Anti-CCR8 antibodies and uses thereof

Abstract

To provide antibodies or antigen-binding portions thereof that specifically bind human CCR8, polynucleotides and vectors encoding the same, and pharmaceutical compositions comprising the same.SOLUTION: Some aspects of the disclosure are directed to methods of treating a disease or condition comprising administering the anti-CCR8 antibody to a subject in need thereof. Certain aspects of the present disclosure are directed to antibodies or antigen-binding portions thereof that specifically bind one or more amino acids within the N-terminal extracellular domain of human CCR8.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This PCT application claims the benefit of U.S. Provisional Patent Application No. 62 / 957,758, filed January 6, 2020, U.S. Provisional Patent Application No. 62 / 985,152, filed March 4, 2020, and U.S. Provisional Patent Application No. 63 / 198,803, filed November 13, 2020, the contents of each of which are incorporated herein by reference in their entirety.

[0002] Sequence Listing Reference The contents of the electronically submitted Sequence Listing submitted with this application (Name: 4416_010PC03_Seqlisting_ST25, Size: 91,925 bytes; Created: January 4, 2021) are incorporated herein by reference in their entirety.

[0003] The present disclosure provides antibodies and antigen-binding portions thereof that specifically bind to human CCR8. [Background technology]

[0004] Immunotherapy has rapidly advanced and is a very promising treatment for various forms of cancer, with many successes achieved to date. However, some patients are limited by a lack of response to current immunotherapy, and others experience relapse after an initial response.

[0005] The human immune system contains checks and balances that act to prevent an overactive immune system from harming the body. Regulatory T cells (Tregs) play an important role in maintaining a functional immune system by suppressing immune responses. However, the ability of Tregs, and especially tumor-infiltrating Tregs, can block natural immune responses against tumors, blunting the immune response.

[0006] Due in part to the essential role of immune cells, it is extremely difficult to create therapies that specifically target Tregs, and more particularly tumor-infiltrating Tregs. Thus, there remains a need for therapies that can specifically target and inhibit the activity of Tregs in the tumor microenvironment. Summary of the Invention [Means for solving the problem]

[0007] Certain embodiments of the present disclosure relate to antibodies or antigen-binding portions thereof that specifically bind to one or more amino acids within the N-terminal extracellular domain of human CCR8. In some embodiments, the antibodies are capable of (a) enhancing immune responses to tumors, (b) reducing, depleting, or killing tumor-infiltrating regulatory T (Treg) cells, (c) inducing CCR8 internalization in tumor-infiltrating regulatory T (Treg) cells, (d) activating NK cells, (e) inducing NK cell-mediated killing of tumor-infiltrating regulatory T (Treg) cells, (f) binding to cynomolgus monkey (cyno) CCR8, and (g) having a K of 10 nM or less as measured by BIACORE™. D or (h) any combination thereof.

[0008] In some embodiments, the N-terminal extracellular domain of human CCR8 comprises the amino acid sequence set forth in SEQ ID NO: 172. In some embodiments, the antibody binds to at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 amino acids set forth in SEQ ID NO: 172. In some embodiments, the antibody binds to at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 consecutive amino acids set forth in SEQ ID NO: 172. In some embodiments, the antibody binds to an amino acid sequence selected from SEQ ID NOs: 180-200.

[0009] In some embodiments, the antibody further binds to cyno CCR8.

[0010] In some embodiments, the antibody has a K of 10 nM or less as measured by BIACORE™. D In some embodiments, the antibody binds to human CCR8 with a K of 1 nM or less as measured by BIACORE™. D It binds to human CCR8.

[0011] In some embodiments, the antibody induces antibody-dependent cellular cytotoxicity (ADCC) in a subject after administration of the anti-CCR8 antibody. In some embodiments, the ADCC comprises an EC50 of 1 μg / mL or less after administration of the antibody or antigen-binding portion thereof. In some embodiments, the ADCC comprises an EC50 of 0.1 μg / mL or less after administration of the antibody or antigen-binding portion thereof.

[0012] In some embodiments, the antibody is capable of inducing activation of NK cells. In some embodiments, the antibody is capable of inducing upregulation of 4-1BB, ICAM-1, or both 4-1BB and ICAM-1NK on the surface of NK cells. In some embodiments, the antibody is capable of inducing downregulation of CD16 on the surface of NK cells in a subject.

[0013] In some embodiments, the antibody is administered to a subject to detect tumor-infiltrating T reg In some embodiments, the antibody is capable of inducing NK cell-mediated killing of tumor-infiltrating T cells prior to administration. reg

[0033] The number of tumor-infiltrating T cells in the subject after administration of the antibody or antigen-binding portion thereof, relative to the number of T cells. reg In some embodiments, the tumor-infiltrating T cells are depleted. reg The number of tumor-infiltrating T cells before administration regIn some embodiments, the number of tumor-infiltrating T cells is depleted by at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, or at least about 50% compared to the number of tumor-infiltrating T cells. reg Induce internalization of CCR8 by cells.

[0014] In some embodiments, the antibody comprises a variable heavy chain (VH) comprising a VH complementarity determining region (CDR) 1, a VH CDR2, and a VH CDR3, wherein the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 47, 57, 67, 77, 87, 97, 107, 117, 127, 137, 147, 157, and 167.

[0015] In some embodiments, the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 46, 56, 66, 76, 86, 96, 106, 116, 126, 136, 146, 156, and 166.

[0016] In some embodiments, the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 105, 115, 125, 135, 145, 155, and 165.

[0017] In some embodiments, the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, and 170.

[0018] In some embodiments, the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 49, 59, 69, 79, 89, 99, 109, 119, 129, 139, 149, 159, and 169.

[0019] In some embodiments, the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 48, 58, 68, 78, 88, 98, 108, 118, 128, 138, 148, 158, and 168.

[0020] In some embodiments, the antibody does not bind to cyno CCR8.

[0021] In some embodiments, the antibody comprises a variable heavy chain (VH) comprising a VH complementarity determining region (CDR) 1, a VH CDR2, and a VH CDR3, wherein the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 47, 107, 117, 137, and 147.

[0022] In some embodiments, the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146.

[0023] In some embodiments, the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 45, 105, 115, 135, and 145.

[0024] In some embodiments, the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 50, 110, 120, 140, and 150.

[0025] In some embodiments, the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 49, 109, 119, 139, and 149.

[0026] In some embodiments, the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 48, 108, 118, 138, and 148.

[0027] In some embodiments, the antibody comprises: (a) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 45, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 46, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 47, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 48, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 49, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 50; (b) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; (c) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 115, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 116, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 117, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 118, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 119. (d) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 135, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 136, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 137, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 138, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 139, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 140, or (e) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150.CDR3, including

[0028] In some embodiments, the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 41, 101, 111, 131, and 141. In some embodiments, the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 42, 102, 112, 132, and 142.

[0029] In some embodiments, the antibody comprises (a) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 41 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 42; (b) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 101 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 102; (c) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 111 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 112; (d) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 131 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 132; or (e) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 141 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 142.

[0030] In some embodiments, the antibody binds to human CCR8 and cyno CCR8.

[0031] In some embodiments, the antibody comprises a variable heavy chain (VH) comprising a VH complementarity determining region (CDR) 1, a VH CDR2, and a VH CDR3, wherein the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167.

[0032] In some embodiments, the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166.

[0033] In some embodiments, the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165.

[0034] In some embodiments, the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170.

[0035] In some embodiments, the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169.

[0036] In some embodiments, the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168.

[0037] In some embodiments, the antibody comprises (a) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO:5, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO:6, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO:7, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO:8, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO:9, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO:10; (b) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO:15, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO:16, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO:17, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO:18, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO:19, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO:20; (c) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO:25, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO:26, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO:27, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO:28, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO:29, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO:30. (d) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 35, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 36, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 37, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 38, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 39, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 40; (e) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 55, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 56, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 57, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 58, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 59, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 60; (f) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 65(g) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 75, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 76, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 77, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 78, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 79, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 80; (h) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 85, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 86, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 87, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 88, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 89, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 90; (i) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 95 (j) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 125, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 126, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 127, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 128, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 129, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 130; (k) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 155, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 156a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157; a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 158; a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 159; and a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 160. CDR3, or (l) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 165, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 166, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 167, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 168, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 169, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 170. CDR3, including

[0038] In some embodiments, the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 1, 11, 21, 31, 51, 61, 71, 81, 91, 121, 151, and 161. In some embodiments, the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 2, 12, 22, 32, 52, 62, 72, 82, 92, 122, 152, and 162.

[0039] In some embodiments, the antibody comprises: (a) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 2; (b) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 11 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 12; (c) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 21 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 22; (d) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 31 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 32; (e) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 51 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 52; (f) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 61 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 62. (g) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 71 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 72; (h) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 81 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 82; (i) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 91 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 92; (j) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 121 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 122; (k) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 151 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 152; or (l) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 161 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 162.

[0040] In some embodiments, the antibody is a human antibody, a humanized antibody, or a chimeric antibody. In some embodiments, the antibody comprises a single-chain variable fragment (scFv) of an antibody.

[0041] In some embodiments, the antibody or antigen-binding portion thereof is defucosylated.

[0042] In some embodiments, the antibody is a bispecific antibody, a bispecific T cell-engaging antibody (BiTE), a multispecific antibody, a biparatopic antibody, an immunoconjugate, an antibody-drug conjugate, or any combination thereof.

[0043] Certain aspects of the present disclosure relate to bispecific antibodies comprising the antibodies or antigen-binding portions thereof disclosed herein.

[0044] Certain aspects of the present disclosure pertain to BiTEs comprising the antibodies or antigen-binding portions thereof disclosed herein.

[0045] Certain aspects of the present disclosure relate to multispecific antibodies comprising the antibodies or antigen-binding portions thereof disclosed herein.

[0046] Certain aspects of the present disclosure relate to biparatopic antibodies comprising the antibodies or antigen-binding portions thereof disclosed herein.

[0047] In some embodiments, the bispecific antibody, BiTE, multispecific antibody, or biparatopic antibody comprises a first VH domain comprising a first VH CDR1, a first VH CDR2, and a first VH CDR3; a first VL domain comprising a first VL CDR1, a first VL CDR2, and a first VL CDR3; a second VH domain comprising a second VH CDR1, a second VH CDR2, and a second VH CDR3; and a second VL domain comprising a second VL CDR1, a second VL CDR2, and a second VL CDR3, wherein (a) the first VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 45, 105, 115, 135, and 145, (b) the first VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146, and (c) the first VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146. CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 47, 107, 117, 137, and 147.

[0048] In some embodiments, (a) the first VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 48, 108, 118, 138, and 148, (b) the first VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 49, 109, 119, 139, and 149, and (c) the first VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 50, 110, 120, 140, and 150. In some embodiments, (a) the second VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165, (b) the second VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166, and (c) the second VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167. In some embodiments, (a) the second VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168; (b) the second VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169; and (c) the second VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170.

[0049] Certain aspects of the present disclosure relate to immunoconjugates comprising the antibodies or antigen-binding portions thereof disclosed herein. In some embodiments, the immunoconjugate is an antibody-drug conjugate.

[0050] Certain aspects of the present disclosure relate to chimeric antigen receptors (CARs) comprising the antibodies or antigen-binding portions thereof disclosed herein.

[0051] Certain aspects of the present disclosure relate to T cell receptors (TCRs) comprising the antibodies or antigen-binding portions thereof disclosed herein.

[0052] Certain aspects of the present disclosure relate to a nucleic acid molecule or set of nucleic acid molecules encoding an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, or a TCR disclosed herein.

[0053] Certain aspects of the present disclosure pertain to a vector or set of vectors comprising a nucleic acid molecule or set of nucleic acid molecules disclosed herein.

[0054] Certain aspects of the present disclosure relate to cells comprising a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, or a vector or set of vectors disclosed herein. In some embodiments, the cell is a host cell. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a T cell.

[0055] Certain aspects of the present disclosure relate to a pharmaceutical composition comprising an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, or a cell disclosed herein, and a pharmaceutically acceptable carrier.

[0056] Certain aspects of the present disclosure relate to a method of treating a tumor in a subject in need thereof, the method comprising administering to the subject an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein.

[0057] Certain aspects of the present disclosure relate to tumor-infiltrating regulatory T ("T reg") cells, the method comprising contacting Treg cells with an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein.

[0058] Certain embodiments of the present disclosure are directed to activating NK cells or tumor-infiltrating regulatory T ("T reg and a method for inducing NK cell-mediated killing of T reg including contacting a cell with an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein.

[0059] In some embodiments, the contacting occurs in vitro or ex vivo. In some embodiments, the contacting occurs in vivo.

[0060] In some embodiments, the antibody or antigen-binding portion thereof induces activation of NK cells. In some embodiments, the antibody or antigen-binding portion thereof induces upregulation of 4-1BB, ICAM-1, or both 4-1BB and ICAM-1 on the surface of NK cells.

[0061] In some embodiments, the antibody or antigen-binding portion thereof induces downregulation of CD16 on the surface of NK cells. In some embodiments, the antibody or antigen-binding portion thereof induces downregulation of CD16 on the surface of tumor-infiltrating T reg In some embodiments, the antibody or antigen-binding portion thereof induces NK cell-mediated killing of tumor-infiltrating T cells in the absence of the antibody or antigen-binding portion thereof. reg Compared with the number of tumor-infiltrating T cells, reg In some embodiments, the antibody or antigen-binding portion thereof depletes the number of tumor-infiltrating T cells in the absence of the antibody or antigen-binding portion thereof. reg at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, or at least about 50%, tumor-infiltrating T cells relative to the number of T cells reg In some embodiments, the antibody or antigen-binding portion thereof depletes the number of tumor-infiltrating T cells. reg Induce internalization of CCR8 by cells.

[0062] In some embodiments, the tumor is Kaposi's sarcoma, leukemia, acute lymphocytic leukemia, acute myeloid leukemia, myeloblastic promyelocytic myelomonocytic monocytic erythroleukemia, chronic leukemia, chronic myeloid (granulocytic) leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, primary central nervous system lymphoma, Burkitt's lymphoma and marginal zone B-cell lymphoma, polycythemia vera lymphoma, Hodgkin's disease, non-Hodgkin's disease, multiple myeloma, Waldenstrom's macroglobulinemia, Blood clots, heavy chain disease, solid tumors, sarcomas, and carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic osteosarcoma, osteosarcoma, chordoma, angiosarcoma, endothelioma, lymphangiosarcoma, lymphangioendothelioma, synovium, mesothelioma, Ewing's sarcoma, leiomyosarcoma, rhabdomyosarcoma, colon sarcoma, colorectal cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatocellular carcinoma (HCC), liver cancer, cholangiocarcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, uterine cancer, testicular tumor, lung cancer, small cell lung cancer, non-small cell lung cancer, bladder cancer, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma, nasopharyngeal carcinoma, esophageal cancer, basal cell carcinoma, biliary tract cancer, bladder cancer, bone cancer, brain and central nervous system (CNS) cancer, cervical cancer, choriocarcinoma, The tumor is selected from the group consisting of colorectal cancer, connective tissue cancer, digestive system cancer, endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer, intraepithelial neoplasia, kidney cancer, laryngeal cancer, liver cancer, lung cancer (small cell, large cell), melanoma, neuroblastoma; oral cancer (e.g., lip, tongue, mouth, and pharynx), ovarian cancer, pancreatic cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer; respiratory system cancer, sarcoma, skin cancer, gastric cancer, testicular cancer, thyroid cancer, uterine cancer, and urinary system cancer, or any combination thereof. In some embodiments, the tumor is refractory or recurrent. In some embodiments, the tumor is progressive, locally advanced, or metastatic.

[0063] In some embodiments, the method further comprises administering an additional anti-cancer agent. In some embodiments, the additional anti-cancer agent is selected from a small molecule, a polypeptide, radiation therapy, surgery, and a combination thereof. In some embodiments, the additional anti-cancer agent comprises chemotherapy. In some embodiments, the chemotherapy comprises platinum-based chemotherapy. In some embodiments, the additional anti-cancer agent comprises a PD-1 antagonist, a PD-L1 inhibitor, a TIM-3 inhibitor, a LAG-3 inhibitor, a TIGIT inhibitor, a CD112R inhibitor, a TAM inhibitor, a STING agonist, a 4-1BB agonist, a CCL22 inhibitor, an agent that induces NK cell activation, or a combination thereof. In some embodiments, the additional anti-cancer agent comprises a PD-1 antagonist. In some embodiments, the PD-1 antagonist is selected from the group consisting of PDR001, nivolumab, pembrolizumab, pidilizumab, MEDI0680, REGN2810, TSR-042, PF-06801591, and AMP-224. In some embodiments, the additional anti-cancer agent comprises a PD-L1 inhibitor. In some embodiments, the PD-L1 inhibitor is selected from the group consisting of FAZ053, atezolizumab, avelumab, durvalumab, and BMS-936559.In some embodiments, the additional anticancer agent is sunitinib (SUTENT®), cabozantinib (CABOMETYX®), axitinib (INLYTA®), lenvatinib (LENVIMA®), everolimus (AFINITOR®), bevacizumab (AVASTIN®), epacadostat, NKTR-214 (a CD-122 biased agonist), tivo Xanib (FOTIVDA®), abexinostat, ipilimumab (YERVOY®), tremelimumab, pazopanib (VOTRIENT®), sorafenib (NEXAVAR®), temsirolimus (TORISEL®), ramucirumab (CYRAMZA®), niraparib, savolitinib, borolinib (X-82), regorafenib (STIVARGO®), trademark), donafenib (multikinase inhibitor), camrelizumab (SHR-1210), pexastimodine devasilepvec (JX-594), ramucirumab (CYRAMZA®), apatinib (YN968D1), encapsulated doxorubicin (THERMODOX®), tivantinib (ARQ197), ADI-PEG20, binimetinib, apatinib mesylate, nintedanib, lirilumab, In some embodiments, the additional anticancer agent comprises an anti-cancer agent selected from the group consisting of volumab (OPDIVO®), pembrolizumab (KEYTRUDA®), atezolizumab (TECENTRIQ®), avelumab (BAVENCIO®), durvalumab (IMFIMZI®), cemiplimab-rwlc (LIBTAYO®), tislelizumab, spartalizumab, and any combination thereof. In some embodiments, the additional anti-cancer agent comprises a TIM-3 inhibitor. In some embodiments, the TIM-3 inhibitor is MGB453 or TSR-022. In some embodiments, the additional anti-cancer agent comprises a LAG-3 inhibitor. In some embodiments, the LAG-3 inhibitor is selected from the group consisting of LAG525, BMS-986016, and TSR-033. In some embodiments, the additional anti-cancer agent comprises a TIGIT inhibitor. In some embodiments, the additional anti-cancer agent comprises a CD112R inhibitor.In some embodiments, the additional anti-cancer agent comprises a TAM (Axl, Mer, Tyro) inhibitor. In some embodiments, the additional anti-cancer agent comprises a 4-1BB agonist. In some embodiments, the additional anti-cancer agent comprises a tyrosine kinase inhibitor (TKI). In some embodiments, the additional anti-cancer agent comprises an agent that induces NK cell activation, thereby enhancing ADCC activity. In some embodiments, the additional anti-cancer agent comprises a CCL2 inhibitor. In some embodiments, the additional anti-cancer agent comprises an agent that induces NK cell activation.

[0064] In some embodiments, the antibody or antigen-binding portion thereof is administered before the additional anti-cancer agent. In some embodiments, the antibody or antigen-binding portion thereof is administered after the additional anti-cancer agent. In some embodiments, the antibody or antigen-binding portion thereof and the additional anti-cancer agent are administered simultaneously.

[0065] Certain aspects of the present disclosure relate to methods of producing an antibody or antigen-binding portion thereof, the method comprising culturing a cell disclosed herein under appropriate conditions. In some embodiments, the method further comprises isolating the antibody or antigen-binding portion thereof.

[0066] In some embodiments, the antibody or antigen-binding portion thereof is defucosylated.

[0067] Certain aspects of the present disclosure relate to use of an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, a pharmaceutical composition disclosed herein for the manufacture of a medicament in treating a tumor in a subject in need thereof.

[0068] Certain embodiments of the present disclosure provide a method for treating tumor-infiltrating T reg The present invention relates to the use of an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein for the manufacture of a medicament for reducing, depleting, or killing a cell.

[0069] Certain aspects of the present disclosure provide a method for the treatment of NK cell activation or tumor-infiltrating T cells in a subject in need thereof. reg The present invention relates to the use of an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein for the manufacture of a medicament in inducing NK cell-mediated killing of a cell.

[0070] Certain aspects of the present disclosure relate to an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, a pharmaceutical composition disclosed herein, for use in a method of treating a tumor in a subject in need thereof.

[0071] Certain embodiments of the present disclosure provide a method for treating tumor-infiltrating T reg The present invention relates to an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein, for use in a method of reducing, depleting, or killing a cell.

[0072] Certain aspects of the present disclosure provide a method for the treatment of NK cell activation or tumor-infiltrating T cells in a subject in need thereof. regThe present invention relates to an antibody or antigen-binding portion thereof disclosed herein, a bispecific antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, an immunoconjugate disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule or set of nucleic acid molecules disclosed herein, a vector or set of vectors disclosed herein, a cell disclosed herein, or a pharmaceutical composition disclosed herein for use in a method of inducing NK cell-mediated killing of a cell. The present invention provides, for example, the following items. (Item 1) An antibody or antigen-binding portion thereof that specifically binds to one or more amino acids within the N-terminal extracellular domain of human CCR8. (Item 2) (a) enhancing the immune response against tumors; (b) reducing, depleting, or killing tumor-infiltrating regulatory T (“Treg”) cells; (c) inducing CCR8 internalization on tumor-infiltrating regulatory T (“Treg”) cells; (d) activating NK cells; (e) inducing NK cell-mediated killing of tumor-infiltrating regulatory T (“Treg”) cells; (f) binding to cynomolgus monkey (“cyno”) CCR8; (g) a K of 10 nM or less as measured by BIACORE™ D or (h) The antibody according to Item 1, which can perform any combination thereof. (Item 3) 3. The antibody or antigen-binding portion thereof according to item 1 or 2, wherein the N-terminal extracellular domain of human CCR8 comprises the amino acid sequence set forth in SEQ ID NO: 172. (Item 4) 4. The antibody or antigen-binding portion thereof according to any one of items 1 to 3, which binds to at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 amino acids set forth in SEQ ID NO: 172. (Item 5) 5. The antibody or antigen-binding portion thereof according to any one of items 1 to 4, wherein the antibody binds to at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 consecutive amino acids set forth in SEQ ID NO: 172. (Item 6) 7. The antibody or antigen-binding portion thereof according to any one of items 1 to 6, which binds to an amino acid sequence selected from SEQ ID NOs: 180 to 200. (Item 7) 8. The antibody or antigen-binding portion thereof according to any one of items 1 to 7, which further binds to cyno CCR8. (Item 8) K<10 nM as measured by BIACORE™ D 8. The antibody or antigen-binding portion thereof according to any one of items 1 to 7, which binds to human CCR8 at (Item 9) K<1 nM as measured by BIACORE™ D 9. The antibody or antigen-binding portion thereof according to any one of items 1 to 8, which binds to human CCR8 at (Item 10) 10. The antibody or antigen-binding portion thereof according to any one of items 1 to 9, which induces antibody-dependent cellular cytotoxicity (ADCC) in a subject after administration of the anti-CCR8 antibody. (Item 11) 11. The antibody or antigen-binding portion thereof of item 10, wherein the ADCC comprises an EC50 of 1 μg / mL or less after administration of the antibody or antigen-binding portion thereof. (Item 12) 12. The antibody or antigen-binding portion thereof of item 10 or 11, wherein the ADCC comprises an EC50 of 0.1 μg / mL or less after administration of the antibody or antigen-binding portion thereof. (Item 13) 13. The antibody or antigen-binding portion thereof according to any one of items 1 to 12, which is capable of inducing NK cell activation. (Item 14) 14. The antibody or antigen-binding portion thereof according to any one of items 1 to 13, which is capable of inducing upregulation of 4-1BB, ICAM-1, or both 4-1BB and ICAM-1 on the surface of NK cells. (Item 15) 15. The antibody or antigen-binding portion thereof according to any one of items 1 to 14, which is capable of inducing downregulation of CD16 on the surface of NK cells in the subject. (Item 16) Tumor-infiltrating T in the subject reg 16. The antibody or antigen-binding portion thereof of any one of items 1 to 15, which is capable of inducing NK cell-mediated killing of a cell. (Item 17) Pre-administration tumor-infiltrating T reg the number of tumor-infiltrating T cells in the subject after administration of the antibody or antigen-binding portion thereof, relative to the number of T cells. reg 17. The antibody or antigen-binding portion thereof according to any one of items 1 to 16, which induces a dramatic decrease in cell number. (Item 18) Tumor-invasive T reg The number of tumor-infiltrating T cells before administration reg 18. The antibody or antigen-binding portion thereof of item 17, wherein the number of cells is depleted by at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, or at least about 50% compared to the number of cells. (Item 19) Tumor-invasive T reg 19. The antibody or antigen-binding portion thereof according to any one of items 1 to 18, which induces internalization of CCR8 by a cell. (Item 20) 20. The antibody or antigen-binding portion thereof according to any one of Items 1 to 19, comprising a variable heavy chain (VH) comprising a VH complementarity-determining region (CDR) 1, a VH CDR2, and a VH CDR3, wherein the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 47, 57, 67, 77, 87, 97, 107, 117, 127, 137, 147, 157, and 167. (Item 21) 22. The antibody or antigen-binding portion thereof according to item 21, wherein the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 46, 56, 66, 76, 86, 96, 106, 116, 126, 136, 146, 156, and 166. (Item 22) 26. The antibody or antigen-binding portion thereof according to any one of Aspects 21 to 25, wherein the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 105, 115, 125, 135, 145, 155, and 165. (Item 23) 29. The antibody or antigen-binding portion thereof according to any one of Aspects 21 to 28, wherein the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, and 170. (Item 24) 32. The antibody or antigen-binding portion thereof according to any one of Aspects 21 to 31, wherein the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 49, 59, 69, 79, 89, 99, 109, 119, 129, 139, 149, 159, and 169. (Item 25) 35. The antibody or antigen-binding portion thereof according to any one of Aspects 21 to 34, wherein the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 48, 58, 68, 78, 88, 98, 108, 118, 128, 138, 148, 158, and 168. (Item 26) 26. The antibody or antigen-binding portion thereof according to any one of items 1 to 6 and 8 to 25, which does not bind to cyno CCR8. (Item 27) 27. The antibody according to item 26, comprising a variable heavy chain (VH) comprising a VH complementarity-determining region (CDR) 1, a VH CDR2, and a VH CDR3, wherein the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 47, 107, 117, 137, and 147. 2. The antibody or antigen-binding portion thereof described herein. (Item 28) 28. The antibody or antigen-binding portion thereof according to item 27, wherein the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146. (Item 29) 29. The antibody or antigen-binding portion thereof according to item 27 or 28, wherein the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 45, 105, 115, 135, and 145. (Item 30) 30. The antibody or antigen-binding portion thereof according to any one of Aspects 27 to 29, wherein the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 50, 110, 120, 140, and 150. (Item 31) 31. The antibody or antigen-binding portion thereof according to any one of Aspects 27 to 30, wherein the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 49, 109, 119, 139, and 149. (Item 32) 32. The antibody or antigen-binding portion thereof according to any one of Aspects 27 to 31, wherein the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 48, 108, 118, 138, and 148. (Item 33) (a) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 45, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 46, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 47, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 48, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 49, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 50; (b) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; (c) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 115, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 116, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 117, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 118, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 119, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 120; (d) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 135, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 136, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 137, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 138, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 139, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 140; (e) The antibody or antigen-binding portion thereof according to any one of Aspects 27 to 32, comprising a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150. (Item 34) The VH chains are set forth in SEQ ID NOs: 41, 101, 111, 131, and 141. 34. The antibody or antigen-binding portion thereof according to any one of items 27 to 33, comprising an amino acid sequence selected from the amino acid sequences: (Item 35) 35. The antibody or antigen-binding portion thereof according to any one of Aspects 27 to 34, wherein the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 42, 102, 112, 132, and 142. (Item 36) (a) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 41 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 42; (b) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 101 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 102; (c) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 111 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 112; (d) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 131, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 132; (e) The antibody or antigen-binding portion thereof according to any one of Aspects 27 to 35, comprising a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 141 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 142. (Item 37) 26. The antibody or antigen-binding portion thereof according to any one of items 1 to 6 and 8 to 25, which binds to human CCR8 and cyno CCR8. (Item 38) 38. The antibody or antigen-binding portion thereof according to Item 37, comprising a variable heavy chain (VH) comprising a VH complementarity-determining region (CDR) 1, a VH CDR2, and a VH CDR3, wherein the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167. (Item 39) 39. The antibody or antigen-binding portion thereof according to item 38, wherein the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166. (Item 40) 40. The antibody or antigen-binding portion thereof of item 38 or 39, wherein the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165. (Item 41) 42. The antibody or antigen-binding portion thereof according to any one of Items 38 to 40, wherein the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170. 42. The antibody or antigen-binding portion thereof according to any one of Aspects 38 to 41, wherein the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169. (Item 43) 43. The antibody or antigen-binding portion thereof according to any one of Aspects 38 to 42, wherein the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168. (Item 44) (a) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 5, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 6, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 7, VL CDR4 comprising the amino acid sequence set forth in SEQ ID NO: 8 DR1, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 9, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 10; (b) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 15, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 16, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 17, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 18, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 19, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 20; (c) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 25, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 26, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 27, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 28, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 29, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 30; (d) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 35, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 36, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 37, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 38, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 39, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 40; (e) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 55, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 56, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 57, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 58, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 59, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 60; (f) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 65, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 66, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 67, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 68, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 69, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 70; (g) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 75, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 76, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 77, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 78, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 79, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 80; (h) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 85, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 86, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 87, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 88, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 89, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 90; (i) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 95, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 96, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 97, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 98, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 99, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 100; (j) a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 125, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 126, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 127, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 128, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 129, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 130; (k) VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 155, VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 156, VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 157, and VH CDR4 comprising the amino acid sequence set forth in SEQ ID NO: 158. a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 159, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 160, (l) The antibody or antigen-binding portion thereof according to any one of Aspects 38 to 43, comprising a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 165, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 166, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 167, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 168, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 169, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 170. (Item 45) 45. The antibody or antigen-binding portion thereof according to any one of Aspects 38 to 44, wherein the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 1, 11, 21, 31, 51, 61, 71, 81, 91, 121, 151, and 161. (Item 46) 46. ​​The antibody or antigen-binding portion thereof according to any one of Aspects 37 to 45, wherein the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 2, 12, 22, 32, 52, 62, 72, 82, 92, 122, 152, and 162. (Item 47) (a) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 2; (b) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 11 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 12; (c) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 21 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 22; (d) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 31, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 32; (e) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 51 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 52; (f) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 61, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 62; (g) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 71, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 72; (h) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 81, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 82; (i) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 91, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 92; (j) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 121 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 122; (k) a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 151, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 152; (l) The antibody or antigen-binding portion thereof according to any one of Aspects 37 to 46, comprising a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 161 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 162. (Item 48) 48. The antibody or antigen-binding portion thereof according to any one of items 1 to 47, which is a human antibody, a humanized antibody, or a chimeric antibody. (Item 49) 49. The antibody or antigen-binding portion thereof according to any one of items 1 to 48, comprising a single-chain variable fragment (scFv) of the antibody. (Item 50) bispecific antibody, bispecific T cell-inducing antibody (BiTE), multispecific antibody, bipara 50. The antibody or antigen-binding portion thereof according to any one of items 1 to 49, which is a topical antibody, an immunoconjugate, an antibody-drug conjugate, or any combination thereof. (Item 51) 50. A bispecific antibody comprising the antibody or antigen-binding portion thereof according to any one of items 1 to 49. (Item 52) (Item 53) A BiTe comprising the antibody or antigen-binding portion thereof according to any one of Items 1 to 49. 50. A multispecific antibody comprising the antibody or antigen-binding portion thereof according to any one of items 1 to 49. (Item 54) 50. A biparatopic antibody comprising the antibody or antigen-binding portion thereof according to any one of items 1 to 49. (Item 55) a first VH domain comprising a first VH CDR1, a first VH CDR2, and a first VH CDR3; a first VL domain comprising a first VL CDR1, a first VL CDR2, and a first VL CDR3; a second VH domain comprising a second VH CDR1, a second VH CDR2, and a second VH CDR3; and a second VL domain comprising a second VL CDR1, a second VL CDR2, and a second VL CDR3, (a) the first VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 45, 105, 115, 135, and 145; (b) the first VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146; and (c) the first VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 47, 107, 117, 137, and 147; (Item 56) (a) the first VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 48, 108, 118, 138, and 148; (b) the first VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 49, 109, 119, 139, and 149; and (c) the first VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 50, 110, 120, 140, and 150; (Item 57) (a) the second VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165; (b) the second VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166; and (c) the second VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167. (Item 58) (a) the second VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168; (b) the second VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169; and (c) The biparatopic antibody according to any one of Aspects 55 to 57, wherein the second VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170. (Item 59) 50. An immune complex comprising the antibody or antigen-binding portion thereof according to any one of items 1 to 49. (Item 60) 60. The immunoconjugate of item 59, which is an antibody-drug conjugate. (Item 61) 50. A chimeric antigen receptor (CAR) comprising the antibody or antigen-binding portion thereof of any one of items 1 to 49. (Item 62) 50. A T cell receptor (TCR) comprising the antibody or antigen-binding portion thereof according to any one of items 1 to 49. (Item 63) A nucleic acid molecule or a set of nucleic acid molecules encoding the antibody or antigen-binding portion thereof according to any one of Items 1 to 50, the bispecific antibody according to Item 51, the BiTE according to Item 52, the multispecific antibody according to Item 53, the biparatopic antibody according to any one of Items 54 to 58, the immune complex according to Item 59 or 60, the CAR according to Item 61, or the TCR according to Item 62. (Item 64) 64. A vector or a set of vectors comprising the nucleic acid molecule or set of nucleic acid molecules according to item 63. (Item 65) A cell comprising the CAR of item 61, the TCR of item 62, the nucleic acid molecule or set of nucleic acid molecules of item 63, or the vector or set of vectors of item 64. (Item 66) 66. The cell of item 65, which is a host cell. (Item 67) 67. The cell of item 65 or 66, which is an immune cell. (Item 68) 68. The cell according to any one of items 65 to 67, which is a T cell. (Item 69) A pharmaceutical composition comprising the antibody or antigen-binding portion thereof according to any one of Items 1 to 50, the bispecific antibody according to Item 51, the BiTE according to Item 52, the multispecific antibody according to Item 53, the biparatopic antibody according to any one of Items 54 to 58, the immunoconjugate according to Item 59 or 60, the CAR according to Item 61, the TCR according to Item 62, the nucleic acid molecule or set of nucleic acid molecules according to Item 63, the vector or set of vectors according to Item 64, or the cell according to any one of Items 65 to 68, and a pharmaceutically acceptable carrier. (Item 70) A method for treating a tumor in a subject in need thereof, comprising the steps of: the antibody or antigen-binding portion thereof according to any one of items 1 to 50; the bispecific antibody according to item 51; the BiTE according to item 52; the multispecific antibody according to item 53; the biparatopic antibody according to any one of items 54 to 58; the immunoconjugate according to item 59 or 60; 62, the nucleic acid molecule or set of nucleic acid molecules according to Item 63, the vector or set of vectors according to Item 64, the cell according to any one of Items 65 to 68, or the pharmaceutical composition according to Item 69 to the subject. (Item 71) Tumor-invasive regulatory T (“T reg 68. A method for reducing, depleting, or killing Treg cells, the method comprising contacting Treg cells with the antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69. (Item 72) Activating NK cells or tumor-infiltrating regulatory T (T reg 1. A method for inducing NK cell-mediated killing of T reg 68. The method of claim 67, wherein the cell is contacted with the antibody or antigen-binding portion thereof according to any one of Items 1 to 50, the bispecific antibody according to any one of Items 1 to 50, the bispecific antibody according to Item 51, the BiTE according to Item 52, the multispecific antibody according to Item 53, the biparatopic antibody according to any one of Items 54 to 58, the immunoconjugate according to Item 59 or 60, the CAR according to Item 61, the TCR according to Item 62, the nucleic acid molecule or set of nucleic acid molecules according to Item 63, the vector or set of vectors according to Item 64, the cell according to any one of Items 65 to 68, or the pharmaceutical composition according to Item 69. (Item 73) 73. The method of item 71 or 72, wherein the contacting is carried out in vitro or ex vivo. (Item 74) 73. The method of claim 71 or 72, wherein the contacting is carried out in vivo. (Item 75) 75. The method of any one of items 70 to 74, wherein the antibody or antigen-binding portion thereof induces activation of NK cells. (Item 76) 76. The method of any one of items 70 to 75, wherein the antibody or antigen-binding portion thereof induces upregulation of 4-1BB, ICAM-1, or both 4-1BB and ICAM-1 on the surface of NK cells. (Item 77) 77. The method of any one of items 70 to 76, wherein the antibody or antigen-binding portion thereof induces downregulation of CD16 on the surface of NK cells. (Item 78) The antibody or antigen-binding portion thereof is reg 78. The method of any one of items 70 to 77, wherein the method induces NK cell-mediated killing of the cell. (Item 79) The antibody or antigen-binding portion thereof is a marker for tumor-infiltrating T cells in the absence of the antibody or antigen-binding portion thereof. reg Compared with the number of tumor-infiltrating T cells, reg 79. The method according to any one of items 70 to 78, wherein the number of cells is depleted. (Item 80) The antibody or antigen-binding portion thereof is a marker for tumor-infiltrating T cells in the absence of the antibody or antigen-binding portion thereof. reg At least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, or less compared to the number of cells at least about 40%, at least about 45%, or at least about 50% tumor-infiltrating T reg 80. The method according to any one of items 70 to 79, wherein the number of cells is depleted. (Item 81) The antibody or antigen-binding portion thereof is reg 81. The method of any one of items 70 to 80, which induces internalization of CCR8 by a cell. (Item 82) The tumors include Kaposi's sarcoma, leukemia, acute lymphocytic leukemia, acute myeloid leukemia, myeloblastic promyelocytic myelomonocytic monocytic erythroleukemia, chronic leukemia, chronic myeloid (granulocytic) leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, primary central nervous system lymphoma, Burkitt's lymphoma and marginal zone B-cell lymphoma, polycythemia vera lymphoma, Hodgkin's disease, non-Hodgkin's disease, multiple myeloma, Waldenstrom's macroglobulinemia, heavy chain disease, solid tumors, Sarcomas and carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic osteosarcoma, osteosarcoma, chordoma, angiosarcoma, endothelioma, lymphangiosarcoma, lymphangioendothelioma, synovium, mesothelioma, Ewing's sarcoma, leiomyosarcoma, rhabdomyosarcoma, colon sarcoma, colorectal cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatocellular carcinoma (HCC), liver carcinoma, cholangiocarcinoma, trophoblastic carcinoma Cancer, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, uterine cancer, testicular tumor, lung cancer, small cell lung cancer, non-small cell lung cancer, bladder cancer, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma, nasopharyngeal carcinoma, esophageal cancer, basal cell carcinoma, biliary tract cancer, bladder cancer, bone cancer, brain and central nervous system (CNS) cancer, cervical cancer, choriocarcinoma, colorectal cancer, connective tissue cancer, digestive system cancer, 82. The method according to any one of items 70 to 81, wherein the cancer is selected from the group consisting of endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer, intraepithelial neoplasia, kidney cancer, laryngeal cancer, liver cancer, lung cancer (small cell, large cell), melanoma, neuroblastoma; oral cancer (e.g., lip, tongue, mouth, and pharynx), ovarian cancer, pancreatic cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer; respiratory system cancer, sarcoma, skin cancer, gastric cancer, testicular cancer, thyroid cancer, uterine cancer, and urinary system cancer, or any combination thereof. (Item 83) 83. The method according to any one of items 70 to 82, wherein the tumor is refractory or recurrent. (Item 84) 84. The method of any one of items 70 to 83, wherein the tumor is progressive, locally progressive, or metastatic. (Item 85) 85. The method of any one of items 70 to 84, further comprising administering an additional anticancer agent. (Item 86) 86. The method of claim 85, wherein the additional anticancer agent is selected from a small molecule, a polypeptide, radiation therapy, surgery, and combinations thereof. (Item 87) 87. The method of item 85 or 86, wherein the additional anti-cancer agent comprises chemotherapy. (Item 88) 88. The method of item 87, wherein the chemotherapy comprises platinum-based chemotherapy. (Item 89) 89. The method of any one of items 85 to 88, wherein the additional anticancer agent comprises a PD-1 antagonist, a PD-L1 inhibitor, a TIM-3 inhibitor, a LAG-3 inhibitor, a TIGIT inhibitor, a CD112R inhibitor, a TAM inhibitor, a STING agonist, a 4-1BB agonist, a CCL22 inhibitor, an agent that induces NK cell activation, or a combination thereof. (Item 90) 90. The method of any one of items 85 to 89, wherein the additional anticancer agent comprises a PD-1 antagonist. (Item 91) 91. The method of item 90, wherein the PD-1 antagonist is selected from the group consisting of PDR001, nivolumab, pembrolizumab, pidilizumab, MEDI0680, REGN2810, TSR-042, PF-06801591, and AMP-224. (Item 92) 92. The method of any one of items 85 to 91, wherein the additional anticancer agent comprises a PD-L1 inhibitor. (Item 93) 93. The method of item 92, wherein the PD-L1 inhibitor is selected from the group consisting of FAZ053, atezolizumab, avelumab, durvalumab, and BMS-936559. (Item 94) The additional anti-cancer agent may be sunitinib (SUTENT®), cabozantinib (CABOMETYX®), axitinib (INLYTA®), lenvatinib (LENVIMA®), everolimus (AFINITOR®), bevacizumab (AVASTIN®), epacadostat, NKTR-214 (a CD-122 biased agonist), tivozanib (FOTIVDA®), or rituximab (rituximab). (Registered Trademark), abexinostat, ipilimumab (YERVOY®), tremelimumab, pazopanib (VOTRIENT®), sorafenib (NEXAVAR®), temsirolimus (TORISEL®), ramucirumab (CYRAMZA®), niraparib, savolitinib, borolinib (X-82), regorafenib (STIVARGO®), donafenib (multidrug-resistant enterobacter pylori), rifapril (RIP), rifapril (RIA ... kinase inhibitors), camrelizumab (SHR-1210), pexastimodin devasilepvec (JX-594), ramucirumab (CYRAMZA®), apatinib (YN968D1), encapsulated doxorubicin (THERMODOX®), tivantinib (ARQ197), ADI-PEG20, binimetinib, apatinib mesylate, nintedanib, lirilumab, nivolumab (OPDIVO®) 94. The method of any one of items 85 to 93, comprising an anticancer agent selected from the group consisting of pembrolizumab (KEYTRUDA®), atezolizumab (TECENTRIQ®), avelumab (BAVENCIO®), durvalumab (IMFIMZI®), cemiplimab-rwlc (LIBTAYO®), tislelizumab, spartalizumab, and any combination thereof. (Item 95) 95. The method of any one of items 85 to 94, wherein the additional anticancer agent comprises a TIM-3 inhibitor. (Item 96) Item 96. The method of item 95, wherein the TIM-3 inhibitor is MGB453 or TSR-022. (Item 97) 97. The method of any one of items 85 to 96, wherein the additional anticancer agent comprises a LAG-3 inhibitor. (Item 98) Item 98. The method of item 97, wherein the LAG-3 inhibitor is selected from the group consisting of LAG525, BMS-986016, and TSR-033. (Item 99) 99. The method of any one of items 85 to 98, wherein the additional anticancer agent comprises a TIGIT inhibitor. (Item 100) 99. The method of any one of items 85 to 99, wherein the additional anticancer agent comprises a CD112R inhibitor. (Item 101) 101. The method of any one of items 85 to 100, wherein the additional anticancer agent comprises a TAM (Axl, Mer, Tyro) inhibitor. (Item 102) 102. The method of any one of items 85 to 101, wherein the additional anticancer agent comprises a 4-1BB agonist. (Item 103) 103. The method of any one of items 85 to 102, wherein the additional anticancer agent comprises a tyrosine kinase inhibitor (TKI). (Item 104) 104. The method of any one of items 85 to 103, wherein the additional anticancer agent comprises a CCL2 inhibitor. (Item 105) 105. The method of any one of items 85 to 104, wherein the additional anticancer agent comprises an agent that induces NK cell activation. (Item 106) 106. The method of any one of items 85 to 105, wherein the antibody or antigen-binding portion thereof is administered before the additional anti-cancer agent. (Item 107) 106. The method of any one of items 85 to 105, wherein the antibody or antigen-binding portion thereof is administered after the additional anti-cancer agent. (Item 108) 106. The method of any one of items 85 to 105, wherein the antibody or antigen-binding portion thereof and the additional anti-cancer agent are administered simultaneously. (Item 109) 69. A method for producing an antibody or an antigen-binding portion thereof, the method comprising culturing under suitable conditions the cell according to any one of items 65 to 68. (Item 110) 110. The method of claim 109, further comprising isolating the antibody or antigen-binding portion thereof. (Item 111) 68. Use of the antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69 for the manufacture of a medicament for the treatment of a tumor in a subject in need thereof. (Item 112) Tumor-infiltrating T in subjects in need thereof reg 68. Use of the antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69 for the manufacture of a medicament for reducing, depleting, or killing a cell. (Item 113) Activating NK cells or tumor-infiltrating T cells in a subject in need thereof reg Any of items 1 to 50 for the manufacture of a medicament in inducing NK cell-mediated killing of cells. 68. Use of the antibody or antigen-binding portion thereof according to item 1, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69. (Item 114) 68. The antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69 for use in a method of treating a tumor in a subject in need thereof. (Item 115) Tumor-infiltrating T in subjects in need thereof reg 68. The antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69 for use in a method for reducing, depleting, or killing a cell. (Item 116) Activating NK cells or tumor-infiltrating T cells in a subject in need thereof reg 68. The antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody according to any one of items 1 to 50, the bispecific antibody according to item 51, the BiTE according to item 52, the multispecific antibody according to item 53, the biparatopic antibody according to any one of items 54 to 58, the immunoconjugate according to item 59 or 60, the CAR according to item 61, the TCR according to item 62, the nucleic acid molecule or set of nucleic acid molecules according to item 63, the vector or set of vectors according to item 64, the cell according to any one of items 65 to 68, or the pharmaceutical composition according to item 69 for use in a method for inducing NK cell-mediated killing of a cell. (Item 117) Item 62. The antibody or antigen-binding portion thereof according to any one of items 1 to 50, the bispecific antibody of item 51, the BiTE of item 52, the multispecific antibody of item 53, the biparatopic antibody of any one of items 54 to 58, the immune complex of item 59 or 60, the CAR of item 61, or the TCR of item 62, wherein the antibody or antigen-binding portion thereof is defucosylated. (Item 118) 111. The method of any one of items 70 to 110, wherein the antibody or antigen-binding portion thereof is defucosylated. [Brief explanation of the drawings]

[0073] [Figure 1A] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-1 antibodies. [Figure 1B] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-1 antibody. [Figure 1C]1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-1-1 antibodies. [Figure 1D] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-1-1 antibody. [Figure 1E] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-1-2 antibodies. [Figure 1F] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-1-2 antibody. [Figure 1G] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-1-3 antibodies. [Figure 1H] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-1-3 antibodies. [Figure 1I] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-1-4 antibodies. [Figure 1J] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-1-4 antibody. [Figure 1K] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-1-5 antibodies. [Figure 1L] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-1-5 antibody. [Figure 2A] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2 antibodies. [Figure 2B] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2 antibody. [Figure 2C] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-1 antibodies. [Figure 2D] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-1 antibody. [Figure 2E] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-2 antibodies. [Figure 2F] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-2 antibody. [Figure 2G] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-3 antibodies. [Figure 2H] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-3 antibody. [Figure 2I] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-4 antibodies. [Figure 2J] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-4 antibody. [Figure 2K] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-5 antibodies. [Figure 2L] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-5 antibody. [Figure 2M] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-6 antibodies. [Figure 2N] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-6 antibody. [Figure 2O] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-7 antibodies. [Figure 2P] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-7 antibody. [Figure 2Q] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-8 antibodies. [Figure 2R] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-8 antibody. [Figure 2S] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-9 antibodies. [Figure 2T] 1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-9 antibody. [Figure 2U] 1 is a graphical representation of binding to human CCR8 (HuCCR8-ECD-Fc) or cyno CCR8 (CyCCR8-ECD-Fc) as measured by fluorescence absorbance, showing binding of anti-CCR8-2-10 antibodies. [Figure 2V]1 is a graphical representation of a comparison of secondary antibody-mediated binding to 293T cells expressing human CCR8, cyno CCR8, human CCR2, mouse CCR8, and negative control 293T cells, showing binding of anti-CCR8-2-10 antibody. [Figure 3] (A) is a bar graph showing the cell surface affinity (KD) of the anti-CCR8-1 antibody for human CCR8, cyno CCR8, and various negative controls (amyloid precursor-like protein 2 (APLP2), alpha 1 antichymotrypsin (SERPINA3), solute carrier family 6 member 9 (SLC6A9), and phospholipid phosphatase 3 (PLPP3)). (B) is a bar graph showing the cell surface affinity (KD) of the anti-CCR8-2 antibody for human CCR8, cyno CCR8, and various negative controls (amyloid precursor-like protein 2 (APLP2), alpha 1 antichymotrypsin (SERPINA3), solute carrier family 6 member 9 (SLC6A9), and phospholipid phosphatase 3 (PLPP3)). [Figure 4] (A) is a graphical representation showing the binding of anti-CCR8-1 and anti-CCR8-2 antibodies to tumor-infiltrating leukocytes (TILs) isolated from breast and kidney tumor samples, indicated by squares and triangles, respectively. (B) is a graphical representation showing a comparison of the binding of isotype control, anti-CCR8-1, anti-CCR8-2, and positive control anti-CCR8 antibodies to regulatory T cells (Treg cells) isolated from renal cell carcinoma samples, as indicated. [Figure 5] As shown, this is a bar graph showing ADCC signaling in 293T cells forced to express human CCR8 or cynomolgus monkey (cyno) CCR8 after contact with anti-CCR8-1 and anti-CCR8-2 antibodies. [Figure 6](A) is a bar graph showing ADCC as evidenced by the percentage of 293T cells expressing human CCR8 that remained after contact with anti-CCR8-1 or anti-CCR8-2 antibodies in samples from two donors (D1 and D2), as shown. (B) is a bar graph showing ADCC as evidenced by the percentage of 293T cells expressing cyno CCR8 that remained after contact with anti-CCR8-1 or anti-CCR8-2 antibodies in samples from two donors (D1 and D2), as shown. [Figure 7] (A) is a line graph showing the percentage of dead target Raji cells expressing human CCR8 after contact with anti-CCR8-1 or anti-CCR8-2 antibodies, as indicated. (B) is a line graph showing the percentage of dead target Raji cells expressing empty vector (EV) after contact with anti-CCR8-1 or anti-CCR8-2 antibodies, as indicated. [Figure 8A] As shown, this is a line graph showing the percentage of 4-1BB+ / CD16- cells (NK cells) in cultures containing Raji cells that were forced to express CCR8 after contacting the cultures with anti-CCR8-1 or anti-CCR8-2 antibodies. [Figure 8B] 1 is a bar graph showing the number of Raji cells expressing the CCR8 surface target (black bars) after exposure to anti-CCR8-1 or anti-CCR8-2 antibodies compared to an isotype control. Control Raji cells not expressing the CCR8 surface target are shown in the right bar. [Figure 8C] 1 is a bar graph showing the level of 4-1BB expression (compared to isotype control) on CD3-NKp46+ NK cells in cultures containing Raji cells forced to express CCR8 (left bar). Control Raji cells not expressing the CCR8 surface target are shown in the right bar. [Figure 9] FIG. 1 is a graphical representation comparing the number (%) of FOXP3+ cells in total CD3+ / CD4+ TILs isolated from freshly resected human tumors and incubated with anti-CCR8-1 or anti-CCR8-2 antibodies, as shown. [Figure 10]1 is a bar graph showing the internalization of CCR8 in 293T cells forced to express human CCR8 or an empty vector. [Figure 11] 1 is a line graph showing the competitive binding of a monoclonal antibody that binds to human CCR8 (purchased from BIOLEGEND®, catalog number 360603) with anti-CCR8-1 or anti-CCR8-2 antibodies as measured by flow cytometry. [Figure 12A] As shown, this is a line graph showing ADCC activity versus antibody concentration in CD16VV Jurkat ADCC reporter cells after incubation with increasing concentrations of anti-CCR8-1 wild-type antibody, defucosylated anti-CCR8-1 antibody, anti-CCR8-2 wild-type antibody, defucosylated anti-CCR8-2 antibody, and an isotype control. [Figure 12B] As shown, this is a line graph showing ADCC activity versus antibody concentration in CD16FF Jurkat ADCC reporter cells after incubation with increasing concentrations of anti-CCR8-1 wild-type antibody, defucosylated anti-CCR8-1 antibody, anti-CCR8-2 wild-type antibody, defucosylated anti-CCR8-2 antibody, and an isotype control. [Figure 13A] Figure 1 is a graphical representation showing binding of anti-CCR8-1 antibody to tumor Tregs. Tregs in TILs isolated from tumors that are CD3+ / FoxP3+ were identified using flow cytometry. Anti-CCR8-1 antibody binding was measured in gated cells from kidney and breast tumors using an APC-conjugated secondary antibody. Figure 2 is a scatter plot showing antibody to positive control binding ratios for Tregs contacted with anti-CCR8-1 antibody, a positive control, and the secondary alone (negative control). [Figure 13B]Figure 1 is a graphical representation showing binding of anti-CCR8-1 antibody to tumor Tregs. Tregs in TILs isolated from tumors that are CD3+ / FoxP3+ were identified using flow cytometry. Anti-CCR8-1 antibody binding was measured in gated cells from kidney and breast tumors using an APC-conjugated secondary antibody. Two histogram traces are shown depicting APC-A staining for gated Tregs from human kidney tumors at frequencies normalized to the mode of the IgG1 isotype control (gray trace) or anti-CCR8-1 (black trace). [Figure 13C] Scatter plots showing the percentage of CD3+ TIL cells isolated from tumors incubated with allogeneic natural killer (NK) cells and contacted with a control antibody, an anti-CCR8-1 antibody, or a positive control antibody. For each antibody condition, the left group is the percentage of CD3+ cells that are FoxP3- cells (e.g., non-Tregs), and the right group is the normalized percentage of CD3+ cells that are FoxP3+ cells (e.g., Tregs). DETAILED DESCRIPTION OF THE INVENTION

[0074] Certain embodiments of the present disclosure relate to antibodies or antigen-binding portions thereof that specifically bind to CCR8 ("anti-CCR8 antibodies"). In certain embodiments, the anti-CCR8 antibodies specifically bind to the N-terminal extracellular domain of human CCR8. Other embodiments of the present disclosure relate to methods of treating a subject in need thereof, comprising administering an anti-CCR8 antibody disclosed herein.

[0075] I. Terminology In order that this disclosure may be more readily understood, certain terms are first defined. As used in this application, unless expressly stated otherwise herein, each of the following terms shall have the meaning set forth below. Additional definitions are also set forth throughout this specification.

[0076] It should be noted that the term "a" or "an" entity refers to one or more of that entity, for example, "a nucleotide sequence" is understood to refer to one or more nucleotide sequences. Thus, the terms "a" (or "an"), "one or more," and "at least one" may be used interchangeably herein.

[0077] Furthermore, "and / or," as used herein, should be construed as a separate disclosure of each of the two specified features or components, with or without the other. Thus, the term "and / or" used herein in phrases such as "A and / or B" is intended to encompass "A and B," "A or B," "A" (alone), and "B" (alone). Similarly, the term "and / or" used in phrases such as "A, B, and / or C" is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

[0078] The term "about" is used herein to mean approximately, roughly, roughly, or within a range. When the term "about" is used in conjunction with a numerical range, the term modifies that range by extending its boundaries above and below the numerical values ​​set forth. In general, the term "about" is used herein to modify a numerical value by plus or minus 10 percent (up or down) around the set forth value.

[0079] Whenever an embodiment is described herein using the word "comprising," it should be understood that other similar embodiments described using the terms "consisting of" and / or "consisting essentially of" are also provided.

[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. For example, the Concise Dictionary of Biomedicine and Molecular Biology, Juo, Pei-Show, 2nd ed., 2002, CRC Press, The Dictionary of Cell and Molecular Biology, 3rd ed., 1999, Academic Press, and the Oxford Dictionary of Biochemistry And Molecular Biology, Revised, 2000, Oxford University Press provide those of ordinary skill in the art with a general dictionary of many of the terms used in this disclosure.

[0081] Units, prefixes, and symbols are denoted in their International System of Units (SI) accepted format. Numerical ranges are inclusive of the numbers defining the range. Unless otherwise noted, nucleotide sequences are written left to right in 5' to 3' orientation. Amino acid sequences are written left to right in amino to carboxy orientation. The headings provided herein are not intended to limit the various aspects of the disclosure, which can be had by reference to the specification in its entirety. Accordingly, the terms defined immediately below are more fully defined by reference to the specification in its entirety.

[0082] As used herein, the term "amount" or "level" is used in the broadest sense and refers to the amount, concentration, or abundance of a substance (e.g., a metabolite, small molecule, protein, mRNA, marker). When referring to a metabolite or small molecule (e.g., a drug), the terms "amount," "level," and "concentration" are generally used interchangeably and generally refer to a detectable amount in a biological sample. An "elevated level" or "increased level" refers to an increase in the amount, concentration, or abundance of a substance in a sample compared to a control sample, such as one derived from one or more individuals not afflicted with a disease or disorder (e.g., cancer), or an internal control. In some embodiments, an elevated level of a substance (e.g., a drug) in a sample refers to an increase in the amount of the substance by about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% compared to the amount of the substance in a control sample, as measured by techniques known in the art (e.g., HPLC). A "reduced level" refers to a decrease in the amount, concentration, or abundance of a substance (e.g., a drug) in an individual compared to a control, such as one or more individuals not suffering from a disease or disorder (e.g., cancer), or an internal control. In some embodiments, a reduced level is a slight or undetectable amount, concentration, or abundance. In some embodiments, a reduced level of a substance (e.g., a drug) in a sample refers to a reduction in the amount of the substance of about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% compared to the amount of the substance in a control sample as measured by techniques known in the art (e.g., HPLC).

[0083] When referring to a protein, mRNA, or marker described herein, the terms "level of expression" or "expression level" are generally used interchangeably and generally refer to the detectable amount of a protein, mRNA, or marker in a biological sample. In some embodiments, the detectable amount or detectable level of a protein, mRNA, or marker is related to the likelihood of a response to an agent such as those described herein. "Expression" generally refers to the process by which the information contained within a gene is converted into structures present and operating within a cell (e.g., a protein marker such as PD-L1). Thus, as used herein, "expression" can refer to transcription into a polynucleotide, translation into a polypeptide, or even polynucleotide and / or polypeptide modifications (e.g., post-translational modifications of a polypeptide). Fragments of a transcribed polynucleotide, a translated polypeptide, or polynucleotide and / or polypeptide modifications (e.g., post-translational modifications of a polypeptide) shall also be considered expressed, regardless of whether they are derived from a transcript generated by alternative splicing or a degraded transcript, or from post-translational processing of a polypeptide, for example, by proteolysis. "Expressed genes" include genes that are transcribed into polynucleotides as mRNA and then translated into polypeptides, and also include genes that are transcribed into RNA but not translated into polypeptides (e.g., transfer RNA and ribosomal RNA). "Elevated expression," "elevated expression level," or "elevated level" refers to an increase in expression or an increase in the level of a substance in a sample compared to a control sample, e.g., one or more individuals not afflicted with a disease or disorder (e.g., cancer), or an internal control.In some embodiments, elevated expression of a substance (e.g., a protein marker such as PD-L1) in a sample refers to an increase in the amount of the substance of about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% compared to the amount of the substance in a control sample, as measured by techniques known in the art (e.g., FACS). "Decreased expression," "decreased expression level," or "decreased level" refers to a decrease in expression or a decrease in the level of a substance (e.g., a protein marker) in an individual compared to a control, e.g., one or more individuals not afflicted with a disease or disorder (e.g., cancer), or an internal control. In some embodiments, decreased expression refers to little or no expression. In some embodiments, decreased expression of a substance (e.g., a protein marker) in a sample refers to a decrease in the amount of the substance of about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% compared to the amount of the substance in a control sample as measured by techniques known in the art (e.g., FACS).

[0084] As used herein, the term "antagonist" refers to any molecule that partially or completely blocks, inhibits, or neutralizes the biological activity of a native polypeptide disclosed herein. Suitable antagonist molecules specifically include antagonist antibodies or antibody fragments, fragments or amino acid sequence variants of native polypeptides, peptides, or proteins. In some embodiments, inhibition in the presence of an antagonist is observed in a dose-dependent manner. In some embodiments, the measured signal (e.g., biological activity) is at least about 5%, at least about 10%, at least about 15%, 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 least about 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%, or at least about 100% lower than the signal measured using a negative control under comparable conditions. Also disclosed herein are methods for identifying antagonists suitable for use in the disclosed methods. For example, these methods include, but are not limited to, binding assays such as enzyme-linked immunosorbent assays (ELISAs), the ForteBio® system, radioimmunoassays (RIAs), Meso Scale Discovery assays (e.g., Meso Scale Discovery Electrochemiluminescence (MSD-ECL)), and bead-based Luminex® assays. These assays measure the ability of an antagonist to bind to a polypeptide of interest (e.g., a receptor or ligand) and thus indicate the ability of the antagonist to inhibit, neutralize, or block the activity of the polypeptide. The effectiveness of an antagonist, such as the ability of an antagonist to inhibit the function of a polypeptide or agonist, can also be measured using functional assays. For example, a functional assay may involve contacting a polypeptide with a candidate antagonist molecule and measuring a detectable change in one or more biological activities normally associated with the polypeptide.The potency of an antagonist is usually determined by its IC. 50 It is defined by the IC value (the concentration required to inhibit 50% of the agonist response). 50 The lower the value, the more potent the antagonist and the lower the concentration required to inhibit the maximal biological response.

[0085] As used herein, the term "anti-CCR8 antibody" refers to an antibody that specifically binds to CCR8. In some embodiments, the anti-CCR8 antibody inhibits CCR8 biological activity and / or downstream pathway(s) mediated by CCR8 signaling or other CCR8-mediated functions. Anti-CCR8 antibodies include antibodies that block, antagonize, inhibit, inhibit, or reduce CCR8 biological activity (e.g., ligand binding, activation of G protein signaling), including downstream pathways mediated by CCR8 signaling or function, such as, but not limited to, receptor binding and / or eliciting a cellular response to CCR8 or its metabolites (e.g., immunosuppression). In some embodiments, the anti-CCR8 antibody provided by the present disclosure binds to human CCR8 and inhibits, blocks, or inhibits binding of human CCR8 to a ligand (e.g., CCL1) or the interaction between CCR8 and a G protein. In some embodiments, the anti-CCR8 antibody inhibits, blocks, or inhibits binding of human CCR8 to CCL1. In some embodiments, the anti-CCR8 antibody inhibits, blocks, or inhibits the binding of human CCR8 to CCL8. In some embodiments, the anti-CCR8 antibody inhibits, blocks, or inhibits the binding of human CCR8 to CCL16. In some embodiments, the anti-CCR8 antibody inhibits, blocks, or inhibits the binding of human CCR8 to CCL18.

[0086] As used herein, the term "antibody" refers to a whole antibody comprising two light polypeptide chains and two heavy polypeptide chains. Whole antibodies include different antibody isotypes, such as IgM, IgG, IgA, IgD, and IgE antibodies. The term "antibody" includes polyclonal antibodies, monoclonal antibodies, chimeric or chimeric antibodies, humanized antibodies, primatized antibodies, deimmunized antibodies, and fully human antibodies. Antibodies may be produced in or derived from any of a variety of species, e.g., mammals, such as humans, non-human primates (e.g., orangutans, baboons, or chimpanzees), horses, cows, pigs, sheep, goats, dogs, cats, rabbits, guinea pigs, gerbils, hamsters, rats, and mice. Antibodies may be purified or recombinant. As used herein, the terms "antibody fragment," "antigen-binding fragment," or similar terms refer to a fragment of an antibody that retains the ability to bind to and inhibit the activity of a target antigen (e.g., CCR8). Such fragments include, for example, single-chain antibodies, single-chain Fv fragments (scFv), Fd fragments, Fab fragments, Fab' fragments, or F(ab')2 fragments. An scFv fragment is a single polypeptide chain that contains both the heavy and light chain variable regions of the antibody from which the scFv is derived. Additionally, intrabodies, minibodies, triabodies, and diabodies are included within the definition of antibody and are compatible for use in the methods described herein. See, e.g., Todorovska et al., (2001) J. Immunol. Methods 248(1):47-66; Hudson and Kortt, (1999) J. Immunol. Methods 231(1):177-189; Poljak, (1994) Structure 2(12):1121-1123; Rondon and Marasco, (1997) Annu. Rev. Microbiol. 51:257-283, the disclosures of each of which are incorporated herein by reference in their entireties.

[0087] As used herein, the term "antibody fragment" also includes single domain antibodies, such as, for example, camelized single domain antibodies. See, e.g., Muyldermans et al., (2001) Trends Biochem. Sci. 26:230-235; Nuttall et al., (2000) Curr. Pharm. Biotech. 1:253-263; Reichmann et al., (1999) J. Immunol. Meth. 231:25-38; PCT Application Publication Nos. WO 94 / 04678 and WO 94 / 25591; and U.S. Patent No. 6,005,079, all of which are incorporated herein by reference in their entireties. In some embodiments, the present disclosure provides single domain antibodies comprising two VH domains that have been modified to form a single domain antibody.

[0088] In some embodiments, the antigen-binding fragment comprises a variable region of a heavy chain polypeptide and a variable region of a light chain polypeptide. In some embodiments, the antigen-binding fragment described herein comprises the CDRs of the light chain polypeptide and the heavy chain polypeptide of the antibody.

[0089] As used herein, the term "bispecific" or "bifunctional antibody" refers to an artificial hybrid antibody having two different heavy / light chain pairs and two different binding sites. Bispecific antibodies can be produced by a variety of methods, including fusion of hybridomas or linking of Fab' fragments. See, e.g., Songsivilai & Lachmann, (1990) Clin. Exp. Immunol. 79:315-321; Kostelny See, e.g., et al., (1992) J. Immunol. 148:1547-1553.

[0090] Traditionally, recombinant production of bispecific antibodies is based on the coexpression of two immunoglobulin heavy / light chain pairs, where the two heavy / light chain pairs have different specificities (Milstein and Cuello, (1983) Nature 305:537-539). Antibody variable domains with the desired binding specificities (antibody-antigen combining sites) can be fused to immunoglobulin constant domain sequences. The heavy chain variable region fusion is preferably with an immunoglobulin heavy chain constant domain, comprising at least part of the hinge, CH2, and CH3 regions. For further details of exemplary currently known methods for generating bispecific antibodies, see, e.g., Suresh et al., (1986) Methods Enzymol. 121:210, PCT Publication No. WO 96 / 27011, Brennan et al., (1985) Science 229:81, Shalaby et al., J. Exp. Med. (1992) 175:217-225, Kostelny et al., (1992) J. Immunol. 148(5):1547-1553, Hollinger et al., (1993) Proc. Natl. Acad. Sci. USA 90:6444-6448, Gruber et al., (1994) J. Immunol. 152:5368, and Tutt et al. See, e.g., W. et al., (1991) J. Immunol. 147:60. Bispecific antibodies also include cross-linked or heteroconjugate antibodies. Heteroconjugate antibodies can be made using any convenient cross-linking method. Suitable cross-linking agents are well known in the art and are disclosed in U.S. Pat. No. 4,676,980, along with several cross-linking techniques.

[0091] Various techniques for producing and isolating bispecific antibody fragments directly from recombinant cell culture have also been described. For example, bispecific antibodies have been produced using leucine zippers. See, e.g., Kostelny et al. (1992) J Immunol 148(5):1547-1553. The leucine zipper peptides from Fos and Jun proteins can be linked to the Fab' portions of two different antibodies by gene fusion. Antibody homodimers are reduced at the hinge region to form monomers and then re-oxidized to form antibody heterodimers. This method can also be used to produce antibody homodimers. The "diabody" technology described in Hollinger et al. (1993) Proc Natl Acad Sci USA 90:6444-6448 provides an alternative mechanism for producing bispecific antibody fragments. The fragments comprise a heavy-chain variable domain (VH) connected to a light-chain variable domain (VL) by a linker that is too short to allow pairing between the two domains on the same chain. Thus, the VH and VL domains of one fragment are paired with the complementary VL and VH domains of another fragment, thereby forming two antigen-binding sites. Another strategy for generating bispecific antibody fragments using single-chain Fv (scFv) dimers has also been reported. See, for example, Gruber et al. (1994) J Immunol 152:5368. Alternatively, the antibody may be a "linear antibody," as described, for example, 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) that form a pair of antigen-binding regions. Linear antibodies may be bispecific or monospecific.

[0092] Antibodies with more than two valencies (eg, trispecific antibodies) are contemplated and are described, for example, in Tutt et al. (1991) J Immunol 147:60.

[0093] As used herein, the term "biparatopic" refers to an antibody that can bind to two epitopes on a single antigen, e.g., polypeptide, target. In some embodiments, a biparatopic antibody comprises a first antigen-binding region and a second antigen-binding region, wherein the first antigen-binding region binds to a first epitope and the second antigen-binding region binds to a second epitope on the same antigen.

[0094] The present disclosure also encompasses variant forms of multispecific antibodies, such as dual variable domain immunoglobulin (DVD-Ig) molecules, as described in Wu et al. (2007) Nat Biotechnol 25(11):1290-1297. DVD-Ig molecules are designed in which two different light chain variable domains (VL) from two different parent antibodies are linked in tandem, either directly or via a short linker using recombinant DNA techniques, followed by a light chain constant domain. Similarly, the heavy chain comprises two different heavy chain variable domains (VH) linked in tandem, followed by a constant domain CH1 and an Fc region. Methods for generating DVD-Ig molecules from two parent antibodies are further described, for example, in PCT Publication Nos. WO08 / 024188 and WO07 / 024715. In some embodiments, bispecific antibodies are tandem Fab immunoglobulins in which a light chain variable region with a second specificity is fused to the heavy chain variable region of a whole antibody. Such antibodies are described, for example, in International Patent Application Publication No. WO2015 / 103072.

[0095] As used herein, "cancer antigen" or "tumor antigen" refers to (i) tumor-specific antigens, (ii) tumor-associated antigens, (iii) cells expressing tumor-specific antigens, (iv) cells expressing tumor-associated antigens, (v) embryonic antigens on tumors, (vi) autologous tumor cells, (vii) tumor-specific membrane antigens, (viii) tumor-associated membrane antigens, (ix) growth factor receptors, (x) growth factor ligands, and (xi) any other type of antigen or antigen-presenting cell or substance associated with cancer.

[0096] As used herein, the term "cancer-specific immune response" refers to an immune response elicited by the presence of a tumor, cancer cells, or cancer antigen. In certain embodiments, the response includes proliferation of cancer antigen-specific lymphocytes. In certain embodiments, the response includes expression and upregulation of antibodies and T cell receptors, and the formation and release of lymphokines, chemokines, and cytokines. Both the innate and adaptive immune systems interact to initiate an antigen response against a tumor, cancer cells, or cancer antigen. In certain embodiments, the cancer-specific immune response is a T cell response.

[0097] The term "carcinoma" is art-recognized and refers to malignant tumors of epithelial or endocrine tissue, including respiratory, digestive, genitourinary, testicular, breast, prostate, endocrine, and melanoma. The anti-CCR8 antibodies described herein can be used to treat patients with, suspected of having, or at risk of developing any type of cancer, including renal or melanoma, or any viral disease. Exemplary cancer types include those formed from tissues of the cervix, lung, prostate, breast, head and neck, colon, and ovary. The term also includes carcinosarcomas, which include malignant tumors composed of carcinomatous and sarcomatous tissue. "Adenocarcinoma" refers to a carcinoma derived from glandular tissue or in which tumor cells form recognizable glandular structures.

[0098] As used herein, the term "CCR8" or "CC chemokine receptor type 8" refers to a G protein-coupled receptor. CCR8 is known to have at least four ligands: CCL1, CCL8, CCL16, and CCL18. CCL1 is thought to enhance human Treg cells by inducing CCR8, Foxp3, CD39, granzyme B, and IL-10 expression in a STAT3-dependent manner. See, e.g., Barsheshet et al., PNAS 114(23):6086-91 (June 6, 2017). CCR8 is primarily expressed on Treg cells and is also expressed on TH2 cells, monocytes, NK cells, and CD8 +It is expressed only slightly in a small fraction of cells. CCR8 is a transmembrane receptor with seven transmembrane domains, an extracellular N-terminal domain (SEQ ID NO: 172), and an intracellular C-terminal domain that interacts with G proteins. The amino acid sequence of human CCR8 (UniProt P51685, SEQ ID NO: 171) is shown in Table 1 below. [Table 1]

[0099] As used herein, the term "compete," when used in the context of antigen-binding proteins (e.g., immunoglobulins, antibodies, or antigen-binding fragments thereof) that compete for binding to the same epitope, refers to an interaction between antigen-binding proteins as measured by an assay (e.g., competitive binding assay, cross-blocking assay) in which a test antigen-binding protein (e.g., a test antibody) inhibits (e.g., reduces or blocks) specific binding of a reference antigen-binding protein (e.g., a reference antibody) to a common antigen (e.g., CCR8 or a fragment thereof).

[0100] A polypeptide or amino acid sequence from which a designed polypeptide or protein is "derived" refers to the origin of the polypeptide. Preferably, a polypeptide or amino acid sequence derived from a particular sequence has an amino acid sequence that is essentially identical to that sequence or a portion thereof, where the portion is composed of at least 10-20 amino acids, preferably at least 20-30 amino acids, more preferably at least 30-50 amino acids, or is otherwise identifiable to one of skill in the art as having that origin in the sequence. A polypeptide derived from another peptide may have one or more mutations, e.g., one or more amino acid residues substituted with another amino acid residue or one or more amino acid residues inserted or deleted, compared to the starting polypeptide.

[0101] Polypeptides may contain amino acid sequences that are not naturally occurring. Such variants necessarily have less than 100% sequence identity or similarity with the starting molecule. In certain embodiments, variants have an amino acid sequence that is about 75% to less than 100%, more preferably about 80% to less than 100%, more preferably about 85% to less than 100%, more preferably about 90% to less than 100% (e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%), and most preferably about 95% to less than 100% amino acid sequence identity or similarity to the amino acid sequence of the starting polypeptide, e.g., over the length of the variant molecule.

[0102] In certain embodiments, the antibodies of the present disclosure are encoded by nucleotide sequences that may be useful for many applications, such as cloning, gene therapy, protein expression and purification, mutagenesis, DNA vaccination of a host in need thereof, antibody generation for passive immunization, PCR, generation of primers and probes, etc.

[0103] Those skilled in the art will also understand that antibodies suitable for use in the methods disclosed herein can be modified to differ in sequence from the naturally occurring or native sequence from which they are derived while retaining the desired activity of the native sequence. For example, nucleotide or amino acid substitutions that result in conservative substitutions or changes at "non-essential" amino acid residues can be made. Mutations can be introduced by standard techniques, such as site-directed mutagenesis and PCR-mediated mutagenesis.

[0104] Antibodies suitable for use in the methods disclosed herein may contain conservative amino acid substitutions at one or more amino acid residues, e.g., essential or non-essential amino acid residues. A "conservative amino acid substitution" is one in which the amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art, including basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine), and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, non-essential amino acid residues in a binding polypeptide are preferably replaced with another amino acid residue from the same side chain family. In certain embodiments, a string of amino acids can be replaced with a structurally similar string of amino acids in a different order and / or with members of a side chain family. Alternatively, in certain embodiments, mutations can be introduced randomly along all or part of the coding sequence, e.g., by saturation mutagenesis, and the resulting mutants can be incorporated into a binding polypeptide of the invention and screened for their ability to bind to a desired target.

[0105] As used herein, the term "cross-reactivity" refers to the ability of an antibody of the present disclosure to bind to CCR8 from a different species. For example, an antibody of the present disclosure that binds to human CCR8 may also bind to CCR8 from another species. As used herein, cross-reactivity is measured by specific reactivity with purified antigen in a binding assay (e.g., SPR, ELISA), or by binding to cells that physiologically express CCR8, or by otherwise detecting functional interaction. Methods for determining cross-reactivity include standard binding assays such as those described herein by BIACORE™ surface plasmon resonance (SPR) analysis using, for example, a BIACORE™ 2000 SPR instrument (BIACORE AB, Uppsala, Sweden), or flow cytometry techniques.

[0106] As used herein, the term "cytotoxic T lymphocyte (CTL) response" refers to an immune response induced by cytotoxic T cells. CTL responses are primarily CD8 + Mediated by T cells.

[0107] As used herein, the term "EC 50 " refers to the concentration of an antibody or antigen-binding portion thereof that induces a response in an in vitro or in vivo assay and is the concentration that is 50% of the maximal response, i.e., the midpoint between the maximal response and baseline.

[0108] As used herein, the term "effective dose" or "effective dosage" is defined as an amount sufficient to achieve, or at least partially achieve, the desired effect. The term "therapeutically effective amount" is defined as an amount sufficient to treat or at least partially arrest the disease and its complications in a patient already suffering from the disease. Amounts effective for this use will depend on the severity of the disease being treated and the general state of the patient's own immune system.

[0109] As used herein, the term "epitope" or "antigenic determinant" refers to the site on an antigen to which an immunoglobulin or antibody specifically binds. The term "epitope mapping" refers to the process or method by which an antibody or antigen-binding fragment thereof recognizes a binding site or epitope on its target protein antigen. Epitope mapping methods and techniques are provided herein. Epitopes can be formed both from contiguous amino acids or non-contiguous amino acids juxtaposed by tertiary folding of a protein. Epitopes formed from contiguous amino acids are typically retained upon exposure to denaturing solvents, while epitopes formed by tertiary folding are typically lost upon treatment with denaturing solvents. Epitopes typically contain at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acids in a unique spatial conformation. Methods for determining which epitope a given antibody binds to (i.e., epitope mapping) are well known in the art and include, for example, immunoblotting and immunoprecipitation assays, in which overlapping or consecutive peptides from CCR8 are tested for reactivity with a given anti-CCR8 antibody. Methods for determining the spatial structure of an epitope include techniques in the art and described herein, such as X-ray crystallography and two-dimensional nuclear magnetic resonance (see, for example, Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66, GE Morris, Ed. (1996)).

[0110] The present disclosure also encompasses antibodies that bind to epitopes on CCR8 that include all or part of the epitopes recognized by the particular antibodies described herein (e.g., the same or overlapping regions, or regions between or spanning the regions).

[0111] The present disclosure also encompasses antibodies that bind to the same epitope as the antibodies described herein and / or that compete with the antibodies described herein for binding to human CCR8. Antibodies that recognize the same epitope or compete for binding can be identified using conventional techniques. Such techniques include, for example, immunoassays that show the ability of one antibody to block the binding of another antibody to a target antigen, i.e., competitive binding assays. Competitive binding is determined in an assay in which the immunoglobulin under test inhibits the specific binding of a reference antibody to a common antigen, such as CCR8. Many types of competitive binding assays are known, such as solid-phase direct or indirect radioimmunoassays (RIA), solid-phase direct or indirect enzyme immunoassays (EIA), sandwich competition assays (see Stahl et al., Methods in Enzymology 9:242 (1983)), solid-phase direct biotin-avidin EIA (see Kirkland et al., J. Immunol. 137:3614 (1986)), solid-phase direct label assays, solid-phase direct label sandwich assays (see Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Press (1988)), solid-phase direct label RIA using I-125 labels (see Morel et al., Mol. Immunol. 25(1):7 (1988)), solid-phase direct biotin-avidin EIA (see Cheung et al., Virology 176:546 (1990)), and direct-labeled RIA (Moldenhauer et al., Scand. J. Immunol. 32:77 (1990)). Typically, such assays involve the use of purified antigen bound to a solid surface, or cells bearing either of these, an unlabeled test immunoglobulin, and a labeled reference immunoglobulin. Competitive inhibition is measured by determining the amount of label bound to the solid surface or cells in the presence of the test immunoglobulin. The test immunoglobulin is usually present in excess.Typically, when a competing antibody is present in excess, it inhibits specific binding of a reference antibody to a common antigen by at least 50-55%, 55-60%, 60-65%, 65-70%, 70-75% or more.

[0112] Other techniques include epitope mapping methods, such as X-ray analysis of crystals of antigen-antibody complexes, which provide atomic-resolution observation of epitopes, and mass spectrometry combined with hydrogen / deuterium (H / D) exchange, which allows for the study of the structure and dynamics of antigen-antibody interactions. Other methods monitor antibody binding to antigen fragments or mutants, where loss of binding due to modification of amino acid residues in the antigen sequence is often considered an indication of epitope components. Additionally, computational combinatorial methods are sometimes used for epitope mapping. These methods rely on the ability of a given antibody to affinity isolate specific short peptides from combinatorial phage-displayed peptide libraries. Furthermore, the peptides are considered to guide the definition of the epitope corresponding to the antibody used to screen the peptide library. For epitope mapping, computational algorithms have been developed that have been shown to map structurally discontinuous epitopes.

[0113] As used herein, the term "Fc-mediated effector function" or "Fc effector function" refers to a biological activity of an antibody other than the primary function and target of the antibody. For example, a therapeutic-agnostic antibody effector function is a biological activity other than activation of a target protein or pathway. Examples of antibody effector functions include C1q binding and complement-dependent cytotoxicity, Fc receptor binding, antibody-dependent cell-mediated cytotoxicity (ADCC), phagocytosis, downregulation of cell surface receptors (e.g., B cell receptors), loss of activation of platelets expressing Fc receptors, and B cell activation. Many effector functions begin with Fc binding to an Fcγ receptor. In some embodiments, an antibody targeting a tumor antigen has an effector function, e.g., ADCC activity. In some embodiments, the antibody targeting a tumor antigen described herein comprises a variant constant region with enhanced effector function (e.g., enhanced ability to mediate ADCC) compared to the unmodified form of the constant region.

[0114] As used herein, the term "Fc receptor" refers to a polypeptide found on the surface of immune effector cells that is bound by the Fc region of an antibody. In some embodiments, the Fc receptor is an Fcγ receptor. There are three subclasses of Fcγ receptors: FcγRI (CD64), FcγRII (CD32), and FcγRIII (CD16). All four IgG isotypes (IgG1, IgG2, IgG3, and IgG4) bind to and activate the Fc receptors FcγRI, FcγRIIA, and FcγRIIIA. FcγRIIB is an inhibitory receptor, so antibodies that bind to this receptor do not activate complement and cellular responses. FcγRI is a high-affinity receptor that binds IgG in a monomeric form, while FcγRIIA and FcγRIIA are low-affinity receptors that bind only IgG in a multimeric form and with slightly lower affinity. Binding of antibodies to Fc receptors and / or C1q is controlled by specific residues or domains within the Fc region. Binding also depends on residues within the hinge region and CH2 portion of the antibody. In some embodiments, the antagonistic and / or therapeutic activity of the antibodies described herein depends on binding of the Fc region to an Fc receptor (e.g., FcγR). In some embodiments, the antagonistic and / or therapeutic activity of the antibodies described herein is enhanced by binding of the Fc region to an Fc receptor (e.g., FcγR).

[0115] As used herein, the term "human antibody" includes antibodies having variable and constant regions, if present, derived from human germline immunoglobulin sequences. The human antibodies of the present disclosure may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo) (see, e.g., Lonberg et al., (1994) Nature 368(6474):856-859; Lonberg, (1994) Handbook of Experimental Pharmacology 113:49-101; Lonberg & Huszar, (1995) Intern. Rev. Immunol. 13:65-93; and Harding & Lonberg, (1995) Ann. NY Acad. Sci. 764:536-546). However, the term "human antibody" does not include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences (eg, humanized antibodies).

[0116] As used herein, the term "humanized" refers to an antibody in which some, most, or all of the amino acids outside the CDR domains of a non-human antibody have been replaced with corresponding amino acids from a human immunoglobulin. In some embodiments of a humanized form of an antibody, some, most, or all of the amino acids outside the CDR domains have been replaced with amino acids from a human immunoglobulin, while some, most, or all of the amino acids within one or more CDR regions remain unchanged. Minor additions, deletions, insertions, substitutions, or modifications of amino acids are permissible as long as they do not abrogate the antibody's ability to bind to a specific antigen. A "humanized" antibody retains antigen specificity similar to that of the original antibody.

[0117] A "chimeric antibody" refers to an antibody whose variable region is derived from one species and whose constant region is derived from another species, e.g., an antibody whose variable region is derived from a murine antibody and whose constant region is derived from a human antibody.

[0118] As used herein, the term "heterologous antibody" is defined in relation to the transgenic non-human organism producing such an antibody. The term refers to an antibody having an amino acid sequence or encoding nucleic acid sequence that corresponds to that found in an organism other than the transgenic non-human animal and generally in a species other than the transgenic non-human animal.

[0119] The terms "inducing an immune response" and "enhancing an immune response" are used interchangeably and refer to the stimulation of an immune response (i.e., passive or adaptive) to a particular antigen. The term "inducing" when used in reference to inducing CDC or ADCC refers to the stimulation of a specific direct cell-killing mechanism.

[0120] As used herein, the term "immunogenic cell death" (also known as "immunogenic apoptosis") refers to a mode of cell death associated with the activation of one or more signaling pathways that induce the pre-death expression and release of tumor cell-derived damage-associated molecular pattern (DAMP) molecules (e.g., adenosine triphosphate, ATP), which enhances the immunogenicity of tumor cells and leads to the death of tumor cells in an immunogenic manner (e.g., by phagocytosis). As used herein, the term "immunogenic cell death-inducing agent" refers to a chemical, biological, or pharmacological agent that induces an immunogenic cell death process, pathway, or mode.

[0121] As used herein, the terms "inhibit," "reduce," or "block" (e.g., referring to the inhibition or reduction of human CCR8-mediated phosphorylation of STAT1 and / or STAT3 in cells) are used interchangeably and encompass both partial inhibition / blocking and complete inhibition / blocking. Inhibition / blocking of CCR8 reduces or alters the normal level or type of activity that occurs without inhibition or blocking. Inhibition and blocking are also intended to include any measurable reduction in the binding affinity of CCR8 when contacted with an anti-CCR8 antibody compared to CCR8 not contacted with the anti-CCR8 antibody, for example, inhibiting CCR8 binding by at least about 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100%.

[0122] As used herein, the term "inhibit growth" (e.g., referring to a tumor or cell, e.g., tumor cell) is intended to include any measurable reduction in tumor or cell growth, e.g., inhibiting tumor growth by at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, or 100%.

[0123] As used herein, a subject "in need of prevention," "in need of treatment," or "in need of" refers to one who, according to the judgment of an appropriate health care professional (e.g., in the case of a human, a physician, nurse, or nurse practitioner; in the case of a non-human mammal, a veterinarian), would reasonably benefit from a given treatment (e.g., treatment with a composition comprising an anti-CCR8 antibody).

[0124] The term "in vivo" refers to a process that occurs inside a living organism.

[0125] As used herein, the term "isolated antibody" is intended to refer to an antibody that is substantially free of other antibodies having different antigen specificities (e.g., an isolated antibody that specifically binds to human CCR8 is substantially free of antibodies that specifically bind to antigens other than CCR8). However, an isolated antibody that specifically binds to an epitope may have cross-reactivity to other CCR8 proteins from different species. However, the antibody continues to exhibit specific binding to human CCR8 in specific binding assays such as those described herein. In addition, an isolated antibody is typically substantially free of other cellular material and / or chemicals. In some embodiments, a combination of "isolated" antibodies with different CCR8 specificities is combined in a well-defined composition.

[0126] As used herein, the term "isolated nucleic acid molecule" refers to an antibody or antibody portion that binds to CCR8 (e.g., V H , V L , CDR3) of the heavy chain (V) of the anti-CCR8 antibody monoclonal antibody described herein, and is intended to refer to a nucleic acid molecule in which the nucleotide sequence encoding the antibody or antibody portion does not include other nucleotide sequences encoding antibodies or antibody portions that bind to antigens other than CCR8, and other sequences may naturally flank the nucleic acid in human genomic DNA. For example, a sequence selected from the sequences set forth in Table 8 may be selected from the heavy chain (V) of the anti-CCR8 antibody monoclonal antibody described herein. H ) and light chain (V L ) corresponds to a nucleotide sequence containing the variable region.

[0127] As used herein, "isotype" refers to the antibody class (e.g., IgM or IgGI) encoded by the heavy chain constant region genes. In some embodiments, the human monoclonal antibodies of this disclosure are of the IgG1 isotype. In some embodiments, the human monoclonal antibodies of this disclosure are of the IgG2 isotype. In some embodiments, the human monoclonal antibodies of this disclosure are of the IgG3 isotype. In some embodiments, the human monoclonal antibodies of this disclosure are of the IgG4 isotype. As will be apparent to one of skill in the art, identifying antibody isotypes (e.g., IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE) is routine in the art and generally involves a combination of sequence alignments with known antibodies, published Fc variant sequences, and conserved sequences.

[0128] As used herein, the terms "KD" or "K D " refers to the equilibrium dissociation constant of the binding reaction between an antibody and an antigen. D The value of K is the ratio between the dissociation rate constant (kd) of an antibody and the association rate constant (ka) of an antibody. D The value of K is inversely related to the binding affinity of the antibody to the antigen. D The smaller the value, the higher the affinity of the antibody for its antigen. Affinity is the strength of binding of a single molecule to its ligand and is usually measured using the equilibrium dissociation constant (K) used to assess and rank the strength of two-molecule interactions. D ) is measured and recorded.

[0129] As used herein, the terms "kd" or "k d (or "koff" or "k off ") is intended to refer to the dissociation rate constant for dissociation of an antibody from the antibody / antigen complex. d The value of is a numerical representation of the rate at which the complex disintegrates or dissociates per second, and is expressed in units of seconds. -1 It is expressed as:

[0130] As used herein, the terms "ka" or "k a (or "kon" or "k on " is intended to refer to the association rate constant for binding of an antibody to an antigen. The value of ka is a numerical expression of the number of antibody / antigen complexes formed per second in a 1 molar (1M) solution of antibody and antigen, and is expressed in units of M -1 seconds -1 It is expressed as:

[0131] As used herein, the term "lymphocyte" refers to a type of white blood cell or leukocyte that is involved in the body's immune defenses. There are two types of lymphocytes: B cells and T cells. The terms "tumor-infiltrating lymphocytes" (abbreviated "TILs") or "tumor-infiltrating Tregs," as used herein, refer to lymphocytes or Tregs, respectively, that are associated with tumor cells, e.g., localized in the tumor mass.

[0132] As used herein, the terms "linked," "fused," or "fusion" are used interchangeably. These terms refer to the joining of two or more elements, components, or domains by any means, including chemical conjugation or recombinant means. Methods of chemical conjugation (e.g., using heterobifunctional crosslinkers) are known in the art.

[0133] As used herein, the term "monoclonal antibody" refers to an antibody that displays a single binding specificity and affinity for a particular epitope. Accordingly, the term "human monoclonal antibody" refers to an antibody that displays a single binding specificity and has variable and optional constant regions derived from human germline immunoglobulin sequences. In some embodiments, human monoclonal antibodies are produced by hybridomas comprising B cells obtained from a transgenic non-human animal, e.g., a transgenic mouse, whose genome comprises human heavy chain and light chain transgenes fused to an immortalized cell.

[0134] As used herein, the term "natural killer (NK) cells" refers to a type of cytotoxic lymphocyte. These are large, usually granular, non-T, non-B lymphocytes that kill certain tumor cells and play an important role in innate immunity against viruses and other intracellular pathogens, as well as antibody-dependent cell-mediated cytotoxicity (ADCC).

[0135] As used herein, the term "naturally occurring," when applied to an object, refers to the fact that an object can be found in nature. For example, a polypeptide or polynucleotide sequence present in an organism (including a virus) that can be isolated from a natural source and has not been intentionally modified by humans in the laboratory is naturally occurring.

[0136] As used herein, the term "nucleic acid" refers to deoxyribonucleotides or ribonucleotides and polymers thereof in single- or double-stranded form. Unless otherwise specified, the term encompasses nucleic acids containing known analogs of natural nucleotides that have similar binding properties as the reference nucleic acid and are metabolized in a manner similar to naturally occurring nucleotides. Unless otherwise specified, a particular nucleic acid sequence implicitly encompasses conservatively modified mutants thereof (e.g., degenerate codon substitutions) and complementary sequences, as well as the sequence explicitly indicated. Specifically, degenerate codon substitutions can be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed-base and / or deoxyinosine residues (Batzer et al., Nucleic Acid Res. 19:5081, 1991; Ohtsuka et al., Biol. Chem. 260:2605-2608, 1985; and Cassol et al., 1992; Rossolini et al., Mol. Cell. Probes 8:91-98, 1994). In the case of arginine and leucine, modifications at the second base can also be conservative. The term nucleic acid is used interchangeably with gene, cDNA, and mRNA encoded by a gene.

[0137] As used herein, a polynucleotide may be composed of any polyribonucleotide or polydeoxyribonucleotide, which may be unmodified RNA or DNA or modified RNA or DNA. For example, a polynucleotide may be composed of single- and double-stranded DNA, DNA with a combination of single- and double-stranded regions, single- and double-stranded RNA, and RNA with a combination of single- and double-stranded regions, or hybrid molecules containing single-stranded, or more typically double-stranded, DNA and RNA with a combination of single- and double-stranded regions. In addition, a polynucleotide may be composed of triple-stranded regions containing RNA or DNA, or both RNA and DNA. A polynucleotide may also contain one or more modified bases or DNA or RNA backbones modified for stability or other reasons. "Modified" bases include, for example, tritylated bases and rare bases such as inosine. Various modifications can be made to DNA and RNA, and thus "polynucleotide" encompasses chemically, enzymatically, or metabolically modified forms.

[0138] A nucleic acid is "operably linked" when it is placed into a functional relationship with another nucleic acid sequence. For example, a promoter or enhancer is operably linked to a coding sequence if it affects the transcription of the sequence. With respect to transcription control sequences, operably linked means that the linked DNA sequences are contiguous, and, where necessary, joins two adjacent protein-coding regions contiguous in reading frame. In the case of switch sequences, operably linked means that the sequences are capable of effecting switch recombination.

[0139] As used herein, "parenteral administration," "administering parenterally," and other grammatically equivalent phrases refer to modes of administration other than enteral and topical administration, usually by injection, including, but not limited to, intravenous, intranasal, intraocular, intramuscular, intra-arterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intra-articular, subcapsular, subarachnoid, intraspinal, epidural, intracerebral, intracranial, intracarotid, and intrasternal injection and infusion.

[0140] As used herein, the term "patient" includes human and other mammalian subjects receiving either prophylactic or therapeutic treatment.

[0141] The term "percent identity," in the context of two or more nucleic acid or polypeptide sequences, refers to two or more sequences or subsequences that have a specified percentage (%) of nucleotide or amino acid residues that are identical when compared and aligned for maximum correspondence, as determined using one of the sequence comparison algorithms described below (e.g., BLASTP and BLASTN, or other algorithms available to those skilled in the art) or by visual inspection. Depending on the application, the "percent identity" may exist over a region of the sequences being compared, e.g., a functional domain, or over the entire length of the two sequences being compared. For sequence comparison, typically, one sequence serves as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity of the test sequence(s) relative to the reference sequence based on the designated program parameters.

[0142] Optimal alignment of sequences for comparison can be performed, for example, by the local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by visual inspection (see generally Ausubel et al., infra).

[0143] One example of an algorithm that is suitable for determining percent sequence identity and sequence similarity is the BLAST algorithm, which is described in Altschul et al., J. Mol. Biol. 215:403-410 (1990). Software for performing BLAST analyses is publicly available via the website of the National Center for Biotechnology Information.

[0144] "Pharmaceutically acceptable," as generally used herein, refers to compounds, materials, compositions and / or formulations that are suitable for use in contact with the tissues, organs and / or body fluids of human beings and animals without undue toxicity, irritation, allergic response, or other problem or complication, within the scope of safe medical judgment and commensurate with a reasonable benefit / risk ratio.

[0145] As used herein, "pharmaceutically acceptable carrier" refers to and includes any and all physiologically compatible solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, etc. The compositions may include pharmaceutically acceptable salts, such as acid addition salts or base addition salts (see, e.g., Berge et al. (1977) J Pharm Sci 66:1-19).

[0146] As used herein, the terms "polypeptide," "peptide," and "protein" are used interchangeably to refer to a polymer of amino acid residues. These terms apply to amino acid polymers in which one or more amino acid residues are artificial chemical mimetics of corresponding naturally occurring amino acids, as well as to naturally occurring amino acid polymers and to non-naturally occurring amino acid polymers.

[0147] As used herein, the term "prevent" when used with respect to a condition refers to the administration of a composition that reduces the frequency of or delays the onset of symptoms of a medical condition in a subject compared to a subject who does not receive the composition.

[0148] As used herein, the terms "purified" or "isolated" when applied to any of the proteins (antibodies or fragments) described herein refer to a polypeptide that has been separated or purified from components that naturally accompany it (e.g., proteins or other naturally occurring biological or organic molecules), such as other proteins, lipids, and nucleic acids in the prokaryotic organism in which the protein is expressed. Typically, a polypeptide is purified when it constitutes at least 60% (e.g., at least 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 97%, or 99%) by weight of the total protein in a sample.

[0149] As used herein, the term "rearranged" refers to a V segment immediately adjacent to a DJ or J segment, respectively, forming a complete V H or V LThis refers to the configuration of a heavy or light chain immunoglobulin locus that essentially encodes a domain. Rearranged immunoglobulin loci can be identified by comparison with germline DNA, and the rearranged locus has at least one recombined heptameric / nonameric homology element.

[0150] As used herein, the term "recombinant host cell" (or simply "recombinant cell") is intended to refer to a cell into which a recombinant expression vector has been introduced. It should be understood that such terms are intended to refer not only to the particular subject cell but to the progeny of such a cell. Because certain modifications may occur in successive generations due to either mutation or environmental influences, such progeny may not, in fact, be identical to the parent cell, but are still included within the scope of the term "host cell" as used herein.

[0151] As used herein, the term "recombinant antibody" includes all human antibodies prepared, expressed, produced, or isolated by recombinant means, such as, for example, (a) antibodies isolated from animals (e.g., mice) that are transgenic or transchromosomal for human immunoglobulin genes or from hybridomas prepared therefrom, (b) antibodies isolated from host cells transformed to express the antibody, e.g., from transfectomas, (c) antibodies isolated from recombinant combinatorial human antibody libraries, and (d) antibodies prepared, expressed, produced, or isolated by any other means involving splicing of human immunoglobulin gene sequences into other DNA sequences. Such recombinant human antibodies contain variable and constant regions that utilize particular human germline immunoglobulin sequences encoded by germline genes, but also include subsequent rearrangements and mutations that occur, for example, during antibody maturation. As known in the art (see, e.g., Lonberg (2005) Nature Biotech. 23(9):1117-1125), variable regions contain antigen-binding domains, which are encoded by different genes that rearrange to form antibodies specific to foreign antigens. In addition to rearrangement, the variable regions are further modified by multiple single amino acid changes (called somatic mutations or hypermutations) to enhance the affinity of the antibody for the foreign antigen. The constant regions will further change in response to antigen (i.e., isotype switching). Thus, rearranged and somatically mutated nucleic acid molecules encoding light and heavy chain immunoglobulin polypeptides in response to antigen may not have sequence identity to the original nucleic acid molecules, but instead will be substantially identical or similar (i.e., have at least 80% identity).

[0152] As used herein, the term "reference antibody" (used interchangeably with "reference mAb") or "reference antigen-binding protein" refers to an antibody or antigen-binding fragment thereof that binds to a particular epitope on CCR8 and is used to establish a relationship between itself and one or more distinct antibodies, where the relationship is the binding of the reference antibody and the one or more distinct antibodies to the same epitope on CCR8. As used herein, the term also refers to an anti-CCR8 antibody that is useful as a competitor in tests or assays such as those described herein (e.g., competitive binding assays), which assays are useful for discovering, identifying, or constructing one or more distinct antibodies that bind to the same epitope.

[0153] As used herein, the terms "specific binding," "selective binding," "selectively binds," and "specifically binds" refer to antibody binding to an epitope on a predetermined antigen. Typically, an antibody binds to an epitope of approximately 10 as determined by surface plasmon resonance (SPR) technology on a BIACORE™ 2000 instrument using recombinant human CCR8 as the analyte and the antibody as the ligand. -6 Less than M, e.g., about 10 -7 , 10 -8 M, 10 -9 M or 10 -10 The equilibrium dissociation constant (K D ) and binds to a predetermined antigen with an affinity that is at least 2-fold greater than its affinity for binding to a nonspecific antigen other than the predetermined antigen or a closely related antigen (e.g., BSA, casein). In certain embodiments, an antibody that specifically binds to CCR8 has an affinity of less than approximately 100 nM (10 -7 M), optionally less than approximately 50 nM (5 x 10 -8 M), optionally less than approximately 15 nM (1.5 x 10 -8 M), optionally less than approximately 10 nM (10 -8 M), optionally less than approximately 5 nM (5 x 10 -9M), optionally less than approximately 1 nM (10 -9 M), optionally less than approximately 0.1 nM (10 -10 M), optionally less than approximately 0.01 nM (10 -11 M) or lower equilibrium dissociation constant (K D ), where binding to a predetermined antigen occurs with an affinity that is at least two-fold greater than the affinity of the antibody for binding to a nonspecific antigen other than the predetermined antigen or a closely related antigen (e.g., BSA, casein). The phrases "antibody that recognizes an antigen" and "antibody specific for an antigen" are used interchangeably herein with the term "antibody that specifically binds to an antigen."

[0154] As used herein, the term "subject" includes any human or non-human animal. For example, the methods and compositions of the present invention can be used to treat a subject having an immune disorder. The term "non-human animal" includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dogs, cows, chickens, amphibians, reptiles, etc.

[0155] With respect to nucleic acids, the term "substantially homologous" means that two nucleic acids or their designated sequences, when optimally aligned and compared, are at least about 80% of the nucleotides identical, usually at least about 90% to 95% of the nucleotides, and more preferably at least about 98% to 99.5% of the nucleotides identical, with appropriate nucleotide insertions or deletions. Alternatively, substantial homology exists when the segments will hybridize under selective hybridization conditions to the complement of the strand.

[0156] The percent identity between the two sequences is a function of the number of identical positions shared by the sequences (i.e., percent homology = number of identical positions / total number of positions × 100), and takes into account the number of gaps and the length of each gap that need to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm, as described in the non-limiting examples below.

[0157] The percent identity between two nucleotide sequences can be determined using the GAP program in the GCG software package (available at http: / / www.gcg.com), which uses a NWSgapdna.CMP matrix and a gap weight of 40, 50, 60, 70, or 80 and a length weight of 1, 2, 3, 4, 5, or 6. The percent identity between two nucleotide or amino acid sequences can also be determined using the algorithm of E. Meyers and W. Miller (CABIOS, 4:11-17 (1989)), which has been incorporated into the ALIGN program (version 2.0), which uses a PAM120 weight residue table, a gap length penalty of 12, and a gap penalty of 4. Additionally, the percent identity between two amino acid sequences can be determined using the Needleman and Wunsch (J. Mol. Biol. (48): 444-453 (1970)) algorithm, which is incorporated into the GAP program in the GCG software package (available at http: / / www.gcg.com), using either a Blossum62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6.

[0158] Furthermore, the nucleic acid and protein sequences of the present disclosure can also be used as "query sequences" to search public databases, for example, to identify related sequences. Such searches can be performed using the NBLAST and XBLAST programs (version 2.0) of Altschul et al. (1990) J. Mol. Biol. 215:403-10. BLAST nucleotide searches can be performed with the NBLAST program, score = 100, word length = 12, to obtain nucleotide sequences homologous to the nucleic acid molecules of the present invention. BLAST protein searches can be performed with the XBLAST program, score = 50, word length = 3, to obtain amino acid sequences homologous to the protein molecules of the present invention. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al. (1997) Nucleic Acids Res. 25(17):3389-3402. When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used. See http: / / www.ncbi.nlm.nih.gov.

[0159] Nucleic acids may be present in whole cells, cell lysates, or in partially purified or substantially pure form. Nucleic acids are "isolated" or "substantially purified" when they have been purified away from other cellular components or other contaminants, such as other intracellular nucleic acids or proteins, by standard techniques, including alkaline / SDS treatment, CsCl banding, column chromatography, agarose gel electrophoresis, and other techniques known in the art. See F. Ausubel, et al., eds., Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York (1987).

[0160] The nucleic acid compositions of the present disclosure are often naturally occurring sequences (except for modified restriction sites, etc.), but may be mutated from either cDNA, genome, or mixtures thereof, according to standard techniques for providing gene sequences. With respect to coding sequences, these mutations can affect the amino acid sequence as needed. Specifically contemplated are DNA sequences that are substantially homologous to or derived from naturally occurring V, D, J, constant, switch, and other such sequences described herein (where "derived" indicates that one sequence is identical to or modified from another sequence).

[0161] The term "T cell" refers to a type of white blood cell that can be distinguished from other white blood cells by the presence of T cell receptors on the cell surface. There are several subsets of T cells, including T helper cells (also known as T H cells or CD4 + T cells) and subtypes, e.g., T H 1. T H 2. T H 3. T H 17, T H 9, and T FH cells, cytotoxic T cells (also known as T C cells, CD8 + T cells, cytotoxic T lymphocytes, T killer cells, killer T cells), memory T cells and subtypes, such as central memory T cells (T CM cells), effector memory T cells (T EM and T EMRA cells), and resident memory T cells (T RM cells), regulatory T cells (also known as T reg cells or suppressor T cells) and subtypes, e.g., CD4 + FOXP3 + T reg cells, CD4 + FOXP3 - T reg cells, Tr1 cells, Th3 cells, and T regThese include, but are not limited to, T cells, such as IL-17 cells, natural killer T cells (also known as NKT cells), mucosal-associated invariant T cells (MAIT), and gamma delta T cells (γδ T cells), e.g., Vγ9 / Vδ2 T cells. Any one or more of the T cells mentioned above or not mentioned may be a target cell type for the methods of use of the present invention.

[0162] As used herein, the term "T cell-mediated response" refers to a response mediated by effector T cells (e.g., CD8 + cells) and helper T cells (e.g., CD4 + "T-cell mediated responses" refers to any response mediated by T cells, including but not limited to T cells. T cell mediated responses include, for example, T cell cytotoxicity and proliferation.

[0163] As used herein, the terms "regulatory T cells," "T regulatory cells," "Tregs," or "T" are used interchangeably herein. reg " refers to a subpopulation of T cells that regulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune disease. Tregs are immunosuppressive factors that generally suppress and downregulate the induction and proliferation of effector T cells. Tregs are known to induce lysis of effector T cells, support tolerogenic dendritic cell formation, support M2 macrophage formation, produce immunosuppressant metabolites and cytokines, function as an IL-2 sink, and promote neovasculature formation. There are many types of Tregs, but many Tregs often express CD4 and FOXP3, with FOXP3 serving as a marker for Tregs.

[0164] As used herein, the term "therapeutically effective amount" or "therapeutically effective dose," or similar terms used herein, is intended to mean an amount of an agent (e.g., an anti-CCR8 antibody or antigen-binding fragment thereof) that can elicit a desired biological or medical response (e.g., improvement in one or more symptoms of cancer).

[0165] The terms "treatment," "treating," and "therapy," as used herein, refer to therapeutic or prophylactic measures described herein. Methods of "treatment" employ administration of a human antibody of the present disclosure to a subject in need of such treatment, e.g., a subject in need of an enhanced immune response to a particular antigen, or a subject who may ultimately contract such a disease, to prevent, cure, delay, reduce the severity of, or ameliorate one or more symptoms of a disease or recurring disease, or to prolong the subject's survival beyond that expected in the absence of such treatment.

[0166] As used herein, the term "tumor microenvironment" (or "cancer microenvironment," abbreviated TME) refers to the cellular milieu or environment in which a tumor or neoplasm resides, including surrounding blood vessels and non-cancerous cells, including, but not limited to, immune cells, fibroblasts, bone marrow-derived inflammatory cells, and lymphocytes. Signaling molecules and the extracellular matrix also comprise the TME. Tumors and the surrounding microenvironment are closely related and constantly interact. Tumors can influence the microenvironment by releasing extracellular signals, promoting tumor angiogenesis, and inducing peripheral immune tolerance, while immune cells within the microenvironment can influence tumor cell growth and development.

[0167] As used herein, the term "vector" is intended to refer to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. One type of vector is a "plasmid," which refers to a circular double-stranded DNA loop into which additional DNA segments can be ligated. Another type of vector is a viral vector, into which additional DNA segments can be ligated into the viral genome. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) can be integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome. Moreover, some vectors are capable of directing the expression of genes to which they are operatively linked. Such vectors are referred to herein as "recombinant expression vectors" (or simply "expression vectors"). In general, expression vectors utilized in recombinant DNA techniques are often in the form of plasmids. As used herein, "plasmid" and "vector" can be used interchangeably as the plasmid is the most commonly used form of vector. However, the invention is intended to include other forms of expression vectors, such as viral vectors (eg, replication defective retroviruses, adenoviruses and adeno-associated viruses), which serve equivalent functions.

[0168] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Preferred methods and materials are described below; however, methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the methods and compositions disclosed herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0169] Various aspects of the disclosure are described in further detail in the following subsections.

[0170] II. Compositions of the Present Disclosure Certain embodiments of the present disclosure relate to antibodies or antigen-binding portions thereof that specifically bind to CCR8 ("anti-CCR8 antibodies"). In certain embodiments, the anti-CCR8 antibodies specifically bind to the N-terminal extracellular domain of human CCR8. Historically, it has been very difficult to generate therapeutic antibodies against CCR8. Like other GPCRs, CCR8 is challenging to generate antibodies against due to its strong membrane binding, lack of exposed sequences on the cell surface, and the difficulty of expressing the full-length CCR8 protein. Many previous attempts utilizing multiple antibody generation platforms have been unsuccessful. (See also Jo and Jung, Experimental & Molecular Medicine 48:e207 (2016)). The present disclosure solves this problem by specifically targeting the N-terminal extracellular domain of human CCR8. By generating antibodies that specifically target the N-terminal domain, the present disclosure focuses on generating antibodies that target the longest cellular portion of CCR8. This allows for the realization of previously unattainable anti-CCR8 antibodies. In doing so, the antibodies described herein are capable of inhibiting CCR8 activity in a manner not previously described. In particular, the antibodies disclosed herein can (a) enhance immune responses to tumors, (b) reduce, deplete, or kill tumor-infiltrating regulatory T ("Treg") cells, (c) induce CCR8 internalization in tumor-infiltrating regulatory T ("Treg") cells, (d) activate NK cells, (e) induce NK cell-mediated killing of tumor-infiltrating regulatory T ("Treg") cells, (f) bind to cynomolgus monkey ("cyno") CCR8, (g) bind to human CCR8 with a KD of 10 nM or less as measured by BIACORE™, or (h) any combination thereof.

[0171] In some embodiments, the antibody or antigen-binding portion thereof is further engineered by removing one or more post-translational modifications. In some embodiments, the antibody or antigen-binding portion thereof is engineered to remove one or more fucose sugar units. In some embodiments, the antibody or antigen-binding portion thereof is modified to remove one or more fucose sugar units from the (IgG1) Fc region of the antibody. In some embodiments, the antibody or antigen-binding portion thereof is defucosylated. In some embodiments, removal of one or more fucose sugar units enhances the ADCC of the antibody or antigen-binding fragment thereof. In some embodiments, the ADCC of an anti-CCR8 antibody modified to remove one or more fucose sugar units (e.g., a defucosylated antibody) is at least about 1.5-fold, at least about 2.0-fold, at least about 2.5-fold, at least about 3.0-fold, at least about 3.5-fold, at least about 4.0-fold, at least about 4.5-fold, or at least about 5.0-fold higher than an anti-CCR8 antibody not modified to remove one or more fucose sugar units (e.g., a fucosylated antibody). In some embodiments, the ADCC of an anti-CCR8 antibody modified to remove one or more fucose sugar units is at least about 3.0-fold higher than an anti-CCR8 antibody that has not been modified to remove one or more fucose sugar units. In some embodiments, the ADCC of an anti-CCR8 antibody modified to remove one or more fucose sugar units is at least about 3.5-fold higher than an anti-CCR8 antibody that has not been modified to remove one or more fucose sugar units. In some embodiments, the ADCC of an anti-CCR8 antibody modified to remove one or more fucose sugar units is at least about 4.0-fold higher than an anti-CCR8 antibody that has not been modified to remove one or more fucose sugar units.

[0172] In certain embodiments, anti-CCR8 antibodies can induce immune responses against tumors. Treg cells act to control immune responses by downregulating the activity of T cells as a means of suppressing the immune system. Tumor-infiltrating Tregs can act to prevent immune responses targeting tumors, thereby allowing the tumor to avoid destruction by the subject's immune system. The antibodies described herein can inhibit tumor-infiltrating Tregs, thereby weakening this barrier to anti-tumor immune responses. In some embodiments, anti-CCR8 antibodies enhance the immune response against tumors in a subject in need thereof by at least about 50%, at least about 100%, at least about 150%, at least about 200%, at least about 250%, at least about 300%, at least about 350%, at least about 400%, at least about 450%, or at least about 500%, compared to the immune response in the absence of the anti-CCR8 antibody.

[0173] Anti-tumor immune response can be measured using any indicator known in the art. In some embodiments, anti-tumor immune response is determined by comparing the number of tumor-infiltrating T cells (TILs) in a tumor sample obtained from a subject before and after contacting the tumor with an anti-CCR8 antibody. In some embodiments, the number of TILs is measured by immunohistochemistry or quantitative polymerase chain reaction (qPCR). In some embodiments, the number of TILs in a tumor sample is increased by at least about 1.5-fold, at least about 2-fold, at least about 2.5-fold, at least about 3-fold, at least about 3.5-fold, at least about 4-fold, at least about 4.5-fold, at least about 5-fold, at least about 6-fold, at least about 7-fold, at least about 8-fold, at least about 9-fold, at least about 10-fold, at least about 15-fold, or at least about 20-fold compared to the number of TILs in a tumor sample obtained from a subject before contacting the tumor with an anti-CCR8 antibody.

[0174] In certain embodiments, the anti-CCR8 antibody can reduce, deplete, or kill tumor-infiltrating Treg cells. In some embodiments, the anti-CCR8 antibody induces a depletion of the number of tumor-infiltrating Treg cells in a subject after administration of the antibody or antigen-binding portion thereof, compared to the number of tumor-infiltrating Treg cells before administration. In some embodiments, the number of tumor-infiltrating Treg cells is depleted by at least about 5%, at least about 10%, at least about 15%, 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 least about 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%, at least about 98%, at least about 99%, or about 100% compared to the number of tumor-infiltrating Treg cells before administration. In some embodiments, anti-CCR8 preferentially reduces, depletes, or kills tumor-infiltrating Treg cells compared to peripheral Treg cells.

[0175] In some embodiments, the anti-CCR8 antibody induces antibody-dependent cellular cytotoxicity (ADCC) in a subject after administration of the anti-CCR8 antibody. In some embodiments, the ADCC comprises an EC50 of about 100 μg / mL or less after administration of the antibody or antigen-binding portion thereof. In some embodiments, ADCC comprises an EC50 of about 100 μg / mL or less, about 90 μg / mL or less, about 80 μg / mL or less, about 70 μg / mL or less, about 60 μg / mL or less, about 50 μg / mL or less, about 45 μg / mL or less, about 40 μg / mL or less, about 35 μg / mL or less, about 30 μg / mL or less, about 30 μg / mL or less, about 25 μg / mL or less, about 20 μg / mL or less, about 15 μg / mL or less, about 10 μg / mL or less, about 5 μg / mL or less, about 1 μg / mL or less, about 0.5 μg / mL or less, about μg / mL or less, about 0.1 μg / mL or less, or about 0.01 μg / mL or less after administration of the anti-CCR8 antibody. In some embodiments, ADCC comprises an EC50 of about 1 μg / mL or less after administration of the antibody or antigen-binding portion thereof. In some embodiments, ADCC comprises an EC50 of about 0.1 μg / mL or less after administration of the antibody or antigen-binding portion thereof.

[0176] Without being bound by any theory or particular mechanism, it is hypothesized that inhibition of CCR8 signaling of tumor-infiltrating Tregs results in the activation of NK cells in the tumor microenvironment. The activated NK cells can then target and kill tumor-infiltrating Tregs, thereby reducing their numbers and enhancing the immune response against the tumor. Thus, in some embodiments, anti-CCR8 antibodies can activate NK cells. In some embodiments, the NK cells are activated in the tumor microenvironment. In some embodiments, the NK cells are tumor-infiltrating NK cells. NK cell activation can be measured using techniques known in the art. In some embodiments, NK cell activation is determined by measuring the percentage of cells expressing one or more markers of activated NK cells. In certain embodiments, NK cell activation is measured by measuring the percentage of cells in the tumor microenvironment that express NKp46 but not CD3 (e.g., NKp46 + / CD3 -The ratio of cytotoxicity to cytotoxicity is determined by measuring the percentage of cytotoxicity (cells).

[0177] In some embodiments, NK cell activation is characterized by increased expression of one or more target genes by NK cells. In some embodiments, an anti-CCR8 antibody can induce upregulation of 4-1BB on the surface of NK cells. In some embodiments, an anti-CCR8 antibody can induce upregulation of ICAM-1 on the surface of NK cells. In some embodiments, an anti-CCR8 antibody can induce upregulation of 4-1BB and ICAM-1 on the surface of NK cells. In some embodiments, the level of 4-1BB and / or ICAM-1 on the surface of NK cells after contacting a tumor with an anti-CCR8 antibody is upregulated by at least about 1.5-fold, 2-fold, 2.5-fold, 3.0-fold, 3.5-fold, 4.0-fold, 4.5-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, or 10-fold compared to the level of 4-1BB and / or ICAM-1 on the surface of NK cells in a tumor sample collected before contact.

[0178] In some embodiments, NK cell activation is characterized by the reduction of the expression of one or more target genes by NK cells. In some embodiments, anti-CCR8 antibody can induce the downregulation of CD16 on the surface of NK cells. In some embodiments, the level of CD16 on the surface of NK cells after contacting tumor with anti-CCR8 antibody is at least about 1.5-fold, 2-fold, 2.5-fold, 3.0-fold, 3.5-fold, 4.0-fold, 4.5-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, or 10-fold downregulated compared to the level of CD16 on the surface of NK cells in tumor sample collected before contact.

[0179] In some embodiments, the number of activated NK cells in the tumor microenvironment is increased by at least about 5%, at least about 10%, at least about 15%, 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 least about 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%, at least about 98%, at least about 99%, or about 100% compared to the percentage of activated NK cells in a tumor sample obtained from the subject before contacting the tumor with the anti-CCR8 antibody. In some embodiments, the proportion of activated NK cells in the tumor microenvironment is increased by at least about 1.5-fold, at least about 2-fold, at least about 2.5-fold, at least about 3-fold, at least about 3.5-fold, at least about 4-fold, at least about 4.5-fold, at least about 5-fold, at least about 6-fold, at least about 7-fold, at least about 8-fold, at least about 9-fold, at least about 10-fold, at least about 15-fold, or at least about 20-fold compared to the number of activated NK cells in a tumor sample obtained from the subject before contacting the tumor with the anti-CCR8 antibody. In some embodiments, the anti-CCR8 antibody can induce NK cell-mediated killing of tumor-infiltrating Tregs.

[0180] The anti-CCR8 antibodies described herein can specifically bind to human CCR8. However, in some embodiments, the anti-CCR8 antibodies can bind to CCR8 from non-human animals. In some embodiments, the anti-CCR8 antibodies can specifically bind to human CCR8 and non-human primate CCR8. In some embodiments, the anti-CCR8 antibodies can bind to human CCR8 and cynomolgus monkey (cyno) CCR8. In some embodiments, the anti-CCR8 antibodies bind to human CCR8 with higher affinity than to non-human CCR8 (e.g., cyno CCR8). In some embodiments, the anti-CCR8 antibodies bind to human CCR8 but not to cyno CCR8.

[0181] In some embodiments, the anti-CCR8 antibody has an equilibrium dissociation constant (K D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 50 nM or less. D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 25 nM or less. D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 20 nM or less. D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 15 nM or less. D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 10 nM or less. D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 5 nM or less. D In some embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 1 nM or less. D In some embodiments, K D is measured by BIACORE™. In certain embodiments, the anti-CCR8 antibody has a K of about 10 nM or less as measured by BIACORE™. D In certain embodiments, the anti-CCR8 antibody binds to human CCR8 with a K of about 1 nM or less as measured by BIACORE™. D It binds to human CCR8.

[0182] Inhibition of CCR8 by the antibodies and antigen-binding portions thereof disclosed herein can occur through any mechanism. Without being bound to any particular mechanism, in some embodiments, the anti-CCR8 antibody induces the internalization of CCR8 by tumor-infiltrating Treg cells. Internalization of the surface CCR8 receptor eliminates the receptor's ability to bind to its ligand, enhancing intracellular signaling and thereby effectively inhibiting CCR8 activity in tumor-infiltrating Treg cells. In certain embodiments, the anti-CCR8 antibody binds to CCR8 expressed on tumor-infiltrating Treg cells.

[0183] In some embodiments, the anti-CCR8 antibody blocks the interaction between CCR8 and its ligand, e.g., through steric hindrance, conformational changes, internalization of the CCR8 receptor, or any combination thereof. In some embodiments, binding of the anti-CCR8 antibody to the N-terminal extracellular domain of CCR8 inhibits the ability of the CCR8 receptor to interact with G proteins, e.g., through conformational changes and / or internalization of the CCR8 receptor.

[0184] II.A. Epitope The antibodies described herein specifically bind to the N-terminal extracellular domain of CCR8 or a fragment thereof. The N-terminal extracellular domain of human CCR8 is generally defined as consisting of amino acids 1-35 of the full-length CCR8 sequence (e.g., amino acids 1-35 of SEQ ID NO: 171) (see uniprot.org / uniprot / P51685). The amino acid sequence of the N-terminal extracellular domain of human CCR8 comprises the amino acid sequence MDYTLDLSVTTVTDYYYPDIFSSPCDAELIQTNGK (SEQ ID NO: 172).

[0185] In some embodiments, the anti-CCR8 antibody binds to at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 amino acids within the N-terminal extracellular domain of human CCR8, e.g., as set forth in SEQ ID NO: 172. In some embodiments, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 amino acids are contiguous within the N-terminal extracellular domain of human CCR8, e.g., as set forth in SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 contiguous amino acids within the N-terminal extracellular domain of human CCR8, e.g., as set forth in SEQ ID NO: 172. In some embodiments, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 amino acids within the N-terminal extracellular domain of human CCR8 are non-contiguous, e.g., as set forth in SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to at least one amino acid within the N-terminal extracellular domain of human CCR8 and at least one amino acid of human CCR8 that is not within the N-terminal extracellular domain of human CCR8.

[0186] In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 1-10 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 1-15 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 1-20 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 1-25 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 1-30 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 5-10 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 5-15 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 5-20 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 5-25 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 5-30 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 5-35 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 10-15 of SEQ ID NO: 172.In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 10-20 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 10-25 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 10-30 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 10-35 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 15-20 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 15-25 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 15-30 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 15-35 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 20-25 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 20-30 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 20-35 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 comprising one or more amino acids selected from amino acid residues 25-30 of SEQ ID NO: 172.In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 that comprises one or more amino acids selected from amino acid residues 25 to 35 of SEQ ID NO: 172. In some embodiments, the anti-CCR8 antibody binds to an epitope on human CCR8 that comprises one or more amino acids selected from amino acid residues 30 to 35 of SEQ ID NO: 172.

[0187] In some embodiments, the anti-CCR8 antibody binds to an epitope of human CCR8 comprising an amino acid sequence selected from SEQ ID NOs: 180-200.

[0188] II.B. Antibody Sequence In some embodiments, the anti-CCR8 antibody comprises a whole antibody, e.g., an antibody comprising two light chain polypeptides and two heavy chain polypeptides. In some embodiments, the anti-CCR8 antibody comprises a fragment of a whole antibody that retains the ability to bind to CCR8. In some embodiments, the anti-CCR8 antibody is a single chain antibody. In some embodiments, the anti-CCR8 antibody is a single chain Fv fragment (scFv). In some embodiments, the anti-CCR8 antibody is an Fd fragment. In some embodiments, the anti-CCR8 antibody is a Fab fragment. In some embodiments, the anti-CCR8 antibody is an Fab' fragment. In some embodiments, the anti-CCR8 antibody is an F(ab')2 fragment. In some embodiments, the anti-CCR8 antibody is selected from an intrabody, a minibody, a triabody, or a diabody.

[0189] In some embodiments, the anti-CCR8 antibody comprises a variable heavy chain (VH) and a variable light chain (VL). In some embodiments, the VH comprises a VH complementarity-determining region (CDR) 1, a VH CDR2, and a VH CDR3, and the VL comprises a VL CDR1, a VL CDR2, and a VL CDR3. In some embodiments, the VH CDR1 comprises the amino acid sequence set forth in Table 2A. In some embodiments, the VH CDR1 comprises the amino acid sequence set forth in SEQ ID NO: 201. In some embodiments, the VH CDR1 comprises the amino acid sequence set forth in SEQ ID NO: 202. In some embodiments, the VH CDR1 comprises the amino acid sequence set forth in SEQ ID NO: 203. In some embodiments, the VH CDR1 comprises the amino acid sequence set forth in SEQ ID NO: 204. [Table 2A]

[0190] In some embodiments, the VH CDR2 comprises the amino acid sequence set forth in Table 2B. In some embodiments, the VH CDR2 comprises the amino acid sequence set forth in SEQ ID NO: 205. In some embodiments, the VH CDR2 comprises the amino acid sequence set forth in SEQ ID NO: 206. In some embodiments, the VH CDR2 comprises the amino acid sequence set forth in SEQ ID NO: 207. In some embodiments, the VH CDR2 comprises the amino acid sequence set forth in SEQ ID NO: 208. [Table 2B]

[0191] In some embodiments, the VH CDR3 comprises the amino acid sequence set forth in Table 2C. In some embodiments, the VH CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the VH CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 210. [Table 2C]

[0192] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 201, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 205, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 204, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 205, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 201, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 208, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 204, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 208, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 201, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 208, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 201, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 208, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 209. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 202, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 206, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 210. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 202, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 207, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 210.In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 203, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 206, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 210. In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 203, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 207, and a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 210.

[0193] In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in Table 3A. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:211. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:212. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:213. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:214. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:215. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:216. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:217. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:218. In some embodiments, the VL CDR1 comprises the amino acid sequence set forth in SEQ ID NO:219. [Table 3A]

[0194] In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in Table 3B. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:220. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:221. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:222. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:223. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:224. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:225. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:226. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:227. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:228. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:229. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:230. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:231. In some embodiments, the VL CDR2 comprises the amino acid sequence set forth in SEQ ID NO:232. [Table 3B]

[0195] In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in Table 3C. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 233. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 234. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 235. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 236. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 236. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 236. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 237. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 238. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 239. In some embodiments, the VL CDR3 comprises the amino acid sequence set forth in SEQ ID NO: 240. [Table 3C]

[0196] In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 211, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 220, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 233. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 212, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 221, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 234. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 213, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 222, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 235. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 213, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 222, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 236. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 213, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 223, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 235. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 213, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 223, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 236. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 217, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 227, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 238. In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 218, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 231, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 239.In some embodiments, the anti-CCR8 antibody comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 219, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 232, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 240.

[0197] In some embodiments, the VH CDR3 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 47, 57, 67, 77, 87, 97, 107, 117, 127, 137, 147, 157, and 167. In some embodiments, the VH CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 46, 56, 66, 76, 86, 96, 106, 116, 126, 136, 146, 156, and 166. In some embodiments, the VH CDR1 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 105, 115, 125, 135, 145, 155, and 165.

[0198] In some embodiments, the VH CDR3 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 47, 107, 117, 137, and 147. In some embodiments, the VH CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146. In some embodiments, the VH CDR1 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 45, 105, 115, 135, and 145.

[0199] In some embodiments, the VH CDR3 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167. In some embodiments, the VH CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166. In some embodiments, the VH CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165.

[0200] In some embodiments, the VL CDR3 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, and 170. In some embodiments, the VL CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 49, 59, 69, 79, 89, 99, 109, 119, 129, 139, 149, 159, and 169. In some embodiments, the VL CDR1 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 48, 58, 68, 78, 88, 98, 108, 118, 128, 138, 148, 158, and 168.

[0201] In some embodiments, the VL CDR3 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 50, 110, 120, 140, and 150. In some embodiments, the VL CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 49, 109, 119, 139, and 149. In some embodiments, the VL CDR1 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 48, 108, 118, 138, and 148.

[0202] In some embodiments, the VL CDR3 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170. In some embodiments, the VL CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169. In some embodiments, the VL CDR2 of the anti-CCR8 antibody comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168.

[0203] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 45, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 46, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 47, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 48, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 49, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 50.

[0204] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 107, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110.

[0205] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 115, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 116, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 117. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 118, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 119, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 120.

[0206] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 135, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 136, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 137. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 137, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 138, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 139, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 140.

[0207] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 147, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150.

[0208] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO:5, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO:6, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO:7, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO:8, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO:9, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO:10.

[0209] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 15, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 16, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 17, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 18, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 19, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 20.

[0210] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 25, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 26, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 27, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 28, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 29, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 30.

[0211] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 35, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 36, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 37, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 38, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 39, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 40.

[0212] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 55, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 56, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 57, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 58, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 59, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 60.

[0213] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 65, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 66, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 67, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 68, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 69, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 70.

[0214] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 75, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 76, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 77, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 78, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 79, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 80.

[0215] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 85, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 86, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 87, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 88, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 89, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 90.

[0216] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 95, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 96, a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 97, a VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 98, a VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 99, and a VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 100.

[0217] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 125, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 126, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 127. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 127, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 128, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 129, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 130.

[0218] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 155, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 156, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 157. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 158, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 159, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 160.

[0219] In some embodiments, the anti-CCR8 antibody comprises a VH CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 165, a VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 166, and a VH CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 167. VH CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 167, VL CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 168, VL CDR2 comprising the amino acid sequence set forth in SEQ ID NO: 169, and VL CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 170.

[0220] In some embodiments, the VH chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from SEQ ID NOs: 41, 101, 111, 131, and 141. In some embodiments, the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 41, 101, 111, 131, and 141. In some embodiments, the VL chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from SEQ ID NOs: 42, 102, 112, 132, and 142. In some embodiments, the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 42, 102, 112, 132, and 142. In some embodiments, the VH chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from SEQ ID NOs: 41, 101, 111, 131, and 141, and the VL chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from SEQ ID NOs: 42, 102, 112, 132, and 142, wherein the anti-CCR8 antibody does not bind to cyno CCR8. In some embodiments, the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 41, 101, 111, 131, and 141, and the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 42, 102, 112, 132, and 142, wherein the anti-CCR8 antibody does not bind to cyno CCR8.

[0221] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 41, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 42, wherein the anti-CCR8 antibody does not bind to cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 41 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 42, wherein the anti-CCR8 antibody does not bind to cyno CCR8.

[0222] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 101, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 102, wherein the anti-CCR8 antibody does not bind to cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 101 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 102, wherein the anti-CCR8 antibody does not bind to cyno CCR8.

[0223] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 111, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 112, wherein the anti-CCR8 antibody does not bind to cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 111, and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 112, wherein the anti-CCR8 antibody does not bind to cyno CCR8.

[0224] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 131, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 132, wherein the anti-CCR8 antibody does not bind to cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 131 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 132, wherein the anti-CCR8 antibody does not bind to cyno CCR8.

[0225] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 141, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 142, wherein the anti-CCR8 antibody does not bind to cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 141 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 142, wherein the anti-CCR8 antibody does not bind to cyno CCR8.

[0226] In some embodiments, the VH chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 1, 11, 21, 31, 51, 61, 71, 81, 91, 121, 151, and 161. In some embodiments, the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 1, 11, 21, 31, 51, 61, 71, 81, 91, 121, 151, and 161. In some embodiments, the VL chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 2, 12, 22, 32, 52, 62, 72, 82, 92, 122, 152, and 162. In some embodiments, the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 2, 12, 22, 32, 52, 62, 72, 82, 92, 122, 152, and 162. In some embodiments, the VH chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 1, 11, 21, 31, 51, 61, 71, 81, 91, 121, 151, and 161, and the VL chain comprises an amino acid sequence having 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% sequence identity to an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 2, 12, 22, 32, 52, 62, 72, 82, 92, 122, 152, and 162, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.In some embodiments, the VH chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 1, 11, 21, 31, 51, 61, 71, 81, 91, 121, 151, and 161, and the VL chain comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 2, 12, 22, 32, 52, 62, 72, 82, 92, 122, 152, and 162, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0227] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 1, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 2, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 2, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0228] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 11 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 12, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0229] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 21, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 22, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 21 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 22, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0230] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 31, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 32, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 31 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 32, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0231] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 51, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 52, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 51 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 52, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0232] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 61, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 62, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 61 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 62, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0233] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 71, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 72, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 71 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 72, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0234] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 81, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 82, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 81 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 82, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0235] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 91, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 92, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 91 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 92, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0236] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 121, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 122, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 121 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 122, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0237] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 151, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 152, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 151 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 152, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0238] In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 161, and a VL chain comprising an amino acid sequence having 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% sequence identity to the amino acid sequence set forth in SEQ ID NO: 162, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8. In some embodiments, the anti-CCR8 antibody comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO: 161 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO: 162, wherein the anti-CCR8 antibody binds to human CCR8 and cyno CCR8.

[0239] In some embodiments, the anti-CCR8 antibody is a human antibody. In some embodiments, the anti-CCR8 antibody is a humanized antibody. In some embodiments, the anti-CCR8 antibody is a chimeric antibody.

[0240] In some embodiments, the anti-CCR8 antibody is selected from the group consisting of IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE antibodies. In some embodiments, the anti-CCR8 antibody is an IgG1 antibody. In some embodiments, the anti-CCR8 antibody is an IgG4 antibody. In some embodiments, the anti-CCR8 antibody comprises a wild-type IgG1 heavy chain constant region. In some embodiments, the anti-CCR8 antibody comprises a wild-type IgG4 heavy chain constant region. In some embodiments, the anti-CCR8 antibody comprises an Fc domain comprising at least one mutation. In some embodiments, the anti-CCR8 antibody comprises a mutated IgG1 heavy chain constant region. In some embodiments, the anti-CCR8 antibody comprises a mutated IgG4 heavy chain constant region. In some embodiments, the mutated IgG4 heavy chain constant region comprises any one of the substitutions S228P, L235E, or L235A according to EU numbering, or a combination thereof.

[0241] In some embodiments, the present disclosure provides an antibody or antigen-binding portion thereof that substantially binds to the same epitope on human CCR8 as an anti-CCR8 antibody according to any one of the above-mentioned embodiments. In some embodiments, the present disclosure provides an antibody or antigen-binding portion thereof that cross-competes with an anti-CCR8 antibody according to any one of the above-mentioned embodiments in binding to human CCR8.

[0242] In some embodiments, the anti-CCR8 antibody comprises a modified heavy chain constant region having improved effector function compared to the corresponding unmodified constant region. The effector function associated with the constant region of the anti-CCR8 antibody can be modulated by modifying the properties of the constant region or Fc region. Modified effector function includes, for example, modulation of one or more activities, such as antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), apoptosis, binding to one or more Fc receptors, and proinflammatory response. Modulation refers to the enhancement, reduction, or elimination of the effector function activity exhibited by the subject antibody comprising the modified constant region compared to the activity of the unmodified form of the constant region. In certain embodiments, modulation includes a situation in which the activity is abolished or completely absent.

[0243] In one embodiment, the anti-CCR8 antibody comprises an IgG4 heavy chain constant region. In one embodiment, the IgG4 heavy chain constant region is a wild-type IgG4 heavy chain constant region. In another embodiment, the IgG4 constant region comprises mutations, for example, S228P and one or both of L235E or L235A, e.g., according to EU numbering (Kabat, EA, et al., supra). In one embodiment, the anti-CCR8 antibody described herein comprises an IgG1 constant region. In one embodiment, the IgG1 heavy chain constant region is a wild-type IgG1 heavy chain constant region. In another embodiment, the IgG1 heavy chain constant region comprises mutations.

[0244] An altered constant region with altered FcR binding affinity and / or ADCC activity and / or altered CDC activity is a polypeptide that has enhanced or decreased FcR binding activity and / or ADCC activity and / or CDC activity compared to the unaltered form of the constant region. An altered constant region that exhibits enhanced FcR binding binds to at least one FcR with higher affinity than the unaltered polypeptide. An altered constant region that exhibits decreased FcR binding binds to at least one FcR with lower affinity than the unaltered form of the constant region. Such variants that exhibit reduced binding to FcR may have little or no measurable binding to FcR, e.g., 0-50% (e.g., 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1%), compared to the level of binding of a native sequence immunoglobulin constant region or Fc region to FcR. Similarly, modified constant regions that exhibit modulated ADCC and / or CDC activity may exhibit enhanced or decreased ADCC and / or CDC activity compared to the unmodified constant region.

[0245] In some embodiments, the anti-CCR8 antibody exhibits enhanced effector function. In some embodiments, the anti-CCR8 antibody comprises a hybrid constant region, or a portion thereof, such as a G2 / G4 hybrid constant region (see, e.g., Burton et al. (1992) Adv Immun 51:1-18, Canfield et al. (1991) J Exp Med 173:1483-1491, and Mueller et al. (1997) Mol Immunol 34(6):441-452).

[0246] In some embodiments, the anti-CCR8 antibody comprises a modified constant region that exhibits enhanced complement-dependent cytotoxicity (CDC). Modulated CDC activity can be achieved by introducing one or more amino acid substitutions, insertions, or deletions into the Fc region of the antibody. See, e.g., U.S. Patent No. 6,194,551. Alternatively or additionally, cysteine ​​residue(s) may be introduced into the Fc region, thereby allowing interchain disulfide bond formation in this region. The homodimeric antibody thus generated may have improved internalization capability and / or enhanced complement-mediated cell killing. See, e.g., Caron et al. (1992) J Exp Med 176:1191-1195 and Shopes (1992) Immunol 148:2918-2922, PCT Publication Nos. WO 99 / 51642 and WO 94 / 29351, Duncan and Winter (1988) Nature 322:738-40, and U.S. Pat. Nos. 5,648,260 and 5,624,821.

[0247] In some embodiments, the anti-CCR8 antibody is a bispecific antibody, a bispecific T cell-engaging antibody (BiTE), a multispecific antibody, a biparatopic antibody, an immunoconjugate, an antibody-drug conjugate, or any combination thereof.

[0248] II.C. Antibody Variants and Immunoconjugates Certain aspects of the present disclosure relate to antibodies comprising a first antigen-binding region that binds to human CCR8 and a second antigen-binding region that binds to a second antigen, wherein the first antigen-binding region comprises an anti-CCR8 antibody described herein. In some embodiments, the antibody is a bispecific antibody, e.g., capable of binding to only two antigens. In some embodiments, the antibody is a multispecific antibody, e.g., capable of binding to three or more antigens. In some embodiments, the multispecific antibody is capable of binding to at least about three antigens, at least about four antigens, at least about five antigens, or at least about six antigens.

[0249] In some embodiments, the antibody is a biparatopic antibody. A biparatopic antibody can bind to two epitopes on a single polypeptide target. In some embodiments, the biparatopic antibody comprises a first antigen-binding region and a second antigen-binding region, wherein the first antigen-binding region and / or the second antigen-binding region comprises an anti-CCR8 antibody disclosed herein.

[0250] In some embodiments, the multispecific antibody is a bispecific T cell-inducing antibody (BiTE). The BiTE construct comprises a first antigen-binding region that binds to the CD3 receptor on T cells and a second antigen-specific binding region. In some embodiments, the BiTE comprises a first antigen-binding region that binds to CD3 and a second antigen-binding region that binds to human CCR8, wherein the second antigen-binding region comprises an anti-CCR8 antibody disclosed herein.

[0251] In some embodiments, the bispecific antibody, multispecific antibody, BiTE, or biparatopic antibody comprises a first VL domain comprising a first VH CDR1, a first VH CDR2, and a first VH CDR3; a first VL CDR1, a first VL CDR2, and a first VL CDR3; a second VH domain comprising a second VH CDR1, a second VH CDR2, and a second VH CDR3; and a second VL domain comprising a second VL CDR1, a second VL CDR2, and a second VL CDR3, wherein (a) the first VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 45, 105, 115, 135, and 145, (b) the first VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146, and (c) the first VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 46, 106, 116, 136, and 146. CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 47, 107, 117, 137, and 147. In some embodiments, (a) the first VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 48, 108, 118, 138, and 148, (b) the first VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 49, 109, 119, 139, and 149, and (c) the first VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 50, 110, 120, 140, and 150.

[0252] In some embodiments, (a) the VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165; (b) the VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166; and (c) the VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167. In some embodiments, (a) the VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168; (b) the VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169; and (c) the VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170.

[0253] In some embodiments, the antibody is a biparatopic antibody, and (a) the second VH CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 5, 15, 25, 35, 55, 65, 75, 85, 95, 125, 155, and 165; (b) the second VH CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 6, 16, 26, 36, 56, 66, 76, 86, 96, 126, 156, and 166; and (c) the second VH CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 7, 17, 27, 37, 57, 67, 77, 87, 97, 127, 157, and 167. In some embodiments, the antibody is a biparatopic antibody, and (a) the second VL CDR1 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 8, 18, 28, 38, 58, 68, 78, 88, 98, 128, 158, and 168; (b) the second VL CDR2 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 9, 19, 29, 39, 59, 69, 79, 89, 99, 129, 159, and 169; and (c) the second VL CDR3 comprises an amino acid sequence selected from the amino acid sequences set forth in SEQ ID NOs: 10, 20, 30, 40, 60, 70, 80, 90, 100, 130, 160, and 170.

[0254] Certain aspects of the present disclosure relate to immunoconjugates comprising the anti-CCR8 antibodies disclosed herein. In some embodiments, the immunoconjugates are antibody-drug conjugates. The immunoconjugates can comprise any cytotoxic agent known in the art linked to the anti-CCR8 antibodies disclosed herein. In some embodiments, the antibody-drug conjugates comprise a cytotoxic agent selected from the group consisting of maytansinoids (e.g., meitaisin), dolastatins, auristatin drug analogs, cryptophycins, duocarmycin derivatives (e.g., CC-1065 analogs and duocarmycins), enediyne antibiotics (e.g., esperamicin and calicheamicin), pyrrolobenzodiazepines (PBDs), and any combination thereof. Antibody-drug conjugates comprising an anti-CCR8 antibody and a cytotoxic agent may enable efficacy in oncology indications where effector cells, including NK cells and macrophages, are scarce.

[0255] II.D. Fc Region Mutants In certain embodiments, one or more amino acid modifications may be introduced into the Fc region of an antibody provided herein, thereby generating an Fc region variant. The Fc region variant may comprise a human Fc region sequence (e.g., a human IgG1, IgG2, IgG3, or IgG4 Fc region) containing an amino acid modification (e.g., substitution) at one or more amino acid positions.

[0256] In certain embodiments, the present invention contemplates antibody variants that retain some but not all effector functions, making them desirable candidates for applications where in vivo antibody half-life 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 performed to confirm reduced / depleted CDC and / or ADCC activity. For example, Fc receptor (FcR) binding assays can be performed to ensure that the antibody lacks FcγR binding (and thus likely lacks ADCC activity) but retains FcRn binding ability. NK cells, the primary cells for mediating ADCC, express only FcγRIII, whereas monocytes express FcγRI, FcγRII, and FcγRIII. FcR expression on hematopoietic cells is summarized in Ravetch and Kinet, Annu. Rev. Immunol. 9:457-492 (1991), page 464, Table 3. Non-limiting examples of in vitro assays to assess ADCC activity of a molecule of interest are described in U.S. Patent No. 5,500,362 (see, e.g., Hellstrom, I. et al., Proc. Nat'l Acad. Sci. USA 83:7059-7063 (1986)), and Hellstrom, I. et al., Proc. Nat'l Acad. Sci. USA 82:1499-1502 (1985), 5,821,337 (see, Bruggemann, M. et al., J. Exp. Med. 166:1351-1361 (1987)). Alternatively, non-radioactive assay methods may be used (see, e.g., ACTI™ Non-Radioactive Cytotoxicity Assay for Flow Cytometry (CellTechnology, Inc. Mountain View, CA, and CytoTox 96® Non-Radioactive Cytotoxicity Assay (Promega, Madison, WI)). Useful effector cells for such assays include peripheral blood mononuclear cells (PBMC) and natural killer (NK) cells.Alternatively, or additionally, ADCC activity of the molecule of interest can be assessed in vivo, e.g., in an animal model such as that disclosed in Clynes et al. Proc. Nat'l Acad. Sci. USA 95:652-656 (1998). C1q binding assays may also be performed to confirm that the antibody is unable to bind C1q and thus lacks CDC activity. See, e.g., C1q and C3c binding ELISAs in WO2006 / 029879 and WO2005 / 100402. To assess complement activation, a CDC assay may be performed (see, e.g., Gazzano-Santoro et al., J. Immunol. Methods 202:163 (1996); Cragg, MS et al., Blood 101:1045-1052 (2003); and Cragg, MS and MJ 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, SB et al., Int'l. Immunol. 18(12):1759-1769 (2006)).

[0257] Antibodies with reduced effector function include those with substitutions at one or more of Fc region residues 238, 265, 269, 270, 297, 327, and 329 (U.S. Patent 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 substitutions of residues 265 and 297 to alanine (U.S. Patent No. 7,332,581).

[0258] Certain antibody variants have been described that have enhanced 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)).

[0259] In certain embodiments, the antibody variant comprises an Fc region with one or more amino acid substitutions that enhance ADCC, for example, substitutions at positions 298, 333, and / or 334 (EU numbering of residues) of the Fc region.

[0260] In some embodiments, modifications are made in the Fc region that result in altered (i.e., either enhanced or decreased) 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).

[0261] Antibodies with extended half-lives and enhanced binding to neonatal Fc receptors (FcRn), which are responsible for the transfer of maternal IgG to the fetus (Guyer et al., J. Immunol. 117:587 (1976) and Kim et al., J. Immunol. 24:249 (1994)), are described in U.S. Patent Publication No. 2005 / 0014934A1 (Hinton et al.). These antibodies comprise an Fc region with one or more substitutions that enhance binding of the Fc region to FcRn. Such Fc variants include those having a substitution at one or more of Fc region residues 238, 252, 254, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, ​​413, 424 or 434, e.g., a substitution at Fc region residue 434 (e.g., U.S. Patent No. 7,371,826).

[0262] See also Duncan & Winter, Nature 322:738-40 (1988), U.S. Patent No. 5,648,260, U.S. Patent No. 5,624,821, and WO 94 / 29351 for other examples of Fc region variants.

[0263] In some embodiments, antibodies are provided wherein the isotype is human IgG1. In some embodiments, antibodies are provided wherein the isotype is human IgG4. In some embodiments, antibodies are provided wherein the isotype is human IgG4 and there is a single mutation at position 228, from serine to proline (S228P). In some embodiments, antibodies are provided wherein the isotype is human IgG4 and there are two mutations, from serine to proline at position 228 (S228P) and from leucine to glutamic acid at position 235 (L235E). The S228P mutation has been reported in the literature to occur at position 228, but the exact location of the mutation in the antibody may vary depending on how the antibody is produced.

[0264] II.E. Chimeric Antigen Receptors (CARs) and T Cell Receptors (TCRs) Certain embodiments of the present disclosure relate to chimeric antigen receptors (CARs) comprising an antigen-binding region that specifically binds to the N-terminal extracellular domain of human CCR8. In some embodiments, the antigen-binding region comprises an anti-CCR8 antibody disclosed herein, or an antibody or antigen-binding fragment thereof that binds to the same epitope as an anti-CCR8 antibody disclosed herein. In some embodiments, the CAR further comprises a transmembrane domain. In some embodiments, the CAR further comprises an intracellular signaling domain. In some embodiments, the CAR further comprises a hinge region and / or a spacer region.

[0265] Certain embodiments of the present disclosure relate to a T cell receptor (TCR) comprising an antigen-binding region that specifically binds to the N-terminal extracellular domain of human CCR8. In some embodiments, the antigen-binding region comprises an anti-CCR8 antibody disclosed herein, or an antibody or antigen-binding fragment thereof that binds to the same epitope as an anti-CCR8 antibody disclosed herein. In some embodiments, the TCR further comprises a transmembrane domain. In some embodiments, the TCR further comprises an intracellular signaling domain.

[0266] II.F. Nucleic Acid Molecules, Vectors, and Cells Certain aspects of the present disclosure relate to nucleic acid molecules encoding the anti-CCR8 antibodies disclosed herein. The nucleic acids may be present in whole cells, cell lysates, or in partially purified or substantially pure form. A nucleic acid is "isolated" or "substantially purified" if it has been purified away from other cellular components or other contaminants, such as other intracellular nucleic acids (e.g., other chromosomal DNA, e.g., chromosomal DNA linked to the essentially isolating DNA) or proteins, by standard techniques, including alkaline / SDS treatment, CsCl banding, column chromatography, restriction enzymes, agarose gel electrophoresis, and other techniques known in the art. See F. Ausubel, et al., ed. (1987) Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York. The nucleic acids described herein may be, for example, DNA or RNA, and may or may not contain intervening sequences. In some embodiments, the nucleic acid is a cDNA molecule.

[0267] The nucleic acids described herein can be obtained using standard molecular biology techniques. In the case of antibodies expressed in hybridomas (e.g., hybridomas generated from transgenic mice carrying human immunoglobulin genes, as described further below), cDNAs encoding the light and heavy chains of the antibodies produced by the hybridomas can be obtained by standard PCR amplification or cDNA cloning techniques. In the case of antibodies obtained from an immunoglobulin gene library (e.g., using phage display techniques), nucleic acids encoding the antibodies can be recovered from the library.

[0268] In some embodiments, the nucleic acid can further encode a signal peptide.

[0269] The nucleic acid molecules described herein may be modified to delete particular sequences, for example, restriction enzyme recognition sequences, or to optimize codons.

[0270] Methods for producing the anti-CCR8 antibodies disclosed herein can include expressing the heavy and light chains in a cell line containing nucleotide sequences encoding the heavy and light chains with signal peptides. Host cells containing these nucleotide sequences are also included herein.

[0271] Once the DNA fragments encoding the VH and VL segments are obtained, these DNA fragments can be further manipulated by standard recombinant DNA techniques, e.g., to convert the variable region genes into full-length antibody chain genes, Fab fragment genes, or scFv genes. In these manipulations, the VL- or VH-encoding DNA fragment is operably linked to another DNA fragment encoding another protein, e.g., an antibody constant region or a flexible linker. As used in this context, the term "operably linked" is intended to mean that the two DNA fragments are joined such that the amino acid sequences encoded by the two DNA fragments remain in frame.

[0272] The isolated DNA encoding the VH region can be converted into a full-length heavy chain gene by operably linking the VH-encoding DNA to another DNA molecule encoding a heavy chain constant region (hinge, CH1, CH2, and / or CH3). The sequences of human heavy chain constant region genes are known in the art (see, e.g., Kabat, EA, et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242), and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The heavy chain constant region can be an IgG1, IgG2, IgG3, IgG4, IgA, IgE, IgM, or IgD constant region, e.g., an IgG1 region. In the case of a Fab fragment heavy chain gene, the VH-encoding DNA can be operably linked to another DNA molecule encoding only the heavy chain CH1 constant region.

[0273] The isolated DNA encoding the VL region can be converted to a full-length light chain gene (and a Fab light chain gene) by operably linking the VL-encoding DNA to another DNA molecule encoding a light chain constant region, CL. The sequences of human light chain constant region genes are known in the art (see, e.g., Kabat, EA, et al. (1991 Sequences of Proteins of Immunological Interest, Fifth Edition, USDapartment of Health and Human Services, NIH Publication No. 91-3242)), and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The light chain constant region can be a kappa or lambda constant region.

[0274] To generate an scFv gene, the VH- and VL-encoding DNA fragment is operably linked to another fragment encoding a flexible linker, e.g., the amino acid sequence (Gly4-Ser)3, such that the VH and VL sequences can be expressed as a continuous single-chain protein, with the VL and VH regions connected by the flexible linker (see, e.g., Bird et al., (1988) Science 242:423-426; Huston et al., (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883; McCafferty et al., (1990) Nature 348:552-554).

[0275] Also provided herein are nucleic acid molecules encoding VH and VL sequences homologous to those of the anti-CCR8 antibodies disclosed herein. Exemplary nucleic acid molecules encode VH and VL sequences that are at least 70% identical, e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical, to the nucleic acid molecules encoding the VH and VL sequences disclosed herein. Also provided herein are nucleic acid molecules with conservative substitutions (i.e., substitutions that do not alter the resulting amino acid sequence upon translation of the nucleic acid molecule), e.g., due to codon optimization.

[0276] Also provided are nucleic acids encoding the VH and / or VL regions of an anti-CCR8 antibody, such as the anti-CCR8 antibodies described herein, wherein the nucleic acid comprises a nucleotide sequence that is at least about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% identical to any of the nucleotide sequences encoding the VH and / or VL regions of the anti-CCR8 antibodies described herein.

[0277] Also provided are nucleic acids encoding the heavy and / or light chains of an anti-CCR8 antibody, such as the anti-CCR8 antibodies described herein, wherein the nucleic acid comprises a nucleotide sequence that is at least about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% identical to any of the nucleotide sequences encoding the heavy and / or light chains of the anti-CCR8 antibodies described herein.

[0278] Certain aspects of the present disclosure relate to vectors comprising the nucleic acid molecules disclosed herein. In some embodiments, the vector is selected from a viral vector, a mammalian vector, and a bacterial vector. In some embodiments, the vector is a viral particle or virus. In some embodiments, the vector is a mammalian vector. In some embodiments, the vector is a bacterial vector.

[0279] In certain embodiments, the viral vector is a retroviral vector. In some embodiments, the viral vector is selected from the group consisting of an adenoviral vector, a lentivirus, a Sendai virus, a baculoviral vector, an Epstein-Barr virus vector, a papovavirus vector, a cowpox virus vector, a herpes simplex virus vector, and an adeno-associated virus (AAV) vector. In certain embodiments, the vector is an AAV vector. In some embodiments, the vector is a lentivirus. In certain embodiments, the vector is an AAV vector. In some embodiments, the vector is a Sendai virus. In some embodiments, the vector is a hybrid vector. For examples of hybrid vectors that can be used in the present disclosure, see Huang and Kamihira, Biotechnol. Adv. 31(2):208-23 (2103), which is incorporated herein by reference in its entirety.

[0280] In some embodiments, the vector further comprises one or more regulatory elements, including, but not limited to, one or more enhancers, promoters, miRNA binding sequences, polyA sequences, intervening sequences, splice acceptor sites, and any combination thereof. In some embodiments, the vector comprises a tissue-specific enhancer. In some embodiments, the vector comprises a tissue-specific promoter.

[0281] Certain aspects of the present disclosure relate to a cell, e.g., a host cell, comprising an anti-CCR8 antibody disclosed herein, a bispecific antibody disclosed herein, a BiTE disclosed herein, a multispecific antibody disclosed herein, a biparatopic antibody disclosed herein, a CAR disclosed herein, a TCR disclosed herein, a nucleic acid molecule disclosed herein, or a vector disclosed herein. The cell can be any type of cell. In some embodiments, the cell is selected from a mammalian cell, a bacterial cell, an insect cell, a plant cell, and a yeast cell. In some embodiments, the cell is selected from the group consisting of an E. coli cell, a fungus such as Saccharomyces cerevisiae and Pichia pastoris, an insect cell such as SF9, a mammalian cell line (e.g., a human cell line), and a primary cell line.

[0282] In some embodiments, the cell is an immune cell. In some embodiments, the cell is a T cell. Accordingly, certain embodiments of the present disclosure relate to immune cells, e.g., T cells, comprising a CAR or TCR disclosed herein.

[0283] II.G. Pharmaceutical Compositions In certain embodiments, the present disclosure provides pharmaceutical compositions comprising an anti-CCR8 antibody together with a pharmaceutically acceptable diluent, carrier, solubilizer, emulsifier, preservative and / or adjuvant.

[0284] In certain embodiments, acceptable formulation materials are preferably non-toxic to recipients at the dosages and concentrations employed. In certain embodiments, the formulation material(s) are for subcutaneous and / or intravenous administration. In certain embodiments, pharmaceutical compositions may contain formulation materials to adjust, maintain, or preserve, for example, pH, osmolality, viscosity, clarity, color, isotonicity, odor, sterility, stability, rate of dissolution or release, adsorption or penetration of the composition.In certain embodiments, suitable formulation materials include amino acids (such as glycine, glutamine, asparagine, arginine, or lysine), antimicrobial agents, antioxidants (such as ascorbic acid, sodium sulfite, or sodium bisulfite), buffers (such as borate, bicarbonate, Tris-HCl, citrate, phosphate, or other organic acids), bulking agents (such as mannitol or glycine), chelating agents (such as ethylenediaminetetraacetic acid (EDTA)), complexing agents (such as caffeine, polyvinylpyrrolidone, beta-cyclodextrin, or hydroxypropyl beta-cyclodextrin), fillers, monosaccharides, disaccharides, and other carbohydrates (such as glucose, mannose, or dextrin), proteins (such as serum albumin, gelatin, or immunoglobulins), colorants, flavoring agents and excipients, emulsifiers, hydrophilic polymers (such as polyvinylpyrrolidone), low molecular weight polypeptides, salt-forming pairs, and the like. These include, but are not limited to, anions (such as sodium), preservatives (such as benzalkonium chloride, benzoic acid, salicylic acid, thimerosal, phenethyl alcohol, methylparaben, propylparaben, chlorhexidine, sorbic acid, or hydrogen peroxide), solvents (such as glycerin, propylene glycol, or polyethylene glycol), sugar alcohols (such as mannitol or sorbitol), suspending agents, surfactants or wetting agents (such as Pluronic®, PEG, sorbitan esters, polysorbates such as polysorbate 20, polysorbate 80, Triton, tromethamine, lecithin, cholesterol, tyloxapol), stability enhancers (such as sucrose or sorbitol), tonicity enhancers (such as alkali metal halides, preferably sodium chloride or potassium chloride, mannitol sorbitol, etc.), delivery vehicles, diluents, excipients, and / or pharmaceutical adjuvants. (Remington's Pharmaceutical Sciences, 18th Edition, A.R. Gennaro, ed., Mack Publishing Company (1995)). In certain embodiments, the formulation comprises PBS; 20 mM NaOAC (pH 5.2), 50 mM NaCl; and / or 10 mM NaOAC (pH 5.2), 9% sucrose.In certain embodiments, the optimal pharmaceutical composition will be determined by one of skill in the art depending on, for example, the intended route of administration, delivery form, and desired dosage. See, e.g., Remington's Pharmaceutical Sciences, supra. In certain embodiments, such compositions may influence the physical state, stability, rate of in vivo release, and / or rate of in vivo clearance of the anti-CCR8 antibody.

[0285] In certain embodiments, the primary vehicle or carrier in a pharmaceutical composition can be either aqueous or non-aqueous in nature. For example, in certain embodiments, a suitable vehicle or carrier can be water for injection, physiological saline, or artificial cerebrospinal fluid, optionally supplemented with other ingredients common in compositions for parenteral administration. In certain embodiments, the physiological saline comprises isotonic phosphate-buffered saline. In certain embodiments, neutral buffered saline or saline mixed with serum albumin are further exemplary vehicles. In certain embodiments, the pharmaceutical composition comprises Tris buffer at a pH of about 7.0-8.5 or acetate buffer at a pH of about 4.0-5.5, which may further comprise sorbitol or a suitable substitute. In certain embodiments, a composition comprising an anti-CCR8 antibody can be prepared for storage by mixing a selected composition having the desired purity with optional formulation agents (Remington's Pharmaceutical Sciences, supra) in the form of a lyophilized cake or aqueous solution. Furthermore, in certain embodiments, a composition comprising an anti-CCR8 antibody can be formulated as a lyophilizate using appropriate excipients, such as sucrose.

[0286] In certain embodiments, pharmaceutical compositions can be selected for parenteral delivery. In certain embodiments, compositions can be selected for inhalation or delivery via the digestive tract, such as orally. The preparation of such pharmaceutically acceptable compositions is within the skill of one of ordinary skill in the art.

[0287] In certain embodiments, formulation components are present in concentrations that are acceptable at the site of administration. In certain embodiments, buffering agents are used to maintain the composition at physiological pH or slightly lower, typically within a pH range of about 5 to about 8.

[0288] In certain embodiments, when parenteral administration is intended, the therapeutic composition may be in the form of a pyrogen-free, parenterally acceptable aqueous solution containing an anti-CCR8 antibody in a pharmaceutically acceptable vehicle. In certain embodiments, the vehicle for parenteral injection is sterile distilled water, in which the anti-CCR8 antibody is formulated as a sterile isotonic solution and properly stored. In certain embodiments, the preparation involves formulating the desired molecule with an agent that can provide controlled or sustained release of the product, which can then be delivered via depot injection, such as injectable microspheres, bioerodible particles, polymeric compounds (e.g., polylactic acid or polyglycolic acid), beads, or liposomes. In certain embodiments, hyaluronic acid may also be used, thereby maintaining the effect of promoting sustained duration in the circulation. In certain embodiments, the desired molecule can be introduced using an implantable drug delivery device.

[0289] In certain embodiments, pharmaceutical compositions can be formulated for inhalation. In certain embodiments, anti-CCR8 antibodies can be formulated as dry powders for inhalation. In certain embodiments, inhalation solutions comprising anti-CCR8 antibodies can be formulated with propellants for aerosol delivery. In certain embodiments, the solution can be nebulized. Pulmonary administration is further described in PCT Application No. PCT / US94 / 001875, which describes pulmonary delivery of chemically modified proteins.

[0290] In certain embodiments, it is contemplated that the formulation can be administered orally. In certain embodiments, the anti-CCR8 antibody administered in this manner can be formulated with or without carriers conventionally used in the compounding of solid dosage forms such as tablets and capsules. In certain embodiments, the capsule can be designed to release the active portion of the formulation at a time when bioavailability is maximized in the gastrointestinal tract and pre-systemic degradation is minimized. In certain embodiments, at least one additional agent can be included to promote absorption of the anti-CCR8 antibody. In certain embodiments, diluents, flavoring agents, low-melting waxes, vegetable oils, lubricants, suspending agents, tablet disintegrating agents, and binders can also be used.

[0291] In certain embodiments, pharmaceutical compositions can contain an effective amount of anti-CCR8 antibody mixed with non-toxic excipients suitable for tablet manufacture. In certain embodiments, solutions can be prepared in unit dose form by dissolving tablets in sterile water or another suitable vehicle. In certain embodiments, suitable excipients include, but are not limited to, inert diluents such as calcium carbonate, sodium carbonate or bicarbonate, lactose, or calcium phosphate; or binders such as starch, gelatin, or gum arabic; or lubricants such as magnesium stearate, stearic acid, or talc.

[0292] Additional pharmaceutical compositions, including formulations in which anti-CCR8 antibodies are incorporated into sustained- or controlled-delivery formulations, will be apparent to those skilled in the art. In certain embodiments, techniques for formulating various other sustained- or controlled-delivery means, such as liposome carriers, bioerodible microparticles or porous beads, and depot injections, are also known to those skilled in the art. See, for example, PCT Application No. PCT / US93 / 00829, which describes the controlled release of porous polymeric microparticles for the delivery of pharmaceutical compositions. In certain embodiments, sustained-release preparations may comprise semipermeable polymer matrices in the form of shaped articles, for example, films, or microcapsules. Sustained-release matrices include polyesters, hydrogels, polylactides (U.S. Pat. No. 3,773,919 and EP 058,481), copolymers of L-glutamic acid and gamma-ethyl-L-glutamate (Sidman et al., Biopolymers, 22:547-556 (1983)), poly(2-hydroxyethyl-methacrylate) (Langer et al., J. Biomed. Mater. Res., 15:167-277 (1981) and Langer, Chem. Tech., 12:98-105 (1982)), ethylene vinyl acetate (Langer et al., supra), or poly-D(-)-3-hydroxybutyrate (EP 133,988). In certain embodiments, sustained-release compositions can also comprise liposomes, which can be prepared by any of several methods known in the art. See, for example, Eppstein et al., Proc. Natl. Acad. Sci. USA, 82:3688-3692 (1985), EP 036,676, EP 088,046, and EP 143,949.

[0293] Pharmaceutical compositions used for in vivo administration are typically sterile.In certain embodiments, this can be achieved by filtration through a sterile filtration membrane.In certain embodiments, when the composition is lyophilized, sterilization using this method can be carried out either before or after lyophilization and solution preparation.In certain embodiments, compositions for parenteral administration can be stored in lyophilized form or in a solution.In certain embodiments, parenteral compositions are generally placed into a container with a sterile access port, for example, an intravenous solution bag or a vial with a stopper that can be pierced by a hypodermic injection needle.

[0294] In certain embodiments, once formulated, the pharmaceutical composition may be stored in a sterile vial as a solution, suspension, gel, emulsion, solid, or dehydrated or lyophilized powder. In certain embodiments, such formulations can be stored either in a ready-to-use form or in a form (e.g., lyophilized) that can be reconstituted with liquid prior to administration.

[0295] In certain embodiments, kits for preparing single-dose units are provided. In certain embodiments, the kits may contain both a first container containing a dried protein and a second container containing an aqueous formulation. In certain embodiments, kits containing single-chamber and multi-chamber pre-filled syringes (e.g., liquid syringes and lyosyringes) are included.

[0296] In certain embodiments, the effective amount of a pharmaceutical composition comprising an anti-CCR8 antibody used for treatment will depend, for example, on the condition and purpose of the treatment. Those skilled in the art will understand that appropriate dosage levels for treatment according to certain embodiments will vary in part depending on the molecule being delivered, the indication for which the anti-CCR8 antibody is being used, the route of administration, and the size (weight, body surface area, or organ size) and / or condition (age and general health) of the patient. In certain embodiments, a clinician can titrate the dosage and modify the route of administration to obtain the optimal therapeutic effect.

[0297] In certain embodiments, the frequency of dosing will take into account the pharmacokinetic parameters of the anti-CCR8 antibody in the formulation used. In certain embodiments, the clinician will administer the composition until a dosage that achieves the desired effect is reached. Thus, in certain embodiments, the composition may be administered as a single dose, or as two or more doses over time (which may or may not contain the same amount of the desired molecule), or as continuous infusion via an implanted device or catheter. Further refinement of the appropriate dosage is routinely performed by those skilled in the art and is within the scope of tasks routinely performed by those skilled in the art. In certain embodiments, the appropriate dosage may be confirmed by using appropriate dose-response data.

[0298] In certain embodiments, the pharmaceutical composition is administered by known methods, such as oral, intravenous, intraperitoneal, intracerebral (intraparenchymal), intracerebroventricular, intramuscular, subcutaneous, intraocular, intraarterial, intraportal injection, or intralesional routes, by sustained release systems, or by implantation devices. In certain embodiments, the composition may be administered by bolus injection, or by continuous infusion, or by implantation devices. In certain embodiments, the individual components of the combination therapy may be administered by different routes.

[0299] In certain embodiments, the composition may be administered locally via implantation of a membrane, sponge, or other suitable material into which the desired molecule is absorbed or encapsulated. In certain embodiments, when an implantation device is used, the device may be implanted into any suitable tissue or organ, and delivery of the desired molecule may be via diffusion, sustained bolus, or continuous administration. In certain embodiments, it may be desirable to use a pharmaceutical composition comprising an anti-CCR8 antibody in an ex vivo manner. In such cases, cells, tissues, and / or organs removed from a patient are exposed to a pharmaceutical composition comprising an anti-CCR8 antibody, and then the cells, tissues, and / or organs are returned to the patient's body by transplantation.

[0300] In certain embodiments, anti-CCR8 antibodies can be delivered by implanting specific cells genetically engineered to express and secrete the polypeptide using methods described herein. In certain embodiments, such cells can be animal or human cells and can be autologous, heterologous, or xenogeneic. In certain embodiments, the cells can be immortalized. In certain embodiments, to reduce the chance of an immune response, the cells can be encapsulated to avoid infiltration of surrounding tissues. In certain embodiments, the encapsulating material is typically a biocompatible, semipermeable polymeric enclosure or membrane that releases the protein product(s) but prevents destruction of the cells by the patient's immune system or other harmful factors from surrounding tissues.

[0301] III. Methods of the Disclosure Certain aspects of the present disclosure relate to methods of making and / or using the anti-CCR8 antibodies disclosed herein.

[0302] III.A. How to use Certain embodiments of the present disclosure relate to methods of reducing, depleting, or killing tumor-infiltrating Tregs, the methods comprising administering to a subject an anti-CCR8 antibody disclosed herein. Some embodiments of the present disclosure relate to methods of reducing, depleting, or killing tumor-infiltrating Tregs, the methods comprising administering to a subject a bispecific antibody, a BiTE, a multispecific antibody, a biparatopic antibody, an immunoconjugate, a CAR, a TCR, a nucleic acid molecule or set of nucleic acid molecules, a vector or set of vectors, a cell, or a pharmaceutical composition disclosed herein.

[0303] Certain embodiments of the present disclosure relate to methods of activating NK cells or inducing NK cell-mediated killing of tumor-infiltrating regulatory Tregs, the methods comprising administering an anti-CCR8 antibody disclosed herein to a subject. Some embodiments of the present disclosure relate to methods of activating NK cells or inducing NK cell-mediated killing of tumor-infiltrating regulatory Tregs, the methods comprising administering a bispecific antibody, BiTE, multispecific antibody, biparatopic antibody, immunoconjugate, CAR, TCR, nucleic acid molecule or set of nucleic acid molecules, vector or set of vectors, cell, or pharmaceutical composition disclosed herein.

[0304] In some embodiments, the contacting occurs in vitro. In some embodiments, the contacting occurs in vivo. In some embodiments, the contacting treats a disease or condition in a subject in need thereof. In some embodiments, the contacting stimulates an immune response in the subject. In some embodiments, the subject has a tumor, and the contacting enhances an immune response against the tumor.

[0305] Certain embodiments of the present disclosure relate to methods of treating a tumor in a subject in need thereof, the method comprising administering to the subject an anti-CCR8 antibody disclosed herein. Some embodiments of the present disclosure relate to methods of treating a tumor in a subject in need thereof, the method comprising administering to the subject a bispecific antibody, a BiTE, a multispecific antibody, a biparatopic antibody, an immunoconjugate, a CAR, a TCR, a nucleic acid molecule or set of nucleic acid molecules, a vector or set of vectors, a cell, or a pharmaceutical composition disclosed herein.

[0306] In some embodiments, the subject has a tumor, ie, Kaposi's sarcoma, leukemia, acute lymphocytic leukemia, acute myeloid leukemia, myeloblastic promyelocytic myelomonocytic monocytic erythroleukemia, chronic leukemia, chronic myeloid (granulocytic) leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, primary central nervous system lymphoma, Burkitt's lymphoma and marginal zone B-cell lymphoma, polycythemia vera lymphoma, Hodgkin's disease, non-Hodgkin's disease, multiple myeloma, Waldenstrom's macroglobulinemia, Blood clots, heavy chain disease, solid tumors, sarcomas, and carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic osteosarcoma, osteosarcoma, chordoma, angiosarcoma, endothelioma, lymphangiosarcoma, lymphangioendothelioma, synovium, mesothelioma, Ewing's sarcoma, leiomyosarcoma, rhabdomyosarcoma, colon sarcoma, colorectal cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatocellular carcinoma (HCC), liver cancer, cholangiocarcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, uterine cancer, testicular tumor, lung cancer, small cell lung cancer, non-small cell lung cancer, bladder cancer, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma, nasopharyngeal carcinoma, esophageal cancer, basal cell carcinoma, biliary tract cancer, bladder cancer, bone cancer, brain and central nervous system (CNS) cancer, cervical cancer, choriocarcinoma, colorectal cancer, connective tissue cancer, digestive system cancer, endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer, intraepithelial neoplasia, kidney cancer, laryngeal cancer, liver cancer, lung cancer (small cell, large cell), melanoma, neuroblastoma; oral cancer (e.g., lip, tongue, mouth, and pharynx), ovarian cancer, pancreatic cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer; respiratory system cancer, sarcoma, skin cancer, stomach cancer, testicular cancer, thyroid cancer, uterine cancer, and urinary system cancer, or any combination thereof.

[0307] In some embodiments, the tumor is refractory to previous treatments. In some embodiments, the tumor is refractory to previous standard treatments. In some embodiments, the previous treatments include immunotherapy, chemotherapy, surgery, radiation therapy, or any combination thereof. In some embodiments, the tumor is refractory to previous chemotherapy. In some embodiments, the tumor is refractory to previous immunotherapy. In some embodiments, the tumor is recurrent.

[0308] In some embodiments, the tumor is aggressive. In some embodiments, the tumor is locally aggressive. In some embodiments, the tumor is metastatic.

[0309] In some embodiments, the anti-CCR8 antibody is administered in combination with an additional anti-cancer agent, hi some embodiments, the additional anti-cancer agent is selected from a small molecule, a polypeptide, radiation therapy, surgery, and combinations thereof.

[0310] In some embodiments, the anti-CCR8 antibody is administered before the additional anti-cancer agent. In some embodiments, the anti-CCR8 antibody is administered after the additional anti-cancer agent. In some embodiments, the anti-CCR8 antibody is administered simultaneously with the additional anti-cancer agent. In some embodiments, the anti-CCR8 antibody and the additional anti-cancer agent are formulated in a single composition.

[0311] In some embodiments, the additional anti-cancer agent comprises chemotherapy. The chemotherapy can be any chemotherapy known in the art. In some embodiments, the chemotherapy is standard treatment for the particular cancer type. In some embodiments, the chemotherapy is platinum-based chemotherapy. In some embodiments, the chemotherapy is selected from the group consisting of doxorubicin (ADRIAMYCIN®), cisplatin, carboplatin, bleomycin sulfate, carmustine, chlorambucil (LEUKERAN®), cyclophosphamide (CYTOXAN®, NEOSAR®), lenalidomide (REVLIMID®), bortezomib (VELCADE®), dexamethasone, mitoxantrone, etoposide, cytarabine, bendamustine (TREANDA®), and others. )), rituximab (RITUXAN®), ifosfamide, vincristine (ONCOVIN®), fludarabine (FLUDARA®), thalidomide (THALOMID®), alemtuzumab (CAMPATH®), ofatumumab (ARZERRA®), everolimus (AFINITOR®, ZORTRESS®), carfilzomib (KYPROLISTM), and any combination thereof.

[0312] In some embodiments, the additional anti-cancer agent comprises an immunotherapy, hi some embodiments, the immunotherapy is selected from a PD-1 antagonist, a PD-L1 inhibitor, a TIM-3 inhibitor, a LAG-3 inhibitor, a TIGIT inhibitor, a CD112R inhibitor, a TAM inhibitor, a STING agonist, a 4-1BB agonist, a CCL22 inhibitor, an agent that induces NK cell activation, and any combination thereof.

[0313] In some embodiments, the additional anti-cancer therapy comprises a PD-1 antagonist. Any PD-1 antagonist known in the art may be used in combination with the anti-CCR8 antibodies disclosed herein. In some embodiments, the PD-1 antagonist is an antibody or antigen-binding portion thereof that specifically binds to PD-1. Non-limiting examples of PD-1 antagonists that can be used in combination with the anti-CCR8 antibodies disclosed herein include PDR001, nivolumab, pembrolizumab, pidilizumab, MEDI0680, REGN2810, TSR-042, PF-06801591, and AMP-224.

[0314] In some embodiments, the additional anti-cancer therapy comprises a PD-L1 inhibitor. Any PD-L1 inhibitor known in the art may be used in combination with the anti-CCR8 antibodies disclosed herein. In some embodiments, the PD-L1 inhibitor is an antibody or antigen-binding portion thereof that specifically binds to PD-L1. Non-limiting examples of PD-L1 inhibitors that can be used in combination with the anti-CCR8 antibodies disclosed herein include FAZ053, atezolizumab, avelumab, durvalumab, and BMS-936559.

[0315] In some embodiments, the additional anti-cancer therapy comprises a TIM-3 inhibitor. Any TIM-3 inhibitor known in the art may be used in combination with the anti-CCR8 antibodies disclosed herein. In some embodiments, the TIM-3 inhibitor is an antibody or antigen-binding portion thereof that specifically binds to TIM-3. Non-limiting examples of TIM-3 inhibitors that can be used in combination with the anti-CCR8 antibodies disclosed herein include MGB453 and TSR-022.

[0316] In some embodiments, the additional anti-cancer therapy comprises a LAG-3 inhibitor. Any LAG-3 inhibitor known in the art may be used in combination with the anti-CCR8 antibodies disclosed herein. In some embodiments, the LAG-3 inhibitor is an antibody or antigen-binding portion thereof that specifically binds to LAG-3. Non-limiting examples of LAG-3 inhibitors that can be used in combination with the anti-CCR8 antibodies disclosed herein include LAG525, BMS-986016, and TSR-033.

[0317] In some embodiments, the additional anti-cancer therapy comprises a TIGIT inhibitor. Any TIGIT inhibitor known in the art may be used in combination with the anti-CCR8 antibody disclosed herein. In some embodiments, the TIGIT inhibitor is an antibody or antigen-binding portion thereof that specifically binds to TIGIT.

[0318] In some embodiments, the additional anti-cancer therapy comprises a CD112R inhibitor. Any CD112R inhibitor known in the art may be used in combination with the anti-CCR8 antibodies disclosed herein. In some embodiments, the CD112R inhibitor is an antibody or antigen-binding portion thereof that specifically binds to CD112R.

[0319] In some embodiments, the additional anti-cancer therapy comprises a CCL22 inhibitor. Any CCL22 inhibitor known in the art may be used in combination with the anti-CCR8 antibodies disclosed herein. In some embodiments, the CCL22 inhibitor is an antibody or antigen-binding portion thereof that specifically binds to CCL22.

[0320] In some embodiments, the additional anti-cancer therapy comprises an agent that induces NK cell activation, thereby enhancing the ADCC activity of the CCR8 antibody. In some embodiments, the agent that induces NK cell activation is an antibody or antigen-binding portion thereof, a small molecule, a cytokine, or a cytokine fusion.

[0321] In certain embodiments, the additional anticancer agent is sunitinib (SUTENT®), cabozantinib (CABOMETYX®), axitinib (INLYTA®), lenvatinib (LENVIMA®), everolimus (AFINITOR®), bevacizumab (AVASTIN®), epacadostat, NKTR-214 (a CD-122 biased agonist), tivo Xanib (FOTIVDA®), abexinostat, ipilimumab (YERVOY®), tremelimumab, pazopanib (VOTRIENT®), sorafenib (NEXAVAR®), temsirolimus (TORISEL®), ramucirumab (CYRAMZA®), niraparib, savolitinib, borolinib (X-82), regorafenib (STIVARGO®), trademark), donafenib (multikinase inhibitor), camrelizumab (SHR-1210), pexastimodine devasilepvec (JX-594), ramucirumab (CYRAMZA®), apatinib (YN968D1), encapsulated doxorubicin (THERMODOX®), tivantinib (ARQ197), ADI-PEG20, binimetinib, apatinib mesylate, nintedanib, lirilumab, The anti-cancer agent includes an anti-cancer agent selected from the group consisting of volumab (OPDIVO®), pembrolizumab (KEYTRUDA®), atezolizumab (TECENTRIQ®), avelumab (BAVENCIO®), durvalumab (IMFIMZI®), cemiplimab-rwlc (LIBTAYO®), tislelizumab, spartalizumab, and any combination thereof.

[0322] In some embodiments, the additional anti-cancer agent comprises a TAM (Axl, Mer, Tyro) inhibitor. In some embodiments, the additional anti-cancer agent comprises a 4-1BB agonist. In some embodiments, the additional anti-cancer agent comprises a tyrosine kinase inhibitor (TKI). Non-limiting examples of TKIs that can be used in combination with the anti-CCR8 antibodies disclosed herein include imatinib mesylate, dasatinib, nilotinib, and bosutinib.

[0323] The anti-CCR8 antibody of the present disclosure can be administered by any suitable route. In some embodiments, the anti-CCR8 antibody is administered intravenously. In some embodiments, the anti-CCR8 antibody is administered subcutaneously. In some embodiments, the anti-CCR8 antibody is administered intramuscularly. In some embodiments, the anti-CCR8 antibody is administered intraperitoneally. In some embodiments, the anti-CCR8 antibody is administered orally.

[0324] III.B. Methods for Producing Anti-CCR8 Antibodies The present disclosure features methods for producing any of the anti-CCR8 antibodies described herein. In some embodiments, the methods for preparing the antibodies described herein can include immunizing a subject (e.g., a non-human mammal) with an appropriate immunogen. Suitable immunogens for generating any of the antibodies described herein are described herein. For example, to generate an antibody that binds to the N-terminal extracellular domain of human CCR8, one skilled in the art can immunize a suitable subject (e.g., a non-human mammal such as a rat, mouse, gerbil, hamster, dog, cat, pig, goat, or horse, or a non-human primate) with a fragment of human CCR8 containing the N-terminal extracellular domain. In some embodiments, a fragment polypeptide containing the amino acid sequence set forth in SEQ ID NO: 172 is used as the immunogen.

[0325] A suitable subject (e.g., a non-human mammal) can be immunized with an appropriate antigen, with subsequent boosts, sufficient times to induce the production of antibodies by the mammal. The immunogen can be administered to the subject (e.g., a non-human mammal) using an adjuvant. Adjuvants useful for producing antibodies in a subject include, but are not limited to, protein adjuvants; bacterial adjuvants, such as whole bacteria (BCG, Corynebacterium parvum, or Salmonella minnesota) and bacterial components, such as cell wall skeletons, trehalose dimycolate, monophosphoryl lipid A, methanol extract residue of tubercle bacillus (MER), complete or incomplete Freund's adjuvant, viral adjuvants, chemical adjuvants, such as aluminum hydroxide, and iodoacetate and cholesteryl hemisuccinate. Other adjuvants that can be used in methods to induce an immune response include, for example, cholera toxin and parapoxvirus proteins. See also Bieg et al. (1999) Autoimmunity 31(1):15-24. See also, e.g., Lodmell et al. (2000) Vaccine 18:1059-1066, Johnson et al. (1999) J Med Chem 42:4640-4649, Baldridge et al. (1999) Methods 19:103-107, and Gupta et al. (1995) Vaccine 13(14):1263-1276.

[0326] In some embodiments, the method involves preparing a hybridoma cell line secreting a monoclonal antibody that binds to the immunogen. For example, a suitable mammal, e.g., a laboratory mouse, is immunized with a CCR8 polypeptide as described above. Antibody-producing cells (e.g., splenic B cells) from the immunized mammal are isolated 2-4 days after at least one booster immunization with the immunogen, then briefly expanded in culture and subsequently fused with cells of a suitable myeloma cell line. The cells can be fused in the presence of a fusion promoter, e.g., cowpox virus or polyethylene glycol. The resulting hybrid cells are cloned, and cell clones secreting the desired antibody are selected. For example, spleen cells from a Balb / c mouse immunized with a suitable immunogen can be fused with cells of the myeloma cell line PAI or the myeloma cell line Sp2 / 0-Ag14. After fusion, the cells are grown in a suitable culture medium periodically supplemented with a selective medium, e.g., HAT medium, to prevent overgrowth of the desired hybridoma cells by normal myeloma cells. The resulting hybrid cells are then screened for secretion of a desired antibody, e.g., an antibody that binds to human CCR8, and in some embodiments, are screened for secretion of a desired antibody, e.g., an antibody that binds to human CCR8, as described in, e.g., U.S. Pat. No. 6,300,064 (Knappik et al.; Morphosys AG) and Schoonbroodt et al. (2005) Nucleic Acids. One skilled in the art can identify anti-CCR8 antibodies from non-immune biased libraries as described in Acids Res 33(9):e81.

[0327] In some embodiments, the methods described herein can be used in combination with other antibody screening techniques, such as phage display, bacterial display, yeast surface display, eukaryotic viral display, mammalian cell display, and cell-free (e.g., ribosome display) techniques (see, e.g., Etz et al. (2001) J Bacteriol 183:6924-6935; Cornelis (2000) Curr Opin Biotechnol 11:450-454; Klemm et al. 2000) Microbiology 146:3025-3032; Kieke et al. (1997) Protein Eng 10:1303-1310; Yeung et al. (2002) Biotechnol Prog...

Claims

1. 1. A pharmaceutical composition for use in a method of treating a subject having a tumor, comprising an antibody or antigen-binding portion thereof that specifically binds to human CCR8, wherein the antibody or antigen-binding portion thereof comprises a VH chain comprising the amino acid sequence set forth in SEQ ID NO:41 and a VL chain comprising the amino acid sequence set forth in SEQ ID NO:43; the method comprises administering the antibody or antigen-binding portion thereof to the subject; The pharmaceutical composition, wherein the antibody or antigen-binding portion thereof is defucosylated.

2. The pharmaceutical composition of claim 1 , wherein the antibody or antigen-binding portion thereof comprises an IgG1 Fc domain.

3. The pharmaceutical composition of claim 1, wherein the antibody or antigen-binding portion thereof is administered as part of an immunoconjugate.

4. The pharmaceutical composition of claim 3 , wherein the immunoconjugate is an antibody-drug conjugate.

5. 2. The pharmaceutical composition of claim 1, wherein the antibody or antigen-binding portion thereof is administered as part of a chimeric antigen receptor (CAR).

6. 2. The pharmaceutical composition of claim 1, wherein the antibody or antigen-binding portion thereof is administered as part of a T cell receptor (TCR).

7. 10. The pharmaceutical composition of claim 1, wherein the method further comprises administering the antibody or antigen-binding portion thereof in combination with an additional anti-cancer agent, radiation therapy, or surgery.

8. 8. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent is a small molecule, a polypeptide, or a combination thereof.

9. 8. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent comprises a chemotherapeutic agent.

10. 10. The pharmaceutical composition of claim 9, wherein the chemotherapeutic agent comprises a platinum-based chemotherapeutic agent.

11. 8. The pharmaceutical composition of claim 7, wherein the additional anticancer agent comprises a PD-1 antagonist, a PD-L1 inhibitor, a TIM-3 inhibitor, a LAG-3 inhibitor, a TIGIT inhibitor, a CD112R inhibitor, a TAM inhibitor, a STING agonist, a 4-1BB agonist, a CCL22 inhibitor, an agent that induces NK cell activation, or a combination thereof.

12. 8. The pharmaceutical composition of claim 7, wherein the additional anticancer agent comprises a PD-1 antagonist.

13. 13. The pharmaceutical composition of claim 12, wherein the PD-1 antagonist is selected from the group consisting of PDR001, nivolumab, pembrolizumab, pidilizumab, MEDI0680, REGN2810, TSR-042, PF-06801591, and AMP-224.

14. The pharmaceutical composition of claim 8, wherein the additional anticancer agent comprises a PD-L1 inhibitor.

15. 15. The pharmaceutical composition of claim 14, wherein the PD-L1 inhibitor is selected from the group consisting of FAZ053, atezolizumab, avelumab, durvalumab, and BMS-936559.

16. The additional anticancer drug may be sunitinib, cabozantinib, axitinib, lenvatinib, everolimus, bevacizumab, epacadostat, NKTR-214, tivozanib, abexinostat, ipilimumab, tremelimumab, pazopanib, sorafenib, temsirolimus, ramucirumab, niraparib, savolitinib, boranib (X-82), regorafenib, donafenib, camrelizumab, pexas 8. The pharmaceutical composition of claim 7, which is thymodine debasilepvec, ramucirumab, apatinib, encapsulated doxorubicin, tivantinib, ADI-PEG20, binimetinib, apatinib mesylate, nintedanib, lirilumab, nivolumab, pembrolizumab, atezolizumab, avelumab, durvalumab, cemiplimab-rwlc, tislelizumab, spartalizumab, or a combination thereof.

17. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent comprises a TIM-3 inhibitor.

18. The pharmaceutical composition of claim 17, wherein the TIM-3 inhibitor is MGB453 or TSR-022.

19. The pharmaceutical composition of claim 7, wherein the additional anticancer agent comprises a LAG-3 inhibitor.

20. 20. The pharmaceutical composition of claim 19, wherein the LAG-3 inhibitor is selected from the group consisting of LAG525, BMS-986016, and TSR-033.

21. The pharmaceutical composition of claim 7 , wherein the additional anticancer agent comprises a TIGIT inhibitor.

22. The pharmaceutical composition of claim 7 , wherein the additional anti-cancer agent comprises a CD112R inhibitor.

23. 8. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent comprises a TAM (Axl, Mer, Tyro) inhibitor.

24. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent comprises a 4-1BB agonist.

25. 8. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent comprises a tyrosine kinase inhibitor (TKI).

26. 8. The pharmaceutical composition of claim 7, wherein the additional anti-cancer agent comprises a CCL2 inhibitor.

27. The tumors include Kaposi's sarcoma, leukemia, acute lymphocytic leukemia, acute myeloid leukemia, myeloblastic promyelocytic myelomonocytic monocytic erythroleukemia, chronic leukemia, chronic myeloid (granulocytic) leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, primary central nervous system lymphoma, Burkitt's lymphoma and marginal zone B-cell lymphoma, polycythemia vera lymphoma, Hodgkin's disease, non-Hodgkin's disease, multiple myeloma, Waldenstrom's macroglobulinemia, heavy chain disease, solid tumors. , sarcomas, and carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic osteosarcoma, osteosarcoma, chordoma, angiosarcoma, endothelioma, lymphangiosarcoma, lymphangioendothelioma, synovioma, mesothelioma, Ewing's sarcoma, leiomyosarcoma, rhabdomyosarcoma, colon sarcoma, colorectal cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatocellular carcinoma (HCC), liver carcinoma, cholangiocarcinoma, Choriocarcinoma, Seminoma, Embryonal carcinoma, Wilms' tumor, Cervical cancer, Uterine cancer, Testicular tumor, Lung cancer, Small cell lung cancer, Non-small cell lung cancer, Bladder cancer, Epithelial carcinoma, Glioma, Astrocytoma, Medulloblastoma, Craniopharyngioma, Ependymoma, Pinealoma, Hemangioblastoma, Acoustic neuroma, Oligodendroglioma, Meningioma, Melanoma, Neuroblastoma, Retinoblastoma, Nasopharyngeal carcinoma, Esophageal cancer, Basal cell carcinoma, Biliary tract cancer, Bladder cancer, Bone cancer, Brain and central nervous system (CNS) cancer, Cervical cancer, Choriocarcinoma, Colorectal cancer, Connective tissue cancer, Digestive 27. The pharmaceutical composition of any one of claims 1 to 26, wherein the cancer is selected from: urinary system cancer, endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer, intraepithelial neoplasia, kidney cancer, laryngeal cancer, liver cancer, lung cancer (small cell, large cell), melanoma, neuroblastoma; oral cancer (e.g., lip, tongue, mouth, and pharynx), ovarian cancer, pancreatic cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer; respiratory system cancer, sarcoma, skin cancer, stomach cancer, testicular cancer, thyroid cancer, uterine cancer, and urinary system cancer, or a combination thereof.

28. The pharmaceutical composition according to any one of claims 1 to 26, wherein the tumor is refractory or recurrent.

29. The pharmaceutical composition of any one of claims 1 to 26, wherein the tumor is advanced, locally advanced, or metastatic.

30. The pharmaceutical composition according to any one of claims 1 to 26, wherein the tumor is head and neck cancer.

31. The pharmaceutical composition according to any one of claims 1 to 26, wherein the tumor is squamous cell carcinoma.

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