Anti-Nectin-4 Antibody and Its Use

Abstract

The present invention provides an anti-Nectin-4 antibody and its use. The anti-Nectin-4 antibody or antigen-binding fragment of the present invention can specifically bind to Nectin-4, has high affinity and strong endocytosis, and can be used for the diagnosis, prevention and / or treatment of tumors (including cancers and benign tumors).

Description

Technical Field

[0001] This application relates to the field of immunology. Specifically, it relates to anti-Nectin-4 antibodies and their use.

Background Art

[0002] Nectin-4 is one of the cell adhesion molecules in the immunoglobulin superfamily (IgSF), a calcium-independent cell adhesion molecule (CAM), also called poliovirus receptor-like protein 4 (PVRL4) or poliovirus receptor-related (PRR4). Nectin-4 is a single-pass transmembrane protein containing an extracellular region, a transmembrane region, and an intracellular region. The extracellular region contains three highly glycosylated domains, namely, two C2 domains close to the cell membrane and one V domain away from the cell membrane. The Nectin-4 molecule binds to the H protein via its N-terminal V domain, thereby enabling viral infection of cells. Nectin-4 is involved in the formation and maintenance of adhesive junctions through its interaction with cadherin. Nectin-4 mediates Ca 2+ -independent adhesion and promotes anchorage-independent growth by driving cell-cell adhesion and activation of matrix-independent integrin β4 / SHP-2 / c-Src.

[0003] Nectin-4 is expressed during fetal development and, unlike the widespread expression of other Nectins in adult tissues, its expression is significantly reduced in adult tissues. Multiple research institutions have demonstrated that Nectin-4 is overexpressed in various tumors, including breast cancer and bladder cancer. Nectin-4 is weakly to moderately expressed in the stratum corneum of the skin, skin appendages (sweat glands and hair follicles), bladder transitional epithelium, salivary glands, esophagus, mammary glands, and stomach in normal adult tissues, and is expressed relatively weakly in the larynx, pituitary gland, placenta, testis, ureter, and uterus.

SUMMARY OF THE INVENTION

MEANS FOR SOLVING THE PROBLEM

[0004] This application relates to anti-Nectin-4 antibodies and their use. Specifically, the present invention relates to the following aspects: 1. An anti-Nectin-4 antibody (e.g., derived from a monkey such as a human or cynomolgus monkey or a mouse) or an antigen-binding fragment, wherein the anti-Nectin-4 antibody comprises one or more of the following HCDR1, HCDR2, and HCDR3 or variants thereof, (1) According to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 181-195, SEQ ID NO: 234-248, and SEQ ID NO: 304-317, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NO: 196-231, SEQ ID NO: 251-303, and SEQ ID NO: 318-358, and the sequence of HCDR3 comprises or consists of the sequence shown in any one of SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 20, SEQ ID NO: 22, and SEQ ID NO: 24, (2) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 7, In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 10, (3) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 11, In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 12, (4) The HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 13 In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 14. (5) The HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 15 In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 16. (6) The HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 17 In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 18. (7) The HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 19 In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 20. (8) The HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 21 In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 22. (9) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 23 In some embodiments, according to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 24. (10) The sequence of HCDR1 comprises or consists of the sequence shown in X1X2X3MS, the sequence of HCDR2 comprises or consists of the sequence shown in X1’IX2’X3’X4’X5’X6’X7’X8’X9’YADSVKG (SEQ ID NO: 368), and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 12, 14, or 16, wherein X1, X2, X3, X1’, X2’, X3’, X4’, X5’, X6’, X7’, X8’, X9’, and X10’ each represent any one amino acid independently selected from G, A, V, L, I, S, T, C, M, N, Q, K, R, D, E, F, Y, H, P, and W. In some embodiments, X1 represents S, N, T, D, or G, X2 represents Y, F, or S, X3 represents A, G, S, or Y, X1’ represents A, R, G, I, or W, X2’ represents S, K, Y, or D, X3’ represents G, P, S, A, Q, or W, X4’ represents S, T, G, Y, H, D, W, or I, X5’ represents G, D, T, S, A, or K, X6’ represents G, S, D, A, or W, X7’ represents S, Y, T, N, D, V, E, or G, X8’ represents T, A, N, K, I, R, S, or P, and X9’ represents Y, S, H, R, N, G, F, or D. In some embodiments, X1 represents S, N, T, D or G, X2 represents Y, N, F or S, X3 represents A, G, S or absent, X1’ represents A, R, G, W or S, X2’ represents S, K, Y or D, X3’ represents G, P, S, T, A, Q or Y, X4’ represents S, T, G, Y, H, D, W or I, X5’ represents G, D, T, S, F or K, X6’ represents G, S, D, A, W or absent, X7’ represents S, Y, T, N, D, V, E or G, X8’ represents T, A, N, K, I, R, S or P, X9’ represents Y, S, H, R, N, F or D, In some embodiments, X1 represents S, N, D, G or T, X2 represents Y, F or S, X3 represents A, D, W, S or Y, X1’ represents A, S, G or V, X2’ represents S, K, I, Y or D, X3’ represents G, P, S, A, Q, Y, T or D, X4’ represents S, T, G, Y, H, D or W, X5’ represents G, D, T, S or K, X6’ represents G, S, D, A or Y, X7’ represents S, Y, T, N, D, V or G, X8’ represents T, A, N, K, I, R or S, X9’ represents Y, S, H, R, N, G, F or D, In some embodiments, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8 and SEQ ID NOs: 181 to 195, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9 and SEQ ID NOs: 196 to 231, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 14, In some embodiments, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 181, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 194, and SEQ ID NOs: 234 to 248, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NO: 202, and SEQ ID NOs: 251 to 303, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 12, In some embodiments, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 235, SEQ ID NO: 238, SEQ ID NO: 241, and SEQ ID NOs: 304-317; the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NOs: 318-358; and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 16. In some embodiments, the sequence of the above HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 241; the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 357; and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 16. In some embodiments, the sequence of the above HCDR1 consists of the sequence shown in SEQ ID NO: 241; the sequence of HCDR2 consists of the sequence shown in 357; and the sequence of HCDR3 consists of the sequence shown in SEQ ID NO: 16. Among them, the mutant sequences have 3, 2, or 1 amino acid differences (preferably conservative amino acid substitutions), respectively, relative to the corresponding CDR sequences, or have at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identity, respectively, and the mutants retain the binding affinity for Nectin-4. For example, the binding dissociation equilibrium constant (KD) for binding to Nectin-4 is about 1 μM or less, or the KD is between about 100 nM and about 1 pM or less.

[0005] In some embodiments, the anti-Nectin-4 antibody or antigen-binding fragment is derived from birds and mammals. In some embodiments, the anti-Nectin-4 antibody is an antibody derived from human, mouse, donkey, rabbit, goat, camel, llama, horse, or chicken.

[0006] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 10.

[0007] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 12.

[0008] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 14.

[0009] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 16.

[0010] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 18.

[0011] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 20.

[0012] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 22.

[0013] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 24.

[0014] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 196, and HCDR3 shown in SEQ ID NO: 14.

[0015] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 182, HCDR2 shown in SEQ ID NO: 197, and HCDR3 shown in SEQ ID NO: 14.

[0016] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 14.

[0017] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 199, and HCDR3 shown in SEQ ID NO: 14.

[0018] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 185, HCDR2 shown in SEQ ID NO: 200, and HCDR3 shown in SEQ ID NO: 14.

[0019] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 201, and HCDR3 shown in SEQ ID NO: 14.

[0020] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 186, HCDR2 shown in SEQ ID NO: 202, and HCDR3 shown in SEQ ID NO: 14.

[0021] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 187, HCDR2 shown in SEQ ID NO: 203, and HCDR3 shown in SEQ ID NO: 14.

[0022] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 204, and HCDR3 shown in SEQ ID NO: 14.

[0023] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 182, HCDR2 shown in SEQ ID NO: 205, and HCDR3 shown in SEQ ID NO: 14.

[0024] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 187, HCDR2 shown in SEQ ID NO: 206, and HCDR3 shown in SEQ ID NO: 14.

[0025] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 188, HCDR2 shown in SEQ ID NO: 207, and HCDR3 shown in SEQ ID NO: 14.

[0026] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 189, HCDR2 shown in SEQ ID NO: 208, and HCDR3 shown in SEQ ID NO: 14.

[0027] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 190, HCDR2 shown in SEQ ID NO: 209, and HCDR3 shown in SEQ ID NO: 14.

[0028] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 210, and HCDR3 shown in SEQ ID NO: 14.

[0029] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 211, and HCDR3 shown in SEQ ID NO: 14.

[0030] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 185, HCDR2 shown in SEQ ID NO: 212, and HCDR3 shown in SEQ ID NO: 14.

[0031] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 213, and HCDR3 shown in SEQ ID NO: 14.

[0032] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 189, HCDR2 shown in SEQ ID NO: 214, and HCDR3 shown in SEQ ID NO: 14.

[0033] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 191, HCDR2 shown in SEQ ID NO: 215, and HCDR3 shown in SEQ ID NO: 14.

[0034] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 216, and HCDR3 shown in SEQ ID NO: 14.

[0035] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 217, and HCDR3 shown in SEQ ID NO: 14.

[0036] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 218, and HCDR3 shown in SEQ ID NO: 14.

[0037] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 192, HCDR2 shown in SEQ ID NO: 219, and HCDR3 shown in SEQ ID NO: 14.

[0038] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 220, and HCDR3 shown in SEQ ID NO: 14.

[0039] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 185, HCDR2 shown in SEQ ID NO: 207, and HCDR3 shown in SEQ ID NO: 14.

[0040] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 190, HCDR2 shown in SEQ ID NO: 222, and HCDR3 shown in SEQ ID NO: 14.

[0041] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 223, and HCDR3 shown in SEQ ID NO: 14.

[0042] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 224, and HCDR3 shown in SEQ ID NO: 14.

[0043] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 193, HCDR2 shown in SEQ ID NO: 225, and HCDR3 shown in SEQ ID NO: 14.

[0044] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 226, and HCDR3 shown in SEQ ID NO: 14.

[0045] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 194, HCDR2 shown in SEQ ID NO: 227, and HCDR3 shown in SEQ ID NO: 14.

[0046] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 228, and HCDR3 shown in SEQ ID NO: 14.

[0047] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 184, HCDR2 shown in SEQ ID NO: 229, and HCDR3 shown in SEQ ID NO: 14.

[0048] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 189, HCDR2 shown in SEQ ID NO: 230, and HCDR3 shown in SEQ ID NO: 14.

[0049] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 190, HCDR2 shown in SEQ ID NO: 231, and HCDR3 shown in SEQ ID NO: 14.

[0050] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 195, HCDR2 shown in SEQ ID NO: 198, and HCDR3 shown in SEQ ID NO: 14.

[0051] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 183, HCDR2 shown in SEQ ID NO: 221, and HCDR3 shown in SEQ ID NO: 14.

[0052] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 234, HCDR2 shown in SEQ ID NO: 251, and HCDR3 shown in SEQ ID NO: 12.

[0053] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 252, and HCDR3 shown in SEQ ID NO: 12.

[0054] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 253, and HCDR3 shown in SEQ ID NO: 12.

[0055] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 254, and HCDR3 shown in SEQ ID NO: 12.

[0056] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 255, and HCDR3 shown in SEQ ID NO: 12.

[0057] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 256, and HCDR3 shown in SEQ ID NO: 12.

[0058] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 235, HCDR2 shown in SEQ ID NO: 257, and HCDR3 shown in SEQ ID NO: 12.

[0059] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 186, HCDR2 shown in SEQ ID NO: 202, and HCDR3 shown in SEQ ID NO: 12.

[0060] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 236, HCDR2 shown in SEQ ID NO: 258, and HCDR3 shown in SEQ ID NO: 12.

[0061] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 259, and HCDR3 shown in SEQ ID NO: 12.

[0062] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 260, and HCDR3 shown in SEQ ID NO: 12.

[0063] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 238, HCDR2 shown in SEQ ID NO: 261, and HCDR3 shown in SEQ ID NO: 12.

[0064] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 262, and HCDR3 shown in SEQ ID NO: 12.

[0065] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 235, HCDR2 shown in SEQ ID NO: 263, and HCDR3 shown in SEQ ID NO: 12.

[0066] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 264, and HCDR3 shown in SEQ ID NO: 12.

[0067] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 265, and HCDR3 shown in SEQ ID NO: 12.

[0068] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 239, HCDR2 shown in SEQ ID NO: 266, and HCDR3 shown in SEQ ID NO: 12.

[0069] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 267, and HCDR3 shown in SEQ ID NO: 12.

[0070] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 236, HCDR2 shown in SEQ ID NO: 268, and HCDR3 shown in SEQ ID NO: 12.

[0071] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 238, HCDR2 shown in SEQ ID NO: 269, and HCDR3 shown in SEQ ID NO: 12.

[0072] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 240, HCDR2 shown in SEQ ID NO: 270, and HCDR3 shown in SEQ ID NO: 12.

[0073] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 241, HCDR2 shown in SEQ ID NO: 271, and HCDR3 shown in SEQ ID NO: 12.

[0074] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 272, and HCDR3 shown in SEQ ID NO: 12.

[0075] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 242, HCDR2 shown in SEQ ID NO: 273, and HCDR3 shown in SEQ ID NO: 12.

[0076] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 242, HCDR2 shown in SEQ ID NO: 274, and HCDR3 shown in SEQ ID NO: 12.

[0077] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 185, HCDR2 shown in SEQ ID NO: 275, and HCDR3 shown in SEQ ID NO: 12.

[0078] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 243, HCDR2 shown in SEQ ID NO: 276, and HCDR3 shown in SEQ ID NO: 12.

[0079] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 187, HCDR2 shown in SEQ ID NO: 277, and HCDR3 shown in SEQ ID NO: 12.

[0080] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 244, HCDR2 shown in SEQ ID NO: 278, and HCDR3 shown in SEQ ID NO: 12.

[0081] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 245, HCDR2 shown in SEQ ID NO: 279, and HCDR3 shown in SEQ ID NO: 12.

[0082] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 240, HCDR2 shown in SEQ ID NO: 280, and HCDR3 shown in SEQ ID NO: 12.

[0083] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 281, and HCDR3 shown in SEQ ID NO: 12.

[0084] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 282, and HCDR3 shown in SEQ ID NO: 12.

[0085] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 283, and HCDR3 shown in SEQ ID NO: 12.

[0086] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 246, HCDR2 shown in SEQ ID NO: 284, and HCDR3 shown in SEQ ID NO: 12.

[0087] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 247, HCDR2 shown in SEQ ID NO: 285, and HCDR3 shown in SEQ ID NO: 12.

[0088] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 286, and HCDR3 shown in SEQ ID NO: 12.

[0089] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 287, and HCDR3 shown in SEQ ID NO: 12.

[0090] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 288, and HCDR3 shown in SEQ ID NO: 12.

[0091] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 194, HCDR2 shown in SEQ ID NO: 289, and HCDR3 shown in SEQ ID NO: 12.

[0092] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 290, and HCDR3 shown in SEQ ID NO: 12.

[0093] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 243, HCDR2 shown in SEQ ID NO: 291, and HCDR3 shown in SEQ ID NO: 12.

[0094] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 292, and HCDR3 shown in SEQ ID NO: 12.

[0095] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 255, and HCDR3 shown in SEQ ID NO: 12.

[0096] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 244, HCDR2 shown in SEQ ID NO: 293, and HCDR3 shown in SEQ ID NO: 12.

[0097] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 247, HCDR2 shown in SEQ ID NO: 294, and HCDR3 shown in SEQ ID NO: 12.

[0098] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 194, HCDR2 shown in SEQ ID NO: 295, and HCDR3 shown in SEQ ID NO: 12.

[0099] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 238, HCDR2 shown in SEQ ID NO: 296, and HCDR3 shown in SEQ ID NO: 12.

[0100] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 297, and HCDR3 shown in SEQ ID NO: 12.

[0101] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 298, and HCDR3 shown in SEQ ID NO: 12.

[0102] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 8, HCDR2 shown in SEQ ID NO: 299, and HCDR3 shown in SEQ ID NO: 12.

[0103] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 248, HCDR2 shown in SEQ ID NO: 300, and HCDR3 shown in SEQ ID NO: 12.

[0104] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 301, and HCDR3 shown in SEQ ID NO: 12.

[0105] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 302, and HCDR3 shown in SEQ ID NO: 12.

[0106] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 237, HCDR2 shown in SEQ ID NO: 9, and HCDR3 shown in SEQ ID NO: 12.

[0107] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 181, HCDR2 shown in SEQ ID NO: 303, and HCDR3 shown in SEQ ID NO: 12.

[0108] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 304, HCDR2 shown in SEQ ID NO: 318, and HCDR3 shown in SEQ ID NO: 16.

[0109] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 304, HCDR2 shown in SEQ ID NO: 319, and HCDR3 shown in SEQ ID NO: 16.

[0110] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 320, and HCDR3 shown in SEQ ID NO: 16.

[0111] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 306, HCDR2 shown in SEQ ID NO: 321, and HCDR3 shown in SEQ ID NO: 16.

[0112] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 307, HCDR2 shown in SEQ ID NO: 322, and HCDR3 shown in SEQ ID NO: 16.

[0113] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 308, HCDR2 shown in SEQ ID NO: 323, and HCDR3 shown in SEQ ID NO: 16.

[0114] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 306, HCDR2 shown in SEQ ID NO: 324, and HCDR3 shown in SEQ ID NO: 16.

[0115] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 306, HCDR2 shown in SEQ ID NO: 321, and HCDR3 shown in SEQ ID NO: 16.

[0116] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 325, and HCDR3 shown in SEQ ID NO: 16.

[0117] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 309, HCDR2 shown in SEQ ID NO: 326, and HCDR3 shown in SEQ ID NO: 16.

[0118] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 327, and HCDR3 shown in SEQ ID NO: 16.

[0119] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 311, HCDR2 shown in SEQ ID NO: 328, and HCDR3 shown in SEQ ID NO: 16.

[0120] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 329, and HCDR3 shown in SEQ ID NO: 16.

[0121] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 238, HCDR2 shown in SEQ ID NO: 330, and HCDR3 shown in SEQ ID NO: 16.

[0122] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 309, HCDR2 shown in SEQ ID NO: 331, and HCDR3 shown in SEQ ID NO: 16.

[0123] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 332, and HCDR3 shown in SEQ ID NO: 16.

[0124] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 308, HCDR2 shown in SEQ ID NO: 333, and HCDR3 shown in SEQ ID NO: 16.

[0125] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 334, and HCDR3 shown in SEQ ID NO: 16.

[0126] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 307, HCDR2 shown in SEQ ID NO: 335, and HCDR3 shown in SEQ ID NO: 16.

[0127] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 312, HCDR2 shown in SEQ ID NO: 336, and HCDR3 shown in SEQ ID NO: 16.

[0128] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 337, and HCDR3 shown in SEQ ID NO: 16.

[0129] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 311, HCDR2 shown in SEQ ID NO: 338, and HCDR3 shown in SEQ ID NO: 16.

[0130] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 313, HCDR2 shown in SEQ ID NO: 339, and HCDR3 shown in SEQ ID NO: 16.

[0131] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 340, and HCDR3 shown in SEQ ID NO: 16.

[0132] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 341, and HCDR3 shown in SEQ ID NO: 16.

[0133] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 314, HCDR2 shown in SEQ ID NO: 339, and HCDR3 shown in SEQ ID NO: 16.

[0134] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 315, HCDR2 shown in SEQ ID NO: 342, and HCDR3 shown in SEQ ID NO: 16.

[0135] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 343, and HCDR3 shown in SEQ ID NO: 16.

[0136] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 344, and HCDR3 shown in SEQ ID NO: 16.

[0137] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 339, and HCDR3 shown in SEQ ID NO: 16.

[0138] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 345, and HCDR3 shown in SEQ ID NO: 16.

[0139] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 346, and HCDR3 shown in SEQ ID NO: 16.

[0140] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 306, HCDR2 shown in SEQ ID NO: 347, and HCDR3 shown in SEQ ID NO: 16.

[0141] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 307, HCDR2 shown in SEQ ID NO: 339, and HCDR3 shown in SEQ ID NO: 16.

[0142] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 235, HCDR2 shown in SEQ ID NO: 348, and HCDR3 shown in SEQ ID NO: 16.

[0143] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 314, HCDR2 shown in SEQ ID NO: 349, and HCDR3 shown in SEQ ID NO: 16.

[0144] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 316, HCDR2 shown in SEQ ID NO: 350, and HCDR3 shown in SEQ ID NO: 16.

[0145] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 306, HCDR2 shown in SEQ ID NO: 351, and HCDR3 shown in SEQ ID NO: 16.

[0146] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 304, HCDR2 shown in SEQ ID NO: 352, and HCDR3 shown in SEQ ID NO: 16.

[0147] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 309, HCDR2 shown in SEQ ID NO: 353, and HCDR3 shown in SEQ ID NO: 16.

[0148] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 310, HCDR2 shown in SEQ ID NO: 354, and HCDR3 shown in SEQ ID NO: 16.

[0149] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 355, and HCDR3 shown in SEQ ID NO: 16.

[0150] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 305, HCDR2 shown in SEQ ID NO: 356, HCDR3 shown in SEQ ID NO: 16, LCDR1 shown in SEQ ID NO: 26, LCDR2 shown in SEQ ID NO: 27, and LCDR3 shown in SEQ ID NO: 28.

[0151] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 241, HCDR2 shown in SEQ ID NO: 357, and HCDR3 shown in SEQ ID NO: 16.

[0152] In some embodiments, the anti-Nectin-4 antibody comprises HCDR1 shown in SEQ ID NO: 317, HCDR2 shown in SEQ ID NO: 358, and HCDR3 shown in SEQ ID NO: 16.

[0153] In some embodiments, the anti-Nectin-4 antibody further comprises LCDR1 shown in SEQ ID NO: 26, LCDR2 shown in SEQ ID NO: 27, and LCDR3 shown in SEQ ID NO: 28.

[0154] 2. The anti-Nectin-4 antibody or antigen-binding fragment according to item 1, wherein the sequences of framework regions HFR1 to HFR4 in the heavy-chain variable region are shown in SEQ ID NOs: 29 to 32, respectively.

[0155] 3. The anti-Nectin-4 antibody or antigen-binding fragment according to item 1, wherein the sequence of framework region HFR1 in the heavy-chain variable region is shown in the amino acid sequence of positions 1 to 30 of the sequence shown in any one of SEQ ID NOs: 41 to 180, and the sequences of HFR2 to HFR4 are shown in SEQ ID NOs: 30 to 32, respectively.

[0156] 4. The anti-Nectin-4 antibody or antigen-binding fragment according to item 1, wherein the anti-Nectin-4 antibody or antigen-binding fragment (1) has a heavy-chain variable region having the sequence shown in SEQ ID NO: 7 or consisting of the same, (2) has a heavy-chain variable region having the sequence shown in SEQ ID NO: 11 or consisting of the same, (3) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 13, (4) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 15, (5) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 17, (6) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 19, (7) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 21, (8) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 23, (9) The heavy chain variable region consisting of or comprising any one of the sequences shown in SEQ ID NOs: 41 to 180, (10) The heavy chain variable region consisting of or comprising the sequence shown in SEQ ID NO: 179, comprising a heavy chain variable region selected from the group consisting of or its variant, Among them, the variant sequence has 3, 2 or 1 amino acid differences (preferably conservative amino acid substitutions) respectively with respect to the corresponding variable region sequence, or has an identity of at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% respectively, and the variant retains the binding affinity for Nectin-4. For example, the binding dissociation equilibrium constant (KD) for binding to Nectin-4 is about 1 μM or less, or the KD is between about 100 nM and about 1 pM or less.

[0157] 5. An anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 4, wherein the amino acid sequence of the heavy chain constant region of the anti-Nectin-4 antibody is shown in SEQ ID NO: 37. In some embodiments, the heavy chain of the anti-Nectin-4 antibody comprises a heavy chain variable region shown in any one of SEQ ID NOs: 7, 11, 13, 15, 17, 19, 21, 23, and 41 to 180, and a heavy chain constant region shown in SEQ ID NO: 37. In some embodiments, the heavy chain amino acid sequence of the anti-Nectin-4 antibody is shown in any one of SEQ ID NOs: 232, 233, 249, and 360 to 363. In some embodiments, the amino acid sequence of the heavy chain of the anti-Nectin-4 antibody is shown in SEQ ID NO: 360.

[0158] 6. An anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 5, wherein the antibody further comprises LCDR1, LCDR2, and LCDR3 contained in the light chain variable region shown in SEQ ID NO: 25. In some embodiments, according to the Kabat numbering system, the sequence of LCDR1 comprises or consists of the sequence shown in SEQ ID NO: 26, the sequence of LCDR2 comprises or consists of the sequence shown in SEQ ID NO: 27, and the sequence of LCDR3 comprises or consists of the sequence shown in SEQ ID NO: 28. In some embodiments, the sequences of framework regions LFR1 to LFR4 in the light chain variable region are shown in SEQ ID NOs: 33 to 36, respectively. In some embodiments, the antibody or antigen-binding fragment comprises the light chain variable region shown in SEQ ID NO: 25. In some embodiments, the antibody or antigen-binding fragment further comprises the light chain constant region shown in SEQ ID NO: 38.

[0159] 7. An anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 6, wherein the antigen-binding fragment is selected from Fab, Fab’, F(ab’)2, F(ab)2, Fd, Fv, dAb, Fab / c, complementarity-determining region fragment, scFv, scFv multimer, disulfide bond-stabilized Fv (dsFv), (dsFv)2, bispecific dsFv (dsFv-dsFv’), diabody, disulfide bond-stabilized diabody (ds-Diabody), multispecific antibody formed from a part of an antibody containing one or more CDRs, single-domain antibody (sdAb), nanobody, domain antibody, or bivalent domain antibody.

[0160] 8. A polypeptide that specifically binds to Nectin-4, (1) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and among them, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 181 to 195, SEQ ID NO: 234 to 248, and SEQ ID NO: 304 to 317; the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NO: 196 to 231, SEQ ID NO: 251 to 303, and SEQ ID NO: 318 to 358; and the sequence of HCDR3 comprises or consists of the sequence shown in any one of SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 20, SEQ ID NO: 22, and SEQ ID NO: 24. (2) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and among them, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8; the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9; and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 10. (3) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Among them, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 181, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 194, and SEQ ID NOs: 234 to 248; the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NO: 202, and SEQ ID NOs: 251 to 303; and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 12. (4) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Among them, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8 and SEQ ID NOs: 181 to 195; the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9 and SEQ ID NOs: 196 to 231; and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 14. (5) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Among them, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 235, SEQ ID NO: 238, SEQ ID NO: 241, and SEQ ID NOs: 304 to 317; the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9 and SEQ ID NOs: 318 to 358; and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 16. (6) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 18. (7) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 20. (8) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 22. (9) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 24. (10) A polypeptide comprising the sequence shown in SEQ ID NO: 7 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 11 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 13 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 15 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 17 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 19 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 21 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 23 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in any one of SEQ ID NOs: 41 to 180 or a variant thereof, and being part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Selected from the group consisting of.

[0161] In some embodiments, the polypeptide further comprises the sequences shown in SEQ ID NO: 26, SEQ ID NO: 27, and SEQ ID NO: 28. In some embodiments, the polypeptide further comprises the sequence shown in SEQ ID NO: 25 or a variant thereof.

[0162] In some embodiments, the variant sequences have 3, 2, or 1 amino acid differences (preferably conservative amino acid substitutions), respectively, relative to the corresponding sequences, or have at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identity, respectively, and the variants retain the binding affinity for Nectin-4.

[0163] In some embodiments, the antibody or antigen-binding fragment of the invention has a dissociation equilibrium constant (KD) for binding to Nectin-4 of about 1 μM or less. In some embodiments, the antibody or antigen-binding fragment of the invention has a KD for binding to Nectin-4 between about 100 nM and about 1 pM or less. In some embodiments, the antibody or antigen-binding fragment of the invention has a KD for binding to Nectin-4 between about 10 nM and about 1 pM or less. In some embodiments, the antibody or antigen-binding fragment of the invention has a KD for binding to Nectin-4 between about 10 nM and about 1 nM or less.

[0164] In some embodiments, the antibody or antigen-binding fragment of the invention has a KD for binding to human Nectin-4 (e.g., the antigen hNectin-4-His shown in SEQ ID NO: 2) between about 100 nM and about 1 pM or less. In some embodiments, the antibody or antigen-binding fragment of the invention has a KD for binding to human Nectin-4 between about 10 nM and about 1 pM or less, or between about 10 nM and about 1 nM or less.

[0165] 9. A biological material, (1) A nucleic acid molecule encoding the anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7, or encoding a polypeptide specifically binding to Nectin-4 according to item 8. (2) A vector comprising a nucleic acid molecule encoding an anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7, or encoding a polypeptide specifically binding to Nectin-4 according to item 8, or (3) A host cell comprising a nucleic acid molecule encoding an anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7, or encoding a polypeptide specifically binding to Nectin-4 according to item 8, It is.

[0166] 10. A conjugate comprising an anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7 and a conjugate moiety, wherein the conjugate moiety is a purification tag (e.g., His tag), a detectable label, a drug, a toxin, a cytokine, an enzyme, or a combination thereof, or the conjugate moiety is a radioisotope, a fluorescent substance such as fluorescein and rhodamine, a chemiluminescent substance such as isoluminol and acridinium ester, a coloring substance such as latex particles and gold colloids, a chemotherapeutic agent, a biological toxin, a therapeutic agent, a prodrug, a peptide, a protein, an enzyme, a virus, a lipid, a biological response modifier, or polyethylene glycol.

[0167] 11. A reagent kit comprising an anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7, a polypeptide specifically binding to Nectin-4 according to item 8, and the conjugate according to item 10. In some embodiments, the reagent kit further comprises a second antibody that specifically recognizes the anti-Nectin-4 antibody. In some embodiments, the second antibody further comprises a detectable label, such as a radioisotope, a fluorescent substance, a chemiluminescent substance, a coloring substance, or an enzyme. In some embodiments, the reagent kit is used to detect the presence or level of Nectin-4 in a sample. In some embodiments, the reagent kit further comprises an antibody or antigen-binding fragment thereof against another antigen, and / or a cytotoxic agent, and optionally an instruction manual.

[0168] 12. A pharmaceutical composition comprising an anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7, a polypeptide specifically binding to Nectin-4 according to item 8, or a conjugate according to item 10, optionally further comprising a pharmaceutically acceptable carrier and / or excipient. In some embodiments, the pharmaceutical composition is in a form suitable for administration by subcutaneous injection, intradermal injection, intravenous injection, intramuscular injection, or intralesional injection.

[0169] 13. Use of an anti-Nectin-4 antibody or antigen-binding fragment according to any one of items 1 to 7, a polypeptide specifically binding to Nectin-4 according to item 8, or a conjugate according to item 10 for the treatment and / or prevention of a disease or in the manufacture of a medicament for treating and / or preventing a disease. In some embodiments, the disease is a disease associated with the expression or overexpression of Nectin-4. In some embodiments, the disease is a disease associated with the abnormal expression of Nectin-4. In some embodiments, the disease is a tumor expressing or overexpressing Nectin-4. In some embodiments, the disease is a cancer expressing or overexpressing Nectin-4. In some embodiments, the disease is a solid tumor or a hematological tumor. In some embodiments, the disease is selected from breast cancer, pancreatic cancer, bladder cancer, urothelial cancer, melanoma, lung cancer, head and neck cancer, cervical cancer, ovarian cancer, choriocarcinoma, skin cancer, esophageal cancer, gastric cancer, uterine cancer, gallbladder cancer, liver cancer, hepatocellular carcinoma, urethral cancer, renal pelvic cancer, ureteral cancer, colorectal cancer, colon cancer, and prostate cancer.

[0170] 14. A method for treating a disease, the method comprising administering to a patient in need thereof an effective amount of the anti-Nectin-4 antibody or antigen-binding fragment thereof according to any one of claims 1 to 7, the polypeptide specifically binding to Nectin-4 according to claim 8, or the conjugate according to claim 10. In some embodiments, the disease is a disease associated with the expression or overexpression of Nectin-4. In some embodiments, the disease is a disease associated with the abnormal expression of Nectin-4. In some embodiments, the disease is a tumor that expresses or overexpresses Nectin-4. In some embodiments, the disease is a cancer that expresses or overexpresses Nectin-4. In some embodiments, the disease is a solid tumor or a hematological tumor. In some embodiments, the disease is selected from breast cancer, pancreatic cancer, bladder cancer, urothelial cancer, melanoma, lung cancer, head and neck cancer, cervical cancer, ovarian cancer, choriocarcinoma, skin cancer, esophageal cancer, gastric cancer, uterine cancer, gallbladder cancer, liver cancer, hepatocellular carcinoma, urethral cancer, renal pelvic cancer, ureteral cancer, colorectal cancer, colon cancer, and prostate cancer.

[0171] 15. A method for producing the anti-Nectin-4 antibody or antigen-binding fragment thereof according to any one of claims 1 to 7 or the polypeptide specifically binding to Nectin-4 according to claim 8, the method comprising culturing a host cell comprising a nucleic acid molecule encoding the antibody or antigen-binding fragment or polypeptide, and optionally further comprising isolating the antibody or antigen-binding fragment or polypeptide.

[0172] Within the scope of the present invention, it should be understood that each of the above technical features of the present invention and each technical feature specifically described below (for example, in the examples) can be combined with each other to form a new or preferred technical solution. For the convenience of the paper, they are not described one by one here.

[0173] The terms related to the present invention have the meanings usually understood by those skilled in the art. When a term has two or more definitions as used and / or permitted in the art, the definition of the term used in this specification is used to include all meanings.

[0174] "Amino acid" refers to an organic compound containing both an amino group and a carboxyl group, such as an α-amino acid, which may be encoded by nucleic acids either as such or in the form of a precursor. A single amino acid is encoded by a nucleic acid consisting of three nucleotides (so-called codon or base triplet). Each amino acid is encoded by at least one codon. Encoding the same amino acid by different codons is called "degeneracy of the genetic code". Amino acids include natural amino acids and non-natural amino acids. Natural amino acids include alanine (three-letter code: Ala, one-letter code: A), arginine (Arg, R), asparagine (Asn, N), aspartic acid (Asp, D), cysteine (Cys, C), glutamine (Gln, Q), glutamic acid (Glu, E), glycine (Gly, G), histidine (His, H), isoleucine (Ile, I), leucine (Leu, L), lysine (Lys, K), methionine (Met, M), phenylalanine (Phe, F), proline (Pro, P), serine (Ser, S), threonine (Thr, T), tryptophan (Trp, W), tyrosine (Tyr, Y) and valine (Val, V).

[0175] "Antibody" refers to a polypeptide or polypeptide complex that specifically recognizes and binds to an antigen. The antibody may be a complete antibody and any antigen-binding fragment thereof or its single chain. Thus, the term "antibody" includes any protein or peptide that contains at least a part of an immunoglobulin molecule having biological activity to bind to an antigen in the molecule. Examples of antibodies include, but are not limited to, heavy chains, light chains, complementarity-determining regions (CDRs) of their ligand-binding portions, heavy chain variable regions (VH), light chain variable regions (VL), heavy chain constant regions (CH), light chain constant regions (CL), framework regions (FR) or any part thereof, or at least a part of a binding protein. The CDR region includes the CDR regions of the light chain (LCDR1-3) and the CDR regions of the heavy chain (HCDR1-3).

[0176] One of ordinary skill in the art can understand that the CDR region of an antibody is involved in the binding specificity of the antibody to an antigen. When the sequences of the heavy and light chain variable regions of an antibody are known, there are currently several methods for determining the CDR region of an antibody, including the Kabat, IMGT, Chothia, and AbM numbering systems. However, each application regarding the definition of the CDR of an antibody or its variant is within the scope of the terms defined and used herein. Given the amino acid sequence of the variable region of the antibody, one of ordinary skill in the art can usually determine which residues are included in a particular CDR without relying on any experimental data other than the sequence itself.

[0177] In the art, the function of a protein is usually not altered when substitutions are made with amino acids having similar or analogous properties. Also, for example, the function of a protein is usually not altered even when one or several amino acids are added to the C-terminus and / or N-terminus. For the purpose of comparing two or more amino acid sequences, the percentage of "sequence homology" (also referred to herein as "amino acid identity") between a first amino acid sequence and a second amino acid sequence is calculated by dividing [the number of amino acid residues in the first amino acid sequence that are identical to the amino acid residues at corresponding positions in the second amino acid sequence] by [the total number of amino acid residues in the first amino acid sequence] and multiplying by [100%], where each deletion, insertion, substitution or addition of an amino acid residue in the second amino acid sequence is considered a difference at a single amino acid residue (position) compared to the first amino acid sequence, i.e., a "amino acid difference" as defined by the present invention. Alternatively, the degree of sequence identity between two amino acid sequences can be calculated using known computer algorithms such as NCBI Multiple Alignment (https: / / www.ncbi.nlm.nih.gov / tools / cobalt / cobalt.cgi?LINK_LOC=BlastHomeLink). Several other techniques, computer algorithms and settings for determining the degree of sequence identity are described, for example, in WO04 / 037999, EP0967284, EP1085089, WO00 / 55318, WO00 / 78972, WO98 / 49185 and GB2357768-A. Usually, for the purpose of determining the percentage of "sequence identity" between two amino acid sequences according to the calculation methods listed above, the amino acid sequence having the largest number of amino acid residues is considered the "first" amino acid sequence, and the other amino acid sequence is considered the "second" amino acid sequence.

[0178] In addition, when determining the degree of sequence identity between two amino acid sequences, one of ordinary skill in the art can take into account so-called "conservative" amino acid substitutions, which can be typically described as amino acid substitutions in which an amino acid residue is replaced with another amino acid residue having a similar chemical structure and that has little or no substantial effect on the function, activity, or other biological properties of the polypeptide. Such conservative amino acid substitutions are known in the art and can be found, for example, in WO04 / 037999, GB-A-3357768, WO98 / 49185, WO00 / 46383, and WO01 / 09300, and such alternative (preferred) types and / or combinations may be selected based on the relevant teachings of WO04 / 037999 and WO98 / 49185 and other references cited therein.

[0179] A "conservative amino acid substitution" is one in which an amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains are defined in the art and include 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), β-branched side chains (e.g., threonine, valine, isoleucine), and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, non-essential amino acid residues of an immunoglobulin polypeptide are preferably replaced with other amino acid residues from the same side chain family. In some other embodiments, a string of amino acids may be replaced with a structurally similar string of amino acids, the latter having a different order and / or composition of side chain families.

[0180] Non-limiting examples of conservative amino acid substitutions are provided in the following table, where a similarity score of 0 or more indicates the presence of a conservative substitution between two amino acids.

Table 0

[0181] In some embodiments, the conservative substitution is a substitution in which one amino acid within the following groups (a) to (e) is replaced by another amino acid residue within the same group: (a) small aliphatic, nonpolar or weakly polar residues: Ala, Ser, Thr, Pro and Gly, (b) polar, negatively charged residues and their (uncharged) amides: Asp, Asn, Glu and Gln, (c) polar, positively charged residues: His, Arg and Lys, (d) large aliphatic, nonpolar residues: Met, Leu, Ile, Val and Cys, and (e) aromatic residues: Phe, Tyr and Trp.

[0182] In some embodiments, the conservative substitutions are as follows: Ala is replaced by Gly or Ser, Arg is replaced by Lys, Asn is replaced by Gln or His, Asp is replaced by Glu, Cys is replaced by Ser, Gln is replaced by Asn, Glu is replaced by Asp, Gly is replaced by Ala or Pro, His is replaced by Asn or Gln, Ile is replaced by Leu or Val, Leu is replaced by Ile or Val, Lys is replaced by Arg, Gln or Glu, Met is replaced by Leu, Tyr or Ile, Phe is replaced by Met, Leu or Tyr, Ser is replaced by Thr, Thr is replaced by Ser, Trp is replaced by Tyr, Tyr is replaced by Trp, and / or Phe is replaced by Val, Ile or Leu.

[0183] As is clear from the general structural formula of α - amino acids, each α - amino acid differs in that the side - chain R group is different. Depending on the chemical structure of the R group, conservative substitutions of amino acids are as follows: Gly, Ala, Val, Leu, and Ile may be substituted for each other; Ser and Thr may be substituted for each other; Cys and Met may be substituted for each other; Asn and Gln may be substituted for each other; Asp and Glu may be substituted for each other; Lys and Arg may be substituted for each other; Phe and Tyr may be substituted for each other.

[0184] The term "antibody fragment" or "antigen-binding fragment" includes, but is not limited to, F(ab’)2, F(ab)2, Fab’, Fab, Fv, Fd, dAb, Fab / c, complementarity-determining region (CDR) fragments, single-chain Fvs (scFv), disulfide-stabilized Fv (dsFv), (dsFv)2, bispecific dsFv (dsFv-dsFv’), diabody, disulfide-bond stabilized diabody (ds-Diabody), scFv multimers (e.g., scFv dimers, scFv trimers), multispecific antibodies formed from parts of an antibody containing one or more CDRs, nanobodies, single-domain antibodies (sdab), domain antibodies, bivalent domain antibodies, or any other antibody fragment that binds an antigen but does not contain the complete antibody structure. Regardless of structure, an antigen-binding fragment includes any polypeptide or polypeptide complex that can bind the same antigen to which the parent antibody or parent antibody fragment binds. Mao C S et al., "Disulfide stabilized Fv Fragments (dsFv): a New Type of Engineering Antibody Fragments", Progress in Biochemistry and Biophysics, 1998, 25(6):525-526 introduced the structure of dsFv. Holt et al., "Domain antibodies: proteins for therapy", Trends in Biotechnology (2003): Vol.21, No.11:484-490 reviewed antigen-binding fragments called "domain antibodies (dAbs)" that contain only the VH or VL domain of an antibody and are thus smaller than, for example, Fab and scFv. A dAb is the smallest known antigen-binding fragment of an antibody at 11 kDa - 15 kDa. The term "antibody fragment" includes aptamers, spiegelmers, and diabodies. The term "antibody fragment" also includes any synthetic or genetically engineered protein that can bind a specific antigen and form a complex, just like an antibody.Generally, an antibody fragment has at least about 50 contiguous amino acids of the antibody of the present invention, preferably at least about 50 contiguous amino acids, more preferably at least about 80 contiguous amino acids, and most preferably at least about 100 contiguous amino acids.

[0185] The antibodies, antigen-binding fragments disclosed by the present invention include modified derivatives, i.e., modified by covalent attachment of any type of molecule to the antibody or antigen-binding fragment, and the covalent attachment does not prevent binding to the epitope of the antibody or antigen-binding fragment. The antibody or antigen-binding fragment may be glycosylated, acetylated, polyethylene glycolated, phosphorylated, amidated, derivatized with known protecting / blocking groups, proteolytically cleaved, conjugated to a cell ligand or other protein, etc. Any one of many chemical modifications may be performed by prior art techniques including, but not limited to, specific chemical cleavage, acetylation, formylation, metabolic synthesis of tunicaamycin, etc.

[0186] In some embodiments, the antibody or antigen-binding fragment can complex with a therapeutic agent, prodrug, peptide, protein, enzyme, virus, lipid, biological response modifier, drug, or polyethylene glycol (PEG).

[0187] In some embodiments, the Nectin-4 antigen is derived from human, monkey (e.g., cynomolgus monkey), or mouse.

[0188] The antibodies described herein can be derived from any animal including birds and mammals. Preferably, the antibody is an antibody derived from human, mouse, donkey, rabbit, goat, camel, llama, or chicken.

[0189] In the present invention, the term "isolated" as used with respect to cells, nucleic acids, polypeptides, antibodies, etc. refers to molecules such as DNA or RNA that are each isolated from one or more other components of the natural environment of the cell. The term "isolated" as used in the present invention further refers to a nucleic acid or peptide that substantially does not contain cell material, viral material, or cell culture medium when produced by recombinant DNA technology, or a substance that substantially does not contain chemical precursors or other chemicals when chemically synthesized. Also, "isolated nucleic acid" includes nucleic acid fragments that do not exist in the natural state and are meant not to exist in the natural state. "Isolated" is also used to mean a cell or polypeptide isolated from other cellular proteins or tissues. Isolated polypeptides are meant to include purified polypeptides and recombinant polypeptides. Isolated polypeptides, antibodies, etc. are generally produced by at least one purification step. In some embodiments, the purity of the isolated nucleic acid, polypeptide, antibody, etc. is at least about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, about 99%, or in the range between any two of these values (including the endpoints) or any of these values.

[0190] Polynucleotides consist of a specific sequence of four nucleotide bases, namely adenine (A), cytosine (C), guanine (G), and thymine (T), or, if the polynucleotide is RNA, thymine is replaced by uracil (U). A "polynucleotide sequence" can be represented by the letters of the polynucleotide molecule. The letters indicate that they can be entered into a database in a computer having a central processing unit and used in bioinformatics applications such as functional genomics and homology searches.

[0191] The terms "polynucleotide" and "nucleic acid" may be used interchangeably and refer to polymeric forms of nucleotides of any length, whether deoxyribonucleotides, ribonucleotides, or analogs thereof. A polynucleotide may have any three-dimensional structure and may perform any function, known or unknown. Non-limiting examples of polynucleotides include genes or gene fragments (e.g., probes, primers, ESTs, or SAGE tags), exons, introns, messenger RNA (mRNA), transfer RNA, ribosomal RNA, ribozymes, cDNA, dsRNA, siRNA, miRNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, nucleic acid probes, and primers. A polynucleotide may include modified nucleotides, such as, for example, methylated nucleotides and nucleotide analogs. When such modifications are present, the modification to the nucleotide structure may be made either before or after assembly of the polynucleotide. The nucleotide sequence may be interrupted by non-nucleotide components. After polymerization, the polynucleotide may be further modified, such as by complexing with a labeling component. The term also refers to double-stranded and single-stranded molecules. Unless otherwise specified or claimed, any example of a polynucleotide of the present disclosure includes the double-stranded form, and each of the two complementary single-stranded forms that are known or predicted to form the double-stranded form.

[0192] The term "encodes," when applied to a polynucleotide, refers to a polynucleotide that is said to "encode" a polypeptide, which, in its native state or when manipulated by methods known to those of skill in the art, can produce the polypeptide and / or a fragment thereof by transcription and / or translation.

[0193] "Treatment" means therapeutic and prophylactic or preventive measures aimed at preventing, alleviating, improving or halting undesirable physiological changes or disorders such as the progression of a disease, including but not limited to results that may or may not be detectable, such as alleviation of symptoms, reduction of disease severity, stabilization of the disease state (i.e., without worsening), delay or alleviation of disease progression, improvement of the disease state, alleviation, reduction or disappearance (partial or complete), and extension of the life expectancy expected in the absence of treatment. Persons in need of treatment include patients already suffering from a medical condition or disorder, patients susceptible to a medical condition or disorder, or patients in need of prevention of the medical condition or disorder, and patients who can or are expected to benefit from administration of an antibody, antigen-binding fragment or pharmaceutical composition disclosed by the present invention for detection, diagnosis processes and / or treatment.

[0194] The effective dose and treatment regimen for treating a particular patient are determined by a variety of factors including the particular antibody, antigen-binding fragment or derivative used, the age and weight of the patient, general health status, sex and diet, and administration times, excretion frequency, drug combinations, and the severity of the particular disease being treated. These factors are determined by medical personnel within the scope of those skilled in the art. The dose used can be determined by pharmacological and pharmacokinetic principles well known in the art. In some embodiments, the antibody of the present invention is administered at a dose of 0.01 mg / kg to 100 mg / kg per administration based on the patient's weight. In some embodiments, it is administered once a week or once a month.

[0195] "Patient" refers to any mammal in need of diagnosis, prognosis or treatment, including humans, dogs, cats, rabbits, mice, horses, cows, etc. In some embodiments, the patient is a human patient.

[0196] "Pharmaceutically acceptable" refers to substances listed in the pharmacopoeia for drugs for animals, particularly humans. Also, "pharmaceutically acceptable carriers and / or excipients" are usually any kind of non-toxic solid, semi-solid or liquid filler, diluent, encapsulating material and formulation aid.

[0197] The term "carrier" refers to a diluent, adjuvant, excipient or vehicle that can be administered to a patient together with an active ingredient. Such pharmaceutical carriers may be, for example, sterile liquids such as water and oils including oils of animal, vegetable or synthetic origin such as peanut oil, soybean oil, mineral oil, sesame oil. When the pharmaceutical composition is administered intravenously, water is a preferred carrier. Aqueous saline solution, aqueous glucose solution and glycerin solution may be used as liquid carriers, especially for injection solutions. Suitable pharmaceutical excipients include starch, glucose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, skimmed milk powder, glycerin, propylene, ethylene glycol, water, ethanol and the like. Optionally, the composition may contain a small amount of wetting agent or emulsifier, or pH buffer. These compositions may adopt forms such as solutions, suspensions, emulsions, tablets, pills, capsules, powders, sustained-release preparations and the like. The composition may be prepared as a suppository with conventional binders and carriers such as triglycerides. Oral formulations may contain standard carriers such as pharmaceutical grade starch, magnesium stearate, sodium saccharin, cellulose, magnesium carbonate and the like. Examples of suitable pharmaceutical carriers are described in Remington’s Pharmaceutical Sciences by E.W. Martin, which is hereby incorporated by reference into the present invention. Such compositions contain a clinically effective dose of an antibody or antigen-binding fragment and preferably, in a purified form, are combined with a suitable number of carriers and / or excipients to provide a dosage form suitable for the patient. The formulation should be suitable for the mode of administration. The parenteral formulation may be enclosed in an ampoule, disposable syringe, or a multi-dose vial made of glass or plastic.

[0198] In some embodiments, the composition is prepared as a pharmaceutical composition suitable for intravenous injection into humans by conventional steps. The composition for intravenous administration is a solution in a sterile isotonic buffer. Generally, the active ingredient is supplied alone or in admixture in the form of unit doses, for example, in a sealed container (e.g., an ampoule or sachet) capable of indicating the amount of the active agent in the form of a dried lyophilized powder or an anhydrous concentrate. When the composition is administered by infusion, the composition can be dispensed by an infusion bottle containing sterile pharmaceutical grade water or physiological saline. When the composition is administered by injection, an ampoule of sterile water for injection or physiological saline can be used to mix the active ingredient prior to administration.

[0199] The antibodies or antigen-binding fragments of the present invention include neutral or salt forms. Pharmaceutically acceptable salts include salts formed with anions derived from, for example, hydrochloric acid, phosphoric acid, acetic acid, oxalic acid, tartaric acid, etc., and salts formed with cations derived from, for example, sodium, potassium, ammonium, calcium, ferric hydroxide, isopropylamine, triethylamine, 2-ethylaminoethanol, histidine, procaine, etc., but are not limited thereto.

[0200] "About" refers to the normal error range of the corresponding numerical value readily known to those skilled in the art. In some embodiments, "about" as referred to herein refers to the recited numerical value and the range of ±10%, ±5% or ±1% thereof.

[0201] The "EC 50 " (concentration for 50% of maximal effect), which is the median effective concentration, refers to the concentration capable of eliciting 50% of the maximal effect.

[0202] Methods for producing antibodies and polynucleotides encoding the antibodies The present invention further discloses a polynucleotide or nucleic acid molecule encoding the antibody, antigen-binding fragment, and derivatives thereof described in the present invention. The polynucleotides disclosed by the present invention can encode a heavy chain variable region, a light chain variable region, an Fc region, a partial heavy chain variable region, a partial light chain variable region, a heavy chain or a light chain, etc. Polynucleotides encoding antibodies and methods for manufacturing antibodies are known in the art and are described in the present invention.

[0203] Antibodies can be produced by various methods known in the art, including the phage display method using an antibody library from immunoglobulin sequences. Reference can also be made to U.S. Patents 4,444,887 and 4,716,111, and PCT publications WO98 / 46645, WO98 / 50433, WO98 / 24893, WO98 / 16654, WO96 / 34096, WO96 / 33735, and WO91 / 10741, the entire contents of each patent being incorporated herein by reference.

[0204] Antibodies can be produced by conventional recombinant DNA techniques. By techniques known to those skilled in the art, vectors and cell lines for producing antibodies can be selected, constructed, and cultured. All of these techniques are described in various laboratory manuals and major publications such as Recombinant DNA Technology for Production of Protein Therapeutics in Cultured Mammalian Cells, D.L. Hacker, F.M. Wurm, in Reference Module in Life Sciences, 2017, and the entire contents thereof, including additional content, are incorporated herein by reference in their entirety.

[0205] In some embodiments, according to conventional methods, based on the antibody amino acid sequences described herein, DNA encoding the antibody is designed and synthesized, inserted into an expression vector, and then host cells are transfected. The transfected host cells are cultured in a medium to produce monoclonal antibodies. In some embodiments, the antibody expression vector includes at least one promoter element, an antibody coding sequence, a transcription termination signal, and a polyA tail. Other elements include enhancers, Kozak sequences, and donor and acceptor sites for RNA splicing on both sides of the insertion sequence. High-efficiency transcription can be obtained by the early and late promoters of SV40, long terminal repeat sequences derived from retroviruses such as RSV, HTLV1, and HIVI, and the early promoter of cytomegalovirus, and several other cellular promoters such as the actin promoter can also be applied. Suitable expression vectors may include pIRES1neo, pRetro-Off, pRetro-On, PLXSN, or Plncx, pcDNA3.1(+ / -), pcDNA / Zeo(+ / -), pcDNA3.1 / Hygro(+ / -), PSVL, PMSG, pRSVcat, pSV2dhfr, pBC12MI, and pCS2, etc. Commonly used mammalian cells include 293 cells, Cos1 cells, Cos7 cells, CV1 cells, mouse L cells, and CHO cells, etc.

[0206] In some embodiments, the inserted gene fragment needs to contain a screening label, and common screening labels include screening genes such as dihydrofolate reductase, glutamine synthetase, neomycin resistance, and hygromycin resistance to facilitate the screening and isolation of cells that have successfully undergone transfection. The constructed plasmid is transfected into host cells without the above genes and cultured in a selective medium, and the cells that have successfully undergone transfection proliferate massively and produce the desired target protein.

[0207] The production of scFv can refer to techniques for generating single-chain units (U.S. Patent 4,694,778, Bird, Science 242:423-442 (1988), Huston et al., Proc Natl.Acad.Sci.USA 55:5879-5883 (1988), Ward et al., Nature 334:544-554 (1989), and Nie et al., Antibody Therapeutics 3(1):18-62 (2020)). Single-chain fusion peptides are produced by forming single-chain units through amino acid cross-linking to the heavy and light chain fragments of the Fv region. Techniques for assembling functional Fv fragments in Escherichia coli can also be used (Skerra et al., Science 242:1038-1041 (1988)).

[0208] Examples of techniques that can be used to produce single-chain Fv (scFv) and antibodies include those described in U.S. Patents 4,946,778 and 5,258,498, as well as Huston et al., Methods in Enzymology 203:46-88 (1991), Shu et al., Proc. Natl. Sci. USA 90:1995-1999 (1993), and Skerra et al., Science 240:1038-1040 (1988). For some uses, including the use of antibodies in the human body and in vitro detection experiments, chimeric antibodies, humanized antibodies, or fully human antibodies can be used. A chimeric antibody is a molecule in which different parts of the antibody are derived from different animal species, for example, an antibody having the variable region of a mouse monoclonal antibody and the constant region of a human immunoglobulin. Methods for producing chimeric antibodies are known in the art and are described in Morrison, Science 229:1202 (1985), Oi et al., BioTechniques 4:214 (1986), Gillies et al., J. Immunol. Methods 125:191-202 (1989), Neuberger et al., Nature 372:604-608 (1984), Takeda et al., Nature 314:452-454 (1985), and U.S. Patents 5,807,715, 4,816,567, and 4,816,397, the entire contents of which are incorporated herein by reference.

Brief Description of the Drawings

[0209]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 4E

Mode for Carrying Out the Invention

[0210] Hereinafter, the present invention will be specifically described by way of examples. Those skilled in the art will understand that the following examples are merely for explaining the present invention and should not be regarded as limiting the scope of the present invention. For those where specific techniques or conditions are not specified in the examples, they shall be carried out according to the techniques or conditions described in the literature of the art (for example, refer to "Molecular Cloning Experiment Guide" written by J. Sambrook et al., translated by Huang Peitang et al., 3rd edition, Science Press) or according to the product specifications. Those for which the manufacturer is not specified for the reagents or equipment used are common products available on the market.

[0211] Example 1: Expression of Human Nectin-4 Extracellular Antigen Human Nectin-4 extracellular antigen (hNectin-4-His) was produced according to the conventional method: the extracellular sequence of human Nectin-4 (sequence derived from GenBank No. Q96NY8) protein signal peptide sequence was replaced with albumin signal peptide (MKWVTFISLLFLFSSAYS, shown in SEQ ID NO: 1), and an 8×His histidine tag was added to its C-terminus to obtain an antigen protein (the sequence is shown in SEQ ID NO: 2, denoted as hNectin-4-His). The DNA sequence of the antigen protein hNectin-4-His was cloned into an expression vector, and eukaryotic cells HEK293F cells were transiently transfected or CHO cells were stably transfected, stable cell lines were selected, purified and expressed.

[0212] MKWVTFISLLFLFSSAYS GELETSDVVTVVLGQDAKLPCFYRGDSGEQVGQVAWARVDAGEGAQELALLHSKYGLHVSPAYEGRVEQPPPPRNPLDGSVLLRNAVQADEGEYECRVSTFPAGSFQARLRLRVLVPPLPSLNPGPALEEGQGLTLAASCTAEGSPAPSVTWDTEVKGTTSSRSFKHSRSAAVTSEFHLVPSRSMNGQPLTCVVSHPGLLQDQRITHILHVSFLAEASVRGLEDQNLWHIGREGAMLKCLSEGQPPPSYNWTRLDGPLPSGVRVDGDTLGFPPLTTEHSGIYVCHVSNEFSSRDSQVTVDVLDPQEDSGKQVDLVSASHHHHHHHH (as shown in SEQ ID NO: 2, the underlined part is the albumin signal peptide).

[0213] Example 2: Control antibody expression The amino acid sequences of the heavy and light chains of the control antibody ASG-22 are shown in Table 1. To facilitate expression in host cells, signal peptides were added to the N-termini of the heavy and light chains, respectively. The signal peptide sequence linked to the N-terminus of the heavy chain is MELGLCWVFLVAILEGVQC (shown in SEQ ID NO: 3), and the signal peptide sequence linked to the N-terminus of the light chain is MDMRVPAQLLGLLLLWFPGSRC (shown in SEQ ID NO: 4). The DNA sequences of the heavy and light chains were synthesized according to conventional methods, and antibodies that normally bind to hNectin-4-His of Example 1 were expressed.

[0214]

Table 1

[0215] Example 3: Production of Anti-Nectin-4 Antibody 1) Antibody Sequence Table 2 shows the light chain variable region and heavy chain variable region of the scFv, and the light chain variable regions have the same amino acid sequence.

[0216]

Table 2-1

Table 2-2

[0217] The sequences of framework regions HFR1 - HFR4 in VH are shown in SEQ ID NOs: 29 - 32, and the sequences of framework regions LFR1 - LFR4 in VL are shown in SEQ ID NOs: 33 - 36.

[0218] Framework Region in VH: HFR1: EVQLVESGGGLVQPGGSLRLSCAASGFTFS (SEQ ID NO: 29) HFR2: WVRQAPGKGLEWVS (SEQ ID NO: 30) HFR3: RFTISRDNSKNTLYLQMNSLRAEDTAVYYCAR (SEQ ID NO: 31) HFR4: WGQGTLVTVSS (SEQ ID NO: 32) Framework region in VL: LFR1: DIQMTQSPSSLSASVGDRVTITC (SEQ ID NO: 33) LFR2: WYQQKPGKAPKLLIY (SEQ ID NO: 34) LFR3: GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO: 35) LFR4: FGQGTKVEIKR (SEQ ID NO: 36)

[0219] 2) Production of scFv The HCDR3s of the above 1F3, 1G8, and 10F4 were cloned into the scFv phage library of HCDR1 and HCDR2, screened, and the supernatants of phage clones were selected and detected. The supernatant was diluted 50-fold, and the binding OD value to hNectin-4-His was measured by ELISA. It was diluted in a 3-fold gradient, and the titer EC 50 of the binding of the supernatant to the antigen was measured by ELISA. Clones with relatively high OD values were selected for sequencing to obtain the heavy-chain variable region sequences and HCDR1 and HCDR2 sequences of each clone shown in Tables 3 to 8. The light-chain variable region sequence is shown in SEQ ID NO: 25. Among them, the OD value represents the value detected by ELISA, and the EC 50 value represents the titer EC 50 of the binding activity of the supernatant to the antigen.

[0220] 3) Production of antibody Antibody construction: The heavy chain variable region and heavy chain constant region (CH) shown in Tables 2 to 5 constitute the heavy chain of the antibody, and the light chain variable region and light chain constant region (CL) shown in SEQ ID NO: 25 constitute the light chain of the antibody. The amino acid sequence of CH is shown in SEQ ID NO: 37, and the amino acid sequence of CL is shown in SEQ ID NO: 38. To facilitate expression in host cells, signal peptides are added to the N-terminals of the heavy chain and light chain, respectively. The signal peptide sequence linked to the N-terminal of the heavy chain is MEWSWVFLFFLSVTTGVHS (shown in SEQ ID NO: 39), and the signal peptide sequence linked to the N-terminal of the light chain is MDMRVPAQLLGLLLLWLPGARC (shown in SEQ ID NO: 40). The antibody number is consistent with the clone number corresponding to the heavy chain variable region. The amino acid sequence of the light chain is shown in SEQ ID NO: 250, and the nucleic acid sequence of the light chain is shown in SEQ ID NO: 359. The nucleic acid sequence was actually synthesized based on the antibody sequence. Taking antibody 1F3 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 232. Taking antibody 1G8 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 233. Taking antibody 10F4 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 249. Taking antibody 10F4-3 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 360, and the nucleic acid sequence of the heavy chain is shown in SEQ ID NO: 364. Taking antibody 1F3-1E4 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 361, and the nucleic acid sequence of the heavy chain is shown in SEQ ID NO: 365. Taking antibody 1F3-2B9 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 362, and the nucleic acid sequence of the heavy chain is shown in SEQ ID NO: 366. Taking antibody 1G8-1C10 as an example, the amino acid sequence of its heavy chain is shown in SEQ ID NO: 363, and the nucleic acid sequence of the heavy chain is shown in SEQ ID NO: 367. According to the conventional operation method, a light chain expression vector and a heavy chain expression vector were constructed, HEK293F cells were transformed, and the antibody was obtained and further detected.

[0221]

Table 3-1

Table 3-2

Table 3-3

Table 3-4

Table 3-5

[0222]

Table 4-1

Table 4-2

Table 4-3

Table 4-4

Table 4-5

Table 4-6

Table 4-7

[0223]

Table 5-1

Table 5-2

Table 5-3

Table 5-4

Table 5-5

[0224]

Table 6-1

Table 6-2

[0225]

Table 7-1

Table 7-2

[0226]

Table 8-1

Table 8-2

[0227] Amino acid sequence of the constant region (CH) of the antibody heavy chain: ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 37)

[0228] Amino acid sequence of the constant region (CL) of the antibody light chain: TVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 38)

[0229] The heavy-chain amino acid sequence of antibody 1F3 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSAISGSGGSTYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARAELLAFDVYTASDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 232)

[0230] The heavy-chain amino acid sequence of antibody 1G8 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSAISGSGGSTYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARQTEDRSYGYDLDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 233)

[0231] The amino acid sequence of the heavy chain of antibody 10F4 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSAISGSGGSTYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAREYSDVVDYVSVRTPLDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 249)

[0232] The heavy chain amino acid sequence of antibody 10F4-3 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFSFGDFAMSWVRQAPGKGLEWVSVIDGHTAYNSYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAREYSDVVDYVSVRTPLDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (for example, SEQ ID NO: 360)

[0233] The heavy chain nucleic acid sequence of antibody 10F4-3 is as follows:

[0234] The heavy chain amino acid sequence of antibody 1F3-1E4 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFSFGTYGMSWVRQAPGKGLEWVSRISGDSANIRYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARAELLAFDVYTASDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 361)

[0235] The heavy chain nucleic acid sequence of antibody 1F3-1E4 is as follows:

[0236] The heavy-chain amino acid sequence of antibody 1F3-2B9 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFNFDSYAMSWVRQAPGKGLEWVSGIKPHTDDIYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARAELLAFDVYTASDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 362)

[0237] The heavy-chain nucleic acid sequence of antibody 1F3-2B9 is as follows:

[0238] The heavy chain nucleic acid sequence of antibody 1G8-1C10 is as follows: EVQLVESGGGLVQPGGSLRLSCAASGFNFSDYSMSWVRQAPGKGLEWVSRIKASSGGSDYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARQTEDRSYGYDLDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 363)

[0239] The heavy chain nucleic acid sequence of antibody 1G8-1C10 is as follows:

[0240] The amino acid sequence of the common light chain is as follows: DIQMTQSPSSLSASVGDRVTITCRASQGISSYLAWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQHYTTPPTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 250)

[0241] The nucleic acid sequence of the common light chain is as follows: gatatccagatgacccagtcccccagctccctgagcgctagcgtgggcgaccgggtgaccatcacctgcagggcctcccagggcatcagctcctacctggcttggtatcagcagaagcctggcaaggcccctaagctgctgatctatgccgcttcctccctgcagtccggcgtgccttccaggttcagcggctccggcagcggcaccgacttcaccctgaccatctcctccctgcagcctgaggacttcgccacctattattgccagcagcactataccacccctcctacctttggccagggcaccaaggtggagatcaagcgtacggtggctgcaccatctgtcttcatcttcccgccatctgatgagcagttgaaatctggaactgcctctgttgtgtgcctgctgaataacttctatcccagagaggccaaagtacagtggaaggtggataacgccctccaatcgggtaactcccaggagagtgtcacagagcaggacagcaaggacagcacctacagcctcagcagcaccctgacgctgagcaaagcagactacgagaaacacaaagtctacgcctgcgaagtcacccatcagggcctgagctcgcccgtcacaaagagcttcaacaggggagagtgttga(SEQ ID NO: 359)

[0242] Example 4: Detection of Binding Activity The binding activity of the whole antibody was detected by ELISA method, and the process is briefly described as follows: The hNectin-4-His antigen protein of Example 1 was coated, and the coating concentration was 1 μg / mL. After blocking overnight with skim milk powder, the serially diluted test antibodies were added and incubated (the starting concentration of the antibodies in Table 9 was 2 μg / mL and diluted in a 2-fold gradient, and the starting concentration of the antibodies in Tables 10 and 11 was 10 μg / mL and diluted in a 3-fold gradient). After incubating at room temperature for 2 hours (h), an HRP-labeled anti-human-kappa (Sigma, A7164) secondary antibody was added and incubated for 1 h. Subsequently, TMB (Huzhou Yingchuang Biotechnology, TMB-S-001) was added for color development, and the color development was stopped with 0.1 M H2SO4. After reading the absorbance at OD450 with a microplate reader, the binding EC 50 values of each antibody were calculated, the binding activities of each antibody were compared, and the results are shown in Tables 9-11.

[0243]

Table 9

[0244]

Table 10

[0245]

Table 11

[0246] Example 5: Affinity Measurement In this study, the affinity between the antibody and the extracellular antigen of human Nectin-4 was detected using the Surface Plasmon Resonance (SPR) technology (BIAcore: GE Healthcare, T200).

[0247] Captured using Protein A chip (Cat#29127556, GE Healthcare), passed the experimental flow channels (Fc2, Fc4) at a flow rate of 10 μl / min with a 5 μg / mL antibody diluent (the diluent is HBS-EP+(10x): GE Healthcare, cat#BR-1006-69, and the working concentration is 1x), captured for 10 seconds (s), then adjusted the flow rate to 30 μl / min, and sequentially added hNectin-4-His diluents at different concentrations (0 nM, 1.23 nM, 3.7 nM, 11.1 nM, 33.3 nM, 100 nM), and simultaneously passed through the surfaces of the experimental flow channels (Fc2, Fc4) and the reference flow channels (Fc1, Fc3). The binding time was 120 s and the dissociation time was 180 s. Finally, the chip was regenerated with Glycine 1.5. Fitting analysis was performed using BiaEvaluation 3.2, the fitting model used was the 1:1 model, and the fitting results are shown in Tables 12 - 13 and Figure 1.

[0248]

Table 12

[0249]

Table 13

[0250] Example 6: Measurement of Endocytosis Efficiency To reflect the endocytosis efficiency, after incubating at 37°C for a certain period of time, the relative quantity of antibodies remaining on the cell surface was measured by FACS. The method is briefly described as follows: T-47D cells (human mammary duct carcinoma cells, derived from the Cell Bank of the Chinese Academy of Sciences, catalog number TCHu 87) were used. The antibody was adjusted to 10 μg / mL and allowed to bind to the cells on ice for 1 h, washed three times with pre-cooled PBS, and then incubated at 37°C for 0 h, 2 h, and 4 h respectively. 0.2% N3Na was added to stop the endocytosis reaction. After washing three times with PBS, a secondary antibody of PE-labeled anti-human Fc (Invitrogen 12-4998-82) was added and incubated at 4°C for 30 min (min). The red fluorescence signal was detected by flow cytometry. The endocytosis results of each test antibody are shown in Tables 14 - 15.

[0251]

Table 14

[0252]

Table 15

[0253] Example 7: Cell Binding Curve This test detected the binding activity of different antibodies to Nectin-4-expressing positive T-47D cells by FACS, and analyzed the EC 50 of the antibody binding to cells by the four-parameter method. The method is briefly described as follows: T-47D cells (Cell Bank of the Chinese Academy of Sciences, TCHu 87) were digested with pancreatin. The antibody was serially diluted and incubated with T-47D cells at 4°C for 0.5 - 1 h. Then, a secondary antibody of PE-labeled anti-human Fc (Invitrogen, 12-4998-82) was added. The signal intensity of the red fluorescence value was detected by flow cytometry and plotted using Graphpad Prism to calculate the EC 50 and the results of the binding curve and EC 50 are shown in Table 16 and Figure 2.

[0254]

Table 16

[0255] Example 8: Detection of Specificity In this test, the binding of different antibodies to human Nectin-4 family proteins hNectin-1 (ACRO, PV1-H5223), hNectin-2 (ACRO, PV2-H52E2), hNectin-3 (ACRO, PV3-H52E4), and hNectin-4-His was detected by the ELISA method to confirm the specificity of the antibodies. The method and process refer to Example 4. After coating the target antigen (1 μg / mL) and blocking, gradient-diluted antibodies (starting concentration 2 μg / mL, 2-fold gradient dilution) were added, and an HRP-labeled anti-human-Kappa secondary antibody was added to develop color. The results are shown in Table 17. Except for antibody 3A10, which has relatively weak binding to hNectin-3, the other antibodies all have good specificity, do not bind to the family proteins hNectin-1 / 2 / 3, and bind to hNectin-4-His. The binding curve is shown in Figure 3.

[0256]

Table 17

[0257] Example 9: Detection of Species Specificity Nectin-4 has relatively high homology in different species.

[0258] The binding status of different antibodies to Nectin-4 proteins of different species was measured by ELISA. Each of hNectin-4-His, cynomolgus cNectin-4 protein (ACRO, NE4-C52H4) and mouse mNectin-4 protein (ACRO, NE4-M52H3) was coated, the antibodies ASG-22, 1F3, 1G8, 3A10 and 10F4 were serially diluted, and an HRP-labeled anti-human-Kappa secondary antibody was added to develop color. The results are shown in Table 18 and Figure 4. The test antibodies had similar binding activities to Nectin-4 of human, cynomolgus monkey and mouse, and there was a weak binding to the binding of the control antibody to mouse Nectin-4.

[0259]

Table 18

Claims

1. An anti-Nectin-4 antibody or antigen-binding fragment thereof, wherein the anti-Nectin-4 antibody comprises one or more of the following HCDR1, HCDR2, and HCDR3 or variants thereof, (1) According to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NOs: 181 to 195, SEQ ID NOs: 234 to 248, and SEQ ID NOs: 304 to 317; the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NOs: 196 to 231, SEQ ID NOs: 251 to 303, and SEQ ID NOs: 318 to 358; the sequence of HCDR3 comprises or consists of the sequence shown in any one of SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 20, SEQ ID NO: 22, and SEQ ID NO: 24, (2) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 7, According to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8; the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9; the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 10, (3) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 11, According to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8; the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9; the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 12, (4) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 13, According to the Kabat numbering system, the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8; the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9; the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 14, (5) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 15, According to the Kabat numbering system, the sequence of HCDR1 includes or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 includes or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

16. (6) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 17 According to the Kabat numbering system, the sequence of HCDR1 includes or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 includes or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

18. (7) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 19 According to the Kabat numbering system, the sequence of HCDR1 includes or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 includes or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

20. (8) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 21 According to the Kabat numbering system, the sequence of HCDR1 includes or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 includes or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

22. (9) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region shown in SEQ ID NO: 23 According to the Kabat numbering system, the sequence of HCDR1 includes or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 includes or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

24. The sequence of HCDR1 comprises or consists of the sequence shown as X1X2X3MS; the sequence of HCDR2 comprises or consists of the sequence shown as X1’IX2’X3’X4’X5’X6’X7’X8’X9’YADSVKG; the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO: 12, 14, or 16, wherein X1, X2, X3, X1’, X2’, X3’, X4’, X5’, X6’, X7’, X8’, X9’, and X10’ each represent any one amino acid independently selected from G, A, V, L, I, S, T, C, M, N, Q, K, R, D, E, F, Y, H, P, and W, For example, X1 represents S, N, T, D, or G; X2 represents Y, F, or S; X3 represents A, G, S, or Y; X1’ represents A, R, G, I, or W; X2’ represents S, K, Y, or D; X3’ represents G, P, S, A, Q, or W; X4’ represents S, T, G, Y, H, D, W, or I; X5’ represents G, D, T, S, A, or K; X6’ represents G, S, D, A, or W; X7’ represents S, Y, T, N, D, V, E, or G; X8’ represents T, A, N, K, I, R, S, or P; X9’ represents Y, S, H, R, N, G, F, or D, Alternatively, X1 represents S, N, T, D, or G; X2 represents Y, N, F, or S; X3 represents A, G, S, or absent; X1’ represents A, R, G, W, or S; X2’ represents S, K, Y, or D; X3’ represents G, P, S, T, A, Q, or Y; X4’ represents S, T, G, Y, H, D, W, or I; X5’ represents G, D, T, S, F, or K; X6’ represents G, S, D, A, W, or absent; X7’ represents S, Y, T, N, D, V, E, or G; X8’ represents T, A, N, K, I, R, S, or P; X9’ represents Y, S, H, R, N, F, or D, Alternatively, X1 represents S, N, D, G, or T; X2 represents Y, F, or S; X3 represents A, D, W, S, or Y; X1’ represents A, S, G, or V; X2’ represents S, K, I, Y, or D; X3’ represents G, P, S, A, Q, Y, T, or D; X4’ represents S, T, G, Y, H, D, or W; X5’ represents G, D, T, S, or K; X6’ represents G, S, D, A, or Y; X7’ represents S, Y, T, N, D, V, or G; X8’ represents T, A, N, K, I, R, or S; X9’ represents Y, S, H, R, N, G, F, or D, Alternatively, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8 and SEQ ID NOs: 181 to 195, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9 and SEQ ID NOs: 196 to 231, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

14. Alternatively, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NOs: 181, 185, 186, 187, 194, and SEQ ID NOs: 234 to 248, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NO: 202, and SEQ ID NOs: 251 to 303, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

12. Alternatively, the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NOs: 235, 238, 241, and SEQ ID NOs: 304 to 317, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NOs: 318 to 358, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

16. Among them, the mutant sequence has 3, 2 or 1 amino acid differences (preferably conservative amino acid substitutions) respectively with respect to the corresponding CDR sequence, or has at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identity respectively, and the mutant retains the binding affinity for nectin-4. Optionally, the anti-nectin-4 antibody or antigen-binding fragment is derived from birds and mammals, or the anti-nectin-4 antibody is an antibody derived from human, mouse, donkey, rabbit, goat, camel, llama, horse, or chicken. Anti-nectin-4 antibody or antigen-binding fragment.

2. The anti-nectin-4 antibody or antigen-binding fragment according to claim 1, wherein the sequences of framework regions HFR1 to HFR4 in the heavy chain variable region are shown in SEQ ID NOs: 29 to 32 respectively.

3. The sequence of framework region HFR1 in the heavy chain variable region is shown by the amino acid sequence at positions 1 to 30 of the sequence shown by any one of SEQ ID NOs: 41 to 180, and the sequences of HFR2 to HFR4 are shown by SEQ ID NOs: 30 to 32 respectively, the anti - Necdin - 4 antibody or antigen - binding fragment according to claim 1.

4. The anti - Necdin - 4 antibody or antigen - binding fragment is (1) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 7; (2) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 11; (3) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 13; (4) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 15; (5) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 17; (6) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 19; (7) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 21; (8) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 23; (9) a heavy chain variable region consisting of or having any one of the sequences shown by SEQ ID NOs: 41 to 180 or consisting of them; (10) a heavy chain variable region consisting of or having the sequence shown by SEQ ID NO: 179; and includes a heavy chain variable region or a variant thereof selected from the group consisting of, wherein the variant sequence has 3, 2 or 1 amino acid differences (preferably conservative amino acid substitutions) respectively with respect to the corresponding variable region sequence, or has at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identity respectively, and the variant retains the binding affinity for Necdin - 4. The anti - Necdin - 4 antibody or antigen - binding fragment according to claim 1.

5. The amino acid sequence of the heavy chain constant region of the anti-Nectin-4 antibody is shown in SEQ ID NO: 37, or the heavy chain of the anti-Nectin-4 antibody comprises a heavy chain variable region shown in any one of SEQ ID NO: 7, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 15, SEQ ID NO: 17, SEQ ID NO: 19, SEQ ID NO: 21, SEQ ID NO: 23, and SEQ ID NO: 41 to 180, and a heavy chain constant region shown in SEQ ID NO: 37, or the heavy chain amino acid sequence of the anti-Nectin-4 antibody is shown in any one of SEQ ID NO: 232, SEQ ID NO: 233, SEQ ID NO: 249, and SEQ ID NO: 360 to 363. The anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 4.

6. The antibody further comprises LCDR1, LCDR2, and LCDR3 contained in the light chain variable region shown in SEQ ID NO:

25. According to the Kabat numbering system, the sequence of LCDR1 includes or consists of the sequence shown in SEQ ID NO: 26, the sequence of LCDR2 includes or consists of the sequence shown in SEQ ID NO: 27, and the sequence of LCDR3 includes or consists of the sequence shown in SEQ ID NO:

28. Alternatively, the sequences of the framework regions LFR1 to LFR4 in the light chain variable region are shown in SEQ ID NO: 33 to 36, respectively. Alternatively, the antibody or antigen-binding fragment comprises the light chain variable region shown in SEQ ID NO:

25. Alternatively, the antibody or antigen-binding fragment further comprises the light chain constant region shown in SEQ ID NO:

38. The anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 5.

7. The antigen-binding fragment is Fab, Fab', F(ab'), ２ , F(ab), ２ , Fd, Fv, dAb, Fab / c, complementarity-determining region fragment, scFv, scFv multimer, disulfide bond-stabilized Fv (dsFv), (dsFv) ２ , bispecific dsFv (dsFv-dsFv'), diabody, disulfide bond-stabilized diabody (ds-Diabody), multispecific antibody formed from a portion of an antibody containing one or more CDRs, single domain antibody (sdAb), nanobody, domain antibody, or bivalent domain antibody, the anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 6.

8. A polypeptide that specifically binds to Nectin-4, (1) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Among them, the sequence of HCDR1 includes or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NOs: 181-195, SEQ ID NOs: 234-248, and SEQ ID NOs: 304-317; the sequence of HCDR2 includes or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NOs: 196-231, SEQ ID NOs: 251-303, and SEQ ID NOs: 318-358; the sequence of HCDR3 includes or consists of the sequence shown in any one of SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 20, SEQ ID NO: 22, and SEQ ID NO:

24. (2) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Among them, the sequence of HCDR1 includes or consists of the sequence shown in SEQ ID NO: 8; the sequence of HCDR2 includes or consists of the sequence shown in SEQ ID NO: 9; the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

10. (3) A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. Among them, the sequence of HCDR1 includes or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 181, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 194, and SEQ ID NOs: 234-248; the sequence of HCDR2 includes or consists of the sequence shown in any one of SEQ ID NO: 9, SEQ ID NO: 202, and SEQ ID NOs: 251-303; the sequence of HCDR3 includes or consists of the sequence shown in SEQ ID NO:

12. (4)A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8 and SEQ ID NOs: 181 to 195, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9 and SEQ ID NOs: 196 to 231, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

14. (5)A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in any one of SEQ ID NO: 8, SEQ ID NO: 235, SEQ ID NO: 238, SEQ ID NO: 241, and SEQ ID NOs: 304 to 317, the sequence of HCDR2 comprises or consists of the sequence shown in any one of SEQ ID NO: 9 and SEQ ID NOs: 318 to 358, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

16. (6)A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

18. (7)A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

20. A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

22. A polypeptide comprising the sequences of HCDR1, HCDR2, and HCDR3 or variants thereof, wherein the polypeptide is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4, and wherein the sequence of HCDR1 comprises or consists of the sequence shown in SEQ ID NO: 8, the sequence of HCDR2 comprises or consists of the sequence shown in SEQ ID NO: 9, and the sequence of HCDR3 comprises or consists of the sequence shown in SEQ ID NO:

24. A polypeptide comprising the sequence shown in SEQ ID NO: 7 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 11 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 13 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 15 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 17 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 19 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 21 or a variant thereof, which is part of an anti-Nectin-4 antibody that specifically binds to Nectin-4. A polypeptide comprising the sequence shown in SEQ ID NO: 23 or a variant thereof, and being part of an anti - Necdin - 4 antibody that specifically binds to Necdin - 4, A polypeptide comprising the sequence shown in any one of SEQ ID NOs: 41 to 180 or a variant thereof, and being part of an anti - Necdin - 4 antibody that specifically binds to Necdin - 4, selected from the group consisting of, Optionally, the polypeptide further comprises the sequences shown in SEQ ID NO: 26, SEQ ID NO: 27, and SEQ ID NO: 28, or the sequence shown in SEQ ID NO: 25, or a variant thereof, wherein the variant sequence has 3, 2, or 1 amino acid differences (preferably conservative amino acid substitutions) respectively with respect to the corresponding sequence, or has at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identity respectively, and the variant retains the binding affinity for Necdin - 4, A polypeptide that specifically binds to Necdin - 4.

9. A biological material, (1) A nucleic acid molecule encoding the anti - Necdin - 4 antibody or antigen - binding fragment according to any one of Claims 1 to 7, or encoding the polypeptide that specifically binds to Necdin - 4 according to Claim 8, (2) A vector comprising a nucleic acid molecule encoding the anti - Necdin - 4 antibody or antigen - binding fragment according to any one of Claims 1 to 7, or encoding the polypeptide that specifically binds to Necdin - 4 according to Claim 8, or (3) A host cell comprising a nucleic acid molecule encoding the anti - Necdin - 4 antibody or antigen - binding fragment according to any one of Claims 1 to 7, or encoding the polypeptide that specifically binds to Necdin - 4 according to Claim 8, being, A biological material.

10. A conjugate comprising an anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 7 and a conjugate moiety, wherein the conjugate moiety is a purification tag (e.g., His tag), a detectable label, a drug, a toxin, a cytokine, an enzyme, or a combination thereof, or wherein the conjugate moiety is a radioisotope, a fluorescent substance, a chemiluminescent substance, a coloring substance, a chemotherapeutic agent, a biological toxin, a therapeutic agent, a prodrug, a peptide, a protein, an enzyme, a virus, a lipid, a biological response modifier, or polyethylene glycol, the conjugate.

11. A reagent kit comprising an anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 7, a polypeptide that specifically binds to Nectin-4 according to claim 8, and a conjugate according to claim 10, optionally, the reagent kit further comprises a second antibody that specifically recognizes the anti-Nectin-4 antibody, optionally, the second antibody further comprises a detectable label, e.g., a radioisotope, a fluorescent substance, a chemiluminescent substance, a coloring substance or an enzyme, optionally, the reagent kit is used to detect the presence or level of Nectin-4 in a sample, optionally, the reagent kit further comprises an antibody or antigen-binding fragment thereof against another antigen, and / or a cytotoxic agent, and optionally an instruction manual, the reagent kit.

12. A pharmaceutical composition comprising an anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 7, a polypeptide that specifically binds to Nectin-4 according to claim 8, and a conjugate according to claim 10, optionally, the pharmaceutical composition further comprises a pharmaceutically acceptable carrier and / or excipient, or wherein the pharmaceutical composition is in a form suitable for administration by subcutaneous injection, intradermal injection, intravenous injection, intramuscular injection, or intralesional injection, the pharmaceutical composition.

13. Use of an anti-Nectin-4 antibody or antigen-binding fragment according to any one of claims 1 to 7, a polypeptide specifically binding to Nectin-4 according to claim 8, or a conjugate according to claim 10, for the treatment and / or prevention of a disease or in the manufacture of a medicament for treating and / or preventing a disease, wherein the disease is a disease associated with abnormal expression of Nectin-4, or the disease is a tumor expressing or overexpressing Nectin-4, or the disease is a cancer expressing or overexpressing Nectin-4, or the disease is a solid tumor or a hematological tumor, or the disease is selected from breast cancer, pancreatic cancer, bladder cancer, urothelial cancer, melanoma, lung cancer, head and neck cancer, cervical cancer, ovarian cancer, choriocarcinoma, skin cancer, esophageal cancer, gastric cancer, uterine cancer, gallbladder cancer, liver cancer, hepatocellular carcinoma, urethral cancer, renal pelvic cancer, ureteral cancer, colorectal cancer, colon cancer, and prostate cancer.

14. A method for treating a disease, comprising administering to a patient in need thereof an effective amount of an anti-Nectin-4 antibody or antigen-binding fragment thereof according to any one of claims 1 to 7, a polypeptide specifically binding to Nectin-4 according to claim 8, or a conjugate according to claim 10, wherein the disease is a disease associated with abnormal expression of Nectin-4, or the disease is a tumor expressing or overexpressing Nectin-4, or the disease is a cancer expressing or overexpressing Nectin-4, or the disease is a solid tumor or a hematological tumor, or the disease is selected from breast cancer, pancreatic cancer, bladder cancer, urothelial cancer, melanoma, lung cancer, head and neck cancer, cervical cancer, ovarian cancer, choriocarcinoma, skin cancer, esophageal cancer, gastric cancer, uterine cancer, gallbladder cancer, liver cancer, hepatocellular carcinoma, urethral cancer, renal pelvic cancer, ureteral cancer, colorectal cancer, colon cancer, and prostate cancer.

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