CDH17-targeting antibody and ADC and use thereof

Abstract

The present application relates to the field of antibody drugs. Specifically, the present application relates to an antibody that specifically recognizes CDH17 and a corresponding ADC targeting CDH17. In addition, the present invention also relates to the therapeutic use of the antibody or ADC.

Description

Antibodies and ADCs targeting CDH17 and uses thereof TECHNICAL FIELD

[0001] The present application relates to the field of antibody drugs, in particular, the present application relates to antibodies specifically recognizing CDH17 and corresponding ADCs targeting CDH17. Furthermore, the present application also relates to the therapeutic use of these antibodies or ADCs. BACKGROUND

[0002] Cadherins, also known as calcium-dependent cell-cell adhesion glycoproteins, are a superfamily of Ca2+-dependent cell adhesion molecules that play a key role in maintaining cell recognition, tissue structure, and morphology. Cadherin-17 (CDH17), also known as liver-intestine cadherin (LI-cadherin), is a new member of the cadherin family expressed in liver and small intestine, which is structurally different from the classic cadherin and belongs to the non-classical 7D cadherin family. CDH17 has a long extracellular region containing seven cadherin domains and a short intracellular region that transduces signals by directly binding to intracellular scaffolding proteins. Its function is to maintain the integrity of epithelial tissues as a polypeptide transporter and cell adhesion molecule, and plays an important role in cell growth and development. CDH17 is expressed in rat liver and small intestine, but not in human normal liver tissue. Under physiological conditions, CDH17 is expressed in normal human small intestinal epithelial cells and some pancreatic duct cells, and is only located and limited to the lateral membrane of the tight junction between intestinal epithelial cells, but not expressed on the apical or basal surface. In contrast, in tumor cells, CDH17 is expressed on the surface of tumor cells due to the lack of polarity. Studies have found that CDH17 is expressed to varying degrees in gastric cancer, colorectal cancer, neuroendocrine cancer, esophageal cancer, cholangiocarcinoma, pancreatic cancer, and liver cancer. Studies have shown that CDH17 is highly expressed in highly differentiated late-stage tumors, but rarely expressed in poorly differentiated tumors, so CDH17 is often used as an immunohistochemical marker for diagnosing digestive system adenocarcinoma in clinic. Abnormal expression of CDH17 can mediate Wnt / β-catenin and MAPK signaling pathways and inhibit apoptosis. At the same time, CDH17 can bind to integrin molecules such as Integrin α2β1 to initiate cell adhesion signals (FAK, Ras, ERK1 / 2, cyclin activation) to promote cell adhesion and proliferation.

[0003] Gastrointestinal (GI) cancers account for approximately 28% of all cancers worldwide and are increasing at a compound annual growth rate of 2%. Due to the heterogeneity of the patient population and different molecular subtypes, current treatment options remain very limited or often ineffective. Therefore, improving early detection rates, biomarkers for monitoring disease progression, and developing low-toxic and effective treatment methods are still challenges and urgent problems in the treatment of gastrointestinal cancers. CDH17 is widely expressed in gastrointestinal cancer (GI), expressed in more than 50% of gastric cancer, 90%-95% of colorectal cancer, 53% of cholangiocarcinoma, 50% of pancreatic cancer and part of liver cancer. At the same time, CDH17 expression is associated with the prognosis of various solid tumors. In gastric and colorectal cancer patients, high expression of CDH17 is associated with shorter survival and disease progression, and is associated with CDH17 level (IHC = 3+ / IHC = 2+ / IHC = 1+). The high expression of CDH17 in tumor tissues makes it a potential therapeutic target and molecular marker for GI tumors.

[0004] Currently, the development of CDH17 targeted therapy drugs is still in the early stage, and the development of CDH17 ADC drugs in the field of gastrointestinal tumor treatment is also in the early stage. Obviously, in the field of gastrointestinal tumor treatment, there is still an urgent need to develop new antibody and ADC drugs targeting the effective biomarker CDH17 to meet the clinical needs of a large number of gastrointestinal tumor patients. The present application meets this need to some extent. SUMMARY

[0005] The present application provides anti-CDH17 antibodies with high selectivity and high biological activity, and ADCs generated by conjugating the antibodies with therapeutic active substances or pharmaceutically active ingredients (such as camptothecin compounds), thereby overcoming drug resistance, increasing the therapeutic window, and benefiting more patients.

[0006] In a first aspect, the present application provides antibodies and antigen-binding fragments thereof targeting CDH17, which have the following advantages:

[0007] (1) high affinity binding to human CDH17;

[0008] (2) cross-reactivity with monkey CDH17;

[0009] (3) no binding to other members of the cadherin family;

[0010] (4) excellent binding, internalization and killing activity to CDH17-expressing cells.

[0011] In some embodiments, the present application provides anti-CDH17 antibodies and antigen-binding fragments thereof that specifically bind to CDH17, which comprise:

[0012] 1) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 25, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 26;

[0013] 2) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 27, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 28;

[0014] 3) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 29, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 30;

[0015] 4) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 31, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 32;

[0016] 5) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 33, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 34;

[0017] 6) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 33, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 35;

[0018] 7) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 36, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 35;

[0019] 8) HCDR1, HCDR2, HCDR3 comprised by a heavy chain variable region as depicted in SEQ ID NO: 36, and / or LCDR1, LCDR2, LCDR3 comprised by a light chain variable region as depicted in SEQ ID NO: 37;

[0020] 9) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38;

[0021] 10) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39;

[0022] 11) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40;

[0023] 12) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41;

[0024] 13) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37;

[0025] 14) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38;

[0026] 15) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39;

[0027] 16) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40;

[0028] 17) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41;

[0029] 18) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:44;

[0030] 19) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45;

[0031] 20) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45;

[0032] 21) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:47;

[0033] 22) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:48;

[0034] 23) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49;

[0035] 24) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45; or

[0036] 25) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49.

[0037] In some embodiments, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, comprising:

[0038] 1) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:25, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:26, wherein the CDRs are shown in bold underline.

[0039] 2) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:27, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:28, wherein the CDRs are shown in bold underline.

[0040] 3) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:29, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:30, wherein the CDRs are shown in bold underline.

[0041] 4) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:31, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:32, wherein the CDRs are shown in bold underline.

[0042] 5) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:33, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:35, wherein the CDRs are shown in bold underline.

[0043] 6) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:35, wherein the CDRs are shown in bold underline;

[0044] 7) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37, wherein the CDRs are shown in bold underline.

[0045] 8) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38, wherein the CDRs are shown in bold underline.

[0046] 9) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39, wherein the CDRs are shown in bold underline.

[0047] 10) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40, wherein the CDRs are shown in bold underline.

[0048] 11) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41, wherein the CDRs are shown in bold underline.

[0049] 12) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37, wherein the CDRs are shown in bold underline.

[0050] 13) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38, wherein the CDRs are shown in bold underline.

[0051] 14) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39, wherein the CDRs are shown in bold underline.

[0052] 15) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40, wherein the CDRs are shown in bold underline.

[0053] 16) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41, wherein the CDRs are shown in bold underline.

[0054] 17) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45, wherein the CDRs are shown in bold underline.

[0055] 18) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45, wherein the CDRs are shown in bold underline.

[0056] 19) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:47, wherein the CDRs are shown in bold underline.

[0057] 20) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:48, wherein the CDRs are shown in bold underline.

[0058] 21) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49, wherein the CDRs are shown in bold underline.

[0059] 22) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45, wherein the CDRs are shown in bold underline; or

[0060] 23) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49.

[0061] In some embodiments, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, comprising:

[0062] 1) Contains or is composed of HCDR1 as shown in SEQ ID NO:57;

[0063] Contains or consists of HCDR2 as shown in SEQ ID NO:60;

[0064] Contains or is composed of HCDR3 as shown in SEQ ID NO:61;

[0065] It includes or is composed of LCDR1 as shown in SEQ ID NO:79;

[0066] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0067] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0068] 2) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0069] Contains or consists of HCDR2 as shown in SEQ ID NO:63;

[0070] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0071] It includes or is composed of LCDR1 as shown in SEQ ID NO:82;

[0072] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0073] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0074] 3) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0075] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0076] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0077] It includes or is composed of LCDR1 as shown in SEQ ID NO:83;

[0078] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0079] Contains or is composed of LCDR3 as shown in SEQ ID NO:85;

[0080] 4) Contains or is composed of HCDR1 as shown in SEQ ID NO:57;

[0081] Contains or consists of HCDR2 as shown in SEQ ID NO:68;

[0082] Contains or is composed of HCDR3 as shown in SEQ ID NO:61;

[0083] It includes or is composed of LCDR1 as shown in SEQ ID NO:86;

[0084] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0085] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0086] 5) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0087] Contains or consists of HCDR2 as shown in SEQ ID NO:63;

[0088] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0089] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0090] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0091] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0092] 6) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0093] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0094] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0095] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0096] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0097] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0098] 7) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0099] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0100] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0101] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0102] Contains or is composed of LCDR2 as shown in SEQ ID NO:88; and

[0103] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0104] 8) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0105] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0106] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0107] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0108] Contains or is composed of LCDR2 as shown in SEQ ID NO:89; and

[0109] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0110] 9) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0111] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0112] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0113] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0114] Contains or is composed of LCDR2 as shown in SEQ ID NO:90; and

[0115] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0116] 10) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0117] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0118] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0119] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0120] Contains or is composed of LCDR2 as shown in SEQ ID NO:91; and

[0121] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0122] 11) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0123] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0124] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0125] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0126] Contains or is composed of LCDR2 as shown in SEQ ID NO:92; and

[0127] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0128] 12) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0129] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0130] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0131] It includes or is composed of LCDR1 as shown in SEQ ID NO:83;

[0132] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0133] Contains or is composed of LCDR3 as shown in SEQ ID NO:85;

[0134] 13) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0135] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0136] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0137] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0138] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0139] Contains or is composed of LCDR3 as shown in SEQ ID NO:85;

[0140] 14) Contains or consists of HCDR1 as shown in SEQ ID NO:65;

[0141] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0142] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0143] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0144] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0145] Contains or is composed of LCDR3 as shown in SEQ ID NO:94;

[0146] 15) Contains or consists of HCDR1 as shown in SEQ ID NO:65;

[0147] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0148] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0149] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0150] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0151] Contains or is composed of LCDR3 as shown in SEQ ID NO:95;

[0152] or

[0153] 16) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0154] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0155] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0156] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0157] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0158] It contains or is composed of LCDR3 as shown in SEQ ID NO:96.

[0159] In some embodiments, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, which includes a heavy chain variable region, wherein:

[0160] 1) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 25, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 25, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 25, or is composed of SEQ ID NO: 25;

[0161] 2) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 27, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 27, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 27, or is composed of SEQ ID NO: 27;

[0162] 3) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 29, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 29, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 29, or is composed of SEQ ID NO: 29;

[0163] 4) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 31, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 31, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 31, or is composed of SEQ ID NO: 31;

[0164] 5) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33;

[0165] 6) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36;

[0166] 7) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42;

[0167] 8) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43;

[0168] 9) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46;

[0169] 10) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO: 50.

[0170] In some embodiments, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, which includes a light chain variable region, wherein:

[0171] 1) The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 26, a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions or insertions, or any combination thereof, relative to SEQ ID NO: 26, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identity with the amino acid sequence of SEQ ID NO: 26, or is composed of SEQ ID NO: 26;

[0172] 2) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 28, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 28, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 28, or is composed of SEQ ID NO: 28;

[0173] 3) The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 30, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 30, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 30, or is composed of SEQ ID NO: 30; or

[0174] 4) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 32, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 32, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 32, or is composed of SEQ ID NO: 32;

[0175] 5) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 34, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 34, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 34, or is composed of SEQ ID NO: 34;

[0176] 6) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35;

[0177] 7) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37;

[0178] 8) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38;

[0179] 9) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39;

[0180] 10) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40;

[0181] 11) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41;

[0182] 12) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 44, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 44, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 44, or is composed of SEQ ID NO: 44;

[0183] 13) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45;

[0184] 14) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 47, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 47, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 47, or is composed of SEQ ID NO: 47;

[0185] 15) The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 48, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 48, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 48, or is composed of SEQ ID NO: 48; or

[0186] 16) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO: 49.

[0187] In other embodiments, the present invention provides anti-CDH17 antibodies that specifically bind to CDH17 and their antigen-binding fragments, comprising a heavy chain variable region and a light chain variable region, wherein:

[0188] 1) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 25, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 25, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 25, or is composed of SEQ ID NO: 25; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 26, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 26, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 26, or is composed of SEQ ID NO: 26;

[0189] 2) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 27, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 27, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 27, or is composed of SEQ ID NO: 27; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 28, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 28, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 28, or is composed of SEQ ID NO: 28;

[0190] 3) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 29, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 29, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 29, or is composed of SEQ ID NO: 29; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 30, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 30, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 30, or is composed of SEQ ID NO: 30; or

[0191] 4) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 31, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 31, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 31, or is composed of SEQ ID NO: 31; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 32, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 32, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 32, or is composed of SEQ ID NO: 32;

[0192] 5) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 34, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 34, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 34, or is composed of SEQ ID NO: 34;

[0193] 6) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35;

[0194] 7) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35;

[0195] 8) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37;

[0196] 9) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38;

[0197] 10) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39;

[0198] 11) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40;

[0199] 12) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41;

[0200] 13) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37;

[0201] 14) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38;

[0202] 15) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39;

[0203] 16) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40;

[0204] 17) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41;

[0205] 18) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 44, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 44, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 44, or is composed of SEQ ID NO: 44;

[0206] 19) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45;

[0207] 20) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45;

[0208] 21) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 47, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 47, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 47, or is composed of SEQ ID NO: 47;

[0209] 22) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 48, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 48, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 48, or is composed of SEQ ID NO: 48;

[0210] 23) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO: 49;

[0211] 24) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO: 50; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45; or

[0212] 25) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO: 50. The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO: 49.

[0213] In some embodiments, the antibody or its antigen-binding fragment further comprises a heavy chain and / or light chain constant region sequence derived from a human antibody germline common sequence. The light chain constant region is preferably a human κ or λ chain constant region. The heavy chain constant region can be a γ, μ, α, δ, or ε chain, and in some embodiments, the heavy chain constant region is preferably derived from the constant region sequence of human IgG1, IgG2, IgG3, or IgG4. In some embodiments, the light chain constant region comprises, or is composed of, the sequence shown in SEQ ID NO: 16. In other embodiments, the heavy chain constant region comprises the sequence shown in SEQ ID NO: 14 or 15.

[0214] It should be understood that sequence variants of these constant region structural domains may also be used, for example, to contain one or more amino acid modifications, wherein the amino acid sites are identified by the EU indexing system of Kabat et al. (1991).

[0215] In one specific embodiment, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, comprising a heavy chain, wherein:

[0216] 1) The heavy chain comprises the heavy chain variable region as described above and the heavy chain constant region sequence shown in SEQ ID NO: 14; or

[0217] 2) The heavy chain comprises the heavy chain variable region as described above and the heavy chain constant region sequence shown in SEQ ID NO: 15.

[0218] In one specific embodiment, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, which comprises a light chain, wherein the light chain comprises a light chain variable region as described above and a light chain constant region sequence as shown in SEQ ID NO: 16.

[0219] In one specific embodiment, the present invention provides an anti-CDH17 antibody that specifically binds to CDH17 and its antigen-binding fragment, comprising a heavy chain and a light chain, wherein the heavy chain is composed of either the variable region of the heavy chain described above combined with SEQ ID NO: 14, or the variable region of the heavy chain described above combined with SEQ ID NO: 15, and the light chain is composed of either the variable region of the light chain described above combined with SEQ ID NO: 16.

[0220] In some embodiments of the antibody described above, the antibody is monoclonal.

[0221] In some embodiments of the antibody mentioned above, the antibody is a full-length antibody.

[0222] In some embodiments, the anti-CDH17 antibody of the present invention is a complete antibody, such as IgG1, IgG2, IgG3, or IgG4 antibody. In other embodiments, the anti-CDH17 antibody of the present invention only covers its antigen-binding portion, such as Fab, Fab'-SH, Fv, scFv, or (Fab')2 fragment.

[0223] Secondly, the present invention provides an antibody-drug conjugate (ADC) targeting CDH17, which has the following advantages:

[0224] (1) It binds to target cells expressing human CDH17 and has a high affinity for them;

[0225] (2) Excellent physical and chemical properties;

[0226] (3) Overcoming drug resistance;

[0227] (4) Excellent in vivo antitumor activity and safety.

[0228] In some embodiments, the present invention provides an antibody-drug conjugate or a salt thereof, the antibody-drug conjugate comprising any of the above-described anti-CDH17 antibodies that specifically bind to CDH17 or an antigen-binding fragment thereof and a drug conjugated thereto, wherein the drug is a therapeutically active substance or a pharmaceutically active ingredient.

[0229] In some embodiments, the present invention provides an antibody-drug conjugate targeting CDH17, which has Ab-(LD) m The structure, wherein:

[0230] Ab is the anti-CDH17 antibody or its antigen-binding fragment as described in the first aspect of the present invention.

[0231] L stands for connector.

[0232] D represents a therapeutically active substance or a pharmaceutically active ingredient.

[0233] m represents the number of LDs connected to Ab, for example m = 1-20, such as 1-10, 1-8, 3-8, 4-8 or 6-8.

[0234] In one specific embodiment, the therapeutically active substance or pharmaceutically active ingredient is a cytotoxin, phytotoxin, small molecule toxin, radioactive isotope, maytansine alkaloid, etc. In one specific embodiment, the cytotoxin is a microtubule inhibitor, such as monomethyl auristatin E (MMAE). In another specific embodiment, the cytotoxin is a topoisomerase I inhibitor, such as camptothecin compounds.

[0235] In some specific embodiments, the antibody-drug conjugates of the present invention have the structures shown in Ab-MF-L6 or Ab-BL20E as follows:

[0236] Ab-MF-L6 (Isomer I)

[0237] Ab-MF-L6 (Isomer II)

[0238] Ab-BL20E (Isomer I)

[0239] Ab-BL20E (Isomer II)

[0240] Thirdly, the present invention provides a pharmaceutical composition comprising (1) an antibody or an antigen-binding fragment thereof of the first aspect, or an ADC of the second aspect, and (2) a pharmaceutically acceptable carrier.

[0241] Fourthly, the present invention provides isolated polynucleotide molecules that encode any of the antibodies or antigen-binding fragments described in the first aspect.

[0242] Fifthly, the present invention provides a vector comprising the nucleic acid molecule of the third aspect. In some embodiments, the vector is an expression vector.

[0243] In a sixth aspect, the present invention provides a host cell comprising the vector of the fourth aspect or the nucleic acid molecule of the third invention. In some embodiments, the host cell is prokaryotic, such as *Escherichia coli*. In other embodiments, the host cell is eukaryotic, such as HEK293 cells, CHO cells, yeast cells, or plant cells.

[0244] In a seventh aspect, the present invention provides a method for treating tumors in a subject in need, comprising administering to the subject a preventively effective amount or a therapeutically effective amount of an antibody of the present invention or an antigen-binding fragment thereof, or an ADC of the second aspect, or a pharmaceutical composition of the third aspect.

[0245] In some implementations, the tumor is gastric cancer, colorectal cancer, neuroendocrine cancer, esophageal cancer, bile duct cancer, pancreatic cancer, and liver cancer.

[0246] In one specific embodiment, the present invention provides a method for killing or inhibiting the growth of CDH17-expressing cells, comprising contacting the cells with an effective amount of an antibody of the present invention or an antigen-binding fragment thereof, an antibody-drug conjugate of the present invention, a polynucleotide molecule, a carrier, a host cell, and a pharmaceutical composition of the present invention.

[0247] In an eighth aspect, the present invention provides the use of an anti-CDH17 antibody or an antigen-binding fragment thereof, or an ADC of the second aspect, or a pharmaceutical composition of the third aspect, in the preparation of a medicament for the prevention or treatment of cancer.

[0248] In some embodiments, the present invention provides an anti-CDH17 antibody or an antigen-binding fragment thereof as a first aspect, or an ADC as a second aspect, or a pharmaceutical composition as a third aspect for treatment.

[0249] In some embodiments, the present invention provides an anti-CDH17 antibody or an antigen-binding fragment thereof as a first aspect, or an ADC as a second aspect, or a pharmaceutical composition as a third aspect for treating cancer.

[0250] In some embodiments, the present invention provides the use of the anti-CDH17 antibody of the present invention or its antigen-binding fragment, antibody-drug conjugate, vector, host cell, or pharmaceutical composition of the present invention in the preparation of a medicament for treating cancer.

[0251] In some implementation schemes, the cancers mentioned above are stomach cancer, colorectal cancer, neuroendocrine cancer, esophageal cancer, bile duct cancer, pancreatic cancer, and liver cancer.

[0252] In a ninth aspect, the present invention provides the use of an anti-CDH17 antibody or an antigen-binding fragment thereof in the preparation of an antibody-drug conjugate for the treatment of cancer.

[0253] In some implementation schemes, the cancers mentioned above are stomach cancer, colorectal cancer, neuroendocrine cancer, esophageal cancer, bile duct cancer, pancreatic cancer, and liver cancer. Attached Figure Description

[0254] Figure 1 shows the IHC staining results of gastrointestinal tumors.

[0255] Figure 2 shows the cytotoxic activity of the CDH17 chimeric antibody on tumor cells. Figure A shows the cytotoxic activity on gastric cancer cells AGS, and Figures B and C show the cytotoxic activity on colorectal cancer cells SK-CO-1.

[0256] Figure 3 shows the internalization detection results of anti-CDH17 antibody-BL20E molecules in different tumor cells. Figure AH shows the detection results in different colorectal cancer cells, and Figure IL shows the detection results in gastric cancer cells.

[0257] Figure 4 shows the results of the killing activity detection of anti-CDH17 antibody-BL20E molecule on different tumor cells. Figure AH shows the results of the killing activity detection on colorectal cancer cells; IL shows the results of the killing activity detection on gastric cancer cells.

[0258] Figure 5 shows the binding of antibodies to different domains of CDH17 proteins. Figure 5A-B shows the binding of antibodies to CDH17 EC1-2 his; Figure 5C-D shows the binding of antibodies to CDH17 EC3-4 mFc; Figure 5E-F shows the binding of antibodies to CDH17 EC5-7 his; Figure 5G-H shows the binding of antibodies to CDH17 EC1-6 his; Figure 5I-J shows the binding of antibodies to CDH17 EC1-7 his.

[0259] Figure 6 shows the binding of antibodies to human CDH17 EC1 and EC2 proteins and monkey CDH17 EC1 and EC2 proteins. Figure 6A-B shows the binding of antibodies to human CDH17 EC1 his; Figure 6C-D shows the binding of antibodies to human CDH17 EC2 his; Figure 6E-F shows the binding of antibodies to cyno CDH17 EC1 his; Figure 6G-H shows the binding of antibodies to cyno CDH17 EC2 his.

[0260] Figure 7 shows the binding, internalization, and cytotoxic activities of humanized antibodies B6 and E1 conjugated with BL20E and MF-L6. Figure 7A shows the binding detection of B6 and E1 conjugated with BL20E to different cells; Figure 7B shows the binding detection of B6 and E1 conjugated with MF-L6 to different cells; Figure 7C shows the internalization results of antibodies conjugated with BL20E and MF-L6 in different cells; Figure 7D shows the cytotoxic activity of antibodies conjugated with BL20E against different cells; Figure 7E shows the cytotoxic activity of antibodies conjugated with MF-L6 against different cells.

[0261] Figure 8 shows the FACS detection results of the 2E1 series antibodies obtained after further modification of humanized antibody E1. Figures A / B / I show the binding of different humanized antibodies to cells overexpressing Rhesus CDH17; Figures C / D / J show the binding of different humanized antibodies to NCI-H716 cells; Figures E / F show the binding of different humanized antibodies to AGS cells; Figures G / H / K show the binding of different humanized antibodies to NCI-H508 cells; and Figure L shows the binding of different humanized antibodies to SNU-16 cells.

[0262] Figure 9 shows the FACS detection results of the 46D5D6 H2L3 humanized antibody. Figures A / B / C show the binding of different humanized antibodies on Rhesus CDH17 overexpressing cells; Figures D / E / F show the binding of different humanized antibodies on NCI-H716 expressing cells; Figure G shows the binding of different humanized antibodies on AGS cells; and Figures H / I / J show the binding of different humanized antibodies on NCI-H508 cells.

[0263] Figure 10 shows the binding activities of different humanized antibodies with different intracellular molecules. Figures A / E / I show the ELISA binding activity of humanized antibodies with insulin, Figures B / F / J show the ELISA binding activity of humanized antibodies with LPS, Figures C / G / K show the ELISA binding activity of humanized antibodies with dsDNA, and Figures D / H / L show the ELISA binding activity of humanized antibodies with ssDNA.

[0264] Figure 11 shows the non-specific binding detection of MF-L6 conjugate antibody to different cells.

[0265] Figure 12 shows that the applicant's derived antibody does not specifically bind to other members of the cadherin superfamily.

[0266] Figure 13 shows that the applicant's derived antibody does not specifically bind to other members of the cadherin superfamily.

[0267] Figure 14 shows that the applicant's derived antibody does not specifically bind to other members of the cadherin superfamily.

[0268] Figure 15 shows the sequence alignment results of CDH17 EC1-2 from different monkey sources. The solid box contains the EC1 sequence, and the dashed box contains the EC2 sequence.

[0269] Figure 16 shows the binding activity of the applicant's derived CDH17 antibody with monkey and mouse CDH17 proteins. Figure 16A shows the binding activity of the antibody with rhesus monkey CDH17 (A0A1D5R2B4) protein, Figure 16B shows the binding activity of the antibody with cynomolgus monkey CDH17 protein (XP_005563762.2), Figures 16C and D show the binding activity of the antibody with monkey CDH17 (A0A2K5X8I8-1) protein, Figure 16E shows the binding activity of the antibody with rat CDH17 protein, and Figure 16F shows the binding activity of the antibody with mouse CDH17 protein.

[0270] Figure 17 shows the mouse pharmacokinetic (PK) results of the ADC-conjugated antibody of this application. Figure 17A shows the PK results of B6-MF-L6 and E1-MF-L6 mice evaluated by the total antibody detection method; Figure 17B shows the PK results of B6-MF-L6 and E1-MF-L6 mice evaluated by the complete ADC detection method; Figure 17C compares the B6-MF-L6 results under the two methods; and Figure 17D compares the E1-MF-L6 results under the two methods.

[0271] Figure 18 shows the mouse pharmacokinetic (PK) results of the applicant's humanized antibody naked antibody. Figure 18A shows the PK results of the humanized antibody, and Figure 18B shows the PK results of the control molecule.

[0272] Figure 19 shows the binding of humanized molecules to CDH17-overexpressing cells. Figures 19A and 19B show the binding of molecules 238B11E1H10L1 and 7D9B6H14L5 to SNU-16 cells, respectively. Figures 19C and 19D show the binding of molecules 238B11E1H10L1 and 7D9B6H14L5 to recombinant CDH17-overexpressing cells, respectively.

[0273] Figure 20 shows the efficacy results of the candidate molecules in the HT55 CDX model. Figures 20A and 20C: Changes in tumor volume in mice; Figures 20B and 20D: Changes in tumor weight in mice.

[0274] Figure 21 shows the efficacy results of the candidate molecule in the CL40 CDX model. Figures 21A and 21C show the changes in tumor volume in mice, and Figures 21B and 21D show the changes in tumor weight in mice.

[0275] Figure 22 shows the efficacy results of the candidate molecule in the SNU-16CDX model. Figures 22A and 22C show the changes in tumor volume in mice, and Figures 22B and 22D show the changes in tumor weight in mice.

[0276] Figure 23 shows the efficacy results of the candidate molecule in the NCI-H716 CDX model. Figures 23A and 23C show the changes in tumor volume in mice, and Figures 23B and 23D show the changes in tumor weight in mice.

[0277] Figure 24 shows the weight changes in CDX model mice.

[0278] Figure 25 shows the internalization activity of humanized antibodies on tumor cells. Figures 25A-B show the internalization activity of humanized antibodies on colorectal cancer cells, and Figure 25C shows the internalization activity of humanized antibodies on gastric cancer cells.

[0279] Figure 26 shows the cytotoxic activity of the humanized antibody on tumor cells. Figures 26A-B show the cytotoxic activity of the humanized antibody on colorectal cancer cells, and Figure 26C shows the cytotoxic activity of the humanized antibody on gastric cancer cells.

[0280] Figure 27 shows the plasma stability results of the humanized antibody molecules. Figures 27A-D show the binding of the humanized antibody molecules to NCI-H716 cells, and Figures 27E-H show the binding of the humanized antibody molecules to SNU-16 cells.

[0281] Figure 28 shows the binding activity of Ab-BL20E ADC molecules on tumor cells. Figures 28A-F show the binding of different BL20E ADC molecules to colorectal cancer cells, and Figures 28G-J show the binding of different BL20E ADC molecules to gastric cancer cells.

[0282] Figure 29 shows the binding activity of Ab-MF-L6 ADC on tumor cells. Figures 29A-E show the binding of different MF-L6 ADC molecules to colorectal cancer cells, and Figures 29F-H show the binding of different MF-L6 ADC molecules to gastric cancer cells.

[0283] Figure 30 shows the internalization activity of ADC molecules in tumor cells. Figures 30A-C show the internalization of different ADC molecules coupled with BL20E in colorectal cancer cells; Figures 30D-E show the internalization of different ADC molecules coupled with BL20E in gastric cancer cells; Figures 30F-H show the internalization of different ADC molecules coupled with MF-L6 in colorectal cancer cells; and Figure 30I shows the internalization of different ADC molecules coupled with MF-L6 in gastric cancer cells.

[0284] Figure 31 shows the killing activity of ADCs on tumor cells. Figures 31A-D show the killing detection of different ADC molecules conjugated with BL20E on colorectal cancer cells; Figures 31E-F show the killing detection of different ADC molecules conjugated with BL20E on gastric cancer cells; Figure 31G shows the killing detection of different ADC molecules conjugated with BL20E on pancreatic cancer cells; Figures 31H-J show the killing detection of different ADC molecules conjugated with MF-L6 on colorectal cancer cells; Figure 31K shows the killing detection of different ADC molecules conjugated with MF-L6 on gastric cancer cells; and Figure 31L shows the killing detection of different ADC molecules conjugated with MF-L6 on pancreatic cancer cells.

[0285] Figure 32 shows the stability results of the ADC molecule of the present invention in monkey plasma. Figures 32A-F are the ELISA detection results of total antibody, corresponding to samples 2E1 H19WVR-L6 MF-L6, 2E1 H19WVR-L8 MF-L6, 2E1 H19WVR-L15 MF-L6, 07-0663-h7 MF-L6, PTA001-A4K MF-L6, and h10C12 MF-L6, respectively; Figures 32G-L are the ELISA detection results of the complete ADC, with the sample order as above.

[0286] Figure 33 shows the tumor-suppressive activity of ADC molecules in the LS513 CDX model of colorectal cancer. Figure 33A shows the changes in tumor volume; Figure 33B shows the changes in tumor weight; Figure 33C shows the changes in mouse body weight.

[0287] Figure 34 shows the tumor-suppressive activity of ADC molecules in the LS1034 CDX model of colorectal cancer. Figure 34A shows the changes in tumor volume; Figure 34B shows the changes in tumor weight; Figure 34C shows the changes in mouse body weight.

[0288] Figure 35 shows the tumor-suppressive activity of ADC molecules in the SNU-C1 CDX model of colorectal cancer. Figure 35A shows changes in tumor volume; Figure 35B shows changes in tumor weight; Figure 35C shows changes in mouse body weight.

[0289] Figure 36 shows the tumor-suppressive activity of ADC molecules in the gastric cancer 23132 / 87CDX model. Figure 36A shows changes in tumor volume; Figure 36B shows changes in tumor weight; Figure 36C shows changes in mouse body weight.

[0290] Figure 37 shows the tumor-suppressive activity of ADC molecules in the Aspc-1 CDX model of pancreatic cancer. Figure 37A shows changes in tumor volume; Figure 37B shows changes in tumor weight; Figure 37C shows changes in mouse body weight.

[0291] Figure 38 shows the tumor-suppressive activity of ADC molecules in the PDX-CRC-015 model. Figure 38A shows changes in tumor volume; Figure 38B shows changes in tumor weight; Figure 38C shows changes in mouse body weight.

[0292] Figure 39 shows the tumor-suppressive activity of ADC molecules in the PDX-CRC-016 model. Figure 39A shows changes in tumor volume; Figure 39B shows changes in tumor weight; Figure 39C shows changes in mouse body weight.

[0293] Figure 40 shows the tumor-suppressive activity of ADC molecules in the LD1-2017-361697 model. Figure 40A shows the changes in tumor volume; Figure 40B shows the changes in mouse body weight.

[0294] Figure 41 shows the toxicity assessment of the ADC molecule in cynomolgus monkeys. Figure 41A shows the toxicokinetics, and Figures 41B-H show the complete blood count, blood biochemistry, and coagulation parameters.

[0295] Invention Details

[0296] Before describing the invention in detail, it should be understood that the invention is not limited to the specific methods and experimental conditions described herein, as these methods and conditions can be modified. Furthermore, the terminology used herein is for illustrative purposes only and is not intended to be restrictive.

[0297] I. Definition

[0298] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. For the purposes of this invention, the following terms are defined below.

[0299] The term “about” when used in conjunction with a numeric value means to cover a range of numeric values ​​that have a lower limit of 10% less than the specified numeric value and an upper limit of 10% greater than the specified numeric value.

[0300] When the term “and / or” is used to connect two or more options, it should be understood to mean any one of the options or any two or more of the options.

[0301] As used herein, the terms “comprising” or “including” mean to include the stated elements, integers, or steps, but do not exclude any other elements, integers, or steps. In this document, when the terms “comprising” or “including” are used, unless otherwise specified, they also cover situations consisting of the mentioned elements, integers, or steps. For example, when referring to an antibody variable region “comprising” a specific sequence, it is also intended to cover the antibody variable region consisting of that specific sequence.

[0302] The term “CDH17” covers any natural CDH17 of any vertebrate origin; it also covers full-length CDH17, unprocessed CDH17, and any form of CDH17 variant produced by cellular processing, such as splice variants or allele variants.

[0303] The term "antibody" is used in the broadest sense herein and encompasses a variety of antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments, provided they exhibit the desired antigen-binding activity. A complete antibody will typically contain at least two full-length heavy chains and two full-length light chains, but in some cases may include fewer chains; for example, naturally occurring antibodies in camels may contain only heavy chains.

[0304] The term "anti-CDH17 antibody" refers to an antibody that specifically binds to CDH17. In some embodiments of the present invention, the anti-CDH17 antibody is a murine anti-CDH17 antibody. In a preferred embodiment, the anti-CDH17 antibody of the present invention is a chimeric antibody containing a human constant region and a human antibody constant region. In some embodiments, the anti-CDH17 antibody of the present invention binds to human CDH17 with high affinity, exhibits cross-immunity with monkey CDH17, but does not exhibit cross-reactivity with rat CDH17 or mouse CDH17.

[0305] The term "antibody fragment" refers to a molecule distinct from the intact antibody, which contains a portion of the intact antibody and is capable of binding to the antigen bound by the intact antibody. Examples of antibody fragments include, but are not limited to, Fv, Fab, Fab', Fab'-SH, F(ab')2; single-chain antibodies (e.g., scFv); single-domain antibodies; and camelid antibodies (heavy chain antibodies).

[0306] The term "variable region" or "variable domain" refers to a domain of the antibody heavy or light chain involved in antibody-antigen binding. The variable domains of the heavy and light chains of natural antibodies typically have similar structures, with each domain containing four conserved framework regions (FRs) and three complementarity-determining regions (CDRs) (see, for example, Kindt et al., Kuby Immunology, 6th ed., WH Freeman and Co., p. 91 (2007)). A single VH or VL domain is sufficient to provide antigen-binding specificity.

[0307] The complementarity-determining region (CDR) or CDR is a region within the antibody variable domain that is highly variable in sequence and forms a structurally defined loop ("hypervariant loop") and / or contains antigen contact residues ("antigen contact sites"). The CDR is primarily responsible for binding to antigen epitopes. CDRs within the variable domain are typically referred to as CDR1, CDR2, and CDR3, numbered sequentially starting from the N-terminus. In a given variable region amino acid sequence, the precise amino acid sequence boundaries of each CDR can be determined using any of a number of known schemes or combinations thereof, including, for example: Chothia (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)) based on antibody sequence variability; Kabat (Kabat et al., Sequences of Proteins of Immunological Interest, 4th edition, USDepartment 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 nearest neighbor propagation clustering based on a large number of crystal structures. The North CDR definition (North et al., “A New Clustering of Antibody CDR Loop Conformations”, Journal of Molecular Biology, 406, 228-256 (2011)) is also available. Furthermore, the Chemical Computing Group has developed the CCG method for classifying CDRs.

[0308] Unless otherwise stated, in this invention, the term "CDR" or "CDR sequence" covers the CDR sequence determined by any of the above schemes.

[0309] CDRs can also be determined based on having the same Kabat number position as a reference CDR sequence (e.g., any of the exemplary CDRs of this invention). Unless otherwise stated, in this invention, when referring to the position of residues in the antibody variable region (including heavy chain variable region residues and light chain variable region residues), it means determined according to the CCG method of Chemical Computing Group.

[0310] The term "Fc region" refers to the C-terminal region of the immunoglobulin heavy chain, including the native Fc region and variant Fc regions, such as the Fc region sequences of various Ig isotypes and their allotypes. In some embodiments, the human IgG heavy chain Fc region has an amino acid sequence extending from Cys226 or Pro230 to the C-terminus of the heavy chain. However, the C-terminal lysine (Lys447) of the Fc region may or may not be present. At least one amino acid in the native Fc region can be modified to reduce hapten formation, mitigate or eliminate effector function, or increase serum half-life. For example, the "LALA" (L234A+L235A) mutation in IgG1 is widely used in the prior art, which can reduce the binding affinity of the antibody Fc region to FcγR by 100-fold.

[0311] The term "antibody-drug conjugate" or "ADC" refers to a conjugate in which an antibody or antibody fragment is covalently coupled to a therapeutically active substance or active pharmaceutical ingredient, thereby enabling the therapeutically active substance or active pharmaceutical ingredient to target the antibody's binding target and exert its pharmacological function. The therapeutically active substance or active pharmaceutical ingredient can be a cytotoxic agent capable of killing cells (preferably cancer cells) targeted by the ADC. The covalent linking of the therapeutically active substance, active pharmaceutical ingredient, or cytotoxic agent can be performed using a linker in a non-site-specific manner or in a site-specific manner.

[0312] The term "site-specific conjugation" refers to a method of linking a therapeutically active substance or active pharmaceutical ingredient specifically to a specific site on an antibody. In one embodiment, the conjugation is accomplished using a linker.

[0313] The term "cytotoxic agent" may be used interchangeably with "cytotoxin," and in this invention refers to a substance that inhibits or disrupts cell function and / or causes cell death or destruction. In some embodiments, the cytotoxic agent may include, but is not limited to, cytotoxic agents known in the art, such as camptothecin compounds like eczetcan (a topoisomerase I inhibitor), Dxd (a novel topoisomerase I inhibitor derivative of exatecan), and auristatin compounds such as monomethylaurestatin E (MMAE).

[0314] Antibody-cytotoxin conjugation typically involves the coupling of the cytotoxin to exposed residues (including lysine or cysteine) on the antibody molecule. Conjugation to cytotoxins (using linkers) can be achieved by alkylation or acylation of lysine residues on the surface of the antibody molecule, or by the reduction of thiol groups.

[0315] The terms "connector" and "linker" are used interchangeably in this application to refer to a chemical module that covalently links an antibody to a therapeutically active substance or active pharmaceutical ingredient in an ADC. In some embodiments, the connector may comprise an amino acid residue that links the antigen to the payload. It should be understood that the connector has functional groups that can form bonds with functional groups of the antibody or its antigen-binding fragment prior to its attachment to the antibody or its antigen-binding fragment. Advantageously, the connector is a "cleavable connector" that facilitates release upon delivery to the target site. For example, acid-instable connectors, peptidase-sensitive connectors, photostable connectors, dimethyl connectors, or disulfide-containing connectors may be used.

[0316] The terms “load,” “drug load,” or “effective load” refer to the average effective load per antibody within the ADC molecule (in this document, “effective load” may be used interchangeably with “therapeutic active substance or active pharmaceutical ingredient”). Drug loads can range from 1 to 20 therapeutic active substances or active pharmaceutical ingredients per antibody.

[0317] The term “linker-payload” or “drug-containing linker” refers to a compound formed by linking a drug (e.g., a small molecule drug) to a linker.

[0318] The terms "drug / antibody ratio," "drug-antibody conjugate ratio," or "DAR" refer to the ratio of a therapeutically active substance or active pharmaceutical ingredient (D) conjugated to an antibody to the antibody. ADCs described herein typically have a DAR of 1-20, and in some specific embodiments, DARs of 1-8, 2-8, 2-6, 2-5, 2-18, 4-16, 5-12, 6-10, 3-8, 4-6, 6-10, and 2-4. Representative DAR values ​​are approximately 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. In some embodiments described herein, the DAR may be expressed by the formula Ab-(LD). m The value of m is determined.

[0319] In some implementations, DAR is the average DAR, which is the overall ratio of the small molecule drug fraction (D) coupled to the Ab moiety described herein in the product, as determined by detection methods (e.g., conventional methods such as UV / Vis spectroscopy, mass spectrometry, ELISA, electrophoresis, and / or HPLC). DAR may be limited by the number of binding sites on the antibody. For example, in the case where the binding site is cysteine ​​thiol, the antibody may have only one or a few cysteine ​​thiol groups or only one or a few sufficiently reactive thiol groups (through which linking units can be attached). In some embodiments, the average DAR value of the conjugate of the present invention is 1 to 10, for example 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 3-8, 3-7, 3-6, for example 1.0-8.0, 1.0-6.0, for example 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4 5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 0, 7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, or 10.0, a range with two of these values ​​as endpoints. Increasing DAR can enhance efficacy, but a higher DAR also increases the drug metabolism rate of the ADC, leading to a shorter half-life and increased systemic toxicity. Ideally, the drug's efficacy is highest when the DAR is around 4. Therefore, in actual production, the DAR value of the ADC needs to be adjusted and controlled. It should be understood that when referring to the average DAR value, the ADC of this invention refers to a population or mixture of ADC molecules containing ADC molecules with the same and / or different DAR values.

[0320] The term "chimeric antibody" refers to an antibody molecule in which a constant region, or a portion thereof, is altered, replaced, or exchanged, thereby linking the antigen-binding site to a different or altered constant region of a class and / or species, or to a completely different molecule (e.g., an enzyme, toxin, hormone, growth factor, drug), which endows the chimeric antibody with new properties. For example, a mouse antibody can be formed by replacing its constant region with a constant region derived from human immunoglobulins. Due to the replacement with a human constant region, the chimeric antibody can retain its specificity in recognizing antigens while exhibiting reduced immunogenicity in humans, as compared to the original mouse antibody.

[0321] As used herein, the terms “binding” or “specific binding” mean that the binding is selective for the antigen and can be distinguished from unwanted or nonspecific interactions. The ability of an antigen-binding site to bind to a specific antigen can be determined by conventional methods known in the art, such as radioimmunoassay (RIA), thin-layer interferometry, MSD assay, or surface plasmon resonance (SPR).

[0322] The term "half-maximal effective concentration (EC50)" 50 "" refers to the concentration of a drug, antibody, or toxicant that induces a 50% response between baseline and maximum after a specific exposure time.

[0323] The term "half-inhibitory concentration (IC50)" refers to the concentration at which a test drug or substance inhibits the measured biological response, biological function, or activity by 50% relative to an untreated control.

[0324] The terms “cross-reactivity,” “cross-immunity,” “cross-binding activity,” or “cross-reactivity” are used interchangeably herein to refer to the ability of an antibody of one species to specifically recognize CDH17 from another species. For example, the antibody of the present invention that binds to human CDH17 can specifically recognize / bind to CDH17 in rhesus monkeys.

[0325] The term "treatment" refers to slowing, interrupting, blocking, alleviating, stopping, reducing, or reversing the progression or severity of existing symptoms, conditions, ailments, or diseases. Desired therapeutic effects include, but are not limited to, preventing the onset or recurrence of disease, alleviating symptoms, reducing any direct or indirect pathological consequences of the disease, preventing metastasis, slowing the rate of disease progression, improving or mitigating the disease state, and alleviating or improving prognosis. In some embodiments, the antibodies of this invention are used to delay disease development or to slow disease progression.

[0326] The term "effective amount" refers to the amount or dose of the antibody, ADC, or composition of the present invention, which, when administered to a patient in a single or multiple doses, produces the intended effect in a patient requiring treatment or prevention. The effective amount can be readily determined by a physician skilled in the art by considering a variety of factors, such as: the species of the mammal; weight, age, and general health condition; the specific disease involved; the degree or severity of the disease; the individual patient's response; the specific antibody administered; the administration modality; the bioavailability characteristics of the administered formulation; the chosen dosing regimen; and the use of any concomitant therapies.

[0327] The term "therapeutic effective amount" refers to the amount that, at the required dose and for the required duration, effectively achieves the desired therapeutic outcome. Therapeutic effective amounts of antibodies or antibody fragments, or their conjugates or compositions, can vary depending on various factors such as disease state, individual age, sex, weight, and the ability of the antibody or antibody moiety to elicit the desired response in the individual. A therapeutic effective amount is also a amount in which any toxic or harmful effects of the antibody or antibody fragment, or its conjugates or compositions, are less than the beneficial therapeutic effect. Relative to untreated subjects, a "therapeutic effective amount" preferably inhibits measurable parameters (e.g., tumor growth rate, tumor volume, etc.) by at least about 20%, more preferably at least about 40%, even more preferably at least about 50%, 60%, or 70%, and still more preferably at least about 80% or 90%. The ability of a compound to inhibit measurable parameters (e.g., cancer) can be evaluated in animal model systems that predict efficacy in human tumors.

[0328] The term "pharmaceutical composition" refers to a composition which is present in a form that allows the biological activity of the active ingredient contained therein to be effective, and which does not contain any additional ingredients that would have unacceptable toxicity to a subject administering the composition.

[0329] The terms "drug combination," "combination product," "drug conjugate," or "combination product" refer to non-fixed combination products or fixed combination products, including but not limited to pillboxes and pharmaceutical compositions. The term "non-fixed combination" means that the active ingredients (e.g., (i) the antibody molecule or ADC molecule of the present invention, and (ii) other therapeutic agents) are administered to a patient simultaneously, without a specific time limit, or sequentially at the same or different time intervals, in separate entities, wherein such administration to the patient provides a preventive or therapeutically effective level. In some embodiments, the antibody molecule or ADC molecule of the present invention and other therapeutic agents used in the drug combination are administered at levels not exceeding those achieved when used alone. The term "fixed combination" means that two or more active agents are administered to a patient simultaneously in the form of a single entity. Preferably, the dosage and / or time interval of the two or more active agents are selected so that the combined use of the components produces an effect greater than that achieved by using any one component alone in treating a disease or condition. The components may each be in a separate formulation, and their formulations may be the same or different.

[0330] II. The ADC prepared in this invention

[0331] The antibody-drug conjugate provided by this invention consists of three parts: an anti-CDH17 antibody or its antigen-binding fragment prepared in this application, a therapeutically active substance or pharmaceutically active ingredient (e.g., a small molecule drug), and a linker that couples the antibody or its antigen-binding fragment to the therapeutically active substance or pharmaceutically active ingredient. In this application, the antibody-drug conjugate provided by this invention can also be described as being obtained by coupling the anti-CDH17 antibody or its antigen-binding fragment prepared in this application with a drug-containing linker.

[0332] In some implementations, the CDH17-targeting antibody-drug conjugate has the formula Ab-(LD). m The structure, wherein:

[0333] Ab represents anti-CDH17 antibody or its antigen-binding fragment.

[0334] L represents connector.

[0335] D indicates a therapeutically active substance or drug active ingredient.

[0336] m represents the number of LDs connected to Ab.

[0337] In some implementations, the molecular formula is Ab-(LD). m The Ab in the formula contains a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region and the light chain variable region each contain the following CDRs:

[0338] 1) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:25, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:26;

[0339] 2) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:27, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:28;

[0340] 3) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:29, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:30;

[0341] 4) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:31, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:32;

[0342] 5) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:33, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:34;

[0343] 6) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:33, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:35;

[0344] 7) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:35;

[0345] 8) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37;

[0346] 9) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38;

[0347] 10) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39;

[0348] 11) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40;

[0349] 12) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41;

[0350] 13) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37;

[0351] 14) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38;

[0352] 15) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39;

[0353] 16) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40;

[0354] 17) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41;

[0355] 18) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:44;

[0356] 19) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45;

[0357] 20) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45;

[0358] 21) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:47;

[0359] 22) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:48;

[0360] 23) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49;

[0361] 24) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45; or

[0362] 25) HCDR1, HCDR2, and HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and LCDR1, LCDR2, and LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49.

[0363] In some implementations, the molecular formula is Ab-(LD). m The Ab in the text contains heavy chain variable regions and light chain variable regions, wherein the heavy chain variable regions and light chain variable regions each contain the following CDR groups:

[0364] 1) Contains or is composed of HCDR1 as shown in SEQ ID NO:57;

[0365] Contains or consists of HCDR2 as shown in SEQ ID NO:60;

[0366] Contains or is composed of HCDR3 as shown in SEQ ID NO:61;

[0367] It includes or is composed of LCDR1 as shown in SEQ ID NO:79;

[0368] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0369] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0370] 2) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0371] Contains or consists of HCDR2 as shown in SEQ ID NO:63;

[0372] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0373] It includes or is composed of LCDR1 as shown in SEQ ID NO:82;

[0374] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0375] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0376] 3) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0377] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0378] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0379] It includes or is composed of LCDR1 as shown in SEQ ID NO:83;

[0380] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0381] Contains or is composed of LCDR3 as shown in SEQ ID NO:85;

[0382] 4) Contains or is composed of HCDR1 as shown in SEQ ID NO:57;

[0383] Contains or consists of HCDR2 as shown in SEQ ID NO:68;

[0384] Contains or is composed of HCDR3 as shown in SEQ ID NO:61;

[0385] It includes or is composed of LCDR1 as shown in SEQ ID NO:86;

[0386] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0387] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0388] 5) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0389] Contains or consists of HCDR2 as shown in SEQ ID NO:63;

[0390] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0391] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0392] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0393] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0394] 6) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0395] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0396] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0397] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0398] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0399] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0400] 7) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0401] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0402] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0403] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0404] Contains or is composed of LCDR2 as shown in SEQ ID NO:88; and

[0405] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0406] 8) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0407] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0408] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0409] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0410] Contains or is composed of LCDR2 as shown in SEQ ID NO:89; and

[0411] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0412] 9) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0413] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0414] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0415] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0416] Contains or is composed of LCDR2 as shown in SEQ ID NO:90; and

[0417] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0418] 10) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0419] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0420] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0421] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0422] Contains or is composed of LCDR2 as shown in SEQ ID NO:91; and

[0423] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0424] 11) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0425] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0426] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0427] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0428] Contains or is composed of LCDR2 as shown in SEQ ID NO:92; and

[0429] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0430] 12) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0431] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0432] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0433] It includes or is composed of LCDR1 as shown in SEQ ID NO:83;

[0434] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0435] Contains or is composed of LCDR3 as shown in SEQ ID NO:85;

[0436] 13) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0437] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0438] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0439] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0440] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0441] Contains or is composed of LCDR3 as shown in SEQ ID NO:85;

[0442] 14) Contains or consists of HCDR1 as shown in SEQ ID NO:65;

[0443] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0444] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0445] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0446] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0447] Contains or is composed of LCDR3 as shown in SEQ ID NO:94;

[0448] 15) Contains or consists of HCDR1 as shown in SEQ ID NO:65;

[0449] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0450] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0451] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0452] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0453] Contains or is composed of LCDR3 as shown in SEQ ID NO:95;

[0454] or

[0455] 16) Contains or is composed of HCDR1 as shown in SEQ ID NO:65;

[0456] Contains or consists of HCDR2 as shown in SEQ ID NO:66;

[0457] Contains or is composed of HCDR3 as shown in SEQ ID NO:67;

[0458] It includes or is composed of LCDR1 as shown in SEQ ID NO:93;

[0459] Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and

[0460] It contains or is composed of LCDR3 as shown in SEQ ID NO:96.

[0461] Preferably, the Ab comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region and the light chain variable region respectively comprise:

[0462] 1) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 25, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 25, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 25, or is composed of SEQ ID NO: 25; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 26, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 26, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 26, or is composed of SEQ ID NO: 26;

[0463] 2) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 27, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 27, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 27, or is composed of SEQ ID NO: 27; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 28, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 28, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 28, or is composed of SEQ ID NO: 28;

[0464] 3) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 29, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 29, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 29, or is composed of SEQ ID NO: 29; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 30, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 30, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 30, or is composed of SEQ ID NO: 30; or

[0465] 4) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 31, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 31, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 31, or is composed of SEQ ID NO: 31; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 32, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 32, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 32, or is composed of SEQ ID NO: 32;

[0466] 5) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 34, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 34, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 34, or is composed of SEQ ID NO: 34;

[0467] 6) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35;

[0468] 7) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35;

[0469] 8) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37;

[0470] 9) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38;

[0471] 10) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39;

[0472] 11) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40;

[0473] 12) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41;

[0474] 13) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37;

[0475] 14) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38;

[0476] 15) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39;

[0477] 16) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40;

[0478] 17) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41;

[0479] 18) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 44, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 44, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 44, or is composed of SEQ ID NO: 44;

[0480] 19) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45;

[0481] 20) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45;

[0482] 21) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 47, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 47, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 47, or is composed of SEQ ID NO: 47;

[0483] 22) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 48, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 48, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 48, or is composed of SEQ ID NO: 48;

[0484] 23) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO: 49;

[0485] 24) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO: 50; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45; or

[0486] 25) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO: 50. The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO: 49.

[0487] Preferably, the Ab comprises:

[0488] (1) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:31, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:32, wherein the CDRs are shown in bold underline, or

[0489] (2) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:33, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:34, wherein the CDRs are shown in bold underline, or

[0490] (3) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41, wherein the CDRs are shown in bold underline, or

[0491] (4) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37, wherein the CDRs are shown in bold underline, or

[0492] (5) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38, wherein the CDRs are shown in bold underline, or

[0493] (6) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39, wherein the CDRs are shown in bold underline, or

[0494] (7) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40, wherein the CDRs are shown in bold underline, or,

[0495] (8) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41, wherein the CDRs are shown in bold underline, or;

[0496] or

[0497] The Ab contains the following CDR combinations:

[0498] (1) Contains or is composed of HCDR1 as shown in SEQ ID NO:57;

[0499] Contains or consists of HCDR2 as shown in SEQ ID NO:68;

[0500] Contains or is composed of HCDR3 as shown in SEQ ID NO:61;

[0501] It includes or is composed of LCDR1 as shown in SEQ ID NO:86;

[0502] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0503] Contains or is composed of LCDR3 as shown in SEQ ID NO:81; or

[0504] (2) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0505] Contains or consists of HCDR2 as shown in SEQ ID NO:63;

[0506] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0507] It includes or is composed of LCDR1 as shown in SEQ ID NO:82;

[0508] Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and

[0509] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0510] (3) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0511] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0512] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0513] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0514] Contains or is composed of LCDR2 as shown in SEQ ID NO:92; and

[0515] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0516] (4) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0517] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0518] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0519] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0520] Contains or is composed of LCDR2 as shown in SEQ ID NO:88; and

[0521] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0522] (5) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0523] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0524] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0525] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0526] Contains or is composed of LCDR2 as shown in SEQ ID NO:89; and

[0527] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0528] (6) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0529] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0530] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0531] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0532] Contains or is composed of LCDR2 as shown in SEQ ID NO:90; and

[0533] Contains or is composed of LCDR3 as shown in SEQ ID NO:81;

[0534] or

[0535] (7) Contains or is composed of HCDR1 as shown in SEQ ID NO:62;

[0536] Contains or consists of HCDR2 as shown in SEQ ID NO:69;

[0537] Contains or is composed of HCDR3 as shown in SEQ ID NO:64;

[0538] It includes or is composed of LCDR1 as shown in SEQ ID NO:87;

[0539] Contains or is composed of LCDR2 as shown in SEQ ID NO:91; and

[0540] It contains or is composed of LCDR3 as shown in SEQ ID NO:81.

[0541] Preferably, the Ab comprises:

[0542] (1) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 31, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 32, or

[0543] (2) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 33, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 34, or

[0544] (3) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 41, or

[0545] (4) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 37, or

[0546] (5) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or

[0547] (6) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or

[0548] (7) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or

[0549] (8) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 36, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 41.

[0550] Preferably, the Ab is an IgG antibody; more preferably, it is a human IgG antibody; most preferably, it is a human IgG1 or human IgG4 antibody; wherein the antigen-binding fragment is Fab, Fab', F(ab')2, Fv, single-chain Fv, or single-chain Fab.

[0551] Preferably, the Ab comprises:

[0552] (1) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 31 and the amino acid sequence shown in SEQ ID NO: 14, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 32 and the amino acid sequence shown in SEQ ID NO: 16; or

[0553] (2) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 31 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 32 and the amino acid sequence shown in SEQ ID NO: 16; or

[0554] (3) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 33 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 34 and SEQ ID NO: 16; or

[0555] (4) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 33 and SEQ ID NO: 15, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 34 and SEQ ID NO: 16; or

[0556] (5) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 41 and SEQ ID NO: 16; or

[0557] (6) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 42 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 41 and the amino acid sequence shown in SEQ ID NO: 16; or

[0558] (7) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 37 and SEQ ID NO: 16; or

[0559] (8) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 15, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 37 and SEQ ID NO: 16; or

[0560] (9) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 38 and SEQ ID NO: 16; or

[0561] (10) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 42 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 38 and the amino acid sequence shown in SEQ ID NO: 16; or

[0562] (11) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 39 and SEQ ID NO: 16; or

[0563] (12) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 42 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 39 and the amino acid sequence shown in SEQ ID NO: 16; or

[0564] (13) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 40 and SEQ ID NO: 16; or

[0565] (14) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 15, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 40 and SEQ ID NO: 16; or

[0566] (15) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 36 and the amino acid sequence shown in SEQ ID NO: 14, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 41 and the amino acid sequence shown in SEQ ID NO: 16; or

[0567] (16) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 36 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 41 and the amino acid sequence shown in SEQ ID NO: 16.

[0568] In some implementations, the formula Ab-(LD) m In this context, D represents a small molecule drug. In a preferred embodiment, D may be selected from one or more of the following: microtubule inhibitors, such as MMAE, DM1, DM4, and derivatives of said drugs; topoisomerase inhibitors, such as camptothecin compounds, SN38, DXD; DNA binders, etc.

[0569] In some embodiments, the small molecule drug is selected from MMAE, SN38, DXD, Exatecan, and camptothecin compounds. In some embodiments, MMAE has the following structure:

[0570] In some implementations, DXD has the following structure:

[0571] In some implementations, Exatecan has the following structure:

[0572] In some implementations, SN38 has the following structure:

[0573] In some embodiments, the camptothecin compounds are as defined below.

[0574] In some implementations, the formula Ab-(LD) m In this context, L is any chemical part that can covalently link the therapeutic or pharmaceutical active ingredient D to Ab.

[0575] In conjugates, linkers can be used to covalently link different entities of the conjugate. Suitable linkers include chemical linkers or peptide linkers. Advantageously, linkers are "cleavable linkers" that facilitate the release of the peptide after delivery to the target site. For example, acid-instable linkers, peptidase-sensitive linkers, photostable linkers, dimethyl linkers, or disulfide-containing linkers can be used. Preferably, part or all of the linker can be cleaved within tumor cells, releasing the antitumor drug moiety and thus exhibiting an antitumor effect.

[0576] In some implementations, the formula Ab-(LD) m In this context, m represents the number of LDs conjugated to a single antibody (Ab), i.e., the DAR value. For example, m = 1-20, m = 1-15, 1-10, 1-8, 3-8, 4-8, or 6-8, or m = approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

[0577] In some embodiments, the antibody-drug conjugates provided by this invention can also be described as being obtained by conjugating an anti-CDH17 antibody or its antigen-binding fragment prepared in this application with a drug-containing linker. Drug-containing linkers that can be conjugated with the anti-CDH17 antibody or its antigen-binding fragment of this application include, for example, VcMMAE and GGFG-Dxd class drug-containing linkers. In some specific embodiments, drug-containing linkers that can be conjugated with the anti-CDH17 antibody or its antigen-binding fragment of this application include:

[0578] In some embodiments, the present invention provides an antibody-drug conjugate targeting CDH17 or a salt thereof, wherein preferably, the antibody-drug conjugate or a salt thereof is prepared using an anti-CDH17 antibody or an antigen-binding fragment thereof provided by the present invention. Therefore, the present invention provides an antibody-drug conjugate or a salt thereof having a structure as shown in structural formulas Ia and / or Ib:

[0579] and / or

[0580] In structural formulas Ia and / or Ib, Ab represents an anti-CDH17 antibody or its antigen-binding fragment. Preferably, the antibody or its antigen-binding fragment is the anti-CDH17 antibody or its antigen-binding fragment as defined above in this invention.

[0581] In structural formulas Ia and / or Ib, and unless otherwise specified in the context of this invention, M is a phenylene or a phenylene substituted with one or more substituents, or a chemical bond; in the substituted phenylene, the substituent is selected from alkyl (e.g., C1-6 alkyl, preferably C1-4 alkyl), haloalkyl (e.g., haloC1-6 alkyl, preferably haloC1-4 alkyl, such as trifluoromethyl), alkoxy (e.g., C1-6 alkoxy, preferably C1-4 alkoxy, preferably methoxy), halogen, ester, amide, and cyano; preferably, M is a halogen-substituted phenylene.

[0582] In structural formulas Ia and / or Ib, and unless otherwise specified in the context of this invention, SP1 is selected from C1-8 alkylene, C1-8 cycloalkylene, or C1-21 (preferably C1-16, more preferably C1-11, more preferably C5-9) straight-chain heteroalkylene, wherein the C1-21 straight-chain heteroalkylene comprises 1-11 (preferably 1-6, more preferably 3-5) heteroatoms selected from N, O, or S, wherein each of the C1-8 alkylene, C1-8 cycloalkylene, and C1-21 straight-chain heteroalkylene is optionally substituted independently by one or more substituents selected from hydroxyl, amino, sulfonic acid, and cyano groups.

[0583] In structural formulas Ia and / or Ib, and unless otherwise specified in the context of this invention, SP2 is selected from -NH(CH2CH2O). a CH2CH2CO-、-NH(CH2CH2O) a CH2CO-、-S(CH2) a CO- or chemical bond, where a is an integer from 1 to 20, preferably an integer from 1 to 10, and more preferably an integer from 1 to 6.

[0584] In structural formulas Ia and / or Ib, and unless otherwise specified in the context of this invention, A represents a short peptide structure consisting of 2-4 amino acids. Wherein, when A represents a short peptide structure formed by 2 amino acids, it can be -Phe-Lys-, -Val-Ala-, -Val-Lys-, -Ala-Lys-, -Val-Cit-, -Phe-Cit-, -Leu-Cit-, -Phe-Arg-, or -Gly-Val-, preferably -Phe-Lys-, -Val-Ala-, or -Val-Cit-; when A represents a short peptide structure formed by 3 amino acids, it can be -Glu-Val-Ala-, -Glu-Val-Cit-, or -Ala-Ala-Ala-, preferably -Glu-Val-Ala- or -Ala-Ala-Ala-; when A represents a short peptide structure formed by 4 amino acids, it can be -Gly-Gly-Phe-Gly- or -Gly-Phe-Gly-Gly-, preferably -Gly-Gly-Phe-Gly-. Preferably, A is -Val-Ala-, -Gly-Gly-Phe-Gly-, or -Ala-Ala-Ala-. In structural formulas Ia and / or Ib, group A is linked to SP2 via an amino group at the amino terminus of its short peptide structure.

[0585] In structural formulas Ia and / or Ib, M is preferably a halogen-substituted phenylene, particularly a fluorine-substituted phenylene.

[0586] In structural formulas Ia and / or Ib, SP1 is preferably C1-11, more preferably C5-9, and more preferably C7 straight-chain heteroalkyl, containing 1-6, more preferably 3-5, and more preferably 4 heteroatoms selected from N, O, or S.

[0587] In structural formulas Ia and / or Ib, SP2 is preferably a chemical bond.

[0588] In structural formulas Ia and / or Ib, and unless otherwise specified in the context of this invention, m is 1 to 10, preferably 1 to 8 (e.g., 1 to 5), and more preferably 3 to 8. m can be an integer or a non-integer.

[0589] Furthermore, the antibody-drug conjugate or its salt provided by the present invention has a structure as shown in structural formulas Ic and / or Id:

[0590] and / or

[0591] In structural formulas Ic and / or Id, Ab, group A, and m are defined in the same way as Ab, group A, and m in structural formulas Ia and / or Ib.

[0592] In any of the structural formulas Ia, Ib, Ic, and Id, and unless otherwise stated in the context of this invention, CPT is a camptothecin compound.

[0593] Furthermore, in any of structural formulas Ia, Ib, Ic, and Id, the structure of CPT is as shown in structural formula I, wherein structural formula I is connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond, preferably with the amino group adjacent to group G in structural formula I connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond.

[0594] In structural formula I, and unless otherwise stated in the context of this invention, R1, R2, R3, and R4 are independently hydrogen, halogen, hydroxyl, C1-6 alkoxy, amino or substituted amino, C1-7 alkyl or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms they are attached to form a C3-6 (preferably C3-5) cyclic alkyl group. When R1, R2, R3, and R4 are independently C1-6 alkoxy, the C1-6 alkoxy group includes straight-chain or branched C1-6 alkoxy groups, preferably straight-chain or branched C1-3 alkoxy groups, more preferably methoxy groups. When R1, R2, R3, and R4 are independently substituted amino groups, the substituted amino group is an amino group substituted by one or more substituents selected from methyl and ethyl groups. When R1, R2, R3, and R4 are independently C1-7 alkyl or substituted C1-7 alkyl, the C1-7 alkyl or substituted C1-7 alkyl includes straight-chain or branched C1-7 (preferably C3-5, more preferably C4) alkyl or substituted C1-7 (preferably C3-5, more preferably C4) alkyl, and the substituted C1-7 alkyl is a C1-7 alkyl substituted by one or more substituents selected from cyclopropyl and cyclobutyl; or, the straight-chain or branched C1-7 alkyl or substituted C1-7 alkyl is preferably a C1-3 alkyl or substituted C1-3 alkyl, such as methyl, halomethyl (preferably trifluoromethyl).

[0595] In structural formula I, and unless otherwise specified in the context of this invention, G is hydrogen, halogen, methyl, or methoxy. Preferably, G is hydrogen, fluorine, or chlorine.

[0596] In structural formula I, and unless otherwise specified in the context of this invention, Y is oxygen, sulfur, sulfone, sulfoxide, methylene, or substituted methylene. A substituted methylene group may be one hydrogen atom of the methylene group being substituted, or both hydrogen atoms may be substituted simultaneously. The substituent may be benzyl or alkyl. When the substituent is alkyl, the alkyl group, together with R3 and / or R4 and the carbon atoms attached thereto, may form a C3-6 membered fused or spirocyclic structure; or, when the substituent is two alkyl groups, the two alkyl groups may, together with group Y, form a C3-6 membered spirocyclic structure. When Y is a substituted methylene group, the substituent is preferably an alkyl group, more preferably a straight-chain or branched C1-4 alkyl group.

[0597] Preferably, Y is oxygen, sulfur, sulfone, sulfoxide, or methylene; or, preferably, Y is oxygen, sulfur, or methylene.

[0598] In structural formula I, and in the context of this invention unless otherwise specified, X is oxygen or sulfur.

[0599] In structural formula I, and in the context of this invention unless otherwise specified, n = 0 or 1.

[0600] In structural formula I, when R1, R2, R3, and R4 are all hydrogen, X is oxygen, and n = 0, when Y is methylene, G cannot be hydrogen or fluorine; and when Y is oxygen or sulfur, G cannot be hydrogen.

[0601] Preferably, R1, R2, R3, and R4 are independently hydrogen, halogen (e.g., fluorine), C1-7 alkyl, or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms they are attached to form a C3-6 cyclic alkyl group (e.g., a C3-5 cyclic alkyl group). Further, R1 and R2 can be the same; and / or, R3 and R4 can be the same.

[0602] Preferably, Y is a methylene group substituted with an alkyl group, and the alkyl group, together with R3 and / or R4 and the carbon atoms attached thereto, can form a C3-6 fused or spirocyclic structure.

[0603] Preferably, X can be oxygen.

[0604] Preferably, X is oxygen, G is hydrogen, halogen (e.g., fluorine or chlorine), methyl or methoxy, and Y and R1, R2, R3, R4 are as defined above.

[0605] Preferably, X is oxygen, G is hydrogen, Y is methylene or substituted methylene, oxygen, sulfur, sulfoxide or sulfone, and R1, R2, R3, R4 are as defined above.

[0606] Preferably, X is oxygen, G is fluorine, Y is methylene or substituted methylene, oxygen or sulfur, and R1, R2, R3, and R4 are as defined above.

[0607] Preferably, X is oxygen, G is chlorine, Y is methylene or substituted methylene, oxygen or sulfur, and R1, R2, R3, and R4 are as defined above.

[0608] Preferably, X is oxygen, G is methyl, Y is methylene or substituted methylene, oxygen or sulfur, and R1, R2, R3, R4 are as defined above.

[0609] Preferably, X is oxygen, G is methoxy, Y is methylene or substituted methylene, oxygen or sulfur, and R1, R2, R3, and R4 are as defined above.

[0610] Preferably, X is oxygen, G is hydrogen, Y is methylene, sulfoxide, sulfone, oxygen or sulfur, R1 and R2 are independently hydrogen, fluorine or methyl, and R3 and R4 are independently hydrogen.

[0611] Preferably, X is oxygen, G is fluorine, Y is methylene, sulfoxide, sulfone, oxygen or sulfur, R1 and R2 are independently hydrogen, fluorine or methyl, and R3 and R4 are independently hydrogen.

[0612] Preferably, n = 0.

[0613] According to a specific embodiment of the present invention, in structural formula I:

[0614] G is hydrogen, Y is methylene, R1 and R2 are methyl, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0615] G is hydrogen, Y is methylene, R1 and R2 are fluorine, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0616] G is hydrogen, Y is methylene, one of R1 and R2 together with one of R3 and R4, along with the carbon atoms they are attached to, forms a C3 cyclic alkyl group, the other of R1 and R2 together with the other of R3 and R4 is hydrogen, X is oxygen, n = 0;

[0617] G is hydrogen, Y is sulfur, R1 and R2 are hydrogen, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0618] G is hydrogen, Y is sulfoxide, R1 and R2 are hydrogen, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0619] G is hydrogen, Y is sulfur, R1 and R2 are fluorine, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0620] G is hydrogen, Y is sulfone, R1 and R2 are hydrogen, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0621] G is hydrogen, Y is methylene, R1 and R2 are hydrogen, R3 and R4 are hydrogen, X is oxygen, and n = 1;

[0622] G is fluorine, Y is oxygen, R1 and R2 are hydrogen, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0623] G is fluorine, Y is sulfur, R1 and R2 are hydrogen, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0624] G is fluorine, Y is oxygen, R1 and R2 are fluorine, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0625] G is fluorine, Y is methylene, R1 and R2 are fluorine, R3 and R4 are hydrogen, X is oxygen, and n = 0;

[0626] G is hydrogen, Y is oxygen, R1 and R2 are fluorine, R3 and R4 are hydrogen, X is oxygen, n = 0; or

[0627] G is fluorine, Y is sulfur, R1 and R2 are fluorine, R3 and R4 are hydrogen, X is oxygen, and n = 0.

[0628] Preferably, in any of structural formulas Ia, Ib, Ic, and Id, the structure of CPT is as shown in structural formula IA, wherein structural formula IA is connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond, preferably with the amino group on the left-hand benzene ring in structural formula IA connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond.

[0629] In structural formula IA, groups R1, R2, R3, and R4 are defined the same as those in structural formula I above, but R1, R2, R3, and R4 are not all hydrogen.

[0630] Alternatively, in any of structural formulas Ia, Ib, Ic, and Id, the structure of CPT is as shown in structural formula II, wherein structural formula II is connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond, preferably with the amino group adjacent to group G in structural formula II connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond.

[0631] In structural formula II, and unless otherwise specified in the context of this invention, R5 is a C1-5 alkyl or a C1-5 alkyl substituted with one or more substituents, a C3-6 cyclic alkyl or a C3-6 cyclic alkyl substituted with one or more substituents, a phenyl or a substituted phenyl. When R5 is a C1-5 alkyl or a substituted C1-5 alkyl, the C1-5 alkyl comprises a straight-chain or branched C1-5 alkyl. Further, R5 is a C1-4 straight-chain alkyl. When R5 is a substituted C1-5 alkyl or a substituted C3-6 cyclic alkyl, the substituent is selected from halogens, hydroxyl groups, methoxy groups, trifluoromethyl groups, amino or substituted amino groups, methanesulfonyl groups, and C3-6 cyclic alkyl groups; and wherein the substituted amino group is an amino group substituted with one or more substituents selected from methyl and ethyl groups. When R5 is a substituted phenyl, the substituent is selected from alkyl groups (e.g., C1-6 alkyl, preferably C1-3) or halogens.

[0632] In structural formula II, and unless otherwise specified in the context of this invention, G is hydrogen, halogen (e.g., fluorine), methyl, or methoxy. Preferably, G is hydrogen, fluorine, or chlorine.

[0633] In structural formula II, X is oxygen or sulfur.

[0634] In structural formula II, n = 0 or 1.

[0635] In structural formula II, when X is oxygen, G is hydrogen, and n = 0, R5 cannot be n-butyl.

[0636] Preferably, in any of structural formulas Ia, Ib, Ic, and Id, the structure of CPT is as shown in structural formula IIA, wherein structural formula IIA is connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond, preferably with the amino group on the left-hand benzene ring of structural formula IIA connected to the carboxyl group in group A of any of structural formulas Ia, Ib, Ic, and Id via an amide bond.

[0637] In structural formula IIA, the group R5 is defined the same as the group R5 in structural formula II above, but R5 cannot be n-butyl.

[0638] According to a specific embodiment of the present invention, in any one of structural formulas Ia, Ib, Ic, and Id, the structure of the CPT is as follows, wherein each structural formula is connected to the carboxyl group in group A of any one of structural formulas Ia, Ib, Ic, and Id via an amide bond, preferably with the amino group on the left benzene ring in each structural formula connected to the carboxyl group in group A of any one of structural formulas Ia, Ib, Ic, and Id via an amide bond:

[0639] Furthermore, in any of structural formulas Ia, Ib, Ic, and Id, the structure of CPT is as shown in structural formula IV, wherein the hydroxyl group on the same carbon as R8 in structural formula IV is linked to the carboxyl group of group A in any of structural formulas Ia, Ib, Ic, and Id via a self-releasing structure.

[0640] Release structure, for example Solid lines represent sites where the group A in any of the structural formulas Ia, Ib, Ic, and Id is linked to a carboxyl group, and wavy lines represent sites where the group IV is linked to a hydroxyl group.

[0641] In structural formula IV, and unless otherwise stated in the context of this invention, R8 is hydrogen, trifluoromethyl, C1-5 alkyl or C1-5 alkyl substituted with one or more substituents, C3-6 cyclic alkyl or C3-6 cyclic alkyl substituted with one or more substituents, or halogen.

[0642] When R8 is a substituted C1-5 alkyl or a substituted C3-6 cyclic alkyl, the substituent is selected from halogen, hydroxyl, methoxy, trifluoromethyl, amino or substituted amino, methanesulfonyl and C3-6 cyclic alkyl; and wherein the substituted amino is an amino group substituted by one or more substituents selected from methyl and ethyl.

[0643] In some embodiments, the present invention provides an antibody-drug conjugate or a salt thereof, said antibody-drug conjugate or salt thereof having a general formula.

[0644] The structure shown indicates that mAb represents an anti-CDH17 antibody or its antigen-binding fragment. Preferably, mAb is the anti-CDH17 antibody or its antigen-binding fragment as defined above in this invention.

[0645] In this general formula, the groups M, SP1, SP2, A and CPT are the same as those defined above; m is 1 to 10, preferably 1 to 8 (e.g., 1 to 5), and more preferably 3 to 8.

[0646] In this general formula, E L Selected from the following groups, wherein, This indicates that it is linked to cysteine ​​in mAb. Indicates connection to M:

[0647] E L -1a and / or E L -1b: E L -2: E L -3: E L -4: E L -5: E L -6:

[0648] III. The Composition of the Invention

[0649] In some embodiments, the present invention provides compositions comprising any of the anti-CDH17 antibodies or ADCs described herein, preferably pharmaceutical compositions. In some embodiments, the compositions further comprise pharmaceutical excipients, such as pharmaceutical carriers, pharmaceutical excipients, including buffers, known in the art. In some embodiments, the compositions (e.g., pharmaceutical compositions) comprise a combination of the anti-CDH17 antibody of the present invention or its antigen-binding fragment or ADC, and one or more other therapeutic agents.

[0650] As used in this article, “pharmaceutical carrier” includes any and all physiologically compatible solvents, dispersion media, isotonic agents, and absorption delay agents.

[0651] For information on the use and applications of pharmaceutical excipients, see "Handbook of Pharmaceutical Excipients", 8th edition, R.C. Rowe, P.J. Seskey and S.C. Swen, Pharmaceutical Press, London, Chicago.

[0652] The compositions of the present invention can be in a variety of forms. These forms include, for example, liquid, semi-solid, and solid dosage forms, such as liquid solutions (e.g., injectable and infusionable solutions), powders or suspensions, liposomes, and suppositories. Preferred forms depend on the intended administration method and therapeutic use.

[0653] The compositions of the present invention can be administered by known methods, such as orally, intravenously, intraperitoneally, intracerebral (internal parenchyma), intraventricularly, intramuscularly, intraocularly, intraarterially, intraportally, or intralesionally; via a continuous release system or via an implanted device. In some embodiments, the compositions can be administered by bolus injection, continuous infusion, or via an implanted device.

[0654] The subject may be a mammal, such as a primate, preferably a higher primate, such as a human (e.g., an individual suffering from or at risk of suffering from the diseases described herein). In some embodiments, the subject suffers from or is at risk of suffering from the diseases described herein (e.g., cancer). In some embodiments, the subject has received or has received other treatments, such as chemotherapy and / or radiation therapy. In some embodiments, the subject has previously received or is currently receiving immunotherapy.

[0655] A drug comprising the antibody or ADC described herein can be prepared by mixing the anti-CDH17 antibody of the present invention, or its antigen-binding fragment or ADC, having the desired purity, with one or more optional pharmaceutical excipients, preferably in the form of a lyophilized formulation or an aqueous solution.

[0656] Sustained-release formulations can be prepared. Suitable examples of sustained-release formulations include a semi-permeable matrix of a solid hydrophobic polymer containing an antibody, said matrix being a shaped article, such as a film or microcapsule.

[0657] IV. Preparation of the antibody of the present invention

[0658] In some embodiments, the present invention provides a method for preparing an anti-CDH17 antibody or an antigen-binding fragment thereof, wherein the method comprises culturing a host cell containing a nucleic acid encoding an anti-CDH17 antibody or an antigen-binding fragment thereof, or an expression vector containing said nucleic acid, under conditions suitable for expressing a nucleic acid encoding said anti-CDH17 antibody or an antigen-binding fragment thereof, and optionally isolating said anti-CDH17 antibody or an antigen-binding fragment thereof. In one embodiment, the method further comprises recovering the anti-CDH17 antibody or an antigen-binding fragment thereof from said host cell (or host cell culture medium).

[0659] To recombinantly generate the anti-CDH17 antibody or its antigen-binding fragment of the present invention, the nucleic acid encoding the anti-CDH17 antibody or its antigen-binding fragment of the present invention is first isolated, and said nucleic acid is inserted into a vector for further cloning and / or expression in host cells. Such nucleic acids are easily isolated and sequenced using conventional procedures, for example, by using oligonucleotide probes capable of specifically binding to the nucleic acid encoding the anti-CDH17 antibody or its antigen-binding fragment of the present invention.

[0660] The anti-CDH17 antibody or its antigen-binding fragment prepared as described herein can be purified using known prior art techniques such as high-performance liquid chromatography (HPLC), ion-exchange chromatography, gel electrophoresis, affinity chromatography, and size exclusion chromatography. The actual conditions used to purify a specific protein also depend on factors such as net charge, hydrophobicity, and hydrophilicity, which are obvious to those skilled in the art. The purity of the anti-CDH17 antibody or its antigen-binding fragment can be determined by any of a variety of well-known analytical methods, including size exclusion chromatography, gel electrophoresis, and HPLC.

[0661] V. Preparation of the antibody ADC of the present invention

[0662] The prior art describes various methods for conjugating cytotoxic agents or other therapeutic agents to antibodies. For example, the conjugation reaction can occur via the amino group of the lysine side chain and the amino group at the N-terminus of the antibody, aspartic acid, glutamic acid, and the carboxyl group or activated cysteine ​​thiol group at the C-terminus.

[0663] The applicant has internally developed a platform technology for the efficient fabrication of ADCs. For details, please refer to the content disclosed in WO2023109965 A1.

[0664] When an antibody-drug conjugate is a composition of conjugates with different drug conjugation sites and / or numbers, the drug loading of the conjugate is expressed as the average DAR, which is the average number of drug molecules per antibody. The average number of drug molecules per antibody in the prepared antibody-drug conjugate composition can be characterized by conventional methods such as mass spectrometry, ELISA assay, and HPLC.

[0665] Therefore, in one aspect of the invention, the antibody-drug conjugate Ab-(LD) m In this context, m represents the number of drug linker (LD) moieties conjugated to a single antibody (Ab), and is preferably 1 to 16, 1 to 12, 1 to 10, or 1 to 8. In this case, the individual ADC conjugate may also be referred to as an ADC compound. In any embodiment herein, about 1, 2, 3, 4, 5, 6, 7, or 8 drug linker moieties may be conjugated to a single antibody on the ADC compound according to the invention.

[0666] In another aspect of the invention, m represents the average DAR of the prepared antibody-drug conjugate composition. In this case, m can be an integer or a decimal in the range of 1 to about 16, 1 to about 12, 1 to about 10, or 1 to about 8, 2 to about 16, 2 to about 12, 2 to about 10, or 2 to about 8. In some aspects, m represents an average DAR of about 3 to about 4. In some aspects, m represents an average DAR of about 4. Example

[0667] The following embodiments further illustrate the present invention; however, it should be understood that the embodiments are described in an illustrative rather than limiting manner, and various modifications can be made by those skilled in the art.

[0668] Unless otherwise expressly stated, the present invention will be practiced using conventional chemical, biochemical, organic chemistry, molecular biology, microbiology, recombinant DNA technology, genetics, immunology, and cell biology methods within the art. Unless otherwise specified, all experimental materials used are commercially available products. Where specific techniques or conditions are not specified in the examples, they shall be performed according to the techniques or conditions described in the literature in the art, or according to the corresponding product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0669] Example 1. Expression of CDH17 in different gastrointestinal tumor tissues

[0670] The expression of CDH17 in relevant gastrointestinal tumor tissues was detected by tumor tissue microarray (TMA) IHC staining. The antigen retrieval and staining steps were performed using a Leica Bond III staining system. The CDH17 antibody PTA001-A4 (Oxford Biotherapeutics, patent US20160039933A1, named PC-A4 in this invention) was diluted to 10 μg / ml with bovine serum albumin and incubated with the sample for 60 minutes. After washing, the sample was stained with the secondary antibody Goat Anti-Human IgG (H+L)-HRP (1:300) using a Leica DS9800 staining system and incubated at room temperature for 30 minutes. After washing, the sample was developed with DAB working solution for 5 minutes and stained with hematoxylin working solution for 15 minutes. The sample was dehydrated with graded ethanol, cleared with xylene, and mounted with neutral resin. The sample was scanned using a fluorescence imaging scanner, analyzed using Halo analysis software, and the results (- / + / ++ / +++) were interpreted by a pathologist, who also calculated the H-score. As shown in Figure 1, CDH17 expression was as high as 99% in colorectal cancer (COAD) and rectal cancer (READ), with a positive rate of 60-70% in gastric cancer (STAD) and cardia cancer (GCA), and was detected in more than 40% of liver cancer (CHOL & LIHC), pancreatic cancer (PAAD), and neuroendocrine tumors (NET), while it was slightly lower in esophageal cancer (ESCA) tissue, with a positive rate of about 14%.

[0671] Example 2. Assessment of CDH17 expression levels in different gastrointestinal tumor cells

[0672] Flow cytometry was used to assess the expression of CDH17 on the surface of different gastrointestinal tumor cells. Various gastrointestinal tumor cell lines from ATCC were cultured in suitable media until they reached optimal growth. When cells were in good condition, adherent cells were collected using Versene (Gibco, 15040-066), and the cell density was adjusted to 2E6 cells / ml. Cells were seeded into 96-well plates at 50 μL / well. Cells were resuspended in serially diluted PC-A4 antibody (starting at 10 μg / ml, with 11 5-fold dilutions) at 50 μL / well, and the plates were incubated at 4°C for 1 hour. After incubation, the plates were centrifuged as before, washed three times with PBS, and then incubated at 1:2000 or 1:5000 dilution of goat anti-human Fcγ fragment-specific APC antibody (Jackson ImmunoResearch, 109-135-098) at 100 μL / well, and incubated at 4°C in the dark for 30 minutes. After washing three times with PBS, the cells were resuspended in 80 μL of PBS and flow cytometry was performed using iQue Screener PLUS. The results were analyzed using GraphPad Prism. The results are shown in Table 1, which showed that gastrointestinal tumor cells all showed high levels of CDH17 expression, as evidenced by high mean fluorescence intensity (MFI), especially colorectal cancer cells.

[0673] Table 1. Expression of CDH17 in different cells

[0674] *The cell expression level is high, and the secondary antibody concentration of 1:2000 exceeds the detection range of the instrument. Therefore, the secondary antibody concentration used for the detection of this cell is 1:5000.

[0675] Example 3. Animal immunization and hybridoma screening

[0676] The recombinant protein human CDH17 EC1-2 hFc protein (SEQ ID NO:13), which is a fusion of CDH17 and human Fc, was prepared using conventional methods. EC represents the extracellular domain of CDH17, and EC1-2 represents extracellular domains 1 and 2 of CDH17.

[0677] Six- to eight-week-old female Balb / c or SJL mice were immunized with recombinant human CDH17 EC1-2 hFc protein, recombinant human CDH17 EC1-7 his protein (Acro Biosystems, CA7-H52H3), or cells overexpressing recombinant human CDH17 (Genomeditech, GM-C25981). The protocol consisted of three immunizations: For the first immunization, antigen emulsified with Freund's complete adjuvant (CFA) was administered subcutaneously at a dose of 50 μg protein / mouse, or intraperitoneally at a dose of 5 E6 cells / mouse. The second and third immunizations were both emulsified with Freund's incomplete adjuvant (IFA), with 25 μg protein / mouse or 5 E6 cells / mouse. The second and third immunizations were spaced 2-3 weeks apart. Starting with the second immunization, orbital blood was collected one week post-immunization. The obtained serum was used for antigen-specific binding detection, and mice with high binding activity were selected for hybridoma fusion.

[0678] After booster immunization of selected mice, their spleens were harvested, ground, and the resulting cells were electrofused with mouse myeloma cells SP20. The fused cells were diluted in DMEM (Corning-cellgro, Cat#10-013-CVR) medium containing HT (Corning-cellgro, Cat#25-047-Cl) and seeded into 96-well plates. The plates were incubated overnight at 37°C with 5% CO2. After 24 hours, DMEM medium containing 2×HAT (Sigma, Cat#H-0262) was added, and the plates were cultured for 10-14 days. The hybridomas were then screened.

[0679] Binding assays at the protein or cellular level were performed using either ELISA or FACS. For human CDH17 protein binding screening, 96-well plates were coated with 1 μg / ml human CDH17 EC1-2 his (Kactusbio, CDH-HM1D5) or human CDH17 EC1-7 his protein (Acro Biosystems, CA7-H52H3), 100 μl / well, and incubated overnight at 4°C. After washing and blocking using standard methods, 100 μl of hybridoma supernatant was added and incubated before binding detection. Cellular binding was screened using CHOK1 cells overexpressing human CDH17. ELISA- or FACS-positive clones were cultured and then bound at the cellular level using FACS, including detection of binding to cells expressing recombinant human CDH17, cells expressing recombinant monkey CDH17, and CDH17-overexpressing tumor cells. FACS-positive clones were selected for the next subcloning step. After 7 days of culture, cell-level binding detection was performed. The clones with good binding activity were then expanded and VH / VL sequences were extracted.

[0680] Example 4. Production and identification of human-mouse chimeric antibodies

[0681] (I) Extraction of candidate cloned genes, construction of chimeric expression vectors, expression and purification of chimeric antibodies

[0682] After culturing the monoclonal hybridoma cells obtained in Example 3 to the logarithmic growth phase, the cells (approximately 1E6 cells / clone) were collected and cryopreserved. The cells were then sent to AZENTA LIFE SCIENCES for sequence extraction. The main steps included Trizol extraction of RNA, reverse transcription to obtain cDNA, amplification and acquisition of the heavy and light chain variable region sequences of the murine antibody, cloning the nucleotide sequences encoding the variable regions into vectors for sequencing, and comparing the sequencing results with the IMGT database to obtain the CDR information of the variable regions. Finally, effective antibody VH / VL sequences were obtained, and the nucleotide sequences encoding the target VH / VL were constructed into pTT5 expression vectors containing the coding sequences of the human IgG heavy chain constant region and light chain constant region, respectively.

[0683] The successfully constructed and correctly sequenced heavy and light chain plasmids were transfected into HEK293 cells at a density of 2E6 / ml using PEI reagent (Polysciences, Cat#24885) at a ratio of 2:3 (1ug plasmid: 4ug PEI). The transfected cells were incubated at 37°C in a 5% CO2 incubator for 5–7 days. The culture supernatant was collected, centrifuged, filtered through a 0.22µm filter, and purified using a Mabselect SuRe agarose gel column (GE Healthcare Bio-sciences, 17543802). The column was first equilibrated with 1xPBS (pH 7.4), and the filtered culture supernatant was loaded onto the column. The column was then washed with 1xPBS (pH 7.4), followed by elution with 50mM sodium citrate (pH 2.5). The eluted sample was then neutralized with 1M Tris-HCl (pH 9.0). The neutralized sample was replaced with 1xPBS (pH 7.4), filtered through a 0.22µm filter for sterilization, and the concentration of the purified antibody was determined using Nano One (Thermo Fisher Scientific Inc).

[0684] (II) Identification of the activity of chimeric antibodies

[0685] 1) Binding of anti-CDH17 chimeric antibody to human and monkey CDH17 overexpressing cells and CDH17 endogenous expressing cells

[0686] Cellular-level binding assays were performed using CHOK1 cells (Genomeditech, GM-C25980) overexpressing human CDH17, HEK293 cells (Genomeditech, GM-C28746) overexpressing Rhesus CDH17, AGS gastric cancer cells endogenously expressing CDH17, and SK-CO-1 colorectal cancer cells endogenously expressing CDH17 to detect the binding of anti-human CDH17 chimeric antibodies. Specifically, well-growing CDH17-expressing cells were collected, and the cell density was adjusted to 2E6 cells / ml. Cells were seeded into 96-well plates, 50 μl / well. Cells were resuspended in serially diluted chimeric antibodies (starting at 10 μg / ml, with 11 five-fold dilutions), 50 μl / well, and the plates were incubated at 4°C for 1 hour. Positive control antibodies were PTA001-A4 (PC-A4, sometimes simply referred to as A4) and 07-0663-h7 (H7), diluted to the same concentration and incubated. After incubation, the cell plates were centrifuged and washed three times with PBS. 100 μl of goat anti-human Fcγ fragment-specific APC antibody (Jackson ImmunoResearch, 109-135-098) diluted 1:1000 was added to each well, and the cells were incubated at 4°C in the dark for 30 min. After washing three times with PBS, the cells were resuspended in 80 μl of PBS. Flow cytometry readings were performed using iQue Screener PLUS, and the results were analyzed using GraphPad Prism. As shown in Table 2, the chimeric antibodies specifically bound to CDH17-overexpressing cells.

[0687] 2) Internalization assessment of anti-CDH17 chimeric antibody

[0688] Antibody internalization was evaluated using a commercial antibody internalization kit (Sartorius, 90565) according to the manufacturer's instructions. Specifically, the concentration of the test antibody and the internalization reagent were first adjusted to 100 μg / ml. The antibody was labeled using a ratio of 1 μl test antibody + 1 μl internalization reagent + 48 μl diluent, and incubated at 37°C for 15 min. After incubation, the mixture was diluted 2-fold in 9 gradients. Simultaneously, CDH17-expressing tumor cells were collected and the cell density was adjusted to 2E6 / ml. 20 μl of the diluted mixture was seeded into 96-well plates, and the diluted mixture (20 μl / well) was added. The seeded cells and antibody-internalization reagent mixture were incubated at 37°C in a CO2 incubator for 24 hours. Cells were collected the next day, and flow cytometry readings were performed using iQue Screener PLUS. The results were analyzed using GraphPad Prism. The results are presented in comparison with the control antibody (PC-A4). Table 2 shows that the detection antibodies were all effectively internalized.

[0689] 3) Evaluation of the cytotoxic activity of anti-CDH17 chimeric antibodies

[0690] The cytotoxic activity of the naked antibody was assessed using the commercially available cytotoxic agent αHFc-CL-MMAE (Moradec, AH-102AE-50). CDH17 expression cells in good growth condition, either AGS or SK-CO-1, were collected and the cell concentrations were adjusted to approximately 1E5 cells / ml (AGS) and 1.2E5 cells / ml (SK-CO-1). The cells were seeded into 96-well blank plates at 50 μl / well and incubated for 4 hours. Diluted antibody (starting at 6 μg / ml, with 9 3-fold dilutions) was added at 10 μl / well; then diluted 20ADCαHFc-CL-MMAE (2.5 μg / ml) was added at 40 μl / well. The plates were incubated at 37℃ in a CO2 incubator for 4 days. After incubation, 100 μl of Bio-Lite Luciferase Assay System reagent (Vazyme, DD1201-03) was added to each well, and the plates were shaken for 5 min. Relative fluorescence units (RLU) were then detected using a Spectra M5e instrument. The results are shown in Figure 2 and Tables 2-1, 2-2, and 2-3. All tested antibodies showed good killing activity on tumor cells, with antibodies 7D9B6, 238B11E1, 177H4G9, 199C4A7, and 182H5F9 showing superior activity compared to the positive control antibody PTA001-A4 (PC-A4, abbreviated as A4).

[0691] The antibodies selected in this step will be directly conjugated to BL20E to further evaluate the cell-killing activity targeted by the antibodies, thereby selecting the better molecules for further study.

[0692] Table 2-1 Results of binding, internalization, and killing assessments of CDH17 chimeric antibodies

[0693] Table 2-2 Results of Binding, Internalization, and Killing Assessment of CDH17 Chimeric Antibodies

[0694] Table 2-3 Results of binding, internalization, and killing assessment of CDH17 chimeric antibodies

[0695] 4) Detection of binding to anti-CDH17 antibody-BL20E conjugate

[0696] The chimeric antibody obtained in this application was constructed and conjugated with BL20E. The binding of the BL20E-conjugated CDH17 antibody to human CDH17-overexpressing cells, monkey CDH17-overexpressing cells, and tumor cells with different CDH17 expression levels was detected according to the method disclosed in this embodiment. Control molecules were constructed using PTA001-A4 (PC-A4) or PTA001-A4K (PC-A4K, a humanized antibody against PC-A4) (Oxford Biotherapeutics, patent US20160039933A1).

[0697] The results (Tables 3-1 and 3-2) showed that the anti-CDH17 antibody-BL20E molecules (abbreviated as CDH17 antibody name-BL20E) exhibited differential binding. Among them, 7D9B6-BL20E and 238B11E1-BL20E showed superior binding activity in cells expressing different levels of CDH17, followed by 46D5D6 H2L3-BL20E, 4H1A5 H3L1-BL20E, and 26A9H6-BL20E.

[0698] Table 3-1: Binding detection of CDH17-BL20E in human CDH17-overexpressing cells, monkey CDH17-overexpressing cells, and gastric cancer cells.

[0699] *The secondary antibody concentration used for this cell assay was 1:2000. The high expression of the cells caused the instrument's detection range to be exceeded, but it did not affect the comparison between antibodies from the same batch.

[0700] Table 3-2: Binding detection of CDH17-BL20E on colorectal cancer cells

[0701] *: Because cell clumping after Versene treatment can lead to a lower MFI, comparisons between antibodies tested in the same batch are unaffected.

[0702] 5) Internalization detection of anti-CDH17 antibody-BL20E conjugate molecule

[0703] The antibody internalization detection method disclosed in Example 4 was used for detection, and the results are shown in Figure 3. The anti-CDH17 antibody-BL20E molecules were all effectively internalized and showed an internalization level comparable to that of the control antibody (PC-A4 BL20E).

[0704] 6) Killing assessment of anti-CDH17 antibody-BL20E conjugate molecule

[0705] Cell-killing activity was assessed after antibody conjugation with BL20E. Colorectal and gastric cancer cells with different CDH17 expression levels were collected, and the cell concentration was adjusted to 6E4-1E5 cells / ml according to cell growth rate. Cells were seeded in 96-well blank plates at a rate of 50 μl / well. Simultaneously, diluted antibody (starting at 1.2 μg / ml, with 11 three-fold dilutions) was added at 50 μl / well, and the plates were incubated at 37°C with CO2 for 7 days. PC-A4-BL20E was used as a positive control. After incubation, 100 μl of Bio-Lite Luciferase Assay System reagent (Vazyme, DD1201-03) was added to each well, and the plates were shaken for 5 minutes. Relative fluorescence (RLU) values ​​were detected using a Spectra M5e instrument.

[0706] The results are shown in Figure 4 and Table 4. The CDH17 antibody-BL20E conjugates all exhibited good cytotoxic activity in tumor cells. Among them, 7D9B6-BL20E, 238B11E1-BL20E, 177H4G9-BL20E, 46D5D6-H2L3-BL20E, and 2D4C11BL20E showed superior cytotoxic activity at different expression levels in cells, with 199C4A7-BL20E showing the second highest activity.

[0707] Table 4. Statistical analysis of the killing activity of CDH17-BL20E molecule on different tumor cells.

[0708] Based on the results of the above cellular-level binding, internalization, and killing activities, chimeric antibodies 7D9B6, 238B11E1, 46D5D6 H2L3, and 2D4C11 were selected for humanization modification and activity evaluation.

[0709] Example 5. Epitope Analysis of Antibodies

[0710] ELISA binding assays were performed using proteins from different domains of recombinant human CDH17. Specifically, 1 μg / ml of recombinant human CDH17 EC1-2 his (Kactusbio, CDH-HM1D5), CDH17 EC3-4 mFc (Kactusbio, CDH-HM3D3), CDH17 EC5-7 his (Kactusbio, CDH-HM1D4), CDH17 EC1-6his (Kactusbio, CDH-HM1D1), and CDH17 EC1-7 his (Acro Biosystems, CA7-H52H3) protein solutions were coated into 96-well plates, 100 μl / well, and incubated overnight at 4°C. The next day, the coated 96-well plate was washed three times with 1xPBST solution, then blocked with 1% BSA solution (prepared with 1xPBST) and incubated at 37°C for 1 hour. After incubation, the plate was washed three times with 1xPBST, and serially diluted purified antibody was added and incubated at 37°C for 1 hour. The control antibodies were 07-0663-h7 (patent WO2023107558A1) and h10C12 (obtained by constructing and expressing the h10G1 VH / VL sequence from the Abeil patent US20190046655A1). After incubation and washing, a 1:5000 dilution of goat anti-human IgG Fcγ fragment-specific HRP antibody (Jackson ImmunoResearch, 109-035-098) was added and incubated at 37°C for 1 hour. After washing with PBST, 100 μl of TMB substrate was added to each well to detect antibody binding, and the reaction was terminated with an equal volume of 1N HCl. The results were analyzed using Spectra. The M5e instrument measures OD450nm.

[0711] As shown in Figure 5, the detected antibodies specifically bound to human CDH17 EC1-7 his, with the epitopes mainly concentrated in EC1-2. Only 46D5D6 differed from the other antibodies, specifically binding to EC3-4, but the binding signal was weak, suggesting that 46D5D6 might bind to the conformational structure of EC3-4.

[0712] Meanwhile, to further clarify the binding epitopes of the antibodies, the binding of EC1-2 to the antibodies was detected using human CDH17 EC1 his (SEQ ID NO:9), human CDH17 EC2 his (SEQ ID NO:10), monkey CDH17 EC1 his (SEQ ID NO:11), and monkey CDH17 EC2 his (SEQ ID NO:12) proteins. The method was the same as above: 96-well flat-bottom plates were coated with 1 μg / ml of different his-tag-carrying CDH17 domain peptide solutions, followed by the addition of serially diluted antibodies. The binding was detected. The control antibodies were PTA001-A4K (PC-A4K), h10C12, and 07-0663-h7 (PC-H7) (patent WO2023107558A1). The results are shown in Figure 6. The results showed that, except for 177H4G9 and the control antibody 10C12, the other detection antibodies had strong and comparable binding to human EC1 and monkey EC1 proteins; however, the binding to EC2 proteins varied, with the control antibody A4K binding to human and monkey EC2 most strongly, followed by the control antibody H7. This result also indicates that the antibody epitopes screened in this invention have certain differences from the control antibodies.

[0713] Example 6. Antibody Humanization

[0714] (I) Design, construction and expression of antibody humanization

[0715] Antibody humanization was performed using a CDR region transplantation method. Specifically, an antibody structural model was established based on the VH / VL sequence (MOE software). A human germline antibody with the highest homology was selected to provide the antibody framework. The CDR region, determined using CCG nomenclature in mouse anti-VH / VL, was transplanted onto the human antibody framework, forming the humanized antibody variable region sequence FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4. Simultaneously, based on the established antibody variable region structural model, potential reversion mutant amino acid residues were selected to ensure the activity of the humanized antibody.

[0716] The production and purification of humanized antibodies were carried out according to the method disclosed in Example 4. By testing the binding, internalization, and killing of humanized antibodies containing different mutations with CDH17 cells (including recombinant human-monkey cells and tumor cells), humanized antibodies 7D9B6 H14L3, 7D9B6 H14L5(B6), 238B11E1 H9L1, 238B11E1 H10L1(E1), 46D5D6 H2L3, 2D4C11 H4L1, 2D4C11 H7L1, and 2D4C11 H8L1 were obtained with comparable or better characterization and activity than the original antibodies. The results are shown in Tables 5-1, 5-2, 5-3, and 5-4.

[0717] Table 5-1 Binding detection of 7D9B6 humanized antibody

[0718] Table 5-2 Binding and internalization detection of the preliminary humanized antibody 238B11E1

[0719] Table 5-3 Binding and killing assays of the preliminary humanized antibody 46D5D6

[0720] Table 5-4 Binding and internalization detection of 2D4C11 preliminary humanized antibody

[0721] (II) Further modification of humanized antibodies

[0722] The humanized antibody was produced and purified according to the method disclosed in Example 4. By testing the binding, internalization, and killing activities of humanized antibodies containing different mutations with CDH17-expressing cells, humanized antibodies with characterization and activity functions equivalent to or better than those of the original antibodies were obtained.

[0723] 1. Evaluation of specific binding of humanized antibodies

[0724] The humanized antibody 238B11E1 H10L1 (E1) was further humanized to remove the PTM site, and the activity of the modified antibody was evaluated. The E1-modified humanized antibodies were named with "2E1" as a prefix. Figure 8 shows the binding activity of different E1-modified humanized antibodies on cells expressing different CDH17 levels. Figure 9 shows the binding activity of the 46D5D6 H2L3 humanized antibody on cells with different CDH17 expression levels. Table 11 shows the binding results of different E1-modified humanized antibodies on tumor cells.

[0725] The results showed that the humanized antibody exhibited different binding activity on cells with different CDH17 expression levels, and some molecules were obtained that had comparable binding activity to the original parent antibody and were superior to the control antibody.

[0726] Table 11. Binding results of humanized antibodies to tumor cells.

[0727] 2. Evaluation of the internalization activity of humanized antibodies

[0728] The internalization activity of the humanized antibodies was evaluated on tumor cells with different CDH17 expression levels using the method described in Example 4(II)2). The results are shown in Figure 25 and Table 12. All constructed humanized antibodies showed good internalization activity.

[0729] Table 12 Results of the internalization activity of humanized antibodies on tumor cells

[0730] 3. Evaluation of the cytotoxic activity of humanized antibodies

[0731] The in vitro cytotoxic activity of the humanized antibodies was evaluated using the method described in Example 4(II)3), and the results are shown in Figure 26 and Table 13. All constructed humanized antibodies exhibited effective cytotoxic activity.

[0732] Table 13 Results of the killing activity of humanized antibodies on tumor cells

[0733] Example 7. Evaluation of nonspecific binding of antibodies

[0734] ELISA and FACS were used to assess the nonspecific binding of antibodies at the protein and cellular levels, respectively, to rule out the influence of nonspecific binding on the in vivo activity of candidate molecules.

[0735] (I) Non-specific binding detection of protein levels

[0736] At the protein level, the binding of candidate molecules to intracellular small molecules (dsDNA, ssDNA, insulin, LPS) was primarily evaluated. Specifically, 5 μg / ml dsDNA, 5 μg / ml ssDNA, 5 μg / ml insulin, and 5 μg / ml LPS were coated into 96-well plates, 100 μl / well, and incubated overnight at 4°C. On the second day, the coated 96-well plates were washed three times with 1xPBST, then blocked with 1% BSA (prepared with 1xPBST) and incubated at 37°C for 1 hour. After incubation, the plates were washed three times with 1xPBST, and serially diluted humanized antibodies (starting at 200 μg / ml, 2-fold dilution) were added and incubated at 37°C for 1 hour. After incubation and washing, goat anti-human IgG Fcγ fragment-specific HRP antibody diluted 1:5000 was added and incubated at 37°C for 1 hour. After washing with PBST, 100 μl of TMB substrate was added to each well to detect antibody binding, and the reaction was terminated with an equal volume of 1N HCl. The results were detected using a Spectra M5e instrument at OD 450 nm.

[0737] As shown in Figure 10, all the detected antibodies did not specifically bind to these molecules, indicating that the antibodies prepared in this application have good specificity.

[0738] (II) Non-specific binding detection at the cellular level

[0739] The binding activity of the antibodies prepared in this application with other members of the cadherin family (CDH1, CDH2, CDH3, CDH6, and CDH16) was evaluated at the cellular level. NCI-H1650 and MCF-7 cells were CDH1 and CDH3 overexpressing cells; EFO27 cells were CDH1 and CDH2 overexpressing cells; CHOK1-CDH3 cells were recombinant CDH3 overexpressing cells (internal construction); OAW28 cells were CDH1 and CDH6 overexpressing cells; OVCAR-3 and 786O cells (provided by Sixin Biotechnology) were CDH6 overexpressing cells; SK-OV-3 cells were CDH16 highly expressing cells; and RKO cells were CDH17 negative cells used for non-specific binding assessment with family members. Except for cells with indicated sources, all other cells were derived from ATCC.

[0740] Specifically, cells were collected and the cell density was adjusted to 2E6 cells / ml. Cells were seeded into 96-well plates, 50 μl / well. Cells were resuspended in serially diluted antibody solutions (starting at 200 μg / ml, with 7 or 4 2-fold dilutions), 50 μl / well, and the plates were incubated at 4°C for 1 hour. Control antibodies A4K and H7 were used, diluted similarly for incubation. After incubation, the plates were centrifuged and washed three times with PBS. 100 μl / well of a 1:1000 dilution of goat anti-human Fcγ fragment-specific APC antibody was added, and the plates were incubated at 4°C in the dark for 30 minutes. After washing three times with PBS, the cells were resuspended in 80 μl of PBS. Cell flow cytometry readings were performed using an iQue Screener PLUS, and the results were analyzed using a GraphPad Prism.

[0741] The results, shown in Figures 12, 13, and 14, indicate that most of the antibodies prepared in this application did not bind non-specifically to these cells, suggesting that the binding of the candidate molecules to the target antigen CDH17 is specific. In Figure 13, antibodies 2E1 H19WVR-L6 and 2E1 H19WVR-L8 only partially bound to OVCAR3 and CHOK1 blank cells at high concentrations (666.7 nM, 200 ug / ml). In Figure 14, the 46D5D6 H2L3 PTM-modified antibodies H2L4, H11L4, H12L4, H13L4, and H11L13 did not bind to other members of the cadherin family; further analysis and testing of these antibodies will be conducted subsequently.

[0742] Example 8. Evaluation of cross-binding between antibody and monkey and mouse CDH17 protein

[0743] (I) Cross-binding activity of candidate molecules with monkey CDH17

[0744] Based on the display of the cynomolgus monkey CDH17 sequence on the NCBI and Uniprot websites, the differences between the cynomolgus monkey CDH17 and rhesus monkey CDH17 sequences were analyzed and binding verification was performed to determine the species cross-activity of the candidate molecules prepared in this application.

[0745] 1. Monkey CDH17 sequence alignment

[0746] The cynomolgus macaque CDH17 genome (Gene ID: 10212965, updated on 10-Mar-2024) in NCBI encodes two proteins, XP_005563762.2 and XP_045254438.1, each 832 amino acids in size. Sequence alignment revealed that the two proteins are completely identical in amino acid sequence. XP_005563762.2 was selected as the Cyno CDH17 sequence for subsequent sequence alignment. This sequence corresponds to the Uniprot Cyno CDH17 (ID: G8F4T0) sequence, with only two amino acid differences in their full-length sequences, showing 99% homology. The rhesus macaque CDH17 genome (Gene ID: 698886, updated on 5-Mar-2024) in NCBI encodes two proteins: isoform X1 (XP_028708609.1) and isoform X2 (XP_028708610.1), with sizes of 840 and 832 amino acids, respectively, and 93% homology. Full-length sequence comparison showed that the Rhesus CDH17 isoform X1 sequence corresponds to the Uniprot Cyno CDH17 (ID: A0A2K5X8I8-1) sequence, with 99% homology; the Rhesus CDH17 isoform X2 sequence is 100% homology to the Uniprot Rhesus CDH17 (ID: A0A1D5R2B4) sequence. Correspondingly, the sequence comparison results between Cyno and Rhesus CDH17 showed that the Cyno CDH17 XP_005563762.2 sequence is 99% homologous to the full-length Rhesus CDH17 isoform X2 XP_028708610.1 sequence; the Cyno CDH17 G8F4T0 sequence is 99% homologous to the full-length Rhesus CDH17 A0A1D5R2B4 sequence; and the Cyno CDH17 XP_005563762.2 sequence is 93% homologous to the full-length Rhesus CDH17 isoform X1 (XP_028708609.1) sequence. Furthermore, according to the mRNA sequences XM_028852776.1 and XM_028852777.1 corresponding to Rhesus CDH17 isoform X1 and isoform X2, respectively, these two Rhesus CDH17 sequences are composed of 15 and 17 exons, respectively, while the human CDH17 mRNA sequence NM_001144663.2 is also composed of 17 exons.Based on the above analysis, and considering the homology between the two monkey species and the exon composition of the human CDH17 sequence, it is inferred that the Rhesus CDH17 isoform X2 (XP_028708610.1) is the dominant sequence. The relationship diagram of the monkey sequences described above is shown in Table 6-2.

[0747] Due to the length of the sequences and the fact that the differences between the sequences are mainly reflected in the sequence before EC1 of CDH17, only the sequence comparison results for EC1-2 are shown. The results summary and sequence comparison results are shown in Figure 15 (refer to Table 6-1 for names). The results in Figure 15 show that the EC2 domain sequences of different monkey sequences are completely identical, and the EC1 domain sequences of the first four monkey CDH17 sequences are completely identical, while the last two (Rhesus CDH17 isoform X1 XP_028708609.1, Cyno CDH17 A0A2K5X8I8-1) are completely identical.

[0748] Table 6-1 Sequence of monkey CDH17 protein

[0749] Table 6-2 Summary of monkey CDH17 sequences

[0750] 2. Validation of CDH17 binding in monkeys

[0751] Based on the above sequence analysis and alignment results, the corresponding monkey CDH17 protein was purchased and ELISA binding detection was performed to determine the binding species and epitopes of the candidate molecules. Specifically, Rhesus CDH17 (Kactusbio, CDH-RM117, A0A1D5R2B4 Gln23-Thr784), Cyno CDH17 (Kactusbio, CDH-CM127, XP_005563762.2Gln23-Thr784), Cyno CDH17 (Kactusbio, CDH-CM117, A0A2K5X8I8-1 Met1-795), and Cyno CDH17 (Acrobiosystems, CA7-C52H4, A0A2K5X8I8-1 Lys30-Thr792) were coated into 96-well plates at 1 μg / ml, 100 μl / well, and incubated overnight. On the second day, the coated 96-well plates were washed three times with 1xPBST, then blocked with 1% BSA (prepared with 1xPBST) and incubated at 37°C for 1 hour. After incubation, the plates were washed three times with 1xPBST, and serially diluted purified antibody (starting at 10 μg / ml, 3-fold dilution) was added and incubated at 37°C for 1 hour. After incubation and washing, 1:5000 diluted goat anti-human IgG Fcγ fragment-specific HRP antibody was added and incubated at 37°C for 1 hour. After washing with PBST, 100 μl of TMB substrate was added to each well to detect antibody binding, and the reaction was terminated with an equal volume of 1N HCl. The OD450nm readings were detected using a Spectra M5e instrument, and the results were analyzed using a GraphPad Prism.

[0752] As shown in Figure 16, the two humanized candidate molecules, 7D9B6 H14L5(B6) (VH and VL are SEQ ID NO:31 & 32, respectively) and 238B11E1 H10L1(E1) (VH and VL are SEQ ID NO:33 & 34, respectively), bind only to monkey CDH17 proteins derived from A0A1D5R2B4 and XP_005563762.2, but not to monkey CDH17 proteins derived from A0A2K5X8I8-1. The 2E1 series antibodies, further humanized from 238B11E1 H10L1(E1), exhibit properties consistent with E1.

[0753] (II) Cross-binding activity of candidate molecules with rat CDH17 and mouse CDH17

[0754] Rat CDH7 his (Sino Biological, 80283-R08H) and mouse CDH17 ((Acrobiosystems, CA7-M52H5)) were coated into 96-well plates at 1 μg / ml, 100 μl / well, and incubated overnight. Diluted antibodies (10 μg / ml, 1 μg / ml) were added and incubated as in Part (I). The control antibody was LI-cadherin Ab(H-1) (Santa Cruz, sc-393533), and the corresponding secondary antibody was goat anti-mouse IgG (H+L) specific HRP antibody (Jackson ImmunoResearch, 115-036-146). The secondary antibody corresponding to the test antibody was goat anti-human IgG Fcγ fragment specific HRP antibody.

[0755] The results, as shown in 16E / F, indicate that none of the candidate molecules bind to rat CDH17 or mouse CDH17, meaning that the antibody does not cross-bind with mouse CDH17.

[0756] Example 9. Properties of humanized antibodies

[0757] 1. Affinity assessment

[0758] Antibody affinity was assessed by detecting antibody kinetic binding using the Octet Red 96 (Forte Bio, Serial No. FB-50482). Specifically, antibodies were captured using an AHC sensor (Forte Bio, REF Num: 18-5060), followed by loading recombinant human CDH17 His protein (2-fold dilution, 200 nM–12.5 nM), recombinant Cyno CDH17 (2-fold dilution, 200 nM–12.5 nM), or recombinant Rhesus CDH17 (2-fold dilution, 200 nM–12.5 nM). The binding constant (Kon) and dissociation constant (Koff) were analyzed using the Octet Red 96 analysis software in a 1:1 binding mode to determine the equilibrium dissociation constant KD (the ratio of Koff / Kon). The results are shown in Tables 14-1, 14-2, and 14-3, indicating that the humanized antibody of the present invention binds to human CDH17 and monkey CDH17 at nanomolar levels of KD.

[0759] Table 14-1 Affinity results of humanized antibodies to human CDH17

[0760] Table 14-2 Affinity results of humanized antibodies with Cyno CDH17

[0761] Table 14-3 Affinity results of humanized antibodies with Rhesus CDH17

[0762] 2. Evaluation of the thermal stability of candidate molecules

[0763] The thermostability of candidate molecules was assessed using RT-PCR. A commercially available kit was used. The Thermal Shift Stability Assay Kit (Cat. No. ENZ-51027-K400) was used for evaluation and detection. The antibody concentration was adjusted to 0.2 mg / ml using different pH histidine solutions (pH 6.0), PBS (pH 7.4), and Tris (pH 9.0). The buffer in the kit was diluted and mixed with samples at different pH values. The sample plate was placed in the instrument (Bia-Rad CFX96 real-time system) and detected using a program of 25°C for 5 min, then 25°C for 1 min, increasing the temperature by 0.5°C every 30 s until reaching 95°C. A Tm value greater than 65°C under different pH conditions indicates good molecular thermal stability. The results are shown in Table 7, demonstrating that the antibodies of this invention have good thermal stability, with consistent thermal stability at different pH levels, and some antibodies outperforming the control antibody.

[0764] Table 7 Summary of thermal stability results for candidate molecules

[0765] 3. Plasma stability assessment of humanized antibodies

[0766] Monkey plasma was used to assess the plasma stability of candidate molecules. Flow cytometry was used to evaluate the binding of samples to CHO cells overexpressing human CDH17 and to NCI-H716 and SNU-16 tumor cells. The antibody concentration was adjusted to 20 μg / ml and mixed with an equal volume of plasma. The prepared samples were incubated at 37°C, and samples were collected on days 0, 3, 7, 10, 14, and 21 and stored at 4°C for testing. The sample collected on day 21 should have been stored at 4°C for at least one day. The collected samples were serially diluted, and the binding of the samples to recombinant human CDH17-overexpressing cells and CDH17-expressing tumor cells was evaluated. The results showed that the binding of the antibody molecules was generally consistent at different time points, indicating good plasma stability (Figures 19 and 27).

[0767] 4. Hydrophobicity assessment of humanized antibodies

[0768] The hydrophobicity of antibodies was assessed using a HIC-HPLC method. A Waters HPLC system equipped with a TSK gel Butyl-NPR column (2.5 μm, 4.6 mm × 35 mm, TOSOH) was employed. The mobile phase consisted of two parts: Phase A was a 20 mM histidine solution containing 1.6 M ammonium sulfate ((NH4)2SO4), pH 6.0; Phase B was also a 20 mM histidine solution, pH 6.0. The antibody sample was diluted to 1.0 mg / mL (70 μg) with PBS and loaded onto the column. A gradient elution mode was used, transitioning the mobile phase from Phase B to Phase A at a flow rate of 0.7 mL / min, and UV absorbance was monitored at 280 nm. The hydrophobicity of the sample was assessed based on the (NH4)2SO4 concentration at the absorption peak time. Hydrophobicity was calculated using the following formula: (NH4)2SO4 concentration (M) = (23 - time + 1.25) × 0.101. In this method, samples with (NH4)2SO4 concentrations exceeding 0.85 M are considered hydrophilic. The results, shown in Table 15, indicate that the antibody molecules of this application exhibit good hydrophilicity, superior to that of the control antibody molecules.

[0769] Table 15 Hydrophobicity Assessment of Humanized Antibodies

[0770] 5. PK activity of humanized antibodies in mice

[0771] The pharmacokinetic (PK) activity of humanized 2E1 series antibodies in mice was evaluated, and a pharmacokinetic assay was designed for the antibodies in mice. Six- to eight-week-old female Balb / c mice were used, and four mice were administered a single intravenous dose of 200 μg of 2E1 series antibodies. Serum samples were collected from mice at different time points (0h, 1h, 4h, 8h, 24h, 48h, 96h, 120h, 144h, and 192h) after administration. The metabolic extent of the antibodies in mice was detected using ELISA. In this study, the antibody was coated with anti-human CDH17 his protein. The metabolism of the antibody in mice was measured, and the T (elimination rate constant) was calculated using K. 1 / 2 That is, T 1 / 2 =0.693 / K. Based on the K value of the drug obtained from the ELISA results, calculate the drug T. 1 / 2 The results are shown in Figure 18 and Table 9. The metabolic trends of the seven antibody drugs of this invention are similar. Including 192 hours, except for 2E1 H19L2, the other six antibodies T 1 / 2 All were above 130 hours; similarly, excluding 192 hours, the T values ​​of the other six antibodies were... 1 / 2It is also longer than 2E1 H19L2. In addition, the antibody molecules of the present invention are superior to the three control antibodies (07-0663-h7, PTA001-A4K, h10C12) in terms of PK in mice.

[0772] Table 9. T-cell matrix of E1 humanized antibody 1 / 2 result

[0773] Example 10. Preparation of ADCA containing the antibody of this application. Synthesis of drug loading.

[0774] 1.1 General methods for the synthesis of camptothecin-like compounds

[0775] In this application, MMAE, DXD, Exatecan, and SN38 were purchased from MedChemExpress:MCE.

[0776] Specifically, the camptothecin compounds of the present invention are synthesized according to the following general method: obtained by reacting the compound shown in Formula A with a CDE tricyclic compound via a Friedlander reaction, the general reaction formula of which is as follows:

[0777] The tricyclic compounds from CDE were purchased from MCE.

[0778] The HCDE tricyclic compound was prepared according to the method described in Bioorganic and Medicinal Chemistry, 2010, vol. 18, #9, p. 3140–3146.

[0779] 1.2 Synthesis of Camptothecin-like Compound 3

[0780] Synthesis of compound B

[0781] Compound B-1 was synthesized according to the method described in Journal of Medcinal Chemstry, 1998, 41(13), 2308-2318. Compound B-1 is a brown solid, and LC-MS (ESI): [M+1]+=177.

[0782] 1 H NMR(400MHz,DMSO-d6)δ6.76(d,J=8.7Hz,1H),6.67(bs,2H),6.42(d,J=8.7Hz, 1H), 4.20 (bs, 2H), 2.56 (t, J = 6.2Hz, 2H), 2.48–2.41 (m, 2H), 1.96–1.84 (m, 2H).

[0783] In a 250 mL three-necked flask, compound B-1 (2.18 g, 124 mmol, 1 eq) was dissolved in tetrahydrofuran (100 mL), and Boc anhydride (8.2 g, 376 mmol, 3 eq) was added. The mixture was stirred at 40–45 °C for 5 hours. The reaction solution was concentrated to dryness and purified by column chromatography with petroleum ether:ethyl acetate as the eluent in a ratio of 1:0 to 1:3 to give compound B-2, 3.0 g of yellow solid, with a yield of 90%.

[0784] 1H NMR (400MHz, CDCl3) δ7.25 (s, 1H), 6.41 (t, J = 10.2Hz, 3H), 5.90 (s, 1H), 2.7 3(t,J=6.2Hz,2H),2.61–2.47(m,2H),2.02–1.86(m,3H),1.49–1.36(m,9H)

[0785] In a 250 mL three-necked flask, compound B-2 (3.0 g, 10.8 mmol, 1 eq) and DIPEA (3.5 g, 27.1 mmol, 1.5 eq) were mixed in dichloromethane (125 mL). The reaction solution was cooled to -5 to 0 °C using an ice-salt bath. Acetyl chloride (1.3 g, 16.5 mmol, 2 eq) was added dropwise. After the addition was complete, the ice-salt bath was removed, and the mixture was allowed to warm naturally. The reaction was stirred at room temperature for 4 hours. The reaction solution was concentrated to dryness, and the residue was purified by column chromatography using petroleum ether:ethyl acetate as the eluent in a ratio of 1:0 to 1:3 to give compound B, a pale yellow solid, 3.48 g, with a yield of 100%.

[0786] 1H NMR (400MHz, CDCl3) δ12.01(s,1H),8.55(d,J=9.1Hz,1H),7.57(t,J=36.2Hz,1H),6.09(s, 1H),2.80(t,J=6.2Hz,2H),2.65–2.58(m,2H),2.15(s,3H),2.07–1.98(m,2H),1.44(s,9H)

[0787] Step 1

[0788] In a 500 mL three-necked flask under nitrogen protection, compound B (2.45 g, 7.7 mmol, 1 eq) was dissolved in tetrahydrofuran (200 mL). The reaction mixture was cooled to -70 to -60 °C using a dry ice-acetone bath. KHMDS (1 M, 31 mL, 31.0 mmol, 4 eq) was slowly added dropwise. After the addition was complete, the mixture was stirred at -70 to -60 °C for 10 minutes. Then, a tetrahydrofuran solution of NFSI (7.35 g, 23 mmol, 3 eq) was added dropwise. Dissolved in tetrahydrofuran (70 ml), the mixture was added dropwise and stirred at -70 to -60°C for 10 minutes. The temperature was then naturally raised to 20 to 30°C and stirred for 3 hours. The reaction was quenched with saturated ammonium chloride aqueous solution (80 ml). The reaction solution was extracted with ethyl acetate (150 ml * 3). The combined organic phases were washed with saturated brine and concentrated to dryness to obtain the crude product. Purification was performed by column chromatography with petroleum ether:ethyl acetate = 1:0-1:3 as the eluent, yielding compound 3a, a yellow solid, 0.85 g, with a yield of 31.2%. LC-MS (ESI): [M+1]+ = 355.8

[0789] 1H NMR (400MHz, CDCl3) δ11.49(s,1H),8.64(d,J=9.2Hz,1H),7.74(d,J=8.5Hz,1H) ,6.06(s,1H),3.01(t,J=6.4Hz,2H),2.55–2.39(m,2H),2.19(s,3H),1.44(s,9H)

[0790] Step 2

[0791] In a 100 mL single-necked flask, compound 3a (0.85 g, 2.4 mmol) was mixed with 6 N hydrochloric acid (30 mL) and heated under reflux for 4 hours. Heating was stopped, and the reaction mixture was allowed to cool to room temperature. The pH was adjusted to 7–8 with sodium bicarbonate, and the mixture was extracted with dichloromethane (30 mL x 3). The combined organic phases were washed with saturated brine, concentrated to dryness, and purified by column chromatography using petroleum ether:ethyl acetate = 1:0–1:3 to give compound 3b, a brown solid, 0.25 g, yield 49.1%. LC-MS (ESI): [M+1]+ = 213.9

[0792] Step 3

[0793] At room temperature, compound 3b (214 mg, 1 eq), a CDE ring compound (315 mg, 1.2 eq), and PPTS (301 mg, 1.2 eq) were mixed in toluene (50 ml) and refluxed for 3–4 hours to remove water. The reaction solution was then concentrated to dryness and purified by column chromatography with petroleum ether as the eluent until methanol / dichloromethane = 1:20, yielding camptothecin compound 3 as a yellowish-brown solid. LC-MS (ESI): [M+1]+ = 440.8.

[0794] 1H NMR (400MHz, Acetone) δ7.89(d,J=9.1Hz,1H),7.48(d,J=9.1Hz,1H),7.37(s,1H),7.31(d,J=8.9Hz,1H), 5.59–5.26(m,5H),3.11–3.05(m,4H),2.73–2.59(m,3H),1.98(dt,J=14.0,7.0Hz,1H),1.05–0.98(m,3H)

[0795] 1.3 Synthesis of Camptothecin-like Compound 12

[0796] Intermediate 12a was prepared from compound D according to the literature method. Intermediate 12a had an LC-MS (ESI) concentration of [M+1]+ = 171.2. At -5 to 5 °C, intermediate 12a (3.4 g) was dissolved in dichloromethane, and triethylamine (3.0 g) was added. AllocCl (2.8 g) was then slowly added dropwise, and the reaction was stirred for 1–2 hours after the addition was complete. The mixture was quenched with water, washed once with water, washed once with saturated brine, dried over anhydrous sodium sulfate, and concentrated to obtain crude intermediate 12b, 5.5 g. LC-MS (ESI) concentration: [M+1]+ = 255.7.

[0797] At room temperature, intermediate 12b (5.5 g) was mixed in TBAF (55 ml) and acrylic acid (110 ml), and the mixture was heated to 50–55 °C and stirred for 24 hours. The reaction mixture was then concentrated to dryness, eluted with petroleum ether to methanol:dichloromethane = 1:50 to obtain approximately 5.2 g of crude intermediate 12c. LC-MS (ESI): [M+1]+ = 327.4

[0798] At room temperature, intermediate 12c (5.0 g) was mixed in 100 ml of a 3:1 mixture of ethanol and water, and then ammonium chloride (5.5 g) and iron powder (5.5 g) were added. The mixture was heated to reflux for 1–2 hours. The reaction was then cooled to room temperature, filtered, and the solid was washed with ethanol, concentrated to dryness, yielding approximately 3.8 g of crude intermediate 12d. LC-MS (ESI): [M+1]+ = 297.4.

[0799] At 20–30°C, intermediate 12d (3.8 g) was mixed in trifluoroacetic acid (38 ml), and trifluoroacetic anhydride (38 ml) was added. The mixture was stirred and reacted for 18–24 hours. Post-treatment: The mixture was directly concentrated to dryness, and column chromatography was performed, eluting with petroleum ether to ethyl acetate:petroleum ether = 1:4 to obtain intermediate 12e: 1.0 g. LC-MS (ESI): [M+1]+ = 375.3.

[0800] At room temperature, intermediate 12e (1.0 g) was mixed in methanol (20 ml), potassium carbonate (2.0 g) and water (5 ml) were added, and the mixture was stirred for 1–2 hours. The reaction solution was diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated to obtain the crude product. Column chromatography was performed, eluting with petroleum ether until the ethyl acetate:petroleum ether ratio was 1:2, yielding intermediate 12f: 0.65 g. LC-MS (ESI): [M+1]+ = 279.3.

[0801] At room temperature, intermediate 12f (220 mg), CDE ring (350 mg), and PPTS (350 mg) were mixed in toluene (50 ml) and refluxed for 3–4 hours to remove water. The reaction solution was then concentrated to dryness and purified by column chromatography with petroleum ether as the eluent until methanol / dichloromethane = 1:20, yielding 0.5 g of crude intermediate 12f. LC-MS (ESI): [M+1]+ = 506.4.

[0802] At room temperature, 12 g (500 mg) of intermediate was dissolved in tetrahydrofuran (20 ml). Under nitrogen protection, pyrrole (120 mg) and tetra-triphenylphosphine palladium (160 mg) were added, and the mixture was stirred for 1–2 hours after the reaction was complete. The reaction solution was concentrated to dryness, slurried with ethyl acetate, filtered, and dried under vacuum to give compound 12 as a brown solid, 30 mg. LC-MS (ESI): [M+1]+ = 422.5

[0803] 1.4 Synthesis of Camptothecin Compound 13

[0804] Intermediate 13a was prepared by fluorination with NFSI following a similar preparation method to that disclosed in Section 1.3 for intermediate 3a. Compound 13 was then prepared as a brown solid using a similar method to that in Section 1.3. LC-MS (ESI): [M+1]+ = 458.4

[0805] 1.5 Synthesis of Camptothecin-like Compound 14

[0806] Synthesized according to the method described in the literature Journal of Medicinal Chemistry, 1998, 41, 13, 2308-2318.

[0807] At 20–30°C, compound E (25 g) was mixed in acetic acid (100 ml), and acetic anhydride (24.9 g) was slowly added. After the addition was complete, the mixture was stirred for 3–4 hours. The reaction solution was then slowly transferred to ice water, and the solid was stirred to precipitate. The solid was filtered, collected, washed with water, and dried under vacuum to obtain intermediate 14a as a yellow solid, 31.0 g. LC-MS (ESI): [M+1]+=197.2

[0808] At 20–30°C, intermediate 14a (29 g), potassium carbonate (40 g), potassium iodide (5 g), and bromopropanol (25 g) were mixed in DMF (300 ml), heated to 100–110°C, and stirred for 3–4 hours. The reaction solution was cooled to room temperature, quenched in ice water, and extracted three times with 2 L of ethyl acetate. The extracts were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated to dryness, and slurried with petroleum ether to obtain a solid. The solid was then dried under vacuum to obtain intermediate 14b, a yellow solid: 33.0 g. LC-MS (ESI): [M+1]+=255.3

[0809] At 20–25°C, intermediate b (23 g) was dissolved in acetonitrile (1 L), followed by the addition of sodium dihydrogen phosphate solution (0.67 mol, pH 6.7, 900 ml), TEMPO (5 g), sodium chlorite solution (52.0 g dissolved in 60 ml water), and sodium hypochlorite (38 ml mixed with 38 ml water). After the addition was complete, the reaction solution turned dark brown. The mixture was stirred for 30 minutes. The reaction solution was cooled to room temperature, and the pH was adjusted to 2–3 with 2N hydrochloric acid. The mixture was extracted with ethyl acetate (1000 ml × 3), and the ethyl acetate layers were combined and washed with saturated brine. The product was dried over anhydrous sodium sulfate, filtered, concentrated, and then slurried with petroleum ether to obtain 24.0 g of crude intermediate 14c. LC-MS (ESI): [M+1]+ = 269.2. At room temperature, intermediate 14c (25 g) and 5% palladium on carbon (5 g) were mixed in methanol (500 ml) and hydrogenated under pressure for 3–4 hours. The palladium on carbon was filtered off, the solid was washed with methanol, the filtrate was concentrated, and the residue was slurried with petroleum ether to obtain crude product. Vacuum drying yielded intermediate 14d, a yellow solid: 18.0 g. LC-MS (ESI): [M+1]+ = 239.5.

[0810] Following a similar method as described in 1.3, intermediate 14h was synthesized from intermediate 14d. Finally, the acetyl group was removed by 6N hydrochloric acid to prepare compound 14, which was a yellow solid with LC-MS (ESI): [M+1]+=406.1.

[0811] B. Synthesis of drug-containing linkers

[0812] The drug-containing linkers MC-GGFG-Dxd and CL2A-SN38 were purchased from MCE; BL20E was synthesized according to the method of patent CN110088086B; MF-L6 was synthesized according to the method of patent WO2023109965A1. MWC-L2 and MF-L6 have the following structures:

[0813] 1.6.1 Synthesis of drug-containing linker MWC-L2

[0814] Linker compound A was synthesized according to the method described in WO2018 / 095422A1. The synthetic route is as follows:

[0815] Connector A is a yellow solid, LC-MS(ESI): M+1 = 858

[0816] Step 1

[0817] Boc-Val-Ala-OH (288 mg, 1 mmol), compound B-1 (176 mg, 1 mmol, 1 eq), DIPEA (322 mg, 2.5 mmol, 2.5 eq), and HATU (456 mg, 1.2 mmol, 1.2 eq) were dissolved in 30 mL of DCM and stirred for 2 h. The reaction solution was evaporated to dryness and purified by column chromatography with an eluent of PE:EA = 10:1 to 5:1, quantitatively yielding intermediate 2-1 as a grayish-green solid of 450 mg.

[0818] Step 2

[0819] Intermediate 2-1 (450 mg, 1 mmol), CDE tricyclic compound (263 mg, 1 mmol, 1 eq), and p-toluenesulfonic acid pyridinium salt (PPTS) (251 mg, 1 mmol, 1 eq) were suspended in 30 mL of toluene and the mixture was heated under reflux for 2 hours. Heating was stopped, and after the reaction solution cooled, the solid precipitate was collected as crude intermediate 2-2, 750 mg of which was a brown solid. LC-MS (ESI): M+1 = 574. The mixture was directly proceeded to the next reaction without purification.

[0820] Step 3

[0821] Connector A (857 mg, 1 mmol), HoSu (138 mg, 1.2 mmol, 1.2 eq), and DCC (310 mg, 1.5 mmol, 1.5 eq) were dissolved in 30 ml of DCM and stirred at room temperature for 3 h. The reaction solution was filtered, and the filtrate was the A-Osu DCM solution. The filtrate was added to a mixed solution of crude intermediate 2-2, DIPEA (323 mg, 2.5 mmol, 2.5 eq), and DCM (30 ml), and the reaction was stirred for 3 h. The reaction solution was cooled to 10 °C, and 1 N hydrochloric acid (20 ml) was added, and the mixture was stirred for 0.5 h. The aqueous phase was extracted with DCM (30 ml * 2), and the organic phases were combined. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. Column chromatography purification, eluent: DCM:MeOH = 50:1 to 10:1, yielded linker MWC-L2 as an orange-red solid, 325 mg, yield 23.0%, LC-MS (ESI): M+1 = 1414, (M+1) / 2 = 707

[0822] 1.6.2 Synthesis of drug-containing linker MWF-L6

[0823] Following the synthetic method for linker MWC-L2, MWF-L6 was prepared by replacing compound B-1 with compound 3b. MWF-L6 was an orange-red solid with LC-MS (ESI): M+1 = 1450. MWF-L6 is the "MF-L6" referred to in this application.

[0824] 1.6.3 Synthesis of drug-containing linker MWF-L9

[0825] After removing the protecting group from intermediate 14e with 6N hydrochloric acid, MWF-L9 was prepared by a similar method to 1.6.1. It was a yellow solid with LC-MS (ESI): M+1 = 1416.4.

[0826] 1.6.4 Synthesis of drug-containing linker MWF-L10

[0827] Intermediate 12f was deprotected with tetratetraphenylphosphine palladium and tetrahydropyrrole to obtain MWF-L10, which was a yellow solid with LC-MS (ESI): M+1 = 1432.4.

[0828] C. Preparation of ADC drugs

[0829] 1.7 General Preparation Method

[0830] a. Site-directed coupling preparation process

[0831] The antibody is reduced to open the disulfide bond, then coupled with a drug-containing linker to form a bridging antibody-drug conjugate. The maleimide ring is then opened by hydrolysis, and finally purified to obtain an antibody-drug conjugate with DAR=4.

[0832] For example, the following experimental method was used:

[0833] I. A site-coupled ADC for MWF-L6 (MF-L6) is prepared according to the method described in patent application publication WO2023109965A1. A specific exemplary method is as follows:

[0834] Antibody reduction: 120 mg of antibody sample was used with a Sephadex G25-supported NAP-25 column, purged to pH 7.0 in a buffer solution containing 50 mM sodium chloride and 50 mM sodium dihydrogen phosphate-disodium hydrogen phosphate, and the antibody concentration was diluted to 10 mg / ml. 10 ml of a total of 100 mg of antibody sample was taken, and 2.1 ml of 10 mg / ml TCEP (Sigma-Aldrich) aqueous solution was added at an antibody-TCEP molar ratio of 1:10. After incubation for 2 hours, the sample was purged using Sephadex G25 column reaction solution to a buffer solution at pH 6.5 containing 50 mM sodium chloride and 50 mM sodium dihydrogen phosphate-disodium hydrogen phosphate.

[0835] Coupling and hydrolysis of antibody with drug-containing linker MF-L6: The reduced antibody was diluted to 5 mg / mL, and 0.38 mL of N,N-dimethylacetamide (DMA) (2% of the total reaction volume) was added as a pre-solvent. A DMA-drug-containing linker mixed solution containing 10 mg / mL of drug-containing linker was added at a molar ratio of 1:5.5 (antibody-MF-L6). The mixture was stirred at room temperature for 30 minutes. The reaction solution was then replaced with a pH 8.0 disodium hydrogen phosphate-sodium dihydrogen phosphate buffer using a Sephadex G25 support NAP-25 column to remove excess drug-containing linker. The mixture was then heated in a 37°C water bath for 3 hours.

[0836] Purification of the antibody-drug conjugate: The above sample was concentrated using an AMICOM ultrafiltration centrifuge tube to approximately 15 mg / mL. A 50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate + 3 M ammonium phosphate buffer solution was added until the conductivity reached 100 mS / cm. The sample was loaded onto a TOYOPEAL Butyl-650M hydrophobic column (purchased from TOSOH). Phase A consisted of 50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate + 0.6 M ammonium sulfate, and Phase B consisted of 50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate buffer solution. Elution was performed using an 8-fold column volume gradient from 0-100% in Phase B, and the main peak was collected.

[0837] The final sample was transferred to a 50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate buffer at pH 7.4 using an AMICOM ultrafiltration centrifuge tube and filtered through a 0.22 μm filter membrane (Sartorius stedim Ministart). The antibody-drug conjugate was then purified.

[0838] II. The BL20E-coupled ADC is prepared according to the method described in patent application publication WO2022228563A1. A specific exemplary method is as follows:

[0839] Sample Reduction and Coupling: The antibody sample was replaced with a Sephadex G-25 carrier-based NAP-25 desalting column to a pH 7.4 buffer solution containing 50 mM sodium chloride and 50 mM sodium dihydrogen phosphate-disodium hydrogen phosphate, and the antibody concentration was diluted to 10 mg / ml. 10 ml of a total of 100 mg of antibody sample was taken, and 10 mg / ml of TCEP (Sigma-Aldrich) aqueous solution was added at an antibody-reducing agent molar ratio of 1:10. After incubation for 2 hours, the reaction solution was replaced with a Sephadex G25 desalting column to a pH 7.0 buffer solution containing 50 mM sodium chloride and 50 mM sodium dihydrogen phosphate-disodium hydrogen phosphate.

[0840] The reduced antibody was diluted to 5 mg / mL, and 1.33 mL of N,N-dimethylacetamide (DMA) (7.4% of the total reaction volume) was added as a presolvent. A DMA-drug linker mixture containing 10 mg / mL of drug linker was added at an antibody-small molecule drug molar ratio of 1:5.5. The mixture was stirred at room temperature for 60 minutes. The reaction solution was then replaced with a pH 8.0 disodium hydrogen phosphate-sodium dihydrogen phosphate buffer using a Sephadex G-25 carrier NAP-25 desalting column to remove excess drug linker. The mixture was then heated in a 37°C water bath for 3 hours. Mass spectrometry analysis of the conjugate structures was performed before and after water bath heating. The analysis results of different conjugates all showed that the conjugate before water bath heating was the structure of formula Ia, and after water bath heating, the completely ring-opening structure of formula Ib was obtained, i.e., 100% hydrolysis.

[0841] Sample purification: The above sample was concentrated using AMICOM ultrafiltration centrifuge tubes to approximately 15 mg / mL. A 50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate + 3 M ammonium phosphate buffer solution was added until the conductivity reached 74 mS / cm. The sample was loaded onto a Butyl-Sepharose 4FF hydrophobic column (purchased from GE Healthcare), using phase A (50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate + 0.45 M ammonium sulfate) and phase B (50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate buffer solution). Elution was performed using a 0-80% linear gradient of 12 column volumes followed by a 100% isocratic gradient in phase B, and the main peak was collected.

[0842] The final sample was transferred to 50 mM disodium hydrogen phosphate-sodium dihydrogen phosphate buffer (pH 7.4) using AMICOM ultrafiltration centrifuge tubes and filtered through a 0.22 μm filter membrane (Sartorius stedim Ministart). The antibody-drug conjugate was then purified.

[0843] b. Random coupling preparation process

[0844] The antibody is reduced to open the disulfide bond, and then coupled with a drug-containing linker to form a bridging antibody-drug conjugate.

[0845] D. Characterization of the physicochemical properties of ADC drugs

[0846] a. Determination of drug-antibody conjugation ratio by ultraviolet spectrophotometry (UV-DAR method)

[0847] According to the literature [Clin Cancer Res. 2004 Oct 15; 10(20):7063-70], DAR is calculated according to the formula:

[0848] DAR=(εAb 280-A280 / Az×εAb Z) / (A280 / Az×εD Z-εD 280),

[0849] Wherein, εAb 280 is the molar absorption coefficient of the antibody at 280 nm, A280 is the UV absorbance of the antibody-drug conjugate at 280 nm, Az is the UV absorbance of the antibody-drug conjugate at the characteristic absorption wavelength Z nm of the drug-containing linker, εAb Z is the molar absorption coefficient of the antibody at the characteristic absorption wavelength Z nm of the drug-containing linker, εD Z is the molar absorption coefficient of the drug-containing linker at its characteristic absorption wavelength Z nm, and εD 280 is the molar absorption coefficient of the drug-containing linker at 280 nm.

[0850] b. Size exclusion high-performance liquid chromatography (SE-HPLC) for the analysis of molecular size heterogeneity

[0851] Perform SE-HPLC with the following parameters:

[0852] Chromatographic column: TOSOH, TSKgel G3000SWXL, 5μm, 7.8mm*300mm;

[0853] Mobile phase: 100 mM PB + 200 mM arginine hydrochloride, 5% isopropanol (pH 6.8);

[0854] Flow rate: 0.6 mL / min;

[0855] Detection wavelength: 280nm;

[0856] Column temperature: 30℃;

[0857] Sample loading volume: 20 μL;

[0858] Washing time: 20 min;

[0859] Elution gradient: isocratic elution.

[0860] According to Example Preparation Method I in Section 1.7 of the Preparation of ADC Drugs section of this application, antibodies targeting CDH17 are conjugated with drug-containing linkers MF-L6 (using isoform II as an example) to prepare antibody-drug conjugates of Ab-MF-L6. According to Example Preparation Method II in Section 1.7 of the Preparation of ADC Drugs section of this application, antibodies targeting CDH17 are conjugated with drug-containing linkers BL20E (using isoform II as an example) to prepare antibody-drug conjugates of Ab-BL20E.

[0861] The drug-antibody conjugate ratio (DAR) was determined by ultraviolet spectrophotometry in the characterization section of the physicochemical properties of ADC drugs in this application, and molecular size heterogeneity was analyzed by size exclusion high performance liquid chromatography (SEC-HPLC).

[0862] The results are shown in the table below.

[0863] Characterization results of antibody-drug conjugates targeting CDH17

[0864] Example 11. Binding activity, internalization activity, and killing activity of the ADC of this application.

[0865] Referring to the method in Example 4, the binding, internalization, and killing of humanized antibodies and ADC molecules conjugated with BL20E (abbreviated as Ab-BL20E), and humanized antibodies conjugated with camptothecin compound MF-L6 (abbreviated as Ab-MF-L6) were evaluated in human CDH17 overexpressing cells, monkey CDH17 overexpressing cells, and cancer cells with different CDH17 expression levels.

[0866] Figure 7 shows the evaluation results of B6-BL20E, E1-BL20E, B6-MF-L6, and E1-MF-L6. The control samples were prepared by conjugating the control antibodies PTA001-A4K (A4K) and 07-0663-h7 (H7) with BL20E and MF-L6 in the same manner.

[0867] The results, as shown in Figures 7A and 7B, indicate that both B6-MF-L6 and E1-MF-L6 can specifically bind to cells expressing different levels of CDH17, and the binding levels of the four molecules are comparable on the same cell type. Furthermore, the ADCs prepared by conjugation with either BL20E or MF-L6 do not affect the binding activity of the contained antibodies, meaning that the antibodies conjugated to the two toxins have comparable binding levels on the same cell type. Figure 7C shows that B6-BL20E, E1-BL20E, B6-MF-L6, and E1-MF-L6 can all be effectively internalized on CDH17-expressing cells, and the internalization levels are comparable on the same cell type. Figure 7D shows that the antibody ADC molecules conjugated with BL20E can effectively kill CDH17-positive tumor cells, and the killing activity of the four molecules is comparable. Figure 7E shows that the antibody conjugated with MF-L6 can effectively kill CDH17-positive cells.

[0868] In summary, the in vitro evaluation results show that the ADC molecule constructed in this application exhibits specific binding activity, high internalization properties, and effective killing activity in recombinant CDH17-overexpressing cells and tumor cells of different cancer types with different CDH17 expression levels.

[0869] Example 12. Binding specificity of the ADC of this application

[0870] The binding activity of the antibody ADC prepared in this application with other members of the cadherin family (CDH1, CDH2, CDH3, CDH6, CDH11 and CDH16), CDH17 negative tumor cells (colorectal cancer cells RKO, liver cancer cells HepG2, pancreatic cancer cells PANC1, gastric cancer cells NCI-N87), and normal cells (CHOK1, HEK293, HAEC, HPAEC, HUVEC) was evaluated at the cellular level for non-specific binding assessment.

[0871] For specific methods, please refer to the method disclosed in Example 7.

[0872] The results, as shown in Figure 11, indicate that the candidate antibody ADC prepared in this application did not bind nonspecifically to these cells, thus proving that the candidate ADC molecule prepared in this application has binding specificity to the target antigen CDH17.

[0873] Example 13. Evaluation of PK activity of antibody drugs in mice

[0874] To preliminarily assess the drug metabolism of antibody drugs in mice, a pharmacokinetic (PK) assay was designed. Six- to eight-week-old female Balb / c mice (Shanghai Sixin Pharmaceutical Technology Co., Ltd.) were used. Four mice were administered B6-MF-L6 ADC and E1-MF-L6 ADC intravenously, 200 μg / mouse, respectively. Serum samples were collected at different time points after administration (0h, 1h, 4h, 8h, 24h, 48h, 96h, 120h, 144h, and 192h). The drug metabolism in mice was detected using an ELISA method. Two assays were used, one coated with anti-human antibodies, to detect the metabolism of human antibodies and the other ADC in mice. The elimination rate constant (K) was used to calculate the Tg. 1 / 2 That is, T 1 / 2 =0.693 / K. Based on the K value of the drug obtained from the ELISA results, calculate the drug T. 1 / 2 The results are shown in Figure 17 and Table 8. The antibody drug metabolism trends assessed by the two methods are similar, with T... 1 / 2 similar.

[0875] Table 8: ADC molecular T 1 / 2 Results Summary

[0876] Example 14. Antitumor activity of the antibody-drug conjugate of this application

[0877] The in vivo efficacy of the ADCs B6-MF-L6 and E1-MF-L6 in this invention was evaluated in mice, and they all showed effective tumor-suppressive activity in different CDX models (cell line-derived xenograft tumor models) of gastrointestinal tumors. The in vivo efficacy results of B6-MF-L6 and E1-MF-L6 are shown below.

[0878] Human colon cancer HT55 cells, human colon cancer CL40 cells, human gastric cancer SNU-16 cells, and human colorectal adenocarcinoma NCI-H716 cells were subcutaneously in the right anterior flank of female BALB / c nude mice. Tumors were allowed to grow to an average size of approximately 200 mm². 3 The mice were administered drugs in groups, as detailed in Table 10. All drugs were administered intravenously. The day of administration was designated PG-D0. Drugs were administered once on PG-D0 or twice, on PG-D0 and PG-D7 (day 7). Tumor volume and body weight were measured twice weekly after grouping. Changes in body weight and tumor volume, and their relationship to drug administration time, were recorded. At the end of the experiment, the tumor-bearing mice were euthanized, and the dissected tumors from both the control and experimental groups were neatly arranged and photographed. The tumor growth inhibition rate (TGI) was calculated.TV (%) and perform statistical analysis.

[0879] Table 10: Dosing regimens for mouse models bearing HT55, CL40, SNU-16, and NCI-H716 tumors

[0880] Note: Dosage volume is 10 μl / g; IV: intravenous injection.

[0881] 1. In vivo efficacy in a human colon cancer HT55 model

[0882] The day of administration was designated PG-D0, and the mice were administered the drug twice, on PG-D0 and PG-D7. At the end of the experiment (PG-D30), the mean tumor volume of mice in groups G1, G2, G3, G4, and G5 was 1945 mm. 3 2091mm 3 625mm 3 2653mm 3 1438mm 3 Compared with the G1 group, the tumor volume inhibition rate (TGI) of each treatment group was significantly higher. TV The percentages were -7%, 68%, -33%, and 26% respectively (Figures 20A and C), with no significant change in body weight (Figure 24A).

[0883] Statistical analysis showed that at PG-D30, the G3 group exhibited a significant tumor-suppressing effect compared with the G1 group (p<0.05).

[0884] At the end of the experiment (PG-D30), the mean tumor weights of groups G1, G2, G3, G4, and G5 were 2.168 g, 2.311 g, 0.748 g, 2.718 g, and 1.553 g, respectively (Figures 20B and D). Statistical analysis showed similar results for tumor weight and tumor volume. In the human HT55 colon cancer model, the test drugs E1-MF-L6 and B6-MF-L6 were administered at doses of 3 mg / kg and 10 mg / kg, respectively, both showing a significant dose-dependent effect in inhibiting tumor weight growth. Meanwhile, tumor-bearing mice showed good tolerance to hIgG1 (10 mg / kg), E1-MF-L6 (3 mg / kg, 10 mg / kg), and B6-MF-L6 (3 mg / kg, 10 mg / kg).

[0885] 2. In vivo efficacy against a human colon cancer CL40 model

[0886] The day of administration was designated PG-D0, and each group received the drug once on PG-D0. At the end of the experiment (PG-D27), the mean tumor volume of mice in groups G1, G2, G3, G4, and G5 was 1787 mm.3 1300mm 3 727mm 3 1374mm 3 1009mm 3 Compared with group G1, the TGI in each treatment group was... TV The percentages were 27%, 60%, 24%, and 43% respectively (Figure 21A, C), with no significant change in body weight (Figure 24B).

[0887] Statistical analysis showed that at PG-D27, the G3 group exhibited a significant tumor-suppressing effect compared with the G1 group (p<0.05).

[0888] At the end of the experiment (PG-D27), the mean tumor weights of groups G1, G2, G3, G4, and G5 were 1.955g, 1.346g, 0.816g, 1.462g, and 1.065g, respectively (Figures 21B and D). Statistical analysis showed that tumor weight and tumor volume yielded similar results.

[0889] Tumor-bearing mice tolerated hIgG1 (10 mg / kg), E1-MF-L6 (3 mg / kg, 10 mg / kg), and B6-MF-L6 (3 mg / kg, 10 mg / kg) well.

[0890] 3. In vivo efficacy in the human gastric cancer SNU-16 model

[0891] The day of administration was designated PG-D0, and each group received the drug once on PG-D0. At the end of the experiment (PG-D28), the mean tumor volume of mice in groups G1, G2, G3, G4, and G5 was 1506 mm. 3 1435mm 3 77mm 3 1368mm 3 510mm 3 Compared with group G1, the TGI in each treatment group was... TV The percentages were 6%, 95%, 12%, and 68% respectively (Figure 22A, C), with no significant change in body weight (Figure 24C).

[0892] Statistical analysis showed that at PG-D28, compared with the G1 group, both the G3 group (p<0.01) and the G5 group (p<0.05) exhibited significant tumor-suppressing effects.

[0893] At the end of the experiment (PG-D28), the mean tumor weights of groups G1, G2, G3, G4, and G5 were 1.595g, 1.603g, 0.093g, 1.573g, and 0.561g, respectively (Figures 22B and D). Statistical analysis showed that the tumor weight results were consistent with the tumor volume results.

[0894] Tumor-bearing mice tolerated hIgG1 (10 mg / kg), E1-MF-L6 (3 mg / kg, 10 mg / kg), and B6-MF-L6 (3 mg / kg, 10 mg / kg) well.

[0895] 4. In vivo efficacy against human colorectal adenocarcinoma NCI-H716 model

[0896] The day of administration for each group is designated as PG-D0. Administration was administered on PG-D0 and PG-D6, for a total of two administrations. Based on the principle of humane endpoints for experimental animals, the experimental observation ended on PG-D23 for group G1, and on PG-D37 for groups E1-MF-L6 5 mg / kg (G2), G3, and B6-MF-L6 10 mg / kg (G4).

[0897] At PG-D23, the mean tumor volume of mice in groups G1, G2, G3, and G4 was 2711 mm. 3 1410mm 3 83mm 3 472mm 3 Compared with group G1, the TGI in each treatment group was... TV The percentages were 48%, 97%, and 83% respectively (Figure 23A, C), with no significant change in body weight (Figure 24D).

[0898] Statistical analysis based on tumor volume data at PG-D23 showed that, compared with group G1, groups G2, G3, and G4 all exhibited highly significant tumor-suppressive effects at PG-D23 (p<0.001).

[0899] At PG-D23, the mean tumor weight in group G1 was 2.686g; at PG-D37, the mean tumor weights in groups G2, G3, and G4 were 2.923g, 0.064g, and 1.269g, respectively (Figures 23B and D). In conclusion, in the BALB / c nude mouse model of human colorectal adenocarcinoma NCI-H716, compared with the Isotype hIgG 10mg / kg (G1) group, the E1-MF-L6 5mg / kg (G2), E1-MF-L6 10mg / kg (G3), and B6-MF-L6 10mg / kg (G4) groups all showed significantly significant tumor-suppressive effects. Meanwhile, tumor-bearing mice showed good tolerance to Isotype hIgG (10mg / kg), E1-MF-L6 (5mg / kg, 10mg / kg), and B6-MF-L6 (10mg / kg).

[0900] Example 15. Activity assessment of ADC molecules

[0901] The ADC molecules constructed according to the method of Example 10 were evaluated using the method of Example 4. The binding affinity, internalization properties, and cytotoxic activity of the ADC molecule (Ab-BL20E) site-conjugated with humanized antibody and the ADC molecule (Ab-MF-L6) site-conjugated with humanized antibody and camptothecin-like compound MF-L6 were mainly evaluated on CDH17 cells at different expression levels and on different cancer cell types.

[0902] (I) Binding assessment of ADC molecules

[0903] The results are shown in Figures 28 and 29 and Tables 16-1 and 16-2. The ADC molecules prepared by conjugating the humanized antibodies of the present invention with BL20E and MF-L6 respectively showed good binding activity on different tumor cells with different CDH17 expression levels.

[0904] Table 16-1 Results of Ab-BL20E ADC binding activity on tumor cells

[0905] Table 16-2 Results of Ab-MF-L6 ADC binding activity on tumor cells

[0906] (II) Evaluation of the internalization activity of ADC molecules

[0907] Figure 30 and Table 17 show the internalization results of different ADC molecules on tumor cells. This indicates that the ADC molecules constructed in this invention exhibit good internalization activity on tumor cells with different CDH17 expression levels and different cancer types.

[0908] Table 17 Results of ADC internalization activity on tumor cells

[0909] (III) Evaluation of the killing activity of ADC molecules

[0910] Figure 31 and Table 18 show the killing effect of ADC molecules on tumor cells. The ADC molecules obtained by conjugating the antibodies of the present invention with BL20E and MF-L6 respectively showed specific killing activity on tumor cells with different CDH17 expression levels and different cancer types.

[0911] Table 18 Killing activity of ADCs on tumor cells

[0912] Example 16. Evaluation of the physicochemical properties of ADC molecules

[0913] 1. CDH17 MF-L6 ADC Affinity Assessment

[0914] The affinity of the ADC molecule conjugated with MF-L6 of the present invention was tested using the affinity assessment method described in Example 9.1 to evaluate the effect of the conjugated drug molecule on antibody affinity. The results are shown in Table 19. The conjugated drug molecule did not affect the affinity of the applicant's derived antibody molecule.

[0915] Table 19 Affinity results of CDH17 MF-L6 ADC

[0916] 2. ADC hydrophobicity assessment

[0917] The hydrophobicity of the ADC molecules was tested using the method disclosed in Example 9.4. Tables 15 and 20 show that the hydrophilicity of the same antibody molecule did not change significantly or decreased slightly after conjugation with MF-L6. Similar to the results for the antibody molecules in Table 15, the ADC molecules obtained after conjugation of the antibodies of this invention with MF-L6 still exhibit good hydrophilicity. Conversely, the control antibody 07-0663-h7 just reached the required hydrophilicity after conjugation with MF-L6, while the control antibodies PTA001-A4K and h10C12 showed increased hydrophobicity after conjugation with MF-L6. In summary, the humanized antibody molecules of this invention maintain good hydrophilicity after conjugation with MF-L6, providing an excellent foundation for further research and development.

[0918] Table 20 Hydrophobicity Assessment of CDH17 MF-L6 ADC

[0919] 3. ADC thermal stability assessment

[0920] The thermal stability of the ADC molecule was tested using the method disclosed in Example 9(2). Table 21 shows that the ADC molecule constructed in this invention exhibits similar stability to its corresponding antibody (Table 7). Compared with the control antibody 07-0663-h7 and 10C12 conjugated with MF-L6, the ADC molecule of this invention has a Tm value that is 5°C higher, showing superior thermal stability. This excellent thermal stability lays a solid foundation for the subsequent development of the molecule.

[0921] Table 21 Thermal stability assessment of MF-L6 ADC

[0922] 4. Plasma stability assessment of ADC molecules

[0923] The plasma stability of the ADC molecules of the present invention was evaluated using a method similar to that disclosed in Example 9(3), except that an indirect ELISA method was used to evaluate the binding of the ADC molecules to the CDH17 protein. The results are shown in Figure 32, indicating that after incubation with monkey plasma, the binding of total antibody (TAB) and ADC (Inact ADC) of each ADC molecule was basically consistent at different times, indicating that the plasma stability of the ADC was good.

[0924] 5. PK assessment of ADC molecules in mice

[0925] The metabolic extent of the ADC molecule of the present invention in mice was evaluated using the method disclosed in Example 13, employing BALB / c mice. The results are shown in Table 22, indicating that the PK of the ADC of the present invention was superior to that of the control.

[0926] Table 22 Mouse pharmacokinetic results of CDH17 MF-L6 ADC

[0927] Example 17. Evaluation of tumor suppressor activity of ADC molecules in CDX model

[0928] The in vivo efficacy of the ADC molecule in this invention was evaluated in mice. Following the method described in Example 14, BALB / C nude mice or NCG mice (Jiangsu Jicui Pharmaceutical Biotechnology Co., Ltd.) were inoculated with human LS513 cells, human LS1034 cells, and human Aspc-1 cells from ATCC, or human 23132 / 87 cells from DSMZ, and administered the drugs in groups (Table 23). After grouping, tumor volume and body weight were measured twice weekly, and changes in body weight and tumor volume in tumor-bearing mice, as well as their relationship with drug administration time, were recorded. At the end of the experiment, the tumor-bearing mice were euthanized, and the dissected tumors from the control and test groups were neatly arranged, photographed, and weighed. The tumor growth inhibition rate (TGI) was calculated. TV (%) and tumor weight inhibition rate TGI TW (%) and perform statistical analysis.

[0929] Table 23 Dosing regimens for mouse models

[0930] Note: The administration volume is 10 μl / g; IV: intravenous injection; SC: subcutaneous injection.

[0931] 1. Antitumor activity of ADC molecules in the LS513 CDX model of colorectal cancer

[0932] As shown in Figure 33, compared with the G1 control group, different doses of 2E1 H19WVR-L15 MF-L6 exhibited dose-dependent tumor-suppressive activity in the LS513 model, with different doses showing tumor growth inhibition rates (TGI). TV The respective effects were 23%, 65%, and 82% (Figure 33A). Furthermore, at the same dose, conjugation of 2E1 H19WVR-L15 with different toxins produced different effects; when conjugated with toxin MF-L6, it exhibited significantly superior antitumor activity compared to conjugated with toxin BL20E (TGI). TV 82% vs 48% (Figure 33A, Table 24) highlights the ability of 2E1 H19WVR-L15 MF-L6 to overcome drug resistance in the treatment of colorectal cancer. Analysis of tumor weight at the end of the trial further confirmed these results (Figure 33B), while the ADC molecule of this invention did not affect mouse body weight (Figure 33C).

[0933] Table 24. Results of tumor-suppressive activity of ADC molecules in the LS513 CDX model of colorectal cancer.

[0934] 2. Antitumor activity of ADC molecules in the LS1034 CDX model of colorectal cancer

[0935] As shown in Figure 34, compared with the G1 control group, different doses of 2E1 H19WVR-L15 MF-L6 exhibited dose-dependent antitumor activity in the LS1034 model, with different doses showing tumor growth inhibition rates (TGI). TV The percentages were 29%, 39%, and 71% respectively (Figure 34A, Table 25). The TGI values ​​for 2E1 H19WVR-L8 MF-L6 at a dose of 3 mg / kg were... TV The figure was 36%. Furthermore, antibody 2E1 H19WVR-L15 conjugated with different toxins, at the same dose, showed significantly better antitumor activity of its conjugate with toxin MF-L6 than that with conjugate with toxin BL20E (TGI). TV (71% vs 46%). The results indicate that the MF-L6-conjugated ADC molecule has the ability to overcome drug resistance in the treatment of colorectal cancer. Analysis of tumor weight at the end of the trial further confirmed these results (Figure 34B), while the ADC molecule of this invention did not affect mouse body weight (Figure 34C).

[0936] Table 25 Results of the antitumor activity of ADC molecules in the LS1034 CDX model of colorectal cancer.

[0937] 3. Antitumor activity of ADC molecules in the SNU-C1 CDX model of colorectal cancer

[0938] As shown in Figure 35, compared with the G1 control group, 2E1 H19WVR-L15 MF-L6 exhibited significant dose-dependent antitumor activity in the SNU-C1 colorectal cancer mouse model. At different doses, the tumor growth inhibition rate (TGI) was significantly different. TV The antitumor effects were 26% and 75% respectively (Figure 35A, Table 26), demonstrating significant antitumor efficacy. In contrast, 07-0663-h7 MF-L6 at a dose of 3 mg / kg showed significant antitumor efficacy. TV The antitumor effect was only 57%, significantly lower than that of 2E1 H19WVR-L15 MF-L6. Similarly, h10C12MF-L6 showed almost no antitumor activity at a dose of 1 mg / kg, while TGI at a dose of 3 mg / kg showed significantly lower activity. TV The efficacy was 56%, which is far lower than the anti-tumor effect of 2E1 H19WVR-L15 MF-L6.

[0939] These results demonstrate that 2E1 H19WVR-L15 MF-L6 exhibits excellent tumor-suppressing effects in the treatment of colorectal cancer, particularly in overcoming drug resistance. At the end of the trial, tumor weight analysis further confirmed the significant antitumor effect of 2E1 H19WVR-L15 MF-L6 (Figure 35B), while the ADC molecule of this invention did not adversely affect the body weight of mice (Figure 35C).

[0940] Table 26. Results of the antitumor activity of ADC molecules in the SNU-C1 CDX model of colorectal cancer.

[0941] 4. Antitumor activity of ADC molecules in the gastric cancer 23132 / 87CDX model

[0942] The pharmacodynamic activity of the ADC molecule of the present invention in gastric cancer was evaluated using the 23132 / 87CDX model. Different doses of 2E1H19WVR-L15 MF-L6 showed dose-dependent antitumor activity in the 23132 / 87 model. The tumor growth inhibition rate (TGI) of 2E1 H19WVR-L15 MF-L6 at doses of 3 mg / kg and 10 mg / kg was significantly higher. TV The TGI values ​​were 17% and 57% respectively (Figure 36A, Table 27). The TGI values ​​of 2E1 H19WVR-L8 MF-L6 at a dose of 3 mg / kg were... TV The tumor weight was 31%. Analysis of tumor weight at the end of the experiment further confirmed these results (Figure 36B). Meanwhile, the ADC molecule of this invention did not affect mouse body weight (Figure 36C). These results indicate that the CDH17 ADC has effective tumor-suppressing activity in gastric cancer.

[0943] Table 27 Results of the antitumor activity of ADC molecules in the gastric cancer 23132 / 87CDX model

[0944] 5. Antitumor activity of ADC molecules in the pancreatic cancer Aspc-1 CDX model

[0945] The antitumor activity of the ADC molecule of the present invention against pancreatic cancer was evaluated using the Aspc-1 CDX model. Different doses of 2E1H19WVR-L15 MF-L6 showed dose-dependent antitumor activity in the Aspc-1 model. The tumor growth inhibition rate (TGI) of 2E1 H19WVR-L15 MF-L6 at doses of 1.5 mg / kg and 3 mg / kg was significantly higher. TV The tumor suppression rates were 34% and 81%, respectively (Figure 37A, Table 28). Compared with the control ADC molecule 07-0663-h7 BL20E, 2E1 H19WVR-L15 MF-L6 showed stronger antitumor efficacy and significantly improved tumor suppression (TGI). TV 81% vs 20%. When 07-0663-h7 was conjugated with toxin MF-L6 (i.e., 07-0663-h7 MF-L6), its antitumor efficacy in the Aspc-1 model was enhanced (TGI). TV 51%, but still lower than the 2E1 H19WVR-L15 MF-L6 molecule (TGI) of the present invention. TV The 51% vs 81% result highlights the ability of 2E1 H19WVR-L15 MF-L6 to overcome drug resistance in pancreatic cancer treatment. Analysis of tumor weight at the end of the trial further confirmed these results (Figure 37B), while the ADC molecule of this invention did not affect mouse body weight (Figure 37C). In summary, in the Aspc-1 model, 2E1H19WVR-L15 MF-L6 demonstrated superior tumor-suppressive activity compared to other ADC molecules.

[0946] Table 28 Results of the antitumor activity of ADC molecules in the pancreatic cancer Aspc-1 CDX model.

[0947] Example 18. Evaluation of tumor suppressor activity of ADC molecules in a PDX model

[0948] This embodiment further evaluates the tumor-suppressive effect of the ADC molecule of the present invention in a patient-derived xenograft (PDX) model. Following conventional methods, 2mm × 2mm × 2mm colorectal or gastric cancer tumor tissue blocks were subcutaneously inoculated into the right anterior flank of BALB / c Nude mice. When the tumor volume reached approximately 200mm², the tumor was allowed to mature.3 Mice were divided into groups of 3-6. The day of grouping was designated PG-D0, and each group received a single intravenous injection of the PG-D0 drug. Tumor volume and body weight were measured twice weekly, and changes in tumor volume and weight, as well as their relationship to drug administration time, were recorded. At the end of the experiment, the tumor-bearing mice were euthanized, and the dissected tumors were neatly arranged, photographed, and weighed. The tumor growth inhibition rate (TGI) was calculated. TV The percentages (%) and TGITW (%) were statistically analyzed. The dosing regimens for each model are shown in Table 29.

[0949] Table 29 Dosing regimens for mouse models

[0950] 1. Antitumor activity of ADC molecules in a colorectal cancer PDX model

[0951] The pharmacodynamic activity of the ADC molecule and control ADC molecule of this invention was evaluated using the colorectal cancer PDX models PDX-CRC-015 and PDX-CRC-016 (Beijing Yikang Pharmaceutical). In the PDX-CRC-015 model, as shown in Figure 38A, compared with the Vehicle group, after 45 days of administration, a single dose of 10 mg / kg of 2E1 H19WVR-L15 MF-L6 showed a tumor growth inhibition rate of 87%, which was also significantly better than the effect of 07-0663-h7 BL20E (TGI). TV 54%). Furthermore, with prolonged observation, the treatment effect of the control 07-0663-h7 BL20E tended to rebound, while 2E1 H19WVR-L15 MF-L6 maintained good tumor-suppressive activity. Similarly, as shown in Figure 39A, in the PDX-CRC-016 model, a single dose of 10 mg / kg of 2E1 H19WVR-L15 MF-L6 demonstrated excellent tumor-suppressive activity, with a TGI of 54% on day 32. TV The antitumor activity reached 94%, significantly higher than that of 07-0663-h7 BL20E (TGI). TV (74%). With prolonged observation, the tumors in the 07-0663-h7 BL20E treatment group gradually increased in size, while no growth was observed in the tumors of the 2E1H19WVR-L15 MF-L6 group, further demonstrating the superior therapeutic effect of the 2E1 H19WVR-L15 MF-L6 molecule of this invention. Analysis of tumor weight at the end of the two PDX model trials further confirmed these results (Figures 38B and 39B), while the ADC molecule of this invention did not significantly affect mouse body weight (Figures 38C and 39C). In summary, the ADC molecule 2E1 H19WVR-L15 MF-L6 of this invention exhibits significant tumor-suppressive activity in a colon cancer PDX model.

[0952] 2. Tumor-suppressive activity of ADC molecules in a gastric cancer PDX model

[0953] The pharmacodynamic activity of the ADC molecule of this invention was evaluated using the gastric cancer PDX model LD1-2017-361697 (Lidi Bio). Following a single administration of 10 mg / kg of 2E1 H19WVR-L15 MF-L6, tumors completely regressed in all three mice by day 32, demonstrating the potent therapeutic potential of the ADC molecule of this invention in a clinically relevant and physiologically representative model (Figure 40).

[0954] Example 19. Safety and toxicological studies of ADC molecules

[0955] Preclinical safety and pharmacokinetic studies of the ADC molecule of this invention were conducted using cynomolgus monkeys. 2E1 H19WVR-L15 MF-L6 was administered intravenously at doses of 15 mg / kg or 20 mg / kg every two weeks for a total of five administrations (on days 1, 15, 29, 43, and 57, respectively). Each dose group included two female and two male cynomolgus monkeys. Animals were clinically observed and recorded daily, including ophthalmic examination, food intake, weight, and body temperature monitoring. Clinical pathological assessments were also performed throughout the study, including hematological examination, plasma chemistry, lymphocyte immunophenotyping, immunoglobulin levels, and complement activity assays. Blood samples were collected at designated time points to monitor pharmacokinetics and clinical parameters. Animals were dissected one week after the last administration to assess gross pathological changes.

[0956] Blood samples were collected during the first and fourth dosing cycles for toxicokinetic analysis, and blood samples were collected before each injection for immunogenicity assessment. Serum concentrations of ADC and total antibody were quantified using ELISA, while the concentration of free MF-6 was determined by LC-MS / MS (Figure 41A). Simultaneously, pharmacokinetic parameters, including peak concentration (Cmax), half-life (t1 / 2), and area under the curve (AUC0-t), were calculated for ADC molecules, total antibody, and free MF-6 (Table 30).

[0957] Table 30 ADC Pharmacokinetic Parameters

[0958] The results showed no significant abnormalities in daily activities, ophthalmological examination, weight, body temperature, or food intake of the cynomolgus monkeys after administration. Furthermore, no anti-drug antibodies (ADA) were detected in any samples. In the 20 mg / kg dose group, one female cynomolgus monkey developed pigmentation changes (darkening) on ​​the right hind limb from day 30 until the end of the study. One female in the 15 mg / kg dose group experienced occasional loose stools on day 8, and one male in the 20 mg / kg dose group also experienced loose stools on day 28. These events also occurred before and after administration, and were of shorter duration or lower frequency; therefore, these phenomena were considered unrelated to ADC administration. In both female and male cynomolgus monkeys in the 20 mg / kg dose group, reticulocyte counts (RET) decreased after the first and third administrations compared to pre-administration levels (Figure 41B). However, no significant changes were found in other hematological parameters and serum chemistry parameters (Figures 41C-H). During dissection, focal melanosis was observed on the right hind limb skin of female animals in the 20 mg / kg dose group, while no other visible abnormalities were found in the other animals.

[0959] Based on the above results, the highest non-serious toxic dose (HNSTD) of the ADC molecule of the present invention in cynomolgus monkeys was determined to be 20 mg / kg.

[0960] sequence list

Claims

1. An anti-CDH17 antibody or its antigen-binding fragment that specifically binds to CDH17, comprising: 1) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:25, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:26; 2) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:27, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:28; 3) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:29, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:30; 4) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:31, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:32; 5) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:33, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:34; 6) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:33, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:35; 7) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:35; 8) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37; 9) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38; 10) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39; 11) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40; 12) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:36, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41; 13) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:37; 14) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:38; 15) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:39; 16) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:40; 17) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:42, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:41; 18) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:44; 19) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:43, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45; 20) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45; 21) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:47; 22) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:48; 23) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:46, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:49; 24) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:45; or 25) HCDR1, HCDR2, HCDR3 contained in the heavy chain variable region as shown in SEQ ID NO:50, and / or LCDR1, LCDR2, LCDR3 contained in the light chain variable region as shown in SEQ ID NO:

49.

2. An anti-CDH17 antibody or its antigen-binding fragment that specifically binds to CDH17, comprising: 1) Contains or is composed of HCDR1 as shown in SEQ ID NO:57; Contains or consists of HCDR2 as shown in SEQ ID NO:60; Contains or is composed of HCDR3 as shown in SEQ ID NO:61; It includes or is composed of LCDR1 as shown in SEQ ID NO:79; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 2) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:63; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:82; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 3) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:83; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:85; 4) Contains or is composed of HCDR1 as shown in SEQ ID NO:57; Contains or consists of HCDR2 as shown in SEQ ID NO:68; Contains or is composed of HCDR3 as shown in SEQ ID NO:61; It includes or is composed of LCDR1 as shown in SEQ ID NO:86; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 5) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:63; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 6) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 7) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:88; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 8) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:89; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 9) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:90; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 10) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:91; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 11) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:92; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 12) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:83; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:85; 13) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:85; 14) Contains or consists of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:94; 15) Contains or consists of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:95; or 16) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and It contains or is composed of LCDR3 as shown in SEQ ID NO:

96.

3. The anti-CDH17 antibody or its antigen-binding fragment according to claim 1 or 2, comprising a heavy chain variable region, wherein: 1) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 25, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 25, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 25, or is composed of SEQ ID NO: 25; 2) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 27, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 27, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 27, or is composed of SEQ ID NO: 27; 3) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 29, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 29, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 29, or is composed of SEQ ID NO: 29; 4) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 31, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 31, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 31, or is composed of SEQ ID NO: 31; 5) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; 6) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; 7) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; 8) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; 9) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; 10) The heavy chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO:

50.

4. The anti-CDH17 antibody or its antigen-binding fragment according to claim 1 or 2, comprising a light chain variable region, wherein: 1) The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 26, a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions or insertions, or any combination thereof, relative to SEQ ID NO: 26, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identity with the amino acid sequence of SEQ ID NO: 26, or is composed of SEQ ID NO: 26; 2) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 28, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 28, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 28, or is composed of SEQ ID NO: 28; 3) The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 30, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 30, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 30, or is composed of SEQ ID NO: 30; or 4) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 32, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 32, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 32, or is composed of SEQ ID NO: 32; 5) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 34, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 34, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 34, or is composed of SEQ ID NO: 34; 6) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35; 7) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37; 8) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38; 9) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39; 10) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40; 11) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41; 12) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 44, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 44, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 44, or is composed of SEQ ID NO: 44; 13) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45; 14) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 47, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 47, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 47, or is composed of SEQ ID NO: 47; 15) The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 48, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 48, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 48, or is composed of SEQ ID NO: 48; or 16) The light chain variable region comprises an amino acid sequence as shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO:

49.

5. The anti-CDH17 antibody or its antigen-binding fragment according to any one of claims 1-4, comprising a heavy chain variable region and / or a light chain variable region, wherein: 1) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 25, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 25, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 25, or is composed of SEQ ID NO: 25; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 26, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 26, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 26, or is composed of SEQ ID NO: 26; 2) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 27, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 27, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 27, or is composed of SEQ ID NO: 27; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 28, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 28, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 28, or is composed of SEQ ID NO: 28; 3) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 29, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 29, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 29, or is composed of SEQ ID NO: 29; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 30, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 30, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 30, or is composed of SEQ ID NO: 30; or 4) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 31, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 31, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 31, or is composed of SEQ ID NO: 31; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 32, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 32, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 32, or is composed of SEQ ID NO: 32; 5) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 34, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 34, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 34, or is composed of SEQ ID NO: 34; 6) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 33, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 33, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 33, or is composed of SEQ ID NO: 33; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35; 7) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 35, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 35, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 35, or is composed of SEQ ID NO: 35; 8) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37; 9) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38; 10) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39; 11) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40; 12) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 36, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 36, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 36, or is composed of SEQ ID NO: 36; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41; 13) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 37, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 37, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 37, or is composed of SEQ ID NO: 37; 14) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 38, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 38, or is composed of SEQ ID NO: 38; 15) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 39, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 39, or is composed of SEQ ID NO: 39; 16) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 40, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 40, or is composed of SEQ ID NO: 40; 17) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 42, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 42, or is composed of SEQ ID NO: 42; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 41, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 41, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 41, or is composed of SEQ ID NO: 41; 18) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 44, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 44, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 44, or is composed of SEQ ID NO: 44; 19) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 43, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 43, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 43, or is composed of SEQ ID NO: 43; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45; 20) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45; 21) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 47, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 47, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 47, or is composed of SEQ ID NO: 47; 22) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 48, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 48, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 48, or is composed of SEQ ID NO: 48; 23) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 46, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 46, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 46, or is composed of SEQ ID NO: 46; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions or any combination thereof relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO: 49; 24) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO: 50; the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 45, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 45, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 45, or is composed of SEQ ID NO: 45; or 25) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 50, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 50, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 50, or is composed of SEQ ID NO:

50. The light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 49, or a sequence containing one or more amino acid substitutions (e.g., conservative substitutions), deletions, or insertions, or any combination thereof, relative to SEQ ID NO: 49, or an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity with the amino acid sequence of SEQ ID NO: 49, or is composed of SEQ ID NO:

49.

6. The anti-CDH17 antibody or antigen-binding fragment thereof according to any one of claims 1 to 5, comprising a constant region sequence, wherein at least a portion of the constant region sequence is a human common constant region sequence, preferably, the heavy chain constant region sequence is as shown in SEQ ID NO: 14 or 15, and the light chain constant region sequence is as shown in SEQ ID NO:

16.

7. The anti-CDH17 antibody or its antigen-binding fragment according to any one of claims 1-6, comprising a heavy chain, wherein: 1) The heavy chain comprises the heavy chain variable region sequence as described in claim 3 and the heavy chain constant region sequence shown in SEQ ID NO: 14; or 2) The heavy chain comprises the heavy chain variable region of claim 3 and the heavy chain constant region sequence shown in SEQ ID NO:

15.

8. The anti-CDH17 antibody or antigen-binding fragment thereof according to any one of claims 1-6, comprising a light chain, wherein the light chain comprises the light chain variable region of claim 4 and the light chain constant region sequence shown in SEQ ID NO:

16.

9. The anti-CDH17 antibody or its antigen-binding fragment according to any one of claims 1-8, comprising a heavy chain and a light chain, wherein: 1) The heavy chain comprises the heavy chain of claim 7, and 2) The light chain comprises the light chain of claim 8.

10. The anti-CDH17 antibody or its antigen-binding fragment according to any one of claims 1 to 9, wherein the antigen-binding fragment is selected from Fab, Fab'-SH, Fv (e.g., scFv) or (Fab')2 fragments.

11. An antibody-drug conjugate or a salt thereof, said antibody-drug conjugate comprising an anti-CDH17 antibody or an antigen-binding fragment thereof that specifically binds to CDH17 according to any one of claims 1-10, and a drug conjugated thereto, wherein said drug is a therapeutically active substance or a pharmaceutically active ingredient.

12. An antibody-drug conjugate or a salt thereof, said antibody-drug conjugate or salt thereof having a structure as shown in structural formulas Ia and / or Ib: and / or in, Ab represents an anti-CDH17 antibody or its antigen-binding fragment that specifically binds to CDH17 as described in any one of claims 1-10; M is a phenylene or a phenylene substituted with one or more substituents, or a chemical bond; in the substituted phenylene, the substituent is selected from alkyl (e.g., C1-6 alkyl, preferably C1-4 alkyl), haloalkyl (e.g., haloC1-6 alkyl, preferably haloC1-4 alkyl, e.g., trifluoromethyl), alkoxy (e.g., C1-6 alkoxy, preferably C1-4 alkoxy, preferably methoxy), halogen, ester, amide, and cyano; SP1 is selected from C1-8 alkylene, C1-8 cycloalkylene, or C1-21 (preferably C1-16, more preferably C1-11, more preferably C5-9) straight-chain heteroalkylene, wherein the C1-21 straight-chain heteroalkylene comprises 1-11 (preferably 1-6, more preferably 3-5) heteroatoms selected from N, O, or S, wherein each of the C1-8 alkylene, C1-8 cycloalkylene, and C1-21 straight-chain heteroalkylene is independently and optionally substituted by one or more substituents selected from hydroxyl, amino, sulfonic acid, and cyano groups; SP2 is selected from -NH(CH2CH2O) a CH2CH2CO-、-NH(CH2CH2O) a CH2CO-、-S(CH2) a CO- or chemical bond, where a is an integer from 1 to 20; A represents a short peptide structure consisting of 2-4 amino acids; m is 1 to 10, preferably 1 to 8 (e.g., 1 to 5), and more preferably 3 to 8; CPT is a camptothecin-type compound.

13. The antibody-drug conjugate or its salt according to claim 12, characterized in that, In structural formulas Ia and / or Ib, M is a halogen-substituted phenylene, preferably a fluorine-substituted phenylene; Preferably, SP1 is a C1-11, more preferably C5-9, more preferably C7 straight-chain heteroalkyl group, which contains 1-6, more preferably 3-5, more preferably 4 heteroatoms selected from N, O or S; Preferably, SP2 is a chemical bond.

14. The antibody-drug conjugate or its salt according to claim 12 or 13, characterized in that, The structure of CPT is shown in structural formula I, wherein structural formula I is connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond, preferably with the amino group adjacent to group G in structural formula I connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond. in, R1, R2, R3, and R4 are independently hydrogen, halogen, hydroxyl, C1-6 alkoxy, amino or substituted amino, C1-7 alkyl or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms attached to them constitute a C3-6 (preferably C3-5) cyclic alkyl group. G is hydrogen, halogen, methyl or methoxy; Y is oxygen, sulfur, sulfone, sulfoxide, methylene, or a substituted methylene group; X represents oxygen or sulfur; n = 0 or 1.

15. The antibody-drug conjugate or its salt according to any one of claims 12 to 14, characterized in that, The structure of CPT is shown in structural formula IA, wherein structural formula IA is connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond, preferably with the amino group on the left benzene ring of structural formula IA connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond. Wherein, groups R1, R2, R3, and R4 are defined in the same way as groups R1, R2, R3, and R4 in structural formula I of claim 5, but R1, R2, R3, and R4 are not all hydrogen.

16. The antibody-drug conjugate or its salt according to claim 12 or 13, characterized in that, The structure of CPT is shown in structural formula II, wherein structural formula II is connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond, preferably with the amino group adjacent to group G in structural formula II connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond. Wherein, R5 is a C1-5 alkyl or a C1-5 alkyl substituted with one or more substituents, a C3-6 cyclic alkyl or a C3-6 cyclic alkyl substituted with one or more substituents, a phenyl or a substituted phenyl; G is hydrogen, halogen (e.g., fluorine), methyl or methoxy; X represents oxygen or sulfur; n = 0 or 1.

17. The antibody-drug conjugate or its salt according to claim 16, characterized in that, The structure of CPT is shown in structural formula IIA, wherein structural formula IIA is connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond, preferably with the amino group on the left benzene ring of structural formula IIA connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond. Wherein, group R5 is defined in the same way as group R5 in structural formula II of claim 7, but R5 cannot be n-butyl.

18. The antibody-drug conjugate or its salt according to any one of claims 12 to 17, characterized in that, The structure of the CPT is shown below, wherein each structural formula is connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond, preferably with the amino group on the left benzene ring of each structural formula connected to the carboxyl group in group A of structural formula Ia and / or Ib via an amide bond:

19. The antibody-drug conjugate or its salt according to claim 12 or 13, characterized in that, The structure of CPT is shown in structural formula IV, wherein the hydroxyl group in structural formula IV, which is attached to the same carbon atom as R8, is linked to the carboxyl group of group A in structural formulas Ia and / or Ib via a self-releasing structure, such as... Solid lines indicate sites where the material is attached to the carboxyl group of group A in structural formula Ia and / or Ib, and wavy lines indicate sites where the material is attached to the hydroxyl group in structural formula IV. R8 is hydrogen, trifluoromethyl, C1-5 alkyl or C1-5 alkyl substituted with one or more substituents, C3-6 cyclic alkyl or C3-6 cyclic alkyl substituted with one or more substituents, or halogen.

20. The antibody-drug conjugate or its salt according to any one of claims 11-19, wherein the Ab comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region and the light chain variable region each comprise the following CDR groups: 1) Contains or is composed of HCDR1 as shown in SEQ ID NO:57; Contains or consists of HCDR2 as shown in SEQ ID NO:60; Contains or is composed of HCDR3 as shown in SEQ ID NO:61; It includes or is composed of LCDR1 as shown in SEQ ID NO:79; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 2) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:63; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:82; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 3) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:83; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:85; 4) Contains or is composed of HCDR1 as shown in SEQ ID NO:57; Contains or consists of HCDR2 as shown in SEQ ID NO:68; Contains or is composed of HCDR3 as shown in SEQ ID NO:61; It includes or is composed of LCDR1 as shown in SEQ ID NO:86; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 5) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:63; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 6) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:80; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 7) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:88; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 8) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:89; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 9) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:90; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 10) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:91; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 11) Contains or is composed of HCDR1 as shown in SEQ ID NO:62; Contains or consists of HCDR2 as shown in SEQ ID NO:69; Contains or is composed of HCDR3 as shown in SEQ ID NO:64; It includes or is composed of LCDR1 as shown in SEQ ID NO:87; Contains or is composed of LCDR2 as shown in SEQ ID NO:92; and Contains or is composed of LCDR3 as shown in SEQ ID NO:81; 12) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:83; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:85; 13) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:85; 14) Contains or consists of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:94; 15) Contains or consists of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and Contains or is composed of LCDR3 as shown in SEQ ID NO:95; or 16) Contains or is composed of HCDR1 as shown in SEQ ID NO:65; Contains or consists of HCDR2 as shown in SEQ ID NO:66; Contains or is composed of HCDR3 as shown in SEQ ID NO:67; It includes or is composed of LCDR1 as shown in SEQ ID NO:93; Contains or is composed of LCDR2 as shown in SEQ ID NO:84; and It contains or is composed of LCDR3 as shown in SEQ ID NO:

96.

21. The antibody-drug conjugate or its salt according to any one of claims 11-20, wherein the Ab comprises a heavy chain variable region and a light chain variable region, wherein (1) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 31, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 32, or (2) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 33, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 34, or (3) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 41, or (4) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO: 37, or (5) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 38, or (6) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 39, or (7) The heavy chain variable region comprises the amino acid sequence shown in SEQ ID NO: 42, and the light chain variable region comprises the amino acid sequence shown in SEQ ID NO: 40, or (8) The heavy chain variable region contains the amino acid sequence shown in SEQ ID NO: 36, and the light chain variable region contains the amino acid sequence shown in SEQ ID NO:

41.

22. The antibody-drug conjugate or a salt thereof according to any one of claims 11-21, wherein the Ab comprises: (1) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 31 and the amino acid sequence shown in SEQ ID NO: 14, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 32 and the amino acid sequence shown in SEQ ID NO: 16; or (2) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 31 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 32 and the amino acid sequence shown in SEQ ID NO: 16; or (3) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 33 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 34 and SEQ ID NO: 16; or (4) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 33 and SEQ ID NO: 15, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 34 and SEQ ID NO: 16; or (5) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 41 and SEQ ID NO: 16; or (6) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 42 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 41 and the amino acid sequence shown in SEQ ID NO: 16; or (7) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 37 and SEQ ID NO: 16; or (8) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 15, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 37 and SEQ ID NO: 16; or (9) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 38 and SEQ ID NO: 16; or (10) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 42 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 38 and the amino acid sequence shown in SEQ ID NO: 16; or (11) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 39 and SEQ ID NO: 16; or (12) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 42 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 39 and the amino acid sequence shown in SEQ ID NO: 16; or (13) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 14, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 40 and SEQ ID NO: 16; or (14) A heavy chain comprising the amino acid sequences shown in SEQ ID NO: 42 and SEQ ID NO: 15, and a light chain comprising the amino acid sequences shown in SEQ ID NO: 40 and SEQ ID NO: 16; or (15) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 36 and the amino acid sequence shown in SEQ ID NO: 14, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 41 and the amino acid sequence shown in SEQ ID NO: 16; or (16) A heavy chain comprising the amino acid sequence shown in SEQ ID NO: 36 and the amino acid sequence shown in SEQ ID NO: 15, and a light chain comprising the amino acid sequence shown in SEQ ID NO: 41 and the amino acid sequence shown in SEQ ID NO:

16.

23. The antibody-drug conjugate or its salt according to any one of claims 11-22, wherein the antibody-drug conjugate or its salt has the following structure:

24. A nucleic acid molecule encoding an anti-CDH17 antibody or an antigen-binding fragment thereof as described in any one of claims 1-10.

25. A vector comprising the nucleic acid molecule of claim 24.

26. A host cell comprising the vector of claim 25 or the nucleic acid molecule of claim 24.

27. A pharmaceutical composition comprising: 1) The anti-CDH17 antibody or its antigen-binding fragment as described in any one of claims 1-10, or the antibody-drug conjugate or its salt as described in any one of claims 11-23, the nucleic acid molecule as described in claim 24, the vector as described in claim 25, the host cell as described in claim 26, and 2) Medicinal carrier.

28. A method of treating cancer in a subject in need, comprising administering to the subject a therapeutically effective amount of the anti-CDH17 antibody or its antigen-binding fragment as described in any one of claims 1-10, or the antibody-drug conjugate or its salt as described in any one of claims 11-23, the nucleic acid molecule as described in claim 24, the carrier as described in claim 25, the host cell as described in claim 26, or the pharmaceutical composition as described in claim 27.

29. Use of the anti-CDH17 antibody or antigen-binding fragment thereof as described in any one of claims 1-10, or the antibody-drug conjugate or salt thereof as described in any one of claims 11-23, the nucleic acid molecule of claim 24, the vector of claim 25, the host cell of claim 26, or the pharmaceutical composition of claim 27 in the preparation of a medicament for treating cancer.

30. Use of the anti-CDH17 antibody or its antigen-binding fragment as described in any one of claims 1-10 in the preparation of an antibody-drug conjugate for the treatment of cancer.

31. The method of claim 28, or the use of claim 29 or 30, wherein the cancer is gastric cancer, colorectal cancer, neuroendocrine cancer, esophageal cancer, bile duct cancer, pancreatic cancer, and liver cancer.

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