Anti-CDH17 antibody, antibody-drug conjugate thereof, and use thereof

Abstract

The present application relates to an antibody that specifically recognizes CDH17, a preparation method therefor, and a use thereof. In addition, the present application further relates to an antibody-drug conjugate (ADC) targeting CDH17 and a composition containing the molecule. The present invention further relates to therapeutic and diagnostic uses of the antibody, an antibody fragment, and the ADC.

Description

Anti-cdh17 antibodies, antibody drug conjugates thereof, and uses thereof TECHNICAL FIELD

[0001] The present application relates to antibodies specifically recognizing CDH17, methods of making and uses thereof. Furthermore, the present application also relates to antibody drug conjugates (ADC) targeting CDH17 and compositions containing the molecules. Furthermore, the present application also relates to therapeutic and diagnostic uses of these antibodies, antibody fragments and antibody drug conjugates. BACKGROUND

[0002] CDH17 is a member of the cadherin family of proteins, which are involved in cell-cell adhesion. It is expressed in the gastrointestinal system, and is found on the epithelial cells of the intestine and some pancreatic duct epithelial cells. CDH17 has a long extracellular region with seven cadherin repeats, and a short intracellular region. The HAV sequence, which determines the cell adhesion properties of the protein, is replaced by an AAL sequence in the cell adhesion recognition region at the amino terminus. The cytoplasmic tail of CDH17 contains only 20 amino acid residues. CDH17 functions as a polypeptide transporter and cell adhesion molecule to maintain the integrity of epithelial tissue.

[0003] CDH17 expression in normal tissues is limited to epithelial tissues, and is commonly found in the surface epithelial tissues of the normal duodenum, ileum, appendix and colon, gastric and intestinal metaplasia, intrahepatic bile duct epithelial cells and pancreatic ducts. CDH17 is not expressed in important tissues including lymph nodes, brain tissue, etc. Similar to Claudin 18 and other specific targets, CDH17 is expressed on the lateral membrane of the tight junction between epithelial cells, and is not expressed on the apical or basal surface.

[0004] CDH17 is highly expressed in a variety of gastrointestinal tumor tissues. Studies have found that CDH17 is expressed at different levels in colorectal cancer, gastric cancer, esophageal cancer, cholangiocarcinoma and pancreatic cancer, and other tumor tissues. High expression of CDH17 is closely related to patient prognosis, survival time and risk assessment. When CDH17 is highly expressed in cancer tissues, it loses the polarized expression characteristics, resulting in the overall distribution of CDH17 protein on the surface of tumor cells. This characteristic results in the fact that the drug does not act on the CDH17 protein in the tight junction of normal tissues, but only acts on the CDH17 exposed on the cell surface. Abnormal structure and function of CDH17 leads to decreased adhesion between tumor cells, loose tissue cells, easy to shed or deform, thereby promoting tumor invasion and metastasis. After abnormal expression of CDH17, it will mediate Wnt, MAPK and integrin-FAK, etc. carcinogenic signaling pathways.

[0005] In summary, CDH17 is an ideal drug target for cancer treatment.

[0006] Although several antibody drugs targeting CDH17 are disclosed in the prior art, as a target expressed by pan-gastrointestinal tumors, there is still an urgent need to develop high-quality anti-CDH17 antibodies, which can be used as the basis for developing antibody-based targeted therapy for CDH17-expressing cancers, and also as a diagnostic tool to detect CDH17 expression in CDH17-related disorders. In addition, based on the good prospects exhibited by ADCs in the field of tumor treatment, there is still an urgent need for ADCs containing CDH17 with effective therapeutic effects, and the present application meets these needs. SUMMARY

[0007] The present application provides novel anti-CDH17 antibodies or antigen-binding fragments thereof, which have advantages such as high affinity and high specificity for human CDH17. The anti-CDH17 antibodies provided by the present application can be used for the treatment of, for example, cancer / tumor as a standalone therapy or in combination with other therapies / other anti-cancer agents. The CDH17 antibodies described can be used in diagnostics on tissue samples from individuals, particularly individuals who can have tumors and / or cancers associated with CDH17-mediated or aberrant expression and / or identifiable by aberrant CDH17 expression. The present application also provides nucleic acid molecules encoding the antibody molecules, expression vectors, host cells, and methods for making the antibody molecules.

[0008] I. Antibodies

[0009] In one aspect, the present application provides an antibody or antigen-binding fragment thereof capable of specifically binding to CDH17, wherein the antibody or antigen-binding fragment thereof comprises complementarity determining regions (CDRs) selected from the group consisting of:

[0010] (a) the CDRs of the following three heavy chain variable regions (VH):

[0011] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence with one or more (e.g., 1, 2 or 3) amino acid substitutions, deletions, or additions as compared to the sequence of SEQ ID NO: 1;

[0012] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence with one or more (e.g., 1, 2 or 3) amino acid substitutions, deletions, or additions as compared to the sequence of SEQ ID NO: 2;

[0013] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 4, or a sequence with one or more (e.g., 1, 2 or 3) amino acid substitutions, deletions, or additions as compared to the sequence of SEQ ID NO: 4;

[0014] and / or the CDRs of the following 3 light chain variable regions (VL):

[0015] (i) a LCDR1 has the sequence set forth in SEQ ID NO: 10, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 10;

[0016] (ii) a LCDR2 has the sequence set forth in SEQ ID NO: 11, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 11;

[0017] (iii) a LCDR3 has the sequence set forth in SEQ ID NO: 12, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 12;

[0018] or,

[0019] (b) the CDRs of the following 3 heavy chain variable regions (VH):

[0020] (i) a HCDR1 has the sequence set forth in SEQ ID NO: 1, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 1;

[0021] (ii) a HCDR2 has the sequence set forth in SEQ ID NO: 6, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 6;

[0022] (iii) a HCDR3 has the sequence set forth in SEQ ID NO: 8, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 8;

[0023] and / or the CDRs of the following 3 light chain variable regions (VL):

[0024] (i) a LCDR1 has the sequence set forth in SEQ ID NO: 10, or a sequence that has one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 10;

[0025] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) compared to the sequence set forth in SEQ ID NO: 11;

[0026] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) compared to the sequence set forth in SEQ ID NO: 12.

[0027] In one aspect, the present application provides an antibody or antigen-binding fragment thereof capable of specifically binding CDH17, wherein the antibody or antigen-binding fragment thereof comprises a complementarity determining region (CDR) selected from the group consisting of:

[0028] (a) the CDRs of the following 3 heavy chain variable regions (VH):

[0029] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) compared to the sequence set forth in SEQ ID NO: 1;

[0030] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) compared to the sequence set forth in SEQ ID NO: 2;

[0031] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 3, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) compared to the sequence set forth in SEQ ID NO: 3;

[0032] and / or the CDRs of the following 3 light chain variable regions (VL):

[0033] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) compared to the sequence set forth in SEQ ID NO: 10;

[0034] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 11;

[0035] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 12;

[0036] or,

[0037] (b) the CDRs of the following 3 heavy chain variable regions (VH):

[0038] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 1;

[0039] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 2;

[0040] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 4, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 4;

[0041] and / or the CDRs of the following 3 light chain variable regions (VL):

[0042] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 10;

[0043] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 11;

[0044] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 5, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 5;

[0045] or,

[0046] (c) the CDRs of the following 3 heavy chain variable regions (VH):

[0047] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 1;

[0048] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 2;

[0049] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 5, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 5;

[0050] and / or the CDRs of the following 3 light chain variable regions (VL):

[0051] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 10;

[0052] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 11;

[0053] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence of SEQ ID NO: 12;

[0054] or,

[0055] (d) the CDRs of the following 3 heavy chain variable regions (VH):

[0056] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 1;

[0057] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 6;

[0058] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 7 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 7;

[0059] and / or the CDRs of the following 3 light chain variable regions (VL):

[0060] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 10;

[0061] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 11;

[0062] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 12;

[0063] or,

[0064] (e) the CDRs of the following 3 heavy chain variable regions (VH):

[0065] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1 or a sequence having one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to that of SEQ ID NO: 1;

[0066] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 6;

[0067] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 9, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 9;

[0068] and / or the CDRs of the following 3 light chain variable regions (VL):

[0069] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 10;

[0070] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 11 ;

[0071] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 12

[0072] or,

[0073] (f) the CDRs of the following 3 heavy chain variable regions (VH):

[0074] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 1 ;

[0075] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 6;

[0076] (iii) HCDR3 having a sequence as set forth in SEQ ID NO: 8, or a sequence with one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) as compared to that of SEQ ID NO: 8;

[0077] and / or the CDRs of the following three light chain variable regions (VL):

[0078] (i) LCDR1 having a sequence as set forth in SEQ ID NO: 10, or a sequence with one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) as compared to that of SEQ ID NO: 10;

[0079] (ii) LCDR2 having a sequence as set forth in SEQ ID NO: 11, or a sequence with one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) as compared to that of SEQ ID NO: 11 ;

[0080] (iii) LCDR3 having a sequence as set forth in SEQ ID NO: 12, or a sequence with one or more amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 substitutions, deletions or additions) as compared to that of SEQ ID NO: 12.

[0081] In one embodiment, the present application provides an anti-CDH17 antibody or antigen binding fragment thereof that specifically binds CDH17, comprising heavy chain complementarity determining regions (HCDRs) and / or light chain complementarity determining regions (LCDRs) selected from the group consisting of:

[0082] (a) the CDRs:

[0083] 1 ) CDRs determined according to the Kabat definition

[0084] (i) HCDR1 having a sequence as set forth in SEQ ID NO: 1 ;

[0085] (ii) HCDR2 having a sequence as set forth in SEQ ID NO: 2;

[0086] (iii) HCDR3 having a sequence as set forth in SEQ ID NO: 4;

[0087] and / or

[0088] (i) LCDR1 having a sequence as set forth in SEQ ID NO: 10;

[0089] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0090] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0091] 2) CDR determined according to IMGT definition

[0092] (i) HCDR1 having the sequence set forth in SEQ ID NO: 73;

[0093] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 74;

[0094] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 82;

[0095] and / or

[0096] (i) LCDR1 having the sequence set forth in SEQ ID NO: 76;

[0097] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 77;

[0098] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0099] 3) CDR determined according to Chothia definition

[0100] (i) HCDR1 having the sequence set forth in SEQ ID NO: 78;

[0101] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 79;

[0102] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 3;

[0103] and / or

[0104] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0105] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0106] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0107] 4) CDR determined according to AbM definition

[0108] (i) HCDR1 having the sequence set forth in SEQ ID NO: 80;

[0109] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 81 ;

[0110] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 3;

[0111] and / or

[0112] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0113] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11 ;

[0114] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0115] or,

[0116] (b) the CDRs:

[0117] 1) CDRs determined according to the Kabat definition

[0118] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1 ;

[0119] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6;

[0120] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 8;

[0121] and / or

[0122] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0123] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11 ;

[0124] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0125] 2) CDRs determined according to the IMGT definition

[0126] (i) HCDR1 having the sequence set forth in SEQ ID NO: 73;

[0127] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 74;

[0128] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 75;

[0129] and / or

[0130] (i) LCDR1 having the sequence set forth in SEQ ID NO: 76;

[0131] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 77;

[0132] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0133] 3) CDR determined according to Chothia definition

[0134] (i) HCDR1 having the sequence set forth in SEQ ID NO: 78;

[0135] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 79;

[0136] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 7;

[0137] and / or

[0138] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0139] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0140] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0141] 4) CDR determined according to AbM definition

[0142] (i) HCDR1 having the sequence set forth in SEQ ID NO: 80;

[0143] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 81;

[0144] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 7;

[0145] and / or

[0146] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0147] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0148] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0149] or,

[0150] (c) the CDRs:

[0151] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1 ;

[0152] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2;

[0153] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 3;

[0154] and / or

[0155] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0156] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0157] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0158] or,

[0159] (d) the CDRs:

[0160] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1 ;

[0161] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2;

[0162] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 5;

[0163] and / or

[0164] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0165] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0166] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0167] or,

[0168] (e) the CDRs of:

[0169] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1;

[0170] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6;

[0171] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 7;

[0172] and / or

[0173] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0174] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0175] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12;

[0176] or,

[0177] (f) the CDRs of:

[0178] (i) HCDR1 having the sequence set forth in SEQ ID NO: 1;

[0179] (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6;

[0180] (iii) HCDR3 having the sequence set forth in SEQ ID NO: 9;

[0181] and / or

[0182] (i) LCDR1 having the sequence set forth in SEQ ID NO: 10;

[0183] (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11;

[0184] (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12.

[0185] The present application provides an antibody or antigen-binding fragment thereof that specifically binds CDH17, wherein the antibody or antigen-binding fragment thereof comprises a CDR in the heavy chain variable region (VH) and / or light chain variable region (VL) selected from the group consisting of:

[0186] (a) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 18; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 37; or,

[0187] (b) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 23; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 37.

[0188] The present application provides an antibody or antigen-binding fragment thereof specifically binding to CDH17, wherein the antibody or antigen-binding fragment thereof comprises a CDR in a heavy chain variable region (VH) and / or a light chain variable region (VL) selected from the group consisting of:

[0189] (a) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 19; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 37; or,

[0190] (b) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 20; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 37; or,

[0191] (c) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 21; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 38; or,

[0192] (d) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 21; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 39; or,

[0193] (e) 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO: 21; and / or, 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO: 40; or,

[0194] (f) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:21; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:41; or,

[0195] (g) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:21; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:42; or,

[0196] (h) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:21; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:43; or,

[0197] (i) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:21; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:44; or,

[0198] (j) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:38; or,

[0199] (k) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:39; or,

[0200] (l) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40; or,

[0201] (m) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:41; or,

[0202] (n) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:42; or,

[0203] (o) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:43; or,

[0204] (p) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:22; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:44; or,

[0205] (q) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:25; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:37; or,

[0206] (r) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:26; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:37; or,

[0207] (s) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO:27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO:38; or,

[0208] (t) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 39; or,

[0209] (u) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 40; or,

[0210] (v) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 41; or,

[0211] (w) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 42; or,

[0212] (x) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 43; or,

[0213] (y) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 27; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 44; or,

[0214] (z) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 38; or,

[0215] (aa) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 39; or,

[0216] (bb) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 40; or,

[0217] (cc) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 41; or,

[0218] (dd) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 42; or,

[0219] (ee) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 43; or,

[0220] (ff) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 28; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 44; or,

[0221] (gg) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as shown in SEQ ID NO: 29; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as shown in SEQ ID NO: 41; or,

[0222] (hh) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:30; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:41; or,

[0223] (ii) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:31; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40; or,

[0224] (jj) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:32; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40; or,

[0225] (kk) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:33; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40; or,

[0226] (ll) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:34; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40; or,

[0227] (mm) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:35; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:38; or,

[0228] (nn) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:36; and / or the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:38; or,

[0229] (oo) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:35; and / or, the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40; or,

[0230] (pp) the 3 CDRs (HCDR1, HCDR2, HCDR3) contained in a VH as set forth in SEQ ID NO:36; and / or, the 3 CDRs (LCDR1, LCDR2, LCDR3) contained in a VL as set forth in SEQ ID NO:40.

[0231] In some embodiments, the present application provides anti-CDH17 antibodies and antigen-binding fragments thereof that specifically bind CDH17, comprising a heavy chain variable region (VH), wherein:

[0232] (a) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 18, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 18, or consists of SEQ ID NO: 18;

[0233] (b) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 19, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 19, or consists of SEQ ID NO: 19;

[0234] (c) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 20, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 20, or consists of SEQ ID NO: 20;

[0235] (d) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21;

[0236] (e) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22;

[0237] (f) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 23, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 23, or consists of SEQ ID NO: 23;

[0238] (g) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 25, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 25, or consists of SEQ ID NO: 25;

[0239] (h) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 26, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 26, or consists of SEQ ID NO: 26;

[0240] (i) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27;

[0241] (j) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28;

[0242] (k) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 29, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 29, or consists of SEQ ID NO: 29;

[0243] (l) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 30, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 30, or consists of SEQ ID NO: 30;

[0244] (m) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 31, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 31, or consists of SEQ ID NO: 31;

[0245] (n) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 32, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 32, or consists of SEQ ID NO: 32;

[0246] (o) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 33, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 33, or consists of SEQ ID NO: 33;

[0247] (p) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 34, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 34, or consists of SEQ ID NO: 34;

[0248] (q) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 35, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 35, or consists of SEQ ID NO: 35;

[0249] (r) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 36, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 36, or consists of SEQ ID NO: 36.

[0250] In some embodiments, the present application provides anti-CDH17 antibodies and antigen-binding fragments thereof that specifically bind CDH17, comprising a heavy chain variable region (VH), wherein:

[0251] (a) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0252] (b) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38;

[0253] (c) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39;

[0254] (d) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0255] (e) the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0256] (f) the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42;

[0257] (g) the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43;

[0258] (h) the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44.

[0259] In one embodiment, the present application provides anti-CDH17 antibodies and antigen-binding fragments thereof that specifically bind CDH17, comprising a heavy chain variable region (VH) and a light chain variable region (VL), wherein:

[0260] (a) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 18, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 18, or consists of SEQ ID NO: 18; and the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0261] (b) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 23, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 23, or consists of SEQ ID NO: 23; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0262] (c) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 31, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 31, or consists of SEQ ID NO: 31; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0263] (d) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 35, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 35, or consists of SEQ ID NO: 35; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40.

[0264] In one embodiment, the present application provides anti-CDH17 antibodies and antigen-binding fragments thereof that specifically bind CDH17, comprising a heavy chain variable region (VH) and a light chain variable region (VL), wherein:

[0265] (a) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 19, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 19, or consists of SEQ ID NO: 19; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0266] (b) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 20, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 20, or consists of SEQ ID NO: 20; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0267] (c) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38;

[0268] (d) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39;

[0269] (e) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0270] (f) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0271] (g) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42;

[0272] (h) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43;

[0273] (i) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44;

[0274] (j) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38;

[0275] (k) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39;

[0276] (l) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0277] (m) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0278] (n) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42;

[0279] (o) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43;

[0280] (p) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44;

[0281] (q) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 25, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 25, or consists of SEQ ID NO: 25; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0282] (r) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 26, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 26, or consists of SEQ ID NO: 26; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37;

[0283] (s) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38;

[0284] (t) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39;

[0285] (u) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0286] (v) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0287] (w) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42;

[0288] (x) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43;

[0289] (y) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44;

[0290] (z) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38;

[0291] (aa) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39;

[0292] (bb) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0293] (cc) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0294] (dd) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42;

[0295] (ee) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43;

[0296] (ff) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44;

[0297] (gg) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 29, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 29, or consists of SEQ ID NO: 29; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0298] (hh) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 30, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 30, or consists of SEQ ID NO: 30; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41;

[0299] (ii) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 31, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 31, or consists of SEQ ID NO: 31; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0300] (jj) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 32, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 32, or consists of SEQ ID NO: 32; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0301] (kk) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO:33, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO:33, or consists of SEQ ID NO:33; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO:40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO:40, or consists of SEQ ID NO:40;

[0302] (ll) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO:34, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO:34, or consists of SEQ ID NO:34; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO:40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO:40, or consists of SEQ ID NO:40;

[0303] (mm) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO:35, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO:35, or consists of SEQ ID NO:35; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO:38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO:38, or consists of SEQ ID NO:38;

[0304] (nn) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 36, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 36, or consists of SEQ ID NO: 36; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38;

[0305] (oo) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 35, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 35, or consists of SEQ ID NO: 35; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40;

[0306] (pp) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 36, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 36, or consists of SEQ ID NO: 36; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40.

[0307] It will be appreciated that sequence variants of these constant region domains can also be used, for example comprising one or more amino acid modifications, wherein the amino acid positions are identified in the EU index system according to Kabat et al. (1991).

[0308] As a specific embodiment, the heavy chain variable region (VH) and / or the light chain variable region (VL) are defined by the Kabat numbering system.

[0309] In embodiments of the antibody of any of the foregoing, the antibody is a monoclonal antibody.

[0310] In embodiments of the antibody of any of the foregoing, the antibody is a full-length antibody.

[0311] In some embodiments, the antibody or antigen-binding fragment of the present application is a murine, chimeric, humanized, or fully human antibody.

[0312] In some embodiments, the anti-CDH17 antibody of the present application is a whole antibody, e.g., an IgGl, IgG2, IgG3, IgG4 antibody.

[0313] In some embodiments, the present application provides an anti-CDH17 antibody or antigen-binding fragment thereof, comprising:

[0314] (a) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 57, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 57, or consists of SEQ ID NO: 57; or

[0315] (b) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 61, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 61, or consists of SEQ ID NO: 61.

[0316] In some embodiments, the present application provides an anti-CDH17 antibody or antigen-binding fragment thereof, comprising a light chain: the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 66, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 66, or consists of SEQ ID NO: 66.

[0317] In some embodiments, the present application provides an anti-CDH17 antibody or antigen-binding fragment thereof, comprising:

[0318] (a) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 57, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 57, or consists of SEQ ID NO: 57, and the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 66, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 66, or consists of SEQ ID NO: 66; or

[0319] (b) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 61, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 61, or consists of SEQ ID NO: 61, and the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 66, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity to the amino acid sequence of SEQ ID NO: 66, or consists of SEQ ID NO: 66.

[0320] In another embodiment, the anti-CDH17 antibody of the present application encompasses only the antigen-binding portion thereof, for example: a Fab, Fab'-SH, Fv, scFv, or (Fab')2 fragment.

[0321] In another aspect, the present application provides an isolated polynucleotide molecule encoding any of the CDH17 antibodies or antigen-binding fragments thereof described herein.

[0322] In another aspect, the present application provides an expression vector comprising the nucleotide molecule described herein. In one embodiment, the vector is a eukaryotic expression vector.

[0323] In another aspect, the present application provides a host cell comprising the expression vector or nucleotide molecule described herein. In some embodiments, the host cell is prokaryotic, for example, E. coli. In other embodiments, the host cell is eukaryotic, for example, a 293 cell, a CHO cell, a yeast cell, or a plant cell.

[0324] Further, the present application provides a pharmaceutical composition comprising the anti-CDH17 antibody or antigen-binding fragment thereof of the present application, or the polynucleotide molecule of the present application, or the expression vector of the present application, or the host cell of the present application, and a pharmaceutically acceptable pharmaceutical carrier or excipient.

[0325] The present application provides a method of making the anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising expressing the antibody or antigen-binding fragment thereof in a host cell described herein under conditions suitable for expression of the antibody or antigen-binding fragment thereof, and recovering the expressed antibody or antigen-binding fragment thereof from the supernatant of the host cell expression.

[0326] The anti-CDH17 antibody or antigen-binding fragment thereof or pharmaceutical composition of the present application can also be administered in combination with one or more other therapies, such as therapeutic modalities and / or other therapeutic agents, for the uses described herein, such as for the prevention and / or treatment of the relevant diseases or disorders mentioned herein.

[0327] The present application also provides a pharmaceutical combination comprising the antibody or antigen-binding fragment thereof or pharmaceutical composition as described herein, and one or more additional therapeutic agents.

[0328] The present application provides a method of preventing or treating a CDH17-mediated disease or disorder in a subject in need thereof, comprising administering to the subject a prophylactically or therapeutically effective amount of the antibody or antigen-binding fragment thereof of the present application, the polynucleotide molecule described herein, the expression vector described herein, the host cell described herein, the pharmaceutical composition described herein, or the pharmaceutical combination described herein. In one embodiment, the CDH17-mediated disease or disorder is a tumor and / or cancer associated with abnormal expression of CDH17. In one embodiment, the tumor and / or cancer is selected from a solid tumor, for example, the solid tumor includes but is not limited to colorectal cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gallbladder cancer, pancreatic cancer, small intestine cancer, liver cancer, neuroendocrine tumor or cancer, bladder cancer, breast cancer, head and neck cancer, endometrial cancer, kidney cancer, liver cancer, lung cancer, prostate cancer, thyroid cancer, melanoma, ovarian cancer, gastrointestinal stromal tumor.

[0329] The present application provides use of an antibody or antigen binding fragment thereof described herein, a polynucleotide molecule described herein, an expression vector described herein, a host cell described herein, a pharmaceutical composition described herein, or a pharmaceutical combination described herein in the manufacture of a medicament for treating and / or preventing a CDH17-mediated disease or disorder. In one embodiment, the CDH17-mediated disease or disorder is a tumor and / or cancer associated with abnormal expression of CDH17. In one embodiment, the tumor and / or cancer associated with abnormal expression of CDH17 is selected from a solid tumor, for example, the solid tumor includes but is not limited to colorectal cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gallbladder cancer, pancreatic cancer, small intestine cancer, liver cancer, neuroendocrine tumor or cancer, bladder cancer, breast cancer, head and neck cancer, endometrial cancer, kidney cancer, liver cancer, lung cancer, prostate cancer, thyroid cancer, melanoma, ovarian cancer, gastrointestinal stromal tumor.

[0330] In one embodiment, the present application provides an antibody or antigen binding fragment thereof described herein, a polynucleotide molecule described herein, an expression vector described herein, a host cell described herein, a pharmaceutical composition described herein, or a pharmaceutical combination described herein for use in treating and / or preventing a CDH17-mediated disease or disorder. In one embodiment, the CDH17-mediated disease or disorder is a tumor and / or cancer associated with abnormal expression of CDH17. In one embodiment, the tumor and / or cancer associated with abnormal expression of CDH17 is selected from a solid tumor, for example, the solid tumor includes but is not limited to colorectal cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gallbladder cancer, pancreatic cancer, small intestine cancer, liver cancer, neuroendocrine tumor or cancer, bladder cancer, breast cancer, head and neck cancer, endometrial cancer, kidney cancer, liver cancer, lung cancer, prostate cancer, thyroid cancer, melanoma, ovarian cancer, gastrointestinal stromal tumor.

[0331] The present application also provides a kit comprising an anti-CDH17 antibody or antigen binding fragment thereof of the present application, a polynucleotide molecule described herein, an expression vector described herein, a host cell described herein, a pharmaceutical composition described herein, or a pharmaceutical combination described herein, or a pharmaceutical composition, and instructions for use. The kit can further comprise a suitable container. In certain embodiments, the kit further comprises a device for administration. The kit generally includes a label indicating the intended use and / or method of use of the contents of the kit. The term "label" includes any writing, recorded matter, or any symbol that is provided on or with a kit, or otherwise accompanies the kit.

[0332] The present application provides a method of detecting the presence of CDH17 in a sample using an antibody or antigen binding fragment thereof described herein or a detection composition comprising the antibody or antigen binding fragment thereof.

[0333] The present application provides a method of detecting CDH17, wherein a sample to be tested is contacted with an antibody or antigen-binding fragment thereof according to the present application under conditions in which a complex can form between the antibody or antigen-binding fragment thereof according to the present application and CDH17.

[0334] The present application provides a kit comprising an antibody or antigen-binding fragment thereof, an expression vector, a host cell, a polynucleic acid fragment or a pharmaceutical composition according to the present application.

[0335] The present application provides a detection system comprising an antibody or antigen-binding fragment thereof according to the present application, or an antibody or antigen-binding fragment thereof produced thereby. The present application also provides the use of said detection system in a diagnostic method.

[0336] The present application provides a method of detecting tumor growth comprising determining the amount of CDH17 expression in a sample from a patient suspected of having a cancer and optionally a negative control sample and further optionally a positive control sample using an antibody or antigen-binding fragment thereof according to the present application, or an antibody or antigen-binding fragment thereof produced thereby.

[0337] The method of detecting tumor growth according to the present application comprises determining the amount of CDH17 expression in a sample from a patient suspected of having a cancer and a negative control sample, further comprising comparing the amount of CDH17 expression between the samples, optionally wherein the amount of expression in the negative control and / or the positive control can be derived from stored data in at least one negative control sample and / or at least one positive control sample obtained in a method of detecting neoplastic growth comprising determining the amount of CDH17 expression, further optionally wherein the amount of expression in the negative control sample and / or the positive control sample can be derived from stored data comprising the average amount of expression in more than one negative control sample and / or more than one positive control sample obtained in a method of detecting neoplastic growth comprising determining the amount of CDH17 expression.

[0338] The sample and controls in the method of detection according to the present application can be positive expressing cells, solid tissue samples or liquid tissue samples.

[0339] The present application provides a method for detecting and / or quantifying CDH17 in a sample comprising (a) using an antibody according to the preceding antibody or produced according to the preceding method, or using the preceding detection system, for determining the amount of CDH17 expression in the sample; and; (b) comparing the amount of CDH17 expression determined in step (a) to (i) a predefined value for the amount of CDH17 expression, (ii) the amount of CDH17 expression determined in a control sample, or (iii) the amount of CDH17 expression determined in a sample obtained from the same source or subject at a previous time point.

[0340] The present application provides a method for diagnosing whether a subject suffers from a CDH17-mediated disease or disorder, comprising: (a) using the aforementioned anti-CDH17 antibody or antigen-binding fragment thereof, or using the aforementioned detection system, for determining the expression amount of CDH17 in a sample from a subject; and (b) comparing the CDH17 expression amount determined in step (a) with: (i) a pre-defined value of CDH17 expression amount; (ii) the CDH17 expression amount determined in a control from a healthy subject, or (iii) the CDH17 expression amount determined in a sample obtained from the same source or subject at a previous time point, wherein when the CDH17 expression amount determined in step (a) is higher than the CDH17 expression amount in (i), (ii) or (iii), the subject is diagnosed as suffering from a CDH17-mediated disease or disorder.

[0341] The antibody or antigen-binding fragment thereof targeting human CDH17 provided by the present application has the following advantages:

[0342] (1) binds to target cells expressing human CDH17 with high affinity, with an affinity range of 0.01-1 nM;

[0343] (2) can enter cells by endocytosis; in some embodiments, the antibody of the present application has high endocytosis efficiency;

[0344] (3) can accurately reach CDH17-positive expressing target cells through blood circulation and exert antibody activity (such as ADCC, CDC, ADCP, etc.) by endocytosis into target cells;

[0345] (4) treats, prevents, ameliorates a CDH17-related disorder (e.g., cancer) in a subject, or treats, prevents, ameliorates one or more symptoms of the disease;

[0346] (5) reduces or inhibits tumor growth or progression in a subject;

[0347] (6) induces CDH17-related tumor regression (e.g., long-term regression).

[0348] II. Antibody drug conjugate

[0349] The present application provides a novel anti-CDH17 antibody drug conjugate, which has the advantages of high affinity and high specificity to human CDH17. The anti-CDH17 antibody drug conjugate provided by the present application can be used as an independent therapy or in combination with other therapies / or other anti-cancer agents for the treatment of diseases such as cancer / tumor.

[0350] The present application provides an anti-CDH17 antibody drug conjugate as shown in formula (I), isomers thereof, pharmaceutically acceptable salts thereof, or mixtures thereof:

[0351] Ab-(L-D)m[Formula (I)]

[0352] wherein,

[0353] L is a linker unit;

[0354] D is a small-molecule drug having cytotoxicity;

[0355] m is the average number of L-D units conjugated to Ab, and m is selected from 1-10, preferably 2-8;

[0356] Ab is an anti-CDH17 antibody or antigen-binding fragment thereof, comprising:

[0357] (1) a) CDRs determined according to the Kabat definition: HCDR1, HCDR2, and HCDR3 having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 4, respectively; and LCDR1, LCDR2, and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively;

[0358] b) CDRs determined according to the IMGT definition: HCDR1, HCDR2, and HCDR3 having the amino acid sequences of SEQ ID NO: 73, SEQ ID NO: 74, and SEQ ID NO: 82, respectively; and LCDR1, LCDR2, and LCDR3 having the amino acid sequences of SEQ ID NO: 76, SEQ ID NO: 77, and SEQ ID NO: 12, respectively;

[0359] c) CDRs determined according to the Chothia definition: HCDR1, HCDR2, and HCDR3 having the amino acid sequences of SEQ ID NO: 78, SEQ ID NO: 79, and SEQ ID NO: 3, respectively; and LCDR1, LCDR2, and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively; or

[0360] d) CDRs determined according to the AbM definition: HCDR1, HCDR2, and HCDR3 having the amino acid sequences of SEQ ID NO: 80, SEQ ID NO: 81, and SEQ ID NO: 3, respectively; and LCDR1, LCDR2, and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively;

[0361] or,

[0362] (2) a) CDRs determined according to the Kabat definition: HCDR1, HCDR2, and HCDR3 of the amino acid sequence set forth in SEQ ID NO: 1, SEQ ID NO: 6, and SEQ ID NO: 8, respectively; and LCDR1, LCDR2, and LCDR3 of the amino acid sequence set forth in SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively;

[0363] b) CDRs determined according to the IMGT definition: HCDR1, HCDR2, and HCDR3 of the amino acid sequence set forth in SEQ ID NO: 73, SEQ ID NO: 74, and SEQ ID NO: 75, respectively; and LCDR1, LCDR2, and LCDR3 of the amino acid sequence set forth in SEQ ID NO: 76, SEQ ID NO: 77, and SEQ ID NO: 12, respectively;

[0364] c) CDRs determined according to the Chothia definition: HCDR1, HCDR2, and HCDR3 of the amino acid sequence set forth in SEQ ID NO: 78, SEQ ID NO: 79, and SEQ ID NO: 7, respectively; and LCDR1, LCDR2, and LCDR3 of the amino acid sequence set forth in SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively; or

[0365] d) CDRs determined according to the AbM definition: HCDR1, HCDR2, and HCDR3 of the amino acid sequence set forth in SEQ ID NO: 80, SEQ ID NO: 81, and SEQ ID NO: 7, respectively; and LCDR1, LCDR2, and LCDR3 of the amino acid sequence set forth in SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively;

[0366] or,

[0367] (3) HCDR1, HCDR2, and HCDR3 of the amino acid sequence set forth in SEQ ID NO: 1, SEQ ID NO: 2, and SEQ ID NO: 3, respectively; and LCDR1, LCDR2, and LCDR3 of the amino acid sequence set forth in SEQ ID NO: 10, SEQ ID NO: 11, and SEQ ID NO: 12, respectively;

[0368] or,

[0369] (4) HCDR1, HCDR2 and HCDR3 having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 7, respectively; and LCDR1, LCDR2 and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11 and SEQ ID NO: 12, respectively;

[0370] or,

[0371] (5) HCDR1, HCDR2 and HCDR3 having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 5, respectively; and LCDR1, LCDR2 and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11 and SEQ ID NO: 12, respectively;

[0372] or,

[0373] (6) HCDR1, HCDR2 and HCDR3 having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 6 and SEQ ID NO: 7, respectively; and LCDR1, LCDR2 and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11 and SEQ ID NO: 12, respectively;

[0374] or,

[0375] (7) HCDR1, HCDR2 and HCDR3 having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 6 and SEQ ID NO: 9, respectively; and LCDR1, LCDR2 and LCDR3 having the amino acid sequences of SEQ ID NO: 10, SEQ ID NO: 11 and SEQ ID NO: 12, respectively.

[0376] In some embodiments, the small molecule drug D is a monomethyl auristatin, a camptothecin, or a maytansinoid.

[0377] In some embodiments, the monomethyl auristatin can be monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF).

[0378] In some embodiments, the maytansinoid can be DM1, DM3, or DM4.

[0379] In some embodiments, the camptothecin derivative can be exatecan, Dxd, Exd, SN-38.

[0380] In some embodiments, the antibody drug conjugate comprises a plurality of D components, which can be a combination of different therapeutically active substances or pharmaceutically active components, or a combination of the same therapeutically active substance or pharmaceutically active component.

[0381] In some embodiments, the antibody drug conjugate has a drug / antibody ratio (DAR) of 1-15, for example, a DAR value of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0382] In some embodiments, the DAR is an average DAR.

[0383] In some embodiments, the average DAR is 1-15.

[0384] As a specific embodiment, the average DAR of the antibody drug conjugate of the present application is preferably 2-10.

[0385] As a specific embodiment, when D is a camptothecin compound, the average DAR of the antibody drug conjugate of the present application is preferably 2-8.

[0386] In some embodiments, the cytotoxin is covalently linked to the anti-CDH17 antibody or antigen binding fragment thereof with a linker in a non-site-specific manner or in a site-specific manner.

[0387] As used herein, "linker", "linker unit" and "linker" are used interchangeably.

[0388] As used herein, "drug-containing linker" refers to a compound obtained by directly or indirectly covalently bonding a drug, such as a small molecule drug having cytotoxicity as described in D, to a linker.

[0389] In some embodiments, the L is a combination of one or more L's.

[0390] In some embodiments, the L' is selected from the group consisting of a carbonyl group, an amino group, an amide group, an aminoacyl group, -(PEG) n -, -(CH2) n -, heteroatom-containing -(CH2) n, -(C=C)-, -(CH=CH)-, -0-, -S-, maleimido, maleimidopropionyl (MP), methylsulfonylpyrimidinyl, valine-citrulline (val-cit), valine-alanine (val-ala), N-succinimidyl-4-(N-maleimidomethyl)cyclohexane-l-carboxylate (SMCC), alanine-phenylalanine (ala-phe), phenylalanine-lysine (phe-lys), p-aminobenzyloxy carbonyl (PAB), dimethyl ethylenediamine (DMED), N-succinimidyl 4-(2-pyridylthio) valerate (SPP), N-succinimidyl 4-(N-maleimidomethyl)-cyclohexane-l-carboxylate (SMCC), N-succinimidyl 4-(iodo-acetyl) aminobenzoate (SIAB), N-succinimidyl 4-(2-pyridyldithio) butyrate (SPDB), N-succinimidyl 3-(pyrid-2-yl dithio)-propionate (SPDP), glycine-glycine-phenylalanine-glycine (GGFG), acetyl-lysine-valine-citrulline-p-aminobenzyloxy carbonyl (AcLys-vc-PABC).

[0391] In some embodiments, n is independently selected from an integer from 1 to 20.

[0392] As a specific embodiment, when L' is selected from (PEG) n , n is independently preferably an integer from 2, 4, 6 or 8.

[0393] As a specific embodiment, when L' is selected from (CH2) n , n is independently preferably an integer from 1 to 16.

[0394] As a specific embodiment, when L' is selected from (CH2) n , n is independently preferably an integer from 1 to 16; and the heteroatom is selected from N, O or S, and the number of heteroatoms is independently preferably an integer from 1 to 8.

[0395] In some embodiments, L can be J-L1-L2-X-L3.

[0396] In some embodiments, J is selected from

[0397] In some embodiments, L1is selected from a single bond, -(PEG) n , or -(CH2) n , and -(CH2) n- optionally containing 1-6 heteroatoms selected from N, O, S; wherein n is independently selected from an integer from 1-20. Preferably, L1is selected from -(PEG) n , wherein n is independently 2, 4, 6 or 8.

[0398] In some embodiments, L2is selected from a combination of one or more of a single bond, -O-, -S-, -CH2-, -NH-, -C(O)-; wherein said -CH2- and -NH- can be optionally substituted 1-3 times with C 1～6 alkyl or halogen.

[0399] In some embodiments, X is selected from a single bond or a combination of 1-4 X', said X' is independently selected from an amino acid.

[0400] In some embodiments, L3is selected from a combination of one or more of a single bond, -O-, -S-, -CH2-, -NH-, -C(O)-, -phenyl-, -cyclopropyl-, -cyclobutyl-, -cyclohexyl-; wherein said -CH2-, -NH-, -phenyl-, -cyclopropyl-, -cyclobutyl-, -cyclohexyl- can be optionally substituted 1-3 times with C 1～6 alkyl, halogen, cyano or hydroxyl.

[0401] In another aspect, the present application provides a linker-cell toxic small molecule drug unit of formula (L-D), such as Cpd3, Cpd5, Cpd6, DXD:

[0402] In some embodiments, the linker-toxin provided by the present application, such as Cpd3, Cpd5, Cpd6, DXD, is suitable for conjugating to an anti-CDH17 antibody or antigen binding fragment thereof with high conjugation efficiency and mild reaction conditions. For example, as demonstrated in the following examples, Cpd3 as a hydrophilic linker-toxin can be used to prepare high DAR value ADC (DAR about 8) with excellent purity.

[0403] Further, the present application provides an anti-CDH17 antibody drug conjugate, isomers thereof, pharmaceutically acceptable salts thereof or mixtures thereof, wherein the anti-CDH17 antibody drug conjugate has a structure of formula (I-C3), (I-C5), (I-C6), (I-DXD):

[0404] wherein,

[0405] m is the average number of linkages, and m is independently selected from an integer from 1-10, for example 2-8, in particular 4-8;

[0406] Ab is an anti-CDH17 antibody of the present application or an antigen-binding fragment thereof, comprising LCDR1, LCDR2 and LCDR3 set forth in SEQ ID NO: 10, SEQ ID NO: 11 and SEQ ID NO: 12 from a light chain variable region, and HCDR1, HCDR2 and HCDR3 of a heavy chain variable region as follows:

[0407] HCDR1, HCDR2 and HCDR3 set forth in SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 4;

[0408] or,

[0409] HCDR1, HCDR2 and HCDR3 set forth in SEQ ID NO: 1, SEQ ID NO: 6 and SEQ ID NO: 8;

[0410] or,

[0411] HCDR1, HCDR2 and HCDR3 set forth in SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3;

[0412] or,

[0413] HCDR1, HCDR2 and HCDR3 set forth in SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 5;

[0414] or,

[0415] HCDR1, HCDR2 and HCDR3 set forth in SEQ ID NO: 1, SEQ ID NO: 6 and SEQ ID NO: 7;

[0416] or,

[0417] HCDR1, HCDR2 and HCDR3 set forth in SEQ ID NO: 1, SEQ ID NO: 6 and SEQ ID NO: 9.3.

[0418] In some embodiments, Ab is an anti-CDH17 antibody of the present application or an antigen-binding fragment thereof, comprising: a heavy chain variable region having an amino acid sequence as set forth in SEQ ID NO: 18 or at least 95%, 96%, 97%, 98%, 99% identical thereto, and a light chain variable region having an amino acid sequence as set forth in SEQ ID NO: 37 or at least 95%, 96%, 97%, 98%, 99% identical thereto, or

[0419] a heavy chain variable region having an amino acid sequence of SEQ ID NO: 21 or at least 95%, 96%, 97%, 98%, 99% identical thereto, and a light chain variable region having an amino acid sequence of SEQ ID NO: 38 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0420] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region having an amino acid sequence of SEQ ID NO: 23 or at least 95%, 96%, 97%, 98%, 99% identical thereto, and a light chain variable region having an amino acid sequence of SEQ ID NO: 37 or at least 95%, 96%, 97%, 98%, 99% identical thereto, or

[0421] a heavy chain variable region having an amino acid sequence of SEQ ID NO: 21 or at least 95%, 96%, 97%, 98%, 99% identical thereto, and a light chain variable region having an amino acid sequence of SEQ ID NO: 38 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0422] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region having an amino acid sequence of SEQ ID NO: 18 and a light chain variable region having an amino acid sequence of SEQ ID NO: 37.

[0423] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region having an amino acid sequence of SEQ ID NO: 23 and a light chain variable region having an amino acid sequence of SEQ ID NO: 37.

[0424] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region having an amino acid sequence of SEQ ID NO: 21 and a light chain variable region having an amino acid sequence of SEQ ID NO: 37.

[0425] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region having an amino acid sequence of SEQ ID NO: 21 and a light chain variable region having an amino acid sequence of SEQ ID NO: 38.

[0426] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 21 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 39.

[0427] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 21 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0428] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 21 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 41.

[0429] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 21 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 42.

[0430] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 21 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 43.

[0431] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 21 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 44.

[0432] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 38.

[0433] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 39.

[0434] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0435] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 41.

[0436] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 42.

[0437] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 43.

[0438] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 22 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 44.

[0439] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 25 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 37.

[0440] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 26 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 37.

[0441] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 38.

[0442] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 39.

[0443] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0444] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 41.

[0445] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 42.

[0446] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 43.

[0447] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 27 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 44.

[0448] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 38.

[0449] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 39.

[0450] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0451] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 41.

[0452] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 42.

[0453] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 43.

[0454] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 28 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 44.

[0455] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 29 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 41.

[0456] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 30 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 41.

[0457] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 31 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0458] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 32 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0459] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 33 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0460] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 34 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0461] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 35 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 38.

[0462] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 36 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 38.

[0463] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 35 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 40.

[0464] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain variable region of the amino acid sequence set forth in SEQ ID NO: 36 and a light chain variable region of the amino acid sequence set forth in SEQ ID NO: 38.

[0465] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising: a heavy chain of the amino acid sequence set forth in SEQ ID NO: 45 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0466] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 46 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0467] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 47 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0468] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 48 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0469] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 49 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0470] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 50 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0471] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 51 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0472] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 52 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0473] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 53 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0474] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 54, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0475] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 55, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0476] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 56, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0477] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 57, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0478] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 58, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0479] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 59, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0480] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 60, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0481] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain of an amino acid sequence as set forth in SEQ ID NO: 61, or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0482] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain having an amino acid sequence of SEQ ID NO: 62 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0483] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 63 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0484] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 64 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0485] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 65 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0486] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 66 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0487] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 67 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0488] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 68 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0489] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a light chain having an amino acid sequence of SEQ ID NO: 69 or at least 95%, 96%, 97%, 98%, 99% identity thereto.

[0490] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain having an amino acid sequence of SEQ ID NO: 63 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0491] In some embodiments, the Ab is an anti-CDH17 antibody or antigen-binding fragment thereof described herein, comprising a heavy chain having an amino acid sequence of SEQ ID NO: 63 or at least 95%, 96%, 97%, 98%, 99% identical thereto.

[0492] In some embodiments, the Ab is an antibody or antigen-binding fragment thereof described herein, which is a murine, chimeric, humanized or fully human antibody.

[0493] As a specific embodiment, the fragment of SEQ ID: 18, SEQ ID: 23, SEQ ID: 37, SEQ ID: 45, SEQ ID: 50, SEQ ID: 63 described herein is a murine antibody.

[0494] As a specific embodiment, the fragment of SEQ ID: 19, SEQ ID: 20, SEQ ID: 21, SEQ ID: 22, SEQ ID: 25, SEQ ID: 26, SEQ ID: 27, SEQ ID: 28, SEQ ID: 29, SEQ ID: 30, SEQ ID: 31, SEQ ID: 32, SEQ ID: 33, SEQ ID: 34, SEQ ID: 35, SEQ ID: 36, SEQ ID: 38, SEQ ID: 39, SEQ ID: 40, SEQ ID: 41, SEQ ID: 42, SEQ ID: 43, SEQ ID: 44, SEQ ID: 45, SEQ ID: 46, SEQ ID: 47, SEQ ID: 48, SEQ ID: 49, SEQ ID: 51, SEQ ID: 52, SEQ ID: 53, SEQ ID: 54, SEQ ID: 55, SEQ ID: 56, SEQ ID: 57, SEQ ID: 58, SEQ ID: 59, SEQ ID: 60, SEQ ID: 61, SEQ ID: 62, SEQ ID: 64, SEQ ID: 65, SEQ ID: 66, SEQ ID: 67, SEQ ID: 68, SEQ ID: 69, SEQ ID: 70 described herein is a humanized antibody.

[0495] In some embodiments, the anti-CDH17 antibody or antigen-binding fragment thereof of the present application is a Fab, Fab', Fab'-SH, Fv, scFv, F(ab')2, or sdAb.

[0496] In some embodiments, the anti-CDH17 antibody or antigen-binding fragment thereof of the present application is any IgG subtype, such as IgGl, IgG2, IgG3, IgG4; preferably, the antibody is low or afucosylated.

[0497] In some embodiments, the Ab of the present application comprises 3 complementarity determining regions from a heavy chain variable region (HCDR), HCDR1, HCDR2, and HCDR3.

[0498] In some embodiments, the Ab of the present application comprises 3 complementarity determining regions from a light chain variable region (LCDR), LCDR1, LCDR2, and LCDR3.

[0499] In some embodiments, the Ab of the present application comprises 3 complementarity determining regions from a heavy chain variable region (HCDR) and 3 complementarity determining regions from a light chain variable region (LCDR).

[0500] In some embodiments, the Ab comprises a heavy chain variable region (VH).

[0501] In some embodiments, the heavy chain variable region comprises 3 complementarity determining regions from a heavy chain variable region (HCDR).

[0502] In some embodiments, the Ab comprises a light chain variable region (VL).

[0503] In some embodiments, the light chain variable region comprises 3 complementarity determining regions from a light chain variable region (LCDR).

[0504] In some embodiments, the Ab heavy chain variable region (VH) and light chain variable region (VL).

[0505] In some embodiments, the heavy chain variable region of the present application:

[0506] (i) comprises or consists of an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 18;

[0507] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 18; or

[0508] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 18, preferably the amino acid alterations do not occur in CDR regions.

[0509] In some embodiments, the heavy chain variable region according to the application:

[0510] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 19;

[0511] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 19; or

[0512] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 19, preferably the amino acid alterations do not occur in CDR regions.

[0513] In some embodiments, the heavy chain variable region according to the application:

[0514] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 20;

[0515] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 20; or

[0516] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 20, preferably the amino acid alterations do not occur in CDR regions.

[0517] In some embodiments, the heavy chain variable region according to the application:

[0518] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 21;

[0519] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 21; or

[0520] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 21, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0521] In some embodiments, the heavy chain variable region according to the application:

[0522] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 22;

[0523] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 22; or

[0524] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 22, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0525] In some embodiments, the heavy chain variable region according to the application:

[0526] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 23;

[0527] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 23; or

[0528] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 23, preferably the amino acid alterations do not occur in CDR regions.

[0529] In some embodiments, the heavy chain variable region according to the application:

[0530] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 25; and / or

[0531] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 25; and / or

[0532] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 25, preferably the amino acid alterations do not occur in CDR regions.

[0533] In some embodiments, the heavy chain variable region according to the application:

[0534] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 26; and / or

[0535] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 26; and / or

[0536] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 26, preferably the amino acid alterations do not occur in CDR regions.

[0537] In some embodiments, the heavy chain variable region according to the application:

[0538] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 27;

[0539] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 27; or

[0540] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 27, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0541] In some embodiments, the heavy chain variable region according to the application:

[0542] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 28;

[0543] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 28; or

[0544] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 28, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0545] In some embodiments, the heavy chain variable region according to the application:

[0546] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 29;

[0547] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 29; or

[0548] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 29, preferably the amino acid alterations do not occur in CDR regions.

[0549] In some embodiments, the heavy chain variable region according to the application:

[0550] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 30; and / or

[0551] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 30; and / or

[0552] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 30, preferably the amino acid alterations do not occur in CDR regions.

[0553] In some embodiments, the heavy chain variable region according to the application:

[0554] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 31; and / or

[0555] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 31; and / or

[0556] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 31, preferably the amino acid alterations do not occur in CDR regions.

[0557] In some embodiments, the heavy chain variable region according to the application:

[0558] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 32;

[0559] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 32; or

[0560] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 32, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0561] In some embodiments, the heavy chain variable region according to the application:

[0562] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 33;

[0563] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 33; or

[0564] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 33, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0565] In some embodiments, the heavy chain variable region according to the application:

[0566] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 34;

[0567] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 34; or

[0568] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 34, preferably the amino acid alterations do not occur in CDR regions.

[0569] In some embodiments, the heavy chain variable region according to the application:

[0570] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 35;

[0571] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 35; or

[0572] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 35, preferably the amino acid alterations do not occur in CDR regions.

[0573] In some embodiments, the heavy chain variable region according to the application:

[0574] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 36;

[0575] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 36; or

[0576] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 36, preferably the amino acid alterations do not occur in CDR regions.

[0577] In some embodiments, the light chain variable region according to the application:

[0578] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 37;

[0579] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 37; or

[0580] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the amino acid sequence of SEQ ID NO: 37, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0581] In some embodiments, the light chain variable region according to the application:

[0582] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 38;

[0583] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 38; or

[0584] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the amino acid sequence of SEQ ID NO: 38, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0585] In some embodiments, the light chain variable region according to the application:

[0586] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 39;

[0587] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 39; or

[0588] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 39, preferably the amino acid alterations do not occur in CDR regions.

[0589] In some embodiments, the light chain variable region of the application:

[0590] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 40;

[0591] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 40; or

[0592] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 40, preferably the amino acid alterations do not occur in CDR regions.

[0593] In some embodiments, the light chain variable region of the application:

[0594] (i) comprises or consists of an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 41;

[0595] (ii) comprises or consists of the amino acid sequence of SEQ ID NO: 41; or

[0596] (iii) comprises or consists of an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the amino acid sequence of SEQ ID NO: 41, preferably the amino acid alterations do not occur in CDR regions.

[0597] In some embodiments, the light chain variable region of the application:

[0598] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 42;

[0599] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 42; or

[0600] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 42, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0601] In some embodiments, the light chain variable region according to the application:

[0602] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 43;

[0603] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 43; or

[0604] (iii) comprises or consists an amino acid sequence which has one or more, preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1, amino acid alteration(s) (preferably amino acid substitution(s), more preferably amino acid conservative substitution(s)) compared to the amino acid sequence of SEQ ID NO: 43, preferably the amino acid sequence alteration(s) do not occur in the CDR regions.

[0605] In some embodiments, the light chain variable region according to the application:

[0606] (i) comprises or consists an amino acid sequence which is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% identical to the amino acid sequence of SEQ ID NO: 44;

[0607] (ii) comprises or consists the amino acid sequence of SEQ ID NO: 44; or

[0608] (iii) comprises or consists of an amino acid sequence having one or more (preferably not more than 10, more preferably not more than 5, 4, 3, 2, 1) amino acid alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the amino acid sequence of SEQ ID NO: 44, preferably the amino acid alterations do not occur in the CDR regions.

[0609] In some embodiments, HCDR1 comprises or consists of the amino acid sequence of SEQ ID NO: 1, or HCDR1 comprises an amino acid sequence having one, two or three alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the sequence of SEQ ID NO: 1.

[0610] In some embodiments, HCDR2 comprises or consists of the amino acid sequence of SEQ ID NO: 2, or HCDR2 comprises an amino acid sequence having one, two or three alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the sequence of SEQ ID NO: 2.

[0611] In some embodiments, HCDR2 comprises or consists of the amino acid sequence of SEQ ID NO: 6, or HCDR2 comprises an amino acid sequence having one, two or three alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the sequence of SEQ ID NO: 6.

[0612] In some embodiments, HCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 3, or HCDR3 comprises an amino acid sequence having one, two or three alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the sequence of SEQ ID NO: 3.

[0613] In some embodiments, HCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 4, or HCDR3 comprises an amino acid sequence having one, two or three alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the sequence of SEQ ID NO: 4.

[0614] In some embodiments, HCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 5, or HCDR3 comprises an amino acid sequence having one, two or three alterations (preferably amino acid substitutions, more preferably amino acid conservative substitutions) compared to the sequence of SEQ ID NO: 5.

[0615] In some embodiments, HCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 7, or HCDR3 comprises an amino acid sequence that has one, two or three alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the sequence of SEQ ID NO: 7.

[0616] In some embodiments, HCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 8, or HCDR3 comprises an amino acid sequence that has one, two or three alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the sequence of SEQ ID NO: 8.

[0617] In some embodiments, HCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 9, or HCDR3 comprises an amino acid sequence that has one, two or three alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the sequence of SEQ ID NO: 9.

[0618] In some embodiments, LCDR1 comprises or consists of the amino acid sequence of SEQ ID NO: 10, or LCDR1 comprises an amino acid sequence that has one, two or three alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the sequence of SEQ ID NO: 10.

[0619] In some embodiments, LCDR2 comprises or consists of the amino acid sequence of SEQ ID NO: 11, or LCDR2 comprises an amino acid sequence that has one, two or three alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the sequence of SEQ ID NO: 11.

[0620] In some embodiments, LCDR3 comprises or consists of the amino acid sequence of SEQ ID NO: 12, or LCDR3 comprises an amino acid sequence that has one, two or three alterations, preferably amino acid substitutions, more preferably amino acid conservative substitutions, compared to the sequence of SEQ ID NO: 12.

[0621] In some embodiments, the Ab of the application comprises a heavy chain constant region.

[0622] In some embodiments, the Ab of the application comprises a light chain constant region.

[0623] In some embodiments, the Ab of the application comprises a heavy chain constant region and a light chain constant region.

[0624] In some embodiments, the heavy chain constant region is an IgGl, IgG2, IgG3, or IgG4 heavy chain constant region.

[0625] The present application provides an antibody drug conjugate targeting human CDH17, an isomer thereof, a pharmaceutically acceptable salt thereof or a mixture thereof, which has the following advantages:

[0626] (1) binds to target cells expressing human CDH17 with high affinity;

[0627] (2) can enter cells by endocytosis, killing target cells; in some embodiments, the ADC of the present application has high endocytosis efficiency;

[0628] (3) treats, prevents, ameliorates a disease (e.g., cancer) associated with abnormal function or expression of CDH17 in a subject, or treats, prevents, ameliorates one or more symptoms of the disease;

[0629] (4) reduces or inhibits tumor growth or progression in a subject (which has a tumor expressing CDH17);

[0630] (5) induces tumor regression (e.g., long-term regression) expressing CDH17;

[0631] (6) exerts cytotoxic activity in cells expressing CDH17;

[0632] The present application provides a pharmaceutical composition comprising the anti-CDH17 antibody drug conjugate, an isomer thereof, a pharmaceutically acceptable salt thereof or a mixture thereof, and a pharmaceutically acceptable excipient.

[0633] The present application provides the use of the anti-CDH17 antibody drug conjugate, an isomer thereof, a pharmaceutically acceptable salt thereof or a mixture thereof, or the pharmaceutical composition for the preparation of a medicament for treating and / or preventing a CDH17-mediated disease or disorder.

[0634] The present application provides the anti-CDH17 antibody drug conjugate, an isomer thereof, a pharmaceutically acceptable salt thereof or a mixture thereof, or the pharmaceutical composition for treating and / or preventing a CDH17-mediated disease or disorder.

[0635] The present application provides a method of treating and / or preventing a CDH17-mediated disease or disorder, comprising administering the antibody drug conjugate, an isomer thereof, a pharmaceutically acceptable salt thereof or a mixture thereof, or the pharmaceutical composition to a subject in need thereof.

[0636] In some embodiments, the CDH17-mediated disease or disorder is cancer or a tumor.

[0637] In some embodiments, the cancer or tumor is selected from a solid tumor, for example, the solid tumor includes but is not limited to colorectal cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gallbladder cancer, pancreatic cancer, small intestine cancer, liver cancer, neuroendocrine tumor or cancer, bladder cancer, breast cancer, head and neck cancer, endometrial cancer, kidney cancer, liver cancer, lung cancer, prostate cancer, thyroid cancer, melanoma, ovarian cancer, gastrointestinal stromal tumor.

[0638] The present application provides a pharmaceutical combination comprising the anti-CDH17 antibody drug conjugate, isomers thereof, pharmaceutically acceptable salts thereof or mixtures thereof, or the pharmaceutical composition, and another therapeutic agent or agents.

[0639] The present application provides a kit comprising the anti-CDH17 antibody drug conjugate, isomers thereof, pharmaceutically acceptable salts thereof or mixtures thereof, or the pharmaceutical composition. BRIEF DESCRIPTION OF DRAWINGS

[0640] Figure 1 shows the results of ELISA detection of the binding of murine antibodies to human CDH17 protein. Figure 1A: results of ELISA detection of the binding of murine antibodies to human CDH17 protein hCDH17-D6; Figure 1B: results of ELISA detection of the binding of murine antibodies to human CDH17 protein hCDH17-D1-2.

[0641] Figure 2 shows the results of SDS-PAGE identification of 31H4C3 chimeric antibody clones.

[0642] Figure 3 shows the results of ELISA detection of chimeric antibodies. Figure 3A: results of ELISA EC50 of chimeric antibodies binding to monkey CDH17 extracellular domain; Figure 3B: results of ELISA affinity detection of chimeric antibodies binding to human CDH17 protein; Figure 3C: results of ELISA affinity detection of chimeric antibodies binding to monkey CDH17 protein; Figure 3D: results of ELISA detection of 31H4C3 and 5F8B4 binding to human CDH17 Domain 5-7.

[0643] Figure 4 shows the results of FACS detection of chimeric antibodies binding to CDH17 overexpressing cells. Figure 4A: binding activity of chimeric antibodies to human CDH17 overexpressing cell lines; Figure 4B: binding activity of chimeric antibodies to monkey CDH17 overexpressing cell lines.

[0644] Figure 5 shows the results of species cross-reactivity of chimeric antibodies. Figure 5A: concentration relationship verification of chimeric antibodies binding to human CDH17; Figure 5B: concentration relationship verification of chimeric antibodies binding to monkey CDH17.

[0645] Figure 6 shows the results of FACS detection of chimeric antibodies binding to SW948 cells.

[0646] Figure 7 shows the FACS detection results of the internalization of the chimeric antibodies into SW948 cells.

[0647] Figure 8 shows the SDS-PAGE identification results of the chimeric antibodies. Figure 8A: SDS-PAGE identification results of the chimeric antibody 5F8B4; Figure 8B: SDS-PAGE identification results of the chimeric antibody 31H4C3-hIgGl.

[0648] Figure 9 shows the FACS detection results of the binding of the humanized antibodies to the cells overexpressing CDH17. Figure 9A: FACS detection results of the 5F8B4 humanized antibody; Figure 9B: FACS detection results of the 31H4C3 humanized antibody.

[0649] Figure 10 shows the detection results of the drugability of the humanized antibodies. Figure 10A and 10D disclose the FACS detection results without treatment; Figure 10B and Figure 10E disclose the FACS detection results after the freezing and thawing of the respective antibodies; Figure 10C and Figure 10F disclose the FACS detection results after the incubation of the humanized antibodies at 40°C for 2 weeks.

[0650] Figure 11 shows the ELISA detection results of the humanized antibodies before and after freezing and thawing.

[0651] Figure 12 shows the binding of the humanized antibodies to cancer cells expressing or not expressing CDH17. Figure 12A: verification of the binding activity of the antibodies to the positive cell NCI-H716; Figure 12B: verification of the binding activity of the antibodies to the positive cell SW948; Figure 12C: verification of the binding activity of the antibodies to the positive cell LS1034; Figure 12D: verification of the binding activity of the antibodies to the positive cell Colo320DM; Figure 12E: verification of the binding activity of the antibodies to the negative cell HT29; Figure 12F: verification of the binding activity of the antibodies to the negative cell SW480.

[0652] Figure 13 shows the internalization properties of the humanized antibodies on tumor cells. Figure 13A: verification of the internalization activity of the antibodies to the positive cell NCI-H716; Figure 13B: verification of the internalization activity of the antibodies to the positive cell LS1034.

[0653] Figure 14 shows the affinity activity of humanized ADCs. Figure 14A: affinity activity of humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to human CDH17 antigen protein; Figure 14B: affinity activity of humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to monkey CDH17 antigen protein; Figure 14C: affinity activity of humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to rat CDH17 antigen protein; Figure 14D: affinity activity of humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to mouse CDH17 antigen protein.

[0654] Figure 15 shows that humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) do not bind to CDH17 homolog protein CDH16.

[0655] FIG. 16 shows the binding activity of ADCs to tumor cells. FIG. 16A: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell NCI-H716; FIG. 16B: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell LS1034; FIG. 16C: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell SW948; FIG. 16D: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell Colo205; FIG. 16E: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell HT-55; FIG. 16F: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell SNU-5; FIG. 16G: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell SNU-16; FIG. 16H: binding activity of ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell OCUM-1; FIG. 161: binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cell IM95;Figure 16J: Binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 positive tumor cells OE19; Figure 16K: Binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 negative tumor cells HT-29; Figure 16L: Binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 negative tumor cells SW480.

[0656] Figure 17 shows the endocytosis properties of ADCs on tumor cells. Figure 17A: Endocytosis efficiency results of hu31H4C3-Cpd3 and hu5F8B4-Cpd3 in NCI-H716 cell line; Figure 17B: Endocytosis efficiency results of hu31H4C3-Cpd3 and hu5F8B4-Cpd3 in LS1034 cell line; Figure 17C: Endocytosis efficiency results of hu31H4C3-Cpd3 and hu5F8B4-Cpd3 in SNU-5 cell line.

[0657] Figure 18 shows the inhibitory activity of ADCs on tumor cell proliferation. Figure 18A: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in NCI-H716 cells; Figure 18B: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in LS1034 cells; Figure 18C: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in SW948 cells; Figure 18D: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in Colo205 cells; Figure 18E: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in HT-55 cells; Figure 18F: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in SNU-5 cells; Figure 18G: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in SNU-16 cells; Figure 18H: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in OCUM-1 cells; Figure 18I: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in IM95 cells; Figure 18J: hu31H4C3-Cpd3 and hu5F8B4-Cpd3 proliferation inhibition in OE19 cells.

[0658] Figure 19 shows the binding activity of ADCs to cells. Figure 19A: FACS binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 overexpressing engineered cell line CHOK1-human CDH17; Figure 19B: FACS binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 overexpressing engineered cell line monkey CDH17-HEK293; Figure 19C: FACS binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 overexpressing engineered cell line rat CDH17-HEK293; Figure 19D: FACS binding activity of candidate antibody drug conjugates (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 overexpressing engineered cell line mouse CDH17-HEK293.

[0659] Figure 20 shows the inhibitory effect of candidate antibody drug conjugates on NCI-H716 colorectal cancer xenograft tumors. Figure 20A: Effect of candidate antibody drug conjugates on animal tumor volume in NCI-H716 CRC model; Figure 20B: Effect of candidate antibody drug conjugates on animal body weight in NCI-H716 CRC model.

[0660] Figure 21 shows the inhibitory effect of candidate antibody drug conjugates on LS1034 colorectal cancer xenograft tumors. Figure 21A: Effect of candidate antibody drug conjugates on animal tumor volume in LS1034 CRC model; Figure 21B: Effect of candidate antibody drug conjugates on animal body weight in LS1034 CRC model.

[0661] Figure 22 shows the inhibitory effect of candidate antibody drug conjugates on SNU-5 colorectal cancer xenograft tumors. Figure 22A: Effect of candidate antibody drug conjugates on animal tumor volume in SNU5 GC model; Figure 22B: Effect of candidate antibody drug conjugates on animal body weight in SNU GC model.

[0662] Figure 23 shows the inhibitory effect of candidate antibody drug conjugates on AsPC-1 mouse pancreatic cancer xenograft tumors. Figure 23A: Effect of candidate antibody drug conjugates on animal tumor volume in the AsPC-1 PC model; Figure 23B: Effect of candidate antibody drug conjugates on animal body weight in the AsPC-1 PC model.

[0663] Figure 24 shows the stability of antibody drug conjugates in different plasma. Figure 24A: Release of toxin from 20ug / mL hu31H4C3-cpd3 in different species (human / monkey / rat / mouse) plasma and PBS; Figure 24B: Release of toxin from 200ug / mL hu31H4C3-cpd3 in different species (human / monkey / rat / mouse) plasma and PBS; Figure 24C: Release of toxin from 20ug / mL hu5F8B4-cpd3 in different species (human / monkey / rat / mouse) plasma and PBS; Figure 24D: Release of toxin from 200ug / mL hu5F8B4-cpd3 in different species (human / monkey / rat / mouse) plasma and PBS.

[0664] Definitions of Terms

[0665] The practice of the present application will employ, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry and immunology, which are within the skill of the art.

[0666] To facilitate the understanding of this application, certain terms are defined with particularity. Unless otherwise defined herein, the terms used herein have the meanings commonly understood by those of ordinary skill in the art to which the present application belongs. For reference regarding definitions and terms of the art, see Current Protocols in Molecular Biology (Ausubel). Abbreviations for amino acid residues are the standard three letter and / or one letter codes used in the art to designate one of the 20 commonly used L-amino acids. As used herein, including the claims, the singular forms "a", "an", and "the" include the corresponding plural forms unless the context clearly dictates otherwise.

[0667] The term "about" when used with a numerical value means a range of numerical values that has a lower limit that is 5% less than the specified numerical value and an upper limit that is 5% greater than the specified numerical value.

[0668] The term "and / or" should be understood to mean either one of the items or any combination of the items.

[0669] The term "CDH17" refers to any recombinant or naturally occurring form of cadherin-17, variants or homologs thereof that maintain at least 50%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of the activity of CDH17. The variants or homologs have at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% amino acid sequence identity to the entire sequence or a partial sequence (e.g., a 50, 100, 150, or 200 continuous amino acid portion) of a naturally occurring CDH17 protein.

[0670] The term "antibody" herein is used in the broadest sense and encompasses various antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments so long as they exhibit the desired antigen-binding activity. An intact antibody will typically comprise at least two full-length heavy chains and two full-length light chains, but can in some cases include fewer chains, such as the naturally occurring heavy chain-only antibodies found in camelids.

[0671] The term "antibody fragment" refers to a molecule other than an intact antibody that comprises a portion of an intact antibody that is capable of binding to an antigen bound by the intact antibody. Examples of antibody fragments include but are not limited to Fv, Fab, Fab', Fab'-SH, F(ab')2; diabodies; linear antibodies; single-chain antibodies (e.g., scFv); single-domain antibodies; bi- or multi-specific antibodies or fragments thereof; camelid antibodies (heavy chain antibodies); and multispecific antibodies (e.g., bispecific antibodies) formed from antibody fragments.

[0672] The term "variable region" or "variable domain" refers to the domain of an antibody heavy or light chain that is involved with binding of the antibody to an antigen. The variable domains of the heavy and light chains of natural antibodies typically have similar structures, with each domain comprising four conserved framework regions (FRs) and three complementary determining regions (CDRs) (see, e.g., Kindt et al. Kuby Immunology, 6th ed., W.H. Freeman and Co. p. 91 (2007)). A single VHor VLdomain is sufficient to confer antigen-binding specificity.

[0673] A "complementarity determining region" or "CDR region" or "CDR" is a region in an antibody variable domain that is hypervariable in sequence and forms structurally defined loops ("hypervariable loops") and / or contains antigen contact residues ("antigen contacts"). CDRs are primarily responsible for binding to an epitope of an antigen. The CDRs in a variable domain are typically referred to as CDR1, CDR2, and CDR3, numbered sequentially from the N-terminus. The precise amino acid sequence boundaries of each CDR in a given variable region amino acid sequence can be determined using any of a number of well-known antibody CDR assignment systems, or combinations thereof, including, for example: Chothia based on the three-dimensional structure of the antibody and the topology of the CDR loops (Chothia et al. (1989) Nature 342: 877-883, Al-Lazikani et al., "Standard conformations for the canonical structures of immunoglobulins", Journal of Molecular Biology, 273, 927-948 (1997)), Kabat based on antibody sequence variability (Kabat et al., Sequences of Proteins of Immunological Interest, 4th Ed., U.S. Department of Health and Human Services, National Institutes of Health (1987)), AbM (University of Bath), Contact (University College London), the international ImMunoGeneTics database (IMGT) (http: / / imgt.cines.fr / ), and North CDR definitions based on affinity propagation clustering with a large number of crystal structures.

[0674] It should be noted that the boundaries of CDRs of a variable region of the same antibody can vary slightly based on the assignment system used. That is, the CDR sequences of the same antibody variable region defined under different assignment systems can vary slightly. Thus, where an antibody is defined in terms of specific CDR sequences as defined herein, the scope of the antibody also encompasses antibodies whose variable region sequences contain the specified CDR sequences but whose claimed CDR boundaries differ from the specific CDR boundaries defined herein due to the application of a different scheme (e.g., a different assignment system or combination).

[0675] Unless otherwise indicated, in the application, the term "CDR" or "CDR sequence" encompasses CDR sequences determined in any of the manners described above.

[0676] CDRs can also be determined based on having the same AbM numbered positions as a reference CDR sequence, such as any of the CDRs exemplified herein. In some embodiments, CDRs of antibodies of the application are determined positions according to the AbM numbering scheme.

[0677] Unless otherwise indicated, in the application, when referring to residue positions in antibody variable regions and CDRs, including heavy chain variable region residues, the numbering of the positions is according to the AbM numbering system.

[0678] As used herein, the term "comprising" or "including," or "having" is used in the inclusive, rather than exclusive, sense unless otherwise indicated. In other words, unless otherwise indicated, the terms "comprising" or "including" or "having" when used in this document are used to indicate the inclusion of one or more elements, integers, or steps, but not to the exclusion of any other element, integer, or step. In other words, when referring to an antibody variable region "comprising" a particular sequence, it is also intended to encompass an antibody variable region consisting of the particular sequence.

[0679] The term "chimeric antibody" is an antibody having a variable domain of a first antibody and a constant domain of a second antibody, wherein the first and second antibodies are from different species. Typically, the variable domain is obtained from an antibody of a rodent or the like ("parent antibody"), while the constant domain sequence is obtained from a human antibody, such that the resulting chimeric antibody is less likely to induce an adverse immune response in a human subject compared to the parent rodent antibody.

[0680] The term "humanized antibody" refers to forms of antibodies that contain sequences from human and non-human (e.g., mouse, rat) antibodies. Generally, a humanized antibody will comprise at least one, and typically two, variable domains, in which all or substantially all of the hypervariable loops correspond to those of a non-human immunoglobulin and all or substantially all of the framework (FR) regions are those of a human immunoglobulin sequence. The humanized antibody optionally can comprise at least a portion of a human immunoglobulin constant region (Fc).

[0681] The term "fully human antibody" refers to an antibody that contains only human immunoglobulin protein sequences. A fully human antibody can contain murine carbohydrate chains if produced in a mouse, in a mouse cell, or in a hybridoma derived from a mouse cell. Likewise, a "mouse antibody" refers to an antibody that contains only mouse immunoglobulin sequences. Alternatively, a fully human antibody can contain rat carbohydrate chains if produced in a rat, in a rat cell, or in a hybridoma derived from a rat cell. Likewise, a "rat antibody" refers to an antibody that contains only rat immunoglobulin sequences.

[0682] The term "Fc region" is used to define a C-terminal region of an immunoglobulin heavy chain that contains at least a portion of the constant region. The term includes native sequence Fc regions and variant Fc regions. In some embodiments, a human IgG heavy chain Fc region extends from Cys226, or Pro230, to the carboxyl terminus of the heavy chain. However, the C-terminal lysine (Lys447) of the Fc region can or can not be present (the numbering in this paragraph is according to the EU numbering system, also referred to as EU index, as described in Rabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991).

[0683] The term "affinity" or "binding affinity" refers to the inherent binding affinity of the interaction between members of a binding pair. The affinity of a molecule X for its partner Y can be generally represented by the equilibrium dissociation constant (KD), which is the ratio of the dissociation rate constant to the association rate constant (kdisand kon, respectively). Affinity can be measured by common methods known in the art. One particular method for measuring affinity is the surface plasmon resonance assay herein.

[0684] The term "does not bind" to a protein or cell means that it does not bind to the protein or cell, or does not bind to it with high affinity, i.e., with a KDof 1.0 x 10 -6 M or higher, more preferably 1.0 x 10 -5 M or higher, more preferably 1.0 x 10 -4 M or higher, 1.0 x 10 -3 M or higher, more preferably 1.0 x 10 -2 M or higher.

[0685] The term "high affinity" for an IgG antibody refers to a KDof 1.0 x 10 -6 M or lower, preferably 5.0 x 10 -8 M or lower, more preferably 1.0 x 10 -8 M or lower, 5.0 x 10 -9 M or lower, more preferably 1.0 x 10 -9 M or lower. For other antibody subtypes, "high affinity" binding can vary. For example, "high affinity" binding for the IgM subtype refers to a KDof 10 -6 M or lower, preferably 10 -7 M or lower, more preferably 10 -8 M or lower.

[0686] As used herein, the term "binds" or "binds specifically" means that the binding is selective for the antigen and can be distinguished from unwanted or non-specific interactions. The ability of an antigen binding site to bind to a particular antigen can be determined by enzyme-linked immunosorbent assay (ELISA) or conventional binding assays known in the art, such as by radioimmunoassay (RIA) or biolayer interferometry assay or MSD assay or surface plasmon resonance (SPR).

[0687] The term "half maximal effective concentration (EC 50 " refers to the concentration of a drug, antibody, or toxic agent that induces a response that is 50% between the baseline and maximum after a particular exposure time.

[0688] The term "therapeutic agent" as described herein encompasses any substance that is effective in the prevention or treatment of a tumor, e.g., a cancer, including chemotherapeutic agents, cytokines, angiogenesis inhibitors, cytotoxic agents, other antibodies, small molecule drugs, or immunomodulatory agents (e.g., immunosuppressive agents).

[0689] The term "antibody drug conjugate" or "ADC" refers to a conjugate obtained by covalently linking an antibody or antibody fragment to a therapeutically active substance or active pharmaceutical ingredient, which enables the therapeutically active substance or active pharmaceutical ingredient of the ADC to target the binding target of the antibody to exhibit a pharmacological function. The therapeutically active substance or active pharmaceutical ingredient can be a cytotoxin capable of killing the cell, preferably a cancer cell, targeted by the ADC. The covalent linkage of the therapeutically active substance, active pharmaceutical ingredient, or cytotoxin can be carried out in a non-site-specific manner using a linker, or in a site-specific manner.

[0690] The term "site-specific conjugation" refers to a mode of linkage that specifically links a therapeutically active substance or active pharmaceutical ingredient to a particular site of an antibody. In some embodiments, the conjugation is accomplished with the aid of a linker.

[0691] The term "cytotoxic agent" can be used interchangeably with "cytotoxin" and refers in the present application to a substance that inhibits or destroys cellular function and / or causes cell death or destruction.

[0692] The terms "linker", "linker unit", and "linker" can be used interchangeably in the present application and refer to a chemical module that covalently links the antibody to the therapeutically active substance or active pharmaceutical ingredient in the ADC. In some embodiments, the linker can comprise amino acid residues that link the antigen to the payload. The amino acid residues can form a dipeptide, tripeptide, tetrapeptide, pentapeptide, hexapeptide, heptapeptide, octapeptide, nonapeptide, decapeptide, undecapeptide, or dodecapeptide unit. The amino acid residues include those that occur naturally as well as non-naturally occurring amino acid analogs, such as citrulline or beta-amino acids, such as beta-alanine, or omega-amino acids such as 4-amino-butyric acid.

[0693] According to the classification by property, linkers suitable for use in the present application can be cathepsin-degradable linkers, such as val-cit linkers, cBu-Cit linkers, and CX linkers; non-cleavable linkers such as SMCC linkers or MD linkers; acid-sensitive linkers, silicon lipid-structured linkers, disulfide-carbamate linkers, MC-GGFG linkers, TRX linkers, galactoside-containing linkers, pyrophosphate linkers, near-infrared sensitive linkers, UV-sensitive linkers such as PC4AP.

[0694] The linkers of the present application can also be a combination of one or more linkers, such as a cathepsin-degradable linker can be combined with other types of linkers to form a new linker. Thus, the term "linker" as used herein encompasses a single type of linker, or a combination of different types of linkers, as long as it is capable of coupling the antibody of the present application to a drug payload.

[0695] The term "payload" or "drug payload" or "therapeutic payload" refers to the average number of therapeutic agents or active pharmaceutical ingredients per antibody in an ADC molecule (herein "therapeutic payload" can be used interchangeably with "active therapeutic agent or active pharmaceutical ingredient"). The drug payload can range from 1 to 20 active therapeutic agents or active pharmaceutical ingredients per antibody. The term "drug / antibody ratio" or "DAR" refers to the ratio of active therapeutic agents or active pharmaceutical ingredients (D) conjugated to the antibody to the antibody. The ADCs described herein generally have a DAR of 1 to 20, in certain embodiments, a DAR of 1 to 8, 2 to 8, 2 to 6, 2 to 5, 2 to 18, 4 to 16, 5 to 12, 6 to 10, 3 to 8, 4 to 6, 6 to 10, and 2 to 4. Representative DAR values are 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and are generally indicated as a combination of a letter D and a number, where the number indicates the value of the DAR, e.g., D2 indicates a drug / antibody ratio with a DAR value of 2. In some embodiments, the DAR is the average DAR, i.e., the overall ratio of small molecule drug moieties (D) conjugated to the Ab moiety to the Ab moiety in the product as measured by detection methods, such as by conventional methods like UV / visible spectroscopy, mass spectrometry, ELISA assays, and with HPLC. The DAR can be limited by the number of ligation sites on the antibody. For example, where the ligation site is a cysteine thiol, the antibody can have only one or a few cysteine thiols or can have only one or a few thiols that are sufficiently reactive (via which a linker unit can be attached) to be used for ligation.

[0696] The terms "CDH17 -related tumor and / or cancer," "CDH17 -mediated tumor and / or cancer," or "tumor and / or cancer associated with abnormal expression of CDH17," and the like are used interchangeably to refer to various types of tumors formed due to abnormal expression, mutation, or malfunction of CDH17 gene or protein, which leads to abnormal cell proliferation, invasion, metastasis, and the like malignant behaviors.

[0697] The term "treatment" refers to slowing, interrupting, arresting, stopping, reducing, or reversing the progression or severity of an existing symptom, disorder, condition, or disease. Desirable effects of treatment include, but are not limited to, preventing occurrence or reoccurrence of the disease, alleviating symptoms, diminishment of any direct or indirect pathological consequences of the disease, preventing metastasis, decreasing rate of disease progression, ameliorating or palliating the disease state, and remission or improved prognosis. In some embodiments, the antibody drug conjugate of the present application is used to delay disease development or to slow the progression of the disease.

[0698] The term "prevention" includes inhibition of the occurrence or development of a disease or disorder or symptoms of a particular disease or disorder. In some embodiments, a subject with a family history of cancer is a candidate for a prophylactic regimen. Generally, in the context of cancer, the term "prevention" refers to administration of a drug prior to the onset of signs or symptoms of cancer, particularly in a subject at risk for cancer.

[0699] The term "effective amount" refers to the amount or dose of an antibody or conjugate / coupling of the present application, or a composition, which, when administered to a patient at one or more dosages, results in an intended effect in the patient being treated or prevented. An effective amount can be readily determined by the attending physician, as one of ordinary skill in the art, by considering a variety of factors, such as species of mammal; body weight, age, and general health condition; the particular disease involved; extent or severity of disease; expected response of the individual patient; particular antibody being administered; mode of administration; bioavailability characteristics of the formulation administered; dosing regimen selected; and use of any concurrent therapy.

[0700] The term "therapeutically effective amount" refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired therapeutic result. A therapeutically effective amount of an antibody or antibody fragment or conjugate / coupled product or composition thereof can vary according to factors such as the disease state, age, sex, and weight of the individual, and the ability of the antibody or antibody moiety to elicit a desired response in the individual. A therapeutically effective amount is also one in which any toxic or detrimental effects of the antibody or antibody fragment or conjugate / coupled product or composition thereof are outweighed by the therapeutically beneficial effects. A "therapeutically effective amount" preferably inhibits a measurable parameter (e.g., tumor growth rate, tumor volume, etc.) by at least about 20%, more preferably by at least about 40%, even more preferably by at least about 50%, 60%, or 70%, and still more preferably by at least about 80% or 90%, relative to untreated subjects. The ability of a compound to inhibit a measurable parameter (e.g., cancer) can be evaluated in animal model systems predictive of efficacy in humans.

[0701] The term "prophylactically effective amount" refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired prophylactic result. Since a prophylactic dose is used in subjects prior to or at an earlier stage of disease, it will generally be less than a therapeutic dose. However, the distinction between a prophylactic dose and a therapeutic dose is not always clear, and ultimately the determination of which is

[0702] The term "pharmaceutical composition" refers to a composition that is in a form suitable for administration into a subject and that does not contain additional ingredients that are unacceptably toxic to the subject to which the composition is administered.

[0703] The term "in combination with" refers to administration of one or more additional therapeutic agents including simultaneous (co-)administration and consecutive administration in any order.

[0704] The term "pharmaceutically acceptable salt" refers to a salt of a pharmaceutical conjugate of the application that is safe and / or effective for use in a mammal, and that possesses the desired biological activity. The antibody pharmaceutical conjugates of the application can form salts with acids.

[0705] The term "pharmaceutically acceptable carrier" refers to an ingredient in a pharmaceutical formulation or composition that does not produce an unacceptable toxic or adverse reaction in a subject.

[0706] The term "subject" includes any human or non-human animal. The term "non-human animal" includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dogs, cats, horses, cows, chickens, amphibians, reptiles, etc. DETAILED DESCRIPTION

[0707] The following examples further illustrate the application, however, it is understood that the examples are described with the intent to illustrate, not limit, the application, and various modifications can be made by those skilled in the art. Where specific conditions are not specified for the examples, they are carried out under conventional conditions or as recommended by the manufacturer. Where manufacturers of reagents or instruments are not indicated, conventional products available from commercial vendors are used.

[0708] In some embodiments, the present application provides a method of making an anti-CDH17 antibody, wherein the method comprises culturing a host cell comprising a nucleic acid encoding an anti-CDH17 antibody, or an expression vector comprising the nucleic acid, under conditions suitable for the expression of the nucleic acid encoding the anti-CDH17 antibody, and optionally isolating the anti-CDH17 antibody. In a certain embodiment, the method further comprises recovering the anti-CDH17 antibody from the host cell (or host cell culture medium).

[0709] To recombinantly produce the anti-CDH17 antibodies of the present application, a nucleic acid encoding an anti-CDH17 antibody of the present application is first isolated and inserted into a vector for further cloning and / or expression in a host cell. Such nucleic acids are readily isolated and sequenced using conventional procedures, e.g., by using oligonucleotide probes that are capable of binding specifically to the nucleic acids encoding the anti-CDH17 antibodies of the present application.

[0710] The anti-CDH17 antibodies of the present application, when prepared as described herein, can be purified by known art such as high performance liquid chromatography, ion exchange chromatography, gel electrophoresis, affinity chromatography, size exclusion chromatography, and the like. The actual conditions used to purify a particular protein also depend on factors such as net charge, hydrophobicity, hydrophilicity, and the like, and these will be apparent to those skilled in the art. The purity of the anti-CDH17 antibodies of the present application can be determined by any of a number of well-known analytical methods, including size exclusion chromatography, gel electrophoresis, high performance liquid chromatography, and the like.

[0711] The art describes a number of methods for conjugating cytotoxic agents or other therapeutic agents to antibodies. For example, the conjugation reaction can be effected in the antibody through the amino groups of lysine side chains and the amino groups of the N-terminus, the carboxyl groups of aspartic acid, glutamic acid and the C-terminus, or the activated cysteine sulfhydryl groups.

[0712] The sequence of the DNA molecule of the antibody or fragment thereof of the present application can be obtained using conventional techniques, such as by methods of PCR amplification or screening of genomic libraries. Furthermore, the coding sequences for the light and heavy chains can be fused together to form a single chain antibody.

[0713] Once the relevant sequences have been obtained, they can be obtained in large quantities using recombinant methods. This is typically done by cloning into a vector, which is then introduced into cells, and then isolating the relevant sequences from the propagated host cells by conventional means.

[0714] In addition, synthetic methods can be used to synthesize the relevant sequences, especially when the sequence fragments are short in length. Typically, fragments of longer sequences are obtained by first synthesizing a plurality of small fragments, which are then ligated.

[0715] The practice of the present application will employ, unless otherwise indicated, conventional methods of the chemical, biochemical, organic, molecular biology, microbiology, recombinant DNA techniques, genetics, immunology, and cell biology within the skill of the art.

[0716] The compounds of the present disclosure can be confirmed structurally by conventional methods well known to those of ordinary skill in the art, and if the present disclosure relates to the absolute configuration of a compound, the absolute configuration can be confirmed by conventional techniques in the art.

[0717] Compounds are named according to the conventions of the art or using software naming, and commercially available compounds are named using the vendor catalog name. When the name of a compound is inconsistent with the structure of the compound, the structure of the compound is controlling.

[0718] Preparation and identification of raw materials in Example 1

[0719] 1.1 Preparation and identification of CDH17 control antibody

[0720] CDH17 Control Antibody 1 Preparation: The anti-CDH17 antibody CDH17vl-IgGl WT (VH-VL portion of CDH17 antibody of CDH17 / TRAILR2 bispecific BI905711 of Boehringer Ingelheim with hlgG constant region) was used as a positive control antibody in this application, and the gene synthesis of the target fragment was performed by GenScript Corporation according to the sequence disclosed in WO 2012 / 054084A2. Through the design of primers, PCR, ligation transformation, positive clone screening, sequencing verification, plasmid transformation, monoclonal screening, inoculation, plasmid extraction, the final expression vector expressing the CDH17vl-IgGl WT antibody was obtained, with clone number CDH17vl-IgGl WT, hereinafter referred to as CDH17vl-IgGl WT. The expression vector was transfected into Expi293F cells (GenScript) by transient transfection to express the antibody CDH17vl-IgGl WT (also referred to herein as NME-CDH17vl-IgGl WT), and after 6 days of transfection, the cell culture supernatant was collected, centrifuged at 15000g for 10 min, and the obtained supernatant was filtered through a 0.22 pm filter membrane. The antibody in the supernatant was affinity purified using Monofinity A Resin (GenScript, item number: L00433). The target antibody was eluted with Elution buffer (Elution buffer 1: 0.1M citric acid buffer, pH=3.0; Elution buffer 2: 0.1M Glycine, pH=2.5), and the eluted antibody was dialyzed against Dialysis buffer (1X PBS, pH=7.4) for 2h, and then replaced with Dialysis buffer and dialyzed in PBS buffer (PH 7.4) at 2-8°C for 16h.

[0721] CDH17 Control Antibody 2 Preparation: The anti-CDH17 antibody Lic5-hlgGl was used as a control antibody identified by antigenic protein in this application, and the gene synthesis of the target fragment was performed by GenScript Corporation according to the sequence disclosed in US11,207,419B2, and the plasmid expression vector was constructed, with clone number Lic5-hlgGl, hereinafter referred to as Lic5-hlgGl. The antibody Lic5-hlgGl was obtained by transient transfection expression and purification.

[0722] CDH17 Control Antibody Identification: Human colon adenocarcinoma cell line CACO-2 cells (GenScript) and human CDH17 overexpression cell line CHO-K1 / hCDH17 constructed in Example 2 were collected, and 1x10 5After 40 min of incubation in a 4°C constant temperature shaker, the 96-well plate was taken out, 150 μL of 1 × PBS was added to each well, and the plate was centrifuged at 300 g for 3-5 min, 2-3 times, and the supernatant was discarded. The primary antibody was incubated with the positive control antibody CDH17v1-IgG1 WT (10 μg / mL), the isotype control Mouse IgG (3 μg / mL), the isotype control Human IgG1 (25 μg / mL), and the negative control PBS; after washing, 100 μL of diluted fluorescent secondary antibody was added to each well, and the plate was incubated in a 4°C constant temperature shaker for 30 min. After taking out the 96-well plate, 150 μL of 1 × PBS was added to each well, and the plate was centrifuged at 300 g for 3-5 min, 2-3 times, and the supernatant was discarded. An appropriate amount of 1 × PBS was added to each well, resuspended with a microplate shaker, and the plate was read using a flow cytometer. The results showed that the expressed control antibody CDH17v1-IgG1 WT was bound to CACO-2 cells and human CDH17 overexpression cell line CHO-K1 / hCDH17 that positively expressed CDH17.

[0723] 1.2 Preparation and identification of CDH17 antigen protein

[0724] Antigen protein preparation: The sequences of human CDH17 proteins hCDH17-D6 (Uniprot ID: Q12864 Domain 6), hCDH17-D1-2 (Uniprot ID: Q12864 Domain 1-2), hCDH17 (Uniprot ID: Q12864), cCDH17-D6-7 (Uniprot ID: A0A2K5X8I8 Domain 6-7), and mCDH17 (Uniprot ID: Q9R100) (GenScript) were added with His tags at the C-terminus, and the nucleic acid sequences encoding the above proteins / polypeptides were constructed into a pTT5 vector, which was then transformed into E. coli and the plasmid was extracted. The obtained plasmid was transiently transfected into CHO-3E7 cells (GenScript), and after 6 days of expression, the cell culture supernatant was harvested and affinity purified to obtain the antigen protein with His-Tag. The above proteins are abbreviated as hCDH17-D6, hCDH17-D1-2, hCDH17, cCDH17-D6-7, and mCDH17 hereinafter.

[0725] Antigen identification: The purity of hCDH17-D6, hCDH17-D1-2, hCDH17, cCDH17-D6-7 and mCDH17 proteins were identified by SDS-PAGE, Western Blot and SEC-HPLC. The results showed that the purity of the above proteins met the standard. The prepared antigens hCDH17-D6 (synthesized by GenScript) and hCDH17-D1-2 (synthesized by GenScript) were detected using the qualified antibody Lic5-hIgG1 (patent source: US11,207,419B2) obtained in Example 1.1. The specific method is as follows: the antigens hCDH17-D6 and hCDH17-D1-2 were diluted to 0.5 μg / mL with coating solution PBS, and after mixing, 100 μL / well was added to the enzyme-labeled plate (Tin Guo Sheng Biotechnology Co., Ltd., item number: CIH-F12T); after coating, it was placed in a 4°C refrigerator overnight for 16 h; the coating solution was discarded, and the plate was washed once and the enzyme-labeled plate was patted dry; 150 μL of blocking solution (self-made by GenScript) was added to each well, and it was placed in a 37°C incubator (Shanghai Yiheng Scientific Instrument Co., Ltd., model: DHP-9602) for incubation for 1 h; the enzyme-labeled plate was taken out, and the blocking solution was discarded; the antibody was diluted at a concentration of 6.0 μg / mL in the first well, and 3-fold gradient dilution was performed to the 11th well, and PBS diluent was added to the remaining 1 well as a blank control, 100 μL / well; 37°C constant temperature incubation for 1 h, the enzyme-labeled plate was taken out, the inner liquid was discarded, and the plate was washed 3 times; 100 μL of diluted enzyme-labeled secondary antibody Mouse Anti-Human IgG Fc Antibody [HRP] (Rockland, item number: 609-103-123) was added to each well, and it was incubated in a 37°C incubator; the enzyme-labeled plate was taken out, the inner liquid was discarded, and the plate was washed 3 times, then it was patted dry and 100 μL of color developing solution (self-made by GenScript) was added, and it was reacted at 25°C for 15 min; 50 μL of 1M HCl was added to terminate the reaction; the OD450 nm reading was taken by the enzyme-labeled instrument (Thermo Fisher Scientific (Shanghai) Instrument Co., Ltd. / Meigu Molecular Instrument (Shanghai) Co., Ltd., model: Multiskan FC MD automated high-throughput enzyme-labeled instrument); the obtained OD450 nm value was substituted into the software to calculate the EC50 data, and the data was processed and plotted by Graphpad prism. The results showed that the self-made CDH17 antigen proteins hCDH17-D6 and hCDH17-D1-2 could effectively bind to the Lic5-hIgG1 antibody.

[0726] Example 2 Construction and identification of CDH17 overexpressing engineering cell lines

[0727] 2.1 Construction and identification of CDH17 overexpressing engineering cell lines

[0728] In this embodiment, the construction of the CHO-K1 cell line overexpressing human CDH17 (hereinafter referred to as CHO-K1 / hCDH17) was as follows: The coding nucleic acid sequence of full-length human CDH17 (Uniprot ID: Q12864) was constructed into GenScript ProBio proprietary lentiviral vectors (LVs). After transformation plasmid extraction, the lentiviral expression plasmid and helper plasmid were co-transfected into HEK293T cells (lentiviral production cells, GenScript) to obtain recombinant lentivirus. CHO-K1 cells were infected with recombinant lentiviral particles. After 48 hours of infection, positive cell pools were selected with 8 μg / mL puromycin. On day 3 of selection, the expression level of the target protein in the cell pools was detected by flow cytometry. The cell pools were seeded into five 96-well cell culture plates at a density of 1 cell per well. The plates were read using a monoclonal imaging system for three consecutive days after seeding, and the wells containing monoclonal cells were marked. Approximately 20 monoclonal cells were collected from 96-well plates and expanded to 6-well plates. The expression level of monoclonal cells was detected by flow cytometry. Positive monoclonal cells were then gradually expanded and cultured into 6cm, 10cm, and 15cm cell culture dishes to finally obtain CHO-K1 / hCDH17 monoclonal cells.

[0729] Logarithmic growth phase CHO-K1 / hCDH17 cells were digested and plated into 96-well plates. After washing with FACS buffer (1×PBS buffer containing 2% FBS), the primary antibody CDH17v1-IgG1WT was serially diluted with PBS and incubated at 4°C for 1 h. After washing, 0.5 μl of prepared fluorescent secondary antibody (PE anti-human IgG Fc Antibody, BioLegend, catalog number: 410708) or 0.5 μl of Goat anti-Human IgG (H+L) Secondary Antibody, Alexa was added. 647 (Thermo Fisher, catalog number: A-21445), incubated at 4°C for 20 min; finally, the results were analyzed by BD FACSCelesta flow cytometry. The results showed that an engineered cell line of CHO-K1 / hCDH17 overexpressing human CDH17 was obtained.

[0730] 2.2 Construction and identification of engineered cell lines overexpressing monkey CDH17

[0731] In this embodiment, the construction of CHO-K1 cell strain overexpressing monkey CDH17 (hereinafter referred to as CHO-K1 / cynoCDH17): the coding nucleic acid sequence of full-length monkey CDH17 (Uniprot ID: A0A2K5X8I8) was constructed into the GenScript ProBio proprietary lentivirus vector. After plasmid extraction, the lentivirus expression plasmid and helper plasmid were co-transfected into HEK293T cells to prepare recombinant lentivirus. The CHO-K1 cells were infected with the recombinant lentivirus particles, and the single clone cells were picked up according to the method in Section 2.1, and finally the CHO-K1 / cynoCDH17 monoclonal cells were obtained.

[0732] The results of FACS verification with the Xiangshen antibody CDH17v1-IgG1 WT showed that the engineered cell line of CHO-K1 / cynoCDH17 overexpressing monkey CDH17 on the surface was obtained.

[0733] Example 3 Animal immunization and construction of immune library

[0734] 3.1 Immunization scheme

[0735] The N-terminal Domain 1-2 (synthesized by GenScript) and C-terminal Domain 6 (synthesized by GenScript) of human antigen protein CDH17 were used to immunize 4 BALB / c mice (Beijing Vital River Laboratory Animal Technology Co., Ltd.), 4 SJL mice (Beijing Vital River Laboratory Animal Technology Co., Ltd.) and 4 A / J mice (Beijing Vital River Laboratory Animal Technology Co., Ltd.) subcutaneously and in the Hock, with an immunization interval of 2-3 weeks. Blood was collected one week after the third and fourth immunizations, respectively, for serum detection with the immunogen.

[0736] 3.2 Detection of antibody titers in sera of immunized mice

[0737] After the antigens hCDH17-D6 (synthesized by GenScript), hCDH17-D1-2 (synthesized by GenScript), hCDH17 (synthesized by GenScript), and cCDH17-D6-7 (synthesized by GenScript) are diluted to 0.5 μg / mL with the coating solution PBS and added to the enzyme-labeled plate, 100 μL / well; then placed in a 4°C refrigerator overnight or a 37°C incubator for 1 h; discard the coating solution, wash the plate once, and pat the enzyme-labeled plate dry; add 150 μL of blocking solution to each well, and place in a 37°C incubator for 1 h or a 4°C refrigerator overnight; remove the enzyme-labeled plate, and discard the blocking solution; serum sample addition step: pre-immune serum detection, 1:1000 dilution per well, a total of 2 wells, and take the average value, 100 μL / well; post-immune serum, 1:100 or 1:1000 dilution for the first well, 100 μL / well, then 2-fold gradient dilution is performed for each first well to obtain 9 dilution gradients, and the remaining 2 wells are added with PBS diluent as blank controls, and the data of the final control wells are represented as the average value of the two blank wells, 100 μL / well; 37°C incubation for 1 h or 4°C refrigerator overnight, remove the enzyme-labeled plate, discard the inner solution, and wash the plate 3 times; add 100 μL of diluted enzyme-labeled secondary antibody Peroxidase-AffiniPure Goat Anti-Mouse IgG, Fcγ Fragment Specific (min X Hu, Bov, Hrs Sr Prot)-HRP (M6) to each well and incubate in a 37°C incubator for 0.5 h; remove the enzyme-labeled plate, discard the inner solution, wash the plate 3 times, pat dry, and add 100 μL of color developing solution, 25°C reaction for 15 min; add 50 μL of 1M HCl to terminate the reaction; and OD450nm reading by an enzyme-labeled instrument.

[0738] The results show that the serum titers of 2 mice meet the standard.

[0739] 3.3 Hybridoma cell fusion and screening

[0740] The A / J mice with better serum titers are preferably subjected to the final immunization 2-3 weeks after the fourth immunization. After 3-5 days, the spleen B cells and SP2 / 0 mouse myeloma cells (Pengbiological) are prepared into hybridoma cells by electrofusion: prepare the SP2 / 0 cell suspension; prepare the spleen cell suspension; mix the SP2 / 0 cell suspension and the spleen cell suspension, and perform cell fusion. After fusion, the fused cells are resuspended with the fusion culture medium, mixed uniformly to prepare a cell suspension, and then plated into a 96-well cell plate; the fused 96-well cell plate is placed in a 5.5% CO2, 37°C carbon dioxide incubator for culture. After 5-8 days of culture, the fusion rate and the whole plate liquid change are counted.

[0741] The results show that the fusion is successful.

[0742] ELISA screening of hybridoma master clones

[0743] 4.1 ELISA primary screening of hybridoma master clones

[0744] The hybridoma master clone cell supernatant to be detected 100 μL was added to the corresponding enzyme-labeled plate coated with hCDH17-D6 (synthesized by GenScript) and hCDH17-D1-2 (synthesized by GenScript); incubated at 37°C for 60 min, washed; added secondary antibody Peroxidase-AffiniPure Goat Anti-Mouse IgG, Fcγ Fragment Specific (min X Hu, Bov, Hrs Sr Prot)-HRP (M6) 25 ng / mL, incubated at 37°C for 30 min, washed; 100 μL TMB was added to each well, incubated at 25°C for 15 min; 50 μL 1M HCl was added to each well to terminate the reaction.

[0745] The ELISA primary screening results showed that positive hybridoma master clones were obtained which bound to human CDH17 protein hCDH17-D6 or hCDH17-D1-2.

[0746] 4.2 ELISA confirmation screening of positive hybridoma clones

[0747] The hybridoma master clone cell supernatant which had been positively screened 100 μL was added to the corresponding enzyme-labeled plate coated with hCDH17-D6 (synthesized by GenScript), hCDH17-D1-2 (synthesized by GenScript), cCDH17 (synthesized by GenScript) and mCDH17 (synthesized by GenScript); incubated at 37°C for 60 min, washed; added secondary antibody Peroxidase-AffiniPure Goat Anti-Mouse IgG, Fcγ Fragment Specific (min X Hu, Bov, Hrs Sr Prot)-HRP (M6) 25 ng / mL, incubated at 37°C for 30 min, washed; 100 μL TMB was added to each well, incubated at 25°C for 15 min; 50 μL 1M HCl was added to each well to terminate the reaction.

[0748] The ELISA confirmation screening results showed that positive master clones were obtained which bound to human CDH17 protein hCDH17-D6 or hCDH17-D1-2 and bound to monkey CDH17 protein cCDH17 and / or mouse CDH17 protein mCDH17.

[0749] Example 5 FACS screening of hybridoma master clones

[0750] 5.1 FACS screening of positive hybridoma master clones

[0751] CACO-2 cells were collected, diluted and added to 96-well plates with 50 μL of cells per well, 1 x 10 5 After 40 min of incubation at 4°C on a constant temperature shaker, the 96-well plates were removed and 150 μL of 1 x PBS was added to each well. The cells were centrifuged at 300 g for 3-5 min, and the supernatant was discarded. The primary antibody was added to the positive hybridoma master clones to be tested, the positive control antibody CDH17 vl-IgGl WT (patent source: WO 2012 / 054084 A2, 10 μg / mL), the isotype control Mouse IgG (3 μg / mL), and the negative control PBS. After washing, 100 μL of diluted secondary antibody Alexa 647 AffiniPure Goat Anti-Mouse IgG, Fcγ fragment specific (min X Hu, Bov, Hrs Sr Prot) (Jackson, Cat. No. 115-605-071) and Alexa 647 AffiniPure Goat Anti-Human IgG (H+L) (min X Bov, Hrs, Ms Sr Prot) (Jackson, Cat. No. 109-605-088) were added to each well. After 30 min of incubation at 4°C on a constant temperature shaker, the 96-well plates were removed and 150 μL of 1 x PBS was added to each well. The cells were centrifuged at 300 g for 3-5 min, and the supernatant was discarded. An appropriate amount of 1 x PBS was added to each well, the cells were resuspended using a microplate shaker, and the plates were read using a flow cytometer.

[0752] The results show that hybridoma master clones that bind positively to CACO-2 cells in FACS were obtained. The positive master clones were then subcloned using the limiting dilution method to obtain positive hybridoma single clone cells.

[0753] Example 6 ELISA screening of hybridoma subclones

[0754] 6.1 Hybridoma clones that bind positively to the antigen were screened by ELISA, and the antibody expression level in the supernatant was tested

[0755] Hybridoma subclone cell supernatant 100 μL was added to the corresponding enzyme-labeled plate coated with hCDH17-D6 (synthesized by GenScript), hCDH17-D1-2 (synthesized by GenScript), cCDH17 (synthesized by GenScript) and mCDH17 (synthesized by GenScript), incubated at 37°C for 60 min, washed, and then added secondary antibody Peroxidase-AffiniPure Goat Anti-Mouse IgG, Fcγ Fragment Specific (min X Hu, Bov, Hrs Sr Prot)-HRP (M6) (Jackson, item number: 115-035-071) 25 ng / mL, incubated at 37°C for 30 min; after washing, 100 μL TMB was added to each well, and incubated at 25°C for 15 min; then 50 μL 1M HCl was added to stop the reaction.

[0756] The results show that the positive hybridoma subclone obtained in Example 5 can be used to evaluate the expression level of antibodies in the supernatant by detecting the OD450 value by ELISA.

[0757] 6.2 Evaluation of antibody subtype by ELISA method

[0758] The enzyme-labeled plate was coated with goat anti-mouse Ig antibody (SBA Clonotyping System-HRP) at a concentration of 1.8 μg / mL, 100 μL / well; blocking incubation; discard the coating solution, wash the plate once, and dry with a paper towel; add 150 μL blocking solution to each well, seal the plate and incubate; discard the blocking solution; add the samples to the plate in the following mode: dilute the positive hybridoma subclone samples with dilution buffer at 1:50 or 1:5, each sample with 9 replicates, 100 μL / well. Seal the plate and incubate; discard the internal solution, wash the plate 3 times; add IgG2c secondary antibody, 100 μL / well to the plate. Seal the plate and incubate; remove the enzyme-labeled plate, discard the internal solution, wash the plate 3 times, and add 100 μL color developing solution after drying, and react at 25°C for 15 min; add 50 μL stop buffer to each well to stop the reaction. Read the plate value at OD 450 nm.

[0759] The results show that the antibody subtypes of each positive hybridoma subclone (including the type of light chain) are mainly IgG1, Kappa subtype, a few are IgG2a, Kappa subtype or IgG2b, Kappa subtype.

[0760] Example 7 FACS screening of hybridoma subclone

[0761] 7.1 Screening of positive hybridoma subclone binding to CACO-2 tumor cells positively expressing CDH17 by FACS method

[0762] Collected CACO-2 cells, diluted and added 50 μL of cells to 96-well plates, 1 x 10 5 After 4 °C constant temperature oscillator incubation for 40 min, the 96-well plate was taken out, 150 μL of 1 x PBS was added to each well, centrifuged at 300 g for 3-5 min, centrifuged 2-3 times, and the supernatant was discarded. The primary antibody was added to the positive hybridoma subclone, CDH17v1-IgG1 WT (10 μg / mL), isotype control Mouse IgG (3 μg / mL), and negative control PBS, respectively, and incubated; after washing, 100 μL of diluted fluorescent secondary antibody was added to each well, and incubated at 4 °C constant temperature oscillator for 30 min. The 96-well plate was taken out, 150 μL of 1 x PBS was added to each well, centrifuged at 300 g for 3-5 min, centrifuged 2-3 times, and the supernatant was discarded. An appropriate amount of 1 x PBS was added to each well, resuspended with a microplate shaker, and the plate was read using a flow cytometer.

[0763] The FACS results showed that the hybridoma subclone obtained by screening combined with CACO-2 cells.

[0764] Example 8. Expression, purification and identification of hybridoma antibodies

[0765] 8.1 Expression and purification of hybridoma antibodies

[0766] The positive hybridoma subclone cell strain obtained by screening was cultured in a shake flask to express antibodies, and then the supernatant containing the antibodies expressed by the hybridoma monoclonal cells was purified by AmMag TM Protein A Magnetic Beads (Kingsway Biological, Catalog No.: L00695) to obtain antibodies. The purity of the antibodies expressed by the positive hybridoma monoclonal expression and purification was identified by SDS-PAGE.

[0767] The results showed that the antibody expressed by the hybridoma subclone expressing the antibody had a purity greater than 90% after purification.

[0768] 8.2 Identification of antibodies expressed by hybridoma subclones with titers meeting the standards by ELISA

[0769] hCDH17-D6 (synthesized by GenScript), hCDH17-D1-2 (synthesized by GenScript), cCDH17 (synthesized by GenScript), and mCDH17 (synthesized by GenScript) were coated on an enzyme-labeled plate at 0.5 μg / mL at 4°C overnight, after washing, the supernatant containing the antibody expressed by the subclone of the hybridoma to be tested was added to the enzyme-labeled plate, and incubation was performed at 37°C for 60 min, the plate was washed, 25 ng / mL of secondary antibody was added, and incubation was performed at 37°C for 30 min; after washing, 100 μL of TMB was added to each well, and incubation was performed at 25°C for 15 min; and then 50 μL of 1M HCl was added to terminate the reaction.

[0770] The results show that the supernatant of the antibody expressed by most of the hybridoma subclones binds to human CDH17 protein hCDH17-D6 or hCDH17-D1-2, and binds to monkey CDH17 protein cCDH17 but not to mouse CDH17 protein mCDH17.

[0771] 8.3 Identification of positive hybridoma subclone expressing purified antibody by FACS

[0772] The CACO-2 cells were collected, and 1×10 5 After incubation at 4°C on a constant temperature shaker for 40 min, the 96-well plate was taken out, 150 μL of 1×PBS was added to each well, and centrifugation was performed at 300 g for 3-5 min, 2-3 times, and the supernatant was discarded. Incubation was performed with the antibody expressed by the hybridoma subclone to be tested, the positive control antibody CDH17v1-IgG1WT (10 μg / mL), the isotype control Mouse IgG (3 μg / mL), and the negative control PBS; after washing, 100 μL of diluted fluorescent secondary antibody was added to each well, and incubation was performed at 4°C on a constant temperature shaker for 30 min, after the 96-well plate was taken out, 150 μL of 1×PBS was added to each well, and centrifugation was performed at 300 g for 3-5 min, 2-3 times, and the supernatant was discarded, an appropriate amount of 1×PBS was added to each well, and resuspension was performed using a microplate shaker, and the plate was read using a flow cytometer.

[0773] The results show that, in addition to some of the purified antibodies expressed by the hybridoma subclones, the other antibodies bind to CACO-2 cells positively expressing CDH17.

[0774] 8.4 Identification of the affinity level of the purified antibody expressed by the positive hybridoma subclone by ELISA

[0775] Antigens hCDH17-D6 (synthesized by GenScript) and hCDH17-D1-2 (synthesized by GenScript) were diluted to 0.5 μg / mL with coating solution, mixed well, and then added to an enzyme-labeled plate at 100 μL / well, and coated at 4°C overnight. The coating solution was discarded, and the plate was washed once and tapped dry. 150 μL of blocking solution was added to each well, and incubated at 37°C for 1 h. The enzyme-labeled plate was removed, and the blocking solution was discarded. The first well of the test antibody had a concentration of 3.0 μg / mL, which was diluted by 3 times to the 11th well. The remaining 1 well was added with diluent as a blank control at 100 μL / well. The positive control antibody was CDH17v1-IgG1WT. Incubation was performed at 37°C for 1 h, the enzyme-labeled plate was removed, the internal solution was discarded, and the plate was washed 3 times. 100 μL of diluted enzyme-labeled secondary antibody was added to each well, and incubated at 37°C for 30 min. The enzyme-labeled plate was removed, the internal solution was discarded, and the plate was washed 3 times. After tapping dry, 100 μL of color developing solution was added, and reaction was performed at 25°C for 15 min. 50 μL of 1M HCl was added to terminate the reaction. OD450 nm reading was performed on an enzyme-labeled instrument. The obtained OD450 nm value was substituted into the software to obtain EC50 data.

[0776] The results showed that more than ten groups of mouse-derived antibodies were combined with human CDH17 protein hCDH17-D6 or hCDH17-D1-2. The specific ELISA detection results are shown in FIGS. 1A-1B.

[0777] Example 9. Hybridoma sequencing

[0778] 9.1 Hybridoma Sanger sequencing

[0779] The RNA of the positive hybridoma subclone cells was extracted, cDNA was synthesized, heavy chain / light chain PCR amplification was performed, and the cDNA was subjected to agarose gel detection of the positive band of the PCR product and the experimental data was recorded. The heavy chain / light chain DNA fragments were purified, and the PCR band with a size consistent with the target fragment was cut off. The MagPure Gel Pure DNA Kit was used to purify the heavy chain / light chain DNA fragments. The purified heavy chain / light chain DNA fragments were ligated to the pCE2 vector and transformed into TOP10 competent cells. 120 μL was spread on a resistant plate, and after 12 h, single colonies were picked and subjected to colony PCR screening for positive clones. 100 μL of the bacterial solution of the positive clones was analyzed for sequencing, and the sequencing results of the paired antibody heavy chain and light chain were analyzed.

[0780] The results showed that the sequencing of the positive subclone was completed, and the candidate sequences were selected to construct human-mouse chimeric antibodies.

[0781] Example 10. Chimeric antibody expression

[0782] 10.1 Plasmid construction of chimeric antibodies and expression and purification of antibodies

[0783] The design of the chimeric antibody is to replace the murine antibody constant region with the human antibody constant region hlgGl-constant sequence by retaining the murine antibody variable region. Through primer design, PCR, ligation transformation, positive clone screening, sequencing verification, plasmid transformation, monoclonal screening, sequencing verification, a plasmid containing a nucleotide sequence encoding the chimeric antibody is obtained.

[0784] The CHO-3E7(4-24) cells were transiently transfected with the above plasmid to express the corresponding antibody, and the cell supernatant was harvested on the 6th day after transfection, and then purified by AmMag TM Protein A Magnetic Beads and identified by SDS-PAGE. The results show that the purity of all antibodies meets the requirements (purity > 90%). For example, the SDS-PAGE identification result of 31H4C3-hlgGl (abbreviated as 31H4C3) is shown in FIG. 2.

[0785] Example 11. In vitro activity verification of chimeric antibody

[0786] 11.1 ELISA affinity identification of chimeric antibody

[0787] The antigens Human Cadherin-17 / CDH17 Protein, His Tag (ACRO, item number: CA7-H52H3), cCDH17 (synthesized by Genscript), Human CDH17 / Cadherin 17 Domain 5-7 Protein (KACTUS, item number: CDH-HM1D4), and Human CDH17 / Cadherin 17 Domain 1 & 2 Protein (KACTUS, item number: CDH-HM1D5) were diluted to 0.5 μg / mL or 1 μg / mL with coating solution PBS, and 100 μL / well was added to the enzyme-labeled plate, which was coated at 4°C overnight. Discard the coating solution, wash the plate once, and pat dry the enzyme-labeled plate. Add 150 μL of blocking solution to each well and incubate at 37°C for 1 h; remove the enzyme-labeled plate, discard the blocking solution; the first well concentration of the antibody to be tested is 3.0 μg / mL, and it is diluted by 3 times to the 11th well, and the remaining 1 well is added with diluent as a blank control, 100 μL / well; incubate at 37°C for 1 h, remove the enzyme-labeled plate, discard the internal solution, and wash the plate 3 times; add 100 μL of diluted enzyme-labeled secondary antibody to each well and incubate at 37°C for 30 min; remove the enzyme-labeled plate, discard the internal solution, and wash the plate 3 times, then add 100 μL of color developing solution after patting dry; react at 25°C for 15 min; add 50 μL of 1M HCl to stop the reaction; read OD450 nm on the enzyme-labeled instrument; and calculate the EC50 data by substituting the obtained OD450 nm value into the software.

[0788] Results show that some of the chimeric antibodies do not bind to monkey antigen protein among all the screened chimeric antibodies. Both candidate chimeric antibodies 31H4C3 and 5F8B4 bind to human and monkey antigen proteins, and 31H4C3 and 5F8B4 bind to hCDH17 Domain 5-7. The specific ELISA detection results are shown in Figures 3A-3D.

[0789] Specifically, the light chain variable region (VL) of the candidate chimeric antibodies 31H4C3 and 5F8B4 is shown in SEQ ID NO. 37, the heavy chain variable region (VH) of the chimeric antibody 31H4C3 is shown in SEQ ID NO. 23; and the heavy chain variable region (VH) of the chimeric antibody 5F8B4 is shown in SEQ ID NO. 18.

[0790] 11.2 FACS species cross-confirmation of chimeric antibodies

[0791] CHO-K1 / hCDH17, CHO-K1 / cynoCDH17 cells were collected, and 1x10 5 After 40 min of incubation on a 4°C constant temperature shaker, the 96-well plate was removed, 150 μL of 1xPBS was added to each well, and the plate was centrifuged at 300g for 3-5 min, 2-3 times, and the supernatant was discarded. Incubate with primary antibodies: chimeric antibodies (50 μL / well, final concentration of 100 nM in the first well, 3-fold dilution, 11 points), isotype control Mouse IgG (50 μL / well, final concentration of 100 nM in the first well, 3-fold dilution, 11 points), positive control antibody NME-CDH17vl-IgGl WT (50 μL / well, final concentration of 100 nM in the first well, 3-fold dilution, 11 points), and negative control PBS; after washing, 100 μL of diluted secondary antibody was added to each well, and the plate was incubated on a 4°C constant temperature shaker for 30 min. After removing the 96-well plate, 150 μL of 1xPBS was added to each well, and the plate was centrifuged at 300g for 3-5 min, 2-3 times, and the supernatant was discarded. An appropriate amount of 1xPBS was added to each well, and the plate was resuspended using a microplate shaker. The plate was read using a flow cytometer.

[0792] Results show that some of the chimeric antibodies do not bind to human CDH17 overexpressing cell line CHO-K1 / hCDH17 and monkey CDH17 overexpressing cell line CHO-K1 / cyno CDH17 among all the screened chimeric antibodies; candidate chimeric antibodies 5F8B4-hIgG1 and 31H4C3-hIgG1 both have good binding to human CDH17 overexpressing cell line CHO-K1 / hCDH17 and monkey CDH17 overexpressing cell line CHO-K1 / cyno CDH17. The specific FACS detection results are shown in Figures 4A-4B.

[0793] 11.3 ELISA species cross confirmation of chimeric antibodies

[0794] Antigen Human Cadherin-17 / CDH17 Protein, His Tag (Acrobiosystems, Cat#: CA7-H52H3) and Cynomolgus Cadherin-17 / CDH17 Protein, His Tag (synthesized by GenScript) were diluted to 0.5 μg / mL with coating buffer PBS, 100 μL / well was added to the ELISA plate, and coated overnight at 4°C. Discard the coating solution, wash the plate once, and pat dry the ELISA plate. Add 150 μL blocking solution to each well, and incubate at 37°C for 1 h; remove the ELISA plate, discard the blocking solution; the first well concentration of the antibody to be tested was 3.0 μg / mL, 3-fold gradient dilution to the 11th well, and the remaining 1 well added diluent as a blank control, 100 μL / well; incubate at 37°C for 1 h, remove the ELISA plate, discard the internal solution, and wash the plate 3 times; add 100 μL of diluted enzyme-labeled secondary antibody Anti-Human IgG (H&L) (GOAT) Antibody Peroxidase Conjugated (Min X Bv Ch Gt GP Ham Hs Ms Rb Rt & Sh Serum Proteins) (H3) to each well, and incubate at 37°C for 30 min; remove the ELISA plate, discard the internal solution, and wash the plate 3 times, then add 100 μL of color developing solution after drying, and react at 25°C for 15 min; add 50 μL of 1M HCl to stop the reaction; read OD450 nm on the ELISA reader; and calculate the EC50 data by substituting the obtained OD450 nm value into the software.

[0795] The results showed that the binding of chimeric antibodies 5F8B4-hIgG1 (also referred to simply as "5F8B4") and 31H4C3-hIgG1 (also referred to simply as "31H4C3") to human CDH17 and monkey CDH17 was concentration-dependent. The specific ELISA detection results are shown in Figures 5A-5B.

[0796] 11.4 FACS affinity level identification of chimeric antibodies

[0797] Target cells SW948 (ATCC, Cat#: CCL-237) were collected and resuspended with experimental buffer (1% FBS + 99% DPBS, pre-cooled at 4°C), and counted. The target cell density was adjusted using experimental buffer, and 50 μl / well of target cells were inoculated into the corresponding wells of the experimental plate (2 x 10 5After the target cells were inoculated, 50 μl / well of test samples (31H4C3-hIgG1, 5F8B4-hIgG1) and positive control (CDH17v1-IgG1 WT) working solution and isotype negative control (anti-HEL hIgG1, Probio synthetic) (starting concentration of 100 nM or 300 nM, 5-fold serial dilution, a total of 8 concentrations) were added, and incubated at 4°C for 1 h. After incubation, the cells were washed by centrifugation at 800 rpm for 5 min, and this step was repeated 3 times. 100 μl / well of secondary antibody was added, and incubated at 4°C in the dark for 0.5 h. The cells were washed by centrifugation at 800 rpm for 5 min, and this step was repeated 3 times. After washing, 100 μl / well of experimental buffer was added to the experimental plate, and the cells were collected and the fluorescence signal value was read using a flow cytometer.

[0798] The results showed that the test samples (31H4C3-hIgG1 and 5F8B4-hIgG1) and the positive control antibody CDH17v1-IgG1 WT all had obvious binding to the target cells SW948, and the negative control Human IgG1 did not show binding activity. The specific FACS detection results are shown in FIG. 6.

[0799] 11.5 Identification of internalization activity of chimeric antibodies

[0800] The target cells SW948 were collected and resuspended with experimental buffer (1% FBS + 99% DPBS, pre-cooled at 4°C), and counted. The target cell density was adjusted using experimental buffer, and 50 μl / well of target cells were inoculated into the corresponding wells of the experimental plate (2×10 5Cells were seeded in 96-well plates (10000 cells / well) and incubated at 37°C for 24 hours. After incubation, the medium was removed and the cells were washed with PBS. Then, 50 μl / well of test sample (31H4C3-hIgG1, 5F8B4-hIgG1) and internalization positive control (E8 Nb VHH-hIgG1-Fc, patent source: CN114044823A) working solution and isotype negative control (Human IgG1, Abeam, Cat: 1039049-1) (initial concentration of 100 nM or 300 nM, 5-fold serial dilution, a total of 8 concentrations) were added, and incubated at 4°C for 1 hour. After incubation, the cells were washed at 800 rpm for 5 minutes. The target cells were resuspended using the corresponding complete medium (final volume: 200 μL / well), and the experimental plate was transferred to a cell incubator (37°C / 5% CO2) for incubation for different times. After incubation, the cells were centrifuged at 800 rpm for 5 minutes to remove the medium in the wells, 100 μl / well of secondary antibody working solution was added, and incubated at 4°C in the dark for 0.5 hours. The cells were washed at 800 rpm for 5 minutes, and this step was repeated 3 times. After washing, 100 μl / well of experimental buffer was added to the experimental plate, and the cells were collected using a flow cytometer and the fluorescence signal value was read. The experimental raw data were exported via the BD FACSDiva Software v8.0.1.1 system and analyzed using FlowJo V10, Microsoft Office Excel 2016 and GraphPad Prism 6 software. The analysis results were expressed as: Internalization % = 100-((MFI t＝x -MFI t＝0背景 ) / (MFI t＝0 -MFI t＝0背景 ))*100; wherein MFI t＝x represents the average fluorescence intensity (MFI) of the test sample at a given time t at 37°C, MFI t＝0 represents the MFI value of the test sample at 0 at 37°C, and MFI t＝0背景 represents the MFI of the background (cell+secondary antibody) at 0 at 37°C.

[0801] The results showed that, using SW948 as the target cells, the internalization positive control E8 Nb VHH-hIgG1-Fc and the test samples 31H4C3-hIgG1 (“31H4C3”) and 5F8B4-hIgG1 (“5F8B4”) all showed internalization effects, and the negative control Human IgG1 did not show internalization activity. After 12 hours of internalization, the test samples 31H4C3-hIgG1 and 5F8B4 reached the internalization platform (internalization rate > 98%), and maintained the maximum internalization efficiency for at least 60 hours or more. The specific results are shown in Figure 7.

[0802] Example 12. Early drugability research of chimeric antibodies

[0803] 12.1 Expression, purification, and identification of candidate chimeric antibodies

[0804] Twenty-four hours prior to transfection, ExpiCHO-S cells were cultured normally in expression medium at a passage density of 3-4 x 10 6 cells / mL, then cultured in a shaker at 37°C, 8% CO2. On transfection D0, a small amount of cells were taken for observation of contamination and for counting, with a viable cell density of about 8-9 x 10 6 cells / mL. Cell viability was 99%. The cells were then diluted to the required density for transfection. In two centrifuge tubes, pre-warmed OptiPRO medium (Gibco, Cat. No. 12309050) was added. To one of the centrifuge tubes, heavy chain plasmid and light chain plasmid were added and mixed well, and to the other centrifuge tube, transfection reagent was added and mixed well; then the plasmid medium and reagent medium were mixed immediately. After mixing, the complex was incubated at room temperature for 10 min. The complex was added to ExpiCHO-S cells (Gibco, Cat. No. A29127), and the shaker flask was placed back in the shaker at 37°C, 8% CO2 for continued culture. On transfection D1, 18-22 h after transfection, feed and supplements were added to the cells, and then the cells were placed in a shaker at 32°C, 5% CO2 for continued culture. On transfection D3, D5, feed was added to the cells, and then the cells were placed in a shaker at 32°C, 5% CO2 for continued culture. On transfection D6, the supernatant was harvested by centrifugation.

[0805] Chimeric antibody 31H4C3-hIgGl was produced using AmMag TMProtein A Magnetic Beads purification: Protein A Magnetic Beads were added to the supernatant and incubated at room temperature for 2h. After incubation, the Protein A Magnetic Beads were equilibrated with Binding buffer for 10 column volumes; the Protein A Magnetic Beads were eluted with Elution buffer 1 and the eluate was collected, 1 / 10 eluate volume of Neutralizing buffer was added to adjust the pH to neutral. After elution, the Protein A Magnetic Beads were equilibrated with Binding buffer for 10 column volumes. The eluted and neutralized antibody solution was loaded into dialysis bags and dialyzed against Dialysis buffer at room temperature for 2h, then the Dialysis buffer was replaced and dialyzed at 2-8°C for 16h. The antibody was transferred from the dialysis bags to centrifuge tubes and filtered through a 0.22μm filter to record the volume. The concentration was determined by Nanodrop 2000 and the purity of the chimeric antibody was identified by SDS-PAGE. The results showed that the purity of all antibodies met the requirements (purity > 90%).

[0806] Chimeric antibody 5F8B4-hIgG1 purification with Monofinity A Resin: The supernatant was added to the Monofinity A Resin affinity column and incubated at room temperature for 2h. After incubation, the Monofinity A Resin affinity column was equilibrated with Binding buffer for 10 column volumes and connected to an ultraviolet detector to equilibrate to A280 to baseline. The Monofinity A Resin affinity column was eluted with Elution buffer 1 and collected according to the A280 of the ultraviolet detector, 1 / 10 eluate volume of Neutralizing buffer was added to adjust the pH to neutral. After elution, the Monofinity A Resin affinity column was equilibrated with Binding buffer for 10 column volumes. The eluted and neutralized antibody was loaded into dialysis bags and dialyzed against Dialysis buffer at room temperature for 2h, then the Dialysis buffer was replaced and dialyzed at 2-8°C for 16h. The antibody was transferred from the dialysis bags to centrifuge tubes and filtered through a 0.22μm filter to record the volume. The concentration was determined by Nanodrop 2000 and the purity of the chimeric antibody was identified by SDS-PAGE. The results showed that the purity of all antibodies met the requirements (purity > 90%). The specific concentration and purity data of the purified antibodies are shown in Table 1. The specific SDS-PAGE results are shown in Figures 8A-8B.

[0807] Table 1. Concentration and purity of chimeric antibodies after purification

[0808] 12.2 Stability analysis of chimeric antibodies

[0809] 31H4C3-hIgG1 and 5F8B4-hIgG1 two chimeric antibody molecules were subjected to stability study after freeze-thaw (-70℃±10℃ / 25℃±2℃) for 3 cycles, high temperature (40℃±2℃) storage for 2 weeks, long-term (5℃±3℃) storage for 2 weeks in 10mM His, pH6.0 buffer system.

[0810] The results of appearance and visible foreign matter, UV280, SEC-HPLC, icIEF and ELISA EC50 detection showed that 31H4C3-hIgG1 and 5F8B4-hIgG1 two chimeric antibody molecules had excellent stability in 10mM His, pH6.0, good stability at high temperature of 40℃, indicating that the two chimeric antibody molecules had high stability and good drugability.

[0811] Example 13. Humanization of chimeric antibodies

[0812] 13.1 Humanization of antibodies based on CDR grafting and back mutation technology

[0813] Modeling the structure of the parent antibody by MOE homology modeling program: using MOE structure software, the optimal human Germline was selected by combining homology modeling and IgBLast data analysis, and the potential key amino acids including Loop interaction site, interface, foundation core and internal database analysis hot spot were analyzed by homology structure analysis of antibodies. The humanized antibody was designed by combining the above key sites.

[0814] Design of humanized antibody using CDR grafting: the CDR grafting was used to design humanized antibody by comparing the sequences of heavy chain variable region and light chain variable region of CDH17 target antibody molecules (chimeric antibody 5F8B4-hIgG1 and chimeric antibody 31H4C3-hIgG1) with human antibody Germline in NCBI Ig blast database, and the human antibody VH Germline and VL Germline with the highest homology were selected as the design template for humanization.

[0815] The CDR of the parent antibody was grafted into the human antibody framework to obtain the humanized light chain and heavy chain of each parent antibody, and then two pairs of 2 heavy chains and 7 light chains were paired.

[0816] 13.2 Humanized molecule screening

[0817] The humanized design sequence was paired and constructed, the light chain was selected as Kappa subtype, the heavy chain was selected as IgG1 subtype, and was constructed into pcDNA3.4 vector, and was combined for expression, purification and detection, and humanized antibodies 5F8B4-VH1-VL1, 5F8B4-VH1-VL2, 5F8B4-VH1-VL3, 5F8B4-VH1-VL4, 5F8B4-VH1-VL5, 5F8B4-VH1-VL6, 5F8B4-VH1-VL7, 5F8B4-VH2-VL1, 5F8B4-VH2-VL2, 5F8B4-VH2-VL3, 5F8B4-VH2-VL4, 5F8B4-VH2-VL5, 5F8B4-VH2-VL6, 5F8B4-VH2-VL7 and 31H4C3-VH3-VL 31H4C3-VH3-VL2, 31H4C3-VH3-VL3, 31H4C3-VH3-VL4, 31H4C3-VH3-VL5, 31H4C3-VH3-VL6, 31H4C3-VH3-VL7, 31H4C3-VH4-VL1, 31H4C3-VH4-VL2, 31H4C3-VH4-VL3, 31H4C3-VH4-VL4, 31H4C3-VH4-VL5, 31H4C3-VH4-VL6, 31H4C3-VH4-VL7 were obtained.

[0818] Through SPR affinity and FACS detection, the results showed that humanized antibodies 5F8B4-VH1-VL1, 5F8B4-VH1-VL3, 5F8B4-VH1-VL4, 5F8B4-VH2-VL1, 5F8B4-VH2-VL3, 31H4C3-VH3-VL1, 31H4C3-VH3-VL3, 31H4C3-VH3-VL4, 31H4C3-VH4-VL1, 31H4C3-VH4-VL3 were obtained. The data of SPR affinity detection of humanized antibodies are shown in Table 2, and the FACS detection results are shown in Figures 9A-9B.

[0819] The above humanized antibodies were then incubated at 40°C for 2 weeks, treated by freeze-thawing 5 times, and the properties of each sample before and after treatment were detected by differential scanning fluorimetry (DSF), SEC-HPLC and FACS. The results showed that, by modifying the parent molecules 5F8B4-VH-VL and 31H4C3-VH-VL, respectively, a plurality of modified humanized antibodies were obtained (in the antibody nomenclature, the antibodies with numbers after VH / VL suffix are humanized antibodies); and the humanized antibody candidate molecules 5F8B4-VH1-VL4, 5F8B4-VH2-VL3, 31H4C3-VH3-VL3, 31H4C3-VH4-VL1 and 31H4C3-VH4-VL3 were screened, which had properties equivalent to or better than the parent chimeric antibodies. The FACS detection results of the untreated antibodies are shown in FIGS. 10A and 10D, the FACS detection results of the freeze-thawed antibodies are shown in FIGS. 10B and 10E, and the FACS detection results of the antibodies incubated at 40°C for 2 weeks are shown in FIGS. 10C and 10F.

[0820] The humanized antibody candidate molecules were subjected to protein translation modification (PTM) risk site removal and expression, and the antibodies after PTM risk site removal were subjected to SPR affinity determination, DSF detection and freeze-thawing preliminary stability research, and the final humanized antibodies 5F8B4-VH2-EG-VL3 and 31H4C3-VH4-EG-VL3 were screened. The results showed that the antibody expression, DSF detection, SEC-HPLC detection before and after freeze-thawing 5 times, ELISA detection before and after freeze-thawing, SPR affinity detection, tumor cell FACS affinity and tumor cell internalization activity of 5F8B4-VH2-EG-VL3 and 31H4C3-VH4-EG-VL3 were equivalent to those of the parent molecules. The DSF detection results are shown in Table 3, the SEC-HPLC results after freeze-thawing 5 times are shown in Table 4, the SPR affinity detection results are shown in Table 5, and the ELISA detection results before and after freeze-thawing are shown in FIGS. 11A-11B. The FACS detection results of the binding with tumor cells are shown in FIGS. 12A-12F, in which the CDH17 positive cells NCI-H716, LS1034, SW948 and human colorectal adenocarcinoma cell Colo320DM (ATCC, catalog number: CCL-220) were all bound with the antibodies, while the CDH17 negative cells HT-29 and SW480 were not bound with the antibodies, indicating that the humanized antibodies after PTM removal had no non-specific binding with CDH17 negative tumor cells, but had different degrees of high affinity with CDH17 positive tumor cells. The internalization activity detection results of the tumor cells are shown in FIGS. 13A-13B. The CDR amino acid sequences of the chimeric antibody parent molecules and the humanized antibodies (including the humanized antibodies after PTM removal) are shown in Table 6.

[0821] Table 2. SPR affinity detection data of humanized antibodies

[0822] Table 3. PTM-removing antibody DSF detection data

[0823] Table 4. PTM-removing antibody SEC-HPLC results after freeze-thaw

[0824] Table 5. PTM-removing humanized antibody SPR affinity detection data

[0825] Table 6. CDR amino acid sequences of chimeric antibody parent and humanized antibodies

[0826] It should be appreciated that different CDR definition schemes can result in different CDR sequences, all of which are intended to be encompassed by the antibody sequences described herein. Table 21 lists the CDR sequences obtained using the IMGT, Chothia, and AbM definition methods. Exemplarily, the CDRs obtained using other CDR definition methods are also within the scope of the present application, taking the chimeric antibodies 31H4C3 and 5F8B4 as examples.

[0827] Table 21. Light and heavy chain CDR sequences of anti-CDH17 antibodies under other numbering / definition methods

[0828] Example 14. Preparation method of linker-toxin

[0829] The linker and toxin used in the present application, such as deruxtecan, GGFG-Dxd, Dxd, GGFG-Exd, Val-Ala-PAB, are prepared according to WO2014057687, WO1997046260, CN101795711, which are incorporated by reference in their entirety.

[0830] The linker-toxin Cpd3 used in the present application and its preparation method are as follows:

[0831] Step 1: (9H-fluoren-9-yl)methyl ((S)-3-methyl-1-(((S)-1-((4-((((4- nitrophenoxy)carbonyl)oxy)methyl)phenyl)amino)-1-oxopropan-2-yl)amino)-1- oxobutan-2-yl)carbamate (3-1, 2.5 g, 3.6 mmol), (1S,9S)-1-amino-9-ethyl-5-fluoro-9- hydroxy-4-methyl-1,2,3,9,12,15-hexahydro-10H,13H-benzo[de]pyrano[3',4':6,7]indolizino[1,2- b]quinoline-10,13-dione (3-2, 1.6 g, 3.6 mmol), N,N-diisopropylamine (965 mg, 7.5 mmol) were dissolved in anhydrous N,N-dimethylformamide (20 mL), the reaction was stirred at room temperature for 16 hours. LCMS monitored the reaction was completed, to obtain 4-((S)-2-(S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3- methylbutanoylamino)propanoylamino)benzyl ((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4- methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2- b]quinolin-1-yl)carbamate (3-3). LCMS (ESI) m / z: 977.3 [M+H] + .

[0832] Step 2: Directly add hexahydropyridine (464 mg, 5.4 mmol) to the reaction solution of step 1, the reaction was stirred at room temperature for 2 hours. LCMS monitored the raw material reaction was completed, the reaction was directly purified by C18 column chromatography to separate 4-((S)-2-((S)-2-amino-3-methylbutanoylamino)propanoylamino)benzyl ((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15- hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)carbamate (3-4) (1.8 g). LCMS (ESI) m / z: 755.2 [M+H] + .

[0833] Step 3: To the reaction solution of step 2 was added hexahydropyridine (409 mg, 4.76 mmol) directly, the reaction solution was stirred at room temperature for 2 hours. LCMS monitoring showed the starting material was consumed completely, the reaction solution was purified by C18 column directly to give 4-((29S,32S)-1-amino-29-isopropyl-32-methyl-27,30-dioxo-3,6,9,12,15,18,21,24- octaoxa-28,31-diazatriacontan-33-ylamino)benzyl ((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4- methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2- b]quinolin-1-yl)carbamate (3-7) (1.2 g). LCMS (ESI) m / z: 1178.4 [M+H] + .

[0834] Step 4: To the reaction solution of step 3 was added hexahydropyridine (409 mg, 4.76 mmol) directly, the reaction solution was stirred at room temperature for 2 hours. LCMS monitoring showed the starting material was consumed completely, the reaction solution was purified by C18 column directly to give 4-((29S,32S)-1-amino-29-isopropyl-32-methyl-27,30-dioxo-3,6,9,12,15,18,21,24- octaoxa-28,31-diazatriacontan-33-ylamino)benzyl ((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4- methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2- b]quinolin-1-yl)carbamate (3-7) (1.2 g). LCMS (ESI) m / z: 1178.4 [M+H] + .

[0835] Step 5: 4-((29S,32S)-1-amino-29-isopropyl-32-methyl-27,30-dioxo-3,6,9,12,15,18,21,24- octaoxa-28,31-diazatri-33-ylamino)benzyl ((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl- 10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2- b]quinolin-1-yl)carbamate (3-7, 20 mg, 0.017 mmol), 2-(methylsulfonyl)pyrimidine-5- carboxylic acid (3-8, 13.7 mg, 0.068 mmol), 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine tetrafluoroborate (22.3 mg, 0.068 mmol) were dissolved in anhydrous N,N- dimethylacetamide (3 mL) and the reaction was stirred at room temperature for 16 hours. Purification by C18 column chromatography gave 4-((31S,34S)-31-isopropyl-34-methyl-1-(2- (methylsulfonyl)pyrimidin-5-yl)-1,29,32-trioxo-5,8,11,14,17,20,23,26-octaoxa-2,30,33- triazatri-35-ylamino-benzyl (1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo- 2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1- yl)carbamate (2.3 mg, yield: 10%) which is Cpd 3.

[0836] 1H NMR (400 MHz, DMSO-d6) δ 9.95 (s, 1H), 9.37 (s, 1H), 9.14 (s, 1H), 8.46 (s, 1H), 8.21 (d, J = 6.8 Hz, 1H), 8.06 (d, J = 7.8 Hz, 1H), 7.89 (d, J = 8.3 Hz, 1H), 7.78 (d, J = 10.9 Hz, 1H), 7.60 (d, J = 8.4 Hz, 2H), 7.36 (d, J = 8.1 Hz, 2H), 7.31 (s, 1H), 6.53 (s, 1H), 5.45 (s, 2H), 5.28 (s, 3H), 5.08 (s, 2H), 4.42 - 4.34 (m, 1H), 4.22 - 4.17 (m, 1H), 3.62 - 3.53 (m, 10H), 3.52 - 3.46 (m, 28H), 2.38 (s, 3H), 2.33 (s, 1H), 2.20 (s, 3H), 2.01 - 1.81 (m, 4H), 1.30 (d, J = 7.0 Hz, 3H), 0.90 - 0.80 (m, 9H).

[0837] The linker-toxin Cpd 5 used in the present application and the method for preparing the same are as follows:

[0838] Step 1: 1-(9H-fluoren-9-yl)-3,6-dioxo-2,9-dioxa-4,7-diazoundecanoic acid (5-1, 440 mg, 1.15 mmol), (1S,9S)-1-amino-9-ethyl-5-fluoro-9-hydroxy-4-methyl-1,2,3,9,12,15- hexahydro-10H,13H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinoline-10,13-dione (500 mg, 1.15 mmol) were dissolved in dry N,N-dimethylformamide (20 mL), N,N'-dicyclohexylcarbodiimide (308 mg, 1.5 mmol), N-hydroxysuccinimide (132 mg, 1.15 mmol) and N,N-diisopropylethylamine (148 mg, 1.15 mmol) were added under ice bath, then the reaction was stirred at room temperature for 16 hours. The reaction was monitored by LCMS, the organic phase was concentrated by extraction with ethyl acetate and water, purified by silica gel column with methanol and dichloromethane system (1:20) to give (9H-fluoren-9-yl)methyl (2-(((2-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-2-oxoethoxy)methyl)amino)-2-oxoethyl)carbamate (5-3, 650 mg). LCMS (ESI) m / z: 802.3 [M+H] + .

[0839] Step 2: (9H-Fluoren-9-yl)methyl (2-(((2-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4- methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7] indolizino[1,2-b]quinolin-1-yl)amino)-2-oxoethoxy)methyl)amino)-2-oxoethyl) carbamate (5-3, 650 mg, 0.81 mmol) was dissolved in N,N-dimethylformamide (10 mL), then hexahydropyridine (69 mg, 5.4 mmol) was added, the reaction was stirred at room temperature for 2 hours. LCMS monitoring showed that the reaction was completed, the reaction was directly purified by C18 column chromatography to obtain 2-amino-N-((2-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo- 2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1- yl)amino)-2-oxoethoxy)methyl)acetamide (5-4, 420 mg). LCMS (ESI) m / z: 580.2 [M+H] + .

[0840] Step 3: 2-Amino-N-((2-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo- 2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin- 1-yl)amino)-2-oxoethoxy)methyl)acetamide (5-4, 420 mg, 0.73 mmol), (((9H-fluoren-9- yl)methoxy)carbonyl)glycylglycyl-L-phenylalanine (5-5, 370 mg, 0.73 mmol) were dissolved in anhydrous N,N-dimethylformamide (10 mL), N,N'-dicyclohexylcarbodiimide (195 mg, 0.95 mmol), N-hydroxysuccinimide (84 mg, 0.73 mmol) and N,N-diisopropyl ethylamine (94 mg, 0.73 mmol) were added under ice-bath, then the reaction was stirred at room temperature for 16 hours. The reaction was monitored by LCMS, the organic phase was concentrated by extraction with ethyl acetate and water, and purified by silica gel column with methanol and dichloromethane system (1:15) to give (9H-fluoren-9-yl)methyl ((S)-10-benzyl-1-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1,6,9,12,15-pentaoxo-3-oxa-5,8,11,14-tetraazahexadec-16-yl)carbamate (5-6, 550 mg). LCMS (ESI) m / z: 1063.5 [M+H] + .

[0841] Step 4: (9H-fluoren-9-yl)methyl ((S)-10-benzyl-l-(((lS,9S)-9-ethyl-5-fluoro-9- hydroxy-4-methyl-10, 13-dioxo-2,3,9,10, 13, 15-hexahydro-lH, 12H-benzo[de] pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l-yl)amino)-l,6,9, 12, 15-pentaoxo-3-oxa- 5,8, 11, 14-tetraazahexadec-16-yl)carbamate (5-6, 550 mg, 0.52 mmol) was dissolved in N,N-dimethylformamide (5 mL), then hexahydropyridine (44 mg, 0.52 mmol) was added, the reaction was stirred at room temperature for 2 hours. LCMS monitoring showed that the raw material was completely reacted, the reaction was directly purified by C18 column chromatography to obtain ((S)-10-benzyl-l-(((lS,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10, 13-dioxo-2,3,9,10, 13, 15-hexahydro-lH, 12H-benzo[de] pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l-yl)amino)-l,6,9, 12, 15-pentaoxo-3-oxa- 5,8, 11, 14-tetraazahexadec-16-yl)amine (5-7, 400 mg). LCMS (ESI) m / z: 841.4 [M+H] + .

[0842] Step 5: 1-(9H-fluoren-9-yl)-3-oxo-2,7,10,13,16,19,22,25,28-nonaoxa-4-aza- hexatriacontan-31-oic acid (347 mg, 0.52 mmol), HATU (274 mg, 0.72 mmol) and N,N- diisopropyl ethylamine (124 mg, 0.96 mmol) were dissolved in dry N,N-dimethylformamide (5 mL), stirred at room temperature for 1 h, then ((S)-10-benzyl-1-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1,6,9,12,15-pentaoxo-3-oxa-5,8,11,14-tetraazahexadecan-16-yl)amine (5-7, 400 mg, 0.48 mmol) was added and stirred at room temperature for 16 h, the reaction was monitored by LCMS and the reaction was completed, the reaction mixture was directly purified by C18 column chromatography to give (9H-fluoren-9-yl)methyl ((S)-10-benzyl-1-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1,6,9,12,15,18-hexaoxo-3,21,24,27,30,33,36,39,42-nonaoxa-5,8,11,14,17-pentaazatetra-decan-44-yl)carbamate (5-9, 350 mg). LCMS (ESI) m / z: 1486.6 [M+H] + .

[0843] Step 6: (9H-fluoren-9-yl)methyl ((S)-10-benzyl-l-(((lS,9S)-9-ethyl-5-fluoro-9- hydroxy-4-methyl-10, 13-dioxo-2,3,9,10, 13, 15-hexahydro-lH, 12H-benzo[de] pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l-yl)amino)-l,6,9, 12, 15, 18-hexaoxo- 3,21,24,27,30,33,36,39,42-nonaoxa-5,8,11,14,17-pentaazatetratetracontan-44- yl)carbamate (5-9, 350 mg, 0.24 mmol) was dissolved in N,N-dimethylformamide (5 mL), then hexahydropyridine (20 mg, 0.24 mmol) was added, the reaction was stirred at room temperature for 2 hours. LCMS monitoring showed that the raw material was completely reacted, the reaction was directly purified by C18 column chromatography to obtain l-amino-N-((S)-10-benzyl-l-(((lS,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10, 13-dioxo-2,3,9,10, 13, 15-hexahydro-lH, 12H-benzo[de]pyrano[3',4':6,7]indolizino[l,2-b]quinolin-l-yl)amino)-l,6,9, 12, 15-pento xo-3-oxa-5,8,11,14-tetraazahexadecan- 16-yl)-3,6,9, 12, 15, 18,21,24-octaoxaheptacosan-27-amide (5-10, 200 mg). LCMS (ESI) m / z: 1264.6 [M+H] + .

[0844] Step 7: 1 -amino-N-((S)-10-benzyl-1 -(((1 S,9S)-9-ethyl-5-fluoro-9-hydroxy-4- methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1 H,12H-benzo[de]pyrano[3',4':6,7] indolizino[1,2-b]quinolin-1 -yl)amino)-1,6,9,12,15-pentaoxo-3-oxa-5,8,11,14- tetraazahexadecan-16-yl)-3,6,9,12,15,18,21,24-octaoxaheptacosan-27- amide (5-10, 100 mg, 0.079 mmol), 2-(methylsulfonyl)pyrimidine-5-carboxylic acid (64 mg, 0.3 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (53 mg, 0.3 mmol), N-methylmorpholine (182 mg, 1.8 mmol) were dissolved in anhydrous N,N-dimethylacetamide (5 mL) and the reaction was stirred at room temperature for 16 h. Purification by C18 column chromatography gave N-((S)-10-benzyl-1 -(((1 S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1 H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1 -yl)amino)-1,6,9,12,15,18-hexaoxo-3,21,24,27,30,33,36,39,42-nonaoxa-5,8,11,14,17-pentaazatetra-decan-44-yl)-2-(methylsulfonyl)pyrimidine-5-carboxamide (5 mg), Cpd 5. LCMS (ESI) m / z: 1448.6 [M+H] + .

[0845] 1H NMR (400 MHz, DMSO-d6) δ 9.37 (d, J = 2.1 Hz, 2H), 9.12 (s, 1H), 8.63 (s, 1H), 8.51 (d, J = 8.6 Hz, 1H), 8.29 (s, 1H), 8.21 - 8.07 (m, 2H), 7.99 (s, 1H), 7.78 (d, J = 10.9 Hz, 1H), 7.31 (s, 1H), 7.21 (t, J = 15.2 Hz, 5H), 6.52 (s, 1H), 5.60 (s, 1H), 5.42 (s, 2H), 5.20 (s, 2H), 4.64 (d, J = 6.3 Hz, 2H), 4.47 (s, 1H), 4.02 (s, 2H), 3.76 - 3.66 (m, 4H), 3.59 - 3.53 (m, 8H), 3.51 - 3.45 (m, 29H), 2.39 (s, 5H), 2.18 (s, 2H), 2.00 (d, J = 7.9 Hz, 1H), 1.84 (dd, J = 15.4, 7.8 Hz, 2H), 1.33 - 1.20 (m, 5H), 1.12 (d, J = 6.6 Hz, 1H), 0.87 (t, J = 6.3 Hz, 3H).

[0846] The linker-toxin Cpd6 used in the present application and its method of preparation are as follows:

[0847] Step 1: ((9H-fluoren-9-yl)methoxy)carbonyl-L-valyl-L-alanine (6-1, 943 mg, 2.3 mmol), (1S,9S)-1-amino-9-ethyl-5-fluoro-9-hydroxy-4-methyl-1,2,3,9,12,15-hexahydro-10H,13H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinoline-10,13-dione (1g, 2.3 mmol) were dissolved in anhydrous N,N-dimethylformamide (20 mL), N,N'-dicyclohexylcarbodiimide (616 mg, 3 mmol), N-hydroxysuccinimide (264 mg, 2.3 mmol) and N,N-diisopropylethylamine (297 mg, 2.3 mmol) were added under ice bath, then the reaction was stirred at room temperature for 16 hours. The reaction was monitored by LCMS, the organic phase was concentrated by extraction with ethyl acetate and water, and purified by silica gel column with methanol and dichloromethane system (1:20) to give ((9H-fluoren-9-yl)methyl ((S)-1-(((S)-1-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1-oxopropan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)carbamate (6-3, 730 mg). LCMS (ESI) m / z: 828.3 [M+H] + .

[0848] Step 2: (9H-fluoren-9-yl)methyl ((S)-1-(((S)-1-(((1S,9S)-9-ethyl-5-fluoro-9- hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H- benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1- oxopropan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)carbamate (6-3, 730 mg, 0.88 mmol) was dissolved in N,N-dimethylformamide (10 mL), then hexahydropyridine (75 mg, 0.88 mmol) was added, the reaction was stirred at room temperature for 2 hours. LCMS monitoring showed that the reaction was completed, the reaction was directly purified by C18 column chromatography to obtain (S)-2-amino-N-((S)-1-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1-oxopropan-2-yl)-3-methylbutanamide (6-4, 450 mg). LCMS (ESI) m / z: 606.2 [M+H] + .

[0849] Step 3: 1-(9H-fluoren-9-yl)-3-oxo-2,7,10,13,16,19,22,25,28-nonaoxa-4- azatridecane-31-oic acid (592 mg, 0.89 mmol), HATU (422 mg, 1.11 mmol) and N,N- diisopropyl ethylamine (143 mg, 1.11 mmol) were dissolved in dry N,N-dimethylformamide (5 mL), stirred at room temperature for 1 h, then (S)-2-amino-N-((S)-1-(((1S,9S)-9- ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H- benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1-oxopropan-2-yl)-3- methylbutanamide (450 mg, 0.74 mmol) was added and stirred at room temperature for 4 h, the reaction was monitored by LCMS and the reaction was purified by C18 column chromatography to give (9H-fluoren-9-yl)methyl ((29S,32S)-33-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl- 10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b] quinolin-1-yl)amino)-29-isopropyl-32-methyl-27,30,33-trioxo-3,6,9,12,15,18,21,24- octaoxa-28,31-diazatriacontyl)carbamate (6-5, 400 mg). LCMS (ESI) m / z: 1251.6 [M+H] + .

[0850] Step 4: (9H-Fluoren-9-yl)methyl ((29S,32S)-33-(((1S,9S)-9-ethyl-5-fluoro-9- hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H- benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-29- isopropyl-32-methyl-27,30,33-trioxo-3,6,9,12,15,18,21,24- octaoxa-28,31-diazatriacontan-1-yl)carbamate (6-5, 400 mg, 0.32 mmol) was dissolved in N,N-dimethylformamide (5 mL), then hexahydropyridine (27 mg, 0.32 mmol) was added, the reaction was stirred at room temperature for 2 hours. LCMS monitoring showed that the raw material was reacted completely, the reaction was directly purified by C18 column chromatography to obtain 1-amino-N-((S)-1-(((S)-1-(((1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1-yl)amino)-1-oxopropan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)-3,6,9,12,15,18,21,24-octaoxa-heptacosan-27- amide (6-6, 210 mg). LCMS (ESI) m / z: 1029.6 [M+H] + .

[0851] Step 5: 1 -amino-N-((S)-1 -(((S)-1 -(((1 S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl- 10,13-dioxo-2,3,9,10,13,15-hexahydro-1 H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2- b]quinolin-1 -yl)amino)-1 -oxopropan-2-yl)amino)-3-methyl-1 -oxobutan-2-yl)-3,6,9,12,15,18,21,24- octaoxa-heptatriacontan-27-amide (6-6, 100 mg, 0.097 mmol), 2-(methylsulfonyl)pyrimidine-5- carboxylic acid (78 mg, 0.39 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (68 mg, 0.39 mmol) and N-methylmorpholine (59 mg, 0.582 mmol) were dissolved in anhydrous N,N- dimethylacetamide (5 mL) and the reaction was stirred at room temperature for 16 hours. Purification by C18 column chromatography gave N-((29S,32S)-33-(((1 S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl- 10,13-dioxo-2,3,9,10,13,15-hexahydro-1 H,12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinolin-1 - yl)amino)-29-isopropyl-32-methyl-27,30,33-trioxo-3,6,9,12,15,18,21,24-octaoxa-28,31 - diaza-triatriacontyl)-2-(methylsulfonyl)pyrimidine-5-carboxamide (11.5 mg), Cpd 6. LCMS (ESI) m / z: 1213.6 [M+H] +

[0852] 1H NMR (400 MHz, DMSO-d6) δ 9.36 (s, 2H), 9.13 (s, 1H), 8.41 (d, J = 8.9 Hz, 1H), 8.10 (d, J = 6.9 Hz, 1H), 7.86 (d, J = 8.4 Hz, 1H), 7.79 (d, J = 11.0 Hz, 1H), 7.30 (s, 1H), 6.53 (s, 1H), 5.54 (s, 1H), 5.42 (s, 2H), 5.24 (d, J = 18.9 Hz, 1H), 5.11 (d, J = 19.0 Hz, 1H), 4.32 - 4.21 (m, 1H), 4.17 - 4.06 (m, 1H), 3.58 - 3.52 (m, 8H), 3.48 (s, 25H), 3.44 (s, 6H), 2.40 (s, 3H), 2.29 (dd, J = 13.7, 7.1 Hz, 1H), 2.13 (s, 2H), 1.91 (ddd, J = 23.2, 22.6, 7.6 Hz, 4H), 1.27 (d, J = 7.0 Hz, 3H), 0.87 (t, J = 7.4 Hz, 3H), 0.83 - 0.72 (m, 6H).

[0853] Example 15 Chimeric antibody conjugate and humanized antibody conjugate

[0854] 15.1 Humanized antibody conjugate

[0855] The antibody 31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3 were coupled with the toxin Exatecan (a DNA topoisomerase inhibitor with anticancer activity) to construct antibody drug conjugates: the antibody stock solution was taken out from the refrigerator (-80°C), after thawing, it was added to a centrifuge tube, then PBS buffer, diethylene triamine pentaacetic acid trisodium salt (DTPA-3Na), tris (2-carboxyethyl) phosphine (TCEP) solution was added, and the reaction was carried out at 25°C for 2 hours. Then the linker-payload was added and the reaction was continued at 25°C for 2 hours. After the reaction was completed, it was added to an ultrafiltration centrifuge tube (30KD), and dialyzed with His / His-HCl to replace it, to obtain the ADC stock solution (DAR: 7.5-8.5, SEC purity ≥95%). The specific preparation method is as follows: the antibody stock solution (31H4C3-VH4-EG-VL3, 15mg) was taken out from the refrigerator (-80°C), after thawing, it was added to a centrifuge tube, then PB (20mM, Ph7.2, 751uL) buffer, DTPA-3Na (10mM, 375uL), TCEP (10mM, 94uL) solution was added, and the reaction was carried out at 25°C for 2 hours. Then cpd3 (5mM, 272uL) was added and the reaction was continued at 25°C for 2 hours. After the reaction was completed, it was added to an ultrafiltration centrifuge tube (30KD), and dialyzed with His / His-HCl (10mM, Ph5.5) to replace it, to obtain the ADC stock solution (11.4mg, DAR: 7.8, SEC purity: 98.7%, free drug: 0.68%).

[0856] This example uses the humanized antibody 31H4C3-VH4-EG-VL3 obtained in Example 13 and the linker-toxin cpd3 obtained in Example 14 for coupling, and the obtained antibody drug conjugate is 31H4C3-VH4-EG-VL3-cpd3, hereinafter referred to as "hu31H4C3-cpd3"; the humanized antibody 5F8B4-VH2-EG-VL3 obtained in Example 13 and the cpd3 obtained in Example 14 are used for antibody and linker-toxin coupling, and the obtained antibody drug conjugate is 5F8B4-VH2-EG-VL3-cpd3, hereinafter referred to as "hu5F8B4-cpd3"; the humanized antibody 31H4C3-VH4-EG-VL3 obtained in Example 13 and the commercially available drubecan are coupled, and the obtained antibody drug conjugate is 31H4C3-VH4-EG-VL3-DXD, hereinafter referred to as "hu31H4C3-DXD"; the humanized antibody 5F8B4-VH2-EG-VL3 obtained in Example 13 and the commercially available drubecan are coupled, and the obtained antibody drug conjugate is 5F8B4-VH2-EG-VL3-DXD, hereinafter referred to as "hu5F8B4-DXD".

[0857] 31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3, and other Linker-Payloads (such as droncicam), ADC stock solutions were prepared by the above method, and the results of detection are as follows:

[0858] 15.2 Chimeric antibody conjugated with droncicam

[0859] This example uses the chimeric antibodies 31H4C3 and 5F8B4 obtained in Example 11.1 and commercially available droncicam for conjugation, and the resulting antibody drug conjugates are 31H4C3-DXD and 5F8B4-DXD.

[0860] The chimeric antibodies 31H4C3 and 5F8B4 were conjugated with the Linker-Payload droncicam to construct antibody drug conjugates, and ADC stock solutions were prepared by the above method, and the results of detection are as follows:

[0861] Example 16 ELISA binding activity detection of ADC of humanized antibody

[0862] In this example, 96-well ELISA plates were coated with 0.5 pg / mL of Human CDH17 protein, Cyno CDH17 protein, Rat CDH17 protein, Mouse CDH17 protein, and Human Cadherin-16 Protein (100 pL / well) at 4°C overnight. The next day, the plates were washed with PBST four times, blocked with 1% BSA for 2 h, washed with PBST four times, and then 100-fold dilutions of the prepared humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) and a negative control Isotype antibody (HYHEL-10, prepared by Genscript Probio) were added and incubated at 37°C for 1 h. After washing with PBST four times, secondary antibody Peroxidase AffiniPure Goat Anti-Human IgG (H+L) (Jackson, Cat#: 109-035-003) was added and incubated for 0.5 h. After incubation, the plates were washed with PBST four times, and TMB (Huzhou Yingchuang, Cat#: TMB-S-002) was added for color development. According to the color development results, Stop solution (BioLegend, Cat#: 423001) was added to terminate the reaction, and the data were read at OD450 by a microplate reader (Molecular Devices, SpecterMax 190).

[0863] The results, as shown in FIGS. 14A-14D, indicated that the prepared humanized ADCs 31H4C3-VH4-EG-VL3-Cpd3 (hereinafter abbreviated as hu31H4C3-Cpd3) and 5F8B4-VH2-EG-VL3-Cpd3 (hereinafter abbreviated as hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) had good affinity activity with the human CDH17 antigen protein Human CDH17 protein, the monkey CDH17 protein Cyno CDH17 protein, and the rat CDH17 protein Rat CDH17 protein, and had a certain degree of affinity activity with the mouse CDH17 antigen protein Mouse CDH17 protein at a concentration of 25 nM or more.

[0864] Example 17 Binding activity analysis of humanized ADCs to CDH17 homologous proteins

[0865] In this example, 96-well ELISA plates were coated with 0.5 pg / mL of Human Cadherin-16 Protein (100 pL / well) at 4°C overnight. The next day, the plates were washed 4 times with PBST and blocked with 1% BSA for 2 h. After washing the plates 4 times with PBST, the prepared humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) and a negative control Isotype antibody (HYHEL-10, Genscript Probio) were added at gradient dilutions (100, 25, 6.25, 1.56, 0.39, 0.098, 0.024, 0.006, 0.0015, 0.00038 nM) and incubated at 37°C for 1 h. After washing the plates 4 times with PBST, secondary antibody Peroxidase AffiniPure Goat Anti-Human IgG (H+L) (Jackson, Cat#: 109-035-003) was added and incubated for 0.5 h. After incubation, the plates were washed 4 times with PBST, and TMB (Huzhou Yingchuang, Cat#: TMB-S-002) was added for color development. According to the color development results, Stop solution (BioLegend, Cat#: 423001) was added to stop the reaction, and the data were read at OD450 by a microplate reader (Molecular Devices, SpecterMax 190).

[0866] The results are shown in Figure 15. Neither the prepared humanized ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) nor their corresponding antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) bound to CDH17 homologous protein CDH16 Human Cadherin-16 protein.

[0867] Example 18 Detection of FACS binding activity of humanized ADCs

[0868] In this embodiment, the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) were detected for the binding ability to human CDH17 protein on CDH17 positive tumor cells (human colorectal cancer cells NCI-H716 (ATCC, Cat No: CCL-251), LS1034 (ATCC, Cat No: CRL-2158), SW948 (ATCC, Cat No: CCL-237), Colo205 (ATCC, Cat No: CCL-222), HT-55 (CoBioer, Cat No: CBP60012) and human gastric cancer cells SNU-5 (ATCC, Cat No: CRL-5973), SNU-16 (ATCC, Cat No: CRL-5974), OCUM-1 (JCRB, Cat No: JCRB0192), IM95 (JCRB, Cat No: JCRB1075.0) and human esophageal cancer cells OE19 (CoBioer, Cat No: CBP60495)) and CDH17 negative tumor cells (human colorectal cancer cells HT-29 (ATCC, Cat No: HTB-38) and SW480 (ATCC, Cat No: CCL-228)) by FACS method.

[0869] The specific method is as follows: logarithmically growing NCI-H716, LS1034, SW948, Colo205, HT-55, SNU-5, SNU-16, OCUM-1, IM95, OE19, HT-29 and SW480 cells were prepared into single cell suspension, the density was adjusted to 1×10 6 4 ​The prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) were added to the 96-well V-bottom plate, centrifuged at 500g for 5 min at 4°C, and the supernatant was removed, and the above steps were repeated twice. Gradient dilution (300, 60, 12, 2.4, 0.48, 0.096, 0.019, 0.00384, 0.000768, 0.0001536 nM) of the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and its corresponding antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) and negative control Isotype antibody (HYHEL-10, Genscript Probio) were added to the corresponding wells, mixed well, and incubated at 4°C for 2 h. After washing the cell mixture twice, 100 μL of secondary antibody PE F(ab')2 Goat anti-human IgG Fcγ antibody (BioLegend, 398004) was added, and the mixture was incubated at 4°C in the dark for 30 min. After washing twice, the mixture was detected by flow cytometry (Thermo, Attune NxT V6).

[0870] The results showed that the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) were combined with CDH17 positive tumor cells (NCI-H716, LS1034, SW948, Colo205, HT-55, SNU-5, SNU-16, OCUM-1, IM95 and OE19 cells). The binding activity of the ADC to each cell after conjugation was comparable to that of the corresponding antibody, with an EC50 of 0.1-2.4 nM. The above ADC and antibody did not bind to CDH17 negative cells (HT-29 and SW480) (almost no binding even at the highest concentration of 300 nM).

[0871] Table 13. FACS detection of EC50 results of ADC and antibody with tumor cells

[0872] Example 19 Detection of internalization activity of humanized ADC

[0873] In this example, NCI-H716, LS1034 and SNU-5 cells were collected by centrifugation, the supernatant was discarded, and the cells were resuspended in complete medium to 5×10 5 cells / mL, and 5×10 4cells / well (100 pL / well). 100 pL / well of the prepared 20 nM ADCs (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) and isotype control HYHEL-10 were added with a total volume of 200 pL / well, and 2 replicates were set for each drug concentration (10 nM final concentration). The 96-well low-attachment microplate was placed in a 4 °C refrigerator for incubation for 1 h. After incubation, the supernatant was discarded by centrifugation at 300 g for 5 min at 4 °C. The cells were washed twice with pre-cooled PBS + 2% FBS, and the supernatant was discarded. 200 pL of complete medium was added to each well to resuspend the cells, which were incubated at 37 °C in a 5% CO2 incubator for different time points (0 / 2 / 4 / 6 / 8 h); the background group (i.e., the group with cells and secondary antibody) and the blank control group (i.e., the group with only cells) were incubated at 37 °C for 0 h. After incubation, the experimental plate was removed from the cell incubator, centrifuged at 300 g for 5 min at 4 °C to discard the supernatant, washed twice with 200 pL of pre-cooled Cell Staining Buffer, and then 100 pL of PE anti-human IgG working solution (2 pL of antibody stock solution was added to 98 pL of Cell Staining Buffer to prepare the working solution) was added, which was incubated at 4 °C in the dark for 30 min. After washing twice with 200 pL of pre-cooled Cell Staining Buffer, 200 pL of Cell Staining Buffer was added to resuspend the cells, and the sample PE MFI signal was analyzed by flow cytometry (Thermo, model: Attune NxT V6). Attune Cytometric Software v5.3.0, Microsoft Office Excel 2021, and GraphPad Prism 9 software were used for analysis. The calculation formula was Internalization% = 100–(MFI t＝x -MFI t＝0背景 ) / (MFI t＝0 -MFI t＝0背景 )*100, where MFI t＝x represents the MFI of the sample group at the time x to be determined at 37 °C, MFI t＝0 represents the MFI value at 0 h at 37 °C, and MFI t＝0背景 is the MFI of the background group (i.e., the group with cells and secondary antibody) at 0 h at 37 °C. The data are expressed as mean ± standard deviation (Mean ± SD).

[0874] The results show that hu31H4C3-Cpd3 and hu5F8B4-Cpd3 mediated receptor endocytosis in NCI-H716, LS1034 and SNU-5 cells started from the time within 2h (the shortest time tested in this experiment) and showed time-dependent increase within 8h. In NCI-H716 cells (Figure 17A), the endocytosis efficiency of hu31H4C3-Cpd3 and hu5F8B4-Cpd3 reached more than 45% at 8h; in LS1034 cells (Figure 17B), the endocytosis efficiency of hu31H4C3-Cpd3 and hu5F8B4-Cpd3 reached more than 60% at 8h; in SNU-5 cells (Figure 17C), the endocytosis efficiency of hu31H4C3-Cpd3 and hu5F8B4-Cpd3 reached more than 74% at 8h.

[0875] Example 20 Cell proliferation inhibition activity of humanized ADC

[0876] In this example, the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibodies (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) were tested for their killing effect on tumor cells using CDH17-positive tumor cells (human colorectal cancer cells NCI-H716, LS1034, SW948, Colo205, HT-55 and human gastric cancer cells SNU-5, SNU-16, OCUM-1, IM95 and human esophageal cancer cells OE19).

[0877] The specific method is as follows: logarithmic growth phase NCI-H716, LS1034, SW948, Colo205, HT-55, SNU-5, SNU-16, OCUM-1, IM95 and OE19 cells were prepared into single cell suspension, NCI-H716 density was adjusted to 9x10 3 cells / well, LS1034 density was adjusted to 1.5x10 3 cells / well, SW948 density was adjusted to 3x10 3 cells / well, Colo205 density was adjusted to 2x10 3 cells / well, HT-55 density was adjusted to 1x10 3 cells / well, SNU-5 density was adjusted to 6x10 3 cells / well, SNU-16 density was adjusted to 4x10 3 cells / well, OCUM-1 density was adjusted to 1x10 3 cells / well, IM95 density was adjusted to 3x10 3 cells / well, OE19 density was adjusted to 2x103 SW948, OCUM-1, IM95, HT-55, Colo205, LS1034, OE19 cells, 400, 100, 25, 6.25, 1.56, 0.39, 0.098, 0.024 nM of ADC samples and Exatecan were added to NCI-H716, SNU-5, SNU-16 cells, and 1000, 100, 10, 1, 0.1, 0.01, 0.001, 0.0001 nM of antibody samples and control antibody Isotype antibody (HYHEL-10, Genscript Probio) were added to the above 10 cells, respectively. After incubation at 37℃, 5% CO2for 144 h, 50 μL of CellTiter-Glo® 2.0 Reagent (Promega, G7573) was added to each well, mixed for 2 min, and incubated at room temperature for 10 min. The chemiluminescence signal value was read by a microplate reader (PerkinElmer, Model: EnVision).

[0878] The results showed that hu31H4C3-Cpd3 and hu5F8B4-Cpd3 had different degrees of cell proliferation inhibition activity on 10 tumor cells NCI-H716, LS1034, SW948, Colo205, HT-55, SNU-5, SNU-16, OCUM-1, IM95 and OE19, as shown in Figures 18A-18J and Table 15.

[0879] Table 15. IC50(nM) of ADCs on cell proliferation inhibition activity

[0880] Example 21 Species Cross Confirmation of Humanized ADCs

[0881] ​In this embodiment, the binding ability of the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) to CDH17 protein on CDH17 overexpression engineering cell lines CHOK1-human CDH17 cell line (Genscript Probio constructed), Cyno_CDH17 HEK293 cell line (Genomeditech constructed), Rat_CDH17 HEK293 cell line (Genomeditech constructed), Mouse_CDH17 HEK293 cell line (Genomeditech constructed) was detected based on FACS method.

[0882] The specific method is as follows: logarithmic growth period CHOK1-human CDH17 cell line, Cyno_CDH17 HEK293 cell line, Rat_CDH17 HEK293 cell line, Mouse_CDH17 HEK293 cell line were prepared into single cell suspension, the density was adjusted to 1×10 6 cells / mL, 50 μL (5×10^4 cells) was added to each well of 96-well V-bottom plate, centrifuged at 4 ℃ 500g for 5 min and the supernatant was removed, repeated 2 times. Gradient dilution (300, 60, 12, 2.4, 0.48, 0.096, 0.019, 0.00384, 0.000768, 0.0001536 nM) of the prepared humanized ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3), antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) and negative control Isotype antibody (HYHEL-10, Genscript Probio prepared) was added to the corresponding wells, mixed and incubated at 4 ℃ for 2 h. After washing the cell mixture after incubation for 2 times, 100 μL of secondary antibody PE F(ab')2 Goat anti-human IgG Fcγ antibody (BioLegend, 398004) was added, and incubated at 4 ℃ in the dark for 30 min, washed for 2 times, and then detected by flow cytometry (Thermo, Attune NxT V6).

[0883] The results showed that the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) and antibody (31H4C3-VH4-EG-VL3 and 5F8B4-VH2-EG-VL3) were all combined with CDH17 overexpression engineering cell lines (CHOK1-human CDH17 cell line, Cyno_CDH17 HEK293 cell line, Rat_CDH17 HEK293 cell line, Mouse_CDH17 HEK293 cell line), and the results are shown in FIGS. 19A-19D and Table 16.

[0884] Table 16. FACS detection EC50 results of ADC and CDH17 overexpression engineering cell lines

[0885] Example 22 Pharmacodynamic test of humanized ADC on NCI-H716 mouse colorectal cancer xenograft tumor model

[0886] In this embodiment, the anti-tumor effect of the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) in animals was verified, with DXD-ADC: 31H4C3-VH4-EG-VL3-druvatikang (hereinafter referred to as hu31H4C3-DXD) and 5F8B4-VH2-EG-VL3-druvatikang (hereinafter referred to as hu5F8B4-DXD) as positive controls, and the tumor cells used were colon cancer cells NCI-H716.

[0887] The specific method is as follows: 7-8 weeks old, 18-22 g of female Balb / C nude mice (Shanghai Lingshang Biotechnology Co., Ltd.) were used, and each mouse was subcutaneously inoculated with 5x10 6 +Matrigel (1:1) tumor cells, with a volume of 0.2 mL, and the average tumor volume reached 150 mm 3The mice were randomly grouped and administered with drugs. Each group contained 6 tumor-bearing nude mice, and there were 9 groups in total, including one vehicle control group (PBS was administered every week for three consecutive weeks (QW x 3 weeks)), 6 ADC drug groups (hu31H4C3-Cpd3, 3 mg / kg (i.e., mpk) (single dose), hu31H4C3-Cpd3, 10 mg / kg (single dose), hu31H4C3-Cpd3, 10 mg / kg (QW x 3 weeks), hu5F8B4-Cpd3, 3 mg / kg (single dose), hu5F8B4-Cpd3, 10 mg / kg (single dose), and hu5F8B4-Cpd3, 10 mg / kg (QW x 3 weeks)), and two control DXD-ADC groups (31H4C3-DXD, 10 mg / kg (QW x 3 weeks) and 5F8B4-DXD 10 mg / kg (single dose)), and the administration was performed via tail vein injection. The tumor volume was measured twice a week. The tumor volume (V) was calculated as follows: V = 0.5a x b (where a and b represent the long diameter and the short diameter of the tumor, respectively). On day 30 (D30) after administration, the mice were euthanized, and the tumors were taken and weighed. The tumor volume, tumor weight, and body weight change data were analyzed, and the tumor inhibition rate was calculated. The tumor inhibition rates are shown in Table 17. 2 2 The results showed that there was no significant difference between the body weights of the mice in each group, and the body weight of the mice in each group did not change significantly during the treatment, indicating that the mice tolerated the ADC well (the results are shown in FIG. 20B); both hu31H4C3-Cpd3 and hu5F8B4-Cpd3 showed significant tumor inhibition effects at a low dose of 3 mpk (single dose), which was comparable to the tumor inhibition effects at a high dose of 10 mpk (single dose) or a high dose of 10 mpk (QW x 3 weeks), and the tumor inhibition effects at the low dose of 3 mpk were comparable to those of the control ADCs hu31H4C3-DXD and hu5F8B4-DXD at the same dose and administration frequency (the results are shown in FIG. 20A).

[0888] The results showed that there was no significant difference between the body weights of the mice in each group, and the body weight of the mice in each group did not change significantly during the treatment, indicating that the mice tolerated the ADC well (the results are shown in FIG. 20B); both hu31H4C3-Cpd3 and hu5F8B4-Cpd3 showed significant tumor inhibition effects at a low dose of 3 mpk (single dose), which was comparable to the tumor inhibition effects at a high dose of 10 mpk (single dose) or a high dose of 10 mpk (QW x 3 weeks), and the tumor inhibition effects at the low dose of 3 mpk were comparable to those of the control ADCs hu31H4C3-DXD and hu5F8B4-DXD at the same dose and administration frequency (the results are shown in FIG. 20A).

[0889] Table 17. Tumor inhibition rates of ADCs in NCI-H716 mouse models

[0890] Example 23 Pharmacodynamic detection of humanized ADCs in LS1034 mouse colorectal cancer xenograft tumor models

[0891] In this embodiment, the tumor-suppressing effect of the prepared ADC (hu31H4C3-Cpd3) in animals was verified, with DXD-ADC (hu31H4C3-DXD) as a positive control and the tumor cells used being colon cancer cells LS1034.

[0892] The specific method is as follows: Using 7-8 week old female Balb / C nude mice (Shanghai Lingchang Biotechnology Co., Ltd.) weighing 18-22g, each mouse was subcutaneously inoculated with 5×10⁵ lb / c dextrose tablets on the right side. 6 Tumor cells in a 1:1 Matrigel solution, with an inoculation volume of 0.2 mL, resulted in an average tumor volume of 150 mm². 3 Six tumor-bearing nude mice were randomly assigned to receive the drug at the time of administration. Six groups were formed, including one Vehicle control group (administered PBS weekly, single dose), four ADC drug groups (hu31H4C3-Cpd3, 1 mg / kg (mpk) single dose), hu31H4C3-Cpd3, 3 mg / kg single dose, hu31H4C3-Cpd3, 10 mg / kg single dose, and hu31H4C3-Cpd3, 30 mg / kg single dose), and one control DXD-ADC group (hu31H4C3-DXD, 10 mg / kg single dose). Administration was via tail vein injection. Tumor volume was measured twice weekly. Tumor volume (V) was calculated as: V = 0.5a × b 2 (Where a and b represent the long and short diameters of the tumor, respectively). Mice were euthanized on day 35 after drug administration, and tumors were harvested and their weight measured. The changes in tumor volume, tumor weight, and mouse body weight were analyzed to calculate the tumor inhibition rate. The tumor inhibition rate is shown in Table 18.

[0893] The experimental results showed that there was no significant difference in body weight among the groups of mice, and the body weight change of each group of mice during the treatment period was less than 10%, indicating that the mice tolerated the ADC well (the results are shown in Figure 21B). The antitumor effect of hu31H4C3-Cpd3 was dose-dependent. hu31H4C3-Cpd3 showed a significant antitumor effect at a medium dose of 3 mpk (single dose), and the antitumor effect at high doses of 10 mpk (single dose) and 30 mpk (single dose) was comparable. It was better than the antitumor effect of the control ADC (hu31H4C3-DXD) at the same dose and frequency of administration (10 mpk, single dose) (the results are shown in Figure 21A).

[0894] Table 18. Tumor inhibition rate of ADC in LS1034 mouse model

[0895] Example 24: Detection of the efficacy of humanized ADC in inhibiting SNU-5 mouse gastric cancer xenograft tumor model.

[0896] In this embodiment, the tumor-suppressing effect of the prepared ADC (hu31H4C3-Cpd3) in animals was verified, with DXD-ADC (hu31H4C3-DXD) as a positive control and SNU-5 gastric cancer cells used.

[0897] The specific method is as follows: Using 7-8 week old female NCG-severely immunodeficient mice (Shanghai Lingchang Biotechnology Co., Ltd.) weighing 18-22g, each mouse was subcutaneously injected with 5×10⁵ NCG-containing mice on its right side. 6 Tumor cells in a 1:1 Matrigel solution, with an inoculation volume of 0.2 mL, resulted in an average tumor volume of 100-150 mm². 3 Six tumor-bearing nude mice were randomly assigned to receive the drug at the time of administration. Six groups were formed, including one vehicle control group (administered PBS weekly, single dose), four ADC drug groups (hu31H4C3-Cpd3, 0.4 mg / kg, single dose), hu31H4C3-Cpd3, 2 mg / kg, single dose, and hu31H4C3-Cpd3, 10 mg / kg, single dose), one control DXD-ADC group (hu31H4C3-DXD, 10 mg / kg, single dose), and one antibody group (31H4C3-VH4-EG-VL3, 10 mg / kg, single dose). Administration was via tail vein injection. Tumor volume was measured twice weekly. Tumor volume (V) was calculated as: V = 0.5a × b 2 (Where a and b represent the long and short diameters of the tumor, respectively). Mice were euthanized on day 28 after drug administration, and tumors were harvested and their weight measured. The changes in tumor volume, tumor weight, and mouse body weight were analyzed to calculate the tumor inhibition rate. The tumor inhibition rate is shown in Table 19.

[0898] The results show that there is no significant difference in the body weight of mice in each group, and the body weight change of mice in each group is less than 10% during the treatment, indicating that the mice have good tolerance to the ADC (as shown in Figure 22B); the tumor inhibition effect of hu31H4C3-Cpd3 has a dose-dependent effect, and hu31H4C3-Cpd3 shows a significant tumor inhibition effect at a medium dose of 2mpk (single dose), and the tumor inhibition effect at a high dose of 10mpk (single dose) is improved, which is equivalent to the tumor inhibition effect of the control ADC (hu31H4C3-DXD) at the same dose and administration frequency (10mpk, single dose), while the antibody group (31H4C3-VH4-EG-VL3, 10mg / kg, single dose) has a weak tumor inhibition effect (as shown in Figure 22A).

[0899] Table 19. Tumor inhibition rate of ADC in SNU-5 mouse model

[0900] Example 25 Pharmacodynamic test of chimeric ADC on AsPC-1 mouse pancreatic cancer xenograft tumor model

[0901] In this embodiment, the tumor inhibition effect of the chimeric antibody ADC (31H4C3-DXD, 5F8B4-DXD) prepared as described in Example 15.2 in animals was verified, with Isotype-DXD as a control drug, and the tumor cells used were pancreatic cancer cells AsPC-1.

[0902] The specific method is as follows: 6-8 week old, 18-22 g weight female NCG severely immunodeficient mice (Shanghai Lingchang Biotechnology Co., Ltd.) were used, and 1×10 6 +Matrigel (1:1) tumor cells, with a volume of 0.2mL, and the average tumor volume reached 100mm 3 When the tumor volume reached 100mm, the mice were randomly divided into groups for administration. Each group had 6 tumor-bearing nude mice, and there were 6 groups in total, including one Vehicle control group (PBS was administered every week, QW*3), three ADC drug groups (31H4C3-DXD, 10mg / kg (QW*3)), 5F8B4-DXD, 10mg / kg (QW*3)), one control DXD-ADC group (Isotype-DXD, 10mg / kg (QW*3)), and three antibody groups (31H4C3, 10mg / kg (QW*3), 5F8B4, 10mg / kg (QW*3), Isotype antibody, 10mg / kg (QW*3)), and the administration method was tail vein injection, and the tumor volume was measured twice a week. The tumor volume (V) was calculated as follows: V=0.5a×b 2(Wherein a and b represent the long diameter and short diameter of the tumor, respectively). The mice were euthanized on D28 after dosing, and the tumors were taken and weighed. The tumor volume, tumor weight and body weight change data were analyzed, and the tumor inhibition rate was calculated. The tumor inhibition rates are shown in Table 20.

[0903] The results showed that there was no significant difference between the body weights of mice in each group, and the body weight change of mice in each group during treatment was less than 10%, indicating that the mice had good tolerance to the ADC (results shown in Figure 23B); 31H4C3-DXD and 5F8B4-DXD showed significant tumor inhibition effect at 10 mpk (QW*3), which was equivalent to the tumor inhibition effect of the control ADC (Isotype-DXD) at the same dose and administration frequency (10 mpk, QW*3), while the antibody group (31H4C3 10 mg / kg (QW*3), 5F8B4 10 mg / kg (QW*3), Isotype antibody 10 mg / kg (QW*3)) showed no significant tumor inhibition effect (results shown in Figure 23A).

[0904] Table 20. Tumor inhibition rate of ADC in AsPC-1 mouse model

[0905] Example 26 Plasma stability of humanized ADC

[0906] In this example, the stability of the prepared ADC (hu31H4C3-Cpd3 and hu5F8B4-Cpd3) in human plasma in vitro was verified. hu31H4C3-Cpd3 and hu5F8B4-Cpd3 were incubated in human plasma, monkey plasma, rat plasma, mouse plasma and PBS at concentrations of 20 ug / mL and 200 ug / mL at 37°C for 21 days, and LC / MS was used to detect the payload Exatecan shed during the incubation of ADC in plasma, and the approved ADC Enhertu (DS-8201, commercially available) was used as a positive control.

[0907] The results show that the hu31H4C3-Cpd3 and hu5F8B4-Cpd3 have almost the same trend of payload release rate at 20 and 200 ug / mL concentration incubated in different species (human / monkey / rat / mouse) plasma and PBS at 37°C for 21 days: the release rate in human, monkey, rat plasma is equivalent to the negative control PBS, no more than 0.5%; in balb / c nude mouse plasma, the release rate is significantly higher than PBS, the release rate is 1.7%. The specific results are shown in Figures 24A-24D. At D21, the release rate of 20 ug / mL hu31H4C3-Cpd3 in human, monkey, rat, mouse, PBS is 0.34%, 0.21%, 0.26%, 1.74% and 0.13% respectively (Figure 24A); the release rate of 200 ug / mL hu31H4C3-Cpd3 in human, monkey, rat, mouse, PBS is 0.432%, 0.265%, 0.309%, 1.64% and 0.317% respectively (Figure 24B). At D21, the release rate of 20 ug / mL 5F8B4-Cpd3 in human, monkey, rat, mouse, PBS is 0.225%, 0.155%, 0.210%, 1.279% and 0.0769% respectively (Figure 24C); the release rate of 200 ug / mL 5F8B4-Cpd3 in human, monkey, rat, mouse, PBS is 0.229%, 0.202%, 0.266%, 1.655% and 0.232% respectively (Figure 24D). While the positive control DS-8201 at a concentration of 100 ug / mL incubated in human plasma, monkey plasma, rat plasma, mouse plasma and PBS at 37°C for 21 days, the release rate of DXD in human plasma is more than 3%, in monkey plasma the release rate is more than 2%, in rat plasma the release rate is about 1%, in mouse plasma the release rate is about 0.7%. The results show that hu31H4C3-Cpd3 and hu5F8B4-Cpd3 have better stability.

[0908] SEQUENCE LISTING

Claims

1. An anti-CDH17 antibody or antigen-binding fragment thereof that specifically binds CDH17, comprising heavy chain complementarity determining regions (HCDRs) and / or light chain complementarity determining regions (LCDRs) selected from the group consisting of: (a) the CDRs of the following 3 heavy chain variable regions (VH): (i) a HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 1; (ii) a HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 2; (iii) a HCDR3 having the sequence set forth in SEQ ID NO: 4, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 4; and the CDRs of the following 3 light chain variable regions (VL): (i) a LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 10; (ii) a LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 11; (iii) a LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 12; or, (b) the CDRs of the following 3 heavy chain variable regions (VH): (i) a HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 1; (ii) a HCDR2 having the sequence set forth in SEQ ID NO: 6, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 6; (iii) a HCDR3 having the sequence set forth in SEQ ID NO: 8, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 8; and the CDRs of the following 3 light chain variable regions (VL): (i) a LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 10; (ii) a LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO: 11; (iii) a LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence with one or more (e.g., 1, 2, or 3) amino acid substitutions, deletions, or additions compared to the sequence of SEQ ID NO:

12. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 1; (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 2; (iii) HCDR3 having the sequence set forth in SEQ ID NO: 3, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 3; and the CDRs of three light chain variable regions (VL) of: (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 10; (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 11; (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 12; or, (d) the CDRs of three heavy chain variable regions (VH) of: (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 1; (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 2; (iii) HCDR3 having the sequence set forth in SEQ ID NO: 3, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to the sequence set forth in SEQ ID NO: 3; ​ ​ (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 1; (ii) HCDR2 having the sequence set forth in SEQ ID NO: 2, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 2; (iii) HCDR3 having the sequence set forth in SEQ ID NO: 5, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 5; and the CDRs of three light chain variable regions (VL) as follows: (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 10; (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 11; (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 12; or, (e) the CDRs of three heavy chain variable regions (VH) as follows: (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 1; (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 6; (iii) HCDR3 having the sequence set forth in SEQ ID NO: 7, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 7; the CDRs of three light chain variable regions (VL) as follows: (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 10; (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 11; (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 12; (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 11; (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 12; or, (f) the CDRs of the following 3 heavy chain variable regions (VH): (i) HCDR1 having the sequence set forth in SEQ ID NO: 1, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 1; (ii) HCDR2 having the sequence set forth in SEQ ID NO: 6, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 6; (iii) HCDR3 having the sequence set forth in SEQ ID NO: 9, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 9; and the CDRs of the following 3 light chain variable regions (VL): (i) LCDR1 having the sequence set forth in SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 10; (ii) LCDR2 having the sequence set forth in SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 11; (iii) LCDR3 having the sequence set forth in SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions or additions (e.g., 1, 2, or 3 substitutions, deletions, or additions) compared to that of SEQ ID NO: 12; or the antibody or antigen-binding fragment thereof comprises the following complementarity determining regions: (a) 1) CDRs determined according to the Kabat definition: HCDR1 having the sequence set forth in SEQ ID NO: 1; HCDR2 having the sequence set forth in SEQ ID NO: 2; HCDR3 having the sequence set forth in SEQ ID NO: 4; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; 2) CDRs determined according to the IMGT definition: HCDR1 having the sequence set forth in SEQ ID NO: 73; HCDR2 having the sequence set forth in SEQ ID NO: 74; HCDR3 having the sequence set forth in SEQ ID NO: 82; LCDR1 having the sequence set forth in SEQ ID NO: 76; LCDR2 having the sequence set forth in SEQ ID NO: 77; LCDR3 having the sequence set forth in SEQ ID NO: 12; 3) CDRs determined according to the Chothia definition HCDR1 having the sequence set forth in SEQ ID NO: 78; HCDR2 having the sequence set forth in SEQ ID NO: 79; HCDR3 having the sequence set forth in SEQ ID NO: 3; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or, 4) CDRs determined according to the AbM definition HCDR1 having the sequence set forth in SEQ ID NO: 80; HCDR2 having the sequence set forth in SEQ ID NO: 81; HCDR3 having the sequence set forth in SEQ ID NO: 3; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or (b) 1) CDRs determined according to the Kabat definition HCDR1 having the sequence set forth in SEQ ID NO: 1; HCDR2 having the sequence set forth in SEQ ID NO: 6; HCDR3 having the sequence set forth in SEQ ID NO: 8; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; 2) CDRs determined according to the IMGT definition HCDR1 having the sequence set forth in SEQ ID NO: 73; HCDR2 having the sequence set forth in SEQ ID NO: 74; HCDR3 having the sequence set forth in SEQ ID NO: 75; LCDR1 having the sequence set forth in SEQ ID NO: 76; LCDR2 having the sequence set forth in SEQ ID NO: 77; LCDR3 having the sequence set forth in SEQ ID NO: 12; 3) CDRs determined according to the Chothia definition HCDR1 having the sequence set forth in SEQ ID NO: 78; HCDR2 having the sequence set forth in SEQ ID NO: 79; HCDR3 having the sequence set forth in SEQ ID NO: 7; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or, 4) CDRs determined according to the AbM definition HCDR1 having the sequence set forth in SEQ ID NO: 80; HCDR2 having the sequence set forth in SEQ ID NO: 81; HCDR3 having the sequence set forth in SEQ ID NO: 7; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or, HCDR1 having the sequence set forth in SEQ ID NO: 1; (c) HCDR2 having the sequence set forth in SEQ ID NO: 2; HCDR3 having the sequence set forth in SEQ ID NO: 3; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or, HCDR1 having the sequence set forth in SEQ ID NO: 1; (d) HCDR2 having the sequence set forth in SEQ ID NO: 2; HCDR3 having the sequence set forth in SEQ ID NO: 5; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or, HCDR1 having the sequence set forth in SEQ ID NO: 1; (e) HCDR2 having the sequence set forth in SEQ ID NO: 6; HCDR3 having the sequence set forth in SEQ ID NO: 7; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO: 12; or, HCDR1 having the sequence set forth in SEQ ID NO: 1; (f) HCDR2 having the sequence set forth in SEQ ID NO: 6; HCDR3 having the sequence set forth in SEQ ID NO: 9; LCDR1 having the sequence set forth in SEQ ID NO: 10; LCDR2 having the sequence set forth in SEQ ID NO: 11; LCDR3 having the sequence set forth in SEQ ID NO:

12. ​ 2. The anti-CDH 17 antibody or antigen-binding fragment thereof of claim 1, comprising a heavy chain variable region (VH) and a light chain variable region (VL), wherein: (a) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 31, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more identical to the amino acid sequence of SEQ ID NO: 31, or consists of SEQ ID NO: 31; and the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (b) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 35, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more identical to the amino acid sequence of SEQ ID NO: 35, or consists of SEQ ID NO: 35; and the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (c) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 18, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or more identical to the amino acid sequence of SEQ ID NO: 18, or consists of SEQ ID NO: 18; and the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or more identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO:

37. ​ ​ ​ (d) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 23, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 23, or consists of SEQ ID NO: 23; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37; (e) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 19, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 19, or consists of SEQ ID NO: 19; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37; (f) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 20, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 20, or consists of SEQ ID NO: 20; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37; (g) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38; (h) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39; (i) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (j) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41; (k) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42; (l) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43; (m) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 21, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 21, or consists of SEQ ID NO: 21; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44; (n) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38; (o) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39; (p) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (q) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41; (r) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42; (s) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43; (t) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 22, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 22, or consists of SEQ ID NO: 22; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44; (u) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 25, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 25, or consists of SEQ ID NO: 25; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37; (v) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 26, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 26, or consists of SEQ ID NO: 26; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 37, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 37, or consists of SEQ ID NO: 37; (w) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38; (x) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39; (y) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (z) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41; (aa) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42; (bb) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43; (cc) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 27, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 27, or consists of SEQ ID NO: 27; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44; (dd) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38; (ee) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 39, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 39, or consists of SEQ ID NO: 39; (ff) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (gg) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41; (hh) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42; (ii) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43; (jj) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 28, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 28, or consists of SEQ ID NO: 28; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 44, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 44, or consists of SEQ ID NO: 44; (kk) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 29, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 29, or consists of SEQ ID NO: 29; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41; (ll) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 30, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 30, or consists of SEQ ID NO: 30; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 41, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 41, or consists of SEQ ID NO: 41; (mm) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 31, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to the amino acid sequence of SEQ ID NO: 31, or consists of SEQ ID NO: 31; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 42, or an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to the amino acid sequence of SEQ ID NO: 42, or consists of SEQ ID NO: 42; (nn) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 31, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to the amino acid sequence of SEQ ID NO: 31, or consists of SEQ ID NO: 31; and / or the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 43, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to the amino acid sequence of SEQ ID NO: 43, or consists of SEQ ID NO: 43; (oo) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 32, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 32, or consists of SEQ ID NO: 32; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (pp) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 33, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 33, or consists of SEQ ID NO: 33; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identical to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (qq) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 34, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 34, or consists of SEQ ID NO: 34; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO: 40; (rr) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 35, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 35, or consists of SEQ ID NO: 35; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38; (ss) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 36, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 36, or consists of SEQ ID NO: 36; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 38, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 38, or consists of SEQ ID NO: 38; (tt) the heavy chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 36, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 36, or consists of SEQ ID NO: 36; the light chain variable region comprises an amino acid sequence as set forth in SEQ ID NO: 40, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more identity to the amino acid sequence of SEQ ID NO: 40, or consists of SEQ ID NO:

40.

3. The anti-CDHl 7 antibody or antigen-binding fragment thereof of claim 1 or 2, which is a murine, chimeric, or humanized antibody.

4. The anti-CDHl 7 antibody or antigen-binding fragment thereof of any one of claims 1-3, which further comprises a heavy chain constant region of a human immunoglobulin or a variant thereof, and a light chain constant region or a variant thereof, wherein the variant has one or more substitutions, deletions, or additions of amino acids (e.g., up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions; e.g., 1, 2, 3, 4, or 5 amino acid substitutions, deletions, or additions) as compared to the wild-type sequence from which it is derived; optionally, the heavy chain constant region is an IgG heavy chain constant region, e.g., an IgGl, IgG2, IgG3, or IgG4 heavy chain constant region; the light chain constant region is selected from a kappa or lambda light chain constant region.

5. The anti-CDHl 7 antibody or antigen-binding fragment thereof of any one of claims 1-4, which is selected from a Fab, Fab'-SH, Fv, scFv, or (Fab')2 fragment.

6. The anti-CDH 17 antibody or antigen-binding fragment thereof of any one of claims 1-5, wherein the antibody or antigen-binding fragment thereof binds CDH 17 with an affinity of about 1 x 10 -7 M or lower.

7. The anti-CDHl 7 antibody or antigen-binding fragment thereof of any one of claims 1-6, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain, wherein: (a) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 57, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 57, or consisting of SEQ ID NO: 57, and the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 66, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 66, or consisting of SEQ ID NO: 66; (b) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 61, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 61, or consisting of SEQ ID NO: 61, and the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 66, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 66, or consisting of SEQ ID NO: 66; (c) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 45, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 45, or consists of SEQ ID NO: 45, and the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 63, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 63, or consists of SEQ ID NO: 63; or (d) the heavy chain comprises an amino acid sequence as set forth in SEQ ID NO: 50, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 50, or consists of SEQ ID NO: 50, and the light chain comprises an amino acid sequence as set forth in SEQ ID NO: 63, or an amino acid sequence that has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more sequence identity to the amino acid sequence of SEQ ID NO: 63, or consists of SEQ ID NO:

63.

8. An isolated nucleotide molecule encoding the anti-CDH17 antibody or antigen binding fragment thereof, or the heavy chain variable region and / or light chain variable region thereof, of any one of claims 1-7.

9. An expression vector comprising the nucleotide molecule of claim 8.

10. A host cell comprising the nucleotide molecule of claim 8 or the expression vector of claim 9.

11. An antibody drug conjugate targeting CDH17, isomers thereof, pharmaceutically acceptable salts thereof, or mixtures thereof, as described by Formula (I): Ab-(L-D)m [Formula (I)] wherein, Ab is an anti-CDH17 antibody or antigen binding fragment thereof as described by any one of claims 1-7; L is a linker unit; D is a small molecule drug having cytotoxicity; and m is the average number of L-D units conjugated to Ab, and m is selected from 1-10, preferably 2-8. D is a monomethyl auristatin, a camptothecin, or a maytansinoid; the monomethyl auristatin can be monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF); the camptothecin derivative can be exatecan, Dxd, Exd, SN-38; the maytansinoid can be DM1, DM3, or DM4; the antibody drug conjugate comprises a plurality of D components, which can be a combination of different therapeutically active substances or pharmaceutically active components, or a combination of the same therapeutically active substance or pharmaceutically active component; and D is a monomethyl auristatin, a camptothecin, or a maytansinoid; the monomethyl auristatin can be monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF); the camptothecin derivative can be exatecan, Dxd, Exd, SN-38; the maytansinoid can be DM1, DM3, or DM4; the antibody drug conjugate comprises a plurality of D components, which can be a combination of different therapeutically active substances or pharmaceutically active components, or a combination of the same therapeutically active substance or pharmaceutically active component; and ​ ​ ​ ​ 12. The antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or a mixture thereof of claim 11, wherein, ​ and / or, the L is a combination of one or more L's, wherein the L' is selected from the group consisting of carbonyl, amino, amido, aminoacyl, -(PEG) n -, n -, n -, -(C≡C)-, -(CH=CH)-, -0-, -S-, maleimido (mc), maleimidopropionyl (MP), methylsulfonylpyrimidinyl, valine-citrulline (val-cit), valine-alanine (val-ala), N-succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC), alanine-phenylalanine (ala-phe), phenylalanine-lysine (phe-lys), p-aminobenzyloxy carbonyl (PAB), dimethyl ethylenediamine (DMED), N-succinimidyl 4-(2-pyridylthio)valerate (SPP), N-succinimidyl 4-(N-maleimidomethyl)-cyclohexane-1-carboxylate (SMCC), N-succinimidyl (4-iodo-acetyl) aminobenzoate (SIAB), N-succinimidyl-4-(2-pyridyl disulfide) butyrate (SPDB), N-succinimidyl 3-(pyridine-2-yl dithio)-propionate (SPDP), glycine-glycine-phenylalanine-glycine (GGFG), acetyl-lysine-valine-citrulline-p-aminobenzyloxy carbonyl (AcLys-vc-PABC); the n is independently selected from an integer from 1 to 20; and / or, said L can be J-L1-L2-X-L3; said J is selected from L1is selected from the group consisting of a single bond, -(PEG) n - or -(CH2) n -, said -(CH2) n - can optionally contain 1 to 6 heteroatoms selected from N, O, S; wherein n is independently selected from an integer between 1 and 20; L2is selected from the group consisting of a single bond, -O-, -S-, -CH2-, -NH-, -C(O)- in combination of one or more; wherein said -CH2- and -NH- can optionally be substituted 1 to 3 times with C 1～6 alkyl or halogen; X is selected from a single bond or a combination of 1 to 4 X', said X' is independently selected from an amino acid; L3is selected from the group consisting of a single bond, -O-, -S-, -CH2-, -NH-, -C(O)-, -phenyl-, -cyclopropyl-, -cyclobutyl-, -cyclohexyl- in combination of one or more; wherein said -CH2-, -NH-, -phenyl-, -cyclopropyl-, -cyclobutyl-, -cyclohexyl- can optionally be substituted 1 to 3 times with C 1～6 alkyl, halogen, cyano or hydroxyl.

13. The antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or a mixture thereof of claim 11, wherein the moiety (L-D) has a structure represented by Formula Cpd3, Formula Cpd5, Formula Cpd6, DXD:

14. The antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or a mixture thereof of claim 11 or 13, wherein the (L-D) moiety is linked by a thio pyrimidine structure formation with a sulfhydryl group on Ab, the antibody drug conjugate having a structure as shown in Formula (I-C3), Formula (I-C5), Formula (I-C6), or Formula (I-DXD): Formula (I-C3) Formula (I-C5) Formula (I-C6) Formula (I-DXD) wherein m is the average number of attachments, and m is independently selected from 1-10; Ab is the anti-CDH17 antibody or antigen-binding fragment thereof of any one of claims 1-7.

15. A composition comprising the antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or mixture thereof of any one of claims 11-14, wherein the molar ratio of D to Ab (DAR value) in the composition is a fraction or an integer between 1-10.

16. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-7, the antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or mixture thereof of any one of claims 11-14, or the composition of claim 15; and a pharmaceutically acceptable excipient.

17. Use of the antibody or antigen-binding fragment thereof of any one of claims 1-7, the antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or mixture thereof of any one of claims 11-14, the composition of claim 15, or the pharmaceutical composition of claim 16 in the manufacture of a medicament for treating and / or preventing a CDH17-mediated disease or disorder.

18. A method of treating and / or preventing a CDH17-mediated disease or disorder, comprising administering to a subject in need thereof the antibody or antigen-binding fragment thereof of any one of claims 1-7, the antibody drug conjugate, isomer thereof, pharmaceutically acceptable salt thereof, or mixture thereof of any one of claims 11-14, the composition of claim 15, or the pharmaceutical composition of claim 16.

19. A method of diagnosing whether a subject is afflicted with a CDH17-mediated disease or disorder, comprising: (a) using the anti-CDH17 antibody or antigen-binding fragment thereof of any one of claims 1-7, or using the detection system of claim 20, to determine the amount of CDH17 expression in a sample from a subject; and (b) comparing the amount of CDH17 expression determined in step (a) to (i) a pre-defined value for CDH17 expression; (ii) the amount of CDH17 expression determined in a control from a healthy subject, or (iii) the amount of CDH17 expression determined in a sample obtained from the same source or subject at a previous time point, wherein the subject is diagnosed as suffering from a CDH17-mediated disease or disorder when the amount of CDH17 expression determined in step (a) is higher than the amount of CDH17 expression in (i), (ii), or (iii).

20. The use or method of any one of claims 17-19, wherein the CDH17-mediated disease or disorder is a cancer and / or tumor associated with abnormal expression of CDH17, optionally, the cancer and / or tumor associated with abnormal expression of CDH17 is a solid tumor, for example, the solid tumor includes, but is not limited to, colorectal cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gallbladder cancer, pancreatic cancer, small intestine cancer, liver cancer, neuroendocrine tumor or cancer, bladder cancer, breast cancer, head and neck cancer, endometrial cancer, kidney cancer, liver cancer, lung cancer, prostate cancer, thyroid cancer, melanoma, ovarian cancer, gastrointestinal stromal tumor.

21. A detection system comprising the anti-CDH17 antibody or antigen-binding fragment thereof of any one of claims 1-7.

22. A method of detecting the presence of or determining the level of CDH17 in a sample comprising: (a) contacting the sample with the anti-CDH17 antibody or antigen-binding fragment thereof of any one of claims 1-7, and (b) detecting the formation of or determining the amount of an immunocomplex between the anti-CDH17 antibody or antigen-binding fragment thereof and CDH17 in the sample to detect the presence of or determine the level of CDH17 in the sample; wherein the sample is a solid tissue sample or a liquid tissue sample.

23. Use of the anti-CDH17 antibody and antigen-binding fragment thereof of any one of claims 1-7 in the detection system of claim 20 and the detection method of claim 21.

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