Dual mechanism of action payload antibody drug conjugates

Abstract

The present disclosure is related to dual mechanism of action payload antibody drug conjugates comprising at least two payload residues, pharmaceutical compositions thereof, and the use of the antibody drug conjugates and compositions thereof for the treatment of diseases and disorders, including proliferative diseases.

Description

DUAL MECHANISM OF ACTION PAYLOAD ANTIBODY DRUG CONJUGATES CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Patent Application No.63 / 705,298 filed October 9, 2024, and U.S. Provisional Application No.63 / 805,680 filed May 14, 2025, the entire contents of which are incorporated herein by reference in their entirety for all purposes. FIELD

[0002] The present disclosure is related to dual payload antibody drug conjugates comprising at least two payloads, pharmaceutical compositions thereof, and the use of the antibody drug conjugates and compositions thereof for the treatment of diseases and disorders, including proliferative diseases. BACKGROUND

[0003] Topoisomerase 1 (Top1) is an essential enzyme that assists with the unwinding of supercoiled double stranded-DNA. Under normal conditions, Top1 “cuts” DNA by attacking a phosphodiester bond of the DNA strand via a tyrosine residue to form a covalent bond with the 3'-phosphate end and release the 5'-hydroxyl terminus. This break in DNA is transient and immediately following uncoiling, the 5'-hydroxyl attacks the 3'-phosphate end to religate the DNA and release Top1.

[0004] In cancerous cells, this break can be exploited to trigger apoptosis. Top1 inhibitors are chemotherapeutic agents that target and trap the Top1-DNA covalent complex (Top1cc), inhibiting the religation step and causing a single-strand break. Further, the trapped Top1cc is toxic and can result in double-stranded breaks during replication. Known Top1 inhibitors include camptothecin and its derivatives, such as topotecan, irinotecan, rubitecan, exatecan, Gly-exatecan, belotecan, and 7-ethyl-10-hydroxycamptothecin (SN-38). Via this stabilization of Top1cc, Top1 inhibitors interrupt DNA replication in cancer cells, ultimately leading to apoptosis.

[0005] Because only 1% of ADCs reach inside a tumor, there is a need for improving the therapeutic index of antibody drug conjugates (ADCs) including outside the tumor by reducing platform toxicity and inside the tumor by higher exposure and potency. One way to improve the efficacy of antibody drug conjugates is to introduce combination therapies. However, such combination therapies suffer from overcoming resistance mechanismsbetween the different payloads, much less encourage synergistic effects between the payloads.

[0006] Therefore, what is needed are new drug delivery platforms that can improve therapeutic efficacy and window of the two individual drugs. SUMMARY

[0007] Described herein are antibody conjugates comprising an antibody or antigen-binding fragment thereof covalently linked to one or more of a first payload (PA1) via a first linker, and covalently linked to one or more of a second payload residue (PA2) via a second linker, wherein the antibody or antigen-binding fragment thereof comprises one or more modified amino acid residues, wherein the first payload is a topoisomerase inhibitor, and wherein the second payload is a cytotoxic agent. In certain embodiments, the synergistic ADCs disclosed herein exhibit improved efficacy and therapeutic index over the administration of the topoisomerase inhibitor and cytotoxic agents individually.

[0008] In some embodiments, the antibody conjugate is represented by the structure of Formula (I):Formula (I) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein Ab is the antibody or antigen-binding fragment thereof; Lais the first linker; Lbis the second linker; PA1 is the first payload, wherein the first payload is a topoisomerase inhibitor; PA2 is the second payload, wherein the second payload is a cytotoxic agent; subscript n is an integer selected from 1 to 10; and subscript m is an integer selected from 1 to 10.

[0009] In another aspect, provided herein are pharmaceutical compositions comprising the ADCs described herein. In a further aspect, provided herein are kits comprising the ADCs described herein or pharmaceutical compositions thereof.

[0010] In another aspect, provided herein is a method for treating diseases, disorders, or conditions, including cancer and proliferative diseases, comprising administering an ADCdescribed herein or a pharmaceutical composition thereof to a subject in need thereof. In some embodiments, the disease, disorder, or condition is cancer. In a further aspect, provided herein are linker payloads comprising a payload residue selected from maytansinoids, auristatins, halichondrin, tubulysins, topoisomerase II inhibitor, among others.

[0011] In another aspect, provided herein is a method of treating a drug-resistant cancer in a subject in need thereof. In certain embodiments, the method comprises administering an antibody conjugate as described herein. In certain embodiments, the antibody conjugate is according to Formula (II):

[0012] In certain embodiments, the first payload PA1 is a topoisomerase inhibitor. In certain embodiments, the second payload PA2 is a cytotoxic moiety or a DNA Damage Response (DDR) inhibitor. BRIEF DESCRIPTION OF FIGURES

[0013] FIG.1 shows payload release in human liver S9 graph for exatecan, MMAE, and hemiasterlin.

[0014] FIG.2 shows payload release in human liver S9 graph for MMAE, and hemiasterlin.

[0015] FIG.3 shows total antibody concentration in mouse plasma following a single IV administration of select conjugates at 3 mg / kg.

[0016] FIG.4A-FIG.4D show the calculated DAR of aHER2 dual conjugates over 21 Days.

[0017] FIG.5A-FIG.5D provide IGROV-1 tumor growth curves. FIG.5A and FIG.5B show response to continuous weekly treatments with 10 mg / kg Enhertu. FIG.5C and FIG. 5D show response to continuous weekly treatment with 10 mg / kg Enhertu (solid gray), followed by 10 mg / kg luveltamab tazevibulin (an anti-FolRα hemiasterlin as described in U.S. Patent Application No.18 / 775,242, which is incorporated by reference in its entirety) ADC (gray dotted background) and 10 mg / kg Conjugate 6 (gray V-patterned background). The tumor in FIG.5A was isolated to generate the IGROV-1-ENR1 cell line, and the tumor in FIG.5B was isolated to generate the IGROV-1-ENR3 cell line.

[0018] FIG.6A-FIG.6D provide IGROV-1 tumor growth curves and tumor volume. FIG. 6A shows IGROV-1-ENR1 tumor growth curves in response to treatment with a single i.v. dose of 10 mg / kg of Conjugate 11, Conjugate 8, or Conjugate 6. FIG.6B shows a scatter plotof individual tumor volumes on day 35 post treatment. Statistical analysis was performed on tumor volumes on day 35 using a one-way ANOVA with Dunnett’s multiple comparisons test versus the vehicle group. FIG.6C shows IGROV-1-ENR3 tumor growth curves in response to treatment with a single i.v. dose of 10 mg / kg of Conjugate 11, Conjugate 8, or Conjugate 6. FIG.6D shows a scatter plot of individual tumor volumes on day 42 post treatment. Statistical analysis was performed on tumor volumes on day 42 using a Welch’s ANOVA with Dunnett’s T3 multiple comparisons test versus the vehicle group. A probability of less than 5% (p<0.05) was considered significant. ** = p<0.01; *** = p<0.001; **** = p<0.0001. All graphs are presented as individual values or mean ^ SEM.

[0019] FIG.7A provides HCT-116 tumor growth curves in response to treatment with a single i.v. dose of 5 mg / kg of Conjugate 11, Conjugate 12, Conjugate 6, Conjugate 13, or Conjugate 8. FIG.7B provides a scatter plot of individual tumor volumes on day 20 post treatment. Statistical analysis was performed on tumor volumes on day 20 using a one-way ANOVA with Dunnett’s multiple comparisons test versus the vehicle group. A probability of less than 5% (p<0.05) was considered significant. *** = p<0.001; **** = p<0.0001. All graphs are presented as individual values or mean ^ SEM.

[0020] FIG.8A provides NCI-N87-Enhertu-R tumor growth curves in response to treatment with a single i.v. dose of 3 mg / kg of conjugate 11, conjugate 13, conjugate 8, or Enhertu. FIG.8B provides a scatter plot of individual tumor volumes on day 35 post treatment. Statistical analysis was performed on tumor volumes on day 35 using a Welch’s ANOVA with Dunnett’s T3 multiple comparisons test versus the vehicle group. A probability of less than 5% (p<0.05) was considered significant. ** = p<0.01. All graphs are presented as individual values or mean ^ SEM.

[0021] FIG.9A provides IGROV-1-ENR1 tumor growth curves in response to treatment with a single i.v. dose of 10 mg / kg of Conjugate 22, or Conjugate 20. FIG.9B provides a scatter plot of individual tumor volumes on day 44 or 46 post treatment. Day 44 tumor volumes were used for the vehicle-, and Conjugated 20-treated groups while day 46 tumor volumes were used for the Conjugate 22-treated group. Statistical analysis was performed on tumor volumes using a Welch’s ANOVA with Dunnett’s T3 multiple comparisons test versus the vehicle group. A probability of less than 5% (p<0.05) was considered significant. ** = p<0.01; *** = p<0.001. All graphs are presented as individual values or mean ^ SEM.

[0022] FIG.10A provides HCT-116 tumor growth curves in response to treatment with a single i.v. dose of 5 mg / kg of Conjugate 22, Conjugate 17, Conjugate 20, or Conjugate 21.FIG.6B provides a scatter plot of individual tumor volumes on day 22 post treatment. Statistical analysis was performed on tumor volumes on day 22 using a Welch’s ANOVA with Dunnett’s T3 multiple comparisons test versus the vehicle group. A probability of less than 5% (p<0.05) was considered significant. **** = p<0.0001. All graphs are presented as individual values or mean ^ SEM.

[0023] FIG.11 provides a graph of TAb Concentration – Time Profiles in Mouse Plasma Following a Single IV Administration of certain dual payload conjugates (5 mg / kg). DETAILED DESCRIPTION

[0024] Described herein are dual payload antibody drug conjugates comprising at least one topoisomerase inhibitor or derivative thereof and at least one cytotoxic agent.

[0025] Definitions

[0026] Unless otherwise defined, all terms of art, notations and other scientific terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and / or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a difference over what is generally understood in the art. The techniques and procedures described or referenced herein are generally well understood and commonly employed using conventional methodologies by those skilled in the art, such as, for example, the widely utilized molecular cloning methodologies described in Green & Sambrook, Molecular Cloning: A Laboratory Manual 4thed. (2012), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY; and Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons. As appropriate, procedures involving the use of commercially available kits and reagents are generally carried out in accordance with manufacturer-defined protocols and conditions unless otherwise noted.

[0027] As used herein, the singular forms “a,” “an,” and “the” include the plural referents unless the context clearly indicates otherwise.

[0028] The term “about” indicates and encompasses an indicated value and a range above and below that value. In certain embodiments, the term “about” indicates the designated value ± 10%, ± 5%, or ± 1%. In certain embodiments, the term “about” indicates the designated value ± one standard deviation of that value. In certain embodiments, for example, logarithmic scales (e.g., pH), the term “about” indicates the designated value ± 0.3, ±0.2, or ± 0.1.

[0029] The term “combinations thereof” includes every possible combination of elements to which the term refers to.

[0030] The term “immunoglobulin” refers to a class of structurally related proteins generally comprising two pairs of polypeptide chains: one pair of light (L) chains and one pair of heavy (H) chains. In an “intact immunoglobulin,” all four of these chains are interconnected by disulfide bonds. The structure of immunoglobulins has been well characterized. See, e.g., Paul, Fundamental Immunology 7th ed., Ch.5 (2013) Lippincott Williams & Wilkins, Philadelphia, PA. Briefly, each heavy chain typically comprises a heavy chain variable region (VH or VH) and a heavy chain constant region (CH or CH). The heavy chain constant region typically comprises three domains, abbreviated CH1 (or CH1), CH2 (or CH2), and CH3 (or CH3). Each light chain typically comprises a light chain variable region (VLor VL) and a light chain constant region. The light chain constant region typically comprises one domain, abbreviated CL or CL.

[0031] The term “antibody” is used herein in its broadest sense. An antibody includes intact antibodies (e.g., intact immunoglobulins), and antibody fragments (e.g., antigen binding fragments of antibodies). Antibodies comprise at least one antigen-binding domain. One example of an antigen-binding domain is an antigen binding domain formed by a VH-VLdimer.

[0032] The VH and VL regions may be further subdivided into regions of hypervariability (“hypervariable regions (HVRs)”; also called “complementarity determining regions” (CDRs)) interspersed with regions that are more conserved. The more conserved regions are called framework regions (FRs). Each VH and VL generally comprises three CDRs and four FRs, arranged in the following order (from N-terminus to C-terminus): FR1 - CDR1 - FR2 - CDR2 - FR3 - CDR3 - FR4. The CDRs are involved in antigen binding, and influence antigen specificity and binding affinity of the antibody. See Kabat et al., Sequences of Proteins of Immunological Interest 5th ed. (1991) Public Health Service, National Institutes of Health, Bethesda, MD, incorporated by reference in its entirety.

[0033] The light chain from any vertebrate species can be assigned to one of two types, called kappa and lambda, based on the sequence of the constant domain.

[0034] The heavy chain from any vertebrate species can be assigned to one of five different classes (or isotypes): IgA, IgD, IgE, IgG, and IgM. These classes are also designated α, δ, ε, γ, and µ, respectively. The IgG and IgA classes are further divided into subclasses on the basis of differences in sequence and function. Humans express the following subclasses: IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2.

[0035] The amino acid sequence boundaries of a CDR can be determined by one of skill in the art using any of a number of known numbering schemes, including those described by Kabat et al., supra (“Kabat” numbering scheme); Al-Lazikani et al., 1997, J. Mol. Biol., 273:927-948 (“Chothia” numbering scheme); MacCallum et al., 1996, J. Mol. Biol.262:732- 745 (“Contact” numbering scheme); Lefranc et al., Dev. Comp. Immunol., 2003, 27:55-77 (“IMGT” numbering scheme); and Honegge and Plückthun, J. Mol. Biol., 2001, 309:657-70 (“AHo” numbering scheme), each of which is incorporated by reference in its entirety.

[0036] Table A provides the positions of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3 as identified by the Kabat and Chothia schemes. For CDR-H1, residue numbering is provided using both the Kabat and Chothia numbering schemes. Table A. Residues in CDRs according to Kabat and Chothia numbering schemes.* The C-terminus of CDR-H1, when numbered using the Kabat numbering convention, varies between H32 and H34, depending on the length of the CDR, as illustrated in FIG.1.

[0037] Unless otherwise specified, the numbering scheme used for identification of a particular CDR herein is the Kabat / Chothia numbering scheme. Where the residues encompassed by these two numbering schemes diverge (e.g., CDR-H1 and / or CDR-H2), the numbering scheme is specified as either Kabat or Chothia. For convenience, CDR-H3 is sometimes referred to herein as either Kabat or Chothia. However, this is not intended to imply differences in sequence where they do not exist, and one of skill in the art can readily confirm whether the sequences are the same or different by examining the sequences.

[0038] CDRs may be assigned, for example, using antibody numbering software, such as Abnum, available at www.bioinf.org.uk / abs / abnum / , and described in Abhinandan and Martin, Immunology, 2008, 45:3832-3839, incorporated by reference in its entirety.

[0039] The “EU numbering scheme” is generally used when referring to a residue in an antibody heavy chain constant region (e.g., as reported in Kabat et al., supra). Unless statedotherwise, the EU numbering scheme is used to refer to residues in antibody heavy chain constant regions described herein.

[0040] An “antibody fragment” comprises a portion of an intact antibody, such as the antigen binding or variable region of an intact antibody. Antibody fragments include, for example, Fv fragments, Fab fragments, F(ab’)2 fragments, Fab’ fragments, scFv (sFv) fragments, and scFv-Fc fragments.

[0041] “Fv” fragments comprise a non-covalently-linked dimer of one heavy chain variable domain and one light chain variable domain.

[0042] “Fab” fragments comprise, in addition to the heavy and light chain variable domains, the constant domain of the light chain and the first constant domain (CH1) of the heavy chain. Fab fragments may be generated, for example, by recombinant methods or by papain digestion of a full-length antibody.

[0043] “F(ab′)2” fragments contain two Fab′ fragments joined, near the hinge region, by disulfide bonds. F(ab′)2fragments may be generated, for example, by recombinant methods or by pepsin digestion of an intact antibody. The F(ab′) fragments can be dissociated, for example, by treatment with β-mercaptoethanol.

[0044] “Single-chain Fv” or “sFv” or “scFv” antibody fragments comprise a VHdomain and a VLdomain in a single polypeptide chain. The VHand VLare generally linked by a peptide linker. See Plückthun A. (1994). In some embodiments, the linker is GGGGSGGGGSGGGGS (SEQ ID NO:5). In some embodiments, the linker is AAGSDQEPKSS (SEQ ID NO:6). Antibodies from Escherichia coli. In Rosenberg M. & Moore G.P. (Eds.), The Pharmacology of Monoclonal Antibodies vol.113 (pp.269-315). Springer-Verlag, New York, incorporated by reference in its entirety.

[0045] “scFv-Fc” fragments comprise an scFv attached to an Fc domain. For example, an Fc domain may be attached to the C-terminus of the scFv. The Fc domain may follow the VHor VL, depending on the orientation of the variable domains in the scFv (i.e., VH-VL or VL-VH). Any suitable Fc domain known in the art or described herein may be used. In some cases, the Fc domain comprises an IgG1 Fc domain. In some embodiments, the IgG1 Fc domain comprises SEQ ID NO:7, or a portion thereof. SEQ ID NO:7 provides the sequence of CH1, CH2, and CH3 of the human IgG1 constant region. SEQ ID NO:7 IgG1 Fc from scFv-Fc: AAGSDQEPKSSDKTHTCPPCSAPELLGGSSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDP EVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIE KTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTP PVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK.

[0046] The term “monoclonal antibody” refers to an antibody from a population of substantially homogeneous antibodies. A population of substantially homogeneous antibodies comprises antibodies that are substantially similar and that bind the same epitope(s), except for variants that may normally arise during production of the monoclonal antibody. Such variants are generally present in only minor amounts. A monoclonal antibody is typically obtained by a process that includes the selection of a single antibody from a plurality of antibodies. For example, the selection process can be the selection of a unique clone from a plurality of clones, such as a pool of hybridoma clones, phage clones, yeast clones, bacterial clones, or other recombinant DNA clones. The selected antibody can be further altered, for example, to improve affinity for the target (“affinity maturation”), to humanize the antibody, to improve its production in cell culture, and / or to reduce its immunogenicity in a subject.

[0047] The term “chimeric antibody” refers to an antibody in which a portion of the heavy and / or light chain is derived from a particular source or species, while the remainder of the heavy and / or light chain is derived from a different source or species.

[0048] “Humanized” forms of non-human antibodies are chimeric antibodies that contain minimal sequence derived from the non-human antibody. A humanized antibody is generally a human immunoglobulin (recipient antibody) in which residues from one or more CDRs are replaced by residues from one or more CDRs of a non-human antibody (donor antibody). The donor antibody can be any suitable non-human antibody, such as a mouse, rat, rabbit, chicken, or non-human primate antibody having a desired specificity, affinity, or biological effect. In some instances, selected framework region residues of the recipient antibody are replaced by the corresponding framework region residues from the donor antibody. Humanized antibodies may also comprise residues that are not found in either the recipient antibody or the donor antibody. Such modifications may be made to further refine antibody function. For further details, see Jones et al., Nature, 1986, 321:522-525; Riechmann et al., Nature, 1988, 332:323-329; and Presta, Curr. Op. Struct. Biol., 1992, 2:593-596, each of which is incorporated by reference in its entirety.

[0049] A “human antibody” is one which possesses an amino acid sequence corresponding to that of an antibody produced by a human or a human cell, or derived from a non-human source that utilizes a human antibody repertoire or human antibody-encoding sequences (e.g., obtained from human sources or designed de novo). Human antibodies specifically exclude humanized antibodies.

[0050] An “isolated antibody” is one that has been separated and / or recovered from a component of its natural environment. Components of the natural environment may includeenzymes, hormones, and other proteinaceous or nonproteinaceous materials. In some embodiments, an isolated antibody is purified to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence, for example by use of a spinning cup sequenator. In some embodiments, an isolated antibody is purified to homogeneity by gel electrophoresis (e.g., SDS-PAGE) under reducing or nonreducing conditions, with detection by Coomassie blue or silver stain. An isolated antibody includes an antibody in situ within recombinant cells, since at least one component of the antibody’s natural environment is not present. In some aspects, an isolated antibody is prepared by at least one purification step.

[0051] In some embodiments, an isolated antibody is purified to at least 80%, 85%, 90%, 95%, or 99% by weight. In some embodiments, an isolated antibody is purified to at least 80%, 85%, 90%, 95%, or 99% by volume. In some embodiments, an isolated antibody is provided as a solution comprising at least 85%, 90%, 95%, 98%, 99% to 100% by weight. In some embodiments, an isolated antibody is provided as a solution comprising at least 85%, 90%, 95%, 98%, 99% to 100% by volume.

[0052] “Affinity” refers to the strength of the sum total of non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an antigen). Unless indicated otherwise, as used herein, “binding affinity” refers to intrinsic binding affinity, which reflects a 1:1 interaction between members of a binding pair (e.g., antibody and antigen). The affinity of a molecule X for its partner Y can be represented by the dissociation constant (KD). Affinity can be measured by common methods known in the art, including those described herein. Affinity can be determined, for example, using surface plasmon resonance (SPR) technology, such as a Biacore®instrument. In some embodiments, the affinity is determined at 25°C.

[0053] With regard to the binding of an antibody to a target molecule, the terms “specific binding,” “specifically binds to,” “specific for,” “selectively binds,” and “selective for” a particular antigen (e.g., a polypeptide target) or an epitope on a particular antigen mean binding that is measurably different from a non-specific or non-selective interaction. Specific binding can be measured, for example, by determining binding of a molecule compared to binding of a control molecule. Specific binding can also be determined by competition with a control molecule that mimics the antibody binding site on the target. In that case, specific binding is indicated if the binding of the antibody to the target is competitively inhibited by the control molecule.

[0054] An “affinity matured” antibody is one with one or more alterations in one or more CDRs or FRs that result in an improvement in the affinity of the antibody for its antigen,compared to a parent antibody which does not possess the alteration(s). In some embodiments, an affinity matured antibody has nanomolar or picomolar affinity for the target antigen. Affinity matured antibodies may be produced using a variety of methods known in the art. For example, Marks et al. (Bio / Technology, 1992, 10:779-783, incorporated by reference in its entirety) describes affinity maturation by VH and VL domain shuffling. Random mutagenesis of CDR and / or framework residues is described by, for example, Barbas et al. (Proc. Nat. Acad. Sci. U.S.A., 1994, 91:3809-3813); Schier et al., Gene, 1995, 169:147-155; Yelton et al., J. Immunol., 1995, 155:1994-2004; Jackson et al., J. Immunol., 1995, 154:3310-33199; and Hawkins et al, J. Mol. Biol., 1992, 226:889-896, each of which is incorporated by reference in its entirety.

[0055] The term “amino acid” refers to the twenty common naturally occurring amino acids. Naturally occurring amino acids include alanine (Ala; A), arginine (Arg; R), asparagine (Asn; N), aspartic acid (Asp; D), cysteine (Cys; C); glutamic acid (Glu; E), glutamine (Gln; Q), Glycine (Gly; G); histidine (His; H), isoleucine (Ile; I), leucine (Leu; L), lysine (Lys; K), methionine (Met; M), phenylalanine (Phe; F), proline (Pro; P), serine (Ser; S), threonine (Thr; T), tryptophan (Trp; W), tyrosine (Tyr; Y), and valine (Val; V), and the less common pyrrolysine and selenocysteine. Natural amino acids also include citrulline. Naturally encoded amino acids include post-translational variants of the 22 naturally occurring amino acids such as prenylated amino acids, isoprenylated amino acids, myrisoylated amino acids, palmitoylated amino acids, N-linked glycosylated amino acids, O-linked glycosylated amino acids, phosphorylated amino acids, and acylated amino acids. The term “amino acid” also includes “non-natural amino acids” and “modified amino acids.” The terms “non-natural amino acids” and “modified amino acids” are used herein interchangeably.

[0056] The term “non-natural amino acid” (or “unnatural amino acid”) or “synthetic amino acids” are ^, ^, ^, or ^ amino acids, and includes but is not limited to, amino acids found in proteins, i.e., glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline, serine, threonine, cysteine, tyrosine, asparagine, glutamine, aspartate, glutamate, lysine, arginine and histidine. In certain embodiments, the amino acid is in the L- configuration. Alternatively, the amino acid can be a derivative of alanyl, valinyl, leucinyl, isoleucinyl, prolinyl, phenylalaninyl, tryptophanyl, methioninyl, glycinyl, serinyl, threoninyl, cysteinyl, tyrosinyl, asparaginyl, glutaminyl, aspartoyl, glutaroyl, lysinyl, argininyl, histidinyl, ^-alanyl, ^-valinyl, ^-leucinyl, ^-isoleuccinyl, ^-prolinyl, ^-phenylalaninyl, ^- tryptophanyl, ^-methioninyl, ^-glycinyl, ^-serinyl, ^-threoninyl, ^-cysteinyl, ^-tyrosinyl, ^-asparaginyl, ^-glutaminyl, ^-aspartoyl, ^-glutaroyl, ^-lysinyl, ^-argininyl or ^-histidinyl. Unnatural amino acids are not proteinogenic amino acids, or post-translationally modified variants thereof that either occur naturally or are chemically synthesized. In particular, the term unnatural amino acid refers to an amino acid that is not one of the 20 common amino acids or pyrrolysine or selenocysteine, or post-translationally modified variants thereof. Non- limiting examples of unnatural amino acids include sulfoalanine, hydroxyproline (Hyp), beta- alanine, citrulline (Cit), ornithine (Orn), norleucine (Nle), 3-nitrotyrosine, nitroarginine, pyroglutamic acid (Pyr), naphtylalanine (Nal), 2,4-diaminobutyric acid (DAB), methionine sulfoxide, and methionine sulfone.

[0057] The term “modified amino acid” is an amino acid or non-natural amino acid that comprises a reactive group capable of forming a covalent bond to a linker payload. The reactive group can be an amino, carboxy, acetyl, hydrazino, hydrazido, hydroxylamine, semicarbazido, sulfanyl, azido or alkynyl group. Non-limiting examples of non-natural amino acids include p-acetyl-L-phenylalanine, O-methyl-L-tyrosine, 3-methyl-phenylalanine, O-4- allyl-L-tyrosine, 4-propyl-L-tyrosine, fluorinated phenylalanine, isopropyl-L-phenylalanine, p-azido-L-phenylalanine, p-acyl-L-phenylalanine, p-benzoyl-L-phenylalanine, p-iodo- phenylalanine, p-bromophenylalanine, p-amino-L-phenylalanine, isopropyl-L-phenylalanine, p-propargyloxy-phenylalanine, and p-azidomethyl-L-phenyl alanine.

[0058] The term “conjugate” or “antibody conjugate” refers to an antibody linked to one or more payload moieties. The antibody can be any antibody described herein. The payload can be any payload described herein. The antibody can be directly linked to the payload via a covalent bond, or the antibody can be linked to the payload indirectly via a linker. Typically, the linker is covalently bonded to the antibody and also covalently bonded to the payload. The term “antibody drug conjugate” or “ADC” refers to a conjugate wherein at least one payload is a therapeutic moiety such as a drug. A “dual payload antibody conjugate” is an antibody conjugate wherein the antibody is linked to two different payloads. In certain embodiments described herein, the dual payload antibody conjugates comprise two different cytotoxic agents. In certain embodiments, the dual payload antibody conjugate is an “immunomodulatory antibody drug conjugate” or “iADC” wherein the antibody is linked, directly or indirectly via a linker, to at least one immunomodulatory agent, including, but not limited to a STING agonist or a TLR7 agonist, and at least one cytotoxic agent.

[0059] The term “epitope” means a portion of an antigen capable of specific binding to an antibody. Epitopes frequently consist of surface-accessible amino acid residues and / or sugarside chains and may have specific three-dimensional structural characteristics, as well as specific charge characteristics. Conformational and non-conformational epitopes are distinguished in that the binding to the former but not the latter is lost in the presence of denaturing solvents. An epitope may comprise amino acid residues that are directly involved in the binding, and other amino acid residues, which are not directly involved in the binding. The epitope to which an antibody binds can be determined using known techniques for epitope determination.

[0060] Percent “identity” between a polypeptide sequence and a reference sequence, is defined as the percentage of amino acid residues in the polypeptide sequence that are identical to the amino acid residues in the reference sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN, MEGALIGN (DNASTAR), CLUSTALW, CLUSTAL OMEGA, or MUSCLE software. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared.

[0061] The term “site-specific” refers to a modification of a polypeptide at a predetermined sequence location in the polypeptide. The modification is at a single, predictable residue of the polypeptide with little or no variation. In particular embodiments, a modified amino acid is introduced at that sequence location, for instance recombinantly or synthetically. Similarly, a moiety can be “site-specifically” linked to a residue at a particular sequence location in the polypeptide. In certain embodiments, a polypeptide can comprise more than one site-specific modification.

[0062] A “conservative substitution” or a “conservative amino acid substitution,” refers to the substitution of an amino acid with a chemically or functionally similar amino acid. Conservative substitution tables providing similar amino acids are well known in the art. Polypeptide sequences having such substitutions are known as “conservatively modified variants.” Such conservatively modified variants are in addition to and do not exclude polymorphic variants, interspecies homologs, and alleles. By way of example, the groups of amino acids provided in Tables B-D are, in some embodiments, considered conservative substitutions for one another.Table B. Selected groups of amino acids that are considered conservative substitutions for one another, in certain embodiments.Table C. Additional selected groups of amino acids that are considered conservative substitutions for one another, in certain embodiments.Table D. Further selected groups of amino acids that are considered conservative substitutions for one another, in certain embodiments.

[0063] Additional conservative substitutions may be found, for example, in Creighton, Proteins: Structures and Molecular Properties 2nd ed. (1993) W. H. Freeman & Co., NewYork, NY. An antibody generated by making one or more conservative substitutions of amino acid residues in a parent antibody is referred to as a “conservatively modified variant.”

[0064] “pAMF” mutation refers to a variant phenylalanine residue, i.e., para-azidomethyl-L- phenylalanine, added or substituted into a polypeptide.

[0065] “pAcF” mutation refers to a variant phenylalanine residue, i.e., p-acetyl-L- phenylalanine, added or substituted into a polypeptide.

[0066] The term “payload” refers to a molecular moiety that can be conjugated to an antibody. In particular embodiments, payloads are selected from the group consisting of therapeutic moieties, for example, the topoisomerase inhibitors and second payload residues, as described herein.

[0067] A “topoisomerase inhibitor” is any compound that interferes with the topoisomerase I (Top1) or the topoisomerase II (Top2) enzyme to inhibit the religation step during the unwinding of DNA. Topoisomerase inhibitors are divided in two classes: topoisomerase I inhibitors, which include, but are not limited to, camptothecin and its derivatives (for example, topotecan, irinotecan, rubitecan, exatecan, Gly-exatecan, belotecan, and 7-ethyl-10- hydroxycamptothecin (SN-38)) and topoisomerase II inhibitors, which include, but are not limited to, etoposide, teniposide, doxorubicin, idarubicin, epirubicin, and mitoxantrone.

[0068] A “cytotoxic agent” is a substance that kills cells, including cancer cells. A cytotoxic agent is any compound that is toxic to cancerous cells. A cytotoxic agent may induce immunogenic cell death. A cytotoxic agent may also reactivate SLFN11 through epigenetic activation. The cytotoxic agent is selected from the group consisting of a DNA-targeting agent, a tubulin-targeting agent, a histone-deacetylase (HDAC) inhibitor, NMT inhibitor, an anti-mitotic agent, an alkylating agent, a DNA-crosslinking agent, an anti-tumor antibiotic, an anti-metabolite, a telomerase inhibitor and an immunogenic cell death agent. The cytotoxic agent can be selected from doxorubicin, mitoxantrone, etoposide, idarubicin, pirarubicin (P- THP), PNU, PNU analogs, and derivatives thereof. The cytotoxic agent can be a tubulin- targeting agent. The tubulin-targeting agent can be selected from a hemiasterlin, monomethyl auristatin-E (MMAE), monomethyl auristatin-F (MMAF), DM1, DM4, and derivatives thereof. In an embodiment, the term “cytotoxic agent” excludes “DNA damage response inhibitors.”

[0069] A “DNA Damage Response (DDR) inhibitor” is any compound that inhibits the repair of single-stranded (SSB) and / or double-stranded (DSB) DNA breaks. In response to DNA damage, cancerous cells will often activate the DDR pathway, or in response to a defective DDR pathway, cancerous cells will become overly reliant on a different DDR pathway. In anembodiment, the cytotoxic agent excludes DDR inhibitors such as PARP1 inhibitors, ATR- inhibitors, ATM-inhibitors, and CHK1 / 2-inhibitors. Examples of PARP inhibitors excluded from the term “cytotoxic agents” include olaparib, veliparib, talazoparib, rucaparib, niraparib, AZD5305, talzenna, and derivatives thereof

[0070] The term “hemiasterlins” refers to a class of tripeptides modified from the original natural product hemiasterlin. Hemiasterlin is isolated from marine sponges Cymbastela sp., Hemiasterella minor, Siphonochalina sp., and Auletta sp. (Talpir et al., Tetrahedron Letters, vol.35, no.25, pp.4453-4456, 1994)

[0071] Hemiasterlins are pseudopeptides which are inhibitors of tubulin polymerization, sharing an antimitotic mechanism of action with dolastatins and cryptophycins. Noncompetitive binding at the vinblastine site on tubulin has been demonstrated. Hemiasterlins are in general poor glycoprotein (P-gp) substrates, rendering them effective against tumors that overexpress P-gp as a resistance mechanism. (Loganzo et al., Cancer Research, vol 63, pp.1838-1845, 15 April 2003)

[0072] The terms “synergy” or “synergism” refers to the interaction of two of more drugs wherein the total effect of the two drugs is greater than the additive effect of each individual drug.

[0073] The term “linker” refers to a molecular moiety that is capable of forming at least two covalent bonds. Typically, a linker is capable of forming at least one covalent bond to an antibody and at least another covalent bond to a payload. In certain embodiments, a linker can form more than one covalent bond to an antibody. In certain embodiments, a linker can form more than one covalent bond to a payload or can form covalent bonds to more than one payload. After a linker forms a bond to an antibody, or a payload, or both, the remaining structure, i.e., the residue of the linker after one or more covalent bonds are formed, may still be referred to as a “linker” herein. The term “linker precursor” refers to a linker having one or more reactive groups capable of forming a covalent bond with an antibody or payload, or both. In some embodiments, the linker is a cleavable linker. For example, a cleavable linker can be one that is released by a bio-labile function, which may or may not be engineered. In some embodiments, the linker is a non-cleavable linker. For example, a non-cleavable linker can be one that is released upon degradation of the antibody.

[0074] When referring to the compounds provided herein, the following terms have the following meanings unless indicated otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one ofordinary skill in the art. In the event that there is a plurality of definitions for a term herein, those in this section prevail unless stated otherwise.

[0075] "Triple negative breast cancer” (TNBC) refers to a breast cancer characterized as estrogen receptor-negative, progesterone receptor-negative and human epidermal growth factor receptor-2-negative (HER2-negative). The TNBC can be BRCA1 / 2 wildtype or BRCA1 / 2 mutated. The determination of negative status of the estrogen, progesterone, and Her2 / neu expression is readily determined by one of skill in the art, e.g., in accordance with the current accepted guidelines. For example, guidelines set forth by the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) are widely accepted. The ASCO / CAP recommends testing by immunohistochemistry (IHC) or in situ hybridization (ISH) techniques. Further, a cancer is Her2 negative if a single test (or all tests) performed on a tumor specimen show: (a) IHC negative, IHC 1+ or IHC 0, or (b) ISH negative using single-probe ISH or dual-probe ISH. One of skill in the art would recognize that the triple negative cancer described herein does not include any cancer having an apparent histopathologic discordance as observed by the pathologist. Wolff, A C et al. J Clin Oncol.2013 Nov.1:31(31):3997-4013. Cancer is ER-negative or PR-negative if <1% of tumor cell nuclei are immunoreactive in the presence of evidence that the sample can express ER or PR (positive intrinsic controls are seen).

[0076] “PARP inhibitor-resistant” refers to the reduced effectiveness of PARP inhibitors in treating, curing, or improving triple negative breast cancer in a subject. In certain embodiments, the PARP inhibitor-resistance develops with prolonged exposure to one or more PARP inhibitors.

[0077] As used herein, EC50 refers to a dosage, concentration, or amount of a particular test compound that elicits a dose-dependent response at 50% of maximal expression of a particular response that is induced, provoked, or potentiated by the particular test compound.

[0078] As used herein, IC50 refers to an amount, concentration, or dosage of a particular test compound that achieves a 50% inhibition of a maximal response in an assay that measures such response.

[0079] As used herein, the terms “subject” and “patient” are used interchangeably herein. The terms “subject” and “subjects” refer to an animal, such as a mammal including a non- primate (e.g., a cow, pig, horse, cat, dog, rat, and mouse) and a primate (e.g., a monkey such as a cynomolgous monkey, a chimpanzee and a human), and for example, a human. In certain embodiments, the subject is refractory or non-responsive to current treatments for hepatitis Cinfection. In another embodiment, the subject is a farm animal (e.g., a horse, a cow, a pig, etc.) or a pet (e.g., a dog or a cat). In certain embodiments, the subject is a human.

[0080] As used herein, the terms “therapeutic agent” and “therapeutic agents” refer to any agent(s) which can be used in the treatment or prevention of a disorder or one or more symptoms thereof. In certain embodiments, the term “therapeutic agent” includes a compound and / or an antibody conjugate provided herein. In certain embodiments, a therapeutic agent is an agent which is known to be useful for, or has been or is currently being used for the treatment or prevention of a disorder or one or more symptoms thereof.

[0081] As used herein, the term “therapeutically effective amount” or “effective amount” refers to an amount of an antibody or composition that when administered to a subject is effective to treat a disease or disorder. In some embodiments, a therapeutically effective amount or effective amount refers to an amount of an antibody or composition that when administered to a subject is effective to prevent or ameliorate a disease or the progression of the disease, or result in amelioration of symptoms. A “therapeutically effective amount” can vary depending on, inter alia, the compound, the disease and its severity, and the age, weight, etc., of the subject to be treated.

[0082] “Treating” or “treatment” of any disease or disorder refers, in certain embodiments, to ameliorating a disease or disorder that exists in a subject. In another embodiment, “treating” or “treatment” includes ameliorating at least one physical parameter, which may be indiscernible by the subject. In yet another embodiment, “treating” or “treatment” includes modulating the disease or disorder, either physically (e.g., stabilization of a discernible symptom) or physiologically (e.g., stabilization of a physical parameter) or both. In yet another embodiment, “treating” or “treatment” includes delaying or preventing the onset of the disease or disorder, or delaying or preventing recurrence of the disease or disorder. In yet another embodiment, “treating” or “treatment” includes the reduction or elimination of either the disease or disorder, or to retard the progression of the disease or disorder or of one or more symptoms of the disease or disorder, or to reduce the severity of the disease or disorder or of one or more symptoms of the disease or disorder.

[0083] As used herein, the term “inhibits growth” (e.g., referring to cells, such as tumor cells) is intended to include any measurable decrease in cell growth (e.g., tumor cell growth) when contacted with an antibody or antibody conjugate, as compared to the growth of the same cells not in contact with the antibody or antibody conjugate. In some embodiments, growth may be inhibited by at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, or 100%. The decrease in cell growth can occur by a variety of mechanisms, including butnot limited to antibody internalization, apoptosis, necrosis, and / or effector function-mediated activity.

[0084] As used herein, the terms “prophylactic agent” and “prophylactic agents” as used refer to any agent(s) which can be used in the prevention of a disorder or one or more symptoms thereof. In certain embodiments, the term “prophylactic agent” includes a compound provided herein. In certain other embodiments, the term “prophylactic agent” does not refer a compound provided herein. For example, a prophylactic agent is an agent which is known to be useful for, or has been or is currently being used to prevent or impede the onset, development, progression, and / or severity of a disorder.

[0085] As used herein, the phrase “prophylactically effective amount” refers to the amount of a therapy (e.g., prophylactic agent) which is sufficient to result in the prevention or reduction of the development, recurrence, or onset of one or more symptoms associated with a disorder (, or to enhance or improve the prophylactic effect(s) of another therapy (e.g., another prophylactic agent).

[0086] The term “alkyl,” as used herein, unless otherwise specified, refers to a saturated straight or branched hydrocarbon. In certain embodiments, the alkyl group is a primary, secondary, or tertiary hydrocarbon. In certain embodiments, the alkyl group includes one to ten carbon atoms, i.e., C1to C10alkyl. The term includes both substituted and unsubstituted alkyl groups, including halogenated alkyl groups. In some or any embodiments, the alkyl is unsubstituted. In some or any embodiments, the alkyl is substituted. In certain embodiments, the alkyl group is a fluorinated alkyl group. Non-limiting examples of moieties with which the alkyl group can be substituted are selected from the group consisting of halogen (fluoro, chloro, bromo or iodo), hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, or phosphonate, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in Greene, et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Second Edition, 1991, hereby incorporated by reference. In certain embodiments, the alkyl group is selected from the group consisting of methyl, CF3, CCl3, CFCl2, CF2Cl, ethyl, CH2CF3, CF2CF3, propyl, isopropyl, butyl, isobutyl, secbutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, and 2,3-dimethylbutyl.

[0087] The term “lower alkyl,” as used herein, and unless otherwise specified, refers to a saturated straight or branched hydrocarbon having one to six carbon atoms, i.e., C1 to C6 alkyl. In certain embodiments, the lower alkyl group is a primary, secondary, or tertiary hydrocarbon. The term includes both substituted and unsubstituted moieties.

[0088] The term “alkylene,” as used herein, unless otherwise specified, refers to a divalent alkyl group, as defined herein. “Substituted alkylene” refers to an alkylene group substituted as described herein for alkyl. In some embodiments, alkylene is unsubstituted.

[0089] The term “alkenyl,” as used herein, refers to an olefinically unsaturated hydrocarbon group, in certain embodiments, having up to about eleven carbon atoms or from two to six carbon atoms (e.g., “lower alkenyl”), which can be straight-chained or branched, and having at least one or from one to two sites of olefinic unsaturation. “Substituted alkenyl” refers to an alkenyl group substituted as described herein for alkyl.

[0090] The term “alkenylene,” as used herein, refers to a divalent alkenyl as defined herein. Lower alkenylene is, for example, C2-C6-alkenylene.

[0091] The term “alkynyl,” as used herein, refers to acetylenically unsaturated hydrocarbon groups, in certain embodiments, having up to about eleven carbon atoms or from two to six carbon atoms (e.g., “lower alkynyl”), which can be straight-chained or branched, and having at least one or from one to two sites of acetylenic unsaturation. Non-limiting examples of alkynyl groups include acetylene (-C≡CH), propargyl (-CH2C≡CH), and the like. “Substituted alkynyl” refers to an alkynyl group substituted as described herein for alkyl.

[0092] The term “Cx-y” when used in conjunction with a chemical moiety, such as alkyl, alkenyl, or alkynyl is meant to include groups that contain from x to y carbons in the chain. For example, the term “C1-6 alkyl” refers to substituted or unsubstituted saturated hydrocarbon groups, including straight-chain alkyl and branched-chain alkyl groups that contain from 1 to 6 carbons. The term “Cx-yalkylene” refers to a substituted or unsubstituted alkylene chain with from x to y carbons in the alkylene chain. For example “-C1-6 alkylene-” may be selected from methylene, ethylene, propylene, butylene, pentylene, and hexylene, any one of which is optionally substituted. The terms “Cx-yalkenyl” and “Cx-yalkynyl” refer to substituted or unsubstituted unsaturated aliphatic groups analogous in length and possible substitution to the alkyls described above, but that contain at least one double or triple bond, respectively. The term “-Cx-yalkenylene-” refers to a substituted or unsubstituted alkenylene chain with from x to y carbons in the alkenylene chain. For example, “-C2-6alkenylene-” may be selected from ethenylene, propenylene, butenylene, pentenylene, and hexenylene, any one of which is optionally substituted. An alkenylene chain may have one double bond or more than one double bond in the alkenylene chain. The term “-Cx-yalkynylene-” refers to a substituted or unsubstituted alkynylene chain with from x to y carbons in the alkenylene chain. For example, “-C2-6alkenylene-” may be selected from ethynylene, propynylene, butynylene, pentynylene, and hexynylene, any one of which is optionally substituted. Analkynylene chain may have one triple bond or more than one triple bond in the alkynylene chain.

[0093] The term “aryl,” as used herein, and unless otherwise specified, refers to phenyl, biphenyl, or naphthyl. The term includes both substituted and unsubstituted moieties. An aryl group can be substituted with any described moiety, including, but not limited to, one or more moieties selected from the group consisting of halogen (fluoro, chloro, bromo or iodo), alkyl, haloalkyl, hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, or phosphonate, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in Greene, et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Second Edition, 1991.

[0094] The term “arylene,” as used herein, and unless otherwise specified refers to a divalent aryl group, as defined herein.

[0095] “Alkoxy” and “alkoxyl,” refer to the group –OR′ where R′ is alkyl or cycloalkyl. Alkoxy groups include, by way of example, methoxy, ethoxy, n-propoxy, isopropoxy, n- butoxy, tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, and the like.

[0096] “Aryloxy,” refer to the group –OR′ where R′ is aryl. Aryloxy groups include, by way of example, phenoxy.

[0097] "Arylalkyl” refers to an alkyl group as described herein substituted with one or two aryl groups as described herein.

[0098] “Alkoxycarbonyl” refers to a radical -C(O)-alkoxy where alkoxy is as defined herein.

[0099] “Amino” refers to the radical -NH2.

[0100] The term “alkylamino,” as used herein, and unless otherwise specified, refers to the group –NHR′ where R′ is C1-10alkyl, as defined herein. In some or any embodiments, the alkylamino is C1-6alkylamino.

[0101] The term “dialkylamino,” as used herein, and unless otherwise specified, refers to the group –NR′R′ where each R′ is independently C1-10alkyl, as defined herein. In some or any embodiments, the dialkylamino is di-C1-6alkylamino.

[0102] The term “haloalkyl” refers to an alkyl group, as defined herein, substituted with one or more halogen atoms (e.g., in some embodiments one, two, three, four, or five) which are independently selected.

[0103] “Carboxyl” or “carboxy” refers to the radical -C(O)OH.

[0104] The term “cycloalkyl,” as used herein, unless otherwise specified, refers to a saturated cyclic hydrocarbon. In certain embodiments, the cycloalkyl group may be a saturated, and / or bridged, and / or non-bridged, and / or a fused bicyclic group. In certain embodiments, thecycloalkyl group includes three to ten carbon atoms, i.e., C3to C10cycloalkyl. In some embodiments, the cycloalkyl has from 3 to 15 (C3-15), from 3 to 10 (C3-10), or from 3 to 7 (C3- 7) carbon atoms. In certain embodiments, the cycloalkyl group is cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, cycloheptyl, bicyclo[2.1.1]hexyl, bicyclo[2.2.1]heptyl, decalinyl, or adamantyl.

[0105] The term “carbocycle” as used herein, unless otherwise specified, refers to a saturated, unsaturated, or aromatic ring in which each atom of the ring is carbon. In certain embodiments, the carbocycle group may be saturated, and / or bridged, and / or non-bridged, and / or a fused bicyclic group, and / or a spirocyclic bicyclic group. In some embodiments, carbocycle includes 3- to 10-membered monocyclic rings, 6-to 12-membered bicyclic rings, and / or 6- to 12-membered bridged rings. In some embodiments, each ring of a bicyclic carbocycle may be selected from saturated, unsaturated, and aromatic rings. In some embodiments, an aromatic ring, for example, phenyl, may be fused to a saturated or unsaturated ring, for example, cyclohexane, cyclopentane, or cyclohexene. A bicyclic carbocycle includes any combination of saturated, unsaturated, and aromatic bicyclic rings, as valence permits. A bicyclic carbocycle includes any combination of ring sizes such as 4-5 fused ring systems, 5-5 fused ring systems, 5-6 fused ring systems, 6-6 fused ring systems, 5- 7 fused ring systems, 6-7 fused ring systems, 5-8 fused ring systems, and 6-8 fused ring systems. In certain embodiments, the carbocycle group includes three to ten carbon atoms (i.e., C3to C10carbocycle). In certain embodiments, the carbocycle group includes three to twelve carbon atoms (i.e., C3to C12carbocycle). In some embodiments, the carbocycle has from three to fifteen carbons (C3-15), from three to twelve carbons (C3-12), from three to ten carbons (C3-10), from three to seven carbons (C3-7), or from three to six carbons (C3-C6). In certain embodiments, the carbocycle group is cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cyclohexadienyl, cyclohexylmethyl, cycloheptyl, bicyclo[2.1.1]hexyl, bicyclo[2.2.1]heptyl, decalinyl, phenyl, indanyl, naphthyl, or adamantyl.

[0106] The term “heterocyclyl,” “heterocyclic,” and “heterocycle” refer to a monovalent monocyclic non-aromatic ring system and / or multicyclic ring system that contains at least one non-aromatic ring, wherein one or more of the non-aromatic ring atoms are heteroatoms independently selected from O, S, and N; and the remaining ring atoms of the non-aromatic ring are carbon atoms, and wherein any aromatic ring atoms are optionally heteroatoms independently selected from O, S, and N and the remaining ring atoms of the non-aromatic ring are carbon atoms. In certain embodiments, the heterocyclyl or heterocyclic group has from 3 to 20, from 3 to 15, from 3 to 10, from 3 to 8, from 4 to 7, from 4 to 11, or from 5 to 6ring atoms. Heterocyclyl groups are bonded to the rest of the molecule through the non- aromatic ring. In certain embodiments, the heterocyclyl is a monocyclic, bicyclic, tricyclic, or tetracyclic ring system, which may include a fused or bridged ring system and in which the nitrogen or sulfur atoms may be optionally oxidized, the nitrogen atoms may be optionally quaternized, and some rings may be partially or fully saturated, or aromatic. The heterocyclyl may be attached to the main structure at any heteroatom or carbon atom of its non-aromatic ring which results in the creation of a stable compound. Heterocycloalkyl refers to a heterocycle which is a monovalent, monocyclic or multicyclic, non-aromatic ring system. In some or any embodiments, heterocycloalkyl is a monovalent, monocyclic or multicyclic, fully-saturated ring system. Examples of such heterocyclic and / or heterocycloalkyl radicals include, but are not limited to, 2,5-diazabicyclo[2.2.2]octanyl, 3,9- diazabicyclo[3.3.2]decanyl), azepinyl, benzodioxanyl, benzodioxolyl, benzofuranonyl, benzopyranonyl, benzopyranyl, benzotetrahydrofuranyl, benzotetrahydrothienyl, benzothiopyranyl, benzoxazinyl, β-carbolinyl, chromanyl, chromonyl, cinnolinyl, coumarinyl, decahydroisoquinolinyl, dihydrobenzisothiazinyl, dihydrobenzisoxazinyl, dihydrofuryl, dihydroisoindolyl, dihydropyranyl, dihydropyrazolyl, dihydropyrazinyl, dihydropyridinyl, dihydropyrimidinyl, dihydropyrrolyl, dioxolanyl, 1,4-dithianyl, furanonyl, imidazolidinyl, imidazolinyl, indolinyl, isobenzotetrahydrofuranyl, isobenzotetrahydrothienyl, isochromanyl, isocoumarinyl, isoindolinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl, octahydroindolyl, octahydroisoindolyl, oxazolidinonyl, oxazolidinyl, oxiranyl, piperazinyl, piperidinyl, 4-piperidonyl, pyrazolidinyl, pyrazolinyl, pyrrolidinyl, pyrrolinyl, quinuclidinyl, tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydropyranyl, tetrahydrothienyl, thiamorpholinyl, thiazolidinyl, tetrahydroquinolinyl, and 1,3,5-trithianyl. In certain embodiments, heterocyclic may also be optionally substituted as described herein. In some or any embodiments, heterocyclic and heterocycloalkyl are substituted with 1, 2, or 3 groups independently selected from halogen (fluoro, chloro, bromo or iodo), alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy. In some embodiments, a hetercycloalkyl group may comprise 1, 2, 3, or 4 heteroatoms. Those of skill in the art will recognize that a 4-membered heterocycloalkyl may generally comprise 1 or 2 heteroatoms, a 5-6 membered heterocycloalkyl may generally comprise 1 or 2 heteroatoms, and a 7-10 membered heterocycloalkyl may generally comprise 1, 2, 3, or 4 heteroatoms.

[0107] The term “heteroaryl” refers to refers to a monovalent monocyclic aromatic group and / or multicyclic aromatic group, wherein at least one aromatic ring contains one or more heteroatoms independently selected from O, S, and N in the ring. Each ring of a heteroarylgroup can contain one or two O atoms, one or two S atoms, and / or one to four N atoms, provided that the total number of heteroatoms in each ring is four or less and each ring contains at least one carbon atom. In certain embodiments, the heteroaryl has from 5 to 20, from 5 to 15, or from 5 to 10 ring atoms. A heteroaryl may be attached to the rest of the molecule via a nitrogen or a carbon atom. In some embodiments, monocyclic heteroaryl groups include, but are not limited to, furanyl, imidazolyl, isothiazolyl, isoxazolyl, oxadiazolyl, oxadiazolyl, oxazolyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridyl, pyrimidinyl, pyrrolyl, imidazolyl, triazolyl, thiadiazolyl, thiazolyl, thienyl, tetrazolyl, triazinyl, and triazolyl. Examples of bicyclic heteroaryl groups include, but are not limited to, benzofuranyl, benzimidazolyl, benzoisoxazolyl, benzopyranyl, benzothiadiazolyl, benzothiazolyl, benzothienyl, benzotriazolyl, benzoxazolyl, furopyridyl, imidazopyridinyl, imidazothiazolyl, indolizinyl, indolyl, indazolyl, isobenzofuranyl, isobenzothienyl, isoindolyl, isoquinolinyl, isothiazolyl, naphthyridinyl, oxazolopyridinyl, phthalazinyl, pteridinyl, purinyl, pyridopyridyl, pyrrolopyridyl, quinolinyl, quinoxalinyl, quinazolinyl, thiadiazolopyrimidyl, and thienopyridyl. Examples of tricyclic heteroaryl groups include, but are not limited to, acridinyl, benzindolyl, carbazolyl, dibenzofuranyl, perimidinyl, phenanthrolinyl, phenanthridinyl, phenarsazinyl, phenazinyl, phenothiazinyl, phenoxazinyl, and xanthenyl. In certain embodiments, heteroaryl may also be optionally substituted as described herein. “Substituted heteroaryl” is heteroaryl substituted as defined for aryl.

[0108] “Partially saturated heteroaryl” refers to a multicyclic (e.g., bicyclic, tricyclic) fused ring system that contains at least one non-aromatic ring and at least one aromatic ring, wherein one or more of the non-aromatic ring atoms and / or one or more of the aromatic ring atoms are heteroatoms independently selected from O, S, and N; and the remaining ring atoms are carbon atoms. Partially saturated heteroaryl groups are bonded to the rest of the molecule through the aromatic ring. In certain embodiments, the partially saturated heteroaryl group has from 6 to 20, from 6 to 15, from 6 to 10, from 6 to 8, or from 8 to 11 ring atoms. In certain embodiments, the partially saturated heteroaryl group has 8, 9, 10, or 11 ring atoms (in some embodiments 9 or 10). The partially saturated heteroaryl may be attached to the main structure at any heteroatom or carbon atom of its aromatic ring which results in the creation of a stable compound. In some or any embodiments, an oxo group may be present as a substituent on one of the ring atoms. A partially saturated heteroaryl radical consists of one of the following or comprises one or more of the following: benzodioxanyl, benzodioxolyl, benzofuranonyl, benzopyranonyl, benzopyranyl, benzotetrahydrofuranyl, benzotetrahydrothienyl, benzothiopyranyl, benzoxazinyl, chromanyl, chromonyl, cinnolinyl,coumarinyl, decahydroisoquinolinyl, dihydrobenzisothiazinyl, dihydrobenzisoxazinyl, dihydrofuryl, dihydroisoindolyl, dihydropyranyl, dihydropyrazolyl, dihydropyrazinyl, tetrahydropyrazinyl, dihydropyrazinonyl, dihydropyridinyl, tetrahydropyridinyl, dihydropyrimidinyl, dihydropyrrolyl, furanonyl, imidazolinyl, indolinyl, tetrahydroindolyl, isoindolinyl, tetrahydroisoindolyl, isobenzotetrahydrofuranyl, isobenzotetrahydrothienyl, isochromanyl, isocoumarinyl, isoindolinyl, dihydroisoxazolyl, oxazinyl, dihydrooxazinyl, oxo-oxazolyl, dihydrooxazolyl, dihydropiperidonyl, dihydro-4-piperidonyl, dihydropyrazolyl, dihydropyrazolinyl, dihydropyrrolyl, azabicyclo[2.2.2]oct-2-enyl, dihydrofuryl, tetrahydroisoquinolinyl, dihydropyranyl, pyranyl, dihydrothienyl, oxathiazinyl, dihydrothiazolyl, tetrahydroquinolinyl, and 5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazinyl. In certain embodiments, the partially saturated heteroaryl radical is benzodioxanyl, benzodioxolyl, benzofuranonyl, benzopyranonyl, benzopyranyl, benzotetrahydrofuranyl, benzotetrahydrothienyl, benzothiopyranyl, benzoxazinyl, chromanyl, chromonyl, coumarinyl, dihydrobenzisothiazinyl, dihydrobenzisoxazinyl, dihydroisoindolyl, indolinyl, isobenzotetrahydrofuranyl, isobenzotetrahydrothienyl, isochromanyl, isocoumarinyl, isoindolinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, or 5,6,7,8-tetrahydro- [1,2,4]triazolo[4,3-a]pyrazinyl. In certain embodiments, partially saturated heteroaryl may also be optionally substituted as described herein.

[0109] Any suitable group may be present on a “substituted” or “optionally substituted” position that forms a stable molecule and includes, but is not limited to, e.g., halogen (which can independently be F, Cl, Br or I); cyano; hydroxyl; nitro; azido; alkoxycarbonyl; alkyl; cycloalkyl; alkenyl; alkynyl; alkoxy; aryloxy such as phenoxy; alkylamino; aryl; arylalkyl; or a heterocyclic group as described herein. In certain embodiments “optionally substituted” includes one or more substituents independently selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy. When a group described herein is optionally substituted, the optional substituent bonded to the group is unsubstituted unless specified otherwise.

[0110] The term “protecting group” as used herein and unless otherwise defined refers to a group that is added to an oxygen, nitrogen, or phosphorus atom to prevent its further reaction or for other purposes. A wide variety of oxygen and nitrogen protecting groups are known to those skilled in the art of organic synthesis.

[0111] “Pharmaceutically acceptable salt” refers to any salt of a compound provided herein which retains its biological properties and which is not toxic or otherwise undesirable for pharmaceutical use. Such salts may be derived from a variety of organic and inorganiccounter-ions well known in the art. Such salts include, but are not limited to: (1) acid addition salts formed with organic or inorganic acids such as hydrochloric, hydrobromic, sulfuric, nitric, phosphoric, sulfamic, acetic, trifluoroacetic, trichloroacetic, propionic, hexanoic, cyclopentylpropionic, glycolic, glutaric, pyruvic, lactic, malonic, succinic, sorbic, ascorbic, malic, maleic, fumaric, tartaric, citric, benzoic, 3-(4-hydroxybenzoyl)benzoic, picric, cinnamic, mandelic, phthalic, lauric, methanesulfonic, ethanesulfonic, 1,2-ethane-disulfonic, 2-hydroxyethanesulfonic, benzenesulfonic, 4-chlorobenzenesulfonic, 2-naphthalenesulfonic, 4-toluenesulfonic, camphoric, camphorsulfonic, 4-methylbicyclo[2.2.2]-oct-2-ene-1- carboxylic, glucoheptonic, 3-phenylpropionic, trimethylacetic, tert-butylacetic, lauryl sulfuric, gluconic, benzoic, glutamic, hydroxynaphthoic, salicylic, stearic, cyclohexylsulfamic, quinic, muconic acid and the like acids; or (2) salts formed when an acidic proton present in the parent compound either (a) is replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion or an aluminum ion, or alkali metal or alkaline earth metal hydroxides, such as sodium, potassium, calcium, magnesium, aluminum, lithium, zinc, and barium hydroxide, ammonia or (b) coordinates with an organic base, such as aliphatic, alicyclic, or aromatic organic amines, such as ammonia, methylamine, dimethylamine, diethylamine, picoline, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, lysine, arginine, ornithine, choline, N,N′-dibenzylethylene-diamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, N-methylglucamine piperazine, tris(hydroxymethyl)-aminomethane, tetramethylammonium hydroxide, and the like.

[0112] Pharmaceutically acceptable salts further include, by way of example only and without limitation, sodium, potassium, calcium, magnesium, ammonium, tetraalkylammonium and the like, and when the compound contains a basic functionality, salts of non-toxic organic or inorganic acids, such as hydrohalides, e.g. hydrochloride and hydrobromide, sulfate, phosphate, sulfamate, nitrate, acetate, trifluoroacetate, trichloroacetate, propionate, hexanoate, cyclopentylpropionate, glycolate, glutarate, pyruvate, lactate, malonate, succinate, sorbate, ascorbate, malate, maleate, fumarate, tartarate, citrate, benzoate, 3-(4-hydroxybenzoyl)benzoate, picrate, cinnamate, mandelate, phthalate, laurate, methanesulfonate (mesylate), ethanesulfonate, 1,2-ethane-disulfonate, 2- hydroxyethanesulfonate, benzenesulfonate (besylate), 4-chlorobenzenesulfonate, 2- naphthalenesulfonate, 4-toluenesulfonate, camphorate, camphorsulfonate, 4- methylbicyclo[2.2.2]-oct-2-ene-1-carboxylate, glucoheptonate, 3-phenylpropionate, trimethylacetate, tert-butylacetate, lauryl sulfate, gluconate, benzoate, glutamate, hydroxynaphthoate, salicylate, stearate, cyclohexylsulfamate, quinate, muconate and the like.

[0113] The term “substantially free of” or “substantially in the absence of” with respect to a composition refers to a composition that includes at least 85 or 90% by weight, in certain embodiments 95%, 98 %, 99% or 100% by weight, of the designated enantiomer of that compound. In certain embodiments, in the methods and compounds provided herein, the compounds are substantially free of enantiomers.

[0114] Similarly, the term “isolated” with respect to a composition refers to a composition that includes at least 85, 90%, 95%, 98%, and 99% to 100% by weight, of the compound, the remainder comprising other chemical species or enantiomers.

[0115] “Solvate” refers to a compound provided herein or a salt thereof that further includes a stoichiometric or non-stoichiometric amount of solvent bound by non-covalent intermolecular forces. Where the solvent is water, the solvate is a hydrate.

[0116] “Isotopic composition” refers to the amount of each isotope present for a given atom, and “natural isotopic composition” refers to the naturally occurring isotopic composition or abundance for a given atom. Atoms containing their natural isotopic composition may also be referred to herein as “non-enriched” atoms. Unless otherwise designated, the atoms of the compounds recited herein are meant to represent any stable isotope of that atom. For example, unless otherwise stated, when a position is designated specifically as "H" or "hydrogen,” the position is understood to have hydrogen at its natural isotopic composition.

[0117] “Isotopic enrichment” refers to the percentage of incorporation of an amount of a specific isotope at a given atom in a molecule in the place of that atom’s natural isotopic abundance. For example, deuterium enrichment of 1% at a given position means that 1% of the molecules in a given sample contain deuterium at the specified position. Because the naturally occurring distribution of deuterium is about 0.0156%, deuterium enrichment at any position in a compound synthesized using non-enriched starting materials is about 0.0156%. The isotopic enrichment of the compounds provided herein can be determined using conventional analytical methods known to one of ordinary skill in the art, including mass spectrometry and nuclear magnetic resonance spectroscopy.

[0118] “Isotopically enriched” refers to an atom having an isotopic composition other than the natural isotopic composition of that atom. “Isotopically enriched” may also refer to a compound containing at least one atom having an isotopic composition other than the natural isotopic composition of that atom.

[0119] As used herein, “alkyl,” “alkylene,” “alkylamino,” “dialkylamino,” “cycloalkyl,” “aryl,” “alkoxy,” “alkoxycarbonyl,” “amino,” “carboxyl,” “heterocyclyl,” “heterocycloalkyl,” “heteroaryl,” “partially saturated heteroaryl,” “carboxyl,” and “amino acid” groups optionallycomprise deuterium at one or more positions where hydrogen atoms are present, and wherein the deuterium composition of the atom or atoms is other than the natural isotopic composition.

[0120] Also as used herein, “alkyl,” “alkylamino,” “dialkylamino,” “cycloalkyl,” “aryl,” “alkoxy,” “alkoxycarbonyl,” “amino,” “carboxyl,” “heterocyclyl,” “heteroaryl,” “carboxyl” and “amino acid” groups optionally comprise carbon-13 at an amount other than the natural isotopic composition.

[0121] In some chemical structures illustrated herein, certain substituents, chemical groups, and atoms are depicted with a curvy / wavy line (e.g.,) that intersects a bond or bonds to indicate the atom through which the substituents, chemical groups, and atoms are bonded. For example, in some structures, such as but not limited to,, the curvy / wavy lines indicates the atoms in the backbone of a conjugate structure to which the illustrated chemical entity is bonded. In some structures, such as but not limited to,, the curvy / wavy lines indicate the atoms in the antibody or antibody fragment as well as the atoms in the backbone of a conjugate or linker-payload structure to which the illustrated chemical entity is bonded.

[0122] As used herein, illustrations showing substituents bonded to a cyclic group (e.g., aromatic, heteroaromatic, fused ring, and saturated or unsaturated cycloalkyl or heterocycloalkyl) through a bond between ring atoms are meant to indicate, unless specified otherwise, that the cyclic group may be substituted with that substituent at any ring position in the cyclic group or on any ring in the fused ring group, according to techniques set forth herein or which are known in the field to which the instant disclosure pertains. For example,the group,, wherein subscripts z and y are integers and in which the positions of substituents RT and RAis described generically, i.e., not directly attached to any vertex of the bond line structure, i.e., specific ring carbon atom, includes the following, non-limiting examples of groups in which the substituent RAand RT is bonded to a specific ring carbon atom:

[0123] Conjugates

[0124] Provided herein are dual payload antibody-drug conjugates (ADCs) that comprise an antibody or antigen binding fragment thereof wherein the antibody, or antigen binding fragment thereof, is covalently linked to at least one first payload via a first linker and alsocovalently linked to a second payload via a second linker. The conjugates comprise an antibody or antigen-binding fragment thereof recognizing a suitable antigen (e.g., a tumor antigen) covalently linked, via linkers, to payloads.

[0125] The first payload is a topoisomerase inhibitor. The topoisomerase inhibitor is a topoisomerase I inhibitor or a topoisomerase II inhibitor. The topoisomerase I inhibitor can be selected from the group consisting of camptothecin, SN-38, exatecan, irinotecan, topotecan, govitecan, deruxtecan, belotecan, and derivatives thereof. In an embodiment, the topoisomerase I inhibitor is exatecan. In an embodiment, the topoisomerase inhibitor is a topoisomerase II inhibitor. The topoisomerase II inhibitor can be selected from the group consisting of amonafide, azonafide-PEABA, etoposide, teniposide, tafluposide, and derivatives thereof.

[0126] The second payload residue can be a cytotoxic agent. The cytotoxic agent can be selected from the group consisting of a DNA-targeting agent, a tubulin-targeting agent, a histone-deacetylase (HDAC) inhibitor, NMT inhibitor, an anti-mitotic agent, an alkylating agent, a DNA-crosslinking agent, an anti-tumor antibiotic, an anti-metabolite, a telomerase inhibitor and an immunogenic cell death agent. In an embodiment, the cytotoxic agent is not a DNA damage response (DDR) inhibitor. In an embodiment, the cytotoxic agent is an anthracycline selected from doxorubicin, mitoxantrone, etoposide, idarubicin, pirarubicin (P- THP), PNU, PNU analogs, and derivatives thereof. The cytotoxic agent can be a tubulin- targeting agent selected from a hemiasterlin, monomethyl auristatin-E (MMAE), monomethyl auristatin-F (MMAF), DM1, DM4, and derivatives thereof. In an embodiment, the cytotoxic agent is hemiasterlin. In an embodiment, the hemiasterlin is 3-aminophenyl hemiasterlin. In some embodiments, the cytotoxic agent is MMAE. In an embodiment, the cytotoxic agent is a microtubule dynamics inhibitor. In an embodiment, the microtubule dynamics inhibitor is eribulin.

[0127] In an embodiment, the second payload is a DNA damage response (DDR) inhibitor. A “DNA Damage Response (DDR) inhibitor” is any compound that inhibits the repair of single-stranded (SSB) and / or double-stranded (DSB) DNA breaks. In response to DNA damage, cancerous cells will often activate the DDR pathway, or in response to a defective DDR pathway, cancerous cells will become overly reliant on a different DDR pathway. For this reason, DDR inhibitors are widely used as anti-cancer agents. DDR inhibitors include, but are not limited to, PARP1 inhibitors, ATR-inhibitors, ATM-inhibitors, and CHK1 / 2- inhibitors.

[0128] In an embodiment, the first payload is exatecan and the second payload is hemiasterlin. In an embodiment, the first payload is exatecan and second payload is MMAE. In an embodiment, the first payload is a topoisomerase I inhibitor and second payload is a topoisomerase II inhibitor.

[0129] In an embodiment, the payloads can include the compounds in Table D.

[0130] Table D: Payloads

[0131] The first linker (La) and second linker (Lb) can be any linkers capable of forming at least one bond to the antibody and at least one bond to a payload wherein the first linker forms at least one bond with the first payload and the second linker forms a bond with the second payload. The first linker and the second linker can have the same structure. In some embodiments, the first linker and the second linker have different structures. In some embodiments, including any of the foregoing, the first and second linker independently comprise a protease cleavable linker, an enzyme cleavable linker, a pH-sensitive linker, or a non-cleavable linker. In some embodiments, the first and second linker independently comprises a cleavable linker, wherein the cleavable linker comprises a cathepsin cleavable linker. In some embodiments, the first and second linker independently comprises a cleavable linker, wherein the cleavable linker comprises a β-glucuronidase-cleavable β-glucuronide.

[0132] Useful linkers include those described herein. In certain embodiments, the first and second linker is independently any divalent or multivalent linker known to those of skill in the art. Useful divalent linkers include alkylene, substituted alkylene, heteroalkylene, substituted heteroalkylene, arylene, substituted arylene, heteroarlyene, and substitutedheteroarylene. In certain embodiments, the first and / or second linker is C1-10alkylene or C1-10heteroalkylene. In some embodiments, the C1-10heteoalkylene is PEG.

[0133] In certain embodiments, the first and / or second linker is hydrolytically stable. Hydrolytically stable linkages means that the linkages are substantially stable in water and do not react with water at useful pH values, including but not limited to, under physiological conditions for an extended period of time, perhaps even indefinitely. In certain embodiments, the first and / or second linker is hydrolytically unstable. Hydrolytically unstable or degradable linkages mean that the linkages are degradable in water or in aqueous solutions, including for example, blood. Enzymatically unstable or degradable linkages mean that the linkage can be degraded by one or more enzymes.

[0134] As understood in the art, PEG and related polymers may include degradable linkages in the polymer backbone or in the linker group between the polymer backbone and one or more of the terminal functional groups of the polymer molecule. For example, ester linkages formed by the reaction of PEG carboxylic acids or activated PEG carboxylic acids with alcohol groups on a biologically active agent generally hydrolyze under physiological conditions to release the agent.

[0135] Other hydrolytically degradable linkages include, but are not limited to, carbonate linkages; imine linkages resulted from reaction of an amine and an aldehyde; phosphate ester linkages formed by reacting an alcohol with a phosphate group; hydrazone linkages which are reaction product of a hydrazide and an aldehyde; acetal linkages that are the reaction product of an aldehyde and an alcohol; orthoester linkages that are the reaction product of a formate and an alcohol; peptide linkages formed by an amine group, including but not limited to, at an end of a polymer such as PEG, and a carboxyl group of a peptide; and oligonucleotide linkages formed by a phosphoramidite group, including but not limited to, at the end of a polymer, and a 5' hydroxyl group of an oligonucleotide.

[0136] A number of different cleavable linkers are known to those of skill in the art. See U.S. Pat. Nos.4,618,492; 4,542,225, and 4,625,014. The mechanisms for release of an agent from these linker groups include, for example, irradiation of a photolabile bond and acid-catalyzed hydrolysis. U.S. Pat. No.4,671,958, for example, includes a description of immunoconjugates comprising linkers which are cleaved at the target site in vivo by the proteolytic enzymes of the patient's complement system. The length of the linker may be predetermined or selected depending upon a desired spatial relationship between the polypeptide and the molecule linked to it. In view of the large number of methods that have been reported for attaching a variety of radiodiagnostic compounds, radiotherapeuticcompounds, drugs, toxins, and other agents to polypeptides one skilled in the art will be able to determine a suitable method for attaching a given agent to a polypeptide.

[0137] The linkers described herein may have a wide range of molecular weight or molecular length. Larger or smaller molecular weight linkers may be used to provide a desired spatial relationship or conformation between the polypeptide and the linked entity. Linkers having longer or shorter molecular length may also be used to provide a desired space or flexibility between the polypeptide and the linked entity. Similarly, a linker having a particular shape or conformation may be utilized to impart a particular shape or conformation to the polypeptide or the linked entity, either before or after the polypeptide reaches its target. The functional groups present on each end of the linker may be selected to modulate the release of a polypeptide or a payload under desired conditions. This optimization of the spatial relationship between the polypeptide and the linked entity may provide new, modulated, or desired properties to the molecule.

[0138] In some embodiments, provided herein are water-soluble bifunctional linkers that have a dumbbell structure that includes: a) an azide, an alkyne, a hydrazine, a hydrazide, a hydroxylamine, or a carbonyl-containing moiety on at least a first end of a polymer backbone; and b) at least a second functional group on a second end of the polymer backbone. The second functional group can be the same or different as the first functional group. The second functional group, in some embodiments, is not reactive with the first functional group. In some embodiments, water-soluble compounds that comprise at least one arm of a branched molecular structure are provided. For example, the branched molecular structure can be a dendritic structure.

[0139] In some embodiments, the first and / or second linker is independently derived from a linker precursor selected from the group consisting of: N-succinimidyl-3-(2- pyridyldithio)propionate (SPDP), N-succinimidyl 4-(2-pyridyldithio)pentanoate (SPP), N- succinimidyl 4-(2-pyridyldithio)butanoate (SPDB), N-succinimidyl-4-(2-pyridyldithio)-2- sulfo-butanoate (sulfo-SPDB), N-succinimidyl iodoacetate (SIA), N-succinimidyl(4- iodoacetyl)aminobenzoate (SIAB), maleimide PEG NHS, N-succinimidyl 4- (maleimidomethyl)cyclohexanecarboxylate (SMCC), N-sulfosuccinimidyl 4- (maleimidomethyl)cyclohexanecarboxylate (sulfo-SMCC) or 2,5-dioxopyrrolidin-1-yl 17- (2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-5,8,11,14-tetraoxo-4,7,10,13-tetraazaheptadecan-1- oate (CX1-1). In a specific embodiment, the linker is derived from the linker precursor N- succinimidyl 4-(maleimidomethyl)cyclohexanecarboxylate (SMCC).

[0140] In some embodiments, the first and / or second linker is derived from a linker precursor selected from the group consisting of dipeptides, tripeptides, tetrapeptides, and pentapeptides. In such embodiments, the linker can be cleaved by a protease. Exemplary dipeptides include, but are not limited to, valine-citrulline (vc or val-cit), alanine-phenylalanine (af or ala-phe); phenylalanine-lysine (fk or phe-lys); phenylalanine-homolysine (phe-homolys); and N-methyl-valine-citrulline (Me-val-cit). Exemplary tripeptides include, but are not limited to, glycine-valine-citrulline (gly-val-cit), glycine-glycine-glycine (gly-gly-gly), and glycine- methoxyethoxyethyl)serine-valine (gly-val-citalanine OMESerValAla).

[0141] In some embodiments, first and / or second linker described herein comprises a self- immolative spacer. In certain embodiments, the self-immolative spacer comprises p- aminobenzyl. In some embodiments, a p-aminobenzyl alcohol is attached to an amino acid unit via an amide bond, and a carbamate, methylcarbamate, or carbonate is made between the benzyl alcohol and the payload (Hamann et al. (2005) Expert Opin. Ther. Patents (2005) 15:1087-1103). In some embodiments, the linker comprises p-aminobenzyloxycarbonyl (PAB). Other examples of self-immolative spacers include, but are not limited to, aromatic compounds that are electronically similar to the PAB group, such as 2-aminoimidazol-5- methanol derivatives (U.S. Pat. No.7,375,078; Hay et al. (1999) Bioorg. Med. Chem. Lett. 9:2237) and ortho- or para-aminobenzylacetals. In some embodiments, spacers can be used that undergo cyclization upon amide bond hydrolysis, such as substituted and unsubstituted 4-aminobutyric acid amides (Rodrigues et al. (1995) Chemistry Biology 2:223), appropriately substituted bicyclo[2.2.1] and bicyclo[2.2.2] ring systems (Storm et al. (1972) J. Amer. Chem. Soc.94:5815) and 2-aminophenylpropionic acid amides (Amsberry, et al. (1990) J. Org. Chem.55:5867). Linkage of a drug to the α-carbon of a glycine residue is another example of a self-immolative spacer that may be useful in conjugates (Kingsbury et al. (1984) J. Med. Chem.27:1447).

[0142] In certain embodiments, linker precursors can be combined to form larger linkers. For instance, in certain embodiments, linkers comprise the dipeptide valine-citrulline and p-aminobenzyloxycarbonyl. These are also referenced as citValCit--PAB linkers.

[0143] The antibody is typically a protein comprising multiple polypeptide chains. In certain embodiments, the antibody is a heterotetramer comprising two identical light (L) chains and two identical heavy (H) chains. Each light chain can be linked to a heavy chain by one covalent disulfide bond. Each heavy chain can be linked to the other heavy chain by one or more covalent disulfide bonds. Each heavy chain and each light chain can also have one or more intrachain disulfide bonds. As is known to those of skill in the art, each heavy chaintypically comprises a variable domain (VH) followed by a number of constant domains. Each light chain typically comprises a variable domain at one end (VL) and a constant domain. As is known to those of skill in the art, antibodies typically have selective affinity for their target molecules, i.e., antigens.

[0144] The antibodies provided herein can have any antibody form known to those of skill in the art. They can be full-length, or fragments. Exemplary full-length antibodies include IgA, IgA1, IgA2, IgD, IgE, IgG, IgG1, IgG2, IgG3, IgG4, IgM, and etc. Exemplary fragments include Fv, Fab, Fc, scFv, scFv-Fc, etc.

[0145] In certain embodiments, the antibody of the conjugate comprises one, two, three, four, five, or six of the CDR sequences described herein. In certain embodiments, the antibody of the conjugate comprises a heavy chain variable domain (VH) described herein. In certain embodiments, the antibody of the conjugate comprises a light chain variable domain (VL) described herein. In certain embodiments, the antibody of the conjugate comprises a heavy chain variable domain (VH) described herein and a light chain variable domain (VL) described herein. In certain embodiments, the antibody of the conjugate comprises a paired heavy chain variable domain and a light chain variable domain described herein (VH - VL pair). In certain embodiments, the antibody of the conjugate comprises a three heavy chain CDRs and three light chain CDRs with sequences consisting of the heavy chain and light chain CDRs of any paired heavy chain variable domain and a light chain variable domain described herein (six CDRs of any VH- VLpair).

[0146] In certain embodiments, the antibody of the conjugate comprises any of the amino acid sequences of the antibodies described herein. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 10 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 9 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 8 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 7 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 6 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 5 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 4 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 3 amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 2 amino acidsubstitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 1 conservative amino acid substitution. In some embodiments, the amino acid substitutions are conservative amino acid substitutions. For example, in certain embodiments, the antibody comprises any of the amino acid sequences above with up to 10 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 9 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 8 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 7 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 6 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 5 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 4 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 3 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 2 conservative amino acid substitutions. In certain embodiments, the antibody comprises any of the amino acid sequences above with up to 1 conservative amino acid substitution.

[0147] In certain embodiments, the antibody conjugate can be formed from an antibody that comprises one or more reactive groups. In certain embodiments, the antibody conjugate can be formed from an antibody comprising all naturally encoded amino acids. Those of skill in the art will recognize that several naturally encoded amino acids include reactive groups capable of conjugation to a payload or to a linker. These reactive groups include cysteine side chains, lysine side chains, and amino-terminal groups suitable for conjugation. In these embodiments, the antibody conjugate can comprise a payload or linker linked to the residue of an antibody reactive group. In these embodiments, the payload precursor or linker precursor comprises a reactive group capable of forming a bond with an antibody reactive group. Typical reactive groups include maleimide groups, activated carbonates (including but not limited to, p-nitrophenyl ester), activated esters (including but not limited to, N- hydroxysuccinimide, p-nitrophenyl ester, and aldehydes). Particularly useful reactive groups include maleimide and succinimide, for instance N-hydroxysuccinimide, for forming bonds to cysteine and lysine side chains. Additional reactive groups include alkynes, for example strained alkynes, azides, and aminooxy groups, for forming bonds to non-natural amino acidsincorporated in antibody polypeptide chains. Further reactive groups are described in the sections and examples below.

[0148] In certain embodiments, the antibody comprises one or more modified amino acids or non-natural amino acids having a reactive group, as described herein. Typically, the modified amino acid is not a naturally encoded amino acid. These modified amino acids can comprise a reactive group useful for forming a covalent bond to a linker precursor or to a payload precursor. One of skill in the art can use the reactive group to link the polypeptide to any molecular entity capable of forming a covalent bond to the modified amino acid. Thus, provided herein are conjugates comprising an antibody comprising a modified amino acid residue linked to a payload directly or indirectly via a linker. Exemplary modified amino acids are described in the sections below. Generally, the modified amino acids have reactive groups capable of forming bonds to linkers or payloads with complementary reactive groups.

[0149] The non-natural or modified amino acids are positioned at select locations in a polypeptide chain of the antibody. These locations were identified as providing optimum sites for substitution with the non-natural or modified amino acids. Each site is capable of bearing a non-natural or modified amino acid with optimum structure, function and / or methods for producing the antibody.

[0150] In certain embodiments, a site-specific position for substitution provides an antibody that is stable. Stability can be measured by any technique apparent to those of skill in the art.

[0151] In certain embodiments, a site-specific position for substitution provides an antibody that has optimal functional properties. For instance, the antibody can show little or no loss of binding affinity for its target antigen compared to an antibody without the site-specific non- natural or modified amino acid. In certain embodiments, the antibody can show enhanced binding compared to an antibody without the site-specific non-natural or modified amino acid.

[0152] In certain embodiments, a site-specific position for substitution provides an antibody that can be made advantageously. For instance, in certain embodiments, the antibody shows advantageous properties in its methods of synthesis, discussed below. In certain embodiments, the antibody can show little or no loss in yield in production compared to an antibody without the site-specific non-natural amino acid. In certain embodiments, the antibody can show enhanced yield in production compared to an antibody without the site- specific non-natural or modified amino acid. In certain embodiments, the antibody can show little or no loss of tRNA suppression compared to an antibody without the site-specific non- natural or modified amino acid. In certain embodiments, the antibody can show enhancedtRNA suppression in production compared to an antibody without the site-specific non- natural or modified amino acid.

[0153] In certain embodiments, a site-specific position for substitution provides an antibody that has advantageous solubility. In certain embodiments, the antibody can show little or no loss in solubility compared to an antibody without the site-specific non-natural or modified amino acid. In certain embodiments, the antibody can show enhanced solubility compared to an antibody without the site-specific non-natural or modified amino acid.

[0154] In certain embodiments, a site-specific position for substitution provides an antibody that has advantageous expression. In certain embodiments, the antibody can show little or no loss in expression compared to an antibody without the site-specific non-natural or modified amino acid. In certain embodiments, the antibody can show enhanced expression compared to an antibody without the site-specific non-natural or modified amino acid.

[0155] In certain embodiments, a site-specific position for substitution provides an antibody that has advantageous folding. In certain embodiments, the antibody can show little or no loss in proper folding compared to an antibody without the site-specific non-natural or modified amino acid. In certain embodiments, the antibody can show enhanced folding compared to an antibody without the site-specific non-natural or modified amino acid.

[0156] In certain embodiments, a site-specific position for substitution provides an antibody that is capable of advantageous conjugation. As described below, several non-natural or modified amino acids have side chains or functional groups that facilitate conjugation of the antibody to a second agent, either directly or via a linker. In certain embodiments, the antibody can show enhanced conjugation efficiency compared to an antibody without the same or other non-natural or modified amino acids at other positions. In certain embodiments, the antibody can show enhanced conjugation yield compared to an antibody without the same or other non-natural or modified amino acids at other positions. In certain embodiments, the antibody can show enhanced conjugation specificity compared to an antibody without the same or other non-natural or modified amino acids at other positions.

[0157] The one or more non-natural or modified amino acids are located at selected site- specific positions in at least one polypeptide chain of the antibody. The polypeptide chain can be any polypeptide chain of the antibody without limitation, including either light chain or either heavy chain. The site-specific position can be in any domain of the antibody, including any variable domain and any constant domain.

[0158] In certain embodiments, the antibodies provided herein comprise one non-natural or modified amino acid at a site-specific position. In certain embodiments, the antibodiesprovided herein comprise two non-natural or modified amino acids at site-specific positions. In certain embodiments, the antibodies provided herein comprise three non-natural or modified amino acids at site-specific positions. In certain embodiments, the antibodies provided herein comprise more than three non-natural or modified amino acids at site- specific positions. In certain embodiments, the antibodies provided herein comprise four non- natural or modified amino acids at site-specific positions.

[0159] In certain embodiments, the antibodies provided herein comprise one or more non- natural or modified amino acids each at a position selected from the group consisting of heavy chain or light chain residues HC-F404, HC-K121, HC-Y180, HC-F241, HC-221, LC- T22, LC-S7, LC-N152, LC-K42, LC-E161, LC-D170, HC-S136, HC-S25, HC-A40, HC- S119, HC-S190, HC-K222, HC-R19, HC-Y52, or HC-S70 according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise one or more non-natural or modified amino acids each at a position selected from the group consisting of heavy chain or light chain residues HC-F404, HC-Y180, HC-F241, LC-K42, and LC-E161, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise one or more non-natural or modified amino acids each at a position selected from the group consisting of heavy chain or light chain residues HC-F404, HC-F241, and LC-K42, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise one or more non-natural or modified amino acids each at a position selected from the group consisting of heavy chain or light chain residues HC-F404 and HC-F241, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-F404 and HC- F241, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise one or more non-natural or modified amino acids each at a position selected from the group consisting of heavy chain or light chain residues HC-F404 and LC-K42, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise one or more non-natural or modified amino acids each at a position selected from the group consisting of heavy chain or light chain residues HC-F241 and LC-K42, according to the Kabat or Chothia or EUnumbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise a non-natural or modified amino acid at position HC-F404 according to the Kabat or Chothia or EU numbering scheme, or a post- translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise a non-natural or modified amino acid at position HC-F241 according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise a non-natural or modified amino acid at position HC-Y180, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC- F404 and HC-Y180, according to the Kabat or Chothia or EU numbering scheme, or a post- translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise a non-natural or modified amino acid at position HC-F241 according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise a non-natural or modified amino acid at position LC-K42 according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise a non-natural or modified amino acid at position LC-E161 according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC-F404, HC-Y180, and LC-K42, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC-F404, HC-Y180, LC-K42, and LC- E161, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC-F404, HC-Y180, and HC-F241, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC-F404, HC-Y180, HC-F241, and LC- K42, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof. In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC-F404, HC-Y180, HC-F241, and LC- K42, according to the Kabat or Chothia or EU numbering scheme, or a post-translationallymodified variant thereof. In these designations, HC indicates a heavy chain residue, and LC indicates a light chain residue.

[0160] In some embodiments, the Fc comprises one or more modifications in at least one of the CH3sequences. In some embodiments, the Fc comprises one or more modifications in at least one of the CH2 sequences. For example, the Fc can include one or modifications selected from the group consisting of: V262E, V262D, V262K, V262R, V262S, V264S, V303R, and V305R. In some embodiments, the modification is V264S. In some embodiments, an Fc is a single polypeptide. In some embodiments, an Fc is multiple peptides, e.g., two polypeptides. Exemplary modifications in the Fc region are described, for example, in International Patent Application No. PCT / US2017 / 037545, filed June 14, 2017.

[0161] In certain embodiments, the antibodies provided herein comprise non-natural or modified amino acids at positions HC-A118, HC-T120, HC-K121, HC-G138, HC-A140, HC- T155, HC-S160, HC-A162, HC-L163, HC-Q196, HC-I199, HC-N203, HC-T209, HC-K210, HC-E258, HC-K290, HC-Y296, HC-T335, HC-I336, HC-S337, HC-R344, HC-E345, HC- R355, HC-M358, HC-Q362, HC-E382, HC-E388, HC-N390, HC-Y391, HC-K392, HC- T393, HC-T411, HC- N421, HC-S424, HC-Q438, HC-L443 according to EU index of Kabat, LC-T109, LC-V110, LC-A111, LC-A112, LC-D122, LC-Q124, LC-K126, LC-S127, LC- T129, LC-N138, LC-R142, LC-E143, LC-Q147, LC-K149, LC-D151, LC-A153, LC-L154, LC-Q155, LC-S159, LC-E165, LC-Q166, LC-S168, LC-K169, LC-S171, LC-T172, LC- T180, LC-A184, LC-E187, LC-H189, LC-K190, LC-V191, LC-E195, LC-L201, LC-S202, LC-S203, LC-V205, and LC-T206 according to Kabat numbering.

[0162] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-S113, HC-A113, HC-T118, HC-T120, HC-K121, HC-G138, HC-A140, HC-T155, HC-S160, HC-A162, HC-L163, HC-Y180, HC-Q196, HC-I199, HC- N203, HC-T209, HC-K210, HC-K222, HC-F241, HC-E258, HC-K290, HC-Y296, HC-T335, HC-I336, HC-S337, HC-R344, HC-E345, HC-R355, HC-M358, HC-Q362, HC-E382, HC- E388, HC-N390, HC-Y391, HC-K392, HC-T393, HC-Y404, HC-T411, HC-N421, HC-S424, HC-Q438, HC-L443, LC-K42, LC-Q42, LC-T109, LC-V110, LC-A111, LC-A112, LC- D122, LC-Q124, LC-K126, LC-S127, LC-T129, LC-N138, LC-R142, LC-E143, LC-Q147, LC-K149, LC-D151, LC-A153, LC-L154, LC-Q155, LC-S159, LC-E161, LC-E165, LC- Q166, LC-S168, LC-K169, LC-D170, LC-S171, LC-T172, LC-T180, LC-A184, LC-E187, LC-H189, LC-K190, LC-V191, LC-E195, LC-L201, LC-S202, LC-S203, LC-V205, or LC- T206, according to the Kabat or Chothia or EU numbering scheme, or a post-translationallymodified variant thereof. In certain embodiments, the antibodies provided herein comprise at least eight non-natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues LC-K42 and HC-Y391.

[0163] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-K121, HC-Y180, HC-F241, HC-221, HC-Y391, LC-T22, LC-S7, LC-N152, LC-K42, LC-E161, LC-D170, HC-S136, HC-S25, HC-A40, HC- S119, HC-S190, HC-K222, HC-R19, HC-Y52, and HC-S70 according to the Kabat, EU, or Chothia numbering scheme.

[0164] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-404, HC-180, HC-391, HC-241, LC-42, LC-161, LC-170, according to the Kabat, EU, or Chothia numbering scheme.

[0165] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-Y180, HC-F241, HC-F404 and HC-Y391, according to the Kabat, EU, or Chothia numbering scheme.

[0166] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-Y391, HC-Y180, and LC-42, according to the Kabat, EU, or Chothia numbering scheme.

[0167] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-Y391, HC-Y180, and LC-42, according to the Kabat, EU, or Chothia numbering scheme.

[0168] In certain embodiments, the antibodies provided herein comprise at least eight non- natural or modified amino acids at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-Y391, HC-Y180, HC-F241, and LC-42, according to the Kabat, EU, or Chothia numbering scheme.

[0169] In some embodiments, the antibody conjugate is of Formula I:Formula (I)or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein Ab is the antibody or antigen-binding fragment thereof; Lais the first linker; Lbis the second linker; PA1 is the first payload, wherein the first payload is a topoisomerase inhibitor; PA2is the second payload, wherein the second payload is a cytotoxic agent; subscript n is an integer selected from 1 to 10; and subscript m is an integer selected from 1 to 10.

[0170] In some embodiments of Formula (I), the first payload is a topoisomerase inhibitor. The topoisomerase inhibitor is a topoisomerase I inhibitor or a topoisomerase II inhibitor. The topoisomerase I inhibitor can be selected from the group consisting of camptothecin, SN- 38, exatecan, irinotecan, topotecan, govitecan, deruxtecan, belotecan, and derivatives thereof. In an embodiment, the topoisomerase I inhibitor is exatecan. In an embodiment, the topoisomerase inhibitor is a topoisomerase II inhibitor. The topoisomerase II inhibitor can be selected from the group consisting of amonafide, azonafide-PEABA, etoposide, teniposide, tafluposide, and derivatives thereof.

[0171] The second payload residue is a cytotoxic agent. The cytotoxic agent can be selected from the group consisting of a DNA-targeting agent, a tubulin-targeting agent, a histone- deacetylase (HDAC) inhibitor, NMT inhibitor, an anti-mitotic agent, an alkylating agent, a DNA-crosslinking agent, an anti-tumor antibiotic, an anti-metabolite, a telomerase inhibitor and an immunogenic cell death agent. In an embodiment, the cytotoxic agent is not a DNA damage response (DDR) inhibitor. In an embodiment, the cytotoxic agent is an anthracycline selected from doxorubicin, mitoxantrone, etoposide, idarubicin, pirarubicin (P-THP), PNU, PNU analogs, and derivatives thereof. The cytotoxic agent can be a tubulin-targeting agent selected from a hemiasterlin, monomethyl auristatin-E (MMAE), monomethyl auristatin-F (MMAF), DM1, DM4, and derivatives thereof. In an embodiment, the cytotoxic agent is hemiasterlin. In an embodiment, the hemiasterlin is 3-aminophenyl hemiasterlin. In some embodiments, the cytotoxic agent is MMAE. In an embodiment, the cytotoxic agent is a microtubule dynamics inhibitor. In an embodiment, the microtubule dynamics inhibitor is eribulin.

[0172] In an embodiment, the first payload is exatecan and the second payload is hemiasterlin. In an embodiment, the first payload is exatecan and second payload is MMAE.In an embodiment, the first payload is a topoisomerase I inhibitor and second payload is a topoisomerase II inhibitor.

[0173] In some embodiments of Formula (I), including any of the foregoing, linker Laand Lbindependently comprise a protease cleavable linker, an enzyme cleavable linker, a pH- sensitive linker, or a non-cleavable linker.

[0174] In certain embodiments, the antibody conjugate of Formula (I) is represented by Formula (Ia):Formula (Ia) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein: Ab is the antibody or antigen-binding fragment thereof; PA1is the first payload, wherein the first payload is a topoisomerase inhibitor; PA2is the second payload, wherein the second payload is a cytotoxic agent; each SP1, SP2, and SP3are independently, at each occurrence, absent or a divalent spacer group; each W1is independently, at each occurrence, absentwherein the -NH- is bound to W2; and eachindicates a point of attachment to the rest of the formula; L1is independently a bond or an optionally substituted C1-6alkylene wherein the C1-6alkylene is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy; each W2is independently, at each occurrence, absent, an amino acid residue, or a peptide residue wherein the amino acid residue or peptide residue is optionally substituted with a HP2group; each HP1, is independently, at each occurrence, absent or a divalent hydrophilic group; each HP2, when present, is a monovalent hydrophilic group;each RAis independently, at each occurrence, optionally substituted C1-6alkyl wherein the C1-6alkyl is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy; each RT is independently, at each occurrence, absent or a release trigger group; each RL is a reactive linker; y is an integer independently selected from 0, 1, and 2; and z is an integer independently selected from 0 and 1.

[0175] In certain embodiments, the antibody conjugate of Formula (I) is represented by Formula (Ib):Formula (Ib) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein: L2is -C1-6 alkylene-; Y is –X1-C1-6 alkylene-[X1-C1-6 alkylene]a-[X1]b–, –X1-C2-6alkenylene-[X1-C2-6alkenylene]a-[X1]b–, or –X1-C2-6 alkynylene-[X1-C2-6 alkynylene]a-[X1]b–, wherein at least one alkylene, alkenylene, or alkynylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene, alkenylene, or alkynylene in Y is optionally substituted with one or more substituents selected from R51; R50is –C1-6 alkylene-X2-[C1-6 alkylene]c-HP2, –C2-6 alkenylene-X2-[C2-6 alkenylene]c- HP2, or –C2-6alkynylene-X2-[C2-6alkynylene]c- HP2, wherein each alkylene, alkenylene, or alkynylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12- membered heterocycle, and C1-10haloalkyl;R51is independently selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, C3-12 carbocycle, 3- to 12-membered heterocycle, and C1-10 haloalkyl; X1and X2are independently selected from –N(R10)–, –C(O)–, and – N(R10)C(O)–; R10is independently selected at each occurrence from hydrogen, C1-10 alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10 haloalkyl; a is an integer selected from zero, one, two, and three; b is an integer selected from zero and one; c is an integer selected from zero and one; Su is a hexose form of a monosaccharide; and PA1, PA2, SP1, W1, W2, HP1, HP2, SP3, RL, Ab, and TOPOi are as defined in Formula (Ia).

[0176] In certain embodiments, the antibody conjugate of Formula (Ib) is represented by Formula (Ib-A):Formula (Ib-A) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof.

[0177] In certain embodiments, the antibody conjugate of Formula (Ib) is represented by Formula (Ib-B):Formula (Ib-B)or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof

[0178] In certain embodiments, SP2and SP3are divalent attaching groups that facilitate incorporation of eliminator groups, release trigger groups, hydrophobic groups, spacer groups, and / or the conjugating group into a compound. Spacer groups that facilitate the spacing of the conjugating group from the other groups of the compounds can lead to more efficient conjugation of the compounds described herein to a second compound as well as more efficient cleavage of the active catabolite. Spacer group can also stabilize the conjugating group and lead to improved overall antibody-drug conjugate properties. Useful attaching groups are known to, and are apparent to, those of skill in the art. Examples of useful attaching groups are provided herein. In certain embodiments, an attaching group can comprise a divalent ketone, divalent ester, divalent ether, divalent amide, divalent amine, alkylene, arylene, sulfide, disulfide, carbonylene, or a combination thereof. In certain embodiments an attaching group can comprise –C(O)–, –O–, –C(O)NH–, –C(O)NH-alkyl–, –OC(O)NH–, –SC(O)NH–, –NH–, –NH-alkyl–, –C(O)N(CH3)–, –C(O)N(CH3)-alkyl–, –N(CH3)–,–N(CH3)-alkyl–, –N(CH3)CH2CH2N(CH3)–, –C(O)CH2CH2CH2C(O)–, –S–, –S- S–, –OCH2CH2O–, or the reverse (e.g. –NHC(O)–) thereof, or a combination thereof.

[0179] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), SP1and SP3are independently absent or selected from C1-6alkylene-; -C(O)-, C1-6alkylene-C(O)- wherein the -C(O)- is bound to W2or HP1, respectively; -C(O)-C1-6alkylene- C(O)-; -C(O)(C1-6alkylene)NR1C(O)-; -C(O)(C1-6alkylene)OC(O)-; and -C(O)(C1- 6alkylene)SC(O)-; wherein R1is hydrogen or optionally substituted C1-6alkyl and the C1- 6alkylene, alone or part of another group, is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy.

[0180] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- wherein the -C(O)- is bound to W2. In certain embodiments of Formula (Ia), including any of the foregoing, SP2is independently C1-6alkylene-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently C1-2alkylene-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B) including any of the foregoing, SP2is independently C3- 4alkylene-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently C5-6alkylene-C(O)-. Incertain embodiments of Formula (Ia), including any of the foregoing, SP2is independently - CH2-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently -CH2CH2-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently -(CH2)5-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is absent.

[0181] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP3is independently absent or -C(O)-C1-6alkylene- C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP3is absent. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP3is independently -C(O)-C1-6alkylene-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP3is independently -C(O)-C1-4alkylene-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP3is independently -C(O)-C4alkylene-C(O)-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP3is independently -C(O)(C1-6alkylene)NR1C(O)- wherein R1is hydrogen.

[0182] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- and SP3is independently absent or -C(O)-C1-6alkylene-C(O)- wherein the -C(O)- of SP2is bound to W2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- and SP3is absent wherein the -C(O)- of SP2is bound to W2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- wherein the -C(O)- of SP2is bound to W2; SP3is independently absent or -C(O)-C1-6alkylene-C(O)-; and SP1is absent.

[0183] In certain embodiments, SP1is a divalent attaching group that facilitates incorporation and the release of the payload. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP1is independently absent or selected from -NR5CH2- and -NR4-arylene-CH2- wherein R5is C1-6alkyl-OCH3 and R4is hydrogen or C1-6 alkyl. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP1is absent. In certainembodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP1is independently -NR5CH2-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP1is - N(CH2CH2OCH3)CH2-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib- A), or Formula (Ib-B), including any of the foregoing, SP1is independently -NR4-arylene- CH2-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib- B), including any of the foregoing, SP1is independently -NH-arylene-CH2-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP1is; and eachis the point of attachment to the rest of the compound.

[0184] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- wherein the -C(O)- of SP2is bound to W2and SP1is absent. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- wherein the -C(O)- of SP2is bound to W2and SP1is independently selected from -NR5CH2- and -NR4-arylene-CH2-.

[0185] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is C2alkylene-C(O)- and SP1is - N(CH2CH2OCH3)CH2- wherein the -C(O)- of SP2is bound to W2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is C2alkylene-C(O)- and SP1is wherein the -C(O)- of SP2is bound to W2.

[0186] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, SP2is independently absent or C1-6alkylene-C(O)- wherein the -C(O)- of SP2is bound to W2; SP3is independently absent or -C(O)-C1-6alkylene-C(O)-; and SP1is independently absent or is selected from -NR5CH2- and -NR4- arylene-CH2-.

[0187] In certain embodiments, W1is an eliminator group. Eliminator groups facilitate separation of a biologically active portion of a compound or conjugate described herein from the remainder of the compound or conjugate in vivo and / or in vitro. Eliminator groups canalso facilitate separation of a biologically active portion of a compound or conjugate described herein in conjunction with a release trigger group. For example, the eliminator group and the release trigger group can react in a Releasing Reaction to release a biologically active portion of a compound or conjugate described herein from the compound or conjugate in vivo and / or in vitro. Upon initiation of the Releasing Reaction by the release trigger, the eliminator group cleaves the biologically active moiety, or a prodrug form of the biologically active moiety, and forms a stable, non-toxic entity that has no further effect on the activity of the biologically active moiety.

[0188] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W1is independently.

[0189] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, z is 0. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, z is 1. When z is 1, the conjugate comprises a release trigger group, designated as RT herein, which facilitates the separation of a biologically active portion of a compound or conjugate described herein from the remainder of the compound or conjugate in vivo and / or in vitro. Release trigger groups can also facilitate separation of a biologically active portion of a compound or conjugate described herein in conjunction with an eliminator group. For example, the eliminator group and the release trigger group can react in a Releasing Reaction to release a biologically active portion of a compound or conjugate described herein from the compound or conjugate in vivo and / or in vitro. In certain embodiment, the release trigger can act through a biologically-driven reaction with high tumor:nontumor specificity, such as the proteolytic action of an enzyme overexpressed in a tumor environment.

[0190] Hydrophilic groups, designated HP1and HP2herein, facilitate increasing the hydrophilicity of the compounds described herein. It is believed that increased hydrophilicity allows for greater solubility in aqueous solutions, such as aqueous solutions found in biological systems. Hydrophilic groups can also function as spacer groups, which are described in further detail herein. Useful hydrophilic groups include those described herein. In certain embodiments, HP1is independently a divalent poly(ethylene glycol). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), includingany of the foregoing, HP1is independentlywherein R2is hydrogen or methyl and x1 is an integer between 1 and 50, inclusive; and eachis the point of attachment to the rest of the compound. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib- A), or Formula (Ib-B), including any of the foregoing, R2is hydrogen. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, R2is methyl.

[0191] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, x1 is independently an integer between 1 and 10, inclusive. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, x1 is independently an integer between 1 and 5, inclusive. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, x1 is 4.

[0192] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, x1 is independently an integer between 1 and 10, inclusive, and R2is hydrogen. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, x1 is independently an integer between 1 and 5, inclusive, and R2is hydrogen. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, x1 is 4 and R2is hydrogen.

[0193] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP1is absent.

[0194] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, RT is a β-glucuronidase-cleavable β-glucuronide. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing,whereinis the point of attachment to the rest of the compound. In certain embodiments of Formula (Ia), Formula(Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, RT is.

[0195] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W1is independently. embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W1is independently. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, y is 0. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, y is 1. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, y is 2.

[0196] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, L1is independently a bond. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, L1is independently unsubstituted C1-6alkylene. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, L1is independently an optionally substituted C1-6alkylene wherein the C1-6alkylene is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy.

[0197] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, RAis independently, at each occurrence, unsubstituted C1-6alkyl. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, RAis independently, at each occurrence, methyl. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, RAis independently, at each occurrence, methyl and y is 1. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, RAis independently, at each occurrence, C1-6alkyl optionallysubstituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy.

[0198] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W1is independently absent,,. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W1is absent. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing,. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W1is. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib- A), or Formula (Ib-B), including any of the foregoing,. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing,. certain embodiments of Formula (Ia), including any of the foregoing,. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including anyof the foregoing,. certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, W1is independently absent,

[0199] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is absent. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently an amino acid residue or a peptide residue wherein the amino acid residue or the peptide residue is optionally substituted with HP2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently an unsubstituted amino acid residue. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently an amino acid residue wherein the amino acid residue is substituted with HP2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently an unsubstituted peptide residue. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently a peptide residue wherein the peptide residue is substituted with HP2.

[0200] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently a peptide residue, and the peptide residue comprises at least one non-natural amino acid. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, W2is independently a peptide residue, and the peptide residue comprises one non-natural amino acid. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib- B), including any of the foregoing, W2is independently a peptide residue, and the peptide residue comprises two non-natural amino acid. In certain embodiments of Formula (Ia),Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently a peptide residue, and the peptide residue comprises at least one non-natural amino acid and the peptide residue is optionally substituted with HP2.

[0201] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, the at least one non-natural amino acid is selected from 3-sulfoalanine, hydroxyproline (Hyp), citrulline (Cit), ornithine (Orn), norleucine (Nle), 3- nitrotyrosine, nitroarginine, pyroglutamic acid (Pyr), naphtylalanine (Nal), 2,4- diaminobutyric acid (DAB), methionine sulfoxide, methionine sulfone, and 2,3- diaminopropionate. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the at least one non-natural amino acid is selected from 3-sulfoalanine, citrulline (Cit), 2,3-diaminopropionate, and beta-alanine.

[0202] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently a peptide residue wherein the peptide residue is optionally substituted with HP2and the peptide residue comprises valine, citrulline (Cit), 3-sulfoalanine, alanine, 2,3-diaminopropionate, or beta-alanine.

[0203] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises citrulline (Cit). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises beta-alanine. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises 2,3-diaminopropionate.

[0204] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises citrulline (Cit) and 3- sulfoalanine. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises beta-alanine and 2,3-diaminopropionate.

[0205] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises valine and citrulline (Cit). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib- B), including any of the foregoing, the peptide residue comprises valine, citrulline (Cit), and 3-sulfoalanine. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises valine and alanine. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises valine, citrulline (Cit),and 2,3-diaminopropionate. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, the peptide residue comprises beta- alanine and 2,3-diaminopropionate.

[0206] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently an amino acid residue wherein the amino acid residue is optionally substituted with HP2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently an amino acid residue and the amino acid residue is a beta-amino acid. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently beta-alanine.

[0207] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently selected from -(C(O)CHR3NR4)a-, -(C(O)CH2CHR3NR4)b-, -(C(O)CHR3CH2NR4)b-, -(C(O)CH2CHR3NR4)b-(C(O)CHR3NR4)a-, -(C(O)CHR3CH2NR4)b-(C(O)CHR3NR4)a-, -(C(O)CHR3NR4)a-(C(O)CH2CHR3NR4)b-, and -(C(O)CHR3NR4)a-(C(O)CHR3CH2NR4)b-; wherein R3is independently an amino acid sidechain residue optionally substituted with HP2; R4is independently hydrogen or C1-6 alkyl; each of a and b is an integer independently between 1 and 10, inclusive; and the - C(O)- of W2is bound to W1.

[0208] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CHR3NR4)a-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CHR3NH)a- wherein a is 1. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CHR3NH)a- wherein a is 2. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CHR3NH)a- wherein a is 3. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CHR3NR4)a- and R3is an amino acid sidechain residue independently selected from valine, citrulline, alanine, glycine, 3- sulfoalanine and 2,3-diaminopropionate.

[0209] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CH2CHR3NR4)b-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CH2CHR3NH)-. In certain embodiments of Formula (Ia), including any of the foregoing, W2is independently -(C(O)CH2CH2NH)-.

[0210] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CH2CHR3NR4)b- (C(O)CHR3NR4)a-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CH2CHR3NH)b- (C(O)CHR3NH)a-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CH2CH2NH)- (C(O)CHR3NH)a-. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently -(C(O)CH2CH2NH)-(C(O)CHR3NH)- wherein R3is an amino acid sidechain residue independently selected from valine, citrulline, alanine, glycine, 3-sulfoalanine and 2,3- diaminopropionate.

[0211] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently of the formula:attachment to the rest of the compound.

[0212] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently of the formula:

[0213] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, W2is independently of the formula:.

[0214] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, -W1-W2- is independently of the formula:,.

[0215] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, -W1-W2- is independently of the formula:.

[0216] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is polyethylene glycol (PEG), methoxypolyethylene glycol (mPEG), poly(propylene glycol) (PPG), copolymers of ethylene glycol and propylene glycol, poly(oxyethylated polyol), poly(olefinic alcohol), poly(vinylpyrrolidone), poly(hydroxyalkylmethacrylamide), poly(hydroxyalkylmethacrylate), poly(saccharides), poly(α-hydroxy acid), poly(vinyl alcohol), polyphosphazene, polyoxazolines (POZ), poly(N-acryloylmorpholine), polysarcosine, or a combination thereof. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is polyethylene glycol (PEG). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is methoxypolyethylene glycol (mPEG). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(propylene glycol) (PPG). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is copolymers of ethylene glycol and propylene glycol. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(oxyethylatedpolyol). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(olefinic alcohol). In some embodiments, HP2is poly(vinylpyrrolidone). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(hydroxyalkylmethacrylamide). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(hydroxyalkylmethacrylate). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(saccharides). In some embodiments, HP2is poly(α-hydroxy acid). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is poly(vinyl alcohol). In some embodiments, HP2is polyphosphazene. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is polyoxazolines (POZ). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, POLY is poly(N- acryloylmorpholine). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is polysarcosine. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is a nonpeptidic, water-soluble polymer.

[0217] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is independently a monovalent poly(ethylene glycol). In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B), including any of the foregoing, HP2is independentlywherein R2is hydrogen or methyl and x2 is an integer between 1 and 50, inclusive; and eachis the point of attachment to the rest of the compound. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, R2is hydrogen. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, R2is methyl.

[0218] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, x2 is independently an integer between 1 and 20, inclusive. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, x2 is independently an integer between 10 and 20,inclusive. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, x2 is 12.

[0219] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, x2 is independently an integer between 1 and 20, inclusive, and R2is hydrogen. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, x is independently an integer between 10 and 20, inclusive, and R2is hydrogen. In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, x is 12 and R2is hydrogen.

[0220] In certain embodiments of Formula (Ia), Formula (Ib), Formula (Ib-A), or Formula (Ib-B),including any of the foregoing, W2is independently of the formula:.

[0221] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, L3is -C1-3 alkylene-. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, L3is -CH2-. In some embodiments, L3is -CH2CH2-. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, L3is -CH2CH2CH2-.

[0222] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, b is one. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-6 alkylene-[X1-C1-6 alkylene]a-X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C2-6alkenylene-[X1-C2-6 alkenylene]a-X1– wherein at least one alkenylene in Y is substituted with one or more substituents selected from R50. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C2-6alkynylene-[X1-C2-6alkynylene]a-X1– wherein at least one alkynylene in Y is substituted with one or more substituents selected from R50. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is zero. In some embodiments, a is one. In certain embodiments of Formula (Ib),(Ib-A), or (Ib-B), including any of the foregoing, a is two. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is three.

[0223] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, b is one. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-4 alkylene-[X1-C1-4 alkylene]a-X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is one. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is two. In some embodiments, a is three.

[0224] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, b is one. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-4 alkylene-X1-C1-4 alkylene-X1-C1-4 alkylene-X1-C1-4 alkylene- X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-4 alkylene-X1-C1-4 alkylene-X1-C1-4 alkylene-X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-4alkylene-X1-C1-4 alkylene-X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50

[0225] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, b is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-6alkylene-[X1-C1-6alkylene]a–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene in Y is optionally substituted with one or more substituents selected from R51. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C2-6alkenylene-[X1- C2-6alkenylene]a–, wherein at least one alkenylene in Y is substituted with one or more substituents selected from R50, and wherein the alkenylene in Y is optionally substituted with one or more substituents selected from R51. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C2-6alkynylene-[X1-C2-6alkynylene]a–, wherein at least one or alkynylene in Y is substituted with one or more substituents selected from R50, and wherein the alkynylene in Y is optionally substituted with one or more substituents selected from R51. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B),including any of the foregoing, a is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is one. In certain embodiments of Formula (Ib), (Ib- A), or (Ib-B), including any of the foregoing, a is two. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is three.

[0226] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, b is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-6alkylene-[X1-C1-6alkylene]a–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene in Y is optionally substituted with one or more substituents selected from R51. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Y is –X1-C1-4alkylene-[X1-C1-4alkylene]a–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene in Y is optionally substituted with one or more substituents selected from R51. In certain embodiments of Formula (Ib), (Ib- A), or (Ib-B), including any of the foregoing, Y is –X1-C1-4alkylene-X1-C1-4alkylene-X1-C1-4alkylene–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene in Y is optionally substituted with one or more substituents selected from R51. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is one. In certain embodiments of Formula (Ib), (Ib- A), or (Ib-B), including any of the foregoing, a is two. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, a is three. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R51is independently selected from halogen, -CN, -NO2, -OH, -NH2, -C(O)NH2, and -C(O)-. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R51is halogen. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R51is -CN. In some embodiments, R51is -NO2. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R51is -OH. In some embodiments, R51is -NH2. In some embodiments, R51is -C(O)NH2. In certain embodiments of Formula (Ib), (Ib-A), or (Ib- B), including any of the foregoing, R51is -C(O)-.

[0227] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, X1and X2are independently selected from –N(R10)–, –C(O)–, and –N(R10)C(O)–. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, X1and X2are independently selected from –NH–, –C(O)–, and –N(R10)C(O)–. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, X1and X2are independently selected from –C(O)–, and –N(R10)C(O)–. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, X1and X2are independently selected from –C(O)–, and –NHC(O)–.

[0228] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R50is –C1-6 alkylene-X2-[C1-6 alkylene]c-HP2, wherein each alkylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10alkyl, C2-10 alkenyl, C2-10 alkynyl, C3-12 carbocycle, 3- to 12-membered heterocycle, and C1-10 haloalkyl. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R50is –C1-4alkylene-X2-[C1-4alkylene]c- HP2, wherein each alkylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, C3-12 carbocycle, 3- to 12-membered heterocycle, and C1-10 haloalkyl. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, each alkylene of R50is optionally substituted with one or more substituents selected from halogen, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl. In some embodiments, c is zero. In some embodiments, c is one.

[0229] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R50is –C2-6alkenylene-X2-[C2-6alkenylene]c- HP2, wherein each alkenylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, C3-12 carbocycle, 3- to 12-membered heterocycle, and C1-10 haloalkyl. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, c is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, c is one.

[0230] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, R50is –C2-6alkynylene-X2-[C2-6alkynylene]c- HP2, wherein each alkynylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, - OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10 alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, c is zero. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, c is one.

[0231] In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Su is a sugar moiety. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, Su is a hexose form of a monosaccharide. Su may be a glucuronic acid or mannose residue. In certain embodiments of Formula (Ib), (Ib-A), or (Ib- B), including any of the foregoing,, whereinrepresents attachment to the remainder of the compound. In certain embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,, whereinrepresents attachment to the remainder of the compound.

[0232] In certain embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, RL is independently selected from the group consisting of ,attachment to the rest of the compound.

[0233] In certain embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,. certain embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, RL is. certain embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,,embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, RL is. In certain embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, RL is.

[0234] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase inhibitor is a topoisomerase I inhibitor or derivative thereof. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase I inhibitor or derivative thereof isa camptothecin derivative. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase I inhibitor or derivative thereof is independently selected from camptothecin, SN-38, exatecan, irinotecan, topotecan, govitecan, deruxtecan, belotecan. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase I inhibitor or derivative thereof is exatecan.

[0235] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase inhibitor is independently selected from the ,thereof; and eachis a point of attachment to the rest of the compound.

[0236] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase inhibitor is independently selected from the group consisting of: ,derivative thereof.

[0237] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase inhibitor is independently selected from thederivative thereof.

[0238] In an alternative embodiment of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase inhibitor is a topoisomerase II inhibitor or derivative thereof. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the topoisomerase II inhibitor or derivative thereof is independently selected from amonafide, azonafide-PEABA, etoposide, teniposide, and tafluposide.

[0239] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, each of m and n is an integer independently between 1 and 10, inclusive. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, each of m and n is an integer independently between 1 and 8, inclusive. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, each of m and n is an integer independently between 1 and 5, inclusive. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, each of m and n is an integer independently between 1 and 4, inclusive.

[0240] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, m is 2 and n is 4. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, m is 4 and n is 4. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, m is 8 and n is 4.

[0241] In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the molar ratio of m to n is 1:1. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the molar ratio of m to n is 2:1. In certain embodiments of Formula (I), Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the molar ratio of m to n is 1:2.

[0242] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,indicates attachment to the rest of the formula. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, is. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib- B), including any of the foregoing,. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,. some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, is. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,.

[0243] In some embodiments of Formula (Ia), including any of the foregoing,.

[0244] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,is selected from the group consisting of:wherein SP1, SP3, RL, R3, x1, a, b, and m are as defined herein; indicates attachment to the rest of the formula.

[0245] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing,is selected from the group consisting of,, ,, and.

[0246] In some embodiments of Formula (Ia), including any of the foregoing,wherein SP1, SP3, RL, R3, a, b, and m are as defined herein;indicates attachment to TOPOi; and indicates attachment to the rest of the formula.

[0247] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof.

[0248] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), in any of theforegoing, is selected from the group consisting of ,,,.

[0249] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), including anyof the foregoing, is selected from the group consisting of.

[0250] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof.

[0251] In some embodiments of Formula (Ia), including any of the foregoing,.

[0252] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0253] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0254] In some embodiments of Formula (Ia), including any of the foregoing,

[0255] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0256] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0257] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0258] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0259] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0260] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;.

[0261] In some embodiments of Formula (Ia), including any of the foregoing,or a mixture thereof;. Additional linker payloads and conjugates are described in PCT Application PCT / US23 / 26338 titled “β-GLUCURONIDE LINKER-PAYLOADS, PROTEIN CONJUGATES THEREOF, AND METHODS THEREOF,” which is incorporated by reference in its entirity for all purposes.

[0262] In some embodiments of Formula (Ia), including any of the foregoing,

[0263] In some embodiments of Formula (Ia), including any of the foregoing,binds to para-azidomethyl-L-phenylalanine(pAMF) at one or more sites and the other ofand binds to para-azidomethyl-L- phenylalanine (pAMF) at one or more sites.

[0264] In some embodiments of Formula (Ia), including any of the foregoing,binds to para-azidomethyl-L-phenylalanine (pAMF) at one or more sitesbinds to para-azidomethyl-L-phenylalanine (pAMF) at one or more sites. In some embodiments of Formula (Ia), including any of the foregoing,binds to para-azidomethyl-L-phenylalanine (pAMF) at HC-F241 and HC-404 andbinds to para-azidomethyl-L-phenylalanine (pAMF) at LC-K42.

[0265] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1101. In some embodiments of Formula (Ia), Formula (Ib), (Ib- A), or (Ib-B), the antibody conjugate comprises Formula 1102. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1103. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1104. In some embodiments of Formula (Ia), Formula (Ib), (Ib- A), or (Ib-B), the antibody conjugate comprises Formula 1105. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1106. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1107. In some embodiments of Formula (Ia), Formula (Ib), (Ib- A), or (Ib-B), the antibody conjugate comprises Formula 1108. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1109. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1110. In some embodiments of Formula (Ia), Formula (Ib), (Ib- A), or (Ib-B), the antibody conjugate comprises Formula 1111. In some embodiments ofFormula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1112. In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises Formula 1113. In some embodiments of Formula (Ia), Formula (Ib), (Ib- A), or (Ib-B), the antibody conjugate comprises Formula 1114.

[0266] In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1201A or 1201B or a mixture thereof.

[0267] In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1101 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1102 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1103 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1104 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1105 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1106 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1107 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1108 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1109 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1110 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1111 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1112 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1113 and Formula 1201A or 1201B or a mixture thereof. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1114 and Formula 1201A or 1201B or a mixture thereof.

[0268] In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1101 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1102 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1103 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), theantibody conjugate comprises Formula 1104 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1105 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1106 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1107 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1108 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1109 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1110 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1111 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1112 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1113 and Formula 1201A or 1201B or a mixture thereof wherein m is 2 and n is 4. In some embodiments of Formula (Ia), the antibody conjugate comprises Formula 1114 and Formula 201A or 1201B or a mixture thereof wherein m is 2 and n is 4.

[0269] In some embodiments of Formula (Ia), Formula (Ib), (Ib-A), or (Ib-B), the antibody conjugate comprises a structure selected from Formula 1101, Formula 1102, Formula 1103, Formula 1104, Formula 1105, Formula 1106, Formula 1107, Formula 1108, Formula 1109, Formula 1110, Formula 1111, Formula 1112, Formula 1113, and Formula 1114 wherein the structure binds to para-azidomethyl-L-phenylalanine (pAMF) at one or more sites.

[0270] In some embodiments of Formula (Ia), the antibody conjugate comprises a structure selected from Formula 1201A or Formula 1201B or a mixture thereof wherein the structure binds to para-azidomethyl-L-phenylalanine (pAMF) at one or more sites.

[0271] In some embodiments of Formula (Ia), the antibody conjugate comprises (a) a structure selected from Formula 1101, Formula 1102, Formula 1103, Formula 1104, Formula 1105, Formula 1106, Formula 1107, Formula 1108, Formula 1109, Formula 1110, Formula 1111, Formula 1112, Formula 1113, and Formula 1114 wherein the structure binds to para- azidomethyl-L-phenylalanine (pAMF) at one or more sites and (b) a structure selected fromFormula 201A or Formula 201B or a mixture thereof wherein the structure binds to para- azidomethyl-L-phenylalanine (pAMF).

[0272] In some embodiments of Formula (Ia), the antibody conjugate comprises (a) a structure selected from Formula 1101, Formula 1102, Formula 1103, Formula 1104, Formula 1105, Formula 1106, Formula 1107, Formula 1108, Formula 1109, Formula 1110, Formula 1111, Formula 1112, Formula 1113, and Formula 1114 wherein the structure binds to para- azidomethyl-L-phenylalanine (pAMF) at at HC-F241 and HC-404 and (b) a structure selected from Formula 1201A or Formula 1201B or a mixture thereof wherein the structure binds to para-azidomethyl-L-phenylalanine (pAMF) at LC-K42.

[0273] In some embodiments of Formula (Ia), the antibody conjugate comprises (a) a structure selected from Formula 1101, Formula 1102, Formula 1103, Formula 1104, Formula 1105, Formula 1106, Formula 1107, Formula 1108, Formula 1109, Formula 1110, Formula 1111, Formula 1112, Formula 1113, and Formula 1114 wherein the structure binds to para- azidomethyl-L-phenylalanine (pAMF) at at HC-F241 and HC-404 and (b) a structure selected from Formula 1201A or Formula 1201B or a mixture thereof wherein each of m and n is an integer independently between 1 and 8, inclusive.

[0274] In some embodiments, the antibody comprises a light chain. In some aspects, the light chain is a kappa light chain. In some aspects, the light chain is a lambda light chain.

[0275] In some embodiments, the antibody comprises a heavy chain. In some aspects, the heavy chain is an IgA. In some aspects, the heavy chain is an IgD. In some aspects, the heavy chain is an IgE. In some aspects, the heavy chain is an IgG. In some aspects, the heavy chain is an IgM. In some aspects, the heavy chain is an IgG1. In some aspects, the heavy chain is an IgG2. In some aspects, the heavy chain is an IgG3. In some aspects, the heavy chain is an IgG4. In some aspects, the heavy chain is an IgA1. In some aspects, the heavy chain is an IgA2.

[0276] In some embodiments, the antibody is an antibody fragment. In some aspects, the antibody fragment is an Fv fragment. In some aspects, the antibody fragment is a Fab fragment. In some aspects, the antibody fragment is a F(ab’)2fragment. In some aspects, the antibody fragment is a Fab’ fragment. In some aspects, the antibody fragment is an scFv (sFv) fragment. In some aspects, the antibody fragment is an scFv-Fc fragment.

[0277] In some embodiments, the antibody is a monoclonal antibody. In some embodiments, the antibody is a polyclonal antibody.

[0278] 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 human antibody.

[0279] In some embodiments, the antibody is an affinity matured antibody. In some aspects, the antibody is an affinity matured antibody derived from an illustrative sequence provided in this disclosure.

[0280] In certain embodiments, the antibody is an anti-tissue factor antibody. In certain embodiments, the antibody is according to US provisional application no.63 / 590,343, filed October 13, 2023, entitled “ANTI-TISSUE FACTOR ANTIBODIES, COMPOSITIONS COMPRISING ANTI-TISSUE FACTOR ANTIBODIES AND METHODS OF MAKING AND USING ANTI-TISSUE FACTOR ANTIBODIES,” and bearing attorney docket no. 108843.00439, which is incorporated by reference in its entirety.

[0281] In certain embodiments, the antibody is an anti-tissue factor antibody. In certain embodiments, the antibody comprises three heavy chain CDRs of heavy chain variable region SEQ ID NO:2752 and comprises three light chain CDRs of light chain variable region SEQ ID NO:3061. In certain embodiments, the antibody comprises a heavy chain variable region according to SEQ ID NO:2752 and a light chain variable region according to SEQ ID NO:3061. In certain embodiments, the antibody comprises heavy chain CDRs according to SEQ ID NOS: 130 or 455, 780 or 1105, and 1430 or 1755 and light chain CDRs according to SEQ ID NOS: 299, 302, and 305.

[0282] In certain embodiments, the antibody is an anti-HER2 antibody. In certain embodiments, the antibody is trastuzumab. In certain embodiments, the antibody comprises three heavy chain CDRs of heavy chain variable region SEQ ID NO:362 and comprises three light chain CDRs of light chain variable region SEQ ID NO:402. In certain embodiments, the antibody comprises a heavy chain variable region according to SEQ ID NO:403 and a light chain variable region according to SEQ ID NO:367. In certain embodiments, the antibody comprises heavy chain CDRs according to SEQ ID NOS:400, 401, 402, provided herein, and light chain CDRs according to SEQ ID NOS:299, 302, 305, of US Patent No.10,596,270.

[0283] In certain embodiments, the antibody is an anti-folate antibody. In certain embodiments, the antibody is according to US Patent No.10,596,270, issued March 24, 2020, entitled “Anti-folate receptor antibody conjugates, compositions comprising anti-folate receptor antibody conjugates, and methods of making and using anti-folate receptor antibody conjugates,” which is incorporated by reference in its entirety. In certain embodiments, the antibody is identified as antibody 1848-H01 of US Patent No.10,596,270. In certain embodiments, the antibody comprises three heavy chain CDRs of heavy chain variable region SEQ ID NO:362 and comprises three light chain CDRs of light chain variable region SEQ ID NO:367, of US Patent No.10,596,270. In certain embodiments, the antibody comprises a heavy chain variable region according to SEQ ID NO:362 and a light chain variable region according to SEQ ID NO:367, of US Patent No.10,596,270. In certain embodiments, the antibody comprises heavy chain CDRs according to SEQ ID NOS:117, 235, 294 and light chain CDRs according to SEQ ID NOS:299, 302, 305, of US Patent No.10,596,270. In certain embodiments, the antibody comprises heavy chain CDRs according to SEQ ID NOS:58, 176, 294 and light chain CDRs according to SEQ ID NOS:299, 302, 305, of US Patent No.10,596,270.

[0284] For any of the preceding embodiments, also contemplated with the scope of embodiments presented herein are antibody drug conjugates where the antibody is selected from various therapeutic antibodies approved for use, in clinical trials, or in development for clinical use. In certain embodiments, the antibody comprises three heavy chain CDRs and three light chain CDRS of the therapeutic antibody. In certain embodiments, the antibody comprises the heavy chain variable region and the light chain variable region of the therapeutic antibody. In certain embodiments, the antibody comprises the heavy chain and the light chain of the therapeutic antibody. In certain embodiments, the antibody further comprises one or more amino mutations. For instance, in certain embodiments, the antibody comprises one or more amino acid substitutions with modified amino acids to facilitate linkage to the linker-payloads as described herein. Exemplary therapeutic antibodies include,but are not limited to, rituximab (Rituxan®, IDEC / Genentech / Roche) (see, for example, U.S. Pat. No.5,736,137), a chimeric anti-CD20 antibody approved to treat Non-Hodgkin's lymphoma; HuMax-CD20, an anti-CD20 currently being developed by Genmab, an anti- CD20 antibody described in U.S. Pat. No.5,500,362, AME-133 (Applied Molecular Evolution), hA20 (Immunomedics, Inc.), HumaLYM (Intracel), and PRO70769 (PCT Application No. PCT / US2003 / 040426), trastuzumab (Herceptin®, Genentech) (see, for example, U.S. Pat. No.5,677,171), a humanized anti-Her2 / neu antibody approved to treat breast cancer; pertuzumab (rhuMab-2C4, Omnitarg®), currently being developed by Genentech; an anti-Her2 antibody (U.S. Pat. No.4,753,894; cetuximab (Erbitux®, Imclone) (U.S. Pat. No.4,943,533; PCT Publication No. WO 96 / 40210), a chimeric anti-EGFR antibody in clinical trials for a variety of cancers; ABX-EGF (U.S. Pat. No.6,235,883), currently being developed by Abgenix-Immunex-Amgen; HuMax-EGFr (U.S. Pat. No. 7,247,301), currently being developed by Genmab; 425, EMD55900, EMD62000, and EMD72000 (Merck KGaA) (U.S. Pat. No.5,558,864; Murthy, et al. (1987) Arch. Biochem. Biophys.252(2): 549-60; Rodeck, et al. (1987) J. Cell. Biochem.35(4): 315-20; Kettleborough, et al. (1991) Protein Eng.4(7): 773-83); ICR62 (Institute of Cancer Research) (PCT Publication No. WO 95 / 20045; Modjtahedi, et al. (1993) J. Cell. Biophys.22(I-3): 129- 46; Modjtahedi, et al. (1993) Br. J. Cancer 67(2): 247-53; Modjtahedi, et al. (1996) Br. J. Cancer 73(2): 228-35; Modjtahedi, et al. (2003) Int. J. Cancer 105(2): 273-80); TheraCIM hR3 (YM Biosciences, Canada and Centro de Immunologia Molecular, Cuba (U.S. Pat. No. 5,891,996; U.S. Pat. No.6,506,883; Mateo, et al. (1997) Immunotechnol.3(1): 71-81); mAb- 806 (Ludwig Institute for Cancer Research, Memorial Sloan-Kettering) (Jungbluth, et al. (2003) Proc. Natl. Acad. Sci. USA.100(2): 639-44); KSB-102 (KS Biomedix); MR1-1 (IVAX, National Cancer Institute) (PCT Publication No. WO 01 / 62931A2); and (Scancell) (PCT Publication No. WO 01 / 88138); alemtuzumab (Campath®, Millenium), a humanized mAb currently approved for treatment of B-cell chronic lymphocytic leukemia; muromonab- CD3 (Orthoclone OKT3®), an anti-CD3 antibody developed by Ortho Biotech / Johnson & Johnson, ibritumomab tiuxetan (Zevalin®), an anti-CD20 antibody developed by IDEC / Schering AG, gemtuzumab ozogamicin (Mylotarg®), an anti-CD33 (p67 protein) antibody developed by Celltech / Wyeth, alefacept (Amevive®), an anti-LFA-3 Fc fusion developed by Biogen), abciximab (ReoPro®), developed by Centocor / Lilly, basiliximab (Simulect®), developed by Novartis, palivizumab (Synagis®), developed by Medimmune, infliximab (Remicade®), an anti-TNFalpha antibody developed by Centocor, adalimumab (Humira®), an anti-TNFalpha antibody developed by Abbott, Humicade®, an anti-TNFalphaantibody developed by Celltech, golimumab (CNTO-148), a fully human TNF antibody developed by Centocor, etanercept (Enbrel®), an p75 TNF receptor Fc fusion developed by Immunex / Amgen, Ienercept, an p55TNF receptor Fc fusion previously developed by Roche, ABX-CBL, an anti-CD147 antibody being developed by Abgenix, ABX-IL8, an anti-IL8 antibody being developed by Abgenix, ABX-MA1, an anti-MUC18 antibody being developed by Abgenix, Pemtumomab (R1549, 90Y-muHMFG1), an anti-MUC1 in development by Antisoma, Therex (R1550), an anti-MUC1 antibody being developed by Antisoma, AngioMab (AS1405), being developed by Antisoma, HuBC-1, being developed by Antisoma, Thioplatin (AS1407) being developed by Antisoma, Antegren® (natalizumab), an anti-alpha-4-beta-1 (VLA-4) and alpha-4-beta-7 antibody being developed by Biogen, VLA-1 mAb, an anti-VLA-1 integrin antibody being developed by Biogen, LTBR mAb, an anti- lymphotoxin beta receptor (LTBR) antibody being developed by Biogen, CAT-152, an anti- TGF-β antibody being developed by Cambridge Antibody Technology, ABT 874 (J695), an anti-IL-12 p40 antibody being developed by Abbott, CAT-192, an anti-TGFβ1 antibody being developed by Cambridge Antibody Technology and Genzyme, CAT-213, an anti- Eotaxin1 antibody being developed by Cambridge Antibody Technology, LymphoStat-B® an anti-Blys antibody being developed by Cambridge Antibody Technology and Human Genome Sciences Inc., TRAIL-R1 mAb, an anti-TRAIL-R1 antibody being developed by Cambridge Antibody Technology and Human Genome Sciences, Inc., Avastin® bevacizumab, rhuMAb-VEGF), an anti-VEGF antibody being developed by Genentech, an anti-HER receptor family antibody being developed by Genentech, Anti-Tissue Factor (ATF), an anti-Tissue Factor antibody being developed by Genentech, Xolair® (Omalizumab), an anti-IgE antibody being developed by Genentech, Raptiva® (Efalizumab), an anti-CD11a antibody being developed by Genentech and Xoma, MLN-02 Antibody (formerly LDP-02), being developed by Genentech and Millenium Pharmaceuticals, HuMax CD4, an anti-CD4 antibody being developed by Genmab, HuMax-IL15, an anti-IL15 antibody being developed by Genmab and Amgen, HuMax-Inflam, being developed by Genmab and Medarex, HuMax-Cancer, an anti-Heparanase I antibody being developed by Genmab and Medarex and Oxford GcoSciences, HuMax-Lymphoma, being developed by Genmab and Amgen, HuMax-TAC, being developed by Genmab, IDEC-131, and anti- CD40L antibody being developed by IDEC Pharmaceuticals, IDEC-151 (Clenoliximab), an anti-CD4 antibody being developed by IDEC Pharmaceuticals, IDEC-114, an anti-CD80 antibody being developed by IDEC Pharmaceuticals, IDEC-152, an anti-CD 23 being developed by IDEC Pharmaceuticals, anti-macrophage migration factor (MIF) antibodiesbeing developed by IDEC Pharmaceuticals, BEC2, an anti-idiotypic antibody being developed by Imclone, IMC-1C11, an anti-KDR antibody being developed by Imclone, DC101, an anti-flk-1 antibody being developed by Imclone, anti-VE cadherin antibodies being developed by Imclone, CEA-Cide® (Iabetuzumab), an anti-carcinoembryonic antigen (CEA) antibody being developed by Immunomedics, LymphoCide® (Epratuzumab), an anti- CD22 antibody being developed by Immunomedics, AFP-Cide, being developed by Immunomedics, MyelomaCide, being developed by Immunomedics, LkoCide, being developed by Immunomedics, ProstaCide, being developed by Immunomedics, MDX-010, an anti-CTLA4 antibody being developed by Medarex, MDX-060, an anti-CD30 antibody being developed by Medarex, MDX-070 being developed by Medarex, MDX-018 being developed by Medarex, Osidem® (IDM-1), and anti-Her2 antibody being developed by Medarex and Immuno-Designed Molecules, HuMax®-CD4, an anti-CD4 antibody being developed by Medarex and Genmab, HuMax-IL15, an anti-IL15 antibody being developed by Medarex and Genmab, CNTO 148, an anti-TNFα antibody being developed by Medarex and Centocor / J&J, CNTO 1275, an anti-cytokine antibody being developed by Centocor / J&J, MOR101 and MOR102, anti-intercellular adhesion molecule-1 (ICAM-1) (CD54) antibodies being developed by MorphoSys, MOR201, an anti-fibroblast growth factor receptor 3 (FGFR-3) antibody being developed by MorphoSys, Nuvion® (visilizumab), an anti-CD3 antibody being developed by Protein Design Labs, HuZAF®, an anti-gamma interferon antibody being developed by Protein Design Labs, Anti-α5β1 Integrin, being developed by Protein Design Labs, anti-IL-12, being developed by Protein Design Labs, ING-1, an anti-Ep- CAM antibody being developed by Xoma, Xolair® (Omalizumab) a humanized anti-IgE antibody developed by Genentech and Novartis, and MLN01, an anti-Beta2 integrin antibody being developed by Xoma. In another embodiment, the therapeutics include KRN330 (Kirin); huA33 antibody (A33, Ludwig Institute for Cancer Research); CNTO 95 (alpha V integrins, Centocor); MEDI-522 (alpha Vβ3integrin, Medimmune); volociximab (alpha Vβ1 integrin, Biogen / PDL); Human mAb 216 (B cell glycosolated epitope, NCl); BiTE MT103 (bispecific CD19×CD3, Medimmune); 4G7×H22 (Bispecific Bcell×FcgammaR1, Medarex / Merck KGa); rM28 (Bispecific CD28×MAPG, EP Patent No. EP1444268); MDX447 (EMD 82633) (Bispecific CD64×EGFR, Medarex); Catumaxomab (removab) (Bispecific EpCAM× anti- CD3, Trion / Fres); Ertumaxomab (bispecific HER2 / CD3, Fresenius Biotech); oregovomab (OvaRex) (CA-125, ViRexx); Rencarex® (WX G250) (carbonic anhydrase IX, Wilex); CNTO 888 (CCL2, Centocor); TRC105 (CD105 (endoglin), Tracon); BMS-663513 (CD137 agonist, Bristol Myers Squibb); MDX-1342 (CD19, Medarex); Siplizumab (MEDI-507)(CD2, Medimmune); Ofatumumab (Humax-CD20) (CD20, Genmab); Rituximab (Rituxan) (CD20, Genentech); veltuzumab (hA20) (CD20, Immunomedics); Epratuzumab (CD22, Amgen); lumiliximab (IDEC 152) (CD23, Biogen); muromonab-CD3 (CD3, Ortho); HuM291 (CD3 fc receptor, PDL Biopharma); HeFi-1, CD30, NCl); MDX-060 (CD30, Medarex); MDX-1401 (CD30, Medarex); SGN-30 (CD30, Seattle Genentics); SGN-33 (Lintuzumab) (CD33, Seattle Genentics); Zanolimumab (HuMax-CD4) (CD4, Genmab); HCD122 (CD40, Novartis); SGN-40 (CD40, Seattle Genentics); Campath1h (Alemtuzumab) (CD52, Genzyme); MDX-1411 (CD70, Medarex); hLL1 (EPB-1) (CD74.38, Immunomedics); Galiximab (IDEC-144) (CD80, Biogen); MT293 (TRC093 / D93) (cleaved collagen, Tracon); HuLuc63 (CS1, PDL Pharma); ipilimumab (MDX-010) (CTLA4, Bristol Myers Squibb); Tremelimumab (Ticilimumab, CP-675,2) (CTLA4, Pfizer); HGS-ETR1 (Mapatumumab) (DR4TRAIL-R1 agonist, Human Genome Science / Glaxo Smith Kline); AMG-655 (DR5, Amgen); Apomab (DR5, Genentech); CS-1008 (DR5, Daiichi Sankyo); HGS-ETR2 (lexatumumab) (DR5TRAIL-R2 agonist, HGS); Cetuximab (Erbitux) (EGFR, Imclone); IMC-11F8, (EGFR, Imclone); Nimotuzumab (EGFR, YM Bio); Panitumumab (Vectabix) (EGFR, Amgen); Zalutumumab (HuMaxEGFr) (EGFR, Genmab); CDX-110 (EGFRvIII, AVANT Immunotherapeutics); adecatumumab (MT201) (Epcam, Merck); edrecolomab (Panorex, 17-1A) (Epcam, Glaxo / Centocor); MORAb-003 (folate receptor a, Morphotech); KW-2871 (ganglioside GD3, Kyowa); MORAb-009 (GP-9, Morphotech); CDX-1307 (MDX-1307) (hCGb, Celldex); Trastuzumab (Herceptin) (HER2, Celldex); Pertuzumab (rhuMAb 2C4) (HER2 (DI), Genentech); apolizumab (HLA-DR beta chain, PDL Pharma); AMG-479 (IGF-1R, Amgen); anti-IGF-1R R1507 (IGF1-R, Roche); CP 751871 (IGF1-R, Pfizer); IMC-A12 (IGF1-R, Imclone); BIIB022 (IGF-1R, Biogen); Mik-beta-1 (IL- 2Rb (CD122), Hoffman LaRoche); CNTO 328 (IL6, Centocor); Anti-KIR (1-7F9) (Killer cell Ig-like Receptor (KIR), Novo); Hu3S193 (Lewis (y), Wyeth, Ludwig Institute of Cancer Research); hCBE-11 (LTβR, Biogen); HuHMFG1 (MUC1, Antisoma / NCl); RAV12 (N- linked carbohydrate epitope, Raven); CAL (parathyroid hormone-related protein (PTH-rP), University of California); CT-011 (PD1, CureTech); MDX-1106 (ono-4538) (PD1, Medarex / Ono); MAb CT-011 (PD1, Curetech); IMC-3G3 (PDGFRa, Imclone); bavituximab (phosphatidylserine, Peregrine); huJ591 (PSMA, Cornell Research Foundation); muJ591 (PSMA, Cornell Research Foundation); GC1008 (TGFb (pan) inhibitor (IgG4), Genzyme); Infliximab (Remicade) (TNFa, Centocor); A27.15 (transferrin receptor, Salk Institute, INSERN WO 2005 / 111082); E2.3 (transferrin receptor, Salk Institute); Bevacizumab (Avastin) (VEGF, Genentech); HuMV833 (VEGF, Tsukuba Research Lab, PCT PublicationNo. WO / 2000 / 034337, University of Texas); IMC-18F1 (VEGFR1, Imclone); IMC-1121 (VEGFR2, Imclone).

[0285] Examples of useful bispecific parent antibodies include, but are not limited to, those with one antibody directed against a tumor cell antigen and the other antibody directed against a cytotoxic trigger molecule such as anti-FcγRI / anti-CD 15, anti-p185HER2 / FcγRIII (CD16), anti-CD3 / anti-malignant B-cell (1D10), anti-CD3 / anti-p185HER2, anti-CD3 / anti-p97, anti-CD3 / anti-renal cell carcinoma, anti-CD3 / anti-OVCAR-3, anti-CD3 / L-D1 (anti-colon carcinoma), anti-CD3 / anti-melanocyte stimulating hormone analog, anti-EGF receptor / anti- CD3, anti-CD3 / anti-CAMA1, anti-CD3 / anti-CD19, anti-CD3 / MoV18, anti-neural cell adhesion molecule (NCAM) / anti-CD3, anti-folate binding protein (FBP) / anti-CD3, anti-pan carcinoma associated antigen (AMOC-31) / anti-CD3; bispecific antibodies with one antibody which binds specifically to a tumor antigen and another antibody which binds to a toxin such as anti-saporin / anti-Id-1, anti-CD22 / anti-saporin, anti-CD7 / anti-saporin, anti-CD38 / anti- saporin, anti-CEA / anti-ricin A chain, anti-interferon-α (IFN-α) / anti-hybridoma idiotype, anti- CEA / anti-vinca alkaloid; bispecific antibodies for converting enzyme activated prodrugs such as anti-CD30 / anti-alkaline phosphatase (which catalyzes conversion of mitomycin phosphate prodrug to mitomycin alcohol); bispecific antibodies which can be used as fibrinolytic agents such as anti-fibrin / anti-tissue plasminogen activator (tPA), anti-fibrin / anti-urokinase-type plasminogen activator (uPA); bispecific antibodies for targeting immune complexes to cell surface receptors such as anti-low density lipoprotein (LDL) / anti-Fc receptor (e.g. FcγRI, FcγRII or FcγRIII); bispecific antibodies for use in therapy of infectious diseases such as anti-CD3 / anti-herpes simplex virus (HSV), anti-T-cell receptor:CD3 complex / anti-influenza, anti-FcγR / anti-HIV; bispecific antibodies for tumor detection in vitro or in vivo such as anti- CEA / anti-EOTUBE, anti-CEA / anti-DPTA, anti- anti-p185HER2 / anti-hapten; bispecific antibodies as vaccine adjuvants (see Fanger, M W et al., Crit Rev Immunol.1992; 12(34):101-24, which is incorporated by reference herein); and bispecific antibodies as diagnostic tools such as anti-rabbit IgG / anti-ferritin, anti-horse radish peroxidase (HRP) / anti- hormone, anti-somatostatin / anti-substance P, anti-HRP / anti-FITC, anti-CEA / anti-β- galactosidase (see Nolan, O et R. O'Kennedy, Biochim Biophys Acta.1990 Aug.1; 1040(1):1-11, which is incorporated by reference herein). Examples of trispecific antibodies include anti-CD3 / anti-CD4 / anti-CD37, anti-CD3 / anti-CD5 / anti-CD37, and anti-CD3 / anti- CD8 / anti-CD37.

[0286] Modified Amino Acids and Non-natural Amino Acids

[0287] In certain embodiments, the amino acid residue is according to any of the following formulas:

[0288] Those of skill in the art will recognize that antibodies are generally comprised of L- amino acids However, with non-natural and modified amino acids, the present methods and compositions provide the practitioner with the ability to use L-, D- or racemic non-natural amino acids at the site-specific positions. In certain embodiments, the non-natural or modified amino acids described herein include D- versions of the natural amino acids and racemic versions of the natural amino acids.

[0289] In the above formulas, the wavy lines indicate bonds that connect to the remainder of the polypeptide chains of the antibodies. These non-natural or modified amino acids can be incorporated into polypeptide chains just as natural or modified amino acids are incorporated into the same polypeptide chains. In certain embodiments, the non-natural or modified amino acids are incorporated into the polypeptide chain via amide bonds as indicated in the formula.

[0290] In the above formulas, R designates any functional group without limitation, so long as the amino acid residue is not identical to a natural amino acid residue. In certain embodiments, R can be a hydrophobic group, a hydrophilic group, a polar group, an acidic group, a basic group, a chelating group, a reactive group, a therapeutic moiety or a labeling moiety. In certain embodiments, R is selected from the group consisting of R1aNR2aR3a, R1aC(=O)R2a, R1aC(=O)OR2a, R1aN3, R1aC(≡CH). In these embodiments, R1ais selected from the group consisting of a bond, alkylene, heteroalkylene, arylene, heteroarylene. R2aand R3aare each independently selected from the group consisting of hydrogen, alkyl and heteroalkyl.

[0291] In some embodiments, the non-naturally encoded or modified amino acids include side chain functional groups that react efficiently and selectively with functional groups not found in the 20 common amino acids (including but not limited to, azido, ketone, aldehyde and aminooxy groups) to form stable conjugates. For example, antigen-binding polypeptide that includes a non-naturally encoded amino acid containing an azido functional group can be reacted with a polymer (including but not limited to, poly(ethylene glycol) or, alternatively, a second polypeptide containing an alkyne moiety to form a stable conjugate resulting for the selective reaction of the azide and the alkyne functional groups to form a Huisgen [3+2] cycloaddition product.

[0292] Exemplary non-naturally encoded or modified amino acids that may be suitable for use in the present invention and that are useful for reactions with water soluble polymers include, but are not limited to, those with carbonyl, aminooxy, hydrazine, hydrazide, semicarbazide, azide and alkyne reactive groups. In some embodiments, non-naturally encoded or modified amino acids comprise a saccharide moiety. Examples of such amino acids include N-acetyl-L-glucosaminyl-L-serine, N-acetyl-L-galactosaminyl-L-serine, N- acetyl-L-glucosaminyl-L-threonine, N-acetyl-L-glucosaminyl-L-asparagine and O- mannosaminyl-L-serine. Examples of such amino acids also include examples where the naturally-occurring N– or O-linkage between the amino acid and the saccharide is replaced by a covalent linkage not commonly found in nature–including but not limited to, an alkene, an oxime, a thioether, an amide and the like. Examples of such amino acids also include saccharides that are not commonly found in naturally-occurring proteins such as 2-deoxy- glucose, 2-deoxygalactose and the like.

[0293] Many of the non-naturally encoded or modified amino acids provided herein are commercially available, e.g., from Sigma-Aldrich (St. Louis, Mo., USA), Novabiochem (a division of EMD Biosciences, Darmstadt, Germany), or Peptech (Burlington, Mass., USA). Those that are not commercially available are optionally synthesized as provided herein or using standard methods known to those of skill in the art. For organic synthesis techniques, see, e.g., Organic Chemistry by Fessendon and Fessendon, (1982, Second Edition, Willard Grant Press, Boston Mass.); Advanced Organic Chemistry by March (Third Edition, 1985, Wiley and Sons, New York); and Advanced Organic Chemistry by Carey and Sundberg (Third Edition, Parts A and B, 1990, Plenum Press, New York). See, also, U.S. Patent Application Publications 2003 / 0082575 and 2003 / 0108885, which is incorporated by reference herein. In addition to unnatural amino acids that contain unnatural side chains, unnatural amino acids that may be suitable for use in the present invention also optionally comprise modified backbone structures, including but not limited to, as illustrated by the structures of Formula II-1 and III-1:wherein Z typically comprises OH, NH2, SH, NH–R', or S–R'; Xband Yb, which can be the same or different, typically comprise S or O, and R and R', which are optionally the same ordifferent, are typically selected from the same list of constituents for the R group described herein for the unnatural amino acids having Formula I-I as well as hydrogen. For example, unnatural or modified amino acids of the invention optionally comprise substitutions in the amino or carboxyl group as illustrated by Formulas II-I and III-I. Unnatural or modified amino acids of this type include, but are not limited to, α-hydroxy acids, α-thioacids, α- aminothiocarboxylates, including but not limited to, with side chains corresponding to the common twenty natural amino acids or unnatural side chains. In addition, substitutions at the α-carbon optionally include, but are not limited to, L, D, or α-α-disubstituted amino acids such as D-glutamate, D-alanine, D-methyl-O-tyrosine, aminobutyric acid, and the like. Other structural alternatives include cyclic amino acids, such as proline analogues as well as 3, 4, 6, 7, 8, and 9 membered ring proline analogues, P and y amino acids such as substituted β- alanine and γ-amino butyric acid.

[0294] Many unnatural or modified amino acids are based on natural amino acids, such as tyrosine, glutamine, phenylalanine, and the like, and are suitable for use in the present invention. Tyrosine analogs include, but are not limited to, para-substituted tyrosines, ortho- substituted tyrosines, and meta substituted tyrosines, where the substituted tyrosine comprises, including but not limited to, a keto group (including but not limited to, an acetyl group), a benzoyl group, an amino group, a hydrazine, an hydroxyamine, a thiol group, a carboxy group, an isopropyl group, a methyl group, a C6-C20 straight chain or branched hydrocarbon, a saturated or unsaturated hydrocarbon, an O-methyl group, a polyether group, a nitro group, an alkynyl group or the like. In addition, multiply substituted aryl rings are also contemplated. Glutamine analogs that may be suitable for use in the present invention include, but are not limited to, α-hydroxy derivatives, γ-substituted derivatives, cyclic derivatives, and amide substituted glutamine derivatives. Example phenylalanine analogs that may be suitable for use in the present invention include, but are not limited to, para- substituted phenylalanines, ortho-substituted phenyalanines, and meta-substituted phenylalanines, where the substituent comprises, including but not limited to, a hydroxy group, a methoxy group, a methyl group, an allyl group, an aldehyde, an azido, an iodo, a bromo, a keto group (including but not limited to, an acetyl group), a benzoyl, an alkynyl group, or the like. Specific examples of unnatural amino acids that may be suitable for use in the present invention include, but are not limited to, a p-acetyl-L-phenylalanine, an O-methyl-L-tyrosine, an L-3-(2-naphthyl)alanine, a 3-methyl-phenylalanine, an O-4-allyl-L- tyrosine, a 4-propyl-L-tyrosine, a tri-O-acetyl-GlcNAcβ-serine, an L-Dopa, a fluorinated phenylalanine, an isopropyl-L-phenylalanine, a p-azido-L-phenylalanine, a p-azido-methyl-L-phenylalanine, a p-acyl-L-phenylalanine, a p-benzoyl-L-phenylalanine, an L-phosphoserine, a phosphonoserine, a phosphonotyrosine, a p-iodo-phenylalanine, a p-bromophenylalanine, a p-amino-L-phenylalanine, an isopropyl-L-phenylalanine, and a p-propargyloxy-phenylalanine, and the like. Examples of structures of a variety of unnatural amino acids that may be suitable for use in the present invention are provided in, for example, WO 2002 / 085923 entitled “In vivo incorporation of unnatural amino acids.” See also Kiick et al., (2002) Incorporation of azides into recombinant proteins for chemoselective modification by the Staudinger ligation, PNAS 99:19-24, for additional methionine analogs.

[0295] Many of the unnatural or modified amino acids suitable for use in the present invention are commercially available, e.g., from Sigma (USA) or Aldrich (Milwaukee, Wis., USA). Those that are not commercially available are optionally synthesized as provided herein or as provided in various publications or using standard methods known to those of skill in the art. For organic synthesis techniques, see, e.g., Organic Chemistry by Fessendon and Fessendon, (1982, Second Edition, Willard Grant Press, Boston Mass.); Advanced Organic Chemistry by March (Third Edition, 1985, Wiley and Sons, New York); and Advanced Organic Chemistry by Carey and Sundberg (Third Edition, Parts A and B, 1990, Plenum Press, New York). Additional publications describing the synthesis of unnatural amino acids include, e.g., WO 2002 / 085923 entitled “In vivo incorporation of Unnatural Amino Acids;” Matsoukas et al., (1995) J. Med. Chem., 38, 4660-4669; King, F. E. & Kidd, D. A. A. (1949) A New Synthesis of Glutamine and of γ-Dipeptides of Glutamic Acid from Phthylated Intermediates. J. Chem. Soc., 3315-3319; Friedman, O. M. & Chatterrji, R. (1959) Synthesis of Derivatives of Glutamine as Model Substrates for Anti-Tumor Agents. J. Am. Chem. Soc.81, 3750-3752; Craig, J. C. et al. (1988) Absolute Configuration of the Enantiomers of 7-Chloro-4 [[4-(diethylamino)-1-methylbutyl]amino]quinoline (Chloroquine). J. Org. Chem.53, 1167-1170; Azoulay, M., Vilmont, M. & Frappier, F. (1991) Glutamine analogues as Potential Antimalarials, Eur. J. Med. Chem.26, 201-5; Koskinen, A. M. P. & Rapoport, H. (1989) Synthesis of 4-Substituted Prolines as Conformationally Constrained Amino Acid Analogues. J. Org. Chem.54, 1859-1866; Christie, B. D. & Rapoport, H. (1985) Synthesis of Optically Pure Pipecolates from L- Asparagine. Application to the Total Synthesis of (+)-Apovincamine through Amino Acid Decarbonylation and Iminium Ion Cyclization. J. Org. Chem.1989:1859-1866; Barton et al., (1987) Synthesis of Novel a-Amino-Acids and Derivatives Using Radical Chemistry: Synthesis of L- and D-a-Amino-Adipic Acids, L-a-aminopimelic Acid and Appropriate Unsaturated Derivatives. Tetrahedron Lett.43:4297-4308; and, Subasinghe et al., (1992)Quisqualic acid analogues: synthesis of beta-heterocyclic 2-aminopropanoic acid derivatives and their activity at a novel quisqualate-sensitized site. J. Med. Chem.35:4602-7. See also, patent applications entitled “Protein Arrays,” filed Dec.22, 2003, Ser. No.10 / 744,899 and Ser. No.60 / 435,821 filed on Dec.22, 2002.

[0296] Amino acids with a carbonyl reactive group allow for a variety of reactions to link molecules (including but not limited to, PEG or other water soluble molecules) via nucleophilic addition or aldol condensation reactions among others.

[0297] Exemplary carbonyl-containing amino acids can be represented as follows:wherein n3 is 0-10; R1bis an alkyl, aryl, substituted alkyl, or substituted aryl; R2bis H, alkyl, aryl, substituted alkyl, and substituted aryl; and R3bis H, an amino acid, a polypeptide, or an amino terminus modification group, and R4bis H, an amino acid, a polypeptide, or a carboxy terminus modification group. In some embodiments, n3 is 1, R1bis phenyl and R2bis a simple alkyl (i.e., methyl, ethyl, or propyl) and the ketone moiety is positioned in the para position relative to the alkyl side chain. In some embodiments, n3 is 1, R1bis phenyl and R2bis a simple alkyl (i.e., methyl, ethyl, or propyl) and the ketone moiety is positioned in the meta position relative to the alkyl side chain.

[0298] In some examples, a non-naturally encoded or modified amino acid bearing adjacent hydroxyl and amino groups can be incorporated into the polypeptide as a “masked” aldehyde functionality. For example, 5-hydroxylysine bears a hydroxyl group adjacent to the epsilon amine. Reaction conditions for generating the aldehyde typically involve addition of molar excess of sodium metaperiodate under mild conditions to avoid oxidation at other sites within the polypeptide. The pH of the oxidation reaction is typically about 7.0. A typical reaction involves the addition of about 1.5 molar excess of sodium meta periodate to a buffered solution of the polypeptide, followed by incubation for about 10 minutes in the dark. See, e.g. U.S. Pat. No.6,423,685, which is incorporated by reference herein.

[0299] The carbonyl functionality can be reacted selectively with a hydrazine-, hydrazide-, hydroxylamine-, or semicarbazide-containing reagent under mild conditions in aqueous solution to form the corresponding hydrazone, oxime, or semicarbazone linkages, respectively, that are stable under physiological conditions. See, e.g., Jencks, W. P., J. Am. Chem. Soc.81, 475-481 (1959); Shao, J. and Tam, J. P., J. Am. Chem. Soc.117:3893-3899 (1995). Moreover, the unique reactivity of the carbonyl group allows for selectivemodification in the presence of the other amino acid side chains. See, e.g., Cornish, V. W., et al., J. Am. Chem. Soc.118:8150-8151 (1996); Geoghegan, K. F. & Stroh, J. G., Bioconjug. Chem.3:138-146 (1992); Mahal, L. K., et al., Science 276:1125-1128 (1997).

[0300] Non-naturally encoded or modified amino acids containing a nucleophilic group, such as a hydrazine, hydrazide or semicarbazide, allow for reaction with a variety of electrophilic groups to form conjugates (including but not limited to, with PEG or other water soluble polymers).

[0301] Exemplary hydrazine, hydrazide or semicarbazide -containing amino acids can be represented as follows:wherein n3 is 0-10; R1cis an alkyl, aryl, substituted alkyl, or substituted aryl or not present; Xc, is O, N, or S or not present; R2cis H, an amino acid, a polypeptide, or an amino terminus modification group, and R3cis H, an amino acid, a polypeptide, or a carboxy terminus modification group.

[0302] In some embodiments, n3 is 4, R1cis not present, and X is N. In some embodiments, n3 is 2, R1cis not present, and X is not present. In some embodiments, n3 is 1, R1cis phenyl, X is O, and the oxygen atom is positioned para to the aliphatic group on the aryl ring.

[0303] Hydrazide-, hydrazine-, and semicarbazide-containing amino acids are available from commercial sources. For instance, L-glutamate-γ-hydrazide is available from Sigma Chemical (St. Louis, Mo.). Other amino acids not available commercially can be prepared by one skilled in the art. See, e.g., U.S. Pat. No.6,281,211, which is incorporated by reference herein.

[0304] Polypeptides containing non-naturally encoded or modified amino acids that bear hydrazide, hydrazine or semicarbazide functionalities can be reacted efficiently and selectively with a variety of molecules that contain aldehydes or other functional groups with similar chemical reactivity. See, e.g., Shao, J. and Tam, J., J. Am. Chem. Soc.117:3893-3899 (1995). The unique reactivity of hydrazide, hydrazine and semicarbazide functional groups makes them significantly more reactive toward aldehydes, ketones and other electrophilic groups as compared to the nucleophilic groups present on the 20 common amino acids (including but not limited to, the hydroxyl group of serine or threonine or the amino groups of lysine and the N-terminus).

[0305] Non-naturally encoded or modified amino acids containing an aminooxy (also called a hydroxylamine) group allow for reaction with a variety of electrophilic groups to form conjugates (including but not limited to, with PEG or other water soluble polymers). Like hydrazines, hydrazides and semicarbazides, the enhanced nucleophilicity of the aminooxy group permits it to react efficiently and selectively with a variety of molecules that contain aldehydes or other functional groups with similar chemical reactivity. See, e.g., Shao, J. and Tam, J., J. Am. Chem. Soc.117:3893-3899 (1995); H. Hang and C. Bertozzi, Acc. Chem. Res.34: 727-736 (2001). Whereas the result of reaction with a hydrazine group is the corresponding hydrazone, however, an oxime results generally from the reaction of an aminooxy group with a carbonyl-containing group such as a ketone.

[0306] Exemplary amino acids containing aminooxy groups can be represented as follows:wherein n3 is 0-10; R1cis an alkyl, aryl, substituted alkyl, or substituted aryl or not present; Xcis O, N, S or not present; m3 is 0-10; Ycis ═C(O) or not present; R2cis H, an amino acid, a polypeptide, or an amino terminus modification group, and R3cis H, an amino acid, a polypeptide, or a carboxy terminus modification group. In some embodiments, n3 is 1, R1ais phenyl, Xcis O, m is 1, and Ycis present. In some embodiments, n3 is 2, R1cand Xcare not present, m3 is 0, and Ycis not present.

[0307] Aminooxy-containing amino acids can be prepared from readily available amino acid precursors (homoserine, serine and threonine). See, e.g., M. Carrasco and R. Brown, J. Org. Chem.68: 8853-8858 (2003). Certain aminooxy-containing amino acids, such as L-2-amino- 4-(aminooxy)butyric acid), have been isolated from natural sources (Rosenthal, G. et al., Life Sci.60: 1635-1641 (1997). Other aminooxy-containing amino acids can be prepared by one skilled in the art.

[0308] The unique reactivity of azide and alkyne functional groups makes them extremely useful for the selective modification of polypeptides and other biological molecules. Organic azides, particularly aliphatic azides, and alkynes are generally stable toward common reactive chemical conditions. In particular, both the azide and the alkyne functional groups are inert toward the side chains (i.e., R groups) of the 20 common amino acids found in naturally- occurring polypeptides. When brought into close proximity, however, the "spring-loaded" nature of the azide and alkyne groups is revealed and they react selectively and efficiently via Huisgen [3+2] cycloaddition reaction to generate the corresponding triazole. See, e.g., ChinJ., et al., Science 301:964-7 (2003); Wang, Q., et al., J. Am. Chem. Soc.125, 3192-3193 (2003); Chin, J. W., et al., J. Am. Chem. Soc.124:9026-9027 (2002).

[0309] Because the Huisgen cycloaddition reaction involves a selective cycloaddition reaction (see, e.g., Padwa, A., in COMPREHENSIVE ORGANIC SYNTHESIS, Vol.4, (ed. Trost, B. M., 1991), p.1069-1109; Huisgen, R. in 1,3-DIPOLAR CYCLOADDITION CHEMISTRY, (ed. Padwa, A., 1984), p.1-176) rather than a nucleophilic substitution, the incorporation of non-naturally encoded or modified amino acids bearing azide and alkyne- containing side chains permits the resultant polypeptides to be modified selectively at the position of the non-naturally encoded or modified amino acid. Cycloaddition reaction involving azide or alkyne-containing antibody can be carried out at room temperature under aqueous conditions by the addition of Cu(II) (including but not limited to, in the form of a catalytic amount of CuSO4) in the presence of a reducing agent for reducing Cu(II) to Cu(I), in situ, in catalytic amount. See, e.g., Wang, Q., et al., J. Am. Chem. Soc.125, 3192-3193 (2003); Tornoe, C. W., et al., J. Org. Chem.67:3057-3064 (2002); Rostovtsev, et al., Angew. Chem. Int. Ed.41:2596-2599 (2002). Exemplary reducing agents include, including but not limited to, ascorbate, metallic copper, quinine, hydroquinone, vitamin K, glutathione, cysteine, Fe2+, Co2+, and an applied electric potential.

[0310] In some cases, where a Huisgen [3+2] cycloaddition reaction between an azide and an alkyne is desired, the antigen-binding polypeptide comprises a non-naturally encoded or modified amino acid comprising an alkyne moiety and the water soluble polymer to be attached to the amino acid comprises an azide moiety. Alternatively, the converse reaction (i.e., with the azide moiety on the amino acid and the alkyne moiety present on the water soluble polymer) can also be performed.

[0311] The azide functional group can also be reacted selectively with a water soluble polymer containing an aryl ester and appropriately functionalized with an aryl phosphine moiety to generate an amide linkage. The aryl phosphine group reduces the azide in situ and the resulting amine then reacts efficiently with a proximal ester linkage to generate the corresponding amide. See, e.g., E. Saxon and C. Bertozzi, Science 287, 2007-2010 (2000). The azide-containing amino acid can be either an alkyl azide (including but not limited to, 2-amino-6-azido-1-hexanoic acid) or an aryl azide (p-azido-phenylalanine).

[0312] Exemplary water soluble polymers containing an aryl ester and a phosphine moiety can be represented as follows:wherein Xccan be O, N, S or not present, Ph is phenyl, W is a water soluble polymer and R can be H, alkyl, aryl, substituted alkyl and substituted aryl groups. Exemplary R groups include but are not limited to –CH2, –C(CH3)3, –OR', –NR'R'', –SR', -halogen, –C(O)R', ―CONR'R'', –S(O)2R', –S(O)2NR'R'', –CN and –NO2. R', R'', R''' and R'''' each independently refer to hydrogen, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, including but not limited to, aryl substituted with 1-3 halogens, substituted or unsubstituted alkyl, alkoxy or thioalkoxy groups, or arylalkyl groups. When a compound of the invention includes more than one R group, for example, each of the R groups is independently selected as are each R', R'', R''' and R'''' groups when more than one of these groups is present. When R' and R'' are attached to the same nitrogen atom, they can be combined with the nitrogen atom to form a 5-, 6-, or 7-membered ring. For example, –NR'R'' is meant to include, but not be limited to, 1-pyrrolidinyl and 4-morpholinyl. From the above discussion of substituents, one of skill in the art will understand that the term "alkyl" is meant to include groups including carbon atoms bound to groups other than hydrogen groups, such as haloalkyl (including but not limited to, –CF3and –CH2CF3) and acyl (including but not limited to, ―C(O)CH3, –C(O)CF3, –C(O)CH2OCH3, and the like).

[0313] The azide functional group can also be reacted selectively with a water soluble polymer containing a thioester and appropriately functionalized with an aryl phosphine moiety to generate an amide linkage. The aryl phosphine group reduces the azide in situ and the resulting amine then reacts efficiently with the thioester linkage to generate the corresponding amide. Exemplary water soluble polymers containing a thioester and a phosphine moiety can be represented as follows:wherein n2 is 1-10; Xc can be O, N, S or not present, Ph is phenyl, and W is a water soluble polymer.

[0314] Exemplary alkyne-containing amino acids can be represented as follows:wherein n3 is 0-10; R1cis an alkyl, aryl, substituted alkyl, or substituted aryl or not present; Xcis O, N, S or not present; m3 is 0-10, R2cis H, an amino acid, a polypeptide, or an aminoterminus modification group, and R3cis H, an amino acid, a polypeptide, or a carboxy terminus modification group. In some embodiments, n3 is 1, R1cis phenyl, Xc is not present, m3 is 0 and the acetylene moiety is positioned in the para position relative to the alkyl side chain. In some embodiments, n3 is 1, R1cis phenyl, Xcis O, m3 is 1 and the propargyloxy group is positioned in the para position relative to the alkyl side chain (i.e., O-propargyl- tyrosine). In some embodiments, n3 is 1, R1cand Xcare not present and m3 is 0 (i.e., proparylglycine).

[0315] Alkyne-containing amino acids are commercially available. For example, propargylglycine is commercially available from Peptech (Burlington, Mass.). Alternatively, alkyne-containing amino acids can be prepared according to standard methods. For instance, p-propargyloxyphenylalanine can be synthesized, for example, as described in Deiters, A., et al., J. Am. Chem. Soc.125: 11782-11783 (2003), and 4-alkynyl-L-phenylalanine can be synthesized as described in Kayser, B., et al., Tetrahedron 53(7): 2475-2484 (1997). Other alkyne-containing amino acids can be prepared by one skilled in the art.

[0316] Exemplary azide-containing amino acids can be represented as follows:wherein n3 is 0-10; R1cis an alkyl, aryl, substituted alkyl, substituted aryl or not present; Xcis O, N, S or not present; m3 is 0-10; R2cis H, an amino acid, a polypeptide, or an amino terminus modification group, and R3cis H, an amino acid, a polypeptide, or a carboxy terminus modification group. In some embodiments, n3 is 1, R1cis phenyl, Xcis not present, m3 is 0 and the azide moiety is positioned para to the alkyl side chain. In some embodiments, n3 is 0-4 and R1cand Xcare not present, and m3=0. In some embodiments, n3 is 1, R1cis phenyl, Xcis O, m3 is 2 and the P-azidoethoxy moiety is positioned in the para position relative to the alkyl side chain.

[0317] Azide-containing amino acids are available from commercial sources. For instance, 4- azidophenylalanine can be obtained from Chem-Impex International, Inc. (Wood Dale, Ill.). For those azide-containing amino acids that are not commercially available, the azide group can be prepared relatively readily using standard methods known to those of skill in the art, including but not limited to, via displacement of a suitable leaving group (including but not limited to, halide, mesylate, tosylate) or via opening of a suitably protected lactone. See, e.g., Advanced Organic Chemistry by March (Third Edition, 1985, Wiley and Sons, New York).

[0318] The unique reactivity of beta-substituted aminothiol functional groups makes them extremely useful for the selective modification of polypeptides and other biological molecules that contain aldehyde groups via formation of the thiazolidine. See, e.g., J. Shao and J. Tam, J. Am. Chem. Soc.1995, 117 (14) 3893-3899. In some embodiments, beta- substituted aminothiol amino acids can be incorporated into antibodies and then reacted with water soluble polymers comprising an aldehyde functionality. In some embodiments, a water soluble polymer, drug conjugate or other payload can be coupled to an antibody polypeptide comprising a beta-substituted aminothiol amino acid via formation of the thiazolidine.

[0319] Particular examples of useful modified amino acids include, but are not limited to, p- acetyl-L-phenylalanine, O-methyl-L-tyrosine, L-3-(2-naphthyl)alanine, 3-methyl- phenylalanine, O-4-allyl-L-tyrosine, 4-propyl-L-tyrosine, tri-O-acetyl-GlcNAc b-serine, L- Dopa, fluorinated phenylalanine, isopropyl-L-phenylalanine, p-azido-methyl-L- phenylalanine, p-azido-L-phenylalanine, p-acyl-L-phenylalanine, p-benzoyl-L-phenylalanine, L-phosphoserine, phosphonoserine, phosphonotyrosine, p-iodo-phenylalanine, p- bromophenylalanine, p-amino-L-phenylalanine, isopropyl-L-phenylalanine, and p- propargyloxy-phenylalanine. Further useful examples include N-acetyl-L-glucosaminyl-L- serine, N-acetyl-L-galactosaminyl-L-serine, N-acetyl-L-glucosaminyl-L-threonine, N-acetyl- L-glucosaminyl-L-asparagine and O-mannosaminyl-L-serine.

[0320] In particular embodiments, the modified amino acids are selected from p-acetyl- phenylalanine, p-ethynyl-phenylalanine, p-propargyloxyphenylalanine, p-azido-methyl- phenylalanine, and p-azido-phenylalanine. Particularly useful modified amino acids are p- azido phenylalanine and p-azido-methyl-phenylalanine (pAMF). These amino acid residues are known to those of skill in the art to facilitate Huisgen [3+2] cyloaddition reactions (so- called “click” chemistry reactions) with, for example, compounds bearing alkynyl groups. This reaction enables one of skill in the art to readily and rapidly conjugate to the antibody at the site-specific location of the modified amino acid.

[0321] In certain embodiments, the first reactive group is an alkynyl moiety (including but not limited to, in the unnatural amino acid p-propargyloxyphenylalanine, where the propargyl group is also sometimes referred to as an acetylene moiety) and the second reactive group is an azido moiety, and [3+2] cycloaddition chemistry can be used. In certain embodiments, the first reactive group is the azido moiety (including but not limited to, in the unnatural amino acid p-azido-L-phenylalanine or p-azido-methyl-phenylalanine) and the second reactive group is the alkynyl moiety.

[0322] Another useful amino acid is p-acetyl-L-phenylalanine (pAcF), which is known to those of skill in the art to facilitate oxime ligation. In certain embodiments, the first reactive group is the acetyl moiety (including but not limited to, in the unnatural amino acid p-acetyl- L-phenylalanine) and the second reactive group is the aminooxy moiety.

[0323] In the above formulas, each L represents a divalent linker. The divalent linker can be any divalent linker known to those of skill in the art. Generally, the divalent linker is capable of forming covalent bonds to the functional moiety R and the cognate reactive group (e.g., alpha carbon) of the non-natural or modified amino acid. Useful divalent linkers a bond, alkylene, substituted alkylene, heteroalkylene, substituted heteroalkylene, arylene, substituted arylene, heteroarlyene and substituted heteroarylene. In certain embodiments, L is C1-10alkylene or C1-10heteroalkylene.

[0324] The non-natural or modified amino acids used in the methods and compositions described herein have at least one of the following four properties: (1) at least one functional group on the sidechain of the non-natural or modified amino acid has at least one characteristics and / or activity and / or reactivity orthogonal to the chemical reactivity of the 20 common, genetically-encoded amino acids (i.e., alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine), or at least orthogonal to the chemical reactivity of the naturally occurring amino acids present in the polypeptide that includes the non-natural or modified amino acid; (2) the introduced non- natural or modified amino acids are substantially chemically inert toward the 20 common, genetically-encoded amino acids; (3) the non-natural or modified amino acid can be stably incorporated into a polypeptide, preferably with the stability commensurate with the naturally-occurring amino acids or under typical physiological conditions, and further preferably such incorporation can occur via an in vivo system; and (4) the non-natural or modified amino acid includes an oxime functional group or a functional group that can be transformed into an oxime group by reacting with a reagent, preferably under conditions that do not destroy the biological properties of the polypeptide that includes the non-natural or modified amino acid (unless of course such a destruction of biological properties is the purpose of the modification / transformation), or where the transformation can occur under aqueous conditions at a pH between about 4 and about 8, or where the reactive site on the non-natural amino acid is an electrophilic site. Any number of non-natural or modified amino acids can be introduced into the polypeptide. Non-natural or modified amino acids may also include protected or masked oximes or protected or masked groups that can be transformedinto an oxime group after deprotection of the protected group or unmasking of the masked group. Non-natural or modified amino acids may also include protected or masked carbonyl or dicarbonyl groups, which can be transformed into a carbonyl or dicarbonyl group after deprotection of the protected group or unmasking of the masked group and thereby are available to react with hydroxylamines or aminooxy groups to form oxime groups.

[0325] In further embodiments, non-natural or modified amino acids that may be used in the methods and compositions described herein include, but are not limited to, amino acids comprising a photoactivatable cross-linker, spin-labeled amino acids, fluorescent amino acids, metal binding amino acids, metal-containing amino acids, radioactive amino acids, amino acids with novel functional groups, amino acids that covalently or non-covalently interact with other molecules, photocaged and / or photoisomerizable amino acids, amino acids comprising biotin or a biotin analogue, glycosylated amino acids such as a sugar substituted serine, other carbohydrate modified amino acids, keto-containing amino acids, aldehyde- containing amino acids, amino acids comprising polyethylene glycol or other polyethers, heavy atom substituted amino acids, chemically cleavable and / or photocleavable amino acids, amino acids with an elongated side chains as compared to natural amino acids, including but not limited to, polyethers or long chain hydrocarbons, including but not limited to, greater than about 5 or greater than about 10 carbons, carbon-linked sugar-containing amino acids, redox-active amino acids, amino thioacid containing amino acids, and amino acids comprising one or more toxic moiety.

[0326] In some embodiments, non-natural or modified amino acids comprise a saccharide moiety. Examples of such amino acids include N-acetyl-L-glucosaminyl-L-serine, N-acetyl- L-galactosaminyl-L-serine, N-acetyl-L-glucosaminyl-L-threonine, N-acetyl-L-glucosaminyl- L-asparagine and O-mannosaminyl-L-serine. Examples of such amino acids also include examples where the naturally-occurring N- or O-linkage between the amino acid and the saccharide is replaced by a covalent linkage not commonly found in nature–including but not limited to, an alkene, an oxime, a thioether, an amide and the like. Examples of such amino acids also include saccharides that are not commonly found in naturally-occurring proteins such as 2-deoxy-glucose, 2-deoxygalactose and the like.

[0327] The chemical moieties incorporated into antibodies via incorporation of non-natural or modified amino acids offer a variety of advantages and manipulations of polypeptides. For example, the unique reactivity of a carbonyl or dicarbonyl functional group (including a keto- or aldehyde-functional group) allows selective modification of antibodies with any of a number of hydrazine- or hydroxylamine-containing reagents in vivo and in vitro. A heavyatom non-natural or modified amino acid, for example, can be useful for phasing x-ray structure data. The site-specific introduction of heavy atoms using non-natural or modified amino acids also provides selectivity and flexibility in choosing positions for heavy atoms. Photoreactive non-natural or modified amino acids (including but not limited to, amino acids with benzophenone and arylazides (including but not limited to, phenylazide) side chains), for example, allow for efficient in vivo and in vitro photocrosslinking of polypeptides. Examples of photoreactive non-natural or modified amino acids include, but are not limited to, p-azido-phenylalanine and p-benzoyl-phenylalanine. The antibodies with the photoreactive non-natural or modified amino acids may then be crosslinked at will by excitation of the photoreactive group-providing temporal control. In a non-limiting example, the methyl group of a non-natural or modified amino can be substituted with an isotopically labeled, including but not limited to, with a methyl group, as a probe of local structure and dynamics, including but not limited to, with the use of nuclear magnetic resonance and vibrational spectroscopy.

[0328] Amino acids with an electrophilic reactive group allow for a variety of reactions to link molecules via various chemical reactions, including, but not limited to, nucleophilic addition reactions. Such electrophilic reactive groups include a carbonyl- or dicarbonyl-group (including a keto- or aldehyde group), a carbonyl-like- or dicarbonyl-like-group (which has reactivity similar to a carbonyl- or dicarbonyl-group and is structurally similar to a carbonyl- or dicarbonyl-group), a masked carbonyl- or masked dicarbonyl-group (which can be readily converted into a carbonyl- or dicarbonyl-group), or a protected carbonyl- or protected dicarbonyl-group (which has reactivity similar to a carbonyl- or dicarbonyl-group upon deprotection). Such amino acids include amino acids having the structure of Formula (I-1):wherein: A is optional, and when present is lower alkylene, substituted lower alkylene, lower cycloalkylene, substituted lower cycloalkylene, lower alkenylene, substituted lower alkenylene, alkynylene, lower heteroalkylene, substituted heteroalkylene, lower heterocycloalkylene, substituted lower heterocycloalkylene, arylene, substituted arylene, heteroarylene, substituted heteroarylene, alkarylene, substituted alkarylene, aralkylene, or substituted aralkylene; B is optional, and when present is a linker selected from the groupconsisting of lower alkylene, substituted lower alkylene, lower alkenylene, substituted lower alkenylene, lower heteroalkylene, substituted lower heteroalkylene, –O–, –O–(alkylene or substituted alkylene)–, –S–, –S–(alkylene or substituted alkylene)–, –S(O)k– where k is 1, 2, or 3, –S(O)k(alkylene or substituted alkylene)–, –C(O)–, –NS(O)2–, –OS(O)2–, –C(O)–(alkylene or substituted alkylene)–, –C(S)–, –C(S)–(alkylene or substituted alkylene)–, ―N(R')–, –NR'–(alkylene or substituted alkylene)–, ―C(O)N(R')–, –CON(R')–(alkylene or substituted alkylene)–, – CSN(R')–, –CSN(R')–(alkylene or substituted alkylene)–, ―N(R')CO–(alkylene or substituted alkylene)–, –N(R')C(O)O–, ―S(O)kN(R')–, ―N(R')C(O)N(R')–, – N(R')C(S)N(R')–, –N(R')S(O)kN(R')–, –N(R')–N═, ―C(R')═N–, ―C(R')═N–N(R')–, – C(R')═N–N═, –C(R')2–N═N–, and –C(R')2–N(R')–N(R')–, where each R' is independently H, alkyl, or substituted alkyl; J isR is H, alkyl, substituted alkyl, cycloalkyl, or substituted cycloalkyl; each R'' is independently H, alkyl, substituted alkyl, or a protecting group, or when more than one R'' group is present, two R'' optionally form a heterocycloalkyl; R1dis H, an amino protecting group, resin, amino acid, polypeptide, or polynucleotide; and R2dis OH, an ester protecting group, resin, amino acid, polypeptide, or polynucleotide; each of R3dand R4dis independently H, halogen, lower alkyl, or substituted lower alkyl, or R3dand R4dor two R3dgroups optionally form a cycloalkyl or a heterocycloalkyl; or the -A-B-J-R groups together form a bicyclic or tricyclic cycloalkyl or heterocycloalkyl comprising at least one carbonyl group, including a dicarbonyl group, protected carbonyl group, including a protected dicarbonyl group, or masked carbonyl group, including a masked dicarbonyl group; or the -J-R group together forms a monocyclic or bicyclic cycloalkyl or heterocycloalkyl comprising at least one carbonyl group, including a dicarbonyl group, protected carbonyl group, including a protected dicarbonyl group, or masked carbonyl group, including a masked dicarbonyl group; with a proviso that when A is phenylene and each R3dis H, B is present; and that when A is –(CH2)4– and each R3dis H, Bis not –NHC(O)(CH2CH2)–; and that when A and B are absent and each R3dis H, R is not methyl. Such non-natural or modified amino acids may be in the form of a salt, or may be incorporated into a non-natural or modified amino acid polypeptide, polymer, polysaccharide, or a polynucleotide and optionally post translationally modified.

[0329] In certain embodiments, compounds of Formula (I-1) are stable in aqueous solution for at least 1 month under mildly acidic conditions. In certain embodiments, compounds of Formula (I-1) are stable for at least 2 weeks under mildly acidic conditions. In certain embodiments, compound of Formula (I-1) are stable for at least 5 days under mildly acidic conditions. In certain embodiments, such acidic conditions are pH 2 to 8.

[0330] In certain embodiments of compounds of Formula (I-1), B is lower alkylene, substituted lower alkylene, –O–(alkylene or substituted alkylene)–, –C(R')═N–N(R')–, ―N(R')CO–, –C(O)-, –C(R')═N–, –C(O)–(alkylene or substituted alkylene)–, –CON(R')– (alkylene or substituted alkylene)–, –S(alkylene or substituted alkylene)–, –S(O)(alkylene or substituted alkylene)–, or ―S(O)2(alkylene or substituted alkylene)–. In certain embodiments of compounds of Formula (I-1), B is –O(CH2)–, –CH═N–, –CH═N–NH–, –NHCH2–, ―NHCO–, –C(O)–, –C(O)–(CH2)–, ―CONH–(CH2)–, –SCH2–, –S(═O)CH2–, or ―S(O)2CH2–. In certain embodiments of compounds of Formula (I-1), R is C1–6alkyl or cycloalkyl. In certain embodiments of compounds of Formula (I-1) R is –CH3, –CH(CH3)2, or cyclopropyl. In certain embodiments of compounds of Formula (I-1), R1dis H, tert- butyloxycarbonyl (Boc), 9-Fluorenylmethoxycarbonyl (Fmoc), N-acetyl, tetrafluoroacetyl (TFA), or benzyloxycarbonyl (Cbz). In certain embodiments of compounds of Formula (I-1), R1dis a resin, amino acid, polypeptide, or polynucleotide. In certain embodiments of compounds of Formula (I-1), R2dis OH, O-methyl, O-ethyl, or O-t-butyl. In certain embodiments of compounds of Formula (I-1), R2dis a resin, amino acid, polypeptide, or polynucleotide. In certain embodiments of compounds of Formula (I-1), R2dis a polynucleotide. In certain embodiments of compounds of Formula (I-1), R2dis ribonucleic acid (RNA). In certain embodiments of compounds of Formula (I-1), R2dis tRNA. In certain embodiments of compounds of Formula (I-1), the tRNA specifically recognizes a selector codon. In certain embodiments of compounds of Formula (I-1) the selector codon is selected from the group consisting of an amber codon, ochre codon, opal codon, a unique codon, a rare codon, an unnatural codon, a five-base codon, and a four-base codon. In certain embodiments of compounds of Formula (I-1), R2dis a suppressor tRNA.

[0331] In certain embodiments of compounds of Formula (I-2),

[0332] is selected from the group consisting of: (i) A is substituted lower alkylene, C4- arylene, substituted arylene, heteroarylene, substituted heteroarylene, alkarylene, substituted alkarylene, aralkylene, or substituted aralkylene; B is optional, and when present is a divalent linker selected from the group consisting of lower alkylene, substituted lower alkylene, lower alkenylene, substituted lower alkenylene, –O–, –O–(alkylene or substituted alkylene)–, –S–, –S(O)–, –S(O)2–, –NS(O)2–, ―OS(O)2–, –C(O)–, –C(O)–(alkylene or substituted alkylene)–, –C(S)–, –N(R')–, –C(O)N(R')–, –CON(R')–(alkylene or substituted alkylene)–, –CSN(R')–, ―N(R')CO–(alkylene or substituted alkylene)–, –N(R')C(O)O–, –N(R')C(S)–, –S(O)N(R'), ―S(O)2N(R'), –N(R')C(O)N(R')–, ―N(R')C(S)N(R')–, –N(R')S(O)N(R')–, ―N(R')S(O)2N(R')–, –N(R')–N═, –C(R')═N–N(R')–, ―C(R')═N–N═, –C(R')2–N═N–, and ―C(R')2–N(R')–N(R')–; (ii) A is optional, and when present is substituted lower alkylene, C4–arylene, substituted arylene, heteroarylene, substituted heteroarylene, alkarylene, substituted alkarylene, aralkylene, or substituted aralkylene; B is a divalent linker selected from the group consisting of lower alkylene, substituted lower alkylene, lower alkenylene, substituted lower alkenylene, –O–, –O–(alkylene or substituted alkylene)–, –S-, –S(O)–, ―S(O)2–, –NS(O)2–, –OS(O)2–, –C(O)–, –C(O)–(alkylene or substituted alkylene)–, ―C(S)–, –N(R')–, –C(O)N(R')–, –CON(R')–(alkylene or substituted alkylene)–, –CSN(R')–, ―N(R')CO–(alkylene or substituted alkylene)–, –N(R')C(O)O–, –N(R')C(S)–, –S(O)N(R'), ―S(O)2N(R'), –N(R')C(O)N(R')–, –N(R')C(S)N(R')–, –N(R')S(O)N(R')–, ―N(R')S(O)2N(R')–, ―N(R')–N═, –C(R')═N–N(R')–, –C(R')═N–N═, –C(R')2–N═N–, and ―C(R')2–N(R')–N(R')–; (iii) A is lower alkylene; B is optional, and when present is a divalent linker selected from the group consisting of lower alkylene, substituted lower alkylene, lower alkenylene, substituted lower alkenylene, –O–, –O–(alkylene or substituted alkylene)–, –S–, –S(O)–, –S(O)2–, –NS(O)2–, ―OS(O)2–, –C(O)–, –C(O)–(alkylene or substituted alkylene)–, –C(S)–, –N(R')–, –C(O)N(R')–, –CSN(R')–, –CON(R')–(alkylene or substituted alkylene)–, –N(R')C(O)O–, –N(R')C(S)–, ―S(O)N(R'), –S(O)2N(R'), ―N(R')C(O)N(R')–, –N(R')C(S)N(R')–, –N(R')S(O)N(R')–, ―N(R')S(O)2N(R')–, –N(R')– N═, –C(R')═N–N(R')–, –C(R')═N–N═, –C(R')2–N═N–, and ―C(R')2–N(R')–N(R')–; and (iv) A is phenylene; B is a divalent linker selected from the group consisting of lower alkylene, substituted lower alkylene, lower alkenylene, substituted lower alkenylene, –O–, ―O-(alkylene or substituted alkylene)–, –S–, –S(O)–, –S(O)2–, –NS(O)2–, ―OS(O)2–,―C(O)–, ―C(O)–(alkylene or substituted alkylene)–, –C(S)–, –N(R')–, –C(O)N(R')-, ―CON(R')–(alkylene or substituted alkylene)–, –CSN(R')–, –N(R')CO–(alkylene or substituted alkylene)–, –N(R')C(O)O–, –N(R')C(S)–, –S(O)N(R'), –S(O)2N(R'), ―N(R')C(O)N(R')–, ―N(R')C(S)N(R')–, –N(R')S(O)N(R')–, –N(R')S(O)2N(R')–, –N(R')– N═, –C(R')'N–N(R')–, ―C(R')═N–N═, –C(R')2–N═N–, and –C(R')2–N(R')–N(R')–; J iseach R’ is independently H, alkyl, or substituted alkyl; R1dis optional, and when present, is H, an amino protecting group, resin, amino acid, polypeptide, or polynucleotide; and R2dis optional, and when present, is OH, an ester protecting group, resin, amino acid, polypeptide, or polynucleotide; and each R3dand R4dis independently H, halogen, lower alkyl, or substituted lower alkyl; and R is H, alkyl, substituted alkyl, cycloalkyl, or substituted cycloalkyl.

[0333] In certain embodiments, the non-natural or modified amino acid can be according to formula XIX:Formula XIX; or a salt thereof, wherein:is

[0334] each of W1a, W2a, and W3ais independently a single bond or lower alkylene; each X1bis independently –NH–, –O–, or –S–; each Y1ais independently a single bond, –NH–, or –O–; each Y2ais independently a single bond, –NH–, –O–, or an N-linked or C-linked pyrrolidinylene; and one of Z1, Z2, and Z3is –N– and the others of Z1, Z2, and Z3are independently –CH–. In certain embodiments, the non-natural or modified amino acid is according to formula XIXa:Formula XIXa; where Dais a defined in the context of formula XIX. In certain embodiments, the non- natural or modified amino acid is according formula XIXb:Formula XIXb; or a salt thereof, wherein W4ais C1-C10 alkylene. In a further embodiment, W4ais C1-C5 alkylene. In an embodiment, W4ais C1-C3 alkylene. In an embodiment, W4ais C1 alkylene. In particular embodiments, the non-natural or modified amino acid is selected from the group consisting of:or a salt thereof. Such non-natural or modified amino acids may be in the form of a salt, or may be incorporated into a non-natural or modified amino acid polypeptide, polymer, polysaccharide, or a polynucleotide and optionally post translationally modified.

[0335] In certain embodiments, the modified amino acid is according to formula I:or a salt thereof, wherein Ar is: ,V is a single bond, lower alkylene, or –W1a–W2a–; one of W1aand W2ais absent or lower alkylene, and the other is –NH–, –O–, or –S–; each X1bis independently –NH–, –O–, or –S–; one of Z1, Z2, and Z3is –CH– or –N– and the others of Z1, Z2, and Z3are each independently –CH–; and R is lower alkyl. In certain embodiments, whenthen one of Z1, Z2, and Z3is –N–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH– .

[0336] In certain embodiments, Ar isand Z1, Z2, Z3and X1bare as defined in the context of formula I. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments according to this paragraph, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments according to this paragraph, Z1is N. In certain embodiments according to this paragraph, Z2is N. In certain embodimentsaccording to this paragraph, Z3is N. In certain embodiments according to this paragraph, Z1is CH, Z3is CH and X1bis S.

[0337] In certain embodiments, Ar isand Z1, Z2, and Z3are as defined in the context of formula I. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, ―O–, or –S–. In certain embodiments according to this paragraph, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments according to this paragraph, Z1is N. In certain embodiments according to this paragraph, Z2is N. In certain embodiments according to this paragraph, Z3is N.

[0338] In certain embodiments, Ar is

[0339] and Z1, Z3and X1are as defined in the context of Formula I-1. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments according to this paragraph, V is a single bond, –NH–, or –CH2NH–. In certain embodiments according to this paragraph, Z1is N. In certain embodiments according to this paragraph, Z3is N. In certain embodiments according to this paragraph, Z1is CH, Z3is CH and X1bis S.

[0340] In certain embodiments, the modified amino acid is according to Formula Ia:Formula I-1a; where Ar, V, and R are defined in the context of Formula I-1.

[0341] In an embodiment, compounds of either of Formulas I-1 and I-1a are provided wherein V is a single bond. In another embodiment, compounds of either of Formulas I-1 andI-1a are provided wherein V is –NH–. In another embodiment, compounds of either of Formulas I-1 and I-1a are provided wherein V is –CH2NH–.

[0342] In certain embodiments, the modified amino acid is according to Formula II-1:Formula II-1; or a salt thereof, wherein V and R are as defined in Formula I-1. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond or –CH2NH–; and R is methyl.

[0343] In certain embodiments, the modified amino acid is according to Formula III-1:or a salt thereof, wherein V and R are as defined in Formula I-1. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0344] In certain embodiments, the modified amino acid is according to Formula IV-1:or a salt thereof, wherein V and R are as defined in Formula I-1. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0345] In certain embodiments, the modified amino acid is according to Formula V-1:Formula V-1; or a salt thereof, wherein V and R are as defined in Formula I. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0346] In certain embodiments, the modified amino acid is according to Formula VI-1:Formula VI-1; or a salt thereof, wherein V and R are as defined in Formula I. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0347] In certain embodiments, the modified amino acid is according to Formula VII-1:Formula VII; or a salt thereof, wherein V and R are as defined in Formula I. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0348] In certain embodiments, the modified amino acid is according to Formula VIII-1:Formula VIII-1; or a salt thereof, wherein V and R are as defined in Formula I. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0349] In certain embodiments, the modified amino acid is according to Formula IX-1:Formula IX-1; or a salt thereof, wherein V and R are as defined in Formula I-1. In certain embodiments according to this paragraph, V is –W1a–W2a–; one of W1aand W2ais absent or –CH2–, and the other is –NH–, –O–, or –S–. In certain embodiments, V is a single bond, –NH–, or ―CH2NH–. In certain embodiments, V is a single bond, –NH–, or –CH2NH–; and R is methyl.

[0350] In certain embodiments, the modified amino acid is according to any of formulas 51- 62:or a salt thereof.

[0351] In any of the foregoing embodiments wherein the conjugate has a structure described herein, for example, according to any one of Formulas 1101-1114 and / or Formula 1201A- 1201B, the bracketed structure can be covalently bonded to one or more non-natural or modified amino acids of the antibody, wherein the one or more non-natural or modified amino acids are located at sites selected from the group consisting of: HC-404, HC-180, HC- 391, HC-241, LC-42, LC-161, LC-170, according to the Kabat or EU numbering scheme of Kabat. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites selected from the group consisting of: HC-F404, HC-Y180, HC-Y391, HC-F241, LC-K42, LC-E161, and LC-D170, according to the Kabat or EU numbering scheme of Kabat. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites selected from the group consisting of: HC-F404, HC-Y180, HC-F241, LC-K42, and LC-E161, according to the Kabat or EU numbering scheme of Kabat. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site HC-F404 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or morenon-natural or modified amino acids at site HC-Y391 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site HC-Y180 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site HC-F241 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site LC-K42 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site LC-E161 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site LC-D170 of the antibody. In some embodiments, the bracketed structures are covalently bonded to non- natural or modified amino acids at sites HC-F404 and HC-Y180 of the antibody. In some embodiments, the bracketed structures are covalently bonded to non-natural or modified amino acids at sites HC-F404, HC-F241, and LC-K42 of the antibody. In some embodiments, the bracketed structures are covalently bonded to non-natural or modified amino acids at sites HC-F404, HC-Y180, and LC-K42 of the antibody. In some embodiments, the bracketed structures are covalently bonded to non-natural or modified amino acids at sites HC-F404, HC-Y180, LC-K42, and LC-E161 of the antibody. In some embodiments, the bracketed structures are covalently bonded to non-natural or modified amino acids at sites HC-F404, HC-Y180, and HC-F241 of the antibody. In some embodiments, the bracketed structures are covalently bonded to non-natural or modified amino acids at sites HC-F404, HC-Y180, HC- F241, and LC-K42 of the antibody.

[0352] In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at heavy chain position 404 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at heavy chain position 180 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at heavy chain position 391 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein whereinAb indicates a residue of the modified amino acid according to Formula (30), below, at heavy chain position 241 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at heavy chain position 222 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at light chain position 7 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at light chain position 161 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at light chain position 170 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (30), below, at light chain position 42 according to the Kabat or Chothia numbering system.

[0353] In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at heavy chain position 404 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at heavy chain position 180 according to the EU numbering system..In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Abindicates a residue of the modified amino acid according to Formula (56), below, at heavy chain position 391 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at heavy chain position 241 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at heavy chain position 222 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at light chain position 7 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at light chain position 161 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at light chain position 170 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a residue of the modified amino acid according to Formula (56), below, at light chain position 42 according to the Kabat or Chothia numbering system.

[0354] In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue of para- azido-L-phenylalanine. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates the modified amino acid residue para-azido-phenylalanine at heavy chain position 404 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue of para- azido-L-phenylalanine at heavy chain position 180 according to the EU numbering system. Inparticular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido-L- phenylalanine at heavy chain position 391 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido-L- phenylalanine at heavy chain position 241 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido-L- phenylalanine at heavy chain position 222 according to the EU numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido-L- phenylalanine at light chain position 7 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido-L- phenylalanine at light chain position 42 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido-L- phenylalanine at light chain position 161 according to the Kabat or Chothia numbering system. In particular embodiments, provided herein are conjugates according to any of the conjugates described herein wherein Ab indicates a modified amino acid residue para-azido- L-phenylalanine at light chain position 170 according to the Kabat or Chothia numbering system.

[0355] When the antibody conjugate comprises a modified amino acid, the modified amino acid can be any modified amino acid deemed suitable by the practitioner. In particular embodiments, the modified amino acid comprises a reactive group useful for forming a covalent bond to a linker precursor or to a payload precursor. In certain embodiments, the modified amino acid is a non-natural amino acid. In certain embodiments, the reactive group is selected from the group consisting of amino, carboxy, acetyl, hydrazino, hydrazido, semicarbazido, sulfanyl, azido and alkynyl. Modified amino acids are also described in, for example, WO 2013 / 185115 and WO 2015 / 006555, each of which is incorporated herein by reference in its entirety.

[0356] In certain embodiments, the modified amino acid is selected from the group consisting of compounds 30, 53, 56, 59, 60, 61, and 62 above. In certain embodiments, the modified amino acid is compound 30. In certain embodiments, the modified amino acid iscompound 56. In some embodiments, the non-natural amino acid is compound 61. In some embodiments, the non-natural amino acid is compound 62.

[0357] In certain embodiments, the one or more non-natural amino acid residues are selected from the group consisting of p-acetyl-L-phenylalanine, O-methyl-L-tyrosine, 3-methyl- phenylalanine, O-4-allyl-L-tyrosine, 4-propyl-L-tyrosine, fluorinated phenylalanine, isopropyl-L-phenylalanine, p-azido-L-phenylalanine, p-acyl-L-phenylalanine, p-benzoyl-L- phenylalanine, p-iodo-phenylalanine, p-bromophenylalanine, p-amino-L-phenylalanine, isopropyl-L-phenylalanine, p-propargyloxy-phenylalanine, and p-azidomethyl-L- phenylalanine. In certain embodiments, the at least one of the one or more non-natural amino acid residues is p-azidomethyl-L-phenylalanine. In certain embodiments, the at least one of the one or more non-natural amino acid residues is p-azido-L-phenylalanine.

[0358] In certain embodiments, the one or more non-natural amino acid residues are selected from the group consisting of p-acetyl-L-phenylalanine, O-methyl-L-tyrosine, 3-methyl- phenylalanine, O-4-allyl-L-tyrosine, 4-propyl-L-tyrosine, fluorinated phenylalanine, isopropyl-L-phenylalanine, p-azido-L-phenylalanine, p-acyl-L-phenylalanine, p-benzoyl-L- phenylalanine, p-iodo-phenylalanine, p-bromophenylalanine, p-amino-L-phenylalanine, isopropyl-L-phenylalanine, p-propargyloxy-phenylalanine, and p-azidomethyl-L- phenylalanine. In certain embodiments, the at least one of the one or more non-natural amino acid residues is p-azidomethyl-L-phenylalanine. In certain embodiments, the at least one of the one or more non-natural amino acid residues is p-azido-L-phenylalanine.

[0359] In some embodiments, the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue, lysine residue, and / or amino-terminal residue suitable for conjugation, wherein the one or more residues are covalently linked to the first linker and / or a second linker.

[0360] In some embodiments, the antibody or the antigen-binding fragment thereof comprises one or more cysteine residues that are covalently linked to the first linker and / or a second linker.

[0361] In some embodiments, the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue covalently linked to the first or second linker and at least one modified amino acid suitable for conjugation that is covalently linked to the other of the first or second linker.

[0362] In some embodiments, the antibody or the antigen-binding fragment thereof comprises at least one modified amino acids suitable for conjugation that is covalently linked to the first linker and / or a second linker.

[0363] In some embodiments, the antibody or the antigen-binding fragment thereof comprises at least two modified amino acids suitable for conjugation that are covalently linked to the first linker and / or a second linker.

[0364] In some embodiments, the antibody or the antigen-binding fragment thereof comprises at least three modified amino acids suitable for conjugation that are covalently linked to the first linker and / or a second linker.

[0365] In some embodiments, the antibody or the antigen-binding fragment thereof is (a) covalently linked to the first linker via a modified amino acid and the antibody or the antigen binding fragment thereof is (b) covalently linked to the second linker via a modified amino acid that is different than the modified amino acid in (a).

[0366] In some embodiments of Formula (Ia), (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue, lysine residue, and / or amino-terminal residue suitable for conjugation, wherein the one or more residues are covalently linked to RL.

[0367] In some embodiments of Formula (Ia), (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the antibody or the antigen-binding fragment thereof comprises one or more cysteine residues that are covalently linked to RL.

[0368] In some embodiments of Formula (Ia), including any of the foregoing, the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue covalentlyand at least one modified amino acid suitable for conjugation that is covalently linked to the other of.

[0369] In some embodiments of Formula (Ia), the antibody or the antigen-binding fragment thereof comprises at least one modified amino acids suitable for conjugation that is.

[0370] In some embodiments of Formula (Ia), the antibody or the antigen-binding fragment thereof comprises at least two modified amino acids suitable for conjugation that are.

[0371] In some embodiments of Formula (Ia), the antibody or the antigen-binding fragment thereof comprises at least three modified amino acids suitable for conjugation that are.

[0372] In some embodiments of Formula (Ia), the antibody or the antigen-binding fragmentthereof is (a) covalently linked to orvia a modified amino acid and the antibody or the antigen binding fragment thereof is (b) covalently linked to the other ofvia a modified amino acid that is different than the modified amino acid in (a).

[0373] In some embodiments of Formula (Ib), (Ib-A), or (Ib-B), including any of the foregoing, the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue covalently linked to orleast one modified amino acid suitable for conjugationthat is covalently linked to the other of or.

[0374] In some embodiments of Formula (Ib), (Ib-A), or (Ib-B), the antibody or the antigen- binding fragment thereof comprises at least one modified amino acids suitable forconjugation that is covalently linked to and / or.

[0375] In some embodiments of Formula (Ib), (Ib-A), or (Ib-B), the antibody or the antigen- binding fragment thereof comprises at least two modified amino acids suitable forconjugation that are covalently linked to.

[0376] In some embodiments of Formula (Ib), (Ib-A), or (Ib-B), the antibody or the antigen- binding fragment thereof comprises at least three modified amino acids suitable forconjugation that are covalently linked to.

[0377] In some embodiments of Formula (Ib), (Ib-A), or (Ib-B), the antibody or the antigen- binding fragment thereof is (a) covalently linked tomodified amino acid and the antibody or the antigen binding fragment thereof is (b)covalently linked to the other of orvia a modified amino acid that is different than the modified amino acid in (a).

[0378] In any of the foregoing embodiments, for instance wherein the antibody conjugate has a structure according to a formula described herein, the bracketed structure can be covalently bonded to one or more non-natural or modified amino acids of the antibody, wherein the one or more non-natural or modified amino acids are located at sites independently selected from the group consisting of: HC-F404, HC-Y180, HC-Y391, HC-F241, LC-K42, LC-E161, and LC-D170 and combinations thereof, according to the Kabat or EU numbering scheme of Kabat. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site HC-F404 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified aminoacids at site HC-Y391 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site HC-Y180 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site HC-F241 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site LC-K42 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site LC- E161 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at site LC-D170 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites HC-F404 and HC-Y180 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites HC-F241, HC-F404, and HC-Y180 of the antibody.

[0379] In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites HC-Y180 and LC-K42 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites HC-F404 and LC-K42 of the antibody. In some embodiments, the bracketed structure is covalently bonded to one or more non-natural or modified amino acids at sites HC-F404, HC-Y180, and LC-K42 of the antibody. In some embodiments, one bracketed structure binds to L-para-acetyl-phenylalanine (pAcF) at one or more sites and the other bracketed structure binds to a residue according to Formula (30) at one or more sites.

[0380] In some embodiments, at least one bracketed structure is covalently bonded to a non- natural or modified amino acid at site HC-F404 of the antibody, and at least one bracketed structure is covalently bonded a non-natural or modified amino acid at site HC-Y180 of the antibody. In some embodiments, at least one bracketed structure is covalently bonded to a non-natural or modified amino acid at site HC-F404 of the antibody, and at least one bracketed structure is covalently bonded a non-natural or modified amino acid at site LC-K42 of the antibody. In some embodiments, at least one bracketed structure is covalently bonded to a non-natural or modified amino acid at site HC-F241 of the antibody, and at least one bracketed structure is covalently bonded a non-natural or modified amino acid at site LC-K42 of the antibody. In some embodiments, at least one bracketed structure is covalently bonded to a non-natural or modified amino acid at site HC-F241 of the antibody and HC-F404, and at least one bracketed structure is covalently bonded a non-natural or modified amino acid at site LC-K42 of the antibody.

[0381] In some embodiments, the non-natural or modified amino acid at the sites described herein are the same non-natural amino acid. For example, the non-natural or modified amino acid at sites HC-F404, HC-F241, HC-Y391, LC-E161, LC-D170, and LC-K42 are the same non-natural amino acid. In preferred embodiments, the non-natural or modified amino acid at sites described herein are the each independently selected from two different non-natural or modified amino acids. In a preferred embodiment, the non-natural amino acid at sites HC-F404, HC-F241, and LC-K42 are the each independently selected from two different non-natural or modified amino acids. For example, the non-natural amino acid at site HC- F404 and HC-F241, may be a first non-natural or modified amino acid, while the non-natural amino acid at site LC-K42 may be a different non-natural or modified amino acid. In some embodiments, the modified amino acid at site HC-F404 and HC-F241, is a residue according to Formula (30), while the modified amino acid at site LC-K42 is L-para-acetyl- phenylalanine.

[0382] Water Soluble Polymers

[0383] In certain embodiments, the conjugate comprises one or more water-soluble polymers, for example HP1or HP2. A wide variety of macromolecular polymers and other molecules can be linked to the polypeptides described herein to modulate biological properties of the polypeptide, and / or provide new biological properties to the polypeptide. These macromolecular polymers can be linked to the polypeptide via a naturally encoded amino acid, via a non-naturally encoded or modified amino acid, or any functional substituent of a natural or modified amino acid, or any substituent or functional group added to a natural or modified amino acid. The molecular weight of the polymer may be of a wide range, including but not limited to, between about 100 Da and about 100,000 Da or more.

[0384] The polymer selected may be water soluble so that a protein to which it is attached does not precipitate in an aqueous environment, such as a physiological environment. The polymer may be branched or unbranched. Preferably, for therapeutic use of the end-product preparation, the polymer will be pharmaceutically acceptable.

[0385] In certain embodiments, the proportion of polyethylene glycol molecules to polypeptide molecules will vary, as will their concentrations in the reaction mixture. In general, the optimum ratio (in terms of efficiency of reaction in that there is minimal excess unreacted protein or polymer) may be determined by the molecular weight of the polyethylene glycol selected and on the number of available reactive groups available. As relates to molecular weight, typically the higher the molecular weight of the polymer, the fewer number of polymer molecules which may be attached to the protein. Similarly,branching of the polymer should be taken into account when optimizing these parameters. Generally, the higher the molecular weight (or the more branches) the higher the polymer:protein ratio.

[0386] The water-soluble polymer may be any structural form including but not limited to linear, forked or branched. Typically, the water soluble polymer is a poly(alkylene glycol), such as poly(ethylene glycol) (PEG), but other water soluble polymers can also be employed. By way of example, PEG is used to describe certain embodiments.

[0387] PEG is a well-known, water-soluble polymer that is commercially available or can be prepared by ring-opening polymerization of ethylene glycol according to methods well known in the art (Sandler and Karo, Polymer Synthesis, Academic Press, New York, Vol.3, pages 138-161). The term “PEG” is used broadly to encompass any polyethylene glycol molecule, without regard to size or to modification at an end of the PEG, and can be represented as linked to a polypeptide by the formula: XO–(CH2CH2O)n–CH2CH2–Y where n is 2 to 10,000, X is H or a terminal modification, including but not limited to, a C1-4alkyl, and Y is the attachment point to the polypeptide.

[0388] In some cases, a PEG terminates on one end with hydroxy or methoxy, i.e., X is H or CH3(“methoxy PEG”). Alternatively, the PEG can terminate with a reactive group, thereby forming a bifunctional polymer. Typical reactive groups can include those reactive groups that are commonly used to react with the functional groups found in the 20 common amino acids (including but not limited to, maleimide groups, activated carbonates (including but not limited to, p-nitrophenyl ester), activated esters (including but not limited to, N-hydroxysuccinimide, p-nitrophenyl ester, and aldehydes) as well as functional groups that are inert to the 20 common amino acids but that react specifically with complementary functional groups present in non-naturally encoded or modified amino acids (including but not limited to, azide groups, alkyne groups). It is noted that the other end of the PEG, which is shown in the above formula by Y, will attach either directly or indirectly to a polypeptide via a naturally-occurring or non-naturally encoded or modified amino acid. For instance, Y may be an amide, carbamate, or urea linkage to an amine group (including but not limited to, the epsilon amine of lysine or the N-terminus) of the polypeptide. Alternatively, Y may be a maleimide linkage to a thiol group (including but not limited to, the thiol group of cysteine). Alternatively, Y may be a linkage to a residue not commonly accessible via the 20 common amino acids. For example, an azide group on the PEG can be reacted with an alkyne group on the polypeptide to form a Huisgen [3+2] cycloaddition product. Alternatively, an alkyne group on the PEG can be reacted with an azide group present in a non-naturally encoded ormodified amino acid, such as the modified amino acids described herein, to form a similar product. In some embodiments, a strong nucleophile (including but not limited to, hydrazine, hydrazide, hydroxylamine, semicarbazide) can be reacted with an aldehyde or ketone group present in a non-naturally encoded or modified amino acid to form a hydrazone, oxime or semicarbazone, as applicable, which in some cases can be further reduced by treatment with an appropriate reducing agent. Alternatively, the strong nucleophile can be incorporated into the polypeptide via a non-naturally encoded or modified amino acid and used to react preferentially with a ketone or aldehyde group present in the water-soluble polymer.

[0389] Any molecular mass for a PEG can be used as practically desired, including but not limited to, from about 100 Daltons (Da) to 100,000 Da or more as desired (including but not limited to, sometimes 0.1-50 kDa or 10-40 kDa). Branched chain PEGs, including but not limited to, PEG molecules with each chain having a MW ranging from 1-100 kDa (including but not limited to, 1-50 kDa or 5-20 kDa) can also be used. A wide range of PEG molecules are described in, including but not limited to, the Shearwater Polymers, Inc. catalog, and the Nektar Therapeutics catalog, incorporated herein by reference.

[0390] Generally, at least one terminus of the PEG molecule is available for reaction with the antibody. For example, PEG derivatives bearing alkyne and azide moieties for reaction with amino acid side chains can be used to attach PEG to non-naturally encoded or modified amino acids as described herein. If the non-naturally encoded or modified amino acid comprises an azide, then the PEG will typically contain either an alkyne moiety to effect formation of the [3+2] cycloaddition product or an activated PEG species (i.e., ester, carbonate) containing a phosphine group to effect formation of the amide linkage. Alternatively, if the non-naturally encoded or modified amino acid comprises an alkyne, then the PEG will typically contain an azide moiety to effect formation of the [3+2] Huisgen cycloaddition product. If the non-naturally encoded or modified amino acid comprises a carbonyl group, the PEG will typically comprise a potent nucleophile (including but not limited to, a hydrazide, hydrazine, hydroxylamine, or semicarbazide functionality) in order to effect formation of corresponding hydrazone, oxime, and semicarbazone linkages, respectively. In other alternatives, a reverse of the orientation of the reactive groups described herein can be used, i.e., an azide moiety in the non-naturally or modified encoded amino acid can be reacted with a PEG derivative containing an alkyne.

[0391] In some embodiments, the polypeptide variant with a PEG derivative contains a chemical functionality that is reactive with the chemical functionality present on the side chain of the non-naturally encoded or modified amino acid.

[0392] In certain embodiments, the water soluble polymer is an azide- or acetylene- containing polymer comprising a water-soluble polymer backbone having an average molecular weight from about 800 Da to about 100,000 Da. The polymer backbone of the water-soluble polymer can be poly(ethylene glycol). However, it should be understood that a wide variety of water soluble polymers including but not limited to poly(ethylene)glycol and other related polymers, including poly(dextran) and poly(propylene glycol), are also suitable for use and that the use of the term PEG or poly(ethylene glycol) is intended to encompass and include all such molecules. The term PEG includes, but is not limited to, poly(ethylene glycol) in any of its forms, including bifunctional PEG, multiarmed PEG, derivatized PEG, forked PEG, branched PEG, pendent PEG (i.e. PEG or related polymers having one or more functional groups pendent to the polymer backbone), or PEG with degradable linkages therein.

[0393] The polymer backbone can be linear or branched. Branched polymer backbones are generally known in the art. Typically, a branched polymer has a central branch core moiety and a plurality of linear polymer chains linked to the central branch core. PEG is commonly used in branched forms that can be prepared by addition of ethylene oxide to various polyols, such as glycerol, glycerol oligomers, pentaerythritol and sorbitol. The central branch moiety can also be derived from several amino acids, such as lysine. The branched poly(ethylene glycol) can be represented in general form as R(-PEG-OH)m in which R is derived from a core moiety, such as glycerol, glycerol oligomers, or pentaerythritol, and m represents the number of arms. Multi-armed PEG molecules, such as those described in U.S. Pat. Nos. 5,932,4625,643,575; 5,229,490; 4,289,872; U.S. Pat. Appl.2003 / 0143596; WO 96 / 21469; and WO 93 / 21259, each of which is incorporated by reference herein in its entirety, can also be used as the polymer backbone.

[0394] Branched PEG can also be in the form of a forked PEG represented by PEG(-YCHZ2)n, where Y is a linking group and Z is an activated terminal group linked to CH by a chain of atoms of defined length.

[0395] Yet another branched form, the pendant PEG, has reactive groups, such as carboxyl, along the PEG backbone rather than at the end of PEG chains.

[0396] In addition to these forms of PEG, the polymer can also be prepared with weak or degradable linkages in the backbone. For example, PEG can be prepared with ester linkages in the polymer backbone that are subject to hydrolysis. As shown herein, this hydrolysis results in cleavage of the polymer into fragments of lower molecular weight: -PEG-CO2- PEG-+H2O→PEG-CO2H+HO-PEG- It is understood by those skilled in the art that the termpoly(ethylene glycol) or PEG represents or includes all the forms known in the art including but not limited to those disclosed herein.

[0397] Many other polymers are also suitable for use. In some embodiments, polymer backbones that are water-soluble, with from 2 to about 300 termini, are particularly suitable. Examples of suitable polymers include, but are not limited to, other poly(alkylene glycols), such as poly(propylene glycol) (“PPG”), copolymers thereof (including but not limited to copolymers of ethylene glycol and propylene glycol), terpolymers thereof, mixtures thereof, and the like. Although the molecular weight of each chain of the polymer backbone can vary, it is typically in the range of from about 800 Da to about 100,000 Da, often from about 6,000 Da to about 80,000 Da.

[0398] Those of ordinary skill in the art will recognize that the foregoing list for substantially water-soluble backbones is by no means exhaustive and is merely illustrative, and that all polymeric materials having the qualities described herein are contemplated as being suitable for use. In some embodiments the polymer derivatives are "multi-functional", meaning that the polymer backbone has at least two termini, and possibly as many as about 300 termini, functionalized or activated with a functional group. Multifunctional polymer derivatives include, but are not limited to, linear polymers having two termini, each terminus being bonded to a functional group which may be the same or different.

[0399] Linker-Payloads and Compounds

[0400] Aminooxy PEGylated valcit Cleavable LPs with Various MoA:

[0401] The aminooxy PEGylated b-glu cleavable Etoposide linker payload is synthesized from Etoposide and similar methods as described herein. The payload can be any payload disclosed herein. In an embodiment, the payload is selected from eribulin, anthracyclines, HDACi, KSPi, STAT3 degrader, BCL-XL inhibitor, or combinations thereof.

[0402] Aminooxy PEGylated β-glucuronidase Cleavable LPs with Various MoA:

[0403] The payload can be any payload disclosed herein. In an embodiment, the payload is selected from eribulin, anthracyclines, HDACi, KSPi, STAT3 degrader, BCL-XL inhibitor, or combinations thereof.

[0404] Described herein are linker payloads. In an embodiment, the linker payload includes a payload that is a tubulin inhibitor, such as MMAE (monomethyl auristatin E). In some embodiments, the linker payload is a compound according to the structure of Formula (I)or a pharmaceutically acceptable salt thereof, wherein L1is -C1-6 alkylene-, wherein the alkylene is optionally substituted with one or more substituents selected from R51; Y is –X1-C1-6alkylene-[X1-C1-6alkylene]n-[X1]p–, –X1-C2-6alkenylene-[X1-C2-6alkenylene]n-[X1]p–, or–X1-C2-6alkynylene-[X1-C2-6alkynylene]n-[X1]p–, wherein at least one alkylene, alkenylene, or alkynylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene, alkenylene, or alkynylene in Y is optionally substituted with one or more substituents selected from R51; R50is –C1-6 alkylene-X2-[C1-6 alkylene]m-POLY, –C2-6 alkenylene-X2-[C2-6 alkenylene]m-POLY, or –C2-6alkynylene-X2-[C2-6alkynylene]m-POLY, wherein each alkylene, alkenylene, or alkynylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12- membered heterocycle, and C1-10haloalkyl; R51is independently selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10 alkyl, C2-10 alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl; X1and X2are independently selected from –N(R10)–, –C(O)–, and –N(R10)C(O)–; R10is independently selected at each occurrence from hydrogen, C1-10 alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl; POLY is a water-soluble polymer; n is an integer selected from zero, one, two, and three; m is an integer selected from zero and one; p is an integer selected from zero and one; Su is a hexose form of a monosaccharide; D is MMAE; and RL is a reactive linker group residue.

[0405] In an embodiment, the linker payload can be according to the following structure:, wherein n is an integer between 1 and 12, and m is an integer between 1 and 6.

[0406] Also described herein are linker payloads including PA1and / or PA2according to LP101-LP110, LP117, LP119, and LP125.

[0407] Optically Active Compounds

[0408] In certain embodiments, compounds, linker-payloads, and conjugates provided herein may have several chiral centers and may exist in and be isolated in optically active and racemic forms. In certain embodiments, some compounds, linker-payloads, or conjugates may exhibit polymorphism. A person of skill in the art will appreciate that compounds, linker-payloads, and conjugates provided herein can exist in any racemic, optically-active, diastereomeric, polymorphic, regioisomeric and / or stereoisomeric form, and / or mixtures thereof.

[0409] A person of skill in the art will also appreciate that such compounds, linker-payloads, and conjugates described herein that possess the useful properties also described herein are within the scope of this disclosure. A person of skill in the art will further appreciate how to prepare optically active forms of the compounds, linker-payloads, and conjugates described herein, for example, by resolution of racemic forms via recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase. In addition, most amino acids are chiral (i.e., designated as L- or D-, wherein the L- enantiomer is the naturally occurring configuration) and can exist as separate enantiomers.

[0410] Examples of methods to obtain optically active materials are known in the art, and include at least the following:i) physical separation of crystals – a technique whereby macroscopic crystals of the individual enantiomers are manually separated. This technique can be used if crystals of the separate enantiomers exist (i.e., the material is a conglomerate, and the crystals are visually distinct); ii) simultaneous crystallization – a technique whereby the individual enantiomers are separately crystallized from a solution of the racemate, only if the latter is a conglomerate in the solid state; iii) enzymatic resolutions – a technique wherein partial or complete separation of a racemate is accomplished by virtue of different rates of reaction of the enantiomers in the presence of an enzyme; iv) enzymatic asymmetric synthesis – a synthetic technique wherein at least one step of the synthesis uses an enzymatic reaction to obtain an enantiomerically pure or enriched synthetic precursor of the desired enantiomer; v) chemical asymmetric synthesis – a synthetic technique wherein the desired enantiomer is synthesized from an achiral precursor using chiral catalysts or chiral auxiliaries to produce asymmetry (i.e., chirality) in the product; vi) diastereomer separations – a technique wherein a racemic compound is treated with an enantiomerically pure reagent (a chiral auxiliary) that converts the individual enantiomers to diastereomers. The resulting diastereomers are then separated by chromatography or crystallization by virtue of their now more distinct diastereomeric differences, and then the chiral auxiliary is removed to obtain each enantiomer; vii) first- and second-order asymmetric transformations – a technique wherein diastereomers of the racemate equilibrate in solution to yield a preponderance of a diastereomer of the desired enantiomer, or where kinetic or thermodynamic crystallization of the diastereomer of the desired enantiomer perturbs the equilibrium such that eventually in principle all the material is converted to the crystalline diastereomer of the desired enantiomer. The desired enantiomer is then derived from the diastereomer; viii) kinetic resolutions – this technique refers to the achievement of partial or complete resolution of a racemate (or of a further resolution of a partially resolved compound) by virtue of unequal reaction rates of the enantiomers with a chiral or non-racemic reagent or catalyst under kinetic conditions;ix) enantiospecific synthesis from non-racemic precursors – a synthetic technique wherein the desired enantiomer is obtained from chiral starting materials and where the stereochemical integrity is not or is only minimally compromised over the course of the synthesis; x) chiral liquid chromatography – a technique wherein the enantiomers of a racemate are separated in a liquid mobile phase by virtue of their different interactions with a stationary phase. The stationary phase can be made of chiral material or the mobile phase can contain an additional chiral material to provoke the different interactions; xi) chiral gas chromatography – a technique wherein the racemate is volatilized and enantiomers are separated by virtue of their different interactions in the gaseous mobile phase with a column containing a fixed non-racemic adsorbent phase; xii) extraction with chiral solvents – a technique wherein the enantiomers are separated by virtue of kinetic or thermodynamic dissolution of one enantiomer into a particular chiral solvent; xiii) transport across chiral membranes – a technique wherein a racemate is placed in contact with a thin membrane barrier. The barrier typically separates two miscible fluids, one containing the racemate, and a driving force such as a concentration or pressure differential causes preferential transport across the membrane barrier. Separation occurs as a result of the non-racemic nature of the membrane which allows only one enantiomer of the racemate to pass through.

[0411] In some embodiments, provided herein are compositions of the compounds, linker- payloads, or conjugates of the present disclosure that are substantially free of a designated stereoisomer of that compound, linker-payload, or conjugate, respectively. In certain embodiments, in the methods, compounds, linker-payloads, and conjugates of this disclosure, the compounds, linker-payloads, or conjugates are substantially free of other stereoisomers. In some embodiments, the composition includes a compound, linker-payload, or conjugate that is at least 85%, 90%, 95%, 98%, or 99% to 100% by weight of the compound, linker- payload or conjugate, respectively, the remainder comprising other chemical species or enantiomers. In some embodiments, provided herein are compositions of conjugates, linker- payloads, or compounds described herein that are substantially free of a designated enantiomer of that conjugate, linker-payload, or compound, respectively. In certain embodiments, in the methods, compounds, linker-payloads, and conjugates of this disclosure, the compounds, linker-payloads, or conjugates are substantially free of other enantiomers. Insome embodiments, the composition includes a compound, linker-payload, or conjugate that is at least 85%, 90%, 95%, 98%, or 99% to 100% by weight of the compound, linker- payload, or conjugate, respectively, the remainder comprising other chemical species or enantiomers.

[0412] Isotopically Enriched Compounds

[0413] Also provided herein are isotopically enriched compounds, linker-payloads, and conjugates of the compounds, linker-payloads, and conjugates described herein.

[0414] Isotopic enrichment (for example, deuteration) of pharmaceuticals to improve pharmacokinetics (“PK”), pharmacodynamics (“PD”), and / or toxicity profiles, has been previously demonstrated within some classes of drugs. See, for example, Lijinsky et al., Food Cosmet. Toxicol., 20: 393 (1982); Lijinsky et al., J. Nat. Cancer Inst., 69: 1127 (1982); Mangold et al., Mutation Res.308: 33 (1994); Gordon et al., Drug Metab. Dispos., 15: 589 (1987); Zello et al., Metabolism, 43: 487 (1994); Gately et al., J. Nucl. Med., 27: 388 (1986); Wade D, Chem. Biol. Interact.117: 191 (1999).

[0415] Isotopic enrichment of a drug can be used, for example, to (1) reduce or eliminate unwanted metabolites; (2) increase the half-life of the parent drug; (3) decrease the number of doses needed to achieve a desired effect; (4) decrease the amount of a dose necessary to achieve a desired effect; (5) increase the formation of active metabolites, if any are formed; and / or (6) decrease the production of deleterious metabolites in specific tissues. Isotopic enrichment of a drug can also be used to create a more effective and / or safer drug for combination therapy, whether the combination therapy is intentional or not.

[0416] Replacement of an atom for one of its isotopes often will result in a change in the reaction rate of a chemical reaction. This phenomenon is known as the Kinetic Isotope Effect (“KIE”). For example, if a C–H bond is broken during a rate-determining step in a chemical reaction (i.e., the step with the highest transition state energy), substitution of a (heavier) isotope for that reactive hydrogen will cause a decrease in the reaction rate. The Deuterium Kinetic Isotope Effect (“DKIE”) is the most common form of KIE. (See, e.g., Foster et al., Adv. Drug Res., vol.14, pp.1-36 (1985); Kushner et al., Can. J. Physiol. Pharmacol., vol.77, pp.79-88 (1999)).

[0417] The magnitude of the DKIE can be expressed as the ratio between the rates of a given reaction in which a C–H bond is broken, and the same reaction where deuterium is substituted for hydrogen and the C–D bond is broken. The DKIE can range from about one (no isotope effect) to very large numbers, such as 50 or more, meaning that the reaction can be fifty, or more, times slower when deuterium has been substituted for hydrogen.

[0418] Substitution of tritium (“T”) for hydrogen results in yet a stronger bond than deuterium and gives numerically larger isotope effects. Similarly, substitution of isotopes for other elements including, but not limited to,13C or14C for carbon;33S,34S, or36S for sulfur;15N for nitrogen; and17O or18O for oxygen may lead to a similar kinetic isotope effect.

[0419] The animal body expresses a variety of enzymes for the purpose of eliminating foreign substances, such as therapeutic agents, from its circulation system. Examples of such enzymes include the cytochrome P450 enzymes (“CYPs”), esterases, proteases, reductases, dehydrogenases, and monoamine oxidases to react with and convert these foreign substances to more polar intermediates or metabolites for renal excretion. Some of the most common metabolic reactions of pharmaceutical compounds involve the oxidation of a carbon- hydrogen (C–H) bond to either a carbon-oxygen (C–O) or carbon-carbon (C=C) pi-bond. The resultant metabolites may be stable or unstable under physiological conditions, and can have substantially different PK / PD, and acute and long-term toxicity profiles relative to the parent compounds. For many drugs, such oxidations are rapid. Therefore, these drugs often require the administration of multiple or high daily doses.

[0420] Therefore, isotopic enrichment at certain positions of a compound provided herein will produce a detectable KIE that will affect the pharmacologic, PK, PD, and / or toxicological profiles of a compound provided herein in comparison with a similar compound having a natural isotopic composition.

[0421] Preparation of Antibodies and Antibody Conjugates

[0422] Antigen Preparation

[0423] The protein to be used for isolation of the antibodies may be intact antigen or a fragment of antigen. The intact protein, or fragment of the antigen, may be in the form of an isolated protein or protein expressed by a cell. Other forms of antigens useful for generating antibodies will be apparent to those skilled in the art.

[0424] Monoclonal Antibodies

[0425] Monoclonal antibodies may be obtained, for example, using the hybridoma method first described by Kohler et al., Nature, 1975, 256:495-497 (incorporated by reference in its entirety), and / or by recombinant DNA methods (see e.g., U.S. Patent No.4,816,567, incorporated by reference in its entirety). Monoclonal antibodies may also be obtained, for example, using phage or yeast-based libraries. See e.g., U.S. Patent Nos.8,258,082 and 8,691,730, each of which is incorporated by reference in its entirety.

[0426] In the hybridoma method, a mouse or other appropriate host animal is immunized to elicit lymphocytes that produce or are capable of producing antibodies that will specificallybind to the protein used for immunization. Alternatively, lymphocytes may be immunized in vitro. Lymphocytes are then fused with myeloma cells using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell. See Goding J.W., Monoclonal Antibodies: Principles and Practice 3rded. (1986) Academic Press, San Diego, CA, incorporated by reference in its entirety.

[0427] The hybridoma cells are seeded and grown in a suitable culture medium that contains one or more substances that inhibit the growth or survival of the unfused, parental myeloma cells. For example, if the parental myeloma cells lack the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT or HPRT), the culture medium for the hybridomas typically will include hypoxanthine, aminopterin, and thymidine (HAT medium), which substances prevent the growth of HGPRT-deficient cells.

[0428] Useful myeloma cells are those that fuse efficiently, support stable high-level production of antibody by the selected antibody-producing cells, and are sensitive media conditions, such as the presence or absence of HAT medium. Among these, preferred myeloma cell lines are murine myeloma lines, such as those derived from MOP-21 and MC-11 mouse tumors (available from the Salk Institute Cell Distribution Center, San Diego, CA), and SP-2 or X63-Ag8-653 cells (available from the American Type Culture Collection, Rockville, MD). Human myeloma and mouse-human heteromyeloma cell lines also have been described for the production of human monoclonal antibodies. See e.g., Kozbor, J. Immunol., 1984, 133:3001, incorporated by reference in its entirety.

[0429] After the identification of hybridoma cells that produce antibodies of the desired specificity, affinity, and / or biological activity, selected clones may be subcloned by limiting dilution procedures and grown by standard methods. See Goding, supra. Suitable culture media for this purpose include, for example, D-MEM or RPMI-1640 medium. In addition, the hybridoma cells may be grown in vivo as ascites tumors in an animal.

[0430] DNA encoding the monoclonal antibodies may be readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes that are capable of binding specifically to genes ...

Claims

CLAIMS What is claimed is:

1. An antibody conjugate comprising an antibody or antigen-binding fragment thereof covalently linked to one or more of a first payload (PA1) via a first linker (La), and covalently linked to one or more of a second payload (PA2) via a second linker (Lb), wherein the antibody or antigen-binding fragment thereof comprises one or more modified amino acid residues, wherein the first payload is a topoisomerase inhibitor, and wherein the second payload is a cytotoxic agent.

2. The antibody conjugate of claim 1, wherein the antibody conjugate is represented by the structure of Formula (I):Formula (I) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein Ab is the antibody or antigen-binding fragment thereof; Lais the first linker; Lbis the second linker; PA1is the first payload, wherein the first payload is a topoisomerase inhibitor; PA2 is the second payload, wherein the second payload is a cytotoxic agent; subscript n is an integer selected from 1 to 12; and subscript m is an integer selected from 1 to 12.

3. The antibody conjugate of claim 2, wherein the topoisomerase inhibitor is a topoisomerase I inhibitor or a topoisomerase II inhibitor.

4. The antibody conjugate of claim 3, wherein the topoisomerase I inhibitor is selected from the group consisting of camptothecin, SN-38, exatecan, irinotecan, topotecan, govitecan, deruxtecan, belotecan, and derivatives thereof.

5. The antibody conjugate of claim 3 or 4, wherein the topoisomerase I inhibitor is exatecan.

6. The antibody conjugate of claims 1-3, wherein the topoisomerase inhibitor is a topoisomerase II inhibitor.

7. The antibody conjugate of claim 6, wherein the topoisomerase II inhibitor is selected from the group consisting of amonafide, azonafide-PEABA, etoposide, teniposide, tafluposide, and derivatives thereof.

8. The antibody conjugate of any one of the previous claims, wherein the cytotoxic agent is selected from the group consisting of a DNA-targeting agent, a tubulin-targeting agent, a histone-deacetylase (HDAC) inhibitor, NMT inhibitor, an anti-mitotic agent, an alkylating agent, a DNA-crosslinking agent, an anti-tumor antibiotic, an anti- metabolite, a telomerase inhibitor and an immunogenic cell death agent.

9. The antibody conjugate of claims 1-8, wherein the second payload is not a DNA damage response (DDR) inhibitor.

10. The antibody conjugate of claims 1-8, wherein the cytotoxic agent is an anthracycline selected from doxorubicin, mitoxantrone, etoposide, idarubicin, pirarubicin (P-THP), PNU, PNU analogs, and derivatives thereof.

11. The antibody conjugate of any one of claims 1-8, wherein the cytotoxic agent is a tubulin-targeting agent selected from a hemiasterlin, monomethyl auristatin-E (MMAE), monomethyl auristatin-F (MMAF), DM1, DM4, and derivatives thereof.

12. The antibody conjugate of claim 11, wherein the cytotoxic agent is hemiasterlin or MMAE.

13. The antibody conjugate of claim 12, wherein the hemiasterlin is 3-aminophenyl hemiasterlin.

14. The antibody conjugate of any one of claims 1-11, wherein the cytotoxic agent is a microtubule dynamics inhibitor.

15. The antibody conjugate of claim 14, wherein the microtubule dynamics inhibitor is eribulin.

16. The antibody conjugate of claim 1 or 2, wherein the PA1is exatecan and PA2is hemiasterlin.

17. The antibody conjugate of claim 1 or 2, wherein the PA1is exatecan and PA2is MMAE.

18. The antibody conjugate of claim 1 or 2, wherein the PA1 is a topoisomerase I inhibitor and PA2 is a topoisomerase II inhibitor.

19. The antibody conjugate of any one of claims 1-18, wherein each of the first and second linker independently comprises a protease cleavable linker, an enzyme cleavable linker, a pH-sensitive linker, or a non-cleavable linker.

20. The antibody conjugate of any one of claims 1-19, wherein each of the first and second linker independently comprises a cleavable linker, wherein the cleavable linker comprises a cathepsin cleavable linker.

21. The antibody conjugate of any one of claims 1-20, wherein each of the first and second linker independently comprises a cleavable linker, wherein the cleavable linker comprises a β-glucuronidase-cleavable β-glucuronide.

22. The antibody conjugate of any one of claims 2-21, wherein the antibody conjugate of Formula (I) is represented by Formula (Ia):Formula (Ia) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein: each SP1, SP2, and SP3are independently, at each occurrence, absent or a divalent spacer group; each W1is independently, at each occurrence, absent orwherein the -NH- is bound to W2and eachindicates a point of attachment to the rest of the formula; L1is independently a bond or an optionally substituted C1-6alkylene wherein the C1-6alkylene is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy; each W2is independently, at each occurrence, absent, an amino acid residue, or a peptide residue wherein the amino acid residue or peptide residue is optionally substituted with a HP2group; each HP1, is independently, at each occurrence, absent or a divalent hydrophilic group; each HP2, when present, is a monovalent hydrophilic group; each RAis independently, at each occurrence, optionally substituted C1-6alkyl wherein the C1-6alkyl is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy; each RT is independently, at each occurrence, absent or a release trigger group;each RL is a reactive linker; y is an integer independently selected from 0, 1, and 2; and z is an integer independently selected from 0 and 1.

23. The antibody conjugate of any one of claims 2-22, wherein the antibody conjugate of Formula (I) is represented by Formula (Ib):Formula (Ib) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein: TOPOi is a residue of a topoisomerase inhibitor; each SP1, SP2, and SP3are independently, at each occurrence, absent or a divalent spacer group; each W1is independently, at each occurrence, absent orwherein the -NH- is bound to W2and eachindicates a point of attachment to the rest of the formula; L1is independently a bond or an optionally substituted C1-6alkylene wherein the C1-6alkylene is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy; each W2is independently, at each occurrence, absent, an amino acid residue, or a peptide residue wherein the amino acid residue or peptide residue is optionally substituted with a HP2group; each HP1, is independently, at each occurrence, absent or a divalent hydrophilic group; each HP2, when present, is a monovalent hydrophilic group; each RAis independently, at each occurrence, optionally substituted C1-6alkyl wherein the C1-6alkyl is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy;each RT is independently, at each occurrence, absent or a release trigger group; each RL is a reactive linker; y is an integer independently selected from 0, 1, and 2; and z is an integer independently selected from 0 and 1; L2is -C1-6 alkylene-; Y is –X1-C1-6 alkylene-[X1-C1-6 alkylene]a-[X1]b–, –X1-C2-6 alkenylene-[X1-C2- 6 alkenylene]a-[X1]b–, or–X1-C2-6alkynylene-[X1-C2-6alkynylene]a-[X1]b–, wherein at least one alkylene, alkenylene, or alkynylene in Y is substituted with one or more substituents selected from R50, and wherein the alkylene, alkenylene, or alkynylene in Y is optionally substituted with one or more substituents selected from R51; R50is –C1-6 alkylene-X2-[C1-6 alkylene]c-HP2, –C2-6 alkenylene-X2-[C2-6 alkenylene]c- HP2, or –C2-6 alkynylene-X2-[C2-6 alkynylene]c- HP2, wherein each alkylene, alkenylene, or alkynylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl; R51is independently selected from halogen, -CN, -NO2, -OH, -N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl; X1and X2are independently selected from –N(R10)–, –C(O)–, and – N(R10)C(O)–; R10is independently selected at each occurrence from hydrogen, C1-10alkyl, C2-10 alkenyl, C2-10 alkynyl, C3-12 carbocycle, 3- to 12-membered heterocycle, and C1-10haloalkyl; a is an integer selected from zero, one, two, and three; b is an integer selected from zero and one; c is an integer selected from zero and one; and Su is a hexose form of a monosaccharide.

24. The antibody conjugate of claim 23, of the Formula (Ib-A):Formula (Ib-A) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof.

25. The antibody conjugate of claim 23, of the Formula (Ib-B):Formula (Ib-B) or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof.

26. The antibody conjugate of any one of claims 22-25, wherein SP2and SP3are independently absent or selected from -C1-6alkylene-, -C(O)-, -C1-6alkylene-C(O)- wherein the -C(O)- is bound to W2or HP1, respectively, -C(O)-C1-6alkylene-C(O)- , -C(O)(C1-6alkylene)NR1C(O)-, -C(O)(C1-6alkylene)OC(O)-, and -C(O)(C1- 6alkylene)SC(O)-; wherein R1is hydrogen or optionally substituted C1-6alkyl; and the C1-6alkylene of SP2or SP3, alone or part of another group, is optionally substituted with one, two, or three substituents selected from halogen, alkyl, haloalkyl, hydroxyl, amino, alkylamino, and alkoxy.

27. The antibody conjugate of claim 26, wherein SP3is independently absent or -C(O)-C1- 6alkylene-C(O)-.

28. The antibody conjugate of claim 26, wherein SP3is absent.

29. The antibody conjugate of any one of claims 22-23, wherein SP2is independently absent or -C1-6alkylene-C(O)- wherein the -C(O)- is bound to W2.

30. The antibody conjugate of claim 29, wherein SP2is independently -C1-2alkylene- C(O)-.

31. The antibody conjugate of any one of claims 22-30, wherein HP1is independentlywherein R2is hydrogen or methyl and x1 is an integer between 1 and 50, inclusive; and eachis the point of attachment to the rest of the compound.

32. The antibody conjugate of claim 31, wherein R2is hydrogen.

33. The antibody conjugate of claim 31 or 32, wherein x1 is independently an integer between 1 and 10, inclusive.

34. The antibody conjugate of claim 33, wherein x1 is independently an integer between 1 and 5, inclusive.

35. The antibody conjugate of claim 34, wherein x1 is 4.

36. The antibody conjugate of any one of claims 22-30, wherein HP1is absent.

37. The antibody conjugate of any one of claims 22-36, wherein W2is absent.

38. The antibody conjugate of any one of claims 22-36, wherein W2is independently an amino acid residue or a peptide residue wherein the amino acid residue or the peptide residue is optionally substituted with HP2.

39. The antibody conjugate of claim 38, wherein W2is independently a peptide residue and the peptide residue comprises at least one non-natural amino acid and the peptide residue is optionally substituted with HP2.

40. The antibody conjugate of claim 39, wherein the at least one non-natural amino acid is selected from 3-sulfoalanine, hydroxyproline (Hyp), citrulline (Cit), ornithine (Orn), norleucine (Nle), 3-nitrotyrosine, nitroarginine, pyroglutamic acid (Pyr), naphtylalanine (Nal), 2,4-diaminobutyric acid (DAB), methionine sulfoxide, methionine sulfone, 2,3-diaminopropionate, and beta-alanine.

41. The antibody conjugate of any one of claims 38-40, wherein W2is independently an amino acid residue and the amino acid residue is a beta-amino acid.

42. The antibody conjugate of claim 41, wherein the beta-amino acid is beta-alanine.

43. The antibody conjugate of any one of claims 22-36, wherein W2is independently selected from -(C(O)CHR3NR4)a-, -(C(O)CH2CHR3NR4)b-, -(C(O)CHR3CH2NR4)b-, -(C(O)CH2CHR3NR4)b-(C(O)CHR3NR4)a-, -(C(O)CHR3CH2NR4)b-(C(O)CHR3NR4)a-, -(C(O)CHR3NR4)a-(C(O)CH2CHR3NR4)b-, and -(C(O)CHR3NR4)a-(C(O)CHR3CH2NR4)b-;wherein R3is independently an amino acid sidechain residue optionally substituted with HP2; R4is independently hydrogen or C1-6 alkyl; each of a and b is an integer independently an integer between 1 and 10, inclusive; and the -C(O)- of W2is bound to W1.

44. The antibody conjugate of claim 43, wherein W2is independently -(C(O)CHR3NR4)a-.

45. The antibody conjugate of claim 43, wherein W2is independently -(C(O)CH2CHR3NR4)b-.

46. The antibody conjugate of claim 43, wherein W2is independently -(C(O)CH2CHR3NR4)b-(C(O)CHR3NR4)a-.

47. The antibody conjugate of any one of claims 43-46, wherein R3is an amino acid sidechain residue independently selected from valine, citrulline, alanine, glycine, 3- sulfoalanine and 2,3-diaminopropionate.

48. The antibody conjugate of any one of claims 43-47, wherein R4is hydrogen.

49. The antibody conjugate of any one of claims 43-48, wherein a is independently an integer between 1 and 3, inclusive.

50. The antibody conjugate of any one of claims 43-49, wherein b is 1.

51. The antibody conjugate of any one of claims 22-25, wherein W2is independently of,is the point of attachment to the rest of the compound.

52. The antibody conjugate of any one of claims 22-25, wherein W2is independently of.

53. The antibody conjugate of any one of claims 22-25, wherein W2is independently ofthe point of attachment to the rest of the compound.

54. The antibody conjugate of claim 45, wherein HP2is independentlywherein R2is hydrogen or methyl and x2 is an integer between 1 and 50, inclusive; and eachis the point of attachment to the rest of the compound.

55. The antibody conjugate of claim 54, wherein x2 is independently an integer between 10 and 20, inclusive.

56. The antibody conjugate of claim 55, wherein x2 is 12.

57. The antibody conjugate of any one of claims 22-56, wherein W1is absent.

58. The antibody conjugate of any one of claims 22-56, wherein W1is independently.

59. The antibody conjugate of claim 58, wherein y is 0.

60. The antibody conjugate of any one of claims 58-59, wherein z is 0.

61. The antibody conjugate of any one of claims 58-59, wherein z is 1.

62. The antibody conjugate of any one of claims 58-59, wherein RT is a β-glucuronidase- cleavable β-glucuronide.

63. The antibody conjugate of any one of claims 58-59, wherein RT is a cathepsin cleavable linker.

64. The antibody conjugate of claim 58, whereinthe point of attachment to the rest of the compound.

65. The antibody conjugate of claim 58, wherein.

66. The antibody conjugate of any one of claims 22-65, wherein SP1is absent.

67. The antibody conjugate of any one of claims 22-65, wherein SP1is independently absent or selected from -NR5CH2- and -NR4-arylene-CH2- wherein R5is C1-6alkyl- OCH3and R4is hydrogen or C1-6alkyl.

68. The antibody conjugate of claim 67, wherein SP1is independently -NR5CH2-.

69. The antibody conjugate of claim 68, wherein SP1is -N(CH2CH2OCH3)CH2-.

70. The antibody conjugate of claim 69, wherein SP1is independently -NR4-arylene-CH2- .

71. The antibody conjugate of claim 70, wherein SP1isis the point of attachment to the rest of the compound.

72. The conjugate of any one of claims 23-71, wherein, whereinrepresents attachment to the remainder of the compound.

73. The conjugate of any one of claims 23-72, wherein, whereinrepresents attachment to the remainder of the compound.

74. The conjugate of any one of claims 23-73, wherein L3is -C1-3alkylene-.

75. The conjugate of any one of claims 23-74, wherein Y is –X1-C1-6alkylene-[X1-C1-6alkylene]a-X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50.

76. The conjugate of any one of claims 23-75, wherein Y iswherein at least one alkylene in Y is substituted with one or more substituents selected from R50.

77. The conjugate of any one of claims 23-75, wherein Y is –X1-C1-4 alkylene-X1-C1-4 alkylene-X1–, wherein at least one alkylene in Y is substituted with one or more substituents selected from R50.

78. The conjugate of any one of claims 23-77, wherein R50is –C1-6 alkylene-X2-[C1-6 alkylene]c-HP2, wherein each alkylene of R50is optionally substituted with one or more substituents selected from halogen, -CN, -NO2, -OH, - N(R10)2, -C(O)N(R10)2, -C(O)-, -C(S)-, -C(O)OCH2C6H5, -NHC(O)OCH2C6H5, C1-10 alkyl,C2-10alkenyl, C2-10alkynyl, C3-12carbocycle, 3- to 12-membered heterocycle, and C1-10 haloalkyl.

79. The conjugate of any one of claims 23-78, wherein c is one.

80. The conjugate of any one of claims 23-79, wherein HP2is polyethylene glycol (PEG), methoxypolyethylene glycol (mPEG), poly(propylene glycol) (PPG), copolymers of ethylene glycol and propylene glycol, poly(oxyethylated polyol), poly(olefinic alcohol), poly(vinylpyrrolidone), poly(hydroxyalkylmethacrylamide), poly(hydroxyalkylmethacrylate), poly(saccharides), poly(α-hydroxy acid), poly(vinyl alcohol), polyphosphazene, polyoxazolines (POZ), poly(N-acryloylmorpholine), polysarcosine, or a combination thereof.

81. The conjugate claim 80, wherein HP2comprises a polyethylene glycol (PEG) or methoxypolyethylene glycol (mPEG).

82. The antibody conjugate of any one of claims 22-81, wherein RL is independentlyconjugate.

83. The antibody conjugate of claim 82, wherein RL is independently selected from ,84. The antibody conjugate of any one of claims 1-83, wherein PA1 is selected from,conjugate.

85. The antibody conjugate of claim 84, wherein PA1is selected from86. The antibody conjugate of claim 85, wherein PA1 is selected from87. The antibody conjugate of any one of claims 1-86, wherein each of m and n is an integer independently between 1 and 16, inclusive.

88. The antibody conjugate of any one of claims 1-86, wherein n is between 1 and 8, inclusive.

89. The antibody conjugate of any one of claims 1-86, wherein m is between 1 and 8, inclusive.

90. The antibody conjugate of any one of claim 1-86, wherein the molar ratio of PA1 to PA2is about 1:1, 2:1, or 4:

3.

91. The antibody conjugate of any one of claim 1-86, wherein m is 8 and n is 4.

92. The antibody conjugate of any one of claims 1-21, wherein the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue, lysine residue, and / or amino-terminal residue suitable for conjugation, wherein the one or more residues are covalently linked to the first linker and / or a second linker.

93. The antibody conjugate of claim 92, wherein the antibody or the antigen-binding fragment thereof comprises one or more cysteine residues that are covalently linked to the first linker and / or a second linker.

94. The antibody conjugate of any one of claims 1-21, wherein the antibody or the antigen-binding fragment thereof comprises at least one cysteine residue covalently linked to the first linker and at least one modified amino acid is covalently linked to the second linker.

95. The antibody conjugate of any one of claims 1-21, wherein (a) the antibody or the antigen-binding fragment thereof is covalently linked to the first linker via a modified amino acid and (b) the antibody or the antigen binding fragment thereof is covalently linked to the second linker via a modified amino acid that is different than the modified amino acid in (a).

96. The antibody conjugate of claim 95, wherein the modified amino acid linked to the first linker and the modified amino acid that is linked to the second linker are the same modified amino acid.

97. The antibody conjugate of any one of the previous claims, wherein the modified acid residue is independently selected from the group consisting of ortho-substituted tyrosine, meta substituted tyrosine, para-substituted phenylalanine, ortho-substituted phenylalanine, and meta-substituted phenylalanine.

98. The antibody conjugate of claim 97, wherein the modified amino acid residue is selected from the group consisting of p-acetyl-L-phenylalanine, O-methyl-L-tyrosine, 3-methyl-phenylalanine, O-4-allyl-L-tyrosine, 4-propyl-L-tyrosine, fluorinated phenylalanine, isopropyl-L-phenylalanine, p-azido-L-phenylalanine, p-acyl-L- phenylalanine, p-A benzoyl-L-phenylalanine, p-iodo-phenylalanine, p- bromophenylalanine, p-amino-L-phenylalanine, isopropyl-L-phenylalanine, p- propargyloxy-phenylalanine, and p-azidomethyl-L-phenylalanine.

99. The antibody conjugate of claim 98, wherein the modified amino acid is selected from p-azidomethyl-L-phenylalanine, p-azido-L-phenylalanine, and p-acetyl-L- phenylalanine.

100. The antibody conjugate of any one of the previous claims, wherein the one or more modified amino acid residues are at positions selected from the group consisting of heavy chain or light chain residues HC-S113, HC-A113, HC-A118, HC-T118, HC-T120, HC-K121, HC-G138, HC-A140, HC-T155, HC-S160, HC-A162, HC- L163, HC-Y180, HC-Q196, HC-I199, HC-N203, HC-T209, HC-K210, HC-K222, HC-F241, HC-E258, HC-K290, HC-Y296, HC-T335, HC-I336, HC-S337, HC-R344, HC-E345, HC-R355, HC-M358, HC-Q362, HC-E382, HC-E388, HC-E258, HC- N203, HC-N390, HC-Y391, HC-K392, HC-T393, HC-T393, HC-Y404, HC-T411,HC- N421, HC-S424, HC-Q438, HC-L443, LC-K42, LC-Q42, LC-T109, LC-V110, LC-A111, LC-A112, LC-D122, LC-Q124, LC-K126, LC-S127, LC-T129, LC-N138, LC-R142, LC-E143, LC-Q147, LC-K149, LC-D151, LC-A153, LC-L154, LC-Q155, LC-S159, LC-E161, LC-E165, LC-Q166, LC-S168, LC-K169, LC-D170, LC-S171, LC-T172, LC-T180, LC-A184, LC-E187, LC-H189, LC-K190, LC-V191, LC-E195, LC-L201, LC-S202, LC-S203, LC-V205, and LC-T206, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof.

101. The antibody conjugate of any one of the previous claims, wherein the one or more modified amino acid residues are at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-K121, HC-Y180, HC-Y391, HC- F241, HC-221, LC-K42, LC-T22, LC-S7, LC-N152, LC-K42, LC-E161, LC-D170, HC-S136, HC-S25, HC-A40, HC-S119, HC-S190, HC-K222, HC-R19, HC-Y52, and HC-S70, according to the Kabat or Chothia or EU numbering scheme, or a post- translationally modified variant thereof.

102. The antibody conjugate of claim 101, wherein the one or more modified amino acid residues are at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-Y180, HC-Y391, HC-F241, LC-K42, LC-E161, and LC-D170.

103. The antibody conjugate of any one of claims 1-99, wherein the antibody conjugate includes at least eight of the one or more modified amino acid residues at positions selected from the group consisting of heavy chain or light chain residues HC-F404, HC-Y180, HC-F241, LC-K42, and LC-E161, according to the Kabat or Chothia or EU numbering scheme, or a post-translationally modified variant thereof.

104. The antibody conjugate of any one of the previous claims, wherein the antibody or the antigen-binding fragment thereof comprises p-azidomethyl-L- phenylalanine at positions selected from the group consisting of HC-F404, HC-Y180, HC-Y391, HC-F241, LC-K42, LC-E161, and LC-D170.

105. The antibody conjugate of any one of the previous claims, wherein the antibody or the antigen-binding fragment thereof comprises p-acetyl-L-phenylalanine at LC-K42 or LC-E161.

106. The antibody conjugate of any one of the previous claims, wherein the antibody or the antigen-binding fragment thereof comprises p-azidomethyl-L- phenylalanine and p-acetyl-L-phenylalanine.

107. The antibody conjugate of any one of claims 1-104, wherein the antibody or the antigen-binding fragment thereof further comprises the amino acid substitution V264S.

108. An antibody conjugate comprising at least one topoisomerase inhibitor moiety covalently linked via a first linker and at least one hemiasterlin moiety covalently linked via a second linker.

109. The antibody conjugate of claim 108, wherein the hemiasterlin moiety is 3- aminophenyl hemiasterlin.

110. The antibody conjugate of claim 108 or 109, wherein the topoisomerase inhibitor moiety is a topoisomerase I inhibitor.

111. The antibody conjugate of claim 108, wherein the topoisomerase inhibitor I moiety is exatecan.

112. The antibody conjugate of any of the previous claims, wherein the antibody is selected from the group consisting of alpha-folate receptor a (aFRa), alpha transcription factor receptor (aTF), and alpha human epidermal growth factor receptor 2 (aHer2).

113. The antibody conjugate of any one of the previous claims, wherein the antibody comprises three heavy chain CDRs according to SEQ ID NOs:400, 401, and 402, and three light chain CDRs according to SEQ ID NOs: 299, 302, and 305; wherein the antibody or the antigen-binding fragment thereof comprises p- azidomethyl-L-phenylalanine at positions selected from the group consisting of HC- F404, HC-Y180, HC-Y391, LC-K42, and LC-E161; wherein the linker-payload is at least one of the following:.

114. The antibody conjugate of claim 112, wherein the antibody comprises three heavy chain CDRs of SEQ ID NO:10 and three light chain CDRs of SEQ ID NO:

14.

115. The antibody conjugate of claim 112, wherein the antibody comprises three heavy chain CDRs according to SEQ ID NOs:11-13 and three light chain CDRs according to SEQ ID NOs:15-17.

116. The antibody conjugate of claim 112, wherein the antibody comprises a heavy chain variable region according to SEQ ID NO:10 and a light chain variable region according to SEQ ID NOs:

14.

117. The antibody conjugate of claim 112, wherein the antibody comprises a heavy chain according to SEQ ID NO:8 and a light chain variable region according to SEQ ID NO:9.

118. A pharmaceutical composition comprising an antibody conjugate of any one of claims 1-117 and a pharmaceutically acceptable carrier, excipient, or diluent.

119. A method of treating or preventing a disease or condition in a subject in need thereof comprising administering to the subject an effective amount of an antibody conjugate of any one of claims 1-117 or the pharmaceutical composition of 118.

120. A method of diagnosing a disease or condition in a subject in need thereof, comprising administering to the subject an effective amount of an antibody conjugate of any one of claims 1-117 or the pharmaceutical composition of 118.

121. The method of claim 119 or 129, wherein the disease or condition is a cancer or inflammatory disease or condition.

122. The method of claim 121, wherein the disease or condition is cancer.

123. The method of claim 122, wherein the cancer is selected from breast cancer, ovarian cancer, prostate cancer, pancreatic cancer, lung cancer, non-small cell lung cancer, gastric cancer, colorectal cancer, cervical cancer, endometrial cancer, colon cancer, head and neck squamous cell carcinoma (HNSCC), and esophageal cancer.

124. The method of claim 123, wherein the cancer is breast cancer.

125. The method of claim 123, wherein the breast cancer is HER2-negative breast cancer.

126. The method of claim 123, wherein the breast cancer is triple negative breast cancer.

127. The method of claim 123, wherein the cancer is p53-mutated cancer.

128. The method of any one of claims 119-127, wherein the disease or condition is a drug-resistant cancer.

129. The method of claim 128, wherein the drug-resistant cancer is a topoisomerase-resistant cancer.

130. The method of claim 129, wherein the topoisomerase-resistant cancer is an fam-trastuzumab deruxtecan-nxki -resistant cancer.

131. The method of claim 128, wherein the drug-resistant cancer is a tubulin- resistant cancer.

132. A method of treating a drug-resistant cancer in a subject in need thereof, comprising administering an antibody conjugate according to Formula (II):Formula (II)or a pharmaceutically acceptable salt, solvate, stereoisomer, regioisomer, or mixture of regioisomers thereof; wherein Ab is the antibody or antigen-binding fragment thereof; Lais the first linker; Lbis the second linker; PA1 is the first payload, wherein the first payload is a topoisomerase inhibitor; PA3is the second payload, wherein the second payload is a cytotoxic agent or DNA Damage Response (DDR) inhibitor; subscript n is an integer selected from 1 to 12; and subscript m is an integer selected from 1 to 12.

133. The method of claim 132, wherein the drug-resistant cancer is a topoisomerase-resistant cancer.

134. The method of claim 133, wherein the topoisomerase-resistant cancer is a fam- trastuzumab deruxtecan-nxki-resistant cancer.

135. The method of claim 132, wherein the drug-resistant cancer is a tubulin- resistant cancer.

136. The method of any one of claims 132-135, wherein the DDR inhibitor is a PARP inhibitor.

137. The method of any one of claims 132-135, wherein the DDR inhibitor is an NAMPT1 inhibitor.

138. The method of any one of claims 132-135, wherein the DDR inhibitor is a CHK1 inhibitor.

139. Use of an effective amount of an antibody conjugate of any one of claims 1- 117 or the pharmaceutical composition of 118 in the preparation of a medicament for treating or preventing a disease or condition in a subject in need thereof.

140. Use of an effective amount of an antibody conjugate of any one of claims 1- 117 or the pharmaceutical composition of 118 in the preparation of a medicament for diagnosing a disease or condition in a subject in need thereof.

141. A kit comprising the antibody conjugate of any one of claims 1-114, and instructions for use.

142. The kit of claim 141, wherein the antibody conjugate or isolated antibody is lyophilized.

143. The kit of claim 141, further comprising a fluid for reconstitution of the lyophilized antibody conjugate.

144. A method of reducing cell proliferation in a subject in need thereof comprising administering to the subject an effective amount of an antibody conjugate of any one of claims 1-117 or the pharmaceutical composition of 118.

145. A process for preparing an antibody conjugate of any one of claims 1-117, comprising preparing a conjugate of the topoisomerase inhibitor with the light chain (LC) of the antibody or antigen binding fragment thereof; and conjugating the cytotoxic agent with the heavy chain (HC) of the antibody or antigen binding fragment thereof.

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