Bioactive matter conjugate as well as preparation method and application thereof

Abstract

The invention relates to a bioactive substance conjugate as well as a preparation method and application thereof, and particularly discloses a ligand drug conjugate as shown in a formula XV, a preparation method thereof and application of the ligand drug conjugate in prevention and / or treatment of diseases related to abnormal cell activity, including but not limited to prevention and / or treatment of tumor diseases. # imgabs0 #

Description

[0001] The applicant submitted a PCT application PCT / CN2022 / 073822 entitled “Biologically Active Conjugates and Preparation Methods and Uses Thereof” on January 25, 2022. The PCT application entered the Chinese national phase on September 7, 2022 with application number 202280003045.7. This application is a divisional application of the Chinese application.

[0002] This application claims the priority of Chinese patent application No. 2021101781361 with a filing date of 2 / 9 / 2021; claims the priority of Chinese patent application No. 2021103408065 with a filing date of 3 / 30 / 2021; claims the priority of Chinese patent application No. 202110825932X with a filing date of 7 / 21 / 2021; claims the priority of Chinese patent application No. 2021108259226 with a filing date of 7 / 21 / 2021, and the file of sequence listing txt was also filed on 7 / 21 / 2021 and Chinese patent application No. 2021108259226 at the same time; claims the priority of Chinese patent application No. 2021108259067 with a filing date of 7 / 21 / 2021, and the file of sequence listing txt was also filed on 7 / 21 / 2021 and Chinese patent application No. 2021108259067 at the same time. This application cites the full text of the above-mentioned Chinese patent application. The sequence listing contained in this application is part of the specification and is herein incorporated by reference in its entirety. Technical Field

[0003] The present disclosure belongs to the field of medical technology, and relates to bioactive substance conjugates (ligand-drug conjugates), compounds, drug-linker conjugates and preparation methods thereof, as well as their use in preventing and / or treating diseases associated with abnormal cell activity, including but not limited to preventing and / or treating tumor diseases. Background Art

[0004] Cytotoxic chemotherapy was once the standard treatment for cancer, but highly lethal cytotoxic molecules can kill normal cells and cause serious toxic side effects. Targeted anti-tumor drugs have become a hot topic in the field of tumor research today because they have both targeting and anti-tumor activity, but they often produce relatively large toxic side effects due to the target selectivity of targeted drugs, thus limiting the therapeutic effect of targeted drugs. Biological macromolecule drugs, such as antibodies or antibody fragments, have strong targeting, but have limited therapeutic effects on solid tumors, or have no therapeutic effect at all. ADC is a conjugate of antibodies and small molecule drugs, which combines the targeting effect of antibodies and the activity of biologically active molecules to become a biological missile with very promising efficacy and safety advantages. Antibodies guide ADCs to bind to target cells and are then internalized by cells. Small molecule drugs are released by enzymatic hydrolysis under the action of specific enzymes in cells to treat diseases.

[0005] ADC drugs have developed rapidly in recent years, and there are 14 ADCs on the market: (1) Mylotarg (Gemtuzumab Ozogamicin, Gemtuzumab (CD33)-Cazitamycin), CD33-positive acute myeloid leukemia (AML), approved by the FDA in 2000, withdrawn from the market in 2010, and re-launched in 2017; (2) Adcetris (Brentuximab Vedotin, CD30 monoclonal antibody-MMAE), classical Hodgkin lymphoma and anaplastic large cell lymphoma, approved by the FDA in 2011; (3) Kadcyla (Trastuzumab Emtansine, Trastuzumab (Her2)-Maytansine alkaloid TM1), HER2-positive breast cancer, approved by the FDA in 2013; (4) Besponsa (Inotuzumab Vedotin, CD30 monoclonal antibody-MMAE), classical Hodgkin lymphoma and anaplastic large cell lymphoma, approved by the FDA in 2011; (5) Lumoxiti (Moxetumomab pasudotox-tdfk, CD22-pseudomonas exotoxin), relapsed or refractory hairy cell leukemia (HCL), launched in 2018; (6) Polivy (Polatuzumab vedotin-piiq, CD79b-MMAE), relapsed or refractory diffuse large B-cell lymphoma (R / R DLBCL), launched in 2019; (7) Padcev (Enfortumab vedotin-ejfv, Nectin4-MMAE), locally advanced or metastatic urothelial carcinoma (UC), launched in 2019; (8) Enhertu (Famtrastuzumab vedotin-ejfv, Nectin4-MMAE), locally advanced or metastatic urothelial carcinoma (UC), launched in 2019; (10) BCMA ADC Belantamab mafodotin (GSK2857916); (11) CD19 ADC Zynlonta (loncastuximab tesirine); (12) EGFR ADC Akalux; (13) Her2 ADC vedicizumab RC48; (14) Tissue Factor ADC Tivadak (tisotumab vedotin).

[0006] ADC drugs are composed of three parts: antibodies, bioactive molecules (drug molecules) and linkers. The bioactive molecules are covalently coupled to the antibodies through linkers. In addition to targeting and bioactivity, the coupling method between bioactive molecules and antibodies is also one of the core of ADC drugs, which determines the uniformity and stability of the drugs, and greatly affects the pharmacokinetic properties and toxicity of ADCs. Improving the stability of the connection between bioactive molecules and antibodies will increase the stability of ADC systemic circulation and reduce the shedding of drugs in non-targeted tissues, thereby relatively increasing the amount of drugs brought into target cells and around target cells, increasing the release of bioactive molecules in and around target cells, and further enhancing efficacy and reducing toxicity. Therefore, increasing the stability of the connection between bioactive molecules and antibodies is one of the extremely important technical fields in ADC drug research.

[0007] There are two main ways to couple the 10 ADC antibodies and linkers currently on the market: (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 is a technology that can achieve site-specific coupling, that is, the carboxyl group of the linker is activated by an activating group, and then an amide bond is formed with the specific lysine ε-amino group in the antibody to complete the coupling. On the one hand, the site-specific quantitative coupling achieved through such amide bonds does not have broad-spectrum practicality and can only be used in certain specific situations; on the other hand, it is prone to hydrolysis under the action of enzymes in the body, resulting in the detachment of the bioactive molecules and antibodies before reaching the target cells, increasing toxicity. (2) The thiol (SH) group of the cysteine ​​of the antibody exists in the form of a disulfide bond. Opening the disulfide bond in the antibody can provide multiple free thiol groups as coupling sites. One method of coupling with the antibody thiol group is to react the free thiol group on the antibody with maleimide through Michael addition reaction, or a specific substrate and the free thiol group on the antibody through two Michael addition reactions to form a unique sulfur bridge bond. However, there are many literature reports that 30% or more of the ADCs obtained by the thiol Michael addition method will undergo reverse Michael addition in the systemic circulation, causing premature shedding of toxins and resulting in toxic reactions.

[0008] Antibody-drug conjugates can be divided into four generations based on their development history:

[0009] The first generation of antibody-drug conjugates are based on mouse antibodies, which have strong toxic side effects due to their complex immunogenicity.

[0010] The second generation of antibody-drug conjugates uses humanized or fully human antibodies based on the first generation, and the drug properties of the second generation of antibody-drug conjugates have been greatly improved. The first and second generation of antibody-drug conjugates are relatively random in the connection between antibodies and drugs, so the final antibody-drug conjugate product is a multi-component mixture. This type of drug is not only highly toxic, but also difficult to control in quality;

[0011] The third generation of antibody-drug conjugates uses humanized or fully human antibodies to simultaneously achieve site-specific and quantitative conjugation of toxin-linker and antibody, thereby generating uniform single-molecule antibody-drug conjugates. The toxicity and quality control of this type of antibody-drug conjugates are greatly improved compared to the second generation of antibody-drug conjugates.

[0012] The fourth generation of antibody-drug conjugates is based on the third generation and has innovated the toxin-linker. The fourth generation of antibody-drug conjugates changed the previous antibody-drug conjugate strategy based on highly toxic toxins, selected relatively low-toxic camptothecin molecules as bioactive ingredients, and adopted a high toxin-antibody ratio (DAR), such as a DAR value of 8. This type of ADC can also produce a good therapeutic effect on tumors with low expression of tumor surface antigens. Although the fourth generation of antibody-drug conjugates started late, due to its significant efficacy, it has emerged as a dark horse and quickly gained clinical recognition. Its representative drugs Enhertu and Trodelvy have been approved for marketing by the FDA. However, the fourth generation of ADCs still have problems with poor stability or low solubility, and the existing technology lacks universality. It is still necessary to further develop new toxin-linkers to solve these problems.

[0013] Existing antibody-drug conjugates generally bind to the antibody in the ADC and the surface antigen of the tumor cell, then undergo endocytosis into the endosome, and then transform from the endosome to the lysosome. Then, under the action of hydrolases in the lysosome, the bioactive molecules (toxins or payloads) are dissociated from the ADC. The dissociated bioactive molecules enter the cytoplasm from the lysosome and kill the tumor cells. The bioactive molecules that escape from the killed tumor cells can further kill the surrounding tumor cells that do not express or express low antigens (the so-called bystander effect). In this whole process, changes in any link can make the ADC resistant and lose its therapeutic effect, such as changes in antigen expression during treatment, weakened or even lost endocytosis, changes in endosome or lysosome function, etc. Therefore, it is necessary to find an ADC that can be stable in the blood circulation system in the body, and at the same time, this ADC can produce extracellular lysis in the tumor microenvironment without the need for cell endocytosis to dissociate and detach the toxin to kill the tumor. This ADC will be able to overcome the various drug resistance mechanisms of traditional ADCs, and will therefore be of great significance in clinical treatment.

[0014] Although there is evidence that Immunomedics and Gilead's Trodelvy can be cleaved outside tumor cells without the need for endocytosis, Trodelvy is very unstable in plasma and aqueous solutions, with a plasma half-life of less than 24 hours. Therefore, this type of ADC can only be used for ADCs composed of toxins with low biological activity to avoid non-targeted toxic side effects caused by premature shedding of ADC toxins.

[0015] In addition, the function of the linker of traditional ADC is to complete enzymatic cleavage in cells or use it to regulate water solubility. How to make the linker meet the requirements of enzymatic cleavage while using the linker to achieve the enrichment of ADC in tumor tissue is also of great significance to reducing the toxic side effects of ADC in normal tissues.

[0016] In addition, B7H3 is a type I transmembrane protein of the B7 family, and has two isoforms in the human body, 2Ig-B7H3 and 4Ig-B7H3. B7H3 is widely expressed in normal tissues, constitutively expressed only in non-immune resting fibroblasts, endothelial cells, osteoblasts and amniotic fluid stem cells, and inducibly expressed on activated T, NK, DC and macrophages, and no positive expression was 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 about 76.5% of early liver cancer patients have serum B7H3 levels about three times higher than normal people (60.79±19.45Vs 20.52±8.46ng / mL), but its correlation with the disease progression is still 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).

[0017] Currently, there are therapeutic strategies targeting B7H3 in preclinical studies. For example, antibodies against mouse B7H3 will enhance CD8-positive T cells infiltrating tumors and inhibit tumor growth (Mod Pathol. 2010Aug; 23(8): 1104-12.). In addition, WO2008 / 066691 shows that antibodies that recognize the B7H3 variant B7H3a have anti-tumor effects on adenocarcinoma in vivo. In clinical studies, a combination drug of mouse B7H3 antibody and radioactive iodine 131 can significantly inhibit the growth of neuroblastoma in patients [Jneufoocol 97(3): 409-18(2010)]. Summary of the invention

[0018] In order to improve the therapeutic effect of antibody drug conjugates (ADC) or other ligand drug conjugates (PDC), reduce drug toxicity and side effects, and increase the therapeutic window, the present disclosure provides a ligand drug conjugate shown in formula (XV) or a pharmaceutically acceptable salt or solvate thereof, which contains a bioactive molecule (drug molecule), a linker and a targeting portion, and the targeting portion is connected to the linker through an active group (such as a thiol group) to form a ligand drug conjugate. The present disclosure also develops a variable light chain domain and / or a variable heavy chain (VH) domain that binds to a B7H3 molecule, and the variable light chain domain and / or variable heavy chain (VH) domain antibody is already from a human antibody.

[0019] To this end, in the first aspect of the present disclosure, the present disclosure provides a ligand drug conjugate as shown in formula XV,

[0020]

[0021] or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof,

[0022] in:

[0023] Tb is a ligand or targeting moiety that binds to the target;

[0024] q is the drug-ligand coupling ratio;

[0025] D is a bioactive molecular fragment;

[0026] L 1 is an extension unit;

[0027] L 2 Does not exist or is a connecting unit; L 3 Selected from amino acid residues or short peptides consisting of 2-10 amino acid residues;

[0028] L 4 Does not exist or exists, L 4When present, L 4 Selected from

[0029] 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[0030] In addition, it should be noted that for “L 1 The 1 position of L is connected to Tb via an S atom. It can be understood by those skilled in the art that 1 The 1 position of L is connected to the thiol group contained in Tb (such as an antibody) after the disulfide bond is opened (for example, the disulfide bond can be opened by reducing the disulfide bond with the reducing agent TCEP to generate a thiol group -SH). 1 The -S- between Tb and the -S- is not an additional sulfur atom. In the above figure, -S- is not an additional sulfur atom, but the thiol group contained in Tb after the disulfide bond is opened. 1 For example The 1 bit is connected to form -S-.

[0031] The extension unit is a component of the ligand drug conjugate or drug linker conjugate or linker, and its function is to connect the ligand or targeting part that binds to the target to the rest of the ligand drug conjugate or the rest of the linker. The extension unit can connect the Tb unit to the L 2 (if present) or L 3 Specific examples include but are not limited to (wherein position 1 is connected to a target-binding ligand or targeting moiety, position 2 is connected to L 2 or L 3 Connected):

[0032] In some embodiments, L 1 Selected from:

[0033]

[0034]

[0035]

[0036]

[0037] Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl group, a 5-10 membered heteroaryl group, an amide group, a sulfonamide group, an imine group, and a CF 2 ;

[0038] Rx and Ry are independently selected from H and C1-4 alkyl;

[0039] Each m is independently selected from 0, 1, 2, 3, 4, 5 and 6;

[0040] y1, y2, y3 and y4 are independently selected from any integer between 0 and 20;

[0041] The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0042] The linker is a component of a ligand-drug conjugate or a drug-linker conjugate or a linker, and its function is to combine the extension unit with an amino acid residue or a short peptide consisting of 2-10 amino acid residues. 1 Connect to L 3 Specific examples include but are not limited to (wherein position 1 is connected to the extension unit, position 2 is connected to L 3 Connected):

[0043] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from:

[0044]

[0045]

[0046] y1, y2, y3 and y4 are independently selected from any integer between 0 and 20, and 1 is the same as L 1 Connected, 2 bits and L 3 connected.

[0047] In some embodiments, L 1 for

[0048] In some embodiments, L 1 Selected from Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl, a 5-10 membered heteroaryl and an amide group (preferably selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond); Rx and Ry are independently selected from H and a C1-4 alkyl group; each m is independently selected from 0, 1, 2, 3, 4, 5 and 6; y1 is independently selected from any integer between 1 and 6 (such as 4, 5, 6); each y2 is independently selected from any integer between 0 and 15 (such as 6-15); each y3 is independently selected from 1, 2 and 3; each y4 is independently selected from 0 and 1; the 1st position is connected to Tb through an S atom, and the 2nd position is connected to L 2 or L 3connected.

[0049] In some embodiments, L 1 Selected from m is selected from 2, 3, 4, y1 is selected from any integer between 1-6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0-10 (such as 6-10), each y3 is independently selected from 1 or 2, the 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0050] In some embodiments, L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0051] In some embodiments, L 1 Selected from

[0052] In some embodiments, L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0053] In some embodiments, L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0054] In some embodiments, L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0055] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from y1 is selected from any integer between 1 and 6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0 and 10 (such as 6-10), each y3 is independently selected from 1 or 2, each y4 is independently selected from 0 or 1, and the 1st position is the same as L 1 Connected, 2 bits and L 3 connected.

[0056] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected.

[0057] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected.

[0058] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected.

[0059] In some embodiments, L 2 Does not exist.

[0060] In some embodiments, L 2 Selected from

[0061] In some embodiments, L 3 selected from amino acid residues or short peptides consisting of 2-10 amino acid residues; the amino acid residues are selected from natural amino acid residues, non-natural amino acid residues, or selected from AA 1 The indicated amino acid residues or stereoisomers thereof.

[0062] In some embodiments, L 3 Selected from amino acid residues Val, D-Val, Cit, Phe, Lys, Lys(Ac), Leu, Gly, Ala, Asn, Asp, Arg, AA 1or 2 to 10 selected from Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, Asp, AA 1 A short peptide composed of amino acid residues.

[0063] In some embodiments, L 3 Selected from 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, Gl y-Gly-Arg, Ala-Ala-Asn, Gly-Gly-Phe, Val-Lys-Gly, Val-Lys-Gly-Gly, Val-Lys and Lys-Ala-Asn.

[0064] In some embodiments, L 3 Selected from AA 1 AA 1 -Gly, Val-Cit, Val-AA 1 -Gly, AA 1 -Ala-Asn and Gly-Gly-Phe-Gly.

[0065] In some embodiments, L 3 Selected from AA 1 and Val-AA 1 -Gly.

[0066] In some embodiments, L 3 Selected from Val-AA 1 -Gly.

[0067] In some embodiments, L 3 Selected from

[0068] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D is connected.

[0069] In some embodiments, L 3 Selected from

[0070]

[0071] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D is connected.

[0072] In some embodiments, L 3 Selected from

[0073] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D is connected.

[0074] In some embodiments, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D is connected.

[0075] In some embodiments, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D is connected.

[0076] In some embodiments, AA 1 The structures of the indicated amino acid residues are shown below,

[0077]

[0078] in:

[0079] R a , R b Each independently selected from H, And R a , R b Not at the same time H;

[0080] Or, R a With R b Together with the carbon atoms to which they are commonly attached, they form a 4-10 membered heterocyclic ring, wherein the 4-10 membered heterocyclic ring is optionally substituted by one or more R 0 replaced by;

[0081] r、r 1 Each is independently selected from any integer from 0 to 20;

[0082] R m1 , R n1 Each independently selected from H, C1-6 alkyl, C3-6 cycloalkyl and -COOR x1 ;

[0083] R x1 Selected from C1-6 alkyl;

[0084] Or, R m1 With R n1 Together with the nitrogen atom to which they are commonly attached, they form a 4-10 membered heterocyclic ring, wherein the 4-10 membered heterocyclic ring is optionally substituted by one or more R 0’ replaced by;

[0085] R z Selected from C1-6 alkyl;

[0086] R 0 , R 0’ Each independently selected from C1-6 alkyl, C3-6 cycloalkyl, -NR m2 R n2 and a 4-10 membered heterocyclic group optionally substituted by a C1-6 alkyl group;

[0087] R m2 , R n2 Each is independently selected from H and C1-6 alkyl.

[0088] In some embodiments, R a , R b Among them, either one is H and the other is selected from

[0089] In some embodiments, R a , R b Among them, either one is H and the other is selected from

[0090] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form the 0 Substituted 5-6 membered heterocyclic ring.

[0091] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form the 0 A substituted piperidine ring or a piperazine ring.

[0092] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form the 0 Substituted piperidine ring.

[0093] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form Carbon atom No. 1 is a and R b Carbon atoms that are linked together.

[0094] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form Carbon atom No. 1 is a and R b Carbon atoms that are linked together.

[0095] In some embodiments, r, r 1 Each is independently selected from 0, 1, 2, 3, 4 and 5.

[0096] In some embodiments, r, r 1 are each independently selected from 0 and 4.

[0097] In some embodiments, r, r 1 Either one is 0 and the other is 4.

[0098] In some embodiments, R m1 , R n1Each is independently selected from H, methyl, ethyl, n-propyl, n-butyl, -COOCH3, -COOCH2CH3, -COOCH2CH2CH3, -COOCH(CH3)2, -COOC(CH3)3 and -COOCH2CH2CH2CH3.

[0099] In some embodiments, R m1 , R n1 Each is independently selected from H, C1-6 alkyl, C3-6 cycloalkyl and tert-butyloxycarbonyl.

[0100] In some embodiments, R m1 , R n1 Each is independently selected from H and C1-6 alkyl.

[0101] In some embodiments, R m1 , R n1 Each is independently selected from H, methyl, ethyl and n-propyl.

[0102] In some embodiments, r, r 1 In the example, r is 4 and r 1 When R is 0, m1 , R n1 Each is independently selected from H, C1-6 alkyl (such as H, methyl); r is 0, r 1 When R is 4, m1 , R n1 Each is independently selected from C1-6 alkyl (such as methyl, ethyl, n-propyl), preferably selected from C2-6 alkyl (such as ethyl, n-propyl).

[0103] In some embodiments, R m1 With R n1 Together with the nitrogen atom to which they are attached, they form an optionally R 0’ Substituted 5-6 membered heterocyclic ring.

[0104] In some embodiments, R m1 With R n1 Together with the nitrogen atom to which they are attached, they form an optionally R 0’ A substituted piperidine ring or a piperazine ring.

[0105] In some embodiments, R m1 With R n1 Together with the nitrogen atoms they are connected to, they form Nitrogen atom No. 1 is m1 and R n1 Nitrogen atoms connected together.

[0106] In some embodiments, R z It is methyl.

[0107] In some embodiments, R 0 , R 0’ Each independently selected from C1-6 alkyl, -NR m2 R n2 and a 5-6 membered heterocyclic group optionally substituted by a C1-6 alkyl group.

[0108] In some embodiments, R 0 The 5-6 membered heterocyclic group is selected from C1-6 alkyl and substituted by C1-6 alkyl, and the 5-6 membered heterocyclic group is selected from piperidinyl and piperazinyl.

[0109] In some embodiments, R 0 The 5-6 membered heterocyclic group is selected from methyl, ethyl and methyl-substituted 5-6 membered heterocyclic group, wherein the 5-6 membered heterocyclic group is piperidinyl.

[0110] In some embodiments, R 0 The 5-6 membered heterocyclic group is selected from methyl and methyl-substituted 5-6 membered heterocyclic group, wherein the 5-6 membered heterocyclic group is piperidinyl.

[0111] In some embodiments, R 0 Selected from methyl, ethyl and

[0112] In some embodiments, R 0 Selected from methyl and

[0113] In some embodiments, R 0’ Selected from C1-6 alkyl and -NR m2 R n2 .

[0114] In some embodiments, R 0’ Selected from methyl and -NR m2 R n2 .

[0115] In some embodiments, R m2 , R n2 It is methyl.

[0116] In some embodiments, AA 1 The amino acid residues are selected from

[0117] In some embodiments, AA 1 The amino acid residues are selected from

[0118]

[0119] In some embodiments, AA 1The amino acid residues are selected from

[0120] In some embodiments, AA 1 The amino acid residues are selected from

[0121] In some embodiments, L 4 Does not exist or exists, L 4 When present, L 4 Selected from 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[0122] In some embodiments, L 4 Does not exist or exists, L 4 When present, L 4 for 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[0123] In some embodiments, L 4 Does not exist.

[0124] In some embodiments, L 4 Selected from 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[0125] In some embodiments, L 4 Selected from 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[0126] In some embodiments, The structure is selected from the following structural fragments:

[0127]

[0128] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof.

[0129] In some embodiments, the antibodies or antigen-binding fragments thereof and monoclonal antibodies or antigen-binding fragments thereof 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.

[0130] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof having endocytic or non-endocytic activity.

[0131] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof having endocytosis activity.

[0132] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has the activity of binding to free antigens in tumor tissues and / or tumor cell surface antigens.

[0133] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has the activity of being internalized by tumor cells and has the activity of binding to free antigens in tumor tissues or antigens on the surface of tumor cells.

[0134] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has the activity of being internalized by tumor cells and has the activity of binding to free antigens in tumor tissues and antigens on the surface of tumor cells.

[0135] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has the activity of being internalized by tumor cells and has no free antigen-binding activity in tumor tissues.

[0136] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has the activity of being internalized by tumor cells and has no activity of binding to tumor cell surface antigens.

[0137] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof having no endocytosis activity or weak endocytosis activity.

[0138] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has no activity of binding to free antigens in tumor tissues and / or tumor cell surface antigens.

[0139] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has no or weak endocytosis activity by tumor cells and has binding activity to free antigens in tumor tissues or antigens on the surface of tumor cells.

[0140] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has no or weak endocytosis activity by tumor cells and has binding activity to free antigens in tumor tissues and antigens on the surface of tumor cells.

[0141] In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has no activity of being endocytosed by tumor cells, or has weak endocytosis activity, and has no activity of binding to antigens on the surface of tumor cells. In some embodiments, Tb is an antibody or antigen-binding fragment thereof that has no activity of being endocytosed by tumor cells, or has weak endocytosis activity, and has no activity of binding to free antigens in tumor tissues.

[0142] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has no endocytosis activity by tumor cells and has no corresponding antigen in the human body.

[0143] In some embodiments, Tb is an antibody that does not bind to a tumor cell-associated antigen.

[0144] In some embodiments, the antibody or antigen-binding fragment thereof is selected from an IgG isotype antibody.

[0145] In some embodiments, the antibody or antigen-binding fragment thereof is selected from isotype IgG1, isotype IgG2, isotype IgG3 or isotype IgG4.

[0146] In some embodiments, the antibody or antigen-binding fragment thereof is an anti-chicken lysozyme human IgG1 isotype antibody.

[0147] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has the activity of binding to non-endocytic antigens (eg, ALCAM / CD166) on the surface of tumor cells.

[0148] In some embodiments, Tb is an antibody that binds to a tumor cell-associated antigen.

[0149] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has binding activity to free antigens in tumor tissues or antigens on the surface of tumor cells.

[0150] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof that has binding activity to free antigens in tumor tissues and antigens on the surface of tumor cells.

[0151] In some embodiments, Tb is an antibody or antigen-binding fragment thereof having B7H3-2Ig and / or B7H-4Ig.

[0152] In some embodiments, Tb is an antibody or an antigen-binding fragment thereof having a higher B7H3-4Ig binding activity than a B7H3-2Ig binding activity.

[0153] In some embodiments of the present disclosure, Tb is a ligand or targeting moiety that binds to a target.

[0154] In some embodiments, the target of Tb is selected from a target that is expressed higher in tumor cells than in normal cells.

[0155] In some embodiments, the target of Tb is selected from targets that are highly expressed in tumor cells and lowly expressed in normal cells.

[0156] 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, etc.

[0157] In some embodiments, the Tb is an antibody or an antigen-binding fragment thereof.

[0158] In some embodiments, Tb is a non-human antibody, a humanized antibody, a chimeric antibody, or a fully human antibody.

[0159] In some embodiments, Tb is a monoclonal antibody, a bispecific antibody, or a multispecific antibody.

[0160] In some embodiments, Tb is a monoclonal antibody or an antigen-binding fragment thereof.

[0161] In some embodiments, Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, an anti-Trop-2 antibody or an antigen-binding fragment thereof, an anti-Her 2 antibody or an antigen-binding fragment thereof, an anti-Her3 antibody or an antigen-binding fragment thereof, or an anti-EGFR antibody or an antigen-binding fragment thereof.

[0162] In some embodiments, Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, such as 1D1, 1D1-01, 2E3, 2E3-02 antibodies, enoblituzumab, mirzotamab, omburtamab or an antigen-binding fragment thereof.

[0163] The sequence of 1D1 is shown in SEQ ID NO: 1. The VH sequence of 1D1-01 is shown in SEQ ID NO: 3, and the VL sequence is shown in SEQ ID NO: 13. The heavy chain sequence of 1D1-01 is shown in SEQ ID NO: 45, and the light chain sequence is shown in SEQ ID NO: 46. The sequence of 2E3 is shown in SEQ ID NO: 2. The VH sequence of 2E3-02 is shown in SEQ ID NO: 23, and the VL sequence is shown in SEQ ID NO: 33. The heavy chain sequence of 2E3-02 is shown in SEQ ID NO: 47, and the light chain sequence is shown in SEQ ID NO: 48.

[0164] In some embodiments, Tb is an anti-B7H3 monoclonal antibody or an antigen-binding fragment thereof.

[0165] In some embodiments, Tb is an anti-Trop-2 antibody or an antigen-binding fragment thereof, such as datopotamab, sacituzumab, or an antigen-binding fragment thereof.

[0166] In some embodiments, Tb is an anti-Trop-2 monoclonal antibody or an antigen-binding fragment thereof.

[0167] In some embodiments, Tb is an anti-Her 2 antibody or an antigen-binding fragment thereof, such as anbenitamab, coprelotamab, disitamab, gancotamab, margetuximab, pertuzumab, timigutuzumab, zanidatamab, trastuzumab, pertuzumab or an antigen-binding fragment thereof.

[0168] In some embodiments, Tb is an anti-Her 2 monoclonal antibody or an antigen-binding fragment thereof, such as trastuzumab, pertuzumab, or an antigen-binding fragment thereof.

[0169] In some embodiments, Tb is an anti-Her3 antibody or an antigen-binding fragment thereof, such as barecetamab, duligotuzumab, elgemtumab, istiratumab, lumretuzumab, patritumab, seribantumab, zenocutuzumab, 202-2-1 antibody or an antigen-binding fragment thereof.

[0170] In some embodiments, Tb is an anti-Her3 monoclonal antibody or an antigen-binding fragment thereof.

[0171] In some embodiments, Tb is an anti-EGFR antibody or an antigen-binding fragment thereof, such as demupitamab, depatuxizumab, futuximab, imgatuzumab, laprituximab, losatuxizumab, matuzumab, modotuximab, necitumumab, nimotuzumab, panitumumab, pimurutamab, serclutamab, tomuzotuximab, zalutumumab, Cetuximab or an antigen-binding fragment thereof.

[0172] In some embodiments, Tb is an anti-EGFR monoclonal antibody or an antigen-binding fragment thereof.

[0173] In some embodiments, the antibody has an antibody that binds to an antigen but does not have endocytosis activity. In some embodiments, the antibody has an antibody that binds to antigens such as B7H3, CD20, CD19, CD30, GPNMB, Her2, Trop-2, EGFR, Her3, GD-2, CD79b, and BCMA but does not have endocytosis activity.

[0174] In some embodiments, the antibody has an antibody that binds to the B7H3 antigen but does not have endocytosis activity. For example, INV721 and I7-01 of WO2021168379A1. More specifically, the Anti-B7H3 antibody has a VH of SEQ ID NO: 2 and a VL of SEQ ID NO: 1 described in WO2021168379A1.

[0175] In some embodiments, the antibody has an antibody that binds to the GD2 antigen but does not have endocytosis activity. For example, INV721 and GD2-5 of WO2021168379A1. More specifically, the Anti-GD2 antibody has a VH of SEQ ID NO: 4 and a VL of SEQ ID NO: 3 described in WO2021168379A1.

[0176] In some embodiments, the antibody has an antibody that binds to the HER3 antigen but has no endocytosis activity, such as the ANTI-HER3 21F06 antibody shown in SEQ ID NO: 22 of US10808032B2.

[0177] In some embodiments, the antibody has the ability to bind to the CD20 antigen but not have endocytosis activity. Although so-called "type II" CD20-specific antibodies have been shown to be poorly internalized by CD20-positive target cells, other so-called "type I" CD20-specific antibodies have been found to be internalized and degraded to some extent, depending on the expression level of activating and inhibitory FcγRs on the target cells that interact with them. In some embodiments, the antibody has the ability to bind to the CD20 antigen but not have endocytosis activity is a "type II" CD20-specific antibody, such as obinutuzumab.

[0178] In some embodiments, the antibody has an antibody that binds to a non-endocytic (e.g., ALCAM / CD166) antigen activity. In some embodiments, the antibody is an antibody comprising VH of SEQ ID No: 73 and VL of SEQ ID No: 74, VH of SEQ ID No: 75 and VL of SEQ ID No: 76, VH of SEQ ID No: 77 and VL of SEQ ID No: 78, or VH of SEQ ID No: 79 and VL of SEQ ID No: 88 in EP3911682A1.

[0179] In some embodiments, the Tb is a targeting moiety, such as a ligand, a protein, a polypeptide, a non-protein agent (such as a sugar, RNA or DNA), an antibody analog, and the like.

[0180] In some embodiments, q is selected from any integer between 0.1-16.0; in a preferred embodiment, q is selected from any integer between 0.1-16.0.

[0181] In some embodiments, q is selected from any integer between 0.1-8.0. In a preferred embodiment, q is selected from any integer between 0.1-8.0.

[0182] In some embodiments, q is selected from any value between 2-8.

[0183] In some embodiments, q is selected from any value between 3-8.

[0184] In some embodiments, q is selected from any value between 4-8.

[0185] In some embodiments, q is selected from any value between 6-8.

[0186] In some embodiments, q is selected from any integer between 2-8.

[0187] In some embodiments, q is selected from any integer between 3-8.

[0188] In some embodiments, q is selected from any integer between 4-8.

[0189] In some embodiments, q is selected from any integer between 6-8.

[0190] In some embodiments, q is selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.

[0191] In some embodiments, q is selected from 2, 4, 6, and 8.

[0192] In the present disclosure, the bioactive molecular fragments are known in the art, in antibody-drug conjugates (or antibody-drug conjugates (ADC)), which can form a bioactive drug (e.g., a small molecule cytotoxic drug, including a group after losing an atom or atom group) or its derivative (e.g., a precursor) after the linker cleavage / degradation / enzymatic cleavage between tumor tissues or in tumor cells. In order to avoid ambiguity, "drug" does not only refer to "drugs" that have been approved by the medical regulatory authorities, but also includes any molecules with potential therapeutic biological activity in clinical, research and development, and academic research.

[0193] In some embodiments, D is a molecular fragment having anti-tumor biological activity.

[0194] In some embodiments, D is a fragment of a molecule with anti-tumor biological activity, wherein the biologically active molecule is selected from a cytotoxic agent or a derivative thereof, such as a DNA topoisomerase inhibitor (e.g., a camptothecin-type biologically active molecule, such as camptothecin, DXD, a camptothecin with a modified substituent, or a DXD with a modified substituent) or a microtubule inhibitor (e.g., an MMAF-type microtubule inhibitor, an MMAE-type microtubule inhibitor).

[0195] In some embodiments, the Ligand Drug Conjugate has the structure of Formula I:

[0196]

[0197] in,

[0198] R 1 , R 2 are each independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or,

[0199] R 1 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0200] R 3 Selected from H, halogen, -OH, -NH 2 , optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or,

[0201] R 3 and X together with the carbon atom to which it is attached form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof, or,

[0202] R 3 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0203] W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected;

[0204] X is selected from a direct bond, an optionally substituted -O-(CH 2) n3 -、-N(R 4 )-(CH 2 ) n3 -、-S-(CH 2 ) n3 -, carbonyl-(CH 2 ) n3 、-SO 2 -(CH 2 ) n3 -、 -(CH 2 ) n1 -, C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L 4 connected; the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups and the carbon atoms connected to them together form a C3-6 cycloalkyl group;

[0205] Each M is independently selected from a direct bond and -CR 5a R 5b -;

[0206] R 4 , R 5 , R 5a , R 5b , R 6 , R 7 Each is independently selected from H, optionally substituted C1-4 alkyl, optionally substituted C1-4 alkoxy and optionally substituted C3-6 cycloalkyl;

[0207] n, n', n1, n2, n3 are each independently selected from any integer between 0 and 6;

[0208] L 4 Does not exist or exists, L 4 When present, L 4 Selected from

[0209]

[0210] 1 bit and L 3 connected, 2 bits are connected to W or X.

[0211] Tb, L 1 , L 2 , L 3 and q have the meanings provided above and in any embodiments specifically described herein.

[0212] In some embodiments, R 1 , R2 Each is independently selected from H, halogen and C1-4 alkyl.

[0213] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached, it forms a 5-6 membered heterocyclic ring containing 1, 2 or 3 O, S or N or any combination thereof.

[0214] In some embodiments, R 1 is selected from H and halogen, R 2 Selected from H and C1-4 alkyl.

[0215] In some embodiments, R 1 and R 2 and the carbon atom to which it is attached The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring.

[0216] In some embodiments, R 1 H or F, R 2 It is H or methyl.

[0217] In some embodiments, R 1 For F, R 2 Methyl or R 1 and R 2 Together with the carbon atom to which it is attached,

[0218] In some embodiments, R 1 For F, R 2 It is methyl.

[0219] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached,

[0220] In some embodiments, R 3 Selected from H and C1-4 alkyl.

[0221] In some embodiments, R 3 Together with X and the carbon atom to which it is attached, it forms a 5-6 membered carbocyclic ring.

[0222] In some embodiments, R 3 H or R 3 Together with X and the carbon atom to which it is attached, The dotted lines indicate where the carbocyclic ring is fused to the benzene and pyridine rings.

[0223] In some embodiments, R 3 For H.

[0224] In some embodiments, W is absent or present, and when W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected.

[0225] In some embodiments, W is absent or present, and when W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected.

[0226] In some embodiments, W is selected from -O-, -NR 4 -and 1 bit is connected to X, 2 bits are connected to L 4 or L 3 connected.

[0227] In some embodiments, W is selected from -O- and -NR 4 -, 1 bit is connected to X, 2 bits are connected to L 4 or L 3 connected.

[0228] In some embodiments, X is selected from optionally substituted -(CH 2 ) n1 -、 C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L 4 connected; the substituent is selected from 1 or 2 C1-4 alkyl groups, or 2 C1-4 alkyl groups and the carbon atoms to which they are simultaneously connected together form a C3-6 cycloalkyl group.

[0229] In some embodiments, X is selected from optionally substituted Position 1 is connected to the mother ring, position 2 is connected to W or L 4 connected; the substituent is selected from 1 or 2 C1-4 alkyl groups (such as methyl), or 2 C1-4 alkyl groups (such as methyl) and the carbon atoms to which they are simultaneously connected together form a C3-6 cycloalkyl group (such as cyclopropyl).

[0230] In some embodiments, X is selected from and Position 1 is connected to the mother ring, position 2 is connected to W or L 4 connected.

[0231] In some embodiments, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0232] In some embodiments, when W is absent, X is selected from Position 1 is connected to the mother ring, position 2 is connected to L 4 When W exists, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0233] In some embodiments, W is selected from -O-, -NR 4 -and 1 bit is connected to X, 2 bits are connected to L 4 or L 3 Connected; X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0234] In some embodiments, R 4 , R 5 Each is independently selected from H, C1-4 alkyl and C3-6 cycloalkyl.

[0235] In some embodiments, each R 4 are independently selected from H, C1-4 alkyl and C3-6 cycloalkyl, R 5 For H.

[0236] In some embodiments, each R 4 R is independently selected from H, methyl, ethyl, n-propyl, isopropyl, tert-butyl and cyclopropyl, 5 For H.

[0237] In some embodiments, R 5a , R 5b Each is independently selected from H and C1-4 alkyl.

[0238] In some embodiments, R 5a , R 5b are each independently selected from H and methyl.

[0239] In some embodiments, each R 7 Independently selected from H and C1-4 alkyl.

[0240] In some embodiments, R 7 For H.

[0241] In some embodiments, n is selected from 1, 2, and 3.

[0242] In some embodiments, n is 1.

[0243] In some embodiments, n1 is selected from 1, 2, 3, and 4.

[0244] In some embodiments, n2 is 1.

[0245] In some embodiments, n3 is 0.

[0246] In some embodiments, L 3 Selected from

[0247] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0248] In some embodiments, L 3 Selected from

[0249] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0250] In some embodiments, L 3 Selected from X - Selected from halogen ions, carboxylate ions, sulfate ions and hydrogen sulfate ions, OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0251] In some embodiments, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0252] In some embodiments, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0253] In some embodiments, L 4 Does not exist or exists, L 4 When present, L 4 Selected from 1 bit and L 3 connected, 2 bits are connected to W or X.

[0254] In some embodiments, L 4 Does not exist or exists, L 4 When present, L 4 for 1 bit and L 3 connected, 2 bits are connected to W or X.

[0255] In some embodiments, L 4 Does not exist.

[0256] In some embodiments, L 4 Selected from 1 bit and L 3 connected, 2 bits are connected to W or X.

[0257] In some embodiments, L 4 Selected from 1 bit and L 3 connected, 2 bits are connected to W or X.

[0258] It should be noted that, as mentioned above, W does not exist or does exist. Therefore, when W does not exist, L 4 The 1 bit and L 3 connected, 2 connected to X; when W exists, L 4 The 1 bit and L 3 1 is connected to 1, and 2 is connected to W. 4 The connection relationship can be understood by referring to the above content.

[0259] In some embodiments, The structure is selected from the following structural fragments:

[0260]

[0261]

[0262]

[0263]

[0264] Among them, bit 1 is connected to Tb and bit 2 is connected to W.

[0265] In some embodiments, D is The structural fragment shown; position 1 and L 3 or L 4 Connection; e.g.

[0266] In some embodiments, The structure is selected from the following structural fragments:

[0267]

[0268]

[0269]

[0270] Among them, 1 and L 4 connected; when L 4 When not present, 1 bit and L 3 connected.

[0271] In some embodiments,

[0272] W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 For example, non-existent, -O-, -NR 4 -or R 4 and R 5 Each is independently selected from H and C1-4 alkyl; n is independently selected from 0, 1, 2, 3 and 4;

[0273] X is selected from

[0274] R 1 is selected from H, halogen, R 2 is selected from H, C1-4 alkyl, or, R 1 and R 2 and the carbon atom to which it is attached The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring;

[0275] R 3 is selected from H and C1-4 alkyl, or, R 3 Together with X and the carbon atom to which it is attached, it forms a 5-6 membered carbocyclic ring;

[0276] Preferably, W is absent or present, and when W is present, W is selected from -O-, -NR 4 -(e.g. -NH-, -N(CH 3 )-、-N(C 2 H 5 )-), R 4 independently selected from H, methyl, ethyl, isopropyl, n-propyl, tert-butyl and cyclopropyl;

[0277] When W does not exist, X is selected from 1 is connected to the parent ring; when W exists, X is selected from

[0278]

[0279] AA 1 wherein r is selected from 0, 1, 2, 3, 4 and 5;

[0280] R a , R b Among them, either one is H and the other is selected from Or, R a With R b Together with the carbon atoms they are connected to, they form the 0 substituted 5-6 membered heterocycle;

[0281] R 1 is selected from H, halogen, R 2 is selected from H, C1-4 alkyl, or, R 1 and R 2 and the carbon atom to which it is attached

[0282] R 3 is selected from H and C1-4 alkyl, or, R 3 Together with X and the carbon atom to which it is attached, form R 3 Together with X and the carbon atom to which it is attached,

[0283] More preferably, W is selected from -O- and -NR 4 -, 1 bit is connected to X, 2 bits are connected to L 4 or L 3 connected;

[0284] X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W;

[0285] for For example

[0286] R 1 For F,

[0287] R 2 Methyl or R 1 and R 2 Together with the carbon atom to which it is attached,

[0288] R 3 For H.

[0289] In some embodiments, the ligand drug conjugate has the structure of Formula I-1:

[0290]

[0291] Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q have the meanings provided above and in any embodiments specifically described herein.

[0292] In some embodiments, the ligand drug conjugate has a structure as shown in Formula I-1A or I-1B:

[0293]

[0294] Among them, Tb, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q have the meanings provided above and in any embodiments specifically described herein.

[0295] In some embodiments, the ligand drug conjugate has the structure of Formula I-2:

[0296]

[0297] Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3and q have the meanings provided above and in any embodiments specifically described herein.

[0298] In some embodiments, the ligand drug conjugate has a structure as shown in Formula I-2A or I-2B:

[0299]

[0300] Among them, Tb, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and q have the meanings provided above and in any embodiments specifically described herein.

[0301] In some embodiments, the ligand drug conjugate has the structure of Formula I-3:

[0302]

[0303] Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 , R 5 , n and q have the meanings provided above and in any embodiments specifically described herein.

[0304] In some embodiments, the ligand drug conjugate has a structure as shown in Formula I-3A or I-3B:

[0305]

[0306] Among them, Tb, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q have the meanings provided above and in any embodiments specifically described herein.

[0307] In some embodiments, the Ligand Drug Conjugate has the structure of Formula IA:

[0308]

[0309] Among them, Tb, X, R 1 , R 2 , R3 , R a , R b and q have the meanings provided above and in any embodiments specifically described herein.

[0310] In some embodiments, the Ligand Drug Conjugate has the structure of Formula IB:

[0311]

[0312] Among them, Tb, X, R 1 , R 2 , R 3 , R a , R b and q have the meanings provided above and in any embodiments specifically described herein.

[0313] In some embodiments, the ligand drug conjugate is selected from the following:

[0314]

[0315]

[0316]

[0317]

[0318]

[0319]

[0320]

[0321]

[0322]

[0323]

[0324]

[0325]

[0326]

[0327]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333]

[0334] The antibody or antigen-binding fragment of the Tb can be prepared by various methods known in the art, such as by genetic engineering recombinant technology. For example, DNA molecules encoding the heavy chain and light chain genes of the antibody of the present disclosure are obtained by chemical synthesis or PCR amplification. The obtained DNA molecules are inserted into expression vectors and then transfected into host cells. Then, the transfected host cells are cultured under specific conditions and express the antibody of the present disclosure.

[0335] In some embodiments of the present disclosure, the targeting moiety is an anti-B7H3 antibody or an antigen-binding fragment thereof. In some embodiments, the anti-B7H3 antibody includes all anti-B7H3 antibodies in the prior art, such as enoblituzumab, mirzotamab, omburtamab, and see CN112521512, WO2021027674, WO2021021543, WO2021006619, CN111662384, CN111454357, WO2020151384, WO2020140094, WO2020103100, WO2020102779, WO2020063673, WO2020047257, WO2020041626, CN112521512, WO2021027674, WO2021021543, WO2021006619, CN111662384, CN111454357, WO2020151384, WO2020140094, WO2020103100, WO2020102779, WO2020063673, WO2020047257, WO2020041626, CN112521512 Anti-B7H3 antibodies in 10684790, CN110642948, WO2019225787, WO2019226017, US20190338030, CN110305213, WO2018209346, WO2018177393, US9150656, WO2016106004, WO2016044383, WO2016033225, WO2015181267, US20120294796, WO2011109400, CN101104639, WO2004093894, WO2002010187, WO2001018021. In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof is selected from: antibody numbered M30-H1-L4 in CN103687945B and antibody numbered mAb-C-DUBA in CN 109069633A.

[0336] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the IMGT numbering system:

[0337] (a) HCDR1 of SEQ ID NO: 10, HCDR2 of SEQ ID NO: 11, and HCDR3 of SEQ ID NO: 12; and / or,

[0338] LCDR1 having a sequence of SEQ ID NO: 20, LCDR2 having a sequence of GTF, and LCDR3 having a sequence of SEQ ID NO: 22;

[0339] (b) HCDR1 of SEQ ID NO: 10, HCDR2 of SEQ ID NO: 11, and HCDR3 of SEQ ID NO: 12; and / or,

[0340] LCDR1 having a sequence of SEQ ID NO:40, LCDR2 having a sequence of GAS, and LCDR3 having a sequence of SEQ ID NO:42;

[0341] (c) HCDR1 of SEQ ID NO: 30, HCDR2 of SEQ ID NO: 31, and HCDR3 of SEQ ID NO: 32; and / or,

[0342] LCDR1 having a sequence of SEQ ID NO:40, LCDR2 having a sequence of GAS, and LCDR3 having a sequence of SEQ ID NO:42;

[0343] or

[0344] (d) HCDR1 with the sequence of SEQ ID NO: 30, HCDR2 with the sequence of SEQ ID NO: 31, and HCDR3 with the sequence of SEQ ID NO: 32; and / or,

[0345] The sequence of LCDR1 is SEQ ID NO:20, the sequence of LCDR2 is GTF, and the sequence of LCDR3 is SEQ ID NO:22.

[0346] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof, as defined by the IMGT numbering system, comprises:

[0347] A VH comprising (a) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (a) light chain LCDR1, LCDR2, LCDR3;

[0348] A VH comprising (b) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (b) light chain LCDR1, LCDR2, LCDR3;

[0349] A VH comprising (c) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (c) light chain LCDR1, LCDR2, LCDR3; or

[0350] (d) VH containing heavy chain HCDR1, HCDR2, HCDR3 and (d) VL containing light chain LCDR1, LCDR2, LCDR3.

[0351] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Chothia numbering system:

[0352] (a) HCDR1 of SEQ ID NO: 4, HCDR2 of SEQ ID NO: 5, and HCDR3 of SEQ ID NO: 6; and / or,

[0353] LCDR1 with the sequence of SEQ ID NO: 14, LCDR2 with the sequence of SEQ ID NO: 15, and LCDR3 with the sequence of SEQ ID NO: 16;

[0354] (b) HCDR1 of SEQ ID NO: 24, HCDR2 of SEQ ID NO: 25, and HCDR3 of SEQ ID NO: 26; and / or,

[0355] LCDR1 with the sequence of SEQ ID NO:34, LCDR2 with the sequence of SEQ ID NO:35, LCDR3 with the sequence of SEQ ID NO:36;

[0356] (c) HCDR1 of SEQ ID NO: 4, HCDR2 of SEQ ID NO: 5, and HCDR3 of SEQ ID NO: 6; and / or,

[0357] LCDR1 with the sequence of SEQ ID NO:34, LCDR2 with the sequence of SEQ ID NO:35, LCDR3 with the sequence of SEQ ID NO:36;

[0358] or

[0359] (d) HCDR1 of SEQ ID NO: 24, HCDR2 of SEQ ID NO: 25, and HCDR3 of SEQ ID NO: 26; and / or,

[0360] The sequence of LCDR1 is SEQ ID NO:14, the sequence of LCDR2 is SEQ ID NO:15, and the sequence of LCDR3 is SEQ ID NO:16.

[0361] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof, as defined by the Chothia numbering system, comprises:

[0362] A VH comprising (a) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (a) light chain LCDR1, LCDR2, LCDR3;

[0363] A VH comprising (b) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (b) light chain LCDR1, LCDR2, LCDR3;

[0364] A VH comprising (c) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (c) light chain LCDR1, LCDR2, LCDR3; or

[0365] (d) VH containing heavy chain HCDR1, HCDR2, HCDR3 and (d) VL containing light chain LCDR1, LCDR2, LCDR3.

[0366] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Kabat numbering system:

[0367] (a) HCDR1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR3 of SEQ ID NO: 9; and / or,

[0368] LCDR1 with the sequence of SEQ ID NO: 17, LCDR2 with the sequence of SEQ ID NO: 18, LCDR3 with the sequence of SEQ ID NO: 19;

[0369] (b) HCDR1 of SEQ ID NO: 27, HCDR2 of SEQ ID NO: 28, HCDR3 of SEQ ID NO: 29; and / or,

[0370] LCDR1 with the sequence of SEQ ID NO:37, LCDR2 with the sequence of SEQ ID NO:38, LCDR3 with the sequence of SEQ ID NO:39;

[0371] (c) HCDR1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR3 of SEQ ID NO: 9; and / or,

[0372] LCDR1 with the sequence of SEQ ID NO:37, LCDR2 with the sequence of SEQ ID NO:38, LCDR3 with the sequence of SEQ ID NO:39;

[0373] or

[0374] (d) HCDR1 of SEQ ID NO: 27, HCDR2 of SEQ ID NO: 28, and HCDR3 of SEQ ID NO: 29; and / or,

[0375] The sequence of LCDR1 is SEQ ID NO:17, the sequence of LCDR2 is SEQ ID NO:18, and the sequence of LCDR3 is SEQ ID NO:19.

[0376] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof, as defined by the Kabat numbering system, comprises:

[0377] A VH comprising (a) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (a) light chain LCDR1, LCDR2, LCDR3;

[0378] A VH comprising (b) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (b) light chain LCDR1, LCDR2, LCDR3;

[0379] A VH comprising (c) heavy chain HCDR1, HCDR2, HCDR3 and a VL comprising (c) light chain LCDR1, LCDR2, LCDR3; or

[0380] (d) VH containing heavy chain HCDR1, HCDR2, HCDR3 and (d) VL containing light chain LCDR1, LCDR2, LCDR3.

[0381] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises:

[0382] (a) a heavy chain variable region (VH) comprising an amino acid sequence selected from the group consisting of:

[0383] (i) the sequence shown in SEQ ID NO: 3 or 23;

[0384] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in SEQ ID NO: 3 or 23 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof); or

[0385] (iii) a sequence 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 compared to the sequence set forth in SEQ ID NO: 3 or 23;

[0386] and / or

[0387] (b) a light chain variable region (VL) comprising an amino acid sequence selected from the group consisting of:

[0388] (iv) the sequence shown in SEQ ID NO: 13 or 33;

[0389] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in SEQ ID NO: 13 or 33 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof); or

[0390] (vi) a sequence 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 compared to the sequence set forth in SEQ ID NO:13 or 33.

[0391] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the VH shown in SEQ ID NO:3, and / or the VL shown in SEQ ID NO:13.

[0392] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the VH set forth in SEQ ID NO:23, and / or the VL set forth in SEQ ID NO:33.

[0393] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the VH set forth in SEQ ID NO:3, and / or the VL set forth in SEQ ID NO:33.

[0394] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises the VH shown in SEQ ID NO:23, and / or the VL shown in SEQ ID NO:13.

[0395] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises:

[0396] (a) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 13;

[0397] (b) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:33;

[0398] (c) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 13;

[0399] (d) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:13;

[0400] (e) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the 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 described in any one of groups (a) to (d), respectively; or

[0401] (f) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) independently have one or more amino acid substitutions, deletions or additions or any combination thereof (e.g., 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 any one of groups (a) to (d), respectively. Preferably, the substitutions are conservative substitutions.

[0402] In some embodiments, the heavy chain of the anti-B7H3 antibody comprises a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof, which has up to 50 conservative substitutions of amino acids compared to the wild-type sequence from which it is derived (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 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids). In certain embodiments, the anti-B7H3 antibody light chain comprises a light chain constant region (CL) of a human immunoglobulin or a variant thereof, which has up to 50 conservative substitutions of amino acids compared to the wild-type sequence from which it is derived (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 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids).

[0403] In some embodiments, the constant region is altered, for example, mutated, to modify the properties of the anti-B7H3 antibody molecule (e.g., to change one or more of the following characteristics: Fc receptor binding, antibody glycosylation, the number of cysteine ​​residues, effector cell function, or complement function). Functional changes can be produced by replacing at least one amino acid residue in the antibody constant region with a different residue, for example, changing the affinity of the antibody for an effector ligand (such as FcR or complement C1q), thereby changing the effector function (e.g., reducing it). The Fc region of an antibody mediates several important effector functions, such as ADCC, phagocytosis (ADCP), CDC, etc.

[0404] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof 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; in particular, selected from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3 and IgG4, and more particularly selected from the heavy chain constant region of IgG1 (for example, human IgG1). In some embodiments, the human IgG1 heavy chain constant region is as shown in SEQ ID NO: 43. In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure has a light chain constant region, which is selected from, for example, a κ or λ light chain constant region, preferably a κ light chain constant region (for example, a human κ light chain constant region). In some embodiments, the light chain constant region has a sequence as shown in SEQ ID NO: 44.

[0405] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises CH as set forth in SEQ ID NO:43 or a variant thereof, wherein the variant has up to 20 conservative substitutions of amino acids compared to SEQ ID NO:43 (e.g., up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids), or has 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.

[0406] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises a light chain constant region or a variant thereof. In some embodiments, the light chain constant region comprises a kappa light chain constant region. In some embodiments, the light chain constant region comprises a light chain constant region (CL) as shown in SEQ ID NO: 44 or a variant thereof, the variant having up to 20 conservative substitutions of amino acids compared to SEQ ID NO: 44 (e.g., up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids; e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids), 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.

[0407] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises a heavy chain constant region (CH) as shown in SEQ ID NO:43 and a light chain constant region (CL) as shown in SEQ ID NO:44.

[0408] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises:

[0409] (a) a heavy chain comprising an amino acid sequence selected from the group consisting of:

[0410] (i) a sequence comprising the VH sequence shown in SEQ ID NO: 3 and the CH sequence shown in SEQ ID NO: 43;

[0411] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0412] (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 shown in (i); and

[0413] (b) a light chain comprising an amino acid sequence selected from the group consisting of:

[0414] (iv) a sequence comprising the VL sequence shown in SEQ ID NO: 13 and the CL sequence shown in SEQ ID NO: 44;

[0415] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0416] (vi) 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 shown in (iv).

[0417] In some embodiments, the substitution described in (ii) or (v) is a conservative substitution.

[0418] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises:

[0419] (a) a heavy chain comprising an amino acid sequence selected from the group consisting of:

[0420] (i) a sequence comprising the VH sequence shown in SEQ ID NO: 23 and the CH sequence shown in SEQ ID NO: 43;

[0421] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0422] (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 shown in (i); and

[0423] (b) a light chain comprising an amino acid sequence selected from the group consisting of:

[0424] (iv) a sequence comprising the VL sequence shown in SEQ ID NO:33 and the CL sequence shown in SEQ ID NO:44;

[0425] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0426] (vi) 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 shown in (iv).

[0427] In some embodiments, the substitution described in (ii) or (v) is a conservative substitution.

[0428] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain,

[0429] The heavy chain comprises:

[0430] (i) the sequence shown in SEQ ID NO:45;

[0431] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0432] (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 to the sequence shown in (i); and

[0433] The light chain comprises:

[0434] (iv) the sequence shown in SEQ ID NO:46;

[0435] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0436] (vi) 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 to the sequence set forth in (iv);

[0437] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0438] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain,

[0439] The heavy chain comprises:

[0440] (i) the sequence shown in SEQ ID NO:47;

[0441] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0442] (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 to the sequence set forth in (i); and

[0443] The light chain comprises:

[0444] (iv) the sequence shown in SEQ ID NO:48;

[0445] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0446] (vi) 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 to the sequence set forth in (iv);

[0447] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0448] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof is a chimeric antibody, a humanized antibody or a fully human antibody.

[0449] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof is selected from scFv, Fab, Fab', (Fab')2, Fv fragment, disulfide-linked Fv (dsFv), and diabody.

[0450] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof is a scFv. In certain embodiments, the scFv of the present disclosure comprises:

[0451] (a) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 13;

[0452] (b) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:33;

[0453] (c) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 33;

[0454] (d) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:13;

[0455] (e) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the 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 described in any one of groups (a) to (d), respectively; or

[0456] (f) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) independently have one or more amino acid substitutions, deletions or additions or any combination thereof (e.g., 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 any one of groups (a) to (d), respectively. Preferably, the substitutions are conservative substitutions.

[0457] In some embodiments, the antibodies of the present disclosure are scFvs. In certain embodiments, the scFvs of the present disclosure comprise:

[0458] (i) the sequence shown in SEQ ID NO: 1 or 2;

[0459] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0460] (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 to the sequence shown in (i);

[0461] Preferably, the substitutions described in (ii) are conservative substitutions.

[0462] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof is a scFv. In certain embodiments, the scFv of the present disclosure comprises the sequence shown in SEQ ID NO: 1 or 2.

[0463] In some embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof is selected from the group consisting of: 1D1 antibody, 1D1-01 antibody, 2E3 antibody, and 2E3-02 antibody.

[0464] In some embodiments of the present disclosure, the targeting moiety is trastuzumab or pertuzumab. Trastuzumab is a monoclonal antibody against Her 2, and its amino acid sequence is known to those skilled in the art, and its schematic sequence can be found, for example, in CN103319599, and the last Lys is easily deleted but does not affect the biological activity, see Dick, LW et al., Biotechnol. Bioeng., 100: 1132-1143.

[0465] Exemplary heavy and light chain sequences of trastuzumab can be found, for example, in IMGT / mAb-DB ID 97. Exemplary heavy and light chain sequences of pertuzumab can be found in SEQ ID No. 16 and SEQ ID No. 15 of US7560111, and can also be found in IMGT / mAb-DB ID 80.

[0466] In some embodiments of the present disclosure, the targeting moiety 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, for example, see antibodies barecetamab, duligotuzumab, elgemtumab, istiratumab, lumretuzumab, patritumab, seribantumab, zenocutuzumab, 202-2-1 antibody, antibody CN 103189392B with heavy chain SEQ ID NO: 10 and light chain SEQ ID NO: 14, and IMGT / mAb-DB SEQ ID NO: 546.

[0467] In some embodiments, the targeting moiety is an anti-Her3 antibody, wherein the anti-Her3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the IMGT numbering system:

[0468] HCDR1 of SEQ ID NO:56, HCDR2 of SEQ ID NO:57, HCDR3 of SEQ ID NO:58; and / or,

[0469] The sequence of LCDR1 is SEQ ID NO:41, the sequence of LCDR2 is AAS, and the sequence of LCDR3 is SEQ ID NO:21.

[0470] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof, as defined by the IMGT numbering system, comprises: the aforementioned VH comprising the aforementioned heavy chain HCDR1, HCDR2, HCDR3 and the aforementioned VL comprising the aforementioned light chain LCDR1, LCDR2, LCDR3.

[0471] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Kabat numbering system:

[0472] HCDR1 of SEQ ID NO:53, HCDR2 of SEQ ID NO:54, HCDR3 of SEQ ID NO:55; and / or,

[0473] The sequence of LCDR1 is SEQ ID NO:59, the sequence of LCDR2 is SEQ ID NO:60, and the sequence of LCDR3 is SEQ ID NO:21.

[0474] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof, as defined by the Kabat numbering system, comprises: the aforementioned VH comprising the aforementioned heavy chain HCDR1, HCDR2, HCDR3 and the aforementioned VL comprising the aforementioned light chain LCDR1, LCDR2, LCDR3.

[0475] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof comprises:

[0476] (a) a heavy chain variable region (VH) comprising an amino acid sequence selected from the group consisting of:

[0477] (i) the sequence shown in SEQ ID NO:49;

[0478] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in SEQ ID NO: 49 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof); or

[0479] (iii) a sequence 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 compared to the sequence set forth in SEQ ID NO:49;

[0480] and / or

[0481] (b) a light chain variable region (VL) comprising an amino acid sequence selected from the group consisting of:

[0482] (iv) the sequence shown in SEQ ID NO:50;

[0483] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in SEQ ID NO: 50 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof); or

[0484] (vi) a sequence 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 compared to the sequence set forth in SEQ ID NO:50.

[0485] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof comprises:

[0486] (a) VH of the sequence shown in SEQ ID NO:49 and VL of the sequence shown in SEQ ID NO:50;

[0487] (b) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the 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 described in group (a), respectively; or

[0488] (c) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) independently have one or more amino acid substitutions, deletions or additions or any combination thereof (e.g., 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), respectively. Preferably, the substitutions are conservative substitutions.

[0489] In some embodiments, the heavy chain of the anti-Her3 antibody comprises a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof, which has up to 50 conservative substitutions of amino acids compared to the wild-type sequence from which it is derived (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 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids). In certain embodiments, the anti-B7H3 antibody light chain comprises a light chain constant region (CL) of a human immunoglobulin or a variant thereof, which has up to 50 conservative substitutions of amino acids compared to the wild-type sequence from which it is derived (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 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids).

[0490] In some embodiments, the constant region is altered, for example, mutated, to modify the properties of the anti-Her3 antibody molecule (e.g., to change one or more of the following characteristics: Fc receptor binding, antibody glycosylation, the number of cysteine ​​residues, effector cell function, or complement function). Functional changes can be produced by replacing at least one amino acid residue in the antibody constant region with a different residue, for example, changing the affinity of the antibody for effector ligands (such as FcR or complement C1q), thereby changing the effector function (e.g., reducing it). The Fc region of an antibody mediates several important effector functions, such as ADCC, phagocytosis (ADCP), CDC, etc.

[0491] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof 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; in particular, selected from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3 and IgG4, more particularly selected from the heavy chain constant region of IgG1 (for example, human IgG1). In some embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure have a light chain constant region, which is selected from, for example, κ or λ light chain constant regions, preferably κ light chain constant regions (for example, human κ light chain constant regions).

[0492] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof comprises a heavy chain constant region (CH) shown in SEQ ID NO:43 and a light chain constant region (CL) shown in SEQ ID NO:44.

[0493] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain,

[0494] The heavy chain comprises:

[0495] (i) the sequence shown in SEQ ID NO:51;

[0496] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0497] (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 to the sequence shown in (i); and

[0498] The light chain comprises:

[0499] (iv) the sequence shown in SEQ ID NO:52;

[0500] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0501] (vi) 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 to the sequence set forth in (iv);

[0502] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0503] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof is a chimeric antibody, a humanized antibody or a fully human antibody.

[0504] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof is selected from scFv, Fab, Fab', (Fab')2, Fv fragment, disulfide-linked Fv (dsFv), and diabody.

[0505] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof is a scFv. In certain embodiments, the scFv of the present disclosure comprises:

[0506] (a) VH of the sequence shown in SEQ ID NO:49 and VL of the sequence shown in SEQ ID NO:50;

[0507] (b) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the 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 described in group (a), respectively; or

[0508] (c) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) independently have one or more amino acid substitutions, deletions or additions or any combination thereof (e.g., 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), respectively. Preferably, the substitutions are conservative substitutions.

[0509] In some embodiments, the anti-Her3 antibody or antigen-binding fragment thereof is selected from: 202-2-1 antibody.

[0510] In some embodiments of the present disclosure, the targeting moiety is cetuximab. Cetuximab is a monoclonal antibody against EGFR, and its amino acid sequence is known to those skilled in the art. Its schematic sequence can be found in the antibody shown in IMGT / mAb-DB ID 151.

[0511] In some embodiments, the ligand drug conjugate is selected from:

[0512]

[0513]

[0514]

[0515] Among them, Tb 1 is an anti-B7H3 antibody or an antigen-binding fragment thereof, such as enoblituzumab, mirzotamab, omburtamab, 1D1-01, 2E3-02 antibody, preferably 1D1-01 or 2E3-02 antibody; 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.

[0516] In some embodiments, the ligand drug conjugate is selected from:

[0517]

[0518] Among them, Tb 2 is an anti-Trop-2 antibody or an antigen-binding fragment thereof, such as datopotamab, sacituzumab, preferably sacituzumab; 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.

[0519] In some embodiments, the ligand drug conjugate is selected from:

[0520]

[0521] Among them, Tb 3 is an anti-Her2 antibody or an antigen-binding fragment thereof, such as anbenitamab, coprelotamab, disitamab, gancotamab, margetuximab, pertuzumab, timigutuzumab, zanidatamab, Trastuzumab, Pertuzumab, preferably Trastuzumab or Pertuzumab; q is selected from any value between 0.1-16.0, preferably any value between 2-8. 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.

[0522] In some embodiments, the ligand drug conjugate is selected from:

[0523]

[0524] Among them, Tb 4It is an anti-Her3 antibody or an antigen-binding fragment thereof, for example, the antibody barecetamab, duligotuzumab, elgemtumab, istiratumab, lumretuzumab, patritumab, seribantumab, zenocutuzumab, 202-2-1 antibody, the antibody shown in heavy chain SEQ: 10 and light chain SEQ: 14 in CN 103189392B, the antibody shown in IMGT / mAb-DB ID: 564, 202-2-1 antibody; preferably 202-2-1 antibody; q is selected from any value between 0.1-16.0, preferably any value between 2-8. 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.

[0525] In some embodiments, the ligand drug conjugate is selected from:

[0526]

[0527] Among them, Tb 5 is an anti-EGFR antibody or an antigen-binding fragment thereof, such as demupitamab, depatuxizumab, futuximab, imgatuzumab, laprituximab, losatuxizumab, matuzumab, modotuximab, necitumumab, nimotuzumab, panitumumab, pimurutamab, serclutamab, tomozutuximab, zalutumumab, Cetuximab; preferably Cetuximab; q is selected from any value between 0.1-16.0, preferably any value between 2-8. 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.

[0528] In some embodiments, the ligand drug conjugate is selected from:

[0529]

[0530] Among them, Tb 6It is an antibody without tumor cell endocytosis activity or an antibody with non-endocytosis (e.g., ALCAM / CD166) antigen binding activity, for example: an IgG isotype antibody without corresponding cell surface antigen in the human body, an anti-CD166 antibody, preferably, an anti-chicken lysozyme human IgG1 isotype antibody; q is selected from any value between 0.1-16.0, preferably any value between 2-8. 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.

[0531] In some embodiments, the ligand drug conjugate is selected from:

[0532]

[0533] Among them, Tb 7 The antibody has weak or no tumor cell endocytosis activity but has tumor cell surface antigen binding activity; 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.

[0534] In some embodiments, the antibody has an antibody that binds to the B7H3 antigen but does not have endocytosis activity. For example, INV721 and I7-01 of WO2021168379A1. More specifically, the Anti-B7H3 antibody has a VH of SEQ ID NO: 2 and a VL of SEQ ID NO: 1 described in WO2021168379A1.

[0535] In some embodiments, the antibody has an antibody that binds to the GD-2 antigen but does not have endocytosis activity. For example, INV721 and GD2-5 of WO2021168379A1. More specifically, the Anti-GD-2 antibody has a VH of SEQ ID NO: 4 and a VL of SEQ ID NO: 3 described in WO2021168379A1.

[0536] In some embodiments, the antibody has an antibody that binds to the HER3 antigen but has no endocytosis activity, such as the ANTI-HER3 21F06 antibody shown in SEQ ID NO: 22 of US10808032B2.

[0537] In some embodiments, the antibody has the ability to bind to the CD20 antigen but not have endocytosis activity. Although so-called "type II" CD20-specific antibodies have been shown to be poorly internalized by CD20-positive target cells, other so-called "type I" CD20-specific antibodies have been found to be internalized and degraded to some extent, depending on the expression level of activating and inhibitory FcγRs on the target cells with which they interact. In some embodiments, the antibody has the ability to bind to the CD20 antigen but not have endocytosis activity is a "type II" CD20-specific antibody, such as obinutuzumab.

[0538] In some embodiments, the antibody has an antibody that binds to a non-endocytic (e.g., ALCAM / CD166) antigen activity. In some embodiments, the antibody is an antibody comprising VH of SEQ ID No: 73 and VL of SEQ ID No: 74, VH of SEQ ID No: 75 and VL of SEQ ID No: 76, VH of SEQ ID No: 77 and VL of SEQ ID No: 78, or VH of SEQ ID No: 79 and VL of SEQ ID No: 88 in EP3911682A1.

[0539] In some embodiments, the ligand drug conjugate is selected from:

[0540]

[0541] Among them, Tb 8 The invention is an antibody having tumor cell endocytosis activity and tumor cell surface antigen binding activity, such as 1D1-01, 2E3-02 antibody, sacituzumab, pertuzumab, trastuzumab or cetuximab antibody; 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.

[0542] In addition, it should be noted that those skilled in the art can understand that L 1 It is connected to the thiol group contained in Tb (such as antibody) after the disulfide bond is opened (for example, the disulfide bond can be opened by reducing the disulfide bond with the reducing agent TCEP to generate thiol -SH). In other words, L 1 The -S- between Tb and L is not another external sulfur atom. For example, -S- is not another external sulfur atom, but the thiol group contained in Tb after the disulfide bond is opened. 1 -S- is formed after the connection.

[0543] In the second aspect of the present disclosure, the present disclosure provides a compound represented by formula II:

[0544]

[0545] or a stereoisomer of the compound, a prodrug thereof, a pharmaceutically acceptable salt thereof, a pharmaceutically acceptable solvate thereof, or a ligand-drug conjugate thereof,

[0546] in:

[0547] R 1 , R 2 are each independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl, optionally substituted C1-6 alkoxy, or,

[0548] R 1 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0549] R 3 Selected from H, halogen, -OH, -NH 2 , optionally substituted C1-6 alkyl, optionally substituted C1-6 alkoxy, or,

[0550] R 3 and X together with the carbon atom to which it is attached form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0551] R 3 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0552] W is absent or present. When W is present, W is selected from -OH, -SH, -NHR 4 ,

[0553] 1 bit is connected to X;

[0554] X is selected from a direct bond, an optionally substituted -O-(CH 2 ) n3 -、-N(R 4 )-(CH 2 ) n3 -、-S-(CH 2 ) n3 -, carbonyl-(CH2 ) n3 、-SO 2 -(CH 2 ) n3 -、-(CH 2 ) n1 -、 C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the parent ring, and the 2 position is connected to W; the substituent is selected from one or more C1-4 alkyl, C3-6 cycloalkyl, or multiple C1-4 alkyl and the carbon atoms connected to them together form a C3-6 cycloalkyl;

[0555] Each M is independently selected from a direct bond, -CR 5a R 5b -;

[0556] R 4 , R 5 , R 5a , R 5b , R 6 , R 7 Each is independently selected from H, optionally substituted C1-4 alkyl, optionally substituted C1-4 alkoxy, optionally substituted C3-6 cycloalkyl;

[0557] n, n', n1, n2, n3 are each independently selected from any integer between 0 and 6;

[0558] Among them, when R 1 , R 2 At the same time, H and X is -(CH 2 ) n1 -, n1 is 1, 2, 3, 4, W is not -OH or -NHR 4 ; and the compound shown in formula II does not contain

[0559]

[0560]

[0561] In some embodiments, R 1 and R 2 Each is independently selected from H, halogen or C1-4 alkyl.

[0562] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached, it forms a 5-6 membered heterocyclic ring containing 1, 2 or 3 O, S or N or any combination thereof.

[0563] In some embodiments, R 1 is selected from H and halogen, R2 Selected from H and C1-4 alkyl.

[0564] In some embodiments, R 1 and R 2 and the carbon atom to which it is attached The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring.

[0565] In some embodiments, R 1 H or F, R 2 It is H or methyl.

[0566] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached,

[0567] In some embodiments, R 1 For F, R 2 is methyl; or R 1 and R 2 Together with the carbon atom to which it is attached,

[0568] In some embodiments, R 1 For F, R 2 It is methyl.

[0569] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached,

[0570] In some embodiments, R 3 Selected from H and C1-4 alkyl.

[0571] In some embodiments, R 3 For H.

[0572] In some embodiments, W is absent or present, and when W is present, W is selected from -OH, -SH, -NHR 4 , 1 bit is connected to X.

[0573] In some embodiments, W is absent or present, and when W is present, W is selected from -OH, -SH, -NHR 4 , 1 bit is connected to X.

[0574] In some embodiments, W is selected from -OH, -NHR 4 and 1 bit is connected to X.

[0575] In some embodiments, W is selected from -OH and -NHR 4 , 1 bit is connected to X.

[0576] In some embodiments, X is selected from optionally substituted -(CH 2 ) n1 -、 C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the parent ring, and the 2 position is connected to W; the substituent is selected from 1 or 2 C1-4 alkyl groups, or 2 C1-4 alkyl groups and the carbon atoms to which they are simultaneously connected form a C3-6 cycloalkyl group.

[0577] In some embodiments, X is selected from optionally substituted The 1 position is connected to the parent ring, and the 2 position is connected to W; the substituent is selected from 1 or 2 C1-4 alkyl groups (such as methyl), or 2 C1-4 alkyl groups (such as methyl) and the carbon atoms to which they are simultaneously connected form a C3-6 cycloalkyl group (such as cyclopropyl).

[0578] In some embodiments, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0579] In some embodiments, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0580] In some embodiments, when W is absent, X is selected from 1 is connected to the parent ring; when W exists, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0581] In some embodiments, W is selected from -OH, -NHR 4 and 1 bit is connected to X, 2 bits are connected to L 4 or L 3 Connected; X is selected from 1 is connected to the parent ring, and 2 is connected to W. In some embodiments, R 4 and R 5 Each is independently selected from H, C1-4 alkyl and C3-6 cycloalkyl.

[0582] In some embodiments, each R 4 are independently selected from H, C1-4 alkyl and C3-6 cycloalkyl, R 5 For H.

[0583] In some embodiments, each R 4 R is independently selected from H, methyl, ethyl, isopropyl, n-propyl, tert-butyl and cyclopropyl, 5 For H.

[0584] In some embodiments, R 5a and R 5b Each independently selected from H and C1-4 alkyl;

[0585] In some embodiments, R 5a and R 5b are each independently selected from H and methyl;

[0586] In some embodiments, each R 7 Independently selected from H and C1-4 alkyl;

[0587] In some embodiments, R 7 For H.

[0588] In some embodiments, n is 1, 2, or 3.

[0589] In some embodiments, n is 1.

[0590] In some embodiments, n1 is 1, 2, 3 or 4.

[0591] In some embodiments, n2 is 1;

[0592] In some embodiments, n3 is 0.

[0593] In some embodiments, the compound represented by Formula II is selected from any of the following compounds:

[0594]

[0595]

[0596]

[0597]

[0598] In the third aspect of the present disclosure, the present disclosure provides a drug-linker conjugate as shown in Formula III,

[0599]

[0600] or a stereoisomer of the drug-linker conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof,

[0601] in:

[0602] R 1 and R 2 are each independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl or optionally substituted C1-6 alkoxy, or,

[0603] R 1 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0604] R 3 Selected from H, halogen, -OH, -NH 2 , optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or,

[0605] R 3 and X together with the carbon atom to which it is attached form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof, or,

[0606] R 3 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[0607] W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected;

[0608] X is selected from a direct bond, an optionally substituted -O-(CH 2 ) n3 -、-N(R 4 )-(CH 2 ) n3 -、-S-(CH 2 ) n3 -, carbonyl-(CH 2 ) n3 、-SO 2 -(CH 2 ) n3 -、 -(CH 2 ) n1 -, C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L4 connected; the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups and the carbon atoms connected to them together form a C3-6 cycloalkyl group;

[0609] Each M is independently selected from a direct bond, -CR 5a R 5b -;

[0610] R 4 , R 5 , R 5a , R 5b , R 6 and R 7 Each is independently selected from H, optionally substituted C1-4 alkyl, optionally substituted C1-4 alkoxy and optionally substituted C3-6 cycloalkyl;

[0611] n, n', n1, n2, n3 are each independently selected from any integer between 0 and 6;

[0612] L 1 Selected from:

[0613]

[0614]

[0615]

[0616] Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl group, a 5-10 membered heteroaryl group, an amide group, a sulfonamide group, an imine group, a CF 2 , Rx, Ry are each independently selected from H, C1-4 alkyl, each m is independently selected from 0, 1, 2, 3, 4, 5, 6, y1, y2, y3, y4 are each independently selected from any integer between 0 and 20, the 1st position is connected to Lg, the 2nd position is connected to L 2 or L 3 connected;

[0617] L 2 Does not exist or exists, L 2 When present, L 2 Selected from:

[0618]

[0619]

[0620] y1, y2, y3, y4 are each independently selected from any integer between 0 and 20, and 1 is the same as L 1 Connected, 2 bits and L 3 connected;

[0621] L 3 Selected from amino acid residues or short peptides consisting of 2-10 amino acid residues;

[0622] L 4 Does not exist or exists, L 4 When present, L 4 Selected from 1 bit and L 3 Connected, 2 bits connected to W or X;

[0623] Lg is a leaving group, and Lg is selected from halogen, sulfone, tertiary amine salt (Me 3 N + , Et 3 N + ), diazonium salt, -OMs, MeSO 2 -、CF 3 SO 3 -.

[0624] In some embodiments, R 1 , R 2 Each is independently selected from H, halogen, and C1-4 alkyl.

[0625] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached, it forms a 5-6 membered heterocyclic ring containing 1, 2 or 3 O, S or N or any combination thereof.

[0626] In some embodiments, R 1 is selected from H, halogen, R 2 Selected from H, C1-4 alkyl.

[0627] In some embodiments, R 1 and R 2 and the carbon atom to which it is attached The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring.

[0628] In some embodiments, R 1 H or F, R 2 It is H or methyl.

[0629] In some embodiments, R 1 For F, R 2 Methyl or R 1 and R 2 Together with the carbon atom to which it is attached,

[0630] In some embodiments, R 1For F, R 2 It is methyl.

[0631] In some embodiments, R 1 and R 2 Together with the carbon atom to which it is attached,

[0632] In some embodiments, R 3 Selected from H, C1-4 alkyl.

[0633] In some embodiments, R 3 Together with X and the carbon atom to which it is attached, it forms a 5-6 membered carbocyclic ring.

[0634] In some embodiments, R 3 H or R 3 Together with X and the carbon atom to which it is attached, The dotted lines indicate where the carbocyclic ring is fused to the benzene and pyridine rings.

[0635] In some embodiments, R 3 For H.

[0636] In some embodiments, R 3 Together with X and the carbon atom to which it is attached, The dotted lines indicate where the carbocyclic ring is fused to the benzene and pyridine rings.

[0637] In some embodiments, W is absent or present, and when W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected.

[0638] In some embodiments, W is absent or present, and when W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected.

[0639] In some embodiments, W is selected from -O-, -NR 4 -、 1 bit is connected to X, 2 bits are connected to L 4 or L 3 connected.

[0640] In some embodiments, W is selected from -O-, -NR 4 -, 1 bit is connected to X, 2 bits are connected to L4 or L 3 connected.

[0641] In some embodiments, X is selected from optionally substituted -(CH 2 ) n1 -、 C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L 4 connected; the substituent is selected from 1 or 2 C1-4 alkyl groups, or 2 C1-4 alkyl groups and the carbon atoms to which they are simultaneously connected together form a C3-6 cycloalkyl group.

[0642] In some embodiments, X is selected from optionally substituted Position 1 is connected to the mother ring, position 2 is connected to W or L 4 connected; the substituent is selected from 1 or 2 C1-4 alkyl groups (such as methyl), or 2 C1-4 alkyl groups (such as methyl) and the carbon atoms to which they are simultaneously connected together form a C3-6 cycloalkyl group (such as cyclopropyl).

[0643] In some embodiments, X is selected from Position 1 is connected to the mother ring, position 2 is connected to W or L 4 connected.

[0644] In some embodiments, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0645] In some embodiments, when W is absent, X is selected from Position 1 is connected to the mother ring, position 2 is connected to L 4 When W exists, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0646] In some embodiments, W is selected from -O-, -NR 4 -、 1 bit is connected to X, 2 bits are connected to L 4 or L 3 Connected; X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[0647] In some embodiments, R 4 , R 5 Each is independently selected from H, C1-4 alkyl, and C3-6 cycloalkyl.

[0648] In some embodiments, each R 4independently selected from H, C1-4 alkyl, C3-6 cycloalkyl, R 5 For H.

[0649] In some embodiments, each R 4 R is independently selected from H, methyl, ethyl, n-propyl, isopropyl, tert-butyl, cyclopropyl, 5 For H.

[0650] In some embodiments, R 5a , R 5b Each is independently selected from H, C1-4 alkyl.

[0651] In some embodiments, R 5a , R 5b Each is independently selected from H and methyl.

[0652] In some embodiments, each R 7 Independently selected from H, C1-4 alkyl.

[0653] In some embodiments, R 7 For H.

[0654] In some embodiments, n is selected from 1, 2, or 3.

[0655] In some embodiments, n is 1.

[0656] In some embodiments, n1 is selected from 1, 2, 3 or 4.

[0657] In some embodiments, n2 is 1.

[0658] In some embodiments, n3 is 0.

[0659] In some embodiments, L 1 Selected from Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl, a 5-10 membered heteroaryl, an amide group (preferably selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond), Rx, Ry are each independently selected from H, a C1-4 alkyl group, each m is independently selected from 0, 1, 2, 3, 4, 5, 6, y1 is selected from any integer between 1-6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0-15 (such as 6-15), each y3 is independently selected from 1, 2 or 3, each y4 is independently selected from 0 or 1, the 1st position is connected to 1g, the 2nd position is connected to L 2 or L 3connected; for example, each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, Rx, Ry are each independently selected from H, C1-4 alkyl, each m is independently selected from 0, 1, 2, 3, 4, 5, 6, y1 is selected from any integer between 1-6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0-15 (such as 6-15), each y3 is independently selected from 1, 2 or 3, each y4 is independently selected from 0 or 1, the 1st position is connected to Lg through the S atom, and the 2nd position is connected to L 2 or L 3 connected.

[0660] In some embodiments, L 1 Selected from m is selected from 2, 3, 4, y1 is selected from any integer between 1-6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0-10 (such as 6-10), each y3 is independently selected from 1 or 2, the 1st position is connected to Lg, the 2nd position is connected to L 2 or L 3 connected.

[0661] In some embodiments, L 1 Selected from 1 is connected to Lg, 2 is connected to L 2 or L 3 connected.

[0662] In some embodiments, L 1 Selected from 1 is connected to Lg, 2 is connected to L 2 or L 3 connected.

[0663] In some embodiments, L 1 Selected from 1 is connected to Lg, 2 is connected to L 2 or L 3 connected.

[0664] In some embodiments, L 1 Selected from 1 is connected to Lg, 2 is connected to L 2 or L 3 connected.

[0665] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from y1 is selected from any integer between 1 and 6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0 and 10 (such as 6-10), each y3 is independently selected from 1 or 2, each y4 is independently selected from 0 or 1, and the 1st position is the same as L 1 Connected, 2 bits and L 3 connected.

[0666] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected.

[0667] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected.

[0668] In some embodiments, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected.

[0669] In some embodiments, L 2 Does not exist.

[0670] In some embodiments, L 2 Selected from

[0671] In some embodiments, L 3 selected from amino acid residues or short peptides consisting of 2-10 amino acid residues; the amino acid residues are selected from natural amino acid residues, non-natural amino acid residues, AA 1 The indicated amino acid residues or stereoisomers thereof.

[0672] In some embodiments, L 3 Selected from amino acid residues Val, D-Val, Cit, Phe, Lys, Lys(Ac), Leu, Gly, Ala, Asn, Asp, Arg, AA 1or 2 to 10 selected from Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, Asp, AA 1 A short peptide composed of amino acid residues.

[0673] In some embodiments, L 3 Selected from 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, Gl y-Gly-Arg, Ala-Ala-Asn, Gly-Gly-Phe, Val-Lys-Gly, Val-Lys-Gly-Gly, Val-Lys, Lys-Ala-Asn.

[0674] In some embodiments, L 3 Selected from AA 1 AA 1 -Gly, Val-Cit, Val-AA 1 -Gly, AA 1 -Ala-Asn, Gly-Gly-Phe-Gly.

[0675] In some embodiments, L 3 Selected from AA 1 、Val-AA 1 -Gly.

[0676] In some embodiments, L 3 Selected from Val-AA 1 -Gly.

[0677] In some embodiments, L 3 Selected from X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions, OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0678] In some embodiments, L 3 Selected from

[0679] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions, OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0680] In some embodiments, L 3 Selected from X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions, OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0681] In some embodiments, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0682] In some embodiments, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or W connected.

[0683] In some embodiments, AA 1 The structures of the indicated amino acid residues are shown below,

[0684]

[0685] in:

[0686] R a , R b Each independently selected from H, And R a , R b Not at the same time H;

[0687] Or, R a With R b Together with the carbon atoms to which they are commonly attached, they form a 4-10 membered heterocyclic ring, wherein the 4-10 membered heterocyclic ring is optionally substituted by one or more R 0 replaced by;

[0688] r、r 1 Each is independently selected from any integer from 0 to 20;

[0689] R m1 , R n1 Each independently selected from H, C1-6 alkyl, C3-6 cycloalkyl, -COOR x1 ;

[0690] R x1 Selected from C1-6 alkyl;

[0691] Or, R m1 With R n1 Together with the nitrogen atom to which they are commonly attached, they form a 4-10 membered heterocyclic ring, wherein the 4-10 membered heterocyclic ring is optionally substituted by one or more R 0’ replaced by;

[0692] R z Selected from C1-6 alkyl;

[0693] R 0 , R 0’ Each independently selected from C1-6 alkyl, C3-6 cycloalkyl, -NR m2 R n2 , a 4-10 membered heterocyclic group optionally substituted by a C1-6 alkyl group;

[0694] R m2 , R n2 Each is independently selected from H, C1-6 alkyl.

[0695] In some embodiments, R a , R b Among them, either one is H and the other is selected from

[0696] In some embodiments, Ra , R b Among them, either one is H and the other is selected from

[0697] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form the 0 Substituted 5-6 membered heterocyclic ring.

[0698] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form the 0 A substituted piperidine ring or a piperazine ring.

[0699] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form the 0 Substituted piperidine ring.

[0700] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form Carbon atom No. 1 is a and R b Carbon atoms that are linked together.

[0701] In some embodiments, R a With R b Together with the carbon atoms they are connected to, they form Carbon atom No. 1 is a and R b Carbon atoms that are linked together.

[0702] In some embodiments, r, r 1 Each is independently selected from 0, 1, 2, 3, 4, and 5.

[0703] In some embodiments, r, r 1 Each is independently selected from 0, 4.

[0704] In some embodiments, r, r 1 Either one is 0 and the other is 4.

[0705] In some embodiments, R m1 , R n1Each is independently selected from H, methyl, ethyl, n-propyl, n-butyl, -COOCH3, -COOCH2CH3, -COOCH2CH2CH3, -COOCH(CH3)2, -COOC(CH3)3, -COOCH2CH2CH2CH3.

[0706] In some embodiments, R m1 , R n1 Each is independently selected from H, C1-6 alkyl, C3-6 cycloalkyl, and tert-butoxycarbonyl.

[0707] In some embodiments, R m1 , R n1 Each is independently selected from H, C1-6 alkyl.

[0708] In some embodiments, R m1 , R n1 Each is independently selected from H, methyl, ethyl, and n-propyl.

[0709] In some embodiments, r, r 1 In the example, r is 4 and r 1 When R is 0, m1 , R n1 Each is independently selected from H, C1-6 alkyl (such as H, methyl); r is 0, r 1 When R is 4, m1 , R n1 Each is independently selected from C1-6 alkyl (such as methyl, ethyl, n-propyl), preferably selected from C2-6 alkyl (such as ethyl, n-propyl).

[0710] In some embodiments, R m1 With R n1 Together with the nitrogen atom to which they are attached, they form an optionally R 0’ Substituted 5-6 membered heterocyclic ring.

[0711] In some embodiments, R m1 With R n1 Together with the nitrogen atom to which they are attached, they form an optionally R 0’ A substituted piperidine ring or a piperazine ring.

[0712] In some embodiments, R m1 With R n1 Together with the nitrogen atoms they are connected to, they form Nitrogen atom No. 1 is m1 and R n1 Nitrogen atoms connected together.

[0713] In some embodiments, R z It is methyl.

[0714] In some embodiments, R 0 , R 0’ Each independently selected from C1-6 alkyl, -NR m2 R n2 , a 5-6 membered heterocyclic group optionally substituted by a C1-6 alkyl group.

[0715] In some embodiments, R 0 The 5-6 membered heterocyclic group is selected from C1-6 alkyl and substituted by C1-6 alkyl, wherein the 5-6 membered heterocyclic group is selected from piperidinyl and piperazinyl.

[0716] In some embodiments, R 0 It is selected from methyl, ethyl, and a 5-6 membered heterocyclic group substituted by methyl, wherein the 5-6 membered heterocyclic group is piperidinyl.

[0717] In some embodiments, R 0 The 5-6 membered heterocyclic group is selected from methyl and substituted by methyl, wherein the 5-6 membered heterocyclic group is piperidinyl.

[0718] In some embodiments, R 0 Selected from methyl, ethyl,

[0719] In some embodiments, R 0 Selected from methyl,

[0720] In some embodiments, R 0’ Selected from C1-6 alkyl, -NR m2 R n2 .

[0721] In some embodiments, R 0’ Selected from methyl, -NR m2 R n2 .

[0722] In some embodiments, R m2 , R n2 It is methyl.

[0723] In some embodiments, AA 1 The amino acid residues are selected from

[0724]

[0725] In some embodiments, AA 1 The amino acid residues are selected from

[0726] In some embodiments, AA 1 The amino acid residues are selected from

[0727] In some embodiments, AA 1 The amino acid residues are selected from

[0728] In some embodiments, L 4 Does not exist or exists, L 4 When present, L 4 Selected from 1 bit and L 3 connected, 2 bits are connected to W or X.

[0729] In some embodiments, L 4 Does not exist or exists, L 4 When present, L 4 for 1 bit and L 3 connected, 2 bits are connected to W or X.

[0730] In some embodiments, L 4 Does not exist.

[0731] In some embodiments, L 4 Selected from 1 bit and L 3 connected, 2 bits are connected to W or X.

[0732] In some embodiments, L 4 Selected from 1 bit and L 3 connected, 2 bits are connected to W or X.

[0733] In some embodiments, Lg is selected from F, Cl, MeSO 2 -.

[0734] In some embodiments, Lg is selected from F, MeSO 2 -.

[0735] In some embodiments, The structure is selected from the following:

[0736]

[0737]

[0738]

[0739]

[0740] Among them, bit 1 is connected to Lg and bit 2 is connected to W.

[0741] In some embodiments, The structure is selected from the following:

[0742]

[0743]

[0744]

[0745]

[0746] Among them, 1 and L 4 connected; when L 4 When not present, 1 bit and L 3 connected.

[0747] In some embodiments, the drug-linker conjugate has a structure as shown in Formula III-(1):

[0748]

[0749] Among them, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and Lg have the meanings provided above and in any embodiments specifically described herein.

[0750] In some embodiments, the drug-linker conjugate has a structure as shown in Formula III-(1A) or III-(1B):

[0751]

[0752] Among them, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and Lg have the meanings provided above and in any embodiments specifically described herein.

[0753] In some embodiments, the drug-linker conjugate has a structure as shown in Formula III-(2):

[0754]

[0755] Among them, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and Lg have the meanings provided above and in any embodiments specifically described herein.

[0756] In some embodiments, the drug-linker conjugate has a structure as shown in Formula III-(2A) or III-(2B):

[0757]

[0758] Among them, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and Lg have the meanings provided above and in any embodiments specifically described herein.

[0759] In some embodiments, the drug-linker conjugate has a structure as shown in Formula III-(3):

[0760]

[0761] Among them, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 , R 5 , n and Lg have the meanings provided above and in any embodiments specifically described herein.

[0762] In some embodiments, the drug-linker conjugate has a structure as shown in Formula III-(3A) or III-(3B):

[0763]

[0764] Among them, Lg, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and Lg have the meanings provided above and in any embodiments specifically described herein.

[0765] In some embodiments, the drug-linker conjugate has the structure of Formula III-A:

[0766]

[0767] Among them, Lg, X, R 1 , R 2 , R 3 , R a and R b has the meaning provided above and in any embodiments specifically described herein.

[0768] In some embodiments, the drug-linker conjugate has the structure of Formula III-B:

[0769]

[0770] Among them, Lg, X, R 1 , R 2 , R 3 , R a and R b has the meaning provided above and in any embodiments specifically described herein.

[0771] In some embodiments, the drug-linker conjugate represented by Formula III is selected from the following structures:

[0772]

[0773]

[0774]

[0775]

[0776]

[0777]

[0778]

[0779]

[0780]

[0781]

[0782]

[0783]

[0784]

[0785]

[0786]

[0787]

[0788]

[0789]

[0790]

[0791]

[0792]

[0794] In some embodiments, compounds are provided wherein the L1-L2-L3 unit in the drug-linker conjugate of Formula III has been partially cleaved, thereby leaving the drug moiety with the amino acid residue bonded thereto.

[0795] In some embodiments, the partially released free drug is a compound of Formula III-(A):

[0796]

[0797] or a stereoisomer or a mixture of stereoisomers thereof, or a pharmaceutically acceptable salt thereof, wherein L 4 , X, W, R 1 , R 2 and R 3 has the meaning provided above and in any embodiments specifically described herein.

[0798] In some embodiments, The structure of III-(A) is selected from the following:

[0799]

[0800]

[0801]

[0802]

[0803]

[0804] The present disclosure also provides a linker in a ligand-drug conjugate, the structure of which contains the following fragments:

[0805]

[0806] Among them, position 2 is connected to the bioactive molecule fragment; position 1 is connected to the ligand end, for example, when it is connected to the linking unit (such as L 2 ) and then connected through an extension unit (such as L 1 ) is connected to the ligand or targeting portion (Tb); or, when the linker unit is absent, is directly connected to the extension unit and further connected to the ligand);

[0807] L 3 , L 4 The definition of is as described in any scheme of this disclosure.

[0808] In some embodiments, the structure of the linker in the ligand drug conjugate is as follows:

[0809]

[0810] Among them, position 1 is connected to the ligand or targeting part that binds to the target, and position 2 is connected to the bioactive molecular fragment;

[0811] L 1 , L 2 , L 3 , L 4 The definition of is as described in any scheme of the present disclosure;

[0812] Preferably, the target binding ligand or targeting portion and the biologically active molecule fragment are defined as Tb and D in any embodiment of the present disclosure, respectively.

[0813] In some embodiments, the linker is connected to the antibody or antigen-binding fragment thereof at position 1 and is connected to the biologically active molecule fragment at position 2.

[0814] In some embodiments, the linker is connected to a cysteine ​​or lysine on the antibody or antigen-binding fragment thereof at position 1, and is connected to a biologically active molecule fragment at position 2;

[0815] Preferably, the antibody or antigen-binding fragment thereof is as described in any embodiment of the present disclosure.

[0816] In the fourth aspect of the present disclosure, the present disclosure also provides a linker shown in formula III-1:

[0817] Lg-L 1 -L 2 -L 3 -L 4 -Lg1

[0818] III-1

[0819] Lg, L 1 , L 2 , L 3 and L 4 has the meaning provided above and in any embodiment specifically described herein; Lg1 is a leaving group when reacting with a drug molecule.

[0820] In some embodiments, Lg1 is preferably -OH, or halogen.

[0821] In the fifth aspect of the present disclosure, the present disclosure also provides a linker shown in formula III-2:

[0822] Lg-L 1 -L 2 -L 3 -Lg2

[0823] III-2

[0824] Lg, L 1 , L 2 and L 3 Has the meaning provided above and in any embodiment specifically described herein; Lg2 is a leaving group when reacting with L4 or a fragment containing a drug molecule.

[0825] In some embodiments, Lg2 is preferably -OH, or halogen.

[0826] In the sixth aspect of the present disclosure, the present disclosure provides a method for preparing the compound (drug molecule, biologically active molecule) of Formula II and the drug-linker conjugate of Formula III.

[0827] In one aspect, the present disclosure provides a method for preparing a compound (drug molecule, biologically active molecule) represented by Formula II. Specifically:

[0828] Compound (VI) can be obtained by alkylating compound (IV) with compound (V) in the presence of an iron compound or other related Minisci reactions.

[0829]

[0830] Alternatively, compound (IV) is subjected to nitrogen oxidation reaction to generate compound (VII), and compound (VII) is treated with trihalogenated phosphorus to generate compound (VIII), which is the halogenated product of compound (IV). Compound (VIII) can be subjected to various reactions, such as Heck reaction, Suzuki reaction, Buchwald reaction, Nigishi reaction, Stille reaction, etc. to obtain compound (VI).

[0831]

[0832] In compound (VI), R 11 Different or more complex molecules can be synthesized through a variety of chemical transformations, such as oxidation, reduction, substitution, and other methods commonly seen in textbooks.

[0833] Alternatively, compound (VI) and compound (IV) can also be obtained by a ring-closing reaction of compound (IX) and compound (X) as shown below.

[0834]

[0835] On the other hand, the present disclosure provides a method for preparing the fragments represented by formula III-1 and formula III-2. Specifically:

[0836] Compound III-a has a functional group Fg 1 and the functional group Fg of compound III-b 2 The reaction can produce compound III-c, which has a functional group Fg a Compound III-d can be obtained, and similar transformations can be used to obtain compounds of the general formula III-2 and III-1. a , Lg b , Lg 1 , Lg 2 For the reactive leaving group, such as -OH, Or halogen, etc.

[0837]

[0838] In yet another aspect, the present disclosure provides a method for preparing a drug-linker conjugate as shown in Formula III. Specifically:

[0839] The target product can be obtained by coupling the B fragment and the C fragment as shown in the following reaction formula. The coupling product is subjected to some commonly used chemical modifications, such as oxidation, deprotection, etc., to obtain the drug-linker conjugate shown in the general formula III.

[0840]

[0841] In a seventh aspect of the present disclosure, the present disclosure provides a method for preparing the aforementioned ligand-drug conjugate, comprising:

[0842] Conjugate Tb with the drug linker shown in formula III Carry out the coupling reaction in a suitable solvent and conditions;

[0843] in:

[0844] Tb has the meaning provided above and in any of the embodiments specifically described herein;

[0845] R 1 , R 2 , R 3 , X, W, L 1 , L 2 , L 3 , L 4 , Lg has the meaning provided above and in any embodiment specifically described herein.

[0846] In some embodiments, the method comprises conjugating Tb with a drug linker conjugate of formula III The step of coupling reaction to form CS bond is carried out under suitable solvent and conditions.

[0847] In some embodiments, the ratio of the amount of Tb to the amount of the drug-linker conjugate is 1:(1-20), such as 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).

[0848] In some embodiments, the coupling reaction is carried out in water and / or an organic solvent.

[0849] In some embodiments, the organic solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, nitriles (eg, acetonitrile), alcohols (eg, methanol, ethanol), or any combination thereof.

[0850] In some embodiments, the method further comprises the step of purifying the coupling product.

[0851] In some embodiments, the coupling product is purified by chromatography.

[0852] In some embodiments, the chromatography method comprises one or more of ion exchange chromatography, hydrophobic chromatography, reverse phase chromatography, or affinity chromatography.

[0853] In an eighth aspect of the present disclosure, the present disclosure provides an antibody or an antigen-binding fragment thereof that binds to B7H3, wherein the antibody or the antigen-binding fragment thereof comprises the following complementarity determining region (CDR):

[0854] HCDR1 or a variant thereof, HCDR2 or a variant thereof, and HCDR3 or a variant thereof contained in the heavy chain variable region (VH) shown in SEQ ID NO: 3 or 23; and / or

[0855] LCDR1 or a variant thereof, LCDR2 or a variant thereof, and LCDR3 or a variant thereof contained in the light chain variable region (VL) shown in SEQ ID NO: 13 or 33.

[0856] In certain embodiments, the antibody or antigen-binding fragment thereof comprises HCDR1 or a variant of its sequence, HCDR2 or a variant of its sequence, and HCDR3 or a variant of its sequence contained in the VH shown in SEQ ID NO:3; and / or LCDR1 or a variant of its sequence, LCDR2 or a variant of its sequence, and LCDR3 or a variant of its sequence contained in the VL shown in SEQ ID NO:13.

[0857] In certain embodiments, the antibody or antigen-binding fragment thereof comprises HCDR1 or a variant of its sequence, HCDR2 or a variant of its sequence, and HCDR3 or a variant of its sequence contained in the VH shown in SEQ ID NO:3; and / or LCDR1 or a variant of its sequence, LCDR2 or a variant of its sequence, and LCDR3 or a variant of its sequence contained in the VL shown in SEQ ID NO:33.

[0858] In certain embodiments, the antibody or antigen-binding fragment thereof comprises HCDR1 or a variant of its sequence, HCDR2 or a variant of its sequence, and HCDR3 or a variant of its sequence contained in the VH shown in SEQ ID NO:23; and / or LCDR1 or a variant of its sequence, LCDR2 or a variant of its sequence, and LCDR3 or a variant of its sequence contained in the VL shown in SEQ ID NO:33.

[0859] In certain embodiments, the antibody or antigen-binding fragment thereof comprises HCDR1 or a variant of its sequence, HCDR2 or a variant of its sequence, and HCDR3 or a variant of its sequence contained in the VH shown in SEQ ID NO:23; and / or LCDR1 or a variant of its sequence, LCDR2 or a variant of its sequence, and LCDR3 or a variant of its sequence contained in the VL shown in SEQ ID NO:13.

[0860] In certain preferred embodiments, the variant of the sequence is a CDR having one or several amino acid substitutions, deletions or additions (eg, 1, 2 or 3 amino acid substitutions, deletions or additions) compared to its source CDR.

[0861] In certain preferred embodiments, the substitutions are conservative substitutions.

[0862] Preferably, the CDRs are defined according to the AbM, Chothia, Kabat or IMGT numbering systems.

[0863] In certain embodiments, the VH and / or VL of the antibody or antigen-binding fragment thereof comprises a framework region (FR) from a human immunoglobulin.

[0864] In certain embodiments, the antibody or antigen binding fragment thereof binds to human B7H3 and / or monkey B7H3. In certain embodiments, the antibody or antigen binding fragment thereof binds to human 2Ig B7H3. In certain embodiments, the antibody or antigen binding fragment thereof binds to human 4Ig B7H3. In certain embodiments, the antibody or antigen binding fragment thereof binds to monkey 4Ig B7H3. In certain embodiments, the antibody or antigen binding fragment thereof binds to human 2Ig B7H3 and human 4Ig B7H3, and more preferentially binds to human 4Ig B7H3. In certain embodiments, the antibody or antigen binding fragment thereof binds to human 4Ig B7H3, but does not bind to human 2Ig B7H3.

[0865] In one aspect, the present disclosure provides an antibody or an antigen-binding fragment thereof capable of binding to B7H3, wherein the antibody or the antigen-binding fragment thereof comprises: a heavy chain variable region (VH) and / or a light chain variable region (VL).

[0866] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein the CDRs are defined according to the IMGT numbering system:

[0867] (a) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 having a sequence of SEQ ID NO: 10 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR2 having a sequence of SEQ ID NO: 11 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR3 having a sequence of SEQ ID NO: 12 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0868] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 20 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of GTF or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 22 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0869] (b) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 having a sequence of SEQ ID NO: 30 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR2 having a sequence of SEQ ID NO: 31 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR3 having a sequence of SEQ ID NO: 32 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0870] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 40 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of GAS or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 42 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0871] (c) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 10 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 11 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 12 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0872] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 40 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of GAS or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 42 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0873] or

[0874] (d) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 having a sequence of SEQ ID NO: 30 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR2 having a sequence of SEQ ID NO: 31 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR3 having a sequence of SEQ ID NO: 32 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0875] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 20 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of GTF or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 22 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom.

[0876] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein the CDRs are defined according to the IMGT numbering system:

[0877] (a) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 10, HCDR2 with a sequence of SEQ ID NO: 11, and HCDR3 with a sequence of SEQ ID NO: 12; and / or,

[0878] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 20, LCDR2 with a sequence of GTF, and LCDR3 with a sequence of SEQ ID NO: 22;

[0879] (b) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 10, HCDR2 with a sequence of SEQ ID NO: 11, and HCDR3 with a sequence of SEQ ID NO: 12; and / or,

[0880] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 40, LCDR2 with a sequence of GAS, and LCDR3 with a sequence of SEQ ID NO: 42;

[0881] (c) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 30, HCDR2 with a sequence of SEQ ID NO: 31, and HCDR3 with a sequence of SEQ ID NO: 32; and / or,

[0882] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 40, LCDR2 with a sequence of GAS, and LCDR3 with a sequence of SEQ ID NO: 42;

[0883] or

[0884] (d) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 30, HCDR2 with a sequence of SEQ ID NO: 31, and HCDR3 with a sequence of SEQ ID NO: 32; and / or,

[0885] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with the sequence of SEQ ID NO: 20, LCDR2 with the sequence of GTF, and LCDR3 with the sequence of SEQ ID NO: 22.

[0886] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein the CDRs are defined according to the Chothia numbering system:

[0887] (a) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 having a sequence of SEQ ID NO: 4 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR2 having a sequence of SEQ ID NO: 5 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR3 having a sequence of SEQ ID NO: 6 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0888] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 14 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 15 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 16 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0889] (b) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 4 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 5 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 6 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0890] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 34 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 35 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 36 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0891] (c) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 24 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 25 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 26 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0892] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 34 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 35 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 36 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0893] or

[0894] (d) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 24 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 25 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 26 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0895] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 14 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 15 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 16 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom.

[0896] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein the CDRs are defined according to the chothia numbering system:

[0897] (a) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 4, HCDR2 with a sequence of SEQ ID NO: 5, and HCDR3 with a sequence of SEQ ID NO: 6; and / or,

[0898] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 14, LCDR2 with a sequence of SEQ ID NO: 15, and LCDR3 with a sequence of SEQ ID NO: 16;

[0899] (b) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 24, HCDR2 with a sequence of SEQ ID NO: 25, and HCDR3 with a sequence of SEQ ID NO: 26; and / or,

[0900] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 34, LCDR2 with a sequence of SEQ ID NO: 35, and LCDR3 with a sequence of SEQ ID NO: 36;

[0901] (c) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 4, HCDR2 with a sequence of SEQ ID NO: 5, and HCDR3 with a sequence of SEQ ID NO: 6; and / or,

[0902] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 34, LCDR2 with a sequence of SEQ ID NO: 35, and LCDR3 with a sequence of SEQ ID NO: 36;

[0903] or

[0904] (d) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 24, HCDR2 with a sequence of SEQ ID NO: 25, and HCDR3 with a sequence of SEQ ID NO: 26; and / or,

[0905] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 14, LCDR2 with a sequence of SEQ ID NO: 15, and LCDR3 with a sequence of SEQ ID NO: 16.

[0906] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein the CDRs are defined according to the Kabat numbering system:

[0907] (a) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 having a sequence of SEQ ID NO: 7 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR2 having a sequence of SEQ ID NO: 8 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, HCDR3 having a sequence of SEQ ID NO: 9 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0908] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 17 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 18 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 19 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0909] (b) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 27 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 28 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 29 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0910] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 37 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 38 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 39 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0911] (c) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 7 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 8 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 9 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0912] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 37 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 38 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 39 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom;

[0913] or

[0914] (d) a heavy chain variable region (VH) comprising the following three CDRs: a HCDR1 having a sequence of SEQ ID NO: 27 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR2 having a sequence of SEQ ID NO: 28 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, a HCDR3 having a sequence of SEQ ID NO: 29 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom; and / or,

[0915] A light chain variable region (VL) comprising the following three CDRs: LCDR1 having a sequence of SEQ ID NO: 17 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR2 having a sequence of SEQ ID NO: 18 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom, LCDR3 having a sequence of SEQ ID NO: 19 or a sequence having one or several amino acid substitutions, deletions or additions (e.g., 1, 2 or 3 amino acid substitutions, deletions or additions) therefrom.

[0916] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein the CDRs are defined according to the Kabat numbering system:

[0917] (a) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 7, HCDR2 with a sequence of SEQ ID NO: 8, and HCDR3 with a sequence of SEQ ID NO: 9; and / or,

[0918] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 17, LCDR2 with a sequence of SEQ ID NO: 18, and LCDR3 with a sequence of SEQ ID NO: 19;

[0919] (b) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 27, HCDR2 with a sequence of SEQ ID NO: 28, and HCDR3 with a sequence of SEQ ID NO: 29; and / or,

[0920] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 37, LCDR2 with a sequence of SEQ ID NO: 38, and LCDR3 with a sequence of SEQ ID NO: 39;

[0921] (c) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 7, HCDR2 with a sequence of SEQ ID NO: 8, and HCDR3 with a sequence of SEQ ID NO: 9; and / or,

[0922] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 37, LCDR2 with a sequence of SEQ ID NO: 38, and LCDR3 with a sequence of SEQ ID NO: 39;

[0923] or

[0924] (d) a heavy chain variable region (VH) comprising the following three CDRs: HCDR1 with a sequence of SEQ ID NO: 27, HCDR2 with a sequence of SEQ ID NO: 28, and HCDR3 with a sequence of SEQ ID NO: 29; and / or,

[0925] A light chain variable region (VL) comprising the following three CDRs: LCDR1 with a sequence of SEQ ID NO: 17, LCDR2 with a sequence of SEQ ID NO: 18, and LCDR3 with a sequence of SEQ ID NO: 19.

[0926] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the following heavy chain variable region (VH) and / or light chain variable region (VL), wherein, compared with the CDR defined by the aforementioned IMGT, chothia or kabat, at least one CDR in the heavy chain variable region (VH) and / or light chain variable region (VL) contains a mutation, and the mutation is a substitution, deletion or addition of one or several amino acids or any combination thereof (e.g., substitution, deletion or addition of 1, 2 or 3 amino acids or any combination thereof).

[0927] Preferably, the substitutions described in the present disclosure are conservative substitutions.

[0928] In certain embodiments, the VH of the antibody or antigen-binding fragment thereof of the present disclosure comprises a framework region (FR) derived from a heavy chain variable region (VH) of a human immunoglobulin, and / or the VL of the antibody or antigen-binding fragment thereof comprises a framework region (FR) derived from a light chain variable region (VL) of a human immunoglobulin. Therefore, in certain embodiments, the antibody or antigen-binding fragment thereof of the present disclosure is humanized. In certain embodiments, the antibody or antigen-binding fragment thereof of the present disclosure is fully human.

[0929] In certain embodiments, the VH of the antibody or antigen-binding fragment thereof of the present disclosure comprises a framework region (FR) derived from a heavy chain variable region (VH) of a human immunoglobulin, and / or the VL of the antibody or antigen-binding fragment thereof comprises a framework region (FR) derived from a light chain variable region (VL) of a human immunoglobulin. Therefore, in certain embodiments, the antibody or antigen-binding fragment thereof of the present disclosure is humanized. In certain embodiments, the antibody or antigen-binding fragment thereof of the present disclosure is fully human.

[0930] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise:

[0931] (a) a heavy chain framework region of a human immunoglobulin or a variant thereof, which has up to 20 conservative substitutions of amino acids compared to the amino acid sequence encoded by the germline antibody gene from which it is derived (e.g., up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids); and / or

[0932] (b) a light chain framework region of a human immunoglobulin or a variant thereof, which has up to 20 conservative substitutions of amino acids compared to the amino acid sequence encoded by the germline antibody gene from which it is derived (e.g., up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids).

[0933] In certain embodiments, the degree of humanization of the antibodies or antigen-binding fragments thereof of the present 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%.

[0934] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise:

[0935] (a) a heavy chain variable region (VH) comprising an amino acid sequence selected from the group consisting of:

[0936] (i) the sequence shown in SEQ ID NO: 3 or 23;

[0937] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in SEQ ID NO: 3 or 23 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof); or

[0938] (iii) a sequence 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 compared to the sequence set forth in SEQ ID NO: 3 or 23;

[0939] and / or

[0940] (b) a light chain variable region (VL) comprising an amino acid sequence selected from the group consisting of:

[0941] (iv) the sequence shown in SEQ ID NO: 13 or 33;

[0942] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in SEQ ID NO: 13 or 33 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof); or

[0943] (vi) a sequence 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 compared to the sequence set forth in SEQ ID NO:13 or 33.

[0944] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the VH set forth in SEQ ID NO:3, and / or the VL set forth in SEQ ID NO:13.

[0945] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the VH set forth in SEQ ID NO:23, and / or the VL set forth in SEQ ID NO:33.

[0946] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the VH set forth in SEQ ID NO:3, and / or, the VL set forth in SEQ ID NO:33.

[0947] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise the VH set forth in SEQ ID NO:23, and / or the VL set forth in SEQ ID NO:13.

[0948] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise:

[0949] (a) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 13;

[0950] (b) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:33;

[0951] (c) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 33;

[0952] (d) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:13.

[0953] (e) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the 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 described in any one of groups (a) to (d), respectively; or

[0954] (f) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) independently have one or more amino acid substitutions, deletions or additions or any combination thereof (e.g., 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 any one of groups (a) to (d), respectively. Preferably, the substitutions are conservative substitutions.

[0955] In certain embodiments, the heavy chain of an antibody or antigen-binding fragment thereof of the present disclosure comprises a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof having up to 50 conservative substitutions of amino acids compared to the wild-type sequence from which it is derived (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 conservative substitutions of amino acids; e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids). In certain embodiments, the light chain of the antibodies or antigen-binding fragments thereof of the present disclosure comprises a light chain constant region (CL) of a human immunoglobulin, or a variant thereof, which has up to 50 conservative substitutions of amino acids compared to the wild-type sequence from which it is derived (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 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids).

[0956] In some embodiments, the constant region is altered, for example, mutated, to modify the properties of the anti-B7H3 antibody molecule (e.g., to change one or more of the following characteristics: Fc receptor binding, antibody glycosylation, the number of cysteine ​​residues, effector cell function, or complement function). Functional changes can be produced by replacing at least one amino acid residue in the antibody constant region with a different residue, for example, changing the affinity of the antibody for an effector ligand (such as FcR or complement C1q), thereby changing the effector function (e.g., reducing it). The Fc region of an antibody mediates several important effector functions, such as ADCC, phagocytosis (ADCP), CDC, etc.

[0957] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure have 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; in particular, selected from, for example, the heavy chain constant regions of IgG1, IgG2, IgG3 and IgG4, more particularly selected from the heavy chain constant region of IgG1 (for example, human IgG1). In some embodiments, the human IgG1 heavy chain constant region is as shown in SEQ ID NO: 43. In some embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure have a light chain constant region, which is selected from, for example, a κ or λ light chain constant region, preferably a κ light chain constant region (for example, a human κ light chain constant region). In some embodiments, the light chain constant region has a sequence as shown in SEQ ID NO: 44.

[0958] In some embodiments, the antibody or antigen-binding fragment thereof comprises the CH shown in SEQ ID NO:43 or a variant thereof, which has up to 20 conservative substitutions of amino acids compared to SEQ ID NO:43 (e.g., up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids), or has 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.

[0959] In some embodiments, the antibody or antigen-binding fragment thereof comprises a light chain constant region or a variant thereof. In some embodiments, the light chain constant region comprises a kappa light chain constant region. In some embodiments, the light chain constant region comprises a light chain constant region (CL) as shown in SEQ ID NO: 44 or a variant thereof, wherein the variant has a conservative substitution of up to 20 amino acids compared to SEQ ID NO: 44 (e.g., a conservative substitution of up to 20, up to 15, up to 10 or up to 5 amino acids; for example, a conservative substitution of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids), or has 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;

[0960] In some embodiments, the antibody or antigen-binding fragment thereof comprises a heavy chain constant region (CH) shown in SEQ ID NO:43 and a light chain constant region (CL) shown in SEQ ID NO:44.

[0961] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise:

[0962] (a) a heavy chain comprising an amino acid sequence selected from the group consisting of:

[0963] (i) a sequence comprising the VH sequence shown in SEQ ID NO: 3 and the CH sequence shown in SEQ ID NO: 43;

[0964] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0965] (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 shown in (i); and

[0966] (b) a light chain comprising an amino acid sequence selected from the group consisting of:

[0967] (iv) a sequence comprising the VL sequence shown in SEQ ID NO: 13 and the CL sequence shown in SEQ ID NO: 44;

[0968] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0969] (vi) 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 shown in (iv).

[0970] In certain embodiments, the substitution described in (ii) or (v) is a conservative substitution.

[0971] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise:

[0972] (a) a heavy chain comprising an amino acid sequence selected from the group consisting of:

[0973] (i) a sequence comprising the VH sequence shown in SEQ ID NO: 23 and the CH sequence shown in SEQ ID NO: 43;

[0974] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0975] (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 shown in (i); and

[0976] (b) a light chain comprising an amino acid sequence selected from the group consisting of:

[0977] (iv) a sequence comprising the VL sequence shown in SEQ ID NO:33 and the CL sequence shown in SEQ ID NO:44;

[0978] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0979] (vi) 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 shown in (iv).

[0980] In certain embodiments, the substitution described in (ii) or (v) is a conservative substitution.

[0981] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise a heavy chain and a light chain,

[0982] The heavy chain comprises:

[0983] (i) the sequence shown in SEQ ID NO:45;

[0984] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0985] (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 to the sequence shown in (i); and

[0986] The light chain comprises:

[0987] (iv) the sequence shown in SEQ ID NO:46;

[0988] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0989] (vi) 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 to the sequence set forth in (iv);

[0990] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[0991] In certain embodiments, the antibodies or antigen-binding fragments thereof of the present disclosure comprise a heavy chain and a light chain,

[0992] The heavy chain comprises:

[0993] (i) the sequence shown in SEQ ID NO:47;

[0994] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0995] (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 to the sequence shown in (i); and

[0996] The light chain comprises:

[0997] (iv) the sequence shown in SEQ ID NO:48;

[0998] (v) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (iv) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[0999] (vi) 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 to the sequence set forth in (iv);

[1000] Preferably, the substitutions described in (ii) or (v) are conservative substitutions.

[1001] In certain embodiments, the antibodies of the present disclosure are chimeric antibodies, humanized antibodies or fully human antibodies. In certain embodiments, the antibodies of the present disclosure or their antigen-binding fragments are selected from scFv, Fab, Fab', (Fab') 2 , Fv fragment, disulfide-linked Fv (dsFv), diabody.

[1002] In certain embodiments, the antibodies of the present disclosure are scFvs. In certain embodiments, the scFvs of the present disclosure comprise:

[1003] (a) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 13;

[1004] (b) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:33;

[1005] (c) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 33;

[1006] (d) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:13.

[1007] (e) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the 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 described in any one of groups (a) to (d), respectively; or

[1008] (f) a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) independently have one or more amino acid substitutions, deletions or additions or any combination thereof (e.g., 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 any one of groups (a) to (d), respectively. Preferably, the substitutions are conservative substitutions.

[1009] In certain embodiments, the antibodies of the present disclosure are scFvs. In certain embodiments, the scFvs of the present disclosure comprise:

[1010] (i) the sequence shown in SEQ ID NO: 1 or 2;

[1011] (ii) a sequence having one or more amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[1012] (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 to the sequence shown in (i);

[1013] Preferably, the substitutions described in (ii) are conservative substitutions.

[1014] In certain embodiments, the antibodies of the disclosure are scFvs.

[1015] In certain embodiments, the scFv of the present disclosure comprises the sequence shown in SEQ ID NO: 1 or 2.

[1016] Antibody derivatives

[1017] The antibodies or antigen-binding fragments thereof disclosed herein may be derivatized, for example, linked to another molecule (e.g., another polypeptide or protein). Generally, the derivatization (e.g., labeling) of an antibody or antigen-binding fragment thereof will not adversely affect its binding to B7H3 (particularly human B7H3). Therefore, the antibodies or antigen-binding fragments thereof disclosed herein are also intended to include such derivatized forms. For example, the antibodies or antigen-binding fragments thereof disclosed herein may be linked (by chemical coupling, genetic fusion, non-covalent linkage or other means) to one or more other molecular groups, such as another antibody (e.g., to form a bispecific antibody), a detection reagent, a pharmaceutical agent, and / or a protein or polypeptide (e.g., an avidin or polyhistidine tag) that is capable of mediating the binding of an antibody or antigen-binding fragment thereof to another molecule.

[1018] One type of derivatized antibody (e.g., bispecific antibody) is produced by cross-linking 2 or more antibodies (of the same type or different types). Methods for obtaining bispecific antibodies are well known in the art, and examples thereof include, but are not limited to, chemical cross-linking, cell engineering (hybridoma) or genetic engineering.

[1019] Another type of derivatized antibody is a labeled antibody. For example, the antibody of the present disclosure or its antigen-binding fragment can be connected to a detectable label. The detectable label described in the present disclosure can be any substance that can be detected by fluorescence, spectroscopy, photochemistry, biochemistry, immunology, electricity, optics or chemical means. Such labels are well known in the art, and examples thereof 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)), acridinium ester compounds, magnetic beads (e.g., ), calorimetric labels such as colloidal gold or colored glass or plastic (e.g., polystyrene, polypropylene, latex, etc.) beads, and biotin for binding to avidin (e.g., streptavidin) modified with the above labels. Patents teaching the use of such labels 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). Detectable labels such as those described above can be detected by methods known in the art. For example, radioactive labels can be detected using photographic film or a scintillation counter, and fluorescent labels can be detected using a photodetector to detect emitted light. Enzyme labels are generally detected by providing a substrate to the enzyme and detecting the reaction product produced by the action of the enzyme on the substrate, and calorimetric labels are detected by simple visualization of a colored label. In certain embodiments, such labels can be suitable for immunological detection (e.g., enzyme-linked immunosorbent assay, radioimmunoassay, fluorescent immunoassay, chemiluminescent immunoassay, etc.). In certain embodiments, detectable labels as described above can be linked to the antibodies or antigen-binding fragments thereof of the present disclosure via linkers of varying lengths to reduce potential steric hindrance.

[1020] In addition, the antibodies or antigen-binding fragments thereof of the present disclosure may also be derivatized with chemical groups, such as polyethylene glycol (PEG), methyl or ethyl groups, or glycosyl groups. These groups may be used to improve the biological properties of antibodies, such as increasing serum half-life.

[1021] The antigen-binding fragments disclosed herein 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 produced by recombinant host cells (reviewed in Hudson, Curr. Opin. Immunol. 11: 548-557 (1999); Little et al., Immunol. Today, 21: 364-370 (2000)). For example, Fab' fragments can be directly obtained from host cells; Fab' fragments can be chemically coupled 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 directly isolated from the culture medium of recombinant host cells. Other techniques for preparing these antigen-binding fragments are well known to those of ordinary skill in the art.

[1022] The IgG isotype control antibodies disclosed in the present invention are fully known to those of ordinary skill in the art and can be purchased or prepared. For example, human anti-hen egg lysosome antibody (human anti-Hen Egg Lysozyme IgG, anti-HEL, such as human IgG1, referred to as hIgG1), whose sequence is derived from the variable region sequence of the Fab F10.6.6 sequence in the study Affinity maturation increases the stability and plasticity of the Fv domain of anti-protein antibodies published by Acierno et al. (Acierno et al. J Mol Biol. 2007; 374 (1): 130-46.). The preparation method is as follows: Nanjing GenScript Biotechnology was commissioned to optimize the amino acid codons and perform gene synthesis on the heavy and light chain (full sequence or variable region) genes of human IgG antibodies. Referring to the standard techniques introduced in the Molecular Cloning Experiment Guide (Third Edition), standard molecular cloning techniques such as PCR, enzyme digestion, DNA gel recovery, ligation transformation, colony PCR or enzyme digestion identification were used to subclone the heavy and light chain genes into the antibody heavy chain expression vector and antibody light chain expression vector of the mammalian expression system, and the heavy and light chain genes of the recombinant expression vector were further sequenced and analyzed. After the sequencing verification was correct, a large amount of endotoxin-free expression plasmids were prepared and the heavy and light chain expression plasmids were transiently co-transfected into HEK293 cells for the expression of recombinant antibodies. After 7 days of culture, the cell culture fluid was collected and affinity purified by rProtein A column (GE). The harvested antibody samples were quality identified by SDS-PAGE and SEC-HPLC standard analysis techniques.

[1023] In a ninth aspect, the present disclosure provides a multispecific antibody comprising the antibody or antigen-binding fragment thereof according to any one of the eighth aspect of the present disclosure, and another antibody or fragment thereof or antibody analog.

[1024] In certain embodiments, the multispecific antibody is a bispecific antibody or a trispecific antibody or a tetraspecific antibody.

[1025] Therefore, in the tenth aspect, the present disclosure provides an isolated nucleic acid molecule comprising a nucleotide sequence encoding an antibody or antigen-binding fragment thereof, or a heavy chain variable region and / or a light chain variable region, or one or more CDRs thereof of the present disclosure. According to codon degeneracy known in the art, in certain embodiments, the nucleotide sequence is replaceable according to codon degeneracy. In certain embodiments, the nucleotide sequence is codon optimized.

[1026] In certain embodiments, the isolated nucleic acid molecules of the present disclosure comprise: (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 antigen-binding fragment thereof of the present disclosure, respectively, or (ii) a first nucleic acid encoding the heavy chain variable region and the heavy chain constant region of the antibody or antigen-binding fragment thereof of the present disclosure, respectively, and a second nucleic acid encoding the light chain variable region and the light chain constant region, or (iii) a first nucleic acid and a second nucleic acid encoding the heavy chain and the light chain of the antibody or antigen-binding fragment thereof of the present disclosure, respectively. In certain embodiments, the first nucleic acid and the second nucleic acid comprise a degenerate sequence or a nucleic acid having a substantially identical sequence to any of the first nucleic acid and the second nucleic acid in (i)-(iii) above. In certain embodiments, the degenerate sequence or the substantially identical sequence refers to a sequence having at least about 85%, 90%, 95%, 99% or higher sequence identity compared to the nucleic acid molecules in (i)-(iii), or a sequence having one or more nucleotide substitutions, or a sequence that differs by no more than 3, 6, 15, 30 or 45 nucleotides.

[1027] In the eleventh aspect, a vector (e.g., a cloning vector or an expression vector) is provided, which comprises an isolated nucleic acid molecule of the present disclosure. In certain embodiments, the vector of the present disclosure is, for example, a plasmid, a cosmid, a phage, a lentivirus, etc. In certain embodiments, the vector is capable of expressing an antibody or an antigen-binding fragment thereof of the present disclosure in a subject (e.g., a mammal, such as a human).

[1028] In the twelfth aspect, a host cell is provided, which comprises the isolated nucleic acid molecule of the present disclosure or the vector of the present disclosure. The host cell can 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 certain embodiments, the host cell of the present disclosure is a mammalian cell, such as CHO (e.g., CHO-K1, CHO-S, CHO DXB11, CHO DG44).

[1029] In a thirteenth aspect, a method for preparing the antibody or its antigen-binding fragment, or multispecific antibody of the present disclosure is provided, which comprises culturing the host cell of the present disclosure under conditions that allow expression of the antibody or its antigen-binding fragment, or multispecific antibody, and recovering the antibody or its antigen-binding fragment from the cultured host cell culture.

[1030] In a fourteenth aspect, an antibody-drug conjugate is provided, wherein the antibody is the above-mentioned anti-B7H3 antibody, which is connected to a coupling portion via a linker. The coupling portion is selected from: a detectable label, a radioisotope, a fluorescent substance, a luminescent substance, a colored substance, an enzyme, polyethylene glycol (PEG), a nuclide, a nucleic acid, a small molecule toxin, a polypeptide with binding activity, a protein, a receptor, a ligand, and other active substances that inhibit tumor cell growth and promote tumor cell apoptosis or necrosis.

[1031] In some embodiments, the antibody-drug conjugate comprises an anti-B7H3 antibody drug conjugate (B7H3-ADC) of the formula:

[1032] Ab-(LD)n,

[1033] in:

[1034] Ab is the antibody or antigen-binding fragment thereof of the eighth aspect, and;

[1035] D is a small molecule toxin drug moiety;

[1036] L is a bond or linking molecule that covalently links Ab and D;

[1037] n is an integer between 1-16 and represents the number of LDs covalently linked to the Ab.

[1038] In some embodiments, L of the antibody-drug conjugate comprises an amino acid residue or a short peptide consisting of 2-10 amino acid residues; the amino acid residue is selected from natural amino acid residues, non-natural amino acid residues, AA 1 The indicated amino acid residue or its stereoisomers;

[1039]

[1040] AA 1 Among the amino acid residues shown:

[1041] R a1 and R b Each independently selected from H,

[1042] Or, R a1 With R b Together with the carbon atoms connected to them, they form a 4-10 membered heterocyclic ring, wherein the heteroatoms in the 4-10 membered heterocyclic ring are selected from 1, 2, 3 or 4 of O, N and S; the 4-10 membered heterocyclic ring is optionally replaced by one or more R 0 replaced by;

[1043] r、r 1 、r 1a and r 1bEach independently is an integer from 0 to 20;

[1044] R m1 , R n1 , R m1a , R n1a , R m1b and R n1b Each independently is H, C 1-6 Alkyl, C 3-6 Cycloalkyl or -COOR x1 , where R x1 C 1-6 alkyl;

[1045] Or, R m1 and R n1 , R m1a and R n1a , and R m1b and R n1b Together with the nitrogen atom they are connected to, they form a 4-10 membered heterocyclic ring, wherein the heteroatoms in the 4-10 membered heterocyclic ring are selected from 1, 2, 3 or 4 of O, N and S; the 4-10 membered heterocyclic ring is optionally replaced by one or more R 0’ replaced by;

[1046] R z Selected from C 1-6 alkyl;

[1047] R 0 , R 0’ Each independently selected from C 1-6 Alkyl, C 3-6 Cycloalkyl, -NR m2 R n2 and optionally C 1-6 An alkyl-substituted 4-10-membered heterocyclic group; in the 4-10-membered heterocyclic ring, the heteroatoms are selected from 1, 2, 3 or 4 of O, N and S;

[1048] R m2 and R n2 Each independently selected from H and C 1-6 alkyl.

[1049] In some embodiments, AA 1 Among the amino acid residues shown, R a1 With R b Together with the carbon atoms connected to them, they form a 5-6 membered heterocyclic ring, wherein the heteroatom in the 5-6 membered heterocyclic ring is N, and the number of heteroatoms is 1 or 2; the 5-6 membered heterocyclic ring is optionally replaced by one or more R 0 The 5-6 membered heterocyclic ring is preferably a piperidine ring or a piperazine ring, and more preferably a piperidine ring, for example Carbon atom No. 1 is a1 and R b Carbon atoms that are linked together.

[1050] In some embodiments, r, r 1 、r 1a and r 1b Each independently represents 0, 1, 2, 3, 4 or 5; preferably, r, r 1 、r 1a and r 1b Each independently is 0 or 4; more preferably, r is 0, r 1 、r 1a and r 1b is 4; or r is 4, r 1 、r 1a and r 1b is 0.

[1051] In some embodiments, r, r 1 、r 1a and r 1b Not all are 0.

[1052] In some embodiments, R m1 , R n1 , R m1a , R n1a , R m1b and R n1b Each independently is H, C 1-6 Alkyl or -COOR x1 , where R x1 C 1-6 Alkyl; preferably each independently H, methyl, ethyl, n-propyl, -COOCH 3 、-COOCH 2 CH 3 、-COOCH 2 CH 2 CH 3 、-COOCH(CH 3 ) 2 、-COOC(CH 3 ) 3 or -COOCH 2 CH 2 CH 2 CH 3 .

[1053] In some embodiments, R m1 and R n1 , R m1a and R n1a , and R m1b and Rn1b Together with the nitrogen atom they are connected to form a 5-6 membered heterocyclic ring, wherein the heteroatom in the 5-6 membered heterocyclic ring is selected from 1 or 2 N atoms; the 5-6 membered heterocyclic ring is optionally replaced by one or more R 0’ The 5-6 membered heterocyclic ring is preferably a piperidine ring or a piperazine ring; further preferably Nitrogen atom No. 1 is m1 and R n1 Nitrogen atoms connected together.

[1054] In some embodiments, R z Preferably C 1-6 Alkyl; more preferably methyl.

[1055] In some embodiments, R 0 and R 0’ Each independently is C 1-6 Alkyl, -NR m2 R n2 Or optionally C 1-6 An alkyl-substituted 5-6-membered heterocyclic group; in the 5-6-membered heterocyclic ring, the heteroatom is selected from 1 or 2 N atoms.

[1056] In some embodiments, R 0 Preferably C 1-6 Alkyl or C 1-6 alkyl-substituted 5-6-membered heterocyclic group, wherein the 5-6-membered heterocyclic group is piperidinyl or piperazinyl; further preferably methyl or piperidinyl substituted by methyl; for example methyl or

[1057] In some embodiments, R 01’ Each is independently preferably C 1-6 Alkyl, -NR m2 R n2 Or optionally C 1-6 Alkyl-substituted 5-6 membered heterocyclic group; in the 5-6 membered heterocyclic ring, the heteroatom is 1 or 2 N; more preferably C 1-6 Alkyl or -NR m2 R n2 More preferably, methyl or -NR m2 R n2 , where R m2 and R n2 Each is independently preferably H or C 1-6 The alkyl group is more preferably a methyl group.

[1058] In some embodiments, R 0’ Preferably C 1-6 Alkyl or -NR m2 Rn2 ; R m2 and R n2 Each is independently preferably H or C 1-6 Alkyl (eg, methyl).

[1059] In some embodiments, AA 1 Among the amino acid residues shown, R a1 and R b Either one is H, and the other is Preferably, R a1 and R b Any one of them is H, and the other is selected from

[1060] In some embodiments, AA 1 The amino acid residues shown are preferably More preferably More preferably

[1061] Most preferably

[1062] In some embodiments, the antibody-drug conjugate consists of antibody-linker-drug, wherein the drug is selected from: microtubule blocking drugs, DNA damaging drugs, Bcl-xL inhibitors, etc.

[1063] In some embodiments, the antibody-drug conjugate consists of antibody-linker-drug, wherein the drug is selected from: Auristatins (e.g., MMAF, MMAE), maytansine derivatives (e.g., DM1, DM4), tubulysin, cryptocolistin, anti-mitotic inhibitors, pyrrole benzazepines and indolechlorobenzazepines, dukamycin, camptothecin, calicheamicin, etc.

[1064] In some embodiments, the antibody-drug conjugate consists of antibody-linker-drug, wherein the drug is selected from camptothecin (CPT) and its derivatives.

[1065] In some embodiments, the antibody-drug conjugate consists of antibody-linker-drug, wherein the drug is selected from topoisomerase I inhibitors.

[1066] In some embodiments, the antibody-drug conjugate consists of antibody-linker-drug, wherein the drug is selected from: SN-38, DXd.

[1067] In some embodiments, in the antibody-drug conjugate, D is a drug unit having Formula II:

[1068]

[1069] in,

[1070] R 1 is H or F,

[1071] R 2 is H or methyl;

[1072] or R 1 and R 2 Together with the carbon atom to which it is attached,

[1073] R 3 is H;

[1074] R 4 Selected from H, -(C1-C4 alkyl)-OH, -(C1-C4 alkenyl)-OH, -(C1-C4 alkyl)-NH 2 , or -(C1-C4alkenyl)-NH 2 ;

[1075] Wherein L is linked via the hydroxyl or amine group present on D.

[1076] In some embodiments, L of the antibody-drug conjugate is selected from:

[1077]

[1078] Wherein, position 1 is connected to Ab, position 2 is connected to D; AA1 is as defined above.

[1079] In addition, it should be noted that those skilled in the art can understand that L is connected to the thiol group contained in Ab (such as antibody) itself after the disulfide bond is opened (for example, the disulfide bond can be opened by reducing the disulfide bond with the reducing agent TCEP to generate thiol group -SH), that is, the -S- between L and Ab is not an additional external sulfur atom. For example, in, -S- is not an additional external sulfur atom, but the -S- formed by the thiol group contained in Tb itself after the disulfide bond is opened and connected to L.

[1080] In some preferred embodiments, the antibody-drug conjugate is selected from:

[1081]

[1082]

[1083]

[1084] Wherein Ab is 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.

[1085] In the fifteenth aspect of the present disclosure, the present disclosure provides a ligand drug conjugate, which comprises the aforementioned ligand drug conjugate or the aforementioned antibody-drug conjugate in the present disclosure, wherein 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.

[1086] In some embodiments, when the ligand drug conjugates having one q value or n value account for the majority of the ligand drug conjugates, the q value or n value is close to the DAR.

[1087] In some embodiments, the drug to antibody ratio (DAR) in the ligand drug conjugate is an integer or decimal selected from 1-10.

[1088] In some embodiments, the drug to 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.

[1089] In some embodiments, the ligand drug conjugate ADC contains ADCs with a distribution of DARs of 1 to 8, for example, 1.5, 2, 4, 6, and 8 (i.e., 1.5, 2, 4, 6, and 8 drug loading species). It is worth noting that degradation products can be produced so that the ligand drug conjugate may also contain DARs of 1, 3, 5, and 7. In addition, the ADC in the ligand drug conjugate may also have a DAR greater than 8. The ligand drug conjugate is produced by interchain disulfide reduction and then conjugation. In some embodiments, the ligand drug conjugate contains both: the ligand drug conjugate with a DAR of 4 or less (i.e., the drug loading species is 4 or less) and the ligand drug conjugate with a DAR of 6 or more (i.e., the drug loading species is 6 or more).

[1090] In another aspect, the use of the antibody or antigen-binding fragment thereof of the present disclosure in preparing a kit is provided, and the kit is used to detect the presence or level of B7H3 in a sample. In another aspect, the present disclosure provides a diagnostic or therapeutic kit, which includes one or more of the following substances: the antibody or antigen-binding fragment thereof, nucleic acid, vector, host cell, multispecific antibody, conjugate or pharmaceutical composition described in the present disclosure. Optionally, the diagnostic or therapeutic kit also includes instructions for use.

[1091] In the sixteenth aspect of the present disclosure, the present disclosure provides a pharmaceutical composition, which comprises a substance A, and optionally one or more pharmaceutical excipients; the substance A is the aforementioned 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, or the aforementioned antibody or antigen-binding fragment thereof, a nucleic acid molecule, a vector, a host cell, a multispecific antibody, and / or a ligand-drug conjugate, a conjugate, or the aforementioned antibody-drug conjugate, or the aforementioned compound, or a stereoisomer of the compound, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof. The substance A may be a therapeutically effective amount.

[1092] In certain embodiments, the pharmaceutical compositions of the present disclosure comprise the antibodies or antigen-binding fragments thereof of the present disclosure, and a pharmaceutically acceptable carrier and / or excipient.

[1093] In certain embodiments, the pharmaceutical composition of the present disclosure comprises the host cell of the present disclosure, and a pharmaceutically acceptable carrier and / or excipient, wherein the host cell comprises the isolated nucleic acid molecule or vector as described above.

[1094] In certain embodiments, the pharmaceutical compositions of the present disclosure comprise the multispecific antibodies of the present disclosure, and a pharmaceutically acceptable carrier and / or excipient.

[1095] In certain embodiments, the pharmaceutical compositions of the present disclosure comprise the conjugates of the present disclosure and a pharmaceutically acceptable carrier and / or excipient.

[1096] In the seventeenth aspect of the present disclosure, the present disclosure provides the use of the aforementioned substance A or the aforementioned pharmaceutical composition in the preparation of a drug for treating and / or preventing a disease associated with abnormal cell activity (e.g., cancer disease). The substance A or the aforementioned pharmaceutical composition may be a therapeutically effective amount.

[1097] In some embodiments, provided is the use of the antibody or antigen-binding fragment thereof, nucleic acid, vector, host cell, antibody-drug conjugate, or multispecific antibody of the present disclosure in the preparation of a drug for regulating (inhibiting or blocking) the activity of B7H3.

[1098] In some embodiments, provided is the use of the antibody or antigen-binding fragment thereof, nucleic acid, vector, host cell, antibody-drug conjugate, or multispecific antibody of the present disclosure in the preparation of a medicament for treating or preventing a disease associated with the activity of B7H3.

[1099] In some embodiments, provided is the use of the antibody or antigen-binding fragment thereof, nucleic acid, vector, host cell, antibody-drug conjugate, or multispecific antibody of the present disclosure in the preparation of a drug for treating or preventing a tumor associated with the activity of B7H3.

[1100] In some embodiments, the cancer disease is selected from esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumor, lung cancer (e.g., small cell lung cancer, non-small cell lung cancer or lung adenocarcinoma), squamous cell carcinoma, bladder cancer, gastric 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 cancer, non-Hodgkin's lymphoma, central nervous system tumors (e.g., glioma, glioblastoma multiforme, glioma or sarcoma), prostate cancer or thyroid cancer.

[1101] In some embodiments, the cancer disease is a cancer disease associated with Trop-2, Her 2, B7H3, Her 3, EGFR. In some embodiments, the cancer disease is a cancer disease associated with Trop-2 or Her 2.

[1102] In some embodiments, the cancer disease is a cancer disease associated with Trop-2.

[1103] In some embodiments, the cancer disease is a Her 3-related cancer disease.

[1104] In some embodiments, the cancer disease is a cancer disease associated with EGFR.

[1105] In some embodiments, the cancer disease is a B7H3-associated cancer disease.

[1106] In some embodiments, the cancer disease is a solid tumor.

[1107] In some embodiments, the cancer disease is breast cancer or lung cancer (preferably non-small cell lung cancer).

[1108] In the seventeenth aspect of the present disclosure, the present disclosure provides the aforementioned substance A or the aforementioned pharmaceutical composition, which is used for treating and / or preventing diseases associated with abnormal cell activity (such as cancer diseases).

[1109] In some embodiments, the cancer disease is selected from esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumor, lung cancer (e.g., small cell lung cancer, non-small cell lung cancer, or lung adenocarcinoma), squamous cell carcinoma, bladder cancer, gastric 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 cancer, non-Hodgkin's lymphoma, central nervous system tumors (e.g., glioma, glioblastoma multiforme, glioma, or sarcoma), prostate cancer, or thyroid cancer.

[1110] In some embodiments, the cancer disease is a cancer disease associated with Trop-2, Her 2, B7H3, Her 3, EGFR. In some embodiments, the cancer disease is a cancer disease associated with Trop-2 or Her 2.

[1111] In some embodiments, the cancer disease is a cancer disease associated with Trop-2.

[1112] In some embodiments, the cancer disease is a Her 3-related cancer disease.

[1113] In some embodiments, the cancer disease is a cancer disease associated with EGFR.

[1114] In some embodiments, the cancer disease is a B7H3-associated cancer disease.

[1115] In some embodiments, the cancer disease is a solid tumor. In some embodiments, the cancer disease is breast cancer or lung cancer (preferably non-small cell lung cancer).

[1116] In the eighteenth aspect of the present disclosure, the present disclosure provides a method for preventing and / or treating diseases associated with abnormal cell activity (such as cancer diseases), which comprises: administering an effective amount of the aforementioned substance A, or the aforementioned pharmaceutical composition, to an individual in need thereof.

[1117] In some embodiments, the cancer disease is selected from esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumor, lung cancer (e.g., small cell lung cancer, non-small cell lung cancer, or lung adenocarcinoma), squamous cell carcinoma, bladder cancer, gastric 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 cancer, non-Hodgkin's lymphoma, central nervous system tumors (e.g., glioma, glioblastoma multiforme, glioma, or sarcoma), prostate cancer, or thyroid cancer.

[1118] In some embodiments, the cancer disease is a cancer disease associated with Trop-2, Her 2, B7H3, Her 3, or EGFR.

[1119] In some embodiments, the cancer disease is a cancer disease associated with Trop-2 or Her 2.

[1120] In some embodiments, the cancer disease is a cancer disease associated with Trop-2.

[1121] In some embodiments, the cancer disease is a Her 3-related cancer disease.

[1122] In some embodiments, the cancer disease is a cancer disease associated with EGFR.

[1123] In some embodiments, the cancer disease is a B7H3-associated cancer disease.

[1124] In some embodiments, the cancer disease is a solid tumor.

[1125] In some embodiments, the cancer disease is breast cancer or lung cancer (preferably non-small cell lung cancer).

[1126] In another aspect, the present disclosure provides the following embodiments:

[1127] 1. A ligand-drug conjugate of formula XV,

[1128]

[1129] or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof,

[1130] in:

[1131] Tb is a ligand or targeting moiety that binds to the target;

[1132] q is the drug-ligand coupling ratio;

[1133] D is a bioactive molecular fragment;

[1134] L 1 is an extension unit;

[1135] L 2 Does not exist or is a connected unit;

[1136] L 3 Selected from amino acid residues or short peptides consisting of 2-10 amino acid residues;

[1137] L 4 Does not exist or exists, L4 When present, L 4 Selected from 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[1138] 2. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in Embodiment 1, characterized in that it satisfies one or more of the following conditions:

[1139] (1) Tb is an antibody or an antigen-binding fragment thereof;

[1140] (2) q is selected from any value between 0.1 and 16.0;

[1141] (3) D is a molecular fragment with anti-tumor biological activity;

[1142] (4)L 1 Selected from:

[1143]

[1144]

[1145]

[1146] Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl group, a 5-10 membered heteroaryl group, an amide group, a sulfonamide group, an imine group, and a CF 2 ;

[1147] Rx and Ry are each independently selected from H and C1-4 alkyl;

[1148] Each m is independently selected from 0, 1, 2, 3, 4, 5 and 6;

[1149] y1, y2, y3 and y4 are each independently selected from any integer between 0 and 20;

[1150] The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected;

[1151] (5)L 2 Does not exist or exists, L 2 When present, L 2 Selected from:

[1152]

[1153]

[1154] y1, y2, y3 and y4 are each independently selected from any integer between 0 and 20, and 1 is the same as L 1 Connected, 2 bits and L 3 connected;

[1155] (6)L 3 selected from amino acid residues or short peptides consisting of 2-10 amino acid residues; the amino acid residues are selected from natural amino acid residues, non-natural amino acid residues, or selected from AA 1 The indicated amino acid residue or its stereoisomers;

[1156] AA 1 The structures of the indicated amino acid residues are shown below,

[1157]

[1158] Where: R a , R b Each independently selected from H, And R a , R b Not at the same time H;

[1159] Or, R a With R b Together with the carbon atoms to which they are commonly attached, they form a 4-10 membered heterocyclic ring, wherein the 4-10 membered heterocyclic ring is optionally substituted by one or more R 0 replaced by;

[1160] r、r 1 Each is independently selected from any integer from 0 to 20;

[1161] R m1 , R n1 Each independently selected from H, C1-6 alkyl, C3-6 cycloalkyl and -COOR x1 ;

[1162] R x1 Selected from C1-6 alkyl;

[1163] Or, R m1 With R n1 Together with the nitrogen atom to which they are commonly attached, they form a 4-10 membered heterocyclic ring, wherein the 4-10 membered heterocyclic ring is optionally substituted by one or more R 0’ replaced by;

[1164] R z Selected from C1-6 alkyl;

[1165] R 0 , R 0’ Each independently selected from C1-6 alkyl, C3-6 cycloalkyl, -NRm2 R n2 and a 4-10 membered heterocyclic group optionally substituted by a C1-6 alkyl group;

[1166] R m2 , R n2 Each independently selected from H and C1-6 alkyl;

[1167] (7)L 4 Does not exist or exists, L 4 When present, L 4 Selected from

[1168] 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[1169] 3. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in Embodiment 2, characterized in that it satisfies one or more of the following conditions:

[1170] (1) Tb is an antibody or an antigen-binding fragment thereof, which satisfies one or more of the following conditions:

[1171] (i) the antibody or antigen-binding fragment thereof includes Fab, Fab', F(ab')2, Fd, Fv, dAb, complementarity determining region fragment, non-human antibody, humanized antibody, chimeric antibody, fully human antibody, pro-antibody, monoclonal antibody, bispecific antibody or multispecific antibody;

[1172] (ii) Tb is a monoclonal antibody or an antigen-binding fragment thereof;

[1173] (iii) Tb is an antibody or antigen-binding fragment thereof that is endocytosed, not endocytosed, or endocytosed weakly;

[1174] (iv) Tb is an antibody or an antigen-binding fragment thereof that has the activity of binding to free antigens in tumor tissues and / or antigens on the surface of tumor cells;

[1175] (v) Tb is an antibody or an antigen-binding fragment thereof that has no activity of binding to free antigens in tumor tissues and / or antigens on the surface of tumor cells;

[1176] (2) q is selected from 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and any value therebetween;

[1177] (3) In the bioactive molecule fragment, the bioactive molecule is a DNA topoisomerase inhibitor or a microtubule protein inhibitor;

[1178] (4)L1 Selected from Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl, a 5-10 membered heteroaryl and an amide group; Rx and Ry are independently selected from H and a C1-4 alkyl group; each m is independently selected from 0, 1, 2, 3, 4, 5 and 6; y1 is independently selected from any integer between 1 and 6; each y2 is independently selected from any integer between 0 and 15; each y3 is independently selected from 1, 2 and 3; each y4 is independently selected from 0 and 1; the 1st position is connected to Tb through an S atom, and the 2nd position is connected to L 2 or L 3 connected;

[1179] (5)L 2 Does not exist or exists, L 2 When present, L 2 Selected from y1 is selected from any integer between 1 and 6, each y2 is independently selected from any integer between 0 and 10, each y3 is independently selected from 1 and 2, each y4 is independently selected from 0 and 1, and the 1st position is the same as L 1 Connected, 2 bits and L 3 connected;

[1180] (6)L 3 is selected from the group consisting of amino acid residues Val, D-Val, Cit, Phe, Lys, Lys(Ac), Leu, Gly, Ala, Asn, Asp, Arg and AA 1 or 2 to 10 selected from Val, Cit, Phe, Lys, D-Val, Leu, Gly, Ala, Asn, Asp and AA 1 A short peptide composed of amino acid residues;

[1181] (7)AA 1 Among the amino acid residues, R a , R b Among them, either one is H and the other is selected from

[1182] Or, AA 1 Among the amino acid residues, R a With R b Together with the carbon atoms they are connected to, they form the 0 substituted 5-6 membered heterocycle;

[1183] (8)AA 1 Among the amino acid residues, r, r 1 Each independently selected from 0, 1, 2, 3, 4 and 5;

[1184] (9)AA 1 Among the amino acid residues, R m1 , R n1 Each is independently selected from H, methyl, ethyl, n-propyl, n-butyl, -COOCH3, -COOCH2CH3, -COOCH2CH2CH3, -COOCH(CH3)2, -COOC(CH3)3 and -COOCH2CH2CH2CH3; or, R m1 With R n1 Together with the nitrogen atoms they are connected to, they form the 0’ substituted 5-6 membered heterocycle;

[1185] (10)AA 1 Among the amino acid residues, R z is methyl;

[1186] (11)AA 1 Among the amino acid residues, R 0 , R 0’ Each independently selected from C1-6 alkyl, -NR m2 R n2 and a 5-6 membered heterocyclic group optionally substituted by a C1-6 alkyl group;

[1187] (12)L 4 Does not exist or exists, L 4 When present, L 4 Selected from 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[1188] 4. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in Embodiment 3, characterized in that it satisfies one or more of the following conditions:

[1189] (1) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, an anti-Trop-2 antibody or an antigen-binding fragment thereof, an anti-Her2 antibody or an antigen-binding fragment thereof, an anti-Her3 antibody or an antigen-binding fragment thereof, an anti-EGFR antibody or an antigen-binding fragment thereof, or an IgG1 isotype antibody anti-chicken lysozyme antibody;

[1190] (2) q is selected from any value between 0.1, 1, 2, 3, 4, 5, 6, 7, 8 and so on;

[1191] (3) When the bioactive molecule in the bioactive molecule fragment is a DNA topoisomerase inhibitor, the DNA topoisomerase inhibitor is a camptothecin bioactive molecule;

[1192] (4) When the bioactive molecule in the bioactive molecule fragment is a tubulin inhibitor, the tubulin inhibitor is an MMAF type tubulin inhibitor or an MMAE type tubulin inhibitor;

[1193] (5)L 1 In, each Z is independently selected from a direct bond, a carbon-carbon triple bond, and a carbon-carbon double bond;

[1194] (6)L 1 In , y1 is 4, 5 or 6;

[1195] (7)L 1 In which, each y2 is independently selected from any integer between 6 and 10;

[1196] (8)L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected;

[1197] (9)L 3 Selected from 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, Gl y-Gly-Arg, Ala-Ala-Asn, Gly-Gly-Phe, Val-Lys-Gly, Val-Lys-Gly-Gly, Val-Lys and Lys-Ala-Asn;

[1198] (10)AA 1 Among the amino acid residues shown, Ra , R b Among them, either one is H and the other is selected from or, R a With R b Together with the carbon atoms they are connected to, they form the 0 The substituted 5-6 membered heterocyclic ring is 0 a substituted piperidine ring or a piperazine ring;

[1199] (11)AA 1 Among the amino acid residues, r, r 1 Each independently selected from 0 and 4;

[1200] (12)AA 1 Among the amino acid residues, R m1 , R n1 are each independently selected from H, C1-6 alkyl, C3-6 cycloalkyl and tert-butyloxycarbonyl; or, R m1 With R n1 Together with the nitrogen atoms they are connected to, they form the 0’ a substituted piperidine ring or a piperazine ring;

[1201] (13)AA 1 Among the amino acid residues, R 0 is selected from C1-6 alkyl and a 5-6 membered heterocyclic group substituted by a C1-6 alkyl, wherein the 5-6 membered heterocyclic group is selected from piperidinyl and piperazinyl;

[1202] (14)AA 1 Among the amino acid residues, R 0’ Selected from C1-6 alkyl and -NR m2 R n2 ;

[1203] (15)AA 1 Among the amino acid residues, R m2 , R n2 is methyl;

[1204] (16)L 4 Does not exist or exists, L 4 When present, L 4 for 1 bit and L 3 Connected to 1, 2 bits are connected to D.

[1205] 5. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in any one of embodiments 1-4, characterized in that it satisfies one or more of the following conditions:

[1206] (1) q is selected from any value among 2, 3, 4, 5, 6, 7, 8 and so on;

[1207] (2) Tb is any of the following:

[1208] (i) Tb is an anti-Her 2 antibody or an antigen-binding fragment thereof, wherein the anti-Her 2 antibody is anbenitamab, coprelotamab, disitamab, gancotamab, margetuximab, pertuzumab, timigutuzumab, zanidatamab, trastuzumab, pertuzumab or an antigen-binding fragment thereof;

[1209] (ii) Tb is an anti-Trop-2 antibody or an antigen-binding fragment thereof, wherein the anti-Trop-2 antibody is datopotamab, Sacituzumab or an antigen-binding fragment thereof; or

[1210] (iii) Tb is an anti-EGFR antibody or an antigen-binding fragment thereof, wherein the anti-EGFR antibody is demupitamab, depatuxizumab, futuximab, imgatuzumab, laprituximab, losatuxizumab, matuzumab, modotuximab, necitumumab, nimotuzumab, panitumumab, pimurutamab, serclutamab, tomozuotuximab, zalutumumab, cetuximab or an antigen-binding fragment thereof; or

[1211] (iv) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, wherein the anti-B7H3 antibody is enoblituzumab, mirzotamab, omburtamab, 1D1-01, 2E3-02 antibody or an antigen-binding fragment thereof; or

[1212] (v) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, wherein the anti-B7H3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Kabat numbering system:

[1213] (a) HCDR1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR3 of SEQ ID NO: 9; and / or,

[1214] LCDR1 with the sequence of SEQ ID NO: 17, LCDR2 with the sequence of SEQ ID NO: 18, LCDR3 with the sequence of SEQ ID NO: 19;

[1215] (b) HCDR1 of SEQ ID NO: 27, HCDR2 of SEQ ID NO: 28, HCDR3 of SEQ ID NO: 29; and / or,

[1216] LCDR1 with the sequence of SEQ ID NO:37, LCDR2 with the sequence of SEQ ID NO:38, LCDR3 with the sequence of SEQ ID NO:39;

[1217] (c) HCDR1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR3 of SEQ ID NO: 9; and / or,

[1218] LCDR1 with the sequence of SEQ ID NO:37, LCDR2 with the sequence of SEQ ID NO:38, LCDR3 with the sequence of SEQ ID NO:39;

[1219] or (d) HCDR1 of SEQ ID NO: 27, HCDR2 of SEQ ID NO: 28, HCDR3 of SEQ ID NO: 29; and / or,

[1220] LCDR1 with the sequence of SEQ ID NO: 17, LCDR2 with the sequence of SEQ ID NO: 18, LCDR3 with the sequence of SEQ ID NO: 19; or

[1221] (vi) Tb is an anti-Her3 antibody or an antigen-binding fragment thereof, wherein the anti-Her3 antibody is barecetamab, duligotuzumab, elgemtumab, lumretuzumab, patritumab, seribantumab, 202-2-1 or an antigen-binding fragment thereof; or

[1222] (vii) Tb is an anti-Her3 antibody or an antigen-binding fragment thereof, wherein the anti-Her3 antibody or the antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Kabat numbering system:

[1223] HCDR1 of SEQ ID NO:53, HCDR2 of SEQ ID NO:54, HCDR3 of SEQ ID NO:55; and / or,

[1224] LCDR1 with the sequence of SEQ ID NO:59, LCDR2 with the sequence of SEQ ID NO:60, LCDR3 with the sequence of SEQ ID NO:21;

[1225] (viii) antibodies or antigen-binding fragments thereof that have tumor cell endocytosis activity and have the activity of binding to free antigens in tumor tissues and / or antigens on the surface of tumor cells;

[1226] (ix) antibodies or antigen-binding fragments thereof that have weak or no tumor cell endocytosis activity and have binding activity to free antigens in tumor tissues and / or antigens on the surface of tumor cells;

[1227] (x) An antibody or antigen-binding fragment thereof having weak or no endocytic activity in tumor cells and no binding activity to free antigens in tumor tissues or antigens on the surface of tumor cells; for example, Tb is an anti-chicken lysozyme human IgG1 isotype antibody

[1228] (xi) antibodies or antigen-binding fragments thereof that bind to non-endocytosed antigens; for example, ALCAM / CD166;

[1229] (3)L 1 Selected from

[1230] m is selected from 2, 3 and 4, y1 is selected from any integer between 1-6, each y2 is independently selected from any integer between 0-10, each y3 is independently selected from 1 or 2, the 1st position is connected to Tb through the S atom, the 2nd position is connected to L 2 or L 3 connected;

[1231] (4)L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected;

[1232] (5)L 3 Selected from AA 1 AA 1 -Gly, Val-Cit, Val-AA 1 -Gly, AA 1 -Ala-Asn and Gly-Gly-Phe-Gly;

[1233] (6)AA 1 Among the amino acid residues shown, R a With Rb Together with the carbon atoms they are connected to, they form the 0 The substituted 5-6 membered heterocyclic ring is 0 Substituted piperidine ring;

[1234] (7)AA 1 Among the amino acid residues, r, r 1 In, either one is 0 and the other is 4;

[1235] (8)AA 1 Among the amino acid residues, R m1 , R n1 are each independently selected from H and C1-6 alkyl; or, R m1 With R n1 Together with the nitrogen atoms they are connected to, they form the 0’ Substituted piperidine ring;

[1236] (10)AA 1 Among the amino acid residues, R 0 is selected from methyl, ethyl and a 5-6 membered heterocyclic group substituted by methyl, wherein the 5-6 membered heterocyclic group is piperidinyl;

[1237] (11)AA 1 Among the amino acid residues, R 0’ Selected from methyl and -NR m2 R n2 ;

[1238] (12) When the bioactive molecule in the bioactive molecule fragment is a DNA topoisomerase inhibitor, and the DNA topoisomerase inhibitor is a camptothecin bioactive molecule, the camptothecin bioactive molecule is camptothecin, DXD, camptothecin with modified substituents, or DXD with modified substituents.

[1239] 6. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in any one of embodiments 1-4, characterized in that it satisfies one or more of the following conditions:

[1240] (1) q is selected from any value among 3, 4, 5, 6, 7, 8 and so on;

[1241] (2) Tb is any of the following:

[1242] (vi) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, wherein the anti-B7H3 antibody or an antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Kabat numbering system:

[1243] (a) HCDR1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR3 of SEQ ID NO: 9; and / or,

[1244] LCDR1 with the sequence of SEQ ID NO: 17, LCDR2 with the sequence of SEQ ID NO: 18, LCDR3 with the sequence of SEQ ID NO: 19;

[1245] (b) HCDR1 of SEQ ID NO: 27, HCDR2 of SEQ ID NO: 28, HCDR3 of SEQ ID NO: 29; and / or,

[1246] LCDR1 with the sequence of SEQ ID NO:37, LCDR2 with the sequence of SEQ ID NO:38, LCDR3 with the sequence of SEQ ID NO:39;

[1247] (c) HCDR1 of SEQ ID NO: 7, HCDR2 of SEQ ID NO: 8, and HCDR3 of SEQ ID NO: 9; and / or,

[1248] LCDR1 with the sequence of SEQ ID NO:37, LCDR2 with the sequence of SEQ ID NO:38, LCDR3 with the sequence of SEQ ID NO:39;

[1249] or (d) HCDR1 of SEQ ID NO: 27, HCDR2 of SEQ ID NO: 28, HCDR3 of SEQ ID NO: 29; and / or,

[1250] LCDR1 with the sequence of SEQ ID NO: 17, LCDR2 with the sequence of SEQ ID NO: 18, LCDR3 with the sequence of SEQ ID NO: 19;

[1251] The anti-B7H3 antibody or antigen-binding fragment thereof comprises a VH comprising a set of heavy chain CDRs in (a)-(d) above and a VL comprising a set of light chain CDRs in (a)-(d);

[1252] (ii) Tb is an anti-Her3 antibody or an antigen-binding fragment thereof,

[1253] The anti-Her3 antibody or antigen-binding fragment thereof comprises the following complementarity determining regions (CDRs), wherein the CDRs are defined according to the Kabat numbering system:

[1254] HCDR1 of SEQ ID NO:53, HCDR2 of SEQ ID NO:54, HCDR3 of SEQ ID NO:55; and / or,

[1255] LCDR1 with the sequence of SEQ ID NO:59, LCDR2 with the sequence of SEQ ID NO:60, LCDR3 with the sequence of SEQ ID NO:21;

[1256] The anti-Her3 antibody or antigen-binding fragment thereof comprises a VH containing the above group of heavy chain CDRs and a VL containing the above group of light chain CDRs;

[1257] (3)L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected;

[1258] (4)L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected;

[1259] (5)L 3 Selected from AA 1 、Val-AA 1 -Gly;

[1260] (6)AA 1 Among the amino acid residues, R 0 Selected from methyl, ethyl and

[1261] 7. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in any one of embodiments 1-4, characterized in that it satisfies one or more of the following conditions:

[1262] (1) q is selected from any value among 4, 5, 6, 7, 8 and so on;

[1263] (2) Tb is any of the following:

[1264] (i) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, wherein the anti-B7H3 antibody or the antigen-binding fragment thereof comprises: VH shown in SEQ ID NO: 3 or 23, and / or VL shown in SEQ ID NO: 13 or 33;

[1265] (ii) Tb is an anti-Her3 antibody or an antigen-binding fragment thereof, wherein the anti-Her3 antibody or the antigen-binding fragment thereof comprises: VH as shown in SEQ ID NO: 49, and / or VL as shown in SEQ ID NO: 50;

[1266] (3)L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 connected;

[1267] (4)L 2 Does not exist or

[1268] (5)L 3 Selected from Val-AA 1 -Gly;

[1269] (6)AA 1 Among the amino acid residues shown, R a With R b Together with the carbon atoms they are connected to, they form Carbon atom No. 1 is a and R b carbon atoms that are linked together;

[1270] (7) r, r 1 In the example, r is 4 and r 1 When R is 0, m1 , R n1 Each is independently selected from H and C1-6 alkyl; r is 0, r 1 When R is 4, m1 , R n1 Each independently selected from C1-6 alkyl, or, R m1 With R n1 Together with the nitrogen atoms they are connected to, they form Carbon atom No. 1 is a and R b Carbon atoms that are linked together.

[1271] 8. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in Embodiment 7, characterized in that:

[1272] (1) q is selected from any value among 6, 7, 8 and ;

[1273] (2) Tb is any of the following:

[1274] (i) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, wherein the anti-B7H3 antibody or the antigen-binding fragment thereof comprises: VH shown in SEQ ID NO: 3 or 23, and / or VL shown in SEQ ID NO: 13 or 33;

[1275] Further including:

[1276] (a) a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof; and / or

[1277] (b) a light chain constant region (CL) of a human immunoglobulin or a variant thereof,

[1278] (ii) Tb is an anti-Her3 antibody or an antigen-binding fragment thereof, wherein the anti-Her3 antibody or the antigen-binding fragment thereof comprises: VH as shown in SEQ ID NO: 49, and / or VL as shown in SEQ ID NO: 50;

[1279] Further including:

[1280] (a) a heavy chain constant region (CH) of a human immunoglobulin or a variant thereof; and / or

[1281] (b) a light chain constant region (CL) of a human immunoglobulin or a variant thereof;

[1282] (3) r, r 1 In the example, r is 4 and r 1 When R is 0, m1 , R n1 Each is independently selected from H and C1-6 alkyl; r is 0, r 1 When R is 4, m1 , R n1 Each independently selected from C2-6 alkyl;

[1283] (4)L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L 2 or L 3 Connected; for example, L 1 Selected from The 1st position is connected to Tb through the S atom, and the 2nd position is connected to L2 or L 3 connected.

[1284] 9. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in Embodiment 8, characterized in that:

[1285] (1) Tb is any of the following:

[1286] (i) Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, wherein the anti-B7H3 antibody or the antigen-binding fragment thereof comprises:

[1287] VH shown in SEQ ID NO:3, CH shown in SEQ ID NO:43 or a variant thereof, and / or, VL shown in SEQ ID NO:13, CL shown in SEQ ID NO:44 or a variant thereof;

[1288] VH shown in SEQ ID NO:23, CH shown in SEQ ID NO:43 or a variant thereof, and / or, VL shown in SEQ ID NO:33, CL shown in SEQ ID NO:44 or a variant thereof;

[1289] Preferably, the B7H3 antibody or antigen-binding fragment thereof comprises:

[1290] The heavy chain shown in SEQ ID NO:45, and / or the light chain shown in SEQ ID NO:46;

[1291] The heavy chain shown in SEQ ID NO:47, and / or the light chain shown in SEQ ID NO:48;

[1292] (ii) Tb is an anti-Her3 antibody or an antigen-binding fragment thereof, wherein the anti-Her3 antibody or the antigen-binding fragment thereof comprises:

[1293] VH shown in SEQ ID NO:49, CH shown in SEQ ID NO:43 or a variant thereof, and / or, VL shown in SEQ ID NO:50, CL shown in SEQ ID NO:44 or a variant thereof;

[1294] Preferably, the anti-Her3 antibody or antigen-binding fragment thereof comprises:

[1295] The heavy chain shown in SEQ ID NO:51, and / or the light chain shown in SEQ ID NO:52;

[1296] (2)R m1 , R n1Each is independently selected from C1-6 alkyl, wherein the C1-6 alkyl is selected from methyl, ethyl and n-propyl; or R m1 , R n1 Each is independently selected from C2-6 alkyl, wherein the C2-6 alkyl is selected from ethyl and n-propyl.

[1297] 10. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate according to any one of embodiments 1 to 9, characterized in that it satisfies one or more of the following conditions:

[1298] (1) When Tb is an antibody or an antigen-binding fragment thereof, and the antibody or the antigen-binding fragment thereof comprises a single-chain antibody, the single-chain antibody is scFv;

[1299] (2) Tb is an antibody or antigen-binding fragment thereof having endocytosis activity;

[1300] (3)AA 1 The amino acid residues are selected from

[1301]

[1302] Preferably, AA 1 The amino acid residues are selected from

[1303] More preferably, AA 1 The amino acid residues are selected from

[1304] Most preferably, AA 1 The amino acid residues are selected from

[1305] 11. The 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 according to any one of embodiments 1 to 10, characterized in that:

[1306] L 3 Selected from

[1307] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L2 Connected, 2 bits and L 4 Or D connected;

[1308] Preferably, L 3 Selected from

[1309] X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D connected;

[1310] More preferably, L 3 Selected from X - Selected from halogen ions, carboxylate ions, sulfate ions, hydrogen sulfate ions and OH - , 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D connected;

[1311] Also preferably, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D connected;

[1312] Most preferably, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 Or D connected;

[1313] For example The structure is selected from the following structural fragments:

[1314]

[1315] 12. The 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 according to any one of embodiments 1 to 11, characterized in that:

[1316] in The structure is selected from the following:

[1317]

[1318]

[1319]

[1320]

[1321] Among them, bit 1 is connected to Tb and bit 2 is connected to D.

[1322] 13. The 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 according to any one of embodiments 1 to 12, characterized in that:

[1323] Wherein, the ligand-drug conjugate has a structure of Formula I:

[1324]

[1325] wherein: Tb, L1, L2, L3, L4 and q are as defined in any one of embodiments 1-12;

[1326] R 1 , R 2 are each independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or,

[1327] R 1 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[1328] R 3 Selected from H, halogen, -OH, -NH 2 , optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or,

[1329] R 3 and X together with the carbon atom to which it is attached form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof, or,

[1330] R 3 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof;

[1331] W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected;

[1332] X is selected from a direct bond, an optionally substituted -O-(CH 2 ) n3 -、-NR 4 -(CH 2 ) n3 -、-S-(CH 2 ) n3 -, carbonyl-(CH 2 ) n3 -、-SO 2 -(CH 2 ) n3 -、-(CH 2 ) n1 -、 C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L 4 connected; the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups and the carbon atoms connected to them together form a C3-6 cycloalkyl group;

[1333] Each M is independently selected from a direct bond and -CR 5a R 5b -;

[1334] R 4 , R 5 , R 5a , R 5b , R 6 , R 7 Each is independently selected from H, optionally substituted C1-4 alkyl, optionally substituted C1-4 alkoxy and optionally substituted C3-6 cycloalkyl;

[1335] n, n', n1, n2, n3 are each independently selected from any integer between 0 and 6;

[1336] Position 1 is connected to the camptothecin nucleus, and position 2 is connected to W or L 4 connected.

[1337] 14. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in Embodiment 13, characterized in that it satisfies one or more of the following conditions:

[1338] (1)R 1 , R 2 are each independently selected from H, halogen, C1-4 alkyl; or, R 1 and R 2 Together with the carbon atom to which it is attached, it forms a 5-6 membered heterocyclic ring containing 1, 2 or 3 O, S or N or any combination thereof;

[1339] (2)R 3 is selected from H, C1-4 alkyl; or, R 3 Together with X and the carbon atom to which it is attached, it forms a 5-6 membered carbocyclic ring;

[1340] (3) W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected;

[1341] (4) X is selected from optionally substituted -(CH 2 ) n1 -、 C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L 4 The substituent is selected from 1 or 2 C1-4 alkyl groups, or 2 C1-4 alkyl groups and the carbon atoms to which they are simultaneously connected together form a C3-6 cycloalkyl group;

[1342] (5)R 4 , R 5 Each independently selected from H, C1-4 alkyl and C3-6 cycloalkyl;

[1343] (6)R 5a , R 5b Each independently selected from H and C1-4 alkyl;

[1344] (7) Each R 7 Independently selected from H and C1-4 alkyl;

[1345] (8) n is selected from 1, 2 and 3;

[1346] (9) n1 is selected from 1, 2, 3 and 4;

[1347] (10) n2 is 1;

[1348] (10)n3 is 0.

[1349] 15. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in embodiment 13 or 14, characterized in that it satisfies one or more of the following conditions:

[1350] (1)R 1 is selected from H and halogen, R 2 is selected from H and C1-4 alkyl; or, R 1 and R 2 and the carbon atom to which it is attached The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring;

[1351] (2)R 3 H; or, R 3 Together with X and the carbon atom to which it is attached, The dotted lines indicate where the carbon ring is fused to the benzene ring and the pyridine ring;

[1352] (3) W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected;

[1353] (4) Each R 4 are independently selected from H, C1-4 alkyl and C3-6 cycloalkyl, R 5 is H;

[1354] (5)R 5a , R 5b are each independently selected from H and methyl;

[1355] (6)R 7 is H;

[1356] (7)n is 1.

[1357] 16. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in any one of embodiments 13-15, characterized in that it satisfies one or more of the following conditions:

[1358] (1)R 1 H or F, R 2 is H or methyl; or, R 1and R 2 Together with the carbon atom to which it is attached, The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring;

[1359] (2) W is selected from -O-, -NR 4 -and 1 bit is connected to X, 2 bits are connected to L 4 or L 3 connected;

[1360] (3) Each R 4 R is independently selected from H, methyl, ethyl, n-propyl, isopropyl, tert-butyl and cyclopropyl, 5 is H;

[1361] (4) X is selected from optionally substituted Position 1 is connected to the mother ring, position 2 is connected to W or L 4 connected; the substituent is selected from 1 or 2 C1-4 alkyl groups, or 2 C1-4 alkyl groups and the carbon atoms to which they are simultaneously connected together form a C3-6 cycloalkyl group; the C1-4 alkyl group is such as methyl; the C3-6 cycloalkyl group is such as cyclopropyl.

[1362] 17. The 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 according to any one of embodiments 13 to 16, characterized in that:

[1363] (1) W is selected from -O- and -NR 4 -;

[1364] (2)X is selected from

[1365] Position 1 is connected to the mother ring, position 2 is connected to W or L 4 connected.

[1366] 18. The 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 according to any one of embodiments 13 to 17, characterized in that:

[1367] When W does not exist, X is selected from Position 1 is connected to the mother ring, position 2 is connected to L 4 When W exists, X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

[1368] 19. The 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 according to any one of embodiments 13 to 18, characterized in that:

[1369] The structure is selected from the following:

[1370]

[1371]

[1372]

[1373] Among them, 1 and L 4 connected; when L 4 When not present, 1 bit and L 3 connected.

[1374] 20. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate according to any one of embodiments 13-19, characterized in that the ligand-drug conjugate has a structure of Formula I-1, Formula I-2 or Formula I-3:

[1375]

[1376] Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q is as defined in any one of embodiments 13-19;

[1377]

[1378] Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and q is as defined in any one of embodiments 13-19;

[1379]

[1380] Among them, Tb, L 1 , L 2 , L 3 , L 4,X,R 1 , R 2 , R 3 , R 4 , R 5 , n and q are as defined in any one of Embodiments 13-19.

[1381] 21. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate as described in any one of embodiments 13-20, characterized in that the ligand drug conjugate has a structure of Formula I-1A, Formula I-1B, Formula I-2A, Formula I-2B, Formula I-3A or Formula I-3B:

[1382]

[1383] Among them, Tb, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q is as defined in any one of embodiments 13-19;

[1384]

[1385] Among them, Tb, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and q is as defined in any one of embodiments 13-19;

[1386]

[1387] Among them, Tb, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q are as defined in any one of Embodiments 13-19.

[1388] 22. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate according to any one of embodiments 13-21, characterized in that, wherein the ligand-drug conjugate has a structure of Formula IA or Formula IB:

[1389]

[1390] Among them, Tb, X, R 1 , R 2 , R 3 , R a , R b and q is as defined in any one of embodiments 13-19;

[1391]

[1392] Among them, Tb, X, R 1 , R 2 , R 3 , R a , R b and q are as defined in any one of Embodiments 13-19.

[1393] 23. The ligand-drug conjugate or the stereoisomer of the ligand-drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate according to any one of embodiments 1 to 22, characterized in that, wherein the ligand-drug conjugate is selected from the following:

[1394]

[1395]

[1396]

[1397]

[1398]

[1399]

[1400]

[1401]

[1402]

[1403]

[1404]

[1405]

[1406]

[1407]

[1408]

[1409]

[1410]

[1411]

[1412]

[1413]

[1414] 24. The ligand drug conjugate or the stereoisomer of the ligand drug conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate according to any one of embodiments 1 to 23, characterized in that, wherein the ligand drug conjugate is selected from:

[1415]

[1416]

[1417]

[1418] Among them, Tb 1 is an anti-B7H3 antibody or an antigen-binding fragment thereof, such as enoblituzumab, mirzotamab, omburtamab, 1D1-01, 2E3-02 antibody; q is selected from any value between 0.1 and 16.0, preferably any value between 2 and 8, and more preferably, q is 2, 4, 6 or 8;

[1419]

[1420]

[1421] Among them, Tb 2 is an anti-Trop-2 antibody or an antigen-binding fragment thereof, such as datopotamab, sacituzumab; q is selected from any value between 0.1-16.0, preferably any value between 2-8, more preferably, q is 2, 4, 6 or 8;

[1422]

[1423]

[1424] Among them, Tb 3It is an anti-Her2 antibody or an antigen-binding fragment thereof, such as anbenitamab, coprelotamab, disitamab, gancotamab, margetuximab, pertuzumab, timigutuzumab, zanidatamab, Trastuzumab; q is selected from any value between 0.1 and 16.0, preferably any value between 2 and 8, and more preferably, q is 2, 4, 6 or 8;

[1425]

[1426]

[1427] Among them, Tb 4 It is an anti-Her3 antibody or an antigen-binding fragment thereof, such as barecetamab, duligotuzumab, elgemtumab, lumretuzumab, patritumab, seribantumab, and the antibody shown in IMGT / mAb-DB ID: 546; q is selected from any value between 0.1 and 16.0, preferably any value between 2 and 8, and more preferably, q is 2, 4, 6 or 8;

[1428]

[1429] Among them, Tb 5 is an anti-EGFR antibody or an antigen-binding fragment thereof, such as demupitamab, depatuxizumab, futuximab, imgatuzumab, laprituximab, losatuxizumab, matuzumab, modotuximab, necitumumab, nimotuzumab, panitumumab, pimurutamab, serclutamab, tomozutuximab, zalutumumab, or cetuximab; q is selected from any value between 0.1 and 16.0, preferably any value between 2 and 8, and more preferably, q is 2, 4, 6, or 8;

[1430]

[1431] Among them, Tb 6An antibody without tumor cell endocytosis activity and tumor cell surface antigen binding activity, or an antibody with non-endocytic (e.g. ALCAM / CD166) antigen binding activity, for example: an IgG isotype antibody without corresponding cell surface antigen in human body, an anti-CD166 antibody; more specifically, an anti-chicken lysozyme human IgG1 isotype antibody; q is selected from any value between 0.1-16.0, preferably any value between 2-8, more preferably, q is 2, 4, 6 or 8;

[1432]

[1433] Among them, Tb 7 The antibody has weak or no tumor cell endocytosis activity but has tumor cell surface antigen binding activity; for example, the antibody has the ability to bind to B7H3, Her3, GD-2, Trop-2, EGFR, CD19, CD30, GPNMB, CD20, CD79b and BCMA antigens but has no endocytosis activity; q is selected from any value between 0.1-16.0, preferably any value between 2-8, and more preferably, q is 2, 4, 6 or 8;

[1434]

[1435] Among them, Tb 8 It is an antibody with tumor cell endocytosis activity and tumor cell surface antigen binding activity, such as 1D1-01, 2E3-02 antibody, sacituzumab, pertuzumab, trastuzumab or cetuximab antibody; q is selected from any value between 0.1-16.0, preferably any value between 2-8, and more preferably, q is 2, 4, 6 or 8.

[1436] 25. A linker in a ligand-drug conjugate, comprising the following fragments:

[1437]

[1438] Among them, position 2 is connected to the bioactive molecular fragment;

[1439] L 3 , L 4 is as defined in any one of embodiments 1-24;

[1440] Preferably, its structure is as follows:

[1441]

[1442] Among them, position 1 is connected to the ligand or targeting part that binds to the target, and position 2 is connected to the bioactive molecular fragment;

[1443] L 3 , L 4 is as defined in any one of embodiments 1-24;

[1444] Preferably, the target binding ligand or targeting portion and the biologically active molecule fragment are defined as Tb and D in any one of embodiments 1-24, respectively.

[1445] 26. The compound represented by formula II:

[1446]

[1447] or a stereoisomer of the compound, a prodrug thereof, a pharmaceutically acceptable salt thereof, a pharmaceutically acceptable solvate thereof, or a ligand-drug conjugate thereof,

[1448] Among them, R 1 , R 2 , R 3 and X is as defined in any one of Embodiments 13-24;

[1449] W is absent or present. When W is present, W is selected from -OH, -SH, -NHR 4 , 1 bit is connected to X;

[1450] Preferably, W is absent or present, and when W is present, W is selected from -OH, -SH, -NHR 4 , 1 bit is connected to X;

[1451] When W does not exist, X is connected to H; 1 , R 2 At the same time, H and X is -(CH 2 ) n1 -, when n1 is 1, 2, 3, or 4, W is not -OH or -NHR 4 ; and the compound shown in formula II does not contain

[1452]

[1453] 27. The compound of embodiment 26, wherein the compound represented by formula II is selected from the following:

[1454]

[1455]

[1456]

[1457]

[1458] 28. The drug-linker conjugate of formula III,

[1459]

[1460] or a stereoisomer of the drug-linker conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof,

[1461] in:

[1462] R 1 , R 2 , R 3 , X, L1, L2, L3 and L4 are as defined in any one of Embodiments 1-24; W is as defined in any one of Embodiments 13-24; position 1 of L1 is connected to Lg;

[1463] Lg is a leaving group, and Lg is selected from halogen, sulfone, tertiary amine salt (Me 3 N + , Et 3 N + ), diazonium salt, -OMs, MeSO 2 - and CF 3 SO 3 -;

[1464] Preferably, Lg is selected from F, Cl and MeSO 2 -; the tertiary amine salt group is selected from Me 3 N + and Et 3 N + ;

[1465] More preferably, Lg is selected from F and MeSO 2 -.

[1466] 29. The drug-linker conjugate or the stereoisomer of the drug-linker conjugate, its prodrug, its pharmaceutically acceptable salt or its pharmaceutically acceptable solvate according to embodiment 28, characterized in that it has a structure of formula III-(1), formula III-(2) or formula III-(3):

[1467]

[1468] Among them, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R2 , R 3 , R 4 and Lg is as defined in Embodiment 28;

[1469]

[1470] Among them, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and Lg is as defined in Embodiment 28,

[1471]

[1472] Among them, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 , R 5 , n and Lg are as defined in Embodiment 28.

[1473] 30. The drug-linker conjugate or a stereoisomer of the drug-linker conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof according to embodiment 28 or 29, characterized in that it has a structure of formula III-(1A), III-(1B), III-(2A), III-(2B), III-(3A) or III-(3B);

[1474] The structure represented by formula III-(1A) or III-(1B):

[1475]

[1476] Among them, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and Lg is as defined in embodiment 28 or 29;

[1477] The structure represented by formula III-(2A) or III-(2B):

[1478]

[1479] Among them, L 2 , L3 , L 4 ,X,R 1 , R 2 , R 3 and Lg is as defined in embodiment 28 or 29;

[1480] The structure represented by formula III-(3A) or III-(3B):

[1481]

[1482] Among them, L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and Lg are as defined in Embodiment 28 or 29.

[1483] 31. The drug-linker conjugate or a stereoisomer of the drug-linker conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof according to any one of embodiments 28 to 30, characterized in that the drug-linker conjugate has a structure of Formula III-A or Formula III-B:

[1484]

[1485] Among them, Lg, X, R 1 , R 2 , R 3 , R a , R b and q is as defined in any one of Embodiments 28-30;

[1486]

[1487] Among them, Lg, X, R 1 , R 2 , R 3 , R a , R b and q are as defined in any one of Embodiments 28-30.

[1488] 32. The drug-linker conjugate or a stereoisomer of the drug-linker conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof according to any one of embodiments 28 to 31, characterized in that the drug-linker conjugate is selected from the following:

[1489]

[1490]

[1491]

[1492]

[1493]

[1494]

[1495]

[1496]

[1497]

[1498]

[1499]

[1500]

[1501]

[1502]

[1503]

[1504]

[1505]

[1506]

[1507]

[1508]

[1509]

[1510]

[1511] 33. A method for preparing a ligand drug conjugate according to any one of embodiments 28-32, comprising:

[1512] Conjugate Tb with the drug linker shown in formula III Carry out the coupling reaction in a suitable solvent and conditions;

[1513] in:

[1514] L 1 , L 2 , L3 , L 4 , Tb is as defined in any one of Embodiments 1-24;

[1515] R 1 , R 2 , R 3 , X, and W are as defined in Embodiments 13-24;

[1516] Lg is as defined in any one of Embodiments 28-32.

[1517] 34. The method of embodiment 33, wherein the method comprises conjugating Tb with a drug linker conjugate of formula III The step of performing a coupling reaction to form a CS bond in a suitable solvent and conditions;

[1518] Preferably, the ratio of the amount of Tb to the amount of the drug-linker conjugate is 1:(1-20);

[1519] Preferably, the coupling reaction is carried out in water and / or an organic solvent; preferably, the organic solvent is selected from N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, nitriles (such as acetonitrile), alcohols (such as methanol, ethanol) or any combination thereof; the nitrile may be acetonitrile, and the alcohol may be methanol or ethanol;

[1520] Preferably, the method further comprises a step of purifying the coupling product; preferably, the coupling product is purified by a chromatography method; preferably, the chromatography method comprises one or more of ion exchange chromatography, hydrophobic chromatography, reverse phase chromatography or affinity chromatography.

[1521] 35. An antibody or antigen-binding fragment thereof that binds to B7H3, wherein the antibody or antigen-binding fragment thereof comprises the following complementarity determining region (CDR):

[1522] (a) HCDR1 or a variant thereof, HCDR2 or a variant thereof, and HCDR3 or a variant thereof contained in the heavy chain variable region VH shown in SEQ ID NO: 3 or 23; and / or

[1523] (b) LCDR1 or a variant thereof, LCDR2 or a variant thereof, and LCDR3 or a variant thereof contained in the light chain variable region VL shown in SEQ ID NO: 13 or 33;

[1524] Preferably, the variant of the sequence is a CDR having one or several amino acid substitutions, deletions or additions compared to its source CDR, such as 1, 2 or 3 amino acid substitutions, deletions or additions; preferably, the substitutions are conservative substitutions.

[1525] 36. The antibody or antigen-binding fragment thereof of embodiment 35, wherein the antibody or antigen-binding fragment thereof comprises:

[1526] (1) VH and / or VL, where defined according to the IMGT numbering system:

[1527] (a) the VH comprises: a HCDR1 with a sequence of SEQ ID NO: 10, a HCDR2 with a sequence of SEQ ID NO: 11, and a HCDR3 with a sequence of SEQ ID NO: 12; and / or,

[1528] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 20, LCDR2 with a sequence of GTF, and LCDR3 with a sequence of SEQ ID NO: 22;

[1529] (b) the VH comprises: a HCDR1 with a sequence of SEQ ID NO: 10, a HCDR2 with a sequence of SEQ ID NO: 11, and a HCDR3 with a sequence of SEQ ID NO: 12; and / or,

[1530] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 40, LCDR2 with a sequence of GAS, and LCDR3 with a sequence of SEQ ID NO: 42;

[1531] (c) the VH comprises: a HCDR1 with a sequence of SEQ ID NO: 30, a HCDR2 with a sequence of SEQ ID NO: 31, and a HCDR3 with a sequence of SEQ ID NO: 32; and / or,

[1532] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 40, LCDR2 with a sequence of GAS, and LCDR3 with a sequence of SEQ ID NO: 42;

[1533] or

[1534] (d) the VH comprises: a HCDR1 with a sequence of SEQ ID NO: 30, a HCDR2 with a sequence of SEQ ID NO: 31, and a HCDR3 with a sequence of SEQ ID NO: 32; and / or,

[1535] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 20, LCDR2 with a sequence of GTF, and LCDR3 with a sequence of SEQ ID NO: 22;

[1536] (2) VH and / or VL, where defined by the chothia numbering system:

[1537] (a) the VH comprises: a HCDR1 of SEQ ID NO: 4, a HCDR2 of SEQ ID NO: 5, and a HCDR3 of SEQ ID NO: 6; and / or,

[1538] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 14, LCDR2 with a sequence of SEQ ID NO: 15, and LCDR3 with a sequence of SEQ ID NO: 16;

[1539] (b) the VH comprises: a HCDR1 of SEQ ID NO: 24, a HCDR2 of SEQ ID NO: 25, and a HCDR3 of SEQ ID NO: 26; and / or,

[1540] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 34, LCDR2 with a sequence of SEQ ID NO: 35, and LCDR3 with a sequence of SEQ ID NO: 36;

[1541] (c) the VH comprises: a HCDR1 with a sequence of SEQ ID NO: 4, a HCDR2 with a sequence of SEQ ID NO: 5, and a HCDR3 with a sequence of SEQ ID NO: 6; and / or,

[1542] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 34, LCDR2 with a sequence of SEQ ID NO: 35, and LCDR3 with a sequence of SEQ ID NO: 36;

[1543] or

[1544] (d) the VH comprises: a HCDR1 of SEQ ID NO: 24, a HCDR2 of SEQ ID NO: 25, and a HCDR3 of SEQ ID NO: 26; and / or,

[1545] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 14, LCDR2 with a sequence of SEQ ID NO: 15, and LCDR3 with a sequence of SEQ ID NO: 16;

[1546] (3) VH and / or VL, wherein the numbering system is defined according to Kabat:

[1547] (a) the VH comprises: a HCDR1 of SEQ ID NO: 7, a HCDR2 of SEQ ID NO: 8, and a HCDR3 of SEQ ID NO: 9; and / or,

[1548] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 17, LCDR2 with a sequence of SEQ ID NO: 18, and LCDR3 with a sequence of SEQ ID NO: 19;

[1549] (b) the VH comprises: a HCDR1 of SEQ ID NO: 27, a HCDR2 of SEQ ID NO: 28, and a HCDR3 of SEQ ID NO: 29; and / or,

[1550] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 37, LCDR2 with a sequence of SEQ ID NO: 38, and LCDR3 with a sequence of SEQ ID NO: 39;

[1551] (c) the VH comprises: a HCDR1 of SEQ ID NO: 7, a HCDR2 of SEQ ID NO: 8, and a HCDR3 of SEQ ID NO: 9; and / or,

[1552] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 37, LCDR2 with a sequence of SEQ ID NO: 38, and LCDR3 with a sequence of SEQ ID NO: 39;

[1553] or

[1554] (d) the VH comprises: a HCDR1 of SEQ ID NO: 27, a HCDR2 of SEQ ID NO: 28, and a HCDR3 of SEQ ID NO: 29; and / or,

[1555] The VL comprises: LCDR1 with a sequence of SEQ ID NO: 17, LCDR2 with a sequence of SEQ ID NO: 18, and LCDR3 with a sequence of SEQ ID NO: 19;

[1556] Optionally, the antibody or antigen-binding fragment thereof of the present disclosure comprises the following heavy chain variable region VH and / or light chain variable region VL, wherein, compared with the CDR defined by IMGT, chothia or kabat, at least one CDR in the heavy chain variable region VH and / or light chain variable region VL contains a mutation, and the mutation is a substitution, deletion or addition of one or several amino acids or any combination thereof, such as a substitution, deletion or addition of 1, 2 or 3 amino acids or any combination thereof; preferably, the substitution is a conservative substitution;

[1557] More preferably, the antibody or antigen-binding fragment thereof binds to human B7-H3 and / or monkey B7-H3.

[1558] 37. The antibody or antigen-binding fragment thereof of embodiment 35 or 36, wherein the antibody or antigen-binding fragment thereof comprises:

[1559] (a) VH shown in SEQ ID NO: 3 or 23, and / or VL shown in any one of SEQ ID NO: 13 or 33;

[1560] (b) a VH 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 any VH in (a); and / or a VL 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 any VL in (a); or

[1561] (c) a VH having one or several amino acid substitutions, deletions or additions or any combination thereof, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof, compared to any VH in (a); and / or a VL having one or several amino acid substitutions, deletions or additions or any combination thereof, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof, compared to any VL in (a); preferably, the substitutions are conservative substitutions.

[1562] 38. The antibody or antigen-binding fragment thereof of any one of embodiments 35-37, wherein the antibody or antigen-binding fragment thereof comprises:

[1563] (a) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 13;

[1564] (b) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:33;

[1565] (c) VH of the sequence shown in SEQ ID NO: 3 and VL of the sequence shown in SEQ ID NO: 33;

[1566] (d) VH of the sequence shown in SEQ ID NO:23 and VL of the sequence shown in SEQ ID NO:13;

[1567] (e) a VH and a VL 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 to the VH and VL in any of groups (a) to (d); and / or a VL 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 to the VH and VL in any of groups (a) to (d); or

[1568] (f) VH and VL, compared with the VH and VL in any group (a) to (d), its VH has one or several amino acid substitutions, deletions or additions or any combination thereof, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof; and / or, its VL has one or several amino acid substitutions, deletions or additions or any combination thereof, such as 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.

[1569] 39. The antibody or antigen-binding fragment thereof of any one of embodiments 35-38, wherein the antibody or antigen-binding fragment thereof is a chimeric antibody, a humanized antibody or a fully human antibody;

[1570] Optionally, the antibody or antigen-binding fragment thereof is selected from scFv, Fab, Fab', (Fab') 2 , Fv fragments, disulfide-linked Fv (dsFv), diabodies, and multispecific antibodies;

[1571] Optionally, the scFv comprises:

[1572] (i) the sequence shown in SEQ ID NO: 1 or 2;

[1573] (ii) a sequence having one or several amino acid substitutions, deletions or additions or any combination thereof compared to the sequence shown in (i) (e.g., substitutions, deletions or additions of 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 acids or any combination thereof; for example, substitutions, deletions or additions of 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids or any combination thereof); or

[1574] (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 to the sequence shown in (i);

[1575] Preferably, the substitutions described in (ii) are conservative substitutions.

[1576] 40. The antibody or antigen-binding fragment thereof of any one of embodiments 35-39, wherein the antibody or antigen-binding fragment thereof further comprises:

[1577] (a) a heavy chain constant region CH of a human immunoglobulin or a variant thereof; and / or

[1578] (b) a light chain constant region CL of a human immunoglobulin or a variant thereof,

[1579] wherein the variant has 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 wild-type sequence from which it is derived; or, the variant has one or more amino acid substitutions, deletions or additions or any combination thereof, such as 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, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acid substitutions, deletions or additions or any combination thereof, compared to the wild-type sequence from which it is derived; preferably, the substitutions are conservative substitutions;

[1580] Preferably, the heavy chain constant region is an IgG heavy chain constant region, such as an IgG1, IgG2, IgG3 or IgG4 heavy chain constant region; and / or, the light chain constant region is a κ or λ light chain constant region;

[1581] More preferably, the antibody or antigen-binding fragment thereof comprises a human IgG1 heavy chain constant region; and / or the antibody or antigen-binding fragment thereof comprises a human κ light chain constant region.

[1582] 41. The antibody or antigen-binding fragment thereof of embodiment 40, wherein:

[1583] The heavy chain constant region includes a CH as shown in SEQ ID NO: 43 or a variant thereof, wherein the variant has up to 20 conservative substitutions of amino acids compared to SEQ ID NO: 43, such as up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids; or has 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; and / or

[1584] The light chain constant region comprises the CL set forth in SEQ ID NO:44 or a variant thereof, which has up to 20 conservative substitutions of amino acids compared to SEQ ID NO:44, such as up to 20, up to 15, up to 10 or up to 5 conservative substitutions of amino acids, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 conservative substitutions of amino acids, or has 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;

[1585] Preferably, the antibody or antigen-binding fragment thereof comprises a heavy chain constant region CH shown in SEQ ID NO:43 and a light chain constant region CL shown in SEQ ID NO:44.

[1586] 42. The antibody or antigen-binding fragment thereof of any one of embodiments 35-41, wherein the antibody comprises:

[1587] (a) comprising a heavy chain of VH shown in SEQ ID NO: 3 and a heavy chain of CH shown in SEQ ID NO: 43, and a light chain of VL shown in SEQ ID NO: 13 and CL shown in SEQ ID NO: 44; preferably comprising a heavy chain shown in SEQ ID NO: 45 and a light chain shown in SEQ ID NO: 46;

[1588] (b) comprises a heavy chain of VH shown in SEQ ID NO:23 and a heavy chain of CH shown in SEQ ID NO:43, and a light chain of VL shown in SEQ ID NO:33 and CL shown in SEQ ID NO:44; preferably comprises a heavy chain shown in SEQ ID NO:47 and a light chain shown in SEQ ID NO:48.

[1589] 43. A multispecific antibody comprising the antibody or antigen-binding fragment thereof according to any one of embodiments 35-42, and another antibody or fragment thereof or antibody analog;

[1590] Preferably, the multispecific antibody is a bispecific antibody or a trispecific antibody or a tetraspecific antibody.

[1591] 44. An isolated nucleic acid molecule encoding the antibody or antigen-binding fragment thereof of any one of embodiments 35-42, or the multispecific antibody of embodiment 43.

[1592] 45. A vector comprising the isolated nucleic acid molecule of embodiment 44; preferably, the vector is a cloning vector or an expression vector.

[1593] 46. ​​A host cell comprising the isolated nucleic acid molecule of embodiment 44 or the vector of embodiment 45.

[1594] 47. A method for preparing the antibody or antigen-binding fragment thereof described in any one of embodiments 35-42, or the multispecific antibody described in embodiment 43, comprising culturing the host cell described in embodiment 46 under conditions that allow 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.

[1595] 48. An antibody-drug conjugate, wherein the antibody is the antibody or antigen-binding fragment thereof of any one of embodiments 35-42, or the multispecific antibody of embodiment 43, which is connected to a coupling portion via a linker, and the coupling portion is selected from: a detectable label, a radioactive isotope, a fluorescent substance, a luminescent substance, a colored substance, an enzyme, polyethylene glycol, a nuclide, a nucleic acid, a small molecule toxin, a polypeptide with binding activity, a protein, a receptor, a ligand, and other active substances that inhibit tumor cell growth and promote tumor cell apoptosis or necrosis.

[1596] 49. A ligand drug conjugate comprising the ligand drug conjugate of any one of embodiments 1-28, wherein the ligand drug conjugate has two or more q values;

[1597] Optionally, the drug to antibody ratio (DAR) in the ligand drug conjugate is an integer or decimal selected from 1-10;

[1598] Preferably, the drug to antibody ratio (DAR) in the ligand drug conjugate is selected from 1.5-2.5, 3.5-4.5, 5.5-6.5 and 7.5-8.5;

[1599] Preferably, the drug to antibody ratio (DAR) in the ligand drug conjugate is selected from about 2.0, 4.0, 6.0 and 8.0;

[1600] Preferably, the drug to 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.

[1601] 50. A pharmaceutical composition comprising substance A, and optionally one or more pharmaceutical excipients, wherein substance A is a ligand-drug conjugate as described in any one of embodiments 1-24, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof, or a compound as described in embodiment 26 or 27, or a drug-linker conjugate as described in any one of embodiments 28-32, or an antibody or antigen-binding fragment thereof as described in any one of embodiments 35-42, or a multispecific antibody as described in embodiment 43, or a nucleic acid molecule as described in embodiment 44, or a vector as described in embodiment 45, or a host cell as described in embodiment 46, or a ligand-drug conjugate as described in embodiment 49; preferably, it also includes a pharmaceutically acceptable carrier and / or excipient.

[1602] 51. Use of a substance A or the pharmaceutical composition of embodiment 50 in the preparation of a medicament for treating and / or preventing a disease associated with abnormal cell activity; the substance A is a ligand-drug conjugate as described in any one of embodiments 1-24, or a stereoisomer of the ligand-drug conjugate, a prodrug thereof, a pharmaceutically acceptable salt or a pharmaceutically acceptable solvate thereof, or a compound as described in embodiment 26 or 27, or a drug-linker conjugate as described in any one of embodiments 28-32, or an antibody or antigen-binding fragment thereof as described in any one of embodiments 35-42, or a multispecific antibody as described in embodiment 43, or a nucleic acid molecule as described in embodiment 44, or a vector as described in embodiment 45, or a host cell as described in embodiment 46, or a ligand-drug conjugate as described in embodiment 49; the disease associated with abnormal cell activity may be a cancer disease;

[1603] Preferably, the cancer disease is selected from esophageal cancer, brain tumor, lung cancer, squamous cell carcinoma, bladder cancer, gastric 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's lymphoma, central nervous system tumor, prostate cancer or thyroid cancer; the esophageal cancer is such as esophageal adenocarcinoma or esophageal squamous cell carcinoma; the lung cancer is such as small cell lung cancer, non-small cell lung cancer or lung adenocarcinoma; the central nervous system tumor is such as glioma, glioblastoma multiforme, glioma or sarcoma; the colon cancer is such as human colon adenocarcinoma;

[1604] Preferably, the cancer disease is selected from colon cancer, colorectal cancer, colon adenocarcinoma, lung cancer, breast cancer, prostate cancer, esophageal squamous cell carcinoma;

[1605] More preferably, the cancer disease is a cancer disease associated with B7H3;

[1606] More preferably, the cancer disease is a cancer disease associated with Her3;

[1607] More preferably, the cancer disease is a cancer disease associated with EGFR;

[1608] More preferably, the cancer disease is a cancer disease associated with Trop-2 or Her 2;

[1609] Most preferably, the cancer disease is breast cancer or the lung cancer is non-small cell lung cancer.

[1610] In the present disclosure, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. In addition, the cell culture, molecular genetics, nucleic acid chemistry, and immunology laboratory operation procedures used herein are conventional procedures widely used in the corresponding fields. At the same time, in order to better understand the present disclosure, the definitions and explanations of the relevant terms are provided below.

[1611] As used herein, examples of the term "pharmaceutically acceptable salts" are organic acid addition salts formed by organic acids that form pharmaceutically acceptable anions, including but not limited to formates, acetates, propionates, benzoates, maleates, fumarates, succinates, tartrates, citrates, ascorbates, α-ketoglutarates, α-glycerophosphates, alkyl sulfonates or aryl sulfonates; preferably, the alkyl sulfonates are methyl sulfonates or ethyl sulfonates; the aryl sulfonates are benzene sulfonates or p-toluene sulfonates. Suitable inorganic salts may also be formed, including but not limited to hydrochlorides, hydrobromides, hydroiodides, nitrates, bicarbonates and carbonates, sulfates or phosphates, etc.

[1612] As used herein, the term "pharmaceutically acceptable carrier and / or excipient" refers to a carrier and / or excipient that is pharmacologically and / or physiologically compatible with a subject and an active ingredient, which is well known in the art (see, e.g., 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.

[1613] Pharmaceutically acceptable salts can be obtained using standard procedures well known in the art, for example, by reacting a sufficient amount of a basic compound with a suitable acid affording a pharmaceutically acceptable anion.

[1614] In this disclosure, the pharmaceutical excipients refer to excipients and additives used in the production of drugs and the preparation of prescriptions. They refer to substances that have been reasonably evaluated in terms of safety and are included in pharmaceutical preparations in addition to active ingredients. In addition to excipients, carriers, and improving stability, pharmaceutical excipients also have important functions such as solubilization, solubilization, and sustained and controlled release. They are important ingredients that may affect the quality, safety, and effectiveness of drugs. According to their sources, they can be divided into natural products, semi-synthetic products, and fully synthetic products. According to their functions and uses, they can be divided into: solvents, propellants, solubilizers, cosolvents, emulsifiers, colorants, adhesives, disintegrants, fillers, lubricants, wetting agents, osmotic pressure regulators, stabilizers, glidants, flavoring agents, preservatives, suspending agents, coating materials, fragrances, anti-adhesives, antioxidants, chelating agents, penetration enhancers, pH regulators, buffers, plasticizers, surfactants, foaming agents, defoamers, thickeners, inclusion agents, humectants, absorbents, diluents, flocculants and deflocculating agents, filter aids, release retardants, etc. According to their administration routes, they can be divided into oral, injection, mucosal, transdermal or topical administration, nasal or oral inhalation administration and ocular administration, etc. The same pharmaceutical excipients can be used in drug preparations with different administration routes and have different functions and uses.

[1615] The pharmaceutical composition can be prepared into various suitable dosage forms according to the administration route, such as tablets, capsules, granules, oral solutions, oral suspensions, oral emulsions, powders, tinctures, syrups, injections, suppositories, ointments, creams, pastes, ophthalmic preparations, pills, implants, aerosols, powder sprays, sprays, etc. The pharmaceutical composition or suitable dosage form may contain 0.01 mg to 1000 mg of the compound of the present disclosure or a pharmaceutically acceptable salt or conjugate thereof, preferably 0.1 mg to 800 mg, preferably 0.5-500 mg, preferably 0.5 to 350 mg, and particularly preferably 1-250 mg.

[1616] The pharmaceutical composition can be used in the form of injection, including injection, sterile powder for injection and concentrated solution for injection. Among them, the carriers and solvents that can be used include water, Ringer's solution and isotonic sodium chloride solution. In addition, sterilized non-volatile oils can also be used as solvents or suspension media, such as monoglycerides or diglycerides.

[1617] As used herein, the term "treat" generally refers to obtaining a desired pharmacological and / or physiological effect. The effect may be preventive, in terms of completely or partially preventing a disease or its symptoms; and / or therapeutic, in terms of partially or completely stabilizing or curing a disease and / or side effects resulting from a disease. As used herein, "treat" encompasses any treatment of a patient's disease, including: (a) preventing the disease or symptoms from occurring in a patient who is susceptible to the disease or symptoms but has not yet been diagnosed with the disease; (b) inhibiting the symptoms of a disease, i.e., preventing its development; or (c) alleviating the symptoms of a disease, i.e., causing the disease or symptoms to regress.

[1618] In the present disclosure, the term "individual" includes humans or non-human animals. Exemplary human individuals include human individuals (referred to as patients) suffering from diseases (e.g., diseases described herein) or normal individuals. The term "non-human animal" in the present disclosure includes all vertebrates, such as non-mammals (e.g., birds, amphibians, reptiles) and mammals, such as non-human primates, livestock and / or domesticated animals (e.g., sheep, dogs, cats, cows, pigs, etc.).

[1619] In this disclosure, the term "effective dose" refers to that amount of a compound which, when administered, will relieve to some extent one or more of the symptoms of the condition being treated.

[1620] In the present disclosure, the term "ligand drug conjugate" refers to a substance obtained by connecting a bioactive molecule (drug molecule) to a targeting portion. In some embodiments of the present disclosure, the bioactive molecule is connected to the targeting portion through a connector. The connector can be broken in a specific environment (e.g., hydrolases and / or low pH environments in tumors) or under a specific action (e.g., the action of lysosomal proteases), thereby separating the bioactive molecule from the targeting portion. In some embodiments of the present disclosure, the connector comprises a cleavable or non-cleavable unit, such as a peptide or a disulfide bond. In some embodiments of the present disclosure, the bioactive molecule is directly connected to the targeting portion through a covalent bond, and the covalent bond can be broken under a specific environment or action, thereby separating the bioactive molecule from the targeting portion. In some embodiments of the present disclosure, the ligand drug conjugate comprises a targeting portion, a connector, and a fragment of a compound of formula II of the present disclosure.

[1621] In the present disclosure, the term "biologically active substance", "biologically active molecule" or "drug molecule" refers to a substance that inhibits or prevents the function of cells and / or causes cell death or destruction. In some embodiments of the present disclosure, the biologically active substance, biologically active molecule or drug molecule in the conjugate is a molecule with anti-tumor biological activity. For ex...

Claims

1. A linker in a ligand-drug conjugate, the structure of which is shown below: in, Position 1 is connected to the ligand or targeting part that binds to the target, and position 2 is connected to the bioactive molecule fragment; L 1 is an extension unit; L 2 Does not exist or is a connected unit; L 3 Selected from Val-AA 1 -Gly; AA 1 The amino acid residues are selected from and L 4 Does not exist or exists, L 4 When present, L 4 Selected from 1 bit and L 3 The 2nd position is connected to the biologically active molecule fragment.

2. The connector according to claim 1, It is characterized in that L 1 Selected from Or, L 1 for Each Z is independently selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond, a C6-10 aryl, a 5-10 membered heteroaryl and an amide group (preferably selected from a direct bond, a carbon-carbon triple bond, a carbon-carbon double bond); Rx and Ry are independently selected from H and a C1-4 alkyl group; each m is independently selected from 0, 1, 2, 3, 4, 5 and 6; y1 is independently selected from any integer between 1 and 6 (such as 4, 5, 6); each y2 is independently selected from any integer between 0 and 15 (such as 6-15); each y3 is independently selected from 1, 2 and 3; each y4 is independently selected from 0 and 1; the 1st position is connected to the ligand or targeting part that binds to the target, and the 2nd position is connected to L 2 or L 3 connected; Preferably, L 1 Selected from Or, L 1 for m is selected from 2, 3, and 4, y1 is selected from any integer between 1 and 6 (such as 4, 5, and 6), each y2 is independently selected from any integer between 0 and 10 (such as 6 and 10), each y3 is independently selected from 1 or 2, the 1st position is connected to the ligand or targeting part that binds to the target, and the 2nd position is connected to L 2 or L 3 connected; Preferably, L 1 Selected from Position 1 is connected to the ligand or targeting part that binds to the target, and position 2 is connected to L 2 or L 3 connected; More preferably, L 1 Selected from Position 1 is connected to the ligand or targeting part that binds to the target, and position 2 is connected to L 2 or L 3 connected; Most preferably, L 1 for Position 1 is connected to the ligand or targeting part that binds to the target, and position 2 is connected to L 2 or L 3 connected.

3. The connector according to claim 1 or 2, It is characterized in that L 2 Does not exist or exists, L 2 When present, L 2 Selected from: y1, y2, y3 and y4 are independently selected from any integer between 0 and 20, and 1 is the same as L 1 Connected, 2 bits and L 3 connected; Preferably, L 2 Does not exist or exists, L 2 When present, L 2 Selected from y1 is selected from any integer between 1 and 6 (such as 4, 5, 6), each y2 is independently selected from any integer between 0 and 10 (such as 6-10), each y3 is independently selected from 1 or 2, each y4 is independently selected from 0 or 1, and the 1st position is the same as L 1 Connected, 2 bits and L 3 connected; Preferably, L 2 Does not exist or exists, L 2 When present, L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected; Preferably, L 2 Does not exist, or L 2 Selected from 1 bit and L 1 Connected, 2 bits and L 3 connected; Most preferably, L 2 Does not exist.

4. The connector according to any one of claims 1 to 3, It is characterized in that L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 or bioactive molecular fragments are linked; Preferably, L 3 Selected from 1 bit and L 1 or L 2 Connected, 2 bits and L 4 or biologically active molecular fragments.

5. The connector according to any one of claims 1 to 4, It is characterized in that L 4 Does not exist.

6. The connector according to any one of claims 1 to 4, It is characterized in that L 4 yes 1 bit and L 3 The 2nd position is connected to the biologically active molecule fragment.

7. The connector according to any one of claims 1 to 6, It is characterized in that The structure is selected from the following:

8. A ligand-drug conjugate of formula XV or a pharmaceutically acceptable salt thereof, in: Tb is a ligand or targeting moiety that binds to the target; q is the drug-ligand coupling ratio; D is a biologically active molecular fragment; and L 1 , L 2 , L 3 , L 4 As defined in any one of claims 1 to 7.

9. The ligand-drug conjugate according to claim 8 or a pharmaceutically acceptable salt thereof, It is characterized in that Tb is an antibody or an antigen-binding fragment thereof; The antibodies or antigen-binding fragments thereof and monoclonal antibodies or antigen-binding fragments thereof 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; Preferably, Tb is a non-human antibody, a humanized antibody, a chimeric antibody, or a fully human antibody; Preferably, Tb is a monoclonal antibody, a bispecific antibody or a multispecific antibody; Preferably, Tb is an anti-B7H3 antibody or an antigen-binding fragment thereof, an anti-Trop-2 antibody or an antigen-binding fragment thereof, an anti-Her2 antibody or an antigen-binding fragment thereof, an anti-Her3 antibody or an antigen-binding fragment thereof or an anti-EGFR antibody or an antigen-binding fragment thereof, preferably, the anti-Trop-2 antibody is datopotamab or sacituzumab.

10. The ligand-drug conjugate according to claim 8 or 9 or a pharmaceutically acceptable salt thereof, It is characterized in that q is selected from any value between 0.1 and 16.0; Preferably, q is selected from any value between 2 and 8; Preferably, q is selected from any value between 4 and 8; Preferably, q is selected from 2, 4, 6 and 8.

11. The ligand-drug conjugate according to any one of claims 8 to 10 or a pharmaceutically acceptable salt thereof, It is characterized in that D is a molecular fragment having anti-tumor biological activity; wherein the biologically active molecule is selected from cytotoxic agents or derivatives thereof, such as DNA topoisomerase inhibitors or microtubulin inhibitors; Preferably, D is a molecular fragment having anti-tumor biological activity; wherein the biologically active molecule is selected from camptothecin biologically active molecules, such as camptothecin, DXD, camptothecin with modified substituents or DXD with modified substituents; Preferably, D is a molecular fragment having anti-tumor biological activity; wherein the biologically active molecule is selected from microtubule inhibitors, such as MMAF type microtubule inhibitors, MMAE type microtubule inhibitors.

12. The ligand-drug conjugate according to any one of claims 8 to 11 or a pharmaceutically acceptable salt thereof, It is characterized in that D is The structural fragment shown; position 1 and L 3 or L 4 connect; Among them, R 1 , R 2 are each independently selected from H, halogen, -OH, optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or, R 1 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof; R 3 Selected from H, halogen, -OH, -NH 2 , optionally substituted C1-6 alkyl and optionally substituted C1-6 alkoxy, or, R 3 and X together with the carbon atom to which it is attached form a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof, or, R 3 and R 2 Together with the carbon atoms to which it is attached, it forms a 5-7 membered carbocyclic ring or a 5-7 membered heterocyclic ring, wherein the heterocyclic ring contains one or more O, S, N, carbonyl, sulfoxide or sulfone groups or any combination thereof; W is absent or present. When W is present, W is selected from -O-, -S-, -NR 4 -、 Bit 1 is connected to X, bit 2 is connected to L 4 or L 3 connected; X is selected from a direct bond, an optionally substituted -O-(CH 2 ) n3 -、-N(R 4 )-(CH 2 ) n3 -、-S-(CH 2 ) n3 -, carbonyl-(CH 2 ) n3 、-SO 2 -(CH 2 ) n3 -、 -(CH 2 ) n1 -, C3-6 cycloalkyl, C6-10 aryl, 5-10 membered heteroaryl and 4-10 membered heterocyclic group, the 1 position is connected to the mother ring, the 2 position is connected to W or L 4 connected; the substituent is selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or multiple C1-4 alkyl groups and the carbon atoms connected to them together form a C3-6 cycloalkyl group; Each M is independently selected from a direct bond and -CR 5a R 5b -; R 4 , R 5 , R 5a , R 5b , R 6 , R 7 Each is independently selected from H, optionally substituted C1-4 alkyl, optionally substituted C1-4 alkoxy and optionally substituted C3-6 cycloalkyl; n, n', n1, n2, and n3 are each independently selected from any integer between 0 and 6.

13. The ligand-drug conjugate according to claim 12 or a pharmaceutically acceptable salt thereof, It is characterized in that D satisfies one or more of the following conditions: (1)R 1 , R 2 are each independently selected from H, halogen, C1-4 alkyl; or, R 1 and R 2 Together with the carbon atom to which it is attached, it forms a 5-6 membered heterocyclic ring containing 1, 2 or 3 O, S or N or any combination thereof; Preferably, R 1 is selected from H and halogen, R 2 is selected from H and C1-4 alkyl; or, R 1 and R 2 and the carbon atom to which it is attached The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring; More preferably, R 1 H or F, R 2 is H or methyl; or, R 1 and R 2 Together with the carbon atom to which it is attached, The dotted line indicates the position where the heterocyclic ring is fused to the benzene ring; (2)R 3 is selected from H, C1-4 alkyl; or, R 3 Together with X and the carbon atom to which it is attached, it forms a 5-6 membered carbocyclic ring; Preferably, R 3 H; or, R 3 Together with X and the carbon atom to which it is attached, The dotted lines indicate where the carbon ring is fused to the benzene ring and the pyridine ring; (3) W is selected from -O-, -NR 4 -and 1 bit is connected to X, 2 bits are connected to L 4 or L 3 connected; (4) Each R 4 are independently selected from H, C1-4 alkyl and C3-6 cycloalkyl, R 5 is H; Preferably, each R 4 R is independently selected from H, methyl, ethyl, n-propyl, isopropyl, tert-butyl and cyclopropyl, 5 is H; (5)n is 1; (6)X is selected from Position 1 is connected to the mother ring, and position 2 is connected to W.

14. The ligand-drug conjugate according to claim 12 or 13, or a pharmaceutically acceptable salt thereof, It is characterized in that The structure is selected from the following: Among them, 1 and L 4 connected; when L 4 When not present, 1 and L 3 connected.

15. The ligand-drug conjugate according to any one of claims 8 to 14 or a pharmaceutically acceptable salt thereof, It is characterized in that The ligand-drug conjugate has a structure of Formula I-1, Formula I-2 or Formula I-3: Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 and q is as defined in any one of claims 8 to 14; Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 and q is as defined in any one of claims 8 to 14; Among them, Tb, L 1 , L 2 , L 3 , L 4 ,X,R 1 , R 2 , R 3 , R 4 , R 5 , n and q are as defined in any one of claims 8-14.

16. The ligand-drug conjugate according to any one of claims 8 to 15 or a pharmaceutically acceptable salt thereof, It is characterized in that The ligand drug conjugate is selected from: wherein Tb and q are as defined in any one of claims 8-15.

17. The ligand-drug conjugate or a pharmaceutically acceptable salt thereof according to any one of claims 8 to 15, It is characterized in that The ligand drug conjugate is selected from: wherein Tb is as defined in any one of claims 8 to 15; and q is selected from any value between 4 and 8.

18. The ligand-drug conjugate according to any one of claims 8 to 15 or a pharmaceutically acceptable salt thereof, It is characterized in that The ligand drug conjugate is selected from: q is selected from any value between 4 and 8.

19. A compound represented by formula III-(A) or a pharmaceutically acceptable salt thereof, in: R 1 , R 2 , R 3 , X, W, L 4 As defined in any one of claims 12 to 14.

20. The compound of formula III-(A) or a pharmaceutically acceptable salt thereof according to claim 19, It is characterized in that The compound represented by formula III-(A) is selected from any of the following compounds:

21. The drug-linker conjugate of formula III, or a pharmaceutically acceptable salt thereof, in: R 1 , R 2 , R 3 , X, W, L 1 , L 2 , L 3 and L 4 The definition as described in any one of claims 1 to 20; L 1 The 1 position of is connected to Lg; and Lg is a leaving group; Preferably, Lg is selected from halogen, sulfone, tertiary amine, diazonium, -OMs, MeSO 2 - and CF 3 SO 3 -, preferably, Lg is selected from F and MeSO 2 -.

22. The drug-linker conjugate of formula III according to claim 21 or a pharmaceutically acceptable salt thereof, It is characterized in that in, The drug-linker conjugate is selected from the following:

23. A pharmaceutical composition comprising the ligand-drug conjugate or a pharmaceutically acceptable salt thereof as described in any one of claims 8 to 17, and optionally one or more pharmaceutical excipients; preferably further comprising a pharmaceutically acceptable carrier and / or excipient.

24. Use of the ligand-drug conjugate or a pharmaceutically acceptable salt thereof according to any one of claims 8 to 18, the drug-linker conjugate according to claim 21 or 22, or the pharmaceutical composition according to claim 23 in the preparation of a drug for treating and / or preventing a disease associated with abnormal cell activity; the disease associated with abnormal cell activity may be a cancer disease; Preferably, the cancer disease is selected from esophageal cancer, brain tumor, lung cancer, squamous cell carcinoma, bladder cancer, gastric 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's lymphoma, central nervous system tumor, prostate cancer or thyroid cancer; the esophageal cancer is such as esophageal adenocarcinoma or esophageal squamous cell carcinoma; the lung cancer is such as small cell lung cancer, non-small cell lung cancer or lung adenocarcinoma; the central nervous system tumor is such as glioma, glioblastoma multiforme, glioma or sarcoma; the colon cancer is such as human colon adenocarcinoma; Preferably, the cancer disease is selected from colon cancer, colorectal cancer, colon adenocarcinoma, lung cancer, breast cancer, prostate cancer, esophageal squamous cell carcinoma; More preferably, the cancer disease is a cancer disease associated with B7H3; More preferably, the cancer disease is a cancer disease associated with Her3; More preferably, the cancer disease is a cancer disease associated with EGFR; More preferably, the cancer disease is a cancer disease associated with Trop-2 or Her 2; Most preferably, the cancer disease is breast cancer or the lung cancer is non-small cell lung cancer.

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