Bioactive substance conjugates, methods for preparing the same, and use thereof

Abstract

The present invention aims to provide a bioactive substance conjugate, a method for preparing the same, and its use. [Solution] Bioactive substance conjugate, method for preparing the same, and use thereof. The present invention relates to a ligand-drug conjugate represented by formula XV, a method for preparing the same, and its use in the prevention and / or treatment of diseases associated with abnormal cell activity, including, but not limited to, its use in the prevention and / or treatment of tumor diseases. JPEG2026137725000598.jpg19128

Description

[Technical Field]

[0001] This application has priority rights to China Patent Application No. 2021101781361 filed on February 9, 2021, China Patent Application No. 2021103408065 filed on March 30, 2021, China Patent Application No. 202110825932X filed on July 21, 2021, and China Patent Application No. 2021108259226 filed on July 21, 2021 (the sequence listing in txt format is also available from July 2021). This application claims priority to China Patent Application No. 2021108259067, filed on July 21, 2021 (a sequence listing in txt format is also filed with China Patent Application No. 2021108259067, filed on July 21, 2021), and the contents of all of these applications are incorporated herein by reference in their entirety. The sequence listing included in this application is part of this specification and is incorporated herein by reference in its entirety.

[0002] This disclosure pertains to the field of pharmaceutical technology and relates to bioactive substance conjugates (ligand-drug conjugates), compounds, drug linker conjugates, methods for preparing them, and their use in the prevention and / or treatment of diseases associated with abnormal cell activity, including but not limited to the prevention and / or treatment of tumor diseases. [Background technology]

[0003] Chemotherapy using cytotoxic agents was once the standard treatment for cancer, but highly lethal cytotoxic molecules can kill normal cells and cause serious toxic side effects. Tumor-targeted drugs are the latest hot topic in cancer research due to their simultaneous tumor specificity and antitumor activity. However, due to issues such as the target selectivity of targeted drugs, high toxicity and side effects are often present, and the therapeutic effect of such targeted drugs is often limited. Biologics such as antibodies or antibody fragments are highly target-selective, but often have limited or no therapeutic effect against solid tumors. ADCs are conjugates of antibodies and small molecule drugs, combining the targeting effect of antibodies with the activity of bioactive molecules. ADCs have become biomissiles with promising advantages in efficacy and safety. Antibodies induce ADCs to bind to target cells, which then internalize the ADCs, and the small molecule drug is subsequently released into the cells by enzymatic hydrolysis under the action of specific enzymes to treat the disease.

[0004] ADC drug research has developed rapidly in recent years, and 14 types of ADCs are approved and marketed: (1) Mylotarg (gemtuzumab ozogamicin, gemtuzumab (CD33)-calicheamicin) for CD33-positive acute myeloid leukemia (AML), approved by the U.S. Food and Drug Administration in 2000, withdrawn from the market in 2010, and reapproved in 2017; (2) Adcetris (brentuximab vedotin, CD30 monoclonal antibody-MMAE) for typical Hodgkin lymphoma and anaplastic large cell lymphoma, approved by the U.S. Food and Drug Administration in 2011. (3) For Her2-positive breast cancer, approved by the U.S. Food and Drug Administration in 2013, Kadcyla (trastuzumab emtansine, trastuzumab monoclonal antibody (Her2)-mytansine™1), (4) For adult relapsed or resistant B-cell lymphocytic leukemia, approved in 2017, Besponsa (inotuzumab ozogamicin, CD22 monoclonal antibody-calicheamicin), (5) For relapsed or resistant pilocytic cell leukemia (HCL), marketed in 2018, Lumoxiti (moxetumomab pasudotox (Moxetumomab (6) Polivy (polatuzumab vedotin-piiq, CD79b-MMAE), marketed in 2019 for relapsed or resistant diffuse large B-cell lymphoma (R / R DLBCL), (7) Padcev (enfortumumab vedotin-ejfv, nectin-4-MMAE), marketed in 2019 for locally advanced or metastatic urothelial carcinoma, (8) Enhertu (Famtrastuzumab deruxtecan-nxki, Her2-topoisomerase I inhibitor), marketed in 2019 for breast cancer, (9) Trodelvy (Trop2-topoisomerase I inhibitor ADC), approved by the U.S. Food and Drug Administration in April 2020 for triple-negative breast cancer, (10) BCMA ADC Belantamab mahodotin (GSK2857916), (11) CD19 ADC Zynlonta (loncastuximab tesirin), (12) EGFR ADC Akalux, (13) Her2 ADC Disitamab vedotin RC48, (14) Tissue factor ADCTivadak (tisotumab vedotin).

[0005] ADC drugs consist of three components: an antibody, a bioactive molecule (drug molecule), and a linker. The bioactive molecule is covalently bound to the antibody via the linker. In addition to targeting and biological activity, the coupling mechanism between the bioactive molecule and the antibody plays a crucial role for ADC drugs, determining the homogeneity and stability of the drug and significantly influencing the pharmacokinetic properties and toxicity of the ADC. Improving the stability of the linkage between the bioactive molecule and the antibody improves the stability of the ADC in systemic circulation, reduces drug release in non-target tissues, and therefore relatively increases the amount of drug delivered into and around target cells, increasing the amount of bioactive molecule released into and around target cells, further enhancing efficacy and reducing toxicity. Therefore, increasing the stability of the binding between the bioactive molecule and the antibody is one of the most important technical aspects in ADC drug research.

[0006] Currently, there are two main methods for coupling antibodies and linkers for 10 commercially available ADCs: (1) Lysine is the most common linking site in antibodies, and its ε-amino group can react with the activated carboxyl group of the linker to form an amide bond. Currently, there are techniques that can achieve this type of site-specific coupling, namely, techniques in which the carboxyl group of the linker is activated with an activating group, and then an amide bond is formed with a specific lysine ε-amino group in the antibody to complete the coupling. On the other hand, such site-specific quantitative coupling via amide bonds does not have widespread practicality and can only be used under certain conditions. On the other hand, under the action of enzymes in vivo, hydrolysis is likely to occur, and bioactive molecules dissociate from the antibody before reaching target cells, thus increasing toxicity. (2) Cysteine ​​thiol (SH) in antibodies exists in the form of disulfide bonds. Cleavage of disulfide bonds in antibodies can provide multiple free thiol groups as coupling sites. Regarding the coupling of antibodies with thiols, one such method is the Michael addition reaction between the free thiol in the antibody and maleimide, or the double Michael addition reaction between the free thiol in the antibody and a specific substrate for forming a structurally unique sulfur crosslink. However, the literature reports that more than 30% of ADCs obtained by the thiol-Michael addition method may undergo retro-Michael addition in systemic circulation, leading to premature toxin release and toxic reactions.

[0007] Antibody-drug conjugates can be classified into four generations according to their development history. First-generation antibody-drug conjugates are based on mouse-derived antibodies and often have strong toxic side effects due to their complex immunogenicity. Second-generation antibody-drug conjugates use humanized or fully human antibodies based on the first generation. The drug activity of second-generation antibody-drug conjugates has been significantly improved. The first two generations employed relatively random coupling between the antibody and the drug, resulting in the final antibody-conjugate drug product being a multi-component mixture. This type of drug product is not only toxic but also difficult to control in terms of quality. Third-generation antibody-drug conjugates, based on the use of humanized or whole-human antibodies, simultaneously apply site-specific quantitative conjugation of toxin-linkers and antibodies, thereby producing homogeneous single-molecule antibody-drug conjugates. The toxicity and quality control of these antibody-drug conjugates are significantly improved compared to the second generation. Fourth-generation antibody-drug conjugates represent an innovation in the toxin-linker portion compared to third-generation conjugates. Fourth-generation antibody-drug conjugates deviate from the strategy of using highly toxic toxins in previous antibody-drug conjugates, instead selecting the relatively less toxic camptothecin molecule as the bioactive component, while simultaneously employing a high toxin-to-antibody ratio (DAR), e.g., a DAR value of 8. This type of ADC can also achieve good therapeutic efficacy against tumors with low tumor surface antigen expression. Despite a late start, fourth-generation antibody-drug conjugates have rapidly gained clinical recognition due to their remarkable therapeutic efficacy. Representative drugs, Enhertu and Trodelvy, have been approved for sale by the U.S. Food and Drug Administration. However, fourth-generation ADCs still suffer from issues such as low stability or low solubility, and existing technologies lack versatility. Further development of new toxin linkers remains necessary to address these problems.

[0008] Existing antibody-drug conjugates function by binding antibodies in the ADC to tumor cell surface antigens, then internalize into endosomes via endocytosis, subsequently moving from endosomes to lysosomes, where the bioactive molecule (toxin or payload) is cleaved from the ADC by lysosomal enzymes. The released bioactive molecule then moves from the lysosome to the cytoplasm, killing tumor cells. Bioactive molecules that escape after killing tumor cells can further kill nearby tumor cells that do not express or have low expression of their surrounding antigens, via the so-called bystander effect. Any changes during the entire process, such as antigen presentation levels, weakening or loss of endocytosis, or loss of function of endosomes or lysosomes, can make the ADC resistant to treatment or cause it to lose its therapeutic effect. Therefore, finding an ADC that is stable in systemic circulation in vivo and, at the same time, can kill tumor cells by releasing toxins via extracellular cleavage in the tumor microenvironment without requiring endocytosis would be extremely important in clinical treatment. This type of ADC can overcome the mechanisms associated with multiple drug resistance problems in traditional ADC products.

[0009] While there is evidence that trodelvy from Immunomedics and Gilead can be cleaved outside tumor cells without endocytosis, trodelvy is highly unstable in plasma and aqueous solutions, with a plasma half-life of less than 24 hours. Therefore, this type of ADC may only be suitable if it consists of toxins with low biological activity to avoid off-target toxic side effects caused by premature cleavage of the ADC toxin.

[0010] In addition, the function of conventional ADC linkers is primarily to regulate intracellular lysosomal enzyme cleavage or water solubility. Therefore, how to use linkers to achieve ADC enrichment in tumor tissue while simultaneously maintaining its enzyme cleavage ability is crucial for reducing the toxic side effects of ADCs in normal tissues.

[0011] B7H3 is a type I transmembrane protein of the B7 family and has two isotypes in humans: 2Ig-B7H3 and 4Ig-B7H3. B7H3 is widely expressed in normal tissues, constitutively expressed in non-immune resting fibroblasts, endothelial cells, osteoblasts, and amniotic fluid stem cells, and inducibly expressed in activated T cells, NK cells, DC cells, and macrophages, but positive expression was not detected in lymphoid organs (Chapoval, AI, et al., B7H3: A costimulatory molecule for T cell activation and IFN production. Nature Immunology, 2001.2(3):p.269-274). Studies have shown that approximately 76.5% of early-stage liver cancer patients have serum B7H3 levels about three times higher than those of normal individuals (60.79±19.45 vs. 20.52±8.46 ng / mL), but the correlation with disease progression remains unclear (Zhao, L., et al., Early Detection of Hepatocellular Carcinoma in Patients with Hepatocirrhosis by Soluble B7H3. Journal of Gastrointestinal Surgery. 21(5):p.807-812).

[0012] Currently, therapeutic approaches targeting B7H3 exist in preclinical studies. For example, antibodies against mouse B7H3 enhance invasive CD8-positive T cells in tumors and inhibit tumor growth (Mod. Pathol. 2010 Aug;23(8):1104-12). In addition, international publication 2008 / 066691 showed that antibodies recognizing B7H3 variants, specifically B7H3a, have in vivo antitumor effects against adenocarcinoma. In clinical studies, the combination of mouse B7H3 antibody and radioactive iodine-131 can significantly inhibit the growth of neuroblastoma in patients (J Neurooncol 97(3):409-18(2010)). [Overview of the Initiative]

[0013] To improve the therapeutic effect of an antibody-drug conjugate (ADC) or other ligand-drug conjugate (PDC), reduce the toxicity and side effects of the drug, and expand the therapeutic range, the present disclosure provides a ligand-drug conjugate of formula (XV) or a pharmaceutically acceptable salt or solvate thereof, which contains a bioactive molecule (drug molecule), a linker, and a targeting moiety linked to the linker via a reactive group (e.g., a sulfhydryl group) to form a ligand-drug conjugate. In the present disclosure, an antibody containing a variable light chain domain and / or a variable heavy chain (VH) domain that binds to the B7H3 molecule has also been developed, which is derived from a human antibody.

[0014] Therefore, in a first aspect of the present disclosure, the present disclosure provides a ligand-drug conjugate of formula XV, wherein

Chemical formula

Chemical formula

[0015] Furthermore, it should be noted that the statement "position 1 of L1 is bonded to Tb via an S atom" can be understood by those skilled in the art as meaning that position 1 of L1 is bonded to a sulfhydryl group contained in Tb after the disulfide bond has opened (for example, reduction of the disulfide bond with the reducing agent TCEP can cleave the disulfide bond and generate a sulfhydryl-SH group). In other words, the -S- between L1 and Tb is not an additional foreign sulfur atom.

[0016] for example, [ka] In this case, -S- is not an additional foreign sulfur atom, [ka] This -S- group is formed by opening the disulfide bond at position 1 of L1 and then linking it to the sulfhydryl group contained in Tb.

[0017] An extension unit is a component of a ligand-drug conjugate or drug-linker conjugate or linker, and its function is to bind the ligand or targeting portion that binds to the target to the remainder of the ligand-drug conjugate or the remainder of the linker. An extension unit can bind a Tb unit to either L2 (if present) or L3, and specific examples include: [ka] These include, but are not limited to, the ligand or targeting moiety at position 1 that binds to the target, and L2 or L3 at position 2.

[0018] In some embodiments, L1 is [ka] [ka] [ka] Selected from, In the formula, each Z is independently selected from direct bonds, carbon-carbon triple bonds, carbon-carbon double bonds, C6-10 aryls, 5-10 member heteroaryls, amides, sulfonamides, iminos, and CF2. Rx and Ry are each independently selected from H and C1-4 alkyl groups. Each m is independently selected from 0, 1, 2, 3, 4, 5, and 6. y1, y2, y3, and y4 are each independently selected from any integer between 0 and 20. The 1st position is bonded to Tb via a sulfur atom, and the 2nd position is bonded to L2 or L3.

[0019] A linking unit is a component of a ligand-drug conjugate or drug-linker conjugate or linker, and its function is to attach an elongation unit to an amino acid residue or a short peptide consisting of 2 to 10 amino acid residues. When a linking unit is present, L1 can be attached to L3. A specific example is: [ka] These are some examples, but are not limited to them (the 1st position is connected to the extension unit, and the 2nd position is connected to L3).

[0020] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] [ka] Selected from, In the formula, y1, y2, y3, and y4 are each independently selected from any integer between 0 and 20, with the ones-digit being joined to L1 and the two-digit being joined to L3.

[0021] In some embodiments, L1 is [ka] That is the case.

[0022] In some embodiments, L1 is [ka] The following are selected from the formula, where each Z is independently selected from direct bonds, carbon-carbon triple bonds, carbon-carbon double bonds, C6-10 aryls, 5-10 member heteroaryls and amides (preferably selected from direct bonds, carbon-carbon triple bonds and carbon-carbon double bonds), Rx and Ry are independently selected from H and C1-4 alkyls, each m is independently selected from 0, 1, 2, 3, 4, 5 and 6, y1 is independently selected from any integer from 1 to 6 (e.g., 4, 5, 6), each y2 is independently selected from any integer from 0 to 15 (e.g., 6 to 15), each y3 is independently selected from 1, 2 and 3, and each y4 is independently selected from 0 and 1, with the 1st position bonded to Tb via an S atom and the 2nd position bonded to L2 or L3.

[0023] In some embodiments, L1 is [ka] The following are selected from the formula, where m is selected from 2, 3, and 4, y1 is selected from any integer from 1 to 6 (e.g., 4, 5, 6), each y2 is independently selected from any integer from 0 to 10 (e.g., 6 to 10), and each y3 is independently selected from 1 and 2, with the 1st position bonded to Tb via an S atom and the 2nd position bonded to L2 or L3.

[0024] In some embodiments, L1 is [ka] Selected from the above, the 1st position is bonded to Tb via an S atom, and the 2nd position is bonded to L2 or L3.

[0025] In some embodiments, L1 is [ka] Selected from.

[0026] In some embodiments, L1 is [ka] Selected from the above, the 1st position is bonded to Tb via an S atom, and the 2nd position is bonded to L2 or L3.

[0027] In some embodiments, L1 is [ka] Selected from the above, the 1st position is bonded to Tb via an S atom, and the 2nd position is bonded to L2 or L3.

[0028] In some embodiments, L1 is [ka] Selected from the above, the 1st position is bonded to Tb via an S atom, and the 2nd position is bonded to L2 or L3.

[0029] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The values ​​are selected from the following, where y1 is selected from any integer between 1 and 6 (e.g., 4, 5, 6), each y2 is independently selected from any integer between 0 and 10 (e.g., 6 to 10), each y3 is independently selected from 1 or 2, and each y4 is independently selected from 0 or 1, with the first digit being joined to L1 and the second digit to L3.

[0030] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The first-ranked element is selected, and it is joined to L1, while the second-ranked element is joined to L3.

[0031] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The first-ranked element is selected, and it is joined to L1, while the second-ranked element is joined to L3.

[0032] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The first-ranked element is selected, and it is joined to L1, while the second-ranked element is joined to L3.

[0033] In some embodiments, L2 is absent.

[0034] In some embodiments, L2 is [ka] Selected from.

[0035] In some embodiments, L3 is selected from an amino acid residue or a short peptide consisting of 2 to 10 amino acid residues, and the amino acid residues are selected from native amino acid residues, non-native amino acid residues, or AA 1 An amino acid residue represented by or its stereoisomer is selected.

[0036] In some embodiments, L3 is an amino acid residue Val, D-Val, Cit, Phe, Lys, Lys(Ac), Leu, Gly, Ala, Asn, Asp, Arg, and AA 1 , or Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, Asp, and AA 1It is selected from short peptides consisting of 2 to 10 amino acid residues selected from

[0037] In some embodiments, L3 is Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, AA 1 , Val-Cit, Cit-Val, Cit-Ala, Val-Ala, Lys-Val, Val-Lys(Ac), Phe-Lys, Phe-Lys(Ac), Ala-Ala, Val-AA 1 , Ala-AA 1 , Gly-AA 1 , AA 1 -Gly, Ala-Ala-Ala, Ala-Ala-Asn, Ala-Ala-Asp, Val-AA 1 -Gly, Ala-AA 1 -Gly, Gly-AA 1 -Gly, Lys-Ala-Ala-Asn, Lys-Ala-Ala-Asp, Gly-Phe-Gly, Gly-Gly-Phe-Gly, D-Val-Leu-Lys, Gly-Gly-Arg, Ala-Ala-Asn, Gly-Gly-Phe, Val-Lys-Gly, Val-Lys-Gly-Gly, Val-Lys, and Lys-Ala-Asn.

[0038] In some embodiments, L3 is AA 1 , AA 1 -Gly, Val-Cit, Val-AA 1 -Gly, AA 1 -Ala-Asn, and Gly-Gly-Phe-Gly.

[0039] In some embodiments, L3 is AA 1 and Val-AA 1 -Gly.

[0040] In some embodiments, L3 is Val-AA 1 -Gly.

[0041] In some embodiments, L3 is [ka] [ka] Selected from, In the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is joined to L1 or L2, and the second choice is joined to L4 or D.

[0042] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is joined to L1 or L2, and the second choice is joined to L4 or D.

[0043] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is joined to L1 or L2, and the second choice is joined to L4 or D.

[0044] In some embodiments, L3 is [ka] The first choice is selected, and the first choice is joined to L1 or L2, and the second choice is joined to L4 or D.

[0045] In some embodiments, L3 is [ka] The first choice is selected, and the first choice is joined to L1 or L2, and the second choice is joined to L4 or D.

[0046] In some embodiments, AA 1 The structure of the amino acid residue represented by is as follows: [ka] During the ceremony, R a and R b Each of them is independent of H, [ka] Selected from, in the formula, R a and R b Is it possible that both of them are H? Or, R a and R b These, together with the carbon atoms to which they are bonded, form a 4-10 membered heterocycle, and this 4-10 membered heterocycle has one or more R 0 Replaced by optional selection, r, r 1 Each of these is independently selected from any integer between 0 and 20. R m1 , R n1 These are, independently, H, C1-6 alkyl, C3-6 cycloalkyl, and -COOR. x1 Selected from, R x1 The C1-6 alkyl group is selected from, Or, R m1 and R n1 These, together with the nitrogen atoms to which they are bonded, form a 4-10 membered heterocycle, and this 4-10 membered heterocycle has one or more R 0’ Replaced by optional selection, R z It is selected from C1-6 alkyl groups. R 0 , R 0’These are, independently, C1-6 alkyl, C3-6 cycloalkyl, and -NR. m2 R n2 and selected from 4-10 membered heterocyclines optionally substituted with C1-6 alkyl groups, R m2 , R n2 Each of these is independently selected from H and C1-6 alkyl groups.

[0047] In some embodiments, R a and R b One of them is H, and the other is, [ka] Selected from.

[0048] In some embodiments, R a and R b One of them is H, and the other is, [ka] Selected from.

[0049] In some embodiments, R a and R b Together with the carbon atoms to which they are both bonded, R 0 It forms a 5-6 member heterocycle with substitutions.

[0050] In some embodiments, R a and R b Together with the carbon atom to which both of them are bonded, R 0 It forms a piperidine ring or piperazine ring substituted with [the specified compound].

[0051] In some embodiments, R a and R b Together with the carbon atoms to which they are both bonded, R 0 It forms a piperidine ring substituted with [a specific compound].

[0052] In some embodiments, R a and R b They, together with the carbon atoms to which they are bonded, [ka] It forms, and the carbon atom numbered 1 is R a and R b It is a carbon atom to which both are bonded.

[0053] In some embodiments, R a and R b They, together with the carbon atoms to which they are bonded, [ka] It forms, and the carbon atom numbered 1 is R a and R b It is a carbon atom to which both are bonded.

[0054] In some embodiments, r and r 1 Each of these is independently selected from 0, 1, 2, 3, 4, and 5.

[0055] In some embodiments, r and r 1 Each of these is independently selected from 0 and 4.

[0056] In some embodiments, r and r 1 One of them is 0, and the other is 4.

[0057] In some embodiments, R m1 and R n1 Each of these is independently selected from H, methyl, ethyl, n-propyl, n-butyl, -COOCH3, -COOCH2CH3, -COOCH2CH2CH3, -COOCH(CH3)2, -COOC(CH3)3, and -COOCH2CH2CH2CH3.

[0058] In some embodiments, R m1 and Rn1 is independently selected from H, C1-6 alkyl, C3-6 cycloalkyl, and tert-butoxycarbonyl.

[0059] In some embodiments, R m1 and R n1 are independently selected from H and C1-6 alkyl.

[0060] In some embodiments, R m1 and R n1 are independently selected from H, methyl, ethyl, and n-propyl.

[0061] In some embodiments, for r and r 1 , when r is 4, r 1 is 0, and R m1 and R n1 are independently selected from H and C1-6 alkyl (e.g., H and CH3), and when r is 0 and r 1 is 4, R[[ID=:32]] m1 and R n1 are independently selected from C1-6 alkyl (e.g., methyl, ethyl, n-propyl), preferably selected from C2-6 alkyl (e.g., ethyl, n-propyl).

[0062] In some embodiments, R m1 and R n1 together with the nitrogen atom to which they are both attached form a 5- to 6-membered heterocyclic ring optionally substituted with R 0’ .

[0063] In some embodiments, R m1 and R n1 together with the nitrogen atom to which they are both attached form a piperidine ring or a piperazine ring optionally substituted with R 0’ .

[0064] In some embodiments, R m1 and R n1Together with the nitrogen atom to which they are both attached, [Chemical formula] forms, and the nitrogen atom numbered 1 is the m1 nitrogen atom to which both R n1 and R

[0065] In some embodiments, R z is methyl.

[0066] In some embodiments, R 0 , R 0’ are each independently selected from C1-6 alkyl, -NR m2 R n2 , and 5- to 6-membered heterocyclyl optionally substituted with C1-6 alkyl.

[0067] In some embodiments, R 0 is selected from C1-6 alkyl and 5- to 6-membered heterocyclyl substituted with C1-6 alkyl, and the 5- to 6-membered heterocyclyl is selected from piperidinyl and piperazinyl.

[0068] In some embodiments, R 0 is selected from methyl, ethyl and 5- to 6-membered heterocyclyl substituted with methyl, and the 5- to 6-membered heterocyclyl is piperidinyl.

[0069] In some embodiments, R 0 is selected from methyl and 5- to 6-membered heterocyclyl substituted with methyl, and the 5- to 6-membered heterocyclyl is piperidinyl. <s

[0070] In some embodiments, R 0 is methyl, ethyl and [Chemical formula] <00s01346> selected from.

[0071] In some embodiments, R 0 methyl and [ka] Selected from.

[0072] In some embodiments, R 0’ These are C1-6 alkyl and -NR m2 R n2 Selected from.

[0073] In some embodiments, R 0’ methyl and -NR m2 R n2 Selected from.

[0074] In some embodiments, R m2 and R n2 It is methyl.

[0075] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0076] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0077] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0078] In some embodiments, AA 1The amino acid residues represented by are [ka] Selected from.

[0079] In some embodiments, L4 is either absent or present, and if L4 is present, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to D.

[0080] In some embodiments, L4 is either absent or present, and if L4 is present, L4 is [ka] The first-ranked node is connected to L3, and the second-ranked node is connected to D.

[0081] In some embodiments, L4 is absent.

[0082] In some embodiments, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to D.

[0083] In some embodiments, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to D.

[0084] In some embodiments, the structure: [ka] It is selected from the following structural fragments. [Table 1]

[0085] In some embodiments, Tb is an antibody or its antigen-binding fragment.

[0086] In some embodiments, the antibody or its antigen-binding fragment and the monoclonal antibody or its antigen-binding fragment include Fab, Fab', F(ab')2, Fd, Fv (e.g., scFv), dAb, complementarity-determining region fragments, non-human antibodies, humanized antibodies, chimeric antibodies, fully human antibodies, probodies, monoclonal antibodies, bispecific antibodies, or multispecific antibodies.

[0087] In some embodiments, Tb is an antibody or antigen-binding fragment thereof, whether endocytosizable or non-endocytosizable.

[0088] In some embodiments, Tb is an endocytogenic antibody or its antigen-binding fragment.

[0089] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has activity to bind to free antigens in tumor tissue and / or tumor cell surface antigens.

[0090] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has tumor cell endocytosis activity and activity to bind to free antigens in tumor tissue or tumor cell surface antigens.

[0091] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has tumor cell endocytosis activity and activity to bind to free antigens in tumor tissue and tumor cell surface antigens.

[0092] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has tumor cell endocytosis activity but does not have activity to bind to free antigens in tumor tissue.

[0093] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has tumor cell endocytosis activity but does not have activity to bind to tumor cell surface antigens.

[0094] In some embodiments, Tb is an antibody or its antigen-binding fragment that has no or weak endocytotic activity.

[0095] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that does not have the activity to bind to free antigens in tumor tissue and / or tumor cell surface antigens.

[0096] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has no or weak endocytotic activity in tumor cells and has the activity to bind to free antigens in tumor tissue or tumor cell surface antigens.

[0097] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has no or weak endocytotic activity in tumor cells and has the activity to bind to free antigens in tumor tissue and tumor cell surface antigens.

[0098] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has no or weak tumor cell endocytosis activity and does not have the activity to bind to tumor cell surface antigens. In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has no or weak tumor cell endocytosis activity and does not have the activity to bind to free antigens in tumor tissue.

[0099] In some embodiments, Tb is an antibody or its antigen-binding fragment that does not have tumor cell endocytosis activity and does not have a corresponding antigen in the human body.

[0100] In some embodiments, Tb is an antibody that does not bind to tumor cell-associated antigens.

[0101] In some embodiments, an antibody or its antigen-binding fragment is selected from IgG isotype antibodies.

[0102] In some embodiments, an antibody or its antigen-binding fragment is selected from isotype IgG1, isotype IgG2, isotype IgG3, or isotype IgG4. In some embodiments, the antibody or its antigen-binding fragment is an anti-chicken lysozyme human IgG1 isotype antibody.

[0103] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has activity to bind to a tumor cell surface non-endocytosis antigen (e.g., ALCAM / CD166).

[0104] In some embodiments, Tb is an antibody that has tumor cell-associated antigen binding.

[0105] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has activity to bind to a free antigen in tumor tissue or a tumor cell surface antigen.

[0106] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has activity to bind to free antigens in tumor tissue and tumor cell surface antigens.

[0107] In some embodiments, Tb is an antibody having B7H3-2Ig and / or B7H-4Ig, or an antigen-binding fragment thereof.

[0108] In some embodiments, Tb is an antibody or its antigen-binding fragment having higher binding activity to B7H3-4Ig than to B7H3-2Ig.

[0109] In some embodiments of this disclosure, Tb is a ligand or targeting moiety that binds to a target.

[0110] In some embodiments, the target of Tb is selected from targets whose expression in tumor cells is higher than that in normal cells.

[0111] In some embodiments, the target of Tb is selected from targets that are highly expressed in tumor cells and low in normal cells.

[0112] In some embodiments, the target of Tb is selected from B7H3, CD20, CD19, CD30, GPNMB, Her2, Trop-2, EGFR, Her3, GD-2, CD79b, and BCMA, among others.

[0113] In some embodiments, Tb is an antibody or its antigen-binding fragment.

[0114] In some embodiments, Tb is a non-human antibody, a humanized antibody, a chimeric antibody, or a fully human antibody.

[0115] In some embodiments, Tb is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0116] In some embodiments, Tb is a monoclonal antibody or its antigen-binding fragment.

[0117] In some embodiments, Tb is an anti-B7H3 antibody or its antigen-binding fragment, an anti-Trop-2 antibody or its antigen-binding fragment, an anti-Her2 antibody or its antigen-binding fragment, an anti-Her3 antibody or its antigen-binding fragment, or an anti-EGFR antibody or its antigen-binding fragment.

[0118] In some embodiments, Tb is an anti-B7H3 antibody or its antigen-binding fragment, such as antibody 1D1, antibody 1D1-01, antibody 2E3, antibody 2E3-02, enobrituzumab, mirzotamab, omburtamab, or their antigen-binding fragments.

[0119] The sequence of 1D1 is as indicated by sequence number 1. The VH sequence of 1D1-01 is as indicated by sequence number 3, and the VL sequence is as indicated by sequence number 13. The heavy chain sequence of 1D1-01 is as indicated by sequence number 45, and the light chain sequence is as indicated by sequence number 46. The sequence of 2E3 is as indicated by sequence number 2. The VH sequence of 2E3-02 is as indicated by sequence number 23, and the VL sequence is as indicated by sequence number 33. The heavy chain sequence of 2E3-02 is as indicated by sequence number 47, and the light chain sequence is as indicated by sequence number 48.

[0120] In some embodiments, Tb is an anti-B7H3 monoclonal antibody or its antigen-binding fragment.

[0121] In some embodiments, Tb is an anti-Trop-2 antibody or its antigen-binding fragment, such as datopotamab, sacituzumab, or their antigen-binding fragments.

[0122] In some embodiments, Tb is an anti-Trop-2 monoclonal antibody or its antigen-binding fragment.

[0123] In some embodiments, Tb is an anti-Her2 antibody or its antigen-binding fragment, such as anbenitamab, coprelotamab, disitamab, gancotamab, margetuximab, pertuzumab, timigutuzumab, zanidatamab, trastuzumab, partuzumab, or their antigen-binding fragments.

[0124] In some embodiments, Tb is an anti-Her2 monoclonal antibody or its antigen-binding fragment, such as trastuzumab, pertuzumab, or an antigen-binding fragment thereof.

[0125] In some embodiments, Tb is an anti-Her3 antibody or its antigen-binding fragment, such as barecetamab, durigotuzumab, ergemzumab, istilatumab, lumretuzumab, patritumab, cerivantuzumab, zenocutuzumab, antibody 202-2-1, or their antigen-binding fragments.

[0126] In some embodiments, Tb is an anti-Her3 monoclonal antibody or an antigen-binding fragment thereof.

[0127] In some embodiments, Tb is an anti-EGFR antibody or its antigen-binding fragment, such as demvitamab, depatuxizumab, futuximab, imatuzumab, laprituximab, losatuxizumab, matuzumab, modotuximab, necitumumab, nimotuzumab, panitumumab, pimurutamab, serclutamab, tomzotusimab, zaltumumab, cetuximab, or their antigen-binding fragments.

[0128] In some embodiments, Tb is an anti-EGFR monoclonal antibody or its antigen-binding fragment.

[0129] In some embodiments, the antibody is an antibody that has activity to bind to an antigen but does not have endocytotic activity. In some embodiments, the antibody is an antibody that has activity to bind to antigens such as B7H3, CD20, CD19, CD30, GPNMB, Her2, Trop-2, EGFR, Her3, GD-2, CD79b, and BCMA, but does not have endocytotic activity.

[0130] In some embodiments, the antibody is an antibody that has activity to bind to the antigen B7H3 but does not have endocytotic activity, such as INV721 and I7-01 disclosed in International Publication No. 2021168379A1. More specifically, the anti-B7H3 antibody has VH of SEQ ID NO: 2 and VL of SEQ ID NO: 1, as described in International Publication No. 2021168379A1.

[0131] In some embodiments, the antibody is an antibody that has activity to bind to the antigen GD2 but does not have endocytotic activity, such as INV721 and GD2-5 disclosed in International Publication No. 2021168379A1. More specifically, the anti-GD2 antibody has SEQ ID NO: VH of SEQ ID NO: 4 and SEQ ID NO: VL of SEQ ID NO: 3, as described in International Publication No. 2021168379A1.

[0132] In some embodiments, the antibody is an antibody that has activity to bind to the antigen HER3 but does not have endocytosis activity, for example, the anti-HER3 antibody 21F06 described in Sequence ID No. 22 of U.S. Patent No. 10808032B2.

[0133] In some embodiments, the antibody is one that has activity to bind to the antigen CD20 but lacks endocytotic activity. While it has been shown that so-called "type II" CD20-specific antibodies are difficult to internalize by CD20-positive target cells, other so-called "type I" CD20-specific antibodies have been found to be internalized and, to some extent, degraded depending on the activation and inhibition of FcγR expression levels in the target cells with which they interact. In some embodiments, antibodies that have activity to bind to the antigen CD20 but lack endocytotic activity are "type II" CD20-specific antibodies such as obinutuzumab.

[0134] In some embodiments, the antibody is an antibody having activity to bind to a non-endocytosis antigen (e.g., ALCAM / CD166). In some embodiments, the antibody is an antibody comprising SEQ ID NO: VH of SEQ ID NO: 73 and VL of SEQ ID NO: 74, SEQ ID NO: VH of SEQ ID NO: 75 and VL of SEQ ID NO: 76, SEQ ID NO: VH of SEQ ID NO: 77 and VL of SEQ ID NO: 78, or SEQ ID NO: VH of SEQ ID NO: 79 and VL of SEQ ID NO: 88, as described in European Patent No. 3911682A1.

[0135] In some embodiments, Tb is a targeting moiety such as a ligand, protein, polypeptide, non-protein reagent (e.g., sugar, RNA, or DNA), or antibody mimetic.

[0136] In some embodiments, q is selected from any number between 0.1 and 16.0. In preferred embodiments, q is selected from any integer between 0.1 and 16.0.

[0137] In some embodiments, q is selected from any number between 0.1 and 8.0. In a preferred embodiment, q is selected from any integer between 0.1 and 8.0.

[0138] In some embodiments, q is selected from any number between 2 and 8.

[0139] In some embodiments, q is selected from any number between 3 and 8.

[0140] In some embodiments, q is selected from any number between 4 and 8.

[0141] In some embodiments, q is selected from any number between 6 and 8.

[0142] In some embodiments, q is selected from any integer between 2 and 8.

[0143] In some embodiments, q is selected from any integer between 3 and 8.

[0144] In some embodiments, q is selected from any integer between 4 and 8.

[0145] In some embodiments, q is selected from any integer between 6 and 8.

[0146] In some embodiments, q is selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.

[0147] In some embodiments, q is selected from 2, 4, 6, and 8.

[0148] In this disclosure, a bioactive molecular fragment means a portion (fragment or group) in an antibody-drug conjugate (referred to as an ADC, or antibody-conjugated drug) that, as is well known in the art, can form a bioactive drug (e.g., a small molecule cytotoxic drug containing a group after the loss of an atom or group of atoms) or a derivative thereof (e.g., a precursor thereof) after cleavage / degradation / enzymatic cleavage of a linker within tumor tissue or tumor cells. To avoid ambiguity, “drug” means not only a “drug product” approved by a drug regulatory authority, but also any molecule that has potential therapeutic bioactivity in clinical practice or research and development and academic research.

[0149] In some embodiments, D is a molecular fragment having antitumor biological activity.

[0150] In some embodiments, D is a molecular fragment having antitumor bioactivity, and the bioactive molecule is selected from cytotoxic agents or derivatives thereof, for example, DNA topoisomerase inhibitors (e.g., camptothecin-type bioactive molecules such as camptothecin, DXD, camptothecin with modified substituents, or DXD with modified substituents) or tubulin inhibitors (e.g., MMAF-type tubulin inhibitors, MMAE-type tubulin inhibitors).

[0151] In some embodiments, the ligand-drug conjugate has a structure represented by formula I, [ka] During the ceremony, R1 and R2 are independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl, and optionally substituted C1-6 alkoxy, or R1 and R2, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups, or any combination thereof. R3 is selected from H, halogen, -OH, -NH2, optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or R3 and X, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups or any combination thereof, or R3 and R2, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups, or any combination thereof. W is either nonexistent or exists, and if W exists, W is -O-, -S-, -NR4-, [ka] Selected from, the 1st place joins to X, the 2nd place joins to L4 or L3, X is a directly bonded, optionally substituted -O-(CH2) n3 -, -NR4-(CH2) n3 -, -S-(CH2) n3 -, carbonyl-(CH2) n3 -, -SO2-(CH2) n3 -, [ka] -(CH2) n1 - Selected from C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclyl, the 1st position is bonded to the parent ring, the 2nd position is bonded to W or L4, and the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups that together with the carbon atoms to which they are both bonded form a C3-6 cycloalkyl group. Each M is independently directly bonded and -CR 5a R 5b - Selected from, R4, R5, R 5a , R 5b R6 and R7 are independently selected from H, optionally substituted C1-4 alkyl groups, optionally substituted C1-4 alkoxy groups, and optionally substituted C3-6 cycloalkyl groups. n, n', n1, n2, and n3 are each independently selected from any integer between 0 and 6. L4 either does not exist or exists, and if L4 exists, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0152] Tb, L1, L2, L3, and q are defined as in the above and any embodiment specifically described herein, In some embodiments, R1 and R2 are each independently selected from H, halogens, and C1-4 alkyl groups.

[0153] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, form a 5-6 membered heterocycle containing 1, 2, or 3 O, S, or N atoms, or any combination thereof.

[0154] In some embodiments, R1 is selected from H and halogens, and R2 is selected from H and C1-4 alkyl groups.

[0155] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] The formula forms a heterocycle, and in the formula, the dotted line indicates the location where the heterocycle is fused to the benzene ring.

[0156] In some embodiments, R1 is H or F, and R2 is H or methyl.

[0157] In some embodiments, R1 is F and R2 is methyl, or R1 and R2 together with the carbon atoms to which they are bonded, [ka] It forms.

[0158] In some embodiments, R1 is F and R2 is methyl.

[0159] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] It forms.

[0160] In some embodiments, R3 is selected from H and C1-4 alkyl groups.

[0161] In some embodiments, R3 and X, together with the carbon atoms to which they are bonded, form a 5-6 membered carbocyclic ring.

[0162] In some embodiments, R3 is H, or R3 and X together are carbon atoms to which they are bonded. [ka] The formula forms a structure where the dotted lines indicate the locations where the carbocyclic ring is condensed with the benzene ring and the pyridine ring.

[0163] In some embodiments, R3 is H.

[0164] In some embodiments, W is either absent or present, and if W is present, W is -O-, -S-, -NR4-, [ka] The first choice is selected, and it is joined to X, and the second choice is joined to L4 or L3.

[0165] In some embodiments, W is either absent or present, and if W is present, W is -O-, -S-, -NR4-, [ka] The first choice is selected, and it is joined to X, and the second choice is joined to L4 or L3.

[0166] In some embodiments, W is -O-, -NR4- and [ka] The first choice is selected, and it is joined to X, and the second choice is joined to L4 or L3.

[0167] In some embodiments, W is selected from -O- and -NR4-, with the first position bonded to X and the second position bonded to L4 or L3.

[0168] In some embodiments, X is optionally replaced by -(CH2) n1 -, [ka] Selected from C6-10 aryls, 5-10 membered heteroaryls, and 4-10 membered heterocyclines, the 1st position is bonded to the parent ring, the 2nd position is bonded to W or L4, and the substituent is selected from one or two C1-4 alkyl groups, or two C1-4 alkyl groups that together with the carbon atoms to which they are both bonded form a C3-6 cycloalkyl group. In some embodiments, X is optionally replaced [ka] A substituent is selected from the following, with the 1st position bonded to the parent ring and the 2nd position bonded to W or L4, and the substituent is selected from one or two C1-4 alkyl groups (e.g., methyl), or two C1-4 alkyl groups (e.g., methyl) together with the carbon atoms to which they are both bonded to form a C3-6 cycloalkyl group (e.g., cyclopropyl).

[0169] In some embodiments, X is [ka] Selected from the options, the first-ranked element is bound to the parent ring, and the second-ranked element is bound to W or L4.

[0170] In some embodiments, X is [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0171] In some embodiments, if W is absent, X is [ka] Selected from, the 1st place joins the parent ring, the 2nd place joins L4, and if W exists, X is, [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0172] In some embodiments, W is -O-, -NR4- and [ka] Selected from, the 1st place joins X, the 2nd place joins L4 or L3, and X is, [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0173] In some embodiments, R4 and R5 are each independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl.

[0174] In some embodiments, each R4 is independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl, and R5 is H.

[0175] In some embodiments, each R4 is independently selected from H, methyl, ethyl, n-propyl, isopropyl, t-butyl, and cyclopropyl, and R5 is H.

[0176] In some embodiments, R 5a , R 5b Each of these is independently selected from H and C1-4 alkyl groups.

[0177] In some embodiments, R 5a , R 5b Each of these is independently selected from H and methyl.

[0178] In some embodiments, each R7 is independently selected from H and C1-4 alkyl groups.

[0179] In some embodiments, R7 is H.

[0180] In some embodiments, n is selected from 1, 2, and 3.

[0181] In some embodiments, n is 1.

[0182] In some embodiments, n1 is selected from 1, 2, 3, and 4.

[0183] In some embodiments, n2 is 1.

[0184] In some embodiments, n3 is 0.

[0185] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0186] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0187] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH -The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0188] In some embodiments, L3 is [ka] The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0189] In some embodiments, L3 is [ka] The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0190] In some embodiments, L4 is either absent or present, and if L4 is present, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0191] In some embodiments, L4 is either absent or present, and if L4 is present, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0192] In some embodiments, L4 is absent.

[0193] In some embodiments, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0194] In some embodiments, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0195] As mentioned above, W either does not exist or exists. Therefore, if W does not exist, the first position of L4 is bound to L3 and the second position is bound to X. If W exists, the first position of L4 is bound to L3 and the second position is bound to W. The following association relationships for L4 can be understood by referring to the above.

[0196] In some embodiments, the structure: [ka] The following structural fragments are selected: [Table 2-1] [Table 2-2] [Table 2-3] In the formula, position 1 is bound to Tb, and position 2 is bound to W.

[0197] In some embodiments, D is [ka] It is a structural fragment represented by, where position 1 is bound to L3 or L4, for example [ka] That is the case.

[0198] In some embodiments, the structure: [ka] The following structural fragments are selected: [ka] [ka] [ka] In the formula, the 1st position is joined to L4, and if L4 does not exist, the 1st position is joined to L3.

[0199] In some embodiments, W is either absent or present, and if W is present, W is -O-, -S-, -NR4-, [ka] Selected from, for example, non-existent, -O-, -NR4- or [ka] R4 and R5 are independently selected from H and C1-4 alkyl groups, and n is independently selected from 0, 1, 2, 3, and 4. X is [ka] Selected from, In the formula, R1 is selected from H and halogens, R2 is selected from H and C1-4 alkyls, or R1 and R2 together with the carbon atoms to which they are bonded. [ka] The formula forms a heterocycle, and in the formula, the dotted line indicates the location where the heterocycle is fused to the benzene ring. R3 is either H and C1-4 alkyl, or R3 and X, together with the carbon atoms to which they are bonded, form a 5-6 membered carbon-cyclic ring. Preferably, W is absent or present, and if W is present, W is -O-, -NR4- (e.g., -NH-, -N(CH3)-, -N(C2H5)-), [ka] Selected from, where R4 is independently selected from H, methyl, ethyl, isopropyl, n-propyl, t-butyl, and cyclopropyl, If W does not exist, X is [ka] Selected from, the 1st is joined to the parent ring, and if W exists, X is, [ka] Selected from, In AA1, [ka] r is selected from 0, 1, 2, 3, 4, and 5. R a and R b One of them is H, and the other is, [ka] Selected from or R a and R b Together with the carbon atoms to which they are both bonded, R 0 It forms a 5-6 member heterocyclic ring by substitution, R1 is selected from H and halogens, R2 is selected from H and C1-4 alkyls, or R1 and R2 together with the carbon atoms to which they are bonded. [ka] Forming, R3 is either H and C1-C4 alkyl, or R3 and X together with the carbon atoms to which they are bonded. [ka] Forming, More preferably, W is selected from -O- and -NR4-, with the first position bonded to X and the second position bonded to L4 or L3. X is [ka] Selected from, the 1st place joins the parent ring, the 2nd place joins W, [ka] For example, [ka] And, R1 is F, R2 is methyl, or R1 and R2, together with the carbon atoms to which they are bonded, [ka] Forming, R3 is H.

[0200] In some embodiments, the ligand-drug conjugate has a structure represented by formula I-1: [ka] It has, In the formula, Tb, L1, L2, L3, L4, X, R1, R2, R3, R4, and q are as defined above and in any embodiment specifically described herein.

[0201] In some embodiments, the ligand-drug conjugate has the structure of formula I-1A or formula I-1B. [ka] In the formula, Tb, L2, L3, L4, X, R1, R2, R3, R4, and q are as defined above and in any embodiment specifically described herein.

[0202] In some embodiments, the ligand-drug conjugate has a structure represented by formula I-2, [ka] In the formula, Tb, L1, L2, L3, L4, X, R1, R2, R3, and q are as defined above and in any embodiment specifically described herein.

[0203] In some embodiments, the ligand-drug conjugate has the structure of formula I-2A or formula I-2B: [ka] It has, In the formula, Tb, L2, L3, L4, X, R1, R2, R3, and q are as defined above and in any embodiment specifically described herein.

[0204] In some embodiments, the ligand-drug conjugate has a structure represented by formula I-3, [ka] In the formula, Tb, L1, L2, L3, L4, X, R1, R2, R3, R4, R5, n, and q are as defined above and in any embodiment specifically described herein.

[0205] In some embodiments, the ligand-drug conjugate has the structure of formula I-3A or formula I-3B: [ka] It has, In the formula, Tb, L2, L3, L4, X, R1, R2, R3, R4, and q are as defined above and in any embodiment specifically described herein.

[0206] In some embodiments, the ligand-drug conjugate has a structure represented by formula IA: [ka] It has, In the formula, Tb, X, R1, R2, R3, R a , R b And q are as defined above and in any embodiment specifically described herein.

[0207] In some embodiments, the ligand-drug conjugate has a structure represented by formula IB: [ka] It has, In the formula, Tb, X, R1, R2, R3, R a , R b And q are as defined above and in any embodiment specifically described herein.

[0208] In some embodiments, the ligand-drug conjugate is selected from the following: [Table 3-1] [Table 3-2] [Table 3-3] [Table 3-4] [Table 3-5] [Table 3-6] [Table 3-7] [Table 3-8] [Table 3-9] [Table 3-10] [Table 3-11] [Table 3-12] [Table 3-13] [Table 3-14] [Table 3-15] [Table 3-16] [Table 3-17] [Table 3-18] [Table 3-19] The Tb antibody or its antigen-binding fragment can be prepared by various methods known in the art, for example, by genetic engineering and recombination techniques. For example, the DNA molecules encoding the heavy and light chain genes of the antibody of this disclosure are obtained by chemical synthesis or PCR amplification. The obtained DNA molecules are inserted into an expression vector and then transfected into host cells. The transfected host cells are then cultured under specific conditions to express the antibody of this disclosure.

[0209] In some embodiments of this disclosure, the targeting portion is an anti-B7H3 antibody or its antigen-binding fragment. In some embodiments, the anti-B7H3 antibody is any of the prior art anti-B7H3 antibodies, such as enobrituzumab, mirzotamab, omblutamab, and CN112521512, International Publication No. 2021027674, International Publication No. 2021021543, International Publication No. 2021006619, Chinese Patent No. 111662384, National Patent No. 111454357, International Publication No. 2020151384, International Publication No. 2020140094, International Publication No. 2020103100, International Publication No. 2020102779, International Publication No. 2020063673, International Publication No. 2020047257, International Publication No. 2020041626, Chinese Patent No. 110684790, Chinese Patent No. 1 Patent No. 10642948, International Publication No. 2019225787, International Publication No. 2019226017, U.S. Patent No. 20190338030, Chinese Patent No. 110305213, International Publication No. 2018209346, International Publication No. 2018177393, U.S. Patent No. 9150656, International Publication No. 2016106004, International Publication No. 20160443 Examples of anti-B7H3 antibodies include those described in Patent No. 83, International Publication No. 2016033225, International Publication No. 2015181267, U.S. Patent No. 20120294796, International Publication No. 2011109400, Chinese Patent No. 101104639, International Publication No. 2004093894, International Publication No. 2002010187, and International Publication No. 2001018021. In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is selected from the antibody M30-H1-L4 in Chinese Patent No. 103687945B and the antibody mAb-C-DUBA in Chinese Patent No. 109069633A.

[0210] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is an antibody or its antigen-binding fragment containing a complementation-determining region (CDR) as shown below, where the CDR is numbered according to the IMGT numbering system: (a) HCDR1 consisting of the sequence of sequence number 10, HCDR2 consisting of the sequence of sequence number 11, HCDR3 consisting of the sequence of sequence number 12, and / or LCDR1 consists of the sequence of sequence number 20, LCDR2 consists of the sequence of GTF, and LCDR3 consists of the sequence of sequence number 22. (b) HCDR1 consisting of the sequence of sequence number 10, HCDR2 consisting of the sequence of sequence number 11, HCDR3 consisting of the sequence of sequence number 12, and / or LCDR1 consists of the sequence with sequence number 40, LCDR2 consists of the sequence with GAS, and LCDR3 consists of the sequence with sequence number 42. (c) HCDR1 consisting of the sequence of sequence number 30, HCDR2 consisting of the sequence of sequence number 31, HCDR3 consisting of the sequence of sequence number 32, and / or LCDR1 consists of the sequence with sequence number 40, LCDR2 consists of the sequence with GAS, and LCDR3 consists of the sequence with sequence number 42. or (d) HCDR1 consisting of the sequence of sequence number 30, HCDR2 consisting of the sequence of sequence number 31, HCDR3 consisting of the sequence of sequence number 32, and / or It is defined by LCDR1, which consists of the array with sequence number 20; LCDR2, which consists of the array with GTF; and LCDR3, which consists of the array with sequence number 22.

[0211] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment, as defined by the IMGT numbering system, (a) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (a) VL containing the light chains LCDR1, LCDR2, LCDR3, (b) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (b) VL containing the light chains LCDR1, LCDR2, LCDR3 (c) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (c) VL containing the light chains LCDR1, LCDR2, LCDR3, or (d) comprises VH containing the heavy chains HCDR1, HCDR2, and HCDR3, and VL containing the light chains LCDR1, LCDR2, and LCDR3.

[0212] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises a complementation-determining region (CDR) as shown below, where the CDR is numbered according to the Chothia numbering system: (a) HCDR1 consisting of the sequence of sequence number 4, HCDR2 consisting of the sequence of sequence number 5, HCDR3 consisting of the sequence of sequence number 6, and / or LCDR1 consists of the sequence of sequence number 14, LCDR2 consists of the sequence of sequence number 15, and LCDR3 consists of the sequence of sequence number 16. (b) HCDR1 consisting of the sequence of sequence number 24, HCDR2 consisting of the sequence of sequence number 25, HCDR3 consisting of the sequence of sequence number 26, and / or LCDR1 consists of the sequence of sequence number 34, LCDR2 consists of the sequence of sequence number 35, and LCDR3 consists of the sequence of sequence number 36. (c) HCDR1 consisting of the sequence of sequence number 4, HCDR2 consisting of the sequence of sequence number 5, HCDR3 consisting of the sequence of sequence number 6, and / or LCDR1 consists of the sequence of sequence number 34, LCDR2 consists of the sequence of sequence number 35, and LCDR3 consists of the sequence of sequence number 36. or (d) HCDR1 consisting of the sequence of sequence number 24, HCDR2 consisting of the sequence of sequence number 25, HCDR3 consisting of the sequence of sequence number 26, and / or It is defined by LCDR1, which consists of the sequence of sequence number 14; LCDR2, which consists of the sequence of sequence number 15; and LCDR3, which consists of the sequence of sequence number 16.

[0213] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment, as defined by the Chothia numbering system, (a) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (a) VL containing the light chains LCDR1, LCDR2, LCDR3, (b) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (b) VL containing the light chains LCDR1, LCDR2, LCDR3 (c) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (c) VL containing the light chains LCDR1, LCDR2, LCDR3, or (d) comprises VH containing the heavy chains HCDR1, HCDR2, and HCDR3, and VL containing the light chains LCDR1, LCDR2, and LCDR3.

[0214] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises a complementation-determining region (CDR) as shown below, where the CDR is numbered according to the Kabat numbering system: (a) HCDR1 consisting of the sequence of sequence number 7, HCDR2 consisting of the sequence of sequence number 8, HCDR3 consisting of the sequence of sequence number 9, and / or LCDR1 consists of the sequence of sequence number 17, LCDR2 consists of the sequence of sequence number 18, and LCDR3 consists of the sequence of sequence number 19. (b) HCDR1 consisting of the sequence of sequence number 27, HCDR2 consisting of the sequence of sequence number 28, HCDR3 consisting of the sequence of sequence number 29, and / or LCDR1 consists of the sequence of sequence number 37, LCDR2 consists of the sequence of sequence number 38, and LCDR3 consists of the sequence of sequence number 39. (c) HCDR1 consisting of the sequence of sequence number 7, HCDR2 consisting of the sequence of sequence number 8, HCDR3 consisting of the sequence of sequence number 9, and / or LCDR1 consisting of sequence number 37, LCDR2 consisting of sequence number 38, and LCDR3 consisting of sequence number 39, or (d) HCDR1 consisting of the sequence of sequence number 27, HCDR2 consisting of the sequence of sequence number 28, HCDR3 consisting of the sequence of sequence number 29, and / or It is defined by LCDR1, which consists of the sequence of sequence number 17; LCDR2, which consists of the sequence of sequence number 18; and LCDR3, which consists of the sequence of sequence number 19.

[0215] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment, as defined by the Kabat numbering system, (a) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (a) VL containing the light chains LCDR1, LCDR2, LCDR3, (b) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (b) VL containing the light chains LCDR1, LCDR2, LCDR3 (c) VH containing the heavy chains HCDR1, HCDR2, HCDR3, and (c) VL containing the light chains LCDR1, LCDR2, LCDR3, or (d) comprises VH containing the heavy chains HCDR1, HCDR2, and HCDR3, and VL containing the light chains LCDR1, LCDR2, and LCDR3.

[0216] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is (a) Below: (i) Sequence described in Sequence ID No. 3 or 23, (ii) A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence described in Sequence ID No. 3 or 23, (iii) A heavy chain variable region (VH) comprising an amino acid sequence selected from sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence described in Sequence ID No. 3 or 23, and / or (b) Below: (iv) Sequences described in Sequence ID No. 13 or 33, (v) A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence described in Sequence ID No. 13 or 33, or (vi) A light chain variable region (VL) comprising an amino acid sequence selected from sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence described in Sequence ID No. 13 or 33.

[0217] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises VH as described in SEQ ID NO: 3, and / or VL as described in SEQ ID NO: 13.

[0218] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises VH as described in SEQ ID NO: 23, and / or VL as described in SEQ ID NO: 33.

[0219] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises VH as described in SEQ ID NO: 3, and / or VL as described in SEQ ID NO: 33.

[0220] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises VH as described in SEQ ID NO: 23, and / or VL as described in SEQ ID NO: 13.

[0221] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is (a) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 13, (b) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 33, (c) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 13, (d) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 13, (e) Heavy chain variable region (VH) and light chain variable region (VL) wherein the heavy chain variable region (VH) and light chain variable region (VL) independently have at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to the VH and VL defined in any one of (a) to (f), or (f) A heavy chain variable region (VH) and a light chain variable region (VL) comprising a heavy chain variable region (VH) and a light chain variable region (VL) which, compared to the VH and VL defined in any one of (a) to (d), independently have one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof). Preferably, the substitutions are conservative substitutions.

[0222] In some embodiments, the heavy chain of the anti-B7H3 antibody comprises the heavy chain constant region (CH) of human immunoglobulin or a variant thereof, the variant having up to 50 amino acid-conserved substitutions (e.g., up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid-conserved substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid-conserved substitutions) compared to the wild-type sequence from which it is derived. In some embodiments, the light chain of the anti-B7H3 antibody comprises the constant region (CL) of the light chain of a human immunoglobulin or a variant thereof, the variant having up to 50 amino acid-conserved substitutions (e.g., up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid-conserved substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid-conserved substitutions) compared to the wild-type sequence from which it is derived.

[0223] In some embodiments, the constant region is modified, e.g., mutated, to alter the properties of an anti-B7H3 antibody molecule (e.g., to change one or more of the following properties: Fc receptor binding, antibody glycosylation, number of cysteine ​​residues, effector cell function, or complement function). Functional changes can be made by substituting at least one amino acid residue in the constant region of the antibody with a different residue, e.g., by changing the antibody's affinity for an effector ligand (e.g., FcR or complement C1q), thereby altering (e.g., decreasing) the effector function. The Fc region of the antibody mediates several important effector functions, such as ADCC, phagocytosis (ADCP), CDC, etc.

[0224] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment has a heavy chain constant region (CH), which is selected from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE, and more particularly from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3, and IgG4, and more particularly from the heavy chain constant region of IgG1 (e.g., human IgG1). In some embodiments, the heavy chain constant region of human IgG1 is as described in SEQ ID NO: 43. In some embodiments, the antibody or its antigen-binding fragment of the present disclosure has a light chain constant region selected from, for example, the κ or λ light chain constant region, preferably the κ light chain constant region (e.g., the human κ light chain constant region). In some embodiments, the light chain constant region has the sequence described in SEQ ID NO: 44.

[0225] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises CH or a variant thereof described in SEQ ID NO: 43, the variant having up to 20 conserved amino acid substitutions (e.g., up to 20, up to 15, up to 10, or up to 5 conserved amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conserved amino acid substitutions) compared to SEQ ID NO: 43, or having at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to SEQ ID NO: 43.

[0226] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment has a light chain constant region or a variant thereof. In some embodiments, the light chain constant region includes a κ light chain constant region. In some embodiments, the light chain constant region includes the light chain constant region (CL) described in SEQ ID NO: 44 or a variant thereof, the variant having up to 20 conserved amino acid substitutions (e.g., up to 20, up to 15, up to 10 or up to 5 amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions) compared to SEQ ID NO: 44, or having at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to SEQ ID NO: 44. In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises a heavy chain constant region (CH) as described in SEQ ID NO: 43 and a light chain constant region (CL) as described in SEQ ID NO: 44.

[0227] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is (a) Below: (i) A sequence including the VH sequence described in Sequence ID 3 and the CH sequence described in Sequence ID 43, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions, or any combination thereof) compared to the sequence shown in (i), (iii) A heavy chain and an amino acid sequence comprising an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (i). (b) Below: (iv) A sequence including the VL sequence described in Sequence ID 13 and the CL sequence described in Sequence ID 44, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or a sequence having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof), (vi)(iv) comprises a light chain containing an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv).

[0228] In some embodiments, the substitutions described in (ii) or (v) are conservative substitutions.

[0229] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is (a) Below: (i) A sequence including the VH sequence described in Sequence ID No. 23 and the CH sequence described in Sequence ID No. 43, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A heavy chain and an amino acid sequence comprising an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (i). (b) Below: (iv) A sequence including the VL sequence described in Sequence ID 33 and the CL sequence described in Sequence ID 44, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or a sequence having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof), (vi)(iv) comprises a light chain containing an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv).

[0230] In some embodiments, the substitutions described in (ii) or (v) are conservative substitutions.

[0231] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises a heavy chain and a light chain. The heavy chain is, (i) Sequence described in Sequence ID No. 45, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence shown in (i), and Light chains are (iv) Sequence described in Sequence ID 46, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) The sequence includes sequences that have at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv).

[0232] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0233] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises a heavy chain and a light chain. The heavy chain is, (i) Sequence described in Sequence ID 47, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence shown in (i), and Light chains are (iv) Sequence described in Sequence ID 48, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) The sequence includes sequences that have at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv).

[0234] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0235] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is a chimeric antibody, a humanized antibody, or a fully human antibody.

[0236] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is selected from scFv, Fab, Fab', (Fab')2, Fv fragment, disulfide-bound Fv (dsFv), and diabody.

[0237] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is an scFv. In a particular embodiment, the scFv of this disclosure is (a) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 13, (b) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 33, (c) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 33, (d) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 13, (e) Heavy chain variable region (VH) and light chain variable region (VL) wherein the heavy chain variable region (VH) and light chain variable region (VL) independently have sequence identity of at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% compared to the VH and VL in any one of groups (a) to (d), or (f) A heavy chain variable region (VH) and a light chain variable region (VL) comprising a heavy chain variable region (VH) and a light chain variable region (VL) wherein each of the heavy chain variable region (VH) and the light chain variable region (VL) independently has one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to any one of the VH and VL from groups (a) to (d). Preferably, the substitutions are conservative substitutions.

[0238] In some embodiments, the antibody of the Disclosure is scFv. In a particular embodiment, the scFv of the Disclosure is (i) Sequence described in Sequence ID 1 or 2, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to the sequence described in (i), Preferably, the substitution described in (ii) is a conservative substitution.

[0239] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is an scFv. In certain embodiments, the scFv of this disclosure comprises the sequence described in SEQ ID NO: 1 or 2.

[0240] In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment is selected from antibody 1D1, antibody 1D1-01, antibody 2E3, and antibody 2E3-02.

[0241] In some embodiments of this disclosure, the targeting moiety is trastuzumab or pertuzumab. Trastuzumab is an anti-Her2 monoclonal antibody whose amino acid sequence is known to those skilled in the art, and an exemplary sequence can be found, for example, in Chinese Patent No. 103319599, in which the terminal Lys is readily deleted and does not affect its biological activity (see Dick, L. Wet al., Biotechnol. Bioeng., 100:1132-1143).

[0242] Exemplary heavy and light chain sequences of trastuzumab may refer, for example, to IMGT / mAb-DB ID 97. Exemplary heavy and light chain sequences of pertuzumab may refer to SEQ ID NOs. 16 and 15 disclosed in U.S. Patent No. 7560111, as well as IMGT / mAb-DB ID 80.

[0243] In some embodiments of this disclosure, the targeted portion is an anti-Her3 antibody or an antigen-binding fragment thereof. In some embodiments, the anti-Her3 antibody includes all anti-Her3 antibodies in the prior art, such as valecetamab, durigotuzumab, ergemzumab, istilatumab, lanletuzumab, patritumab, celivanzumab, xenoctuzumab, 202-2-1 antibody, as well as antibodies having a heavy chain as described in SEQ ID NO: 10 and a light chain as described in SEQ ID NO: 14 disclosed in Chinese Patent No. 103189392B, and the antibody represented by IMGT / mAb-DB ID: 546.

[0244] In some embodiments, the targeting portion is an anti-Her3 antibody, and the anti-Her3 antibody or its antigen-binding fragment is an antibody or its antigen-binding fragment containing a complementarity-determining region (CDR) as shown below, where the CDR is numbered according to the IMGT numbering system: HCDR1 consisting of the sequence of sequence number 56, HCDR2 consisting of the sequence of sequence number 57, HCDR3 consisting of the sequence of sequence number 58, and / or It is defined by LCDR1, which consists of the sequence with sequence number 41; LCDR2, which consists of the sequence AAS; and LCDR3, which consists of the sequence with sequence number 21.

[0245] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment, as defined by the IMGT numbering system, It includes VH containing the heavy chains HCDR1, HCDR2, and HCDR3 mentioned above, and VL containing the light chains LCDR1, LCDR2, and LCDR3 mentioned above.

[0246] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment is an antibody or its antigen-binding fragment containing a complementation-determining region (CDR) as shown below, where the CDR is numbered according to the Kabat numbering system: HCDR1 consisting of the sequence of sequence number 53, HCDR2 consisting of the sequence of sequence number 54, HCDR3 consisting of the sequence of sequence number 55, and / or It is defined by LCDR1, which consists of the sequence with sequence number 59; LCDR2, which consists of the sequence with sequence number 60; and LCDR3, which consists of the sequence with sequence number 21.

[0247] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment, as defined by the Kabat numbering system, comprises VH, which includes the heavy chains HCDR1, HCDR2, and HCDR3 described above, and VL, which includes the light chains LCDR1, LCDR2, and LCDR3 described above.

[0248] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment is (a) Below: (i) Sequence described in Sequence ID No. 49, (ii) A sequence having one or more amino acid substitutions, deletions or additions, or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions, or any combination thereof) compared to the sequence described in Sequence ID No. 49, (iii) A heavy chain variable region (VH) comprising an amino acid sequence selected from sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence described in Sequence ID No. 49, and / or (b) Below: (iv) Sequence described in Sequence ID 50, (v) A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence described in Sequence ID No. 50, (vi) A light chain variable region (VL) comprising an amino acid sequence selected from sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence described in Sequence ID No. 50.

[0249] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment is (a) VH as described in Sequence ID No. 49 and VL as described in Sequence ID No. 50, (b) Heavy chain variable region (VH) and light chain variable region (VL) wherein the heavy chain variable region (VH) and light chain variable region (VL) each independently have at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to the VH and VL described in group (a), or (c) Heavy chain variable region (VH) and light chain variable region (VL), wherein the heavy chain variable region (VH) and light chain variable region (VL) each independently have one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the VH and VL described in group (a). Preferably, the substitutions are conservative substitutions.

[0250] In some embodiments, the heavy chain of the anti-Her3 antibody comprises the heavy chain constant region (CH) of human immunoglobulin or a variant thereof, the variant having up to 50 amino acid-conserved substitutions (e.g., up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid-conserved substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid-conserved substitutions) compared to the wild-type sequence from which it is derived. In some embodiments, the light chain of the anti-B7H3 antibody comprises the constant region (CL) of the light chain of a human immunoglobulin or a variant thereof, the variant having up to 50 amino acid-conserved substitutions (e.g., up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid-conserved substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid-conserved substitutions) compared to the wild-type sequence from which it is derived.

[0251] In some embodiments, the constant region is modified, e.g., mutated, to alter the properties of an anti-Her3 antibody molecule (e.g., to change one or more of the following properties: Fc receptor binding, antibody glycosylation, number of cysteine ​​residues, effector cell function, or complement function). Functional changes can be made by substituting at least one amino acid residue in the constant region of the antibody with a different residue, e.g., by changing the antibody's affinity for an effector ligand (e.g., FcR or complement C1q), thereby altering (e.g., decreasing) the effector function. The Fc region of the antibody mediates several important effector functions, such as ADCC, phagocytosis (ADCP), CDC, etc.

[0252] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment has a heavy chain constant region (CH), which is selected from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE, and more particularly from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3, and IgG4, and more particularly from the heavy chain constant region of IgG1 (e.g., human IgG1). In some embodiments, the antibody or its antigen-binding fragment of the present disclosure has a light chain constant region selected from, for example, the κ or λ light chain constant region, preferably the κ light chain constant region (e.g., the human κ light chain constant region).

[0253] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment has a heavy chain constant region (CH) as described in SEQ ID NO: 43 and a light chain constant region (CL) as described in SEQ ID NO: 44.

[0254] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment comprises a heavy chain and a light chain. The heavy chain is, (i) Sequence described in Sequence ID No. 51, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence shown in (i), and Light chains are (iv) Sequence described in Sequence ID 52, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) The sequence includes sequences that have at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv). Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0255] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment is a chimeric antibody, a humanized antibody, or a fully human antibody.

[0256] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment is selected from scFv, Fab, Fab', (Fab')2, Fv fragment, disulfide-bound Fv (dsFv), and diabody.

[0257] In some embodiments, the anti-Her3 antibody or its antigen-binding fragment is an scFv. In a particular embodiment, the scFv of this disclosure is (a) VH as described in Sequence ID No. 49 and VL as described in Sequence ID No. 50, (b) Heavy chain variable region (VH) and light chain variable region (VL) wherein the heavy chain variable region (VH) and light chain variable region (VL) each independently have sequence identity of at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% compared to the VH and VL of group (a), or (c) Heavy chain variable region (VH) and light chain variable region (VL), wherein the heavy chain variable region (VH) and light chain variable region (VL) each independently have one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the VH and VL of group (a). Preferably, the substitutions are conservative substitutions.

[0258] In some embodiments, an anti-Her3 antibody or its antigen-binding fragment is selected from antibody 202-2-1.

[0259] In some embodiments of this disclosure, the targeting moiety is cetuximab. Cetuximab is an anti-EGFR monoclonal antibody whose amino acid sequence is known to those skilled in the art, and whose exemplary sequence can refer to an antibody represented by IMGT / mAb-DB ID151.

[0260] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] [ka] [ka] In the formula, Tb1 is an anti-B7H3 antibody or its antigen-binding fragment, for example, enobrituzumab, mirzotamab, omblutamab, antibody 1D1-01, antibody 2E3-02, preferably antibody 1D1-01 or antibody 2E3-02, and q is selected from any number between 0.1 and 16.0, preferably any number between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8. In some embodiments, the ligand-drug conjugate is selected from the following: [ka] In the formula, Tb2 is an anti-Trop-2 antibody or its antigen-binding fragment, for example, datopotamab, sacituzumab, preferably sacituzumab, and q is selected from any numerical value between 0.1 and 16.0, preferably any numerical value between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, more preferably, q is 2, 4, 6, or 8.

[0261] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] In the formula, Tb3 is an anti-Her2 antibody or its antigen-binding fragment, for example, ambenitamab, coplerotamab, disitamab, gancotamab, margetuximab, pertuzumab, timigutuzumab, zanidatamab, trastuzumab, and partuzumab, preferably trastuzumab and partuzumab, and q is selected from any number between 0.1 and 16.0, preferably any number between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8.

[0262] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] Tb4 is an anti-Her3 antibody or its antigen-binding fragment, for example, valecetamab, durigotuzumab, ergemzumab, istilazumab, lanretuzumab, patrizumab, celivanzumab, xenoctuzumab, antibody 202-2-1, an antibody having the heavy chain described in SEQ ID NO. 10 and the light chain described in SEQ ID NO. 14 disclosed in Chinese Patent No. 103189392B, an antibody represented by IMGT / mAb-DB ID:546, and antibody 202-2-1, preferably antibody 202-2-1, where q is selected from any number between 0.1 and 16.0, preferably any number between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8.

[0263] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] Tb5 is an anti-EGFR antibody or its antigen-binding fragment, for example, demvitamab, depatucizumab, futuximab, imatuzumab, lapritusimab, rosatucizumab, matuzumab, modotuzumab, nesitumumab, nimotuzumab, panitumumab, pimlutamab, cerculutamab, tomzotusimab, zaltumumab, cetuximab, preferably cetuximab, and q is selected from any number between 0.1 and 16.0, preferably any number between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8.

[0264] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] In the formula, Tb6 is an antibody that does not have tumor cell endocytosis activity, or an antibody that has binding activity to a non-endocytosis antigen (e.g., ALCAM / CD166), for example, an antibody of an IgG isotype that does not have a corresponding cell surface antigen in humans, an anti-CD166 antibody, preferably an anti-chicken lysozyme human IgG1 isotype antibody, and q is selected from any number between 0.1 and 16.0, preferably any number between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8.

[0265] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] In the formula, Tb7 is an antibody that has weak tumor cell endocytosis activity or does not have tumor cell endocytosis activity but has tumor cell surface antigen binding activity, and q is selected from any value between 0.1 and 16.0, preferably any value between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8.

[0266] In some embodiments, the antibody is an antibody that has activity to bind to the B7H3 antigen but does not have endocytosis activity, such as INV721 and I7-01 disclosed in International Publication No. 2021168379A1. More specifically, the anti-B7H3 antibody has VH as described in SEQ ID NO: 2 and VL as described in SEQ ID NO: 1 disclosed in International Publication No. 2021168379A1.

[0267] In some embodiments, the antibody is an antibody that has activity to bind to the GD-2 antigen but does not have endocytosis activity, such as INV721 and GD2-5 disclosed in International Publication No. 2021168379A1. More specifically, the anti-GD-2 antibody has VH as described in SEQ ID NO: 4 and VL as described in SEQ ID NO: 3 disclosed in International Publication No. 2021168379A1.

[0268] In some embodiments, the antibody is an antibody that has activity to bind to the HER3 antigen but does not have endocytosis activity, for example, the anti-HER3 antibody 21F06 described in Sequence ID No. 22 disclosed in U.S. Patent No. 10808032B2.

[0269] In some embodiments, the antibody is one that has activity to bind to the CD20 antigen but lacks endocytotic activity. While it has been shown that "type II" CD20-specific antibodies are difficult to internalize by CD20-positive target cells, other so-called "type I" CD20-specific antibodies have been found to be internalized and, to some extent, degraded depending on the activation and inhibition of FcγR expression levels in the target cells with which they interact. In some embodiments, antibodies that have activity to bind to the antigen CD20 but lack endocytotic activity are "type II" CD20-specific antibodies such as obinutuzumab.

[0270] In some embodiments, the antibody is an antibody having activity to bind to a non-endocytosis antigen (e.g., ALCAM / CD166). In some embodiments, the antibody is an antibody comprising VH as described in SEQ ID NO: 73 and VL as described in SEQ ID NO: 74, VH as described in SEQ ID NO: 75 and VL as described in SEQ ID NO: 76, VH as described in SEQ ID NO: 77 and VL as described in SEQ ID NO: 78, or VH as described in SEQ ID NO: 79 and VL as described in SEQ ID NO: 88, as described in European Patent No. 3911682A1.

[0271] In some embodiments, the ligand-drug conjugate is selected from the following: [ka] In the formula, Tb8 is an antibody having tumor cell endocytosis activity and tumor cell surface antigen binding activity, for example, antibody 1D1-01, antibody 2E3-02, sacituzumab, pertuzumab, trastuzumab, or cetuximab antibody, and q is selected from any number between 0.1 and 16.0, preferably any number between 2 and 8. In some embodiments, q is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some preferred embodiments, q is 2, 4, 6, or 8.

[0272] In addition, it should be noted that L is bonded to a sulfhydryl group contained in Tb (e.g., an antibody) after the disulfide bond is cleaved, which can be understood by those skilled in the art (for example, reduction of a disulfide bond with the reducing agent TCEP can cleave the disulfide bond and produce sulfhydryl-SH), that is, the -S- between L and Tb is not an additional foreign sulfur atom. For example, in the formula, -S- is not an additional foreign sulfur atom, but is formed by linking the sulfhydryl group contained in Tb after the disulfide bond to L is opened.

[0273] In a second aspect of this disclosure, this disclosure relates to a compound of formula II: [ka] Alternatively, the present invention provides stereoisomers of the compound, its prodrugs, its pharmaceutically acceptable salts, its pharmaceutically acceptable solvates, or its drug linker conjugates. During the ceremony, R1 and R2 are independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl, and optionally substituted C1-6 alkoxy, or R1 and R2, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups, or any combination thereof. R3 is selected from H, halogen, -OH, -NH2, optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or R3 and X, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups or any combination thereof. R3 and R2, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups, or any combination thereof. W is either nonexistent or exists, and if W exists, W is -O-, -S-, -NHR4-, [ka] Selected from, the 1st place is combined with X, X is a directly bonded, optionally substituted -O-(CH2) n3 -, -NR4-(CH2) n3 -, -S-(CH2) n3 -, carbonyl-(CH2) n3 -, -SO2-(CH2) n3 -,-(CH2) n1 -, [ka] Selected from C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl, and 4-10 membered heterocyclyl, the 1st position is bonded to the parent ring, the 2nd position is bonded to W, and the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups that together with the carbon atoms to which they are both bonded form a C3-6 cycloalkyl group. Each M is independently directly bonded and -CR 5a R 5b - Selected from, R4, R5, R 5a , R 5b , R6, R7 Each of these is independently selected from H, optionally substituted C1-4 alkyl groups, optionally substituted C1-4 alkoxy groups, and optionally substituted C3-6 cycloalkyl groups. n, n', n1, n2, and n3 are each independently selected from any integer between 0 and 6. Both R1 and R2 are H, and X is -(CH2) n1 -If n1 is 1, 2, 3, and 4, then W is not -OH or -NHR4, and the compound of formula II is [ka] It does not include.

[0274] In some embodiments, R1 and R2 are each independently selected from H, halogens, or C1-4 alkyl groups.

[0275] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, form a 5-6 membered heterocycle containing 1, 2, or 3 O, S, or N atoms, or any combination thereof.

[0276] In some embodiments, R1 is selected from H and halogens, and R2 is selected from H and C1-4 alkyl groups.

[0277] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] The formula forms a heterocycle, and in the formula, the dotted line indicates the location where the heterocycle is fused to the benzene ring.

[0278] In some embodiments, R1 is H or F, and R2 is H or methyl.

[0279] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] It forms.

[0280] In some embodiments, R1 is F and R2 is methyl, or R1 and R2 together with the carbon atoms to which they are bonded, [ka] It forms.

[0281] In some embodiments, R1 is F and R2 is methyl.

[0282] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] It forms.

[0283] In some embodiments, R3 is selected from H and C1-4 alkyl groups.

[0284] In some embodiments, R3 is H.

[0285] In some embodiments, W is absent or present, and if W is present, W is -OH, -SH, -NHR4, [ka] Selected from the options, the top choice is joined to X.

[0286] In some embodiments, W is absent or present, and if W is present, W is -OH, -SH, -NHR4, [ka] Selected from the options, the top choice is joined to X.

[0287] In some embodiments, W is -OH, -NHR4 and [ka] Selected from the options, the top choice is joined to X.

[0288] In some embodiments, W is selected from -OH and -NHR4, and the 1-position is bonded to X.

[0289] In some embodiments, X is optionally replaced by -(CH2) n1 -, [ka] The substituents are selected from C6-10 aryls, 5-10 membered heteroaryls, and 4-10 membered heterocyclines, with the 1st position bonded to the parent ring and the 2nd position bonded to W, and the substituents are selected from one or two C1-4 alkyl groups, or two C1-4 alkyl groups that together with the carbon atoms to which they are both bonded to form a C3-6 cycloalkyl group.

[0290] In some embodiments, X is optionally replaced [ka] A substituent is selected from the following, with the 1st position bonded to the parent ring and the 2nd position bonded to W, and the substituent is selected from one or two C1-4 alkyl groups (e.g., methyl), or two C1-4 alkyl groups (e.g., methyl) together with the carbon atoms to which they are both bonded to form a C3-6 cycloalkyl group (e.g., cyclopropyl).

[0291] In some embodiments, X is [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0292] In some embodiments, X is [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0293] In some embodiments, if W is absent, X is [ka] Selected from, the 1st is joined to the parent ring, and if W exists, X is, [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0294] In some embodiments, W is -OH, -NHR4 and [ka] Selected from, the 1st place joins X, the 2nd place joins L4 or L3, and X is, [ka] The group is selected from the group, with the 1st position bonded to the parent ring and the 2nd position bonded to W. In some embodiments, R4 and R5 are each independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl groups.

[0295] In some embodiments, each R4 is independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl, and R5 is H.

[0296] In some embodiments, each R4 is independently selected from H, methyl, ethyl, isopropyl, n-propyl, t-butyl, and cyclopropyl, and R5 is H.

[0297] In some embodiments, R 5a and R5b Each is independently selected from H and C1-4 alkyl groups. In some embodiments, R 5a and R 5b Each is independently selected from H and methyl, In some embodiments, each R 7 These are independently selected from H and C1-4 alkyl groups. In some embodiments, R 7 H is H.

[0298] In some embodiments, n is 1, 2, or 3.

[0299] In some embodiments, n is 1.

[0300] In some embodiments, n1 is 1, 2, 3, or 4.

[0301] In some embodiments, n2 is 1, In some embodiments, n3 is 0.

[0302] In some embodiments, the compound represented by formula II is the following compound: [ka] [ka] [ka] One of the following will be selected. In a third aspect of this disclosure, this disclosure relates to a drug linker conjugate of formula III. [ka] Alternatively, the present invention provides stereoisomers of the drug linker conjugate, prodrugs thereof, pharmaceutically acceptable salts thereof, or pharmaceutically acceptable solvates thereof. During the ceremony, R1 and R2 are independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl, and optionally substituted C1-6 alkoxy, or R1 and R2, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups, or any combination thereof. R3 is selected from H, halogen, -OH, -NH2, optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or R3 and X, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups or any combination thereof, or R3 and R2, together with the carbon atoms to which they are bonded, form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring containing one or more O, S, N, carbonyl, sulfoxide, or sulfone groups, or any combination thereof. W is either nonexistent or exists, and if W exists, W is -O-, -S-, -NR4-, [ka] Selected from, the 1st place joins to X, the 2nd place joins to L4 or L3, X is a directly bonded, optionally substituted -O-(CH2) n3 -, -N(R4)-(CH2) n3 -, -S-(CH2) n3 -, carbonyl-(CH2) n3 -SO2-(CH2) n3 -, [ka] -(CH2) n1- Selected from C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclyl, the 1st position is bonded to the parent ring, the 2nd position is bonded to W or L4, and the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups that together with the carbon atoms to which they are both bonded form a C3-6 cycloalkyl group. Each M is independently directly bonded and -CR 5a R 5b - Selected from, R4, R5, R 5a , R 5b R6 and R7 are independently selected from H, optionally substituted C1-4 alkyl groups, optionally substituted C1-4 alkoxy groups, and optionally substituted C3-6 cycloalkyl groups. n, n', n1, n2, and n3 are each independently selected from any integer between 0 and 6. L1 is [ka] [ka] Selected from, In the formula, each Z is independently selected from direct bonds, carbon-carbon triple bonds, carbon-carbon double bonds, C6-10 aryls, 5-10 member heteroaryls, amides, sulfonamides, iminos, and CF2; Rx and Ry are independently selected from H and C1-4 alkyls; each m is independently selected from 0, 1, 2, 3, 4, 5, and 6; y1, y2, y3, and y4 are independently selected from any integer from 0 to 20; the 1st position is bonded to Lg, and the 2nd position is bonded to L2 or L3. L2 either does not exist or exists, and if L2 exists, L2 is [ka] [ka] Selected from, In the formula, y1, y2, y3, and y4 are each independently selected from any integer between 0 and 20, with the ones-digit being combined with L1 and the two-digit being combined with L3. L3 is selected from amino acid residues or short peptides consisting of 2 to 10 amino acid residues. L4 either does not exist or exists, and if L4 exists, L4 is [ka] Selected from, the 1st place joins L3, the 2nd place joins W or X, Lg is a leaving group, and Lg is a halogen, sulfone group, or tertiary amine salt group (Me3N + , Et3N + ), selected from the diazonium salt groups -OMs, MeSO2-, and CF3SO3-.

[0303] In some embodiments, R1 and R2 are each independently selected from H, halogens, and C1-4 alkyl groups.

[0304] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, form a 5-6 membered heterocycle containing 1, 2, or 3 O, S, or N atoms, or any combination thereof.

[0305] In some embodiments, R1 is selected from H and halogens, and R2 is selected from H and C1-4 alkyl groups.

[0306] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] The formula forms a heterocycle, and in the formula, the dotted line indicates the location where the heterocycle is fused to the benzene ring.

[0307] In some embodiments, R1 is H or F, and R2 is H or methyl.

[0308] In some embodiments, R1 is F and R2 is methyl, or R1 and R2 together with the carbon atoms to which they are bonded, [ka] It forms.

[0309] In some embodiments, R1 is F and R2 is methyl.

[0310] In some embodiments, R1 and R2, together with the carbon atoms to which they are bonded, [ka] It forms.

[0311] In some embodiments, R3 is selected from H, C1-4 alkyl groups.

[0312] In some embodiments, R3 and X, together with the carbon atoms to which they are bonded, form a 5-6 membered carbocyclic ring.

[0313] In some embodiments, R3 is H, or R3 and X together are carbon atoms to which they are bonded. [ka] The formula forms a structure where the dotted lines indicate the locations where the carbocyclic ring is condensed with the benzene ring and the pyridine ring.

[0314] [In some embodiments, R3 is H.

[0315] In some embodiments, R3 and X, together with the carbon atoms to which they are bonded, [ka] The formula forms a structure where the dotted lines indicate the locations where the carbocyclic ring is condensed with the benzene ring and the pyridine ring.

[0316] In some embodiments, W is either absent or present, and if W is present, W is -O-, -S-, -NR4-, [ka] The first choice is selected, and it is joined to X, and the second choice is joined to L4 or L3.

[0317] In some embodiments, W is either absent or present, and if W is present, W is -O-, -S-, -NR4-, [ka] The first choice is selected, and it is joined to X, and the second choice is joined to L4 or L3.

[0318] In some embodiments, W is -O-, -NR4-, [ka] The first choice is selected, and it is joined to X, and the second choice is joined to L4 or L3.

[0319] In some embodiments, W is selected from -O- and -NR4-, with the first position bonded to X and the second position bonded to L4 or L3.

[0320] In some embodiments, X is optionally replaced by -(CH2) n1 -, [ka] Selected from C6-10 aryls, 5-10 membered heteroaryls, and 4-10 membered heterocyclines, the 1st position is bonded to the parent ring, the 2nd position is bonded to W or L4, and the substituent is selected from one or two C1-4 alkyl groups, or two C1-4 alkyl groups that together with the carbon atoms to which they are both bonded form a C3-6 cycloalkyl group.

[0321] In some embodiments, X is optionally replaced [ka] The substituent is selected from the following, with the 1st position bonded to the parent ring and the 2nd position bonded to W or L4. The substituent is selected from one or two C1-4 alkyl groups (e.g., methyl), or two C1-4 alkyl groups, together with the carbon atoms to which they are both bonded, form a C3-6 cycloalkyl group (e.g., cyclopropyl).

[0322] In some embodiments, X is [ka] Selected from the options, the first-ranked element is bound to the parent ring, and the second-ranked element is bound to W or L4.

[0323] In some embodiments, X is [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0324] In some embodiments, if W is absent, X is [ka] Selected from, the 1st place joins the parent ring, the 2nd place joins L4, and if W exists, X is, [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0325] In some embodiments, W is -O-, -NR4-, [ka] Selected from, the 1st place joins X, the 2nd place joins L4 or L3, and X is, [ka] The first choice is selected, and the first choice joins the parent ring, while the second choice joins W.

[0326] In some embodiments, R4 and R5 are each independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl.

[0327] In some embodiments, each R4 is independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl, and R5 is H.

[0328] In some embodiments, each R4 is independently selected from H, methyl, ethyl, n-propyl, isopropyl, t-butyl, and cyclopropyl, and R5 is H.

[0329] In some embodiments, R 5a , R 5b Each of these is independently selected from H and C1-4 alkyl groups.

[0330] In some embodiments, R 5a , R 5b Each of these is independently selected from H and methyl.

[0331] In some embodiments, each R 7 These are independently selected from H and C1-4 alkyl groups.

[0332] In some embodiments, R 7 H is H.

[0333] In some embodiments, n is selected from 1, 2, or 3.

[0334] In some embodiments, n is 1.

[0335] In some embodiments, n1 is selected from 1, 2, 3, or 4.

[0336] In some embodiments, n2 is 1.

[0337] In some embodiments, n3 is 0.

[0338] In some embodiments, L1 is [ka] The formula is selected from, where each Z is independently selected from direct bonds, carbon-carbon triple bonds, carbon-carbon double bonds, C6-10 aryls, 5-10 member heteroaryls, and amides (each Z is preferably selected from direct bonds, carbon-carbon triple bonds, and carbon-carbon double bonds), Rx and Ry are independently selected from H and C1-4 alkyls, each m is independently selected from 0, 1, 2, 3, 4, 5, and 6, y1 is selected from any integer from 1 to 6 (e.g., 4, 5, 6), each y2 is independently selected from any integer from 0 to 15 (e.g., 6 to 15), each y3 is independently selected from 1, 2, or 3, and each y4 is independently selected from 0 or Each Z is selected from 1, with the 1st position bonded to Lg and the 2nd position bonded to L2 or L3. For example, each Z is independently selected from a direct bond, a carbon-carbon triple bond, or a carbon-carbon double bond; Rx and Ry are independently selected from H and C1-4 alkyl groups, respectively; each m is independently selected from 0, 1, 2, 3, 4, 5, and 6; y1 is selected from any integer from 1 to 6 (e.g., 4, 5, 6); each y2 is independently selected from any integer from 0 to 15 (e.g., 6 to 15); each y3 is independently selected from 1, 2, or 3; each y4 is independently selected from 0 or 1, with the 1st position bonded to Lg via an S atom and the 2nd position bonded to L2 or L3.

[0339] In some embodiments, L1 is [ka] The values ​​are selected from the following, where m is selected from 2, 3, and 4; y1 is selected from any integer between 1 and 6 (e.g., 4, 5, 6); each y2 is independently selected from any integer between 0 and 10 (e.g., 6 to 10); and each y3 is independently selected from 1 or 2, with the first digit joined to Lg and the second digit joined to L2 or L3.

[0340] In some embodiments, L1 is [ka] The first choice is selected, and the first choice is bound to Lg, and the second choice is bound to L2 or L3.

[0341] In some embodiments, L1 is [ka] The first choice is selected, and the first choice is bound to Lg, and the second choice is bound to L2 or L3.

[0342] In some embodiments, L1 is [ka] The first choice is selected, and the first choice is bound to Lg, and the second choice is bound to L2 or L3.

[0343] In some embodiments, L1 is [ka] The first choice is selected, and the first choice is bound to Lg, and the second choice is bound to L2 or L3.

[0344] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The values ​​are selected from the following, where y1 is selected from any integer between 1 and 6 (e.g., 4, 5, 6), each y2 is independently selected from any integer between 0 and 10 (e.g., 6 to 10), each y3 is independently selected from 1 or 2, and each y4 is independently selected from 0 or 1, with the first digit being joined to L1 and the second digit to L3.

[0345] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The first-ranked element is selected, and it is joined to L1, while the second-ranked element is joined to L3.

[0346] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The first-ranked element is selected, and it is joined to L1, while the second-ranked element is joined to L3.

[0347] In some embodiments, L2 is either absent or present, and if L2 is present, L2 is [ka] The first-ranked element is selected, and it is joined to L1, while the second-ranked element is joined to L3.

[0348] In some embodiments, L2 is absent.

[0349] In some embodiments, L2 is [ka] Selected from.

[0350] In some embodiments, L3 is selected from an amino acid residue or a short peptide consisting of 2 to 10 amino acid residues, and the amino acid residues are selected from native amino acid residues, non-native amino acid residues, or AA 1 An amino acid residue represented by or its stereoisomer is selected.

[0351] In some embodiments, L3 is an amino acid residue Val, D-Val, Cit, Phe, Lys, Lys(Ac), Leu, Gly, Ala, Asn, Asp, Arg, and AA 1 , or Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, Asp, and AA 1 Selected from short peptides consisting of 2 to 10 amino acid residues, In some embodiments, L3 is Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, AA 1 , Val-Cit, Cit-Val, Cit-Ala, Val-Ala, Lys-Val, Val-Lys(Ac), Phe-Lys, Phe-Lys(Ac), Ala-Ala, Val-AA 1 , Ala-AA 1 Gly-AA 1 AA 1 -Gly, Ala-Ala-Ala, Ala-Ala-Asn, Ala-Ala-Asp, Val-AA 1 -Gly, Ala-AA 1 -Gly, Gly-AA 1 -Selected from Gly, Lys-Ala-Ala-Asn, Lys-Ala-Ala-Asp, Gly-Phe-Gly, Gly-Gly-Phe-Gly, D-Val-Leu-Lys, Gly-Gly-Arg, Ala-Ala-Asn, Gly-Gly-Phe, Val-Lys-Gly, Val-Lys-Gly-Gly, Val-Lys, and Lys-Ala-Asn.

[0352] In some embodiments, L3 is AA 1 AA 1 -Gly, Val-Cit, Val-AA 1 -Gly AA 1 -Selected from Ala-Asn and Gly-Gly-Phe-Gly.

[0353] In some embodiments, L3 is AA 1 Val-AA 1 - Selected from Gly.

[0354] In some embodiments, L3 is Val-AA 1 - Selected from Gly.

[0355] In some embodiments, L3 is [ka] [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0356] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0357] In some embodiments, L3 is [ka] Selected from, in the formula, X - These include halide ions, carboxylate ions, sulfate ions, bisulfate ions, and OH - The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0358] In some embodiments, L3 is [ka] The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0359] In some embodiments, L3 is [ka] The first choice is selected, and the first choice is bound to L1 or L2, and the second choice is bound to L4 or W.

[0360] In some embodiments, AA 1 The structure of the amino acid residue represented by is as follows: [ka] During the ceremony, R a and R b Each of them is independent of H, [ka] Selected from, R a and R b Is it possible that both of them are H? Or, R a and R b These, together with the carbon atoms to which they are bonded, form a 4-10 membered heterocycle, and this 4-10 membered heterocycle has one or more R 0 Replaced by optional selection, r, r 1 Each of these is independently selected from any integer between 0 and 20. R m1 , R n1 These are, independently, H, C1-6 alkyl, C3-6 cycloalkyl, and -COOR. x1 Selected from, R x1 The C1-6 alkyl group is selected from, Or, R m1 and R n1 These, together with the nitrogen atoms to which they are bonded, form a 4-10 membered heterocycle, and this 4-10 membered heterocycle has one or more R 0’ Replaced by optional selection, R z It is selected from C1-6 alkyl groups. R 0 , R 0’ These are, independently, C1-6 alkyl, C3-6 cycloalkyl, and -NR. m2 R n2 and selected from 4-10 membered heterocyclines optionally substituted with C1-6 alkyl groups, R m2 , Rn2 Each is independently selected from H and C1-6 alkyl groups. In some embodiments, R a and R b One of them is H, and the other is, [ka] Selected from.

[0361] In some embodiments, R a and R b One of them is H, and the other is, [ka] Selected from.

[0362] In some embodiments, R a and R b Together with the carbon atoms to which they are both bonded, R 0 It forms a 5-6 member heterocycle with substitutions.

[0363] In some embodiments, R a and R b Together with the carbon atom to which both of them are bonded, R 0 It forms a piperidine ring or piperazine ring substituted with [the specified compound].

[0364] In some embodiments, R a and R b Together with the carbon atoms to which they are both bonded, R 0 It forms a piperidine ring substituted by...

[0365] In some embodiments, R a and R b They, together with the carbon atoms to which they are bonded, [ka] It forms, and the carbon atom numbered 1 is Ra and R b It is a carbon atom to which both are bonded.

[0366] In some embodiments, R a and R b They, together with the carbon atoms to which they are bonded, [ka] It forms, and the carbon atom numbered 1 is R a and R b It is a carbon atom to which both are bonded.

[0367] In some embodiments, r and r 1 Each of these is independently selected from 0, 1, 2, 3, 4, and 5.

[0368] In some embodiments, r and r 1 Each of these is independently selected from 0 and 4.

[0369] In some embodiments, r and r 1 One of them is 0, and the other is 4.

[0370] In some embodiments, R m1 and R n1 Each of these is independently selected from H, methyl, ethyl, n-propyl, n-butyl, -COOCH3, -COOCH2CH3, -COOCH2CH2CH3, -COOCH(CH3)2, -COOC(CH3)3, and -COOCH2CH2CH2CH3.

[0371] In some embodiments, R m1 and R n1 Each of these is independently selected from H, C1-6 alkyl, C3-6 cycloalkyl, and t-butoxycarbonyl.

[0372] In some embodiments, R m1 and R n1Each of these is independently selected from H and C1-6 alkyl groups.

[0373] In some embodiments, R m1 and R n1 Each of these is independently selected from H, methyl, ethyl, and n-propyl.

[0374] In some embodiments, r and r 1 Regarding this, if r is 4, 1 is 0, and R m1 and R n1 Each is independently selected from H and C1-6 alkyl (e.g., H, methyl), and r is 0, r 1 If R is 4, m1 and R n1 Each of these is independently selected from C1-6 alkyl groups (e.g., methyl, ethyl, n-propyl), preferably C2-6 alkyl groups (e.g., ethyl, n-propyl).

[0375] In some embodiments, R m1 and R n1 Together with the nitrogen atom to which they are both bonded, R 0’ It forms a 5-6 membered heterocycle with substitutions.

[0376] In some embodiments, R m1 and R n1 Together with the nitrogen atom to which they are both bonded, R 0’ It forms a piperidine ring or piperazine ring substituted with [the specified compound].

[0377] In some embodiments, R m1 and R n1 They, together with the nitrogen atom to which they are bonded, [ka] It forms, and the nitrogen atom numbered 1 is R m1 and R n1 It is a nitrogen atom to which both are bonded.

[0378] In some embodiments, R z It is methyl. In some embodiments, R 0 and R 0’ Each of these is independently C1-6 alkyl, -NR m2 R n2 The selection is made from 5-6 member heterocyclines optionally substituted with C1-6 alkyl groups.

[0379] In some embodiments, R 0 The C1-6 alkyl group is selected from C1-6 alkyl groups and C1-6 alkyl-substituted 5-6 membered heterocyclines, and the 5-6 membered heterocycline is selected from piperidinyl and piperazinyl.

[0380] In some embodiments, R 0 It is selected from methyl, ethyl, and methyl-substituted 5-6 membered heterocyclines, the 5-6 membered heterocycline being piperidinyl.

[0381] In some embodiments, R 0 It is selected from methyl and methyl-substituted 5-6 membered heterocyclines, the 5-6 membered heterocycline being piperidinyl.

[0382] In some embodiments, R 0 methyl, ethyl and [ka] Selected from.

[0383] In some embodiments, R 0 methyl and [ka] Selected from.

[0384] In some embodiments, R 0’These are C1-6 alkyl and -NR m2 R n2 Selected from.

[0385] In some embodiments, R 0’ methyl and -NR m2 R n2 Selected from.

[0386] In some embodiments, R m2 and R n2 It is methyl.

[0387] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0388] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0389] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0390] In some embodiments, AA 1 The amino acid residues represented by are [ka] Selected from.

[0391] In some embodiments, L4 is either absent or present, and if L4 is present, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0392] In some embodiments, L4 is either absent or present, and if L4 is present, L4 is [ka] The first position is bound to L3, and the second position is bound to W or X.

[0393] In some embodiments, L4 is absent.

[0394] In some embodiments, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0395] In some embodiments, L4 is [ka] The first choice is selected, and it is joined to L3, and the second choice is joined to W or X.

[0396] In some embodiments, Lg is selected from F, Cl, and MeSO2-.

[0397] In some embodiments, Lg is selected from F and MeSO2-.

[0398] In some embodiments, [ka] The structure is selected from the following: [Table 4-1] [Table 4-2] [Table 4-3] The first one is bound to Lg, and the second one is bound to W.

[0399] In some embodiments, the structure [ka] The following can be selected: [ka] [ka] [ka] In the formula, the 1st position is joined to L4, and if L4 does not exist, the 1st position is joined to L3.

[0400] In some embodiments, the drug linker conjugate has the structure of formula III-(1): [ka] It has, In the formula, L1, L2, L3, L4, X, R1, R2, R3, R4, and Lg are as defined above and in any embodiment specifically described herein.

[0401] In some embodiments, the drug linker conjugate has the structure of formula III-(1A) or III-(1B): [ka] It has, In the formula, L2, L3, L4, X, R1, R2, R3, R4, and Lg are as defined above and in any embodiment specifically described herein.

[0402] In some embodiments, the drug linker conjugate has the structure of formula III-(2): [ka] It has, In the formula, L1, L2, L3, L4, X, R1, R2, R3, and Lg are as defined in any embodiment specifically described above and herein.

[0403] In some embodiments, the drug linker conjugate has the structure of formula III-(2A) or III-(2B): [ka] It has, In the formula, L2, L3, L4, X, R1, R2, R3, and Lg are as defined above and in any embodiment specifically described herein.

[0404] In some embodiments, the drug linker conjugate has the structure of formula III-(3): [ka] It has, In the formula, L1, L2, L3, L4, X, R1, R2, R3, R4, R5, n, and Lg are as defined above and in any embodiment specifically described herein.

[0405] In some embodiments, the drug linker conjugate has the structure of formula III-(3A) or III-(3B): [ka] It has, In the formula, Lg, L2, L3, L4, X, R1, R2, R3, R4, and Lg are as defined above and in any embodiment specifically described herein.

[0406] In some embodiments, the drug linker conjugate has the structure of formula III-A: [ka] It has, In the formula, Lg, X, R1, R2, R3, R a , R b And q are as defined above and in any embodiment specifically described herein.

[0407] In some embodiments, the drug linker conjugate has the structure of formula III-B: [ka] It has, In the formula, Lg, X, R1, R2, R3, R a , R b And q are as defined above and in any embodiment specifically described herein.

[0408] In some embodiments, the drug linker conjugate represented by formula III is selected from the following structures. [Table 5-1] [Table 5-2] [Table 5-3] [Table 5-4] [Table 5-5] [Table 5-6] [Table 5-7] [Table 5-8] [Table 5-9] [Table 5-10] [Table 5-11] [Table 5-12] [Table 5-13] [Table 5-14] [Table 5-15] [Table 5-16] [Table 5-17] [Table 5-18] [Table 5-19] [Table 5-20] [Table 5-21] [Table 5-22]

[0409] In some embodiments, compounds are provided in which the L1-L2-L3 unit in the drug linker conjugate of formula III is partially cleaved, and thus a drug moiety to which an amino acid residue is bound remains.

[0410] In some embodiments, the partially released free drug is a compound of formula III-(A): [ka] or its stereoisomers or mixtures thereof, or pharmaceutically acceptable salts thereof, wherein L4, X, W, R1, R2, and R3 are as defined above and in any embodiment specifically described herein.

[0411] In some embodiments, the structure: [ka] III-(A) is selected from the following: [ka] [ka] [ka] [ka] [ka] This disclosure also provides a linker in a ligand-drug conjugate comprising the following fragments: [ka] The 2nd position binds to the bioactive molecular fragment (the 1st position binds to the ligand end, for example, if it binds to a linking unit (e.g., L2) and then to the ligand or targeting portion (Tb) via an extension unit (e.g., L1), or if no linking unit is present, the 1st position binds directly to the extension unit and then to the ligand), L3 and L4 are defined as in any one of the embodiments of this disclosure.

[0412] In some embodiments, the linker in the ligand-drug conjugate has the following structure: [ka] The first position binds to the ligand or targeting moiety that binds to the target, and the second position binds to the bioactive molecular fragment. L1, L2, L3, and L4 are defined as in any one of the embodiments of this disclosure, Preferably, the ligand or targeting moiety and the bioactive molecular fragment that bind to the target are defined for Tb and D in any one embodiment of the present disclosure.

[0413] In some embodiments, the linker is bound to an antibody or its antigen-binding fragment at position 1, and to a biologically active molecular fragment at position 2.

[0414] In some embodiments, the linker is bound to cysteine ​​or lysine in the antibody or its antigen-binding fragment, and to a biologically active molecular fragment at position 1, Preferably, the antibody or its antigen-binding fragment is one of those described in any embodiment of the present disclosure.

[0415] In a fourth aspect of this disclosure, the disclosure also provides a linker represented by formula III-1, [ka] Lg, L1, L2, L3, and L4 are defined in the above and any embodiments specifically described herein, where Lg1 is a leaving group in the reaction with the drug molecule.

[0416] In some embodiments, Lg1 is preferably -OH, [ka] Or it is halogen.

[0417] In a fifth aspect of this disclosure, the present invention also provides a linker represented by formula III-2, [ka] Lg, L1, L2, and L3 are defined above and in any embodiment specifically described herein, where Lg2 is a leaving group in reaction with L4 or a fragment containing a drug molecule.

[0418] In some embodiments, Lg2 is preferably -OH, [ka] Or it is halogen.

[0419] In a sixth aspect of this disclosure, the disclosure provides methods for preparing compounds of formula II (drug molecules, bioactive molecules) and drug linker conjugates of formula III.

[0420] In one embodiment, this disclosure provides a method for preparing a compound of formula II (a pharmaceutical molecule, a bioactive molecule). Specifically, this method is as follows: Compound (VI) is obtained by an alkylation reaction of compound (IV) and compound (V) catalyzed by an iron compound, or by other related Minisci reactions. [ka]

[0421] Alternatively, compound (VII) can be synthesized by the N-oxidation reaction of compound (IV), and then compound (VIII), a halogen of compound (IV), can be obtained by treating compound (VII) with phosphorus oxyhalogenate. Compound (VI) can then be obtained from compound (VIII) by various reactions such as the Heck reaction, Suzuki reaction, Buchwald reaction, Nigishi reaction, and Stille reaction. [ka]

[0422] Different or more complex molecules are R in compound (VI). 11 It can be synthesized by various chemical transformations, such as oxidation, reduction, substitution, and other methods commonly found in textbooks.

[0423] Alternatively, compounds (VI) and (IV) can be produced from compounds (IX) and (X) by a ring-closing reaction, as shown below. [ka]

[0424] In another embodiment, the present disclosure provides a method for preparing fragments represented by formulas III-1 and III-2. In particular, Compound III-c was obtained by the reaction of functional group Fg1 in compound III-a and functional group Fg2 in compound III-b, and then compound III-d was obtained by the reaction of functional group Fg in compound III-c a It can be synthesized by the reaction. Compounds III-2 and III-1, represented by the general formula, can be obtained by similar transformations. Lg a , Lg b Lg1 and Lg2 are, for example, -OH, [ka] Alternatively, it may be a reactive leaving group such as a halogen. [ka]

[0425] In yet another embodiment, the present disclosure provides a method for preparing a drug linker conjugate of formula III. In particular, The target product can be obtained by coupling fragment B and fragment C, as shown in the reaction scheme below. The conjugate product is subjected to several common chemical modifications, such as oxidation and deprotection, to obtain a drug linker conjugate represented by general formula III.

[0426] [ka]

[0427] In a seventh aspect of this disclosure, the disclosure provides a method for preparing the aforementioned ligand-drug conjugate, including: Tb is obtained in a suitable solvent and under suitable conditions, formula III [ka] Coupled to a drug linker conjugate represented by, During the ceremony, Tb is defined as in the above and any embodiment specifically described herein, R1, R2, R3, X, W, L1, L2, L3, L4, and Lg are defined in any embodiment described above and specifically herein.

[0428] In some embodiments, this method involves mixing Tb and formula III in a suitable solvent and under suitable conditions. [ka] The process includes the step of performing a coupling reaction between the drug linker conjugate and the drug linker conjugate to form a CS bond.

[0429] In some embodiments, the ratio of Tb in molar amount to the drug linker conjugate is 1:(1-20), for example, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:12, 1:14, 1:16, 1:18, 1:(10-20), 1:(12-20), 1:(14-20), 1:(16-20), or 1:(18-20).

[0430] In some embodiments, the coupling reaction is carried out in water and / or an organic solvent.

[0431] In some embodiments, the organic solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, nitriles (e.g., acetonitrile), alcohols (e.g., methanol, ethanol), or any combination thereof.

[0432] In some embodiments, the process further includes a step of purifying the coupling product.

[0433] In some embodiments, the coupling product is purified by chromatography.

[0434] In some embodiments, the chromatography includes one or more of ion exchange chromatography, hydrophobic chromatography, reversed-phase chromatography, or affinity chromatography.

[0435] In an eighth aspect of this disclosure, the disclosure provides an antibody or antigen-binding fragment thereof that binds to B7H3, the antibody or antigen-binding fragment comprising a complementation-determining region (CDR) such as the following: Variants of HCDR1 or its sequence, HCDR2 or its sequence, and HCDR3 or its sequence included in the heavy chain variable region (VH) described in Sequence ID No. 3 or 23, and / or Variants of LCDR1 or its sequence, LCDR2 or its sequence, and LCDR3 or its sequence included in the light chain variable region (VL) described in SEQ ID NO: 13 or 33.

[0436] In certain embodiments, the antibody or its antigen-binding fragment includes variants of HCDR1 or its sequence, HCDR2 or its sequence, and HCDR3 or its sequence, as contained in VH described in SEQ ID NO: 3, and / or variants of LCDR1 or its sequence, LCDR2 or its sequence, and LCDR3 or its sequence, as contained in VL described in SEQ ID NO: 13.

[0437] In certain embodiments, the antibody or its antigen-binding fragment includes variants of HCDR1 or its sequence, HCDR2 or its sequence, and HCDR3 or its sequence, as contained in VH described in SEQ ID NO: 3, and / or variants of LCDR1 or its sequence, LCDR2 or its sequence, and LCDR3 or its sequence, as contained in VL described in SEQ ID NO: 33.

[0438] In certain embodiments, the antibody or its antigen-binding fragment includes variants of HCDR1 or its sequence, HCDR2 or its sequence, and HCDR3 or its sequence, as contained in VH described in SEQ ID NO: 23, and / or variants of LCDR1 or its sequence, LCDR2 or its sequence, and LCDR3 or its sequence, as contained in VL described in SEQ ID NO: 33.

[0439] In certain embodiments, the antibody or its antigen-binding fragment includes variants of HCDR1 or its sequence, HCDR2 or its sequence, and HCDR3 or its sequence, as contained in VH described in SEQ ID NO: 23, and / or variants of LCDR1 or its sequence, LCDR2 or its sequence, and LCDR3 or its sequence, as contained in VL described in SEQ ID NO: 13.

[0440] In a particular preferred embodiment, the variant of the sequence is a CDR having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to the CDR from which it is derived.

[0441] In a particular preferred embodiment, the substitution is a conservative substitution.

[0442] Preferably, the CDR is defined according to the AbM, Chothia, Kabat, or IMGT numbering system.

[0443] In a particular embodiment, the VH and / or VL of the antibody or its antigen-binding fragment comprises a framework region (FR) derived from human immunoglobulin.

[0444] In certain embodiments, the antibody or its antigen-binding fragment binds to human B7H3 and / or monkey B7H3. In certain embodiments, the antibody or its antigen-binding fragment binds to human 2Ig B7H3. In certain embodiments, the antibody or its antigen-binding fragment binds to human 4Ig B7H3. In certain embodiments, the antibody or its antigen-binding fragment binds to monkey 4Ig B7H3. In certain embodiments, the antibody or its antigen-binding fragment binds to human 2Ig B7H3 and human 4Ig B7H3, preferably human 4Ig B7H3. In certain embodiments, the antibody or its antigen-binding fragment binds to human 4Ig B7H3 but not to human 2Ig B7H3.

[0445] In one embodiment, the Disclosure provides an antibody or antigen-binding fragment thereof that can bind to B7H3, the antibody or antigen-binding fragment thereof comprising a heavy chain variable region (VH) and / or a light chain variable region (VL).

[0446] In certain embodiments, the antibody or antigen-binding fragment according to this disclosure comprises the following heavy chain variable region (VH) and / or light chain variable region (VL), where CDR is the IMGT numbering system: (a) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 10; HCDR2 consisting of the sequence of SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 11; HCDR3 consisting of the sequence of SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 12; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 20, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 20 (e.g., 1, 2, or 3 amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of the GTF, or a sequence having one or more amino acid substitutions, deletions, or additions compared to the GTF (e.g., 1, 2, or 3 amino acid substitutions, deletions, or additions); LCDR3 consisting of the sequence of SEQ ID NO: 22, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 22 (e.g., 1, 2, or 3 amino acid substitutions, deletions, or additions); (b) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 30, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 30; HCDR2 consisting of the sequence of SEQ ID NO: 31, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 31; HCDR3 consisting of the sequence of SEQ ID NO: 32, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 32; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 40, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 40 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of GAS, or a sequence having one or more amino acid substitutions, deletions, or additions compared to GAS (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 42, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 42 (e.g., one, two, or three amino acid substitutions, deletions, or additions), are included in the light chain variable region (VL). (c) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 10, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 10; HCDR2 consisting of the sequence of SEQ ID NO: 11, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 11; HCDR3 consisting of the sequence of SEQ ID NO: 12, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 12; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 40, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 40 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of GAS, or a sequence having one or more amino acid substitutions, deletions, or additions compared to GAS (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 42, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 42 (e.g., one, two, or three amino acid substitutions, deletions, or additions), are included in the light chain variable region (VL). or (d) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 30, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 30; HCDR2 consisting of the sequence of SEQ ID NO: 31, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 31; HCDR3 consisting of the sequence of SEQ ID NO: 32, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 32; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 20, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 20 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of the GTF, or a sequence having one or more amino acid substitutions, deletions, or additions compared to the GTF (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 22, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 22 (e.g., one, two, or three amino acid substitutions, deletions, or additions). It is defined according to the following.

[0447] In certain embodiments, the antibody or antigen-binding fragment according to this disclosure comprises the following heavy chain variable region (VH) and / or light chain variable region (VL), where CDR is the IMGT numbering system: (a) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 10, HCDR2 consisting of the sequence of SEQ ID NO: 11, HCDR3 consisting of the sequence of SEQ ID NO: 12, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 20, LCDR2 consisting of the sequence GTF, and LCDR3 consisting of the sequence of sequence number 22, are included in the light chain variable region (VL), (b) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 10, HCDR2 consisting of the sequence of SEQ ID NO: 11, HCDR3 consisting of the sequence of SEQ ID NO: 12, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 40, LCDR2 consisting of sequence GAS, and LCDR3 consisting of the sequence of sequence number 42, are included in the light chain variable region (VL), (c) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 30, HCDR2 consisting of the sequence of SEQ ID NO: 31, HCDR3 consisting of the sequence of SEQ ID NO: 32, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 40, LCDR2 consisting of sequence GAS, and LCDR3 consisting of the sequence of sequence number 42, are included in the light chain variable region (VL), or (d) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 30, HCDR2 consisting of the sequence of SEQ ID NO: 31, HCDR3 consisting of the sequence of SEQ ID NO: 32, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 20, LCDR2 consisting of the sequence GTF, and LCDR3 consisting of the sequence of sequence number 22, are included in the light chain variable region (VL). It is defined according to the following.

[0448] In certain embodiments, the antibody or antigen-binding fragment according to this disclosure comprises the following heavy chain variable region (VH) and / or light chain variable region (VL), where CDR is the Chothia numbering system: (a) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 4, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 4; HCDR2 consisting of the sequence of SEQ ID NO: 5, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 5; HCDR3 consisting of the sequence of SEQ ID NO: 6, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 6; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 14, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 14 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of SEQ ID NO: 15, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 15 (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 16, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 16 (e.g., one, two, or three amino acid substitutions, deletions, or additions), comprising a light chain variable region (VL), (b) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 4, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 4; HCDR2 consisting of the sequence of SEQ ID NO: 5, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 5; HCDR3 consisting of the sequence of SEQ ID NO: 6, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 6; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 34, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 34 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of SEQ ID NO: 35, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 35 (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 36, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 36 (e.g., one, two, or three amino acid substitutions, deletions, or additions), comprising a light chain variable region (VL), (c) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 24, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 24; HCDR2 consisting of the sequence of SEQ ID NO: 25, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 25; HCDR3 consisting of the sequence of SEQ ID NO: 26, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 26; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 34, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 34 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of SEQ ID NO: 35, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 35 (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 36, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 36 (e.g., one, two, or three amino acid substitutions, deletions, or additions), comprising a light chain variable region (VL), or (d) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 24, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 24; HCDR2 consisting of the sequence of SEQ ID NO: 25, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 25; HCDR3 consisting of the sequence of SEQ ID NO: 26, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 26; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 14, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 14 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of SEQ ID NO: 15, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 15 (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 16, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 16 (e.g., one, two, or three amino acid substitutions, deletions, or additions). It is defined according to the following. In certain embodiments, the antibody or antigen-binding fragment according to this disclosure comprises the following heavy chain variable region (VH) and / or light chain variable region (VL), where CDR is the Chothia numbering system: (a) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of sequence number 4, HCDR2 consisting of the sequence of sequence number 5, and HCDR3 consisting of the sequence of sequence number 6, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 14, LCDR2 consisting of the sequence of sequence number 15, and LCDR3 consisting of the sequence of sequence number 16, are included in the light chain variable region (VL), (b) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 24, HCDR2 consisting of the sequence of SEQ ID NO: 25, HCDR3 consisting of the sequence of SEQ ID NO: 26, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 34, LCDR2 consisting of the sequence of sequence number 35, and LCDR3 consisting of the sequence of sequence number 36, are included in the light chain variable region (VL), (c) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 4, HCDR2 consisting of the sequence of SEQ ID NO: 5, HCDR3 consisting of the sequence of SEQ ID NO: 6, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 34, LCDR2 consisting of the sequence of sequence number 35, and LCDR3 consisting of the sequence of sequence number 36, are included in the light chain variable region (VL), or (d) The following three CDRs: HCDR1 consisting of the sequence of sequence number 24, HCDR2 consisting of the sequence of sequence number 25, HCDR3 consisting of the sequence of sequence number 26, and / or a heavy chain variable region (VH) including these CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 14, LCDR2 consisting of the sequence of sequence number 15, and LCDR3 consisting of the sequence of sequence number 16, are included in the light chain variable region (VL). It is defined according to the following. In certain embodiments, the antibody or antigen-binding fragment according to this disclosure comprises the following heavy chain variable region (VH) and / or light chain variable region (VL), where CDR is the Kabat numbering system: (a) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 7, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 7; HCDR2 consisting of the sequence of SEQ ID NO: 8, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 8; HCDR3 consisting of the sequence of SEQ ID NO: 9, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 9; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 17, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 17 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of SEQ ID NO: 18, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 18 (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 19, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 19 (e.g., one, two, or three amino acid substitutions, deletions, or additions), comprising a light chain variable region (VL), (b) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 27, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 27; HCDR2 consisting of the sequence of SEQ ID NO: 28, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 28; HCDR3 consisting of the sequence of SEQ ID NO: 29, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 29; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 37, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 37; LCDR2 consisting of the sequence of SEQ ID NO: 38, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 38; and LCDR3 consisting of the sequence of SEQ ID NO: 39, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 39, comprising a light chain variable region (VL), (c) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 7, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 7; HCDR2 consisting of the sequence of SEQ ID NO: 8, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 8; HCDR3 consisting of the sequence of SEQ ID NO: 9, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 9; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 37, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 37; LCDR2 consisting of the sequence of SEQ ID NO: 38, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 38; and LCDR3 consisting of the sequence of SEQ ID NO: 39, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 39, comprising a light chain variable region (VL), or (d) A heavy chain variable region (VH) comprising the following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 27, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 27; HCDR2 consisting of the sequence of SEQ ID NO: 28, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 28; HCDR3 consisting of the sequence of SEQ ID NO: 29, or a sequence having one or more amino acid substitutions, deletions, or additions (e.g., one, two, or three amino acid substitutions, deletions, or additions) compared to SEQ ID NO: 29; and / or The following three CDRs: LCDR1 consisting of the sequence of SEQ ID NO: 17, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 17 (e.g., one, two, or three amino acid substitutions, deletions, or additions); LCDR2 consisting of the sequence of SEQ ID NO: 18, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 18 (e.g., one, two, or three amino acid substitutions, deletions, or additions); and LCDR3 consisting of the sequence of SEQ ID NO: 19, or a sequence having one or more amino acid substitutions, deletions, or additions compared to SEQ ID NO: 19 (e.g., one, two, or three amino acid substitutions, deletions, or additions). It is defined according to the following.

[0449] In certain embodiments, the antibody or antigen-binding fragment according to this disclosure comprises the following heavy chain variable region (VH) and / or light chain variable region (VL), where CDR is the Kabat numbering system: (a) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 7, HCDR2 consisting of the sequence of SEQ ID NO: 8, and HCDR3 consisting of the sequence of SEQ ID NO: 9, including a heavy chain variable region (VH), and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 17, LCDR2 consisting of the sequence of sequence number 18, and LCDR3 consisting of the sequence of sequence number 19, are included in the light chain variable region (VL), (b) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 27, HCDR2 consisting of the sequence of SEQ ID NO: 28, HCDR3 consisting of the sequence of SEQ ID NO: 29, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 37, LCDR2 consisting of the sequence of sequence number 38, and LCDR3 consisting of the sequence of sequence number 39, are included in the light chain variable region (VL), (c) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 7, HCDR2 consisting of the sequence of SEQ ID NO: 8, HCDR3 consisting of the sequence of SEQ ID NO: 9, and / or a heavy chain variable region (VH) including these three CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 37, LCDR2 consisting of the sequence of sequence number 38, and LCDR3 consisting of the sequence of sequence number 39, are included in the light chain variable region (VL), or (d) The following three CDRs: HCDR1 consisting of the sequence of SEQ ID NO: 27, HCDR2 consisting of the sequence of SEQ ID NO: 28, HCDR3 consisting of the sequence of SEQ ID NO: 29, and / or a heavy chain variable region (VH) including these CDRs, and / or The following three CDRs: LCDR1 consisting of the sequence of sequence number 17, LCDR2 consisting of the sequence of sequence number 18, and LCDR3 consisting of the sequence of sequence number 19, are included in the light chain variable region (VL). It is defined according to the following.

[0450] In certain embodiments, the antibody or antigen-binding fragment of the Disclosure comprises a heavy chain variable region (VH) and / or a light chain variable region (VL), wherein at least one CDR of the heavy chain variable region (VH) and / or the light chain variable region (VL) contains a mutation compared to a CDR as defined above by IMGT, chothia, or Kabat, the mutation being one or more amino acid substitutions, deletions, or additions or any combination thereof (one, two, or three amino acid substitutions, deletions, or additions or any combination thereof).

[0451] Preferably, the substitutions referred to in this disclosure are conservative substitutions.

[0452] In certain embodiments, the VH of the antibody or antigen-binding fragment of the Disclosure comprises a framework region (FR) derived from the heavy chain variable region (VH) of human immunoglobulin, and / or the VL of the antibody or antigen-binding fragment comprises a framework region (FR) derived from the light chain variable region (VL) of human immunoglobulin. Thus, in certain embodiments, the antibody or antigen-binding fragment of the Disclosure is humanized. In certain embodiments, the antibody or antigen-binding fragment of the Disclosure is fully humanized.

[0453] In certain embodiments, the VH of the antibody or antigen-binding fragment of the Disclosure comprises a framework region (FR) derived from the heavy chain variable region (VH) of human immunoglobulin, and / or the VL of the antibody or antigen-binding fragment comprises a framework region (FR) derived from the light chain variable region (VL) of human immunoglobulin. Thus, in certain embodiments, the antibody or antigen-binding fragment of the Disclosure is humanized. In certain embodiments, the antibody or antigen-binding fragment of the Disclosure is fully humanized.

[0454] In a particular embodiment, the antibody or antigen-binding fragment thereof is (a) A heavy chain framework region of a human immunoglobulin or a variant thereof, wherein the variant has up to 20 conserved amino acid substitutions (e.g., up to 20, up to 15, up to 10, or up to 5 conserved amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conserved amino acid substitutions) compared to the amino acid sequence encoded by the germline antibody gene from which it is derived, and / or (b) A light chain framework region of a human immunoglobulin or a variant thereof, wherein the variant has up to 20 conserved amino acid substitutions (e.g., up to 20, up to 15, up to 10, or up to 5 conserved amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conserved amino acid substitutions) compared to the amino acid sequence encoded by the germline antibody gene from which it is derived. In certain embodiments, the degree of humanization of the antibody or antigen-binding fragment of the Disclosure is at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%.

[0455] In a particular embodiment, the antibody or antigen-binding fragment thereof is (a) Below: (i) Sequence described in Sequence ID No. 3 or 23, (ii) A sequence having one or more substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence described in Sequence ID No. 3 or 23, or (iii) A heavy chain variable region (VH) comprising an amino acid sequence selected from sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence described in Sequence ID No. 3 or 23, and / or (b) Below: (iv) Sequences described in Sequence ID No. 13 or 33, (v) A sequence having one or more substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence described in Sequence ID No. 13 or 33, or (vi) A light chain variable region (VL) comprising an amino acid sequence selected from sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence described in Sequence ID No. 13 or 33.

[0456] In certain embodiments, the antibody of this disclosure or its antigen-binding fragment comprises VH as described in SEQ ID NO: 3 and / or VL as described in SEQ ID NO: 13.

[0457] In certain embodiments, the antibody of this disclosure or its antigen-binding fragment comprises VH as described in SEQ ID NO: 23 and / or VL as described in SEQ ID NO: 33.

[0458] In certain embodiments, the antibody of this disclosure or its antigen-binding fragment comprises VH as described in SEQ ID NO: 3 and / or VL as described in SEQ ID NO: 33.

[0459] In certain embodiments, the antibody of this disclosure or its antigen-binding fragment comprises VH as described in SEQ ID NO: 23 and / or VL as described in SEQ ID NO: 13.

[0460] In a particular embodiment, the antibody or antigen-binding fragment thereof is (a) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 13, (b) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 33, (c) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 33, (d) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 13,

[0461] (e) Heavy chain variable region (VH) and / or light chain variable region (VL) wherein the heavy chain variable region (VH) and / or light chain variable region (VL) each independently have at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to the VH and VL in any one of (a) to (f), or (f) A heavy chain variable region (VH) and / or a light chain variable region (VL) comprising a heavy chain variable region (VH) and / or a light chain variable region (VL) that independently have one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the VH and VL in any one of (a) to (d). Preferably, the substitutions are conservative substitutions.

[0462] In certain embodiments, the antibody or antigen-binding fragment of the Disclosure comprises a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof, the variant having up to 50 conserved amino acid substitutions (e.g., up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 conserved amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conserved amino acid substitutions) compared to the wild-type sequence from which it is derived. In certain embodiments, the antibody or antigen-binding fragment of the Disclosure comprises a light chain constant region (CL) of a human immunoglobulin or a variant thereof, the variant having up to 50 conserved amino acid substitutions (e.g., up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 conserved amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conserved amino acid substitutions) compared to the wild-type sequence from which it is derived.

[0463] In some embodiments, the constant region is modified, e.g., mutated, to alter the properties of an anti-B7H3 antibody molecule (e.g., to change one or more of the following properties: Fc receptor binding, antibody glycosylation, number of cysteine ​​residues, effector cell function, or complement function). Functional changes can be made by substituting at least one amino acid residue in the constant region of the antibody with a different residue, e.g., by changing the antibody's affinity for an effector ligand (e.g., FcR or complement C1q), thereby altering (e.g., decreasing) the effector function. The Fc region of the antibody mediates several important effector functions, such as ADCC, phagocytosis (ADCP), CDC, etc.

[0464] In some embodiments, the antibody or antigen-binding fragment of the Disclosure has a heavy chain constant region (CH), which is selected from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE, and more particularly from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3, and IgG4, and more particularly from the heavy chain constant region of IgG1 (e.g., human IgG1). In some embodiments, the heavy chain constant region of human IgG1 has the sequence described in SEQ ID NO: 43. In some embodiments, the antibody or antigen-binding fragment of the Disclosure has a light chain constant region selected from, for example, the κ or λ light chain constant region, preferably the κ light chain constant region (e.g., the human κ light chain constant region). In some embodiments, the light chain constant region has the sequence described in SEQ ID NO: 44.

[0465] In some embodiments, the antibody or its antigen-binding fragment has CH or a variant thereof as described in SEQ ID NO: 43, the variant having up to 20 conserved amino acid substitutions (e.g., up to 20, up to 15, up to 10, or up to 5 conserved amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conserved amino acid substitutions) compared to SEQ ID NO: 43, or having at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to SEQ ID NO: 43.

[0466] In some embodiments, the antibody or its antigen-binding fragment has a light chain constant region or a variant thereof. In some embodiments, the light chain constant region includes a κ light chain constant region. In some embodiments, the light chain constant region includes the light chain constant region (CL) described in SEQ ID NO: 44 or a variant thereof, the variant having up to 20 conserved amino acid substitutions (e.g., up to 20, up to 15, up to 10 or up to 5 amino acid substitutions, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions) compared to SEQ ID NO: 44, or at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity compared to SEQ ID NO: 16. In some embodiments, the antibody or its antigen-binding fragment comprises a heavy chain constant region (CH) as described in SEQ ID NO: 43 and a light chain constant region (CL) as described in SEQ ID NO: 44.

[0467] In some embodiments, the antibody or antigen-binding fragment thereof is (a) Below: (i) A sequence including the VH sequence described in Sequence ID 3 and the CH sequence described in Sequence ID 43, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions, or any combination thereof) compared to the sequence shown in (i), (iii) A heavy chain comprising an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (i), and (b) Below: (iv) A sequence including the VL sequence described in Sequence ID 13 and the CL sequence described in Sequence ID 44, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) comprises a light chain containing an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv).

[0468] In some embodiments, the substitutions described in (ii) or (v) are conservative substitutions.

[0469] In some embodiments, the antibody or antigen-binding fragment thereof is (a) Below: (i) A sequence including the VH sequence described in Sequence ID No. 23 and the CH sequence described in Sequence ID No. 43, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A heavy chain comprising an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (i), and (b) Below: (iv) A sequence including the VL sequence described in Sequence ID 33 and the CL sequence described in Sequence ID 44, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) comprises a light chain containing an amino acid sequence selected from sequences having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequences shown in (vi)(iv).

[0470] In some embodiments, the substitutions described in (ii) or (v) are conservative substitutions.

[0471] In some embodiments, the antibody or antigen-binding fragment of the present disclosure comprises a heavy chain and a light chain. The heavy chain is, (i) Sequence described in Sequence ID No. 45, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (i), and Light chains are (iv) Sequence described in Sequence ID 46, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (vi)(iv), Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0472] In some embodiments, the antibody or antigen-binding fragment of the present disclosure comprises a heavy chain and a light chain. The heavy chain is, (i) Sequence described in Sequence ID 47, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions, or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence shown in (i), and Light chains are (iv) Sequence described in Sequence ID 48, A sequence having one or more amino acid substitutions, deletions, or additions, or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions, or additions, or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions, or additions, or any combination thereof) compared to the sequences shown in (v)(iv), or (vi)(iv) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with the sequence shown in (vi)(iv), Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0473] In some embodiments, the antibody or antigen-binding fragment of the Disclosure is a chimeric antibody, a humanized antibody, or a fully human antibody. In some embodiments, the antibody or antigen-binding fragment of the Disclosure is selected from scFv, Fab, Fab', (Fab')2, Fv fragment, disulfide-bonded Fv (dsFv), and diabody.

[0474] In some embodiments, the antibody of the Disclosure is scFv. In a particular embodiment, the scFv of the Disclosure is (a) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 13, (b) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 33, (c) VH as described in Sequence ID No. 3 and VL as described in Sequence ID No. 33, (d) VH as described in Sequence ID No. 23 and VL as described in Sequence ID No. 13, (e) Heavy chain variable region (VH) and light chain variable region (VL) wherein the heavy chain variable region (VH) and light chain variable region (VL) independently have sequence identity of at least 70%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% compared to the VH and VL in any one of groups (a) to (d), or (f) A heavy chain variable region (VH) and a light chain variable region (VL) comprising a heavy chain variable region (VH) and a light chain variable region (VL) wherein each of the heavy chain variable region (VH) and the light chain variable region (VL) independently has one or more amino acid substitutions, deletions or additions or any combination thereof (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions or any combination thereof) compared to any one of the VH and VL from groups (a) to (d). Preferably, the substitutions are conservative substitutions.

[0475] In some embodiments, the antibody of the Disclosure is scFv. In a particular embodiment, the scFv of the Disclosure is (i) Sequence described in Sequence ID 1 or 2, (ii)A sequence having one or more amino acid substitutions, deletions or additions or any combination thereof (for example, up to 50, up to 45, up to 40, up to 35, up to 30, up to 25, up to 20, up to 15, up to 10, or up to 5 amino acid substitutions, deletions or additions or any combination thereof, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions, deletions or additions, or any combination thereof) compared to the sequence shown in (i), (iii) A sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with respect to the sequence described in (i), Preferably, the substitution described in (ii) is a conservative substitution.

[0476] In some embodiments, the antibody of this disclosure is scFv.

[0477] In some embodiments, the scFv of this disclosure comprises the sequence described in SEQ ID NO: 1 or 2.

[0478] antibody derivative The antibodies or antigen-binding fragments of the present disclosure may be derivatized and, for example, linked to another molecule (e.g., another polypeptide or protein). In general, derivatization (e.g., labeling) of the antibodies or antigen-binding fragments does not adversely affect their binding to B7H3 (particularly human B7H3). Therefore, the antibodies or antigen-binding fragments of the present disclosure are also intended to include such derivatized forms. For example, the antibodies or antigen-binding fragments of the present disclosure may be linked (by chemical coupling, gene fusion, non-covalent bonding, etc.) to one or more other molecules, such as proteins or polypeptides, which can mediate the binding of the antibodies or antigen-binding fragments to another antibody (e.g., to form a bispecific antibody), a detection agent, a pharmaceutical, and / or another molecule (e.g., an avidin or polyhistidine tag).

[0479] One type of derivatized antibody (e.g., a bispecific antibody) is produced by crosslinking two or more antibodies (belonging to the same or different types). Methods for obtaining bispecific antibodies are well known in the art and include, but are not limited to, chemical crosslinking, cell engineering (hybridoma method), or genetic engineering.

[0480] Another type of derivatized antibody is a labeled antibody. For example, the antibody or its antigen-binding fragment may be bound to a detectable marker. The detectable marker described herein may be any substance detectable by fluorescence, spectroscopic, photochemical, biochemical, immunological, electrical, optical, or chemical means. Such markers are well known in the art and include, but are not limited to, enzymes (e.g., horseradish peroxidase, alkaline phosphatase, β-galactosidase, urease, glucose oxidase, etc.), radionuclides (e.g., 3H, 125I, 35S, 14C, or 32P), fluorescent dyes (e.g., fluorescein isothiocyanate (FITC), fluorescein, tetramethylrhodamine isothiocyanate (TRITC), phycoerythrin (PE), Texas Red, rhodamine, quantum dots, or cyanine dye derivatives (e.g., Cy7, Alexa750)), acridine esters, magnetic beads (e.g., Dynabeads®), colorimetric markers (e.g., colloidal gold or colored glass or plastic (e.g., polystyrene, polypropylene, latex, etc.) beads), and biotin for binding avidin modified with the above markers (e.g., streptavidin). Patents teaching the use of markers include, but are not limited to, U.S. Patents 3,817,837, 3,850,752, 3,939,350, 3,996,345, 4,277,437, 4,275,149, and 4,366,241 (all of which are incorporated herein by reference in their entirety). Such detectable markers can be detected by methods known in the art. For example, radioactive markers can be detected using photographic film or a scintillation counter, and fluorescent markers can be detected using a photodetector for detecting synchrotron radiation. Enzyme markers are generally detected by supplying a substrate to an enzyme and detecting the reaction product produced by the enzyme's action on the substrate, while colorimetric markers are detected by simple visualization of a colored marker.In certain embodiments, such labeling may be suitable for immunological detection (e.g., enzyme-linked immunoassay, radioimmunoassay, fluorescence immunoassay, chemiluminescence immunoassay, etc.). In certain embodiments, such detectable markers may be conjugated to the antibody or antigen-binding fragment of the Disclosure by linkers of different lengths to reduce potential steric hindrance.

[0481] In addition, the antibodies or antigen-binding fragments of the present disclosure may be derivatized with chemical groups such as polyethylene glycol (PEG), methyl or ethyl, or glycosyl. These groups can be used to improve the biological properties of the antibodies, such as increasing their serum half-life.

[0482] The antigen-binding fragments of this disclosure can be obtained by hydrolyzing intact antibody molecules (see Morimoto et al., J. Biochem. Biophys. Methods 24:107-117 (1992) and Brennan et al., Science 229:81 (1985)). In addition, these antigen-binding fragments can also be directly generated by recombinant host cells (referred to as Hudson, Curr. Opin. Immunol. 11:548-557 (1999); Little et al., Immunol. Today, 21:364-370 (2000)). For example, Fab' fragments can be obtained directly from host cells. Fab' fragments can be chemically linked to form F(ab')2 fragments (Carter et al., Bio / Technology, 10:163-167 (1992)). In addition, Fv, Fab, or F(ab')2 fragments can also be isolated directly from recombinant host cell cultures. Other techniques for preparing these antigen-binding fragments are well known to those skilled in the art.

[0483] The IgG isotype control antibodies disclosed herein are well known to those skilled in the art and can be purchased or prepared. For example, the sequence of human anti-egg lysozyme IgG (anti-HEL such as human IgG1, abbreviated as hIgG1) is derived from the variable region of the Fab F10.6.6 sequence in "A affinity maturation increases the stability and plasticity of the Fv domain of anti-protein antibodies" (Acierno et al. J Mol Biol. 2007;374(1):130-46), published by Acierno et al. The preparation method is as follows: Amino acid codon optimization and gene synthesis of the heavy and light chain (complete sequence or variable region) genes of the human IgG antibody are performed by Nanjing GenScript Biotech Corp. according to the standard techniques described in "Molecular Cloning, A Laboratory Manual (3rd Edition)". The heavy and light chain genes were subcloned into mammalian antibody heavy chain expression vectors and antibody light chain expression vectors, respectively, using standard molecular cloning techniques such as PCR, enzyme digestion, DNA gel recovery, ligation transformation, colony PCR, or enzyme digestion identification. The heavy and light chain genes of the recombinant expression vectors were then sequenced. After accurate sequence confirmation by sequencing, numerous endotoxin-free expression plasmids were prepared. The heavy and light chain expression plasmids were then transiently and simultaneously transfected into HEK293 cells for recombinant antibody expression. After 7 days of culture, the cell cultures were harvested and purified using an rProtein A affinity column (GE). The quality of the collected antibody samples was determined by standard analytical techniques of SDS-PAGE and SEC-HPLC.

[0484] In a ninth aspect, the Disclosure provides a multispecific antibody comprising an antibody or antigen-binding fragment thereof as described in any of the eighth aspects of the Disclosure, and an additional antibody or fragment thereof or antibody mimetic.

[0485] In a particular embodiment, the multispecific antibody is a bispecific antibody, a triplicate antibody, or a quadruplicate antibody.

[0486] Accordingly, in a tenth embodiment, the Disclosure provides an isolated nucleic acid molecule comprising an antibody or an antigen-binding fragment thereof, or a nucleotide sequence encoding one or more CDRs thereof. In certain embodiments, the nucleotide sequence may be substituted according to codon degeneracy, as known in the Art. In certain embodiments, the nucleotide sequence is codon-optimized.

[0487] In certain embodiments, an isolated nucleic acid molecule of the Disclosure includes (i) a first nucleic acid and a second nucleic acid encoding the heavy chain variable region and the light chain variable region of the antibody or its antigen-binding fragment, respectively; (ii) a first nucleic acid and a second nucleic acid encoding the heavy chain variable region and the heavy chain constant region, as well as the light chain variable region and the light chain constant region, respectively, of the antibody or its antigen-binding fragment; or (iii) a first nucleic acid and a second nucleic acid encoding the heavy chain and the light chain, respectively, of the antibody or its antigen-binding fragment. In certain embodiments, the first and second nucleic acids include nucleic acids that are degenerate sequences of the sequences of the first and second nucleic acids in any of the above items (i) to (iii). In certain embodiments, a degenerate sequence or substantially identical sequence means a sequence that has at least about 85%, 90%, 95%, or more sequence identity, or has one or more nucleotide substitutions, or has differences of 3, 6, 15, 30, or 45 nucleotides or less, compared to the nucleic acid molecules described in items (i) to (iii).

[0488] In an eleventh embodiment, a vector (e.g., a cloning vector or an expression vector) comprising an isolated nucleic acid molecule of the present disclosure is provided. In certain embodiments, the vector of the present disclosure is, for example, a plasmid, cosmid, bacteriophage, lentivirus, etc. In certain embodiments, the vector can express an antibody of the present disclosure or an antigen-binding fragment thereof in vivo in a subject (e.g., a mammal such as a human).

[0489] In a twelfth embodiment, a host cell comprising an isolated nucleic acid molecule of the Disclosure or a vector of the Disclosure is provided. The host cell may be a eukaryotic cell (e.g., a mammalian cell, an insect cell, a yeast cell) or a prokaryotic cell (e.g., Escherichia coli). Suitable eukaryotic cells include, but are not limited to, NS0 cells, Vero cells, Hela cells, COS cells, CHO cells, HEK293 cells, BHK cells, and MDCKII cells. Suitable insect cells include, but are not limited to, Sf9 cells. In a particular embodiment, the host cell of the Disclosure is a mammalian cell such as CHO (e.g., CHO-K1, CHO-S, CHO DXB11, CHO DG44).

[0490] In a thirteenth aspect, a method is provided for preparing an antibody or its antigen-binding fragment or a multispecific antibody according to the Disclosure, the method comprising culturing host cells according to the Disclosure under conditions that enable the expression of the antibody or its antigen-binding fragment or a multispecific antibody, and recovering the antibody or its antigen-binding fragment from the cultured host cell culture.

[0491] In a fourteenth embodiment, an antibody-drug conjugate is provided, the antibody being the anti-B7H3 antibody described above, the antibody being linked by a linker to a coupling portion selected from detectable markers, radioisotopes, fluorescent agents, luminescent agents, colorants, enzymes, polyethylene glycol (PEG), radionuclides, nucleic acids, small molecule toxins, polypeptides, proteins, receptors, ligands having binding activity, and other active agents that inhibit tumor cell proliferation and promote tumor cell apoptosis or necrosis.

[0492] In a particular example, the antibody-drug conjugate is expressed by the following formula: Ab-(LD)n, It contains an anti-B7H3 antibody drug conjugate (B7H3-ADC), During the ceremony, Ab is an antibody or its antigen-binding fragment in the eighth embodiment, D is the small molecule toxic drug portion. L is a covalent bond or linker between Ab and D. n is an integer between 1 and 16, representing the number of LDs covalently connected to Ab.

[0493] In some examples, L in the antibody-drug conjugate is selected from amino acid residues or short peptides consisting of 2 to 10 amino acid residues, and the amino acid residues include native amino acid residues, non-native amino acid residues, and AA. 1 Selected from amino acid residues represented by or their stereoisomers, [ka] AA 1 In the amino acid residue represented by, R a1 and R b Each of them is independent of H, [ka] Select from, Or, R a1 and R b These, together with the carbon atoms to which they are bonded, form a 4- to 10-membered heterocycle, in which the heteroatoms are selected from 1, 2, 3 or 4 O, N and S atoms, and the 4- to 10-membered heterocycle has one or more R 0 Replaced by optional selection, r, r 1 , r 1a and r 1b Each of these is independently selected from any integer between 0 and 20. R m1, R n1 , R m1a , R n1a , R m1b and R n1b These are H and C, which are independent of each other. 1~6 Alkyl, C 3~6 Cycloalkyl and -COOR x1 Selected from, R x1 C 1~6 Is it alkyl? Or, R m1 and R n1 , R m1a and R n1a , and R m1b and R n1b These, together with the nitrogen atom to which they are both bonded, form a 4- to 10-membered heterocycle, in which the heteroatoms are selected from 1, 2, 3 or 4 O, N and S atoms, and the 4- to 10-membered heterocycle has one or more R 0’ Replaced by optional selection, R z C 1~6 Selected from alkyl groups, R 0 , R 0’ Each of them is independent of C 1~6 Alkyl, C 3~6 Cycloalkyl, -NR m2 R n2 and C 1~6 Selected from 4- to 10-membered heterocyclines optionally substituted with alkyl groups, wherein the heteroatoms in the 4- to 10-membered heterocycle are selected from 1, 2, 3, or 4 O, N, and S atoms. R m2 , R n2 These are H and C, each independently. 1~6 Selected from alkyl groups.

[0494] In some embodiments, AA 1 In the amino acid residue represented by R a1 and R b These, together with the carbon atoms to which they are bonded, form a 5-6 membered heterocycle in which the heteroatom is N and the number of heteroatoms is 1 or 2, and the 5-6 membered heterocycle has one or more R 0The 5-6 member heterocycle is optionally substituted. The 5-6 member heterocycle is preferably a piperidine ring or a piperazine ring, and more preferably a piperidine ring, for example, [ka] Therefore, the carbon atom numbered 1 is R a1 and R b It is a carbon atom to which both are bonded.

[0495] In some embodiments, r, r 1 , r 1a and r 1b Each of these is independently 0, 1, 2, 3, 4, or 5, preferably r, r 1 , r 1a and r 1b Each of them is independently 0 or 4, and more preferably r is 0, and r 1 , r 1a and r 1b is 4, or r is 4, and r 1 , r 1a and r 1b It is 0.

[0496] In some embodiments, r, r 1 , r 1a , r 1b It is not the case that everything is zero.

[0497] In some embodiments, R m1 , R n1 , R m1a , R n1a , R m1b and R n1b These are H and C, which are independent of each other. 1~6 Alkyl, or -COOR x1 And R x1 C 1~6 The alkyl group is preferably independently H, methyl, ethyl, n-propyl, -COOCH3, -COOCH2CH3, -COOCH2CH2CH3, -COOCH(CH3)2, -COOC(CH3)3, or -COOCH2CH2CH2CH3.

[0498] In some embodiments, R m1 and R n1 , R m1a and R n1a , and R m1b and R n1b Together with the nitrogen atom to which they are both bonded, they form a 5-6 membered heterocycle in which the heteroatom is selected from 1 or 2 N atoms, and the 5-6 membered heterocycle has one or more R 0’ The 5-6 membered heterocycle is optionally substituted, and is preferably a piperidine ring or a piperazine ring, and more preferably, [ka] Therefore, the nitrogen atom numbered 1 is R m1 and R n1 It is a nitrogen atom to which both are bonded.

[0499] In some embodiments, R z Preferably, C 1~6 Alkyl, more preferably methyl.

[0500] In some embodiments, R 0 and R 0’ Each of them is independent of C 1~6 Alkyl, -NR m2 R n2 or C 1~6 A 5-6 membered heterocycline optionally substituted with an alkyl group, wherein the heteroatom is selected from 1 or 2 N atoms.

[0501] In some embodiments, R 0 Preferably, C 1~6 Alkyl or C 1~6 A 5-6 member heterocycline substituted with an alkyl group, wherein the 5-6 member heterocycline is piperidinyl or piperazinyl, and more preferably methyl or methyl-substituted piperidinyl, for example methyl or [ka] That is the case.

[0502] In some embodiments, each R 01’ Independently, preferably C 1~6 Alkyl, -NR m2 R n2 or C 1~6 A 5-6 membered heterocycline optionally substituted with alkyl, wherein the heteroatom is selected from 1 or 2 N atoms, and more preferably each R 01’ C 1~6 Alkyl or -NR m2 R n2 And more preferably, each R 01’ These are independently methyl or -NR m2 R n2 And R m2 and R n2 Each of these is independently preferably H or C 1~6 It is alkyl, and more preferably methyl.

[0503] In some embodiments, R 0’ Preferably, C 1~6 Alkyl or -NR m2 R n2 Yes, R m2 and R n2 Each of these is independently preferably H or C 1~6 It is an alkyl group (for example, methyl).

[0504] In some embodiments, AA 1 In the amino acid residue, R a1 and R b One of them is H, and the other is, [ka] Preferably, R a1 and R b One of them is H, and the other is, [ka] Selected from.

[0505] In some embodiments, AA 1 The amino acid residue represented by is preferably, [ka] And more preferably, [ka] And, moreover, [ka] And, Most preferably, [ka] That is the case.

[0506] In some embodiments, the antibody-drug conjugate consists of an antibody-linker-drug, the drug being selected from microtubule blockers, DNA damage agents, Bcl-xL inhibitors, and the like.

[0507] In some embodiments, the antibody-drug conjugate consists of an antibody-linker-drug, and the drug is selected from auristatins (e.g., MMAF, MMAE), maytansine derivatives (e.g., DM1, DM4), tubulinin, cryptomycins, antimitotic inhibitors, pyrrobenzazepines and indolechlorobenzazepines, ducamycin, camptothecin, calicheamycin, and the like.

[0508] In some embodiments, the antibody-drug conjugate consists of an antibody-linker-drug, where the drug is selected from camptothecin (CPT) and its derivatives.

[0509] In some embodiments, the antibody-drug conjugate consists of an antibody-linker-drug, where the drug is selected from topoisomerase I inhibitors.

[0510] In some embodiments, the antibody-drug conjugate consists of an antibody-linker-drug, and the drug is selected from SN-38 and DXd.

[0511] In some embodiments, D in the antibody-drug conjugate is represented by formula II: [ka] It is a drug unit represented by, During the ceremony, R1 is either H or F. R2 is either H or methyl, Alternatively, R1 and R2, together with the carbon atoms to which they are bonded, [ka] Forming, R3 is H, R4 is selected from H, -(C1~C4 alkyl)-OH, -(C1~C4 alkenyl)-OH, -(C1~C4 alkyl)-NH2, or -(C1~C4 alkenyl)-NH2. L is linked by a hydroxyl group or amine group in D.

[0512] In some embodiments, L in the antibody-drug conjugate is selected from the following: [ka] The first position is associated with Ab, the second position is associated with D, and AA1 is as defined above.

[0513] In addition, it should be noted that L is bonded to a sulfhydryl group contained in Ab (e.g., an antibody) after the disulfide bond is cleaved, which can be understood by those skilled in the art (for example, reduction of a disulfide bond with the reducing agent TCEP can cleave the disulfide bond and produce a sulfhydryl-SH group), that is, the -S- between L and Ab is not an additional foreign sulfur atom. For example, in the formula, the -S- is not an additional foreign sulfur atom, but is formed by linking the sulfhydryl group contained in Tb after the disulfide bond opens up to L.

[0514] In some preferred embodiments, the antibody-drug conjugate is selected from the following: [Table 6-1] [Table 6-2] In the formula, Ab is the anti-B7H3 antibody 1D1-01 or 2E3-02, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and q is preferably 1, 2, 3, 4, 5, 6, 7, 8.

[0515] In a 15th aspect of this disclosure, the disclosure provides a ligand-drug conjugate comprising the ligand-drug conjugate or antibody-drug conjugate described above. The ligand-drug conjugate has two or more q values, and the antibody-drug conjugate has two or more n values. The ligand-drug conjugate refers to a ligand-drug conjugate or antibody-drug conjugate (ADC) comprising a heterogeneous DAR distribution.

[0516] In some embodiments, when ligand-drug conjugates having a particular q-value or n-value constitute the majority of the ligand-drug conjugates, the q-value or n-value is close to the DAR.

[0517] In some embodiments, the drug-antibody ratio (DAR) in the ligand-drug conjugate is selected from an integer or decimal number between 1 and 10.

[0518] In some embodiments, the drug-antibody ratio (DAR) in the ligand-drug conjugate is selected from 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.2, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.7, 8.9, and 9.

[0519] In some embodiments, ligand-drug conjugate ADCs include ADCs having DAR distributions of 1 to 8, e.g., 1.5, 2, 4, 6, and 8 (i.e., payload species 1.5, 2, 4, 6, and 8). It should be noted that degradation products may be generated so that ligand-drug conjugates may also contain DARs of 1, 3, 5, and 7. Furthermore, ADCs in ligand-drug conjugates may also have DARs greater than 8. Ligand-drug conjugates are produced by reduction and subsequent coupling of interchain disulfides. In some embodiments, ligand-drug conjugates include both: ligand-drug conjugates having DARs of 4 or less (i.e., payload species of 4 or less) and ligand-drug conjugates having DARs of 6 or more (i.e., payload species of 6 or more).

[0520] In another embodiment, the Disclosure provides the use of the antibody or its antigen-binding fragment in the manufacture of a kit for detecting the presence or level of B7H3 in a sample. In another embodiment, the Disclosure provides a diagnostic or therapeutic kit comprising one or more of the following: the antibody or its antigen-binding fragment, nucleic acids, vectors, host cells, multispecific antibodies, conjugates, or pharmaceutical compositions. Optionally, the diagnostic or therapeutic kit further comprises instructions for use.

[0521] In a sixteenth aspect of this disclosure, the disclosure provides a pharmaceutical composition comprising substance A and optionally one or more pharmaceutically acceptable adjuvants, wherein substance A is the aforementioned ligand-drug conjugate, or a stereoisomer of a ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt, or its pharmaceutically acceptable solvate, or the aforementioned antibody or its antigen-binding fragment, nucleic acid molecule, vector, host cell, multispecific antibody, and / or ligand-drug conjugate, conjugate, or the aforementioned antibody-drug conjugate, or the aforementioned compound, or a stereoisomer of said compound, its prodrug, its pharmaceutically acceptable salt, or its pharmaceutically acceptable solvate. Substance A may be in a therapeutically effective amount.

[0522] In certain embodiments, the pharmaceutical composition of the Disclosure comprises an antibody or antigen-binding fragment thereof and a pharmaceutically acceptable carrier and / or excipient.

[0523] In certain embodiments, the pharmaceutical composition of the Disclosure comprises a host cell of the Disclosure and a pharmaceutically acceptable carrier and / or excipient, the host cell comprising the aforementioned isolated nucleic acid molecule or vector.

[0524] In certain embodiments, the pharmaceutical composition of the Disclosure comprises the multispecific antibody of the Disclosure and a pharmaceutically acceptable carrier and / or excipient.

[0525] In certain embodiments, the pharmaceutical composition of the Disclosure comprises the conjugate of the Disclosure and a pharmaceutically acceptable carrier and / or excipient.

[0526] In a 17th aspect of this disclosure, the disclosure provides the aforementioned substance A or the aforementioned pharmaceutical composition for the manufacture of a medicament for the treatment and / or prevention of a disease associated with abnormal cell activity (e.g., cancer). The substance A or the aforementioned pharmaceutical composition may be in a therapeutically effective amount.

[0527] In some examples, the Disclosure provides the use of antibodies or their antigen-binding fragments, nucleic acids, vectors, host cells, antibody-drug conjugates, or multispecific antibodies according to the Disclosure in the manufacture of a pharmaceutical product, the pharmaceutical product being used to modulate (inhibit or block) the activity of B7H3.

[0528] In some cases, the present disclosure provides the use of antibodies or their antigen-binding fragments, nucleic acids, vectors, host cells, antibody-drug conjugates, or multispecific antibodies according to the present disclosure in the manufacture of pharmaceuticals, which are used for the treatment or prevention of diseases related to B7H3 activity. In some cases, the Disclosure provides the use of antibodies or their antigen-binding fragments, nucleic acids, vectors, host cells, antibody-drug conjugates, or multispecific antibodies according to the Disclosure in the manufacture of pharmaceuticals, which are used for the treatment or prevention of tumors related to B7H3 activity.

[0529] In some embodiments, cancerous diseases are selected from esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumors, lung cancer (e.g., small cell lung cancer, non-small cell lung cancer or lung adenocarcinoma), squamous cell carcinoma, bladder cancer, stomach cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colon cancer (e.g., human colon adenocarcinoma), rectal cancer, colorectal cancer, liver cancer, kidney cancer, urothelial carcinoma, epidermal carcinoma, non-Hodgkin lymphoma, central nervous system tumors (e.g., neuroglioma, glioblastoma multiforme, glioma or sarcoma), prostate cancer, or thyroid cancer.

[0530] In some embodiments, the cancer is a cancer associated with Trop-2, Her2, B7H3, Her3, or EGFR. In some embodiments, the cancer is a cancer associated with Trop-2 or Her2.

[0531] In some embodiments, the cancerous disease is a Trop-2-related cancerous disease.

[0532] In some embodiments, the cancerous disease is a cancerous disease associated with Her3.

[0533] In some embodiments, the cancerous disease is an EGFR-related cancerous disease.

[0534] In some embodiments, the cancerous disease is a cancerous disease associated with B7H3.

[0535] In some embodiments, cancerous diseases are solid tumors.

[0536] In some embodiments, the cancerous disease is breast cancer or lung cancer (preferably non-small cell lung cancer).

[0537] In a 17th aspect of this disclosure, the disclosure provides the aforementioned substance A or the aforementioned pharmaceutical composition for use in the treatment and / or prevention of diseases associated with abnormal cell activity (e.g., cancer).

[0538] In some appropriate terms, cancerous diseases are selected from esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumors, lung cancer (e.g., small cell lung cancer, non-small cell lung cancer, or lung adenocarcinoma), squamous cell carcinoma, bladder cancer, stomach cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colon cancer (e.g., human colon adenocarcinoma), rectal cancer, colorectal cancer, liver cancer, kidney cancer, urothelial carcinoma, epidermal carcinoma, non-Hodgkin lymphoma, central nervous system tumors (e.g., glioma, glioblastoma multiforme, glioma, or sarcoma), prostate cancer, or thyroid cancer.

[0539] In some embodiments, the cancer is a cancer associated with Trop-2, Her2, B7H3, Her3, or EGFR. In some embodiments, the cancer is a cancer associated with Trop-2 or Her2.

[0540] In some embodiments, the cancerous disease is a Trop-2-related cancerous disease.

[0541] In some embodiments, the cancerous disease is a cancerous disease associated with Her3.

[0542] In some embodiments, the cancerous disease is an EGFR-related cancerous disease.

[0543] In some embodiments, the cancerous disease is a cancerous disease associated with B7H3.

[0544] In some embodiments, the cancerous disease is a solid tumor. In some embodiments, the cancerous disease is breast cancer or lung cancer (preferably non-small cell lung cancer).

[0545] In a 18th aspect of this disclosure, the disclosure provides a method for preventing and / or treating a disease associated with abnormal cell activity (e.g., cancer), which includes administering a preventive and / or therapeutically effective amount of the aforementioned substance A or the aforementioned pharmaceutical composition to an individual in need thereof.

[0546] In some appropriate terms, cancerous diseases are selected from esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumors, lung cancer (e.g., small cell lung cancer, non-small cell lung cancer, or lung adenocarcinoma), squamous cell carcinoma, bladder cancer, stomach cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colon cancer (e.g., human colon adenocarcinoma), rectal cancer, colorectal cancer, liver cancer, kidney cancer, urothelial carcinoma, epidermal carcinoma, non-Hodgkin lymphoma, central nervous system tumors (e.g., glioma, glioblastoma multiforme, glioma, or sarcoma), prostate cancer, or thyroid cancer.

[0547] In some embodiments, the cancerous disease is a cancerous disease associated with Trop-2, Her2, B7H3, Her3, and EGFR.

[0548] In some embodiments, the cancerous disease is a cancerous disease associated with Trop-2 or Her2.

[0549] In some embodiments, the cancerous disease is a Trop-2-related cancerous disease.

[0550] In some embodiments, the cancerous disease is a cancerous disease associated with Her3.

[0551] In some embodiments, the cancerous disease is an EGFR-related cancerous disease.

[0552] In some embodiments, the cancerous disease is a cancerous disease associated with B7H3.

[0553] In some embodiments, cancerous diseases are solid tumors.

[0554] In some embodiments, the cancerous disease is breast cancer or lung cancer (preferably non-small cell lung cancer).

[0555] In this disclosure, unless otherwise specified, the scientific and technical terms used herein have meanings that are generally understood by those skilled in the art. Furthermore, all cell culture, molecular genetics, nucleic acid chemistry, and immunology laboratory procedures used herein are commonplace procedures widely used in their respective fields. On the other hand, for a better understanding of the present invention, definitions and explanations of relevant terms are provided below.

[0556] As used herein, the term “pharmaceutically acceptable salt” is an example of an organic acid addition salt formed using an organic acid that provides a pharmaceutically acceptable anion, and examples of organic acid addition salts include, but are not limited to, formate, acetate, propionate, benzoate, maleate, fumarate, succinate, tartrate, citrate, ascorbate, α-ketoglutarate, α-glycerophosphate, alkylsulfonate, or arylsulfonate. Preferably, alkylsulfonates are methylsulfonate or ethylsulfonate, and arylsulfonates are benzenesulfonate or p-toluenesulfonate. Suitable inorganic salts may also be formed, but are not limited to, hydrochloride, hydrobromide, hydroiodide, nitrate, bicarbonate, carbonate, sulfate, or phosphate.

[0557] As used herein, the term “pharmaceutically acceptable carrier and / or excipient” means a carrier and / or excipient that is pharmacologically and / or physiologically compatible with the subject and active ingredient, which is known in the art (see, for example, Remington's Pharmaceutical Sciences. Edited by Gennaro AR, 19th ed. Pennsylvania: Mack Publishing Company, 1995), and includes, but is not limited to, pH adjusters, surfactants, adjuvants, ionic strength enhancers, diluents, agents for maintaining osmotic pressure, agents for delaying absorption, and preservatives.

[0558] A pharmaceutically acceptable salt can be obtained, for example, by reacting a sufficient amount of a basic compound with a suitable acid that provides a pharmaceutically acceptable anion, using standard procedures well known in the art.

[0559] In this disclosure, pharmaceutically acceptable adjuvants refer to excipients and additives used in the manufacture of pharmaceuticals and formulations, and include substances other than the active ingredient that are reasonably evaluated for their safety in pharmaceutical formulations. In addition to improving shaping, carrier function, and stability, pharmaceutically acceptable adjuvants also have important functions such as solubilization, hydrotroping, sustained release, and controlled release, and are important components that can affect the quality, safety, and efficacy of drugs. Depending on their source, they can be classified as natural, semi-synthetic, and fully synthetic. Depending on their function and use, these can be classified as solvents, propellants, solubilizers, co-solvents, emulsifiers, colorants, binders, disintegrants, fillers, lubricants, wetting agents, osmotic pressure regulators, stabilizers, flow enhancers, flavoring agents, preservatives, suspending agents, coating materials, fragrances, anti-stick agents, antioxidants, chelating agents, penetration enhancers, pH adjusters, buffers, plasticizers, surfactants, foaming agents, defoaming agents, thickeners, inclusion agents, humectants, absorbents, diluents, flocculants and deglucans, filtration aids, release blockers, etc. Depending on their route of administration, these can be classified as oral, injectable, mucosal, transdermal or topical administration, nasal or oral inhalation administration, and intraocular administration. The same pharmaceutically acceptable adjuvant can be used in pharmaceutical formulations with different routes of administration, resulting in different effects and uses.

[0560] The pharmaceutical composition can be prepared in various suitable dosage forms according to the route of administration. For example, these may be tablets, capsules, granules, oral liquids, oral suspensions, oral emulsions, powders, tinctures, syrups, injections, suppositories, ointments, creams, pastes, ophthalmic preparations, pills, implants, aerosols, powdered aerosols, sprays, etc. The pharmaceutical composition or suitable dosage form may contain 0.01 mg to 1000 mg, preferably 0.1 mg to 800 mg, more preferably 0.5 mg to 500 mg, more preferably 0.5 mg to 350 mg, and particularly preferably 1 mg to 250 mg of the compound of this disclosure or a pharmaceutically acceptable salt or conjugate thereof.

[0561] Pharmaceutical compositions can be administered in the form of injectable preparations, including injectable solutions, sterile powders for injection, and concentrated solutions for injection. Of these, useful vehicles and solvents are water, Ringer's solution, and physiological saline. In addition, sterile non-volatile oils (e.g., monoglycerides or diglycerides) can also be used as solvents or suspension media.

[0562] As used herein, the term “treatment” generally refers to obtaining a desired pharmacological and / or physiological effect. The effect may be prophylactic in relation to the complete or partial prevention of a disease or its symptoms, and / or therapeutic in relation to the partial or complete stabilization or cure of a disease and / or side effects caused by the disease. As used herein, “treatment” encompasses any treatment of a disease in a patient, including (a) prevention of the disease or symptoms in a patient who is susceptible to the disease or symptoms but has not yet been diagnosed with the disease or symptoms, (b) suppression of the symptoms of the disease, i.e., prevention of its onset, or (c) relief of the symptoms of the disease, i.e., regression of the disease or symptoms.

[0563] In this disclosure, the term “individual” includes humans and non-human animals. Examples of human individuals include human individuals with a disease (referred to as patients) or healthy individuals. The term “non-human animals” in this disclosure includes all vertebrates, such as non-mammals (e.g., birds, amphibians, reptiles), as well as mammals, such as non-human primates, livestock, and / or domesticated animals (e.g., sheep, dogs, cats, cattle, pigs, etc.).

[0564] In this disclosure, the term “effective dose” means the amount of a compound that, after administration, alleviates to some extent one or more symptoms of the disorder being treated.

[0565] In this disclosure, the term “ligand-drug conjugate” refers to a substance in which a bioactive molecule (drug molecule) is linked to a target moiety. In some embodiments of this disclosure, the bioactive molecule is linked to the targeting moiety by a linker. The linker can be cleaved under specific conditions (e.g., in the presence of hydrolase in a tumor and / or a low pH environment) or under specific action (e.g., the action of a lysosomal protease) so that the bioactive molecule is separated from the target moiety. In some embodiments of this disclosure, the linker comprises cleavable or non-cleavable units such as peptides or disulfide bonds. In some embodiments of this disclosure, the bioactive molecule is directly linked to the target moiety by a covalent bond that can be cleaved under specific conditions or action, thereby separating the bioactive molecule from the target moiety. In some embodiments of this disclosure, the ligand-drug conjugate comprises a targeting moiety, a linker, and a compound fragment of Formula II of this disclosure.

[0566] In this disclosure, the terms “bioactive substance,” “bioactive molecule,” or “drug molecule” refer to a substance that inhibits or prevents the function of cells and / or causes cell death or destruction. In some embodiments of this disclosure, the bioactive substance, bioactive molecule, or drug molecule in the conjugate is a molecule having antitumor bioactivity. For example, radioisotopes, e.g., At 211 , I 131 , I 125 , Y 90 Re 186 Re 188 Sm 153 , Bi 212 , P 32 Pb 212and Lu, metal complexes, e.g., metal-platinum complexes, metal-gold complexes, oxaliplatin, etc., glycopeptide antibiotics, e.g., bleomycin, pinyanmycin, DNA topoisomerase inhibitors, e.g., topoisomerase I inhibitors, camptothecin, hydroxylcamptothecin, 9-aminocamptothecin, SN-38, irinotecan, topotecan, berothecan, rubitecan, topoisomerase II inhibitors, actinomycin D, adriamycin, doxorubicin, duocalmycin, daunorubicin, mitoxantrone, podophyllotoxin, etoposide, etc., drugs that inhibit DNA synthesis, e.g., methotrexate, 5-fluorouracil, cytarabine, gemcitabine, mercaptopurine, pentostatin, fludarabine, cladribine, nerarabine, etc., drugs that act on structural proteins, e.g., tubulin inhibitors, vinca alkaloids, This includes tumor signaling pathway inhibitors such as vincristine, vinblastine, paclitaxel, docetaxel, cabazitaxel, proteasome inhibitors, histone deacetylase inhibitors, tumor angiogenesis inhibitors, cyclin inhibitors, maytansine derivatives, calicheamicin derivatives, auristatin derivatives, pyrrolobenzodiazepine (PBD) derivatives, melphalan, mitomycin C, chlorambucil, or other active substances that inhibit tumor cell proliferation and promote tumor cell apoptosis and necrosis, enzymes and their fragments such as nucleolysin, antibiotics, toxins such as small molecule toxins or enzymatically active toxins (including their fragments and / or variants) derived from bacteria, fungi, plants or animals, growth inhibitors, and drug modules. The term "toxin" refers to a substance that can have a detrimental effect on cell growth or proliferation.

[0567] In this disclosure, the term “small molecule” refers to a bioactive small molecule drug. The term “small molecule toxin” refers to a state having cytotoxic activity, i.e., a state that causes pathological changes in cells in several forms, and cytotoxicity is not limited to direct damage but includes all kinds of damage to the structure and function of cells, such as DNA breakage, base dimerization, chromosome breakage, damage to the cell division mechanism, and reduction of various enzyme activity.

[0568] In this disclosure, the term "linker" refers to a fragment that links a biologically active molecule (drug molecule) to a targeting portion.

[0569] In this disclosure, the term “targeting portion” refers to a portion of a conjugate that can specifically bind to a target (or a portion of a target) on a cell surface. Through interaction between the targeting portion and the target, the conjugate can be delivered to a particular population of cells.

[0570] In this disclosure, if the targeted portion of the conjugate is an antibody, the conjugate may be referred to as a "drug-antibody conjugate."

[0571] In this disclosure, an antibody or its antigen-binding fragment includes a derivatized antibody or its antigen-binding fragment, for example, an antibody or its antigen-binding fragment having a thiol group, where derivatization enables the antibody to have a group or ability to react with a drug-linker conjugate. Thiol-SH can be derivatized by cleaving a disulfide bond (for example, by reduction with the reducing agent TCEP).

[0572] As used herein, the terms “cancer” and “tumor” are used interchangeably.

[0573] As used herein, the term “gene” includes not only DNA, but also its mRNA, cDNA, and cRNA.

[0574] As used herein, the term "polynucleotide" is used synonymously with "nucleic acid" and includes DNA, RNA, probes, oligonucleotides, and primers.

[0575] As used herein, the term "Tb" is an abbreviation for "target binding" and includes an antibody or any molecule that binds to a target, and the term "Ab" is an abbreviation for "antibody" and is used interchangeably with "antibody".

[0576] As used herein, the terms “polypeptide” and “protein” are interchangeable.

[0577] As used herein, the term “cell” includes cells within individual animals as well as cultured cells.

[0578] The B7H3 involved in the anti-B7H3 antibody described herein may be conventional B7H3 in the art, such as soluble B7H3 or membrane-type B7H3, and may also represent B7H3 variant 1 and / or B7H3 variant 2.

[0579] KD refers to the dissociation constant obtained from the ratio of Kd (dissociation rate of the specific binding molecule-target protein interaction) to Ka (binding rate of the specific binding molecule-target protein interaction) (or expressed as Kd / Ka, in molar concentration (M)). The KD value can be determined using methods well established in the art. A preferred method for determining the KD of a binding molecule is by using a biosensor system such as surface plasmon resonance, e.g., the Biacore® (GE Healthcare Life Sciences) system.

[0580] The term "B7H3 variant" refers to a polypeptide that has similar or identical function to a B7H3 polypeptide, B7H3 fragment, anti-B7H3 antibody, or antibody fragment, but does not necessarily contain the amino acid sequence of a similar or identical B7H3 polypeptide, B7H3 fragment, anti-B7H3 antibody, or fragment, or has a similar or identical structure to a B7H3 polypeptide, B7H3 fragment, anti-B7H3 antibody, or fragment.

[0581] The term "Her3 variant" refers to a polypeptide that has similar or identical function to a HER3 polypeptide, HER3 fragment, anti-HER3 antibody, or antibody fragment, but does not necessarily contain the amino acid sequence or structure of a similar or identical HER3 polypeptide, HER3 fragment, anti-HER3 antibody, or fragment.

[0582] As used herein, the percentage homology between two amino acid sequences is equal to the percentage identity between the two sequences. The percentage of sequence identity between two sequences is a function of the number of identical positions shared by the sequences, taking into account the number of gaps that need to be introduced for optimal alignment of the two sequences and the length of each gap (i.e., homology % = number of identical positions / total number of positions × 100). Sequence comparison and determination of the percentage of identity between sequences can be performed by methods generally known in the art, and such sequence comparison and determination of the percentage of identity can be achieved by mathematical algorithms. For example, the algorithm in Meyers and Miller, 1988, Comput.Appl.Biosci.4:11-17 (integrated in the ALIGN program (version 2.0)) can be used to determine the percentage of identity between amino acid sequences and / or between nucleotide sequences. In addition, the GAP program in the GCG package obtained online from Accelrys (using its default parameters) can be used to determine the percentage of identity between amino acid sequences or between nucleotide sequences. In one embodiment, the two arrays are of equal length.

[0583] The term “epitope” refers to a portion of a B7H3 polypeptide or protein that has antigenic or immunogenic activity in an animal, preferably a mammal. The epitopes of the anti-B7H3 antibodies or their antigen-binding fragments in this disclosure can be determined by existing techniques such as synthetic peptide methods, immunoinformatics prediction, polypeptide activity determination, epitope peptide scanning, phage display techniques, X-ray diffraction and nuclear magnetic resonance analysis, and homologous antibody modeling protein docking prediction methods. As used herein, the phrase “antibodies that bind to the same epitope” refers to different antibodies that bind to a common epitope. If a second antibody binds to a portion of the peptide or tertiary structure to which the first antibody binds, then the first and second antibodies may be determined to bind to the same epitope.

[0584] In this disclosure, the term “antibody” is used in its broadest sense, as long as they possess all the necessary biological activity, including intact monoclonal antibodies, polyclonal antibodies, and multispecific antibodies (e.g., bispecific antibodies) formed from at least two intact antibodies. In this disclosure, “antibody” and “immunoglobulin” are used interchangeably. As used herein, “antibody molecule” or “antibody” refers to an immunoglobulin molecule and a molecule containing an immunologically active portion of an immunoglobulin molecule, i.e., an antigen-binding site that enables immune-specific binding to an antigen. Thus, the term “antibody” broadly encompasses not only the entire antibody molecule but also fragments of said antibody and variants (including derivatives) of said antibody and antibody fragments. When “antibody molecule” or “antibody” is used in the same context as an antigen-binding fragment, “antibody molecule” or “antibody” refers to an intact antibody molecule or a full-length antibody. The term antibody molecule as used herein includes, but is not limited to, single-chain Fv(scFv), Fab fragment, Fab' fragment, F(ab')2, disulfide-linked Fv(sdFv), Fv, and intact or full-length antibodies. The terms "single-chain Fv" or "scFv" refer to a polypeptide comprising the VL domain of an antibody linked to the VH domain of the antibody. For example, an antibody that immunospecifically binds to B7H3 can cross-react with other antigens, and preferably cannot. Antibodies that immunospecifically bind to B7H3 can be identified, for example, by immunoassay or other methods known to those skilled in the art. An "intact" antibody or "full-length" antibody refers to a protein containing two heavy chains (H) and two light chains (L) linked to each other by disulfide bonds, the protein comprising (1) a variable region of the heavy chain (abbreviated herein as "VH") containing three domains CH1, CH2, and CH3, and a constant region, and (2) a variable region of the light chain (abbreviated herein as "VL") and a constant region of the light chain containing domain CL.The antibodies of this disclosure include, but are not limited to, monoclonal antibodies, multispecific antibodies, human antibodies or chimeric antibodies, single-chain antibodies, Fab fragments, F(ab') fragments, anti-idiotype (anti-Id) antibodies (e.g., including anti-Id antibodies of the antibodies of this disclosure), and epitope-binding fragments of any of the aforementioned antibodies. The immunoglobulin molecules of this disclosure may be any type of immunoglobulin (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), any class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or any subclass. Preferably, the antibodies of this disclosure include or consist of a VH domain, VH CDR (referred to herein as HCDR), VL domain, or VL CDR (often represented herein as LCDR), having either an amino acid sequence or a fragment or variant thereof as described in the table of sequences and their specific information.

[0585] In this disclosure, the term “monoclonal antibody” refers to an antibody from a substantially homogeneous population of antibodies, i.e., each antibody in the population is identical except for potential minor innate variations. Monoclonal antibodies have high specificity for one determinant (epitope) of an antigen, while polyclonal antibodies contain different antibodies for different determinants (epitopes). In addition to specificity, an advantage of monoclonal antibodies is that they can be synthesized without contamination by other antibodies. As used herein, the modifier “monoclonal” means that the antibody is characterized as originating from a substantially homogeneous population of antibodies and should not be interpreted as requiring a specific preparation method.

[0586] In some embodiments of this disclosure, monoclonal antibodies also include chimeric antibodies, i.e., insofar as they have the desired biological activity, a portion of the heavy chain and / or light chain is identical or homologous to one type, class or subclass of antibody, and the remainder is identical or homologous to another type, another class or another subclass of antibody (see, for example, U.S. Patent No. 4,816,567 and Morrison et al., 1984, PNAS, 81:6851-6855). Useful chimeric antibodies in this disclosure include primate-like antibodies that include a variable region antigen-binding sequence and a human constant region sequence derived from a non-human primate (e.g., ancient monkeys, chimpanzees, etc.).

[0587] The term "antigen-binding fragment" refers to a portion of an antibody, preferably an antigen-binding or variable region. Examples of antibody fragments include Fab, Fab', F(ab')2, Fd, Fv, dAb, and complementarity-determining region fragments, diabodies, linear antibodies, and single-chain antibody molecules. As used herein, the term "antigen-binding fragment" refers to a partial fragment of an antibody having antigen-binding activity, which possesses the complete or partial functionality of the antibody and includes, but is not limited to, single-chain Fv(scFv), Fab, Fab', F(ab')2, disulfide-bonded Fv(sdFv), Fv, di-scFv, etc., and also includes Fab', a monovalent fragment of the variable region of an antibody obtained by treating F(ab')2 under reducing conditions. However, the term is not limited to these molecules as long as the fragment has binding affinity to the antigen. Furthermore, these functional fragments include not only fragments obtained by treating the full-length molecule of an antibody protein with a suitable enzyme, but also proteins produced in a suitable host cell using a genetically modified antibody gene.

[0588] As used herein, the term "Fab" refers to a monovalent fragment of the variable region of an antibody obtained by treating F(ab')2 under the reducing conditions described above. However, Fab' as used herein also includes Fab' generated using a genetically modified antibody gene.

[0589] As used herein, the term "scFv" refers to a single polypeptide chain containing VL and VH domains, where VL and VH are linked by a linker or directly (see, for example, Bird et al., Science 242:423-426 (1988); Huston et al., Proc. Natl. Acad. Sci. USA 85:5879-5883 (1988); and Pluckthun, The Pharmacology of Monoclonal Antibodies, Vol. 113, Eds. Roseburg and Moore, Springer-Verlag, New York, pp. 269-315 (1994)). Such scFv molecules may have the general structure: NH₂-VL-linker-VH-COOH or NH₂-VH-linker-VL-COOH. Preferred linkers in the prior art consist of repeating GGGGS amino acid sequences or variants thereof. For example, a linker having the amino acid sequence (GGGGS)4 can be used, and its variants can also be used (Holliger et al. (1993), Proc. Natl. Acad. Sci. USA 90:6444-6448). Other linkers that may be used in this disclosure were described in Alfthan et al. (1995), Protein Eng. 8:725-731, Choi et al. (2001), Eur. J. Immunol. 31:94-106, Hu et al (1996), Cancer Res. 56:3055-3061, Kipriyanov et al (1999), J. Mol. Biol. 293:41-56, and Roovers et al (2001), Cancer Immunol. In some cases, a disulfide bond may also be present between the VH and VL of scFv. As used herein, the term "di-scFv" refers to an antibody fragment formed by ligating two scFvs.

[0590] As used herein, an antibody or its antigen-binding fragment still possesses antigen-binding activity even if it contains variants, amino acid substitutions, deletions, or additions.

[0591] The term "bispecific antibody," also known as a "bifunctional antibody conjugate," refers to a conjugate formed by a first antibody (fragment) and a second antibody (fragment) via a coupling arm. Because the conjugate retains the activity of each antibody, it is bifunctional and bispecific.

[0592] The term "multispecific antibody" includes, for example, triplicate antibodies, which are antibodies with three different antigen-binding specificities, and quadruplicate antibodies, which are antibodies with four different antigen-binding specificities.

[0593] The terms "intact antibody" or "full-length antibody" refer to an antibody that includes an antigen-binding variable region and a light chain constant region (CL) and heavy chain constant regions (CH1, CH2, and CH3). The constant regions may be the natural sequence (e.g., the human natural constant region sequence) or a variant of its amino acid sequence. Intact antibodies preferably have one or more effector functions.

[0594] The term "probody" refers to a modified antibody containing an antibody or antibody fragment that can specifically bind to its target and can be coupled to a masking group, where the masking group means that the cleavage constant of the antibody or antibody fragment having the masking group to its target is at least 100 times, 1,000 times, or 10,000 times greater than that of an antibody or antibody fragment without the masking group.

[0595] In this disclosure, the “humanized” form of a non-human (e.g., mouse) antibody refers to a chimeric antibody containing a minimal non-human immunoglobulin sequence. Most humanized antibodies are human recipient immunoglobulins having hypervariable region residues substituted with non-human (e.g., mouse, rat, rabbit, or non-human primate) hypervariable region residues (donor antibody) that have the desired specificity, affinity, and function. In some embodiments, framework region (FR) residues of the human immunoglobulin are also substituted with non-human residues. Furthermore, the humanized antibody may also contain residues not found in the recipient antibody or donor antibody. These modifications are intended to further optimize the performance of the antibody. Humanized antibodies generally contain at least one, usually two, variable regions, where all or almost all of the hypervariable loops correspond to the hypervariable loops of the non-human immunoglobulin, and the FR is a complete or nearly complete human immunoglobulin protein sequence. The humanized antibody may also contain at least a portion of the immunoglobulin constant region (Fc, typically human immunoglobulin Fc). For further details, see, for example, Jones et al, 1986, Nature, 321:522-525; Riechmann et al, 1988, Nature, 332:323-329; and Presta, 1992, Curr Op Struct Bwl 2:593-596.

[0596] Intact antibodies can be classified into different "classes" based on the amino acid sequence of their heavy chain constant region. The five main classes are IgA, IgD, IgE, IgG, and IgM, some of which can also be classified into different "subclasses" (isotypes) (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2). The heavy chain constant regions of different classes of antibodies are called α, β, ε, γ, and μ, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known in the art.

[0597] In this specification, the CDRs contained in the antibodies or antigen-binding fragments of the Disclosure may be identified according to various numbering systems known in the Art. In certain embodiments, the CDRs contained in the antibodies or antigen-binding fragments of the Disclosure are preferably determined by the Kabat, Chothia, AbM, or IMGT numbering system. According to the IMGT numbering system, the corresponding numbers of CDRs and FRs are as follows: [Table 7] As used herein, the terms “framework residue region” or “FR residue” refer to amino acid residues in the variable region of an antibody other than the CDR residues defined above.

[0598] As used herein, the term “germline antibody gene” means a gene that encodes an immunoglobulin expressed by a non-lymphocyte and has not undergone the maturation process that results in the genetic rearrangement and maturation of the specific immunoglobulin it expresses. One advantage provided by various embodiments of this disclosure is the recognition that the amino acid sequence encoded by a germline antibody gene preserves a more characteristic and important amino acid sequence structure of an individual animal species than that encoded by a mature antibody gene. Therefore, when applied therapeutically to that species, it is less likely to be recognized as a foreign substance by that species.

[0599] With regard to amino acid substitutions, conservative amino acid substitutions are preferred in this specification. Conservative amino acid substitutions refer to substitutions that occur within a set of amino acids related to the amino acid side chain. Preferred sets of amino acids are as follows: acidic set (aspartic acid and glutamic acid), basic set (lysine, arginine and histidine), nonpolar set (alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine and tryptophan), and non-charged family (glycine, asparagine, glutamine, cysteine, serine, threonine and tyrosine). More preferred sets of amino acids are as follows: aliphatic hydroxyl (serine and threonine), amide-containing set (asparagine and glutamine), aliphatic set (alanine, valine, leucine and isoleucine), and aromatic set (phenylalanine, tryptophan and tyrosine). Such amino acid substitutions are preferably carried out insofar as they do not impair the properties of the substance having the original amino acid sequence.

[0600] In addition, it is known that antibodies produced in mammalian cultured cells lack a lysine residue at the carboxyl terminus of the heavy chain (Journal of Chromatography A, 705:129-134 (1995)), and that two amino acid residues (glycine and lysine) at the carboxyl terminus of the heavy chain of antibodies produced in mammalian cultured cells are also missing, with a new proline residue at the carboxyl terminus being amidated (Analytical Biochemistry, 360:75-83 (2007)). However, such deletions and modifications of the heavy chain sequence do not affect the antigen-binding affinity or effector function (complement activation, antibody-dependent cytotoxicity, etc.) of the antibody.

[0601] The 20 conventional amino acids mentioned herein are written according to conventional usage. See, for example, Immunology-A Synthesis (2nd Edition, ESGolub and DRGren, Eds., Sinauer Associates, Sunderland, Mass. (1991)), which is incorporated herein by reference. Where used herein, the terms “polypeptide” and “protein” have the same meaning and are used interchangeably. In addition, in this disclosure, amino acids are generally represented by one- and three-letter abbreviations well known in the art. For example, alanine may be represented by A or Ala, arginine by R or Arg, glycine by G or Gly, and glutamine by Q or Gln.

[0602] As used herein, the term “prevention” refers to methods taken to prevent or delay the onset of a disease, disorder, or condition (e.g., tumors and infections) in a subject. As used herein, the term “treatment” refers to methods taken to obtain a beneficial or desired clinical outcome. For the purposes of this disclosure, beneficial or desired clinical outcomes include, but are not limited to, symptom relief, reduction of disease severity, stabilization of the disease state (i.e., no worsening), delay or slowing of disease progression, improvement or mitigation of the disease state, and symptom relief (whether partial or complete), whether detectable or undetectable. In addition, “treatment” may also mean extending survival compared to the expected survival time (if no treatment is received).

[0603] As used herein, the term “Subject” refers to a mammal, for example, a non-human primate mammal or a primate mammal such as a human. In certain embodiments, the subject (e.g., a human) has or is at risk of having tumors and infectious diseases.

[0604] As used herein, the term “effective dose” means an amount sufficient to achieve, or at least partially achieve, the desired effect. For example, an effective dose for preventing a disease (e.g., tumors and infections) is an amount sufficient to prevent, stop, or delay the onset of the disease (e.g., tumors and infections). An effective dose for treating a disease is an amount sufficient to cure or at least partially stop the disease and its complications in a patient who already has the disease and its complications. Determining such an effective dose is entirely within the scope of the skills of those skilled in the art. For example, an effective dose for therapeutic use depends on the severity of the disease being treated, the overall state of the patient’s own immune system, the patient’s overall condition such as age, weight and sex, the method of administration of the drug, and other treatments administered concurrently.

[0605] As used herein, the term "effector function" refers to the biological activity resulting from the Fc region of an antibody (either the native sequence Fc region or the amino acid sequence variant Fc region), which varies depending on the antibody isotype.

[0606] The term "pharmaceutically acceptable" means that a molecule, molecular fragment, or composition, when appropriately administered to an animal or human, does not produce any harmful, allergic, or other adverse reaction. Specific examples of some substances that may be pharmaceutically acceptable carriers or components include sugars (e.g., lactose), starch, cellulose and its derivatives, vegetable oils, gelatin, polyols (e.g., propylene glycol), and alginic acid.

[0607] The in vivo therapeutic effects of antibodies and antibody-drug conjugates on cancer can be determined using experimental animals, for example, by administering antibodies to nude mice transplanted with B7H3-expressing tumor cell lines and measuring any changes in the cancer cells.

[0608] In this disclosure, amino acid substitutions in antibodies are, in most cases, substituted with L-amino acids, but are not limited thereto. In some embodiments, one or more D-amino acids may be included in the antibody peptide chain. Peptides containing D-amino acids are more stable and less susceptible to degradation in the oral cavity, intestines, or plasma than peptides containing only L-amino acids.

[0609] The monoclonal antibodies used in this disclosure can be produced by several methods. For example, the monoclonal antibodies used in this disclosure can be obtained by hybridoma technology using several species (including mouse, hamster, rat, and human-derived cells) (see, e.g., Kohler et al., 1975, Nature, 256:495), or by recombinant DNA technology (see, e.g., U.S. Patent No. 4,816,567), or by isolation from phage antibody libraries (see, e.g., Clackson et al., 1991, Nature, 352:624-628, and Marks et al., 1991, Journal of Molecular Biology, 222:581-597).

[0610] In this specification, the expressions “selected independently from each…” and “selected independently from each…” as used herein are interchangeable and should be understood in a broad sense, unless otherwise explicitly stated, to mean that in different groups, specific choices expressed for the same or different symbols do not affect each other, and may also mean that in the same group, specific choices expressed for the same or different symbols do not affect each other.

[0611] In this specification, the term “direct bond” is defined as Formula II [ka] This means that the groups on both sides of the compound are directly bonded, as shown by the compound. If X is directly bonded, then its structural formula is: [ka] Other direct connections can be understood by referring to the above.

[0612] As used herein, the term “non-existent” is defined as Formula II [ka] In compounds represented by this, it means that the group is absent, and if W is absent, the structural formula is: [ka] That is the case.

[0613] Formula II [ka] In the compound represented by, R1 and R2, together with the carbon atoms to which they are both bonded, [ka] The formula forms a heterocycle formed by the condensation of a benzene ring, for example, [ka] This indicates that it forms.

[0614] In this specification, Equation III [ka] In a drug linker conjugate represented by, L4 [ka] In this case, symbols 1 and 2 indicate the binding positions of L4 and other groups, specifically, when position 1 is bound to L3 and position 2 is bound to the drug molecule, i.e. [ka] This is formed. The remaining marks 1 and 2 can be understood by referring to the above content.

[0615] In this specification, Formula II [ka] In the compound represented by, R3 and X together with the carbon atoms to which they are both bonded [ka] The formula forms a heterocycle formed by condensation of a benzene ring, where the dotted line indicates that the heterocycle condenses with the benzene ring. [ka] This indicates that it forms.

[0616] In this specification, X is, for example, "X is optionally replaced." [ka] If defined as "selected from and having substituents selected from 1 or 2 C1-4 alkyl groups (e.g., methyl)", then X is, for example, [ka] It is possible. Other similar definitions of X can be understood by referring to the above.

[0617] In this specification, X is, for example, "X is optionally replaced." [ka] If defined as "selected from and having substituents selected from two C1-4 alkyl groups (e.g., methyl), both of which together with the carbon atom to which they are bonded, form a C3-6 cycloalkyl group (e.g., cyclopropyl)", then X is, for example, [ka] It is possible. Other similar definitions of X can be understood by referring to the above.

[0618] AA 1 In the structure of amino acid residues represented by, [ka] If r is 0, AA 1 Those skilled in the art will understand that the structure of the amino acid residue represented by is as follows. [ka]

[0619] AA 1 In the structure of amino acid residues represented by, [ka] R a and R b These together form a 4- to 10-membered heterocycle with the carbon atoms to which they are bonded, and one or more R4- to 10-membered heterocycles 0 If the substitution is optional, then "one or more R 4-10 member complex rings 0 The term "arbitrarily substituted" means that even if a 4- to 10-membered heterocycle is unsubstituted, it is not necessarily the case that it is substituted by one or more R12s. 0 It is also acceptable for them to be replaced by arbitrary selection, and multiple R 0 In each R 0 This means that the definition may be the same or different. Other similar definitions can be understood by referring to the above.

[0620] In this specification, for example, when L3 is selected from Lys, Val-Cit, Ala-Ala-Asn, Ala-Ala-Asp, Gly-Gly-Phe-Gly, Val-Lys-Gly, Val-Ala, and Lys-Ala-Asn, the statement "the distal amino group of lysine (Lys) is optionally substituted with one, two, or three substituents selected from tert-butoxycarbonyl, C1-6 alkyl (preferably methyl), and O" means that the distal amino group of Lys in each of the L3 options is optionally substituted with one, two, or three substituents selected from tert-butoxycarbonyl, C1-6 alkyl (preferably methyl), and O. "Distal amino group of Lys" refers to the lysine residue. [ka] This refers to the bare amino group -NH2 in . The phrase "the distal amino group of lysine (Lys) is optionally substituted with one, two, or three substituents selected from tert-butoxycarbonyl, C1-6 alkyl (preferably methyl), and O" indicates that the distal amino group of lysine (Lys) may not be substituted, or it may be substituted with one, two, or three substituents selected from tert-butoxycarbonyl, C1-6 alkyl (preferably methyl), and O. For example, it may be substituted with one tert-butoxycarbonyl group, i.e., it is, [ka] It may become, or it may be substituted with two methyl groups, that is, [ka] It may be substituted with two methyl atoms and one oxygen atom, that is, [ka] This means that "the distal amino group of lysine (Lys) is substituted with oxygen" means that the distal amino group of lysine (Lys) is substituted with oxo, that is, [ka] When the distal amino group is further substituted with two methyl groups, the distal amino group becomes [ka] It means that it will become.

[0621] In various parts of this specification, substituents of the compounds in this disclosure are disclosed according to the type or range of the group. Specifically, the present invention includes each individual secondary combination of each element of these types and ranges of groups. For example, the term "C1-6 alkyl" specifically refers to methyl, ethyl, C3 alkyl, C4 alkyl, C5 alkyl and C6 alkyl, which are disclosed independently.

[0622] As used herein, the term "C1-6 alkyl" refers to a linear or branched alkyl group containing 1 to 6 carbon atoms, such as "C1-3 alkyl" or "C1-4 alkyl," methyl, ethyl, etc. Specific examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl.

[0623] When used herein, "C 1~4 The term "alkyl" refers to linear or branched alkyl groups containing 1 to 4 carbon atoms, including, for example, "C1-3 alkyl," methyl, and ethyl. Specific examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0624] When used herein, "C 2~6 The term "alkenyl" refers to a linear, branched, or cyclic alkenyl group containing at least one double bond and 2 to 6 carbon atoms, for example, "C 2~4Examples include "alkenyls." Examples include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 1,3-butadienyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 1,3-pentadienyl, 1,4-pentadienyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 1,4-hexadienyl, cyclopentenyl, 1,3-cyclopentadienyl, cyclohexenyl, 1,4-cyclohexadienyl, etc., but are not limited to these.

[0625] When used herein, "C 2~6 The term "alkynyl" refers to a linear or branched alkynyl group containing at least one triple bond and 2 to 6 carbon atoms, for example, "C 2~4 Examples include "alkynyl," etc. Examples include ethinyl, propynyl, 2-butynyl, 2-pentynyl, 3-pentynyl, 4-methyl-2-pentynyl, 2-hexynyl, 3-hexynyl, and 5-methyl-2-hexynyl, but are not limited to these.

[0626] As used herein, the term "halogen" includes fluorine, chlorine, bromine, and iodine.

[0627] As used herein, "3-6 membered cycloalkyl" or "C 3~6 The term "cycloalkyl" refers to saturated cyclic alkyl groups containing 3 to 6 carbon atoms, including cyclopropanyl (i.e., cyclopropyl), cyclobutanyl (i.e., cyclobutyl), cyclopentanyl (i.e., cyclopentyl), and cyclohexyl.

[0628] As used herein, "3-7 membered carbocycloalkyl" or "C 3~7 The term "cycloalkyl" refers to saturated cyclic alkyl groups containing 3 to 7 carbon atoms, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

[0629] When used herein, "C 1~6The term "alkoxy" refers to the alkyl group defined above, which is bonded to the parent molecule by an oxygen atom. Specific examples include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, pentoxy, and hexyloxy.

[0630] When used herein, "C 1~4 The term "alkoxy" refers to the alkyl group defined above, which is bonded to the parent molecule by an oxygen atom. Specific examples include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, and tert-butoxy.

[0631] As used herein, the term “4- to 10-membered heterocyclic group” means a cyclic group containing 4 to 10 ring atoms, where at least one ring atom is a heteroatom such as nitrogen, oxygen, or sulfur. The term “4- to 6-membered heterocyclic group” means a cyclic group containing 4 to 6 ring atoms (where at least one ring atom is a heteroatom such as nitrogen, oxygen, or sulfur). Optionally, the ring atoms in the cyclic structure (e.g., carbon, nitrogen, or sulfur) may be substituted with oxygen. Examples of "4- to 8-membered heterocyclic groups" include "4- to 8-membered nitrogen-containing heterocyclic groups," "4- to 8-membered oxygen-containing heterocyclic groups," "4- to 7-membered heterocyclic groups," "4- to 7-membered oxygen-containing heterocyclic groups," "4- to 7-membered heterocyclic groups," "4- to 6-membered heterocyclic groups," "4- to 6-membered heterocyclic groups," "5- to 7-membered heterocyclic groups," and "5- to 6-membered nitrogen-containing heterocyclic groups," and include, but are not limited to, oxocyclobutanil, pyrrolidinil, tetrahydrofuryl, piperdinil, piperazinil, tetrahydropyranil, and homopiperazinil.

[0632] As used herein, the term "4- to 10-membered heterocycle" refers to a ring containing 4 to 10 ring atoms (at least one of which is a heteroatom, such as a nitrogen, oxygen, or sulfur atom). The term "5- to 6-membered heterocycle" refers to a ring containing 5 to 6 ring atoms (at least one of which is a heteroatom, such as a nitrogen, oxygen, or sulfur atom), and includes, but is not limited to, pyrrolidine, tetrahydrofuran, piperidine, piperazine, and tetrahydropyran.

[0633] As used herein, the term "aryl" refers to aromatic monocyclic or polycyclic hydrocarbon groups, such as 6- to 10-membered aryls and 5- to 8-membered aryls. Specific examples include, but are not limited to, phenyl, naphthyl, anthracenyl, and phenanthryl. "6- to 10-membered aryl" refers to an aryl group having 6 to 10 ring atoms. "C6-10 aryl" refers to an aryl group containing 6 to 10 carbon atoms.

[0634] As used herein, the term “heteroaryl” refers to an aromatic cyclic group in which at least one ring atom is a heteroatom such as a nitrogen, oxygen, or sulfur atom. Optionally, the ring atom in the ring structure (e.g., carbon, nitrogen, or sulfur atom) may be substituted with oxygen. Specifically, 5-10 membered heteroaryls, 5-6 membered heteroaryls, 5-10 membered nitrogen-containing heteroaryls, 6-10 membered oxygen-containing heteroaryls, 6-8 membered nitrogen-containing heteroaryls, 5-8 membered oxygen-containing heteroaryls, e.g., furyl, thienyl, pyrrolyl, thiazolyl, isothiazolyl, thiadiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, imidazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4- Examples include, but are not limited to, oxadiazolyl, pyridyl, 2-pyridonyl, 4-pyridonyl, pyrimidinyl, 1,4-dioxynyl, 2H-1,2-oxazinyl, 4H-1,2-oxazinyl, 6H-1,2-oxazinyl, 4H-1,3-oxazinyl, 6H-1,3-oxazinyl, 4H-1,4-oxazinyl, pyridazinyl, pyrazinyl, 1,2,3-triazinyl, 1,3,5-triazinyl, 1,2,4,5-tetradinyl, azacycloheptatrielinyl, 1,3-diazacycloheptatrielinyl, and azacyclooctatetraenyl.

[0635] In this specification, bonds in structural formulas represented by a tilde "~" are intended to indicate that the structure represents a cis or trans isomer, or a mixture of cis and trans isomers in any ratio.

[0636] The term "drug-antibody ratio" or "DAR" refers to the amount of a drug, such as a small molecule toxin, bound to an antibody of an ADC. The DAR of an ADC can range from 1 to 16, but depends on the number of binding sites in the antibody, and therefore higher loadings (e.g., 20) are also possible. The term DAR can be used to refer to the amount of drug loaded onto a single antibody, or to refer to the average or mean DAR of a group of ADCs.

[0637] Beneficial effects of the present invention: Through extensive research, the present invention has provided a highly potent and highly cell-permeable bioactive drug (bioactive molecule or payload). This includes linker-driven ADC enrichment in the tumor microenvironment through the modification of linker physicochemical properties such as basicity and lipophilicity, linker-driven ADC enrichment through in vivo linker cleavage properties, and coupling modes between the targeting moiety and the linker. Combined with numerous in vitro and in vivo screenings and trials, these findings have provided a novel class of antibody-drug conjugates offering several remarkable technological advantages. The conjugate products obtained according to the above method have better solubility and superior chemical stability, and avoid the retro-Michael reaction of conventional maleimide-based ADCs. Therefore, the ADC products of this disclosure can have a high drug-to-antibody ratio (DAR). In some embodiments, the DAR value of the conjugate can reach 6 to 8. High bonding efficiency. In some embodiments, the bonding efficiency can reach or exceed 90%. Through numerous experimental studies, a class of linkers with high plasma stability has been discovered, which can be cleaved both intracellularly and extracellularly in the tumor microenvironment. The ADC products of this disclosure can achieve good antitumor effects in tumors with low or no antigen expression. By modifying the physical and chemical properties of the linker and the overall ADC molecule, the ADC product obtained according to the above method increases exposure in a relatively acidic tumor environment, and therefore the ADC product of this disclosure has better tumor tissue targeting. The ability of ADC to enrich in the tumor microenvironment increases the concentration ratio of the payload between the tumor and the blood. It reduces ADC mechanism-related toxicity (i.e., toxicity of ADC after binding to cell surface antigens and endocytosis in non-tumor tissues, or referred to as "on-target toxicity"), and therefore a higher therapeutic index can be achieved. The conjugates obtained according to the above method exhibit high stability in in vivo circulation, low cleavage of drug molecules in non-target tissues, and therefore reduce "off-target" toxicity caused by cleavage of toxins in non-target tissues. The bioactive molecules of the conjugate of the present invention have higher antitumor cell activity and therefore exhibit excellent bystander effects. As a result, ADCs can more effectively kill tumor cells with high antigen expression, as well as tumor cells that have low antigen expression or no antigen expression in tumor tissue. By utilizing the extracellular cleavage capability of the linker of the present invention in the tumor microenvironment, the toxin-linker of this disclosure can form antibody-drug conjugates with antibodies that do not possess endocytotic ability, and such antibody-drug conjugates have high in vivo antitumor activity. By utilizing both extracellular cleavage ability and tumor microenvironment enrichment ability, the toxin-linker of this disclosure can form antibody-drug conjugates with antibodies that lack endocytosis ability or are unable to bind to cell surface antigens, and such antibody-drug conjugates have high in vivo antitumor activity. The antibodies provided in this disclosure are highly humanized or fully human antibodies that can be safely administered to human subjects without inducing an immunogenic response. These molecules particularly involve antibody molecules that have high binding affinity to human and non-human B7H3 and cross-reactivity with B7H3 of non-human primates (e.g., cynomolgus monkeys). In conclusion, the linker, antibody, and ADC described herein have significant clinical value. [Brief explanation of the drawing]

[0638] Explanation of the diagram [Figure 1A] This involves the detection of the binding of anti-B7H3 antibody 1D1-01 to human B7H3-4IgG-His protein by ELISA.

[0639] [Figure 1B]This involves detecting the binding of the anti-B7H3 antibody 2E3-02 to the human B7H3-4IgG-His protein using ELISA.

[0640] [Figure 2A] This involves detecting the binding of anti-B7H3 antibody 1D1-01 to monkey B7H3-4IgG-His protein using ELISA.

[0641] [Figure 2B] This involves detecting the binding of anti-B7H3 antibody 2E3-02 to monkey B7H3-4IgG-His protein using ELISA.

[0642] [Figure 3A] This involves detecting the binding of the anti-B7H3 antibody 1D1-01 to MCF-7 tumor cells by flow cytometry.

[0643] [Figure 3B] This involves detecting the binding of the anti-B7H3 antibody 2E3-02 to MCF-7 tumor cells using flow cytometry.

[0644] [Figure 4A] This involves detecting the binding of the anti-B7H3 antibody 1D1-01 to A549 tumor cells by flow cytometry.

[0645] [Figure 4B] This involves detecting the binding of the anti-B7H3 antibody 2E3-02 to A549 tumor cells by flow cytometry.

[0646] [Figure 5] This involves detecting the binding of the anti-B7H3 antibody 2E3-02 to PC-3 tumor cells using flow cytometry.

[0647] [Figure 6A] This involves detecting the specific binding of the anti-B7H3 antibody 1D1-01 to the B7H3 protein.

[0648] [Figure 6B] This involves detecting the specific binding of the anti-B7H3 antibody 2E3-02 to the B7H3 protein.

[0649] [Figure 7A] This involves the detection of endocytosis of tumor cell A549 against candidate antibody 1D1-01.

[0650] [Figure 7B] This involves detecting endocytosis of tumor cell A549 against candidate antibody 2E3-02.

[0651] [Figure 7C] This involves the detection of endocytosis of tumor cell A549 against candidate antibody 202-2-1.

[0652] [Figure 8] This is the SEC profile before and after conjugation.

[0653] [Figure 9] This is assay I for anti-B7H3-ADCs that inhibit tumor growth in an NCI-HT29 xenograft model.

[0654] [Figure 10] This is assay II for anti-B7H3-ADCs that inhibit tumor growth in an NCI-HT29 xenograft model.

[0655] [Figure 11] This assay identifies anti-B7H3-ADCs that inhibit tumor growth in an NCI-H358 xenograft model.

[0656] [Figure 12] This assay is for anti-B7H3-ADC, which inhibits tumor growth in an esophageal squamous cell carcinoma (PDX) model.

[0657] [Figure 13]This assay is for anti-B7H3-ADCs that inhibit tumor growth in a prostate PDX model.

[0658] [Figure 14] This assay is for anti-Her3-ADCs that inhibit tumor growth in an NCI-H358 xenograft model.

[0659] [Figure 15] This is assay I for anti-Her3-ADCs that inhibit tumor growth in the SW480 xenograft model.

[0660] [Figure 16] This is assay II for anti-Her3-ADCs that inhibit tumor growth in the SW480 xenograft model.

[0661] [Figure 17] This shows the distribution ratio of A1.9 in plasma and tumors in the HT29 model.

[0662] [Figure 18] This shows the distribution ratio of ADCs in plasma and tumors in the HT29 model.

[0663] [Figure 19A] This is the detection result of incubation of antibody-drug conjugates in tumor homogenates.

[0664] [Figure 19B] This is the incubation result of antibody-drug conjugates in muscle tissue homogenates. [Examples]

[0665] The present disclosure will be further illustrated below by specific examples, but this will not limit the present disclosure. Based on the teachings of the present disclosure, those skilled in the art can make various modifications or improvements without departing from the basic spirit and scope of the present disclosure. Reagents or equipment used without manufacturer's instructions are conventional products available on the market.

[0666] The abbreviations used in this disclosure have the following meanings: [Table 8] Sequence and its specific information: [Table 9-1] [Table 9-2] [Table 9-3] [Table 9-4] Next, the Disclosure will be described with reference to the following embodiments, which are intended to illustrate (but do not limit) the Disclosure.

[0667] Unless otherwise specified, the molecular biological experimental and immunodetection methods used in this disclosure are essentially based on the methods described in J. Sambrook et al., Molecular Cloning: Laboratory Handbook, 2nd Edition, Cold Spring Harbor Laboratory Press, 1989, and FMAusubel et al., Short Protocols in Molecular Biology, 3rd Edition, John Wiley & Sons, Inc., 1995. Those skilled in the art will understand that these examples are illustrative of this disclosure and are not intended to limit the scope of protection claimed herein.

[0668] Preparation Procedure The structures of the compounds described in the following examples are based on nuclear magnetic resonance ( 1 The determination was made by 1H NMR or mass spectrometry (MS).

[0669] Nuclear magnetic resonance ( 1 The instrument used to detect 1H NMR is a Bruker 400 MHz nuclear magnetic resonance spectrometer, the test solvent is deuterated methanol (CD3OD), deuterated chloroform (CDCl3), or hexavalent dimethyl sulfoxide (DMSO-d6), and the internal standard is tetramethylsilane (TMS).

[0670] The abbreviations for the nuclear magnetic resonance (NMR) spectra used in the examples are shown below.

[0671] s: singlet, d: doublet, t: triplet, q: quartet, dd: double doublet, qd: quartet doublet, ddd: double double doublet, ddt: double double triplet, dddd: double double double doublet, m: multiplet, br: broad, J: coupling constant, Hz: Hertz, DMSO-d6: deuterated dimethyl sulfoxide. δ values ​​are expressed in ppm.

[0672] An Agilent (ESI) mass spectrometer (model Agilent 6120B) was used as the instrument for testing mass spectrometry (MS).

[0673] I. Synthesis of bioactive molecules and intermediates used in the synthesis procedure of "drug-linker compounds". A. Synthesis of bioactive molecules Example A1.1: Synthesis of (S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-11-(1H-pyrazole-4-yl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolidino[1,2-b]quinoline-3,14(4H)-dione (A1.1) [ka] Step 1: Dissolve 4-bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole (4.6 g) in anhydrous tetrahydrofuran (50 ml), cool the solution to -78°C in dry ice-acetone under nitrogen protection, and then add n-butyllithium (12 ml, 2 M) dropwise. Stir the reaction solution at -78°C for 20 minutes, then add methyl 2-amino-4-fluoro-5-methylbenzoate (1.83 g). After the addition, allow the reaction mixture to rise naturally to room temperature and stir continuously for 5 hours. Quench the reaction mixture by adding methanol (3 ml), then add ethyl acetate (200 ml). Wash the solution with water (100 ml x 3), and then dry the organic phase. The organic solvent was removed, and the residue was separated by silica gel column chromatography to obtain the target product (2-amino-4-fluoro-5-methylphenyl)(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-yl)methanone. ESI-MS (m / z): 304[M+H] + .

[0674] Step 2: (S)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indridine-3,6,10(4H)-trione (2.63 g), (2-amino-4-fluoro-5-methylphenyl)(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-yl)methanone (3.03 g), and p-toluenesulfonic acid (1.74 g) were dissolved in dichloromethane (50 ml), and the solvent was removed. The mixture was heated to 120°C under nitrogen protection and reacted for 4 hours. The mixture was dissolved in ethyl acetate (300 ml), the organic phase was washed with water (100 ml x 2), dried, and the organic solvent was removed. The residue was separated by silica gel column chromatography to obtain the target product (S)-4-ethyl-8-fluoro-4-hydroxy-9-methyl-11-(1H-pyrazole-4-yl)-1,12-dihydro-14H-pyrano[3',4':6,7]indolidino[1,2-b]quinoline-3,14(4H)-dione (A1.1). ESI-MS (m / z): 447[M+H] + .

[0675] Example A1.2: Synthesis of (S)-7-ethyl-7-hydroxy-14-(1H-pyrazole-4-yl)-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.2) [ka] Using the same method and reaction conditions as in Example A1.1, methyl 2-amino-4-fluoro-5-methylbenzoate was replaced with methyl 6-aminobenzo[d][1,3]dioxolane-5-carboxylate to obtain the target product (S)-7-ethyl-7-hydroxy-14-(1H-pyrazole-4-yl)-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.2). ESI-MS(m / z):459[M+H] + .

[0676] Example A1.3: Synthesis of (S)-14-(3-aminophenyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.3) [ka] Compound (A1.3-A) (1.4g), compound (A1.3-B) (2.2g), Pd2(DBA)3 (300mg), tricyclohexylphosphane (300mg), and potassium acetate (1.1g) were sequentially added to a mixed solvent of dioxane (30ml) and water (5ml). The mixture was heated to 100°C and reacted for 12 hours with stirring under nitrogen protection. After cooling, ethyl acetate (200ml) was added, and the resulting solution was washed with water (100ml). After drying, the target product (S)-14-(3-aminophenyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.3) was obtained by silica gel column chromatography. ESI-MS (m / z): 484[M+H] + .

[0677] Example A1.4: Synthesis of (S)-14-(4-aminophenyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.4) [ka] Compound (A1.4-A) (1.4g), compound (A1.4-B) (2.2g), Pd2(DBA)3 (300mg), tricyclohexylphosphane (300mg), and potassium acetate (1.1g) were sequentially added to a mixed solvent of dioxane (30ml) and water (5ml). The mixture was heated to 100°C and reacted for 12 hours with stirring under nitrogen protection. After cooling, ethyl acetate (200ml) was added, and the resulting solution was washed with water (100ml). After drying, the target product (S)-14-(4-aminophenyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.4) was obtained by separation by silica gel column chromatography.

[0678] ESI-MS (m / z): 484 [M+H]. + , 1 H NMR(400MHz,DMSO)δ7.56(s,1H),7.34(d,J=8.0Hz,2H),7.27(s,1H),7.14(s,1H),6.89(d,J= 7.8Hz,2H),6.26(s,2H),5.40(s,2H),5.05(s,2H),1.96-1.78(m,2H),0.88(t,J=7.2Hz,3H).

[0679] Example A1.5: Synthesis of (S)-14-(3-aminopropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.5) [ka] Step 1: Synthesis of (S)-14-(3-chloropropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione [ka] In an ice bath, a 75% sulfuric acid solution (5 ml) of compound (S)7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indeno[1,2-b]quinoline-8,11(7H)-dione (A1.5-A, 500 mg) was mixed with ferrous sulfate heptahydrate (570 mg of ferrous sulfate heptahydrate dissolved in 1 ml of water) and 4-dimethoxychlorobutane (3.89 g). The reaction solution was stirred for 3 minutes, and then hydrogen peroxide (29%, 2.5 ml) was added dropwise. The reaction solution was stirred at 0°C for 5 minutes, then heated to room temperature, and reacted for 3 hours with stirring. The reaction solution was diluted with water (50 ml) and extracted with ethyl acetate (80 ml x 2). The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated to obtain the crude product. This was further purified by C18 column chromatography (acetonitrile / 0.05% formic acid aqueous solution: 5%~60%) to obtain the target compound (yellow solid, 400 mg, yield: 67%).

[0680] LCMS(ESI)[M+H] + :468.9, 1 H NMR(400MHz,DMSO-d6)δ7.65(s,1H),7.51(s,1H),7.24(s,1H),6.50(s,1H),6.30(s,2H),5.42(s, 2H),5.26(s,2H),3.81(d,J=5.9Hz,2H),3.22(s,2H),1.98(d,J=6.7Hz,4H),0.88(t,J=7.2Hz,3H).

[0681] Step 2: Synthesis of (S)-14-(3-azidopropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione [ka] To a solution of compound (S)-14-(3-chloropropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (200 mg) in N,N-dimethylformamide (3 ml), sodium azide (284 mg) was added, and the reaction solution was stirred at 100°C for 1 hour. Water (30 ml) was added to the reaction solution, and the resulting solution was extracted with ethyl acetate (60 ml x 2). The organic phase was washed with saturated saline solution, dried over anhydrous sodium sulfate, and concentrated to obtain the target compound (S)-14-(3-azidopropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (yellow solid, 180 mg, yield: 88%).

[0682] LCMS(ESI)[M+H] + :476, 1 H NMR(400MHz,DMSO-d6)δ7.65(s,1H),7.51(s,1H),7.24(s,1H),6.48(s,1H),6.29(s,2H),5.42(s, 2H),5.25(s,2H),3.53-3.49(m,2H),3.16-3.12(m,2H),1.93-1.80(m,4H),0.88(t,J=7.2Hz,3H).

[0683] Step 3: Synthesis of (S)-14-(3-aminopropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione [ka] To a mixed solvent solution of compound (S)-14-(3-azidopropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (130 mg, 0.274 mmol) in tetrahydrofuran (3 ml) and water (1 ml), triphenylphosphine (108 mg, 0.411 mmol) was added, and the mixture was reacted at 55°C for 16 hours. LC-MS indicated that the reaction was complete. After adding water (5 ml) to the reaction solution, the resulting solution was acidified with 2N hydrochloric acid (3 ml) and then extracted with ethyl acetate (10 ml). The aqueous phase was purified by high-performance liquid chromatography (HPLC) (acetonitrile / 0.05% formic acid aqueous solution) to obtain the target compound (S)-14-(3-aminopropyl)-7-ethyl-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.5, yellow solid, 15 mg, yield: 12%).

[0684] LCMS(ESI)[M+H]+:449.9, 1 H NMR(400MHz,DMSO-d6)δ7.72(s,3H),7.53(s,1H),7.25(s,1H),6.50(s,1H),6.30(s,2H),5.43(s,2H) ,5.24(s,2H),3.15(d,J=6.4Hz,2H),3.03(t,J=6.9Hz,2H),1.96-1.81(m,4H),0.88(t,J=7.3Hz,3H).

[0685] Example A1.6: Synthesis of (S)-N-ethyl-N-(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-14-yl)ethyl)-2-hydroxyacetamide (A1.6) [ka] Step 1: Preparation of (S)-2-(ethyl(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-14-yl)ethyl)amino)-2-oxoethyl acetate (A1,6-B): [ka] Compound (S)-7-ethyl-14-(2-(ethylamine)ethyl)-7-hydroxy-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-8,11(7H)-dione (A1.6-A, 50 mg), acetyloxyacetyl chloride (73 mg), and triethylamine (50 mg) were sequentially added to dichloromethane (5 ml), and the mixture was stirred and reacted at room temperature for 1 hour. The reaction solution was evaporated by rotation to remove the solvent and obtain 75 mg of crude oily compound.

[0686] LCMS(ESI)[M+H] + :564.2.

[0687] Step 2: Synthesis of (S)-N-ethyl-N-(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-14-yl)ethyl)-2-hydroxyacetamide (A1.6) [ka] The crude compound (S)-2-(ethyl(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-14-yl)ethyl)amino)-2-oxoethyl acetate (75 mg, 0.13 mmol) was dissolved in a mixed solution of concentrated hydrochloric acid and anhydrous ethanol (volume ratio 1 / 2, 3 ml), and the reaction solution was refluxed at 85°C for 1 hour. LC-MS indicated that the reaction was complete. The reaction solution was concentrated, and the crude product was purified by preparative chromatography (0.01% aqueous trifluoroacetic acid solution, acetonitrile) to obtain the target compound (S)-N-ethyl-N-(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-14-yl)ethyl)-2-hydroxyacetamide (A1.6) (15 mg, yield 26%) as a white solid.

[0688] LCMS(ESI)[M+H] + :522.0, 1 H NMR(400MHz,DMSO)δ7.92(s,1H),7.53(m,1H),7.25(s,1H),6.50(s,1H),6.31(s,2H),5.43(s,2H),5.34(m,2H),4. 65(m,1H),4.07(m,2H),3.52(m,2H),3.41(m,2H),2.00(m,2H),1.88(m,2H),1.16-1.04(m,3H),0.89-0.83(m,3H).

[0689] Example A1.7: Synthesis of (S)-N-methyl-N-(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3',4':6,7]indolidino[1,2-b]quinoline-14-yl)ethyl)-2-hydroxyacetamide (A1.7) [ka] Step 1: Preparation of the compound benzylmethyl(3-(6-nitrobenzo[d][1,3]dioxol-5-yl)-3-oxopropyl)carbamate [ka] Compound 1-(6-nitrobenzo[d][1,3]dioxin-5-yl)ethane-1-one (A1.7-A, 500 mg), methylamine hydrochloride (1.6 g), and paraformaldehyde (714 mg) were dissolved in ethanol (8 ml), and the mixture was reacted in a sealed container at 100°C for 16 hours. The reaction solution was cooled to room temperature and concentrated under reduced pressure. The resulting residue was dissolved in dichloromethane (80 ml), and the organic phase was extracted with water (50 ml x 3). The resulting aqueous phase was adjusted to pH=9 with sodium bicarbonate, and then benzyl chloroformate (513 mg, 3.0 mmol) was added. The reaction was carried out at room temperature for 16 hours. The reaction solution was extracted with ethyl acetate (30 ml x 3), the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. This was separated and purified by C18 column chromatography (acetonitrile / 0.05% formic acid-containing water = 5-95%) to obtain the target compound (A1.7-B, 180 mg, yield 23%).

[0690] LCMS(ESI)[M+H] + :387.1.

[0691] 1 H NMR (400MHz, CDCl3) δ7.56(s,1H),7.35(m,5H),7.32(m,1H),6.17(s,2H),5.13(s,2H),3.71(m,2H),3.03(m,3H),2.99-2.86(m,2H).

[0692] Step 2: Preparation of compound benzyl(3-(6-aminobenzo[d][1,3]dioxin-5-yl)-3-oxopropyl)(methyl)carbamate(A1.7-C). [ka] Compound A1.7-B, methylbenzyl(3-(6-nitrobenzo[d][1,3]dioxol-5-yl)-3-oxopropyl)carbamate (180 mg, 0.47 mmol), was dissolved in a mixed solution of saturated ammonium chloride aqueous solution (8 ml) and ethanol (8 ml). Iron powder (130 mg) was then added to the reaction solution. The reaction mixture was stirred at 80°C for 2 hours. The reaction solution was filtered, and the filtrate was concentrated to a solid under reduced pressure. The crude product was purified by TLC (petroleum ether:ethyl acetate = 2 / 1) to obtain target compound A1.7-C (76 mg).

[0693] LCMS(ESI)[M+H] + :357.0.

[0694] Step 3: Preparation of benzyl(S)-(2-(7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyra...

Claims

1. Formula I-A or Formula I-B: 【Chemistry 1】 [During the ceremony, Tb is an anti-B7H3 antibody or its antigen-binding fragment, and the anti-B7H3 antibody or its antigen-binding fragment includes the complementarity-determining region (CDR) shown below, and the CDR is numbered according to the Kabat numbering system: HCDR1 consisting of the sequence of SEQ ID NO: 27, HCDR2 consisting of the sequence of SEQ ID NO: 28, HCDR3 consisting of the sequence of SEQ ID NO: 29, and / or LCDR1 consists of the sequence of sequence number 37, LCDR2 consists of the sequence of sequence number 38, and LCDR3 consists of the sequence of sequence number 39. Defined by; R １ and R ２ Each of these is independently selected from H, halogen, and C1-4 alkyl; or R １ and R ２ Together with the carbon atoms to which they are bonded, 【Chemistry 2】 The formula forms a benzene ring, where the dotted line indicates the location where the heterocycle is fused to the benzene ring; R ３ H is; X is 【Transformation 3】 Selected from, the first position is joined to the parent ring, and the second position is joined to O; R ａ and R ｂ One of them is H, and the other is, 【Chemistry 4】 And; R ｍ１ and R ｎ１ are each independently selected from H, C1-6 alkyl, C3-6 cycloalkyl and t-butoxycarbonyl; r １ is selected from 0, 1, 2, 3, 4 and 5; [q is a drug-to-ligand coupling ratio selected from any value between 0.1 and 16.0] A ligand-drug conjugate, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.

2. R ｍ１ and R ｎ１ Each is independently selected from H, C1-6 alkyl, C3-6 cycloalkyl, and t-butoxycarbonyl; R is optionally selected. ｍ１ and R ｎ１ However, each is independently selected from H and C1-6 alkyl groups, the ligand-drug conjugate according to claim 1, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.

3. R １ and R ２ However, together with the carbon atoms to which they are bonded, 【Transformation 5】 A ligand-drug conjugate according to claim 1 or 2, wherein the formula is formed such that the dotted line indicates the location where the heterocycle is condensed with the benzene ring, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.

4. formula: 【Transformation 6】 [In the formula, Tb and q are as defined in any one of claims 1 to 3.] A ligand-drug conjugate according to any one of claims 1 to 3, having, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.

5. A ligand-drug conjugate according to any one of claims 1 to 4, wherein q is a drug-to-ligand coupling ratio selected from any number between 2 and 8, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.

6. A ligand-drug conjugate according to any one of claims 1 to 5, wherein the anti-B7H3 antibody or its antigen-binding fragment comprises VH as described in SEQ ID NO: 23 and / or VL as described in SEQ ID NO:

33.

7. The ligand-drug conjugate according to claim 6, comprising an anti-B7H3 antibody or its antigen-binding fragment, the heavy chain described in SEQ ID NO: 47 and / or the light chain described in SEQ ID NO:

48.

8. The ligand-drug conjugate according to claim 7, comprising an anti-B7H3 antibody or its antigen-binding fragment, the heavy chain described in SEQ ID NO: 47 and the light chain described in SEQ ID NO:

48.

9. The following formula: 【Transformation 7】 [During the ceremony, Tb is an anti-B7H3 antibody having the heavy chain described in SEQ ID NO: 47 and the light chain described in SEQ ID NO: 48; q is between 1 and 10, preferably between 7.5 and 8.

5. A ligand-drug conjugate, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.

10. A process for preparing a ligand-drug conjugate according to any one of claims 1 to 9, Under suitable conditions in a suitable solvent, Tb and formula IIIA or IIIB: 【Transformation 8】 [During the ceremony, X, R １ , R ２ , R ３ , R ａ , R ｂ , and q are as defined in any one of claims 1 to 9; Lg is a leaving group, and is a halogen, sulfone group, or tertiary amine salt group (Me ３ N ＋ , Et ３ N ＋ ), diazonium salt group, -OMs, MeSO ２ - and CF ３ SO ３ - Selected from; Preferably, Lg is F, Cl and MeSO4. ２ - Selected from, the group of the tertiary amine salt is Me ３ N ＋ and Et ３ N ＋ Selected from, More preferably, Lg is F and MeSO ２ - Selected from the following: A process that includes carrying out a coupling reaction with a drug linker conjugate.

11. The process includes the step of performing a coupling reaction between Tb and a drug linker conjugate of formula IIIA or IIIB in a suitable solvent and under suitable conditions to form a C-S bond, Preferably, the molar ratio of Tb to the drug linker conjugate is 1:(1 to 20), Preferably, the coupling reaction is carried out in water and / or an organic solvent, and preferably, the organic solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, nitrile (e.g., acetonitrile), alcohol (e.g., methanol, ethanol), or any combination thereof, wherein the nitrile may be acetonitrile, and the alcohol may be methanol or ethanol. Preferably, the process further comprises a step of purifying the coupling product, preferably, the coupling product is purified by chromatography, preferably, the chromatography comprises one or more of ion exchange chromatography, hydrophobic chromatography, reversed-phase chromatography, or affinity chromatography, according to claim 10.

12. Compounds of formula IIIA or formula IIIB are as follows: Table 1-1 Table 1-2 Table 1-3 Table 1-4 A process according to claim 10 or 11, selected from the above.

13. An antibody or antigen-binding fragment thereof that binds to B7H3, wherein the antibody or antigen-binding fragment thereof (a) The heavy chain variable region VH described in Sequence ID No. 23, and (b) Light chain variable region VL as described in Sequence ID No. 33 An antibody that binds to B7H3, or an antigen-binding fragment thereof, including the above.

14. The heavy chain contains the CH described in Sequence ID No. 43, and The light chain contains CL as described in Sequence ID No.

44. The antibody or antigen-binding fragment thereof according to claim 13.

15. The antibody according to claim 13 or 14, or the antigen-binding fragment thereof, wherein the antibody comprises the heavy chain described in SEQ ID NO: 47 and the light chain described in SEQ ID NO:

48.

16. A multispecific antibody comprising an antibody or an antigen-binding fragment thereof according to any one of claims 13 to 15, and an additional antibody or a fragment thereof or an antibody mimetic, wherein the multispecificity is a bispecific antibody, a tripspecific antibody, or a quadruplespecific antibody.

17. An isolated nucleic acid molecule encoding an antibody or an antigen-binding fragment thereof according to any one of claims 13 to 15, or an isolated nucleic acid molecule encoding a multispecific antibody according to claim 16.

18. A vector comprising an isolated nucleic acid molecule as described in claim 17, wherein the vector is a cloning vector or an expression vector.

19. A host cell comprising an isolated nucleic acid molecule according to claim 17 or a vector according to claim 18.

20. A method for preparing an antibody or antigen-binding fragment thereof according to any one of claims 13 to 15, or a multispecific antibody according to claim 16, comprising: culturing host cells according to claim 19 under conditions that enable the expression of the antibody or antigen-binding fragment thereof; and recovering the antibody or antigen-binding fragment thereof, or the multispecific antibody, from the cultured host cell culture.

21. A ligand-drug conjugate according to any one of claims 1 to 9, wherein Tb is an antibody that binds to B7H3 according to any one of claims 13 to 15 or an antigen-binding fragment thereof, or a polyspecific antibody according to claim 16, or a process according to any one of claims 10 to 12.

22. An antibody-drug conjugate wherein the antibody is an antibody or antigen-binding fragment thereof according to any one of claims 13 to 15, or a multispecific antibody according to claim 16, wherein the antibody is linked by a linker to a coupling portion selected from detectable labels, radioisotopes, fluorescent agents, luminescent agents, colorants, enzymes, polyethylene glycol, radionuclides, nucleic acids, small molecule toxins, binding-active polypeptides, proteins, receptors, ligands, and other active agents that inhibit tumor cell proliferation and / or promote tumor cell apoptosis or necrosis.

23. A group of ligand-drug conjugates comprising a ligand-drug conjugate according to any one of claims 1 to 9, wherein the ligand-drug conjugate has two or more q values ​​in the group, and the mean value of the drug-antibody ratio (DAR) in the group of ligand-drug conjugates is selected from 7.5 to 8.

5.

24. A pharmaceutical composition comprising substance A and optionally one or more pharmaceutically acceptable adjuvants, wherein substance A is a ligand-drug conjugate according to any one of claims 1 to 9, 21 or 22, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof, or an antibody or antigen-binding fragment thereof according to any one of claims 13 to 15, or a multispecific antibody according to claim 16, or a nucleic acid molecule according to claim 17, or a vector according to claim 18, or a host cell according to claim 19, or a group of ligand-drug conjugates according to claim 23, and preferably the composition further comprises a pharmaceutically acceptable carrier and / or excipient.

25. The use of substance A or a pharmaceutical composition according to claim 24 for preparing an agent for the treatment and / or prevention of a disease associated with abnormal cell activity, wherein substance A is a ligand-drug conjugate according to any one of claims 1 to 9, 21 or 22, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof, or an antibody or antigen-binding fragment thereof according to any one of claims 13 to 15, or a multispecific antibody according to claim 16, or a nucleic acid molecule according to claim 17, or a vector according to claim 18, or a host cell according to claim 19, or a group of ligand-drug conjugates according to claim 23, wherein the disease associated with abnormal cell activity may be a cancerous disease. Preferably, the cancerous disease is selected from esophageal cancer, brain tumor, lung cancer, squamous cell carcinoma, bladder cancer, stomach cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colon cancer, rectal cancer, colorectal cancer, liver cancer, kidney cancer, urothelial carcinoma, epidermal cancer, non-Hodgkin lymphoma, central nervous system tumor, prostate cancer, or thyroid cancer, wherein the esophageal cancer is, for example, esophageal adenocarcinoma or esophageal squamous cell carcinoma, the lung cancer is, for example, small cell lung cancer, non-small cell lung cancer, or lung adenocarcinoma, the central nervous system tumor is, for example, glioma, glioblastoma multiforme, glioma, or sarcoma, and the colon cancer is, for example, human colon adenocarcinoma. Preferably, the cancerous disease is selected from colon cancer, colorectal cancer, colon adenocarcinoma, lung cancer, breast cancer, prostate cancer, and esophageal squamous cell carcinoma. More preferably, the cancerous disease is a cancerous disease related to B7H3, More preferably, the cancerous disease is breast cancer, or the lung cancer is non-small cell lung cancer.

Images