Combination therapy of b7-h3-targeting antibody-drug conjugate and PARP-1 inhibitor

Abstract

Provided is a pharmaceutical combination comprising a B7-H3-targeting antibody-drug conjugate or a salt thereof and a PARP-1 inhibitor. The B7-H3-targeting antibody-drug conjugate or the salt thereof is formed by coupling an anti-B7-H3 antibody to a camptothecin topoisomerase I inhibitor, and the use of the B7-H3-targeting antibody-drug conjugate or the salt thereof in combination with the PARP-1 inhibitor exhibits a significant synergistic anti-tumor effect. Provided is therapeutic use of the pharmaceutical combination for a B7-H3-overexpressing or -positive tumor or cancer.

Description

Combination therapy of antibody-drug conjugates targeting B7-H3 with PARP-1 inhibitors

[0001] Cross-reference to related applications

[0002] This patent application claims priority to Chinese invention patent application No. CN202510284641.2, filed on March 11, 2025, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This invention relates to the field of biopharmaceuticals, and more specifically, to a combination therapy of an antibody-drug conjugate targeting B7-H3 and a PARP-1 inhibitor. Background Technology

[0004] B7-H3 (CD276) is a type I transmembrane protein and a member of the B7 immune co-stimulatory and co-inhibitory family. It plays a crucial role in angiogenesis and metastasis, tumor migration and invasion, and tumor growth. Studies have shown that B7-H3 is highly expressed in various solid tumors, including non-small cell lung cancer, prostate cancer, ovarian cancer, and breast cancer, while its expression level is low in normal tissues. Therefore, B7-H3 is an ideal target for developing antibody-drug conjugates.

[0005] Poly(ADP-ribose) polymerase-1 (PARP-1) is the most structurally typical and important isoform of the PARP superfamily. With a molecular weight of 116 kDa, PARP-1 is a multifunctional ribozyme with post-translational modification functions, playing a crucial role in DNA mutation repair, especially single-strand break repair, and maintaining genomic stability. DNA damage repair activity is highly active in tumor cells, and it has been reported that inhibiting PARP-1 activity can suppress tumor growth.

[0006] PARP-1 inhibitors, as novel anti-tumor drugs, were the first anticancer drugs to be approved for clinical use successfully utilizing the concept of synthetic lethality. Single-strand damage to DNA activates the PARP-1 enzyme, initiating repair functions. PARP-1 inhibitors restrict the PARP-1 enzyme to the damaged DNA site, preventing DNA repair. The primary mechanism of action of PARP-1 inhibitors is synthetic lethality; therefore, they are most effective against tumor cells with missing or mutated homologous recombination genes. For example, when PARP-1 inhibitors are used to block single-strand DNA damage repair in BRCA1 / 2-mutated tumor cells, synthetic lethality is achieved, ultimately leading to cell death. Several PARP-1 inhibitors are currently approved for marketing or are in clinical trials, such as olaparib, rucaparib, and AZD5305 (Saruparib).

[0007] Topoisomerase I inhibitors, as cytotoxic drugs, cause DNA damage in tumor cells and are currently widely used as payloads in antibody-drug conjugates (ADCs). Combining ADCs containing topoisomerase I inhibitors as the toxic component with PARP-1 inhibitors holds promise for overcoming the limitations of monotherapy and providing a novel strategy with improved efficacy in cancer treatment. Summary of the Invention

[0008] The inventors of this invention have discovered that combining an antibody-drug conjugate that targets B7-H3 and is coupled with a camptothecin-like compound (a topoisomerase I inhibitor) as the toxic component with a PARP-1 inhibitor exhibits significant synergistic antitumor effects both in vitro and in vivo.

[0009] Therefore, the object of the present invention is to provide a combination therapy of antibody-drug conjugates or salts thereof targeting B7-H3 with other antitumor drugs, particularly PARP-1 inhibitors, in tumors.

[0010] The technical solution of the present invention is as follows.

[0011] On one hand, the present invention provides a pharmaceutical combination comprising:

[0012] (1) Antibody-drug conjugates or their salts targeting B7-H3; and

[0013] (2) PARP-1 inhibitors.

[0014] The term "drug combination" refers to non-fixed combination products or fixed combination products, including but not limited to pillboxes and pharmaceutical compositions. The term "non-fixed combination" means that the active ingredients (e.g., (1) an antibody-drug conjugate targeting B7-H3 or a salt thereof, and (2) a PARP-1 inhibitor) are administered to a patient in separate entities, either simultaneously or sequentially without a specific time limit or at the same or different time intervals, wherein such administration to the patient provides a preventive or therapeutically effective level of said two active ingredients. The term "fixed combination" means that two active ingredients are administered to a patient simultaneously in the form of a single entity. Each ingredient may be in a separate formulation, and the formulations may be the same or different.

[0015] Antibody-drug conjugates or their salts targeting B7-H3

[0016] In the drug combination provided by the present invention, the antibody-drug conjugate targeting B7-H3 or its salt has a structure as shown in structural formulas Ia and / or Ib:

[0017] and / or

[0018] In structural formulas Ia and / or Ib, Ab is an anti-B7-H3 antibody or a fragment thereof.

[0019] The term "anti-B7-H3 antibody" as used in this invention encompasses any known antibody form capable of specifically binding to or targeting B7-H3, including naturally occurring, artificially obtained, or artificially constructed functional antibody proteins. The term "fragment" as used in this invention encompasses various functional or active fragments of the anti-B7-H3 antibody, such as its antigen-binding fragment.

[0020] In structural formulas Ia and / or Ib, M is a phenylene or a phenylene substituted with one or more substituents, or a chemical bond; in the substituted phenylene, the substituent is selected from alkyl (e.g., C1-6 alkyl, preferably C1-4 alkyl), haloalkyl (e.g., haloC1-6 alkyl, preferably haloC1-4 alkyl, such as trifluoromethyl), alkoxy (e.g., C1-6 alkoxy, preferably C1-4 alkoxy, preferably methoxy), halogen, ester, amide, and cyano.

[0021] In structural formulas Ia and / or Ib, SP1 is selected from C1-8 alkylene, C1-8 cycloalkylene, or C1-21 (preferably C1-16, more preferably C1-11, more preferably C5-9) straight-chain heteroalkylene, wherein the C1-21 straight-chain heteroalkylene comprises 1-11 (preferably 1-6, more preferably 3-5) heteroatoms selected from N, O, or S, wherein each of the C1-8 alkylene, C1-8 cycloalkylene, and C1-21 straight-chain heteroalkylene is independently optionally substituted by one or more substituents selected from hydroxyl, amino, sulfonic acid, and cyano groups.

[0022] In structural formulas Ia and / or Ib, SP2 is selected from -NH(CH2CH2O). a CH2CH2CO-、-NH(CH2CH2O) a CH2CO-、-S(CH2) a CO- or chemical bond, where a is an integer from 1 to 20.

[0023] In structural formulas Ia and / or Ib, A represents a short peptide structure consisting of 2-4 amino acids. Wherein, when A represents a short peptide structure formed by 2 amino acids, it can be -Phe-Lys-, -Val-Ala-, -Val-Lys-, -Ala-Lys-, -Val-Cit-, -Phe-Cit-, -Leu-Cit-, -Phe-Arg-, or -Gly-Val-, preferably -Phe-Lys-, -Val-Ala-, or -Val-Cit-; when A represents a short peptide structure formed by 3 amino acids, it can be -Glu-Val-Ala-, -Glu-Val-Cit-, or -Ala-Ala-Ala-, preferably -Glu-Val-Ala- or -Ala-Ala-Ala-; when A represents a short peptide structure formed by 4 amino acids, it can be -Gly-Gly-Phe-Gly- or -Gly-Phe-Gly-Gly-, preferably -Gly-Gly-Phe-Gly-. Preferably, A is -Val-Ala-, -Gly-Gly-Phe-Gly-, or -Ala-Ala-Ala-. In structural formulas Ia and / or Ib, group A is linked to SP2 via an amino group at the amino terminus of its short peptide structure.

[0024] In structural formulas Ia and / or Ib, m is 1 to 10 and can be an integer or a non-integer.

[0025] In structural formulas Ia and / or Ib, CPT is a camptothecin-type compound.

[0026] In structural formulas Ia and / or Ib, M can be further preferably a halogen-substituted phenylene, particularly a fluorine-substituted phenylene.

[0027] In structural formulas Ia and / or Ib, SP1 may be further preferably C1-11, more preferably C5-9, more preferably C7 straight-chain heteroalkyl, which contains 1-6, more preferably 3-5, more preferably 4 heteroatoms selected from N, O or S.

[0028] In structural formulas Ia and / or Ib, 'a' in SP2 can be further preferably an integer from 1 to 10, more preferably an integer from 1 to 6. In particular, SP2 can be preferably a chemical bond.

[0029] In structural formulas Ia and / or Ib, m can be further preferably an integer or non-integer of 1 to 8 (e.g., 1 to 5 or 1 to 6), more preferably an integer or non-integer of 3 to 8. For example, m can be further preferably an integer or non-integer of 3 to 5, such as 4.

[0030] Preferably, the structure of CPT is as shown in structural formula IA, wherein structural formula IA is connected to the carboxyl group of the amino acid in group A of any one of structural formulas Ia and Ib via an amide bond, and more preferably, the amino group on the left benzene ring in structural formula IA is connected to the carboxyl group of the amino acid in group A of any one of structural formulas Ia and Ib via an amide bond.

[0031] In structural formula IA, R1, R2, R3, and R4 are independently hydrogen, halogen, hydroxyl, C1-6 alkoxy, amino or substituted amino, C1-7 alkyl or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms they are attached to form a C3-6 (preferably C3-5) cyclic alkyl group; however, R1, R2, R3, and R4 are not all hydrogen at the same time.

[0032] When R1, R2, R3, and R4 are independently C1-6 alkoxy groups, the C1-6 alkoxy groups include straight-chain or branched C1-6 alkoxy groups, preferably straight-chain or branched C1-3 alkoxy groups, and more preferably methoxy groups. When R1, R2, R3, and R4 are independently substituted amino groups, the substituted amino groups are amino groups substituted by one or more substituents selected from methyl and ethyl groups. When R1, R2, R3, and R4 are independently C1-7 alkyl or substituted C1-7 alkyl, the C1-7 alkyl or substituted C1-7 alkyl includes straight-chain or branched C1-7 (preferably C3-5, more preferably C4) alkyl or substituted C1-7 (preferably C3-5, more preferably C4) alkyl, and the substituted C1-7 alkyl is a C1-7 alkyl substituted by one or more substituents selected from cyclopropyl and cyclobutyl; or, the straight-chain or branched C1-7 alkyl or substituted C1-7 alkyl is preferably a C1-3 alkyl or substituted C1-3 alkyl, such as methyl, halomethyl (preferably trifluoromethyl).

[0033] Preferably, R1, R2, R3, and R4 are independently hydrogen, halogen (e.g., fluorine), C1-7 alkyl, or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms they are attached to form a C3-6 cyclic alkyl group (e.g., a C3-5 cyclic alkyl group). Further, R1 and R2 can be the same; and / or, R3 and R4 can be the same.

[0034] According to a specific embodiment of the present invention, in structural formula IA, it is particularly preferred that:

[0035] (1) R1 and R2 are methyl groups, and R3 and R4 are hydrogen groups;

[0036] (2) R1 and R2 are fluorine, and R3 and R4 are hydrogen; or

[0037] (3) One of R1 and R2 together with one of R3 and R4, along with the carbon atoms they are attached to, forms a C3 cyclic alkyl group, and the other of R1 and R2 together with the other of R3 and R4 is hydrogen.

[0038] According to a specific embodiment of the present invention, in any of structural formulas Ia and Ib, the structure of the CPT is as follows, wherein each structural formula is connected to the carboxyl group of the amino acid in group A of any one of structural formulas Ia and Ib via an amide bond, preferably with the amino group on the left benzene ring in each structural formula connected to the carboxyl group of the amino acid in group A of any one of structural formulas Ia, Ib, Ic, and Id via an amide bond:

[0039] Furthermore, the antibody-drug conjugate or its salt provided by the present invention has a structure as shown in structural formulas Ic and / or Id:

[0040] and / or

[0041] In structural formulas Ic and / or Id, Ab, group A, CPT, and m are defined in the same way as in structural formulas Ia and / or Ib.

[0042] According to a specific embodiment of the present invention, in the drug combination provided by the present invention, the antibody-drug conjugate targeting B7-H3 or its salt has the following structure:

[0043] and / or

[0044] As described above, in the antibody-drug conjugate targeting B7-H3 or its salt, Ab is an anti-B7-H3 antibody or a fragment thereof. Specifically, the anti-B7-H3 antibody or its fragment comprises a heavy chain and a light chain, wherein the heavy chain and the light chain respectively comprise complementarity-determining regions (CDRs) 1 (H-CDR1), 2 (H-CDR2) and 3 (H-CDR3) and CDRs 1 (L-CDR1), 2 (L-CDR2) and 3 (L-CDR3).

[0045] According to a specific embodiment of the present invention, in the anti-B7-H3 antibody or a fragment thereof, the heavy chain complementarity-determining region originates from the heavy chain variable region comprising the amino acid sequence shown in SEQ ID NO:1, and the light chain complementarity-determining region originates from the light chain variable region comprising the amino acid sequence shown in SEQ ID NO:7.

[0046] The amino acid sequences shown in SEQ ID NO:1 and SEQ ID NO:7 are, respectively, the heavy chain variable region and light chain variable region of the anti-B7-H3 antibody (“hz10B4m1”) in the antibody-drug conjugate provided in the “Best Mode for Carrying Out the Invention” section of this document. Using tools known in the art for defining complementarity-determining regions (CDRs) in antibody heavy or light chain variable regions (e.g., Chothia, Kabat, IMGT, Contact, etc.), those skilled in the art can easily determine the heavy chain CDRs and light chain CDRs contained therein. According to a specific embodiment of the present invention, the Kabat tool can be used to delineate the CDRs in the variable region sequence.

[0047] Preferably, as described above, the Kabat tool is used to delimit the CDRs in each variable region sequence of the above amino acid sequence pairings. Accordingly, the anti-B7-H3 antibody or its fragment may contain the following heavy chain CDRs and light chain CDRs:

[0048] H-CDR1, H-CDR2, and H-CDR3, sequentially comprising the amino acid sequences shown in SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4; and L-CDR1, L-CDR2, and L-CDR3, sequentially comprising the amino acid sequences shown in SEQ ID NO:8, SEQ ID NO:9, and SEQ ID NO:10.

[0049] The anti-B7-H3 antibody or fragment thereof is an antibody or fragment thereof against mammalian B7-H3, preferably primate or rodent B7-H3, more preferably human B7-H3. For example, the sequence of the target protein human B7-H3 can be found in GenBank accession number AAH62581.1.

[0050] Furthermore, in the antibody-drug conjugate targeting B7-H3 or its salt provided by the present invention, the anti-B7-H3 antibody or its fragment comprises a heavy chain variable region and a light chain variable region, both of which include the aforementioned CDRs and the framework region (FR) therebetween, and the arrangement of each region is FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4.

[0051] Preferably, in the antibody-drug conjugate targeting B7-H3 or its salt provided by the present invention, the heavy chain variable region of the anti-B7-H3 antibody or its fragment contains the amino acid sequence shown in SEQ ID NO:1 or an amino acid sequence having at least 75% identity with the amino acid sequence; and / or, the light chain variable region contains the amino acid sequence shown in SEQ ID NO:7 or an amino acid sequence having at least 75% identity with the amino acid sequence.

[0052] The "at least 75% identity" of this invention refers to a maximum 25% difference in the amino acid sequence that can exist in any frame region within the heavy chain variable region or the light chain variable region, or in any domain or sequence outside the heavy chain variable region and the light chain variable region. This difference can be caused by amino acid deletions, additions, or substitutions at any position, wherein the substitutions can be conservative or non-conservative. The "at least 75% identity" encompasses any percentage of identity between at least 75% and 100%, such as 75%, 80%, 85%, 90%, or even 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or even 100% identity.

[0053] According to specific embodiments of the present invention, in the antibody-drug conjugate or its salt provided by the present invention, the anti-B7-H3 antibody or its fragment can be a mouse antibody, chimeric antibody, or a fully or partially humanized antibody that binds to B7-H3. Alternatively, the anti-B7-H3 antibody or its fragment can be a monoclonal antibody or a single-chain antibody or any antigen-binding fragment that binds to B7-H3, such as a single-chain variable fragment (scFv), a bivalent single-chain variable fragment (BsFv), a disulfide-stabilized variable fragment (dsFv), (dsFv)2, an antigen-binding fragment (Fab), Fab' fragment (Fab'), (Fab' fragment)2 (F(ab')2), or a variable fragment (Fv).

[0054] Furthermore, in the antibody-drug conjugate or its salt provided by the present invention, the anti-B7-H3 antibody or its fragment may further include a constant region. Preferably, the anti-B7-H3 antibody or its fragment further includes a human or mouse heavy chain constant region (CH) and / or a light chain constant region (CL), more preferably a heavy chain constant region selected from IgG, IgA, IgM, IgD or IgE and / or a kappa(κ) or lambda(λ) type light chain constant region.

[0055] Preferably, the anti-B7-H3 antibody is a monoclonal antibody, preferably a murine, chimeric, or humanized monoclonal antibody. More preferably, the heavy chain constant region of the monoclonal antibody is IgG1 or IgG4 subtype, and the light chain constant region is κ type. Alternatively, for example, the anti-B7-H3 antibody is an immunoglobulin, specifically IgA, IgD, IgE, IgG, or IgM, such as human subtypes of IgA, IgD, IgE, IgG, or IgM, more preferably human IgG1, IgG2, IgG3, or IgG4 subtype.

[0056] According to a specific embodiment of the present invention, the anti-B7-H3 antibody or a fragment thereof comprises a heavy chain constant region, the heavy chain constant region comprising the amino acid sequence shown in SEQ ID NO:5 or an amino acid sequence having at least 75% identity with said amino acid sequence. Alternatively, the anti-B7-H3 antibody or a fragment thereof comprises a light chain constant region, the light chain constant region comprising the amino acid sequence shown in SEQ ID NO:11 or an amino acid sequence having at least 75% identity with said amino acid sequence.

[0057] More specifically, in the drug combination provided by the present invention, the antibody-drug conjugate or its salt is obtained by conjugating a humanized monoclonal antibody against B7-H3 with a small molecule compound with the structure shown above. The heavy chain of the humanized monoclonal antibody contains the amino acid sequence shown in SEQ ID NO:6 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:12 or an amino acid sequence having at least 75% identity with the amino acid sequence shown in SEQ ID NO:12.

[0058] Furthermore, in the drug combination provided by the present invention, the salt of the antibody-drug conjugate is a pharmaceutically acceptable salt of the antibody-drug conjugate.

[0059] PARP-1 inhibitors

[0060] In the drug combination provided by the present invention, the PARP-1 inhibitor refers to a reagent that can inhibit the enzymatic activity of PARP by binding to the catalytic domain active site of PARP, and may or may not have selective inhibitory activity for different PARP subtypes.

[0061] Various PARP-1 inhibitors are known in the art, which exert their therapeutic effects as monotherapy based on the concept of synthetic lethality, such as olaparib, rucaparib, niraparib, talazoparib, fluzoparib, pamiparib, AZD5305 (Saruparib), etc.; these drugs or their pharmaceutically acceptable salts can be used in the drug combinations provided by the present invention.

[0062] Preferably, in the drug combination provided by the present invention, the PARP-1 inhibitor is olaparib and / or AZD5305 or saruparib or a pharmaceutically acceptable salt thereof.

[0063] On the other hand, the present invention provides the use of the pharmaceutical combination in the preparation of a medicament for treating tumors.

[0064] In the context of this invention, the term "treatment" refers to one or more of the following: delaying or inhibiting tumor growth, reducing tumor cell load or tumor burden, promoting tumor regression, causing tumor shrinkage, necrosis and / or disappearance, preventing tumor recurrence, prolonging individual survival time, etc.

[0065] Preferably, the tumor is a solid tumor that expresses (including overexpresses) B7-H3, such as a B7-H3 overexpressing or positive solid tumor. For example, the tumor may be gastric cancer, colorectal cancer, liver cancer, pancreatic cancer, esophageal cancer, non-small cell carcinoma, prostate cancer, ovarian cancer, breast cancer, small cell lung cancer, neuroblastoma, rhabdomyosarcoma, osteosarcoma, Ewing sarcoma, nephroblastoma, or desmoplastic small round cell tumor. When preparing a medicament for treating tumors using the drug combination provided by this invention, the antibody-drug conjugate targeting B7-H3 or its salt and the PARP-1 inhibitor may be in one drug system or in separate drug systems. When using the medicament, the antibody-drug conjugate targeting B7-H3 or its salt and the PARP-1 inhibitor may be administered simultaneously or at time intervals.

[0066] In another aspect, the present invention provides a method for treating tumors, the method comprising administering the following to a subject in need:

[0067] (1) Antibody-drug conjugates or their salts targeting B7-H3; and

[0068] (2) PARP-1 inhibitors.

[0069] In the method provided by this invention, the antibody-drug conjugate targeting B7-H3 or its salt, and the PARP-1 inhibitor are all as described above.

[0070] The method provided by this invention is used to treat tumors. Preferably, the tumor is B7-H3 expressing (including overexpressing), such as a tumor that is B7-H3 overexpressing or positive. Preferably, the tumor is a solid tumor, such as gastric cancer, colorectal cancer, liver cancer, pancreatic cancer, esophageal cancer, non-small cell carcinoma, prostate cancer, ovarian cancer, breast cancer, small cell lung cancer, neuroblastoma, rhabdomyosarcoma, osteosarcoma, Ewing sarcoma, nephroblastoma, and desmoplastic small round cell tumor.

[0071] In the method provided by this invention, the subject is a mammal, preferably a primate or rodent, and more preferably a human.

[0072] Regarding the use of the two reagents in the subject in the method provided by this invention, the antibody-drug conjugate targeting B7-H3 or its salt and the PARP-1 inhibitor can be administered to the subject simultaneously or sequentially; the administration route can be parenteral (e.g., subcutaneous, intraperitoneal, intramuscular, intrasternal, intravenous, intraarterial, intrathecal, intraventricular, intraurethral, ​​intracranial, intratumoral, or intrasynovial injection or infusion; renal dialysis infusion; local perfusion; oral administration; etc.). In particular, the antibody-drug conjugate targeting B7-H3 or its salt can be administered intravenously, subcutaneously, intraperitoneally, or intramuscularly, with intravenous administration being preferred; the PARP-1 inhibitor is usually administered orally.

[0073] In another aspect, the present invention provides a medicine box for treating tumors, the medicine box comprising the drug combination provided by the present invention.

[0074] In the kit provided by this invention, the antibody-drug conjugate targeting B7-H3 or its salt, the PARP-1 inhibitor, and the tumor are all as described above.

[0075] The medication kit may include containers for holding antibody-drug conjugates targeting B7-H3 or their salts, or PARP-1 inhibitors. The containers may be boxes, ampoules, bottles, vials, tubes, bags, pouches, blister packs, or other forms of containers known in the art, and may be made of plastic, glass, metal foil, or other materials suitable for preserving the medication.

[0076] Depending on the intended administration or treatment method, the kit may also contain other reagents, such as buffer solutions; or instructions for use.

[0077] Compared with the prior art, the present invention proposes an antibody-drug conjugate or its salt targeting B7-H3 in combination with a PARP-1 inhibitor for the immunotherapy of tumors or cancers expressing (including overexpressing) B7-H3.

[0078] The antibody-drug conjugate targeting B7-H3, or its salt, is formed by conjugating an anti-B7-H3 antibody with a camptothecin-based topoisomerase I inhibitor. Experiments have demonstrated that the combination of this B7-H3-targeting ADC with PARP-1 inhibitors (Olaparib and AZD5305) exhibits significant synergistic antitumor effects both in vitro and in vivo, providing a superior therapeutic strategy for B7-H3-expressing (including overexpressing) tumors or cancers. Attached Figure Description

[0079] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein:

[0080] Figures 1A and 1B illustrate the inhibitory effects of antibody-drug conjugates targeting B7-H3 and PARP-1 inhibitors, used alone or in combination, on tumor cell growth.

[0081] Figure 2 illustrates the effects of antibody-drug conjugates targeting B7-H3, PARP-1 inhibitors, alone or in combination, on the cell cycle.

[0082] Figures 3A and 3B to 4A and 4B show the combination index scores when antibody-drug conjugates targeting B7-H3 are used in combination with PARP-1 inhibitors. In the figures, the numbers represent the administration points for the combination, the horizontal axis "Effect" represents the effect size after combination, and the vertical axis "CI" represents the combination index score.

[0083] Figures 5A and 5B show the curves of tumor volume vs. time and mouse body weight vs. time when the antibody-drug conjugate targeting B7-H3 and the PARP-1 inhibitor (AZD5305) are used alone or in combination.

[0084] Figures 6A and 6B show the curves of tumor volume vs. time and mouse body weight vs. time when antibody-drug conjugates targeting B7-H3 and PARP-1 inhibitors (Olaparib) are used alone or in combination.

[0085] The best way to implement an invention

[0086] The present invention will be described below with reference to specific embodiments. Those skilled in the art will understand that these embodiments are for illustrative purposes only and do not limit the scope of the invention in any way.

[0087] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, all raw materials and reagents used in the following examples are commercially available products.

[0088] The antibody-drug conjugate (named "hz10B4m1-CPT") used in the following examples was prepared according to the method described in PCT application publication WO2024 / 251149A1, and its structure is as follows:

[0089] m represents the drug-antibody ratio (DAR), which was confirmed to be 4 by hydrophobic interaction chromatography.

[0090] In the structure shown, Ab is the humanized monoclonal antibody hz10B4m1 against B7-H3, and its amino acid sequence is shown below (heavy chain CDRs and light chain CDRs were separated using Kabat tool):

[0091] DS-7300: Prepared according to the method described in patent publication CN104755494B.

[0092] Olaparib: Purchased from MCE, item number: HY-10162.

[0093] AZD5305: Purchased from MCE, item number: HY-132167.

[0094] Example 1: Inhibitory effect of antibody-drug conjugates targeting B7-H3 in combination with PARP-1 inhibitors on tumor cell growth.

[0095] This embodiment tested the inhibitory effect of antibody-drug conjugates targeting B7-H3 on tumor cell growth when used in combination with two PARP-1 inhibitors (Olaparib and AZD5305). The experimental procedure is as follows.

[0096] Tumor cells were seeded in 96-well plates and cultured overnight at 37°C and 5% CO2. The next day, the culture medium was discarded; the following settings were configured in the 96-well plates:

[0097] (1) Single-drug administration test well:

[0098] Add 200 μL of hz10B4m1-CPT or DS-7300 diluted with RPMI 1640 medium containing 10% fetal bovine serum at a concentration of 19.431 ng / mL;

[0099] Add 200 μL of 2 μM Olaparib or 3 μM AZD5305 diluted in RPMI 1640 medium containing 10% fetal bovine serum;

[0100] (2) Combined drug delivery test well:

[0101] Add 100 μL of hz10B4m1-CPT or DS-7300 diluted in RPMI 1640 medium containing 10% fetal bovine serum at a concentration of 39.06 ng / mL, and then add 100 μL of 4 μM Olaparib or 6 μM AZD5305.

[0102] (3) Reference hole:

[0103] Add 200 μL of RPMI 1640 medium containing 10% fetal bovine serum;

[0104] In addition, blank wells are pre-set in the 96-well plate, which contain only 200 μL of RPMI 1640 medium containing 10% fetal bovine serum and contain no cells.

[0105] After thorough mixing, the 96-well plate was incubated at 37°C and 5% CO2 for 7 days. Subsequently, 20 μL of Cell Counting Kit-8 was added to each well of the 96-well plate, and the plate was incubated in a CO2 incubator for 1 hour. The luminescence intensity of each well was then measured.

[0106] The cell growth inhibition rate (%) under each condition was calculated using the following formula:

[0107] Cell growth inhibition rate (%) = [(CT) / (CB)] × 100

[0108] C: Average luminous intensity of the control aperture

[0109] T: Average luminous intensity of the test well

[0110] B: Average luminous intensity of the blank aperture

[0111] The above tests were performed in the constructed pancreatic cancer cell line BxPC-3 (BxPC-3-B7H3-1-P1-D10) that highly expresses B7-H3. The test results are shown in Figures 1A and 1B. In the results shown, the concentration of hz10B4m1-CPT or DS-7300 in each cell well was 19.531 ng / mL, the concentration of Olaparib (Figure 1A) was 2 μM, and the concentration of AZD5305 (Figure 1B) was 3 μM.

[0112] As the results showed, the cell growth inhibition rates of hz10B4m1-CPT monotherapy and DS-7300 monotherapy were 21.5% and 14.3%, respectively, while the cell growth inhibition rates of PARP-1 inhibitor Olaparib monotherapy and AZD5305 monotherapy were 21.6% and 16.6%, respectively. In contrast, the cell growth inhibition rate of the Olaparib and hz10B4m1-CPT combination group was 66.2%, and the cell growth inhibition rate of the Olaparib and DS-7300 combination group was 36.3%. The cell growth inhibition rate of the AZD5305 and hz10B4m1-CPT combination group was 70.3%, and the cell growth inhibition rate of the AZD5305 and DS-7300 combination group was 37.9%.

[0113] Example 2: Effects of combining B7-H3 antibody-drug conjugates with PARP-1 inhibitors on the cell cycle.

[0114] This example tested the effects of antibody-drug conjugates targeting B7-H3 in combination with two PARP-1 inhibitors (Olaparib and AZD5305) on the cell cycle. The experimental procedure is as follows.

[0115] BxPC-3-B7H3-1-P1-D10 cells, which highly express B7-H3, were seeded in 6-well plates and cultured overnight at 37°C and 5% CO2. The next day, the culture medium was discarded; then, a dilution of hz10B4m1-CPT or DS-7300 in RPMI 1640 medium containing 10% fetal bovine serum was added to each well, followed by the addition of Olaparib or AZD5305. After thorough mixing, the 6-well plates were incubated at 37°C and 5% CO2 for 48 hours. Cells were then collected, washed with PBS, fixed overnight in pre-chilled 70% ethanol at 4°C, washed twice with PBS, treated with ribonuclease and PI (propidium iodide) staining solution, and subjected to flow cytometry to evaluate cell cycle effects. The results are shown in Table 1 and Figure 2.

[0116] As the results showed, after 48 hours of treatment with each reagent, compared with the proportion of S phase cells (28.92%) and G2 / M phase cells (10.06%) detected when treated with solvent alone, the proportion of S phase cells detected when treated with PARP-1 inhibitors olaparib and AZD5305 alone were 30.19% and 30.68%, respectively, with no significant arrest effect on cell entry into the mitotic cycle; the proportion of S phase cells detected when treated with hz10B4m1-CPT alone and DS-7300 alone were 48.95% and 34.89%, respectively.

[0117] Of particular note is that the combination of these two PARP-1 inhibitors with hz10B4m1-CPT significantly increased the proportion of cells in S phase: the proportion of S phase cells detected in the combination of Olaparib and hz10B4m1-CPT was 57.34%, and the proportion of S phase cells detected in the combination of AZD5305 and hz10B4m1-CPT was 61.46%. In contrast, the combination of these two PARP-1 inhibitors with DS-7300 did not further increase the proportion of S phase cells: the proportion of S phase cells detected in the combination of Olaparib and DS-7300 was 34.3%, and the proportion of S phase cells detected in the combination of AZD5305 and DS-7300 was 35.80%.

[0118] The above results indicate that the combined use of hz10B4m1-CPT with Olaparib or AZD5305 can arrest most proliferating cells and effectively prevent cells from entering the mitotic cycle.

[0119] Table 1. Effects of combined use of B7-H3-targeting ADCs and PARP-1 inhibitors on cell cycle

[0120] The dosage of each reagent in Table 1 represents the final reagent concentration in each cell well.

[0121] Example 3: The combination of antibody-drug conjugates targeting B7-H3 and PARP-1 inhibitors exhibits synergistic effects.

[0122] This example tested the synergistic effect of the antibody-drug conjugate hz10B4m1-CPT in combination with two PARP-1 inhibitors (Olaparib and AZD5305) in two B7-H3-expressing cell lines: the constructed breast cancer cell line MDA_MB_468 (MDA_MB_468-B7H3-1-P2-F9) which highly expresses B7-H3, and the naturally low-expressing breast cancer cell line MDA_MB_468. The experimental procedure is as follows.

[0123] (1)MDA_MB_468-B7H3-1-P2-F9:

[0124] MDA_MB_468-B7H3-1-P2-F9 cells were seeded in 96-well plates and cultured overnight at 37°C and 5% CO2. The next day, the culture medium was discarded; the following settings were configured in the 96-well plates:

[0125] (1) Single-drug administration test well:

[0126] Add 200 μL / well of hz10B4m1-CPT diluted in RPMI 1640 medium containing 10% fetal bovine serum at concentrations of 5000 ng / mL, 1250 ng / mL, 312.5 ng / mL, 78.13 ng / mL, and 19.53 ng / mL.

[0127] Add 200 μL / well of Olaparib or AZD5305 diluted in RPMI 1640 medium containing 10% fetal bovine serum at 2500 nM, 625 nM, 156.25 nM, 39.06 nM, and 9.77 nM.

[0128] (2) Combined drug delivery test well:

[0129] Add 100 μL / well of hz10B4ml-CPT diluted in RPMI 1640 medium containing 10% fetal bovine serum at concentrations of 10000 ng / mL, 2500 ng / mL, 625 ng / mL, 156.25 ng / mL, and 39.06 ng / mL; then add 100 μL / well of olaparib diluted in RPMI 1640 medium containing 10% fetal bovine serum at concentrations of 400 nM or AZD5305 diluted at concentrations of 600 nM.

[0130] (3) Reference hole:

[0131] Add 200 μL of RPMI 1640 medium containing 10% fetal bovine serum.

[0132] In addition, blank wells are pre-set in the 96-well plate, which contain only 200 μL of RPMI 1640 medium containing 10% fetal bovine serum and contain no cells.

[0133] After thorough mixing, the 96-well plate was incubated at 37°C and 5% CO2 for 7 days. Then, 20 μL of Cell Counting Kit-8 was added to each well of the 96-well plate, and the plates were incubated in a CO2 incubator at room temperature for 1 hour. The luminescence intensity of each well was then measured.

[0134] (2)MDA_MB_468:

[0135] MDA_MB_468 cells were seeded in 96-well plates and cultured overnight at 37°C and 5% CO2. The next day, the culture medium was discarded; the following settings were configured in the 96-well plates:

[0136] (1) Single-drug administration test well:

[0137] Add 200 μL / well of hz10B4m1-CPT diluted in RPMI 1640 medium containing 10% fetal bovine serum at concentrations of 5000 ng / mL, 1250 ng / mL, 312.5 ng / mL, 78.13 ng / mL, and 19.53 ng / mL.

[0138] Add 200 μL / well of Olaparib diluted in RPMI 1640 medium containing 10% fetal bovine serum at 2500 nM, 625 nM, 156.25 nM, 39.06 nM, and 9.77 nM; or AZD5305 diluted in 1000 nM, 250 nM, 62.5 nM, 15.63 nM, and 3.91 nM.

[0139] (2) Combined drug delivery test well:

[0140] Add 100 μL / well of hz10B4m1-CPT diluted in RPMI 1640 medium containing 10% fetal bovine serum at concentrations of 10000 ng / mL, 2500 ng / mL, 625 ng / mL, 156.25 ng / mL, and 39.06 ng / mL; then add 100 μL / well of olaparib diluted in RPMI 1640 medium containing 10% fetal bovine serum at concentrations of 40 nM or AZD5305 diluted at concentrations of 60 nM.

[0141] (3) Reference hole:

[0142] Add 200 μL of RPMI 1640 medium containing 10% fetal bovine serum.

[0143] In addition, blank wells are pre-set in the 96-well plate, which contain only 200 μL of RPMI 1640 medium containing 10% fetal bovine serum and contain no cells.

[0144] After thorough mixing, the 96-well plate was incubated at 37°C and 5% CO2 for 7 days. Then, 20 μL of Cell Counting Kit-8 was added to each well of the 96-well plate, and the plates were incubated in a CO2 incubator at room temperature for 1 hour. The luminescence intensity of each well was then measured.

[0145] The cell growth inhibition rate (%) under each condition was calculated in the same manner as in Example 1, and this cell growth inhibition rate (%) was used as the effect value. Based on the effect value, the combination index (CI) was further calculated using the Chou-Talalay method to determine whether the two reagents had a synergistic effect. A combination index CI = 1 indicates an additive effect between the two reagents; a combination index CI > 1 indicates an antagonistic effect between the two reagents; and a combination index CI < 1 indicates a synergistic effect between the two reagents.

[0146] The effect size and joint index score results in MDA_MB_468-B7H3-1-P2-F9 cells are shown in Figures 3A and 3B. The effect size and joint index score results in MDA_MB_468 cells are shown in Figures 4A and 4B.

[0147] The results showed that hz10B4m1-CPT had a significant synergistic effect when used in combination with two PARP-1 inhibitors.

[0148] Example 4: Inhibitory effect of combination of B7-H3 antibody-drug conjugate and PARP-1 inhibitor on tumor growth in vivo (NCI-H524 tumor-bearing mouse model).

[0149] This embodiment tested the inhibitory effect of the antibody-drug conjugate hz10B4m1-CPT on tumor growth in vivo when used in combination with the PARP-1 inhibitor (AZD5305). The experimental procedure is as follows.

[0150] A tumor-bearing mouse model was constructed using 5- to 6-week-old female nude mice and the human small cell lung cancer cell line NCI-H524. Approximately 5 × 10⁻⁶ cells were used to construct the tumor-bearing mouse model. 6 After mixing 100 μL of PBS and an equal volume of Matrigel, NCI-H524 cells were subcutaneously injected into the right back near the armpit of 65 mice (including 17 reserve mice). The mice were anesthetized with 3-4% isoflurane prior to injection. Injection was initiated when the tumor reached approximately 100-150 mm.3 Tumors of similar size were randomly assigned to treatment groups, as shown in Table 2.

[0151] Table 2. Grouping of tumor-bearing mice PO: Oral administration (per os); QD: Once daily (quaque die) administration

[0152] The drug dosage for each animal was calculated based on its individual body weight on the day of administration. hz10B4m1-CPT and AZD5305 were administered on the same day, with hz10B4m1-CPT administered approximately 1 hour after the AZD5305 PO administration. The dosing cycle was 28 days: on day 1, hz10B4m1-CPT was administered as a single dose at a dose of 3 mg / kg or 10 mg / kg, and AZD5305 was administered at a dose of 0.1 mg / kg QD, depending on the group, for 28 days.

[0153] Preparation of hz10B4m1-CPT dosing solution: On the day of administration, the dosing solution is prepared by diluting the hz10B4m1-CPT stock solution (6.9 mg / mL) to 0.3 mg / mL or 1 mg / mL in PBS. The dosing volume is 10 mL / kg.

[0154] Preparation of AZD5305 dosing solution: Weigh 5 mg of AZD5305, dissolve it in DMSO using sonication to prepare a 5 mg / mL stock solution. Take 1 mL of this 5 mg / mL stock solution, add 15 μL of 1M HCl, mix thoroughly, then add 39.2 mL of sterile water and mix thoroughly. Adjust the pH of the solution to pH 3.74 (pH range 3.5–4.0) with approximately 13 μL of 1M HCl. Add 9.772 mL of sterile water and mix thoroughly to obtain a 0.1 mg / mL dosing solution. The dosing volume is 1 mL / kg.

[0155] The anti-tumor effect is examined by measuring tumor volume.

[0156] The tumor volume (V) is calculated as follows: V = (length × width) 2 ) / 2.

[0157] The relative tumor volume (RTV) per nude mouse is calculated as follows: RTV = V t / V0; where V t V0 represents the volume measured each time, and V0 represents the volume at the start of treatment.

[0158] The calculation method for tumor growth inhibition (TGI) is: TGI% = (1-T / C)×100%, where T and C are the relative tumor volume (RTV) of the test group and the solvent group at a specific time point, respectively, and T / C% is the relative tumor proliferation rate, that is, the percentage value of the relative tumor volume (RTV) of the test group and the solvent group at a certain time point.

[0159] Drug tolerance was assessed by weighing the mice.

[0160] The percentage change in body weight per mouse (BW Loss) is calculated as follows: BW Loss% = (W0 - W t / W0)×100%, where W0 and W t The figures represent the weights of the nude mice at the start of treatment and at a specific time point, respectively.

[0161] The results are shown in Table 3 and Figures 5A and 5B. Table 3 shows the tumor volume and TGI response (TGI%) on day 22 and the body weight change rate (BW Loss%) on day 29 in the constructed NCI-H524 xenograft model for each group of mice. Figure 5A shows the changes in tumor volume over time for each group; Figure 5B shows the changes in body weight over time for each group of mice.

[0162] Table 3. Effects of the combination of B7-H3-targeting ADCs and PARP-1 inhibitors on tumor growth in vivo.

[0163] As the results showed, on day 22 of the dosing cycle, AZD5305 alone achieved a TGI of 51.65%; hz10B4m1-CPT alone at 3 mg / kg achieved a TGI of 87.06%, and at 10 mg / kg achieved a TGI of 89.35%. In contrast, the tumor-suppressing effect was quite significant when the two agents were administered in combination: AZD5305 combined with 3 mg / kg hz10B4m1-CPT achieved a TGI of 99.17%; AZD5305 combined with 10 mg / kg hz10B4m1-CPT achieved a TGI of 99.35%.

[0164] During the treatment, mice in the Olaparib monotherapy group gained more than 12% of their body weight; the 3 mg / kg and 10 mg / kg hz10B4m1-CPT monotherapy groups gained 5.7% and 3.47% of their body weight, respectively; the average body weight of mice in the combination therapy group remained stable during the study, with no more than 2% of their body weight changed.

[0165] Example 5: Inhibitory effect of antibody-drug conjugates targeting B7-H3 in combination with PARP-1 inhibitors on tumor growth in vivo (SKOV-3 tumor-bearing mouse model).

[0166] This embodiment tested the inhibitory effect of the antibody-drug conjugate hz10B4m1-CPT on tumor growth in vivo when used in combination with the PARP-1 inhibitor (Olaparib). The experimental procedure is as follows.

[0167] A tumor-bearing mouse model was constructed using 5- to 6-week-old female nude mice and the human ovarian cancer cell line SKOV-3. Approximately 3 × 10⁻⁶ tumor-bearing mice were used. 6 After mixing 100 μL of PBS and an equal volume of Matrigel, 42 SKOV-3 cells were subcutaneously injected into the right back near the armpit of 42 mice (including 10 reserve mice) (the mice were anesthetized with 3-4% isoflurane before injection). Injection was initiated when the tumor reached approximately 100-150 mm. 3 Tumors of similar size were randomly assigned to treatment groups, as shown in Table 4.

[0168] Table 4. Grouping of tumor-bearing mice PO: Oral administration (per oral); QD: Once daily (quaque die); QW: Once weekly (quaque week)

[0169] The drug dosage for each animal was calculated based on its individual body weight on the day of administration. hz10B4m1-CPT and Olaparib were administered on the same day, with hz10B4m1-CPT administered approximately 1 hour after Olaparib PO administration. The dosing cycle was 2 weeks: hz10B4m1-CPT was administered at a single dose of 3 mg / kg on days 1 and 8, and Olaparib was administered at a QD of 50 mg / kg, five days a week, for a total of 2 weeks (days 1-5 and 8-12).

[0170] Preparation of hz10B4m1-CPT dosing solution: On the day of administration, the dosing solution was prepared by diluting the hz10B4m1-CPT stock solution (6.9 mg / mL) to 0.3 mg / mL in PBS. The dosing volume was 10 mL / kg.

[0171] Preparation of Olaparib Dosing Solution: Weigh 50 mg of Olaparib, dissolve it in DMSO using ultrasound, and prepare a 50 mg / mL DMSO stock solution. Take 100 μL of this stock solution and add it to 900 μL of 30% Kleptose saline solution, mix well to obtain a 5 mg / mL dosing solution. The dosing volume is 10 mL / kg.

[0172] Similar to Example 4, the anti-tumor effect was examined by measuring tumor volume; drug tolerance was examined by weighing the mice.

[0173] The results are shown in Table 5 and Figures 6A and 6B. Table 5 shows the tumor volume, TGI response (TGI%), and body weight loss (BW Loss%) of mice in each group on day 28 in the constructed SKOV-3 xenograft model. Figure 6A shows the changes in tumor volume over time in each group; Figure 6B shows the changes in body weight over time in each group.

[0174] Table 5. Effects of the combination of B7-H3-targeting ADCs and PARP-1 inhibitors on tumor growth in vivo.

[0175] As the results showed, on day 28 of the dosing cycle, Olaparib alone did not show any tumor growth inhibition effect; hz10B4m1-CPT alone achieved a TGI of 28.5%; in contrast, the tumor inhibition effect was significant when the two agents were administered in combination: 50 mg / kg of Olaparib combined with 3 mg / kg of hz10B4m1-CPT achieved a TGI of 47.6%.

[0176] During the treatment, mice in the Olaparib monotherapy group lost more than 18% of their body weight; mice in the hz10B4m1-CPT monotherapy group lost 8.99% of their body weight; the average body weight of mice in the combined therapy group remained stable during the study, with a weight loss of 0.9%, indicating good tolerability.

[0177] The above description of specific embodiments of the present invention does not limit the present invention. Those skilled in the art can make various changes or modifications based on the present invention, and as long as they do not depart from the spirit of the present invention, they should all fall within the scope of the appended claims.

Claims

1. A drug combination comprising: (1) Antibody-drug conjugates or salts thereof targeting B7-H3; in, The antibody-drug conjugate targeting B7-H3 or its salts have structures as shown in structural formulas Ia and / or Ib: and / or In structural formulas Ia and / or Ib: Ab is an anti-B7-H3 antibody or a fragment thereof; M is a phenylene or a phenylene substituted with one or more substituents, or a chemical bond; in the substituted phenylene, the substituent is selected from alkyl, haloalkyl, alkoxy, halogen, ester, amide, and cyano groups; SP1 is selected from C1-8 alkylene, C1-8 cycloalkylene, or C1-21 linear heteroalkylene, wherein the C1-21 linear heteroalkylene comprises 1-11 heteroatoms selected from N, O, or S, wherein each of the C1-8 alkylene, C1-8 cycloalkylene, and C1-21 linear heteroalkylene is independently and optionally substituted by one or more substituents selected from hydroxyl, amino, sulfonic acid, and cyano groups; SP2 is selected from -NH(CH2CH2O) a CH2CH2CO-、-NH(CH2CH2O) a CH2CO-、-S(CH2) a CO- or chemical bond, where a is an integer from 1 to 20; A represents a short peptide structure consisting of 2-4 amino acids, and SP2 is linked to the amino group at the amino terminus of the short peptide structure. m is an integer or non-integer from 1 to 10; CPT is a camptothecin-type compound; and (2) PARP-1 inhibitors.

2. The drug combination according to claim 1, characterized in that, Structural formulas Ia and / or Ib have one or more of the following characteristics: (1) M is a halogen-substituted phenylene, preferably a fluorine-substituted phenylene; (2) SP1 is a C1-11, preferably C5-9, more preferably C7 straight-chain heteroalkyl group, which contains 1-6, preferably 3-5, more preferably 4 heteroatoms selected from N, O or S; (3) In SP2, 'a' is an integer from 1 to 10, more preferably an integer from 1 to 6, or SP2 is a chemical bond; and (4) m is an integer or non-integer of 1 to 8, preferably 3 to 8, and more preferably an integer or non-integer of 3 to 5, for example 4.

3. The drug combination according to claim 1 or 2, characterized in that, In structural formulas Ia and / or Ib, the structure of CPT is as shown in structural formula IA, wherein structural formula IA is connected to the carboxyl group of an amino acid in group A of any of structural formulas Ia and Ib via an amide bond, preferably with the amino group on the left-hand benzene ring of structural formula IA connected to the carboxyl group of an amino acid in group A of any of structural formulas Ia and Ib via an amide bond: In structural formula IA, R1, R2, R3, and R4 are independently hydrogen, halogen, hydroxyl, C1-6 alkoxy, amino or substituted amino, C1-7 alkyl or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms they are attached to form a C3-6 cyclic alkyl group; however, R1, R2, R3, and R4 are not all hydrogen at the same time.

4. The drug combination according to claim 3, characterized in that: When R1, R2, R3, and R4 are independently C1-6 alkoxy groups, the C1-6 alkoxy groups include straight-chain or branched C1-6 alkoxy groups, preferably straight-chain or branched C1-3 alkoxy groups, and more preferably methoxy groups; When R1, R2, R3, and R4 are independently substituted amino groups, the substituted amino group is an amino group substituted by one or more substituents selected from methyl and ethyl groups; When R1, R2, R3, and R4 are independently C1-7 alkyl or substituted C1-7 alkyl, the C1-7 alkyl or substituted C1-7 alkyl includes straight-chain or branched C1-7 alkyl or substituted C1-7 alkyl, and the substituted C1-7 alkyl is a C1-7 alkyl substituted by one or more substituents selected from cyclopropyl and cyclobutyl; or, the straight-chain or branched C1-7 alkyl or substituted C1-7 alkyl is preferably a C1-3 alkyl or substituted C1-3 alkyl, such as methyl or halomethyl.

5. The drug combination according to claim 3 or 4, characterized in that, R1, R2, R3, and R4 are independently hydrogen, halogen, C1-7 alkyl, or substituted C1-7 alkyl, or any two of R1, R2, R3, and R4 together with the carbon atoms they are attached to form a C3-6 cyclic alkyl group. More preferably, R1 and R2 are the same; and / or, R3 and R4 are the same.

6. The pharmaceutical combination according to any one of claims 3 to 5, characterized in that, In structured IA: (1) R1 and R2 are methyl groups, and R3 and R4 are hydrogen groups; (2) R1 and R2 are fluorine, and R3 and R4 are hydrogen; or (3) One of R1 and R2 together with one of R3 and R4, along with the carbon atoms they are attached to, forms a C3 cyclic alkyl group; the other of R1 and R2 together with the other of R3 and R4 is hydrogen. Alternatively, the structure of the CPT is as follows, wherein each structural formula is connected to the carboxyl group of an amino acid in group A of any one of structural formulas Ia and Ib via an amide bond, preferably with the amino group on the left benzene ring of each structural formula connected to the carboxyl group of an amino acid in group A of any one of structural formulas Ia, Ib, Ic, and Id via an amide bond:

7. The pharmaceutical combination according to any one of claims 1 to 6, characterized in that, The antibody-drug conjugate targeting B7-H3 or its salts have structures as shown in structural formulas Ic and / or Id: and / or In structural formulas Ic and / or Id, Ab, group A, CPT, and m are defined in the same way as in structural formulas Ia and / or Ib. Preferably, the antibody-drug conjugate targeting B7-H3 or its salt has the structure shown below: and / or 8. The pharmaceutical combination according to any one of claims 1 to 7, characterized in that, The Ab contains a heavy chain and a light chain, and the heavy chain complementarity-determining regions (H-CDR1, H-CDR2, H-CDR3) contain the amino acid sequences shown in SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, respectively, and the light chain complementarity-determining regions (L-CDR1, L-CDR2, L-CDR3) contain the amino acid sequences shown in SEQ ID NO:8, SEQ ID NO:9, and SEQ ID NO:10, respectively. Preferably, Ab comprises a heavy chain variable region and a light chain variable region, and the heavy chain variable region comprises an amino acid sequence shown in SEQ ID NO:1 or an amino acid sequence having at least 75% identity with the amino acid sequence; and / or, the light chain variable region comprises an amino acid sequence shown in SEQ ID NO:7 or an amino acid sequence having at least 75% identity with the amino acid sequence.

9. The pharmaceutical combination according to any one of claims 1 to 8, characterized in that, The Ab is a monoclonal antibody or a single-chain antibody or any antigen-binding fragment that binds to B7-H3, such as a single-chain variable fragment (scFv), a bivalent single-chain variable fragment (BsFv), a disulfide-stabilized variable fragment (dsFv), (dsFv)2, an antigen-binding fragment (Fab), Fab' fragment (Fab'), (Fab' fragment)2 (F(ab')2), or a variable fragment (Fv); Preferably, the Ab further comprises constant regions, preferably heavy chain constant regions (CH) and / or light chain constant regions (CL) of humans or mice; More preferably, the Ab further comprises a heavy chain constant region selected from IgG, IgA, IgM, IgD or IgE and / or a kappa(κ) or lambda(λ) type light chain constant region.

10. The pharmaceutical combination according to any one of claims 1 to 9, characterized in that, The Ab is a monoclonal antibody, preferably a murine, chimeric, or humanized monoclonal antibody; preferably, the heavy chain constant region of the monoclonal antibody is IgG1 or IgG4 subtype, and the light chain constant region is κ type; or, The Ab is an immunoglobulin of IgA, IgD, IgE, IgG or IgM, such as the human subtype of IgA, IgD, IgE, IgG or IgM, more preferably the human IgG1, IgG2, IgG3 or IgG4 subtype.

11. The pharmaceutical combination according to any one of claims 1 to 10, characterized in that, The Ab contains a heavy chain constant region, which contains the amino acid sequence shown in SEQ ID NO:5 or an amino acid sequence having at least 75% identity with the amino acid sequence; or, the Ab contains a light chain constant region, which contains the amino acid sequence shown in SEQ ID NO:11 or an amino acid sequence having at least 75% identity with the amino acid sequence. Preferably, the Ab is a humanized monoclonal antibody, the heavy chain of which comprises the amino acid sequence shown in SEQ ID NO:6 or an amino acid sequence having at least 75% identity with the amino acid sequence, and the light chain comprises the amino acid sequence shown in SEQ ID NO:12 or an amino acid sequence having at least 75% identity with the amino acid sequence.

12. The pharmaceutical combination according to any one of claims 1 to 11, characterized in that, The PARP-1 inhibitor is selected from one or more of the following: Olaparib, Rucaparib, Niraparib, Talazoparib, Fluzoparib, Pamiparib, AZD5305 (Saruparib), or pharmaceutically acceptable salts thereof; Preferably, the PARP-1 inhibitor is olaparib and / or AZD5305 (Saruparib) or a pharmaceutically acceptable salt thereof.

13. Use of the pharmaceutical combination as defined in any one of claims 1 to 12 in the preparation of a medicament for treating tumors; Preferably, the tumor is B7-H3 overexpressing or positive, such as a solid tumor that is B7-H3 overexpressing or positive; and / or The tumors mentioned are gastric cancer, colorectal cancer, liver cancer, pancreatic cancer, esophageal cancer, non-small cell carcinoma, prostate cancer, ovarian cancer, breast cancer, small cell lung cancer, neuroblastoma, rhabdomyosarcoma, osteosarcoma, Ewing sarcoma, nephroblastoma, and desmoplastic small round cell tumor.

14. A method for treating a tumor, the method comprising administering to a subject in need of the combination of drugs as defined in any one of claims 1 to 12; Preferably, the tumor is B7-H3 overexpressing or positive, such as a solid tumor that is B7-H3 overexpressing or positive; and / or The tumors mentioned are gastric cancer, colorectal cancer, liver cancer, pancreatic cancer, esophageal cancer, non-small cell carcinoma, prostate cancer, ovarian cancer, breast cancer, small cell lung cancer, neuroblastoma, rhabdomyosarcoma, osteosarcoma, Ewing sarcoma, nephroblastoma, and desmoplastic small round cell tumor. Preferably, the subject is a mammal, preferably a primate or rodent, and more preferably a human.

15. A pillbox for treating tumors, the pillbox comprising a combination of drugs as defined in any one of claims 1 to 12; Preferably, the kit further includes containers for containing an antibody-drug conjugate targeting B7-H3 or its salt, and a PARP-1 inhibitor.

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