Antibody drug conjugates

Abstract

The present disclosure provides an antibody-drug conjugate (ADC) having an antibody, antigen-binding fragment thereof, or cell-penetrating fragment thereof; a cathepsin cleavable linker; and an exatecan payload moiety. Compositions including the ADC and methods of using the ADC are also provided.

Description

ANTIBODY DRUG CONJUGATES STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT

[0001] This invention was made with government support under R35 CA197574, awarded by National Institutes of Health. The Government has certain rights in the invention. CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and benefit of U.S. Provisional Application No. 63 / 574,739, filed April 4, 2024, which is hereby incorporated by reference in its entirety. SEQUENCE LISTING

[0003] The content of the electronically submitted sequence listing (Name: 2681_157PC01_Sequencelisting_ST26.xml; Size: 183,257 bytes; and Date of Creation: April 3, 2025) is herein incorporated by reference in its entirety. BACKGROUND

[0004] Antibody-drug conjugates (ADCs), a rapidly growing class of targeted therapeutics, represent a promising new approach to improving the selectivity and cytotoxic activity of drugs. These therapeutic agents are comprised of an antibody (or antibody fragment) that is covalently linked to a payload drug to form an immunoconjugate. The antibody directs the ADC to bind to the targeted cell. Upon entry into the cell, the ADC can localize in and around the cell nucleus and release its payload, which treats or kills the cell.

[0005] The monoclonal 3E10 antibody (“3E10”), has been developed as a molecular delivery vehicle that transports a variety of biologically important molecules into target cells, and 3E10 has been shown to preferentially target cancer cells. 3E10 penetrates cells in an Fc-independent mechanism, as evidenced by the ability of 3E10 fragments lacking an Fc to penetrate cells, that involves the presence of the nucleoside transporter ENT2 (Weisbart et al., Scientific Reports volume 5, Article number: 12022 (2015), Zack et al., J Immunol 157, 2082-2088 (1996), Hansen et al., J Biol Chem 282, 20790-20793 (2007)). A 3E10 single chain variable fragment, 3E10 scFv has previously been shown to be capable of penetrating living cells and nuclei in an ENT2- dependent manner, with efficiency of uptake impaired in ENT2-deficient cells (Hansen, et al., J. Biol. Chem.282, 20790-20793 (2007)).

[0006] 3E10 has not shown any cellular toxicity in vitro or in vivo in studies to date. In contrast, several antibodies that penetrate living cells are frequently toxic or injurious and can trigger some of the pathologic manifestations of the autoimmune diseases in which they are found. The 3E10 antibody is an ideal molecular delivery vehicle due to its efficiency in penetrating living cells with specific nuclear localization, absence of toxicity, and successful delivery of therapeutic cargo proteins in vitro and in vivo.

[0007] Currently, most ADCs are designed to target chemotherapeutic warheads to specific cancer types based on expression of a cell surface antigen. ADCs designed to address breast cancer, for instance, are often designed to target HER2, a cell surface receptor often expressed in breast cancer cells. There is a need for new ADCs for improved delivery of drugs to the targeted cell, including new ADCs having the ability to deliver drugs to multiple types of cancer cells. SUMMARY

[0008] As described herein, the disclosure provides a conjugate of A-(L-Pr)q, wherein A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63, L is a linker comprising -XAA-, wherein -XAA- is a cathepsin cleavable amino acid sequence comprising 1 to 6 amino acid moieties, P is exatecan, r is an integer from 1 to 4, and q is an integer from 1 to 16. In some embodiments, the linker includes a dipeptide selected from Val-Ala, Phe-Gln, Val-Gln, Leu-Gln, Tyr-Met, Phe-Arg, Phe-Gly, Trp- Thr, Tyr-Gly, Phe-Thr, and Val-Gly.

[0009] As described herein, the present disclosure also provides a method for treating a subject in need thereof, the method comprising administering a therapeutically effective amount of a conjugate of the disclosure to the subject.

[0010] As described herein, the disclosure provides a conjugate of Formula (I): A-(L-Pr)q Formula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell- penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63; L is a linkercomprising -XAA-, wherein -XAA- is a cathepsin cleavable amino acid sequence comprising 1 to 6 amino acid moieties; P is a topoisomerase I inhibitor; r is an integer from 1 to 4; and q is an integer from 1 to 16.

[0011] As described herein, the disclosure provides a conjugate of Formula (I): A-(L-Pr)q Formula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell- penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63; L is a linker comprising -XAA-, wherein -XAA- is a cathepsin cleavable amino acid sequence comprising 1 to 6 amino acid moieties; P is exatecan; r is an integer from 1 to 4; and q is an integer from 1 to 16.

[0012] In some aspects, -XAA- comprises a dipeptide selected from Val-Ala, Val-Cit, Phe-Gln, Val-Gln, Leu-Gln, Tyr-Met, Phe-Arg, Phe-Gly, Trp-Thr, Tyr-Gly, Phe-Thr, and Val-Gly.

[0013] In some aspects, -XAA- comprises a Val-Ala dipeptide.

[0014] In some aspects, -XAA- comprises a Val-Cit dipeptide.

[0015] In some aspects, the linker L is of Formula (L-1):Formula (L-1), wherein in Formula (L-1): LA is a connecting moiety through which A is covalently attached to L′; L′ comprises the -XAA-; and LPis a connecting moiety through which P is covalently attached to L′.

[0016] In some aspects, the linker L is of Formula (L-10):Formula (L-10), wherein in Formula (L-10): LA is selected from a bond, -NRa′-, and -S-; L1is a bond or comprises one or more groups selected from optionally substituted C1-C18alkylene, -C≡C-, -CRa═CRa-, optionally substituted 6- to 14-membered arylene, optionally substituted C3-C20 cycloalkylene, -[CH2O]1-18-, -[CH2CH2O]1-18-, -[CH2CH2CH2O]1-18-, optionally substituted 5- to 18-membered heteroarylene, optionally substituted 3- to 20-membered heterocycloalkylene, -NRa-, -N═CRa-, -CRa═N-, -S-, -OP(O)ORaO-, -O-, -CRb2-, -C(O)-, -C(O)O-, -OC(O)-, -C(O)S-, -SC(O)-, -C(O)NRa-, -NRaC(O)-, -OC(O)O-, -OC(O)S-, -SC(O)O-, -OC(O)NRa-, -NRaC(O)O-, -SC(O)NRa-, -NRaC(O)S-, and -XAA1-; LC comprises the -XAA-; L2isa bond or comprises one or more groups selected from optionally substituted C1-C18alkylene, -C≡C-, -CRa═CRa-, optionally substituted 6- to 14-membered arylene, optionally substituted C3-C20cycloalkylene, -[CH2O]1-18-, -[CH2CH2O]1-18-, -[CH2CH2CH2O]1-18-, optionally substituted 5- to 18-membered heteroarylene, optionally substituted 3- to 20-membered heterocycloalkylene, -NRa-, -N═CRa-, -CRa═N-, -S-, -OP(O)ORaO-, -O-, -CRb2-, -C(O)-, -C(O)O-, -OC(O)-, -C(O)S-, -SC(O)-, -C(O)NRa-, -NRaC(O)-, -OC(O)O-, -OC(O)S-, -SC(O)O-, -OC(O)NRa-, -NRaC(O)O-, -SC(O)NRa-, -NRaC(O)S-, and -XAA1-; LPis selected from a bond, -NRa′-, -S-, and -O-; each Rais independently selected at each occurrence from hydrogen, optionally substituted alkyl, optionally substituted fluoroalkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroalkyl, optionally substituted heterocycloalkyl, optionally substituted heterocycloalkylalkyl, optionally substituted heteroaryl, and optionally substituted heteroarylalkyl; each Ra′is independently selected at each occurrence from hydrogen, optionally substituted alkyl, and optionally substituted heteroalkyl; each Rbis independently selected at each occurrence from hydrogen, halide, -OH, -SO3H, -OPO3H2, -PO3H2, -C(O)NRa2, -CO2Ra, -NRa2, optionally substituted alkyl, optionally substituted fluoroalkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroalkyl, optionally substituted heterocycloalkyl, optionally substituted heterocycloalkylalkyl, optionally substituted heteroaryl, and optionally substituted heteroarylalkyl; or two independent Rbgroups are taken together to form optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heterocycloalkyl, or optionally substituted heteroaryl; and -XAA1- is an amino acid sequence comprising 1 to 4 amino acid moieties.

[0017] In some aspects, the cathepsin cleavable linker is conjugated to a lysine of the antibody or antigen-binding fragment thereof.

[0018] In some aspects, the cathepsin cleavable linker is conjugated to a cysteine of the antibody or antigen-binding fragment thereof.

[0019] In some aspects, the cathepsin cleavable linker is conjugated to a histidine of the antibody or antigen-binding fragment thereof.

[0020] In some aspects, the cathepsin cleavable linker is conjugated to an arginine of the antibody or antigen-binding fragment thereof.

[0021] In some aspects, the cathepsin cleavable linker is conjugated to an aspartic acid of the antibody or antigen-binding fragment thereof.

[0022] In some aspects, the cathepsin cleavable linker is conjugated to a glutamine of the antibody or antigen-binding fragment thereof.

[0023] In some aspects, the conjugate has a drug to antibody ratio (DAR) of at least 4:1.

[0024] In some aspects, the conjugate has a drug to antibody ratio (DAR) of at least 6:1.

[0025] In some aspects, the conjugate has a drug to antibody ratio (DAR) of at least 7:1.

[0026] In some aspects, the conjugate has a drug to antibody ratio (DAR) of at least 8:1.

[0027] In some aspects, the conjugate has a drug to antibody ratio (DAR) between 2:1 and 12:1.

[0028] In some aspects, the conjugate has a drug to antibody ratio (DAR) between 4:1 and 12:1.

[0029] In some aspects, the conjugate has a drug to antibody ratio (DAR) between 6:1 and 12:1.

[0030] In some aspects, the conjugate has a drug to antibody ratio (DAR) between 6:1 and 10:1.

[0031] In some aspects, the linker is a branched linker attached to at least two copies of the payload P.

[0032] In some aspects, L comprises the structure:.

[0033] In some aspects, L comprises the structure:.

[0034] In some aspects, (L-Pr) comprises the structure:.

[0035] In some aspects, (L-Pr) comprises the structure:.

[0036] In some aspects, (L-Pr) comprises the structure:.

[0037] In some aspects, (L-Pr) comprises the structure:.

[0038] In some aspects, the VL CDR1 comprises the amino acid sequence of SEQ ID NO:9, CDR2 comprises the amino acid sequence of SEQ ID NO:10, CDR3 comprises SEQ ID NO:11; and the VH CDR1 comprises the amino acid sequence of SEQ ID NO:15, CDR2 comprises the amino acid sequence of SEQ ID NO:4, CDR3 comprises the amino acid sequence of SEQ ID NO:5.

[0039] In some aspects, the VL CDR1 comprises the amino acid sequence of SEQ ID NO:29, CDR2 comprises the amino acid sequence of SEQ ID NO:10, CDR3 comprises SEQ ID NO:11; and the VH CDR1 comprises the amino acid sequence of SEQ ID NO:15, CDR2 comprises the amino acid sequence of SEQ ID NO:26, CDR3 comprises the amino acid sequence of SEQ ID NO:5.

[0040] In some aspects, the linker comprises a MC-VA-PAB linker.

[0041] As described herein, the disclosure provides a conjugate of Formula (I): A-(L-Pr)q Formula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63; L is a linker comprising MC-VA- PAB; P is exatecan; r is an integer from 1 to 4; and q is an integer from 1 to 16.

[0042] The conjugate as described herein, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises a light chain variable region (VL) comprising an amino acid sequence of SEQ ID NO:21 and a heavy chain variable region (VH) comprising an amino acid sequence of SEQ ID NO:14.

[0043] In some aspects of the conjugates described herein, the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises a full length light chain (LC) comprising an amino acid sequence of SEQ ID NO:20 and a full length heavy chain (HC) comprising an amino acid sequence of SEQ ID NO:13.

[0044] In some aspects of the conjugates described herein, the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-VL-H1 (SEQ ID NO:85), 3E10-VL-H2 (SEQ ID NO:86), 3E10-VL-H3 (SEQ ID NO:87), 3E10-VL-H4 (SEQ ID NO:88), 3E10-VL-H5 (SEQ ID NO:89), and 3E10-VL-H6 (SEQ ID NO:90); and a heavy chain variable domain (VH) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-VH-H1 (SEQ ID NO:64), 3E10-VH-H2 (SEQ ID NO:65), 3E10-VH-H3 (SEQ ID NO:66), 3E10-VH-H4 (SEQ ID NO:67), 3E10-VH-H5 (SEQ ID NO:68), 3E10-VH-H6 (SEQ ID NO:69), and 3E10-VH-H7 (SEQ ID NO:70).

[0045] In some aspects of the conjugates described herein, the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising an amino acid sequence selected from the group consisting of 3E10-VL-H1 (SEQ ID NO:85), 3E10-VL-H2 (SEQ ID NO:86), 3E10-VL-H3 (SEQ ID NO:87), 3E10-VL-H4 (SEQ ID NO:88), 3E10-VL-H5 (SEQ ID NO:89), and 3E10-VL-H6 (SEQ ID NO:90); and a heavy chain variable domain (VH) comprising an amino acid sequence selected from the group consisting of 3E10-VH-H1 (SEQ ID NO:64), 3E10-VH-H2 (SEQ ID NO:65), 3E10-VH-H3 (SEQ ID NO:66), 3E10-VH-H4 (SEQ ID NO:67), 3E10-VH-H5 (SEQ ID NO:68), 3E10-VH-H6 (SEQ ID NO:69), and 3E10-VH-H7 (SEQ ID NO:70).

[0046] In some aspects of the conjugates described herein, the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises a VL / VH pair selected from the group consisting of (a) VL1 (SEQ ID NO:85) and VH1 (SEQ ID NO:64), (b) VL1 (SEQ ID NO:85) and VH2 (SEQ ID NO:65), (c) VL1 (SEQ ID NO:85) and VH3 (SEQ ID NO:66), (d) VL1 (SEQ ID NO:85) and VH4 (SEQ ID NO:67), (e) VL2 (SEQ ID NO:86) and VH1 (SEQ ID NO:64), (f) VL2 (SEQ ID NO:86) and VH2 (SEQ ID NO:65), (g) VL2 (SEQ ID NO:86) and VH3 (SEQ ID NO:66), (h) VL2 (SEQ ID NO:86) and VH4 (SEQ ID NO:67), (i) VL3 (SEQ ID NO:87) and VH1 (SEQ ID NO:64), (j) VL3 (SEQ ID NO:87) and VH2 (SEQ ID NO:65), (k) VL3 (SEQ ID NO:87) and VH3 (SEQ ID NO:66), (l) VL3 (SEQ ID NO:87) and VH4 (SEQ ID NO:67), (m) VL4 (SEQ ID NO:88) and VH1 (SEQ ID NO:64), (n) VL4 (SEQ ID NO:88) and VH2 (SEQ ID NO:65), (o) VL4 (SEQ ID NO:88) and VH3 (SEQ ID NO:66), (p) VL4 (SEQ ID NO:88) and VH4 (SEQ ID NO:67), (q) VL5 (SEQ ID NO:89) and VH5 (SEQ ID NO:68), (r) VL5 (SEQ ID NO:89) and VH6 (SEQ ID NO:69), (s) VL6 (SEQ ID NO:90) and VH5 (SEQ ID NO:68), and (t) VL6 (SEQ ID NO:90) and VH6 (SEQ ID NO:69).

[0047] In some aspects of the conjugates described herein, the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising 3E10-VL-H6 (SEQ ID NO:90) and a heavy chain variable domain (VH) comprising 3E10-VH-H6 (SEQ ID NO:69).

[0048] As described herein, the disclosure provides a conjugate of Formula (I): A-(L-Pr)qFormula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a light chain variable domain (VL) comprising 3E10-VL-H6 (SEQ ID NO:90) and a heavy chain variable domain (VH) comprising 3E10-VH-H6 (SEQ ID NO:69);L is a linker comprising MC-VA-PAB; P is exatecan; r is an integer from 1 to 4; and q is an integer from 1 to 16.

[0049] In some aspects of the conjugates described herein, the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising the amino acid sequence (DIQMTQSPSSLSASLGDRATITCRASKTVSTSSYSYMHWYQQKPGQPPKLLIKYASYLES GVPSRFSGSGSGTDFTLTISSLQPEDAATYYCQHSREFPWTFGGGTKVEIK) (SEQ ID NO:167) and a heavy chain variable domain (VH) comprising the amino acid sequence (EVQLVESGGGLVQPGGSLRLSCAASGFTFSNYGMHWVRQAPGKGLEWVSYISSGSSTIY YADSVKGRFTISRDNAKNSLYLQMNSLRAEDTAVYYCARRGLLLDYWGQGTTVTVSS) (SEQ ID NO:168).

[0050] As described herein, the present disclosure also provides a method for treating a subject in need thereof, the method comprising administering a therapeutically effective amount of a conjugate described herein to the subject.

[0051] As described herein, the present disclosure also provides a method for treating cancer in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a conjugate described herein to the subject.

[0052] In some aspects of the methods described herein, the cancer comprises tumor cells that express functional ENT2.

[0053] In some aspects of the methods described herein, the cancer is a carcinoma, a sarcoma, a blastoma, a papilloma, or an adenoma.

[0054] In some aspects of the methods described herein, the cancer is metastatic cancer.

[0055] In some aspects of the methods described herein, the cancer is selected from the group consisting of bladder cancer, blood cancer, brain cancer, breast cancer, bone cancer, cervical cancer, colorectal cancer, endocrine cancer, esophageal cancer, gastric cancer, head and neck cancer, hepatobiliary cancer, leukemia, lung cancer, lymphoma, melanoma, myeloma, ovarian cancer, pancreatic cancer, prostate cancer, renal cancer, thyroid cancer, and uterine cancer.

[0056] In some aspects of the methods described herein, the cancer is a skin cancer selected from the group consisting of basal cell carcinoma, squamous cell carcinoma, and melanoma.

[0057] In some aspects of the methods described herein, the cancer is melanoma.

[0058] In some aspects of the methods described herein, the cancer is ovarian cancer.

[0059] In some aspects of the methods described herein, the cancer is colorectal cancer.

[0060] In some aspects of the methods described herein, the cancer is breast cancer.

[0061] In some aspects of the methods described herein, the cancer comprises a mutation in one or more genes associated with a DNA damage response pathway.

[0062] In some aspects of the methods described herein, the cancer comprises a mutation in BRCA1 and / or BRCA2.

[0063] In some aspects of the methods described herein, the cancer is triple negative breast cancer.

[0064] In some aspects of the methods described herein, the cancer is lung cancer.

[0065] In some aspects of the methods described herein, the cancer is non-small cell lung cancer (NSCLC).

[0066] In some aspects of the methods described herein, the cancer is a cancer of the central nervous system.

[0067] In some aspects of the methods described herein, the cancer is a neuroepithelial brain or spinal tumor selected from the group consisting of a medulloblastoma, an astrocytic tumor, an oligodendroglial tumor, an oligoastrocytic tumor, an ependymal tumor, a choroid plexus tumor, a neuronal or mixed neuronal-glial tumor, a tumor of the pineal region, an embryonal tumor, or an otherwise uncategorized neuroepithelial tumor.

[0068] In some aspects of the methods described herein, the cancer is a medulloblastoma.

[0069] In some aspects of the methods described herein, the subject is treated with radiation therapy before the conjugate is administered.

[0070] In some aspects of the methods described herein, the subject is treated with radiation therapy at least about 12 hours, at least about 24 hours, at least about 48 hours, at least about 72 hours, or at least about 96 hours before the conjugate is administered.

[0071] In some aspects of the methods described herein, treatment with the radiation therapy increases cellular uptake of the conjugate.

[0072] In some aspects of the methods described herein, the administering is by parenteral administration.

[0073] In some aspects of the methods described herein, the parenteral administration is intramuscular administration, intravenous administration, or subcutaneous administration.

[0074] In some aspects of the methods described herein, the conjugate can cross the blood- brain barrier. BRIEF DESCRIPTION OF THE FIGURES

[0075] Figure 1 (SEQ ID NOs:1-12) illustrates amino acid sequences for the parent 3E10 monoclonal antibody.

[0076] Figures 2A (SEQ ID NOs:13-25), 2B (SEQ ID NOs:26-30), and 2C (SEQ ID NOs:31-33) illustrate amino acid sequences for the D31N variant (Figure 2A), other CDR variants (Figure 2B), and additionally contemplated CDR variants (Figure 2C) of the 3E10 monoclonal antibody, in accordance with some embodiments of the present disclosure.

[0077] Figure 3 (SEQ ID NOs:34-57) illustrates example charge-conserved CDR variants of the 3E10 monoclonal antibody, in accordance with various embodiments of the present disclosure.

[0078] Figure 4 (SEQ ID NOs:58-63) illustrates example CDR variants containing a combination of amino acid substitutions, charged-conserved amino acid substitutions, and rationally-designed amino acid substitutions of the 3E10 monoclonal antibody, in accordance with various embodiments of the present disclosure.

[0079] Figure 5 (SEQ ID NOs:103-112) illustrates a sequence alignment of examples of humanized 3E10 heavy chain variable regions, with CDRs underlined as indicated.

[0080] Figure 6 (SEQ ID NOs:113-121) illustrates a sequence alignment of examples of humanized 3E10 light chain variable regions, with CDRs and putative nuclear localization signals (NLS) underlined as indicated.

[0081] Figures 7A, 7B, 7C, 7D, and 7E (SEQ ID NOs:122-137) collectively illustrate a sequence alignment of example of humanized di-scFv constructs of the 3E10 monoclonal antibody.

[0082] Figure 8 illustrates amino acid sequences of humanized 3E10 variable heavy (3E10-VH) domains (SEQ ID NOs:64-70), in accordance with various embodiments of the present disclosure.

[0083] Figure 9 illustrates amino acid sequences of mature humanized 3E10 heavy chains (3E10-HC) lacking a signal peptide (SEQ ID NOs:71-77), in accordance with various embodiments of the present disclosure.

[0084] Figure 10 illustrates amino acid sequences of humanized 3E10 heavy chains (3E10- HC) (SEQ ID NOs:78-84), in accordance with various embodiments of the present disclosure.

[0085] Figure 11 illustrates amino acid sequences of humanized 3E10 variable light (3E10-VL) domains (SEQ ID NOs:85-90), in accordance with various embodiments of the present disclosure.

[0086] Figure 12 illustrates amino acid sequences of mature humanized 3E10 light chains (3E10-LC) lacking a signal peptide (SEQ ID NOs:91-96), in accordance with various embodiments of the present disclosure.

[0087] Figure 13 illustrates amino acid sequences of humanized 3E10 light chains (3E10- LC) (SEQ ID NOs:97-98, 100-102, and 1045), in accordance with various embodiments of the present disclosure.

[0088] Figures 14A and 14B illustrate electrostatic surface potential renderings of a molecular model of a 3E10-scFv construct, revealing a putative Nucleic Acid Binding pocket (NAB1). Figure 14A additionally shows predicted structural and electrostatic potential changes induced by amino acid substitutions at residue HC CDR1 residue 31. Figure 14B is an illustration of molecular modeling of 3E10-scFv (Pymol) with NAB1 amino acid residues highlighted by punctate dots.

[0089] Figure 14C illustrates mapping of the putative nucleic acid binding pocket, as identified by the molecular modeling shown in Figures 14A and 14B, onto the amino acid sequence of the 3E10-scFv construct.

[0090] Figure 15 shows two schematics of ADC / AOCs having cathepsin substrate linkers.

[0091] Figure 16 shows a schematic of an AOCs having a cathepsin substrate linker.

[0092] Figure 17A shows LEFT Panel: IVIS Spectrum imaging system monitoring V66 biodistribution in mice bearing orthotopic medulloblastoma (DAOY) tumors. RIGHT Panel: : IVIS Spectrum imaging for biodistribution experiment in mice bearing orthotopic pancreatic KPC bioluminescent tumors.

[0093] Figure 17B shows Western Blot (WB) analysis of MC38 cancer cell line following a 30-min treatment with V66 or IgG1 isotype control (Palivizumab) antibodies.

[0094] Figure 17C shows WB analysis of ENT2 protein expression in cell lysates prepared from the indicated tumor cell lines and from the indicated non-malignant murine tissues (C57Bl / 6). Quantification of relative ENT2 expression normalized to the Vinculin loading controls is shown.

[0095] Figure 17D shows IVIS Spectrum imaging: Ex vivo imaging of harvested HCT116 tumors injected with fluorescently labeled V66, for one (1X) or three consecutive days (3X). Statistical analyses performed by student’s t-test for individual comparison. (**** p-value<0.0001, **pvalue < 0.001, n=3-5).

[0096] Figure 18A reports EC50 values for cytotoxicity assays of V66-Exatecan (DAR=8) in a panel of tumor cell lines.

[0097] Figure 18B illustrates cytotoxicity in BRCA2 deficient cell lines following V66- Exatecan (DAR=8) or Pali-Exatecan (Palivizumab, IgG1 isotype control) (DAR=8) treatment. Data are presented as means ± SEM. Statistical analyses performed by two-way ANOVA, interaction p-value (**** p-value<0.0001) n=3 technical replicates.

[0098] Figure 18C shows WB analysis of DNA Damage Repair (DDR) pathway activation and Topoisomerase1 downregulation in DLD1 WT and DLD1 BRCA2- / - cell lines treated for 24h with 100nM V66-Exatecan (V66-Exa) or 100nM Palivizumab-Exatecan (Pali-Exa).

[0099] Figure 19A illustrates the tumor volume of DLD1 BRCA2KO cells implanted subcutaneously in athymic nude mice following treatment with intraperitoneal (I.P.) injections of PBS, V66-Exatecan (V66-Exa, DAR=8) or Exatecan Mesylate for two (2X) or four (4X) consecutive days, followed by 5 or 3 days of recovery, respectively. All data are represented as mean ± SEM. Black (4X) or Gray (2X) arrows indicate the timing of doses administered for either V66-Exatecan or Exatecan Mesylate. Statistical analysis performed by student’s t-test for individual comparison (n.s. p-value>0.05; * p-value<0.05; **** p-value<0.0001).

[0100] Figure 19B illustrates body weight variations of each group over time. Data are expressed as mean ± SEM, n = 10.

[0101] Figure 19C illustrates a survival curve following treatment. Statistical analysis performed by Log-rank (Mantel–Cox) test. (n.s. p-value>0.05; *** p-value<0.001; **** p- value<0.0001).

[0102] Figure 19D shows representative images of the tumors on the right flank of the athymic nude mice following 3 cycles of IP injections (Day 30).

[0103] Figure 20A is a schematic timeline illustrating the experimental design (created in BioRender) for assessing the short-term (7 days post-treatment) and long-term (30 days post- treatment) toxic effects of V66-Exatecan ADC (DAR=8), evaluating CBC composition, liver and kidney functionality, and muscle damage in mice bearing DLD1 BRCA2KO flank tumors.

[0104] Figure 20B shows peripheral blood cell analysis in PBS, Exatecan Mesylate (2X and 4X) and V66-Exatecan ADC (2X and 4X)-treated mice. Analysis were performed 7 days after the end of the treatment. n = 3. WBC, white blood cells; Hb, Hemoglobin; RBC, red blood cells.

[0105] Figures 20C, 20D, and 20E collectively show evaluation of the hemato-biochemical markers of mouse serum following treatment with PBS or V66-Exa ADC (2X or 4X). Upon sacrifice, the following plasma activities were assessed: (C) Liver-specific (AST and ALT) and bone-related (ALP) enzymes; (D) Kidney-specific (CREA and BUN) enzymes and total protein (TPRO); (E) Muscle-specific (MYOG) and muscle damage-related (CPK) enzymes. n = 5. ALP, alkaline phosphatase; ALT, alanine transaminase; AST, aspartate transaminase; CREA creatinine; BUN blood urea nitrogen; TPRO total protein; MYOG, myoglobin; CPK, creatine phosphokinase.

[0106] Figure 20F shows representative images of hematoxylin and Eosin (H&E) staining of Quadriceps (left) and Heart (Right). No muscle damage was observed. n = 3. G. Flow cytometry-based analysis of indicated fluorescently labeled antibody (IR680) in liver parenchymal or non- parenchymal cells, demonstrating enhanced uptake by non-parenchymal cells.

[0107] Figure 21 illustrates an example 3E10-exatecan conjugate linked through an mc-Val- Ala-PAB linker, in accordance with some embodiments of the present disclosure.

[0108] Figure 22A is a schematic of a mouse model of the in vivo mechanism of action of the V66 antibody after systemic administration. Figure 22B is a schematic of an in vivo biodistribution experiment in athymic J: Nu mice with subcutaneous DLD1 tumors. Figure 22C shows IVIS Spectrum imaging of the biodistribution of fluorescently labeled V66 or control buffer (PBS) 24 hours after injection in DLD1 tumor tissue, liver tissue, spleen tissue, lung tissue, kidney tissue, and heart tissue. Quantification of the biodistribution of fluorescently labeled V66 or control buffer (PBS) in the tissues is also represented graphically. Figure 22D shows Western Blot analysis of fractionated CT26 cancer cell line following a 30-min treatment with V66 or IgG1 isotype control antibodies. Figure 22E is a schematic of an in vivo nuclear targeting experiment in athymic J: Nu mice with subcutaneous DLDl tumors after injection with fluorescently labeled V66. Figure 22F shows Western Blot analysis of fractionated DLD1 tumor cells from mice injected with V66. Figure 22G is a schematic of the biodistribution experiment in athymic J: Nu mice with subcutaneous HCTI 16 tumors. Figure 22H shows IVIS Spectrum imaging of the biodistribution of fluorescently labeled V66 (100 μg) administered once (V661x), fluorescently labeled 100 μg of V66 administered one daily for three days (V663x), or PBS 24 hours after treatment in tumor tissue and liver tissue. Quantification of the biodistribution of fluorescently labeled V661x, V66 3x, or control buffer (PBS) in the liver and tumor tissue is also represented graphically. Figure 23A is a schematic of in vivo nuclear targeting experiment in athymic J: Nu mice with subcutaneous DLDl tumors after injection with fluorescently labeled V66-exatecan ADC. Figure 23B shows Western Blot analysis of fractionated DLD1 tumor cells following treatment with V66-exatecan ADC or PBS (control). Figure 23C illustrates cytotoxicity in MDA-MB-231 cell line following V66-Exatecan ADC (DAR=8) or IgG1 isotype control (DAR=8) treatment. Data are presented as means ± SEM. Statistical analyses performed by two-way ANOVA, interaction p-value (**** p- value<0.0001) n=3 technical replicates. Figure 23D shows Western Blot analysis of DNA Damage Repair (DDR) pathway activation and Topoisomerase1 downregulation in MDA-MB-231 cells following no treatment, treatment with V66, treatment with V66-exatecan for 1 hr, treatment with IgG1-exatecan (control) for 1 hr, treatment with V66-exatecan for 24 hrs, and treatment with IgG1- exatecan (control) for 24 hrs. Figure 23E is a schematic showing an in vivo anti-tumor efficacy model using mice bearing subcutaneous MDA-MB-231 TNBC tumors receiving control buffer (PBS), two (2x) or four (4x) intraperitoneal injections weekly of V66-exatecan (10 mg / kg),unconjugated exatecan mesylate (equimolar dose, 0.26 mg / kg), or V66 antibody alone (10 mg / kg) (n=5 mice per group). Figure 23F illustrates the change in tumor volume in MDA-MB-231 TNBC tumors following treatment with control buffer (PBS), V66 antibody (10 mg / kg), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X). Figure 23G illustrates the change in weight (gr) of the mouse over 60 days following treatment with control buffer (PBS), V66 antibody (10 mg / kg), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X). Figure 23H show the survival percentage of mice following treatment with control buffer (PBS), V66 antibody (10 mg / kg), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66- exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X). Figure 23I shows median survival and P-value of the groups treated with control buffer (PBS), V66 antibody (10 mg / kg), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X).

[0109] Figure 24A shows the results of a viability assay of a panel of cell lines with varying BRCA2 status after treatment with increasing concentrations of V66-exatecan ADC for 24 hrs after 7 days. Figure 24B shows the percentage of cell viability of wild-type DLD1 cells and DLD1 cell with BRCA2 knockout after treatment with V66-exatecan ADC. Statistical analyses performed by two-way ANOVA, interaction p-value (**** p-value<0.0001). Figure 24C shows Western Blot analysis of V66-exatecan uptake, TOP1 target engagement, and induction of the DDR pathway in DLD1 wild-type cells and DLD1 BRCA2 knockout cells following treatment for 1 or 24 hrs with 100 nM V66-exatecan ADC or IgG1-exatecan (control). Figure 24D is a schematic showing an in vivo anti-tumor efficacy model using mice bearing subcutaneous DLD1 BRCA2KO tumors receiving intraperitoneal injections of control buffer (PBS), two (2x) or four (4x) intraperitonealinjections weekly of V66-exatecan (10 mg / kg), unconjugated exatecan mesylate (equimolar dose, 0.26 mg / kg), or V66 antibody alone (10 mg / kg) (n=10 mice per group). Figure 24E shows the change in the tumor volume of DLD1 BRCA2KO tumors following treatment with control buffer (PBS), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administed four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66- exatecan 4X). Figure 24F shows the change in weight (gr) of the mouse over 60 days following treatment with control buffer (PBS), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X). Figure 24G show the survival percentage of mice following treatment with control buffer (PBS), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66- exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X). Figure 24H shows median survival and P-value of the groups treated with control buffer (PBS), unconjugated exatecan mesylate administered two times weekly (equimolar dose, 0.26 mg / kg) (exatecan 2X), unconjugated exatecan mesylate administered four times weekly (equimolar dose, 0.26 mg / kg) (exatecan 4X), V66-exatecan ADC administered two times weekly (10 mg / kg) (V66-exatecan 2X), or V66-exatecan ADC administered four times weekly (10 mg / kg) (V66-exatecan 4X).

[0110] Figure 25A shows Western Blot analysis of the V66 Fc domain, TOP1 (nuclear control), and GAPDH (cytoplasmic control) in nuclear and cytoplasmic fractions of DLD1 wild- type and DLD1 BRCA2KO cells under normal condition or following pre-treatment with DNase I to reduce any ecDNA released by cancer cells. Quantification of the relative signal of the V66 Fc domain in DLD1 WT and DLD1 BRCA2KO cells is also represented graphically. Figure 25B shows Western Blot analysis of V66 Fc domain and GAPDH (cytoplasmic control) in DLD1 WT cells and DLD1 BRCA2KO cells following 2 Gy of radiation, either 1 hr or 24 hrs before treatment with V66. Figure 25C shows the relative ENT2 expression levels in DLD1 wild-type and DLD1 BRCA2KO cell lines. The ENT2 expression levels were measured by quantitative real-time PCR (qRT-PCR). Figure 25D is a schematic of an mouse model to test V66-mediated delivery efficiency in vivo. One group of DLD1 tumor-bearing mice was pre-treated with 10 Gy of radiationfor two days to induce DNA damage. The other group of DLD1 tumor-being mice was not pre- treated with radiation. On day 3, both groups of mice were treated with 100 μg of fluorescently labeled V66. Figure 25E shows IVIS Spectrum imaging of the internalization of fluorescently labeled V66 on tumors treated with control buffer (PBS), V66 antibody, and V66 antibody in combination with 10 Gy radiation. Quantification of the internalization of fluorescently labeled V66 or control buffer (PBS) in the tumors treated with control buffer (PBS), V66 antibody, and V66 antibody in combination with 10 Gy radiation is also represented graphically.

[0111] Figure 26A is a schematic of an in vivo mouse model to test the efficacy of V66- exatecan ADC in treating medulloblastoma. Mice carrying the Brca1- / -; Trp53- / - or Brca2- / -; Trp53- / - mutations were monitored until day 60 post-birth, at which point medullary tumors had developed. Starting on day 60, the mice were treated with V66-exatecan ADC, administered four times per week for three consecutive weeks, and subsequently monitored for survival. Figure 26B shows the survival percentage of Brca1- / -, Trp53- / - mice treated with V66-exatecan ADC (10 mg / kg). Figure 26C shows the survival percentage of Brca2- / -, Trp53- / - mice treated with V66- exatecan ADC (10 mg / kg). Figure 26D shows the percentage of Brca1- / - and Brca2- / - cell viability following treatment with 100 nM of V66-exatecan ADC for 1 hr or 24 hrs, or with unconjugated V66 antibody for 24 hrs. Figure 26E shows Western Blot analysis of DDR pathway activation of Brca1- / - and Brca2- / - cells following treatment with 100 nM of V66-exatecan ADC for 1 hr or 24 hrs, or with unconjugated V66 antibody for 24 hrs.

[0112] Figure 27A is a schematic of a mouse model for testing the in vivo toxicity of exatecan. DLD1 BRCA2KO tumor-bearing mice were injected with V66-exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg, or 200 mg / kg (n=6). Figure 27B shows the change in weight (gr) of the mouse following treatment with control buffer (PBS) or V66-exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg, or 200 mg / kg (n=6). Figure 27C shows change in DLD1 BRCA2KO tumor volume following treatment with control buffer (PBS) or V66- exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg, or 200 mg / kg. Figure 27D shows Western Blot analysis of induction of DNA damage in DLD1 BRCA2KO tumors treated with V66-exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg or 200 mg / kg (n=3). Figure 27E shows the bone marrow cellularity of DLD1 BRCA2KO tumor-bearing mice 48 hours after treatment with control buffer (PBS) or V66-exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg, or 200 mg / kg (n=3). Figure 27F shows the kidney function (total protein level and blood urea nitrogen (BUN)) of mice treated with control buffer (PBS) or V66- exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg or 200 mg / kg. Figure 27G shows the liver function (alkaline phosphatase (ALP), alanine aminotransferase (ALT) andaspartate aminotransferase (AST)) of mice treated with control buffer (PBS) or V66-exatecan ADC at 5 mg / kg, 10 mg / kg, 25 mg / kg, 50 mg / kg, 100 mg / kg, or 200 mg / kg.

[0113] Figure 28 shows IVIS Spectrum imaging of the biodistribution of fluorescently labeled V66 or control buffer (PBS) 24 hours after injection in EMT6 mouse breast cancer tumor tissue, liver tissue, spleen tissue, lung tissue, kidney tissue, and heart tissue. Quantification of the biodistribution of fluorescently labeled V66 or control buffer (PBS) in the tissues is also represented graphically.

[0114] Figure 29 shows the serum half-life of V66 in mice after administration of V66 at 25, 50, or 100 mg / kg in a single intravenous dose, and blood samples were collected from the mice 0.5 min, 15 min, 30 min, 1-hr, 2-hrs, 4-hrs, 6-hrs, 12-hrs, 24-hrs, 72-hrs, and 96-hrs post-treatment. Serum antibody concentrations were quantified using an Fc capture ELISA on the MSD platform. Each sample was analyzed in triplicate, and the results were reported in µg / mL.

[0115] Figure 30A shows high-performance liquid chromatography (HLPC) analysis of the V66-exatecan ADC. Figure 30B shows mass spectrometry analysis of the V66-exatecan ADC (DAR=8). Figure 30C shows MDA-MB-231 cell viability following treatment with V66-exatecan ADC alone (0.5 μM or 4 μM) and co-treatment of V66-exatecan ADC (0.5 μM or 4 μM) in combination with the CatB inhibitor CA-074Me (10 μM). Figure 30D shows Western Blot analysis of DDR markers following co-treatment with V66-exatecan ADC (100 μM) and CA- 074Me at 1 μM, 5 μM, 10 μM, 50 μM, or 100 μM. Figure 30E shows MDA-MB-231 cell viability following treatment with V66-exatecan ADC alone (0.5 μM or 4 μM) and co-treatment of V66- exatecan ADC (0.5 μM or 4 μM) in combination with proteasome inhibitor MG132 (0.5 μM). Figure 30F shows Western Blot analysis of DDR markers and TOP1 following treatment with V66-exatecan ADC (100 μM) in combination with MG132 at 0.01 μM, 0.1 μM, 1 μM, 2.5 μM, or 5 μM.

[0116] Figure 31 shows Western Blot analysis of the V66 Fc domain in nuclear and cytoplasmic fractions of wild-type HCT116 and HCT116 with IDH1 mutations cell lines after treatment with V66 antibody. Quantification of the relative signal of the V66 Fc domain in HCT116 WT and HCT116 IDH1 mutation cells is also represented graphically. DETAILED DESCRIPTION I. Introduction

[0117] Advantageously, methods and compositions were developed for targeting therapeutic agents, e.g., drugs such as anti-tumor drug, or oligonucleotides, to various cancer tissues in vivoand facilitating delivery of these therapeutic polynucleotides into diseased cells, e.g., cancer cells displaying high levels of ENT2 on their cell surface. Thus, the present disclosure provides compositions, conjugates, and methods for delivering therapeutic agents to cancerous tissue. In some embodiments, the methods and compositions find particular use for the treatment of cancers. For instance, compositions comprising a conjugate of (i) a 3E10 antibody or antigen-binding fragment or variant thereof, and (ii) a therapeutic agent, as well as methods for using such compositions for the treatment of cancers, are described.

[0118] The studies described herein demonstrate that ADCs comprising a cell-penetrating and nucleic acid-binding 3E10 antibody conjugated via a cathepsin L-cleavable linker to an anti-tumor drug or a oligonucleotide can effectively penetrate and kill tumor cells with specificity. Advantageously, the ADCs comprising cathepsin-cleavable linkers allow for nuclear payload release. II. Definitions

[0119] The terminology used in the present disclosure is for the purpose of describing particular aspects only and is not intended to be limiting.

[0120] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. Unless the context requires otherwise, it will be further understood that the terms “includes,” “comprising,” or any variation thereof, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, to the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and / or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” Additionally, where the terms “comprising,” “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and / or the claims, alternatives reciting “consisting of” or “consisting essentially of” are intended to be encompassed within such disclosures.

[0121] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.

[0122] Use of the term “about” is intended to describe values either above or below the stated value in a range of approx. + / - 10%.

[0123] As used herein, the term “antibody” refers to an immunoglobulin molecule that recognizes and specifically binds to a target, such as a protein, polypeptide, peptide, carbohydrate, polynucleotide, lipid, or combinations of the foregoing through at least one antigen recognition site within the variable region of the immunoglobulin molecule. The term “antibody,” as used herein, is used in the broadest sense and encompasses monoclonal antibodies (including full length monoclonal antibodies), polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), chimeric antibodies, humanized antibodies, human antibodies, fusion proteins comprising an antigen determination portion of an antibody, and antibody fragments (such as Fab, Fab’, F(ab’)2, Fv fragments, scFv molecules), and any other modified immunoglobulin molecule comprising an antigen recognition site, so long as they exhibit one or more of the desired biological activities. In embodiments, “desired biological activity” of an antibody refers to the ability of the antibody to bind to its target antigen, e.g., a nucleic acid, e.g., DNA. In embodiments, “desired biological activity” can further include antibody binding to its target antigen and resulting in a measurable biological response which can be measured in vitro or in vivo. Such activity can be antagonistic or agonistic. In embodiments, “desired biological activity” of an antibody refers to the ability of the antibody to bind to a target, e.g., nucleic acid molecules. In embodiments, “desired biological activity” of an antibody refers to the ability of the antibody to bind to a cellular receptor, e.g., ENT2. In embodiments, “desired biological activity” of an antibody refers to the ability of the antibody to be internalized by a target cell. “Target antigen,” as used herein, refers to the molecule that is bound specifically by the antigen-binding domain comprising the variable regions of a given antibody. The term “specifically binds” refers to the binding of an antibody to its cognate antigen (e.g., a nucleic acid, e.g., DNA) while not significantly binding to other antigens.

[0124] Depending on the amino acid sequences of the constant domains of their heavy chains, antibodies (immunoglobulins) can be assigned to different classes. There are five major classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these can be further divided into subclasses or isotypes, e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. “Isotype,” as used herein, refers to any of the subclasses of immunoglobulins defined by the chemical and antigenic characteristics of their constant regions. The heavy chain constant domains that correspond to the different classes of immunoglobulins are called α, γ, ε, γ, and μ, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known and described generally in, for example, Abbas et al. Cellular and Mol. Immunology, 4thed. (W.B.Saunders, Co., 2000). It should be understood that antibodies disclosed herein can also comprise hybrids of isotypes and / or subclasses.

[0125] Antibodies of the present disclosure are generally isolated or recombinant. “Isolated,” when used to describe the various polypeptides disclosed herein, refers to a polypeptide that has been identified and separated and / or recovered from a cell or cell culture from which it was expressed. Ordinarily, an isolated polypeptide will be prepared by at least one purification step. An “isolated antibody,” refers to an antibody which is substantially free of other antibodies having different antigenic specificities. As used herein, “recombinant antibody” refers to an antibody that is generated using recombinant nucleic acid techniques in exogenous host cells, and recombinant antibodies can be isolated as well.

[0126] “Native antibodies” are usually heterotetrameric glycoproteins of about 150,000 Daltons, composed of two identical light (L) chains and two identical heavy (H) chains. Each light chain is linked to a heavy chain by one covalent disulfide bond, while the number of disulfide linkages varies among the heavy chains of different immunoglobulin isotypes. Each heavy and light chain also has regularly spaced intrachain disulfide bridges. Each heavy chain has at one end a variable domain (VH) followed by a number of constant domains. Each light chain has a variable domain at one end (VL) and a constant domain at its other end; the constant domain of the light chain is aligned with the first constant domain of the heavy chain, and the light chain variable domain is aligned with the variable domain of the heavy chain. Particular amino acid residues are believed to form an interface between the light chain and heavy chain variable domains.

[0127] The term “constant domain” refers to the portion of an immunoglobulin molecule having a more conserved amino acid sequence relative to the other portion of the immunoglobulin, the variable domain, which contains the antigen-binding site. The constant domain contains the CH1, CH2 and CH3 domains (collectively, CH) of the heavy chain and the CHL (or CL) domain of the light chain.

[0128] The “variable region” or “variable domain” of an antibody refers to the amino-terminal domains of the heavy or light chain of the antibody. The variable domain of the heavy chain may be referred to as “VH.” The variable domain of the light chain may be referred to as “VL.” These domains are generally the most variable parts of an antibody and contain the antigen-binding sites. The term “variable” refers to the fact that certain portions of the variable domains differ extensively in sequence among antibodies and are used in the binding and specificity of each particular antibody for its particular antigen. However, the variability is not evenly distributed throughout the variable domains of antibodies. It is concentrated in three segments called hypervariable regions (HVRs) or complementary determining regions (CDRs), both in the light-chain and theheavy-chain variable domains, that confer antigen specificity. A “variable heavy domain” pairs with a “variable light domain” to form an antigen-binding domain (ABD) that specifically binds a target antigen. The more highly conserved portions of variable domains are called the framework regions (FR). The variable domains of native heavy and light chains each comprise four FR regions, largely adopting a beta-sheet configuration, connected by three CDRs / HVRs, which form loops connecting, and in some cases forming part of, the beta-sheet structure. The CDRs / HVRs in each chain are held together in close proximity by the FR regions and, with the CDRs / HVRs from the other chain, contribute to the formation of the antigen-binding site of antibodies (see Kabat et al., Sequences of Proteins of Immunological Interest, Fifth Edition, National Institute of Health, Bethesda, Md. (1991)). The constant domains are not involved directly in the binding of an antibody to an antigen, but exhibit various effector functions, such as participation of the antibody in antibody-dependent cellular toxicity.

[0129] The terms “hypervariable region,” “HVR,” “HV,” “complementary determining region,” and “CDR,” used interchangeably herein, refer to the regions of an antibody variable domain which are hypervariable in sequence and / or form structurally defined loops. Generally, antibodies comprise six HVRs or CDRs; three in the VH (H1, H2, H3; or VH CDR1, VH CDR2, VH CDR3), and three in the VL (L1, L2, L3; or VL CDR1, VL CDR2, VL CDR3).

[0130] The “light chains” of antibodies (immunoglobulins) from any mammalian species can be assigned to one of two clearly distinct types, called kappa (“κ”) and lambda (“λ”), based on the amino acid sequences of their constant domains.

[0131] Together, the CDRs of the VH and VL domains form an Fv region. In embodiments, a VH and a VL domain comprise the six CDRs of the ABD. In a “Fab” format, the variable heavy domain (VH; containing VH CDR1, VH CDR2, and VH CDR3) and the variable light domain (VL or VL; containing the VL CDR1, VL CDR2 and VL CDR3), comprise the set of 6 CDRs, with the C-terminus of the VH domain being attached to the N-terminus of the CH1 domain of the heavy chain and the C-terminus of the VL domain being attached to the N-terminus of the constant light domain (and thus forming the light chain). In an “scFv” format, the VH and VL domains are covalently attached, generally through the use of a linker (e.g., an “scFv linker”), into a single polypeptide sequence, which can have the N- to C-terminus arrangement of VH-linker-VL or VL- linker-VH. In general, the C-terminus of the scFv domain is attached to the N-terminus of the hinge in the second monomer.

[0132] “Fab” or “Fab region,” as used herein, refers to a polypeptide that comprises VH, CH1, VL, and CL immunoglobulin domains, generally on two different polypeptide chains (e.g., VH- CH1 on one chain and VL-CL on the other). Fab can refer to this region in isolation, or this regionin the context of an antibody of the disclosure. In embodiments, a Fab comprises an Fv region in addition to CH1 CL domains.

[0133] Another part of the heavy chain is the hinge region. As used herein, “hinge,” “hinge region,” “antibody hinge region,” or “hinge domain” refers to the flexible polypeptide comprising the amino acids between the first and second constant domains of an antibody. Structurally, the IgG CH1 domain ends at EU position 215, and the IgG CH2 domain begins at residue EU position 231. Thus, for IgG, the antibody hinge is herein defined to include positions 216 (E216 in IgG1) to 230 (p230 in IgG1), wherein the numbering is according to the EU index as in Kabat. In some cases, a “hinge fragment” is used, which contains fewer amino acids at either or both of the N- and C-termini of the hinge domain.

[0134] “Heavy chain constant region,” as used herein, refers to the CH1-hinge-CH2-CH3 portion of an antibody or fragment thereof, excluding the variable heavy domain. In embodiments, the heavy chain constant region comprises amino acids 118-447 of human IgG1, in EU numbering. As used herein, “heavy chain constant region fragment” refers to a heavy chain constant region that contains fewer amino acids from either or both of the N- and C-termini but still retains the ability to form a dimer with another heavy chain constant region.

[0135] “Fv,” “Fv fragment,” or “Fv region,” as used herein, refers to a polypeptide that comprises VL and VH domains of an antibody binding domain. Fv regions can be formatted as both Fabs and scFvs, where the VL and VH domains are combined (e.g., by way of a linker, as discussed herein) to form an scFv.

[0136] “Fc,” “Fc region,” or “Fc domain,” as used herein, refers to a polypeptide comprising CH2-CH3 domains of an IgG molecule, and, in some cases, inclusive of the hinge. In EU numbering for human IgG1, the CH2-CH3 domain comprises amino acids 231 to 447, and the hinge is 216 to 230. Thus, the definition of “Fc domain” includes both amino acids 231-447 (CH2- CH3) and 216-447 (hinge-CH2-CH3) of IgG1, or fragments thereof. An “Fc fragment” in this context can contain fewer amino acids from either or both of the N- and C-termini but still retains the ability to form a dimer with another Fc domain or Fc fragment as can be detected using standard methods, generally based on size (e.g., non-denaturing chromatography, size exclusion chromatography, etc.). In embodiments, the disclosed ADCs comprise human Fc domains. In embodiments, the disclosed ADCs comprise Fc domains from human IgG1, IgG2, or IgG4.

[0137] A “variant Fc domain” contains amino acid modifications as compared to a parental Fc domain. Thus, a “variant human IgG1 Fc domain” is one that contains amino acid modifications (generally amino acid substitutions, although in the case of ablation variants, amino acid deletions are included) as compared to the human IgG1 Fc domain. In embodiments, variant Fc domainshave at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 97%, at least about 98%, or at least about 99% identity to the corresponding parental human IgG Fc domain. In embodiments, the percent identity is calculated using the identity algorithms discussed below. In embodiments, the percent identity is calculated using the BLAST algorithm known in the art, using default parameters. In embodiments, variant Fc domains have from 1 to about 20 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20) amino acid modifications as compared to the parental Fc domain. In embodiments, variant Fc domains retain the ability to form a dimer with Ir Fc domain as measured using known techniques as described herein, such as non-denaturing gel electrophoresis.

[0138] For all positions discussed in the present disclosure that relate to antibodies, unless otherwise noted, amino acid position numbering is according to the EU index. The EU index or EU index as in Kabat or EU numbering scheme refers to the numbering of the EU antibody. Kabat et al. collected numerous primary sequences of the variable regions of heavy chains and light chains. Based on the degree of conservation of the sequences, they classified individual primary sequences into the CDR and the framework and made a list thereof. See, SEQUENCES OF IMMUNOLOGICAL INTEREST, 5thedition, NIH publication, No. 91-3242, E.A. Kabat et al.; Edelman et al., 1969, Proc Natl Acad Sci USA 63:78-85, the contents of which are incorporated herein by reference. In embodiments of the present disclosure, amino acid position numbering is according to the IMGT system.

[0139] The terms “full length antibody,” “intact antibody” and “whole antibody” are used herein interchangeably to refer to an antibody in its substantially intact form, not antibody fragments as defined below. The terms particularly refer to an antibody with heavy chains that contain an Fc region.

[0140] “Antibody fragments” comprise a portion of an intact antibody, preferably comprising the antigen-binding region thereof. Examples of antibody fragments include Fab, Fab′, F(ab′)2, and Fv fragments; diabodies; linear antibodies; single-chain antibody molecules; and multispecific antibodies formed from antibody fragments.

[0141] A “naked antibody” for the purposes herein is an antibody that is not conjugated to a cytotoxic moiety or radiolabel.

[0142] The term “monoclonal antibody” as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, e.g., the individual antibodies comprising the population are identical except for possible mutations, e.g., naturally occurring mutations, that can be present in minor amounts. Thus, the modifier “monoclonal” indicates the character of the antibody as not being a mixture of discrete antibodies. In certain embodiments, such a monoclonalantibody typically includes an antibody comprising a polypeptide sequence that binds a target, wherein the target-binding polypeptide sequence was obtained by a process that includes the selection of a single target binding polypeptide sequence from a plurality of polypeptide sequences. 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, or recombinant DNA clones. It should be understood that a selected target binding sequence can be further altered, for example, to improve affinity for the target, to humanize the target binding sequence, to improve its production in cell culture, to reduce its immunogenicity in vivo, to create a multispecific antibody, etc., and that an antibody comprising the altered target binding sequence is also a monoclonal antibody of this disclosure. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a single determinant on an antigen. In addition to their specificity, monoclonal antibody preparations are advantageous in that they are typically uncontaminated by other immunoglobulins.

[0143] Antibodies herein specifically include “chimeric” antibodies in which a portion of the heavy and / or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit one or more of the desired biological activities (see, e.g., U.S. Pat. No.4,816,567; and Morrison et al., Proc. Natl. Acad. Sci. USA 81:6851-6855 (1984)). Typically, the variable region of both light and heavy chains corresponds to the variable region of antibodies derived from one species of mammals (e.g., mouse, rat, rabbit, etc.) with the desired specificity, affinity, and / or capability, while the constant regions are homologous to the sequences of antibodies derived from another species of mammals (e.g., human) to avoid eliciting an immune response In that species.Chimeric antibodies include PRIMATTZED® antibodies wherein the antigen-binding region of the antibody is derived from an antibody produced by, e.g., immunizing macaque monkeys with the antigen of interest.

[0144] “Humanized” forms of non-human (e.g., murine) antibodies are chimeric antibodies that contain minimal sequence derived from non-human immunoglobulin. In embodiments, a humanized antibody is a human immunoglobulin (recipient antibody) in which residues from a CDR / HVR of the recipient are replaced by residues from a CDR / HVR of a non-human species (donor antibody) such as mouse, rat, rabbit, or nonhuman primate having the desired specificity, affinity, and / or capacity. In some instances, FR residues of the human immunoglobulin arereplaced by corresponding non-human residues. Furthermore, humanized antibodies can comprise residues that are not found in the recipient antibody or in the donor antibody. These modifications can be made to further refine antibody performance. In general, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the hypervariable loops correspond to those of a non-human immunoglobulin, and all or substantially all of the FRs are those of a human immunoglobulin sequence. The humanized antibody optionally will also comprise at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. See, e.g., Jones et al., Nature 321:522-525 (1986); Riechmann et al., Nature 332:323-329 (1988); and Presta, Curr. Op. Struct. Biol.2:593- 596 (1992). See also, e.g., Vaswani and Hamilton,Allergy, Asthma & Immunol.1:105-115 (1998); Harris, Biochem. Soc. Transactions 23:1035-1038 (1995); Hurle and Gross, Curr. Op. Biotech.5:428-433 (1994); and U.S. Pat. Nos. 6,982,321 and 7,087,409. Examples of methods used to generate humanized antibodies are described in U.S. Pat. 5,225,539 or 5,639,641, incorporated herein by reference in their entireties.

[0145] As used herein, the term “human antibody” refers to an antibody which possesses an amino acid sequence which corresponds to that of an antibody produced by a human and / or has been made using any technique known in the art. This definition of a human antibody includes intact or full-length antibodies, fragments thereof, and / or antibodies comprising at least one human heavy and / or light chain polypeptide. This definition of a human antibody specifically excludes a humanized antibody comprising non-human antigen-binding residues. Human antibodies can be produced using various techniques known in the art, including phage-display libraries. Hoogenboom and Winter, J. Mol. Biol., 227:381 (1991); Marks et al., J. Mol. Biol., 222:581 (1991). Also available for the preparation of human monoclonal antibodies are methods described in Cole et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p.77 (1985); Boerner et al., J. Immunol., 147(1):86-95 (1991). See also van Dijk and van de Winkel, Curr. Opin. Pharmacol., 5: 368-74 (2001). Human antibodies can be prepared by administering the antigen to a transgenic animal that has been modified to produce such antibodies in response to antigenic challenge, but whose endogenous loci have been disabled, e.g., immunized xenomice (see, e.g., U.S. Pat. Nos. 6,075,181 and 6,150,584 regarding XENOMOUSE™ technology). See also, for example, Li et al., Proc. Natl. Acad. Sci. USA, 103:3557-3562 (2006) regarding human antibodies generated via a human B-cell hybridoma technology.

[0146] A “species-dependent antibody” is one which has a stronger binding affinity for an antigen from a first mammalian species than it has for a homologue of that antigen from a second mammalian species. Normally, the species-dependent antibody “binds specifically” to a humanantigen (e.g., has a binding affinity (Kd) value of no more than about 1×10−7M, preferably no more than about and preferably no more than about 1×10−9M) but has a binding affinity for a homologue of the antigen from a second nonhuman mammalian species which is at least about 50 fold, or at least about 500 fold, or at least about 1000 fold, weaker than its binding affinity for the human antigen. The species-dependent antibody can be any of the various types of antibodies as defined above, but preferably is a humanized or human antibody.

[0147] The expression “linear antibodies” refers to the antibodies described in Zapata et al. (1995 Protein Eng, 8(10):1057-1062). Briefly, these antibodies comprise a pair of tandem Fd segments (VH-CH1-VH-CH1) which, together with complementary light chain polypeptides, form a pair of antigen-binding regions. Linear antibodies can be bispecific or monospecific.

[0148] “Modification,” as used herein, refers to an amino acid substitution, insertion, deletion, and / or any other mutation in a polypeptide sequence.

[0149] “Variant protein,” or “protein variant,” or “variant,” as used herein refers to a protein that differs from that of a parent protein by virtue of at least one amino acid modification. The protein variant has at least one amino acid modification compared to the parent protein, yet not so many that the variant protein will not align with the parental protein using an alignment program such as that described below. In general, variant proteins (such as variant Fc domains, etc., described herein, are generally at least about 75%, at least about 76%, at least about 77%, at least about 78%, at least about 79%, at least about 80%, at least about 81%, at least about 82%, at least about 83%, at least about 84%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at least about 99.5% identical to the parent polypeptide, using any alignment program known in the art, such as BLAST.

[0150] Sequence identity between two similar sequences (e.g., antibody variable domains) can be measured by algorithms such as that of Smith, T.F. & Waterman, M.S. (1981) “Comparison Of Biosequences,” Adv. Appl. Math.2:482 [local homology algorithm]; Needleman, S.B. & Wunsch, CD. (1970) “A General Method Applicable To The Search For Similarities In The Amino Acid Sequence Of Two Proteins,” J. Mol. Biol.48:443 [homology alignment algorithm], Pearson, W.R. & Lipman, D.J. (1988) “Improved Tools For Biological Sequence Comparison,” Proc. Natl. Acad. Sci. (U.S.A.) 85:2444 [search for similarity method]; or Altschul, S.F. et al, (1990) “Basic Local Alignment Search Tool,” J. Mol. Biol. 215:403-10 , the “BLAST” algorithm, see the webpage located at URL blast.ncbi.nlm.nih.gov / Blast.cgi. When using any of the aforementioned algorithms, the default parameters (for Window length, gap penalty, etc.) are used. Unlessspecifically stated otherwise, sequence identity is determined using the BLAST algorithm, using default parameters.

[0151] In embodiments, a parent polypeptide, for example an Fc parent polypeptide, is a human wild type sequence, such as the heavy constant domain or Fc region from IgG1, IgG2, IgG3 or IgG4, although human sequences with variants can also serve as “parent polypeptides.” In embodiments, antibody sequences described herein have at least about 75%, at least about 76%, at least about 77%, at least about 78%, at least about 79%, at least about 80%, at least about 81%, at least about 82%, at least about 83%, at least about 84%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at least about 99.5% sequence identity with a parent polypeptide sequence. Accordingly, “antibody variant” or “variant antibody” as used herein refers to an antibody that differs from a parent antibody by virtue of at least one amino acid modification; “IgG variant” or “variant IgG” as used herein refers to an IgG that differs from a parent IgG (e.g., from a human IgG sequence) by virtue of at least one amino acid modification; “immunoglobulin variant” or “variant immunoglobulin” as used herein refers to an immunoglobulin sequence that differs from that of a parent immunoglobulin sequence by virtue of at least one amino acid modification; and “Fc variant” or “variant Fc” as used herein refers to an Fc that differs from a parent Fc, e.g., an Fc domain of human IgG1, IgG2, IgG3, or IgG4, by virtue of at least one amino acid modification.

[0152] “IgG subclass modification” or “isotype modification,” as used herein, refers to amino acid modifications that convert one amino acid of one IgG isotype to the corresponding amino acid in a different, aligned IgG isotype. For example, because IgG1 comprises a tyrosine and IgG2 a phenylalanine at EU position 296, a F296Y substitution in IgG2 is considered an IgG subclass modification.

[0153] “Non-naturally occurring modification” as used herein is meant an amino acid modification that is not isotypic. For example, because none of the human IgGs comprise a serine at position 434, the substitution 434S in IgG1, IgG2, IgG3, or IgG4 (or hybrids thereof) is considered a non-naturally occurring modification.

[0154] As used herein, “oligonucleotide” or “polynucleotide,” used interchangeably, refers to a linear polymer of natural or modified nucleoside monomers linked by phosphodiester bonds or analogs thereof. The term “oligonucleotide” usually refers to a shorter polymer, e.g., comprising from about 3 to about 100 monomers, and the term “polynucleotide” usually refers to longer polymers, e.g., comprising from about 100 monomers to many thousands of monomers, e.g.,10,000 monomers, or more. Oligonucleotides and polynucleotides can be natural or synthetic. Oligonucleotides and polynucleotides can include deoxyribonucleosides, ribonucleosides, and / or non-natural analogs thereof. In embodiments, oligonucleotides or polynucleotides are capable of specifically binding to a target genome by way of a regular pattern of monomer-to-monomer interactions, such as Watson-Crick type of base pairing, base stacking, Hoogsteen or reverse Hoogsteen types of base pairing, or the like.

[0155] As used herein, a “3E10 antibody” refers to an antibody with a set of heavy chain CDRs (VH CDR1, VH CDR2, and VH CDR3), identified according to the Kabat system, comprising amino acid sequences that vary from SEQ ID NOS: 58, 59, and 60 by no more than two amino acids each, respectively, a set of light chain CDRs (VL CDR1, VL CDR2, and VL CRD3) comprising amino acid sequences that vary from SEQ ID NOS: 61, 62, and 63 by no more than two amino acids each, respectively, that binds nucleic acids and is cell-penetrating at least when bound to a nucleic acid. As described herein, the 3E10 antigen is a polynucleotide.

[0156] As used herein, the term “cell-penetrating” refers to an antibody or antigen binding fragment thereof that can penetrate a cell, e.g., a mammalian cell, without the aid of an exogeneous transport vehicle, such as a liposome, or a conjugated cell-penetrating peptide. With respect to 3E10 antibodies and antigen binding fragments thereof, the cell-penetrating antibody or antigen binding fragment thereof can penetrate a cell expressing an ENT2 receptor on its cell surface in the presence of nucleic acids, e.g., non-covalently bound and / or conjugated to the 3E10 antibody or antigen binding fragment thereof, resulting in internalization of the 3E10 antibodies and antigen binding fragments thereof. In some embodiments, the cell-penetrating 3E10 antibody or antigen binding fragment thereof is conjugated to a functional molecule, e.g., a chemical agent, polynucleotide, or polypeptide. Although the cell-penetrating molecules are generally referred to herein as “cell-penetrating antibodies,” it will be appreciated that fragments, including antigen-binding fragments, variants, binding proteins and fusion proteins such as scFv, di- scFv, tri-scFv, and other single chain variable fragments, and other cell-penetrating molecules disclosed herein are also expressly provided for use in compositions, conjugates, and methods disclosed herein. Autoantibodies to double-stranded deoxyribonucleic acid (dsDNA) are frequently identified in the serum of patients with systemic lupus erythematosus (SLE) and are often implicated in disease pathogenesis. Therefore, in embodiments, cell-penetrating antibodies (e.g., cell-penetrating anti-DNA antibodies) can be derived or isolated from patients with SLE or animal models of SLE.

[0157] As used herein, “antibody drug conjugate” or “ADC” refers to an antibody or antigen- binding fragment or variant thereof that is covalently linked or conjugated to a biologically active molecule, for example, a drug or an anti-tumor drug.

[0158] As used herein, a “linker” is any chemical moiety that is capable of linking or connecting a compound, usually a drug or an anti-tumor drug, to a cell-binding agent such as an antibody, such as a 3E10 antibody or a fragment thereof, in a stable, covalent manner. In embodiments, a “linker” is any chemical moiety that is capable of linking or connecting a compound such as a DNA damage-inducing agent, a DNA repair inhibitor, an immune modulatory molecule, an alkylating agent, a microtubule inhibitor, an immune checkpoint inhibitor, an angiogenesis inhibitor, an adoptive cell therapy, or a topoisomerase inhibitor, to a cell-binding agent such as a 3E10 antibody or a fragment thereof, in a stable, covalent manner. Linkers can be susceptible to or be substantially resistant to acid-induced cleavage, light-induced cleavage, peptidase-induced cleavage, esterase-induced cleavage, and / or disulfide bond cleavage, at conditions under which the compound and / or the antibody remains active. Suitable linkers are well known in the art and include, for example, disulfide groups, thioether groups, acid labile groups, photolabile groups, peptidase labile groups and esterase labile groups. Linkers also include charged linkers, and hydrophilic forms thereof as described herein and know in the art.

[0159] As used herein, the term “subject” refers to any individual who is the target of administration. The subject can be any animal (e.g., a mammal), including, but not limited to, humans, and non-human animals (including, but not limited to, non-human primates, dogs, cats, rodents, horses, cows, pigs, mice, rats, hamsters, rabbits, and the like (e.g., which is to be the recipient of a particular treatment). In embodiments, the subject is a human.

[0160] In embodiments, methods of the disclosure are useful in treatment a human subject. In embodiments, the human may be referred to as a patient. In embodiments, the human is a female. In embodiments, the human is a male. In embodiments, the human has an age in a range of from about 1 to about 18 months old, from about 18 to about 36 months old, from about 1 to about 5 years old, from about 5 to about 10 years old, from about 10 to about 15 years old, from about 15 to about 20 years old, from about 20 to about 25 years old, from about 25 to about 30 years old, from about 30 to about 35 years old, from about 35 to about 40 years old, from about 40 to about 45 years old, from about 45 to about 50 years old, from about 50 to about 55 years old, from about 55 to about 60 years old, from about 60 to about 65 years old, from about 65 to about 70 years old, from about 70 to about 75 years old, from about 75 to about 80 years old, from about 80 to about 85 years old, from about 85 to about 90 years old, from about 90 to about 95 years old or from about 95 to about 100 years old.

[0161] The terms “cancer” and “cancerous” refer to or describe the physiological condition in mammals in which a population of cells are characterized by unregulated cell growth. Examples of cancer include, but are not limited to, colorectal cancer, pancreatic cancer, lung cancer, ovarian cancer, liver cancer, breast cancer, brain cancer, kidney cancer, prostate cancer, gastrointestinal cancer, melanoma, cervical cancer, bladder cancer, glioblastoma, head and neck cancer, lymphomas, Hodgkin lymphoma, Non-Hodgkin lymphoma, cutaneous B-cell lymphoma, cutaneous T-cell lymphoma, Waldenstrom macroglobulinemia, chronic lymphocytic leukemia, leukemia, neuroblastoma, Wilms tumor, bone cancer, brain stem tumor, childhood diffuse intrinsic pontine glioma (DIPG), retinoblastoma, rhabdoid tumor, sarcoma, spinal cord tumor, endocrine cancer, esophageal cancer, gastric cancer, hepatobiliary cancer, myeloma, renal cancer, thyroid cancer, uterine cancer, carcinoma, blastoma, papilloma, adenoma, an astrocytic tumor, an oligodendroglial tumor, an oligoastrocytic tumor, an ependymal tumor, a choroid plexus tumor, a neuronal or mixed neuronal-glial tumor, tumor of the pineal region, embryonal tumor, or an otherwise uncategorized neuroepithelial tumors.

[0162] “Tumor” and “neoplasm” refer to any mass of tissue that results from excessive cell growth or proliferation, either benign (noncancerous) or malignant (cancerous), including pre- cancerous lesions.

[0163] The terms “cancer cell,” “tumor cell,” and grammatical equivalents thereof refer to the total population of cells derived from a tumor or a pre-cancerous lesion, including both non- tumorigenic cells, which comprise the bulk of the tumor cell population, and tumorigenic stem cells (cancer stem cells).

[0164] The term “chemotherapeutic warhead” refers to a cytotoxic drug or anti-tumor drug covalently linked to an antibody in an ADC.

[0165] As used herein, the term “pharmaceutically effective amount” means that the amount of the composition used is of sufficient quantity to ameliorate one or more causes or symptoms of a disease or disorder. Such amelioration only requires a reduction or alteration, not necessarily elimination. The precise dosage will vary according to a variety of factors such as subject- dependent variables (e.g., age, immune system health, etc.), the disease or disorder being treated, as well as the route of administration and the pharmacokinetics of the agent being administered.

[0166] As used herein, the term “carrier” or “excipient” refers to an organic or inorganic ingredient, natural or synthetic inactive ingredient in a formulation, with which one or more active ingredients are combined. In embodiments, a carrier or excipient is selected to minimize degradation of the active ingredient or to minimize adverse side effects in the subject, as would be well known to one of skill in the art.

[0167] As used herein, the term “treat” refers to the medical management of a patient with the intent to cure, ameliorate, stabilize, or prevent a disease, pathological condition, or disorder. This term includes active treatment, that is, treatment directed specifically toward the improvement of a disease, pathological condition, or disorder, and also includes causal treatment, that is, treatment directed toward removal of the cause of the associated disease, pathological condition, or disorder. In addition, this term includes palliative treatment, that is, treatment designed for the relief of symptoms rather than the curing of the disease, pathological condition, or disorder; preventative treatment, that is, treatment directed to minimizing or partially or completely inhibiting the development of the associated disease, pathological condition, or disorder; and supportive treatment, that is, treatment employed to supplement another specific therapy directed toward the improvement of the associated disease, pathological condition, or disorder.

[0168] A “pharmacologically effective amount,” “pharmacologically effective dose,” “therapeutically effective amount,” or “effective amount” refers to an amount sufficient to produce the desired physiological effect or amount capable of achieving the desired result, particularly for treating or preventing the disorder or disease. An effective amount as used herein would include an amount sufficient to, for example, delay the development of a symptom of the disorder or disease, alter the course of a symptom of the disorder or disease (e.g., slow the progression of a symptom of the disease), reduce or eliminate one or more symptoms or manifestations of the disorder or disease, and reverse a symptom of a disorder or disease. Therapeutic benefit also includes halting or slowing the progression of the underlying disease or disorder, regardless of whether improvement is realized.

[0169] Effective amounts, toxicity, and therapeutic efficacy can be determined by standard pharmaceutical procedures in cell cultures, tissue samples, tissue homogenates or experimental animals, e.g., for determining the LD50 (the dose lethal to about 50% of the population) and the ED50 (the dose therapeutically effective in about 50% of the population) or the maximum tolerated dose. The dosage can vary depending upon the dosage form employed and the route of administration utilized. The dose ratio between toxic and therapeutic effects is the therapeutic index and can be expressed as the ratio LD50 / ED50. In embodiments, compositions, conjugates, and methods that exhibit large therapeutic indices are preferred. A therapeutically effective dose can be estimated initially from in vitro assays, including, for example, cell culture assays or measurements. Also, a dose can be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 as determined in cell culture, or in an appropriate animal model. Levels of the described compositions in plasma can be measured, for example, by high performance liquid chromatography. The effects of any particular dosage can be monitored by asuitable bioassay. The dosage can be determined by a physician and adjusted, as necessary, to suit observed effects of the treatment.

[0170] In embodiments, the effect will result in a quantifiable change of at least about 10%, at least about 20%, at least about 30%, at least about 50%, at least about 70%, or at least about 90%. In embodiments, the effect will result in a quantifiable change of about 10%, about 20%, about 30%, about 50%, about 70%, or even about 90% or more. Therapeutic benefit also includes halting or slowing the progression of the underlying disease or disorder, regardless of whether improvement is realized. III. Antibody Drug Conjugates (ADCs)

[0171] The present disclosure is directed, in part, to antibody drug conjugates (ADCs) comprising a cell-penetrating antibody, e.g., a 3E10 antibody or a or antigen-binding fragment or variant thereof, conjugated via a linker to a biologically active molecule or a therapeutic agent.

[0172] As used herein “antibody drug conjugate” or “ADC” refers to an antibody or antigen- binding fragment or variant thereof that is linked or conjugated to a biologically active molecule or a therapeutic agent, for example, a drug or anti-tumor drug. In embodiments, an ADC specifically binds its epitope, and triggers cell death via delivery of the drug or anti-tumor drug. In embodiments, an antibody-drug conjugate (ADC) has the formula A-(L-Pr)q, wherein: A is a 3E10 antibody or antigen-binding fragment or variant thereof, L is a linker, and P is a payload as described herein.

[0173] In embodiments, the present disclosure relates to the use of 3E10 antibodies, and derivatives thereof, for delivering therapeutic agents to a subject. Although generally referred to herein as “3E10” or “3E10 antibodies,” it will be appreciated that fragments, variants, and binding proteins, including antigen-binding fragments and fusion proteins, such as scFv, di-scFv, tr-scFv, and other single chain variable fragments, and other cell-penetrating, nucleic acid transporting molecules disclosed herein, are encompassed by the phrase and are also expressly provided for use in compositions, conjugates, and methods disclosed herein. Thus, the antibodies and other binding proteins are also referred to herein as cell-penetrating.

[0174] In embodiments, the antibody is conjugated to the therapeutic agent via a linker. In embodiments, the antibody is a 3E10 antibody or antigen-binding fragment or variant thereof, as described herein. In embodiments, the antibody is a humanized 3E10 antibody or antigen-binding fragment or variant thereof, as described herein. Any variety of agents can be transported via conjugation to the 3E10 antibody or antigen-binding fragment or variant thereof, or humanized 3E10 antibody or antigen-binding fragment or variant thereof, herein, such as inorganic andorganic molecules, pharmaceutical agents, drugs, peptides, proteins, genetic material, and the like. In embodiments, the antibody-drug conjugate (ADC) comprises a drug, or an anti-tumor drug. A. Antigen-Binding Domains (ABDs)

[0175] As used herein, the term “antigen-binding domain” or “ABD” refers to a domain comprising a three-dimensional structure capable of immunospecifically binding to an epitope of an antigen. Thus, in embodiments, an ABD comprises a hypervariable region, optionally a VH and / or VL domain of an antibody, optionally at least a VH domain. In embodiments, an ABD comprises at least one complementarity determining region (CDR) of an antibody. In embodiments, an ABD comprises at least two CDRs of an antibody. In embodiments, an ABD comprises at least three CDRs of an antibody. In embodiments, an ABD comprises at least four CDRs of an antibody. In embodiments, an ABD comprises at least five CDRs of an antibody. In embodiments, an ABD comprises six CDRs of an antibody. 1.3E10 Antibodies

[0176] In embodiments, the present disclosure relates to the use of 3E10 antibodies, and derivatives thereof, for delivering therapeutic agents to a subject. Although generally referred to herein as “3E10” or “3E10 antibodies,” it will be appreciated that fragments, variants, and binding proteins, including antigen-binding fragments and fusion proteins, such as scFv, di-scFv, tr-scFv, and other single chain variable fragments, and other cell-penetrating, nucleic acid transporting molecules disclosed herein, are encompassed by the phrase and are also expressly provided for use in compositions, conjugates, and methods disclosed herein. Thus, the antibodies and other binding proteins are also referred to herein as cell-penetrating.

[0177] In embodiments, a 3E10 antibody comprises VL CDRs of SEQ ID NOs: 61, 62, and 63 and VH CDRs of SEQ ID NOs: 58, 59, and 60. In embodiments, a 3E10 antibody comprises VL CDRs of SEQ ID NOs: 9, 10, and 11 and VH CDRs of SEQ ID NOs: 3, 4, and 5. In embodiments, a 3E10 antibody comprises VL CDRs of SEQ ID NOs: 22, 23, and 24 and VH CDRs of SEQ ID NOs: 15, 17, and 18. In embodiments, a 3E10 antibody comprises VL CDRs of SEQ ID NOs: 9, 10, and 11 and VH CDRs of SEQ ID NOs: 16, 4, and 5.

[0178] In embodiments, a 3E10 antibody has nucleic acid binding affinity.

[0179] In embodiments, a 3E10 antibody is competent for ENT2-mediated cell internalization when bound to nucleic acid.

[0180] In embodiments, targeting of an ADC described herein is not limited to a tissue- or cancer-specific antigen or tumor epitope when used in a method of treating cancer, or whentargeting a cancer cell or tumor or tumor cell. Accordingly, an ADC provided herein can widely target cancers based on cell surface expression of ENT2, a nucleoside transporter overexpressed in cancer cells and tumor cells. Advantageously, an ADC described herein can target ENT2 and extracellular DNA simultaneously. Importantly, 3E10 has been shown to preferentially localize into tumor cell nuclei in vivo, likely due to increased DNA in the local environment released from ischemic and necrotic regions of tumor. Targeting of the 3E10 antibody to extracellular DNA is described in, for example in Weisbart, Sci Reports, 2015, which is herein incorporated by reference. By targeting ENT2 as well as extracellular DNA, the 3E10 ADC described herein presents a platform to target a variety of cancers and deliver chemotherapeutic drugs to target and kill cancer cells.

[0181] In embodiments of the present disclosure, the antibody or antigen-binding fragment or variant thereof is murine, chimeric, humanized, or human.

[0182] In embodiments, an ADC of the present disclosure penetrates into cells and nuclei in an ENT2-dependent manner.

[0183] In embodiments, an ADC of the present disclosure further comprises a bound polynucleotide, wherein A binds the polynucleotide. In embodiments, the bound polynucleotide is precomplexed with the ADC. In embodiments, the bound polynucleotide is an extracellular polynucleotide that is bound by the ADC at a site of interest, such as, for example, at a site of tumor ischemia and necrosis. In embodiments, the polynucleotide is DNA. In embodiments, the polynucleotide is RNA.

[0184] In embodiments, an ABD comprises a VH and / or VL domain of a 3E10 antibody. In embodiments, the ABD comprises a VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2, and / or VL CDR3 of a 3E10 antibody.

[0185] In embodiments, the present disclosure provides an antibody-drug conjugate (ADC) having the formula A-(L-Pr)q, wherein: A is a 3E10 antibody or antigen-binding fragment or variant thereof, L is a linker, and P is a payload as described herein, wherein the linker L links A to P. In embodiments of the present disclosure, the amino acid residue corresponding with D31 of the heavy chain CDR1 of the 3E10 antibody or antigen-binding fragment or variant thereof is substituted with N. It is known in the art that mutation of aspartic acid at residue 31 of VH CDR1 to asparagine increases the cationic charge of this residue and enhanced nucleic acid binding and delivery in vivo (3E10-D31N). In embodiments, additional 3E10 antibody variants include mutation of aspartic acid at residue 31 of VH CDR1 to arginine (3E10-D31R), which modeling indicates expands cationic charge, or lysine (3E10-D31K) which modeling indicates changes charge orientation. Thus, in embodiments, the 3E10 antibody or antigen-binding fragment orvariant thereof includes a D31R or D31K substitution. In embodiments, additional 3E10 antibody variants include mutation a R96N, and / or S30D substitution, alone or in combination with D31N, D31R, or D31K. All of the sequences disclosed herein having the residue corresponding to 3E10 D31 or N31, are expressly disclosed with a D31R or D31K or N31R or N31K substitution.

[0186] In embodiments, the present disclosure provides an antibody-drug conjugate (ADC) having the formula A-(L-Pr)q, wherein: A is a 3E10 antibody or antigen-binding fragment or variant thereof, L is a linker, P is a payload as described herein, r is an integer from 1 to 4, and q is an integer from 1 to 16, wherein the linker L links A to (P); wherein the 3E10 antibody or antigen- binding fragment thereof comprises a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of X1YGMX2, where X1 is D, E, N, Q, R, or K and X2 is K, R, or H (SEQ ID NO:58). In embodiments, the antibody or antigen-binding fragment or variant thereof comprises (a) a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of X1ASX2X3VSTSSYSYX4X5, where X1 is K, R, or H, X2 is K, R, or H, X3 is T or S, X4 is M or L, and X5 is K, R, H, or A (SEQ ID NO:61), (b) a VL CDR2 comprising the amino acid sequence of YASYLX1S, where X1 is D, E, N, or Q (SEQ ID NO:62), and (c) a VL CDR3 comprising the amino acid sequence of QX1SX2X3FPWT, where X1 is K, R, or H, X2 is K, R, or H, and X3 is D or E (SEQ ID NO:63), and (d) a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of X1YGMX2, where X1 is D, E, N, Q, R, or K and X2 is K, R, or H (SEQ ID NO:58), (e) a VH CDR2 comprising the amino acid sequence of YISSX1SSTIYYAX2X3VX4G, where X1 is G or S, X2 is D or E, X3 is T or S, and X4 is K, R, or H (SEQ ID NO:59), and (f) a VH CDR3 comprising the amino acid sequence of X1GLLLX2Y, where X1 is K, R, or H, and X2 is D or E (SEQ ID NO:60).

[0187] In embodiments, the present disclosure provides an antibody-drug conjugate (ADC) having the formula A-(L-Pr)q, wherein: A is a 3E10 antibody or antigen-binding fragment or variant thereof, L is a linker, P is a payload as described herein, r is an integer from 1 to 4, and q is an integer from 1 to 16, wherein the linker L links A to P; wherein the 3E10 antibody or antigen- binding fragment thereof comprises a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of NYGMH (SEQ ID NO: 15). In embodiments, the antibody or antigen- binding fragment or variant thereof comprises (a) a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of RASKSVSTSSYSYMH (SEQ ID NO:9), (b) a VL CDR2 comprising the amino acid sequence of YASYLES (SEQ ID NO:10), and (c) a VL CDR3 comprising the amino acid sequence of QHSREFPWT (SEQ ID NO: 11), and (d) a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of NYGMH (SEQ ID NO: 15), (e) a VH CDR2 comprising the aminoacid sequence of YISSGSSTIYYADTVKG (SEQ ID NO: 4), and (f) a VH CDR3 comprising the amino acid sequence of RGLLLDY (SEQ ID NO: 5). In embodiments, the antibody or antigen- binding fragment or variant thereof comprises a light chain variable region (VL) comprising an amino acid sequence that is identical to SEQ ID NO:21. In embodiments, the antibody or antigen- binding fragment or variant thereof comprises a heavy chain variable region (VH) comprising an amino acid sequence that is identical to SEQ ID NO:14. In embodiments, the antibody or antigen- binding fragment or variant thereof comprises a full length light chain (LC) comprising an amino acid sequence that is identical to SEQ ID NO:20. In embodiments, the antibody or antigen-binding fragment or variant thereof comprises a full length heavy chain (HC) comprising an amino acid sequence that is identical to SEQ ID NO:13.

[0188] In embodiments, the antibody or antigen-binding fragment or variant thereof comprises a light chain variable region (VL) comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identical to SEQ ID NO:21. In embodiments, the antibody or antigen-binding fragment or variant thereof comprises a heavy chain variable region (VH) comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identical to SEQ ID NO:14. In embodiments, the antibody or antigen-binding fragment or variant thereof comprises a full length light chain (LC) comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identical to SEQ ID NO:20. In embodiments, the antibody or antigen-binding fragment or variant thereof comprises a full length heavy chain (HC) comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identical to SEQ ID NO:13.

[0189] In embodiments, the 3E10 antibody or antigen-binding fragment or variant thereof can be transported into the cytoplasm and / or nucleus of the cells without the aid of a carrier or conjugate. For example, monoclonal antibody 3E10 and active fragments thereof that are transported in vivo to the nucleus of mammalian cells without cytotoxic effect are disclosed in U.S. Patent Nos. 4,812,397 and 7,189,396 to Richard Weisbart (each of which is incorporated by reference herein, in its entirety).

[0190] Amino acid sequences of 3E10 monoclonal antibodies and antigen-binding fragments thereof are known in the art. Example sequences of 3E10 heavy and light chains are provided below herein.

[0191] The murine version of the 3E10 antibody is described in Zack, et al., Immunology and Cell Biology, 72:513-520 (1994) (which is incorporated by reference herein, in its entirety).

[0192] Amino acid variants of the 3E10 antibody are also known in the art, for example, as described in Zack, et al., J. Immunol., 157(5):2082-8 (1996). For example, amino acid position 31, in CDR1 of the heavy chain variable region of 3E10, influences nucleic acid binding and the antibody’s ability to penetrate nuclei. Substitution of the ‘wild-type’ (e.g., relative to the original murine antibody) aspartic acid by asparagine (the ‘D31N’ mutation) improves nucleic acid binding and nuclei penetration of the antibody, relative to the ‘wild type’ murine antibody. See, for example, Zack, et al., Immunology and Cell Biology, 72:513-520 (1994); Weisbart, et al., J. Autoimmun., 11, 539-546 (1998); and Weisbart, Int. J. Oncol., 25, 1867-1873 (2004) (which are incorporated by reference herein, in their entireties).

[0193] Sequences for 3E10 antibodies and antigen-binding fragments or variants thereof, with the D31N substitution, are disclosed herein. In embodiments, the 3E10 antibodies and binding fragments or variants thereof disclosed herein include the D31N substitution. In embodiments, other amino acids are substituted at position 31 in the 3E10 antibodies and antigen-binding fragments or variants thereof disclosed herein. For example, D31R, D31K, or D31R substitutions are incorporated in embodiments of the present disclosure.

[0194] Other 3E10 light chain sequences are known in the art. See, for example, Zack, et al., J. Immunol., 15;154(4):1987-94 (1995); GenBank: L16981–1 - Mouse Ig rearranged L-chain gene, partial cds; GenBank: AAA65681–1 - immunoglobulin light chain, partial [Mus musculus]).

[0195] Traditional antibody structural units typically comprise a tetramer. Each tetramer is typically composed of two identical pairs of polypeptide chains, each pair having one “light” (typically having a molecular weight of about 25 kDa) and one “heavy” chain (typically having a molecular weight of about 50-70 kDa). Human light chains are classified as kappa and lambda light chains. In embodiments, antibodies disclosed herein are IgA, IgD, IgE, IgG, or IgM, including any subtype or isotype thereof. In embodiments, antibodies disclosed herein are based on the IgG class. In embodiments, antibodies disclosed herein are based on one of the subclasses of IgG, including, but not limited to IgG1, IgG2, IgG3, and IgG4. In general, IgG1, IgG2 and IgG4 are used more frequently than IgG3. It should be noted that IgG1 has different allotypes with polymorphisms at 356 (D or E) and 358 (L or M), and in embodiments, antibodies disclosed herein are based on IgG1 having D or E at position 356 and / or L or M at position 358.

[0196] The light chain generally comprises two domains, the variable light domain (containing the light chain CDRs and together with the variable heavy domains forming the Fv region), and a constant light chain region (often referred to as CL or Cκ). The heavy chain comprises a variableheavy domain and a constant domain, which includes a CH1-optional hinge-Fc domain comprising a CH2-CH3.

[0197] The hypervariable region of an antibody generally encompasses amino acid residues from about amino acid residues 24-34 (LCDR1; “L” denotes light chain), 50-56 (LCDR2) and 89- 97 (LCDR3) in the light chain variable region and around about 31-35B (HCDR1; “H” denotes heavy chain), 50-65 (HCDR2), and 95-102 (HCDR3) in the heavy chain variable region; Kabat et al., SEQUENCES OF PROTEINS OF IMMUNOLOGICAL INTEREST,5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) and / or those residues forming a hypervariable loop (e.g., residues 26-32 (LCDR1), 50-52 (LCDR2) and 91-96 (LCDR3) in the light chain variable region and 26-32 (HCDR1), 53-55 (HCDR2) and 96-101 (HCDR3) in the heavy chain variable region; Chothia and Lesk (1987) J. Mol. Biol.196:901-917. Specific CDRs useful for the compositions, conjugates, and methods described herein are described below.

[0198] As will be appreciated by those in the art, the exact numbering and placement of the CDRs can be different among different numbering systems. However, it should be understood that the disclosure of a variable heavy and / or variable light sequence includes the disclosure of the associated (inherent) CDRs. Accordingly, the disclosure of each variable heavy region is a disclosure of the VH CDRs (e.g., VH CDR1, VH CDR2 and VH CDR3) and the disclosure of each variable light region is a disclosure of the VL CDRs (e.g., VL CDR1, VL CDR2 and VL CDR3).

[0199] Throughout the present disclosure, the Kabat numbering system is generally used when referring to a residue in the variable domain (approximately, residues 1-107 of the light chain variable region and residues 1-113 of the heavy chain variable region) and the EU numbering system for Fc regions (e.g., Kabat et al., supra (1991)). In embodiments, the present specification uses the the IMGT system to define the complementarity determining regions (CDRs) provided herein.

[0200] The present disclosure provides a large number of different CDR sets. In this case, a “full CDR set” comprises the three variable light CDRs, e.g., a VL CDR1, VL CDR2, and VL CDR3, and the three variable heavy CDRs, e.g., VH CDR1, VH CDR2, and VH CDR3. These can be part of a larger variable light or variable heavy domain, respectfully. In addition, as more fully outlined herein, the variable heavy and variable light domains can be on separate polypeptide chains, when a heavy and light chain is used (for example when Fabs are used), or on a single polypeptide chain in the case of scFv sequences.

[0201] As noted above herein, the present disclosure refers to different antibody domains of a 3E10 antibody or antigen-binding fragment or variant thereof. These domains include, but are not limited to, the Fc domain, the CH1 domain, the CH2 domain, the CH3 domain, the hinge domain,the heavy constant domain (CH1-hinge-Fc domain or CH1-hinge-CH2-CH3), the variable heavy (VH) domain, the variable light (VL) domain, the light constant domain, Fab domains and scFv domains. 2. Humanized Antibodies

[0202] In embodiments, antibodies of the disclosure comprise a heavy chain variable region from a particular germline heavy chain immunoglobulin gene and / or a light chain variable region from a particular germline light chain immunoglobulin gene. For example, such antibodies can comprise or consist of murine, chimeric, humanized, or human antibodies or antigen-binding fragments or variants thereof comprising heavy or light chain variable regions that are “the product of” or “derived from” a particular germline sequence, e.g., that of the 3E10 antibody. A human antibody that is “the product of” or “derived from” a human germline immunoglobulin sequence can be identified as such by comparing the amino acid sequence of the human antibody to the amino acid sequences of human germline immunoglobulins and selecting the human germline immunoglobulin sequence that is closest in sequence (i.e., greatest % identity) to the sequence of the human antibody (using the methods outlined herein). A human antibody that is “the product of” or “derived from” a particular human germline immunoglobulin sequence can contain amino acid differences as compared to the germline sequence, due to, for example, naturally-occurring somatic mutations or intentional introduction of site-directed mutation. However, a humanized antibody typically is at least about 90% identical in amino acids sequence to an amino acid sequence encoded by a human germline immunoglobulin gene and contains amino acid residues that identify the antibody as being derived from human sequences when compared to the germline immunoglobulin amino acid sequences of other species (e.g., murine germline sequences). In certain cases, a humanized antibody can be at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about or 99% identical in amino acid sequence to the amino acid sequence encoded by the germline immunoglobulin gene. Typically, a humanized antibody derived from a particular human germline sequence will display no more than 10-20 amino acid differences from the amino acid sequence encoded by the human germline immunoglobulin gene. In certain cases, the humanized antibody can display no more than 5, or even no more than 4, 3, 2, or 1 amino acid difference from the amino acid sequence encoded by the germline immunoglobulin gene.

[0203] In one aspect, the parent antibody has been affinity matured, as is known in the art. Structure-based methods can be employed for humanization and affinity maturation, for example as described in USSN 11 / 004,590, which is incorporated herein by reference. Selection basedmethods can be employed to humanize and / or affinity mature antibody variable regions, including but not limited to methods described in Wu et al., 1999, J. Mol. Biol. 294:151-162; Baca et al., 1997, J. Biol. Chem. 272(16):10678-10684; Rosok et al., 1996, J. Biol. Chem. 271(37): 22611- 22618; Rader et al., 1998, Proc. Natl. Acad. Sci. USA 95: 8910-8915; Krauss et al., 2003, Protein Engineering 16(10):753-759, all of which are incorporated herein by reference. Other humanization methods can involve the grafting of only parts of the CDRs, including but not limited to methods described in USSN 09 / 810,510; Tan et al., 2002, J. Immunol. 169:1119-1125; De Pascalis et al., 2002, J. Immunol.169:3076-3084, all of which are incorporated herein by reference. 3. Fc variants

[0204] In embodiments, one or more amino acid modifications can be introduced into the Fc region of an antibody provided herein, thereby generating an Fc region variant. The Fc region variant can comprise a human Fc region sequence (e.g., a human IgG1, IgG2, IgG3 or IgG4 Fc region) comprising an amino acid modification (e.g. a substitution) at one or more amino acid positions.

[0205] In embodiments, an Fc region variant possesses some but not all effector functions, which make it a desirable candidate for applications in which the half-life of the antibody in vivo is important yet certain effector functions (such as complement and ADCC) are unnecessary or deleterious. In vitro and / or in vivo cytotoxicity assays can be conducted to confirm the reduction / depletion of CDC and / or ADCC activities. For example, Fc receptor (FcR) binding assays known in the art can be conducted to ensure that the antibody lacks FcγR binding (hence likely lacking ADCC activity), but retains FcRn binding ability. To assess complement activation, a CDC assay can be performed (see, for example, Gazzano-Santoro et al., J. Immunol. Methods 202:163 (1996); Cragg, M.S. et al., Blood 101:1045-1052 (2003); and Cragg, M. S. and M. J. Glennie, Blood 103:2738-2743 (2004)). FcRn binding and in vivo clearance / half life determinations can also be performed using methods known in the art (see, e.g., Petkova, S.B. et al., Int’l. Immunol.18(12):1759-1769 (2006)).

[0206] In embodiments, an antibody provided herein can have reduced effector function and thus can comprise a substitution of one or more of Fc region residues 238, 265, 269, 270, 297, 327 and 329 (U.S. Pat. No.6,737,056). Such Fc mutants include Fc mutants with substitutions at two or more of amino acid positions 265, 269, 270, 297 and 327, including the so-called “DANA” Fc mutant with substitution of residues 265 and 297 to alanine (U.S. Pat. No.7,332,581).

[0207] In embodiments, an Fc region variant provided herein can have improved or diminished binding to FcRs. (See, e.g., U.S. Pat. No.6,737,056; WO 2004 / 056312, and Shields et al., J. Biol. Chem.9(2): 6591-6604 (2001).)

[0208] In embodiments, an Fc region variant provided herein comprises an Fc region with one or more amino acid substitutions which improve ADCC, e.g., substitutions at positions 298, 333, and / or 334 of the Fc region (EU numbering of residues).

[0209] In embodiments, an Fc region variant provided herein comprises alterations that result in altered (i.e., either improved or diminished) C1q binding and / or Complement Dependent Cytotoxicity (CDC), e.g., as described in U.S. Pat. No.6,194,551, WO 99 / 51642, and Idusogie et al. J. Immunol.164: 4178-4184 (2000).

[0210] In embodiments, an Fc region variant provided herein comprises alterations that result in increased half-lives and improved binding to the neonatal Fc receptor (FcRn), which is responsible for the transfer of maternal IgGs to the fetus (Guyer et al., J. Immunol.117:587 (1976) and Kim et al., J. Immunol.24:249 (1994)), e.g., as described in US2005 / 0014934A1 (Hinton et al.). Those antibodies comprise an Fc region with one or more substitutions therein which improve binding of the Fc region to FcRn. Such Fc variants include those with substitutions at one or more of Fc region residues: 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434, e.g., substitution of Fc region residue 434 (U.S. Pat. No. 7,371,826).

[0211] In embodiments, an Fc region variant provided herein comprises “knob-in-hole” or “skew” variants, which refer to amino acid engineering that creates stearic influences to favor heterodimeric formation and disfavor homodimeric formation, as described in USSN 61 / 596,846, Ridgway et al, Protein Engineering 9(7):617 (1996); Atwell et al, J. Mol. Biol.1997270:26; US Patent No.8,216,805, all of which are hereby incorporated by reference in their entirety.

[0212] In embodiments, an Fc region variant provided herein comprises alterations described in Duncan & Winter, Nature 322:738-40 (1988); U.S. Pat. No.5,648,260; U.S. Pat. No.5,624,821; and WO 94 / 29351. 4. Antibody Fragments

[0213] In embodiments, the antibody portion of an ADC described herein comprises an antigen-binding fragment of a 3E10 antibody or variant thereof. In embodiments, the antigen- binding fragment retains the desired biological activity of a 3E10 antibody. In embodiments, the antigen-binding fragment retains at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at leastabout 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95% of the desired biological activity of a 3E10 antibody. In embodiments, the antigen-binding fragment retains the ability of the antibody to bind to its target antigen, e.g., a nucleic acid, e.g., DNA. In embodiments, the antigen-binding fragment retains the ability of the antibody to bind to a cellular receptor, e.g., ENT2. In embodiments, the antigen-binding fragment retains the ability of the antibody to be internalized by a target cell.

[0214] In embodiments, the 3E10 antibody or antigen binding fragment thereof comprises a single-chain fragment variable (scFv), a tandem double scFv, an (scFv)2, a minibody, a VHH, an scFv-Fc, a CrossMab, a dual variable domain immunoglobulin (DVD-Ig), a single-chain tandem fragment variable (scTaFv), a diabody, a tandem diabody (TandAb), a Fabsc, a modular IgG-scFv, a Fab, or an F(ab’)2.

[0215] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a CrossMab. In the CrossMab format, complementary mutations are introduced in the heavy chain constant region of each arm to generate so-called “holes and knobs,” resulting in preferred association between different arms, forming a heterodimer, rather than a homodimer of two of the same arms. The exact residues that are mutated in the heavy chain constant region of a CrossMab bispecific antibody to form “holes” and “knobs” can vary depending on the specific design and optimization goals of the antibody. For more information on CrossMab antibodies see, for example, Huang, J., et al., Journal of Biological Chemistry, 294(50):19001–10 (2019), the disclosure of which is incorporated herein by reference in its entirety.

[0216] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a divalent, dual-variable domain immunoglobulin (DVD-Ig) of a 3E10 antibody or antigen binding fragment thereof. In the DVD-Ig format, each arm of the antibody contains two VH / VL pairs. In some embodiments, one of the VH / VL pairs comprises 3E10 VH and VL CDRs. For more information on DVD-Ig antibodies see, for example, Polson AG, et al., Journal of immunotherapy.29(3):241-50 (2006) and U.S. Patent No.7,612,181, the disclosures of which are incorporated herein by reference in their entireties.

[0217] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a single-chain variable fragment (scFv). “Single chain Fv” or “scFv,” as used herein, refers to a VH domain covalently attached to a VL domain through a linker, e.g., a scFv linker as discussed herein, to form a continuous protein chain. A scFv domain can be in either arrangement from N- to C-terminus (i.e., VH-linker-VL or VL-linker-VH). In the sequences depicted in the sequence listing and in the figures herein, the order of the VH and VL domain is indicated in thename, e.g., H.X_L.Y means the N- to C-terminus arrangement is VH-linker-VL, and L.Y_H.X means the N- to C-terminus arrangement is VL-linker-VH.

[0218] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a tandem double scFv. A tandem double scFv has two scFv domains linked in a linear fashion. In some embodiments, each scFv domain is derived from a different antibody and provides independent antigen-binding specificity. In some embodiments, one of the scFv domains comprises 3E10 VH and VL CDRs. For more information on tandem double scFvs see, for example, Bossen C, et al., MAbs, 4(2):200-08 (2012), the disclosure of which is incorporated herein by reference in its entirety.

[0219] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a dimeric scFv antibody (scFv)2. A dimeric scFv antibody has two scFv domains linked in a dimeric arrangement. In some embodiments, each scFv domain is derived from a different antibody and provides independent antigen-binding specificity. In some embodiments, one of the scFv domains comprises 3E10 VH and VL CDRs. For more information on dimeric scFv antibodies see, for example, Llewellyn C, et al., Journal of immunological methods, 273(1-2):33- 44 (2002), the disclosure of which is incorporated herein by reference in its entirety.

[0220] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a scFv-Fc. An “scFv-Fc,” as meant herein, is a polypeptide that consists of a heavy and a light chain variable region of an antibody joined by a linker, which is followed by an Fc polypeptide chain of an antibody, optionally the Fc region of a human IgG antibody, such as an IgG1, IgG2, IgG3, or IgG4 antibody.

[0221] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a single-chain tandem fragment variable (scTaFv) antibody. A single-chain tandem fragment variable (scTaFv) antibody is a type of bispecific antibody that consists of two variable fragment (VH and VL) domains linked in a tandem arrangement. In some embodiments, one of the variable fragment domains comprises 3E10 VH and VL CDRs. For more information on scTaFv antibodies see, for example, Schramm C, et al., MAbs 5(3):442-49 (2013), the disclosure of which is incorporated herein by reference in its entirety.

[0222] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a VHH. As used herein, the term “VHH” refers to a variable domain of heavy chain of heavy-chain antibody. A VHH is a molecule that can recognize an antigen through a single domain and is the smallest unit among antibody molecules that have been found to date. In embodiments, a VHH can include one or more variable domains of heavy chain derived from a heavy-chainantibody, and the number of the variable domains of heavy chain included in the VHH is not limited.

[0223] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a diabody. As used herein, “diabody” refers to a divalent antibody comprising two polypeptide chains, wherein each polypeptide chain is too short for a pair to form between two domains on the same chain such that each domain is paired with a complementary domain on another polypeptide chain (see, e.g., Holliger et al., 1993, Proc. Natl. Acad. Sci. USA 90: 6444-48 and Poljak et al., 1994 , Structure 2: 1121-23). If the two polypeptide chains of the diabody are identical, there will be two identical antigen-binding sites in the diabody resulting from their pairing. In embodiments, one of the antigen binding domains of the diabody comprises 3E10 VH and VL CDRs. For more information on diabodies see, for example, Hoogenboom HR, et al., Trends Biotechnol., 21(12):553-57 (2003), the disclosure of which is incorporated herein by reference in its entirety. Polypeptide chains of different sequences can be used to prepare diabodies with two different antigen-binding sites. Similarly, as used herein, “triabodies” and “tetrabodies” refer to antibodies that contain three and four polypeptide chains, respectively, and form three and four antigen-binding sites (which can be the same or different), respectively.

[0224] The term “minibody” is used to refer to an scFv-CH3 fusion protein that self- assembles into a bivalent dimer of 80 kDa (ScFv-CH3)2.

[0225] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a tandem diabody (TandAb). A tandem diabody has wo antigen-binding domains (VH and VL) linked in a tandem arrangement by a flexible peptide linker. In some embodiments, one of the antigen binding domains comprises 3E10 VH and VL CDRs. For more information on diabodies see, for example, Sidelmann JG, et al., Mol Immunol., 45(9):2597-607 (2008), the disclosure of which is incorporated herein by reference in its entirety.

[0226] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a Fabsc. As used herein, a “Fabsc” format antibody molecule typically refers to a bispecific antibody molecule having a Fab fragment, which generally includes a hinge region, which is at the C-terminus of the Fab fragment linked to the N- terminus of a CH2 domain, of which the C-terminus is in turn linked to the N-terminus of a scFv fragment.

[0227] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises a scFab. A scFab, also known as a single-chain fragment antigen binding (Fab), is a type of antibody fragment that combines the variable heavy chain (VH) and variable light chain (VL) domains into a single polypeptide chain, linked by a peptide linker. The domain structure of a Fabsc includes the variable domains of both the heavy chain and light chain (VH and VL), and apeptide linker that connects the two domains. In addition to the variable domains, a Fabsc also includes the constant domains of the light chain (CL) and the hinge region of the heavy chain. In some embodiments, one of the antigen binding domains comprises 3E10 VH and VL CDRs. For more information on Fabscs see, for example, Kettner, C., et al., Frontiers in Immunology, 8(8):453 (2017), the disclosure of which is incorporated herein by reference in its entirety.

[0228] In embodiments, an antigen-binding fragment of a 3E10 antibody or variant thereof comprises an IgG-scFv. An IgG-scFv is an antibody in which a scFv is fused to the light chain or heavy chain of an IgG. In some embodiments, the scFv comprises 3E10 VH and VL CDRs. In some embodiments, the IgG comprises 3E10 VH and V LCDRs. In some embodiments, the antibody is an F(ab’)2. 5. Bispecific Antibodies

[0229] In embodiments, 3E10 antibodies and antigen-binding fragments or variants thereof can be modified to improve their therapeutic potential. For example, in embodiments, the cell- penetrating anti-DNA antibody is conjugated to another antibody specific for a second therapeutic target in the cytoplasm and / or nucleus of a target cell. For example, in embodiments, the cell- penetrating 3E10 antibody is a bispecific antibody having a first heavy chain and a first light chain from 3E10 and a second heavy chain and a second light chain from a monoclonal antibody that specifically binds a second therapeutic target.

[0230] Bispecific antibodies and other binding proteins having a first heavy chain and a first light chain from 3E10 and a second heavy chain and a second light chain from a monoclonal antibody that specifically binds a second target are discussed in Weisbart, et al., Mol. Cancer Ther., 11(10):2169-73 (2012), and Weisbart, et al., Int. J. Oncology, 25:1113-8 (2004), and U.S. Patent Application No.2013 / 0266570, which are specifically incorporated by reference in their entireties. In embodiments, the second target is specific for a target cell-type, tissue, organ, etc. Thus the second heavy chain and second light chain can serve as a targeting moiety that targets the complex to the target cell-type, tissue, organ. In embodiments, the second heavy chain and second light chain target, hematopoietic stem cells, CD34+cells, T cells or any another cell type of interest, e.g., by targeting a receptor or ligand expressed on the cell type of interest. In embodiments, the second heavy chain and second light chain target the thymus, spleen, or cancer cells.

[0231] Bispecific antibodies can be used to direct cytotoxic agents or drugs to cells which express a particular antigen. These antibodies possess two binding sites directed at two different antigens or two different epitopes on the same antigen. For example, in embodiments the bispecific can comprise one arm for ENT2 engagement and another arm for a second target. Bispecificantibody design can include a variety of antibody designs with multiple binding arms. Techniques for making bispecific antibodies are common in the art (Millstein et al., 1983, Nature 305:537-539; Brennan et al., 1985, Science 229:81; Suresh et al, 1986, Methods in Enzymol. 121:120; Traunecker et al., 1991, EMBO J.10:3655-3659; Shalaby et al., 1992, J. Exp. Med.175:217-225; Kostelny et al., 1992, J. Immunol.148:1547-1553; Gruber et al., 1994, J. Immunol.152:5368; and U.S. Patent 5,731,168). Antibodies with more than two valencies are also contemplated. For example, trispecific antibodies can be prepared (Tutt et al., J. Immunol. 147:60 (1991)). In embodiments the contemplated bispecific antibody disclosed herein can be conjugated as a bispecific ADC.

[0232] Heteroconjugate antibodies are also within the scope of the present disclosure. Heteroconjugate antibodies are composed of two covalently joined antibodies. Such antibodies have, for example, been proposed to target immune cells to unwanted cells (U.S. Pat. No. 4,676,980). It is contemplated that the antibodies can be prepared in vitro using known methods in synthetic protein chemistry, including those involving crosslinking agents. For example, immunotoxins can be constructed using a disulfide exchange reaction or by forming a thioether bond. Examples of suitable reagents for this purpose include iminothiolate and methyl-4- mercaptobutyrimidate. In embodiments the contemplated herteoconjugate antibody disclosed herein can be conjugated as a heteroconjugate ADC. 6.3E10 Sequences

[0233] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein includes CDR sequences corresponding to the parent 3E10 antibody.

[0234] Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof comprises (a) a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of X1ASX2X3VSTSSYSYX4X5, where X1 is K, R, or H, X2 is K, R, or H, X3 is T or S, X4 is M or L, and X5 is K, R, H, or A (SEQ ID NO:61), (b) a VL CDR2 comprising the amino acid sequence of YASYLX1S, where X1 is D, E, N, or Q (SEQ ID NO:62), and (c) a VL CDR3 comprising the amino acid sequence of QX1SX2X3FPWT, where X1 is K, R, or H, X2 is K, R, or H, and X3 is D or E (SEQ ID NO:63), and (d) a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of X1YGMX2, where X1 is D, E, N, Q, R, or K and X2 is K, R, or H (SEQ ID NO:58), (e) a VH CDR2 comprising the amino acid sequence of YISSX1SSTIYYAX2X3VX4G, where X1 is G or S, X2 is D or E, X3 is T or S, and X4 is K, R, or H (SEQ ID NO:59), and (f) a VH CDR3 comprisingthe amino acid sequence of X1GLLLX2Y, where X1 is K, R, or H, and X2 is D or E (SEQ ID NO:60).

[0235] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of 3E10-VL-CDR1 (SEQ ID NO:9), a VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2 (SEQ ID NO:10), a VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3 (SEQ ID NO:11), a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of 3E10-VH-CDR1 (SEQ ID NO:3), a VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2 (SEQ ID NO:4), and a VH CDR3 comprising the amino acid sequence of 3E10-VH-CDR3 (SEQ ID NO:5).

[0236] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein includes CDR sequences from a variant 3E10 antibody that includes a D31N amino acid substitution in the VH CDR1. Accordingly, in embodiments, the a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of 3E10-VL- CDR1_D31N (SEQ ID NO:22), a VL CDR2 comprising the amino acid sequence of 3E10-VL- CDR2_D31N (SEQ ID NO:23), a VL CDR3 comprising the amino acid sequence of 3E10-VL- CDR3_D31N (SEQ ID NO:24), a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of 3E10-VH-CDR1_D31N (SEQ ID NO:15), a VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2_D31N (SEQ ID NO:17), and a VH CDR3 comprising the amino acid sequence of 3E10-VH-CDR3_D31N (SEQ ID NO:18).

[0237] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein refers to CDR sequences corresponding to the parent 3E10 antibody, optionally including a D31N amino acid substitution in the VH CDR1. Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of 3E10-VL-CDR1 (SEQ ID NO:9), a VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2 (SEQ ID NO:10), a VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3 (SEQ ID NO:11), a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of 3E10-VH-CDR1a (SEQ ID NO:16), a VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2 (SEQ ID NO:4), and a VH CDR3 comprising the amino acid sequence of 3E10-VH-CDR3 (SEQ ID NO:5).

[0238] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein includes CDR sequences corresponding to the parent 3E10 antibody, witha known amino acid substitution in one or more CDR. Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein includes one or more amino acid substitution, relative to the CDR sequences of the parent 3E10 or 3E10-D31N variant, selected from a G to S substitution at position 5 of VH CDR2, a T to S substitution at position 14 of VH CDR2, an S to T substitution at position 5 of VL CDR1, an M to L substitution at position 14 of VL CDR1, an H to A substitution at position 15 of VL CDR1, and an E to Q substitution at position 6 of VL CDR2.

[0239] Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2.1 (SEQ ID NO:26) or 3E10-VH-CDR2.2 (SEQ ID NO:27). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody or relative to the 3E10- D31N variant.

[0240] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL-CDR1.1 (SEQ ID NO:28) or 3E10-VL-CDR1.2 (SEQ ID NO:29). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1- 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen- binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody or relative to the 3E10- D31N variant.

[0241] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2.1 (SEQ ID NO:30). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof furtherincludes VL CDRs 1 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody or relative to the 3E10- D31N variant.

[0242] While some of the amino acid substitutions described above are fairly conservative substitutions—e.g., an S to T substitution at position 5 of VL CDR1—other substitutions are to amino acids that have vastly different properties—e.g., an M to L substitution at position 14 of VL CDR1, an H to A substitution at position 15 of VL CDR1, and an E to Q substitution at position 6 of VL CDR2. This suggests, without being bound by theory, that at least these positions within the 3E10 CDR framework are tolerant to other amino acid substitutions.

[0243] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2.3 (SEQ ID NO:31). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody or relative to the 3E10- D31N variant, e.g., as described herein.

[0244] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL-CDR1.3 (SEQ ID NO:32). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody or relative to the 3E10- D31N variant, e.g., as described herein.

[0245] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof, includes VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2.2 (SEQ ID NO:33). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the 3E10- D31N variant.In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody or relative to the 3E10- D31N variant, e.g., as described herein.

[0246] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR1 comprising the amino acid sequence of 3E10-VH-CDR1.c1 (SEQ ID NO:34), 3E10-VH-CDR1.c2 (SEQ ID NO:35), 3E10-VH-CDR1.c3 (SEQ ID NO:36), 3E10-VH- CDR1.c4 (SEQ ID NO:37), or 3E10-VH-CDR1.c5 (SEQ ID NO:38). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 2 and 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 2 and 3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0247] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2.c1 (SEQ ID NO:39), 3E10-VH-CDR2.c2 (SEQ ID NO:40), or 3E10-VH-CDR2.c3 (SEQ ID NO:41). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0248] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR3 comprising the amino acid sequence of 3E10-VH-CDR3.c1 (SEQ ID NO:42), 3E10-VH-CDR3.c2 (SEQ ID NO:43), or 3E10-VH-CDR3.c3 (SEQ ID NO:44). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 2 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 2 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 2 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0249] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL-CDR1.c1 (SEQ ID NO:45), 3E10-VL-CDR1.c2 (SEQ ID NO:46), 3E10-VL-CDR1.c3 (SEQ ID NO:47), 3E10-VL- CDR1.c4 (SEQ ID NO:48), 3E10-VL-CDR1.c5 (SEQ ID NO:49), or 3E10-VL-CDR1.c6 (SEQ ID NO:50). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0250] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2.c1 (SEQ ID NO:51). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0251] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3.c1 (SEQ ID NO:52), 3E10-VL-CDR3.c2 (SEQ ID NO:53), 3E10-VL-CDR3.c3 (SEQ ID NO:54), 3E10-VL- CDR3.c4 (SEQ ID NO:55), 3E10-VL-CDR3.c5 (SEQ ID NO:56), or 3E10-VL-CDR3.c6 (SEQ ID NO:57). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 2, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 2, and VH CDRs 1-3 according to the 3E10- D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 2, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0252] It is also contemplated that a 3E10 antibody or variant thereof, or antigen-binding fragment thereof, as described herein, includes any combination of the 3E10 CDR amino acid substitutions described above.

[0253] Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR1 comprising the amino acid sequence of 3E10-VH-CDR1m (SEQ ID NO:58). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 2 and 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 2 and 3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0254] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2m (SEQ ID NO:59). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 according to the 3E10-D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0255] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VH CDR3 comprising the amino acid sequence of 3E10-VH-CDR3m (SEQ ID NO:60). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 2 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 2 according to the 3E10-D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3, and VH CDRs 1 and 2 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0256] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL-CDR1m (SEQ ID NO:61). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 according to the 3E10-D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0257] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2m (SEQ ID NO:62). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 according to the 3E10-D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody,e.g., as described herein.

[0258] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3m (SEQ ID NO:63). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 2, and VH CDRs 1-3 according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 2, and VH CDRs 1-3 according to the 3E10-D31N variant. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 2, and VH CDRs 1-3 having one or more amino acid substitutions relative to the CDRs of the parent 3E10 antibody, e.g., as described herein.

[0259] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein includes a VL CDR 1 comprising the amino acid sequence of 3E10-VL- CDR1m (SEQ ID NO:61), a VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2m (SEQ ID NO:62), a VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3m (SEQ ID NO:63), a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of 3E10- VH-CDR1m (SEQ ID NO:58), a VH CDR2 comprising the amino acid sequence of 3E10-VH- CDR2m (SEQ ID NO:59), and a VH CDR3 comprising the amino acid sequence of 3E10-VH- CDR3m (SEQ ID NO:60).

[0260] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein refers to CDR sequences having no more than one amino acid substitution relative to the parent 3E10 antibody optionally including a D31N amino acid substitution in the VH CDR1. Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes a VL CDR 1 comprising an amino acid sequence having no more than one amino acid substitution relative to 3E10-VL-CDR1 (SEQ ID NO:9), a VL CDR2 comprising an amino acid sequence having no more than one amino acid substitution relative to 3E10-VL- CDR2 (SEQ ID NO:10), a VL CDR3 comprising an amino acid sequence having no more than oneamino acid substitution relative to 3E10-VL-CDR3 (SEQ ID NO:11), a heavy chain variable region (VH) CDR1 comprising an amino acid sequence having no more than one amino acid substitution relative to 3E10-VH-CDR1a (SEQ ID NO:16), a VH CDR2 comprising an amino acid sequence having no more than one amino acid substitution relative to 3E10-VH-CDR2 (SEQ ID NO:4), and a VH CDR3 comprising an amino acid sequence having no more than one amino acid substitution relative to 3E10-VH-CDR3 (SEQ ID NO:5).

[0261] In embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof described herein refers to CDR sequences having no more than two amino acid substitution relative to the parent 3E10 antibody optionally including a D31N amino acid substitution in the VH CDR1. Accordingly, in embodiments, a 3E10 antibody or variant thereof, or antigen-binding fragment thereof includes a VL CDR 1 comprising an amino acid sequence having no more than two amino acid substitutions relative to 3E10-VL-CDR1 (SEQ ID NO:9), a VL CDR2 comprising an amino acid sequence having no more than two amino acid substitutions relative to 3E10-VL- CDR2 (SEQ ID NO:10), a VL CDR3 comprising an amino acid sequence having no more than two amino acid substitutions relative to 3E10-VL-CDR3 (SEQ ID NO:11), a heavy chain variable region (VH) CDR1 comprising an amino acid sequence having no more than two amino acid substitutions relative to 3E10-VH-CDR1a (SEQ ID NO:16), a VH CDR2 comprising an amino acid sequence having no more than two amino acid substitutions relative to 3E10-VH-CDR2 (SEQ ID NO:4), and a VH CDR3 comprising an amino acid sequence having no more than two amino acid substitutions relative to 3E10-VH-CDR3 (SEQ ID NO:5).

[0262] Other variants of a 3E10 antibody or variant thereof, or antigen-binding fragment thereof are also known in the art, as disclosed for example, in Zack, et al., J. Immunol., 157(5):2082-8 (1996). For example, amino acid position 31 of the heavy chain variable region of 3E10 has been determined to be influential in the ability of the antibody and fragments thereof to penetrate nuclei and bind to DNA. A D31N mutation in CDR1 penetrates nuclei and binds DNA with much greater efficiency than the original antibody (Zack, et al., Immunology and Cell Biology, 72:513-520 (1994), Weisbart, et al., J. Autoimmun., 11, 539-546 (1998); Weisbart, Int. J. Oncol., 25, 1867-1873 (2004)). In embodiments, the antibody or antigen-binding fragment or variant described herein has the D31N substitution.

[0263] ADCs described herein can be prepared with any 3E10 antibodies or antigen-fragments thereof, or any humanized 3E10 antibodies or antigen-fragments thereof, disclosed in the prior art. See, for example WO 2015 / 106290, 2016 / 033324, WO 2019 / 018426, and WO 2019 / 018428 (each of which is specifically incorporated by reference herein, in its entirety).

[0264] In embodiments, an ADC comprises a humanized 3E10 antibody. Generally, a humanized antibody has one or more amino acid residues introduced into it from a source that is non-human. These non-human amino acid residues are often referred to as “import” residues, which are typically taken from an “import” variable domain. Antibody humanization techniques generally involve the use of recombinant DNA technology to manipulate the DNA sequence encoding one or more polypeptide chains of an antibody molecule.

[0265] In embodiments, the disclosure provides humanized antibodies, or antigen-binding fragments thereof, that incorporate any combination of the humanized VL and VH sequences disclosed here, as well as VL and VH sequences having sequence identity thereto, e.g., having at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% identity to a VH or VL sequence described herein.

[0266] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of any one of SEQ ID NOs:1, 13, or 71-84. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:1. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:13. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:71. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:72. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:73. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:74. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:75. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:76. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain havingthe sequence of SEQ ID NO:77. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:78. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:79. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:80. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:81. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:82. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:83. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a heavy chain having the sequence of SEQ ID NO:84.

[0267] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of any one of SEQ ID NOs:2, 14, 64-70, 103-112. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:2. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:14. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:64. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:65. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:66. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:67. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:68. In embodiments, an ADC provided herein comprises a 3E10antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:69. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:70. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:103. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:104. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:105. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:106. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:107. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:108. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:109. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:110. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:111. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VH having the sequence of SEQ ID NO:112.

[0268] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of any one of SEQ ID NOs:7, 20, or 91-102. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:7. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:20. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQID NO:91. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:92. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:93. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:94. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:95. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:96. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:97. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:98. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:99. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:100. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:101. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a light chain having the sequence of SEQ ID NO:102.

[0269] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of any one of SEQ ID NOs:8, 21, 85-90, or 113-121. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:8. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:21. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:85. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragmentor variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:86. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:87. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:88. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:89. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:90. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:113. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:114. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:115. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:116. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:117. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:118. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:119. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:120. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, or three CDRs of a VL having the sequence of SEQ ID NO:121.

[0270] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of any one of SEQ ID NOs:122-137. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:122. Inembodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:123. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:124. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:125. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:167. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:168. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:128. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:129. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:130. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:131. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:132. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:133. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:134. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:135. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:136. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment orvariant thereof comprising one, two, three, four, five, or six CDRs of an scFv having the sequence of SEQ ID NO:137.

[0271] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to any one of SEQ ID NOs:1, 13, or 71-84. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:1. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:13. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:71. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:72. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:73. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:74. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:75. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereofhaving a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:76. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:77. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:78. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:79. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:80. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:81. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:82. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:83. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a heavy chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:84.

[0272] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to any one of SEQ ID NOs:7, 20, or 91-102. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:7. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:20. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:91. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:92. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:93. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:94. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:95. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at leastabout 99%, or 100% identity to SEQ ID NO:96. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:97. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:98. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:99. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:100. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:101. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a light chain sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:102.

[0273] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to any one of SEQ ID NOs: 2, 14, 64-70, or 103-112. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:2. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:14. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:64. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:65. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:66. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:67. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:68. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:69. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:70. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:103. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at leastabout 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:104. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:105. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:106. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:107. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:108. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:109. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:110. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:111. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a VH sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:112.

[0274] In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen- binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about97%, at least about 98%, at least about 99%, or 100% identity to any one of SEQ ID NOs: 8, 21, 85-90, or 113-121. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:8. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:21. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:85. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:86. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:87. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:88. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:89. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:90. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about98%, at least about 99%, or 100% identity to SEQ ID NO:113. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:114. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:115. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:116. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:117. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:118. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:119. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:120. In embodiments, an ADC provided herein comprises a 3E10 antibody or antigen-binding fragment or variant thereof having a VL sequence having at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identity to SEQ ID NO:121.

[0275] In embodiments, an ADC provided herein comprises a humanized 3E10 antibody, or antigen-binding fragment thereof, comprising a light chain variable domain (3E10-VL) comprising an amino acid sequence that is at least about 97% identical to an amino acid sequence selectedfrom the group consisting of 3E10-VL-h1 (SEQ ID NO:85), 3E10-VL-h2 (SEQ ID NO:86), 3E10- VL-h3 (SEQ ID NO:87), 3E10-VL-h4 (SEQ ID NO:88), 3E10-VL-h5 (SEQ ID NO:89), and 3E10- VL-h6 (SEQ ID NO:90) and a heavy chain variable domain (3E10-VH) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-VH-h1 (SEQ ID NO:64), 3E10-VH-h2 (SEQ ID NO:65), 3E10-VH-h3 (SEQ ID NO:66), 3E10-VH-h4 (SEQ ID NO:67), 3E10-VH-h5 (SEQ ID NO:68), 3E10-VH-h6 (SEQ ID NO:69), and 3E10-VH-h7 (SEQ ID NO:70).

[0276] In embodiments, the sequence of the 3E10-VL is at least about 97% identical to 3E10- VL-h1 (SEQ ID NO:85). In embodiments, the sequence of the 3E10-VL is at least about 98% identical to 3E10-VL-h1 (SEQ ID NO:85). In embodiments, the sequence of the 3E10-VL is at least about 99% identical to 3E10-VL-h1 (SEQ ID NO:85). In embodiments, the sequence of the 3E10-VL is 3E10-VL-h1 (SEQ ID NO:85).

[0277] In embodiments, the sequence of the 3E10-VL is at least about 97% identical to 3E10- VL-h2 (SEQ ID NO:86). In embodiments, the sequence of the 3E10-VL is at least about 98% identical to 3E10-VL-h2 (SEQ ID NO:86). In embodiments, the sequence of the 3E10-VL is at least about 99% identical to 3E10-VL-h2 (SEQ ID NO:86). In embodiments, the sequence of the 3E10-VL is 3E10-VL-h2 (SEQ ID NO:86).

[0278] In embodiments, the sequence of the 3E10-VL is at least about 97% identical to 3E10- VL-h3 (SEQ ID NO:87). In embodiments, the sequence of the 3E10-VL is at least about 98% identical to 3E10-VL-h3 (SEQ ID NO:87). In embodiments, the sequence of the 3E10-VL is at least about 99% identical to 3E10-VL-h3 (SEQ ID NO:87). In embodiments, the sequence of the 3E10-VL is 3E10-VL-h3 (SEQ ID NO:87).

[0279] In embodiments, the sequence of the 3E10-VL is at least about 97% identical to 3E10- VL-h4 (SEQ ID NO:88). In embodiments, the sequence of the 3E10-VL is at least about 98% identical to 3E10-VL-h4 (SEQ ID NO:88). In embodiments, the sequence of the 3E10-VL is at least about 99% identical to 3E10-VL-h4 (SEQ ID NO:88). In embodiments, the sequence of the 3E10-VL is 3E10-VL-h4 (SEQ ID NO:88).

[0280] In embodiments, the sequence of the 3E10-VL is at least about 97% identical to 3E10- VL-h5 (SEQ ID NO:89). In embodiments, the sequence of the 3E10-VL is at least about 98% identical to 3E10-VL-h5 (SEQ ID NO:89). In embodiments, the sequence of the 3E10-VL is at least about 99% identical to 3E10-VL-h5 (SEQ ID NO:89). In embodiments, the sequence of the 3E10-VL is 3E10-VL-h5 (SEQ ID NO:89).

[0281] In embodiments, the sequence of the 3E10-VL is at least about 97% identical to 3E10- VL-h6 (SEQ ID NO:90). In embodiments, the sequence of the 3E10-VL is at least about 98%identical to 3E10-VL-h6 (SEQ ID NO:90). In embodiments, the sequence of the 3E10-VL is at least about 99% identical to 3E10-VL-h6 (SEQ ID NO:90). In embodiments, the sequence of the 3E10-VL is 3E10-VL-h6 (SEQ ID NO:90).

[0282] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h1 (SEQ ID NO:64). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h1 (SEQ ID NO:64). In embodiments, the sequence of the 3E10-VH is at least about 97% identical to 3E10-VH-h1 (SEQ ID NO:64). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h1 (SEQ ID NO:64). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h1 (SEQ ID NO:64). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h1 (SEQ ID NO:64).

[0283] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h2 (SEQ ID NO:65). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h2 (SEQ ID NO:65). In embodiments, the sequence of the 3E10-VH is at least about 97% identical to 3E10-VH-h2 (SEQ ID NO:65). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h2 (SEQ ID NO:65). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h2 (SEQ ID NO:65). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h2 (SEQ ID NO:65).

[0284] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h3 (SEQ ID NO:66). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h3 (SEQ ID NO:66). In embodiments, the sequence of the 3E10-VH is at least about 97% identical to 3E10-VH-h3 (SEQ ID NO:66). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h3 (SEQ ID NO:66). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h3 (SEQ ID NO:66). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h3 (SEQ ID NO:66).

[0285] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h4 (SEQ ID NO:67). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h4 (SEQ ID NO:67). In embodiments, the sequence of the 3E10-VH is at least about 97% identical to 3E10-VH-h4 (SEQ ID NO:67). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h4 (SEQ ID NO:67). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h4 (SEQ ID NO:67). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h4 (SEQ ID NO:67).

[0286] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h5 (SEQ ID NO:68). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h5 (SEQ ID NO:68). In embodiments, the sequence of the 3E10-VH is atleast about 97% identical to 3E10-VH-h5 (SEQ ID NO:68). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h5 (SEQ ID NO:68). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h5 (SEQ ID NO:68). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h5 (SEQ ID NO:68).

[0287] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h6 (SEQ ID NO:69). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h6 (SEQ ID NO:69). In embodiments, the sequence of the 3E10-VH is at least about 97% identical to 3E10-VH-h6 (SEQ ID NO:69). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h6 (SEQ ID NO:69). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h6 (SEQ ID NO:69). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h6 (SEQ ID NO:69).

[0288] In embodiments, the sequence of the 3E10-VH is at least about 95% identical to 3E10- VH-h7 (SEQ ID NO:70). In embodiments, the sequence of the 3E10-VH is at least about 96% identical to 3E10-VH-h7 (SEQ ID NO:70). In embodiments, the sequence of the 3E10-VH is at least about 97% identical to 3E10-VH-h7 (SEQ ID NO:70). In embodiments, the sequence of the 3E10-VH is at least about 98% identical to 3E10-VH-h7 (SEQ ID NO:70). In embodiments, the sequence of the 3E10-VH is at least about 99% identical to 3E10-VH-h7 (SEQ ID NO:70). In embodiments, the sequence of the 3E10-VH is 3E10-VH-h7 (SEQ ID NO:70).

[0289] In embodiments, an ADC comprising a humanized 3E10 antibody, or antigen-binding fragment thereof, described herein includes a light chain (3E10-LC) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-LC-h1m (SEQ ID NO:91), 3E10-LC-h2m (SEQ ID NO:92), 3E10-LC-h3m (SEQ ID NO:93), 3E10-LC-h4m (SEQ ID NO:94), 3E10-LC-h5m (SEQ ID NO:95), and 3E10- LC-h6m (SEQ ID NO:96) and a heavy chain (3E10-HC) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-HC-h1m (SEQ ID NO:71), 3E10-HC-h2m (SEQ ID NO:72), 3E10-HC-h3m (SEQ ID NO:73), 3E10-HC-h4m (SEQ ID NO:74), 3E10-HC-h5m (SEQ ID NO:75), 3E10-HC-h6m (SEQ ID NO:76), and 3E10-HC-h7m (SEQ ID NO:77).

[0290] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h1m (SEQ ID NO:91). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h1m (SEQ ID NO:91). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h1m (SEQ ID NO:91). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h1m (SEQ ID NO:91). In embodiments, thesequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h1m (SEQ ID NO:91). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h1m (SEQ ID NO:91).

[0291] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h2m (SEQ ID NO:92). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h2m (SEQ ID NO:92). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h2m (SEQ ID NO:92). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h2m (SEQ ID NO:92). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h2m (SEQ ID NO:92). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h2m (SEQ ID NO:92).

[0292] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h3m (SEQ ID NO:93). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h3m (SEQ ID NO:93). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h3m (SEQ ID NO:93). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h3m (SEQ ID NO:93). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h3m (SEQ ID NO:93). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h3m (SEQ ID NO:93).

[0293] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h4m (SEQ ID NO:94). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h4m (SEQ ID NO:94). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h4m (SEQ ID NO:94). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h4m (SEQ ID NO:94). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h4m (SEQ ID NO:94). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h4m (SEQ ID NO:94).

[0294] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h5m (SEQ ID NO:95). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h5m (SEQ ID NO:95). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h5m (SEQ ID NO:95). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h5m (SEQ ID NO:95). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h5m (SEQ ID NO:95). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h5m (SEQ ID NO:95).

[0295] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h6m (SEQ ID NO:96). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h6m (SEQ ID NO:96). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h6m (SEQ ID NO:96). In embodiments, the sequence of the3E10-LC is at least about 98% identical to 3E10-LC-h6m (SEQ ID NO:96). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h6m (SEQ ID NO:96). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h6m (SEQ ID NO:96).

[0296] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h1m (SEQ ID NO:71). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h1m (SEQ ID NO:71). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h1m (SEQ ID NO:71). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h1m (SEQ ID NO:71). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h1m (SEQ ID NO:71). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h1m (SEQ ID NO:71).

[0297] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h2m (SEQ ID NO:72). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h2m (SEQ ID NO:72). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h2m (SEQ ID NO:72). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h2m (SEQ ID NO:72). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h2m (SEQ ID NO:72). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h2m (SEQ ID NO:72).

[0298] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h3m (SEQ ID NO:73). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h3m (SEQ ID NO:73). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h3m (SEQ ID NO:73). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h3m (SEQ ID NO:73). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h3m (SEQ ID NO:73). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h3m (SEQ ID NO:73).

[0299] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h4m (SEQ ID NO:74). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h4m (SEQ ID NO:74). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h4m (SEQ ID NO:74). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h4m (SEQ ID NO:74). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h4m (SEQ ID NO:74). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h4m (SEQ ID NO:74).

[0300] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h5m (SEQ ID NO:75). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h5m (SEQ ID NO:75). In embodiments, the sequence of the 3E10-HC is atleast about 97% identical to 3E10-HC-h5m (SEQ ID NO:75). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h5m (SEQ ID NO:75). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h5m (SEQ ID NO:75). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h5m (SEQ ID NO:75).

[0301] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h6m (SEQ ID NO:76). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h6m (SEQ ID NO:76). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h6m (SEQ ID NO:76). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h6m (SEQ ID NO:76). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h6m (SEQ ID NO:76). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h6m (SEQ ID NO:76).

[0302] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h7m (SEQ ID NO:77). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h7m (SEQ ID NO:77). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h7m (SEQ ID NO:77). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h7m (SEQ ID NO:77). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h7m (SEQ ID NO:77). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h7m (SEQ ID NO:77).

[0303] In embodiments, an ADC provided herein comprises a humanized 3E10 antibody, or antigen-binding fragment thereof, comprising a light chain (3E10-LC) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-LC-h1 (SEQ ID NO:97), 3E10-LC-h2 (SEQ ID NO:98), 3E10-LC-h3 (SEQ ID NO:99), 3E10-LC-h4 (SEQ ID NO:100), 3E10-LC-h5 (SEQ ID NO:101), and 3E10-LC-h6 (SEQ ID NO:102) and a heavy chain (3E10-HC) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-HC-h1 (SEQ ID NO:78), 3E10-HC-h2 (SEQ ID NO:79), 3E10-HC-h3 (SEQ ID NO:80), 3E10-HC-h4 (SEQ ID NO:81), 3E10-HC-h5 (SEQ ID NO:82), 3E10-HC-h6 (SEQ ID NO:83), and 3E10-HC-h7 (SEQ ID NO:84).

[0304] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h1 (SEQ ID NO:97. In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h1 (SEQ ID NO:97). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h1 (SEQ ID NO:97). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h1 (SEQ ID NO:97). In embodiments, thesequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h1 (SEQ ID NO:97). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h1 (SEQ ID NO:97).

[0305] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h2 (SEQ ID NO:98). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h2 (SEQ ID NO:98). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h2 (SEQ ID NO:98). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h2 (SEQ ID NO:98). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h2 (SEQ ID NO:98). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h2 (SEQ ID NO:98).

[0306] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h3 (SEQ ID NO:99). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h3 (SEQ ID NO:99). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h3 (SEQ ID NO:99). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h3 (SEQ ID NO:99). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h3 (SEQ ID NO:99). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h3 (SEQ ID NO:99).

[0307] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h4 (SEQ ID NO:100). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h4 (SEQ ID NO:100). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h4 (SEQ ID NO:100). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h4 (SEQ ID NO:100). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h4 (SEQ ID NO:100). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h4 (SEQ ID NO:100).

[0308] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h5 (SEQ ID NO:101). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h5 (SEQ ID NO:101). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h5 (SEQ ID NO:101). In embodiments, the sequence of the 3E10-LC is at least about 98% identical to 3E10-LC-h5 (SEQ ID NO:101). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h5 (SEQ ID NO:101). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h5 (SEQ ID NO:101).

[0309] In embodiments, the sequence of the 3E10-LC is at least about 95% identical to 3E10- LC-h6 (SEQ ID NO:102). In embodiments, the sequence of the 3E10-LC is at least about 96% identical to 3E10-LC-h6 (SEQ ID NO:102). In embodiments, the sequence of the 3E10-LC is at least about 97% identical to 3E10-LC-h6 (SEQ ID NO:102). In embodiments, the sequence of the3E10-LC is at least about 98% identical to 3E10-LC-h6 (SEQ ID NO:102). In embodiments, the sequence of the 3E10-LC is at least about 99% identical to 3E10-LC-h6 (SEQ ID NO:102). In embodiments, the sequence of the 3E10-LC is 3E10-LC-h6 (SEQ ID NO:102).

[0310] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h1 (SEQ ID NO:78). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h1 (SEQ ID NO:78). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h1 (SEQ ID NO:78). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h1 (SEQ ID NO:78). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h1 (SEQ ID NO:78). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h1 (SEQ ID NO:78).

[0311] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h2 (SEQ ID NO:79). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h2 (SEQ ID NO:79). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h2 (SEQ ID NO:79). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h2 (SEQ ID NO:79). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h2 (SEQ ID NO:79). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h2 (SEQ ID NO:79).

[0312] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h3 (SEQ ID NO:80). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h3 (SEQ ID NO:80). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h3 (SEQ ID NO:80). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h3 (SEQ ID NO:80). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h3 (SEQ ID NO:80). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h3 (SEQ ID NO:80).

[0313] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h4 (SEQ ID NO:81). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h4 (SEQ ID NO:81). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h4 (SEQ ID NO:81). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h4 (SEQ ID NO:81). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h4 (SEQ ID NO:81). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h4 (SEQ ID NO:81).

[0314] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h5 (SEQ ID NO:82). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h5 (SEQ ID NO:82). In embodiments, the sequence of the 3E10-HC is atleast about 97% identical to 3E10-HC-h5 (SEQ ID NO:82). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h5 (SEQ ID NO:82). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h5 (SEQ ID NO:82). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h5 (SEQ ID NO:82).

[0315] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h6 (SEQ ID NO:83). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h6 (SEQ ID NO:83). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h6 (SEQ ID NO:83). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h6 (SEQ ID NO:83). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h6 (SEQ ID NO:83). In some aspects, the sequence of the 3E10-HC is 3E10-HC-h6 (SEQ ID NO:83).

[0316] In embodiments, the sequence of the 3E10-HC is at least about 95% identical to 3E10- HC-h7 (SEQ ID NO:84). In embodiments, the sequence of the 3E10-HC is at least about 96% identical to 3E10-HC-h7 (SEQ ID NO:84). In embodiments, the sequence of the 3E10-HC is at least about 97% identical to 3E10-HC-h7 (SEQ ID NO:84). In embodiments, the sequence of the 3E10-HC is at least about 98% identical to 3E10-HC-h7 (SEQ ID NO:84). In embodiments, the sequence of the 3E10-HC is at least about 99% identical to 3E10-HC-h7 (SEQ ID NO:84). In embodiments, the sequence of the 3E10-HC is 3E10-HC-h7 (SEQ ID NO:84).

[0317] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein has CDR sequences corresponding to those in the parent 3E10 antibody, optionally including a D31N amino acid substitution in the VH CDR1. Accordingly, in embodiments, a humanized 3E10 antibody or antigen-binding fragment thereof includes a light chain variable domain (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of 3E10-VL-CDR1 (SEQ ID NO: 9), a VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2 (SEQ ID NO: 10), a VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3 (SEQ ID NO: 11), a heavy chain variable domain (VH) CDR1 comprising the amino acid sequence of 3E10-VH-CDR1a (SEQ ID NO: 16), a VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2 (SEQ ID NO: 4), and a VH CDR3 comprising the amino acid sequence of 3E10-VH-CDR3 (SEQ ID NO: 5).

[0318] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes CDR sequences from a variant humanized 3E10 antibody that includes a D31N amino acid substitution in the VH CDR1 (SEQ ID NO:15).

[0319] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs)collectively having no more than seven amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0320] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than ten amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0321] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than nine amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0322] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than eight amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0323] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than seven amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0324] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than six amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0325] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than five amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0326] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than four amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0327] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than three amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0328] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than two amino acid substitutions, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0329] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than one amino acid substitution, relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11), 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0330] Accordingly, in embodiments, an ADC described herein can comprise a humanized 3E10 antibody or antigen-binding fragment thereof includes a light chain variable domain (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of 3E10-VL- CDR1 (SEQ ID NO: 9), a VL CDR2 comprising the amino acid sequence of 3E10-VL-CDR2(SEQ ID NO: 10), a VL CDR3 comprising the amino acid sequence of 3E10-VL-CDR3 (SEQ ID NO: 11), a heavy chain variable domain (VH) CDR1 comprising the amino acid sequence of 3E10- VH-CDR1_D31N (SEQ ID NO: 15), a VH CDR2 comprising the amino acid sequence of 3E10- VH-CDR2 (SEQ ID NO: 4), and a VH CDR3 comprising the amino acid sequence of 3E10-VH- CDR3 (SEQ ID NO: 5).

[0331] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a set of complementarity determining regions (CDRs) collectively having no more than 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid substitutions, relative to the CDR sequences of 3E10-D31N variant (SEQ ID NOs:15-18 and 22-24), selected from, but not limited to, a G to S substitution at position 5 of VH CDR2, a T to S substitution at position 14 of VH CDR2, an S to T substitution at position 5 of VL CDR1, an M to L substitution at position 14 of VL CDR1, an H to A substitution at position 15 of VL CDR1, and an E to Q substitution at position 6 of VL CDR2.

[0332] Accordingly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2.1 (SEQ ID NO: 26) or 3E10-VH-CDR2.2 (SEQ ID NO: 27). In embodiments, the 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 1 and 3 (SEQ ID NOs:3 and 5) according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:22-24), and VH CDRs 1 and 3 (SEQ ID NOs:15 and 18) according to the 3E10- D31N variant.

[0333] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL- CDR1.1 (SEQ ID NO: 28) or 3E10-VL-CDR1.2 (SEQ ID NO: 29). In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:10 and 11), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:23 and 24), and VH CRDs 1-3 (SEQ ID NOs:15, 17 and 18) according to the 3E10- D31N variant.

[0334] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR2 comprising the amino acid sequence of 3E10-VL- CDR2.1 (SEQ ID NO: 30). In embodiments, the 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:9 and 11), and VH CDRs 1-3 (SEQ ID NOs: 3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibodyor antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:22 and 24), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18)according to the 3E10-D31N variant.

[0335] While some of the amino acid substitutions described above are fairly conservative substitutions—e.g., an S to T substitution at position 5 of VL CDR1—other substitutions are to amino acids that have vastly different properties—e.g., an M to L substitution at position 14 of VL CDR1, an H to A substitution at position 15 of VL CDR1, and an E to Q substitution at position 6 of VL CDR2. This suggests, without being bound by theory, that at least these positions within the 3E10 CDR framework are tolerant to other amino acid substitutions.

[0336] Accordingly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH-CDR2.3 (SEQ ID NO: 31). In embodiments, the humanized 3E10 antibody or antigen- binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 1 and 3 (SEQ ID NOs:3 and 5) according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:22-24), and VH CDRs 1 and 3 (SEQ ID NOs:15 and 18) according to the 3E10- D31N.

[0337] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL- CDR1.3 (SEQ ID NO: 32). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:10 and 11), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18) according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:23 and 24), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18) according to the 3E10- D31N variant.

[0338] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof, includes VL CDR2 comprising the amino acid sequence of 3E10-VL- CDR2.2 (SEQ ID NO: 33). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:9 and 11), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:22 and 24), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18) according to the 3E10- D31N variant.

[0339] Accordingly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof includes VH CDR1 comprising the amino acid sequence of 3E10-VH-CDR1.c1 (SEQ ID NO: 34), 3E10-VH-CDR1.c2 (SEQ ID NO: 35), 3E10-VH-CDR1.c3(SEQ ID NO: 36), 3E10-VH-CDR1.c4 (SEQ ID NO: 37), or 3E10-VH-CDR1.c5 (SEQ ID NO: 38). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 2 and 3 (SEQ ID NOs:4 and 5) according to the parent 3E10 antibody.

[0340] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH- CDR2.c1 (SEQ ID NO: 39), 3E10-VH-CDR2.c2 (SEQ ID NO: 40), or 3E10-VH-CDR2.c3 (SEQ ID NO: 41). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 1 and 3 (SEQ ID NOs:3 and 5) according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:22-24), and VH CDRs 1 and 3 (SEQ ID NOs:15 and 18) according to the 3E10-D31N variant.

[0341] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VH CDR3 comprising the amino acid sequence of 3E10-VH- CDR3.c1 (SEQ ID NO: 42), 3E10-VH-CDR3.c2 (SEQ ID NO: 43), or 3E10-VH-CDR3.c3 (SEQ ID NO: 44). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 1 and 2 (SEQ ID NOs:3 and 4) according to the parent 3E10 antibody. In embodiments, the 3E10 antibody or variant thereof, or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:22-24), and VH CDRs 1 and 2 (SEQ ID NOs:15 and 17) according to the 3E10-D31N variant.

[0342] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL- CDR1.c1 (SEQ ID NO: 45), 3E10-VL-CDR1.c2 (SEQ ID NO: 46), 3E10-VL-CDR1.c3 (SEQ ID NO: 47), 3E10-VL-CDR1.c4 (SEQ ID NO: 48), 3E10-VL-CDR1.c5 (SEQ ID NO: 49), or 3E10- VL-CDR1.c6 (SEQ ID NO: 50). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:10 and 11), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:23 and 24), and VH CRDs 1-3 (SEQ ID NOs:15, 17, 18) according to the 3E10-D31N variant.

[0343] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR2 comprising the amino acid sequence of 3E10-VL- CDR2.c1 (SEQ ID NO: 51). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:9 and 11), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:22 and 24), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18) according to the 3E10-D31N variant.

[0344] Similarly, in some aspects, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR3 comprising the amino acid sequence of 3E10-VL- CDR3.c1 (SEQ ID NO: 52), 3E10-VL-CDR3.c2 (SEQ ID NO: 53), 3E10-VL-CDR3.c3 (SEQ ID NO: 54), 3E10-VL-CDR3.c4 (SEQ ID NO: 55), 3E10-VL-CDR3.c5 (SEQ ID NO: 56), or 3E10- VL-CDR3.c6 (SEQ ID NO: 57). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 2 (SEQ ID NOs:9 and 10), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 2 (SEQ ID NOs:22 and 23), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18) according to the 3E10-D31N variant.

[0345] It is also contemplated that an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof, as described herein, includes no more than 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 CDR amino acid substitutions of the CDR amino acid substitutions described above. Further examples of 3E10 variant CDR sequences are described herein (SEQ ID NOs:58-63).

[0346] Accordingly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof includes VH CDR1 comprising the amino acid sequence of 3E10-VH-CDR1m (SEQ ID NO: 58). In embodiments, the humanized 3E10 antibody or antigen- binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 2 and 3 (SEQ ID NOs:4 and 5) according to the parent 3E10 antibody.

[0347] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VH CDR2 comprising the amino acid sequence of 3E10-VH- CDR2m (SEQ ID NO: 59). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 1 and 3 (SEQ ID NOs: 3 and 5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:22-24), and VH CDRs 1 and 3 (SEQ ID NOs:15 and 18) according to the 3E10-D31N variant.

[0348] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VH CDR3 comprising the amino acid sequence of 3E10-VH- CDR3m (SEQ ID NO: 60). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:9-11), and VH CDRs 1 and 2 (SEQ ID NOs:3 and 4) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1-3 (SEQ ID NOs:22-24), and VH CDRs 1 and 2 (SEQ ID NOs:15 and 17) according to the 3E10-D31N variant.

[0349] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR1 comprising the amino acid sequence of 3E10-VL- CDR1m (SEQ ID NO: 61). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:10 and 11), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 2 and 3 (SEQ ID NOs:23 and 24), and VH CDRs 1-3 (SEQ ID NOs:15,17, and 18) according to the 3E10-D31N variant.

[0350] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR2 comprising the amino acid sequence of 3E10-VL- CDR2m (SEQ ID NO: 62). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:9 and 11), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 3 (SEQ ID NOs:22 and 24), and VH CDRs 1-3 (SEQ ID NOs:15, 17 and 18) according to the 3E10-D31N variant.

[0351] Similarly, in embodiments, an ADC comprising a humanized 3E10 antibody or antigen- binding fragment thereof includes VL CDR3 comprising the amino acid sequence of 3E10-VL- CDR3m (SEQ ID NO: 63). In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 2 (SEQ ID NOs:9 and 10), and VH CDRs 1-3 (SEQ ID NOs:3-5) according to the parent 3E10 antibody. In embodiments, the humanized 3E10 antibody or antigen-binding fragment thereof further includes VL CDRs 1 and 2 (SEQ ID NOs:9 and 10), and VH CDRs 1-3 (SEQ ID NOs: 15, 17 and 18) according to the 3E10-D31N variant.

[0352] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a light chain variable domain (3E10-VL) comprising an amino acid sequence that is at least about 90% identical to an amino acid sequence selected from the group consisting of 3E10-VL-h1 (SEQ ID NO:85), 3E10-VL-h2 (SEQ ID NO:86), 3E10- VL-h3 (SEQ ID NO:87), 3E10-VL-h4 (SEQ ID NO:88), 3E10-VL-h5 (SEQ ID NO:89), and 3E10- VL-h6 (SEQ ID NO:90), where the light chain variable domain (3E10-VL) further comprises one or more amino acid residues selected from proline (Pro) at position 15, threonine (Thr) at position 22, tyrosine (Tyr) at position 49, Thr at position 74, asparagine (Asn) at position 76, alanine (Ala) at position 80, Asn at position 81, Thr at position 83, Asn at position 85, and valine (Val) at position 104, of the 3E10-VL according to Kabat numbering, and a set of 3E10-VL CDRs collectively having no more than 6 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL- CDR3 (SEQ ID NO:11), and where the antibody includes a set of 3E10-VL CDRs collectivelyhaving no more than 6 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL- CDR3 (SEQ ID NO:11).

[0353] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VL CDRs comprising no more than 5 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11).

[0354] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VL CDRs comprising no more than 4 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11).

[0355] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VL CDRs comprising no more than 3 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11).

[0356] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VL CDRs comprising no more than 2 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11).

[0357] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VL CDRs comprising no more than 1 amino acid substitution relative to the set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL-CDR3 (SEQ ID NO:11).

[0358] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VL CDRs comprising a set of CDRs having the amino acid sequences of 3E10-VL-CDR1 (SEQ ID NO:9), 3E10-VL-CDR2 (SEQ ID NO:10), 3E10-VL- CDR3 (SEQ ID NO:11).

[0359] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a lysine (Lys) residue at position 49 of the 3E10- VL according to Kabat numbering.

[0360] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a glutamic acid (Glu) residue at position 81 of the 3E10-VL according to Kabat numbering.

[0361] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a proline (Pro) residue at position 15 of the 3E10-VL according to Kabat numbering.

[0362] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a valine (Val) residue at position 104, of the 3E10-VL according to Kabat numbering.

[0363] In embodiments, an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof described herein includes a heavy chain variable domain (3E10-VH) comprising an amino acid sequence that is at least about 90% identical to an amino acid sequence selected from the group consisting of 3E10-VH-h1 (SEQ ID NO:64), 3E10-VH-h2 (SEQ ID NO:65), 3E10- VH-h3 (SEQ ID NO:66), 3E10-VH-h4 (SEQ ID NO:67), 3E10-VH-h5 (SEQ ID NO:68), 3E10- VH-h6 (SEQ ID NO:69), and 3E10-VH-h7 (SEQ ID NO:70), where the heavy chain variable domain (3E10-VH) further comprises one or more amino acid residues selected from glutamine (Gln) at position 13, leucine (Leu) at position 18, arginine (Arg) at position 19, glycine (Gly) at position 42, serine (Ser) at position 49, Ser at position 77, tyrosine (Tyr) at position 79, Asn at position 82, Ala at position 84, Val at position 89, leucine (Leu) at position 108, Val at position 109, and Ser at position 113, of the 3E10-VH according to Kabat numbering, and where the antibody includes a set of 3E10-VH CDRs collectively having no more than 6 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VH- CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0364] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VH CDRs comprising no more than 5 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VH- CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0365] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VH CDRs comprising no more than 4 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VH- CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0366] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VH CDRs comprising no more than 3 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VH-CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0367] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes set of 3E10-VH CDRs comprising no more than 2 amino acid substitutions relative to the a set of CDRs having the amino acid sequences of 3E10-VH- CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0368] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VH CDRs comprising no more than 1 amino acid substitution relative to the set of CDRs having the amino acid sequences of 3E10-VH- CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0369] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof includes a set of 3E10-VH CDRs comprising no more than 5, 4, 3, 2, or 1 amino acid substitutions relative to the set of CDRs having the amino acid sequences of 3E10-VH- CDR1_D31N (SEQ ID NO:15), 3E10-VH-CDR2 (SEQ ID NO:4), and 3E10-VH-CDR3 (SEQ ID NO:5).

[0370] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with an arginine (Arg) residue at position 18 of the 3E10-VH according to Kabat numbering.

[0371] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a (Lys) residue at position 19 of the 3E10-VH according to Kabat numbering.

[0372] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with an alanine (Ala) residue at position 49 of the 3E10-VH according to Kabat numbering.

[0373] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a glutamine (Gln) residue at position 13, of the 3E10-VH according to Kabat numbering.

[0374] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a leucine (Leu) residue at position 108, of the 3E10-VH according to the Kabat numbering.

[0375] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a valine (Val) residue at position 109, of the 3E10-VH according to Kabat numbering.

[0376] In one aspect, the present disclosure provides an ADC comprising a humanized antibody or antigen-binding fragment thereof with a serine (Ser) residue at position 113, of the 3E10-VH according to Kabat numbering.

[0377] In embodiments, the present disclosure provides an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof with a fragment crystallizable (Fc) region.

[0378] In embodiments, the present disclosure provides an ADC comprising a humanized 3E10 antibody or antigen-binding fragment thereof with an Fc region selected from a human IgG1 Fc, a human IgG2a Fc, a human IgG2b Fc, a human IgG3 Fc, and a human IgG4 Fc.

[0379] In embodiments, the present disclosure provides an ADC comprising humanized 3E10 antibodies or variants thereof, or antigen-binding fragments thereof comprising a heavy chain constant domain (CH).

[0380] In embodiments, a ADC comprising the humanized 3E10 antibody or variant thereof, or antigen-binding fragment thereof comprises an Fc region selected from a human γ1 CH1, a human γ2 CH1, a human γ3 CH1, and a human γ4 CH1.

[0381] In embodiments, the present disclosure provides an ADC comprising a humanized 3E10 antibody or variant thereof, or antigen-binding fragment thereof comprising a light chain constant domain (CL).

[0382] In one aspect, the present disclosure provides an ADC comprising a humanized 3E10 antibody or variant comprising an Fc region selected from the group consisting of a human λ CL and a human κ CL.

[0383] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof comprising a combination of a light chain variable domain (VL) and a heavy chain variable domain (VH) selected from 3E10-VL-h1 (SEQ ID NO:85) and 3E10-VH-h1 (SEQ ID NO:64), 3E10-VL-h1 (SEQ ID NO:85) and 3E10-VH-h2 (SEQ ID NO:65), 3E10-VL-h1 (SEQ ID NO:85) and 3E10-VH-h3 (SEQ ID NO:66), 3E10-VL-h1 (SEQ ID NO:85) and 3E10-VH-h4 (SEQ ID NO:67), 3E10-VL-h2 (SEQ ID NO:86) and 3E10-VH-h1 (SEQ ID NO:64), 3E10-VL-h2 (SEQ ID NO:86) and 3E10-VH-h2 (SEQ ID NO:65), 3E10-VL-h3 (SEQ ID NO:87) and 3E10- VH-h1 (SEQ ID NO:64), 3E10-VL-h5 (SEQ ID NO:89) and 3E10-VH-h5 (SEQ ID NO:68), 3E10- VL-h5 (SEQ ID NO:89) and 3E10-VH-h6 (SEQ ID NO:69), 3E10-VL-h6 (SEQ ID NO:90) and 3E10-VH-h5 (SEQ ID NO:68), and 3E10-VL-h6 (SEQ ID NO:90) and 3E10-VH-h6 (SEQ ID NO:69).

[0384] In embodiments, an ADC comprising the humanized 3E10 antibody or antigen-binding fragment thereof comprises a combination of a light chain variable domain (VL) of 3E10-VL-h6 (SEQ ID NO:90) and a heavy chain variable domain (VH) of 3E10-VH-h6 (SEQ ID NO:69).

[0385] Antibodies useful in the compositions, conjugates, and methods described herein include whole immunoglobulin (i.e., an intact antibody) of any class, fragments thereof, and synthetic proteins containing at least the antigen-binding variable domain of an antibody. The variable domains differ in sequence among antibodies and are used in the binding and specificity of each particular antibody for its particular antigen. However, the variability is not usually evenly distributed through the variable domains of antibodies. It is typically concentrated in three segments called complementarity determining regions (CDRs) or hypervariable regions both in the light chain and the heavy chain variable domains. The more highly conserved portions of the variable domains are called the framework (FR). The variable domains of native heavy and light chains each comprise four FR regions, largely adopting a beta-sheet configuration, connected by three CDRs, which form loops connecting, and in some cases forming part of, the beta-sheet structure. The CDRs in each chain are held together in close proximity by the FR regions and, with the CDRs from the other chain, contribute to the formation of the antigen-binding site of antibodies. Therefore, the antibodies typically contain at least the CDRs necessary to maintain DNA binding and / or interfere with DNA repair.

[0386] The 3E10 antibody is typically a monoclonal 3E10, or a variant, derivative, fragment, fusion, or humanized form thereof that binds the same or different epitope(s) as 3E10.

[0387] A deposit according to the terms of the Budapest Treaty of a hybridoma cell line producing monoclonal antibody 3E10 was received on September 6, 2000, and accepted by, American Type Culture Collection (ATCC), 10801 University Blvd., Manassas, VA 20110-2209, USA, and given Patent Deposit Number PTA-2439. Thus, the antibody can have the same or different epitope specificity as monoclonal antibody 3E10 produced by ATCC No. PTA 2439 hybridoma. The antibody can have the paratope of monoclonal antibody 3E10. The antibody can be a single chain variable fragment of 3E10, or a variant, e.g., a conservative variant thereof. For example, the antibody can be a single chain variable fragment of 3E10 (3E10 Fv), or a variant thereof.

[0388] Additionally, or alternatively, the heavy chain complementarity determining regions (CDRs) can be defined according to the IMGT system. The complementarity determining regions (CDRs) as identified by the IMGT system include CDR H1.3 (original sequence): GFTFSDYG; CDR H1.4 (with D31N mutation): GFTFSNYG; CDR H2.2: ISSGSSTI and variant ISSSSSTI; CDR H3.2: ARRGLLLDY.

[0389] Additionally, or alternatively, the light chain complementarity determining regions (CDRs) can be defined according to the IMGT system. The complementarity determining regions (CDRs) as identified by the IMGT system include CDR L1.2 KSVSTSSYSY and variant KTVSTSSYSY; CDR L2.2: YAS; CDR L3.2: QHSREFPWT.

[0390] The disclosed compositions, conjugates, and methods typically utilize antibodies that maintain the ability to penetrate cells, and optionally nuclei. The mechanisms of cellular internalization by autoantibodies are diverse. Some are taken into cells through electrostatic interactions or FcR-mediated endocytosis, while others utilize mechanisms based on association with cell surface myosin or calreticulin, followed by endocytosis (Ying-Chyi et al., Eur J Immunol 38, 3178-3190 (2008), Yanase et al., J Clin Invest 100, 25-31 (1997)). The 3E10 antibodies and antigen-binding fragments or variants thereof can transit cellular membranes via an equilibrative nucleoside (ENT) transporter. In embodiments, 3E10 transits cellular membranes via an ENT1, ENT2, ENT3 or ENT4 transporter (See, e.g., WO 2015 / 106290 A1 and WO 2016 / 033324 A1, each of which is incorporated by reference herein, in its entirety). In embodiments, 3E10 penetrates cells in an Fc-independent mechanism (as evidenced by the ability of 3E10 fragments lacking an Fc to penetrate cells) but involves presence of the nucleoside transporter ENT2 (Weisbart et al., Sci Rep 5:12022. doi: 10.1038 / srep12022. (2015), Zack et al., J Immunol 157, 2082-2088 (1996), Hansen et al., J Biol Chem 282, 20790-20793 (2007)). Thus, in embodiments, the antibodies utilized in the disclosed compositions, conjugates, and methods are ones that penetrates cells in an Fc- independent mechanism but involves presence of the nucleoside transporter ENT2.

[0391] Mutations in 3E10 that interfere with its ability to bind DNA can render the antibody incapable of nuclear penetration. Thus, typically the disclosed variants and humanized forms of the antibody maintain the ability to bind nucleic acids, particularly DNA. In addition, 3E10 scFv has previously been shown capable of penetrating into living cells and nuclei in an ENT2- dependent manner, with efficiency of uptake impaired in ENT2-deficient cells (Hansen, et al., J. Biol. Chem. 282, 20790-20793 (2007)). Thus, in embodiments, the disclosed variants and humanized forms of the antibody maintain the ability penetrate into cell nuclei in an ENT2- dependent manner. B. Therapeutic Agents

[0392] As used herein, the terms “therapeutic agent,” “payload moiety,” “payload,” “drug moiety,” “drug,” “anti-tumor drug,” “biologically active molecule,” “active molecule,” and “chemotherapeutic warhead” all refer to a molecule that has a biological, a cytotoxic, or a therapeutic effect in a cell. In embodiments, the drug or active molecule can be an inorganicmolecule, an organic molecule, a small organic molecule, a drug compound, a peptide, or a polypeptide. In embodiments, the drug or active molecule can be a functional nucleic acid, such as an oligonucleotide or a polynucleotide. 1. Small Molecules

[0393] In embodiments, the therapeutic agent is an anti-tumor drug or active molecule. In embodiments, the anti-tumor drug or active molecule can be a cytotoxic agent. The term “cytotoxic agent” refers generally to substances that destroy cells. In embodiments, the anti-tumor drug or active molecule can be a DNA damage inducing agent, a DNA repair inhibitor, an immune modulatory molecule, an alkylating agent, a microtubule inhibitor, an immune checkpoint inhibitor, an angiogenesis inhibitor, adoptive cell therapy, or a topoisomerase inhibitor, or any other cytotoxic agent or chemotherapeutic small molecule known in the art.

[0394] In embodiments of an ADC provided herein, P is a DNA damage inducing agent, a DNA repair inhibitor, an immune modulatory molecule, an alkylating agent, a microtubule inhibitor, an immune checkpoint inhibitor, an angiogenesis inhibitor, adoptive cell therapy, or a topoisomerase inhibitor. In some embodiments, P comprises exatecan ((1S,9S)-1-Amino-9-ethyl- 5-fluoro-9-hydroxy-4-methyl-1,2,3,9,12,15-hexahydro-10H,13H- benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinoline-10,13-dione)).

[0395] In embodiments, the anti-tumor drug or active molecule can be selected from maytansinoids, benzodiazepines, auristatins, tecans, taxoids, CC-1065, (4S)-4,11-Diethyl-4,9- dihydroxy-1,4-dihydro-3H,14H-pyrano[3′,4′:6,7]indolizino[1,2-b]quinoline-3,14-dione (SN38), exatecan, monomethyl auristatin E (MMAE), monomethyl auristatin F (MMAF), pyrrolobenzodiazepines (PBDs), PROteolysis TArgeting Chimera (PROTAC), deruxtecan (Dxd), calicheamicins, duocarmycins, stimulator of interferon genes (STING) agonists, PNU-159682, NMS249, IMGN Camp 1, duocarmycin hydroxybenzamide azaindole (DUBA), exatecan, and a prodrug anti-tumor drug thereof. In embodiments, the anti-tumor drug can be Pseudomonas aeruginosa exotoxin PE38, calicheaamicin, diphtheria toxin, irinotecans, duocarmycin, exatecan, staphylococcus aureus enterotoxin A / E-120, doxorubicin, tubulysin, antibacterial antibiotic, shigatoxin, ricin, or urease. In embodiments, the anti-tumor drug can be N(2’)-deacetyl-N(2’)-(3- mercapto-1-oxopropyl)-maytansine (“DM1”). In embodiments, the anti-tumor drug can be N2’- deacetyl-N2’-(4-mercapto-4-methyl-1-oxopentyl) maytansine (“DM4”). In embodiments, the anti- tumor drug can be SN38. In embodiments, the anti-tumor drug can be PNU-159682, NMS249. In embodiments, the anti-tumor drug can be NMS249.

[0396] In embodiments, the anti-tumor drug or active molecule can be doxorubicin (ADRIAMYCIN®), cisplatin, carboplatin, bleomycin sulfate, carmustine, chlorambucil (LEUKERAN®), cyclophosphamide (CYTOXAN®; NEOSAR®), lenalidomide (REVLIMID®), bortezomib (VELCADE®), dexamethasone, mitoxantrone, etoposide, cytarabine, bendamustine (TREANDA®), rituximab (RITUXAN®), ifosfamide, vincristine (ONCOVIN®), fludarabine (FLUDARA®), thalidomide (THALOMID®), alemtuzumab (CAMPATH®, ofatumumab (ARZERRA®), everolimus (AFINITOR®, ZORTRESS®), carfilzomib (KYPROLISTM), a proteasome inhibitor, thalidomide analogues that are immunomodulatory drugs (IMiDs), Bet inhibitors or any other cytotoxic agent or chemotherapeutic agents known in the art.

[0397] In some embodiments, the drug moiety is selected from any of the following:

[0398] In embodiments of an ADC provided herein, P is a maytansinoid. In embodiments, P is N(2’)-deacetyl-N(2’)-(3-mercapto-1-oxopropyl)-maytansine (DM1). In embodiments, P is N2’- deacetyl-N2’-(4-mercapto-4-methyl-1-oxopentyl) maytansine (DM4).

[0399] In embodiments of an ADC provided herein, P is a topoisomerase inhibitor. In embodiments, P is PNU-159682. In embodiments, P is (4S)-4,11-Diethyl-4,9-dihydroxy-1,4- dihydro-3H,14H-pyrano[3′,4′:6,7]indolizino[1,2-b]quinoline-3,14-dione (SN38).

[0400] In embodiments of an ADC provided herein, P is a tubulin inhibitor. In embodiments, P is monomethyl auristatin E (MMAE).

[0401] In embodiments of an ADC provided herein, P is PNU-159682. In embodiments, P is NMS249.

[0402] In embodiments of an ADC provided herein, P is an oligonucleotide.

[0403] In embodiments, the present disclosure provides an antibody-drug conjugate (ADC) having the formula A-(L-Pr)q, wherein: A is a humanized 3E10 antibody or antigen-binding fragment thereof comprising: (a) a light chain variable region (VL) complementarity determining region (CDR) 1 comprising the amino acid sequence of RASKSVSTSSYSYMH (SEQ ID NO:9), (b) a VL CDR2 comprising the amino acid sequence of YASYLES (SEQ ID NO:10), and (c) a VL CDR3 comprising the amino acid sequence of QHSREFPWT (SEQ ID NO: 11), and (d) a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of NYGMH (SEQ ID NO: 15), (e) a VH CDR2 comprising the amino acid sequence of YISSGSSTIYYADTVKG (SEQ ID NO: 4), and (f) a VH CDR3 comprising the amino acid sequence of RGLLLDY (SEQ ID NO: 5), L is a linker, P is SN38, r is an integer from 1 to 4, and q is an integer from 1 to 16.

[0404] In embodiments, ADCs disclosed herein have the formula A-(L-Pr)q, wherein: A is a 3E10 antibody or antigen-binding fragment or variant thereof, L is a linker, P is a payload as described herein, r is an integer from 1 to 4, and q is an integer from 1 to 16; wherein the 3E10 antibody or antigen-binding fragment thereof comprises a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of XYGMH (SEQ ID NO: 16), wherein X = D, N, R, L, or K and corresponds to an amino acid residue at position 31 of the 3E10 heavy chain, and wherein D31 is wild-type 3E10 CDR1. 2. Oligonucleotides

[0405] In embodiments, the therapeutic agent is or encodes a functional nucleic acid. Functional nucleic acids are nucleic acid molecules that have a specific function, such as binding a target molecule or catalyzing a specific reaction. In embodiments, functional nucleic acid molecules can be divided into the following non-limiting categories: antisense molecules, siRNA, miRNA, aptamers, ribozymes, RNAi, external guide sequences, and cyclic dinucleotides. In embodiments, functional nucleic acid molecules can act as effectors, inhibitors, modulators, and / or stimulators of a specific activity possessed by a target molecule, or functional nucleic acid molecules can possess a de novo activity independent of any other molecules.

[0406] In embodiments, functional nucleic acid molecules can interact with any macromolecule, such as DNA, RNA, polypeptides, or carbohydrate chains. Thus, functional nucleic acids can interact with the mRNA or the genomic DNA of a target polypeptide or they can interact with the polypeptide itself. In embodiments, functional nucleic acids are designed to interact with other nucleic acids based on sequence homology between the target molecule and the functional nucleic acid molecule. In embodiments, the specific recognition between a functional nucleic acid molecule and a target molecule is not based on sequence homology between thefunctional nucleic acid molecule and the target molecule, but rather is based on the formation of tertiary structure that allows specific recognition to take place.

[0407] In embodiments, the therapeutic agent can include one or more functional nucleic acids designed to reduce expression of a gene, or a gene product thereof. For example, the functional nucleic acid or polypeptide can be designed to target and reduce or inhibit expression or translation of an mRNA; or to reduce or inhibit expression, reduce activity, or increase degradation of a protein.

[0408] In embodiments, functional nucleic acids can be or encode antisense molecules. Antisense molecules are designed to interact with a target nucleic acid molecule through either canonical or non-canonical base pairing. The interaction of the antisense molecule and the target molecule is designed to promote the destruction of the target molecule through, for example, RNAse H mediated RNA-DNA hybrid degradation. Alternatively the antisense molecule is designed to interrupt a processing function that normally would take place on the target molecule, such as transcription or replication. Antisense molecules can be designed based on the sequence of the target molecule. There are numerous methods for optimization of antisense efficiency by finding the most accessible regions of the target molecule. Exemplary methods include in vitro selection experiments and DNA modification studies using DMS and DEPC. In embodiments, antisense molecules bind the target molecule with a dissociation constant (Kd) less than or equal to 10-6, 10-8, 10-10, or 10-12.

[0409] In embodiments, functional nucleic acids induce gene silencing through RNA interference. In embodiments, functional nucleic acids comprise short interfering RNA (siRNA). siRNA is a double-stranded RNA that can induce sequence-specific post-transcriptional gene silencing, thereby decreasing or even inhibiting gene expression. In embodiments, an siRNA triggers the specific degradation of homologous RNA molecules, such as mRNAs, within the region of sequence identity between both the siRNA and the target RNA. For example, WO 02 / 44321 discloses siRNAs capable of sequence-specific degradation of target mRNAs when base- paired with 3’ overhanging ends, herein incorporated by reference for the method of making these siRNAs. In embodiments, the functional nucleic acid comprises siRNA, shRNA, or miRNA.

[0410] In embodiments, functional nucleic acids comprise or encode an aptamer. Aptamers are molecules that interact with a target molecule, preferably in a specific way. Typically aptamers are small nucleic acids ranging from 15-50 bases in length that fold into defined secondary and tertiary structures, such as stem-loops or G-quartets. Aptamers can bind small molecules, such as ATP and theophiline, as well as large molecules, such as reverse transcriptase and thrombin.

[0411] In embodiments, functional nucleic acids comprise or encode ribozymes. Ribozymes are nucleic acid molecules that are capable of catalyzing a chemical reaction, either intramolecularly or intermolecularly. There are a number of different types of ribozymes that catalyze nuclease or nucleic acid polymerase type reactions which are based on ribozymes found in natural systems, such as hammerhead ribozymes. There are also a number of ribozymes that are not found in natural systems, but which have been engineered to catalyze specific reactions de novo. In embodiments, ribozymes cleave RNA or DNA substrates. Ribozymes typically cleave nucleic acid substrates through recognition and binding of the target substrate with subsequent cleavage. This recognition is often based mostly on canonical or non-canonical base pair interactions. This property makes ribozymes particularly good candidates for target specific cleavage of nucleic acids because recognition of the target substrate is based on the target substrates sequence.

[0412] In embodiments, functional nucleic acids comprise or encode external guide sequences. External guide sequences (EGSs) are molecules that bind a target nucleic acid molecule forming a complex, which is recognized by RNase P, which then cleaves the target molecule. EGSs can be designed to specifically target a RNA molecule of choice. RNAse P aids in processing transfer RNA (tRNA) within a cell. Bacterial RNAse P can be recruited to cleave virtually any RNA sequence by using an EGS that causes the target RNA:EGS complex to mimic the natural tRNA substrate. Similarly, eukaryotic EGS / RNAse P-directed cleavage of RNA can be utilized to cleave desired targets within eukaryotic cells. Representative examples of how to make and use EGS molecules to facilitate cleavage of a variety of different target molecules are known in the art.

[0413] Methods of making and using vectors for in vivo expression of functional nucleic acids such as antisense oligonucleotides, siRNA, shRNA, miRNA, EGSs, ribozymes, and aptamers are known in the art.

[0414] In embodiments, functional nucleic acids comprise or encode a cyclic dinucleotide. Cyclic dinucleotides bind directly to the STING adaptor protein, resulting in production of IFN-γ (Zhang, et al., Mol Cell., 51(2):226-35 (2013). doi: 10.1016 / j.molcel.2013.05.022.). Several canonical and noncanonical dinucleotides are known in the art, and include, but are not limited to, 2’3’-cGAMP , 2’3’-cGAMP , 3’3’-cGAMP, c-di-AMP, c-di-GMP, cAIMP (CL592), cAIMP Difluor (CL614), cAIM(PS)2 Difluor (Rp / Sp) (CL656), 2’2’-cGAMP, 2’3’-cGAM(PS)2 (Rp / Sp), 3’3’-cGAMP Fluorinated, c-di-AMP Fluorinated, 2’3’-c-di-AMP, 2’3’-c-di-AM(PS)2 (Rp,Rp), 2’3’-c-di-AM(PS)2 (Rp,Rp), c-di-GMP Fluorinated, 2’3’-c-di-GMP, c-di-IMP, DMXAA.

[0415] In embodiments, functional nucleic acids comprise or encode an oligonucleotide ligand. Examples include, but are not limited to, pattern recognition receptors (PRRs) ligands, such as theToll-like family of signaling molecules that play a role in the initiation of innate immune responses and also influence the later and more antigen specific adaptive immune responses. In embodiments, functional nucleic acids comprise oligonucleotides that can serve as a ligand for a Toll-like family signaling molecule, such as Toll-Like Receptor 9 (TLR9), e.g., oligonucleotides comprising one or more unmethylated cytosine-guanine (CG or CpG, used interchangeably) dinucleotide motifs. In embodiments, functional nucleic acids comprise oligonucleotides that can serve as a ligand for TLR3, e.g., a double-stranded RNA. In embodiments, functional nucleic acids comprise oligonucleotides that can serve as a ligand for TLR7, e.g., a single-stranded RNA or a short double- stranded RNA. In embodiments, functional nucleic acids comprise oligonucleotides that can serve as a ligand for retinoic acid-inducible gene I (RIG-I)-like receptors, e.g., RIG-I and melanoma differentiation-associated gene 5 (MDA5), e.g., a double-stranded RNA. In embodiments, functional nucleic acids comprise oligonucleotides that contain a functional ligand for TLR3, TLR7, TLR8, TLR9, or RIG-I-like receptors, or combinations thereof. Examples of immunostimulatory oligonucleotides, and methods of making them are known in the art and commercially available, see for example, Bodera, P. Recent Pat Inflamm Allergy Drug Discov. 5(1):87-93 (2011), incorporated herein by reference. C. Linkers

[0416] In embodiments, the universal antibody-drug conjugate (ADC) provided herein comprises a linker. The linker (L) described herein can be used to link or conjugate the 3E10 antibody or antigen-binding fragment or variant thereof to an oligonucleotide, a drug, or anti-tumor drug, or any biologically active molecule considered a toxic agent, chemotherapeutic agent, or warhead for use in killing cancer cells. The term “linker” as used herein includes, without limitation, any known linker for use antibody-drug-conjugates known in the art. In embodiments, an ADC conjugate comprises, one, two, three, four, or more linkers. 1. Conjugation Sites and Methods

[0417] In embodiments, one or more amino acids suitable conjugation of a 3E10 antibody or cell-penetrating fragment thereof provided herein are selected from lysine, cysteine, histidine, arginine, aspartic acid, glutamine, serine, threonine, and tyrosine. In embodiments, one or more amino acids suitable for conjugation are introduced by substitution of one or more amino acids in the 3E10 antibody or cell-penetrating fragment thereof. In embodiments, the one or more conjugated amino acids are lysine (Lys) or arginine (Arg), and conjugation is conducted via amine conjugation. In embodiments, one or more conjugated amino acids are glutamine (Gln), andconjugation is conducted via transglutaminase (TGase) mediated enzymatic conjugation. In some embodiments, one or more conjugated amino acids are cysteine (Cys), and conjugation is conducted via thiol conjugation.

[0418] In embodiments, a method of site-specific conjugation is by means of transglutaminase. Transglutaminases (TGases) which also include bacterial transglutaminase (BTG) are a family of enzymes which catalyze the formation of a covalent bond between the γ-carbonyl-amide group of glutamines and the primary amine group of lysines.

[0419] A peptide or antibody can be a substrate for transglutaminase according to the methods of the present disclosure. Thus, in some embodiments, the peptide or antibody contains a Gln or a Lys residue, and in particular a Gln residue. In some embodiments, the peptide or antibody is not a transglutaminase substrate, so one or more Gln or Lys residues, and in particular Gln residues, are inserted into the peptide or antibody sequence to make the peptide or antibody a substrate for transglutaminase. In embodiments, a Gln or Lys residue can be inserted at any position in the peptide or antibody sequence, however, it is preferably inserted at a position where the physiological properties, such as the therapeutic activity of the peptide, is not affected to a degree where the peptide is not useful anymore, e.g., in a therapeutic intervention. Insertions of amino acid residues in peptides can be brought about by standard techniques known to persons skilled in the art, such as post-translational chemical modification or transgenic techniques, as described in US Patent No.11,123,439 and US / 2016 / 0355859, the contents of which are hereby incorporated by reference.

[0420] Since such transglutaminases also accept substrates other than lysine as amine donors, they are used to modify proteins including antibodies at suitable acceptor glutamines (Josten et al., J. Immunol. Methods 240, 47-54 (2000); Mindt et al., Bioconjugate Chem. 19, 271-278 (2008); Dennler et al., in Antibody Drug Conjugates (Ducry, L., Ed.), pp 205-215, Humana Press. (2013), the contents of which are incorporated herein by reference). Transglutaminases have been used for the conjugation of drugs to antibodies containing artificial glutamine tags which are acceptor glutamine residues which have been introduced into the antibody by genetic engineering (Strop et al., Chem. Biol.20, 161-167 (2013)). Furthermore, the conserved glutamine residue Q295 (Kabat EU numbering) of the constant region of the heavy chain of antibodies is the only γ-carbonyl- amide donor for the bacterial transglutaminase (EC 2.3.2.13) in the backbone of aglycosylated IgG1 molecules, and is thus an acceptor glutamine, whereas no acceptor glutamine is present in the backbone of IgG1 when the antibody has been glycosylated at position N297 (Kabat EU numbering) of the heavy chain. In summary, bacterial transglutaminase can be used for the conjugation of an amine-donor substrate, for example a drug-linker construct, at an acceptorglutamine residue of an antibody. Such acceptor glutamines can be introduced by engineering of the antibody by mutations or by the generation of aglycosylated antibodies. Such aglycosylated antibodies can be introduced by deglycosylation using N-glycosidase F (PNGase F) or by mutation of N297 of the glycosylation site of the heavy chain (Kabat EU numbering) to any other amino acid except N. The enzymatic conjugation of such aglycosylated antibodies using bacterial transglutaminase has been described for aglycosylated antibody variants containing the mutations N297D, N297Q or N297S (see U.S. Pat Nos. US 9,764,038 and US 9,764,038, the contents of which are incorporated by reference). The enzymatic conjugation of such aglycosylated antibodies by means of transglutaminase generally affords AOCs having a DAR of 2, in which both heavy chains are specifically functionalized at position Q295 (Kabat EU numbering). Only mutation N297Q of the heavy chain affords an additional conjugation site per heavy chain. The conjugation of such variants leads to ADCs having a DAR of 4, in which both heavy chains are specifically functionalized at positions Q295 and Q297.

[0421] In embodiments, the chemical modification strategy utilized to create ADCs described herein is lysine conjugation. Lysine residues in proteins, e.g., antibodies, possess a primary amine group (-NH2) in their side chains, making them suitable targets for chemical modification. This primary amine group can react with various chemical reagents, including small molecules or polymers (e.g., cleavable and non-cleavable linkers).

[0422] In embodiments, lysine conjugation can be either site-specific or random. In site- specific conjugation, specific lysine residues within a protein, e.g., antibody, can be targeted ensuring precise control over the modification. In contrast, random conjugation involves modifying lysine residues without selectivity.

[0423] However, tryptic peptide mapping of 3E10 conjugated at lysine residues has shown that V region lysines in both VL and VH were observed to be modified and, in fact, VL K53 is the most modified lysine, occurred in nearly 2 / 3 of instances. Furthermore, the humanization trials described in WO 2023 / 168352, demonstrated that any modification to VL K53 negatively impacted the immunoreactivity to nucleic acids of the humanized 3E10-D31N monoclonal antibody (V66).

[0424] In embodiments, the conjugation strategy is selected from one of the following:a. Lysine Attachment

[0425] In some embodiments of the ADCs described herein, the linker moiety is conjugated to the antibody or antigen binding fragment therein through an amine linkage at one or more surface-exposed lysine residues on the antibody or antigen binding fragment thereof. Generally, lysine conjugation is a random process, with respect to which lysines are conjugated to the liker- payload. However, some preference for conjugation at certain lysines can occur due to the context of the primary, secondary, ternary, and / or quaternary structure surrounding a particular lysine residue. Many different chemistries are known in the art for attaching payloads to proteins at lysine groups. For example, activated esters on the drug-linker complexes, often O- succinimide reagents such as N-hydroxysuccinimidyl (NHS) or sulfo-NHS esters, can react with the antibody lysine residues and achieve conjugation via amide bonds, or stable amidine bonds can be generated on an antibody by the reaction of imido ester compounds, such as Traut’s reagent, with antibody lysine residues. Further description of lysine conjugation techniques are described, for example, in Walker, J.M., et al., “Antibody-drug conjugates,” Humana Press (2013); Bhat, A.S., et al., “The next step in homogenous bioconjugate development: optimizing payload placement and conjugate composition,” BioProcess International (2014); and Jain, N., et al., “Current ADC linker chemistry,” Pharm Res., 32:3526–40 (2015), the disclosure of which are incorporated herein by reference, in their entireties, for all purposes.

[0426] Accordingly, in some embodiments, the present disclosure provides pharmaceutical compositions comprising an antibody-drug conjugate (ADC) having the formula A-(L-Pr)q, where: A is a 3E10 antibody or antigen-binding fragment thereof as described herein, L is a linker as described herein, P is a payload moiety as described herein, r is an integer from 1 to 4, and q is an integer from 1 to 16, in which L is conjugated to A through lysine moieties.

[0427] Advantageously, because the structural regions of antibodies contain many lysine residues, lysine conjugation can be used to generate ADC molecules with a high drug to antibody ratio (DAR). Accordingly, in some embodiments, a composition comprising an ADC where lysine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein will have an average DAR of at least 4 (an average of at least four drug moieties attached to each antibody). In some embodiments, such a composition will have an average DAR of at least 6. In some embodiments, such a composition will have an average DAR of at least 8. In some embodiments, such a composition will have an average DAR of at least 10. In someembodiments, such a composition will have an average DAR of at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, or more.

[0428] Accordingly, in some embodiments, a composition comprising an ADC where lysine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, r is 1 and q is at least 4. In some embodiments, r is 1 and q is at least 6. In some embodiments, r is 1 and q is at least 8. In some embodiments, r is 1 and q is at least 10. In some embodiments, r is 1 and q is at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, or more. In some embodiments, a composition comprising an ADC where lysine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, r is 2 (e.g., the linker is a branched linker) and q is at least 2. In some embodiments, r is 2 and q is at least 3. In some embodiments, r is 2 and q is at least 4. In some embodiments, r is 2 and q is at least 5. In some embodiments, r is 2 and q is at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, or more. In yet other embodiments, a composition comprising an ADC where lysine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, the linker is highly branched, e.g., r is at least 3. In some embodiments, r is at least 4. In some embodiments, r is at least 5, 6, 7, 8, or more. b. Cysteine Attachment

[0429] In some embodiments of the ADCs described herein, the linker moiety is conjugated to the antibody or antigen binding fragment therein through a sulfide linkage at one or more surface- exposed cysteine residues on the antibody or antigen binding fragment thereof. In some embodiments of the ADCs described herein, the linker moiety is conjugated to the antibody or antigen binding fragment therein through a thiol side chain of one or more cysteine residues on the antibody or antigen binding fragment thereof. In general, antibodies do not possess free thiols, and all cysteine residues form disulfide bonds. In human IgG1, which is commonly used in modern ADCs, there are 4 interchain and 12 intrachain disulfide bonds. The 4 interchain disulfides, which are generally not critical for structural stability of IgG1, can be selectively reduced under mild conditions to give 2, 4, 6, or 8 free thiols while keeping the 12 intrachain disulfides intact. Due to the limited number of conjugation sites and the distinct reactivity of the thiol group, cysteine-based conjugation allows for controlled DAR and heterogeneity. Engineered Cys residues can also be used for site specific conjugation without the partial reduction of the endogenous disulfide bonds using, e.g., EnCys-mAb technology. Many different chemistries are known in the art for attaching payloads to proteins at cystine groups. For example, 8 nucleophilic cysteine residues can first beliberated from the reduced inter-chain disulfide bonds via reducing agents and later conjugated with drug-linker complexes. This approach generates ADCs with heterogeneous conjugation sites and a different number of drugs attached, resulting in a drug to antibody ratio (DAR) ranging from 0~8. Alternatively, partial reduction with either dithiothreitol (DTT) or tris(2-carboxyethyl) phosphine (TCEP) can be used to result in the disruption of the heavy-light inter-chain disulfides to release free Cys for drug conjugation, while treatment using 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) yields drug conjugates connect to the Cys residues usually involved in heavy-heavy inter- chain disulfides. Further description of cysteine conjugation techniques are described, for example, in Behrens, C.R.; et al., “Methods for site-specific drug conjugation to antibodies,” mAbs.2014, 6 (1): 46–53; Dennler, P.; et al., “Antibody conjugates: from heterogeneous populations to defined reagents,” Antibodies. 2015, 4: 197-224; and Agarwal, P.; et al., “Site-specific antibody−drug conjugates: the nexus of bioorthogonal chemistry, protein engineering, and drug development,” Bioconjugate Chem. 2015, 26: 176−192, the disclosure of which are incorporated herein by reference, in their entireties, for all purposes.

[0430] Accordingly, in some embodiments, the present disclosure provides pharmaceutical compositions comprising an antibody-drug conjugate (ADC) having the formula A-(L-Pr)q, where: A is a 3E10 antibody or antigen-binding fragment thereof as described herein, L is a linker as described herein, P is a payload moiety as described herein, r is an integer from 1 to 4, and q is an integer from 1 to 16, in which L is conjugated to A through cysteine moieties.

[0431] Advantageously, because of the limited number of conjugation sites and the distinct reactivity of the thiol group, cysteine-based conjugation can be used to generate ADC molecules with a controlled DAR and heterogeneity.

[0432] Accordingly, in some embodiments, a composition comprising an ADC where cysteine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein will have an average DAR of at least 2. In some embodiments, such a composition will have an average DAR of at least 3. In some embodiments, such a composition will have an average DAR of at least 4. In some embodiments, such a composition will have an average DAR of at least 5. In some embodiments, such a composition will have an average DAR of at least 6. In some embodiments, such a composition will have an average DAR of at least 7. In some embodiments, such a composition will have an average DAR of about 8. In some embodiments, such a composition will have an average DAR of at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, or about 8.

[0433] Accordingly, in some embodiments, a composition comprising an ADC where cysteine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof asdescribed herein, r is 1 and q is at least 2. In some embodiments, r is 1 and q is at least 3. In some embodiments, r is 1 and q is at least 4. In some embodiments, r is 1 and q is at least 5. In some embodiments, r is 1 and q is at least 6. In some embodiments, r is 1 and q is at least 7. In some embodiments, r is 1 and q is about 8. In some embodiments, r is 1 and q is at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, or 8. In some embodiments, a composition comprising an ADC where cysteine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, r is 2 (e.g., the linker is a branched linker) and q is at least 2. In some embodiments, r is 2 and q is at least 3. In some embodiments, r is 2 and q is at least 4. In some embodiments, r is 2 and q is at least 5. In some embodiments, r is 2 and q is at least 6. In some embodiments, r is 2 and q is at least 7. In some embodiments, r is 2 and q is about 8. In some embodiments, r is 2 and q is at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, or about 8. In yet other embodiments, a composition comprising an ADC where cysteine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, the linker is highly branched, e.g., r is at least 3. In some embodiments, r is at least 4. In some embodiments, r is at least 5, 6, 7, 8, or more. c. Transglutaminase-based Attachment

[0434] In some embodiments of the ADCs described herein, the linker moiety is conjugated to the antibody or antigen binding fragment therein through the primary amide side chain of one or more glutamine residues on the antibody or antigen binding fragment thereof. Generally, transglutaminase derived from Streptomyces mobaraensis catalyzes transpeptidation where a primary amine-containing linker is covalently attached to the primary amide side chain of a specific glutamine (Q295) within deglycosylated antibodies, resulting in ADCs with a defined DAR of 2 (one conjugation site per heavy chain) (Jeger et al., “Site-specific and stoichiometric modification of antibodies by bacterial transglutaminase,” Angew Chem Int Ed Engl 2010 49:9995–9997; and Dennler et al., “Transglutaminase-based chemo-enzymatic conjugation approach yields homogeneous antibody-drug conjugates,” Bioconjugate Chem 2014 25:569–578 the disclosure of which are incorporated herein by reference, in their entireties, for all purposes). An N297Q mutation prior to this conjugation provides two more reaction sites (DAR = 4). This method is quite advantageous in terms of practical ADC production as the glycosidase and transglutaminase directly modify and conjugate native mAbs with the payload, without the need for genetic engineering. An alternative version using a peptide sequence-specific transglutaminase can also be used (Strop et al., “Location matters: site of conjugation modulates stability and pharmacokineticsof antibody drug conjugates,” Chem Biol 2013 20:161–167). This enzyme recognizes and utilizes LLQG motif that is genetically incorporated, resulting in site-specific antibody-drug conjugation.

[0435] Accordingly, in some embodiments, the present disclosure provides pharmaceutical compositions comprising an antibody-drug conjugate (ADC) having the formula A-(L-P r)q, where: A is a 3E10 antibody or antigen-binding fragment thereof as described herein, L is a linker as described herein, P is a payload moiety as described herein, r is an integer from 1 to 4, and q is an integer from 1 to 16, in which L is conjugated to A through glutamine moieties.

[0436] Accordingly, in some embodiments, a composition comprising an ADC where glutamine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein will have an average DAR of about 2. In some embodiments, such a composition will have an average DAR of at least 2. In some embodiments, such a composition will have an average DAR of at least 3. In some embodiments, such a composition will have an average DAR of about 4. In some embodiments, such a composition will have an average DAR of about 2, at least 2, at least 3, or about 4.

[0437] Accordingly, in some embodiments, a composition comprising an ADC where glutamine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, r is 1 and q is about 2. In some embodiments, r is 1 and q is at least 2. In some embodiments, r is 1 and q is at least 3. In some embodiments, r is 1 and q is about 4. In some embodiments, r is 1 and q is about 2, at least 2, at least 3, or about 4. In some embodiments, a composition comprising an ADC where glutamine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, r is 2 (e.g., the linker is a branched linker) and q is about 2. In some embodiments, r is 2 and q is at least 2. In some embodiments, r is 2 and q is at least 3. In some embodiments, r is 2 and q is about 4. In some embodiments, r is 2 and q is about 2, at least 2, at least 3, or about 4. In yet other embodiments, a composition comprising an ADC where cysteine attachment is used to conjugate the drug to the antibody or antigen binding fragment thereof as described herein, the linker is highly branched, e.g., r is at least 3. In some embodiments, r is at least 4. In some embodiments, r is at least 5, 6, 7, 8, or more. 2. Linkers

[0438] In embodiments, the linker is a cleavable linker. As used herein, “cleavable linker” refers to a linker which can connect two or more molecules and then be cleaved once exposed to an agent. Cleavable linkers can include chemically or enzymatically unstable or degradable linkages. Cleavable linkers generally rely on processes inside the cell to liberate the drug, such asreduction in the cytoplasm, exposure to acidic conditions in the lysosome, or cleavage by specific proteases or other enzymes within the cell. Cleavable linkers generally incorporate one or more chemical bonds that are either chemically or enzymatically cleavable while the remainder of the linker is non-cleavable.

[0439] In some embodiments, the linker L comprises:. a. Cathepsin-cleavable linkers

[0440] In some embodiments of the ADCs described herein, the linker moiety is conjugated to the antibody or antigen binding fragment therein through a cathepsin-cleavable linker.

[0441] ADCs can enter cells via receptor-mediated endocytosis, during intracellular transit or trafficking, and thus they may ultimately encounter the acidic degradative environment of the lysosome which contains multiple proteases and other catalytic enzymes for breakdown of internalized biologic substances. Most often, cleavable linkers therefore leverage an attribute of the lysosome for payload release such as lability to low pH environment, disulfide reducing environment, or cleavage by a lysosomal protease such as cathepsin B. Protease cleavable linkers or (peptide linkers) typically contain a dipeptide sequence based on deduced canonical cleavage specificity for a given protease. Common dipeptide sequences are Valine-Citrulline or Valine- Alanine. These linkers have been used frequently for conjugation of both ADCs and AOCs.

[0442] Upon release via linker cleavage, the payloads then require escape from the endosome to traffic to the specific subcellular region in order to mediate an effect: ADCs: e.g. cell killing agents (cytosol - tubulin inhibitors such as auristatin or maytansine; or nuclear – direct or indirect DNA damaging agents such as duocarmycin or topoisomerase inhibitors).

[0443] 3E10 and its derivatives, including the humanized V66 IgG1κ, are anti-DNA antibodies with the unique property of direct cell entry and subsequent trafficking to the nucleus of cells. This occurs via interaction of antibody:DNA complexes with the cell surface transporter ENT2 (equilibrative nucleoside transporter-2) and so does require the classical endocytic mechanism employing clathrin or dynamin mediated internalization. Further, upon internalization, theantibody does not encounter early or late endosomes and, importantly, does not encounter the harsh environment of the lysosome. As a result, trafficking occurs directly to the nucleus. As such, 3E10 and its derivatives can serve as delivery vehicles for therapeutic payloads that are mechanistically active within the nucleus of target cells.

[0444] A challenge for generating an effective ADC with 3E10 or a derivative (e.g. V66) is that without encountering the lysosome and its acidic environment and battery of degradative enzymes, it is not clear what enzymes the conjugate may encounter en route or within the nucleus to deliver its cargo. In embodiments, an ADC described herein comprises a cleavable linker for which the catalytic agent is present within the within the nucleus for selective release within that organelle.

[0445] It has been found that the cysteine protease Cathepsin-L can also be present within the nucleus of cells. See, e.g., Goulet et al., “Increased expression and activity of nuclear cathepsin-L in cancer cells suggests a novel mechanism of cell transformation,” Mol Cancer Res. 2007 Sep;5(9):899-907, incorporated herein by reference in its entirety. This ubiquitous protease has previously been shown to be present primarily in lysosomes as well as in secreted form. Translation initiation within the cathepsin-L mRNA for both mouse and human cells has been shown to take place at alternative internal start sites resulting in a polypeptide lacking an NH2-terminal signal peptide. Other cathepsins typically identified in lysosomes have also been identified in the nucleus, including cathepsin-D, cathepsin-V, and cathepsin-B.

[0446] A literature review identified the existence of a nuclear form of the cysteine protease cathepsin-L in mouse tumor cells (and also in human tumor cells) (Goulet et al., “Increased expression and activity of nuclear cathepsin-L in cancer cells suggests a novel mechanism of cell transformation,” Mol Cancer Res. 2007 Sep;5(9):899-907; and Soond et al., “Lost or Forgotten: The nuclear cathepsin protein isoforms in cancer,” Cancer Lett. 2019 Oct 10;462:43-50, each incorporated herein by reference in their entireties. Indeed there have been identified several proteases ident...

Claims

CLAIMS 1. A conjugate of Formula (I): A-(L-Pr)qFormula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63; L is a linker comprising -XAA-, wherein -XAA- is a cathepsin cleavable amino acid sequence comprising 1 to 6 amino acid moieties; P is a topoisomerase I inhibitor; r is an integer from 1 to 4; and q is an integer from 1 to 16.

2. A conjugate of Formula (I): A-(L-Pr)q Formula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63; L is a linker comprising -XAA-, wherein -XAA- is a cathepsin cleavable amino acid sequence comprising 1 to 6 amino acid moieties; P is exatecan; r is an integer from 1 to 4; and q is an integer from 1 to 16.

3. The conjugate of claim 1 or 2, wherein -XAA- comprises a dipeptide selected from Val-Ala, Val-Cit, Phe-Gln, Val-Gln, Leu-Gln, Tyr-Met, Phe-Arg, Phe-Gly, Trp-Thr, Tyr-Gly, Phe-Thr, and Val-Gly.

4. The conjugate of claim 1 or 2, wherein -XAA- comprises a Val-Ala dipeptide.

5. The conjugate of claim 1 or 2, wherein -XAA- comprises a Val-Cit dipeptide.

6. The conjugate of any one of claims 1 to 5, wherein the linker L is of Formula (L-1):Formula (L-1), wherein in Formula (L-1): LA is a connecting moiety through which A is covalently attached to L′; L′ comprises the -XAA-; and LPis a connecting moiety through which P is covalently attached to L′.

7. The conjugate of any one of claims 1 to 6, wherein the linker L is of Formula (L-10):Formula (L-10), wherein in Formula (L-10): LAis selected from a bond, -NRa′-, and -S-; L1is a bond or comprises one or more groups selected from optionally substituted C1-C18 alkylene, -C≡C-, -CRa═CRa-, optionally substituted 6- to 14-membered arylene, optionally substituted C3-C20 cycloalkylene, -[CH2O]1-18-, -[CH2CH2O]1-18-, -[CH2CH2CH2O]1-18-, optionally substituted 5- to 18-membered heteroarylene, optionally substituted 3- to 20-membered heterocycloalkylene, -NRa-, -N═CRa-, -CRa═N-, -S-, -OP(O)ORaO-, -O-, -CRb2-, -C(O)-, -C(O)O-, -OC(O)-, -C(O)S-, -SC(O)-, -C(O)NRa-, -NRaC(O)-, -OC(O)O-, -OC(O)S-, -SC(O)O-, -OC(O)NRa-, -NRaC(O)O-, -SC(O)NRa-, -NRaC(O)S-, and -XAA1-; LCcomprises the -XAA-; L2is a bond or comprises one or more groups selected from optionally substituted C1-C18alkylene, -C≡C-, -CRa═CRa-, optionally substituted 6- to 14-membered arylene, optionally substituted C3-C20 cycloalkylene, -[CH2O]1-18-, -[CH2CH2O]1-18-, -[CH2CH2CH2O]1-18-, optionally substituted 5- to 18-membered heteroarylene, optionally substituted 3- to 20-membered heterocycloalkylene, -NRa-, -N═CRa-, -CRa═N-, -S-, -OP(O)ORaO-, -O-, -CRb2-, -C(O)-, -C(O)O-,-OC(O)-, -C(O)S-, -SC(O)-, -C(O)NRa-, -NRaC(O)-, -OC(O)O-, -OC(O)S-, -SC(O)O-, -OC(O)NRa-, -NRaC(O)O-, -SC(O)NRa-, -NRaC(O)S-, and -XAA1-; LPis selected from a bond, -NRa′-, -S-, and -O-; each Rais independently selected at each occurrence from hydrogen, optionally substituted alkyl, optionally substituted fluoroalkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroalkyl, optionally substituted heterocycloalkyl, optionally substituted heterocycloalkylalkyl, optionally substituted heteroaryl, and optionally substituted heteroarylalkyl; each Ra′is independently selected at each occurrence from hydrogen, optionally substituted alkyl, and optionally substituted heteroalkyl; each Rbis independently selected at each occurrence from hydrogen, halide, -OH, -SO3H, -OPO3H2, -PO3H2, -C(O)NRa2, -CO2Ra, -NRa2, optionally substituted alkyl, optionally substituted fluoroalkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroalkyl, optionally substituted heterocycloalkyl, optionally substituted heterocycloalkylalkyl, optionally substituted heteroaryl, and optionally substituted heteroarylalkyl; or two independent Rbgroups are taken together to form optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heterocycloalkyl, or optionally substituted heteroaryl; and -XAA1- is an amino acid sequence comprising 1 to 4 amino acid moieties.

8. The conjugate of any one of claims 1-7, wherein the cathepsin cleavable linker is conjugated to a lysine of the antibody or antigen-binding fragment thereof.

9. The conjugate of any one of claims 1-7, wherein the cathepsin cleavable linker is conjugated to a cysteine of the antibody or antigen-binding fragment thereof.

10. The conjugate of any one of claims 1-7, wherein the cathepsin cleavable linker is conjugated to a histidine of the antibody or antigen-binding fragment thereof.

11. The conjugate of any one of claims 1-7, wherein the cathepsin cleavable linker is conjugated to an arginine of the antibody or antigen-binding fragment thereof.

12. The conjugate of any one of claims 1-7, wherein the cathepsin cleavable linker is conjugated to an aspartic acid of the antibody or antigen-binding fragment thereof.

13. The conjugate of any one of claims 1-7, wherein the cathepsin cleavable linker is conjugated to a glutamine of the antibody or antigen-binding fragment thereof.

14. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) of at least 4:

1.

15. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) of at least 6:

1.

16. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) of at least 7:

1.

17. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) of at least 8:

1.

18. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) between 2:1 and 12:

1.

19. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) between 4:1 and 12:

1.

20. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) between 6:1 and 12:

1.

21. The conjugate of any one of claims 1-13, wherein the conjugate has a drug to antibody ratio (DAR) between 6:1 and 10:

1.

22. The conjugate of any one of claims 1-21, wherein the linker is a branched linker attached to at least two copies of the payload P.

23. The conjugate of any one of claims 1-22, wherein L comprises the structure:.

24. The conjugate of any one of claims 1-22, wherein L comprises the structure:.

25. The conjugate of any one of claims 1-22, wherein (L-Pr) comprises the structure:.

26. The conjugate of any one of claims 1-22, wherein (L-Pr) comprises the structure:.

27. The conjugate of any one of claims 1-22, wherein (L-Pr) comprises the structure:.

28. The conjugate of any one of claims 1-22, wherein (L-Pr) comprises the structure:.

29. The conjugate of any one of claims 1-28, wherein the VL CDR1 comprises the amino acid sequence of SEQ ID NO:9, CDR2 comprises the amino acid sequence of SEQ ID NO:10, CDR3 comprises SEQ ID NO:11; and the VH CDR1 comprises the amino acid sequence of SEQ ID NO:15, CDR2 comprises the amino acid sequence of SEQ ID NO:4, CDR3 comprises the amino acid sequence of SEQ ID NO:

5.

30. The conjugate of any one of claims 1-28, wherein the VL CDR1 comprises the amino acid sequence of SEQ ID NO:29, CDR2 comprises the amino acid sequence of SEQ ID NO:10, CDR3 comprises SEQ ID NO:11; and the VH CDR1 comprises the amino acid sequence of SEQ ID NO:15, CDR2 comprises the amino acid sequence of SEQ ID NO:26, CDR3 comprises the amino acid sequence of SEQ ID NO:

5.

31. The conjugate of any one of claims 1-30, wherein the linker comprises a MC-VA-PAB linker.

32. A conjugate of Formula (I): A-(L-Pr)q Formula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a heavy chain variable region (VH) CDR1 comprising the amino acid sequence of SEQ ID NO:58, CDR2 comprising the amino acid sequence of SEQ ID NO:59, CDR3 comprising SEQ ID NO:60; and a light chain variable region (VL) CDR1 comprising the amino acid sequence of SEQ ID NO:61, CDR2 comprising the amino acid sequence of SEQ ID NO:62, CDR3 comprising the amino acid sequence of SEQ ID NO:63; L is a linker comprising MC-VA-PAB; P is exatecan; r is an integer from 1 to 4; andq is an integer from 1 to 16.

33. The conjugate of any one of claims 1-32, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises a light chain variable region (VL) comprising an amino acid sequence of SEQ ID NO:21 and a heavy chain variable region (VH) comprising an amino acid sequence of SEQ ID NO:

14.

34. The conjugate of any one of claims 1-32, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises a full length light chain (LC) comprising an amino acid sequence of SEQ ID NO:20 and a full length heavy chain (HC) comprising an amino acid sequence of SEQ ID NO:

13.

35. The conjugate of any one of claims 1-32, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-VL-H1 (SEQ ID NO:85), 3E10-VL-H2 (SEQ ID NO:86), 3E10-VL-H3 (SEQ ID NO:87), 3E10-VL-H4 (SEQ ID NO:88), 3E10-VL-H5 (SEQ ID NO:89), and 3E10-VL-H6 (SEQ ID NO:90); and a heavy chain variable domain (VH) comprising an amino acid sequence that is at least about 95% identical to an amino acid sequence selected from the group consisting of 3E10-VH-H1 (SEQ ID NO:64), 3E10-VH-H2 (SEQ ID NO:65), 3E10-VH-H3 (SEQ ID NO:66), 3E10-VH-H4 (SEQ ID NO:67), 3E10-VH-H5 (SEQ ID NO:68), 3E10-VH-H6 (SEQ ID NO:69), and 3E10-VH-H7 (SEQ ID NO:70).

36. The conjugate of any one of claims 1-32, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising an amino acid sequence selected from the group consisting of 3E10-VL-H1 (SEQ ID NO:85), 3E10-VL-H2 (SEQ ID NO:86), 3E10-VL-H3 (SEQ ID NO:87), 3E10-VL-H4 (SEQ ID NO:88), 3E10-VL-H5 (SEQ ID NO:89), and 3E10-VL-H6 (SEQ ID NO:90); and a heavy chain variable domain (VH) comprising an amino acid sequence selected from the group consisting of 3E10-VH-H1 (SEQ ID NO:64), 3E10-VH-H2 (SEQ ID NO:65), 3E10-VH-H3 (SEQ ID NO:66), 3E10-VH-H4 (SEQ ID NO:67), 3E10-VH-H5 (SEQ ID NO:68), 3E10-VH-H6 (SEQ ID NO:69), and 3E10-VH-H7 (SEQ ID NO:70).

37. The conjugate of any one of claims 1-32, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises a VL / VH pair selected from the group consisting of (a) VL1 (SEQ ID NO:85) and VH1 (SEQ ID NO:64), (b) VL1 (SEQ ID NO:85) andVH2 (SEQ ID NO:65), (c) VL1 (SEQ ID NO:85) and VH3 (SEQ ID NO:66), (d) VL1 (SEQ ID NO:85) and VH4 (SEQ ID NO:67), (e) VL2 (SEQ ID NO:86) and VH1 (SEQ ID NO:64), (f) VL2 (SEQ ID NO:86) and VH2 (SEQ ID NO:65), (g) VL2 (SEQ ID NO:86) and VH3 (SEQ ID NO:66), (h) VL2 (SEQ ID NO:86) and VH4 (SEQ ID NO:67), (i) VL3 (SEQ ID NO:87) and VH1 (SEQ ID NO:64), (j) VL3 (SEQ ID NO:87) and VH2 (SEQ ID NO:65), (k) VL3 (SEQ ID NO:87) and VH3 (SEQ ID NO:66), (l) VL3 (SEQ ID NO:87) and VH4 (SEQ ID NO:67), (m) VL4 (SEQ ID NO:88) and VH1 (SEQ ID NO:64), (n) VL4 (SEQ ID NO:88) and VH2 (SEQ ID NO:65), (o) VL4 (SEQ ID NO:88) and VH3 (SEQ ID NO:66), (p) VL4 (SEQ ID NO:88) and VH4 (SEQ ID NO:67), (q) VL5 (SEQ ID NO:89) and VH5 (SEQ ID NO:68), (r) VL5 (SEQ ID NO:89) and VH6 (SEQ ID NO:69), (s) VL6 (SEQ ID NO:90) and VH5 (SEQ ID NO:68), and (t) VL6 (SEQ ID NO:90) and VH6 (SEQ ID NO:69).

38. The conjugate of any one of claims 1-32, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising 3E10-VL-H6 (SEQ ID NO:90) and a heavy chain variable domain (VH) comprising 3E10-VH-H6 (SEQ ID NO:69).

39. A conjugate of Formula (I): A-(L-Pr)q Formula (I), wherein in Formula (I): A is an antibody or antigen-binding fragment thereof or cell-penetrating fragment thereof comprising a light chain variable domain (VL) comprising 3E10-VL-H6 (SEQ ID NO:90) and a heavy chain variable domain (VH) comprising 3E10-VH-H6 (SEQ ID NO:69). L is a linker comprising MC-VA-PAB; P is exatecan; r is an integer from 1 to 4; and q is an integer from 1 to 16.

40. The conjugate of any one of claims 1-39, wherein the antibody, antigen-binding fragment thereof or cell-penetrating fragment thereof comprises: a light chain variable domain (VL) comprising the amino acid sequence (DIQMTQSPSSLSASLGDRATITCRASKTVSTSSYSYMHWYQQKPGQPPKLLIKYASYLES GVPSRFSGSGSGTDFTLTISSLQPEDAATYYCQHSREFPWTFGGGTKVEIK) (SEQ ID NO:167) and a heavy chain variable domain (VH) comprising the amino acid sequence(EVQLVESGGGLVQPGGSLRLSCAASGFTFSNYGMHWVRQAPGKGLEWVSYISSGSSTIY YADSVKGRFTISRDNAKNSLYLQMNSLRAEDTAVYYCARRGLLLDYWGQGTTVTVSS) (SEQ ID NO:168).

41. A method for treating a subject in need thereof, the method comprising administering a therapeutically effective amount of a conjugate according to any one of claims 1-40 to the subject.

42. A method for treating cancer in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a conjugate according to any one of claims 1-40 to the subject.

43. The method of claim 42, wherein the cancer comprises tumor cells that express functional ENT2.

44. The method of claim 42 or 43, wherein the cancer is a carcinoma, a sarcoma, a blastoma, a papilloma, or an adenoma.

45. The method of claim any one of claims 42-44, wherein the cancer is metastatic cancer.

46. The method of any one of claims 42-45, wherein the cancer is selected from the group consisting of bladder cancer, blood cancer, brain cancer, breast cancer, bone cancer, cervical cancer, colorectal cancer, endocrine cancer, esophageal cancer, gastric cancer, head and neck cancer, hepatobiliary cancer, leukemia, lung cancer, lymphoma, melanoma, myeloma, ovarian cancer, pancreatic cancer, prostate cancer, renal cancer, thyroid cancer, and uterine cancer.

47. The method of claim 46, wherein the cancer is a skin cancer selected from the group consisting of basal cell carcinoma, squamous cell carcinoma, and melanoma.

48. The method of claim 47, wherein the cancer is melanoma.

49. The method of claim 42 or 43, wherein the cancer is ovarian cancer.

50. The method of claim 42 or 43, wherein the cancer is colorectal cancer.

51. The method of claim 42 or 43, wherein the cancer is breast cancer.

52. The method of any one of claims 42-51, wherein the cancer comprises a mutation in one or more genes associated with a DNA damage response pathway.

53. The method of claim 52, wherein the cancer comprises a mutation in BRCA1 and / or BRCA2.

54. The method of claim 53, wherein the cancer is triple negative breast cancer.

55. The method of claim 42 or 43, wherein the cancer is lung cancer.

56. The method of claim 42 or 43, wherein the cancer is non-small cell lung cancer (NSCLC).

57. The method of any one of claims 42 or 43, wherein the cancer is a cancer of the central nervous system.

58. The method of claim 57, wherein the cancer is a neuroepithelial brain or spinal tumor selected from the group consisting of a medulloblastoma, an astrocytic tumor, an oligodendroglial tumor, an oligoastrocytic tumor, an ependymal tumor, a choroid plexus tumor, a neuronal or mixed neuronal-glial tumor, a tumor of the pineal region, an embryonal tumor, or an otherwise uncategorized neuroepithelial tumor.

59. The method of claim 58, wherein the cancer is a medulloblastoma.

60. The method of any one of claims 42-59, wherein the subject is treated with radiation therapy before the conjugate is administered.

61. The method of claim 60, wherein the subject is treated with radiation therapy at least about 12 hours, at least about 24 hours, at least about 48 hours, at least about 72 hours, or at least about 96 hours before the conjugate is administered.

62. The method of claim 60 or 61, wherein treatment with the radiation therapy increases cellular uptake of the conjugate.

63. The method of any one of claims 41-62, wherein the administering is by parenteral administration.

64. The method of claim 63, wherein the parenteral administration is intramuscular administration, intravenous administration, or subcutaneous administration.

65. The method of any one of claims 41-62, wherein the conjugate can cross the blood-brain barrier.

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