compound. In some embodiments, a radical is formed by removing a hydrogen atom. In some embodiments, the moiety is monovalent. In some embodiments, the moiety is divalent. In some embodiments, the moiety is polyvalent.

[0073] In some embodiments, LG is R LG -L LG - or contains R LG is or comprises a target binding moiety, and L LG is the L described herein LG1In some embodiments, L LG -L LG1 -L LG2 - and L LG1 and L LG2 and each of L is independently as described herein. LG -L LG1 -L LG2 -L LG3 - and L LG1 , L LG2 and L LG3 and each of L is independently as described herein. LG -L LG1 -L LG2 -L LG3 -L LG4 - and L LG1 , L LG2 , L LG3 and L LG4 and each of L is independently as described herein. LG1 is R LG In some embodiments, L LG1 is attached to a moiety of interest. LG -L LG1 - and the reactive group is L LG2 , L LG3 and L LG4 In some embodiments, L LG -L LG1 -L LG2 - and the reactive group is L LG3 and L LG4 In some embodiments, L LG -L LG1 -L LG2 -L LG3 - and the reactive group is L LG4 Includes.

[0074] In some embodiments, the target binding moiety, the first group, and / or LG are released after reaction, for example, after the partner compound reacts with the targeting agent. In some embodiments, the first group is released after reaction. In some embodiments, the target binding moiety is released after reaction. In some embodiments, LG is released after reaction. In some embodiments, the first group is released as part of a compound having the structure LG-H or a salt thereof. In some embodiments, the target binding moiety is released as part of a compound having the structure LG-H or a salt thereof. In some embodiments, LG is released as part of a compound having the structure LG-H or a salt thereof. In some embodiments, the first group is R LG -L LG1 -L LG2 -L LG3 -L LG4 In some embodiments, the target binding moiety is released as part of a compound having the structure —H or a salt thereof. LG -L LG1 -L LG2 -L LG3 -L LG4 In some embodiments, the target binding moiety is released as part of a compound having the structure —H or a salt thereof. LG -L LG1 -L LG2 -L LG3 -L LG4 -H or a salt thereof, and R LG is or comprises a target binding moiety. In some embodiments, LG is R LG -L LG1 -L LG2 -L LG3 -L LG4 -H or a salt thereof, and LG is released as a part of a compound having the structure R LG -L LG and L LG -L LG1 -, -L LG1 -L LG2 -, -L LG1 -L LG2 -L LG3 - or -L LG1 -L LG2 -L LG3 -LLG4 In some embodiments, LG is R LG -L LG1 -L LG2 -L LG3 -L LG4 -H or a salt thereof, and LG is released as a part of a compound having the structure R LG -L LG1 In some embodiments, LG is R LG -L LG1 -L LG2 -L LG3 -L LG4 -H or a salt thereof, and LG is released as a part of a compound having the structure R LG -L LG1 -L LG2 In some embodiments, LG is R LG -L LG1 -L LG2 -L LG3 -L LG4 -H or a salt thereof, and LG is released as a part of a compound having the structure R LG -L LG1 -L LG2 -L LG3 In some embodiments, LG is R LG -L LG1 -L LG2 -L LG3 -L LG4 -H or a salt thereof, and LG is released as a part of a compound having the structure R LG -L LG1 -L LG2 -L LG3 -L LG4 is.

[0075] In some embodiments, L is a covalent bond or a divalent optionally substituted straight-chain or branched C alkyl group comprising one or more aliphatic moieties, aryl moieties, heteroaliphatic moieties each independently having 1 to 20 heteroatoms, heteroaromatic moieties each independently having 1 to 20 heteroatoms, or any combination of any one or more of such moieties. 1~100 is a group, wherein one or more methylene units of the group are optionally and independently selected from C 1~6 Alkylene, C 1~6Alkenylene, divalent C with 1 to 5 heteroatoms 1~6 Heteroaliphatic group, -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')- , -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S- , -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P(S)(SR')-, -P( S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n In some embodiments, L is a covalent bond or a divalent optionally substituted straight or branched C 1~100 an aliphatic or heteroaliphatic group having 1 to 20 heteroatoms, wherein one or more methylene units of the group are optionally and independently selected from: -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR') -, -P(S)(SR')-, -P(S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, or -[(-OC(R')2-C(R')2-) n In some embodiments, L is a covalent bond or a divalent optionally substituted linear or branched C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C27, C28, C29, C30, C31, C32, C33, C44, C55, C34, C35, C36, C37, C48, C56, C57, C58, C69, C70, C71, C72, C73, C74, C75, C76, C77, C78, ​​C79, C81, C82, C83, C84, C85, C86, C87, C88, C89, C91, C92, C93, C94, C95, C96, C97, C98, C99, C91 ...5, C96, C97, C98, C99, C99, C100, C99, C111, C99, C122, C99, C132, C99, C142, C99, C152, C99, C163, C99, C174, C185, C195, C196, C197, C198, C199, C199, C199, C199, C199, C101, 10 , C 15 , C 20 , C25 , C 30 , C 40 , C 50 , C 60 , C 1~2 , C 1~5 , C 1~10 , C 1~15 , C 1~20 , C 1~30 , C 1~40 , C 1~50 , C 1~60 , C 1~70 , C 1~80 , or C 1~90 an aliphatic or heteroaliphatic group having 1 to 10 heteroatoms, wherein one or more methylene units of the group are optionally and independently selected from the group consisting of -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O )2-, -S(O)2N(R')-, -C(O)S-, -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P( S)(SR')-, -P(S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n In some embodiments, L is a covalent bond or a divalent optionally substituted linear or branched C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C27, C28, C29, C30, C31, C32, C33, C44, C55, C34, C35, C36, C37, C48, C56, C57, C58, C69, C70, C71, C72, C73, C74, C75, C76, C77, C78, ​​C79, C81, C82, C83, C84, C85, C86, C87, C88, C89, C91, C92, C93, C94, C95, C96, C97, C98, C99, C91 ...5, C96, C97, C98, C99, C99, C100, C99, C111, C99, C122, C99, C132, C99, C142, C99, C152, C99, C163, C99, C174, C185, C195, C196, C197, C198, C199, C199, C199, C199, C199, C101, 10 , C 15 , C 20 , C 25 , C 30 , C 40 , C 50 , C 60 , C 1~2 , C 1~5 , C 1~10 , C 1~15 , C 1~20 , C 1~30 , C 1~40 , C 1~50 , C 1~60 , C 1~70, C 1~80 , or C 1~90 an aliphatic or heteroaliphatic group having 1 to 10 heteroatoms, wherein one or more methylene units of the group are optionally and independently selected from -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, -C(O)O-, an amino acid residue, or -[(-OC(R')2-C(R')2-) n In some embodiments, L is a covalent bond or a divalent optionally substituted linear or branched C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C27, C28, C29, C30, C31, C32, C33, C34, C35, C36, C37, C38, C40, C51, C52, C53, C54, C55, C56, C57, C58, C59, C69, C69, C69, C70, C71, C72, C73, C74, C75, C76, C77, C78, ​​C79, C80, C81, C82, C83, C84, C85, C86, C87, C88, C89, C91, C92, C93, C94, C95, C96, C97, C98, C99, C91 ...5, C96, C97, C98, C99, C99, C100, C99, C111, C99, C122, C99, C133, C99, C143, C99, C152, C163, C174, C185, C195, C196, C197, C198, C199, C 10 , C 15 , C 20 , C 25 , C 30 , C 40 , C 50 , C 60 , C 1~2 , C 1~5 , C 1~10 , C 1~15 , C 1~20 , C 1~30 , C 1~40 , C 1~50 , C 1~60 , C 1~70 , C 1~80 , or C 1~90 is an aliphatic group, wherein one or more methylene units of the group are optionally and independently -O-, -N(R')-, -C(O)-, -C(O)N(R')-, -C(O)C(R')N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)-, -S(O)N(R')-, or -[(-OC(R')-C(R')-) n In some embodiments, L is a covalent bond or a divalent optionally substituted linear or branched C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C27, C28, C29, C30, C31, C32, C33, C34, C35, C36, C37, C38, C40, C51, C52, C53, C54, C55, C56, C57, C58, C59, C69, C69, C69, C70, C71, C72, C73, C74, C75, C76, C77, C78, ​​C79, C80, C81, C82, C83, C84, C85, C86, C87, C88, C89, C91, C92, C93, C94, C95, C96, C97, C98, C99, C91 ...5, C96, C97, C98, C99, C99, C100, C99, C111, C99, C122, C99, C133, C99, C143, C99, C152, C163, C174, C185, C195, C196, C197, C198, C199, C 10 , C 15 , C 20 , C25 , C 30 , C 40 , C 50 , C 60 , C 1~2 , C 1~5 , C 1~10 , C 1~15 , C 1~20 , C 1~30 , C 1~40 , C 1~50 , C 1~60 , C 1~70 , C 1~80 , or C 1~90 is an aliphatic group, wherein one or more methylene units of the group are optionally and independently -O-, -N(R')-, -C(O)-, -C(O)N(R')-, -C(O)C(R')N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)-, -S(O)N(R')-, or -[(-OC(R')-C(R')-) n In some embodiments, L is replaced by a covalent bond or a divalent optionally substituted straight or branched C 1~10 is an aliphatic group, wherein one or more methylene units of the group are optionally and independently -O-, -N(R')-, -C(O)-, -C(O)N(R')-, -C(O)C(R')N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)-, -S(O)N(R')-, -Cy-, or -[(-OC(R')-C(R')-) n In some embodiments, L is replaced by a covalent bond or a divalent optionally substituted straight or branched C 1~10 is an aliphatic group, wherein one or more methylene units of the group are optionally and independently -O-, -N(R')-, -C(O)-, -C(O)N(R')-, -C(O)C(R')N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)-, -S(O)N(R')-, or -[(-OC(R')-C(R')-) n]- (wherein n is 1 to 10). In some embodiments, L does not contain -C(O)O-. In some embodiments, L does not contain -C(O)-N(R')-. In some embodiments, L does not contain -S-. In some embodiments, L does not contain -S-Cy-. In some embodiments, L does not contain -SS-. In some embodiments, L does not contain one or more, or any, of -C(O)O-, -C(O)-N(R')-, -S-, and -SS-. In some embodiments, L does not contain one or more, or any, of -C(O)O-, -C(O)-N(R')-, -S-Cy-, and -SS-. In some embodiments, L does not contain one or more, or any, of -C(O)O-, -C(O)-N(R')-, -S-Cy-, and -SS-. In some embodiments, L does not contain one or more, or any, of -C(O)O-, -S-Cy-, and -SS-. In some embodiments, L does not contain any of -C(O)O-, -S-, and -SS-. In some embodiments, L does not contain any of -C(O)O-, -S-Cy-, and -SS-. In some embodiments, L does not contain any of -C(O)O- and -SS-.

[0076] In some embodiments, each amino acid residue is independently a residue of an amino acid having the structure of formula AI, or a salt thereof. In some embodiments, each amino acid residue is independently -N(R a1 )-L a1 -C(R a2 )(R a3 )-L a2 In some embodiments, each amino acid residue independently has the structure -N(R a1 )-C(R a2 )(R a3 )-CO- or a salt thereof.

[0077] In some embodiments, L is a covalent bond. In some embodiments, L is not a covalent bond.

[0078] In some embodiments, L LG1is a covalent bond. In some embodiments, L LG1 is not a covalent bond. LG1 In some embodiments, L is or includes -(CHCHO)-. LG1 is or includes -(CH2)nO-(CH2CH2O)n-(CH2)n-, where each n is independently as described herein and each -CH2- is independently optionally substituted. In some embodiments, L LG1 is —(CH)O—(CHCHO)—(CH)—, where each n is independently as described herein and each —CH— is independently optionally substituted. In some embodiments, L LG1 is —(CH)—O—(CHCHO)—(CH)—, where n is as described herein, and each —CH— is independently optionally substituted. In some embodiments, L LG1 is —(CH 2 ) 2 —O—(CH 2 CH 2 O) n —(CH 2 ) 2 —, where n is as described herein.

[0079] In some embodiments, L LG1 is -CH-. In some embodiments, L LG1 is —(CH)—. In some embodiments, L LG1 is —(CH)—C(O)—. In some embodiments, L LG1 is —(CH)—C(O)—NH—. In some embodiments, L LG1 is —(CH)—. In some embodiments, L LG1 is —(CH 2 ) 3 NH—. In some embodiments, L LG1 is —(CH)NH—C(O)—. In some embodiments, L LG1 is —C(O)—(CH)NH—C(O)—. In some embodiments, L LG1 is —C(O)—(CH)—. In some embodiments, L LG1 is —NH—C(O)—(CH)—. In some embodiments, LLG1 is —NHC(O)—(CH 2 ) 3 NH—C(O)—. In some embodiments, —CH 2 — is attached to a target binding moiety.

[0080] In some embodiments, L LG1 is —CH2CH2—O—CH2CH2—O—CH2CH2—. In some embodiments, L LG1 is —CH2CH2—O—CH2CH2—O—CH2CH2—C(O)—. In some embodiments, L LG1 is —CH2CH2—O—CH2CH2—O—CH2CH2—C(O)NH—. In some embodiments, L LG1 is -CH2CH2-O-CH2CH2-O-CH2CH2-C(O)NH-CH2-. In some embodiments, -CH2CH2- is attached to a target binding moiety.

[0081] In some embodiments, L LG1 is —(CH2CH2O)n—. In some embodiments, L LG1 is —(CH2CH2O)n-CH2-CH2-. In some embodiments, L LG1 is —(CH2CH2O)n-CH2-CH2-C(O)—. In some embodiments, L LG1 is —(CH2CH2O)2—CH2—CH2—C(O)—. In some embodiments, L LG1 is —(CH2CH2O)4—CH2—CH2—C(O)—. In some embodiments, L LG1 is —(CH 2 CH 2 O) 8 —CH 2 —CH 2 —C(O)—. In some embodiments, —C(O)— is attached to a target binding moiety.

[0082] In some embodiments, L LG1 is -N(R')-. In some embodiments, L LG1 In some embodiments, L LG1 is -NH-[(-CHCH-O-)]-. In some embodiments, L LG1is —NH—[(—CHCH—O—)]—CHCH—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—NH—. In some embodiments, L LG1 is -NH-[(-CH2CH2-O-)]n-CH2CH2-NH-C(O)-. In some embodiments, n is 1. In some embodiments, n is 2. In some embodiments, n is 3. In some embodiments, n is 4. In some embodiments, n is 5. In some embodiments, L LG1 is —NH—CHCH—O—. In some embodiments, L LG1 is —NH—CH2CH2—O—CH2CH2—. In some embodiments, L LG1 is —NH—CHCH—O—CHCH—NH—. In some embodiments, L LG1 is -NH-CH2CH2-O-CH2CH2-NH-C(O)-.

[0083] In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—NH—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—NH—C(O)—.

[0084] In some embodiments, L LG1 is -NH-[(-CHCH-O-)]-. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—NH—. In some embodiments, L LG1is —NH—[(—CHCH—O—)]—CHCH—NH—C(O)—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—NH—. In some embodiments, L LG1 is —NH—[(—CHCH—O—)]—CHCH—NH—C(O)—. In some embodiments, L LG1 is -NH-[(-CHCH-O-)]-. In some embodiments, L LG1 is -NH-[(-CHCH-O-)]-CHCH-. In some embodiments, L LG1 is -NH-[(-CHCH-O-)]-CHCH-NH-. In some embodiments, L LG1 is -NH-[(-CH2CH2-O-)]5-CH2CH2-NH-C(O)-. In some embodiments, -NH- is attached to a target binding moiety.

[0085] In some embodiments, L LG1 is -CH-. In some embodiments, L LG1 is -CHCH-. In some embodiments, L LG1 is —CH2CH2NH—. In some embodiments, L LG1 is —CH 2 CH 2 NH—(CO)—. In some embodiments, —CH 2 — is attached to a target binding moiety.

[0086] In some embodiments, L LG1 is -CH-. In some embodiments, L LG1 is —CHC(O)—. In some embodiments, L LG1 is —CHC(O)NH—. In some embodiments, L LG1is —CH 2 (CO)NHCH 2 —. In some embodiments, —CH 2 —C(O)— is attached to the target binding moiety at —CH 2 —.

[0087] In some embodiments, L LG2 is a covalent bond. In some embodiments, L LG2 is not a covalent bond. LG2 is —N(R′)C(O)—. In some embodiments, L LG2 is —NHC(O)—. In some embodiments, L LG2 is —(CH)N(R′)C(O)—, where —(CH)— is optionally substituted. In some embodiments, L LG2 is —(CH)—OC(O)—, where —(CH)— is optionally substituted. In some embodiments, L LG2 is —(CH)—OC(O)N(R′)—, where —(CH)— is optionally substituted. In some embodiments, L LG2 is -(CH2)n-OC(O)NH-, where -(CH2)n- is optionally substituted. In some embodiments, n is 1 to 10, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, n is 1. In some embodiments, n is 2. In some embodiments, n is 3. In some embodiments, -(CH2)n- is substituted. In some embodiments, -(CH2)n- is unsubstituted. In some embodiments, L LG2 is —CHN(CHCHCHS(O)OH)—C(O)—. In some embodiments, L LG2 is —C(O)—NHCH—. In some embodiments, L LG2 is —C(O)—NHCH2CH2—. In some embodiments, L LG2 is —C(O)O—CH—. In some embodiments, L LG2 is -NH-C(O)O-CH-. In some embodiments, -C(O)- is L LG3In some embodiments, the -N(R')-, -NH-, or optionally substituted -CH2- unit (of optionally substituted -(CH2)n-) is bonded to L LG3 is connected to

[0088] In some embodiments, L LG2 is -N(R')-. In some embodiments, L LG2 is -N(R)-. In some embodiments, L LG2 is -NH-.

[0089] In some embodiments, L LG2 is an optionally substituted divalent C 1~6 In some embodiments, L LG2 is -CH-. In some embodiments, L LG2 is —CHNH—. In some embodiments, L LG2 is —CHNH—C(O)—. In some embodiments, L LG2 is -CH2NH-C(O)-CH2-.

[0090] In some embodiments, L LG3 is or includes an optionally substituted aryl ring. In some embodiments, L LG3 is or includes an optionally substituted phenyl ring. In some embodiments, L LG3is a phenyl ring substituted with one or more electron-withdrawing groups. As will be appreciated by one of ordinary skill in the art, a variety of electron-withdrawing groups are known in the art and may be utilized in accordance with the present disclosure. In some embodiments, the electron-withdrawing group is a halogen. In some embodiments, the electron-withdrawing group is -F. In some embodiments, the electron-withdrawing group is -Cl. In some embodiments, the electron-withdrawing group is -Br. In some embodiments, the electron-withdrawing group is -I. In some embodiments, the electron-withdrawing group comprises an X=Y double bond, where X is bonded to a group to which the electron-withdrawing group is a substituent, and at least one of X and Y is a heteroatom. In some embodiments, X is a heteroatom. In some embodiments, Y is a heteroatom. In some embodiments, each of X and Y is independently a heteroatom. In some embodiments, Y is O. In some embodiments, Y is S. In some embodiments, X is C. In some embodiments, X is N. In some embodiments, X is P. In some embodiments, X is S. In some embodiments, X=Y is C=O. In some embodiments, X=Y is N=O. In some embodiments, X=Y is S=O. In some embodiments, X=Y is P=O. In some embodiments, the electron withdrawing group is -C(O)-L-R'. In some embodiments, the electron withdrawing group is -C(O)-R'. In some embodiments, it is -NO2. In some embodiments, it is S(O)-L-R'. In some embodiments, it is -S(O)-R'. In some embodiments, it is -S(O)-L-R'. In some embodiments, it is -S(O)-O-R'. In some embodiments, it is -S(O)-N(R')2. In some embodiments, it is -P(O)(-L-R')2. In some embodiments, it is -P(O)(R')2. In some embodiments, it is -P(O)(OR')2. In some embodiments, it is -P(O)[N(R')2]2.

[0091] In some embodiments, L LG3 -L LG3a -L LG3b - and L LG3ais a covalent bond or —C(O)O—CH—, where —CH— is optionally substituted; L LG3b is an optionally substituted aryl ring. In some embodiments, L LG3a L LG2 is bonded to L LG3b L LG4 is connected to

[0092] In some embodiments, L LG3a is a covalent bond. In some embodiments, L LG3a is —C(O)O—CH—, where —CH— is optionally substituted. In some embodiments, L LG3a is —C(O)O—CH—, wherein —CH— is substituted. LG3a is —C(O)O—CH—, where —CH— is unsubstituted.

[0093] In some embodiments, the first group, the target binding moiety, and / or LG is R LG -L LG1 -L LG2 It is released as part of a compound having the structure —H or a salt thereof.

[0094] In some embodiments, L LG3b is an optionally substituted phenyl ring. In some embodiments, at least one substituent is an electron-withdrawing group as described herein.

[0095] In some embodiments, L LG3 teeth, [ka] s is 0 to 4, and each R s are independently halogen, -NO2, -L-R', -C(O)-L-R', -S(O)-L-R', -S(O)2-L-R', or -P(O)(-L-R')2. LG4 In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] is.

[0096] In some embodiments, L LG3b teeth, [ka] wherein s is 0 to 4, and each R s are independently halogen, -NO2, -L-R', -C(O)-L-R', -S(O)-L-R', -S(O)2-L-R', or -P(O)(-L-R')2. LG4 In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] is.

[0097] In some embodiments, s is 0. In some embodiments, s is 1-4. In some embodiments, s is 1. In some embodiments, s is 2. In some embodiments, s is 3. In some embodiments, s is 4.

[0098] In some embodiments, s is 1 to 4 and at least one R s is an electron withdrawing group, such as those described above. In some embodiments, at least one R s is —NO. In some embodiments, at least one R s is -F. In some embodiments, each R s is independently an electron-withdrawing group. s is —NO. In some embodiments, each R s is -F.

[0099] In some embodiments, the electron withdrawing group or R s is at C2. In some embodiments, an electron withdrawing group or R s is at C3. In some embodiments, an electron withdrawing group or Rs is at C4. In some embodiments, an electron withdrawing group or R s are in C2 and C5.

[0100] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] In some embodiments, L LG3 teeth, [ka] is.

[0101] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] In some embodiments, L LG3b teeth, [ka] is.

[0102] In some embodiments, L LG3b is optionally substituted [ka] In some embodiments, the nitrogen atom is —O—. LG4 In some embodiments, the nitrogen atom is bonded to L, which is —O—. LG4 is connected to -L RG1 -L RG2 - is -C(O)-.

[0103] In some embodiments, -L LG4 -L RG1 -L RG2 - is -OC(O)-. In some embodiments, -L LG4 -L RG1 -L RG2 - is -SC(O)-. In some embodiments, -L LG4 -L RG1 -L RG2 - is -SC(O)-.

[0104] In some embodiments, L LG4 is a covalent bond. In some embodiments, L LG4 is not a covalent bond. LG4 is —O—. In some embodiments, L LG4 is -N(R')-. In some embodiments, L LG4 In some embodiments, L LG4 is —N(CH)—. In some embodiments, L LG4 is -N(R')-, and L LG3 In some embodiments, R' is an optionally substituted C 1~6 In some embodiments, L LG4 is -S-.

[0105] target binding moiety As will be appreciated by those of skill in the art, a variety of target binding moieties can be utilized in accordance with the present disclosure. A variety of techniques for developing and evaluating target binding moieties are also available in the art and can be utilized in accordance with the present disclosure.

[0106] In some embodiments, the target binding moiety is or comprises a small molecule moiety. In some embodiments, the target binding moiety is or comprises a polymer moiety. In some embodiments, the target binding moiety is or comprises a nucleic acid or a fragment thereof. In some embodiments, the target binding moiety is or comprises a peptide moiety. In some embodiments, the target binding moiety is a polypeptide moiety.

[0107] In some embodiments, the provided technology comprises one or less target-binding moieties. In some embodiments, the provided technology comprises two or more target-binding moieties. For example, in some embodiments, the provided compounds may comprise two or more target-binding moieties capable of binding to a targeted antibody drug.

[0108] a. Small molecules In some embodiments, the target-binding moiety is or includes a small molecule moiety that can selectively bind to a targeting agent. Small molecule binding agents for targeting agents, including various protein drugs, are widely known in the art and can be utilized in accordance with the present disclosure. In some embodiments, the small molecule binding agent is or is part of a therapeutic agent (e.g., a drug, an antibody-drug conjugate, etc.).

[0109] In some embodiments, the target binding moiety is a small molecule moiety. In some embodiments, the small molecule moiety has a molecular weight of 8000, 7000, 6000, 5000, 4000, 3000, 2000, 1500, 1000, 900, 800, 700, or 600 or less. In some embodiments, the small molecule moiety has a molecular weight of 8000 or less. In some embodiments, the small molecule moiety has a molecular weight of 7000 or less. In some embodiments, the small molecule moiety has a molecular weight of 6000 or less. In some embodiments, the small molecule moiety has a molecular weight of 5000 or less. In some embodiments, the small molecule moiety has a molecular weight of 4000 or less. In some embodiments, the small molecule moiety has a molecular weight of 3000 or less. In some embodiments, the small molecule moiety has a molecular weight of 2000 or less. In some embodiments, the small molecule moiety has a molecular weight of 1500 or less. In some embodiments, the small molecule moiety has a molecular weight of 1000 or less. In some embodiments, the small molecule moiety has a molecular weight of 900 or less.

[0110] b. Peptide drugs In some embodiments, the target-binding moiety is or comprises a peptide drug. In some embodiments, the target-binding moiety is a peptide moiety. In some embodiments, the peptide moiety can be linear or cyclic. In some embodiments, the target-binding moiety is or comprises a cyclic peptide moiety. A variety of peptide target-binding moieties are known in the art and can be utilized in accordance with the present disclosure.

[0111] In some embodiments, the target binding moiety is or includes a peptide aptamer drug.

[0112] As described herein, in some embodiments, R LG is or comprises a target binding moiety. In some embodiments, R LG is or comprises a protein-binding moiety. In some embodiments, R LG is or comprises an antibody binding moiety. In some embodiments, R LG is a target binding moiety. In some embodiments, RLG is a protein-binding moiety. In some embodiments, R LG is the antibody binding moiety.

[0113] C. Aptamer drug In some embodiments, the target-binding moiety is or comprises a nucleic acid drug. In some embodiments, the target-binding moiety is or comprises an oligonucleotide moiety. In some embodiments, the target-binding moiety is or comprises an aptamer drug. A variety of aptamer drugs are known in the art or can be readily developed using common techniques and can be utilized with the techniques provided in accordance with the present disclosure.

[0114] In some embodiments, the target-binding moiety is an antibody-binding moiety, for, among other things, conjugating a moiety of interest to an antibody drug.

[0115] antibody binding part In some embodiments, the target is an antibody drug. In some embodiments, the target-binding moiety is an antibody-binding moiety. In some embodiments, provided compounds and / or drugs comprise an antibody-binding moiety. A variety of antibody-binding moieties can be utilized in accordance with the present disclosure. In some embodiments, the antibody-binding moiety is a universal antibody-binding moiety and can bind to antibodies with different Fab regions and different specificities. In particular, compounds comprising such antibody-binding moieties can be utilized for conjugation with antibodies with different specificities. In some embodiments, the antibody-binding moiety of the present disclosure, e.g., a universal antibody-binding moiety, binds to the Fc region. In some embodiments, binding of the antibody-binding moiety to the Fc region can occur simultaneously with binding of an Fc receptor (e.g., CD16a) to the same Fc region (e.g., at a different position / amino acid residue in the same Fc region). In some embodiments, upon binding of the antibody binding moiety (e.g., in a provided agent, compound, method, etc.), the Fc region is still able to interact with an Fc receptor and carry out one or more or all of its immune activities, including recruiting immune cells (e.g., effector cells such as NK cells) and / or inducing, generating, promoting, and / or enhancing activity of the immune system (e.g., antibody-dependent cell-mediated cytotoxicity (ADCC) and / or ADCP) against target cells, tissues, objects, and / or entities.

[0116] A variety of antibody binding moieties, including universal antibody binding moieties, can be utilized in accordance with the present disclosure. Specific antibody binding moieties, as well as techniques for identifying and / or evaluating antibody binding moieties, are described in WO / 2019 / 023501 and WO / 2019 / 136442, which are incorporated herein by reference. Those skilled in the art will appreciate that additional techniques in the art may be suitable for identifying and / or evaluating antibody binding moieties in accordance with the present disclosure. In some embodiments, the antibody binding moieties each independently comprise one or more amino acid residues that are natural or non-natural.

[0117] In some embodiments, the target-binding moiety, e.g., a protein-binding moiety (e.g., an antibody-binding moiety (e.g., a universal antibody-binding moiety)), is [ka] or a salt thereof, wherein: R 1 , R 3 , and R 5 Each of is independently hydrogen or C 1~6 an optionally substituted group selected from an aliphatic, a 3-8 membered saturated or partially unsaturated monocyclic carbocycle, a phenyl, an 8-10 membered bicyclic aromatic carbocycle, a 4-8 membered saturated or partially unsaturated monocyclic heterocycle having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 5-6 membered monocyclic heteroaromatic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaromatic ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R 1 and R 1’ optionally, together with their intervening carbon atoms, form a 3- to 8-membered optionally substituted saturated or partially unsaturated spirocyclic carbocycle or a 3- to 8-membered saturated or partially unsaturated spirocyclic heterocycle having 1 to 2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R 3 and R 3’ optionally, together with their intervening carbon atoms, form a 3- to 8-membered optionally substituted saturated or partially unsaturated spirocyclic carbocycle or a 3- to 8-membered saturated or partially unsaturated spirocyclic heterocycle having 1 to 2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R attached to the same carbon atom 5 Groups and R 5’ groups optionally taken together with their intervening carbon atoms form a 3- to 8-membered optionally substituted saturated or partially unsaturated spirocyclic carbocyclic ring or a 3- to 8-membered saturated or partially unsaturated spirocyclic heterocyclic ring having 1 to 2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; or The Two R's5 The groups, optionally together with their intervening atoms, are C 1~10 wherein 1 to 3 methylene units of the chain are independently and optionally selected from -S-, -SS-, -N(R)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -C(O)N(R)-, -N(R)C(O)-, -S(O)-, -S(O)2-, or -Cy 1 - and each -Cy 1 - is independently a 5-6 membered heteroarylenyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R 1’ , R 3’ , and R 5’ Each of is independently hydrogen or an optionally substituted C 1~3 is aliphatic, R 2 , R 4 , and R 6 Each of is independently hydrogen or an optionally substituted C 1~4 aliphatic or R 2 and R 1 optionally taken together with their intervening atoms, form an optionally substituted 4-8 membered saturated or partially unsaturated monocyclic heterocycle having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R 4 and R 3 optionally together with their intervening atoms form a 4-8 membered, optionally substituted, saturated or partially unsaturated, monocyclic heterocycle having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; or R 6 group and its adjacent R 5 groups optionally taken together with their intervening atoms form an optionally substituted 4-8 membered saturated or partially unsaturated monocyclic heterocycle having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; L 1is a trivalent linker moiety, Each of m and n is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20.

[0118] In some embodiments, L 1 is C1~C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by -C(R')2-, -Cy-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, or -C(O)O-.

[0119] In some embodiments, the target-binding moiety, e.g., a protein-binding moiety (e.g., an antibody-binding moiety (e.g., a universal antibody-binding moiety)), is [ka] or a salt thereof, wherein: R 7 Each of is independently hydrogen or C 1~6 an optionally substituted group selected from an aliphatic, a 3-8 membered saturated or partially unsaturated monocyclic carbocycle, a phenyl, an 8-10 membered bicyclic aromatic carbocycle, a 4-8 membered saturated or partially unsaturated monocyclic heterocycle having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 5-6 membered monocyclic heteroaromatic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaromatic ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R attached to the same carbon atom 7 Groups and R 7’groups optionally taken together with their intervening carbon atoms form a 3- to 8-membered optionally substituted saturated or partially unsaturated spirocyclic carbocyclic ring or a 3- to 8-membered optionally substituted saturated or partially unsaturated spirocyclic heterocyclic ring having 1 to 2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R 7’ each independently represents hydrogen or an optionally substituted C 1~3 is aliphatic, R 8 each independently represents hydrogen or an optionally substituted C 1~4 aliphatic or R 8 group and its adjacent R 7 groups optionally taken together with their intervening atoms form an optionally substituted 4-8 membered saturated or partially unsaturated monocyclic heterocycle having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur; R 9 is hydrogen or an optionally substituted C 1~3 It is aliphatic, or -C(O)-.

[0120] In some embodiments, the antibody binding moiety, e.g., the universal antibody binding moiety, can be a peptide moiety (e.g., R c -(Xaa)z-) or a salt form thereof, wherein R c Each of Xaa, z, and Xaa is independently as described herein. In some embodiments, one or more Xaa is independently a non-natural amino acid residue. In some embodiments, the side chains of two or more amino acid residues may be linked together to form a bridge. For example, in some embodiments, the side chains of two cysteine ​​residues may form a disulfide bridge containing -SS- (which may be formed by two -SH groups, as in many proteins).

[0121] In some embodiments, the target-binding moiety, e.g., a protein-binding moiety (e.g., an antibody-binding moiety (e.g., a universal antibody-binding moiety)), is a cyclic peptide moiety, e.g., [ka] or a salt form thereof, wherein: each Xaa is independently a residue of an amino acid or amino acid analog; t is 0 to 50; z is 1 to 50; L is a linker moiety, Each R c independently, -L a -R', Each L a are independently a covalent bond or C1 to C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by -C(R')2-, -Cy-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, or -C(O)O-; Each -Cy- is independently an optionally substituted divalent monocyclic, bicyclic, or polycyclic group, and each monocyclic ring is independently C 3~20 Alicyclic ring, C 6~20 an aryl ring, a 5-20 membered heteroaryl ring having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon, and a 3-20 membered heterocyclyl ring having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon; each R' is independently -R, -C(O)R, -COR, or -SOR; Each R is independently —H or C 1~30 Aliphatic, C having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon 1~30 Heteroaliphatic, C 6~30Aryl, C 6~30 Arylaliphatic, C having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon 6~30 an optionally substituted group selected from arylheteroaliphatic, 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon, and 3-30 membered heterocyclyl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon; or two R groups, optionally and independently, together form a covalent bond; or two or more R groups on the same atom optionally and independently combine with that atom to form an optionally substituted 3-30 membered monocyclic, bicyclic, or polycyclic ring having, in addition to that atom, 0-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon; or Two or more R groups on two or more atoms may optionally and independently be joined together with their intervening atoms to form an optionally substituted 3-30 membered monocyclic, bicyclic, or polycyclic ring having, in addition to the intervening atoms, 0-10 heteroatoms.

[0122] In some embodiments, the heteroatoms are independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon.

[0123] In some embodiments, the target binding moiety is R c In some embodiments, the protein-binding moiety is or includes -(Xaa)z-, or a salt form thereof, wherein each variable is as described herein. c In some embodiments, the antibody binding moiety, e.g., the universal antibody binding moiety, is or comprises R c In some embodiments, the target binding moiety is or comprises -(Xaa)z-, or a salt form thereof, wherein each variable is as described herein. [ka] In some embodiments, the protein binding moiety is or comprises: [ka] or a salt form thereof, wherein each variable is as described herein. In some embodiments, the antibody binding moiety, e.g., a universal antibody binding moiety, is or comprises: [ka] In some embodiments, the antibody binding moiety, e.g., the universal antibody binding moiety, is or comprises R c -(Xaa)z- or [ka] or a salt form thereof, and is or comprises a peptide unit. In some embodiments, -(Xaa)z- is or comprises a peptide unit. In some embodiments, amino acid residues may form bridges, e.g., linkages formed by side chains, optionally via a linker moiety (e.g., L); for example, as in many polypeptides, cysteine ​​residues may form disulfide bridges. In some embodiments, a peptide unit is an amino acid residue (e.g., a "positively charged amino acid residue" at physiological pH about 7.4, Xaa P ), e.g., a residue of an amino acid of formula AI having a positively charged side chain. In some embodiments, the peptide unit comprises R. In some embodiments, at least one Xaa is R. In some embodiments, the peptide unit is or comprises APAR. In some embodiments, the peptide unit is or comprises RAPA. In some embodiments, the peptide unit is a hydroxyl group-containing amino acid residue ("aromatic amino acid residue", Xaa A) (e.g., residues of amino acids of formula AI). In some embodiments, the peptide unit comprises a positively charged amino acid residue and an aromatic amino acid residue. In some embodiments, the peptide unit comprises W. In some embodiments, the peptide unit comprises a positively charged amino acid residue and an aromatic amino acid residue. In some embodiments, the peptide unit comprises a Xaa A XaaXaa P Xaa P In some embodiments, the peptide unit is or comprises Xaa P Xaa P XaaXaa A In some embodiments, the peptide unit is or comprises Xaa P Xaa A Xaa P In some embodiments, the peptide unit is or comprises two or more Xaa P Xaa A Xaa P In some embodiments, the peptide unit is or comprises Xaa P Xaa A Xaa P XaaXaa P Xaa A Xaa P In some embodiments, the peptide unit is or comprises Xaa P Xaa P Xaa A Xaa A Xaa P In some embodiments, the peptide unit is or comprises Xaa P Xaa P Xaa P Xaa A In some embodiments, the peptide unit is or comprises two or more Xaa A Xaa A Xaa PIn some embodiments, the peptide unit is or comprises HWRGWA (SEQ ID NO: 1). In some embodiments, the peptide unit is or comprises WGRR (SEQ ID NO: 2). In some embodiments, the peptide unit is or comprises RRGW (SEQ ID NO: 3). In some embodiments, the peptide unit is or comprises NKFRGKYK (SEQ ID NO: 4). In some embodiments, the peptide unit is or comprises NRFRGKYK (SEQ ID NO: 5). In some embodiments, the peptide unit is or comprises NARKFYK (SEQ ID NO: 6). In some embodiments, the peptide unit is or comprises NARKFYKG (SEQ ID NO: 7). In some embodiments, the peptide unit is or comprises HWRGWV (SEQ ID NO: 8). In some embodiments, the peptide unit is or comprises KHFRNKD (SEQ ID NO: 9). In some embodiments, the peptide units comprise a positively charged amino acid residue, an aromatic amino acid residue, and an amino acid residue, e.g., a residue of an amino acid of formula AI having a negatively charged side chain (e.g., a "negatively charged amino acid residue," Xaa at a physiological pH of about 7.4). N). In some embodiments, the peptide unit comprises RHRFNKD (SEQ ID NO: 10). In some embodiments, the peptide unit is RHRFNKD (SEQ ID NO: 10). In some embodiments, the peptide unit comprises TY. In some embodiments, the peptide unit is TY. In some embodiments, the peptide unit comprises TYK. In some embodiments, the peptide unit is TYK. In some embodiments, the peptide unit comprises RTY. In some embodiments, the peptide unit is RTY. In some embodiments, the peptide unit comprises RTYK (SEQ ID NO: 11). In some embodiments, the peptide unit is RTYK (SEQ ID NO: 11). In some embodiments, the peptide unit is or comprises a sequence selected from PAM. In some embodiments, the peptide unit comprises WHL. In some embodiments, the peptide unit is WHL. In some embodiments, the peptide unit is or comprises WXL, where X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue including -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit comprises WDL. In some embodiments, the peptide unit is WDL. In some embodiments, the peptide unit comprises ELVW (SEQ ID NO: 12). In some embodiments, the peptide unit is ELVW (SEQ ID NO: 12). In some embodiments, the peptide unit comprises GELVW (SEQ ID NO: 13). In some embodiments, the peptide unit is GELVW (SEQ ID NO: 13). In some embodiments, the peptide unit is or comprises a sequence selected from AWHLGELVW (SEQ ID NO: 14). In some embodiments, the peptide unit is or comprises AWHLGELVW (SEQ ID NO: 14). In some embodiments, the peptide unit is or comprises a sequence selected from AWDLGELVW (SEQ ID NO: 15). In some embodiments, the peptide unit is or comprises AWDLGELVW (SEQ ID NO: 15).In some embodiments, the peptide unit is or comprises AWXLGELVW (SEQ ID NO: 16), where X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue containing -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises a sequence selected from DCAWHLGELVWCT (SEQ ID NO: 17), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises DCAWHLGELVWCT (SEQ ID NO: 17), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises a sequence selected from DCAWXLGELVWCT (SEQ ID NO: 18), wherein the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins, and X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue comprising -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises DCAWXLGELVWCT (SEQ ID NO: 18), wherein the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins, and X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue comprising -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, X comprises -COOH, or a salt or activated form thereof, in its side chain. In some embodiments, the peptide unit is or comprises a sequence selected from DCAWDLGELVWCT (SEQ ID NO: 19), wherein the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises DCAWDLGELVWCT (SEQ ID NO: 19), wherein the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins.In some embodiments, the peptide unit is or comprises a sequence selected from Fc-III. In some embodiments, the peptide unit is or comprises Fc-III. In some embodiments, the peptide unit is or comprises DpLpAWXLGELVW (SEQ ID NO: 20), where X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue comprising -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises DpLpAWXLGELVW (SEQ ID NO: 20), where X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue comprising -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises a sequence selected from DpLpAWDLGELVW (SEQ ID NO: 21). In some embodiments, the peptide unit is or comprises DpLpAWDLGELVW (SEQ ID NO: 21). In some embodiments, the peptide unit is or comprises a sequence selected from DpLpAWHLGELVW (SEQ ID NO: 22), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises DpLpAWHLGELVW (SEQ ID NO: 22) (e.g., FcBP-1), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises a sequence selected from FcBP-1. In some embodiments, the peptide unit is or comprises a sequence selected from DpLpDCAWXLGELVWCT (SEQ ID NO: 23), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins, and X is an amino acid residue described herein, e.g., one suitable for attachment to another moiety (e.g., an amino acid residue including -COOH, or a salt or activated form thereof, e.g., D, E, etc.).In some embodiments, the peptide unit is or comprises DpLpDCAWXLGELVWCT (SEQ ID NO: 23), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins, and X is an amino acid residue described herein, e.g., one suitable for connection to another moiety (e.g., an amino acid residue containing -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises a sequence selected from DpLpDCAWHLGELVWCT (SEQ ID NO: 24), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises DpLpDCAWHLGELVWCT (SEQ ID NO: 24) (e.g., FcBP-2), where the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises a sequence selected from DpLpDCAWDLGELVWCT (SEQ ID NO: 25), wherein the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises DpLpDCAWDLGELVWCT (SEQ ID NO: 25), wherein the two cysteine ​​residues are capable of forming a disulfide bond as found in naturally occurring proteins. In some embodiments, the peptide unit is or comprises a sequence selected from FcBP-2. In some embodiments, the peptide unit is or comprises a sequence selected from CDCAWXLGELVWCTC (SEQ ID NO: 26), wherein the first and last cysteines and the two central cysteines of the sequence are each independently capable of forming a disulfide bond as in a naturally occurring protein, and X is an amino acid residue described herein, e.g., one suitable for attachment to another moiety (e.g., an amino acid residue containing -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises CDCAWXLGELVWCTC (SEQ ID NO: 26), wherein the first and last cysteines and the two central cysteines of the sequence are each independently capable of forming a disulfide bond as in a naturally occurring protein, and X is an amino acid residue described herein, e.g., one suitable for attachment to another moiety (e.g., an amino acid residue containing -COOH, or a salt or activated form thereof, e.g., D, E, etc.). In some embodiments, the peptide unit is or comprises a sequence selected from CDCAWHLGELVWCTC (SEQ ID NO: 27), wherein the first and last cysteines and the two central cysteines of the sequence are each independently capable of forming a disulfide bond as in a naturally occurring protein. In some embodiments, the peptide unit is or comprises a sequence selected from CDCAWHLGELVWCTC (SEQ ID NO: 27), wherein the first and last cysteines and the two central cysteines of the sequence are each independently capable of forming a disulfide bond as in a naturally occurring protein. In some embodiments, the peptide unit is or comprises a sequence selected from CDCAWDLGELVWCTC (SEQ ID NO: 28), wherein the first and last cysteines and the two central cysteines of the sequence are each independently capable of forming a disulfide bond as in a naturally occurring protein.In some embodiments, the peptide unit is or includes CDCAWDLGELVWCTC (SEQ ID NO: 28), and the first and last cysteines and the two cysteines in the middle of the sequence can each independently form a disulfide bond as in a native protein. In some embodiments, the peptide unit is or includes a sequence selected from Fc-III-4c. In some embodiments, the peptide unit is or includes a sequence selected from FcRM. In some embodiments, the peptide unit is or includes a cyclic peptide unit. In some embodiments, the cyclic peptide unit includes an amide group formed by a side chain amino group and a C-terminal -COOH. Those skilled in the art will understand that in various embodiments, when a peptide unit is connected to another moiety, the amino acid residues of the peptide unit can be connected at various positions, e.g., via its backbone, its side chain, etc. In some embodiments, the amino acid residues are modified for connection. In some embodiments, the amino acid residues are replaced with another suitable residue for connection while maintaining one or more properties and / or activities of the peptide unit (e.g., binding to an antibody described herein). For example, in some embodiments, an amino acid residue is replaced with an amino acid residue having a side chain comprising -COOH, or a salt or activated form thereof (e.g., the side chain is -CH-COOH, or a salt or activated form thereof). As exemplified herein, in various sequences, H may be replaced with D (e.g., in various peptide units including WHL). In some embodiments, a peptide unit is connected to another moiety via -COOH, or a salt or activated form thereof, e.g., via the formation of -CON(R')-. In some embodiments, R' is -H. In some embodiments, -COOH is in the side chain of the amino acid residue.In some embodiments, in a sequence described herein (e.g., DCAWHLGELVWCT) SEQ ID NO: 17), 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally replaced with another amino acid residue, 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally deleted, and / or 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally inserted. In some embodiments, the peptide moiety is connected to the remainder of the molecule through its N-terminus. In some embodiments, it is connected to the remainder of the molecule through its C-terminus. In some embodiments, it is connected to the remainder of the molecule through the side chain of an amino acid residue (e.g., the various X residues described in this disclosure). In some embodiments, two cysteine ​​residues may independently and optionally form a disulfide bond. In some embodiments, the total number of substitutions, deletions, and insertions is 10 or less (e.g., 0, or 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or less). In some embodiments, the total number is 0. In some embodiments, the total number is 1 or less. In some embodiments, the total number is 2 or less. In some embodiments, the total number is 3 or less. In some embodiments, the total number is 4 or less. In some embodiments, the total number is 5 or less. In some embodiments, the total number is 6 or less. In some embodiments, the total number is 7 or less. In some embodiments, the total number is 8 or less. In some embodiments, the total number is 9 or less. In some embodiments, the total number is 10 or less. In some embodiments, there are no insertions. In some embodiments, there are no deletions.

[0124] In some embodiments, -(Xaa)z- is [X 1 ] p1 [X 2 ] p2 -X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10X 11 X 12 -[X 13 ] p13 -[X 14 ] p14 [X 15 ] p15 [X 16 ] p16 wherein X is or comprises 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , X 12 , and X 13 Each of p1, p2, p13, p14, p15, and p16 is independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , X 12 , and X 13 Each of X is independently an amino acid residue of an amino acid of formula AI. 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , X 12 , and X 13 Each of X is independently a naturally occurring amino acid residue. 1 , X 2 , X 3 , X 4 , X5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , X 12 , and X 13 One or more of are independently a non-natural amino acid residue as described in this disclosure.

[0125] In some embodiments, a peptide unit comprises a functional group on an amino acid residue that can react with a functional group on another amino acid residue. In some embodiments, a peptide unit comprises an amino acid residue having a side chain that comprises a functional group that can react with another functional group on the side chain of another amino acid residue to form a linkage (see, e.g., Table A-1, Table 8, etc.). In some embodiments, a functional group on one amino acid residue is connected to a functional group on another amino acid residue to form a linkage (or bridge). The linkage is attached to a backbone atom of the peptide unit, but does not include a backbone atom. In some embodiments, a peptide unit comprises a linkage formed by two side chains of non-adjacent amino acid residues. In some embodiments, the linkage is attached to two backbone atoms of two non-adjacent amino acid residues. In some embodiments, both backbone atoms attached to the linkage are carbon atoms. In some embodiments, the linkage is formed by a linkage formed by two side chains of non-adjacent amino acid residues. b It has the structure of L b is the L described in this disclosure a and L a is not a covalent bond. a In some embodiments, L a In some embodiments, -Cy- includes -Cy-, where -Cy- is an optionally substituted heteroaryl. [ka] In some embodiments, L a teeth, [ka] In some embodiments, such L acan be formed by the -N3 group of the side chain of one amino acid residue and the -≡- of the side chain of another amino acid residue. In some embodiments, the linkage is formed through the connection of two thiol groups (e.g., of two cysteine ​​residues). In some embodiments, L a In some embodiments, L a is -CH2-SS-CH2-. In some embodiments, the linkage is formed through the connection of an amino group (e.g., -NH2 of the side chain of a lysine residue) and a carboxylic acid group (e.g., -COOH of the side chain of an aspartic acid or glutamic acid residue). In some embodiments, L a In some embodiments, L a In some embodiments, L a is -CHCONH-(CH)-. In some embodiments, L a comprises -C(O)-N(R')-, where R' is R, which, together with the R groups on the peptide backbone, forms a ring (e.g., A-34). a is —(CH)—N(R′)—CO—(CH). In some embodiments, —Cy- is optionally substituted phenylene. In some embodiments, —Cy- is optionally substituted 1,2-phenylene. In some embodiments, L a teeth, [ka] In some embodiments, L a teeth, [ka] In some embodiments, L a is an optionally substituted divalent C 20 In some embodiments, L a is optionally substituted -(CH2)9-CH=CH-(CH2)9-. In some embodiments, L a is -(CH2)3-CH=CH-(CH2)3-.

[0126] In some embodiments, the two amino acid residues joined at the linkage are separated by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more than 15 amino acid residues between them (excluding the two amino acid residues joined at the linkage). In some embodiments, the number is 1. In some embodiments, the number is 2. In some embodiments, the number is 3. In some embodiments, the number is 4. In some embodiments, the number is 5. In some embodiments, the number is 6. In some embodiments, the number is 7. In some embodiments, the number is 8. In some embodiments, the number is 9. In some embodiments, the number is 10. In some embodiments, the number is 11. In some embodiments, the number is 12. In some embodiments, the number is 13. In some embodiments, the number is 14. In some embodiments, the number is 15.

[0127] In some embodiments, each of p1, p2, p13, p14, p15, and p16 is 0. In some embodiments, -(Xaa)z- is -X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 - is or comprises -, wherein X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue; X 6 is Xaa A or Xaa P and X 9 is Xaa N and X 12 is Xaa A or Xaa P is.

[0128] In some embodiments, X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 Each of X is independently an amino acid residue of an amino acid of formula AI described in the present disclosure. 5 is Xaa A or Xaa P In some embodiments, X 5 is Xaa A In some embodiments, X 5 is Xaa P In some embodiments, X 5 is an amino acid residue whose side chain comprises an optionally substituted saturated, partially saturated, or aromatic ring. 5 teeth, [ka] In some embodiments, X 5 teeth, [ka] In some embodiments, X 6 is Xaa A In some embodiments, X 6 is Xaa P In some embodiments, X 6 is His. 12 is Xaa A In some embodiments, X 12 is Xaa P In some embodiments, X 9 is Asp. 9is Glu. 12 teeth, [ka] In some embodiments, X 12 teeth, [ka] In some embodiments, X 7 , X 10 , and X 11 each independently being an amino acid residue having a hydrophobic side chain (a "hydrophobic amino acid residue", Xaa H In some embodiments, X 7 is Xaa H In some embodiments, X 7 teeth, [ka] In some embodiments, X 7 In some embodiments, X is Val. 10 is Xaa H In some embodiments, X 10 is Met. 10 teeth, [ka] In some embodiments, X 11 is Xaa H In some embodiments, X 11 teeth, [ka] In some embodiments, X 8 is Gly. 4 is Pro. In some embodiments, X 3 is Lys. 12 -COOH of Lys(X 3 ) and forms an amide bond with the amino group in the side chain of Lys(X3 The other amino group of ) is connected to a linker moiety and then to a target binding moiety.

[0129] In some embodiments, -(Xaa)z- is -X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 - is or comprises -, wherein X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue; At least two amino acid residues are linked by one or more L b are connected via L b is C1~C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by —C(R′)2—, —Cy—, —O—, —S—, —SS—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —C(O)N(R′)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —S(O)—, —S(O)2N(R′)—, —C(O)S—, or —C(O)O—; L b is bound to a backbone atom of one amino acid residue and a backbone atom of another amino acid residue, but does not include the backbone atom, X 6 is Xaa A or Xaa P and X 9 is Xaa N and X12 is Xaa A or Xaa P is.

[0130] In some embodiments, X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue of an amino acid of formula AI described in the present disclosure. In some embodiments, two non-adjacent amino acid residues are b In some embodiments, X 5 and X 10 L b In some embodiments, one link L b In some embodiments, X 6 is Xaa A In some embodiments, X 6 is Xaa P In some embodiments, X 6 is His. 9 is Asp. 9 is Glu. 12 is Xaa A In some embodiments, X 12 teeth, [ka] In some embodiments, X 12 teeth, [ka] In some embodiments, X 12 teeth, [ka] In some embodiments, X 4 , X7 , and X 11 Each of Xaa H In some embodiments, X 4 is Xaa H In some embodiments, X 4 is Ala. 7 is Xaa H In some embodiments, X 7 teeth, [ka] In some embodiments, X 11 is Xaa H In some embodiments, X 11 teeth, [ka] In some embodiments, X 8 is Gly. 3 is Lys. 12 -COOH of Lys(X 3 ) and forms an amide bond with the amino group in the side chain of Lys(X 3 The other amino group of L is connected to a linker moiety and then to a target binding moiety. b teeth, [ka] In some embodiments, L b teeth, [ka] In some embodiments, L b connects two alpha carbon atoms of two different amino acid residues. 5 and X 10 Both of the amino acids are Cys, and the two -SH groups in their side chains form -SS- (L b is -CH2-SS-CH2-).

[0131] In some embodiments, -(Xaa)z- is -X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 - is or comprises -, wherein X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue; At least two amino acid residues are linked by one or more L b are connected via L b is C1~C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by —C(R′)2—, —Cy—, —O—, —S—, —SS—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —C(O)N(R′)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —S(O)—, —S(O)2N(R′)—, —C(O)S—, or —C(O)O—; L b is bound to a backbone atom of one amino acid residue and a backbone atom of another amino acid residue, but does not include the backbone atom, X 4 is Xaa A and X 5 is Xaa A or Xaa P and X 8 is Xaa Nand X 11 is Xaa A is.

[0132] In some embodiments, X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue of an amino acid of formula AI described in the present disclosure. In some embodiments, two non-adjacent amino acid residues are b In some embodiments, one link L b In some embodiments, X 2 and X 12 L b In some embodiments, L b is -CH-SS-CH-. In some embodiments, L b is -CH-CH-S-CH-. In some embodiments, L b teeth, [ka] In some embodiments, L b teeth, [ka] In some embodiments, L b is -CH2CH2CO-N(R')-CH2CH2-. In some embodiments, R', together with the R group on the backbone atom to which -N(R')-CH2CH2- is attached, forms a ring, e.g., A-34. In some embodiments, the ring formed is 3, 4, 5, 6, 7, or 8-membered. In some embodiments, the ring formed is monocyclic. In some embodiments, the ring formed is saturated. In some embodiments, L b teeth, [ka] In some embodiments, L b connects two alpha carbon atoms of two different amino acid residues. 4 is Xaa A In some embodiments, X 4 is Tyr. 5 is Xaa A In some embodiments, X 5 is Xaa P In some embodiments, X 5 is His. 8 is Asp. 8 is Glu. X 11 is Tyr. 2 and X 12 Both of the amino acids are Cys, and the two -SH groups in their side chains form -SS- (L b is -CH-SS-CH-). In some embodiments, X 3 , X 6 , X 9 , and X 10 Each of Xaa H In some embodiments, X 3 is Xaa H In some embodiments, X 3 is Ala. 6 is Xaa H In some embodiments, X 6 is Leu. 9 is Xaa H In some embodiments, X 9 is Leu. 9 teeth, [ka] In some embodiments, X 10 is Xaa HIn some embodiments, X 10 In some embodiments, X is Val. 10 teeth, [ka] In some embodiments, X 7 In some embodiments, p1 is 1. In some embodiments, X 1 is Asp. In some embodiments, p13 is 1. In some embodiments, p14, p15, and p16 are 0. In some embodiments, X 13 is a polar uncharged side chain (e.g., a "polar uncharged amino acid residue" at physiological pH, Xaa L In some embodiments, X is an amino acid residue comprising 13 is Thr. In some embodiments, X 13 In some embodiments, p13 is 0. In some embodiments, R c is —NHCHCH(OH)CH. In some embodiments, R c is (R)-NHCHCH(OH)CH. In some embodiments, R c is (S)-NHCH2CH(OH)CH3.

[0133] In some embodiments, -(Xaa)z- is -X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 - is or comprises -, wherein X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12are independently an amino acid residue; At least two amino acid residues are linked by one or more L b are connected via L b is C1~C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by —C(R′)2—, —Cy—, —O—, —S—, —SS—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —C(O)N(R′)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —S(O)—, —S(O)2N(R′)—, —C(O)S—, or —C(O)O—; L b is bound to a backbone atom of one amino acid residue and a backbone atom of another amino acid residue, but does not include the backbone atom, X 5 is Xaa A or Xaa P and X 8 is Xaa N and X 11 is Xaa A is.

[0134] In some embodiments, X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue of an amino acid of formula AI described in the present disclosure. In some embodiments, two non-adjacent amino acid residues are b In some embodiments, one link L b In some embodiments, there are two or more linked L b In some embodiments, there are two linked Lb In some embodiments, X 2 and X 12 L b In some embodiments, X 4 and X 9 L b In some embodiments, X 4 and X 10 L b In some embodiments, L b is -CH-SS-CH-. In some embodiments, L b teeth, [ka] In some embodiments, L b teeth, [ka] In some embodiments, X 2 and X 12 Both of the amino acids are Cys, and the two -SH groups in their side chains form -SS- (L b is -CH-SS-CH-). In some embodiments, X 4 and X 10 Both of the amino acids are Cys, and the two -SH groups in their side chains form -SS- (L b is -CH-SS-CH-). In some embodiments, X 4 and X 9 L b Connected by L b teeth, [ka] In some embodiments, X 4 and X 9 L b Connected by L b teeth, [ka] In some embodiments, X 5 is Xaa A In some embodiments, X 5 is Xaa P In some embodiments, X 5 is His. 8 is Asp. 8 is Glu. 11 is Tyr. 11 teeth, [ka] In some embodiments, X 2 and X 12 L b Connected by L b is -CH-S-CHCH-. In some embodiments, L b connects two alpha carbon atoms of two different amino acid residues. 3 , X 6 , and X 9 Each of Xaa H In some embodiments, X 3 is Xaa H In some embodiments, X 3 is Ala. 6 is Xaa H In some embodiments, X 6 is Leu. 6 teeth, [ka] In some embodiments, X 9 is Xaa H In some embodiments, X 9 is Leu. 9 teeth, [ka] In some embodiments, X 10 is Xaa H In some embodiments, X 10 In some embodiments, X is Val. 7 In some embodiments, p1 is 1. In some embodiments, X 1 is Xaa N In some embodiments, X 1 is Asp. 1 In some embodiments, p13 is 1. In some embodiments, p14, p15, and p16 are 0. In some embodiments, X 13 is Xaa L In some embodiments, X 13 is Thr. In some embodiments, X 13 is Val.

[0135] In some embodiments, -(Xaa)z- is -X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 X 12 X 13 X 14 X 15 X 16 - is or comprises -, wherein X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , X 12 , X 13 , X 14 , X 15 , and X 16 are independently an amino acid residue; At least two amino acid residues are linked together by the L bConnected via L b is C1~C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by —C(R′)2—, —Cy—, —O—, —S—, —SS—, —N(R′)—, —C(O)—, —C(S)—, —C(NR′)—, —C(O)N(R′)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —S(O)—, —S(O)2N(R′)—, —C(O)S—, or —C(O)O—; L b is bound to a backbone atom of one amino acid residue and a backbone atom of another amino acid residue, but does not include the backbone atom, X 3 is Xaa N and X 6 is Xaa A and X 7 is Xaa A or Xaa P and X 9 is Xaa N and X 13 is Xaa A is.

[0136] In some embodiments, X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , and X 12 are independently an amino acid residue of an amino acid of formula AI described in the present disclosure. In some embodiments, two non-adjacent amino acid residues are b In some embodiments, one link L bAs will be appreciated by those skilled in the art, an amino acid residue may be replaced by another amino acid residue having similar properties, for example, a Xaa H (e.g., Val, Leu, etc.) can be replaced by another Xaa H (e.g., Leu, Ile, Ala, etc.), and certain Xaa A is another Xaa A Xaa may be replaced by P is another Xaa P Xaa may be replaced by N is another Xaa N Xaa may be replaced by L is another Xaa L may be substituted with, etc.

[0137] In some embodiments, the target binding moiety is or comprises an optionally substituted moiety of Table A-1. In some embodiments, the protein binding moiety is or comprises an optionally substituted moiety of Table A-1. In some embodiments, the antibody binding moiety, e.g., a universal antibody binding moiety, is or comprises an optionally substituted moiety of Table A-1. In some embodiments, the target binding moiety is selected from Table A-1. In some embodiments, the protein binding moiety is selected from Table A-1. In some embodiments, the antibody binding moiety, e.g., a universal antibody binding moiety, is selected from Table A-1. In some embodiments, the C-terminus and / or N-terminus are optionally capped (e.g., for the C-terminus, by converting -COOH to -C(O)N(R') such as -C(O)NH; for the N-terminus, by adding R'C(O)- such as CHC(O)- to the amino group). [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4] [Table 1-5] [Table 1-6] [Table 1-7] [Table 1-8] [Table 1-9] [Table 1-10] [Table 1-11] [Table 1-12] [Table 1-13]

[0138] In some embodiments, the target-binding moiety is an antibody-binding moiety described herein. In some embodiments, the protein-binding moiety is an antibody-binding moiety described herein. In some embodiments, the —COOH and / or amino group of an amino acid residue, e.g., a C-terminal or N-terminal amino acid residue, is optionally capped. For example, in some embodiments, a —COOH group (e.g., a C-terminal —COOH) is amidated (e.g., converted to —CON(R′)2, e.g., —C(O)NHR (e.g., —C(O)NH2)), and in some embodiments, an amino group, e.g., —NH2 (e.g., an N-terminal —NH2) is capped with R′— or R′C(O)— (e.g., in some embodiments, by converting —NH2 to —NHR′ (e.g., —NHC(O)R, (e.g., —NHC(O)CH3))).

[0139] In some embodiments, the target binding moiety is an optionally substituted A-1, A-2, A-3, A-4, A-5, A-6, A-7, A-8, A-9, A-10, A-11, A-12, A-13, A-14, A-15, A-16, A-17, A-18, A-19, A-20, A-21, A-22, A-23, A-24, A-25, A-26, A- A-27, A-28, A-29, A-30, A-31, A-32, A-33, A-34, A-35, A-36, A-37, A-38, A-39, A-40, A-41, A-42, A-43, A-44, A-45, A-46, A-47, A-48, A-49, or A-50, each of which is optionally substituted. In some embodiments, such target-binding moieties are antibody-binding moieties. In some embodiments, such target-binding moieties are universal antibody-binding moieties.

[0140] In some embodiments, the target-binding moiety, e.g., a protein-binding moiety (e.g., an antibody-binding moiety (e.g., a universal antibody binding moiety)), comprises a peptide unit and is connected to a linker moiety through the C-terminus of the peptide unit. In some embodiments, it is connected to a linker moiety through the N-terminus of the peptide unit. In some embodiments, it is connected to a linker through a side chain group of the peptide unit. In some embodiments, the antibody-binding moiety, e.g., a universal antibody binding moiety, comprises a peptide unit and is connected to the target-binding moiety through the C-terminus of the peptide unit, optionally through a linker moiety. In some embodiments, the target-binding moiety, e.g., a protein-binding moiety (e.g., an antibody-binding moiety (e.g., a universal antibody binding moiety)), comprises a peptide unit and is connected to the target-binding moiety through the N-terminus of the peptide unit, optionally through a linker moiety. In some embodiments, the target-binding moiety, e.g., a protein-binding moiety (e.g., an antibody-binding moiety (e.g., a universal antibody binding moiety)), comprises a peptide unit and is connected to the target-binding moiety through a side chain of the peptide unit, optionally through a linker moiety.

[0141] In some embodiments, the target binding moiety is or comprises (DCAWHLGELVWCT, (SEQ ID NO: 17))-, in which 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally replaced with another amino acid residue, 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally deleted, and / or 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally inserted. In some embodiments, it is connected to the rest of the molecule through its N-terminus. In some embodiments, it is connected to the rest of the molecule through its C-terminus. In some embodiments, it is connected to the rest of the molecule through the side chain of an amino acid residue (e.g., the various X residues described in this disclosure). In some embodiments, the two cysteine ​​residues form a disulfide bond. In some embodiments, the target binding moiety is [ka] wherein X is or comprises an amino acid residue attached to the remainder of the compound or agent, wherein 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally replaced with another amino acid residue, 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally deleted, and / or 1 to 5 (e.g., 1, 2, 3, 4, or 5) amino acid residues may be independently and optionally inserted. In some embodiments, the total number of replacements, deletions, and insertions is 10 or less (e.g., 0, or 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or less). In some embodiments, the total number is 0. In some embodiments, the total number is 1 or less. In some embodiments, the total number is 2 or less. In some embodiments, the total number is 3 or less. In some embodiments, the total number is 4 or less. In some embodiments, the total number is 5 or less. In some embodiments, the total number is 6 or less. In some embodiments, the total number is 7 or less. In some embodiments, the total number is 8 or less. In some embodiments, the total number is 9 or less. In some embodiments, the total number is 10 or less. In some embodiments, there are no insertions. In some embodiments, there are no deletions. In some embodiments, there are no substitutions. In some embodiments, X is an amino acid residue attached to the remainder of the compound or agent. In some embodiments, X is -N(R')-CH(-)-C(O)-. In some embodiments, X is -N(R')-CH(-L LG1 In some embodiments, X is —N(R′)—CH(-L LG1 -L LG2 In some embodiments, X is —N(R′)—CH(-L LG1 -L LG2 -L LG3 In some embodiments, X is —N(R′)—CH(-L LG1 -L LG2 -L LG3 -L LG4 -)-C(O)-.

[0142] In some embodiments, X is [ka] is a residue of one of

[0143] In some embodiments, X is K. In some embodiments, X is D. In some embodiments, X is the residue of a Dab. In some embodiments, X is E.

[0144] In some embodiments, the antibody binding moiety, e.g., universal antibody binding moiety, is or comprises a small molecular entity, e.g., having a molecular weight of less than 10,000, 9,000, 8,000, 7,000, 6,000, 5,000, 4,000, 3,000, 2,000, 1,500, 1,000, etc. Suitable such antibody binding moieties include, for example, small molecule Fc binder moieties such as those described in US 9,745,339, US 201 / 30131321. In some embodiments, the antibody binding moiety is of a structure such that the corresponding compound is a compound described in US 9,745,339 or US 2013 / 0131321 (each of which compounds is independently incorporated herein by reference). In some embodiments, the antibody binding moiety ABT is structured such that H-ABT is a compound described in US9,745,339 or US2013 / 0131321 (each of which compounds is independently incorporated herein by reference). In some embodiments, such compounds are capable of binding to an antibody. In some embodiments, such compounds are capable of binding to the Fc region of an antibody.

[0145] In some embodiments, the target binding moiety is [ka] and each of which is optionally substituted.

[0146] In some embodiments, the target binding moiety is [ka] wherein R can be, for example, hydrogen, C1-C4 alkyl, or C3-C6 cycloalkyl.

[0147] In some embodiments, the target binding moiety is [ka] It is or includes any of the following:

[0148] In some embodiments, the target binding moiety is [ka] wherein each variable is independently as described herein. In some embodiments, m is 4 to 13.

[0149] In some embodiments, the target binding moiety is [ka] wherein b is 1 to 20, and each other variable is independently as described herein.

[0150] In some embodiments, b is 4 to 13. In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is as follows: [ka] wherein R is, for example, H or C1-C4 alkyl, and R' is, for example, H or C1-C4 alkyl.

[0151] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is [ka] ,for example, [ka] is or contains

[0152] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is [ka] ,for example, [ka] is or contains

[0153] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is [ka] is or contains

[0154] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is as follows: [ka] ,for example, [ka] It is or includes any of the following:

[0155] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is [ka] is or contains

[0156] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is [ka] is or contains

[0157] In some embodiments, -NH- is R c In some embodiments, R c is RC(O)—. In some embodiments, R c is CH3C(O)-. In some embodiments, such target binding moieties are antibody binding moieties.

[0158] In some embodiments, the target binding moiety, e.g., [ka] or R c -(Xaa)z- is as follows: [ka] [ka] It is or includes any of the following:

[0159] In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is or includes a Z33 peptide moiety. In some embodiments, a target binding moiety, e.g., R c -(Xaa)z- is or comprises -FNMQQQRRFYEALHDPNLNEEQRNAKIKSIRDD-NH2 (SEQ ID NO: 29) or a fragment thereof. In some embodiments, the target binding moiety, e.g., R c -(Xaa)z- is or comprises FNMQCQRRFYEALHDPNLNEEQRNAKIKSIRDDC (SEQ ID NO: 30) or a fragment thereof. In some embodiments, the target binding moiety, e.g., [ka] or R c-(Xaa)z- is FNMQCQRRFYEALHDPNLNEEQRNAKIKSIRDDC (SEQ ID NO: 30), RGNCAYHRGQLVWCTYH (SEQ ID NO: 31), RGNCAYHKGQLVWCTYH, RGNCKYHRGQLVWCTYH (SEQ ID NO: 32), RGNCAWHRGKLVWCTYH (SEQ ID NO: 33), RGNCAWHRGKLVWCTYH (SEQ ID NO: 34), RGNCKWHRGELVWCTYH (SEQ ID NO: 35), RGNCKWHRGQLVWCTYH (SEQ ID NO: 36), RGNCKYHLGELVWCTY H (SEQ ID NO: 37), RGNCKYHLGQLVWCTYH (SEQ ID NO: 38), DCKWHLGELVWCT (SEQ ID NO: 39), DCKYHLGELVWCT (SEQ ID NO: 40), DCKWHRGELVWCT (SEQ ID NO: 41), DCKWHLGQLVWCT (SEQ ID NO: 42), DCKYHRGELVWCT (SEQ ID NO: 43), DCKYHLGQLVWCT (SEQ ID NO: 44), DCKWHRGQLVWCT (SEQ ID NO: 45), DCKYHRGQLVWCT (SEQ ID NO: 46), FNKQCQRRFYEALHDPNLNEEQRNARIRSIR DDC (SEQ ID NO: 47), FNMQCQRRFYEALHDPNLNEEQRNARIRSIKDDC (SEQ ID NO: 48), FNMQCQRRFYEALHDPNLNKEQRNARIRSIRDDC (SEQ ID NO: 49), FNMQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 50), RGNCAWHLGQLVWCKYH (SEQ ID NO: 51), RGNCAWHLGELVWCKYH (SEQ ID NO: 52), RGNCAYHLGQLVWCTKH (SEQ ID NO: 53), RGNCAYHLGQLVWCTYK (SEQ ID NO: 54) ), RGNCAYHRGQLVWCTKH (SEQ ID NO: 55), KNMQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 56), FNMQCQKRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 57), FNMQCQRRFYEAKHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 58), FNMQCQRRFYEALHDPNLNEEQRKARIRSIRDDC (SEQ ID NO: 59), FNMQCQRRFYEALHDPNLNKEQRNARIRSIRDDC (SEQ ID NO: 49),FNMQCQRRFYEALHDPNLNEEQRNARIRSIKDDC (SEQ ID NO: 48), FNKQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 47), FNMQCKRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 60), FNMQCQRRFYEALHDPNLNEEQRNARIRSIRKDC (SEQ ID NO: 61), Fc-III, FcBP-2, Fc-III-4C, [ka] and wherein the two cysteine ​​residues may optionally form a disulfide bond. In some embodiments, in the peptides described herein, the two cysteine ​​residues form a disulfide bond. In some embodiments, the peptides described herein may be part of or include peptides such as Z33, FNMQCQRRFYEALHDPNLNEEQRNAKIKSIRDDC (SEQ ID NO: 30), RGNCAYHRGQLVWCTYH (SEQ ID NO: 31), RGNCKYHRGQLVWCTYH (SEQ ID NO: 33), RGNCAYHKGQLVWCTYH (SEQ ID NO: 32), RGNCAWHRGKLVWCTYH (SEQ ID NO: 34), RGNCKWHRGQLVWCTYH (SEQ ID NO: 36), RGNCKWHRGELVWCTYH (SEQ ID NO: 34). ), RGNCKYHLGELVWCTYH (SEQ ID NO: 37), RGNCKYHLGQLVWCTYH (SEQ ID NO: 38), DCKWHLGELVWCT (SEQ ID NO: 39), DCKYHLGELVWCT (SEQ ID NO: 40), DCKWHRGELVWCT (SEQ ID NO: 41), DCKWHLGQLVWCT (SEQ ID NO: 42), DCKYHRGELVWCT (SEQ ID NO: 43), DCKYHLGQLVWCT (SEQ ID NO: 44), DCKWHRGQLVWCT (SEQ ID NO: 45), DCKYHRGQLVWC T (SEQ ID NO: 46), FNKQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 47), FNMQCQRRFYEALHDPNLNEEQRNARIRSIKDDC (SEQ ID NO: 48), FNMQCQRRFYEALHDPNLNKEQRNARIRSIRDDC (SEQ ID NO: 49), FNMQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 50), RGNCAWHLGQLVWCKYH (SEQ ID NO: 51), RGNCAWHLGELV WCKYH (SEQ ID NO: 52), RGNCAYHLGQLVWCTKH (SEQ ID NO: 53), RGNCAYHLGQLVWCTYK (SEQ ID NO: 54), RGNCAYHRGQLVWCTKH (SEQ ID NO: 55), KNMQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 56), FNMQCQKRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 57), FNMQCQRRFYEAKHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 58),FNMQCQRRFYEALHDPNLNEEQRKARIRSIRDDC (SEQ ID NO: 59), FNMQCQRRFYEALHDPNLNKEQRNARIRSIRDDC (SEQ ID NO: 49), FNMQCQRRFYEALHDPNLNEEQRNARIRSIKDDC (SEQ ID NO: 48), FNKQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 47), FNMQCKRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 60), FNMQCQRRFYEALHDPNLNEEQRNARIRSIRKDC (SEQ ID NO: 61), Fc-III, FcBP-2, Fc-III-4C, [ka] and the like may be at their N-terminus, C-terminus, or side chain (e.g., K (e.g., [ka] In some embodiments, one or more amino acid residues of the sequence may be independently and optionally replaced (e.g., 1-5), deleted (e.g., 1-5), and / or inserted (e.g., 1-5), as described herein. In some embodiments, the target binding moiety, e.g., [ka] or R c -(Xaa)z- is -CXYHXXXLVWC- (SEQ ID NO: 63), -XCXYHXXXLVWC- (SEQ ID NO: 64), -CXYHXXXLVWCX- (SEQ ID NO: 65), -X 0~3 CXYHXXXLVWCX 0~3 -(SEQ ID NO:66), -XCXYHXXXLVWCXXX (SEQ ID NO:67), --XXXCXYHXXXLVWCXXX (SEQ ID NO:66)-, where each X is independently an amino acid residue, and two C residues optionally form a disulfide bond. 8 (X after H) is Orn. ​​In some embodiments, X 8In some embodiments, X is Dab. 8 is Lys(Ac). In some embodiments, X 8 is Orn(Ac). In some embodiments, X 8 is Dab(Ac). In some embodiments, X 8 is Arg. 8 In some embodiments, X is Nle. 8 In some embodiments, X is Nva. 8 In some embodiments, X is Val. 8 In some embodiments, X is Tle. 8 is Leu. 8 is Ala(tBu). 8 is Cha. In some embodiments, X 8 is Phe. In some embodiments, the target binding moiety, e.g., [ka] , or R c -(Xaa)z- is or includes DCAWHLGELVWCT (SEQ ID NO: 17). In some embodiments, the C-terminus and / or N-terminus of the protein drug / peptide drug moiety are independently capped (e.g., for the N-terminus, RC(O)- such as CHC(O)-; for the C-terminus, -N(R')2 such as -NH2, etc.). In some embodiments, such target-binding moieties are antibody-binding moieties. In some embodiments, as described herein, residues may be modified or substituted for attachment to another moiety; for example, in some embodiments, H may be replaced with an amino acid residue comprising a -COOH-containing side chain or a salt or activated form thereof (e.g., D).

[0160] In some embodiments, the target binding moiety, e.g., [ka] , or R c -(Xaa)z- is (X1~3 )-C-(X2)-H-(Xaa1)-G-(Xaa2)-LVWC-(X 1~3 ) (SEQ ID NO: 68), wherein each of X and Xaa is independently an amino acid residue, optionally not a cysteine ​​residue. In some embodiments, Xaa1 is R, L, L, D, E, a 2-aminosuberic acid residue, or a diaminopropionic acid residue. In some embodiments, Xaa2 is L, D, E, N, or Q. In some embodiments, Xaa1 is a lysine residue, a cysteine ​​residue, an aspartic acid residue, a glutamic acid residue, a 2-aminosuberic acid residue, or a diaminopropionic acid residue. In some embodiments, Xaa2 is a glutamic acid residue or an aspartic acid residue. In some embodiments, Xaa1 is an arginine residue or a leucine residue. In some embodiments, Xaa2 is a lysine residue, a glutamine residue, or an aspartic acid residue. In some embodiments, such target-binding moieties are antibody-binding moieties.

[0161] In some embodiments, the target binding moiety, e.g., [ka] , or R c-(Xaa)z- is or includes (X1-3)-C-(Xaa3)-(xaa4)-H-(Xaa1)-G-(Xaa2)-LVWC-(Xaa5)-(Xaa6)-(Xaa7) (SEQ ID NO: 68), wherein each of X and Xaa is independently an amino acid residue, optionally not a cysteine ​​residue. In some embodiments, Xaa3 is an alanine residue or a lysine residue. In some embodiments, Xaa4 is a tryptophan residue or a tyrosine residue. In some embodiments, Xaa1 is an arginine residue, leucine residue, lysine residue, aspartic acid residue, glutamic acid residue, 2-aminosuberic acid residue, or diaminopropionic acid residue. In some embodiments, Xaa2 is a lysine residue, glutamine residue, glutamic acid residue, asparagine residue, or aspartic acid residue. In some embodiments, Xaa5 is a threonine residue or a lysine residue. In some embodiments, Xaa6 is a tyrosine residue, a lysine residue, or is absent. In some embodiments, Xaa7 is a histidine residue, a lysine residue, or is absent. In some embodiments, such target-binding moieties are antibody-binding moieties.

[0162] In some embodiments, the target binding moiety, e.g., [ka] , or R c-(Xaa)z- is or includes DC-(Xaa3)-(Xaa4)-H-(Xaa1)-G-(Xaa2)-LVWC-(Xaa5)-(Xaa6)-(Xaa7) (SEQ ID NO: 69), wherein each of X and Xaa is independently an amino acid residue, optionally not a cysteine ​​residue. In some embodiments, Xaa3 is an alanine residue or a lysine residue. In some embodiments, Xaa4 is a tryptophan residue or a tyrosine residue. In some embodiments, Xaa1 is an arginine residue, leucine residue, lysine residue, aspartic acid residue, glutamic acid residue, 2-aminosuberic acid residue, or diaminopropionic acid residue. In some embodiments, Xaa2 is a lysine residue, glutamine residue, glutamic acid residue, asparagine residue, or aspartic acid residue. In some embodiments, Xaa5 is a threonine residue or a lysine residue. In some embodiments, Xaa6 is a tyrosine residue, a lysine residue, or is absent. In some embodiments, Xaa7 is a histidine residue, a lysine residue, or is absent. In some embodiments, such target-binding moieties are antibody-binding moieties.

[0163] In some embodiments, the target binding moiety, e.g., [ka] , or R c-(Xaa)z- is or comprises DC-(Xaa3)-(Xaa4)-H-(Xaa1)-G-(Xaa2)-LVWCT (SEQ ID NO: 70), wherein each of X and Xaa is independently an amino acid residue, optionally not a cysteine ​​residue. In some embodiments, Xaa3 is an alanine residue or a lysine residue. In some embodiments, Xaa4 is a tryptophan residue or a tyrosine residue. In some embodiments, Xaa1 is an arginine residue, a leucine residue, a lysine residue, an aspartic acid residue, a glutamic acid residue, a 2-aminosuberic acid residue, or a diaminopropionic acid residue. In some embodiments, Xaa2 is a lysine residue, a glutamine residue, a glutamic acid residue, an asparagine residue, or an aspartic acid residue. In some embodiments, such target-binding moieties are antibody-binding moieties.

[0164] In some embodiments, the target binding moiety, e.g., [ka] , or R c-(Xaa)z- is or comprises RGNC-(Xaa3)-(Xaa4)-H-(Xaa1)-G-(Xaa2)-LVWC-(Xaa5)-(Xaa6)-(Xaa7) (SEQ ID NO: 71), where each of X and Xaa is independently an amino acid residue, optionally not a cysteine ​​residue. In some embodiments, Xaa3 is an alanine residue or a lysine residue. In some embodiments, Xaa4 is a tryptophan residue or a tyrosine residue. In some embodiments, Xaa1 is an arginine residue, leucine residue, lysine residue, aspartic acid residue, glutamic acid residue, 2-aminosuberic acid residue, or diaminopropionic acid residue. In some embodiments, Xaa2 is a lysine residue, glutamine residue, glutamic acid residue, asparagine residue, or aspartic acid residue. In some embodiments, Xaa5 is a threonine residue or a lysine residue. In some embodiments, Xaa6 is a tyrosine residue, a lysine residue, or is absent. In some embodiments, Xaa7 is a histidine residue, a lysine residue, or is absent. In some embodiments, such target-binding moieties are antibody-binding moieties.

[0165] In some embodiments, the target-binding moiety, such as the various target-binding moieties described above, is a protein-binding moiety. In some embodiments, the target-binding moiety is an antibody-binding moiety. In some embodiments, the LG is or comprises such a target-binding moiety. In some embodiments, the LG is or comprises a protein-binding moiety. In some embodiments, the LG is or comprises an antibody-binding moiety.

[0166] In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is or includes an adaptor protein agent, e.g., as described in Hui, et al., Bioconjugate Chem. 2015, 26, 1456-1460, doi:10.1021 / acs.bioconjchem.5b00275. In some embodiments, when utilized in accordance with the present disclosure, the adaptor protein does not require a reactive residue (e.g., BPA) to achieve one or more or all of the benefits.

[0167] In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is or includes a triazine moiety, such as those described in US2009 / 0286693. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is of a structure such that its corresponding compound is a compound described in US2009 / 0286693, which compounds are independently incorporated by reference herein. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is ABT. In some embodiments, ABT is of a structure such that H-ABT is a compound described in US2009 / 0286693, which compounds are independently incorporated by reference herein. In some embodiments, such compounds are capable of binding to an antibody. In some embodiments, such compounds are capable of binding to the Fc region of an antibody.

[0168] In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is or includes a triazine moiety, such as those described in Teng, et al., "A strategy for the generation of biomimetic ligands for affinity chromatography. Combinatorial synthesis and biological evaluation of an IgG binding ligand," J. Mol. Recognit. 1999;12:67-75 ("Teng"). In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is of a structure such that its corresponding compound is a compound described in Teng, which compounds are independently incorporated by reference herein. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, ABT, is of a structure such that H-ABT is a compound described in Teng, which compounds are independently incorporated by reference herein. In some embodiments, such compounds are capable of binding to an antibody. In some embodiments, such compounds are capable of binding to the Fc region of an antibody.

[0169] In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is a triazine moiety, such as those described in Uttamchandani, et al., Microarrays of Tagged Combinatorial Triazine Libraries in the Discovery of Small-Molecule Ligands of Human IgG, J Comb Chem. 2004 Nov-Dec;6(6):862-8 ("Uttamchandani"). In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is of a structure such that its corresponding compound is a compound described in Uttamchandani, which compounds are independently incorporated by reference herein. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, ABT, is of a structure such that H-ABT is a compound described in Uttamchandani, which compounds are independently incorporated by reference herein. In some embodiments, such compounds are capable of binding to an antibody. In some embodiments, such compounds are capable of binding to the Fc region of an antibody.

[0170] In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein A. In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein G. In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein L. In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein Z. In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein LG. In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein LA. In some embodiments, the antibody binding moiety binds to one or more binding sites of Protein AG.

[0171] In some embodiments, the target binding moiety, e.g., antibody binding moiety, can bind to the nucleotide binding site. In some embodiments, the target binding moiety, e.g., antibody binding moiety, is a small molecule moiety that can bind to the nucleotide binding site. In some embodiments, the small molecule is tryptamine. In some embodiments, the target binding moiety, e.g., antibody binding moiety, ABT, is structured such that H-ABT is tryptamine.

[0172] In some embodiments, the antibody binding moiety is a moiety (e.g., a small molecule moiety, a peptide moiety, a nucleic acid moiety, etc.) that can selectively bind to IgG and, when used in the provided technologies, can provide and / or stimulate ADCC and / or ADCP. In some embodiments, peptide display technologies (e.g., phase display, non-cellular display, etc.) can be used to identify the antibody binding moiety. In some embodiments, the antibody binding moiety is a moiety (e.g., a small molecule moiety, a peptide moiety, a nucleic acid moiety, etc.) that can bind to IgG and, optionally, compete with known antibody binders (e.g., Protein A, Protein G, Protein L, etc.).

[0173] As will be appreciated by those skilled in the art, antibodies of various properties and activities (e.g., antibodies recognizing different antigens, with optional modifications, etc.) can be targeted by the antibody binding moieties described in this disclosure. In some embodiments, such antibodies include, for example, antibodies administered to a subject for therapeutic purposes. In some embodiments, the antibody binding moieties described herein may bind to antibodies against different antigens, making them useful for conjugating moieties of interest to a variety of antibodies.

[0174] In some embodiments, the target binding moiety, e.g., antibody binding moiety, is or comprises a meditope drug moiety. In some embodiments, meditope drugs are described, for example, in US2019 / 0111149.

[0175] In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is capable of binding to human IgG. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, is capable of binding to rabbit IgG. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, binds to IgG1. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, binds to IgG2. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, binds to IgG3. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, binds to IgG4. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, binds to IgG1, IgG2 and / or IgG4. In some embodiments, the target-binding moiety, e.g., antibody-binding moiety, binds to IgG1, IgG2 and IgG4.

[0176] In some embodiments, the target-binding moiety (e.g., antibody-binding moiety) binds to a target (e.g., an antibody drug for an antibody-binding moiety) with a Kd that is about 1 mM to 1 pM or less. In some embodiments, the Kd is about 1 mM, 0.5 mM, 0.2 mM, 0.1 mM, 0.05 mM, 0.02 mM, 0.01 mM, 0.005 mM, 0.002 mM, 0.001 mM, 500 nM, 200 nM, 100 nM, 50 nM, 20 nM, 10 nM, 5 nM, 2 nM, 1 nM, 0.5 nM, 0.2 nM, 0.1 nM, or less. In some embodiments, the Kd is about 1 mM or less. In some embodiments, the Kd is about 0.5 mM or less. In some embodiments, the Kd is about 0.1 mM or less. In some embodiments, the Kd is about 0.05 mM or less. In some embodiments, the Kd is about 0.01 mM or less. In some embodiments, the Kd is about 0.005 mM or less. In some embodiments, the Kd is about 0.001 mM or less. In some embodiments, the Kd is about 500 nM or less. In some embodiments, the Kd is about 200 nM or less. In some embodiments, the Kd is about 100 nM or less. In some embodiments, the Kd is about 50 nM or less. In some embodiments, the Kd is about 20 nM or less. In some embodiments, the Kd is about 10 nM or less. In some embodiments, the Kd is about 5 nM or less. In some embodiments, the Kd is about 2 nM or less. In some embodiments, the Kd is about 1 nM or less. For example, in some embodiments, the antibody binding moiety binds to an IgG antibody drug with a Kd described herein.

[0177] amino acid In some embodiments, provided compounds and agents may include one or more amino acid moieties, for example, in antibody binding moieties, linker moieties, etc. The amino acid moieties may be either naturally occurring amino acid or unnatural amino acid moieties. In some embodiments, the amino acid has the structure of formula AI: NH(R a1 )-L a1 -C(R a2 )(R a3 )-L a2 -COOH AI or a salt thereof, wherein: R a1 , R a2 and R a3 each independently represents -L a -R', or an amino acid side chain; L a1 and L a2 Each of the a and Each L a are independently a covalent bond or C1 to C 20 Aliphatic or C1-C with 1-5 heteroatoms 20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently replaced by -C(R')2-, -Cy-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, or -C(O)O-; Each -Cy- is independently an optionally substituted divalent monocyclic, bicyclic, or polycyclic group, and each monocyclic ring is independently C 3~20 Alicyclic ring, C 6~20 an aryl ring, a 5-20 membered heteroaryl ring having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon, and a 3-20 membered heterocyclyl ring having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon; each R' is independently -R, -C(O)R, -COR, or -SOR; Each R is independently —H or C 1~30 Aliphatic, C having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon 1~30 Heteroaliphatic, C 6~30 Aryl, C 6~30 Arylaliphatic, C having 1 to 10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon 6~30an optionally substituted group selected from arylheteroaliphatic, 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon, and 3-30 membered heterocyclyl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon; or two R groups, optionally and independently, together form a covalent bond; or two or more R groups on the same atom optionally and independently combine with that atom to form an optionally substituted 3-30 membered monocyclic, bicyclic, or polycyclic ring having, in addition to that atom, 0-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon; or Provided is a compound or salt thereof, wherein two or more R groups on two or more atoms optionally and independently, taken together with their intervening atoms, form an optionally substituted 3- to 30-membered monocyclic, bicyclic, or polycyclic ring having, in addition to the intervening atoms, 0-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon.

[0178] In some embodiments, the amino acid residue, e.g., the amino acid residue of an amino acid having the structure of formula AI, is -N(R a1 )-L a1 -C(R a2 )(R a3 )-L a2 In some embodiments, each amino acid residue of the peptide independently has the structure -N(R a1 )-L a1 -C(R a2 )(R a3 )-L a2 It has the structure -CO-.

[0179] In some embodiments, the disclosure provides a derivative of an amino acid of formula AI, or a salt thereof. In some embodiments, the derivative is an ester. In some embodiments, the disclosure provides a derivative of an amino acid of formula NH(R a1 )-L a1 -C(R a2 )(Ra3 )-L a2 -COOR CT or a salt thereof, wherein R CT is R', and each other variable is independently as described herein, or a salt thereof. CT is R. In some embodiments, R CT is an optionally substituted aliphatic. In some embodiments, R CT is t-butyl.

[0180] In some embodiments, L a1 is a covalent bond. In some embodiments, the compound of formula AI has the structure NH(R a1 )-C(R a2 )(R a3 )-L a2 In some embodiments, L a2 is -CH2SCH2-.

[0181] In some embodiments, L a2 is a covalent bond. In some embodiments, the compound of formula AI has the structure NH(R a1 )-L a1 -C(R a2 )(R a3 In some embodiments, the amino acid residue is a compound of the formula -N(R a1 )-L a1 -C(R a2 )(R a3 In some embodiments, L a1 is -CH2CH2S-. In some embodiments, L a1 is -CH2CH2S-, where CH2 is NH(R a1 )

[0182] In some embodiments, L a1 is a covalent bond, and L a2 is a covalent bond. In some embodiments, the compound of formula AI has the structure NH(R a1 )-C(R a2 )(Ra3 )-COOH, NH(R a1 )-CH(R a2 )-COOH, NH(R a1 )-CH(R a3 )-COOH, NH2-CH(R a2 )-COOH, NH2-CH(R a3 )-COOH, -N(R a1 )-C(R a2 )(R a3 )-CO-, N(R a1 )-CH(R a2 )-CO-, -N(R a1 )-CH(R a3 )-CO-, -NH-CH(R a2 )-CO-, or -NH-CH(R a3 )-CO-.

[0183] In some embodiments, L a is a covalent bond, and L a is an optionally substituted C 1~6 Divalent aliphatic, L a is an optionally substituted C 1~6 alkylene, and L a is -CH2-, and L a is -CH2CH2- or L a is -CH2CH2CH2-.

[0184] In some embodiments, L a is a divalent optionally substituted C 1~20 In some embodiments, L is aliphatic, wherein one or more methylene units are independently replaced with -C(O)-, -N(R')-, -Cy-, and / or -O-. a is a divalent optionally substituted C 1~20 In some embodiments, L is aliphatic, wherein one or more methylene units are independently replaced with -C(O)N(R')-, -Cy-, and -O-. a is a divalent optionally substituted C 1~20is aliphatic, wherein two or more methylene units are independently replaced with -C(O)N(R')- and -Cy-, in addition to other optional replacements. In some embodiments, -Cy- is optionally substituted. In some embodiments, -Cy- is optionally substituted with an electron-withdrawing group as described herein. In some embodiments, -Cy- is substituted with one or more -F. In some embodiments, -Cy- is optionally substituted 1,3-phenylene. In some embodiments, -Cy- is optionally substituted 1,4-phenylene. In some embodiments, L a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises ateeth, [ka] In some embodiments, L is or comprises a teeth, [ka] In some embodiments, L is or comprises a teeth, [ka] is or contains

[0185] In some embodiments, R' is R. In some embodiments, R a1 is R, and R is as described in this disclosure. In some embodiments, R a1 is R and R is methyl. In some embodiments, R a2 is R, and R is as described in this disclosure. In some embodiments, R a3 is R, and R is as described in this disclosure. In some embodiments, R a1 , R a2 , and R a3 Each of is independently R, where R is as described in this disclosure.

[0186] In some embodiments, R a1 is hydrogen. In some embodiments, R a1 is a protecting group. In some embodiments, R a1 is -Fmoc. In some embodiments, R a1 is -Dde.

[0187] In some embodiments, R a1 , R a2 and R a3 each independently represents -L a -R'.

[0188] In some embodiments, R a2is hydrogen. In some embodiments, R a3 is hydrogen. In some embodiments, R a1 is hydrogen and R a2 and R a3 At least one of R is hydrogen. a1 is hydrogen and R a2 and R a3 is hydrogen and the other is not hydrogen. a2 -L a -R and R a3 is —H. In some embodiments, R a3 -L a -R and R a2 is —H. In some embodiments, R a2 is -CH2-R, and R a3 is —H. In some embodiments, R a3 is -CH2-R, and R a2 is —H. In some embodiments, R a2 is R and R a3 is —H. In some embodiments, R a3 is R and R a2 is -H.

[0189] In some embodiments, R a2 -L a -R, where R is as described in this disclosure. In some embodiments, R a2 -L a -R, where R is C 3~30 Alicyclic, C 5~30 aryl, 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon, and 3-30 membered heterocyclyl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon. a2 -L a -R, where R is C 6~30aryl and 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon. a2 is the side chain of an amino acid. In some embodiments, R a2 is the side chain of a standard amino acid.

[0190] In some embodiments, R a3 -L a -R, where R is as described in this disclosure. In some embodiments, R a3 -L a -R, where R is C 3~30 Alicyclic, C 5~30 aryl, 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon, and 3-30 membered heterocyclyl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon. a3 -L a -R, where R is C 6~30 aryl and 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon. a3 is the side chain of an amino acid. In some embodiments, R a3 is the side chain of a standard amino acid.

[0191] In some embodiments, one or R a2 and R a3 is —H. In some embodiments, one or R a2 and R a3 -L a -R and L a is as described herein. In some embodiments, L a is not a covalent bond. aare independently and optionally replaced as described herein, such as, for example, with -C(O)-, -N(R')-, -O-, -C(O)-N(R')-, and / or -Cy-. In some embodiments, L a is or includes -C(O)-, -N(R')-, and -Cy-. In some embodiments, L a is or includes C(O)N(R')- and -Cy-. In some embodiments, -Cy- is substituted as described herein, and one or more substituents are independently electron-withdrawing groups.

[0192] In some embodiments, the amino acid side chain is R a2 or R a3 In some embodiments, the amino acid side chain is -L LG1 -L LG2 -L LG3 -L LG4 In some embodiments, the amino acid side chain is or comprises -L LG2 -L LG3 -L LG4 In some embodiments, the amino acid side chain is or comprises -L LG3 -L LG4 In some embodiments, the amino acid side chain is or comprises -L LG4 In some embodiments, such side chains are or include: [ka] In some embodiments, such side chains are: [ka] In some embodiments, such side chains are: [ka] In some embodiments, such side chains are: [ka] is.

[0193] In some embodiments, R is optionally substituted C 1~6 In some embodiments, R is an optionally substituted C 1~6 In some embodiments, R is alkyl. In some embodiments, R is -CH. In some embodiments, R is optionally substituted pentyl. In some embodiments, R is n-pentyl.

[0194] In some embodiments, R is a cyclic group. In some embodiments, R is an optionally substituted C 3~30 In some embodiments, R is cyclopropyl.

[0195] In some embodiments, R is an optionally substituted aromatic group and the amino acid residue of the amino acid of formula AI is Xaa A In some embodiments, R a2 or R a3 is -CH2-R, where R is an optionally substituted aryl or heteroaryl group. In some embodiments, R is an optionally substituted phenyl. In some embodiments, R is phenyl. In some embodiments, R is an optionally substituted phenyl. In some embodiments, R is 4-trifluoromethylphenyl. In some embodiments, R is 4-phenylphenyl. In some embodiments, R is an optionally substituted 5-30 membered heteroaryl having 1-10 heteroatoms independently selected from oxygen, nitrogen, sulfur, phosphorus, and silicon. In some embodiments, R is an optionally substituted 5-14 membered heteroaryl having 1-5 heteroatoms independently selected from oxygen, nitrogen, and sulfur. In some embodiments, R is [ka] In some embodiments, R is an optionally substituted pyridinyl. In some embodiments, R is 1-pyridinyl. In some embodiments, R is 2-pyridinyl. In some embodiments, R is 3-pyridinyl. In some embodiments, R is [ka] is.

[0196] In some embodiments, R' is -COOH. In some embodiments, the compound and amino acid residue of the amino acid of formula AI is Xaa N is.

[0197] In some embodiments, R' is -NH2. In some embodiments, the compound of the amino acid residue of the amino acid of formula AI is Xaa P is.

[0198] In some embodiments, R a2 or R a3 is R, and R is a C 1~20 In some embodiments, the compound of amino acid residues of the amino acid of formula AI is Xaa H In some embodiments, R is -CH3. In some embodiments, R is ethyl. In some embodiments, R is propyl. In some embodiments, R is n-propyl. In some embodiments, R is butyl. In some embodiments, R is n-butyl. In some embodiments, R is pentyl. In some embodiments, R is n-pentyl. In some embodiments, R is cyclopropyl.

[0199] In some embodiments, R a1 , R a2 , and R a3 and two or more of are R and taken together form an optionally substituted ring as described in this disclosure.

[0200] In some embodiments, R a1 and Ra2 and R a3 One of them is R, and together they form R a1 forms an optionally substituted 3- to 6-membered ring with no additional ring heteroatoms other than the nitrogen atom to which it is attached. In some embodiments, the ring formed is a 5-membered ring, such as proline.

[0201] In some embodiments, R a2 and R a3 is R and taken together form an optionally substituted 3-6 membered ring as described in this disclosure. In some embodiments, R a2 and R a3 is R and taken together form an optionally substituted 3-6 membered ring having one or more nitrogen ring atoms. In some embodiments, R a2 and R a3 is R and together form an optionally substituted 3-6 membered ring having one and no more than one ring heteroatom being a nitrogen atom. In some embodiments, the ring is a saturated ring.

[0202] In some embodiments, the amino acid is a natural amino acid. In some embodiments, the amino acid is an unnatural amino acid. In some embodiments, the amino acid is an alpha-amino acid. In some embodiments, the amino acid is a beta-amino acid. In some embodiments, the compound of formula AI is a natural amino acid. In some embodiments, the compound of formula AI is an unnatural amino acid.

[0203] In some embodiments, the amino acid comprises a hydrophobic side chain. In some embodiments, the amino acid with a hydrophobic side chain is A, V, I, L, M, F, Y, or W. In some embodiments, the amino acid with a hydrophobic side chain is A, V, I, L, M, or F. In some embodiments, the amino acid with a hydrophobic side chain is A, V, I, L, or M. In some embodiments, the amino acid with a hydrophobic side chain is A, V, I, or L. In some embodiments, the hydrophobic side chain is R, where R is C. 1~10 In some embodiments, R is C 1~10In some embodiments, R is alkyl. In some embodiments, R is methyl. In some embodiments, R is ethyl. In some embodiments, R is propyl. In some embodiments, R is butyl. In some embodiments, R is pentyl. In some embodiments, R is n-pentyl. In some embodiments, the amino acid having a hydrophobic side chain is NHCH(CHCHCHCHCHCH)COOH. In some embodiments, the amino acid having a hydrophobic side chain is (S)-NHCH(CHCHCHCHCHCH)COOH. In some embodiments, the amino acid having a hydrophobic side chain is (R)-NHCH(CHCHCHCHCHCH)COOH. In some embodiments, the hydrophobic side chain is -CHR, and R is an optionally substituted phenyl. In some embodiments, R is phenyl. In some embodiments, R is phenyl substituted with one or more hydrocarbon groups. In some embodiments, R is 4-phenylphenyl. In some embodiments, an amino acid having a hydrophobic side chain is NHCH(CH-4-phenylphenyl)COOH. In some embodiments, an amino acid having a hydrophobic side chain is (S)-NHCH(CH-4-phenylphenyl)COOH. In some embodiments, an amino acid having a hydrophobic side chain is (R)-NHCH(CH-4-phenylphenyl)COOH.

[0204] In some embodiments, the amino acid comprises a positively charged side chain as described herein (e.g., at physiological pH). In some embodiments, such an amino acid comprises a basic nitrogen in its side chain. In some embodiments, such an amino acid is Arg, His, or Lys. In some embodiments, such an amino acid is Arg. In some embodiments, such an amino acid is His. In some embodiments, such an amino acid is Lys.

[0205] In some embodiments, the amino acid comprises a negatively charged side chain as described herein (e.g., at physiological pH). In some embodiments, the amino acid comprises a -COOH in its side chain. In some embodiments, the amino acid is Asp. In some embodiments, the amino acid is Glu.

[0206] In some embodiments, the amino acid comprises a side chain comprising an aromatic group as described herein. In some embodiments, the amino acid is Phe, Tyr, Trp, or His. In some embodiments, the amino acid is Phe. In some embodiments, the amino acid is Tyr. In some embodiments, the amino acid is Trp. In some embodiments, the amino acid is His. In some embodiments, the amino acid is NH2-CH(CH2-4-phenylphenyl)-COOH. In some embodiments, the amino acid is (S)-NH2-CH(CH2-4-phenylphenyl)-COOH. In some embodiments, the amino acid is (R)-NH2-CH(CH2-4-phenylphenyl)-COOH.

[0207] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] In some embodiments, the amino acid is [ka] or a salt thereof. In some embodiments, provided compounds are [ka] In some embodiments, the present disclosure provides a polypeptide agent comprising one or more amino acid residues described in this disclosure.

[0208] reactive groups In some embodiments, provided compounds (e.g., those useful as reaction partners) include a reactive group (e.g., RG). As exemplified herein, in many embodiments, in provided compounds, the reactive group (e.g., RG) is located between a first group (e.g., LG) and a moiety of interest (e.g., MOI), and is optionally and independently linked to the first group and the moiety of interest via a linker. In some embodiments, RG is a reactive group as described herein.

[0209] In some embodiments, as provided herein, reactive groups, when utilized in compounds that do not include a target-binding moiety, react slowly, resulting in low levels of conjugation of the moiety of interest with the targeting agent, and in some embodiments, substantially no conjugation. As provided herein, the combination of a reactive group and a target-binding moiety in the same compound, such as in a compound of formula RI or a salt thereof, can, among other things, facilitate the reaction between the reactive group and the targeting agent, enhance reaction efficiency, reduce side reactions, and / or improve reaction selectivity (e.g., with respect to the target site at which conjugation of the moiety of interest with the targeting agent occurs).

[0210] The reactive groups in the provided compounds can react with various types of groups in a targeting agent. In some embodiments, the reactive groups in the provided compounds selectively react with amino groups of a targeting agent, e.g., —NH2 groups on the side chains of lysine residues in proteins. In some embodiments, when utilized in a provided compound (e.g., one of formula RI or a salt thereof), the reactive groups selectively react with specific sites of a targeting agent, e.g., one or more of K246, K248, K288, K290, K317, etc. of IgG1, K251, K253, etc. of IgG2, and K239, K241, etc. of IgG4, as shown in the examples herein. In some embodiments, the site is K246 or K248 of an antibody heavy chain. In some embodiments, the site is K246 and / or K248 of an antibody heavy chain. In some embodiments, the site is K246 of an antibody heavy chain. In some embodiments, the site is K248 of an antibody heavy chain. In some embodiments, the site is K288 or K290 of the antibody heavy chain. In some embodiments, the site is K288 of the antibody heavy chain. In some embodiments, the site is K290 of the antibody heavy chain. In some embodiments, the site is K317. In some embodiments, the site is K414 of the antibody heavy chain. In some embodiments, the site is K185 of the antibody light chain. In some embodiments, the site is K187 of the antibody light chain. In some embodiments, the site is K251 and / or K253 of an IgG2 heavy chain. In some embodiments, the site is K251 of an IgG2 heavy chain. In some embodiments, the site is K253 of an IgG2 heavy chain. In some embodiments, the site is K239 and / or K241 of an IgG4 heavy chain. In some embodiments, the site is K239 of an IgG4 heavy chain. In some embodiments, the site is K241 of an IgG4 heavy chain. In some embodiments, conjugation occurs preferentially at one or more heavy chain sites over light chain sites, and in some embodiments, for technologies that do not have target binding moieties, conjugation occurs at light chain sites over heavy chain sites (see, e.g., Figure 15).

[0211] In some embodiments, the reactive group (e.g., RG) is or includes an ester group. In some embodiments, the reactive group (e.g., RG) is or includes an electrophilic group (e.g., a Michael acceptor).

[0212] In some embodiments, the reactive group (e.g., RG) is -L RG1 -L RG2 - or contains L RG1 and L RG2 and each independently is L, as described herein. In some embodiments, the reactive group (e.g., RG) is -L LG4 -L RG1 -L RG2 In some embodiments, the reactive group (e.g., RG) is or includes -L LG3 -L LG4 -L RG1 -L RG2 In some embodiments, the reactive group (e.g., RG) is or includes -L LG2 -L LG3 -L LG4 -L RG1 -L RG2 In some embodiments, the reactive group (e.g., RG) is or includes -L LG4 -L RG2 In some embodiments, the reactive group (e.g., RG) is or includes -L LG3 -L LG4 -L RG2 In some embodiments, the reactive group (e.g., RG) is or includes -L LG2 -L LG3 -L LG4 -L RG2 -, where each variable is as described herein.

[0213] In some embodiments, LLG4 is —O—. In some embodiments, L LG4 is -N(R)-. In some embodiments, L LG4 is -NH-.

[0214] In some embodiments, L LG3 is or includes an optionally substituted aryl ring. In some embodiments, L LG3 is or includes a phenyl ring. In some embodiments, the aryl or phenyl ring is substituted. In some embodiments, the substituent is an electron-withdrawing group as described herein, such as -NO, -F, etc.

[0215] In some embodiments, L RG1 is a covalent bond. In some embodiments, L RG1 is not a covalent bond. RG1 is -S(O)2-.

[0216] In some embodiments, L RG2 is —C(O)—. In some embodiments, the reactive group is —L LG4 In some embodiments, the reactive group is or includes -C(O)-, where each variable is as described herein. LG3 -L LG4 In some embodiments, the reactive group is or includes -C(O)-, where each variable is as described herein. LG2 -L LG3 -L LG4 is or includes -C(O)-, where each variable is as described herein.

[0217] In some embodiments, L RG2 -L RG3 -C(=CR RG1 R RG2 )-CR RG3 R RG4 - and R RG1 , R RG2 , R RG3 and RRG4 each independently is -L-R', and L RG3 is —C(O)—, —C(O)O—, —C(O)N(R′)—, —S(O)—, —S(O)—, —P(O)(OR′)—, —P(O)(SR′)—, or —P(O)(N(R′))—. In some embodiments, R RG1 , R RG2 , R RG3 and R RG4 Each of is independently R'. In some embodiments, R RG1 , R RG2 , R RG3 and R RG4 and one or more of L are independently -H. RG3 is —C(O)—. In some embodiments, L RG3 is —C(O)O—. In some embodiments, L RG3 -O-, -N(R')-, etc. are L PM is connected to

[0218] In some embodiments, R RG1 is —H. In some embodiments, R RG3 is -H.

[0219] In some embodiments, L RG2 is optionally substituted -L RG3 -C(=CHR RG2 )-CHR RG4 - where each variable is as described herein.

[0220] In some embodiments, R RG2 and R RG4are taken together with their intervening atoms to form an optionally substituted ring as described herein. In some embodiments, the ring formed is an optionally substituted 3-10 membered monocyclic or bicyclic ring having 0-5 heteroatoms. In some embodiments, the ring formed is an optionally substituted 3-10 membered alicyclic ring. In some embodiments, the ring formed is an optionally substituted 3-8 membered alicyclic ring. In some embodiments, the ring formed is an optionally substituted 5-8 membered alicyclic ring. In some embodiments, the ring formed is an optionally substituted 5-membered alicyclic ring. In some embodiments, the ring formed is an optionally substituted 6-membered alicyclic ring. In some embodiments, the ring formed is an optionally substituted 7-membered alicyclic ring. In some embodiments, the ring formed is substituted. In some embodiments, the ring formed is unsubstituted. In some embodiments, the ring formed is C(=CHR RG2 ) or C(=CR RG1 R RG2 ) does not contain additional unsaturation in addition to the double bond in

[0221] In some embodiments, —C(═CHR RG2 )-CHR RG4 or -C(=CR RG1 R RG2 )-CR RG3 R RG4 is optionally substituted [ka] In some embodiments, -C(=CHR RG2 )-CHR RG4 or -C(=CR RG1 R RG2 )-CR RG3 R RG4 teeth, [ka] In some embodiments, -[C(=CHR RG2 )-CHR RG4 ]-LRG3 -or-[C(=CR RG1 R RG2 )-CR RG3 R RG4 ]-L RG3 - is optionally substituted [ka] In some embodiments, -[C(=CHR RG2 )-CHR RG4 ]-L RG3 -or-[C(=CR RG1 R RG2 )-CR RG3 R RG4 ]-L RG3 -teeth, [ka] In some embodiments, -L RG1 -[C(=CHR RG2 )-CHR RG4 ]-L RG3 -or-L RG1 -[C(=CR RG1 R RG2 )-CR RG3 R RG4 ]-L RG3 - is optionally substituted [ka] In some embodiments, -L RG1 -[C(=CHR RG2 )-CHR RG4 ]-L RG3 -or-L RG1 -[C(=CR RG1 R RG2 )-CR RG3 R RG4 ]-L RG3 - is optionally substituted [ka] is.

[0222] In some embodiments, the reactive group is a structure selected from the following table: LG2 -L LG3 -L LG4 -L RG1 -L RG2 - is a structure selected from the table below. LG2 -L LG3 -L LG4 -RG- is a structure selected from the table below. [Table 2]

[0223] In some embodiments, -L LG4 -L RG2 - is -OC(O)-. In some embodiments, -L LG4 -L RG2 - is -SC(O)-. In some embodiments, -L LG4 -L RG1 -L RG2 - is -SC(O)-.

[0224] In some embodiments, -L LG4 -L RG2 - is -N(-)-C(O)-, where N is a ring atom of an optionally substituted heteroaryl ring. LG4 -L RG2 - is -N(-)-C(O)-, where N is or comprises an optionally substituted heteroaryl ring; LG4 In some embodiments, -L LG4 -L RG2 - is -N(-)-C(O)-, where N is or comprises an optionally substituted heteroaryl ring; LG4 is a ring atom of

[0225] In some embodiments, L RG2is an optionally substituted —CH—C(O)—, where —CH— is bonded to an electron-withdrawing group that comprises or is connected to a target binding moiety. RG2 is an optionally substituted —CH— bonded to an electron withdrawing group that comprises or is connected to a target binding moiety. RG1 is an electron withdrawing group. RG1 is —C(O)—. In some embodiments, L RG1 is —S(O)—. In some embodiments, L RG1 is -S(O)-. In some embodiments, L RG1 is -P(O(OR)-. In some embodiments, L RG1 is —P(O(SR)—. In some embodiments, L RG1 is -P(O(N(R)2)-. In some embodiments, L RG1 is -OP(O(OR)-. In some embodiments, L RG1 is -OP(O(SR)-. In some embodiments, L RG1 is -OP(O(N(R)2)-.

[0226] In some embodiments, L RG2 is an optionally substituted —CH—C(O)—, where —CH— is attached to a leaving group that includes or is connected to a target binding moiety. RG2 is an optionally substituted —CH— bonded to a leaving group that comprises or is connected to a target binding moiety. RG1 is -OC(O)-. In some embodiments, L RG1 is —OS(O)—. In some embodiments, L RG1 is -OP(O(OR)-. In some embodiments, L RG1 is -OP(O(SR)-. In some embodiments, L RG1 is -OP(O(N(R)2)-.

[0227] In some embodiments, the reactive group reacts with an amino group of the targeting agent, hi some embodiments, the amino group is -NH2 of the side chain of a lysine residue.

[0228] In some embodiments, the targeting agent is a protein drug. In some embodiments, the targeting agent is an antibody drug. In some embodiments, the reactive group reacts with an amino acid residue of such a protein or antibody drug. In some embodiments, the amino acid residue is a lysine residue. In some embodiments, the reactive group reacts with -NH2 of the side chain of the lysine residue. In some embodiments, the reactive group is or includes -C(O)-O-, which reacts with -NH2 (e.g., of the side chain of the lysine residue) to form an amide group, -C(O)-O-, with -NH2.

[0229] Linker part In some embodiments, the moieties are optionally connected to one another via a linker moiety. For example, in some embodiments, the reactive group (e.g., RG) is linked to a linker (e.g., L RM In some embodiments, the moiety (e.g., LG) is also connected to the moiety of interest (e.g., MOI) via one or more linkers, e.g., L, for linking to various moieties. LG1 , L LG2 , L LG3 , L LG4 In some embodiments, L LG is a linker moiety as described herein. In some embodiments, L LG1 is a linker moiety as described herein. In some embodiments, L LG2 is a linker moiety as described herein. In some embodiments, L LG3 is a linker moiety as described herein. In some embodiments, L LG4 is a linker moiety as described herein. In some embodiments, L RM is a linker moiety as described herein. In some embodiments, L PM is L as described herein. In some embodiments, L PMis a linker moiety as described herein. In some embodiments, L PM is L as described herein.

[0230] Linker moieties of various types and / or for various purposes (such as those utilized in antibody-drug conjugates) may be utilized in accordance with the present disclosure.

[0231] Linker moieties can be either bivalent or multivalent depending on how they are used. In some embodiments, the linker moiety is bivalent. In some embodiments, the linker is multivalent and connects more than two moieties.

[0232] In some embodiments, the linker moiety, e.g., L z (wherein z represents a superscript, e.g., L PM , L RM , L LG , L LG1 etc.) is or contains L.

[0233] In some embodiments, L is a covalent bond or a divalent or polyvalent optionally substituted straight or branched C alkyl group comprising one or more aliphatic, aryl, heteroaliphatic having 1 to 20 heteroatoms, heteroaromatic having 1 to 20 heteroatoms, or any combination thereof. 1~100 is a group, wherein one or more methylene units of the group are optionally and independently selected from C 1~6 Alkylene, C 1~6 Alkenylene, divalent C with 1 to 5 heteroatoms 1~6Heteroaliphatic group, -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')- , -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S- , -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P(S)(SR')-, -P( S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n ]-, where n is 1 to 20. In some embodiments, each amino acid residue is independently a residue of an amino acid having the structure of formula AI, or a salt thereof. In some embodiments, each amino acid residue is independently replaced with -N(R a1 )-L a1 -C(R a2 )(R a3 )-L a2 It has the structure —CO— or a salt thereof.

[0234] In some embodiments, L is divalent. In some embodiments, L is a covalent bond.

[0235] In some embodiments, L is C 1~00 Aliphatic and C with 1-50 heteroatoms 1~100 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently selected from C 1~6 Alkylene, C 1~6 Alkenylene, divalent C with 1 to 5 heteroatoms 1~6Heteroaliphatic group, -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')- , -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S- , -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P(S)(SR')-, -P( S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n ] has been replaced with

[0236] In some embodiments, L is C 1~20 Aliphatic and C with 1-10 heteroatoms 1~20 heteroaliphatic, wherein one or more methylene units of the group are optionally and independently selected from C 1~6 Alkylene, C 1~6 Alkenylene, divalent C with 1 to 5 heteroatoms 1~6 Heteroaliphatic group, -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')- , -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S- , -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P(S)(SR')-, -P( S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n ]- has been replaced.

[0237] In some embodiments, L is C 1~20 a divalent or optionally substituted straight or branched group selected from aliphatic, wherein one or more methylene units of the group are optionally and independently selected from -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)- , -S(O)2-, -S(O)2N(R')-, -C(O)S-, -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, - P(S)(SR')-, -P(S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, amino acid residue, or -[(-OC(R')2-C(R')2-) n ]- has been replaced.

[0238] In some embodiments, L is C 1~20 a divalent or optionally substituted straight or branched group selected from aliphatic, wherein one or more methylene units of the group are optionally and independently selected from -C≡C-, -Cy-, -C(R')2-, -O-, -S-, -SS-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, -C(O)S-, -C(O)O-, an amino acid residue, or -[(-OC(R')2-C(R')2-) n ]- is replaced by

[0239] In some embodiments, L is C 1~20a divalent or optionally substituted straight or branched group selected from aliphatic, wherein one or more methylene units of the group are optionally and independently selected from -C≡C-, -Cy-, -C(R')2-, -O-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R')2N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O)2-, -S(O)2N(R')-, an amino acid residue, or -[(-OC(R')2-C(R')2-) n ]- has been replaced.

[0240] In some embodiments, a linker moiety (e.g., L, L PM , L RM etc.) contain an acidic group, e.g., —S(O)2OH.

[0241] In some embodiments, L is -[(-OC(R')2-C(R')2-) n In some embodiments, L is or includes -[(-O-CH-CH-) n ]-. In some embodiments, L is or comprises -[(-CH2-CH2-O)6]-CH2-CH2-. In some embodiments, L is -[(-CH2-CH2-O)8]-CH2-CH2-. In some embodiments, -CH2-CH2-O- is attached to the target binding moiety at -CH2-. In some embodiments, -CH2-CH2-O- is attached to the moiety of interest at -CH2-. In some embodiments, L PM is L as described herein. In some embodiments, L RM is L as described herein.

[0242] In some embodiments, the linker moiety is trivalent or multivalent. For example, in some embodiments, the linker moiety is L, as described herein, and L is trivalent or multivalent. In some embodiments, L is trivalent. For example, in some embodiments, L is -CH2-N(-CH2-)-C(O)-.

[0243] In some embodiments, L is or includes a product moiety of a bioorthogonal or enzymatic reaction. In some embodiments, L is or includes an optionally substituted triazole moiety (optionally part of a bicyclic or polycyclic ring system). In some embodiments, L is or includes LPXTG. In some embodiments, L is or includes LPETG. In some embodiments, L is or includes LPXT(G)n, where n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, L is or includes LPET(G)n, where n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0244] In some embodiments, the provided compounds / agents (e.g., reaction partners, agents (e.g., products of the provided methods and / or steps therein) do not comprise cleavable groups (other than one or more reactive groups and / or moieties therein) that can be cleaved under conditions that do not substantially damage or transform the targeting agent and / or agent comprising a targeting agent moiety (e.g., a conjugation product comprising a targeting agent moiety). In some embodiments, the provided compounds / agents (e.g., reaction partners, agents (e.g., products of the provided methods and / or steps therein) do not comprise cleavable groups (other than one or more reactive groups and / or moieties therein) that can be cleaved under conditions that do not render the targeting agent and / or agent comprising a targeting agent moiety (e.g., a conjugation product comprising a targeting agent moiety) ineffective for one or more uses (e.g., use as a diagnostic agent, therapeutic agent, etc.). In some embodiments, the provided compounds / agents (e.g., reaction partners, agents (e.g., products of the provided methods and / or steps therein) can be cleaved under bioorthogonal conditions. In some embodiments, provided compounds / agents (e.g., reaction partners, agents (e.g., products of provided methods and / or steps therein) do not contain a cleavable group that can be cleaved without substantially damaging and / or transforming the protein. In some embodiments, the cleavable group is selected from the group consisting of -S-, -SS-, -S-Cy-, -C(O)-O-, -C(O)-S-, an acetal moiety, -N=N-, an imine moiety, -CH=N-, a -P(O)(OR)O- moiety, -P(O)(OR)-N is or contains an (R)-moiety, a --C(O)-CH2-C(COOH)=CHC(O)- moiety, a -CHOH-CHOH- moiety, a -Se- moiety, Si bonded to two oxygen atoms, a -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO2-, a -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted at the o-position with -NO2-, or a -C(O)-N(-)- moiety in which N is a ring atom of a heteroaryl ring.In some embodiments, the cleavable group is or includes a -SS-, -S-CH2-Cy-, -S-Cy-, -C(O)-O-, -C(O)-S-, an acetal moiety, -N=N-, an imine moiety, -CH=N-, -P(O)(OR)O- moiety, -P(O)(OR)-N(R)- moiety, a -C(O)-CH2-C(COOH)=CHC(O)- moiety, a -CHOH-CHOH- moiety, a -Se- moiety, a Si bonded to two oxygen atoms, -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO2-, -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted at the o-position with -NO2-, or a -C(O)-N(-)- moiety where N is a ring atom of a heteroaryl ring.

[0245] In some embodiments, the linker moiety does not contain the above cleavage groups: In some embodiments, the linker moiety does not contain one or more, or any, of the following moieties: -SS-, -S-CH2-Cy-, -S-Cy-, -C(O)-O-, -C(O)-S-, acetal moiety, -N=N-, imine moiety, -CH=N-, -P(O)(OR)O- moiety, -P(O)(OR)-N(R)- moiety, -C(O)-CH2-C(COOH)=CHC(O)- moiety, -CHOH-CHOH- moiety, -Se- moiety, Si bonded to two oxygen atoms, -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO2-, -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO2- at the o-position, or a -C(O)-N(-)- moiety in which N is a ring atom of a heteroaryl ring. In some embodiments, the linker moiety does not contain one or more, or any, of the following moieties: -SS-, -S-CH2-Cy-, -S-Cy-, -C(O)-O-, -C(O)-S-, an acetal moiety, -N=N-, an imine moiety, -CH=N-, a -P(O)(OR)O- moiety, a -P(O)(OR)-N(R)- moiety, a -C(O)-CH2-C(COOH)=CHC(O)- moiety, a -CHOH-CHOH- moiety, a -Se- moiety, a Si bonded to two oxygen atoms, a -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO2-, a -C(O)-CH2- in which -CH2- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO2- at the o-position, or a -C(O)-N(-)- moiety in which N is a ring atom of a heteroaryl ring. In some embodiments, the linker moiety does not comprise -S-. In some embodiments, the linker moiety does not include -SS- (optionally excluding a disulfide moiety formed by two amino acid residues, and in some embodiments, optionally excluding a disulfide moiety formed by two cysteine ​​residues). In some embodiments, the linker moiety does not include -S-Cy-. In some embodiments, the linker moiety does not include -S-CH2-Cy-. In some embodiments, the linker moiety does not include -C(O)-O-.In some embodiments, the linker moiety does not comprise a —C(O)—S— moiety. In some embodiments, the linker moiety does not comprise an acetal moiety. In some embodiments, the linker moiety does not comprise a —N═N— moiety. In some embodiments, the linker moiety does not comprise an imine moiety. In some embodiments, the linker moiety does not comprise a —CH═N— moiety (optionally except within a ring, and in some embodiments, optionally except within a heteroaryl ring). In some embodiments, the linker moiety does not comprise a —P(O)(OR)O— moiety. In some embodiments, the linker moiety does not comprise a —P(O)(OR)—N(R)— moiety. In some embodiments, the linker moiety does not comprise a —C(O)—CH2—C(COOH)═CHC(O)— moiety. In some embodiments, the linker moiety does not comprise a —CHOH—CHOH— moiety. In some embodiments, the linker moiety does not comprise a —Se— moiety. In some embodiments, the linker moiety does not comprise a Si bonded to two oxygen atoms. In some embodiments, the linker moiety does not include -C(O)-CH-, where -CH- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO-. In some embodiments, the linker moiety does not include -C(O)-CH-, where -CH- is bonded to the benzyl carbon and the phenyl ring of the benzyl group is substituted with -NO- at the o-position. In some embodiments, the linker moiety does not include a -C(O)-N(-)- moiety, where N is a ring atom of a heteroaryl ring. In some embodiments, the linker moiety does not contain either of these groups. In some embodiments, L. RM is such a linker moiety. In some embodiments, L PM is such a linker moiety. In some embodiments, L LG is such a linker moiety. In some embodiments, the agents of the present disclosure do not contain one or more, or all, of such moieties.

[0246] In some embodiments, L is a covalent bond. In some embodiments, L is a divalent optionally substituted straight or branched C 1~100In some embodiments, L is a divalent optionally substituted linear or branched C alkyl group, wherein one or more methylene units of the group are optionally and independently replaced. 6~100 In some embodiments, L is a divalent optionally substituted linear or branched C alkyl group having 1 to 20 heteroatoms, wherein one or more methylene units of the group are optionally and independently replaced. 5~100 In some embodiments, L is a divalent optionally substituted linear or branched C alkyl group having 1 to 20 heteroatoms, wherein one or more methylene units of the group are optionally and independently replaced. 1~100 It is a heteroaliphatic group, in which one or more methylene units of the group are optionally and independently replaced.

[0247] In some embodiments, the linker moiety (e.g., L) is or includes one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more) polyethylene glycol units. In some embodiments, the linker moiety is -(CH2CHO) n -, where n is as described herein. In some embodiments, one or more methylene units of L are independently -(CH2CH2O) n - has been replaced with

[0248] As described herein, in some embodiments, n is 1. In some embodiments, n is 2. In some embodiments, n is 3. In some embodiments, n is 4. In some embodiments, n is 5. In some embodiments, n is 6. In some embodiments, n is 7. In some embodiments, n is 8. In some embodiments, n is 9. In some embodiments, n is 10. In some embodiments, n is 11. In some embodiments, n is 12. In some embodiments, n is 13. In some embodiments, n is 14. In some embodiments, n is 15. In some embodiments, n is 16. In some embodiments, n is 17. In some embodiments, n is 18. In some embodiments, n is 19. In some embodiments, n is 20.

[0249] In some embodiments, the linker moiety (e.g., L) is or includes one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more) amino acid residues. As used in this disclosure, "one or more" can be 1 to 100, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 1 to 5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 or more. In some embodiments, one or more methylene units of L are independently replaced with an amino acid residue. In some embodiments, one or more methylene units of L are independently replaced with an amino acid residue, wherein the amino acid residue is of Formula AI or a salt thereof. In some embodiments, one or more methylene units of L are independently replaced with an amino acid residue, each amino acid residue being independently selected from the group consisting of -N(R a1 )-L a1 -C(R a2 )(R a3 )-L a2 It has the structure —CO— or a salt thereof.

[0250] In some embodiments, a linker moiety comprises one or more moieties (e.g., amino, carbonyl, etc.) that can be utilized to connect to other moieties. In some embodiments, a linker moiety comprises one or more -NR'-, where R' is as described in this disclosure. In some embodiments, -NR'- improves solubility. In some embodiments, -NR'- serves as a connection point to another moiety. In some embodiments, R' is -H. In some embodiments, one or more methylene units of L are independently replaced with -NR'-, where R' is as described in this disclosure.

[0251] In some embodiments, a linker moiety (e.g., L) comprises a -C(O)- group that can be used to connect to a moiety. In some embodiments, one or more methylene units of L are independently replaced with -C(O)-.

[0252] In some embodiments, a linker moiety (e.g., L) comprises an -NR'- group that can be used to connect moieties, in some embodiments, one or more methylene units of L are independently replaced with -N(R')-.

[0253] In some embodiments, a linker moiety (e.g., L) comprises a -C(O)NR'- group that can be used to connect moieties. In some embodiments, one or more methylene units of L are independently replaced with -C(O)N(R')-.

[0254] In some embodiments, a linker moiety (e.g., L) comprises a -C(R')2- group. In some embodiments, one or more methylene units of L are independently replaced with -C(R')2-. In some embodiments, -C(R')2- is -CHR'-. In some embodiments, R' is -(CH2)2C(O)NH(CH2) 11 In some embodiments, R' is -COOH. In some embodiments, R' is -(CH2)2COOH. In some embodiments, R' is -COOH.

[0255] In some embodiments, the linker moiety is or includes one or more ring moieties, e.g., one or more methylene units of L are replaced with -Cy-. In some embodiments, the linker moiety (e.g., L) includes an aryl ring. In some embodiments, the linker moiety (e.g., L) includes a heteroaryl ring. In some embodiments, the linker moiety (e.g., L) includes an aliphatic ring. In some embodiments, the linker moiety (e.g., L) includes a heterocyclyl ring. In some embodiments, the linker moiety (e.g., L) includes a polycyclic ring. In some embodiments, the ring of the linker moiety (e.g., L) has 3 to 20 members. In some embodiments, the ring is 5 members. In some embodiments, the ring is 6 members. In some embodiments, the ring of the linker is the product of a cycloaddition reaction (e.g., click chemistry and variations thereof) utilized to link different moieties together.

[0256] In some embodiments, the linker moiety (e.g., L) is [ka] In some embodiments, the methylene units of L are or include: [ka] In some embodiments, a methylene unit of L is replaced with -Cy-. In some embodiments, -Cy- is [ka] is.

[0257] In some embodiments, a linker moiety (e.g., L) is or includes -Cy-. In some embodiments, a methylene unit of L is replaced with -Cy-. In some embodiments, -Cy- is [ka] In some embodiments, -Cy- is [ka] In some embodiments, -Cy- is [ka] is.

[0258] In some embodiments, the linker moiety (e.g., L) is [ka] is or contains

[0259] In some embodiments, L RM is a covalent bond. In some embodiments, L RM is not a covalent bond. RM In some embodiments, L is or includes -(CHCHO)-. RM is or includes -(CH2)nO-(CH2CH2O)n-(CH2)n-, where each n is independently as described herein and each -CH2- is independently optionally substituted. In some embodiments, L RM is —(CH)O—(CHCHO)—(CH)—, where each n is independently as described herein and each —CH— is independently optionally substituted. In some embodiments, L RM is —(CH)—O—(CHCHO)—(CH)—, where n is as described herein, and each —CH— is independently optionally substituted. In some embodiments, L RM is —(CH 2 ) 2 —O—(CH 2 CH 2 O) n —(CH 2 ) 2 —, where n is as described herein.

[0260] In some embodiments, L PM is a covalent bond. In some embodiments, L PM is not a covalent bond. PMIn some embodiments, L is or includes -(CHCHO)-. PM is or includes -(CH2)nO-(CH2CH2O)n-(CH2)n-, where each n is independently as described herein and each -CH2- is independently optionally substituted. In some embodiments, L PM is —(CH)O—(CHCHO)—(CH)—, where each n is independently as described herein and each —CH— is independently optionally substituted. In some embodiments, L PM is —(CH)—O—(CHCHO)—(CH)—, where n is as described herein, and each —CH— is independently optionally substituted. In some embodiments, L PM is —(CH 2 ) 2 —O—(CH 2 CH 2 O) n —(CH 2 ) 2 —, where n is as described herein.

[0261] In some embodiments, L PM (eg, in the product of a first agent and a second agent) is or includes the reaction product moiety that forms the first reactive moiety and the second reactive moiety.

[0262] In some embodiments, a linker moiety (e.g., L) in the product of the first drug and the second drug may be PM )teeth, [ka] In some embodiments, the methylene unit of the linker moiety (e.g., L) or L (e.g., L RM , L PM In some embodiments, the linker moiety, which may be -Cy-, is replaced with -Cy-. In some embodiments, -Cy- is optionally substituted [ka] In some embodiments, -Cy- is [ka] In some embodiments, -Cy- is [ka] In some embodiments, -Cy- is [ka] In some embodiments, -Cy- is [ka] is.

[0263] Purpose Those skilled in the art reading this disclosure will understand that various types of moieties of interest can be utilized for various purposes in accordance with this disclosure. For purposes of this disclosure, the moiety of interest is or includes monomethyl auristatin E (MMAE), or a close analog of MMAE.

[0264] In some embodiments of the present disclosure, the moiety of interest is or includes MMAE. MMAE is an anti-neoplastic agent used in drug-antibody conjugates, such as MAB-MMAE conjugates. MMAE is linked to the monoclonal antibody via a linker that can be cleaved when the drug-antibody conjugate binds to tumor cells. The linker comprises a cathepsin-cleavable sequence (valine-citrulline) and a spacer. The spacer can be varied. [ka]

[0265] In some embodiments, the moiety of interest is or comprises an MMAD. [ka]

[0266] In some embodiments, the moiety of interest is or comprises MMAF, i.e., monomethyl auristatin F or desmethyl auristatin F, the linking structures of which are shown below. [ka]

[0267] In some embodiments, provided methods include: The method further includes reacting a first agent comprising a first reactive moiety (e.g., in a first moiety of interest) with a second agent comprising a second reactive moiety. In various embodiments, the first reactive moiety is in the first moiety of interest, which can be incorporated, for example, via a method described herein (e.g., via contact with a compound having the structure of formula RI or a salt thereof).

[0268] In some embodiments, the second moiety of interest is in a compound that does not include a target binding moiety. In some embodiments, the second moiety of interest is in a compound of formula PI or P-II, or a salt thereof. In some embodiments, the second moiety of interest is in a compound of formula RI, or a salt thereof. In some embodiments, the second agent has a structure of formula PI or P-II, or a sat thereof. In some embodiments, the second reactive moiety is in a moiety of interest of the second agent. In some embodiments, the second agent comprises a targeting agent moiety described herein. For example, in some embodiments, the targeting agent moiety in the second agent is or comprises a peptide moiety. For example, in some embodiments, the targeting agent moiety in the second agent is or comprises an antibody drug moiety described herein. In some embodiments, it comprises an scFv moiety. In some embodiments, the targeting agent moiety in the second agent provides a different specificity compared to that of the first agent. In some embodiments, such first and second agents react with each other to provide different product agents comprising moieties with different specificities as described herein.

[0269] In some embodiments, the reaction between the first reactive moiety and the second reactive moiety is a bioorthogonal reaction. In some embodiments, the reaction is a cycloaddition reaction. In some embodiments, the reaction is a [3+2] reaction. Suitable such reactions and corresponding first and second reactive moieties are widely known in the art and can be utilized in accordance with the present disclosure. In some embodiments, the first reactive moiety is or includes -N3 and the second reactive moiety is or includes -≡- (e.g., an alkyne moiety suitable for click chemistry, including a moiety suitable for metal-free click chemistry). In some embodiments, the second reactive moiety is or includes -N3 and the first reactive moiety is or includes -≡- (e.g., an alkyne moiety suitable for click chemistry, including a moiety suitable for metal-free click chemistry).

[0270] As described herein, in some embodiments, the reaction between the first reactive moiety and the second reactive moiety is an enzymatic reaction. In some embodiments, the reaction is a sortase-mediated reaction. In some embodiments, each of the first and second reactive moieties independently is or includes a substrate moiety for a reaction, e.g., an enzymatic reaction. For example, in some embodiments, for sortase-mediated conjugation, the reactive moiety is or includes (G)n (e.g., n is 3, 4, 5, etc.) and the reactive moiety is or includes LPXTG (e.g., LPETG). In some embodiments, the reactive moiety is or includes LPXTG-(X)n (e.g., LPETG-(X)n, LPETG-XX, etc.). Those of skill in the art reading this disclosure will understand that a variety of reactive moieties can be utilized for conjugation via either enzymatic and / or non-enzymatic routes in accordance with this disclosure.

[0271] In some embodiments, the second agent is or comprises a second moiety of interest, which is a moiety of interest described herein. In some embodiments, the second reactive moiety and the second moiety of interest are linked via a linker (e.g., a linker described herein (e.g., a L PM, L, etc.). In some embodiments, the second moiety of interest is as described herein (e.g., a detection moiety, a therapeutic moiety, a moiety of interest that can interact with, recognize, and / or bind to a protein, a nucleic acid, an immune cell, a diseased cell, etc.). In some embodiments, the second moiety of interest is or comprises an antibody drug. In some embodiments, the second moiety of interest is or comprises an scFv antibody drug. In some embodiments, such an antibody drug has a different specificity compared to the initial targeted antibody drug. Thus, in some embodiments, the present disclosure provides bispecific antibody drugs, compositions, and methods thereof. In some embodiments, the targeted drug is or comprises a first antibody drug and is conjugated to a moiety of interest that comprises a first reactive moiety. In some embodiments, a drug comprising a first antibody drug and a first reactive moiety is reacted with a second drug comprising a second moiety of interest that is or comprises a second reactive moiety and a second antibody drug to provide a drug comprising the first and second antibody drugs. In some embodiments, the first antibody drug and the second antibody drug are different. In some embodiments, they are the same.

[0272] In some embodiments, a drug comprises two or more antibody drug moieties. In some embodiments, the antibody drug moieties in a single drug molecule have different target specificities. In some embodiments, some or all antibody drug moieties in a single drug molecule have the same target specificity. In some embodiments, a drug described herein is or comprises moieties with different target specificities (e.g., antibody moieties with different target specificities). In some embodiments, a drug is a bispecific antibody drug. In some embodiments, a drug comprises a first moiety (e.g., a first antibody drug moiety) and a second moiety (e.g., a second antibody drug moiety). In some embodiments, the first moiety (e.g., the first antibody drug moiety) is or comprises an IgG or a fragment thereof. In some embodiments, the first moiety (e.g., the first antibody drug moiety) is or comprises an antibody drug moiety or fragment thereof (e.g., an Fc region or fragment thereof) to which a target-binding moiety can bind. In some embodiments, the second moiety (e.g., the second antibody drug moiety) is or comprises an IgG or a fragment thereof. In some embodiments, the second moiety (e.g., a second antibody drug moiety) is or comprises an antibody drug moiety or fragment thereof (e.g., an Fc region or fragment thereof) to which a target-binding moiety can bind. In some embodiments, the antibody drug moiety, e.g., a second antibody drug moiety, does not comprise a moiety to which a target-binding moiety can bind. In some embodiments, the antibody drug moiety, e.g., a second antibody drug moiety, does not comprise an Fc region to which a target-binding moiety can bind. In some embodiments, the antibody drug moiety, e.g., a second antibody drug moiety, is or comprises an scFv. In some embodiments, the first moiety is or comprises a drug moiety of the first drug. In some embodiments, the second moiety is or comprises a moiety of interest of the second drug. In some embodiments, a first drug (e.g., one comprising a first antibody drug moiety) is contacted with a second drug (e.g., one comprising a second antibody drug moiety) to provide a drug comprising two or more moieties (e.g., antibody drug moieties) with target specificity.

[0273] In some embodiments, the moiety (e.g., first moiety) is or includes an antibody drug moiety that binds to a target (e.g., a protein, lipid, carbohydrate, object, etc.) associated with a condition, disorder, or disease (e.g., cancer). In some embodiments, the moiety (e.g., first moiety) is or includes an antibody drug moiety suitable for preventing or treating a condition, disorder, or disease (e.g., cancer). In some embodiments, the moiety (e.g., first moiety) is or includes an antibody drug moiety that targets a cancer cell, tissue, organ, etc. For example, in some embodiments, the first moiety is or includes a portion of an anti-CD20 antibody or fragment thereof. In some embodiments, the first moiety is or includes rituximab or a fragment thereof. In some embodiments, the moiety (e.g., second moiety) is a second moiety of interest. In some embodiments, the moiety (e.g., second moiety) is or includes an antibody drug moiety that can recruit and / or activate immune activity (e.g., one or more immune cells). In some embodiments, the moiety (e.g., the second moiety) is or comprises an antibody drug moiety capable of recruiting and / or activating T cells. In some embodiments, the moiety (e.g., the second moiety) is a portion of an anti-CD3 antibody or fragment thereof. In some embodiments, the atnti-CD3 antibody is a CD3-directed scFv. In some embodiments, the moiety (e.g., the first moiety) is a targeted drug moiety. In some embodiments, provided drugs comprise an anti-CD20 moiety and an anti-CD3 moiety. In some embodiments, provided drugs comprise an anti-CD20 moiety and an anti-CD3 moiety, the two moieties being linked by a linker. In some embodiments, the linker comprises a moiety that is not an amino acid residue. In some embodiments, the linker comprises a moiety that is not a naturally occurring proteinogenic amino acid residue. In some embodiments, the linker is a linker moiety described herein.Those skilled in the art will appreciate that agents comprising two or more target-specific moieties (e.g., antibody drug moieties) can be prepared with various advantages and properties in accordance with the present disclosure, e.g., high site specificity, high homogeneity, low levels of damage, low levels of reduction or substantial absence of desired properties and / or activities (e.g., target binding, immune recruitment and / or activation, etc.). Those skilled in the art will also appreciate that the provided technology allows antibody drugs, e.g., those that are readily available (e.g., "off-the-shelf" therapeutic antibodies), to be readily conjugated to other moieties, e.g., in some embodiments, other antibody drugs, e.g., to produce bispecific agents. In some embodiments, the first and second moieties are linked by a linker as described herein.

[0274] In some embodiments, the provided product drug comprises a linker moiety connecting the targeting drug moiety and a second moiety of interest (e.g., two antibody drug moieties). In some embodiments, the linker is RG2 , L PM or one or more fragments thereof, and one or more moieties formed by a first and a second reactive moiety (e.g., in the case of click chemistry, a triazole moiety). In some embodiments, the linker is or comprises a product linker moiety (e.g., formed by reaction between a first reactive moiety and a second reactive moiety). In some embodiments, the product linker moiety is or comprises LPXTG. In some embodiments, the product linker moiety is or comprises LPXT(G)n, where n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, the product linker moiety is or comprises a bioorthogonal reaction product moiety (e.g., a click chemistry reaction product moiety).

[0275] In some embodiments, the techniques provided herein are used to prepare agents comprising a second reactive moiety and a second moiety of interest. In some embodiments, the second moiety of interest is or comprises a protein drug moiety. In some embodiments, the second moiety of interest is or comprises an antibody drug moiety. In some embodiments, to utilize certain provided methods (e.g., targeting agents (e.g., protein drugs (e.g., antibody drugs, etc.)) with a reaction partner comprising a moiety of interest (e.g., that is or comprises a second reactive moiety), a reactive group, and a target binding moiety that can bind to the targeting agent to provide the second agent), the second moiety of interest (e.g., a protein drug (e.g., an antibody drug)) can function as the targeting agent moiety and the second reactive moiety can function as the moiety of interest (e.g., an MOI of a compound of formula RI or a salt thereof).

[0276] In some embodiments, each of the first and second agents is independently and optionally an agent of formula PI or P-II, or a salt thereof. In some embodiments, each of the first and second agents is independently an agent of formula PI or P-II, or a salt thereof. In some embodiments, at least one of the first and second agents is prepared using a method of the present disclosure. In some embodiments, each of the first and second agents is independently prepared using a method of the present disclosure. In some embodiments, the targeting agent portion of the first agent is an antibody agent. In some embodiments, the moiety of interest of the first agent is or includes a first reactive moiety. In some embodiments, the targeting agent portion of the second agent is an antibody agent. In some embodiments, the moiety of interest of the second agent is or includes a second reactive moiety. As described herein, in many embodiments, the first reactive moiety and the second reactive moiety can react with each other to provide a product agent. In some embodiments, the reaction between the first reactive moiety and the second reactive moiety is or includes a reaction compatible with the targeting agent in the first drug and the second drug, e.g., a protein drug (e.g., an antibody drug). In some embodiments, such a reaction is a bioorthogonal reaction. In some embodiments, such a reaction is a cycloaddition reaction. In some embodiments, such a reaction is a click reaction. In some embodiments, such a reaction is a metal-free click reaction. In some embodiments, the product drug is of formula PI or P-II, or a salt thereof. In some embodiments, in a product drug of formula PI or P-II, or a salt thereof, the targeting agent moiety is a protein drug (e.g., an antibody drug), in some embodiments, the targeting agent moiety of the first drug. In some embodiments, in a product drug of formula PI or P-II, or a salt thereof, the moiety of interest is a protein drug (e.g., an antibody drug), in some embodiments, the targeting agent moiety of the second drug. In some embodiments, the product drug includes two or more antibody drugs. In some embodiments, the two or more antibody drugs have different antigen specificities. In some embodiments, the two or more antibody agents are directed against different antigens.In some embodiments, a method is provided. The method includes reacting a first agent having a structure of formula PI or P-II, or a salt thereof, with a second agent having a structure of formula PI or P-II, or a salt thereof, to provide a product agent.

[0277] Methods and Products In some embodiments, the provided techniques involve contacting a targeting agent (e.g., to which a moiety of interest is attached) with a reaction partner. In some embodiments, the contacting is performed under conditions and for a time such that the targeting agent reacts with the reaction partner to form the agent as a product. Many reaction conditions / reaction times in the art may be evaluated and utilized as suitable for the desired purpose in accordance with the present disclosure, and specific such conditions, reaction times, evaluations, etc. are described in the Examples.

[0278] In some embodiments, the drug formed comprises a targeting drug moiety, a moiety of interest, and optionally a linker moiety connecting the targeting drug moiety and the moiety of interest. In some embodiments, the targeting drug moiety is derived from the targeting drug (e.g., by removing one or more -H from the targeting drug). In some embodiments, the targeting drug moiety maintains one or more, most, or substantially all of the structural features and / or biological functions of the targeting drug. For example, in some embodiments, the targeting drug is an antibody drug and the targeting drug moiety in the drug formed is the corresponding antibody drug moiety, maintaining the primary functions of the antibody drug (e.g., interacting with various receptors (e.g., Fc receptors such as FcRn), recognizing antigens with specificity, triggering, promoting, and / or enhancing immunological activity against diseased cells, etc.). In some embodiments, the drug formed provides one or more functions beyond those of the targeting drug, e.g., functions from the moiety of interest and / or the drug formed as a whole.

[0279] In some embodiments, the agent formed has a structure of formula PI or P-II, or a salt thereof. In some embodiments, the moiety of interest in the agent formed (e.g., MOI of formula PI or P-II, or a salt thereof) is the same as the moiety of interest in the reaction partner utilized to prepare the agent formed (e.g., MOI of formula RI, or a salt thereof). In some embodiments, P is a protein moiety. In some embodiments, P is an antibody moiety.

[0280] In some embodiments, the linker moiety (or a portion thereof) connected to the moiety of interest is a reactive partner (e.g., L RM or a salt thereof). In some embodiments, the linker moiety (e.g., L PM ) is a linker moiety in the reaction partner (e.g., between the reactive group and the moiety of interest, e.g., L RM In some embodiments, L PM L RM In some embodiments, L is or comprises PM -L RM -L RG2 In some embodiments, L RG2 is —C(O)—. In some embodiments, L RG2 is —C(O)— and is attached to —NH— of the targeting agent moiety, e.g., —NH— in the side chain of a lysine residue of the protein moiety, which in some embodiments is an antibody moiety.

[0281] The reactive partner, e.g., a compound of Formula RI or a salt thereof, typically does not contain a moiety capable of reacting with the reactive group under conditions in which the reactive group reacts with a targeting drug. In some embodiments, to the extent that some moieties in the reactive partner are capable of reacting with the reactive group under conditions in which the reactive group reacts with a targeting drug, the reaction between such moieties and the reactive group is significantly slower and / or less efficient than the reaction between the reactive group and the targeting drug. In some embodiments, the reaction between such moieties and the reactive group does not significantly reduce the efficiency, yield, rate, and / or conversion rate, etc., of the reaction between the reactive group and the targeting drug (e.g., by no more than about 5%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.). In some embodiments, the reactive group (e.g., an ester group, an activated carboxylic acid derivative, etc.) reacts with an amino group (e.g., an —NH group) of a targeting drug (e.g., a protein drug such as an antibody drug). In some embodiments, the reaction partner, e.g., a compound of formula RI or a salt thereof, does not contain an amine group. In some embodiments, a compound of formula RI or a salt thereof (or a portion thereof, e.g., R LG , L LG , L LG1 , L LG2 , L LG3 , L LG4 , L RG1 , L RG2 , L RM , and / or MOI) do not contain amine groups. In some embodiments, they do not contain primary amine groups (—NH). In some embodiments, they do not contain —CHNH. In some embodiments, they do not contain —CHCHNH. In some embodiments, they do not contain —CHCHCHNH. In some embodiments, they do not contain —CHCHCHCHNH. In some embodiments, they do not contain —CHCHCHCHNH. In some embodiments, amine groups, e.g., primary amine groups, are capped (e.g., by introduction of an acyl group (e.g., RC(O)— (e.g., acetyl)) to form an amide group) to prevent or reduce undesired reactions.

[0282] In some embodiments, the reaction is carried out in a buffer system. In some embodiments, the buffer system of the present disclosure maintains the structure and / or function of the target agent, moiety of interest, etc. In some embodiments, the buffer is a phosphate buffer. In some embodiments, the buffer is a PBS buffer. In some embodiments, the buffer is a borate buffer. In some embodiments, the buffer of the present disclosure provides, and optionally maintains, a specific pH value or range. For example, in some embodiments, a useful pH is about 7-9, e.g., 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 9.0, etc. In some embodiments, the pH is 7.4. In some embodiments, the pH is 7.5. In some embodiments, the pH is 7.8. In some embodiments, the pH is 8.0. In some embodiments, the pH is 8.2. In some embodiments, the pH is 8.3.

[0283] The provided techniques can offer various advantages. Notably, in some embodiments, the connection of a moiety of interest in a provided reaction partner (e.g., a compound comprising a reactive group located between a first group and a moiety of interest (e.g., a compound of formula RI or a salt thereof)) to a targeting agent and the release of the target-binding moiety in the provided reaction partner can be accomplished in one reaction and / or one pot. Thus, in many embodiments, a separate reaction / step to remove the target-binding moiety is not performed. As will be appreciated by those skilled in the art, by performing the attachment of the moiety of interest and the release of the target-binding moiety in a single reaction / operation, the provided techniques can avoid a separate step for removal of the target-binding moiety, improving overall efficiency (e.g., by simplifying the operation, increasing overall yield, etc.), reducing production costs, and improving product purity (e.g., by avoiding exposure to target-binding moiety removal conditions that typically involve one or more of conditions such as reduction, oxidation, hydrolysis (e.g., of ester groups), etc., which may damage the target drug moiety (e.g., protein drug moiety, protein amino acid residues, overall structure, and / or post-translational modifications (e.g., glycans of antibodies)). Indeed, as demonstrated herein, among other things, the provided techniques can provide improved efficiency (e.g., in terms of reaction rate and / or conversion percentage), increased yield, increased purity / homogeneity, and / or enhanced selectivity, especially compared to reference techniques in which reaction partners that do not contain the target-binding moiety are used and which do not introduce a step for target-binding moiety removal (e.g., in which the target-binding moiety is removed in the same step as conjugation of the moiety of interest).

[0284] In some embodiments, the present disclosure provides, inter alia, products of the provided processes that include a lower level of damage to the targeting agent moiety compared to processes that include steps performed for removal of the target-binding moiety but not for substantial conjugation of the moiety of interest. In some embodiments, the provided product compositions have a high degree of homogeneity compared to reference product compositions (e.g., from techniques that do not use a target-binding moiety or that do not utilize an additional step for target-binding moiety removal (e.g., do not utilize a reaction partner described herein that includes a reactive group positioned between the target-binding moiety and the moiety of interest)).

[0285] In some embodiments, the product drug is a targeting drug moiety; and The purpose of MMAD etc. and optionally one or more linker moieties.

[0286] In some embodiments, the targeting drug moiety is a protein drug moiety. In some embodiments, the targeting drug moiety is an antibody drug moiety. In some embodiments, the antibody drug moiety comprises an IgG Fc region. In some embodiments, the targeting drug moiety is connected to the moiety of interest through an amino group, optionally via a linker. In some embodiments, it is through a lysine residue whose side chain amino group is connected to the moiety of interest, optionally via a linker (e.g., as part of an amide group, carbamate group, etc., to form -NH-C(O)-).

[0287] In some embodiments, a selected position of the targeting agent is utilized for conjugation. For example, in some embodiments, K246 or K248 (EU numbering, or corresponding residues) of an antibody agent is a conjugation position. In some embodiments, the conjugation position is K246 of the heavy chain (unless otherwise specified, positions herein include corresponding residues, for example, in modified sequences (e.g., longer, shorter, rearranged, etc. sequences). In some embodiments, the position is K248 of the heavy chain. In some embodiments, the position is K288 or K290 of the heavy chain. In some embodiments, the position is K288 of the heavy chain. In some embodiments, the position is K290 of the heavy chain. In some embodiments, the position is K317.

[0288] In some embodiments, when the targeting agent is a replacement agent, the heavy chain is selectively labeled over the light chain.

[0289] Among other things, the present disclosure can provide a controlled moiety / targeting agent ratio of interest (e.g., for antibody-drug conjugates, drug / antibody ratio (DAR)). For example, in some embodiments, the ratio is about 0.5 to 6, e.g., 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, etc.). In some embodiments, the ratio is about 0.5 to 2.5. In some embodiments, the ratio is about 0.5 to 2. In some embodiments, the ratio is about 1 to 2. In some embodiments, the ratio is about 1.5 to 2. In some embodiments, the ratio is the ratio of the moiety of interest conjugated to the targeting agent moiety to the moiety of interest, hi some embodiments, the ratio is the ratio of the moiety of interest conjugated to the targeting agent moiety to all the targeting agent moieties in the composition.

[0290] In some embodiments, in a provided agent (e.g., an agent of formula PI or P-II, or a salt thereof), substantially all of the conjugation sites of the targeting agent moieties have the same modification (e.g., all share the same moiety of interest, optionally connected via the same linker moiety). In some embodiments, the conjugation moieties do not have different modifications (e.g., different moieties of interest and / or non-moieties of interest and / or different linker moieties).

[0291] In some embodiments, in provided compositions comprising multiple provided agents (e.g., agents of formula PI or P-II, or salts thereof), substantially all of the conjugation sites of the targeting agent moieties have the same modification (e.g., all share the same moiety of interest, optionally connected via the same linker moiety). In some embodiments, the conjugation moieties do not have different modifications (e.g., different moieties of interest and / or non-moieties of interest and / or different linker moieties). In some embodiments, such compositions do not contain agents that share the same (or substantially the same) targeting agent moiety but different modifications (e.g., different moieties of interest and / or non-moieties of interest and / or different linker moieties). In some embodiments, agents that share the same (or substantially the same) targeting agent moiety but different modifications (e.g., different moieties of interest and / or non-moieties of interest and / or different linker moieties) are intermediates in a multi-step preparation of a final product agent (e.g., including a step for removal of the target binding moiety in addition to a step for conjugation of the moiety of interest).

[0292] In some embodiments, the present disclosure provides a composition comprising multiple agents, each of which independently: a targeting drug moiety; and The objective part and optionally a linker moiety connecting the targeting agent moiety and the moiety of interest; the multiple agents independently share the same or substantially the same targeting agent moiety and a common modification at at least one common position; Compositions are provided in which between about 1% and 100% of all drugs, including targeting drug moieties and moieties of interest, are multiple drugs.

[0293] In some embodiments, the target binding moiety is or comprises a protein moiety. In some embodiments, the multiple agents independently share a common modification (e.g., conjugation of a moiety of interest, optionally via a linker moiety) in at least one amino acid residue. In some embodiments, the multiple agents are each independently of the formula PI or P-II, or a salt thereof.

[0294] In some embodiments, the present disclosure provides a composition comprising multiple agents, each of which independently: a protein drug moiety; and The objective part and optionally a linker moiety connecting the protein drug moiety and the moiety of interest; the protein drug moieties of the plurality of agents comprise a common amino acid sequence, and the plurality of agents independently share a common modification to at least one common amino acid residue of the protein drug moieties; Compositions are provided in which between about 1% and 100% of all drugs comprising a protein drug moiety that includes a common amino acid sequence and a moiety of interest are multiple drugs.

[0295] In some embodiments, the multiple drugs are each independently of the formula PI or P-II, or a salt thereof. In some embodiments, each protein drug moiety is independently an antibody drug moiety.

[0296] In some embodiments, the present disclosure provides a composition comprising multiple agents, each of which independently: an antibody drug moiety; and The objective part and optionally a linker moiety connecting the antibody drug moiety and the moiety of interest; the antibody drug moieties of the multiple agents comprise a common amino acid sequence or are capable of binding to a common antigen, and the multiple agents independently share a common modification in at least one common amino acid residue in the protein drug moieties; Compositions are provided in which about 1% to 100% of all drugs are multiple drugs that contain an antibody drug moiety that contains a common amino acid sequence or is capable of binding to a common antigen and a moiety of interest.

[0297] In some embodiments, the multiple agents are each independently of the formula PI or P-II, or a salt thereof. In some embodiments, the antibody drug moieties of the multiple agents comprise a common amino acid sequence. In some embodiments, the antibody drug moieties of the multiple agents comprise a common amino acid sequence in the Fc region. In some embodiments, the antibody drug moieties of the multiple agents comprise a common Fc region. In some embodiments, the antibody drug moieties of the multiple agents can specifically bind to a common antigen. In some embodiments, the antibody drug moieties are monoclonal antibody moieties. In some embodiments, the antibody drug moieties are polyclonal antibody moieties. In some embodiments, the antibody drug moieties bind to two or more different antigens. In some embodiments, the antibody drug moieties bind to two or more different proteins. In some embodiments, the antibody drug moieties are IVIG moieties.

[0298] As used in this disclosure, in some embodiments, "at least one" or "one or more" means 1 to 1000, 1 to 500, 1 to 200, 1 to 100, 1 to 90, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 1 to 5, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more. In some embodiments, it is 1. In some embodiments, it is 2 or more. In some embodiments, it is about 3. In some embodiments, it is about 4. In some embodiments, it is about 5. In some embodiments, it is about 6. In some embodiments, it is about 7. In some embodiments, it is about 8. In some embodiments, it is about 9. In some embodiments, it is about 10. In some embodiments, it is about 10 or more.

[0299] In some embodiments, the common amino acid sequence is 1 to 1000, 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 100, 1 to 50, 10 to 1000, 10 to 500, 10 to 400, 10 to 300, 10 to 200, 10 to 100, 10 to 50, 20 to 1000, 20 to 500, 20 to 400, 20 to 300, 20 to 200, 20 to 100, 20 to 50, 50 to 1000, The length may be 50-500, 50-400, 50-300, 50-200, 50-100, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 200, 250, 300, 400, 500, 600 or more amino acid residues. In some embodiments, the length is at least 5 amino acid residues. In some embodiments, the length is at least 10 amino acid residues. In some embodiments, the length is at least 50 amino acid residues. In some embodiments, the length is at least 100 amino acid residues. In some embodiments, the length is at least 150 amino acid residues. In some embodiments, the length is at least 200 amino acid residues. In some embodiments, the length is at least 300 amino acid residues. In some embodiments, the length is at least 400 amino acid residues. In some embodiments, the length is at least 500 amino acid residues. In some embodiments, the length is at least 600 amino acid residues.

[0300] In some embodiments, the common amino acid sequence is at least 10%-100%, 50%-100%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the amino acid sequence of the targeting drug moiety, protein drug moiety, antibody drug moiety, etc. In some embodiments, it is 100%.

[0301] In some embodiments, protein drug moieties share a high percentage of amino acid sequence homology. In some embodiments, it is 50%-100%. In some embodiments, it is 50%. In some embodiments, it is 60%. In some embodiments, it is 70%. In some embodiments, it is 80%. In some embodiments, it is 90%. In some embodiments, it is 91%. In some embodiments, it is 50%. In some embodiments, it is 92%. In some embodiments, it is 93%. In some embodiments, it is 94%. In some embodiments, it is 95%. In some embodiments, it is 96%. In some embodiments, it is 97%. In some embodiments, it is 98%. In some embodiments, it is 99%. In some embodiments, it is 100%. In some embodiments, it is at least 50%. In some embodiments, it is at least 60%. In some embodiments, it is at least 70%. In some embodiments, it is at least 80%. In some embodiments, it is at least 90%. In some embodiments, it is at least 91%. In some embodiments, it is at least 50%. In some embodiments, it is at least 92%. In some embodiments, it is at least 93%. In some embodiments, it is at least 94%. In some embodiments, it is at least 95%. In some embodiments, it is at least 96%. In some embodiments, it is at least 97%. In some embodiments, it is at least 98%. In some embodiments, it is at least 99%.

[0302] In some embodiments, the protein drug moiety or antibody drug moiety is or comprises a protein complex, hi some embodiments, at least one or each independent chain shares a common amino acid sequence and / or has homology as described herein.

[0303] In some embodiments, the multiple agents share a common moiety of interest. In some embodiments, each of the multiple agents is independently an agent of formula PI or P-II, or a salt thereof. In some embodiments, each of the multiple agents is independently an agent of formula PI or P-II, or a salt thereof, and the MOI is the same for each of the multiple agents. In some embodiments, the multiple agents are the product of a method described herein. In some embodiments, a composition comprising the multiple agents is the product of a method described herein.

[0304] In some embodiments, the modification is or comprises a moiety of interest and optionally a linker. PM - is or contains the MOI.

[0305] In some embodiments, the multiple agents share a common modification at at least one position independently. In some embodiments, the modification is or includes a moiety of interest and optionally a linker connecting the moieties of interest. As described herein, each position independently has its common modification. In some embodiments, the common modification at two or more or all positions includes a common moiety of interest. In some embodiments, the common modification is the same. In some embodiments, the multiple agents share a common modification at each position that has a modification that is or includes a moiety of interest and optionally a linker. In some embodiments, the multiple agents include -L PM - share a common modification at each position that has a modification that is or contains an MOI.

[0306] In some embodiments, protein drugs (e.g., antibody drugs) share a common modification at at least one amino acid residue. In some embodiments, multiple drugs share a common modification at each position that has a modification that is or includes a moiety of interest and, optionally, a linker ... linker. PM - share a common modification at each position that has a modification that is or contains an MOI.

[0307] In some embodiments, the position is selected from K246, K248, K288, K290, K317, and positions corresponding thereto, of an antibody agent. In some embodiments, the position is selected from K246 and K248, and positions corresponding thereto. In some embodiments, the position is selected from K288 and K290, and positions corresponding thereto. In some embodiments, the position is K246, or a position corresponding thereto. In some embodiments, the position is K248, or a position corresponding thereto. In some embodiments, the position is K288, or a position corresponding thereto. In some embodiments, the position is K290, or a position corresponding thereto. In some embodiments, the position is K317, or a position corresponding thereto. In some embodiments, the position is K185 of the light chain, or a position corresponding thereto. In some embodiments, the position is K187 of the light chain, or a position corresponding thereto. In some embodiments, the position is K133 of the heavy chain, or a position corresponding thereto. In some embodiments, the position is K246 or K248 of the heavy chain, or a position corresponding thereto. In some embodiments, the position is K414 of the heavy chain, or a position corresponding thereto.

[0308] In some embodiments, compositions are provided in which about 1% to 100% of all drugs comprising a targeting drug moiety and a moiety of interest are multiple drugs. In some embodiments, compositions are provided in which about 1% to 100% of all drugs comprising a protein drug moiety comprising a common amino acid sequence and a moiety of interest are multiple drugs. In some embodiments, about 1% to 100% of all drugs comprising an antibody drug moiety and a moiety of interest that comprise a common amino acid sequence or that can bind to a common antigen are multiple drugs. In some embodiments, about 1% to 100% of all drugs comprising a targeting drug moiety are multiple drugs. In some embodiments, about 1% to 100% of all drugs comprising a protein drug moiety comprising a common amino acid sequence are multiple drugs. In some embodiments, about 1% to 100% of all drugs comprising an antibody drug moiety that comprises a common amino acid sequence or that can bind to a common antigen are multiple drugs. In some embodiments, that is 50% to 100%. In some embodiments, that is 50%. In some embodiments, that is 60%. In some embodiments, that is 70%. In some embodiments, that is 80%. In some embodiments, it is 90%. In some embodiments, it is 91%. In some embodiments, it is 50%. In some embodiments, it is 92%. In some embodiments, it is 93%. In some embodiments, it is 94%. In some embodiments, it is 95%. In some embodiments, it is 96%. In some embodiments, it is 97%. In some embodiments, it is 98%. In some embodiments, it is 99%. In some embodiments, it is 100%. In some embodiments, it is at least 50%. In some embodiments, it is at least 60%. In some embodiments, it is at least 70%. In some embodiments, it is at least 80%. In some embodiments, it is at least 90%. In some embodiments, it is at least 91%. In some embodiments, it is at least 50%. In some embodiments, it is at least 92%. In some embodiments, it is at least 93%. In some embodiments, it is at least 94%.In some embodiments, it is at least 95%. In some embodiments, it is at least 96%. In some embodiments, it is at least 97%. In some embodiments, it is at least 98%. In some embodiments, it is at least 99%.

[0309] In some embodiments, the provided agents, compounds, and the like (e.g., those of formula RI, PI, P-II, etc.) and salts thereof have a high purity. In some embodiments, it is 50% to 100%. In some embodiments, it is 50%. In some embodiments, it is 60%. In some embodiments, it is 70%. In some embodiments, it is 80%. In some embodiments, it is 90%. In some embodiments, it is 91%. In some embodiments, it is 50%. In some embodiments, it is 92%. In some embodiments, it is 93%. In some embodiments, it is 94%. In some embodiments, it is 95%. In some embodiments, it is 96%. In some embodiments, it is 97%. In some embodiments, it is 98%. In some embodiments, it is 99%. In some embodiments, it is 100%. In some embodiments, it is at least 50%. In some embodiments, it is at least 60%. In some embodiments, it is at least 70%. In some embodiments, it is at least 80%. In some embodiments, it is at least 90%. In some embodiments, it is at least 91%. In some embodiments, it is at least 50%. In some embodiments, it is at least 92%. In some embodiments, it is at least 93%. In some embodiments, it is at least 94%. In some embodiments, it is at least 95%. In some embodiments, it is at least 96%. In some embodiments, it is at least 97%. In some embodiments, it is at least 98%. In some embodiments, it is at least 99%.

[0310] In some embodiments, the present disclosure provides a product drug composition comprising a product drug (e.g., a drug of formula PI or P-II, or a salt thereof). In some embodiments, the product drug composition (e.g., a drug composition formed from a particular method) comprises a targeting drug moiety and a moiety of interest, and optionally a linker (e.g., a drug of formula PI or P-II, or a salt thereof), a released target binding moiety (e.g., R LG -(L LG1 ) 0~1 -(L LG2 ) 0~1 -(L LG3 ) 0~1 -(L LG4 ) 0~1 -)) or a compound containing a released target binding moiety (e.g., R LG -(L LG1 ) 0~1 -(L LG2 ) 0~1 -(L LG3 ) 0~1 -(L LG4 ) 0~1 The product drug includes a compound having the structure -H, or a salt thereof, and a reaction partner (e.g., a compound of formula RI, or a salt thereof). In some embodiments, the released target binding moiety may bind to the target drug and / or the target drug moiety in the formed product drug. For example, in accordance with the present disclosure, in some embodiments, the composition is contacted with a composition comprising glycine at a specific pH. Various techniques are available for separating the released target binding moiety from the target drug moiety.

[0311] Specific Embodiments of Variables By way of example, exemplary embodiments of variables are described throughout this disclosure. As will be appreciated by those skilled in the art, embodiments for different variables may optionally be combined.

[0312] In some embodiments, ABT is an antibody binding moiety described herein. In some embodiments, ABT is a compound selected from MMAE-1, MMAE-2, MMAE-3, MMAE-4, MMAE-5, MMAE-6, and MMAE-7. In some embodiments, ABT is a moiety selected from Table A-1.

[0313] In some embodiments, L is a linker moiety of a compound selected from those set forth in the following compounds: MMAE-1, MMAE-2, MMAE-3, MMAE-4, MMAE-5, MMAE-6, and MMAE-7.

[0314] General methods, reagents and conditions In accordance with the present disclosure, various techniques may be utilized to provide the compounds and agents herein.

[0315] In some embodiments, specific protecting groups ("PG"), leaving groups ("LG"), or transformation conditions are shown; one of skill in the art will recognize that other protecting groups, leaving groups, and transformation conditions are also suitable and contemplated. Such groups and transformations are discussed in detail in March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, M.B. Smith and J. March, 5 th Edition,John Wiley & Sons,2001,Comprehensive Organic Transformations,RCLarock,2 nd Edition,John Wiley & Sons,1999,and Protecting Groups in Organic Synthesis,TWGreene and PGMWuts,3 rd edition, John Wiley & Sons, 1999, each of which is incorporated herein by reference in its entirety.

[0316] In some embodiments, leaving groups include, but are not limited to, halogens (e.g., fluoride, chloride, bromide, iodide), sulfonates (e.g., mesylate, tosylate, benzenesulfonate, brosylate, nosylate, trifluoromethanesulfonate), diazonium, and the like.

[0317] In some embodiments, oxygen protecting groups include, for example, carbonyl protecting groups, hydroxyl protecting groups, etc. Hydroxyl protecting groups are well known in the art and are described in Protecting Groups in Organic Synthesis, T.W. Greene and P.G.M.Wuts, 3 rdedition, John Wiley & Sons, 1999, the entire contents of which are incorporated herein by reference. Examples of suitable hydroxyl protecting groups include, but are not limited to, esters, allyl ethers, ethers, silyl ethers, alkyl ethers, arylalkyl ethers, and alkoxyalkyl ethers. Examples of such esters include formates, acetates, carbonates, and sulfonates. Specific examples include formate, benzoylformate, chloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, p-chlorophenoxyacetate, 3-phenylpropionate, 4-oxopentanoate, 4,4-(ethylenedithio)pentanoate, pivalate (trimethylacetyl), crotonate, 4-methoxy-crotonate, benzoate, p-phenylbenzoate, 2,4,6-trimethylbenzoate, carbonate (e.g., methyl, 9-fluorenylmethyl, ethyl, 2,2,2-trichloroethyl, 2-(trimethylsilyl)ethyl, 2-(phenylsulfonyl)ethyl, vinyl, allyl, and p-nitrobenzyl). Examples of such silyl ethers include trimethylsilyl ether, triethylsilyl ether, t-butyldimethylsilyl ether, t-butyldiphenylsilyl ether, triisopropylsilyl ether, and other trialkylsilyl ethers. Alkyl ethers include methyl ether, benzyl ether, p-methoxybenzyl ether, 3,4-dimethoxybenzyl ether, trityl ether, t-butyl ether, allyl ether, and allyloxycarbonyl ether or derivatives. Alkoxyalkyl ethers include acetals such as methoxymethyl ether, methylthiomethyl ether, (2-methoxyethoxy)methyl ether, benzyloxymethyl ether, β-(trimethylsilyl)ethoxymethyl ether, and tetrahydropyranyl ether.Examples of arylalkyl ethers include benzyl ether, p-methoxybenzyl (MPM) ether, 3,4-dimethoxybenzyl ether, O-nitrobenzyl ether, p-nitrobenzyl ether, p-halobenzyl ether, 2,6-dichlorobenzyl ether, p-cyanobenzyl ether, and 2- and 4-picolyl ethers.

[0318] Amino protecting groups are well known in the art and are described in Protecting Groups in Organic Synthesis, T.W. Greene and P.G.M. Butts, 3 rd edition, John Wiley & Sons, 1999, the entire contents of which are incorporated herein by reference. Suitable amino-protecting groups include, but are not limited to, aralkylamines, carbamates, cyclic imides, allylamines, amides, and the like. Examples of such groups include t-butyloxycarbonyl (BOC), ethyloxycarbonyl, methyloxycarbonyl, trichloroethyloxycarbonyl, allyloxycarbonyl (Alloc), benzyloxycarbonyl (CBZ), allyl, phthalimide, benzyl (Bn), fluorenylmethylcarbonyl (Fmoc), formyl, acetyl, chloroacetyl, dichloroacetyl, trichloroacetyl, phenylacetyl, trifluoroacetyl, benzoyl, and the like.

[0319] Those skilled in the art will understand that compounds / agents may contain one or more stereocenters and may exist as racemic or diastereomeric mixtures. Those skilled in the art will also understand that there are many methods known in the art for the separation of isomers to obtain stereochemically enriched or stereochemically pure isomers of those compounds, including, but not limited to, HPLC, chiral HPLC, fractional crystallization of diastereomeric salts, kinetic enzymatic resolution (e.g., lipases or esterases of fungal, bacterial, or animal origin), and formation of covalent diastereomeric derivatives using enantioenriched reagents.

[0320] Those skilled in the art will understand that various functional groups present in the compounds of the present disclosure, such as aliphatic groups, alcohols, carboxylic acids, esters, amides, aldehydes, halogens, and nitriles, can be interconverted by techniques well known in the art, including, but not limited to, reduction, oxidation, esterification, hydrolysis, partial oxidation, partial reduction, halogenation, dehydration, partial hydration, and hydration. See "March's Advanced Organic Chemistry," 5 th Ed., Ed.: Smith, MB and March, J., John Wiley & Sons, New York: 2001, which is incorporated herein by reference in its entirety. Such interconversions may require one or more of the techniques described above, and specific methods for synthesizing compounds of the disclosure are described in the Examples below.

[0321] Use, Formulation, and Administration The compounds, agents, compositions, etc. of the present disclosure may be provided in various forms depending on the desired use. In some embodiments, they are provided as pharmaceutical compositions. As will be understood by those skilled in the art, pharmaceutical compositions often contain controlled amounts and are prepared for administration to a subject, such as a human patient. In some embodiments, the present disclosure provides a composition comprising a compound, agent, and / or composition described herein, or a pharmaceutically acceptable derivative thereof, and a pharmaceutically acceptable carrier. In some embodiments, the present disclosure provides a pharmaceutical composition comprising a compound, agent, or composition of the present disclosure and a pharmaceutically acceptable carrier. In some embodiments, the present disclosure provides a pharmaceutical composition comprising a therapeutically effective amount of a compound, agent, or composition of the present disclosure and a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutical composition is packaged for storage, transportation, administration, etc. In some embodiments, the pharmaceutical composition does not contain a significant amount of organic solvents (e.g., a total amount of organic solvents equal to or less than 50%, 40%, 30%, 25%, 20%, 15%, 10%, 5%, 4%, 3%, 2%, or 1% by weight and / or volume of the pharmaceutical composition).

[0322] In some embodiments, a pharmaceutically acceptable carrier is or includes a non-toxic carrier, adjuvant, or vehicle that does not destroy the pharmacological activity of the compound it is formulated in. Pharmaceutically acceptable carriers, adjuvants, or vehicles may include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes (e.g., protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts), colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol, and wool fat.

[0323] In some embodiments, pharmaceutically acceptable derivatives are non-toxic salts, esters, salts of esters, or other derivatives of the compounds, which, upon administration to a recipient, are capable of providing, either directly or indirectly, the compound, or an active metabolite, or residue thereof.

[0324] The compositions may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, bucally, vaginally, or via an implanted reservoir. In some embodiments, parenteral administration includes subcutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intrahepatic, intralesional, and intracranial injection or infusion techniques. In some embodiments, the compositions are administered orally, intraperitoneally, or intravenously. Sterile injectable forms of the compositions may be aqueous or oily suspensions. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Acceptable vehicles and solvents that may be used include water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile fixed oils are conventionally used as solvents or suspending media.

[0325] In some embodiments, non-irritating fixed oils, including synthetic monoglycerides or diglycerides, may be used. Fatty acids, such as oleic acid and its glyceride derivatives, especially in their polyoxyethylated forms, are useful for preparing injectables, as are natural pharmaceutically acceptable oils such as olive oil or castor oil. These oil solutions or suspensions may contain long-chain alcohol diluents or dispersants (e.g., carboxymethylcellulose or similar dispersants) commonly used in the preparation of pharmaceutically acceptable dosage forms, including emulsions and suspensions. For formulation purposes, other commonly used surfactants, such as Tween and Span, and other emulsifiers or bioavailability enhancers commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms may also be used.

[0326] Pharmaceutically acceptable compositions can be orally administered in any orally acceptable dosage form, including but not limited to capsules, tablets, aqueous suspensions or solutions.For tablets for oral use, commonly used carriers include lactose and cornstarch.Lubricants such as magnesium stearate are also typically added.For oral administration in capsule form, useful diluents include lactose and dry cornstarch.When aqueous suspension is required for oral use, active ingredient is combined with emulsifier and suspending agent.If desired, certain sweeteners, flavorings or colorings can also be added.

[0327] In some embodiments, the pharmaceutically acceptable composition may be administered in the form of a suppository for rectal administration. In some embodiments, these can be prepared by mixing the agent with a suitable non-irritating excipient that is solid at room temperature but liquid at rectal temperature (and therefore melts in the rectum to release the drug). Such materials include cocoa butter, beeswax, and polyethylene glycol.

[0328] In some embodiments, pharmaceutically acceptable compositions may be administered topically, particularly when the target of treatment includes areas or organs readily accessible by topical application, including diseases of the eye, skin, or lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas or organs.

[0329] Topical application for the lower intestinal tract can be effected in a rectal suppository formulation (see above) or in a suitable enema formulation. Topical-transdermal patches may also be used.

[0330] For topical application, pharmaceutically acceptable compositions can be formulated in a suitable ointment containing the active ingredient suspended or dissolved in one or more carriers.Carriers for topical administration of the compounds of the present disclosure include, but are not limited to, mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compounds, emulsifying wax, and water.Alternatively, provided pharmaceutically acceptable compositions can be formulated in a suitable lotion or cream containing the active ingredient suspended or dissolved in one or more pharmaceutically acceptable carriers.Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl ester wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol, and water.

[0331] For ophthalmic use, the pharmaceutically acceptable composition may be formulated as a micronized suspension in isotonic, pH-adjusted, sterile saline, or preferably as a solution in isotonic, pH-adjusted, sterile saline, with or without a preservative such as benzylalkonium chloride. Alternatively, for ophthalmic use, the pharmaceutically acceptable composition may be formulated in an ointment such as petrolatum.

[0332] Pharmaceutically acceptable compositions may also be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well known in the art of pharmaceutical formulation, and may be prepared as solutions in saline using benzyl alcohol or other suitable preservatives, absorption enhancers to enhance bioavailability, fluorocarbons, and / or other conventional solubilizing or dispersing agents.

[0333] In some embodiments, the pharmaceutically acceptable composition is formulated for oral administration. Such formulations can be administered with or without food. In some embodiments, the pharmaceutically acceptable composition is administered without food. In other embodiments, the pharmaceutically acceptable composition is administered with food.

[0334] The amount of compound that can be combined with a carrier material to produce a composition in a single dosage form will vary depending on the host being treated, the particular mode of administration, etc. In some embodiments, provided compositions are formulated so that a dosage of 0.01 to 100 mg / kg body weight / day of the inhibitor can be administered to a patient receiving these compositions.

[0335] In some embodiments, the present invention relates to compositions comprising a therapy enhancer agent containing a moiety of interest conjugated to a targeting agent moiety at a specific location.

[0336] In one embodiment, the composition comprises: Structure of Formula (P-II) PNL PM -MOI (P-II) A first compound having the formula: PN is a protein drug moiety containing a lysine residue, L PM is the linker, The MOI comprises a first compound, which is a moiety of interest comprising monomethyl auristatin E (MMAE); The following structure LG-OH (LG-I) wherein LG is a group comprising a target binding moiety that binds to a targeting agent.

[0337] In another embodiment, the composition comprises: Formula (RI) LG-RG-L RM -MOI (RI) wherein LG is a group comprising a target binding moiety that binds to a targeting agent and is identical to LG in formula (LG-I); RG is a reactive group, L RM is a linker, and is the same as in formula (P-II), The MOI comprises a third compound, which is a moiety of interest comprising monomethyl auristatin E (MMAE); Formula (R-III) HO-RG-L RM -MOI (R-III) or a fourth compound having the formula:

[0338] In some embodiments, the composition may include an equimolar amount of a first compound and a second compound. In some embodiments, the amount of the second compound may be 50 mole percent (mole%) or less, based on the total number of moles of the first compound and the second compound in the composition. In some embodiments, the amount of the second compound may be 50 mole% or less, 45 mole% or less, 40 mole% or less, 35 mole% or less, 30 mole% or less, 25 mole% or less, 20 mole% or less, 15 mole% or less, 10 mole% or less, or 5 mole% or less, based on the total number of moles of the first compound and the second compound in the composition. In some embodiments, the amount of the second compound may be 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less, based on the total number of m...

Claims

1. Formula R-I: LG-RG-L ＲＭ -MOI (R-I) [wherein, LG is R ＬＧ -L ＬＧ and is R ＬＧ is 【Chemical 1】 R ｃ -(Xaa)z-, a nucleic acid moiety, or a small molecule moiety, each Xaa is independently a residue of an amino acid or an amino acid analog, t is from 0 to 50, z is from 1 to 50, Each R ｃ is independently, -L ａ -R', and Each L ａ is, independently, a substituted or unsubstituted divalent group selected from a covalent bond, or C １ to C ２０ aliphatic or C having 1 to 5 heteroatoms １ to C ２０ heteroaliphatic, and one or more methylene units of said group are independently replaced by -C(R') ２ -, -Cy-, -O-, -S-, -S-S-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O) ２ -, -S(O) ２ N(R)-, -C(O)S-, or -C(O)O- and may be Each -Cy- is independently an optionally substituted divalent monocyclic, bicyclic, or polycyclic group, and each monocyclic ring is independently selected from a C ３～２０ alicyclic ring, a C ６～２０ aryl ring, a 5- to 20-membered heteroaryl ring having 1 to 10 heteroatoms, and a 3- to 20-membered heterocyclyl ring having 1 to 10 heteroatoms, L ＬＧ is -L ＬＧ１ -, -L ＬＧ１ -L ＬＧ２ -, -L ＬＧ１ -L ＬＧ２ -L ＬＧ３ -, or -L ＬＧ１ -L ＬＧ２ -L ＬＧ３ -L ＬＧ４ - and RG is, -L ＲＧ１ -L ＲＧ２ -, -L ＬＧ４ -L ＲＧ１ -L ＲＧ２ -, -L ＬＧ３ -L ＬＧ４ -L ＲＧ１ -L ＲＧ２ -, -L ＬＧ２ -L ＬＧ３ -L ＬＧ４ -L ＲＧ１ -L ＲＧ２ - and L ＬＧ１ 、 L ＬＧ２ 、 L ＬＧ３ 、 L ＬＧ４ 、 L ＲＧ１ 、 L ＲＧ２ 、 and L ＲＭ each of which is, independently, L, Each L is independently a covalent bond, or a divalent, optionally substituted, straight-chain or branched C containing one or more aliphatic moieties, aryl moieties, heteroaliphatic moieties each having independently from 1 to 20 heteroatoms, heteroaromatic moieties each having independently from 1 to 20 heteroatoms, or any combination of any one or more of such moieties １～１００ group, and one or more methylene units of said group are independently C １～６ alkylene, C １～６ alkenylene, a divalent C having from 1 to 5 heteroatoms １～６ heteroaliphatic group [Chemical Formula 2] -Cy-, -C(R') ２ -, -O-, -S-, -S-S-, -N(R')-, -C(O)-, -C(S)-, -C(NR')-, -C(O)N(R')-, -C(O)C(R') ２ N(R')-, -N(R')C(O)N(R')-, -N(R')C(O)O-, -S(O)-, -S(O) ２ -, -S(O) ２ N(R')-, -C(O)S-, -C(O)O-, -P(O)(OR')-, -P(O)(SR')-, -P(O)(R')-, -P(O)(NR')-, -P(S)(OR')-, -P(S)(SR')-, -P(S)(R')-, -P(S)(NR')-, -P(R')-, -P(OR')-, -P(SR')-, -P(NR')-, an amino acid residue, or -[(-O-C(R') ２ -C(R') ２ -) ｎ -(wherein n is 1 to 20) may be replaced, Each R' is independently -R, -C(O)R, -COR, or -SOR ２ R, or -SO ２ R, and Each R is independently -H or C １～３０ aliphatic, C having 1 to 10 heteroatoms １～３０ heteroaliphatic, C ６～３０ aryl, C ６～３０ arylalkyl, C having 1 to 10 heteroatoms ６～３０ arylheteroaliphatic, optionally substituted group selected from 5- to 30-membered heteroaryl having 1 to 10 heteroatoms, and 3- to 30-membered heterocyclyl having 1 to 10 heteroatoms, or two R groups may independently combine together to form a covalent bond, or two or more R groups on the same atom may independently combine with said atom to form an optionally substituted 3- to 30-membered monocyclic, bicyclic, or polycyclic ring having 0 to 10 heteroatoms in addition to said atom, or two or more R groups on two or more atoms may independently combine with their intervening atoms to form an optionally substituted 3- to 30-membered monocyclic, bicyclic, or polycyclic ring having 0 to 10 heteroatoms in addition to said intervening atoms, MOI is the moiety of interest comprising monomethyl auristatin E (MMAE)] A compound having the structure or a salt thereof.

2. The compound or a salt thereof according to claim 1, wherein LG is a target binding moiety that binds to a target agent or comprises the same, and the target agent is an antibody agent.

3. The compound or a salt thereof according to claim 1 or 2, wherein LG is a target binding moiety that binds to the Fc region of an antibody agent or comprises the same.

4. The compound or a salt thereof according to claim 3, wherein LG is a target binding moiety that binds to a target agent or comprises the same, and the target agent is enfortumab, brentuximab, or trastuzumab, or an antibody agent comprising the same.

5. LG is selected from A-1 to A-50 of Table A-1: 【Table 1-1】 【Table 1-2】 【Table 1-3】 【Table 1-4】 【Table 1-5】 【Table 1-6】 【Table 1-7】 【Table 1-8】 【Table 1-9】 【Table 1-10】 【Table 1-11】 【Table 1-12】 【Table 1-13】 The compound or a salt thereof according to claim 2, which is a group selected from or comprises the same.

6. R ＬＧ The compound or a salt thereof according to claim 1, wherein R is DCAWXLGELVWCT (SEQ ID NO: 18), or includes the same, two cysteine residues may form a disulfide bond, and X is an amino acid residue.

7. The compound or a salt thereof according to claim 1, wherein the compound or a salt thereof comprises one or more groups selected from the following [Chemical Formula 3] The compound or a salt thereof according to claim 1, which is a group selected from or comprises the same.

8. L ＲＭ is -(CH ２ CH ２ O)n- or contains it, wherein n is independently selected, in each occurrence, from the integers 2, 3, 4, 5, 6, 7, and 8, the compound according to claim 1 or a salt thereof.

9. L ＲＭ is -(CH ２ CH ２ O)n-(CH ２ )n-NHC(O)-(CH ２ )n-, -[(CH ２ CH ２ O)n-(CH ２ )n-NHC(O)]m-(CH ２ )n-, and -(CH ２ CH ２ O)n-(CH ２ )n-N((CH ２ CH ２ O)n-(CH ２ )n)((CH ２ CH ２ O)n-(CH ２ )n), or includes the same, wherein m is independently selected, in each occurrence, from the integers 1, 2, 3, and 4, the compound according to claim 1 or a salt thereof.

10. P-I: P-L ＰＭ -MOI (P-I) [wherein, P is a target agent moiety, L ＰＭ is a linker, MOI is monomethyl auristatin E (MMAE) or a moiety of interest comprising the same] A method for preparing a compound having the structure or a salt thereof, comprising: 1) contacting a target agent with a reaction partner having the structure of formula R-I: LG-RG-L ＲＭ -MOI (R-I) [wherein, LG is a group comprising a target binding moiety that binds to a target agent, RG is a reactive group, L ＲＭ is a linker, MOI is MMAE or a moiety of interest comprising the same] or a salt thereof, and 2) forming a compound having the structure of P-I or a salt thereof; A method comprising: or P-II: P-N-L ＰＭ -MOI (P-II) wherein P-N is a protein agent moiety containing a lysine residue, L ＰＭ is a linker, MOI is monomethyl auristatin E (MMAE) or a moiety of interest containing the same A method for preparing a compound having the structure of or a salt thereof, comprising contacting P-N with a reaction partner having the structure of formula R-I: LG-RG-L ＲＭ -MOI (R-I) wherein LG is a group containing a protein-binding moiety that binds to P-N, RG is a reactive group, L ＲＭ is a linker, MOI is MMAE or a moiety of interest containing the same or a salt thereof. **Claim 11** The method according to claim 10, wherein the target agent is an antibody agent or comprises the same. **Claim 12** The method according to claim 10, wherein the antibody agent is an anti-CD30 monoclonal antibody such as brentuximab or an anti-nectin-4 monoclonal antibody such as enfortumab or comprises the same. **Claim 13** The method according to claim 11 or 12, wherein the moiety of interest is selectively connected to the antibody agent at K246 or K248 of the IgG1 heavy chain or at the corresponding position. **Claim 14** The method according to claim 11 or 12, wherein the moiety of interest is selectively connected to the antibody agent at K251 or K253 of the IgG2 heavy chain or at the corresponding position. **Claim 15** The method according to claim 11 or 12, wherein the moiety of interest is selectively connected to the antibody agent at K239 or K241 of the IgG4 heavy chain or at the corresponding position. **Claim 16** The method according to claim 10, wherein the contacting step and the forming step are carried out in one chemical reaction. **Claim 17** A composition providing a plurality of agents, each independently comprising an antibody agent moiety, monomethyl auristatin E (MMAE) or a moiety of interest containing the same, and optionally comprising a linker moiety linking the antibody agent moiety and the moiety of interest, wherein the antibody agent moieties of the plurality of agents comprise a common amino acid sequence or can bind to a common antigen, and the plurality of agents independently share a common modification at at least one common amino acid residue of the antibody agent moiety. About 1% to 100% of all drugs comprising an antibody drug moiety that comprises the common amino acid sequence or that can bind to the common antigen and the moiety of interest are the plurality of drugs, Composition. Claim 18 The composition according to claim 17, wherein the antibody drug moiety of the plurality of drugs can bind to a common antigen. Claim 19 The composition according to claim 18, wherein the common amino acid residue is K246 or K248 of the IgG1 heavy chain or an amino acid residue corresponding thereto. Claim 20 The composition according to claim 18, wherein the common amino acid residue is K251 or K253 of the IgG2 heavy chain or an amino acid residue corresponding thereto. Claim 21 The composition according to claim 18, wherein the common amino acid residue is K239 or K241 of the IgG4 heavy chain or an amino acid residue corresponding thereto. Claim 22 Each of the plurality of drugs does not contain -S-Cy-, -Cy- is an optionally substituted 5-membered monocyclic ring, does not contain -S-S- formed by a cysteine residue, and does not contain -SH or a salt form thereof that is not of a cysteine residue. The composition according to claim 18. Claim 23 Each of the plurality of said agents does not contain -S-CH ２ -CH ２ -, The composition according to claim 18. Claim 24 The following 【Chemical 4】 The composition according to claim 18, comprising one or more groups selected from Claim 25 R ＬＧ is Polypeptide, 【Chemical Formula 5】 Or the following compounds: [Chemical Formula 6] R containing at least one amino acid residue among them ｃ The compound or a salt thereof according to claim 1, which is -(Xaa)z-, or a salt thereof. Claim 26 The compound or a salt thereof is [Chemical Formula 7] 【Chemical Formula 8】 【Chemical Formula 9】 【Chemical 10】 【Chemical Formula 11】 【Chemical 12】 【Chemical 13】 【Chemical 14】 And 【Chemical Formula 15】 And salts thereof The compound or a salt thereof according to claim 1, selected from Claim 27 Formula R-I: LG-RG-L ＲＭ -MOI (R-I) [Wherein, LG is a group containing a target binding moiety that binds to a target drug, RG is a reactive group, L ＲＭ is a linker, MOI is a moiety of interest containing MMAE] A compound having the structure of or a salt thereof, The target drug is an antibody comprising an IgG heavy chain containing K246 or K248, The target binding moiety brings the reactive group into proximity to K246 or K248 of the IgG heavy chain to enable a reaction between K246 or K248 and the reactive group, and is configured to bind to the antibody so as to effect attachment of a moiety containing L ＲＭ -MOI and removal of the group containing the target binding moiety from the compound or a salt thereof. Compound or a salt thereof. Claim 28 Formula R-I: LG-RG-L ＲＭ -MOI (R-I) [Wherein, LG is a group containing a target binding moiety that binds to a target drug, RG is a reactive group, L ＲＭ is a linker, MOI is a moiety of interest containing monomethyl auristatin E (MMAE)] A compound having the structure of or a salt thereof. Claim 29 A composition, Formula (P-II): P-N-L ＰＭ -MOI (P-II) [Wherein, P-N is a protein drug moiety containing a lysine residue, L ＰＭ is a linker, MOI is a moiety of interest containing monomethyl auristatin E (MMAE)] A first compound having the structure of or a salt thereof and, Structure: LG-OH (LG-I) [wherein, LG is a group containing a target-binding moiety that binds to a target agent] a second compound having the same or a salt thereof, and a composition comprising the same.

30. Formula (R-I): LG-RG-L ＲＭ -MOI (R-I) [wherein,[[]]END]] LG is a group containing a target-binding moiety that binds to a target agent and is the same as LG in formula (LG-I), RG is a reactive group, L ＲＭ is a linker and is identical to LRM in formula (P-II), MOI is a moiety of interest containing monomethyl auristatin E (MMAE)] a third compound having the same or a salt thereof, or Formula (R-III): HO-RG-L ＲＭ -MOI (R-III) a fourth compound having the same or a salt thereof, or a combination thereof The composition according to claim 29, further comprising the same.

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