Antibody-drug conjugate for use in treatment of chemotherapy-resistant cancer

Abstract

FIELD: medicine.SUBSTANCE: used to treat cancer resistant to chemotherapy. The use of a medicinal product for the treatment of a cancer expressing cadherin-6 is proposed, comprising an antibody-drug conjugate (ADC), wherein the ADC comprises an antibody or a functional fragment of an antibody that specifically binds to the amino acid sequence of the EC3 domain of cadherin-6 shown in SEQ ID NO: 4, and the drug in the ADC is a topoisomerase I inhibitor. Wherein the cadherin-6-expressing cancer is resistant to platinum-based chemotherapy; is resistant to a chemotherapy regimen that includes a platinum-based drug or a platinum-based drug in combination with a taxane; is a relapse of a cancer previously treated with a chemotherapy regimen that includes a platinum-based drug alone or a platinum-based drug in combination with a taxane; or is a cancer previously treated with a chemotherapy regimen that includes a platinum-based drug, a taxane, or both a platinum-based drug and a taxane. Also disclosed are uses of the said medicinal product for the treatment of ovarian cancer resistant to platinum-based chemotherapy and / or recurrent ovarian cancer, as well as for the treatment of ovarian cancer that was previously treated with a chemotherapy regimen including a platinum-based drug, a taxane, or both a platinum-based drug and a taxane.EFFECT: excellent antitumor effect and safety.32 cl, 21 dwg, 2 tbl, 5 ex

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0000] This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 244,458, filed September 15, 2021. The contents of that application are hereby incorporated by reference in their entirety. Statement regarding the sequence listing

[0001] The sequence listing associated with the present application is provided in text format instead of a paper copy and is hereby incorporated into the description by reference. The name of the text file containing the sequence listing is 098065-0296_SL.txt. The text file has a size of ~112 KB, was created on September 9, 2021, and is provided electronically via the EFS network. Field of the invention [0001.1] The present invention relates to the field of therapeutic methods, to the use of an antibody-drug conjugate (ADC), pharmaceutical preparations of such ADC for the treatment of cancer, etc. Background of the invention

[0002] Cadherins are glycoproteins present on the surface of cell membranes and act as intercellular adhesion molecules through calcium-dependent binding of their N-terminal extracellular domains, or as signaling molecules responsible for intercellular interactions. Classical cadherins belong to the cadherin superfamily and are single-pass transmembrane proteins consisting of five extracellular domains (EC domains), one transmembrane region, and an intracellular domain. Classical cadherins are divided into family type I, typical representatives of which are E-cadherin and N-cadherin, and family type II according to the homology of their amino acid sequences.

[0003] Cadherin-6 (CDH6) is a 790-amino acid long, single-pass transmembrane protein that belongs to the type II cadherin family and has an N-terminal extracellular domain and a C-terminal intracellular domain. The human CDH6 gene was first cloned in 1995 (Non-Patent Reference 1), and its sequence can be found, for example, under accession numbers NM_004932 and NP_004923 (NCBI).

[0004] CDH6 is specifically expressed in the brain or kidney during development and is reported to play an important role in the formation of central nervous system connections (Non-patent references 2 and 3) and the development of nephrons in the kidney (Non-patent references 4 and 5). In normal adult tissues, CDH6 expression is localized in renal tubules, bile duct epithelial cells, etc.

[0005] Meanwhile, CDH6 is known to be specifically overexpressed in tumor foci of some types of adult cancer. The correlation of CDH6 expression with poor prognosis and its applicability as a tumor marker have been reported for human renal cell carcinoma, particularly renal cell clear cell carcinoma (Non-Patent References 6 and 7). High expression of CDH6 has also been reported for human ovarian cancer (Non-Patent Reference 8). CDH6 has also been reported to be involved in the epithelial-mesenchymal transition of human thyroid cancer (Non-Patent Reference 9). Furthermore, CDH6 has been reported to be expressed in tumors of human bile duct cancer and human small cell lung cancer (Non-Patent References 12 and 13).

[0006] Cancer is a leading cause of death. Although the number of cancer patients is expected to increase as the population ages, the treatment needs remain unmet. The disadvantages of traditional chemotherapeutic agents include their low selectivity, which makes them toxic not only to tumor cells but also to normal cells, causing adverse reactions. Therefore, chemotherapeutic agents cannot be administered in sufficient quantities and, therefore, are ineffective.Consequently, in recent years, more selective molecular targeted drugs or antibody-based drugs have been developed that target molecules that exhibit mutations or high expression characteristic of cancer cells, or specific molecules involved in malignant transformation of cells.

[0007] Furthermore, a serious problem is that conventional cancer treatment with traditional chemotherapy agents (such as platinum-based chemotherapy) often results in the development of cancer cells that are resistant to one or more chemotherapy agents. Chemotherapy-resistant cancer cells cause relapse or recurrence of the cancer, which is the cause of cancer metastasis.

[0008] Antibodies are very stable in the blood and bind specifically to their target antigens. For these reasons, a reduction in adverse reactions is expected. A large number of antibody-based therapeutics have been developed against molecules overexpressed on the surface of cancer cells. One technology that exploits the antigen-specific binding of antibodies is the use of antibody-drug conjugates (ADCs). An ADC is a conjugate in which an antibody that binds to an antigen expressed on the surface of cancer cells and can induce internalization of the antigen into the cell through binding is conjugated to a drug with cytotoxic activity.An ADC can effectively deliver a drug to cancer cells and thus can be expected to kill cancer cells when the drug accumulates in the cancer cells (Non-Patent Literature 10 and Patent Literatures 1 and 2). For example, Adcetris™ (brentuximab vedotin), which contains an anti-CD30 monoclonal antibody conjugated to monomethyl auristatin E, has been approved as a therapeutic agent for the treatment of Hodgkin lymphoma and anaplastic large cell lymphoma. In addition, Kadcyla™ (trastuzumab emtansine), which contains an anti-HER2 monoclonal antibody conjugated to emtansine, is used in the treatment of HER2-positive advanced or recurrent breast cancer.

[0009] The characteristics of a target antigen suitable for an ADC as an antitumor drug are as follows: the antigen is specifically expressed at a high level on the surface of cancer cells, but has low expression or is not expressed in normal cells; the antigen can be internalized into cells; the antigen is not secreted from the cell surface; etc. The internalization ability of an antibody depends on the properties of both the target antigen and the antibody. It is difficult to predict the antigen-binding site suitable for internalization from the molecular structure of the target, or to predict an antibody with high internalization ability based on the binding strength, physical properties, etc. of the antibody. Therefore, an important task in developing an ADC with high efficacy is to obtain an antibody with high internalization ability against the target antigen (Non-Patent Literature 11).

[0010] An ADC comprising DM4 conjugated with an anti-CDH6 antibody that specifically binds to the EC domain 5 (EC5) of CDH6 is known as an ADC targeting CDH6 (Patent Literature 3, Non-Patent Literatures 14 and 15).Citation ListPatent Literature

[0011] Patent source 1: WO 2014 / 057687Patent source 2: US 2016 / 0297890Patent source 3: WO 2016 / 024195Patent source 4: WO 2018 / 212136Non-patent literature

[0012] Non-patent reference 1: Shimoyama Y, et al., Cancer Research, 2206–2211, 55, May 15, 1995 Non-patent reference 2: Inoue T, et al., Developmental Biology, 183–194, 1997 Non-patent reference 3: Osterhout JA, et al., Neuron, 632–639, 71, Aug 25, 2011 Non-patent reference 4: Cho EA, et al., Development, 803–812, 125, 1998 Non-patent reference 5: Mah SP, et al., Developmental Biology, 38–53, 223, 2000 Non-patent reference 6: Paul R, et al., Cancer Research, 2741–2748, July 1, 57, 1997Non-patent reference 7: Shimazui T, et al., Cancer, 963-968, 101(5), Sep. 1, 2004Non-patent reference 8: Koebel M, et al., PLoS Medicine, 1749-1760, 5(12), e232, Dec. 2008 Non-patent reference 9: Gugnoni M, et al., Oncogene, 667–677, 36, 2017 Non-patent reference 10: Polakis P, Pharmacological Reviews, 3–19, 68, 2016 Non-patent reference 11: Peters C, et al., Bioscience Reports, 1–20, 35, 2015 Non-patent reference 12: Goeppert B, et al., Epigenetics, 780–790, 11(11), 2016 Non-patent reference 13: Yokoi S, et al., American Journal of Pathology, 207-216, 161, 1, 2002Non-patent source 14: Bialucha et al., Cancer Discovery, 1030-1045, 7, 9. 2017.Non-patent source 15: Schoffski et al., Oncology Research and Treatment, 547-556, 44, 10, 2021.Summary of the inventionTechnical problem.

[0013] The object of the present invention is to provide a therapeutic method for treating cancer using an ADC, a pharmaceutical preparation comprising an ADC for treating cancer, and the like. Specifically, the ADC is composed of an anti-cadherin-6 (CDH6) antibody linked via a linker to a topoisomerase I inhibitor such as an exatecan derivative, wherein the cancer can be resistant to chemotherapy.Solution to the problem

[0014] The present inventors have conducted intensive studies aimed at achieving the above-described objective and unexpectedly discovered that the ADC of the present invention exhibits excellent antitumor activity and safety. In particular, the present inventors discovered that an anti-CDH6 antibody-drug conjugate in which the antibody specifically binds to extracellular domain 3 (also referred to herein as EC3) exhibits excellent antitumor activity and safety.

[0015] The present invention includes the following aspects:

[0001] A therapeutic method for treating cancer, comprising a method of administering to a subject in need thereof an antibody-drug conjugate (ADC).

[0002] The therapeutic method according to item [1], wherein the antibody drug conjugate (ADC) has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

[0003] The therapeutic method according to [1] or [2], wherein the antibody drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate.

[0004] The therapeutic method according to any one of items [1] to [3], wherein the cancer is selected from the group consisting of renal cell cancer, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0005] The therapeutic method according to any one of items [1] to [3], wherein the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0006] The therapeutic method according to any one of [1] to [3], wherein the cancer is ovarian cancer.

[0007] The therapeutic method according to item [6], wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.

[0008] The therapeutic method according to item [6] or [7], wherein the ovarian cancer is metastatic.

[0009] The therapeutic method according to any one of items [1] to [8], wherein the antibody is an antibody comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1) to (4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 69, (2) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 73, and(4) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain,consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77.,

[0010] The therapeutic method according to any one of items [1] to [9], wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 69, or a functional fragment of an antibody.

[0011] The therapeutic method according to any one of items [1] to [9], wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77, or a functional fragment of an antibody.

[0012] The therapeutic method according to any one of items [1] to

[11] g, wherein the heavy chain or the light chain has undergone one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0013] The therapeutic method according to any one of items [1] to

[11] g, wherein the heavy chain or the light chain has undergone two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0014] The therapeutic method according to any one of items [1] to

[13] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 1 to 10.

[0015] The therapeutic method according to any one of items [1] to

[14] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 2 to 8.

[0016] The therapeutic method according to any one of items [1] to

[14] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 5 to 8.

[0017] The therapeutic method according to any one of items [1] to

[14] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 7 to 8.

[0018] The therapeutic method according to any one of items [1] to

[17] , wherein the cancer comprises one or more tumors expressing CDH6.

[0019] The therapeutic method according to any one of paragraphs [1] to

[18] , wherein the subject has a history of treatment with a chemotherapy regimen including a platinum drug.

[0020] The therapeutic method according to any one of paragraphs [1] to

[18] , wherein the subject has a history of treatment with a chemotherapy regimen comprising a platinum drug and a taxane.

[0021] The therapeutic method according to any one of paragraphs [1] to

[20] , wherein the subject has previously been treated with a chemotherapy regimen including a platinum drug.

[0022] The therapeutic method according to any one of paragraphs [1] to

[20] , wherein the subject has previously been treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0023] The therapeutic method according to any one of items [1] to

[22] , wherein the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents simultaneously or at different times.

[0024] The therapeutic method according to item

[23] , wherein the antibody drug conjugate (ADC) is administered after one or more chemotherapeutic agents.

[0025] The therapeutic method according to item

[23] , wherein an antibody drug conjugate (ADC) and one or more chemotherapeutic agents are separately included as active ingredients in different formulations and administered simultaneously or at different times.

[0026] The therapeutic method according to item

[23] , wherein an antibody drug conjugate (ADC) and one or more chemotherapeutic agents are included together as active ingredients in the same formulation and administered simultaneously.

[0027] The therapeutic method according to any one of paragraphs

[23] to

[26] , wherein the one or more chemotherapeutic agents are an antimetabolite, a platinum drug, a taxane, or both a platinum drug and a taxane.

[0028] The therapeutic method according to any one of items [1] to

[27] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen including a platinum drug.

[0029] The therapeutic method according to any one of items [1] to

[27] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug.

[0030] The therapeutic method according to any one of [1] to

[27] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0031] The therapeutic method according to any one of items [1] to

[27] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0032] The therapeutic method according to any one of paragraphs [1] to

[31] , wherein the subject has a cancer that is resistant to platinum chemotherapy.

[0033] The therapeutic method according to any one of paragraphs [1] to

[32] , wherein the subject has a cancer that is resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0034] The therapeutic method according to any one of items [1] to

[33] , wherein the subject exhibits a recurrence of cancer prior to administration of the ADC.

[0035] The therapeutic method according to item

[34] , wherein a relapse of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug.

[0036] The therapeutic method according to item

[34] , wherein a recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0037] The therapeutic method according to item

[34] , wherein a recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen including a platinum drug.

[0038] The therapeutic method according to item

[34] , wherein a recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0039] The therapeutic method according to any one of paragraphs [1] to

[38] , wherein the subject is administered an ADC with a second drug.

[0040] The therapeutic method according to item

[39] , wherein the ADC is administered before the second drug.

[0041] The therapeutic method according to item

[39] , wherein the ADC is administered after the second drug.

[0042] The therapeutic method according to item

[39] , wherein the ADC is administered simultaneously with the second drug.

[0043] A therapeutic method for treating cancer, comprising administering a pharmaceutical composition to a subject who has ovarian cancer that is resistant to chemotherapy using a platinum drug and / or who exhibits a relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed from its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0044] A therapeutic method for treating cancer, comprising administering a pharmaceutical composition to a subject who has ovarian cancer and who has previously been treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed from its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0045] The therapeutic method according to any one of items [1] to

[44] , comprising using a biological sample obtained from a test subject to detect the presence or absence of CDH6 in the biological sample and administering a pharmaceutical composition to the test subject in whom CDH6 is detected.

[0046] The therapeutic method according to any one of items [1] to

[45] , wherein the cancer has become resistant to a chemotherapy regimen including a platinum drug.

[0047] The therapeutic method according to any one of paragraphs [1] to

[45] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0048] The therapeutic method according to any one of paragraphs [1] to

[47] , wherein the antimetabolite is gemcitabine.

[0049] The therapeutic method according to any one of items [1] to

[47] , wherein the platinum drug is carboplatin.

[0050] The therapeutic method according to any one of paragraphs [1] to

[47] , wherein the platinum drug is carboplatin and the taxane is paclitaxel.

[0016]

[0051] A therapeutic antitumor agent comprising an antibody-drug conjugate (ADC) as disclosed herein.

[0052] The therapeutic agent according to item

[51] , wherein the antibody drug conjugate (ADC) has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

[0053] The therapeutic agent according to item

[51] or

[52] , wherein the antibody drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate.

[0054] The therapeutic agent according to any one of items

[51] to

[53] , wherein the cancer is selected from the group consisting of renal cell cancer, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0055] The therapeutic agent according to any one of items

[51] to

[53] , wherein the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0056] . The therapeutic agent according to any one of

[51] to

[53] , wherein the cancer is ovarian cancer.

[0057] The therapeutic agent according to item

[56] , wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.

[0058] The therapeutic agent according to item

[56] or

[57] , wherein the ovarian cancer is metastatic.

[0059] The therapeutic agent according to any one of items

[51] to

[58] , wherein the antibody is an antibody comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1) to (4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 69, (2) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 73, and(4) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain,consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77.,

[0060] . The therapeutic agent according to any one of items

[51] to

[59] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 69, or a functional fragment of an antibody.

[0061] The therapeutic agent according to any one of items

[51] to

[59] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77, or a functional fragment of an antibody.

[0062] The therapeutic agent according to any one of items

[51] to

[61] , wherein the heavy chain or the light chain has undergone one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0063] The therapeutic agent according to any one of items

[51] to

[61] , wherein the heavy chain or the light chain has undergone two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0064] The therapeutic agent according to any one of

[51] to

[63] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 1 to 10.

[0065] The therapeutic agent according to any one of

[51] to

[64] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 2 to 8.

[0066] The therapeutic agent according to any one of

[51] to

[64] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 5 to 8.

[0067] The therapeutic agent according to any one of

[51] to

[64] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 7 to 8.

[0068] The therapeutic agent according to any one of

[51] to

[67] , wherein the cancer comprises one or more tumors expressing CDH6.

[0069] The therapeutic agent according to any one of paragraphs

[51] to

[68] , wherein the subject has a history of treatment with a chemotherapy regimen that includes a platinum drug.

[0070] The therapeutic agent according to any one of paragraphs

[51] to

[68] , wherein the subject has a history of treatment with a chemotherapy regimen that includes a platinum drug and a taxane.

[0071] The therapeutic agent according to any one of

[51] to

[70] , wherein the subject has previously been treated with a chemotherapy regimen including a platinum drug.

[0072] The therapeutic agent according to any one of paragraphs

[51] to

[70] , wherein the subject has previously been treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0073] The therapeutic agent according to any one of items

[51] to

[72] , wherein the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents simultaneously or at different times.

[0074] The therapeutic agent according to item

[73] , wherein the antibody drug conjugate (ADC) is administered after one or more chemotherapeutic agents.

[0075] The therapeutic agent according to item

[73] , wherein an antibody drug conjugate (ADC) and one or more chemotherapeutic agents are separately included as active ingredients in different formulations and administered simultaneously or at different times.

[0076] The therapeutic agent according to item

[73] , wherein the antibody drug conjugate (ADC) and one or more chemotherapeutic agents are included together as active ingredients in the same formulation and administered simultaneously.

[0077] The therapeutic agent according to any one of paragraphs

[73] to

[76] , wherein the one or more chemotherapeutic agents is an antimetabolite, a platinum drug, a taxane, or both a platinum drug and a taxane.

[0078] The therapeutic agent according to any one of

[51] to

[77] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen including a platinum drug.

[0079] The therapeutic agent according to any one of

[51] to

[77] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug.

[0080] The therapeutic agent according to any one of

[51] to

[77] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0081] The therapeutic agent according to any one of

[51] to

[77] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0082] The therapeutic agent according to any one of

[51] to

[81] , wherein the subject has a cancer that is resistant to platinum chemotherapy.

[0083] The therapeutic agent according to any one of paragraphs

[51] to

[82] , wherein the subject has a cancer that is resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0084] The therapeutic agent according to any one of

[51] to

[83] , wherein the subject exhibits a recurrence of cancer prior to administration of the ADC.

[0085] The therapeutic agent according to item

[84] , wherein the recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug.

[0086] The therapeutic agent according to item

[84] , wherein the recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0087] The therapeutic agent according to item

[84] , wherein the recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen including a platinum drug.

[0088] The therapeutic agent according to item

[84] , wherein the recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0089] The therapeutic agent according to any one of paragraphs

[51] to

[88] , wherein the subject is administered an ADC with a second drug.

[0090] The therapeutic agent according to item

[89] , wherein the ADC is administered before the second medicinal agent.

[0091] The therapeutic agent according to item

[89] , wherein the ADC is administered after the second medicinal agent.

[0092] The therapeutic agent according to item

[89] , wherein the ADC is administered simultaneously with a second medicinal agent.

[0093] A therapeutic antitumor agent comprising a pharmaceutical composition for administration to a subject who has ovarian cancer resistant to platinum chemotherapy and / or who exhibits relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are deleted at the C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0094] A therapeutic agent for the treatment of cancer, comprising a pharmaceutical composition for administration to a subject who has ovarian cancer and who has previously been treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0095] The therapeutic agent according to any one of

[51] to

[94] , wherein the biological sample obtained from the test subject is used to detect the presence or absence of CDH6 in the biological sample before administering the pharmaceutical composition to the test subject in whom CDH6 is detected.

[0096] The therapeutic agent according to any one of

[51] to

[95] , wherein the cancer has become resistant to a chemotherapy regimen including a platinum drug.

[0097] The therapeutic agent according to any one of

[51] to

[95] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0098] The therapeutic agent according to any one of items

[51] to

[97] , wherein the antimetabolite is gemcitabine.

[0099] The therapeutic agent according to any one of items

[51] to

[97] , wherein the platinum drug is carboplatin.

[0100] The therapeutic agent according to any one of

[51] to

[97] , wherein the platinum drug is carboplatin and the taxane is paclitaxel.

[0017]

[0101] An antibody drug conjugate (ADC) as disclosed herein for use in the treatment of cancer.

[0102] The antibody-drug conjugate (ADC) according to item

[101] , wherein the antibody-drug conjugate (ADC) has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

[0103] The antibody drug conjugate (ADC) according to item

[101] or

[102] , wherein the antibody drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate.

[0104] The antibody drug conjugate (ADC) according to any one of items

[101] to

[103] , wherein the cancer is selected from the group consisting of renal cell cancer, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0105] An antibody drug conjugate (ADC) according to any one of items

[101] to

[103] , wherein the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0106] An antibody drug conjugate (ADC) according to any one of

[101] to

[103] , wherein the cancer is ovarian cancer.

[0107] The antibody drug conjugate (ADC) according to item

[106] , wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.

[0108] The antibody drug conjugate (ADC) according to

[106] or

[107] , wherein the ovarian cancer is metastatic.

[0109] The antibody drug conjugate (ADC) according to any one of items

[101] to

[108] , wherein the antibody is an antibody comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1) to (4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 69, (2) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 73, and (4) a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61,and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77.,

[0110] An antibody drug conjugate (ADC) according to any one of items

[101] to

[109] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 69, or a functional fragment of an antibody.

[0111] An antibody drug conjugate (ADC) according to any one of items

[101] to

[109] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77, or a functional fragment of an antibody.

[0112] The antibody drug conjugate (ADC) according to any one of items

[101] to

[111] , wherein the heavy chain or the light chain has undergone one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0113] The antibody drug conjugate (ADC) according to any one of items

[101] to

[111] , wherein the heavy chain or the light chain has undergone two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0114] An antibody-drug conjugate (ADC) according to any one of

[101] to

[113] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 1 to 10.

[0115] An antibody-drug conjugate (ADC) according to any one of

[101] to

[114] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 2 to 8.

[0116] An antibody-drug conjugate (ADC) according to any one of

[101] to

[114] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 5 to 8.

[0117] An antibody-drug conjugate (ADC) according to any one of

[101] to

[114] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 7 to 8.

[0118] An antibody drug conjugate (ADC) according to any one of items

[101] to

[117] , wherein the cancer comprises one or more tumors expressing CDH6.

[0119] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[118] , wherein the subject has a history of treatment with a chemotherapy regimen comprising a platinum drug.

[0120] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[118] , wherein the subject has a history of treatment with a chemotherapy regimen comprising a platinum drug and a taxane.

[0121] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[120] , wherein the subject has previously been treated with a chemotherapy regimen comprising a platinum drug.

[0122] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[120] , wherein the subject has previously been treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0123] The antibody drug conjugate (ADC) according to any one of items

[101] to

[122] , wherein the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents simultaneously or at different times.

[0124] The antibody drug conjugate (ADC) according to item

[123] , wherein the antibody drug conjugate (ADC) is administered after one or more chemotherapeutic agents.

[0125] The antibody-drug conjugate (ADC) according to item

[123] , wherein the antibody-drug conjugate (ADC) and one or more chemotherapeutic agents are separately included as active ingredients in different formulations and administered simultaneously or at different times.

[0126] The antibody-drug conjugate (ADC) according to item

[123] , wherein the antibody-drug conjugate (ADC) and one or more chemotherapeutic agents are included together as active ingredients in the same formulation and administered simultaneously.

[0127] An antibody drug conjugate (ADC) according to any one of paragraphs

[123] to

[126] , wherein the one or more chemotherapeutic agents is an antimetabolite, a platinum drug, a taxane, or both a platinum drug and a taxane.

[0128] An antibody drug conjugate (ADC) according to any one of

[101] to

[127] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug.

[0129] An antibody drug conjugate (ADC) according to any one of

[101] to

[127] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug.

[0130] An antibody drug conjugate (ADC) according to any one of

[101] to

[127] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0131] An antibody drug conjugate (ADC) according to any one of

[101] to

[127] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0132] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[131] , wherein the subject has a cancer that is resistant to platinum chemotherapy.

[0133] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[132] , wherein the subject has a cancer that is resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0134] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[133] , wherein the subject exhibits cancer recurrence prior to administration of the ADC.

[0135] An antibody drug conjugate (ADC) according to item

[134] , wherein the cancer recurrence occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug.

[0136] An antibody drug conjugate (ADC) according to item

[134] , wherein the cancer recurrence occurs less than six months or within about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0137] . The antibody drug conjugate (ADC) according to

[134] , wherein the cancer recurrence occurs within or about six months after completion of a chemotherapy regimen including a platinum drug.

[0138] An antibody drug conjugate (ADC) according to

[134] , wherein the cancer recurrence occurs within or about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0139] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[138] , wherein the ADC is administered to the subject with a second drug.

[0140] An antibody drug conjugate (ADC) according to item

[139] , wherein the ADC is administered before the second drug.

[0141] An antibody drug conjugate (ADC) according to item

[139] , wherein the ADC is administered after the second drug.

[0142] An antibody drug conjugate (ADC) according to

[139] , wherein the ADC is administered simultaneously with a second drug.

[0143] An antibody-drug conjugate (ADC) for the treatment of cancer in a subject who has ovarian cancer resistant to platinum chemotherapy and / or who exhibits a relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the ADC has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0144] An antibody-drug conjugate (ADC) for the treatment of cancer in a subject who has ovarian cancer and who has been previously treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the ADC has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0145] An ADC according to any one of paragraphs

[101] to

[144] , wherein a biological sample obtained from a test subject is used to detect the presence or absence of CDH6 in the biological sample prior to administering the ADC to the test subject in whom CDH6 is detected.

[0146] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[145] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug.

[0147] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[145] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0148] An antibody drug conjugate (ADC) according to any one of paragraphs

[101] to

[147] , wherein the antimetabolite is gemcitabine.

[0149] An antibody drug conjugate (ADC) according to any one of items

[101] to

[147] , wherein the platinum drug is carboplatin.

[0150] The therapeutic method according to any one of paragraphs

[101] to

[147] , wherein the platinum drug is carboplatin and the taxane is paclitaxel.

[0018]

[0151] A pharmaceutical composition for treating cancer, comprising an antibody-drug conjugate (ADC) or a salt thereof as disclosed herein as an active component and a pharmaceutically acceptable formulation component.

[0152] The pharmaceutical composition according to item

[151] , wherein the antibody drug conjugate (ADC) has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

[0153] The pharmaceutical composition according to item

[151] or

[152] , wherein the antibody drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate.

[0154] The pharmaceutical composition according to any one of items

[151] to

[153] , wherein the cancer is selected from the group consisting of renal cell cancer, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0155] The pharmaceutical composition according to any one of items

[151] to

[153] , wherein the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0156] The pharmaceutical composition according to any one of

[151] to

[153] , wherein the cancer is ovarian cancer.

[0157] The pharmaceutical composition according to item

[156] , wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.

[0158] The pharmaceutical composition according to item

[156] or

[157] , wherein the ovarian cancer is metastatic.

[0159] The pharmaceutical composition according to any one of items

[151] to

[158] , wherein the antibody is an antibody comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1) to (4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 69, (2) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 65 and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 73, and(4) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain,consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77.,

[0160] The pharmaceutical composition according to any one of items

[151] to

[159] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 69, or a functional fragment of an antibody.

[0161] The pharmaceutical composition according to any one of items

[151] to

[159] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77, or a functional fragment of an antibody.

[0162] The pharmaceutical composition according to any one of items

[151] to

[161] , wherein the heavy chain or the light chain has undergone one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0163] The pharmaceutical composition according to any one of items

[151] to

[161] , wherein the heavy chain or the light chain has undergone two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0164] The pharmaceutical composition according to any one of items

[151] to

[163] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 1 to 10.

[0165] The pharmaceutical composition according to any one of items

[151] to

[164] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 2 to 8.

[0166] The pharmaceutical composition according to any one of items

[151] to

[164] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 5 to 8.

[0167] The pharmaceutical composition according to any one of items

[151] to

[164] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 7 to 8.

[0168] The pharmaceutical composition according to any one of items

[151] to

[167] , wherein the cancer comprises one or more tumors expressing CDH6.

[0169] The pharmaceutical composition according to any one of paragraphs

[151] to

[168] , wherein the subject has a history of treatment with a chemotherapy regimen including a platinum drug.

[0170] The pharmaceutical composition according to any one of paragraphs

[151] to

[168] , wherein the subject has a history of treatment with a chemotherapy regimen comprising a platinum drug and a taxane.

[0171] The pharmaceutical composition according to any one of items

[151] to

[170] , wherein the subject has previously been treated with a chemotherapy regimen including a platinum drug.

[0172] The pharmaceutical composition according to any one of paragraphs

[151] to

[170] , wherein the subject has previously been treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0173] The pharmaceutical composition according to any one of items

[151] to

[172] , wherein the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents simultaneously or at different times.

[0174] The pharmaceutical composition according to item

[173] , wherein the antibody drug conjugate (ADC) is administered after one or more chemotherapeutic agents.

[0175] The pharmaceutical composition according to item

[173] , wherein the antibody drug conjugate (ADC) and one or more chemotherapeutic agents are separately included as active ingredients in different formulations and administered simultaneously or at different times.

[0176] The pharmaceutical composition according to item

[173] , wherein the antibody drug conjugate (ADC) and one or more chemotherapeutic agents are included together as active ingredients in the same formulation and administered simultaneously.

[0177] The pharmaceutical composition according to any one of items

[173] to

[176] , wherein the one or more chemotherapeutic agents are an antimetabolite, a platinum drug, a taxane, or both a platinum drug and a taxane.

[0178] The pharmaceutical composition according to any one of

[151] to

[177] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen including a platinum drug.

[0179] The pharmaceutical composition according to any one of

[151] to

[177] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug.

[0180] The pharmaceutical composition according to any one of

[151] to

[177] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0181] The pharmaceutical composition according to any one of

[151] to

[177] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0182] The pharmaceutical composition according to any one of

[151] to

[181] , wherein the subject has a cancer resistant to platinum chemotherapy.

[0183] The pharmaceutical composition according to any one of items

[151] to

[182] , wherein the subject has a cancer that is resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0184] The pharmaceutical composition according to any one of

[151] to

[183] , wherein the subject exhibits a recurrence of cancer prior to administration of the ADC.

[0185] The pharmaceutical composition according to item

[184] , wherein the recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug.

[0186] The pharmaceutical composition according to item

[184] , wherein the recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0187] The pharmaceutical composition according to item

[184] , wherein the recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen including a platinum drug.

[0188] The pharmaceutical composition according to item

[184] , wherein the recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0189] The pharmaceutical composition according to any one of paragraphs

[151] to

[188] , wherein the ADC is administered to the subject with a second drug.

[0190] The pharmaceutical composition according to item

[189] , wherein the ADC is administered before the second medicinal product.

[0191] The pharmaceutical composition according to item

[189] , wherein the ADC is administered after the second medicinal product.

[0192] The pharmaceutical composition according to item

[189] , wherein the ADC is administered simultaneously with the second drug.

[0193] A pharmaceutical composition for treating cancer in a subject who has ovarian cancer resistant to platinum chemotherapy and / or who exhibits a relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0194] A pharmaceutical composition for treating cancer in a subject who has ovarian cancer and who has previously been treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0195] The pharmaceutical composition according to any one of items

[151] to

[194] , wherein the biological sample obtained from the test subject is used to detect the presence or absence of CDH6 in the biological sample before administering the pharmaceutical composition to the test subject in whom CDH6 is detected.

[0196] The pharmaceutical composition according to any one of

[151] to

[195] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug.

[0197] The pharmaceutical composition according to any one of

[151] to

[195] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0198] The pharmaceutical composition according to any one of items

[151] to

[197] , wherein the antimetabolite is gemcitabine.

[0199] The pharmaceutical composition according to any one of items

[151] to

[197] , wherein the platinum drug is carboplatin.

[0200] The pharmaceutical composition according to any one of items

[151] to

[197] , wherein the platinum drug is carboplatin and the taxane is paclitaxel.

[0019]

[0201] Use of an antibody-drug conjugate (ADC) as disclosed herein in the manufacture of a medicament for the treatment of cancer.

[0202] The use according to item

[201] , wherein the antibody drug conjugate (ADC) has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

[0203] The use according to

[201] or

[202] , wherein the antibody drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate.

[0204] The use according to any one of

[201] to

[203] , wherein the cancer is selected from the group consisting of renal cell cancer, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0205] The use according to any one of

[201] to

[203] , wherein the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.

[0206] The use according to any one of

[201] to

[203] , wherein the cancer is ovarian cancer.

[0207] The use according to item

[206] , wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.

[0208] Use according to

[206] or

[207] , where the ovarian cancer is metastatic.

[0209] The use according to any one of items

[201] to

[208] , wherein the antibody is an antibody comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1) to (4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 69, (2) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21 to 233 in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 73, and(4) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain,consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77.,

[0210] The use according to any one of items

[201] to

[209] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 69, or a functional fragment of an antibody.

[0211] The use according to any one of items

[201] to

[209] , wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 77, or a functional fragment of an antibody.

[0212] The use according to any one of items

[201] to

[211] , wherein the heavy chain or the light chain has undergone one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0213] The use according to any one of items

[201] to

[211] , wherein the heavy chain or the light chain has undergone two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

[0214] The use according to any one of

[201] to

[213] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 1 to 10.

[0215] The use according to any one of paragraphs

[201] to

[214] , wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 2 to 8.

[0216] The use according to any one of paragraphs

[201] to

[214] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 5 to 8.

[0217] The use according to any one of paragraphs

[201] to

[214] , wherein the average number of units of the selected drug-linker structure conjugated to each antibody is in the range of 7 to 8.

[0218] The use according to any one of

[201] to

[217] , wherein the cancer comprises one or more tumors expressing CDH6.

[0219] Use according to any one of paragraphs

[201] to

[218] , wherein the subject has a history of treatment with a chemotherapy regimen that includes a platinum drug.

[0220] Use according to any one of paragraphs

[201] to

[218] , wherein the subject has a history of treatment with a chemotherapy regimen that includes a platinum drug and a taxane.

[0221] Use according to any one of

[201] to

[220] , wherein the subject has previously been treated with a chemotherapy regimen that includes a platinum drug.

[0222] Use according to any one of paragraphs

[201] to

[220] , wherein the subject has previously been treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0223] The use according to any one of

[201] to

[222] , wherein the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents simultaneously or at different times.

[0224] The use according to

[223] , wherein the antibody drug conjugate (ADC) is administered after one or more chemotherapeutic agents.

[0225] The use according to item

[223] , wherein the antibody drug conjugate (ADC) and one or more chemotherapeutic agents are separately included as active ingredients in different formulations and administered simultaneously or at different times.

[0226] The use according to item

[223] , wherein the antibody drug conjugate (ADC) and one or more chemotherapeutic agents are included together as active ingredients in the same formulation and administered simultaneously.

[0227] The use according to any of paragraphs

[223] to

[226] , wherein the one or more chemotherapeutic agents are an antimetabolite, a platinum drug, a taxane, or both a platinum drug and a taxane.

[0228] Use according to any one of

[201] to

[227] , wherein the subject has shown a complete response (CR), a partial response (PR), or a stable disease (SD) when treated with a chemotherapy regimen including a platinum drug.

[0229] Use according to any of

[201] to

[227] , where the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug.

[0230] Use according to any of

[201] to

[227] , wherein the subject has shown a complete response (CR), partial response (PR), or stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0231] Use according to any of

[201] to

[227] , wherein the subject has shown a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen comprising a platinum drug and a taxane.

[0232] The use according to any one of

[201] to

[231] , wherein the subject has a cancer that is resistant to platinum chemotherapy.

[0233] The use according to any one of paragraphs

[201] to

[232] , wherein the subject has a cancer that is resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0234] The use according to any one of

[201] to

[233] , wherein the subject exhibits a recurrence of cancer prior to administration of the ADC.

[0235] Use according to item

[234] , where a recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug.

[0236] Use according to

[234] , where a recurrence of cancer occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug and a taxane.

[0237] Use according to

[234] , where a recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen including a platinum drug.

[0238] Use according to

[234] , where a recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.

[0239] Use according to any one of paragraphs

[201] to

[238] , wherein the subject is administered an ADC with a second drug.

[0240] Use according to

[239] , wherein the ADC is administered before the second medicinal product.

[0241] Use according to

[239] , wherein the ADC is administered after the second medicinal product.

[0242] Use according to

[239] , wherein the ADC is administered simultaneously with the second medicinal product.

[0243] Use of a pharmaceutical composition for treating cancer, wherein the use comprises administering the pharmaceutical composition to a subject who has ovarian cancer that is resistant to platinum chemotherapy and / or who exhibits a relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0244] Use of a pharmaceutical composition for treating cancer, wherein the use comprises administering the pharmaceutical composition to a subject who has ovarian cancer and who has previously been treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.

[0245] The use according to any one of paragraphs

[201] to

[244] , comprising using a biological sample obtained from a test subject to detect the presence or absence of CDH6 in the biological sample and administering the pharmaceutical composition to the test subject in whom CDH6 is detected.

[0246] Use according to any one of

[201] to

[245] , wherein the cancer has become resistant to a chemotherapy regimen including a platinum drug.

[0247] Use according to any one of

[201] to

[245] , wherein the cancer has become resistant to a chemotherapy regimen comprising a platinum drug and a taxane.

[0248] Use according to any of paragraphs

[201] to

[247] , wherein the antimetabolite is gemcitabine.

[0249] Use according to any of paragraphs

[201] to

[247] , wherein the platinum drug is carboplatin.

[0250] The use according to any one of paragraphs

[201] to

[247] , wherein the platinum drug is carboplatin and the taxane is paclitaxel. In some aspects, the disclosed treatment broadly refers to a therapeutic use or method for treating cancer, wherein the use or method comprises administering to a subject in need thereof an antibody-drug conjugate (ADC). In some aspects, the antibody-drug conjugate (ADC) has a structure represented by the following formula: where AB is an antibody or a functional fragment of an antibody, n is the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody. In some aspects, the antibody-drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate. In some aspects, the antibody-drug conjugate (ADC) is an anti-CDH6 antibody drug conjugate in which the antibody specifically binds to extracellular domain 3. In some aspects, the cancer is selected from the group consisting of renal cell cancer, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, cancer head and neck, sarcoma, osteosarcoma, small cell lung cancer, breast cancer,Bladder cancer, endometrial cancer, and castration-resistant prostate cancer. In some aspects, the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer. In some aspects, the cancer is ovarian cancer. In some aspects, the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer. In some aspects, the ovarian cancer is metastatic. In some aspects, the antibody is an antibody comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1)-(4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 69, (2) a light chain,consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 73, and (4) a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 77. In some aspects, the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61, and a heavy a chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 69, or a functional fragment of an antibody. In some aspects, the antibody is an antibody comprising a light chain consisting of the amino acidsequences at positions 21-233 of SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 77, or a functional fragment of an antibody. In some aspects, the heavy chain or the light chain is subjected to one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of an N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus. In some aspects, the heavy chain or the light chain is subjected to two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation,adding a methionine residue to the N-terminus, amidating a proline residue, converting an N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deleting one or two amino acids at the C-terminus. In some aspects, the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 1 to 10. In some aspects, the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 2 to 8. In some aspects, the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 5 to 8. In some aspects, the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 7 to 8. In some aspects, the cancer comprises one or more tumors expressing CDH6. In some aspectsthe subject has a history of treatment with a chemotherapy regimen that includes a platinum drug. In some aspects, the subject has a history of treatment with a chemotherapy regimen that includes a platinum drug and a taxane. In some aspects, the subject has previously been treated with a chemotherapy regimen that includes a platinum drug. In some aspects, the subject has previously been treated with a chemotherapy regimen that includes a platinum drug and a taxane. In some aspects, the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents, either simultaneously or at different times. In some aspects, the antibody drug conjugate (ADC) is administered after one or more chemotherapeutic agents. In some aspects, the antibody drug conjugate (ADC) is administered after the antibody drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents. In some aspects, the conjugatean antibody drug conjugate (ADC) and one or more chemotherapeutic agents are separately included as active ingredients in different formulations and administered simultaneously or at different times. In some aspects, an antibody drug conjugate (ADC) and one or more chemotherapeutic agents are included together as active ingredients in the same formulation and administered simultaneously. In some aspects, the one or more chemotherapeutic agents are an antimetabolite, a platinum drug, a taxane, or both a platinum drug and a taxane. In some aspects, the one or more chemotherapeutic agents are an antimetabolite. In some aspects, the one or more chemotherapeutic agents are a platinum drug. In some aspects, the one or more chemotherapeutic agents are a platinum drug and a taxane. In some aspects, the subject has shown a complete response (CR), a partial response (PR), or stable disease (SD) when treated withusing a chemotherapy regimen including a platinum drug. In some aspects, the subject has demonstrated a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug. In some aspects, the subject has demonstrated a complete response (CR), a partial response (PR), or stable disease (SD) when treated with a chemotherapy regimen including a platinum drug and a taxane. In some aspects, the subject has demonstrated a complete response (CR) or a partial response (PR) when treated with a chemotherapy regimen including a platinum drug and a taxane. In some aspects, the subject has cancer that is resistant to platinum drug chemotherapy. In some aspects, the subject has cancer that is resistant to a chemotherapy regimen including a platinum drug and a taxane. In some aspects, the subject exhibits cancer recurrence prior to administration of the ADC. In some aspects, the subject has cancer that is resistant to a chemotherapy regimen including a platinum drug and a taxane. In some aspects, the cancer recurrence occursless than six months or within about six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs less than about six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs within about six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs less than or within six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs less than six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within or about six months aftercompletion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs approximately six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs approximately six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs less than six months or within about six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs less than about six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within about six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs less than or within six months after completion of a chemotherapy regimen includinga platinum drug. In some aspects, cancer recurrence occurs less than six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs within six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs within or about six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within about six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within or ... six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within six months after completion of a chemotherapy regimen including a platinum drug and a taxane. In some aspects, cancer recurrence occurs within or six months after completion of a chemotherapy regimen including a platinum drug. In some aspects, cancer recurrence occurs within six months after completion of a chemotherapy regimen including a platinum drug.chemotherapy comprising a platinum drug. In some aspects, cancer recurrence occurs six months after completion of a chemotherapy regimen comprising a platinum drug. In some aspects, cancer recurrence occurs during or six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane. In some aspects, cancer recurrence occurs within six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane. In some aspects, cancer recurrence occurs six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane. In some aspects, the subject is administered an ADC with a second drug. In some aspects, the ADC is administered before the second drug. In some aspects, the ADC is administered after the second drug. In some aspects, the ADC is administered concurrently with the second drug. In some aspects, the invention is generally directed to a therapeutic method for treating cancer, whereinThe method comprises administering a pharmaceutical composition to a subject who has ovarian cancer that is resistant to platinum chemotherapy and / or who exhibits a relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.In some aspects, the invention is generally directed to a therapeutic method for treating cancer, wherein the method comprises administering a pharmaceutical composition to a subject who has ovarian cancer and who has previously been treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the ADC is a salt or hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88.In some aspects, the invention is generally directed to a therapeutic method for treating cancer, wherein the method comprises using a biological sample obtained from a test subject to detect the presence or absence of CDH6 in the biological sample and administering a pharmaceutical composition to the test subject in whom CDH6 is detected. In some aspects, the cancer has become resistant to a chemotherapy regimen comprising a platinum drug. In some aspects, the cancer has become resistant to a chemotherapy regimen comprising a platinum drug and a taxane. In some aspects, the antimetabolite is gemcitabine. In some aspects, the platinum drug is carboplatin. In some aspects, the platinum drug is carboplatin and the taxane is paclitaxel.The present invention includes the following aspects of the invention: [1A] A therapeutic method for treating cancer, comprising administering to a subject in need thereof an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB is an antibody or a functional fragment of an antibody, n is the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.[2A] The therapeutic method according to paragraph [1A], wherein the cancer is selected from the group consisting of ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer.[3A] The therapeutic method according to paragraph [2A], wherein the cancer is ovarian cancer.[4A] The therapeutic method according to paragraph [3A], wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.[5A] The therapeutic method according to paragraph [3A], wherein the ovarian cancer is metastatic.[6A] The therapeutic method according to paragraph [1A], where the antibody is an antibody,comprising a light chain and a heavy chain in any combination selected from the group consisting of the following combinations (1) to (4), or a functional fragment of an antibody: (1) a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 69, (2) a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 73, (3) a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 65 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO: 73, and(4) a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61, and a heavy chain,consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 77.[7A] The therapeutic method according to paragraph [1A], wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 69, or a functional fragment of an antibody.[8A] The therapeutic method according to paragraph [1A], wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 of SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 of SEQ ID NO: 77, or a functional fragment of an antibody.[9A] The therapeutic method according to paragraph [1A], wherein the heavy chain or the light chain is subjected to one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing,deamidation, isomerization of aspartic acid, oxidation of methionine, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of the N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.[10A] The therapeutic method according to paragraph [1A], wherein the heavy chain or the light chain has undergone two or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, isomerization of aspartic acid, oxidation of methionine, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of the N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.[11A] The therapeutic method according to paragraph [1A], wherein the average number of units of the selected drug-linker structure conjugated to each antibody isis in the range of 1 to 10.[12A] The therapeutic method of paragraph [11A], wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 2 to 8.[13A] The therapeutic method of paragraph [11A], wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 5 to 8.[14A] The therapeutic method of paragraph [11A], wherein the average number of units of the selected linker-drug structure conjugated to each antibody is in the range of 7 to 8.[15A] The therapeutic method of paragraph [1A], wherein the cancer comprises one or more tumors expressing CDH6.[16A] The therapeutic method of paragraph [1A], wherein the subject has a cancer resistant to chemotherapy with a platinum drug.[17A] The therapeutic method according to paragraph [1A],wherein the subject exhibits a recurrence of cancer prior to administration of the ADC.[18A] The therapeutic method of paragraph [1A], wherein the subject has a cancer that is resistant to a chemotherapy regimen comprising a platinum drug and a taxane.[19A] The therapeutic method of paragraph [17A], wherein the recurrence of cancer occurs within about six months after completion of a chemotherapy regimen comprising a platinum drug.[20A] The therapeutic method of paragraph [17A], wherein the recurrence of cancer occurs within about six months after completion of a chemotherapy regimen comprising a platinum drug and a taxane.[21A] The therapeutic method of paragraph [1A], wherein the subject is administered an ADC with a second drug.[22A] The therapeutic method of paragraph [21A], wherein the ADC is administered before the second drug.[23A] The therapeutic method of paragraph [21A], wherein the ADC is administered after the second drug.,

[0024] The therapeutic method according to item [21A], wherein the ADC is administered simultaneously with a second drug.[25A] A therapeutic method for treating cancer, comprising administering a pharmaceutical composition to a subject who has ovarian cancer that is resistant to platinum chemotherapy and / or who exhibits a relapse of ovarian cancer prior to administration of the pharmaceutical composition, wherein the pharmaceutical composition comprises an antibody-drug conjugate (ADC) having a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group originating from the antibody; and where the ADC is a salt or a hydrate of the ADC or salt, wherein the average number of units of the linker-drug structure conjugated to each antibody is 7-8, wherein the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are deleted at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO: 88, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 88, in which one or two amino acids are deleted at its C-terminus.Beneficial effects of the invention.

[0020] The present invention provides a therapeutic method for treating cancer using an ADC and a pharmaceutical product comprising the ADC for treating cancer, etc. The present invention also provides a therapeutic method using an anti-CDH6 antibody drug conjugate in which the antibody specifically binds to EC3 for the treatment of chemotherapy-resistant cancer with an excellent antitumor effect in both the development and maintenance of a tumor regression effect and safety. The present invention also provides a pharmaceutical composition comprising the anti-CDH6 antibody drug conjugate. Brief Description of the Drawings

[0021] [Figure 1] Figure 1 shows the results of flow cytometry analysis of the binding activity of four rat anti-CDH6 monoclonal antibodies (clones rG019, rG055, rG056, and rG061) or control rat IgG to control cells or hCDH6-transfected 293T cells. The abscissa axis indicates the FITC fluorescence intensity, which indicates the amount of bound antibody, and the ordinate axis indicates the number of cells.[Figure 2-1] Figure 2-1 shows the binding activity of four rat anti-CDH6 monoclonal antibodies (rG019, rG055, rG056, and rG061) or negative control rat IgG2b antibody to control cells or 293 cells transfected with full-length hCDH6. The abscissa axis shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate axis shows the number of cells.[Figure 2-2] Figure 2-2 shows the binding activity of four rat anti-CDH6 monoclonal antibodies (rG019, rG055, rG056, and rG061) or control rat IgG against control cells or 293 cells transfected with hCDH6 having EC1 deletion. The abscissa axis indicates the FITC fluorescence intensity, which indicates the amount of bound antibody, and the ordinate axis indicates the number of cells. [Figure 2-3] Figure 2-3 shows the binding activity of four rat anti-CDH6 monoclonal antibodies (rG019, rG055, rG056, and rG061) or control rat IgG against control cells or 293 cells transfected with hCDH6 having EC2 deletion. The abscissa axis shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate axis shows the number of cells.[Figure 2-4] Figure 2-4 shows the binding activity of four rat anti-CDH6 monoclonal antibodies (rG019, rG055, rG056, and rG061) or control rat IgG against control cells or 293 cells transfected with EC3-deleted hCDH6. The abscissa axis indicates the FITC fluorescence intensity, which indicates the amount of bound antibody, and the ordinate axis indicates the number of cells. [Figure 2-5] Figure 2-5 shows the binding activity of four rat anti-CDH6 monoclonal antibodies (rG019, rG055, rG056, and rG061) or control rat IgG against control cells or 293 cells transfected with EC4-deleted hCDH6. The abscissa axis shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate axis shows the number of cells.[Figure 2-6] Figure 2-6 shows the binding activity of four rat anti-CDH6 monoclonal antibodies (rG019, rG055, rG056, and rG061) or control rat IgG against control cells or 293 cells transfected with EC5-deleted hCDH6. The abscissa axis indicates the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate axis indicates the number of cells. [Figure 3] Figure 3 shows the flow cytometry results for evaluating the expression of CDH6 on the cell membrane surface of 4 types of human tumor cell lines (NIH human tumor cell lines: OVCAR-3, PA-1, and ES-2, and human kidney tumor cell line 786-0). The abscissa axis shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate axis shows the number of cells.[Figure 4] Figure 4 shows a graph evaluating the internalization activity of 4 types of rat anti-CDH6 antibodies (rG019, rG055, rG056, and rG061) or control rat IgG in NIH:OVCAR-3 cells and 786-O cells using the anti-rat IgG reagent Rat-ZAP conjugated with a toxin (saporin) that inhibits protein synthesis or the goat anti-rat IgG antibody specific for the Fc (gamma) fragment without conjugation with a toxin as a negative control. The ordinate axis of the graph indicates the ATP activity (RLU). Below each graph, the percentage of cell viability (%) is shown, calculated as the relative viability when the number of living cells in the well to which the negative control was added instead of Rat-ZAP was defined as 100%.[Figure 5] Figure 5 shows the binding of human anti-CDH6 chimeric antibody chG019 to human CDH6 and monkey CDH6.The abscissa axis indicates the concentration of antibodies, and the ordinate axis indicates the amount of bound antibodies based on the average fluorescence intensity. [Figure 6-1] Figures 6-1 and 6-2 show the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02) or a negative control human IgG1 antibody against human CDH6, monkey CDH6, mouse CDH6, and rat CDH6. The abscissa axis indicates the antibody concentration, and the ordinate axis indicates the amount of bound antibody based on the average fluorescence intensity. [Figure 6-2] Figures 6-1 and 6-2 show the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02) or a negative control human IgG1 antibody against human CDH6, monkey CDH6, mouse CDH6, and rat CDH6. The abscissa axis indicates the antibody concentration, and the ordinate axis indicates the amount of bound antibody based on the average fluorescence intensity.[Figure 7-1] Figure 7-1 shows the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 antibody against control cells or 293α cells transfected with full-length hCDH6. The abscissa axis indicates the fluorescence intensity of APC, indicating the amount of bound antibody. The ordinate axis indicates the number of cells. [Figure 7-2] Figure 7-2 shows the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 antibody against control cells or 293a cells transfected with hCDH6 with EC1 deletion. The abscissa axis indicates the fluorescence intensity of APC, indicating the amount of bound antibody. The ordinate axis indicates the number of cells.[Figure 7-3] Figure 7-3 shows the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 antibody against control cells or 293α cells transfected with EC2-deleted hCDH6. The abscissa axis indicates the fluorescence intensity of APC, indicating the amount of bound antibody. The ordinate axis indicates the number of cells. [Figure 7-4] Figure 7-4 shows the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 antibody against control cells or 293α cells transfected with EC3-deleted hCDH6. The abscissa axis indicates the fluorescence intensity of APC, indicating the amount of bound antibody. The ordinate axis indicates the number of cells.[Figure 7-5] Figure 7-5 shows the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 against control cells or 293α cells transfected with EC4-deleted hCDH6. The abscissa axis indicates the fluorescence intensity of APC, indicating the amount of bound antibody. The ordinate axis indicates the number of cells. [Figure 7-6] Figure 7-6 shows the binding activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 against control cells or 293α cells transfected with EC5-deleted hCDH6. The abscissa axis indicates the fluorescence intensity of APC, indicating the amount of bound antibody. The ordinate axis indicates the number of cells.[Figure 8] Figure 8 shows the flow cytometry results of a human CDH6 expression assay in the stably expressing cell line 786-O / hCDH6 and its parent cell line 786-0. The abscissa axis indicates the Alexa Fluor 647 fluorescence intensity, which indicates the amount of bound antibody, and the ordinate axis indicates the number of cells. [Figure 9] Figure 9 shows a competitive binding assay of four unlabeled humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, or negative control hIgG1 using (a) labeled NOV0712 or (b) labeled H01L02. The abscissa axis shows the final concentration of added unlabeled antibody, and the ordinate axis shows the amount of bound antibody based on the mean fluorescence intensity.[Figure 10-1] Figure 10-1 shows a graph in which the internalization activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, and negative control antibody were evaluated in NIH:OVC7AR-3 cells using anti-human IgG Hum-ZAP reagent conjugated with a toxin (saporin) that inhibits protein synthesis or goat anti-human IgG F(ab')2 fragment specific for the Fc (gamma) fragment not conjugated with a toxin as a negative control. The ordinate axis of the graph indicates ATP activity (RLU). Below each graph is the percentage of cell viability (%), calculated as the relative viability when the number of viable cells in the well to which the negative control was added instead of Hum-ZAP was defined as 100%.[Figure 10-2] Figure 10-2 shows a graph in which the internalization activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, and negative control antibody were evaluated in 786-O cells using anti-human IgG Hum-ZAP reagent conjugated with a toxin (saporin) that inhibits protein synthesis or goat anti-human IgG F(ab')2 fragment specific for Fc (gamma) fragment not conjugated with a toxin as a negative control. The ordinate axis of the graph indicates ATP activity (RLU). Below each graph is the percentage of cell viability (%), calculated as the relative viability when the number of viable cells in the well to which the negative control was added instead of Hum-ZAP was defined as 100%.[Figure 10-3] Figure 10-3 shows a graph in which the internalization activity of four humanized hG019 antibodies (H01L02, H02L02, H02L03, and H04L02), anti-CDH6 antibody NOV0712, and negative control antibody were evaluated in PA-1 cells using anti-human IgG Hum-ZAP reagent conjugated with a toxin (saporin) that inhibits protein synthesis or goat anti-human IgG F(ab')2 fragment specific for Fc (gamma) fragment not conjugated with a toxin as a negative control. The ordinate axis of the graph indicates ATP activity (RLU). Below each graph is the percentage of cell viability (%), calculated as the relative viability when the number of viable cells in the well to which the negative control was added instead of Hum-ZAP was defined as 100%.[Figure 11] Figure 11 shows the results of evaluation of the in vitro cell growth inhibitory activity of four humanized hG019-drug conjugates (H01L02-DXd, H02L02-DXd, H02L03-DXd, and H04L02-DXd) or NOV0712-DM4 against PA-1 cells. The abscissa axis indicates the concentration of the antibody-drug conjugate, and the ordinate axis indicates the cell survival percentage (%). [Figure 12] Figure 12 shows the in vivo antitumor effects of four humanized hG019-drug conjugates (H01L02-DXd, H02L02-DXd, H02L03-DXd, and H04L02-DXd) or NOV0712-DM4. The evaluation was conducted using animal models in which the CDH6-positive human kidney tumor cell line 786-O was inoculated into immunodeficient mice. The abscissa axis indicates the number of days, and the ordinate axis indicates tumor volume. The error bars reflect the standard error (SE).[Figure 13] Figure 13 shows the in vivo antitumor effects of the humanized hG019-drug conjugate H01L02-DXd or NOV0712-DM4 or NOV0712-DXd. The evaluation was performed using animal models in which the CDH6-positive human ovarian tumor cell line PA-1 was inoculated into immunodeficient mice. The abscissa axis indicates the number of days, and the ordinate axis indicates the tumor volume. The error range reflects the SE value. [Figure 14] Figure 14 shows the in vivo antitumor effects of the humanized hG019-drug conjugate H01L02-DXd or NOV0712-DM4. The evaluation was conducted using animal models in which the CDH6-positive human ovarian tumor cell line NIH:OVCAR-3 was inoculated into immunodeficient mice. The abscissa axis shows the number of days, and the ordinate axis shows tumor volume. The error bars represent the SE value.[Figure 15] Figure 15 shows the in vivo antitumor effects of the humanized hG019-drug conjugate H01L02-DXd or NOV0712-DM4. The evaluation was performed using animal models in which the CDH6-positive human kidney tumor cell line 786-O was inoculated into immunodeficient mice. The abscissa axis indicates the number of days, and the ordinate axis indicates the tumor volume. The error range reflects the SE value. [Figure 16] Figure 16 shows the in vivo antitumor effects of the humanized hG019-drug conjugate H01L02-DXd or NOV0712-DM4. The evaluation was performed using animal models in which the CDH6-negative human ovarian tumor cell line ES-2 was inoculated into immunodeficient mice. The abscissa axis shows the number of days, and the ordinate axis shows the tumor volume. The error bars represent the SE value.[Figure 17] Figure 17 shows the in vivo antitumor effect of the antibody-drug conjugate (1) after long-term treatment with carboplatin and paclitaxel. The evaluation was performed using animal models in which the CDH6-positive human ovarian tumor cell line NIH:OVCAR-3 was inoculated into immunodeficient mice. After 9 times of administration of carboplatin 50 mg / kg and paclitaxel 30 mg / kg (white triangles), mice whose calculated tumor volumes were between 150 mm3 and 500 mm3 were selected and administered with the antibody-drug conjugate (1) 10 mg / kg (black triangles). The abscissa axis indicates the number of days, and the ordinate axis indicates the tumor volume. The error range represents the SE value (Vehicle Group: N=6, Treatment Group: N=5).[Figure 18] Figure 18 is a graph showing the tumor growth suppression effect in mice subcutaneously transplanted with NIH:OVCAR-3 cells in the single administration groups of the antibody-drug conjugate (1) and carboplatin, respectively, and in the combined administration group of the antibody-drug conjugate (1) and carboplatin. [Figure 19] Figure 19 is a graph showing the tumor growth suppression effect in mice subcutaneously transplanted with OV-90 cells in the single administration groups of the antibody-drug conjugate (1) and carboplatin, respectively, and in the combined administration group of the antibody-drug conjugate (1) and carboplatin.[Figure 20] Figure 20 is a graph showing the tumor growth suppression effect in mice subcutaneously transplanted with OV-90 cells in a single administration group of the antibody-drug conjugate (1), in a combination administration group of carboplatin and paclitaxel, and in a combination administration group of the antibody-drug conjugate (1), carboplatin, and paclitaxel. [Figure 21] Figure 21 is a graph showing the tumor growth suppression effect in mice subcutaneously transplanted with OV-90 cells in a single administration group of the antibody-drug conjugate (1) and gemcitabine, respectively, and in a combination administration group of the antibody-drug conjugate (1) and gemcitabine. Description of Embodiments.

[0022] Next, preferred embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described below merely illustrate typical embodiments of the present invention, and the scope of the present invention should not be narrowly interpreted based on these examples.

[0023] In this description, the term "cancer" is used in the same meaning as the term "tumor".

[0024] In the present description, the term "gene" is used to mean not only DNA but also the corresponding mRNA and cDNA, as well as their cRNA.

[0025] In this description, the term "polynucleotide" or "nucleotide" is used in the same meaning as the term "nucleic acid" and also includes DNA, RNA, probe, oligonucleotide, and primer. In this description, the terms "polynucleotide" and "nucleotide" may be used interchangeably with each other unless otherwise specified.

[0026] In the present description, the terms "polypeptide" and "protein" may be used interchangeably with each other.

[0027] In the present description, the term "cell" includes cells of an individual animal and cultured cells.

[0028] In this description, the term "CDH6" may be used with the same meaning as the CDH6 protein. In this description, human CDH6 is also referred to as "hCDH6".

[0029] In this description, the term "cytotoxic activity" is used to indicate that a pathological change is induced in cells by a specific mechanism. This term encompasses not only direct damage but also all types of structural or functional cellular disturbances, such as DNA cleavage, base dimer formation, chromosome segregation, damage to the mitotic apparatus, and decreased activity of various enzymes.

[0030] In this description, the phrase "exert a toxic effect on cells" is used to indicate that toxicity manifests itself in cells in one way or another. This term refers not only to direct damage, but also to all types of structural, functional, or metabolic effects on cells, such as DNA cleavage, base dimer formation, chromosome segregation, damage to the cellular mitotic apparatus, decreased activity of various types of enzymes, and suppression of cell growth factors.

[0031] In the present description, the term "functional antibody fragment", also referred to as "antigen-binding antibody fragment", is used to refer to a partial antibody fragment having binding activity against an antigen, and includes Fab, F(ab')2, scFv, diabody, linear antibody, and multispecific antibody formed from antibody fragments, etc. Fab', which is a monovalent fragment from the variable regions of an antibody obtained by treating F(ab')2 under reducing conditions, is also included in the antigen-binding fragment of an antibody. However, the antigen-binding fragment of an antibody is not limited to these molecules, as long as the antigen-binding fragment has antigen-binding ability.Such antigen-binding fragments include not only fragments obtained by treating a full-length antibody protein molecule with the appropriate enzyme, but also proteins produced in appropriate host cells using a genetically modified antibody gene.

[0032] In the present description, the term "epitope" is used to refer to a partial peptide or partial three-dimensional structure of CDH6 to which a specific anti-CDH6 antibody binds. Such an epitope, which is the above-described partial peptide of CDH6, can be determined by a method well known to those skilled in the art, such as an immunoassay. First, various partial structures of the antigen are obtained. With regard to the production of such partial structures, a known oligopeptide synthesis technique can be used. For example, a series of polypeptides in which CDH6 is sequentially shortened to an appropriate length from the C-terminus or N-terminus are obtained using genetic recombination technology well known to those skilled in the art. Then, the reactivity of the antibody to such polypeptides is examined, and the recognition sites are approximately determined.Additional shorter peptides are then synthesized, and reactivity to these peptides can be tested to determine the epitope. When an antibody that binds to a membrane protein with multiple extracellular domains targets a three-dimensional structure consisting of multiple domains as an epitope, the domain to which the antibody binds can be determined by modifying the amino acid sequence of the specific extracellular domain and thereby modifying the three-dimensional structure. The epitope, which is a partial three-dimensional structure of the antigen that binds to a specific antibody, can also be determined by identifying the amino acid residues of the antigen in contact with the antibody using X-ray crystallography.

[0033] In the present description, the phrase "antibodies binding to the same epitope" is used to refer to antibodies that bind to a common epitope. If a second antibody binds to a partial peptide or partial three-dimensional structure to which the first antibody binds, it can be determined that the first antibody and the second antibody bind to the same epitope. Alternatively, by confirming that the second antibody competes with the first antibody for the binding of the first antibody to the antigen (i.e., the second antibody interferes with the binding of the first antibody to the antigen), it can be determined that the first antibody and the second antibody bind to the same epitope, even if the specific sequence or structure of the epitope has not been determined.As used herein, the phrase "binding to the same epitope" refers to a case where the first antibody and the second antibody are determined to bind to a common epitope using one or both of these detection methods. If the first antibody and the second antibody bind to the same epitope and, in addition, the first antibody exhibits specific effects, such as antitumor activity or internalization activity, then the second antibody can be expected to exhibit the same activity as the first antibody.

[0034] In the present description, the term "CDR" is used to refer to the complementarity determining region. It is known that the heavy chain and light chain of an antibody molecule each contain three CDR regions. Such a CDR region is also called a hypervariable region and is located in the variable regions of the heavy chain and light chain of the antibody. These regions have the most highly variable primary structure and are divided into three regions of the primary structure of the polypeptide chain in each heavy chain and light chain. In the present description, regarding the CDRs of an antibody, the CDR regions of the heavy chain are designated CDRH1, CDRH2, and CDRH3, respectively, from the N-terminal side of the amino acid sequence of the heavy chain, while the CDR regions of the light chain are designated CDRL1, CDRL2, and CDRL3, respectively, from the N-terminal side of the amino acid sequence of the light chain. These regions are located close to each other in a three-dimensional structure and determine the specificity of the antibody to the antigen to which the antibody binds.

[0035] In the present invention, the phrase "hybridization under stringent conditions" is used to mean that hybridization is carried out in a commercially available hybridization solution ExpressHyb Hybridization Solution (manufactured by Clontech Laboratories, Inc.) at 68°C, or that hybridization is carried out under conditions in which hybridization is carried out using a DNA-immobilized filter in the presence of 0.7-1.0 M NaCl at 68°C, and then the resulting product is washed at 68°C with a 0.1-2-fold concentration of SSC solution (where 1-fold concentration of SSC consists of 150 mM NaCl and 15 mM sodium citrate) for identification, or under conditions equivalent thereto.

[0036] In the present description, the term "one or more" is used to mean 1 to 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, or 1 or 2.

[0037] In this description, the term "resistant" is used to denote a lack of response to treatment with an anticancer agent. This term may also be expressed as "refractory," "unresponsive," or "unresponsive." Furthermore, this term may also be expressed as "intolerable," since tumor growth cannot be prevented due to its unresponsive nature.

[0038] In the present specification, the term "resistant" may mean "having resistance acquired by cancer as a result of treatment with an antitumor agent" or may mean "having resistance characteristic of cancer regardless of treatment with an antitumor agent."

[0039] In this description, the term "chemotherapy-resistant" is used to mean lack of response to chemotherapy treatment.

[0040] In this description, the term "refractory to a chemotherapy regimen" is used to mean the lack of response to chemotherapy administered according to a chemotherapy regimen.

[0041] In this description, the term "platinum-based chemotherapy resistance" is used to refer to the lack of response to treatment with platinum-based chemotherapy.

[0042] In the present description, the term "chemotherapy" is used to refer to therapy using one or more chemotherapeutic agents used to treat cancer.

[0043] In the present description, the term "chemotherapeutic agents" is used to refer to a chemotherapeutic agent used for the treatment of cancer.Chemotherapeutic agents include, but are not limited to: alkylating agents (e.g., mechlorethamine, cyclophosphamide, ifosfamide, melphalan, chlorambucil, hexamethylmelamine, thiotepa, busulfan, carmustine, lomustine, semustine, streptozocin, dacarbazine), antimetabolites (e.g., gemcitabine, methotrexate, fluorouracil, doxifluridine, capecitabine, floxuridine, cytarabine, mercaptopurine, thioguanine, pentostatin), vinca alkaloids (e.g., vinblastine, vincristine), epipodophyllotoxins (e.g., etoposide, teniposide), antibiotics (e.g., dactinomycin, daunorubicin, doxorubicin, bleomycin, plicamycin, mitomycin), platinum complexes (e.g., cisplatin, carboplatin, oxaliplatin), taxanes (eg, paclitaxel, docetaxel), anthracenediones (eg, mitoxantrone), urea derivatives (eg, hydroxyurea), methylhydrazines (eg, procarbazine hydrochloride), vitamin A metabolite (eg, tretinoin).

[0044] In the present description, the term "platinum chemotherapy" is used to refer to antitumor therapy using one or more platinum drugs with or without one or more other chemotherapeutic agents.

[0045] As used herein, the term "platinum drug" refers to platinum complexes used for the treatment of cancer. Platinum drugs include, but are not limited to, cisplatin, carboplatin, and oxaliplatin.

[0046] As used herein, the term "cancer recurrence" refers to the return of cancer in the same location as the primary tumor or in another area of ​​the body after a period of time during which the cancer was undetectable. This term is defined based on "recurrence" in the following reference. NCI Dictionaries, "recurrence," NCI Dictionary of Cancer Terms [online]. National Cancer Institute [retrieved 09 / 06 / 2022]. Retrieved from<cancer.gov / publications / dictionaries / cancer-terms / clef / recurrence> .

[0047] In the present description, the term "chemotherapy regimen" is used to refer to a treatment plan for chemotherapy that specifies the drug(s), dosage, frequency, etc.

[0048] As used herein, the term "complete response (CR)" is used to indicate that all signs of cancer have disappeared in response to treatment. "Complete response (CR)" does not always mean that the cancer has been cured. This term can also be expressed as "complete remission." The term is defined based on "complete response" in the following reference. NCI Dictionaries, "complete response," NCI Dictionary of Cancer Terms [online]. National Cancer Institute [retrieved 09 / 06 / 2022]. Retrieved from<cancer.gov / publications / dictionaries / cancer-terms / def / complete-response> .

[0049] As used herein, the term "partial response (PR)" is used to indicate that the tumor size or the extent of cancer in the body has decreased in response to treatment. This term may also be expressed as "partial remission." The term is defined based on "partial response" in the following reference. NCI Dictionaries, "partial response," NCI Dictionary of Cancer Terms [online]. National Cancer Institute [retrieved 09 / 06 / 2022]. Retrieved from<cancer.gov / publications / dictionaries / cancer-terms / def / partial-response> .

[0050] As used herein, the term "stable disease (SD)" is used to indicate that the extent or severity of cancer is neither decreasing nor increasing. The term is defined based on "partial response" in the following reference. NCI Dictionaries, "stable disease," NCI Dictionary of Cancer Terms [online]. National Cancer Institute [retrieved 09 / 06 / 2022]. Retrieved from<cancer.gov / publications / dictionaries / cancer-terms / def / stable-disease> .

[0051] 1. CDH6 Cadherins are glycoproteins present on the surface of cell membranes and function as intercellular adhesion molecules through calcium-dependent binding of their N-terminal extracellular domains or as signaling molecules responsible for intercellular interactions. Classical cadherins belong to the cadherin superfamily and are single-pass transmembrane proteins consisting of five extracellular domains (EC domains), one transmembrane region, and an intracellular domain.

[0052] CDH6 (cadherin-6) is a 790-amino acid long single-pass transmembrane protein classified as a member of the type II cadherin family. This protein has an N-terminal extracellular domain and a C-terminal intracellular domain. The human CDH6 gene was first cloned in 1995 (Non-patent reference 1), and its sequence can be accessed, for example, under accession numbers NM_004932 and NP_004923 (NCBI).

[0053] The CDH6 protein used in the present invention can be purified directly from CDH6-expressing cells of a human or non-human mammal (e.g., a rat, mouse, or monkey) and then used, or a fraction of the cell membranes of the above-mentioned cells can be obtained and used as the CDH6 protein. Alternatively, CDH6 can also be produced by in vitro synthesis or by allowing host cells to produce CDH6 through genetic manipulation. According to such genetic manipulation, the CDH6 protein can be produced, in particular, by incorporating CDH6 cDNA into a vector capable of expressing CDH6 cDNA and then synthesizing CDH6 in a solution containing enzymes, a substrate, and energy materials necessary for transcription and translation, or by transforming host cells of other prokaryotes or eukaryotes so that they can express CDH6.Furthermore, CDH6-expressing cells, based on the genetic manipulations described above, or a CDH6-expressing cell line, can be used to present the CDH6 protein. Alternatively, an expression vector containing the CDH6 cDNA can be directly administered to the animal to be immunized, allowing CDH6 to be expressed in the immunized animal.

[0054] In addition, a protein that consists of an amino acid sequence including a substitution, deletion and / or addition of one or more amino acids in the above-described amino acid sequence of CDH6, and has a biological activity equivalent to that of the CDH6 protein, is also included in the term "CDH6".

[0055] The amino acid sequence of the human CDH6 protein is shown in SEQ ID NO: 1. The extracellular region of the human CDH6 protein consists of an extracellular domain 1 (herein also referred to as EC1) having the amino acid sequence at positions 54-159 in the amino acid sequence shown in SEQ ID NO: 1, an extracellular domain 2 (herein also referred to as EC2) having the amino acid sequence at positions 160-268 in the amino acid sequence shown in SEQ ID NO: 1, an extracellular domain 3 (herein also referred to as EC3) having the amino acid sequence at positions 269-383 in the amino acid sequence shown in SEQ ID NO: 1, an extracellular domain 4 (herein also referred to as EC4) having the amino acid sequence at positions 384-486 in the amino acid sequence shown in SEQ ID NO: 1, and extracellular domain 5 (herein also referred to as EC5),having the amino acid sequence at positions 487-608 in the amino acid sequence shown in SEQ ID NO: 1. The amino acid sequences of EC1-EC5 are shown in SEQ ID NO: 2-6, respectively (Table 1).,

[0056] 2. Production of anti-CDH6 antibodyOne example of an anti-CDH6 antibody according to the present invention may include an anti-CDH6 antibody that recognizes an amino acid sequence comprising the amino acid sequence shown in SEQ ID NO: 4 and has internalization activity.One example of an anti-CDH6 antibody according to the present invention may include an anti-CDH6 antibody that specifically recognizes an amino acid sequence comprising the amino acid sequence shown in SEQ ID NO: 4 and has internalization activity.One example of an anti-CDH6 antibody according to the present invention may include an anti-CDH6 antibody that recognizes an amino acid sequence consisting of the amino acid sequence shown in SEQ ID NO: 4 and has internalization activity.One example of an anti-CDH6 antibody according to the present invention may include an anti-CDH6 antibody that specifically recognizes an amino acid sequence consisting of the amino acid sequence shown in SEQ ID NO: 4 and has internalization activity. The phrases "specifically recognizes an amino acid sequence comprising the amino acid sequence shown in SEQ ID NO: 4" or "specifically recognizes the EC3 domain" when applied to an antibody are used to indicate that the antibody effectively recognizes or strongly binds to the EC3 domain of CDH6 compared to other extracellular domains of CDH6.

[0057] The anti-CDH6 antibody of the present invention can be obtained from any biological species. Preferred examples of species include humans, monkeys, rats, mice, and rabbits. When the anti-CDH6 antibody of the present invention is obtained from a biological species other than humans, the anti-CDH6 antibody is preferably chimerized or humanized using a well-known method. The antibody of the present invention can be a polyclonal antibody or a monoclonal antibody, with a monoclonal antibody being preferred.

[0058] The anti-CDH6 antibody according to the present invention is an antibody that can target tumor cells. Specifically, the anti-CDH6 antibody according to the present invention has the ability to recognize tumor cells, the ability to bind to tumor cells, and / or the ability to be internalized into tumor cells upon cellular uptake, etc. Therefore, the anti-CDH6 antibody according to the present invention can be conjugated with a compound having antitumor activity via a linker to produce an antibody-drug conjugate.

[0059] The antibody's binding activity to tumor cells can be confirmed by flow cytometry. Antibody uptake by tumor cells can be confirmed by: (1) an assay visualizing the antibody taken up by the cell under a fluorescence microscope using a secondary antibody (fluorescently labeled) that binds to the antibody (Cell Death and Differentiation, 2008, 15, 751-761), (2) an assay measuring the amount of fluorescence taken up by the cells using a secondary antibody (fluorescently labeled) that binds to the antibody (Molecular Biology of the Cell Vol. 15, 5268-5282, December 2004), or (3) a Mab-ZAP assay using immunotoxin binding to the antibody, where the toxin is released upon cell uptake, inhibiting cell growth (Bio Techniques 28: 162-165, January 2000). A recombinant conjugated protein of the catalytic region of diphtheria toxin and protein G can be used as an immunotoxin.

[0060] In the present specification, the term "high internalization ability" is used to mean that the survival rate (which is indicated by the ratio to the survival rate of cells without the addition of an antibody, defined as 100%) of the CDH6-expressing cells to which the above-mentioned antibody and the saporin-labeled anti-rat IgG antibody are added is preferably 70% or less, and more preferably 60% or less.

[0061] The antitumor antibody-drug conjugate of the present invention comprises a conjugated compound that exhibits antitumor activity. Thus, it is preferable, but not necessary, that the antibody itself exhibit antitumor activity. To specifically and / or selectively exhibit cytotoxicity of the antitumor compound in tumor cells, it is important and preferable that the antibody possess the ability to be internalized and transported into tumor cells.

[0062] An anti-CDH6 antibody can be produced by immunizing an animal with a polypeptide serving as an antigen using a method commonly used in the art, and then collecting and purifying the antibody produced in the animal. Preferably, CDH6, which retains its three-dimensional structure, is used as the antigen. Examples of such a method include a DNA immunization method.

[0063] The antigen's origin is not limited to humans, and thus animals can also be immunized with an antigen derived from a non-human animal, such as a mouse or rat. In this case, the antibody used for the human disease can be selected by testing the cross-reactivity of the resulting antibody, which binds to the heterologous antigen, with the human antigen.

[0064] In addition, antibody-producing cells that produce an antibody against an antigen can be fused with shelloma cells according to a known method (e.g., Kohler and Milstein, Nature (1975) 256, 495-497; and Kennet, R. ed., Monoclonal Antibodies, 365-367, Plenum Press, NY (1980)), to create hybridomas and obtain a monoclonal antibody.

[0065] Next, a method for producing an anti-CDH6 antibody will be specifically described.

[0066] (1) Antigen ProductionAn antigen can be produced by genetically manipulating host cells to produce a gene encoding an antigen protein. Specifically, a vector capable of expressing the antigen gene is produced and then introduced into host cells, whereupon the gene is expressed. The expressed antigen can then be purified. An antibody can also be produced by immunizing an animal with antigen-expressing cells based on the genetic manipulation described above or with a cell line expressing the antigen.

[0067] Alternatively, the antibody can also be produced without using an antigen protein by incorporating cDNA of the antigen protein into an expression vector, followed by introducing the expression vector into an animal to be immunized and expressing the antigen protein in the body of the animal thus immunized, resulting in the production of an antibody against the antigen protein.

[0068] (2) Production of an anti-CDH6 monoclonal antibody. The anti-CDH6 antibody used in the present invention is not particularly limited. For example, an antibody defined by the amino acid sequence shown in the sequence listing of the present application can be suitably used. The anti-CDH6 antibody used in the present invention is preferably an antibody having the following properties: (1) an antibody having the following properties: (a) specifically binds to CDH6, and (b) has an internalization activity into CDH6-expressing cells upon binding to CDH6; (2) the antibody according to (1) above, wherein CDH6 is human CDH6; or (3) the antibody according to (1) or (2) above, wherein the antibody specifically recognizes EC3 in human CDH6 and has internalization activity. The method for producing the anti-CDH6 antibody according to the present invention is not particularly limited, as long as the anti-CDH6 antibody can be produced.It is preferable to use CDH6, which maintains its conformation, as an antigen.

[0069] One preferred example of a method for producing an antibody may include a DNA immunization method. The DNA immunization method is an approach that involves transfecting an individual animal (e.g., a mouse or rat) with a plasmid expressing an antigen, followed by expressing the antigen in the animal to induce immunity against the antigen. The transfection method includes a method of directly introducing a plasmid into a muscle, a method of injecting a transfection reagent such as a liposome or polyethyleneimine into a vein, a method using a viral vector, a method of introducing gold particles to which a plasmid is attached using a gene gun, a hydrodynamic method of rapidly introducing a plasmid solution in large quantities into a vein, and the like.Regarding the transfection method by injecting the expression plasmid into the muscle, a method called in vivo electroporation is used, which involves the use of electroporation at the site of intramuscular injection of the plasmid, known as an approach to increase the expression level (Aihara H, Miyazaki J. Nat Biotechnol. 1998 Sep; 16 (9): 867-70 or Mir LM, Bureau MF, Gehl J, Rangara R, Rouy D, Caillaud JM, Delaere P, Branellec D, Schwartz B, Scherman D. Proc Natl Acad Sci USA. 1999 Apr 13; 96 (8): 4262-7). This approach further improves the expression level by treating the muscle with hyaluronidase prior to intramuscular injection of the plasmid (McMahon JM1, Signori E, Wells KE, Fazio VM, Wells DJ., Gene Ther. 2001 Aug; 8 (16): 1264-70). In addition, hybridoma production can be performed by a known method, as well as using, for example, the Hybrimune hybridoma production system (Cyto Pulse Sciences, Inc.).

[0070] Specific examples of producing a monoclonal antibody may include the following procedures: (a) an immune response can be induced by incorporating CDH6 cDNA into an expression vector (e.g., pcDNA3.1; Thermo Fisher Scientific Inc.) and directly introducing the vector into an animal (e.g., a rat or a mouse) for immunization by a method such as electroporation or gene gun to express CDH6 in the animal. The introduction of the vector by electroporation or the like may be carried out one or more times, preferably multiple times, if necessary to increase the antibody titer;(b) collecting tissue (e.g., lymph node) containing antibody-producing cells from the above-mentioned animal in which an immune response has been induced;(c) obtaining myeloma cells (hereinafter referred to as "myeloma cells") (e.g., SP2 / 0-agl4 mouse myeloma cells);(d) fusing the antibody-producing and myeloma cells;(e) selecting a group of hybridomas producing the antibody of interest;(f) division into single-cell clones (cloning);(g) optionally, culturing hybridomas for mass production of monoclonal antibodies or breeding animals inoculated with hybridomas; and / or(h) studying the physiological activity (internalization activity) and binding specificity of the monoclonal antibody thus obtained or studying the properties of the antibody as a labeling reagent.

[0071] Examples of the method for measuring antibody titer used herein may include, but are not limited to, flow cytometry and cell-based ELISA.

[0072] Examples of the hybridoma strain thus obtained may include anti-CDH6 antibody-producing hybridomas rG019, rG055, rG056, and rG071. It should be noted that, in the present description, the antibody produced by the anti-CDH6 antibody-producing hybridoma rG019 is referred to as "rG019 antibody" or simply "rG019", the antibody produced by the hybridoma rG055 is referred to as "rG055 antibody" or simply "rG055", the antibody produced by the hybridoma rG056 is referred to as "rG056 antibody" or simply "rG056", and the antibody produced by the hybridoma rG061 is referred to as "rG061 antibody" or simply "rG061".

[0073] The variable region of the light chain of the rG019 antibody consists of the amino acid sequence shown in SEQ ID NO: 10. The amino acid sequence of the variable region of the light chain of the rG019 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 11. The variable region of the light chain of the rG019 antibody comprises CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 12, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 13, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 14. The variable region of the heavy chain of the rG019 antibody consists of the amino acid sequence shown in SEQ ID NO: 15. The amino acid sequence of the variable region of the heavy chain of the rG019 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 16.The variable region of the heavy chain of the antibody rG019 comprises CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 18, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19. The sequence of the antibody rG019 is shown in Table 1.

[0074] The variable region of the light chain of the rG055 antibody consists of the amino acid sequence shown in SEQ ID NO: 20. The amino acid sequence of the variable region of the light chain of the rG055 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 21. The variable region of the light chain of the rG055 antibody comprises CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 22, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 23, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 24. The variable region of the heavy chain of the rG055 antibody consists of the amino acid sequence shown in SEQ ID NO: 25. The amino acid sequence of the variable region of the heavy chain of the rG055 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 26.The heavy chain variable region of the rG055 antibody comprises CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 27, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 28, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 29. The sequence of the rG055 antibody is shown in Table 1.

[0075] The variable region of the light chain of the rG056 antibody consists of the amino acid sequence shown in SEQ ID NO: 30. The amino acid sequence of the variable region of the light chain of the rG056 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 31. The variable region of the light chain of the rG056 antibody comprises CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 32, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 33, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 34. The variable region of the heavy chain of the rG056 antibody consists of the amino acid sequence shown in SEQ ID NO: 35. The amino acid sequence of the variable region of the heavy chain of the rG056 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 36.The heavy chain variable region of the rG056 antibody comprises CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 37, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 38, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 39. The sequence of the rG056 antibody is shown in Table 1.

[0076] The variable region of the light chain of the rG061 antibody consists of the amino acid sequence shown in SEQ ID NO: 40. The amino acid sequence of the variable region of the light chain of the rG061 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 41. The variable region of the light chain of the rG061 antibody comprises CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 42, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 43, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 44. The variable region of the heavy chain of the rG061 antibody consists of the amino acid sequence shown in SEQ ID NO: 45. The amino acid sequence of the variable region of the heavy chain of the rG061 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 46.The variable region of the heavy chain of the antibody rG061 comprises CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 47, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 48, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 49. The sequence of the antibody rG061 is shown in Table 1.

[0077] Furthermore, in the case where steps (a) to (h) in the above section "2. Production of anti-CDH6 antibody" are performed again to independently produce a monoclonal antibody separately, and also in the case where the monoclonal antibody is produced separately by other methods, an antibody having an internalization activity equivalent to that of antibody rG019, antibody rG055, antibody rG056, or antibody rG061 can be obtained. One example of such an antibody may include an antibody binding to the same epitope as that bound by antibody rG019, antibody rG055, antibody rG056, or antibody rG061. If the newly obtained monoclonal antibody binds to a partial peptide or partial three-dimensional structure to which antibody rG019, antibody rG055, antibody rG056, or antibody rG061 binds, then it can be determined that the monoclonal antibody binds to the same epitope to which antibody rG019, antibody rG055, antibody rG056, or antibody rG061 binds.Moreover, by confirming that the monoclonal antibody competes with the rG019 antibody, the rG055 antibody, the rG056 antibody, or the rG061 antibody in binding the antibody to CDH6 (i.e., the monoclonal antibody interferes with the binding of the rG019 antibody, the rG055 antibody, the rG056 antibody, or the rG061 antibody to CDH6), it can be determined that the monoclonal antibody binds to the same epitope that the anti-CDH6 antibody binds to, even if the specific sequence or structure of the epitope has not been determined. If a monoclonal antibody is confirmed to bind to the same epitope as antibody rG019, antibody rG055, antibody rG056, or antibody rG061, then the monoclonal antibody is highly likely to be expected to have an antigen-binding ability, biological activity, and / or internalization activity that is equivalent to that of antibody rG019, antibody rG055, antibody rG056, or antibody rG061.

[0078] (3) Other AntibodiesThe antibody of the present invention also includes genetically recombinant antibodies that have been artificially modified to reduce heterogeneous antigenicity to humans, such as a chimeric antibody, a humanized antibody, and a human antibody, as well as the above-described anti-CDH6 monoclonal antibody. These antibodies can be produced by known methods.[007 9] An example of a chimeric antibody may include antibodies in which a variable region and a constant region are heterologous to each other, such as a chimeric antibody obtained by conjugating a variable region of a mouse or rat antibody to a human constant region (see Proc. Natl. Acad. Sci. USA, 81, 6851-6855, (1984)).

[0080] Examples of the chimeric antibody derived from the rat anti-human CDH6 antibody include an antibody consisting of a light chain including the light chain variable region of each rat anti-human CDH6 antibody described herein (e.g., rG019 antibody, rG055 antibody, rG056 antibody, or rG061 antibody) and a human constant region, and a heavy chain including its heavy chain variable region and a human constant region.

[0081] Other examples of the chimeric antibody derived from the rat anti-human CDH6 antibody include an antibody consisting of a light chain comprising a light chain variable region with a substitution of one to several residues, 1 to 3 residues, 1 or 2 residues, preferably 1 residue, of the amino acids in the light chain variable region of each rat anti-human CDH6 antibody described herein (e.g., rG019 antibody, rG055 antibody, rG056 antibody, or rG061 antibody) with other amino acid residues, and a heavy chain comprising a heavy chain variable region with a substitution of one to several residues, 1 to 3 residues, 1 or 2 residues, preferably 1 residue, of the amino acids in its heavy chain variable region with other amino acid residues. Such an antibody may have any human constant region.

[0082] Other examples of the chimeric antibody derived from the rat anti-human CDH6 antibody include an antibody consisting of a light chain comprising a light chain variable region with a substitution of 1 or 2 residues, preferably 1 amino acid residue in any one of 1 to 3 CDR regions in the light chain variable region of each rat anti-human CDH6 antibody described herein (e.g., rG019 antibody, rG055 antibody, rG056 antibody, or rG061 antibody), with other amino acid residues, and a heavy chain comprising a heavy chain variable region with a substitution of 1 or 2 residues, preferably 1 amino acid residue in any one of 1 to 3 CDR regions in the heavy chain variable region with other amino acid residues. Such an antibody may have any human constant region.

[0083] Examples of a chimeric antibody derived from the rG019 antibody include an antibody comprising a light chain comprising a light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 10, and a heavy chain comprising a heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 15. Such an antibody may have any human constant region.

[0084] Other examples of the chimeric antibody derived from the rG019 antibody include an antibody consisting of a light chain comprising a light chain variable region with a substitution of one to several residues, 1 to 3 residues, 1 or 2 residues, preferably 1 residue, of amino acids in the light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 10, with other amino acid residues, and a heavy chain comprising a heavy chain variable region with a substitution of one to several residues, 1 to 3 residues, 1 or 2 residues, preferably 1 residue, of amino acids in the heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 15, with other amino acid residues. Such an antibody may have any human constant region.

[0085] Other examples of the chimeric antibody derived from the rG019 antibody include an antibody consisting of a light chain comprising a light chain variable region with 1 or 2 amino acid residues (preferably 1 residue) replaced in any one of 1 to 3 CDR regions in the light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 10 with other amino acid residues, and a heavy chain comprising a heavy chain variable region with 1 or 2 amino acid residues (preferably 1 residue) replaced in any one of 1 to 3 CDR regions in the heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 15 with other amino acid residues. Such an antibody may have any human constant region.

[0086] Other examples of a chimeric antibody derived from the rG019 antibody include an antibody comprising a light chain comprising a light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 10 and a heavy chain comprising a heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 58. Such an antibody may have any human constant region. The amino acid sequence shown in SEQ ID NO: 58 is a sequence with a replacement of a cysteine ​​residue with a proline residue in CDRH2 in the amino acid sequence shown in SEQ ID NO: 15.

[0087] Specific examples of the chimeric antibody derived from the rG019 antibody include an antibody comprising a light chain comprising the full-length amino acid sequence of the light chain shown in SEQ ID NO: 53 and a heavy chain comprising the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 56. In the present description, this anti-human CDH6 chimeric antibody is referred to as "chimeric antibody G019," "chG019 antibody," or "chG019." The full-length amino acid sequence of the light chain of the chG019 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 54, and the full-length amino acid sequence of the heavy chain of the chG019 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 57.

[0088] The amino acid sequence of the light chain variable region of the chG019 antibody is identical to the amino acid sequence of the light chain variable region of the rG019 antibody and consists of the amino acid sequence shown in SEQ ID NO: 10. The light chain of the chG019 antibody comprises CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 12, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 13, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 14, which are identical to CDRL1, CDRL2, and CDRL3 of the rG019 light chain, respectively. The amino acid sequence of the light chain variable region of the chG019 antibody is encoded by the nucleotide sequence shown in SEQ ID NO: 55.[008 9] The amino acid sequence of the heavy chain variable region of the chG019 antibody consists of the amino acid sequence shown in SEQ ID NO: 58.The heavy chain of the chG019 antibody comprises a CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, a CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 60, and a CDRH3 consisting of the amino acid sequence shown in SEQ ID NO: 19. The amino acid sequence shown in SEQ ID NO: 58 is a sequence with a substitution of a cysteine ​​residue with a proline residue in CDRH2 in the amino acid sequence shown in SEQ ID NO: 15. CDRH2, consisting of the amino acid sequence shown in SEQ ID NO: 60, is a sequence with a substitution of a cysteine ​​residue with a proline residue in CDRH2 of rG019 shown in SEQ ID NO: 18. The amino acid sequence of the variable region of the heavy chain of the chG019 antibody encoded by the nucleotide sequence shown in SEQ ID NO: 59.

[0090] The sequence of antibody chG019 is shown in Table 1.

[0091] Examples of a chimeric antibody derived from the rat anti-human CDH6 antibody rG055 include a chimeric antibody consisting of a light chain including a light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 20 and a heavy chain including a heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 25. Such an antibody may have any human constant region.

[0092] Examples of a chimeric antibody derived from the rat anti-human CDH6 antibody rG056 include a chimeric antibody consisting of a light chain including a light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 30 and a heavy chain including a heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 35. Such an antibody may have any human constant region.

[0093] Examples of a chimeric antibody derived from the rat anti-human CDH6 antibody rG061 include a chimeric antibody consisting of a light chain including a light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 40 and a heavy chain including a heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 45. Such an antibody may have any human constant region.

[0094] Examples of the humanized antibody may include an antibody obtained by incorporating only complementarity determining regions (CDRs) into a human antibody (see Nature (1986) 321, p. 522-525), an antibody obtained by incorporating amino acid residues from some framework sequences as well as from CDR sequences into a human antibody according to the CDR grafting method (International Publication WO90 / 07861), and an antibody obtained by modifying the amino acid sequences of some CDRs while maintaining the antigen-binding ability.

[0095] In the present description, a humanized antibody derived from antibody rG019, antibody rG055, antibody rG056, antibody rG061, or antibody chG019 is not limited to a specific humanized antibody, as long as the humanized antibody retains all 6 CDR sequences unique to antibody rG019, antibody rG055, antibody rG056, antibody rG061, or antibody chG019 and has internalization activity. The amino acid sequences of some CDR regions of such a humanized antibody may be further modified, as long as it has internalization activity.

[0096] Specific examples of the humanized antibody chG019 may include any specific combination of: a light chain comprising a light chain variable region consisting of any amino acid sequence selected from the group consisting of (1) the amino acid sequence shown in SEQ ID NO: 63 or 67, (2) an amino acid sequence having at least 95% or more identity (preferably an amino acid sequence having at least 95% or more sequence identity with a framework region sequence other than each CDR sequence) with the above-described amino acid sequence (1), and (3) an amino acid sequence comprising a deletion, substitution, or addition of one or more amino acids in the above-described amino acid sequence (1);and a heavy chain comprising a heavy chain variable region consisting of any amino acid sequence selected from the group consisting of (4) the amino acid sequence shown in SEQ ID NO: 71, 75, or 79, (5) an amino acid sequence having at least 95% or greater sequence identity (preferably an amino acid sequence having at least 95% or greater sequence identity to a framework region sequence other than each CDR sequence) with the above-described amino acid sequence (4), and (6) an amino acid sequence comprising a deletion, substitution, or addition of one or more amino acids in the above-described amino acid sequence (4).;

[0097] Alternatively, an antibody having a humanized heavy chain or a light chain and another chain derived from a rat antibody or a chimeric antibody may also be used. Examples of such an antibody may include any specific combination of: a light chain comprising a light chain variable region consisting of any amino acid sequence selected from the group consisting of (1) the amino acid sequence shown in SEQ ID NO: 63 or 67, (2) an amino acid sequence having at least 95% or more sequence identity (preferably an amino acid sequence having at least 95% or more sequence identity with a framework region sequence other than each CDR sequence) with the above-described amino acid sequence (1), and (3) an amino acid sequence including a deletion,a substitution or addition of one or more amino acids in the above-described amino acid sequence (1); and a heavy chain comprising a heavy chain variable region consisting of any amino acid sequence selected from the group consisting of (4) the amino acid sequence shown in SEQ ID NO: 15, 25, 35, 45 or 58, (5) an amino acid sequence having at least 95% or more sequence identity (preferably an amino acid sequence having at least 95% or more sequence identity to a framework region sequence other than each CDR sequence) with the above-described amino acid sequence (4), and (6) an amino acid sequence comprising a deletion, substitution or addition of one or more amino acids in the above-described amino acid sequence (4). Other examples of such an antibody may include any combination of: a light chain,comprising a light chain variable region consisting of any amino acid sequence selected from the group consisting of (1) the amino acid sequence shown in SEQ ID NO: 10, 20, 30, or 40, (2) an amino acid sequence having at least 95% or greater sequence identity (preferably an amino acid sequence having at least 95% or greater sequence identity to a framework region sequence other than each CDR sequence) with the above-described amino acid sequence (1), and (3) an amino acid sequence comprising a deletion, substitution, or addition of one or more amino acids in the above-described amino acid sequence (1); and a heavy chain comprising a heavy chain variable region consisting of any amino acid sequence selected from the group consisting of (4) the amino acid sequence shown in SEQ ID NO: 71, 75, or 79,(5) an amino acid sequence having at least 95% or greater sequence identity (preferably an amino acid sequence having at least 95% or greater sequence identity with a framework region sequence other than each CDR sequence) with the above-described amino acid sequence (4), and (6) an amino acid sequence comprising a deletion, substitution, or addition of one or more amino acids in the above-described amino acid sequence (4).,

[0098] The amino acid substitution in the present specification is preferably a conservative amino acid substitution. A conservative amino acid substitution is a substitution occurring in a group of amino acids associated with certain amino acid side chains. Preferred amino acid groups are as follows: acidic group=aspartic acid and glutamic acid; basic group=lysine, arginine, and histidine; non-polar group=alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, and tryptophan; and uncharged polar family=glycine, asparagine, glutamine, cysteine, serine, threonine, and tyrosine. Other preferred amino acid groups are as follows: aliphatic hydroxy group=serine and threonine; amide-containing group=asparagine and glutamine; aliphatic group=alanine, valine, leucine, and isoleucine; and aromatic group = phenylalanine, tryptophan and tyrosine.Such amino acid substitution is preferably carried out without deteriorating the properties of the substance having the original amino acid sequence.

[0099] Examples of the antibody having the preferred combination of the above-described light chains and heavy chains include an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 63 (hereinafter also referred to as the amino acid sequence of a light chain variable region hL02) or a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 67 (hereinafter also referred to as the amino acid sequence of a light chain variable region hL03), and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 71 (hereinafter also referred to as the amino acid sequence of a heavy chain variable region hH01), a heavy chain having the amino acid sequence of a heavy chain variable region,shown in SEQ ID NO: 75 (hereinafter also referred to as the amino acid sequence of the heavy chain variable region hH02), or a heavy chain having the amino acid sequence of the heavy chain variable region shown in SEQ ID NO: 79 (hereinafter also referred to as the amino acid sequence of the heavy chain variable region hH04). Preferred examples include: an antibody consisting of a light chain having the amino acid sequence of the light chain variable region shown in SEQ ID NO: 63 and a heavy chain having the amino acid sequence of the heavy chain variable region shown in SEQ ID NO: 71; an antibody consisting of a light chain having the amino acid sequence of the light chain variable region shown in SEQ ID NO: 63 and a heavy chain having the amino acid sequence of the heavy chain variable region shown in SEQ ID NO: 75; an antibody consisting of a light chain,having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 63 and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 79; an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 67 and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 71; an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 67 and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 75; and an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 67 and a heavy chain having the amino acid sequence of a heavy chain variable region,shown in SEQ ID NO: 79. More preferred examples include: an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 63 and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 71; an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 63 and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 75; an antibody consisting of a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 63 and a heavy chain having the amino acid sequence of a heavy chain variable region shown in SEQ ID NO: 79; and an antibody comprising a light chain having the amino acid sequence of a light chain variable region shown in SEQ ID NO: 67,and a heavy chain having the heavy chain variable region amino acid sequence shown in SEQ ID NO: 75.,

[0100] Other examples of the antibody having the preferred combination of the above-described light chains and heavy chains include an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 in the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61 (hereinafter also referred to as the full-length amino acid sequence of the hL02 light chain), or a light chain consisting of the amino acid sequence at positions 21-233 in the full-length amino acid sequence of the light chain shown in SEQ ID NO: 65 (hereinafter also referred to as the full-length amino acid sequence of the hL03 light chain), and a heavy chain consisting of the amino acid sequence at positions 20-471 in the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 69 (hereinafter also referred to as the full-length amino acid sequence of the hH01 heavy chain), a heavy chain,consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 73 (herein also referred to as the full-length amino acid sequence of the hH02 heavy chain), or a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 77 (herein also referred to as the full-length amino acid sequence of the hH04 heavy chain). Preferred examples include: an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 69; an antibody consisting of a light chain,consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 73; an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 77; an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 65, and a heavy chain,consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 69; an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 65 and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 73; and an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 65 and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 77. More preferred examples include: an antibody consisting of a light chain,consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 69 (also referred to herein as the "H01L02 antibody" or "H01L02"); an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 73 (also referred to herein as the "H02L02 antibody" or "H02L02"); an antibody consisting of a light chain,consisting of the amino acid sequence at positions 21-233 in the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20-471 in the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 77 (herein also referred to as the "H04L02 antibody" or "H04L02"); and an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 in the full-length amino acid sequence of the light chain shown in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 in the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 73 (herein also referred to as the "H02L03 antibody" or "H02L03"). The sequences of antibody H01L02, antibody H02L02, antibody H02L03 or antibody H04L02 are shown in Table 1.,

[0101] By combining the sequences exhibiting high identity with the above-described heavy chain amino acid sequences and light chain amino acid sequences, an antibody having a biological activity equivalent to that of each of the above-described antibodies can be selected. Such identity is usually 80% or more, preferably 90% or more, more preferably 95% or more, and most preferably 99% or more. Furthermore, also by combining the amino acid sequences of the heavy chain and the light chain comprising the substitution, deletion, or addition of one or more amino acid residues compared to the amino acid sequence of the heavy chain or the light chain, an antibody having a biological activity equivalent to that of each of the above-described antibodies can be selected.

[0102] The identity between two types of amino acid sequences can be determined by aligning the sequences using the default parameters of Clustal W version 2 (Larkin MA, Blackshields G, Brown NP, Chenna R, McGettigan PA, McWilliam H, Valentin F, Wallace IM, Wilm A, Lopez R, Thompson JD, Gibson TJ and Higgins DG (2007) "Clustal W and Clustal X version 2.0", Bioinformatics. 23 (21): 2947–2948).

[0103] It should be noted that, in the full-length amino acid sequence of the hL02 light chain shown in SEQ ID NO: 61, the amino acid sequence consisting of amino acid residues at positions 1 to 20 is a signal sequence, the amino acid sequence consisting of amino acid residues at positions 21 to 128 is a variable region, and the amino acid sequence consisting of amino acid residues at positions 129 to 233 is a constant region. In the full-length nucleotide sequence of the hL02 light chain shown in SEQ ID NO: 62, the nucleotide sequence consisting of nucleotides at positions 1-60 encodes a signal sequence, the nucleotide sequence consisting of nucleotides at positions 61-384 encodes a variable region, and the nucleotide sequence consisting of nucleotides at positions 385-699 encodes a constant region.

[0104] In the full-length amino acid sequence of the hL03 light chain shown in SEQ ID NO: 65, the amino acid sequence consisting of amino acid residues at positions 1-20 is a signal sequence, the amino acid sequence consisting of amino acid residues at positions 21-128 is a variable region, and the amino acid sequence consisting of amino acid residues at positions 129-233 is a constant region. In the full-length nucleotide sequence of the hL03 light chain shown in SEQ ID NO: 66, the nucleotide sequence consisting of nucleotides at positions 1-60 encodes a signal sequence, the nucleotide sequence consisting of nucleotides at positions 61-384 encodes a variable region, and the nucleotide sequence consisting of nucleotides at positions 385-699 encodes a constant region.

[0105] In the full-length amino acid sequence of the hH01 heavy chain shown in SEQ ID NO: 69, the amino acid sequence consisting of amino acid residues at positions 1-19 is a signal sequence, the amino acid sequence consisting of amino acid residues at positions 20-141 is a variable region, and the amino acid sequence consisting of amino acid residues at positions 142-471 is a constant region. In the full-length nucleotide sequence of the hH01 heavy chain shown in SEQ ID NO: 70, the nucleotide sequence consisting of nucleotides at positions 1-57 encodes a signal sequence, the nucleotide sequence consisting of nucleotides at positions 58-423 encodes a variable region, and the nucleotide sequence consisting of nucleotides at positions 424-1413 encodes a constant region.

[0106] In the full-length amino acid sequence of the hH02 heavy chain shown in SEQ ID NO: 73, the amino acid sequence consisting of amino acid residues at positions 1-19 is a signal sequence, the amino acid sequence consisting of amino acid residues at positions 20-141 is a variable region, and the amino acid sequence consisting of amino acid residues at positions 142-471 is a constant region. In the full-length nucleotide sequence of the hH02 heavy chain shown in SEQ ID NO: 74, the nucleotide sequence consisting of nucleotides at positions 1-57 encodes a signal sequence, the nucleotide sequence consisting of nucleotides at positions 58-423 encodes a variable region, and the nucleotide sequence consisting of nucleotides at positions 424-1413 encodes a constant region.

[0107] In the full-length amino acid sequence of the hH04 heavy chain shown in SEQ ID NO: 77, the amino acid sequence consisting of amino acid residues at positions 1-19 is a signal sequence, the amino acid sequence consisting of amino acid residues at positions 20-141 is a variable region, and the amino acid sequence consisting of amino acid residues at positions 142-471 is a constant region. In the full-length nucleotide sequence of the hH04 heavy chain shown in SEQ ID NO: 78, the nucleotide sequence consisting of nucleotides at positions 1-57 encodes a signal sequence, the nucleotide sequence consisting of nucleotides at positions 58-423 encodes a variable region, and the nucleotide sequence consisting of nucleotides at positions 424-1413 encodes a constant region.

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119] [0 120]

[0121]

[0122]

[0123] In the present description, Tables 1-1-1-16 are also collectively referred to as Table 1. Other examples of the antibody according to the present invention may include a human antibody binding to CDH6. A human anti-CDH6 antibody means a human antibody having only an antibody gene sequence derived from human chromosomes. A human anti-CDH6 antibody can be produced by a method using a human antibody-producing mouse that carries a human chromosomal fragment including the heavy chain and light chain genes of a human antibody (see Tomizuka, K. et al., Nature Genetics (1997) 16, p. 133-143; Kuroiwa, Y. et al., Nucl. Acids Res. (1998) 26, p. 3447-3448; Yoshida, H. et al., Animal Cell Technology: Basic and Applied Aspects vol. 10, p. 69-73 (Kitagawa, Y., Matsuda, T. and Iijima, S. eds.), Kluwer Academic Publishers, 1999; Tomizuka, K. et al., Proc. Natl. Acad. Sci. USA (2000) 97, p. 722-727; etc.).

[0124] Such a human antibody-producing mouse can be, in particular, obtained by using a genetically modified animal in which the gene loci of the endogenous immunoglobulin heavy chain and light chain have been deleted and then replaced with the gene loci of the human immunoglobulin heavy chain and light chain using a yeast artificial chromosome (YAC) vector or the like, after which a knockout animal and a transgenic animal are obtained from such a genetically modified animal, and such animals are crossed with each other.

[0125] In another case, a human anti-CDH6 antibody can also be obtained by transforming eukaryotic cells with cDNA encoding each of the heavy chain and the light chain of such a human antibody, or preferably with a vector including the cDNA, according to genetic recombination methods, and then culturing the transformed cells producing a genetically modified human monoclonal antibody, wherein the antibody can be obtained from the culture supernatant.

[0126] In this context, eukaryotic cells and preferably mammalian cells such as CHO cells, lymphocytes or myeloma cells can be used as the host, for example.

[0127] Furthermore, a method for producing a human antibody obtained by phage display, which was selected from a human antibody library (see Wormstone, I. M. et al., Investigative Ophthalmology & Visual Science. (2002) 43 (7), p. 2301-2308; Carmen, S. et al., Briefings in Functional Genomics and Proteomics (2002), 1 (2), p. 189-203; Siriwardena, D. et al., Ophthalmology (2002) 109 (3), p. 427-431; etc.) is provided.

[0128] For example, a phage display method can be used, which involves expressing the variable regions of a human antibody as a single-chain antibody (scFv) on the surface of phages and then selecting phage that have bound to the antigen (Nature Biotechnology (2005), 23, (9), p. 1105-1116).

[0129] By analyzing the gene of a phage that has been selected for its ability to bind to an antigen, DNA sequences encoding the variable regions of a human antibody that binds to the antigen can be identified.

[0130] After determining the DNA sequence of an scFv that binds to an antigen, an expression vector containing the above sequence is prepared, and then the obtained expression vector is introduced into a suitable host where it can be expressed to produce a human antibody (International Publications WO92 / 01047, WO92 / 20791, WO93 / 06213, W093 / 11236, W093 / 19172, WO95 / 01438 and W095 / 15388, Annu. Rev. Immunol (1994) 12, p.433-455, Nature Biotechnology (2005) 23 (9), p.1105-1116).

[0131] If the newly produced human antibody binds to a partial peptide or a partial three-dimensional structure to which any rat anti-human CDH6 antibody, chimeric anti-human CDH6 antibody, or humanized anti-human CDH6 antibody described in the present specification (e.g., rG019 antibody, rG055 antibody, rG056 antibody, rG061 antibody, chG019 antibody, H01L02 antibody, H02L02 antibody, H02L03 antibody, or H04L02 antibody) binds, it can be determined that the human antibody binds to the same epitope as the rat anti-human CDH6 antibody, chimeric anti-human CDH6 antibody, or humanized anti-human CDH6 antibody. Alternatively, upon confirmation that the human antibody competes with the rat anti-human CDH6 antibody, the chimeric anti-human CDH6 antibody, or the humanized anti-human CDH6 antibody described herein (e.g., the rG019 antibody, the rG055 antibody,antibody rG056, antibody rG061, antibody chG019, antibody H01L02, antibody H02L02, antibody H02L03, or antibody H04L02) when the antibody binds to CDH6 (e.g., the human antibody interferes with the binding of antibody rG019, antibody rG055, antibody rG056, antibody rG061, antibody chG019, antibody H01L02, antibody H02L02, antibody H02L03, or antibody H04L02 to CDH6, preferably to EC3 of CDH6), it can be determined that the human antibody binds to the same epitope as the rat anti-human CDH6 antibody, the chimeric anti-human CDH6 antibody, or the humanized anti-human CDH6 antibody described herein binds, even if the specific sequence or structure epitope is not defined. In the present description, when it is determined by at least one of these determination methods that a human antibody "binds to the same epitope," then it is concluded that the newly obtained human antibody "binds to the same epitope,"that of the rat anti-human CDH6 antibody, the chimeric anti-human CDH6 antibody, or the humanized anti-human CDH6 antibody described herein. If the human antibody is confirmed to bind to the same epitope, the human antibody is expected to have a biological activity equivalent to that of the rat anti-human CDH6 antibody, the chimeric anti-human CDH6 antibody, or the humanized anti-human CDH6 antibody (e.g., rG019 antibody, rG055 antibody, rG056 antibody, rG061 antibody, chG019 antibody, H01L02 antibody, H02L02 antibody, H02L03 antibody, or H04L02 antibody).

[0132] The chimeric antibodies, humanized antibodies, or human antibodies obtained by the above-described methods are evaluated for their antigen-binding activity according to a known method, etc., as a result of which a preferable antibody can be selected.

[0133] One example of another metric for comparing antibody properties might include antibody stability. A differential scanning calorimeter (DSC) is a device that quickly and accurately measures the midpoint of thermal denaturation (Tp), which serves as a good indicator of the relative structural stability of a protein. By measuring Tp values ​​using DSC and comparing the resulting values, differences in thermal stability can be compared. It is known that antibody stability during storage has some correlation with the thermal stability of the antibody (Lori Burton, et al., Pharmaceutical Development and Technology (2007) 12, pp. 265-273), and thus, a preferred antibody can be selected using thermal stability as an metric. Other examples of metrics for selecting an antibody might include high yield in suitable host cells and low agglutination in aqueous solution.For example, since the antibody with the highest yield does not always exhibit the highest thermal stability, it is necessary to select the antibody most suitable for human administration through its comprehensive characterization based on the above indicators.

[0134] The antibody of the present invention also includes a modification of the antibody. The modification is used to refer to an antibody of the present invention that is chemically or biologically modified. Examples of such a chemical modification include the attachment of a chemical group to the amino acid skeleton and the chemical modification of an N-linked or O-linked carbohydrate chain. Examples of such a biological modification include antibodies that have been subjected to post-translational modification (e.g., N- or O-glycosylation, N-terminal or C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, and conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid), and antibodies in which a methionine residue has been added to the N-terminus as a result of expression using prokaryotic host cells.In addition, it is contemplated that such a modification includes labeled antibodies to ensure detection or isolation of the antibody according to the present invention or an antigen, for example, an enzymatically labeled antibody, a fluorescently labeled antibody, and an affinity labeled antibody. Such a modification of the antibody according to the present invention is useful for improving the stability and retention of the antibody in the blood; reducing antigenicity; detection or isolation of the antibody or antigen; etc.

[0135] Furthermore, by adjusting the modification of the sugar chain (glycosylation, defucosylation, etc.) that binds to the antibody of the present invention, antibody-dependent cellular cytotoxic activity can be enhanced. As methods for adjusting the modification of the sugar chains of antibodies, methods described in International Publications WO1999 / 54342, WO2000 / 61739 and WO2002 / 31140, etc., are known, although such methods are not limited thereto. The antibody of the present invention also includes antibodies in which the above-mentioned modification of the sugar chain has been adjusted.

[0136] After the antibody gene is isolated, the gene can be introduced into a suitable host to produce the antibody using a suitable combination of host and expression vector. A specific example of an antibody gene may be a combination of a gene encoding the heavy chain sequence of the antibody described herein and a gene encoding the light chain sequence of the antibody described herein. When transforming host cells, such a gene with a heavy chain sequence and a gene with a light chain sequence may be inserted into a single expression vector, or, alternatively, each of these genes may be inserted into separate expression vectors.

[0137] If eukaryotic cells are used as hosts, animal cells, plant cells, or eukaryotic microorganisms can be used. In particular, examples of animal cells may include mammalian cells such as COS cells, which are monkey cells (Gluzman, Y., Cell (1981) 23, pp. 175-182, ATCC CRL-1650), mouse fibroblasts NIH3T3 (ATCC No. CRL-1658), dihydrofolate reductase-deficient Chinese hamster ovary cell line (CHO cells, ATCC CCL-61) (Urlaub, G. and Chasin, LA Proc. Natl. Acad. Sci. USA (1980) 77, pp. 4126-4220), and FreeStyle 293F cells (Invitrogen Corp.).

[0138] If prokaryotic cells are used as hosts, then, for example, Escherichia coli or Bacillus subtilis can be used.

[0139] The antibody gene of interest is introduced into these cells for transformation, and then the transformed cells are cultured in vitro to produce the antibody. In the above-mentioned culturing, there are cases where the yield differs depending on the antibody sequence. Thus, it is possible to select an antibody that is easily produced as a drug from antibodies having equivalent binding activity, using the yield as an indicator. Therefore, the antibody of the present invention also includes an antibody obtained by the above-described method for producing an antibody, which includes the step of culturing the transformed host cells and the step of collecting the antibody of interest or a functional antibody fragment from the culture obtained in the above-mentioned step.

[0140] It is known that the lysine residue at the C-terminus of the heavy chain of the antibody produced in cultured mammalian cells is deleted (Journal of Chromatography A, 705: 129-134 (1995)), and it is also known that two amino acid residues at the C-terminus of the heavy chain, glycine and lysine, are deleted, and that the proline residue that appears at the C-terminus is amidated (Analytical Biochemistry, 360: 75-83 (2007)). However, such deletion and modification of these heavy chain sequences does not affect the antigen-binding activity and effector function (complement activation, antibody-dependent cellular cytotoxicity, etc.) of the antibody.Accordingly, the antibody of the present invention also includes an antibody that has undergone the above-mentioned modification and a functional fragment of the antibody, and specific examples of such an antibody include a deletion mutant comprising a deletion of 1 or 2 amino acids at the C-terminus of the heavy chain, and a deletion mutant obtained by amidation of the above-mentioned deletion mutant (for example, with a heavy chain in which the proline residue at the C-terminus is amidated). However, deletion mutants comprising a deletion at the C-terminus of the heavy chain of the antibody of the present invention are not limited to the deletion mutants described above, provided that they retain the antigen-binding activity and effector function.The two heavy chains constituting the antibody of the present invention may be any heavy chain type selected from the group consisting of a full-length antibody and the deletion mutants described above, or may be a combination of any two types selected from the aforementioned group. The ratio of individual deletion mutants may be influenced by the types of cultured mammalian cells that produce the antibody of the present invention and the culture conditions. Examples of the main ingredient of the antibody of the present invention may include antibodies in which one amino acid residue is deleted from each C-terminus of the two heavy chains.

[0141] Examples of the isotype of the antibody according to the present invention may include IgG (IgG1, IgG2, IgG3 and IgG4). Among others, IgG1 and IgG4 are preferable.

[0142] Examples of the biological activity of an antibody may generally include antigen-binding activity, internalization activity into cells expressing an antigen upon binding to an antigen, antigen-neutralizing activity, antigen-enhancing activity, antibody-dependent cellular cytotoxic activity (ADCC), complement-dependent cytotoxic activity (CDC), and antibody-dependent cellular phagocytosis (ADCP). The function of the antibody of the present invention is CDH6 binding activity and is preferably internalization activity into cells expressing CDH6 upon binding to CDH6. Moreover, the antibody of the present invention may have ADCC activity, CDC activity, and / or ADCP activity, as well as cellular internalization activity.

[0143] The obtained antibody can be purified to a homogeneous state. Separation and purification methods used for general proteins can be used to separate and purify the antibody. For example, column chromatography, filtration, ultrafiltration, salting out, dialysis, preparative polyacrylamide gel electrophoresis, and isoelectric focusing are appropriately selected and combined with each other so that the antibody can be separated and purified (Strategies for Protein Purification and Characterization: A Laboratory Course Manual, Daniel R. Marshak et al. eds., Cold Spring Harbor Laboratory Press (1996); and Antibodies: A Laboratory Manual. Ed Harlow and David Lane, Cold Spring Harbor Laboratory (1988)), although examples of separation and purification methods are not limited to these.

[0144] Examples of chromatography may include affinity chromatography, ion exchange chromatography, hydrophobic interaction chromatography, gel filtration chromatography, reversed phase chromatography, and absorption chromatography.

[0145] These chromatographic methods can be carried out using liquid chromatography such as HPLC or EPLC.

[0146] Examples of columns used in affinity chromatography may include a protein A column and a protein G column. Examples of columns using protein A may include Hyper D, POROS, and Sepharose FF (Pharmacia).

[0147] In addition, the antibody can be purified by using a carrier with an immobilized antigen, utilizing the binding activity of the antibody to the antigen.

[0148] 3. Anti-CDH6 Antibody-Drug Conjugate. (1) DrugThe anti-CDH6 antibody obtained in "2. Production of Anti-CDH6 Antibody" above can be conjugated with a drug via a moiety of the linker structure to obtain an anti-CDH6 antibody-drug conjugate. The drug is not particularly limited as long as it has a substituent or a partial structure that can be linked to the linker structure. The anti-CDH6 antibody-drug conjugate can be used for various purposes depending on the conjugated drug.Examples of such a drug may include substances having antitumor activity, substances effective for blood diseases, substances effective for autoimmune diseases, anti-inflammatory substances, antimicrobial substances, antifungal substances, antiparasitic substances, antiviral substances, and antibody-based anesthetics.[014 9] (1)-1 Antitumor CompoundAn example of using an antitumor compound as a conjugation compound in an anti-CDH6 antibody drug conjugate according to the present invention will be described below. The antitumor compound is not particularly limited as long as it has an antitumor effect and has a substituent or a partial structure that can be connected to a linker structure.When part or all of the linker is cleaved in tumor cells, the antitumor compound molecule is released, resulting in the antitumor compound exhibiting its antitumor activity. Because the linker is cleaved at the drug-binding position, the antitumor compound is released in its original structure and exerts its original antitumor activity.

[0150] The anti-CDH6 antibody obtained in "2. Production of Anti-CDH6 Antibody" above can be conjugated with an antitumor compound via a linker structure moiety to obtain an anti-CDH6 antibody-drug conjugate.

[0151] As one example of the antitumor compound used in the present invention, exatecan, a camptothecin derivative ((1S,9S)-1-amino-9-ethyl-5-fluoro-2,3-dihydro-9-hydroxy-4-methyl-1H, 12H-benzo[de]pyrano[3',4':6,7]indolizino[1,2-b]quinoline-10,13(9H,15H)-dione, represented by the following formula) can be used.

[0152]

[0153] The compound can be readily prepared, for example, by the method described in US Patent Publication US 2016 / 0297890 or other known methods, with the amino group at position 1 preferably being used as the attachment point to the linker structure. Furthermore, exatecan can be released in tumor cells while a portion of the linker remains bound to it. However, even in this state, the compound exhibits excellent antitumor activity.

[0154] Since exatecan has a camptothecin structure, it is known that in an acidic aqueous medium (e.g., about pH 3), the equilibrium is shifted toward a structure with a lactone ring (closed ring), while in a basic aqueous medium (e.g., about pH 10), the equilibrium is shifted toward a structure with an open lactone ring (open ring). It is expected that a drug conjugate into which exatecan residues corresponding to such a closed ring structure and an open ring structure have been introduced will have equivalent antitumor effects, and it is needless to say that any of such drug conjugates are included in the scope of the present invention.

[0155] Other examples of the antitumor compound may include antitumor compounds reported in the literature (Pharmacological Reviews, 68, p. 3-19, 2016). Specific examples may include doxorubicin, calicheamicin, dolastatin 10, auristatins such as monomethyl auristatin E (MMAE) and monomethyl auristatin F (MMAF), maytansinoids such as DM1 and DM4, pyrrolobenzodiazepine dimer SG2000 (SJG-136), camptothecin derivative SN-38, duocarmycins such as CC-1065, amanitin, daunorubicin, mitomycin C, bleomycin, cyclocytidine, vincristine, vinblastine, methotrexate, platinum-based antineoplastic agents (cisplatin and its derivatives), and taxol and its derivatives.

[0156] In an antibody-drug conjugate, the number of conjugated drug molecules per antibody molecule is a key factor affecting its efficacy and safety. The preparation of an antibody-drug conjugate is achieved by determining reaction conditions, such as the amounts of starting materials and reagents used for the reaction, to achieve a constant number of conjugated drug molecules. Unlike a chemical reaction of a small molecule, a mixture containing varying numbers of conjugated drug molecules is typically obtained. The number of conjugated drug molecules per antibody molecule is determined and reported as an average value, i.e., the average number of conjugated drug molecules. Unless otherwise specified, i.e.,Except for the case where an antibody-drug conjugate containing a certain number of conjugated drug molecules is included in a mixture of antibody-drug conjugates having different numbers of conjugated drug molecules, the number of conjugated drug molecules according to the present invention generally also means an average value. The number of exatecan molecules conjugated to an antibody molecule can be adjusted, and as an average number of conjugated drug molecules, approximately 1 to 10 exatecan molecules can be conjugated per antibody. The number of exatecan molecules is preferably 2 to 8, 3 to 8, 4 to 8, 5 to 8, 6 to 8, or 7 to 8, more preferably 5 to 8, even more preferably 7 to 8, even more preferably 8.It should be noted that a person skilled in the art can develop a reaction for conjugating a required number of drug molecules with an antibody molecule based on the description in the Examples of this application and can obtain an antibody-drug conjugate with a controlled number of conjugated exatecan molecules.

[0157] (2) Linker StructureA linker structure that conjugates a drug with an anti-CDH6 antibody in an anti-CDHG antibody-drug conjugate according to the present invention will be described.

[0158] In the antibody-drug conjugate in the present application, the linker structure that conjugates the anti-CDH6 antibody with the drug is not particularly limited as long as the resulting antibody-drug conjugate can be used. The linker structure can be appropriately selected and used according to the purpose of use. One example of the linker structure may include a linker described in known literature (Pharmacol Rev 68: 3-19, January 2016, Protein Cell DOI 10.1007 / s13238-016-0323-0, etc.). Additional specific examples may include VC (valine citrulline), MC (maleimidocaproyl), SMCC (succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate), SPP (N-succinimidyl 4-(2-pyridyldithio)pentanoate, SS (disulfide), SPDB (N-succinimidyl 4-(2-pyridyldithio)butyrate, SS / hydrazone, hydrazone, and carbonate.

[0260] -

[0289] ). Any linker structure shown below can be preferably used. It should be noted that the left end of the structure is the position of attachment to the antibody, and its right end is the position of attachment to the drug. Moreover, GGFG in the linker structures below is an amino acid sequence consisting of glycine-glycine-phenylalanine-glycine (GGFG) linked by peptide bonds. - (Succinimide-3-yl-N)-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2-O-CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH 2 -C(=O)-GGFG-NH-CH2CH2CH2-C(=O)- and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-.

[0160] More preferred are the following:- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2-O-CH2-C(=O)- and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-. Even more preferred are the following:- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-С(=O)-GGFG-NH-CH2-O-CH2-С(=O)- and- (Succinimid-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-С(=O)-GGFG-NH-CH2CH2CH2-C(=O)-.

[0161] An antibody is bonded to the end of the structure -(Succinimide-3-yl-N) (for example, the end opposite (left end) to the end to which -CH2CH2CH2CH2CH2- is bonded in the structure "-(Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O) -"), and an antitumor compound is bonded to the end (carbonyl group of the structure CH2-O-CH2-C-(=O) - at the right end in the above example) opposite to the end to which the antibody is bonded with -(Succinimide-3-yl-N). "-(Succinimide-3-yl-N)-" has a structure represented by the following formula:

[0162]

[0163] Position 3 of this partial structure is the attachment site of the anti-CDH6 antibody. This attachment of the antibody at position 3 is characterized by the formation of a thioether bond. The nitrogen atom at position 1 of this structural moiety is linked to the methylene carbon atom present in the linker comprising the structure.

[0164] In the antibody-drug conjugate of the present invention containing exatecan as a drug, a fragment of the linker-drug structure having any of the structures shown below is preferable for conjugation with the antibody. The average number of such fragments of the linker-drug structure conjugated to the antibody may be 1-10 and is preferably 2-8, more preferably 5-8, even more preferably 7-8, and most preferably 8.- (Succinimide-3-yl-N) -CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-(NH-DX),- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-(NH-DX),- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-(NH-DX),- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2-O-CH2-C(=O)-(NH-DX),- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-(NH-DX) and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-(NH-DX).

[0165] More preferred are the following:- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-(NH-DX),- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2-O-CH2-C(=O)-(NH-DX) and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-(NH-DX).

[0166] Even more preferred are the following:- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-(NH-DX) and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-(NH-DX).

[0167] -(NH-DX) has a structure represented by the following formula:

[0168]

[0169] and is a group that is formed by removing one hydrogen atom from the amino group at position 1 of exatecan.

[0170] (3) Method for Producing Antibody-Drug ConjugateAn antibody that can be used in the antibody-drug conjugate of the present invention is not particularly limited as long as it is an anti-CDH6 antibody having internalization activity or a functional fragment of an antibody as described in the above "2. Production of Anti-CDH6 Antibody" and the Examples.

[0171] Next, a typical method for producing the antibody-drug conjugate of the present invention will be described. It should be noted that in the description below, "compound (number)" shown in each reaction scheme is used to refer to the compound. Specifically, each compound is referred to as "compound of formula (1)", "compound (1)", etc. The same applies to other compounds with numbers.

[0172] (3)-1 Method of obtaining 1

[0336] -

[0374] )). Such an antibody-drug conjugate can be obtained, for example, by the following method.

[0173]

[0174] where AB denotes an antibody with a sulfhydryl group, where L 1 has a structure represented by - (Succinimide-3-yl-N) -, and L 1, is a maleimidyl group represented by the following formula.

[0175]

[0176] -LL 1Xhas a structure represented by any of the following formulas:- (Succinimide-3-yl-N)-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2-O-CH2-C(=O) -- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-С(=O)-GGFG-NH-CH2CH2CH2-C(=O)- and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-.

[0177] Of these, the following are more preferable:- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)-- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2CH2-O-CH2-C(=O)- and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2O-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-.

[0178] Even more preferred are the following:- (Succinimide-3-yl-N)-CH2CH2CH2CH2CH2-C(=O)-GGFG-NH-CH2-O-CH2-C(=O)- and- (Succinimide-3-yl-N)-CH2CH2-C(=O)-NH-CH2CH2O-CH2CH2-CH2CH2-C(=O)-GGFG-NH-CH2CH2CH2-C(=O)-.

[0179] From the reaction scheme described above, it can be understood that the antibody-drug conjugate (1) has a structure in which one structural fragment from the drug to the end of the linker is linked to a single antibody. However, this description is given for convenience, and in reality, there are many cases in which multiple of the above-mentioned structural fragments are linked to a single antibody molecule. The same applies to the explanation of the production method described below.

[0180] Specifically, the antibody-drug conjugate (1) can be obtained by reacting a compound (2), which can be obtained by a known method (for example, can be obtained by a method described in patent literature US 2016 / 297890 (for example, can be obtained by a method described in paragraphs

[0336] to

[0374] )), with an antibody (3a) having a sulfhydryl group.

[0181] The antibody (3a) having a sulfhydryl group can be produced by a method well known to one skilled in the art (Hermanson, GT, Bioconjugate Techniques, pp. 56-136, pp. 456-493, Academic Press (1996)). Examples of such a method may include, but are not limited to: reacting Traut's reagent with an amino group of an antibody; reacting N-succinimidyl-S-acetylthioalkanoates with an amino group of an antibody, followed by reaction with hydroxylamine; reacting N-succinimidyl-3-(pyridyldithio)propionate with an antibody, followed by reaction with a reducing agent; reacting the antibody with a reducing agent such as dithiothreitol, 2-mercaptoethanol, or tris(2-carboxyethyl)phosphine hydrochloride (TCEP) to reduce the interchain disulfide bond in the antibody to form a sulfhydryl group.

[0182] Specifically, an antibody with partially or completely reduced interchain disulfide bonds can be obtained by using 0.3-3 molar equivalents of TCEP as a reducing agent per interchain disulfide bond in the antibody and reacting the reducing agent with the antibody in a buffer solution containing a complexing agent. Examples of the complexing agent include ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA). The complexing agent can be used at a concentration of 1 mM to 20 mM. Sodium phosphate, sodium borate, sodium acetate, etc. can be used as a buffer solution. As a specific example, an antibody (3a) having partially or completely reduced sulfhydryl groups can be obtained by reacting the antibody with TCEP at a temperature of 4°C to 37°C for 1-4 hours.

[0183] It should be noted that, when carrying out the reaction of adding a sulfhydryl group to a drug-linker moiety, the drug-linker moiety may be conjugated via a thioether bond.

[0184] Then, by using 2-20 molar equivalents of compound (2) per antibody (3a) having a sulfhydryl group, an antibody-drug conjugate (1) in which one antibody is conjugated with 2-8 drug molecules can be obtained. Specifically, a solution containing compound (2) dissolved therein can be added to a buffer solution containing antibody (3a) having a sulfhydryl group for reaction. In this context, a solution of sodium acetate, sodium phosphate, sodium borate, or the like can be used as a buffer solution. The pH for the reaction is from 5 to 9, and more preferably, the reaction can be carried out at a pH of about 7. An organic solvent such as dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), or N-methyl-2-pyrrolidone (NMP) can be used as a solvent for dissolving the compound (2).The reaction can be carried out by adding a solution containing compound (2) dissolved in an organic solvent at a concentration of 1 to 20% by volume to a buffer solution containing antibody (3a) having a sulfhydryl group. The reaction temperature is 0 to 37°C, more preferably 10 to 25°C, and the reaction time is 0.5 to 2 hours. The reaction can be stopped by deactivating the reactivity of unreacted compound (2) with a thiol-containing reagent. The thiol-containing reagent is, for example, cysteine ​​or N-acetyl-L-cysteine ​​(NAC). In particular, the reaction can be stopped by adding 1 to 2 molar equivalents of NAC to the compound (2) used and incubating the resulting mixture at room temperature for 10 to 30 minutes.

[0185] (4) Identification of the antibody-drug conjugateThe obtained antibody-drug conjugate (1) can be subjected to concentration, buffer exchange, purification, and measurement of the antibody concentration and the average number of conjugated drug molecules per antibody molecule according to the general procedures described below to identify the antibody-drug conjugate (1).

[0186] (4)-1 General Procedure A: Concentration of an Aqueous Solution of an Antibody or an Antibody-Drug ConjugateAn antibody or an antibody-drug conjugate solution was added to an Amicon Ultra container (50,000 MWCO, Millipore Corporation), and the antibody or the antibody-drug conjugate solution was concentrated by centrifugation (centrifugation at 2000-3800 g for 5-20 minutes) using a centrifuge (Allegra X-15R, Beckman Coulter, Inc.)

[0187] (4)-2 General Procedure B: Measurement of Antibody ConcentrationThe antibody concentration was measured using a UV detector (Nanodrop 1000, Thermo Fisher Scientific Inc.) according to the method specified by the manufacturer. In this regard, the absorbance value of 280 nm, which differs between antibodies (from 1.3 mlmg -1 cm -1 up to 1.8 mlmg -1 cm -1 ).

[0188] (4)-3 General Procedure C: Antibody Buffer ExchangeA NAP-25 column (cat. no. 17-0852-02, GE Healthcare Japan Corporation) containing Sephadex G-25 was equilibrated with a phosphate buffer (50 mM, pH 6.0) (referred to as PBS6.0 / EDTA in this description) containing sodium chloride (50 mM) and EDTA (2 mM) according to the manufacturer's method. An aqueous solution of the antibody was applied to the NAP-25 column in an amount of 2.5 mL, and the fraction (3.5 mL) eluted with 3.5 mL of PBS6.0 / EDTA was collected. This fraction was concentrated according to General Procedure A. After measuring the antibody concentration according to General Procedure B, the antibody concentration was adjusted to 20 mg / mL using PBS6.0 / EDTA.[018 9] (4)-4 General Procedure D: Antibody-Drug Conjugate Purification The NAP-2 5 column was equilibrated with any commercially available buffer solution, such as acetate buffer containing sorbitol (5%) (10 mM, pH 5.5; referred to herein as ABS).The aqueous reaction solution of the antibody-drug conjugate (approximately 2.5 mL) was loaded onto a NAP-25 column and then eluted with a buffer solution in the amount specified by the manufacturer to collect the antibody fraction. The gel filtration purification process, in which the collected fraction was again loaded onto the NAP-25 column and eluted with a buffer solution, was repeated a total of 2 or 3 times to obtain the antibody-drug conjugate, excluding the unconjugated linker-drug and small molecular weight compounds (tris(2-carboxyethyl)phosphine hydrochloride (TCEP), N-acetyl-L-cysteine ​​(NAC), and dimethyl sulfoxide).

[0190] (4)-5 General Method E: Measurement of the antibody concentration in the antibody-drug conjugate and determination of the average number of conjugated drug molecules per antibody molecule. The concentration of the conjugated drug in the antibody-drug conjugate can be calculated by measuring the UV absorbance of an aqueous solution of the antibody-drug conjugate at two wavelengths of 280 nm and 370 nm, and then performing the calculation shown below.

[0191] The total absorbance at any given wavelength is equal to the sum of the absorbances of all light-absorbing chemical compounds present in the system [absorbance additivity]. Therefore, based on the hypothesis that the molar absorbances of the antibody and drug do not change before and after conjugation of the antibody and drug, the antibody concentration and drug concentration in the antibody-drug conjugate are represented by the following equations.A 280 =A D , 280+A A , 280=ε D , 280C D +ε A , 280C A Equation (1)A 370 =A D , 370+A A , 370=ε D , 370C D +ε A , 370C A Equation (2)In this context, A 280 is the absorbance of an aqueous solution of the antibody-drug conjugate at 280 nm, A 370is the absorbance of an aqueous solution of the antibody-drug conjugate at 370 nm, A A,280 represents the absorbance of the antibody at 280 nm, A A,370 represents the absorbance of the antibody at 370 nm, A D,280 represents the absorbance of the conjugate precursor at 280 nm, A D,370 represents the absorption of the conjugate precursor at 370 nm, ε A,280 is the molar absorbance of the antibody at 280 nm, ε A,370 is the molar absorbance of the antibody at 370 nm, ε D,280 is the molar absorbance of the conjugate precursor at 280 nm, ε D,370 is the molar absorbance of the antibody at 370 nm, C A is the concentration of antibody in the antibody-drug conjugate, and C D represents the concentration of drug in the antibody-drug conjugate.

[0192] In this context, in relation to ε A,280 , ε A,370 , ε D,280 and ε D,370 Pre-determined values ​​(calculated values ​​based on calculated or measured values ​​obtained by measuring the UV absorbance of the compound) are used. For example, ε A,280 can be estimated from the amino acid sequence of the antibody using a known calculation method (Protein Science, 1995, vol 4, 2411-2423). ε A,370 is usually equal to zero. ε D,280 and ε D,370 can be obtained in accordance with the Lambert-Beer law (Absorbance = Molar concentration × Molar absorption coefficient × optical path length of the cuvette) by measuring the optical density of a solution in which the conjugate precursor used is dissolved in a certain molar concentration. C A and C D can be determined by measuring A 280 and A 370an aqueous solution of the antibody-drug conjugate, and then solving the system of equations (1) and (2) by substituting these values. Then, dividing C D on C A , the average number of conjugated drug molecules per antibody can be determined.

[0193] (4)-6 General Procedure F: Measurement of the Average Number of Conjugated Drug Molecules per Antibody Molecule in an Antibody-Drug Conjugate - (2)The average number of conjugated drug molecules per antibody molecule in an antibody-drug conjugate can also be determined by high-performance liquid chromatography (HPLC) analysis using the following method in addition to the above-mentioned "(4)-5 General Procedure E". The following will describe a method for measuring the average number of conjugated drug molecules by HPLC when an antibody is conjugated to a drug linker via a disulfide bond. A person skilled in the art will be able to appropriately measure the average number of conjugated drug molecules by HPLC, depending on the bonding method between the antibody and the drug linker, using this method.

[0194] F-1. Sample Preparation for HPLC Analysis (Antibody-Drug Conjugate Recovery)An antibody-drug conjugate solution (approximately 1 mg / mL, 60 μL) was mixed with an aqueous solution of dithiothreitol (DTT) (100 mM, 15 μL). When the mixture was incubated at 37°C for 30 minutes, the disulfide bond between the light and heavy chains of the antibody-drug conjugate was cleaved. The resulting sample was used for HPLC analysis.

[0195] F-2. HPLC analysisHPLC analysis is carried out under the following measurement conditions.

[0196] HPLC system: Agilent 1290 HPLC system (Agilent Technologies, Inc.). Detector: UV spectrometer (measurement wavelength: 280 nm). Column: ACQUITY UPLC BEH Phenyl (2.1×50 mm, 1.7 μm, 130 angstroms; Waters Corp., P / N 186002884). Column temperature: 80°C. Mobile phase A: An aqueous solution containing 0.10% trifluoroacetic acid (TFA) and 15% 2-propanol. Mobile phase B: An acetonitrile solution containing 0.075% TFA and 15% 2-propanol. Gradient program: 14-36% (0 min-15 min), 36-80% (15 min-17 min), 80-14% (17 min-17.01 min) and 14% (17.01 min-25 min)Injection volume: 10 μlF-3. Data analysisF-3-1.Compared to the light (L0) and heavy (H0) chains of an unconjugated antibody, the light chain bound to the drug molecule(s) (light chain bound to the drug molecule(s): Li) and the heavy chain bound to the drug molecule(s): Hi) exhibit higher hydrophobicity in proportion to the number of conjugated drug molecules and thus have a longer retention time. These chains are therefore eluted in the following order, for example: L0 and L1 or H0, H1, H2 and H3. Detection peaks can be assigned to any of L0, L1, H0, H1, H2 and H3 by comparing the retention time with L0 and H0. The number of conjugated drug molecules can be determined by one of skill in the art, but preferably corresponds to L0, L1, H0, H1, H2 and H3.

[0197] F-3-2. Since the linker-drug exhibits absorption in the UV range, the peak area values ​​are corrected depending on the number of conjugated linker-drug molecules according to the following expression using the molar absorption values ​​of the light chain or heavy chain and the linker-drug.

[0198]

[0199]

[0200] In this context, the value calculated based on the amino acid sequence of the light chain or heavy chain of each antibody using a known calculation method (Protein Science, 1995, vol. 4, 2411-2423) can be used as the molar absorbance value (280 nm) of the light chain or heavy chain of the antibody. In the case of H01L02, the molar absorbance value of 31710 and the molar absorbance value of 79990 were used as the calculated values ​​for the light chain and heavy chain, respectively, based on the amino acid sequence of the antibody. The actually measured molar absorbance value (280 nm) of the compound in which the maleimide group was converted to succinimide thioester by the reaction of each linker drug with monothioglycol or N-acetylcysteine ​​was used as the molar absorbance value (280 nm) of the linker drug.The wavelength for measuring the absorbance can be appropriately set by a person skilled in the art, but is preferably a wavelength at which the peak of the antibody can be measured, and more preferably 280 nm.

[0201] F-3-3. The peak area ratio (%) of each chain was calculated for the sum of the adjusted peak area values ​​according to the following expression.

[0202]

[0203] F-3-4. The average number of conjugated drug molecules per antibody molecule in the antibody-drug conjugate was calculated according to the following expression.

[0204] Average number of conjugated drug molecules = (peak area ratio L0×0 + peak area ratio L1×1 + peak area ratio H0×0 + peak area ratio H1×1 + peak area ratio H2×2 + peak area ratio H3×3) / 100×2. It should be noted that in order to maintain the amount of antibody-drug conjugate, different antibody-drug conjugates having almost the same average number of conjugated drug molecules (e.g., about ±1), which were obtained under similar conditions, can be mixed to produce a new batch. In this case, the average number of drug molecules in the new batch falls between the average numbers of drug molecules before mixing.

[0205] One specific example of the antibody-drug conjugate according to the present invention may include an antibody-drug conjugate having a structure represented by the following formula:

[0206]

[0207] or the following formula:

[0208]

[0209]

[0210] In this context, AB is an anti-CDH6 antibody disclosed herein, wherein the antibody is conjugated to a linker drug via a sulfhydryl group derived from the antibody. In this context, n has the same meaning as the so-called DAR (drug-to-antibody ratio) and represents the ratio of the drug and the antibody to the antibody. In particular, n is the number of drug molecules conjugated per antibody molecule and is a numerical value determined and indicated as an average value, i.e., the average number of conjugated drug molecules. In the case of the antibody-drug conjugate represented by [Formula 9] or [Formula 10] in the present invention, n may be from 2 to 8 and is preferably 5-8, more preferably 7-8, and even more preferably 8 when measured by General Procedure F.

[0211] One example of the antibody-drug conjugate according to the present invention may include an antibody-drug conjugate having a structure represented by the above-described formula [Formula 9] or [Formula 10], wherein the antibody denoted as AB includes any antibody selected from the group consisting of the following antibodies (a) to (g), or a functional fragment of an antibody, or a pharmacologically acceptable salt of an antibody-drug conjugate: (a) an antibody consisting of a light chain consisting of the amino acid sequence at positions 21 to 233 in the full-length amino acid sequence of the light chain shown in SEQ ID NO: 61, and a heavy chain consisting of the amino acid sequence at positions 20 to 471 in the full-length amino acid sequence of the heavy chain shown in SEQ ID NO: 69;(b) an antibody comprising a light chain comprising the amino acid sequence at positions 21-233 of the full-length light chain amino acid sequence shown in SEQ ID NO: 61 and a heavy chain comprising the amino acid sequence at positions 20-471 of the full-length heavy chain amino acid sequence shown in SEQ ID NO: 73; (c) an antibody comprising a light chain comprising the amino acid sequence at positions 21-233 of the full-length light chain amino acid sequence shown in SEQ ID NO: 61 and a heavy chain comprising the amino acid sequence at positions 20-471 of the full-length heavy chain amino acid sequence shown in SEQ ID NO: 77;(d) an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length light chain amino acid sequence shown in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length heavy chain amino acid sequence shown in SEQ ID NO: 69; (e) an antibody consisting of a light chain consisting of the amino acid sequence at positions 21-233 of the full-length light chain amino acid sequence shown in SEQ ID NO: 65, and a heavy chain consisting of the amino acid sequence at positions 20-471 of the full-length heavy chain amino acid sequence shown in SEQ ID NO: 73;(f) an antibody comprising a light chain comprising the amino acid sequence at positions 21-233 of the full-length light chain amino acid sequence shown in SEQ ID NO: 65 and a heavy chain comprising the amino acid sequence at positions 20-471 of the full-length heavy chain amino acid sequence shown in SEQ ID NO: 77;and(g) any antibody selected from the group consisting of antibodies of (a)-(f), wherein the heavy chain or the light chain comprises one or two or more modifications selected from the group consisting of post-translational modifications, typical examples of which are N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue to the N-terminus, amidation of a proline residue, and conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus;

[0212] 4. Medicine Since the anti-CDH6 antibody of the present invention or the functional antibody fragment described in the above section "2. Production of anti-CDH6 antibody" and the Examples bind to CDH6 on the surface of tumor cells and have internalization activity, it can be used as a medicine and, in particular, as a therapeutic agent for cancer such as renal cell tumor or ovarian tumor, for example, renal cell carcinoma, clear cell renal cell carcinoma, papillary renal cell carcinoma, ovarian cancer, ovarian serous adenocarcinoma, thyroid cancer, bile duct cancer, lung cancer (e.g., small cell lung cancer or non-small cell lung cancer), glioblastoma, mesothelioma, uterine cancer, pancreatic cancer, Wilms' tumor or neuroblastoma, alone or in combination with an additional drug.

[0213] Furthermore, the anti-CDH6 antibody of the present invention or a functional fragment of the antibody can be used to detect cells expressing CDH6.

[0214] Furthermore, since the anti-CDH6 antibody of the present invention or a functional fragment of the antibody has an internalization activity, it can be used as an antibody in an antibody-drug conjugate.

[0215] If a drug having an antitumor activity such as cytotoxic activity is used as a drug, the anti-CDH6 antibody-drug conjugate of the present invention described in the above section "3. Anti-CDH6 Antibody-Drug Conjugate" and in the Examples is a conjugate of an anti-CDH6 antibody and / or a functional fragment of an antibody having internalization activity and a drug having an antitumor activity such as cytotoxic activity. Since this anti-CDH6 antibody-drug conjugate exhibits antitumor activity against cancer cells expressing CDH6, it can be used as a drug, and in particular as a therapeutic agent and / or a prophylactic agent in the treatment of cancer.

[0216] The anti-CDH6 antibody drug conjugate of the present invention may adsorb moisture or contain adsorbed water, for example, by converting it into a hydrate when exposed to air or subjected to recrystallization or purification procedures. Such a compound or a pharmacologically acceptable salt containing water is also included in the present invention.

[0217] When the anti-CDH6 antibody drug conjugate of the present invention has a basic group such as an amino group, it can form a pharmacologically acceptable acid addition salt if necessary. Examples of such an acid addition salt may include: hydrohalides such as hydrofluoride, hydrochloride, hydrobromide and hydroiodide; inorganic acid salts such as nitrate, perchlorate, sulfate and phosphate; lower alkane sulfonates such as methanesulfonate, trifluoromethanesulfonate and ethanesulfonate; arylsulfonates such as benzenesulfonate and p-toluenesulfonate; organic acid salts such as formate, acetate, trifluoroacetate, malate, fumarate, succinate, citrate, tartrate, oxalate and maleate; and amino acid salts such as ornithine salt, glutamate and aspartate.

[0218] When the anti-CDH6 antibody drug conjugate of the present invention has an acidic group such as a carboxyl group, it can form a pharmacologically acceptable base addition salt if necessary. Examples of such a base addition salt may include: alkali metal salts such as sodium salt, potassium salt and lithium salt; alkaline earth metal salts such as calcium salt and magnesium salt; inorganic salts such as ammonium salt; and organic amine salts such as dibenzylamine salt, morpholine salt, phenylglycine alkyl ether salt, ethylenediamine salt, N-methylglucamine salt, diethylamine salt, triethylamine salt, cyclohexylamine salt, dicyclohexylamine salt, N,N'-dibenzylethylenediamine salt, diethanolamine salt, N-benzyl-N-(2-phenylethoxy)amine salt, piperazine salt, tetramethylammonium salt and tris(hydroxymethyl)aminomethane salt.

[0219] The present invention may also include an anti-CDH6 antibody drug conjugate in which one or more atoms constituting the antibody-drug conjugate are replaced by isotopes of atoms. There are two types of isotopes: radioisotopes and stable isotopes. Examples of the isotope may include hydrogen isotopes (2H and 3H), carbon isotopes (HC, 13C and 14C), nitrogen isotopes (13N and 15N), oxygen isotopes (150, 170 and 180) and fluorine isotopes (18F). A composition including an antibody-drug conjugate labeled with such an isotope can be used, for example, as a therapeutic agent, a prophylactic agent, a research reagent, an assay reagent, a diagnostic agent and an imaging agent for in vivo diagnostics. All isotopically labeled antibody-drug conjugates and mixtures of isotopically labeled antibody-drug conjugates in any given ratio are included in the present invention.An isotopically labeled antibody-drug conjugate can be produced, for example, by using an isotopically labeled starting material instead of the starting material for the production method of the present invention mentioned below, according to a method known in the art.

[0220] In vitro cytotoxicity can be measured, for example, by its activity in suppressing cell proliferative responses. For example, a CDH6-overexpressing cancer cell line is cultured, and an anti-CDH6 antibody-drug conjugate is added to the culture system at various concentrations. Its suppressive activity against foci formation, colony formation, and spheroid growth can then be measured. In this context, for example, using a cancer cell line derived from a renal cell tumor or ovarian tumor, the growth inhibitory activity against the renal cell tumor or ovarian tumor can be studied.

[0221] The therapeutic effects in vivo on cancer in an experimental animal can be measured, for example, by administering an anti-CDH6 antibody-drug conjugate to a nude mouse inoculated with a tumor cell line highly expressing CDH6 and then measuring the change in cancer cells. In this context, for example, by using an animal model derived from an immunodeficient mouse by inoculating renal cell carcinoma, clear cell renal cell carcinoma, papillary renal cell carcinoma, ovarian cancer, ovarian serous adenocarcinoma, or thyroid cancer cells, the therapeutic effects on renal cell carcinoma, clear cell renal cell carcinoma, papillary renal cell carcinoma, ovarian cancer, ovarian serous adenocarcinoma, or thyroid cancer can be measured.

[0222] The type of cancer to which the anti-CDH6 antibody drug conjugate of the present invention is used is not particularly limited as long as the cancer expresses CDH6 in the cancer cells to be treated. Examples thereof may include renal cell carcinoma (e.g., clear cell renal cell carcinoma or papillary renal cell carcinoma), ovarian cancer, ovarian serous adenocarcinoma, thyroid cancer, bile duct cancer, lung cancer (e.g., small cell lung cancer or non-small cell lung cancer), glioblastoma, mesothelioma, uterine cancer, pancreatic cancer, Wilms tumor, and neuroblastoma, although the cancer is not limited to this as long as the cancer expresses CDH6.Its examples may also include renal cell carcinoma, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer, and castration-resistant prostate cancer. More preferred examples of cancer may include renal cell carcinoma (e.g., clear cell renal cell carcinoma and papillary renal cell carcinoma) and ovarian cancer. In addition, preferred examples of cancer may include ovarian cancer (e.g., epithelial ovarian cancer, fallopian tube cancer, and primary peritoneal cancer).

[0223] The anti-CDH6 antibody drug conjugate of the present invention can be preferably administered to a mammal, and more preferably to a human.

[0224] The substance used in the pharmaceutical composition including the anti-CDH6 antibody drug conjugate of the present invention can be appropriately selected from pharmaceutical additives and other additives generally used in the field based on the applied dose or applied concentration, and then used.

[0225] The anti-CDH6 antibody drug conjugate of the present invention can be administered as a pharmaceutical composition comprising one or more pharmaceutically compatible components. For example, the pharmaceutical composition typically comprises one or more pharmaceutical carriers (e.g., sterilized liquids (e.g., water and oil (including paraffin oil and oil of animal, vegetable or synthetic origin (e.g., peanut oil, soybean oil, mineral oil) oil and sesame oil))). A more typical carrier for intravenous administration of the pharmaceutical composition is water. An aqueous saline solution, an aqueous dextrose solution and an aqueous glycerol solution can also be used as a liquid carrier, particularly for an injection solution. Suitable pharmaceutical carriers are known in the art.If desired, the composition may also include trace amounts of a wetting agent, emulsifier, or pH buffer. Examples of suitable pharmaceutical carriers are disclosed in "Remington's Pharmaceutical Sciences" by E. W. Martin. The formulation is tailored to the method of administration.

[0226] In some aspects, the antibody drug conjugate (ADC) comprises formula 4. In some aspects, the ADC comprising formula 4 is administered to cancer patients with platinum resistance. In some aspects, the ADC comprising formula 4 is administered to platinum-resistant cancer patients who have had a cancer relapse within 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months after completion of platinum-based cancer treatment. In some aspects, the ADC comprising formula 4 is administered to platinum-resistant cancer patients who have had a disease relapse for at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months after completion of platinum-based cancer treatment. In some aspects, an ADC comprising formula 4 is administered to platinum-resistant cancer patients who have relapsed for at least 2, 3, 4, 5, 6, 8, 8, 9, 10, 11, or 12 months after completion of a regimen containing carboplatin and / or paclitaxel.

[0227] In some aspects, an ADC comprising formula 4 is administered following treatment with a platinum / taxane chemotherapy regimen, such as carboplatin / paclitaxel, carboplatin / docetaxel, cisplatin / paclitaxel, and carboplatin / paclitaxel / bevacizumab regimens.

[0228] In some aspects, an ADC comprising formula 4 is administered after treatment with one or more of the following platinum chemotherapeutic agents, such as carboplatin / paclitaxel, carboplatin / liposomal doxorubicin, carboplatin / gemcitabine, cisplatin / gemcitabine, carboplatin / ifosfamide, cisplatin / ifosfamide, oxaliplatin / 5-FU / leucovorin, and oxaliplatin / capecitabine.

[0229] In some aspects, an ADC comprising formula 4 is administered to a patient in need thereof for the treatment of platinum-resistant, preferably relapsed, ovarian cancer, non-small cell lung cancer (NSCLC), breast cancer, bladder cancer, endometrial cancer, castration-resistant prostate cancer (CRPC), and other forms of cancer expressing CDH6. In some aspects, ovarian cancer includes epithelial ovarian cancer, fallopian tube cancer, and primary peritoneal cancer.

[0230] In some aspects, an ADC comprising Formula 4 is indicated for the treatment of patients with ovarian cancer whose disease has progressed or recurred following platinum-based chemotherapy. In some aspects, an ADC comprising Formula 4 is indicated for the treatment of advanced ovarian cancer in women who have failed first-line platinum-based chemotherapy. In some aspects, an ABS comprising Formula 4 is indicated for the treatment of ovarian cancer following disease progression following chemotherapy.

[0231] In some aspects, an ADC comprising Formula 4 is indicated for the treatment of patients with metastatic ovarian cancer following disease progression during or after initial or subsequent chemotherapy as a single agent. In some aspects, an ABS comprising Formula 4 is indicated for the treatment of patients with metastatic ovarian carcinoma following failure of first-line or subsequent therapy.

[0232] Various delivery systems are known and can be used to administer the anti-CDH6 antibody-drug conjugate of the present invention. Examples of the administration route may include, but are not limited to, intradermal, intramuscular, intraperitoneal, intravenous, and subcutaneous routes. Administration can be carried out, for example, by injection or bolus injection. According to a particularly preferred embodiment, the administration of the above-described antibody-drug conjugate is carried out by injection. Parenteral administration is a preferred route of administration.

[0233] According to a representative embodiment, the pharmaceutical composition is administered as a pharmaceutical composition suitable for intravenous administration to humans, according to standard procedures. The composition for intravenous administration is typically a solution in a sterile isotonic aqueous buffer solution. If necessary, the drug may also contain a solubilizing agent and a local anesthetic to relieve pain at the injection site (e.g., lignocaine). Typically, the above-described ingredients are provided either individually or together, as a mixture in a unit dosage form, as a lyophilized powder or anhydrous concentrate contained in a sealed container, such as an ampoule or sachet indicating the amount of the active ingredient.If the medication is to be administered by injection, it can be administered, for example, using an injection vial containing sterile water or pharmaceutical-grade sodium chloride solution. If the medication is to be administered by injection, an ampoule of sterile water or sodium chloride solution for injection may be provided to mix the above ingredients before administration.

[0234] The pharmaceutical composition according to the present invention may be a pharmaceutical composition comprising only the anti-CDH6 antibody drug conjugate of the present application, or may be a pharmaceutical composition comprising the anti-CDH6 antibody drug conjugate and at least one other therapeutic agent for cancer. The anti-CDH6 antibody drug conjugate according to the present invention can also be administered together with an additional therapeutic agent for cancer and thereby enhance the anti-cancer effect. The additional anti-tumor agent used for such a purpose can be administered to the patient simultaneously, separately, or continuously together with the antibody drug conjugate. Otherwise, the additional anti-tumor agent and the anti-CDH6 antibody drug conjugate can be administered to the subject at different intervals between administrations.In the present invention, the phrase "second drug" refers to a therapeutic agent other than the anti-CDH6 antibody-drug conjugate of the present invention. Additional antitumor agents may be "second drugs." However, in the present invention, the "second drug" need not be a drug used for so-called "second-line therapy."Examples of such a therapeutic agent or a second drug for treating cancer or an additional antitumor agent may include tyrosine kinase inhibitors including imatinib, sunitinib and regorafenib, CBK4 / 6 inhibitors including palbociclib, HSP90 inhibitors including TAS-116, MEK inhibitors including MEK162, and immune checkpoint inhibitors including nivolumab, pembrolizumab and ipilimumab, although the therapeutic agent for treating cancer is not limited to them, provided that the drug has antitumor activity.

[0235] Such a pharmaceutical composition may be prepared as a lyophilized formulation or a liquid formulation having the selected composition and the required purity. A pharmaceutical composition prepared as a lyophilized formulation may be a composition containing a suitable pharmaceutical additive used in the given field. Similarly, a liquid formulation may be prepared such that the liquid formulation contains various pharmaceutical additives used in the given field.

[0236] The composition and concentration of the pharmaceutical composition also vary depending on the administration route. Regarding the affinity of the anti-CDH6 antibody drug conjugate contained in the pharmaceutical composition of the present invention for the antigen, that is, the dissociation constant (Kd value) of the anti-CDH6 antibody drug conjugate for the antigen, when the affinity increases (i.e., when the Kd value becomes low), the pharmaceutical composition can exert therapeutic effects even if its application dose is reduced. Accordingly, the application dose of the antibody drug conjugate can also be determined by setting the application dose based on the affinity status of the antibody drug conjugate for the antigen.When the antibody-drug conjugate of the present invention is administered to a human, it can be administered at a dose of, for example, from about 0.001 to 100 mg / kg once or multiple times at intervals of 1 to 180 days. Preferably, it can be administered at a dose of 0.1 to 50 mg / kg, and more preferably 1 to 50 mg / kg, 1 to 30 mg / kg, 1 to 20 mg / kg, 1 to 15 mg / kg, 2 to 50 mg / kg, 2 to 30 mg / kg, 2 to 20 mg / kg or 2 to 15 mg / kg multiple times at intervals of 1 to 4 weeks, preferably 2 to 3 weeks.

[0237] When the platinum drug or chemotherapeutic agent used in the present invention is cisplatin, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 15-20 mg / m 2(body surface area) Cisplatin is administered once daily for 5 consecutive days, followed by a break of at least 2 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, 50-70 mg / m 2 (body surface area) Cisplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 25-35 mg / m 2 (body surface area) Cisplatin is administered once daily, followed by a break of at least 1 week. This is considered one course, and the administration is repeated. As a different dose and administration, for example, 10-20 mg / m 2 (body surface area) Cisplatin is administered once daily for 5 consecutive days, followed by a break of at least 2 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 70-90 mg / m 2(body surface area) Cisplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. For another dose and administration, for example, 20 mg / m 2 (body surface area) Cisplatin is administered once daily for 5 consecutive days, followed by a break of at least 2 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 100 mg / m 2 (body surface area) Cisplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. For another dose and administration, for example, 75 mg / m 2 (body surface area) Cisplatin is administered once daily, followed by a break of at least 20 days. This is considered one course, and the administration is repeated. Another dose and administration, for example, 25 mg / m 2(body surface area) cisplatin is administered by intravenous drip infusion over 60 minutes and continued weekly for two consecutive weeks, followed by a break during the third week. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with doxorubicin hydrochloride, 100 mg / m 2 (body surface area) Cisplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with doxorubicin hydrochloride, 50 mg / m 2 (body surface area) cisplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with one or more other antineoplastic agents, 100 mg / m 2(body surface area) per day, cisplatin is administered by continuous intravenous infusion for 1 day, followed by a break of at least 20 days. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with one or more other antineoplastic agents, 25 mg / m 2 (body surface area) per day, cisplatin is administered by continuous intravenous infusion for 4 consecutive days, followed by a break of at least 17 days. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with one or more other antineoplastic agents, 60-100 mg / m 2 (body surface area) cisplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with one or more other antineoplastic agents, 20 mg / m2 (body surface area) Cisplatin is administered once daily for 5 consecutive days, followed by a break of at least 2 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with methotrexate, vinblastine sulfate, and doxorubicin hydrochloride, 70 mg / m 2 (body surface area) Cisplatin is usually administered by a single intravenous infusion. As a standard dose and route of administration, 30 mg / m 2 methotrexate is administered on Day 1, followed by an intravenous infusion of 3 mg / m 2 vinblastine sulfate, 30 mg / m 2 doxorubicin hydrochloride (titer) and 70 mg / m 2 cisplatin on Day 2. 30 mg / m 2 methotrexate and 3 mg / m 2 Vinblastine sulfate is administered intravenously on days 15 and 22. This is considered as one course, and the course is repeated every 4 weeks. As another dose and administration, cisplatin injection was administered at a dose of 20 mg / m 2intravenously daily for 5 days per course. As another dose and administration, cisplatin for injection was administered at a dose of 75-100 mg / m 2 intravenously per course, once every 3-4 weeks on Day 1. As another dose and administration, cisplatin for injection was administered at a dose of 50-70 mg / m 2 intravenously per course, once every 3-4 weeks. For patients who have previously undergone intensive treatment, an initial dose of 50 mg / m2 may be used. 2 for a course that is repeated every 4 weeks.

[0238] When the platinum drug or chemotherapeutic agent used in the present invention is carboplatin, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 300-400 mg / m 2(body surface area) Carboplatin is administered once daily, followed by a break of at least 4 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with trastuzumab (genetic recombination) and taxanes, 300-400 mg / m 2 (body surface area) carboplatin is administered once daily, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. As another dose and administration, for example, in combination with pembrolizumab (genetic recombination) and gemcitabine hydrochloride, carboplatin is administered at a dose equivalent to AUC 2 [(mg / mL)⋅min], once daily. Weekly administration is continued for 2 consecutive weeks, followed by a break during the third week. This is considered one course, and the administration is repeated. As another dose and administration, for example, in combination with ifosfamide and etoposide, 635 mg / m 2(body surface area) carboplatin is administered by intravenous drip infusion over 1 day or 400 mg / m 2 (body surface area) Carboplatin is administered by intravenous drip infusion over 2 days, followed by a break of at least 3-4 weeks. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with vincristine sulfate and etoposide, 560 mg / m 2 (body surface area) Carboplatin is administered by intravenous drip infusion over 1 day, and the drug is discontinued for at least 3-4 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 360 mg / m 2 Carboplatin is administered intravenously on day 1, every 4 weeks. As a different dose and administration, for example, 300 mg / m 2carboplatin is administered intravenously on day 1, every 4 weeks for 6 courses. As another dose and administration, for example, carboplatin AUC 1.0-10 [(mg / mL)⋅min] is administered by intravenous infusion over 0.1-48 hours, followed by intravenous administration of 1-100 mg / m 2 pegylated liposomal doxorubicin for 0.1-48 hours, and the treatment is repeated every 2-4 weeks for 1-10 courses. As another dose and administration, for example, carboplatin AUC 5 [(mg / ml)⋅min] is administered by intravenous infusion over 30 minutes, followed by intravenous administration of 30 mg / m 2 pegylated liposomal doxorubicin over 60 minutes, and the treatment is repeated every 3 or 4 weeks for 3 or 6 courses. As another dose and administration, for example, carboplatin AUC 5 [(mg / mL)⋅min] is administered by intravenous infusion over 30 minutes, followed by intravenous administration of 30 mg / m 2pegylated liposomal doxorubicin over 60 minutes, and the treatment is repeated every 3 weeks for 3 courses. As another dose and administration, for example, carboplatin AUC 5 [(mg / mL)⋅min] is administered by intravenous infusion over 30 minutes, followed by intravenous administration of 30 mg / m 2 pegylated liposomal doxorubicin for 60 minutes, and the treatment is repeated every 3 weeks for 6 cycles. As another dose and administration, for example, carboplatin AUC 5 [(mg / mL)⋅min] is administered by intravenous infusion over 30 minutes, followed by intravenous administration of 30 mg / m 2 pegylated liposomal doxorubicin for 60 minutes, and the treatment is repeated every 4 weeks for 3 cycles. As another dose and administration, for example, carboplatin AUC 5 [(mg / mL)⋅min] is administered by intravenous infusion over 30 minutes, followed by intravenous administration of 30 mg / m 2pegylated liposomal doxorubicin for 60 minutes, and treatment is repeated every 4 weeks for 6 cycles.

[0239] When the taxane or chemotherapeutic agent used in the present invention is paclitaxel, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 210 mg / m 2 (body surface area) Paclitaxel is administered once daily by intravenous drip infusion over 3 hours, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 100 mg / m 2 (body surface area) of paclitaxel is administered once daily by intravenous drip infusion over 1 hour, and weekly administration is continued for 6 consecutive weeks, followed by a break of at least 2 weeks. This is considered one course, and the administration is repeated. As another dose and administration, for example, 80 mg / m 2(body surface area) of paclitaxel is administered once daily by intravenous drip infusion over 1 hour, and weekly administration is continued for 3 consecutive weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 135 mg / m 2 (body surface area) Paclitaxel is administered once daily by intravenous drip infusion over 24 hours, followed by a break of at least 3 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 80 mg / m 2 (body surface area) of paclitaxel is administered once daily by intravenous drip infusion over 1 hour, with weekly administration continued for 3 consecutive weeks, followed by a break of at least 2 weeks. This is considered one course, and the administration is repeated. Another dose and administration, for example, 260 mg / m 2(body surface area) Paclitaxel is administered once daily by intravenous drip infusion over 30 minutes, followed by a break of at least 20 days. This is considered one course, and the administration is repeated. Another dose and administration, for example, 100 mg / m 2 (body surface area) Paclitaxel is administered once daily by intravenous drip infusion over 30 minutes, followed by a break of at least 6 days. Weekly administration is continued for 3 consecutive weeks. This is considered one course, and the administration is repeated. Another dose and administration method, for example, in combination with gemcitabine, is 125 mg / m 2 (body surface area) Paclitaxel is administered once daily by intravenous drip infusion over 30 minutes, followed by a break of at least 6 days. Weekly administration is continued for 3 consecutive weeks. This is considered one course, and the administration is repeated. Another dose and administration method, for example, 100 mg / m2 (body surface area) of paclitaxel is administered once daily by intravenous drip infusion over 30 minutes, followed by a break of at least 6 days. Weekly administration is continued for 3 consecutive weeks, and the drug is suspended during the fourth week. This is considered one course, and the administration is repeated. As a different dose and administration, for example, in combination with one or more other antineoplastic agents, 100 mg / m 2 (body surface area) of paclitaxel is administered once daily by intravenous drip infusion over 30 minutes, followed by a break of at least 6 days. Weekly administration is continued for 3 consecutive weeks, followed by a break during the fourth week. This is considered one course, and the administration is repeated. Other doses and administration options include 50, 90, 100, 135, or 175 mg / m 2Paclitaxel is administered intravenously over 3 or 24 hours every 2 or 3 weeks.

[0240] When the taxane or chemotherapeutic agent used in the present invention is docetaxel, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 60 mg / m 2 (body surface area) docetaxel is administered once daily by intravenous drip infusion over 1 hour once every 3-4 weeks. As another dose and administration, for example, 70 mg / m 2 (body surface area) docetaxel is administered once daily by intravenous drip infusion over 1 hour once every 3-4 weeks. As another dose and administration, for example, 75 mg / m 2 (body surface area) docetaxel is administered once daily by intravenous drip infusion over 1 hour once every 3 weeks. As another dose and administration, for example, 60-100 mg / m 2Docetaxel is administered intravenously over 1 hour every 3 weeks. As a different dose and administration, for example, 75 mg / m 2 docetaxel is administered intravenously 1 hour after 50 mg / m 2 doxorubicin and 500 mg / m 2 cyclophosphamide every 3 weeks for 6 courses. As a different dose and administration, for example, 75 mg / m 2 Docetaxel is administered intravenously over 1 hour every 3 weeks. As a different dose and administration, for example, 75 mg / m 2 Docetaxel is administered intravenously over 1 hour, followed immediately by 75 mg / m 2 cisplatin for 30-60 minutes every 3 weeks. As a different dose and administration, for example, 75 mg / m 2 Docetaxel is administered every 3 weeks by 1-hour intravenous infusion. Prednisone 5 mg orally twice daily can be used on a continuous basis. Other doses and administration options, such as 75 mg / m 2 Docetaxel is administered by 1-hour intravenous infusion, followed by 75 mg / m2 cisplatin by 1-3 hour intravenous infusion (both on day 1 only), followed by 750 mg / m 2 Fluorouracil daily by 24-hour continuous intravenous infusion for 5 days, beginning at the end of the cisplatin infusion. Treatment is repeated every three weeks. Other dose and administration options, such as 75 mg / m 2 Docetaxel is administered by 1-hour intravenous infusion, followed by 75 mg / m 2 cisplatin intravenously over 1 hour per day, followed by fluorouracil by continuous intravenous infusion at a dose of 750 mg / m 2 per day for five days. This regimen is used every 3 weeks for 4 courses. Another dose and administration, for example, 75 mg / m 2 Docetaxel is administered as a 1-hour intravenous infusion on day 1, followed by 100 mg / m 2 cisplatin administered by 30-minute to 3-hour infusion, followed by 1000 mg / m 2 / day of fluorouracil by continuous infusion from day 1 to day 4. This regimen is used every 3 weeks for 3 courses.

[0241] When the platinum drug and taxane used in the present invention are cisplatin and paclitaxel, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 10-300 mg / m 2 Paclitaxel is administered by continuous intravenous infusion over 0.1-48 hours on Day 1, followed by intraperitoneal administration of 1-200 mg / m 2 cisplatin on Day 1 or Day 2, and 10-30 mg / m 2 Paclitaxel is administered intraperitoneally on Day 8, and the treatment is repeated every 2-5 weeks for 1-10 courses. As a different dose and administration, for example, 135 or 175 mg / m 2 Paclitaxel is administered by continuous and intravenous infusion over 3 or 24 hours on Day 1, followed by intraperitoneal administration of 75-100 mg / m 2 cisplatin on Day 1 or Day 2, and 60 mg / m 2Paclitaxel is administered intraperitoneally on Day 8, and the treatment is repeated every 3 weeks for 3-6 courses. As a different dose and administration, for example, 135 mg / m 2 Paclitaxel is administered by continuous intravenous infusion over 24 hours on Day 1, followed by intraperitoneal administration of 75 mg / m 2 cisplatin on Day 2, and 60 mg / m 2 Paclitaxel is administered intraperitoneally on Day 8, and the treatment is repeated every 3 weeks for 6 courses. As a different dose and administration, for example, 135 mg / m 2 Paclitaxel is administered by continuous intravenous infusion over 24 hours on Day 1, followed by intraperitoneal administration of 100 mg / m 2 cisplatin on Day 2, and 60 mg / m 2 Paclitaxel is administered intraperitoneally on Day 8, and the treatment is repeated every 3 weeks for 6 courses. As a different dose and administration, for example, paclitaxel is administered intravenously over 3 hours at a dose of 175 mg / m 2 , followed by the administration of cisplatin at a dose of 75 mg / m2 , and the regimen can be prescribed every 3 weeks. As a different dose and administration, for example, paclitaxel is administered intravenously over 24 hours at a dose of 135 mg / m 2 , followed by cisplatin at a dose of 75 mg / m 2 , and the regimen can be prescribed every 3 weeks.

[0242] When the platinum drug and taxane used in the present invention are carboplatin and paclitaxel, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 10-300 mg / m 2 paclitaxel is administered by intravenous infusion over 0.1-48 hours, followed by carboplatin by intravenous infusion AUC 1.0-10 [(mg / mL)⋅min] on Day 1, and the treatment is repeated every 21 days for 1-10 courses. As another dose and administration, for example, 175 mg / m 2 or 180 mg / m 2paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5-6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 3-6 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 3 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 4 courses. As another dose and administration, for example, 175 mg / m 2paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 5 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 3 courses. As another dose and administration, for example, 175 mg / m 2paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 4 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5.5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 5 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5.5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 175 mg / m 2paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 3 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 4 courses. As another dose and administration, for example, 175 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 5 courses. As another dose and administration, for example, 175 mg / m 2paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 180 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 180 mg / m 2 paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 5.5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 180 mg / m 2paclitaxel is administered by intravenous infusion over 3 hours, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 21 days for 6 courses. As a different dose and administration, for example, 80 mg / m 2 paclitaxel is administered at reduced intervals by intravenous infusion over 1 hour on Days 1, 8, and 15, followed by carboplatin by intravenous infusion AUC 5-6 [(mg / mL)⋅min] over 1 hour on Day 1, and treatment is repeated every 21 days for 6 courses. As a different dose and administration, for example, 80 mg / m 2 paclitaxel is administered at reduced intervals by intravenous infusion over 1 hour on Days 1, 8, and 15, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 80 mg / m 2paclitaxel is administered at reduced intervals by intravenous infusion over 1 hour on Days 1, 8, and 15, followed by carboplatin by intravenous infusion AUC 5.5 [(mg / mL)⋅min] over 1 hour on Day 1, and treatment is repeated every 21 days for 6 courses. As a different dose and administration, for example, 80 mg / m 2 paclitaxel is administered at reduced intervals by intravenous infusion over 1 hour on Days 1, 8, and 15, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and treatment is repeated every 21 days for 6 courses. As another dose and administration, for example, 60 mg / m 2 paclitaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 2 [(mg / mL)⋅min] over 30 minutes on Days 1, 8, and 15, and the course is repeated every 21 days for 6 courses (18 weeks). As another dose and administration, for example, 80 mg / m 2paclitaxel is administered at reduced intervals by intravenous infusion over 1 hour every week, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] every 3 weeks. As another dose and administration, for example, 80 mg / m 2 Paclitaxel is administered at reduced intervals intravenously over 1 hour every week, and AUC 6 [(mg / mL)⋅min] of carboplatin is administered every 3 weeks.

[0243] When the platinum drug and taxane used in the present invention are carboplatin and docetaxel, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 10-300 mg / m 2 Docetaxel is administered by intravenous infusion over 0.1-48 hours, followed by carboplatin by intravenous infusion AUC 1.0-10 [(mg / mL)⋅min] over 0.1-48 hours on Day 1, and the treatment is repeated every 21 days for 1-10 courses. As another dose and administration, for example, 60-75 mg / m 2Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 5-6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 60 mg / m 2 Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 65 mg / m 2 Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 70 mg / m 2Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 75 mg / m 2 Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 5 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 60-75 mg / m 2 Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 60 mg / m 2Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 65 mg / m 2 Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 70 mg / m 2 Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and the treatment is repeated every 3 weeks for 6 courses. As another dose and administration, for example, 75 mg / m 2Docetaxel is administered by intravenous infusion over 1 hour, followed by carboplatin by intravenous infusion AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1, and treatment is repeated every 3 weeks for 6 courses.

[0244] When the antimetabolite or chemotherapeutic agent used in the present invention is gemcitabine, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 1000 mg / m 2 Gemcitabine is administered as a single intravenous drip infusion over 30 minutes, and weekly administration is continued for three consecutive weeks, followed by a break during the fourth week. This is considered one course, and the administration is repeated. Another dose and administration method, for example, 1250 mg / m 2Gemcitabine is administered as a single intravenous infusion over 30 minutes, and weekly administration is continued for two consecutive weeks, followed by a break during the third week. This is considered one course, and the administration is repeated. Another dose and administration method, for example, in combination with cisplatin, is 1250 mg / m 2 Gemcitabine is administered as a single intravenous infusion over 30 minutes, and weekly administration is continued for two consecutive weeks, followed by a break during the third week. This is considered one course, and the administration is repeated. Another dose and administration method, for example, 1000 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course. As a different dose and administration, for example, 1000 mg / m 2Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course in combination with carboplatin AUC 4[(mg / mL)⋅min] administered intravenously on Day 1 after gemcitabine administration. As a different dose and administration, for example, 800 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course in combination with carboplatin AUC 4 [(mg / mL)⋅min] administered intravenously on Day 1 after gemcitabine administration. As a different dose and administration, for example, 800 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course in combination with carboplatin AUC 4 [(mg / mL)⋅min] administered intravenously on Day 1 after gemcitabine administration. As a different dose and administration, for example, 1000 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Day 1 and 800 mg / m 2gemcitabine is administered intravenously over 30 minutes on Day 8 of each 21-day course in combination with carboplatin AUC 4 [(mg / mL)⋅min] administered intravenously on Day 1 after gemcitabine administration. As a different dose and administration, for example, 1250 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course. As a different dose and administration, for example, 1250 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Day 1 and Day 8 of each 21-day course in combination with paclitaxel 175 mg / m 2 , administered by 3-hour intravenous infusion on Day 1 prior to gemcitabine administration. As a different dose and administration, for example, 1000 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1, 8, and 15 of each 28-day course. As a different dose and administration, for example, 1000 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1, 8, and 15 of each 28-day course in combination with 100 mg / m 2cisplatin administered intravenously over 3 hours on Day 1 after gemcitabine administration. As a different dose and administration, for example, 1250 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course. As a different dose and administration, for example, 1250 mg / m 2 Gemcitabine is administered intravenously over 30 minutes on Days 1 and 8 of each 21-day course in combination with 100 mg / m 2 cisplatin administered intravenously on Day 1 after gemcitabine administration. As a different dose and administration, for example, 1000 mg / m 2 Gemcitabine is administered intravenously over 30 minutes once weekly for the first 7 weeks, followed by a one-week rest period and weekly dosing on Days 1, 8, and 15 of each 28-day course.

[0245] When the platinum drug and taxane used in the present invention are carboplatin and paclitaxel, and the second drug is bevacizumab, examples of the administration method include, but are not limited to, the following doses and administrations. For example, 10-300 mg / m 2 Paclitaxel is administered intravenously over 0.1-48 hours, followed by intravenous carboplatin AUC 1.0-10 [(mg / mL)⋅min] over 0.1-48 hours, and 1.0-50 mg / kg bevacizumab is administered intravenously over 0.1-48 hours. Treatment is repeated every 2-5 weeks for 1-10 courses. Bevacizumab can be administered for up to 30 additional courses. As another dose and administration, for example, 175 mg / m 2Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 5 or 6 [(mg / mL)⋅min] over 30-60 minutes, and 7.5 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 3 weeks for 5 or 6 courses. Bevacizumab can be administered for up to 12 additional courses. As another dose and administration, for example, 175 mg / m 2 Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 6 [(mg / mL)⋅min] over 30-60 minutes, and 7.5 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 3 weeks for 6 courses. Bevacizumab can be administered for up to 12 additional courses. As a different dose and administration, for example, 175 mg / m 2Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 6 [(mg / mL)⋅min] over 30-60 minutes, and 7.5 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 3 weeks for 5 courses. Bevacizumab can be administered for up to 12 additional courses. As a different dose and administration, for example, 175 mg / m 2 Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 5 [(mg / mL)⋅min] over 30-60 minutes, and 7.5 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 3 weeks for 6 courses. Bevacizumab can be administered for up to 12 additional courses. As a different dose and administration, for example, 175 mg / m 2Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 5 [(mg / mL)⋅min] over 30-60 minutes, and 7.5 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 3 weeks for 5 courses. Bevacizumab can be administered for up to 12 additional courses. As a different dose and administration, for example, 175 mg / m 2 Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 6 [(mg / mL)⋅min] over 30 minutes on Day 1. Starting with Course 2, 15 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 21 days for 6 courses. Starting with Course 7, bevacizumab alone is administered intravenously over 30-90 minutes on Day 1. Bevacizumab treatment is repeated every 21 days for a maximum of 22 courses. As a different dose and administration, for example, 175 mg / m 2Paclitaxel is administered intravenously over 3 hours, followed by intravenous carboplatin AUC 6 [(mg / mL)⋅min] over 1 hour on Day 1. Beginning with Cycle 2, 15 mg / kg bevacizumab is administered intravenously over 30-90 minutes on Day 1. Treatment is repeated every 21 days for 6 cycles. Beginning with Cycle 7, bevacizumab alone is administered intravenously over 30-90 minutes on Day 1. Bevacizumab treatment is repeated every 21 days for a maximum of 22 cycles. Examples

[0246] Next, the present invention will be specifically described in the following examples. However, these examples are not intended to limit the scope of the present invention. Moreover, these examples should not be construed as limited in any way. It should be noted that in the following examples, unless otherwise indicated, individual operations involving genetic manipulations were carried out in accordance with the method described in the Handbook of Molecular Cloning (Sambrook, J., Eritsch, E.F. and Maniatis, T., published by Cold Spring Harbor Laboratory Press in 1989) or other methods described in experimental manuals used by those skilled in the art, or when commercial reagents or kits were used, the examples were carried out in accordance with the instructions included in the commercial products. In the present description, reagents, solvents and starting materials are readily available from commercial sources unless otherwise indicated.

[0247] [Comparative Example 1: Production of a Rat Anti-Human CDH6 Antibody Having Internalization Activity]1)-1 Construction of Human, Mouse, Rat, and Cynomolgus Macaque CDH6 Expression VectorsUsing a cDNA expression vector encoding the human CDH6 protein (NP_004923) (OriGene Technologies Inc., RC217889), the cDNA was incorporated into a mammalian cell expression vector according to a method known to a person skilled in the art to obtain a human CDH6 expression vector pcDNA3.1-hCDH6. The amino acid sequence of the ORF (open reading frame) of human CDH6 is shown in SEQ ID NO: 1.

[0248] Using a cDNA expression vector encoding the mouse CDH6 protein (NP_031692) (OriGene Technologies Inc., MC221619), the cDNA was incorporated into a mammalian cell expression vector according to a method known to those skilled in the art to obtain mouse CDH6 expression vectors pcDNA3.1-mCDH6 and p3xFLAG-CMV-9-mCDH6. The amino acid sequence of the mouse CDH6 ORF is shown in SEQ ID NO: 7.

[0249] Using each cDNA fragment of the rat CDH6 protein-encoding cDNA expression vector (NP_037059) (OriGene Technologies Inc., RN211850), the cDNA was incorporated into a mammalian cell expression vector according to a method known to those skilled in the art to obtain rat CDH6 expression vectors pcDNA3.1-rCDH6 and p3xFLAG-CMV-9-rCDH6. The amino acid sequence of the rat CDH6 ORF is shown in SEQ ID NO: 8.

[0250] The cDNA encoding the cynomolgus macaque CDH6 protein was cloned using cDNA synthesized from cynomolgus macaque kidney total RNA as a template using primer 1 (5'-CACCATGAGAACTTACCGCTACTTCTTGCTGCTC-3') (SEQ ID NO: 85) and primer 2 (5')-TTAGGAGTCTTTGTCACTGTCCACTCCTCC-3') (SEQ ID NO: 86). The obtained sequence was confirmed to be consistent with the extracellular region of cynomolgus macaque CDH6 (NCBI, XP_005556691.1). The sequence was also confirmed to be consistent with the full-length cynomolgus macaque CDH6 sequence (ENH54180.1) registered in EMBL. The cDNA was incorporated into a mammalian cell expression vector according to a method known to one skilled in the art to produce the cynomolgus monkey CDH6 expression vector pcDNA3.1-cynoCDH6. The amino acid sequence of the cynomolgus monkey CDH6 ORF is shown in SEQ ID NO: 9.

[0252] EndoFree Plasmid Giga Kit (Qiagen NV) was used for large-scale production of the obtained plasmid DNA.

[0252] 1)-2 Immunization Female WKY / Izm rats (Japan SLC, Inc.) were used for immunization. First, the lower limbs of each rat were pretreated with hyaluronidase (Sigma-Aldrich Co. LLC), and then the human CDH6 expression vector pcDNA3.1-hCDH6 obtained in Comparative Example 1)-1 was intramuscularly injected into the same areas. Then, in vivo electroporation was performed on the same areas using ECM830 (BTX) using a two-needle electrode. The same in vivo electroporation was repeated approximately every two weeks, after which the lymph nodes or spleen were collected from the rat and then used to obtain hybridomas.

[0253] 1)-3 Preparation of hybridomas. Lymph node cells or spleen cells were fused with SP2 / 0-ag14 mouse myeloma cells (ATCC No. CRL-1 581) by electrical cell fusion using an LF301 cell fusion machine (BEX Co., Ltd.), and the cells were suspended and diluted with ClonaCell-HY Selection Medium D (StemCell Technologies Inc.) and then cultured under conditions of 37°C and 5% CO2. Individual colonies of hybridomas that appeared in the culture medium were collected as monoclonal hybridomas, suspended in ClonaCell-HY Selection Medium E (StemCell Technologies Inc.), and then cultured under conditions of 37°C and 5% CO2. After moderate cell proliferation, frozen stocks of individual hybridoma cells were prepared, and the resulting hybridoma culture supernatant was used to screen for hybridomas producing antibodies against human CDH6.

[0254] 1)-4 Screening of antibody-producing hybridomas by cell-based ELISA.1)-4-1 Preparation of cells expressing the antigen gene for use in cell-based ELISA. 293α cells (a stable expression cell line derived from HEK293 cells expressing integrin βv and integrin β3) were prepared at a concentration of 5×10 5 cells / ml in DMEM supplemented with 10% FBS. According to transduction procedures using Lipofectamine 2000 (Thermo Fisher Scientific Inc.), 293α cells were transfected with pcDNA3.1-hCDH6 or pcDNA3.1-cynoCDH6 DNA, or pcDNA3.1 as a negative control, and the cells were added at 100 μl / well in a 96-well plate (Corning Inc.). The cells were then cultured at 37°C and 5% CO2 in DMEM supplemented with 10% FBS for 24-27 h. The resulting transfected cells were used for cell adherence ELISA.

[0255] 1)-4-2 Cell ELISAThe culture supernatant of 293α cells transfected with the expression vector obtained in Comparative Example 1)-4-1 was removed, and then the culture supernatant from each hybridoma was added to 293α cells transfected with pcDNA3.1-hCDH6 or pcDNA3.1-cynoCDH6, or pcDNA3.1. The cells were left at 4°C for 1 hour. The cells in the wells were washed once with PBS (+) supplemented with 5% FBS, and then peroxidase-conjugated anti-rat IgG antibody produced in rabbit (Sigma-Aldrich Co. LLC), which was diluted 500-fold with PBS (+) supplemented with 5% FBS, was added to the wells. The cells were left at 4°C for 1 hour. The cells in the wells were washed three times with PBS (+) supplemented with 5% FBS, and then OPD staining solution (which was prepared by dissolving o-phenylenediamine dihydrochloride (Wako Pure Chemical Industries, Ltd.) and H2O2 in OPD solution (0.05 M trisodium citrate, 0.1 M disodium hydrogen phosphate, 12-aqueous; pH 4.5) to obtain a concentration of substances of 0.4 mg / mL and 0.6% (v / v), respectively, in an amount of 100 μL / well. The staining reaction was carried out with periodic mixing. After this, 1 M HCl (100 μL / well) was added to the plate to stop the staining reaction, followed by measurement of optical density at 490 nm using a plate reader (ENVISION: PerkinElmer, Inc.). Hybridomas that produced a culture supernatant exhibiting a higher optical density in 293α cells transfected with the pcDNA3.1-hCDH6 or pcDNA3.1-cynoCDH6 expression vector than in 293α cells transfected with the pcDNA3.1-hCDH6 or pcDNA3.1-cynoCDH6 expression vector were selected. The control pcDNA3.1 was selected as hybridomas producing antibodies binding to human CDH6 and cynomolgus monkey CDH6.

[0256] 1)-5. Selective screening for antibody binding to cynomolgus monkey CDH6 by flow cytometry 1)-5-1 Preparation of cells expressing the antigen gene for use in flow cytometric analysis 293T cells were seeded in a 225 cm flask 2 (Sumitomo Bakelite Co., Ltd.) at a concentration of 5×10 4 cells / cm 2 , and then the cells were cultured overnight at 37°C and 5% CO2 in DMEM supplemented with 10% FBS. pcDNA3.1-cynoCDH6 or pcDNA3.1 as a negative control were introduced into 293T cells using Lipofectamine 2000, and the cells were further cultured overnight at 37°C and 5% CO2. 293T cells transfected with each vector were treated with TrypLE Express (Thermo Fisher Scientific Corp.) and washed with DMEM supplemented with 10% FBS, and then suspended in PBS supplemented with 5% FBS. The resulting cell suspension was used for flow cytometry analysis.

[0257] 1)-5-2 Flow Cytometry AnalysisThe binding specificity of the antibody obtained from the hybridomas producing antibodies binding to human CDH6 and cynomolgus monkey CDH6, which were selected by cell-based ELISA in Comparative Example 1)-4, to cynomolgus monkey CDH6 was further confirmed by flow cytometry. The transiently expressing 293T cell suspension obtained in Comparative Example 1)-5-1 was centrifuged, and the supernatant was removed. The cells were then suspended by adding the culture supernatant of each hybridoma. The cells were left at 4°C for 1 hour. The cells were washed twice with PBS supplemented with 5% FBS and then suspended in FITC-conjugated anti-rat IgG (Sigma-Aldrich Co. LLC), which was diluted 500-fold in PBS supplemented with 5% FBS. The cells were incubated at 4°C for 1 hour.Cells were washed twice with PBS supplemented with 5% FBS and then resuspended in PBS supplemented with 5% FBS and 2 μg / ml 7-aminoactinomycin D (Molecular Probes, Inc.) followed by detection on a flow cytometer (FC500; Beckman Coulter, Inc.). Data were analyzed using FlowJo (Tree Star, Inc.). After excluding dead cells from the analysis by subtracting the signal of 7-aminoactinomycin D-positive cells, a histogram of FITC fluorescence intensity from living cells was constructed. Hybridomas producing antibodies that specifically bind to cynomolgus monkey CDH6 expressed on the cell membrane surface were selected based on results where the antibody histogram shifted toward strong fluorescence intensity in 293T cells transfected with pcDNA3.1-cynoCDH6 compared to 293T cells transfected with control pcDNA3.1.

[0258] 1)-6 Isotype Determination of Rat Monoclonal AntibodyClones rG019, rG055, rG056, and rG061, which were expected to specifically and strongly bind to human CDH6 and monkey CDH6, were selected from the anti-CDH6 antibody-producing rat hybridomas collected in Comparative Example 1)-5, and the isotype of each antibody was identified. The heavy chain subclass and light chain type of the antibody were determined using the RAT MONOCLONAL ANTIBODY ISOTYPING TEST KIT (DS Pharma Biomedical Co., Ltd.). As a result, it was confirmed that these four clones, rG019, rG055, rG056, and rG061, all had a heavy chain of the IgG2b subclass and a light chain of the κ type.

[0259] 1)-7 Preparation of rat anti-human CDH6 antibody. 1)-7-1 Preparation of culture supernatant Rat anti-human CDH6 monoclonal antibodies were purified from hybridoma culture supernatants. First, the volume of each rat anti-CDH6 monoclonal antibody-producing hybridoma was sufficiently expanded with ClonaCell-HY E selective medium (StemCell Technologies Inc.), and then the medium was changed to Hybridoma SFM (Thermo Fisher Scientific Corp.) supplemented with 20% FBS with ultra-low IgG content (Thermo Fisher Scientific Corp.). After this, the hybridoma was cultured for 4-5 days. The resulting culture supernatant was collected, and undissolved substances were removed by passing it through a 0.8 μm filter and then through a 0.2 μm filter.

[0260] 1)-7-2 Purification of Rat Anti-CDH6 AntibodyAntibody (rat anti-CDH6 antibody (rG019, rG055, rG056, or rG061)) was purified from the hybridoma culture supernatant obtained in Comparative Example 1)-7-1 according to protein G affinity chromatography. The antibody was adsorbed on a protein G column (GE Healthcare Biosciences Corp.), then the column was washed with PBS, and the antibody was eluted with 0.1 M glycine / HCl aqueous solution (pH 2.7). 1 M Tris-HCl (pH 9.0) was added to the eluate to adjust the pH to 7.0-7.5. The buffer was then exchanged for HBSor (25 mM histidine / 5% sorbitol, pH 6.0) using a VIVASPIN20 UF Filter Device (molecular weight cutoff, Sartorius Inc.) and the antibody was concentrated to a concentration of 1 mg / mL. Finally, the antibody was filtered through a Minisart-Plus filter (Sartorius Inc.) to obtain the purified sample.

[0261] [Comparative Example 2: In vitro evaluation of rat anti-CDH6 antibody]2)-1 Evaluation of the binding ability of rat anti-CDH6 antibody by flow cytometry. The binding activity of the rat anti-CDH6 antibody obtained in Comparative Example 1)-7 to human CDH6 was evaluated by flow cytometry. Using Lipofeetamine 2000 (Thermo Fisher Scientific Inc.), pcDNA3.1-hCDH6 obtained in Comparative Example 1)-1 was transiently introduced into 293T cells (ATCC). The cells were cultured overnight under conditions of 37°C and 5% CO2, and then a cell suspension was prepared. The transfected 293T cell suspension was centrifuged, and the supernatant was removed. Thereafter, the cells were suspended with the addition of each of the 4 rat anti-CDH6 monoclonal antibodies (clones: rG019, rG055, rG056, and rG061) that were prepared in Comparative Examples 1)-7 or control rat IgG (R&D Systems, Inc.) (final concentration: 10 ng / ml).Cells were incubated at 4°C for 1 hour. Cells were washed twice with PBS supplemented with 5% FBS and then suspended in the presence of FITC-labeled rabbit anti-rat IgG (whole molecule) (Sigma-Aldrich Co. LLC) diluted 50-fold in PBS supplemented with 5% FBS. Cells were incubated at 4°C for 1 hour. Cells were washed twice with PBS supplemented with 5% FBS and then detected on a flow cytometer (FC500; Beckman Coulter, Inc.). Data were analyzed using FlowJo (Tree Star, Inc.). The results are shown in Figure 1. In the histogram in Figure 1, the abscissa shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate shows the number of cells. The shaded histogram shows that negative control 293T cells not transfected with hCDH6 were used, and the open histogram with a solid line shows that 293T cells transfected with hCDH6 were used.As can be seen, fluorescence intensity increased upon antibody binding to hCDH6 on the cell surface. Control rat IgG did not bind to any of the cells. This confirmed that the four resulting rat monoclonal antibodies against CDH6 bind to 293T cells transfected with pcDNA3.1-hCDH6.

[0262] 2)-2 Analysis of CDH6 Binding Site of Rat Anti-CDH6 Antibody by Flow Cytometry.2)-2-1 Construction of Expression Vector for Each Domain Deletion Mutant of Human CDH6The full-length extracellular region of human CDH6 contains five extracellular domains: EC1 (SEQ ID NO: 2), EC2 (SEQ ID NO: 3), EC3 (SEQ ID NO: 4), EC4 (SEQ ID NO: 5), and EC5 (SEQ ID NO: 6). An expression gene in which each of the five EC domains could be deleted from full-length human CDH6 was synthesized at GeneArt and inserted into p3xFLAG-CMV-9 mammalian cell expression vectors (Sigma-Aldrich Co. LLC) according to a method known to one skilled in the art to produce an expression vector for each domain deletion mutant lacking any of EC1-EC5.

[0263] 2)-2-2 Epitope Analysis of Rat Anti-CDH6 Antibody by Flow Cytometry Using Domain Deletion Mutant. Epitopes bound by rat anti-human CDH6 antibodies were identified by flow cytometric analysis using the 293α cell line transfected with each EC domain deletion vector. Using Lipofectamine 2000 (Thermo Fisher Scientific Inc.), each domain deletion mutant expression vector obtained in Comparative Example 2)-2-1 or pcDNA3.l-hCDH6 for expressing full-length human CDH6 was transiently introduced into the 293α cell line, which was a cell line derived from HEK293 cells by stably transfecting with integrin αv and integrin β3 expression vectors. The cells were cultured overnight at 37°C and 5% CO2, after which a cell suspension was prepared. The transfected 293α cell suspension was centrifuged, and the supernatant was removed.Afterwards, the cells were suspended with the addition of each of the four rat anti-CDH6 monoclonal antibodies (clones: rG019, rG055, rG056, and rG061) obtained in Comparative Examples 1)-7 or control rat IgG (R&D Systems, Inc.) (final concentration: 20 nM). The cells were left at 4°C for 1 hour. The cells were washed twice with PBS supplemented with 5% FBS and then suspended with the addition of FITC-labeled anti-rat IgG (whole molecule) antibody produced in rabbit (Sigma-Aldrich Co. LLC), which was diluted 50-fold with PBS supplemented with 5% FBS. The cells were left at 4°C for 1 hour. Cells were washed twice with PBS supplemented with 5% FBS and then detected on a flow cytometer (Canto II; BD Biosciences). Data were analyzed using FlowJo (Tree Star, Inc.). The results are shown in Figures 2-1-2-6.In the histograms in Figures 2-1–2-6, the abscissa shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate shows the cell number. The shaded histogram indicates that untransfected 293α negative control cells were used, while the open histogram with a solid line indicates that 293α cells expressing full-length hCDH6 or a mutant with a deletion of each EC domain were used. Fluorescence intensity increased upon antibody binding to full-length hCDH6 or to each mutant with a deletion of the EC domain on the cell surface. Control rat IgG did not bind to any of the transfected cells. Four anti-CDH6 rat monoclonal antibodies obtained bind to full-length hCDH6, the EC1 deletion mutant, the EC2 deletion mutant, the EC4 deletion mutant, and the EC5 deletion mutant, but do not bind to the EC3 deletion mutant.Based on this result, it was demonstrated that four rat anti-CDH6 monoclonal antibodies specifically bind to hCDH6 with EC3 as the epitope.

[0264] 2)-3 Internalization Activity of Rat Anti-CDH6 Antibody 2)-3-1 Confirmation of CDH6 Expression in Human Tumor Cell Lines To select a CDH6-positive human tumor cell line for use in evaluating the resulting antibodies, CDH6 expression information was obtained from a known database, and CDH6 expression on the cell membrane surface was assessed by flow cytometry. NIH human ovarian tumor cell lines: OVCAR-3, PA-1, and ES-2, and human renal cell tumor cell line 786-O (all cell lines were obtained from ATCC) were cultured under 37°C and 5% CO2, and then the cell suspension was prepared. The cells were centrifuged, and the supernatant was removed. The cells were then suspended with the addition of a commercially available anti-human CDH6 antibody (MABU2715, R&D Systems, Inc.) or mouse IgG1 (BD Pharmingen) as a negative control (final concentration: 50 μg / ml). The cells were incubated at 4°C for 1 hour.Cells were washed twice with PBS supplemented with 5% FBS and then suspended in FITC-conjugated goat anti-mouse F(ab')2 fragment (Dako), which was diluted 50-fold in PBS supplemented with 5% FBS. Cells were incubated at 4°C for 1 hour. Cells were washed twice with PBS supplemented with 5% FBS and then detected on a flow cytometer (Canto II; BD Biosciences). Data were analyzed using FlowJo (Tree Star, Inc.). The results are shown in Figure 3. In the histogram in Figure 3, the abscissa shows the FITC fluorescence intensity, indicating the amount of bound antibody, and the ordinate shows the number of cells. The shaded histogram shows that the negative control mIgG1 was used for staining, and the open histogram with a solid line shows that the anti-human CDH6 antibody was used for staining.As can be seen, fluorescence intensity increased upon antibody binding to hCDH6 on the cell surface. Control mIgG1 did not bind to any cells. This confirmed that the NIH:OVCAR-3, PA-1, and 786-O cell lines endogenously express CDH6 on the cell surface. On the other hand, it was demonstrated that the ES-2 cell line does not express CDH6.

[0265] 2)-3-2 Evaluation of Internalization Activity of Rat Anti-CDH6 AntibodyThe internalization activity of rat anti-CDH6 antibodies was evaluated using the anti-rat IgG reagent Rat-ZAP (Advanced Targeting Systems) conjugated to a protein synthesis inhibiting toxin (saporin). Specifically, the CDH6-positive human ovarian tumor cell line NIH:OVCAR-3 (ATCC) was seeded at a density of 4×103 cells / well in a 96-well plate and then cultured overnight under conditions of 37°C and 5% CO2. The CDHG-positive human renal cell tumor cell line 786-O (ATCC) was seeded at a density of 1×10 3cells / well in a 96-well plate and then cultured overnight. The next day, each rat anti-CDH6 antibody (final concentration: 1 nM) or rat IgG2b antibody (R&D Systems, Inc.) was added to the plate as a negative control antibody. Rat-ZAP (final concentration: 0.5 nM) or goat anti-rat IgG, Fc (gamma) fragment-specific antibody (Jackson IminunoResearch Laboratories, Inc.) unconjugated with toxin (final concentration: 0.5 nM) as a negative cont...

Claims

1. Use of a medicament for the treatment of a cancer expressing cadherin-6, wherein the medicament comprises an antibody-drug conjugate (ADC), wherein the ADC comprises an antibody or a functional fragment of an antibody that specifically binds to the amino acid sequence of the EC3 domain of cadherin-6 shown in SEQ ID NO: 4, wherein the drug in the ADC is a topoisomerase I inhibitor; where cancer expressing cadherin-6, (i) is resistant to platinum-based chemotherapy; (ii) is resistant to a chemotherapy regimen containing a platinum-based drug or a platinum-based drug in combination with a taxane; (iii) is a relapse of cancer previously treated with a chemotherapy regimen containing a platinum drug alone or a platinum drug in combination with a taxane; or (iv) is a cancer previously treated with a chemotherapy regimen that includes a platinum drug, a taxane, or both a platinum drug and a taxane.

2. The use according to claim 1, wherein the antibody-drug conjugate (ADC) has a structure represented by the following formula: where AB denotes an antibody or a functional fragment of an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

3. The use according to claim 1, wherein the antibody-drug conjugate (ADC) has a structure represented by the following formula: where AB denotes the antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody.

4. The use according to any one of claims 1-3, wherein the cadherin-6 expressing cancer is selected from the group consisting of renal cell carcinoma, ovarian cancer, mesothelioma, thyroid cancer, uterine cancer, bile duct cancer, pancreatic cancer, non-small cell lung cancer, cervical cancer, brain tumor, head and neck cancer, sarcoma, osteosarcoma, small cell lung cancer, breast cancer, bladder cancer, endometrial cancer and castration-resistant prostate cancer.

5. The use according to any one of claims 1-3, wherein the cadherin-6 expressing cancer is ovarian cancer.

6. The use according to claim 5, wherein the ovarian cancer is selected from the group consisting of epithelial ovarian cancer, fallopian tube cancer or primary peritoneal cancer.

7. Use according to item 5 or 6, wherein the ovarian cancer is metastatic.

8. The use according to any one of claims 1 to 7, wherein the antibody comprises CDRL1 consisting of the amino acid sequence shown in SEQ ID NO: 12, CDRL2 consisting of the amino acid sequence shown in SEQ ID NO: 13, and CDRL3 consisting of the amino acid sequence shown in SEQ ID NO: 14, and CDRH1 consisting of the amino acid sequence shown in SEQ ID NO: 17, CDRH2 consisting of the amino acid sequence shown in SEQ ID NO: 60, and CDRH3 consisting of the amino acid sequence shown in SEQ ID NO:

19.

9. The use according to any one of claims 1-8, wherein the antibody comprises a light chain variable region consisting of the amino acid sequence shown in SEQ ID NO: 63 and a heavy chain variable region consisting of the amino acid sequence shown in SEQ ID NO:

71.

10. The use according to any one of claims 1-9, wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-471 in SEQ ID NO:

69.

11. The use according to any one of claims 1 to 10, wherein the heavy chain or the light chain has been subjected to one or more modifications selected from the group consisting of N-glycosylation, O-glycosylation, N-terminal processing, C-terminal processing, deamidation, aspartic acid isomerization, methionine oxidation, addition of a methionine residue at the N-terminus, amidation of a proline residue, conversion of N-terminal glutamine or N-terminal glutamic acid to pyroglutamic acid, and deletion of one or two amino acids at the C-terminus.

12. The use according to any one of claims 1-9, wherein the antibody is an antibody comprising a light chain consisting of the amino acid sequence at positions 21-233 in SEQ ID NO: 61 and a heavy chain consisting of the amino acid sequence at positions 20-470 in SEQ ID NO:

69.

13. The use according to any one of claims 1-12, wherein the average number of units of the linker-drug structure conjugated to each antibody is in the range of 7 to 8.

14. The use according to any one of claims 1-13, wherein the antibody-drug conjugate (ADC) is administered in combination with one or more chemotherapeutic agents, wherein the antibody-drug conjugate (ADC) and one or more chemotherapeutic agents (i) are included separately in different formulations and administered simultaneously or at different times; or (ii) are included together in the same composition and are administered simultaneously.

15. The use according to claim 14, wherein one or more chemotherapeutic agents are an antimetabolite, a platinum drug, a taxane, or a platinum drug and a taxane.

16. The use according to claim 14, wherein the one or more chemotherapeutic agents are gemcitabine, carboplatin, paclitaxel, or both carboplatin and paclitaxel.

17. The use according to any one of claims 1-16, wherein the medicinal product is administered to a subject who has shown a complete response (CR), a partial response (PR) or a stable disease (SD) when treated with a chemotherapy regimen comprising a platinum drug or a platinum drug in combination with a taxane.

18. The use according to any one of claims 1-17, wherein the cadherin-6 expressing cancer is a relapse of cancer that arose before the administration of the ADC.

19. The use according to claim 18, wherein the recurrence of the cancer occurs less than six months or within about six months after completion of a chemotherapy regimen comprising a platinum drug or a platinum drug in combination with a taxane.

20. The use according to claim 18, wherein the recurrence of cancer occurs within or about six months after completion of a chemotherapy regimen comprising a platinum drug or a platinum drug in combination with a taxane.

21. The use according to any one of claims 1-20, wherein the ADC is administered with a second drug, wherein the ADC is administered before the second drug, after the second drug, or simultaneously with the second drug.

22. Use of a medicinal product for the treatment of ovarian cancer resistant to platinum chemotherapy and / or relapse of ovarian cancer, wherein the medicinal product comprises an antibody-drug conjugate (ADC), wherein the ADC has a structure represented by the following formula: where AB denotes an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the average number of units of the linker-drug structure conjugated to each antibody is 7-8, where the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO:

88.

23. Use of a medicinal product for the treatment of ovarian cancer that has previously been treated with a chemotherapy regimen that includes a platinum drug, a taxane, or both a platinum drug and a taxane, wherein the medicinal product comprises an antibody-drug conjugate (ADC), wherein the ADC has a structure represented by the following formula: where AB denotes an antibody, n denotes the average number of units of the linker-drug structure conjugated to the antibody per antibody, and the antibody is connected to the linker via a sulfhydryl group derived from the antibody; and where the average number of units of the linker-drug structure conjugated to each antibody is 7-8, where the antibody comprises: an amino acid sequence of a heavy chain represented by SEQ ID NO: 87, or an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 87, in which one or two amino acids are removed at its C-terminus; and an amino acid sequence of a light chain represented by SEQ ID NO:

88.

24. The use according to claim 22 or 23, wherein one amino acid is removed from each of the carboxyl termini of both heavy chains of the antibody in the ADC.

25. The use according to any one of claims 22-24, wherein the ovarian cancer is epithelial ovarian cancer, fallopian tube cancer or primary peritoneal cancer.

26. The use according to any one of claims 1-25, wherein the cancer has acquired resistance to a chemotherapy regimen including a platinum drug.

27. The use according to any one of claims 1 to 25, wherein carboplatin is used as a platinum drug in platinum drug chemotherapy.

28. The use according to any one of claims 1 to 27, wherein carboplatin is used as a platinum drug and / or paclitaxel is used as a taxane in the chemotherapy regimen.

29. The use according to any one of claims 1-22, wherein the cadherin-6 expressing cancer is resistant to platinum chemotherapy.

30. The use according to any one of claims 1-22, wherein the cadherin-6 expressing cancer is resistant to a chemotherapy regimen comprising a platinum drug or a platinum drug in combination with a taxane.

31. The use according to any one of claims 1-22, wherein the cadherin-6 expressing cancer is a relapse of cancer previously treated with a chemotherapy regimen comprising a platinum drug or a platinum drug in combination with a taxane.

32. The use according to any one of claims 1-22, wherein the cadherin-6 expressing cancer is a cancer previously treated with a chemotherapy regimen comprising a platinum drug, a taxane, or both a platinum drug and a taxane.

Images