WO2025167929A1 - Combined use of antibody-drug conjugate and androgen receptor antagonist - Google Patents

Abstract

The present invention relates to use of an antibody-drug conjugate alone or in combination in preparing a drug for preventing and/or treating cancers. Specifically, provided in the present invention is use of an antibody-drug conjugate or a pharmaceutically acceptable salt thereof, a metabolite thereof, or a solvate thereof alone or in combination with an androgen receptor antagonist in preparing a drug for preventing and/or treating cancers.

Description

Combination therapy of antibody-drug conjugates and androgen receptor antagonists Technical Field

This application belongs to the field of medicine and relates to the use of an antibody-drug conjugate, alone or in combination, in the preparation of a drug for the prevention and/or treatment of cancer. Specifically, the present invention provides the use of an antibody-drug conjugate, or a pharmaceutically acceptable salt, metabolite, or solvate thereof, alone or in combination with an androgen receptor antagonist, in the preparation of a drug for the prevention and/or treatment of cancer.

Background Art

Prostate cancer is one of the most common malignant tumors of the male genitourinary system. In 2020, there were 1.414 million new cases of prostate cancer and 375,000 deaths worldwide, ranking second in the incidence of male cancer and fifth in cancer mortality. According to the Chinese Cancer Epidemiology Data published in 2022, there were 125,000 new cases of prostate cancer in my country, with an incidence rate of approximately 10.2 per 100,000, approximately 56,000 deaths, and a mortality rate of approximately 4.36 per 100,000. The incidence and mortality rates are showing a clear upward trend. The etiology and pathogenesis of prostate adenocarcinoma are very complex and are closely related to genetics, age, and exogenous factors (such as environmental factors and dietary habits). Currently, treatments for prostate cancer include active surveillance, surgery, chemotherapy, endocrine therapy, immunotherapy, and palliative care. Early-stage prostate cancer has the opportunity to be cured through surgical resection of the prostate, but most patients are in the late stage at the time of initial diagnosis. Patients with advanced, unresectable prostate cancer primarily receive endocrine therapy, specifically androgen deprivation therapy (ADT) in combination with novel endocrine therapy (NHT) or chemotherapy. Although the vast majority of patients respond initially to treatment, almost all progress to metastatic castration-resistant prostate cancer (mCRPC) after an average of 18 to 24 months. Currently, mCRPC is a rare disease with a poor prognosis. Standard first-line treatments include androgen receptor signaling inhibitors (ARSIs) and docetaxel-based chemotherapy.

B7-H3, a member of the B7 family of immune checkpoint proteins, is highly expressed in cancer cells. It negatively regulates immune cells, helping them evade immune surveillance. B7-H3 is also involved in tumor proliferation, metastasis, and drug resistance, and its expression is associated with poor patient prognosis. In mCRPC, B7-H3 expression is as high as 93%. The Phase 1/2 clinical trial of DS7300-A-J101 demonstrated that DS7300 (B7-H3 antibody-drug conjugate) demonstrated promising efficacy in mCRPC patients, with an ORR of 25.4%, a mPFS of 5.3 months (range, 4.1-6.9), and a mOS of 13.0 months (range, 14.5-18.6), all with a favorable safety profile.

There is still a need to develop more novel cancer treatments, and there is a need to develop therapies that are more effective than existing therapies. The combination therapy of the present invention utilizes an antibody-drug conjugate targeting B7-H3 in combination with the androgen receptor (AR) inhibitor enzalutamide. This combination can synergistically inhibit the AR signaling axis while simultaneously activating the conjugated toxin to kill tumor cells. This combination demonstrates greater efficacy and a favorable safety profile than either drug alone.

Summary of the Invention

The present disclosure provides a use of an antibody drug conjugate and an androgen receptor antagonist in combination in the preparation of a drug for treating cancer. The structure of the antibody drug conjugate is shown in formula (I):

wherein n is a non-zero integer or decimal from 1 to 10, preferably a decimal or integer from 1 to 8, preferably a decimal or integer from 2 to 8, more preferably from 3 to 8, and can be an integer or a decimal, more preferably 4.1.

Pc is an anti-B7H3 antibody or an antigen-binding fragment thereof.

In some embodiments, the anti-B7H3 antibody or its antigen-binding fragment comprises: heavy chain HCDR1, HCDR2, HCDR3 as shown in SEQ ID NO: 01, 02 and 03 amino acid sequences, respectively, and light chain LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 04, 05 and 06 amino acid sequences, respectively.

In the present invention, the amino acid sequences of the CDRs listed above are all shown according to the Kabat definition rules. However, it is well known in the art that antibody CDRs can be defined by various methods in the art. Although the scope of protection claimed in the present invention is based on the sequences shown in the Kabat definition rules, amino acid sequences corresponding to other CDR definition rules should also fall within the scope of protection of the present invention.

Among them, the CDR sequences mentioned above are shown in the following table:

Table 1 Heavy chain and light chain CDR sequences

Note: CDR sequences are derived from those shown in the Kabat definition.

Preferably, the anti-B7H3 antibody or antigen-binding fragment thereof is selected from a humanized antibody or a fragment thereof.

In some alternative embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof described herein is an antibody fragment selected from the group consisting of Fab, Fab'-SH, Fv, scFv, and (Fab') ₂ fragments.

In some optional embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof described herein comprises a heavy chain constant region of human IgG1, IgG2, IgG3 or IgG4 isotype, preferably a heavy chain constant region of IgG1 or IgG4 isotype.

In other alternative embodiments, the anti-B7H3 antibody or antigen-binding fragment thereof comprises a light chain constant region of kappa or lambda.

Furthermore, it is preferred that the heavy chain variable region sequence of the anti-B7H3 antibody or its antigen-binding fragment is the sequence shown in SEQ ID NO: 07 or a variant thereof, and the light chain variable region sequence is the sequence shown in SEQ ID NO: 08 or a variant thereof.

The sequences of the heavy and light chain variable regions of the aforementioned anti-B7H3 antibodies or antigen-binding fragments thereof are shown below:

Heavy chain variable region sequence

Light chain variable region sequence

Note: The order is FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4. The italics in the sequence are FR sequences, and the underlines are CDR sequences. The CDR sequences are derived from the Kabat definition rules.

Furthermore, it is preferred that the heavy chain sequence of the anti-B7H3 antibody or its antigen-binding fragment is the sequence shown in SEQ ID NO: 09 or a variant thereof, and the light chain sequence is the sequence shown in SEQ ID NO: 10 or a variant thereof.

The sequences of the heavy and light chains of the aforementioned anti-B7H3 antibodies or antigen-binding fragments thereof are shown below:

Heavy chain (IgG1) amino acid sequence: (SEQ ID NO: 09)

Light chain (λ) amino acid sequence: (SEQ ID NO: 10)

In some embodiments, the androgen receptor antagonist is Enzalutamide, Rezvilutamide, Proxalutamide, Darolutamide, Apalutamide, Bicalutamide, Flutamide, Nilutamide, Deuterated enzalutamide, Pyrilutamide, Dimethylcurcumin, APC-100, CB-03-01, TRC-253, INO-464, Liproca Depot, IONIS-AR-2.5Rx.

In an alternative embodiment, the antibody drug conjugate and the androgen receptor antagonist are contained in different preparations as active ingredients, and are administered simultaneously or at different times.

In another aspect, the antibody drug conjugate and the androgen receptor antagonist are contained in a single formulation as active ingredients and administered.

In an optional embodiment, the dose of the antibody drug conjugate is 1.0 mg/kg to 20.0 mg/kg, preferably 1.0 mg/kg to 12.0 mg/kg, more preferably 4.0 mg/kg to 12.0 mg/kg, more preferably 1.0 mg/kg, 1.2 mg/kg, 1.4 mg/kg, 1.6 mg/kg, 1.8 mg/kg, 2.0 mg/kg, 2.2 mg/kg, 2.4 mg/kg, 2.6 mg/kg, 2.8 mg/kg, 3.0 mg/kg, 3.2 mg/kg, 3.4 mg/kg, 3.6 mg/kg, 3.8 mg/kg, 4.0 mg/kg, 4.2 mg/kg, 4.4 mg/kg, 4.6 mg/kg, 4.8 mg/kg, 5.0 mg/kg, 5.2 mg/kg, 5.4 mg/kg, 5.6 mg/kg kg, 5.8mg/kg, 6.0mg/kg, 6.2mg/kg, 6.4mg/kg, 6.6mg/kg, 6.8mg/kg, 7.0mg/kg, 7.2mg/kg, 7.4mg/kg, 7.6mg/kg, 7.8mg/kg, 8.0mg/kg, 8.2mg/kg, 8.4mg/kg, 8.6mg/kg, 8.8mg/kg, 9.0m g/kg, 9.2mg/kg, 9.4mg/kg, 9.6mg/kg, 9.8mg/kg, 10.0mg/kg, 10.2mg/kg, 10.4mg/kg, 10.6 mg/kg, 10.8mg/kg, 11.0mg/kg, 11.2mg/kg, 11.4mg/kg, 11.6mg/kg, 11.8mg/kg or 12.0mg/kg.

In alternative embodiments, the antibody drug conjugate is administered once a week, once every two weeks, once every three weeks, or once every four weeks.

In a preferred embodiment, the antibody drug conjugate is administered at a starting dose of 6.0 mg/kg or 8.0 mg/kg, with a dosing frequency of once every three weeks.

In an alternative embodiment, the dosage of the androgen receptor antagonist is 1 mg to 1000 mg, with exemplary dosages selected from 1 mg, 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg, 17.5 mg, 20 mg, 22.5 mg, 25 mg, 27.5 mg, 30 mg, 32.5 mg, 35 mg, 37.5 mg, 40 mg, 42.5 mg, 45 mg, 47.5 mg, 50 mg, 52.5 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 10 0mg, 105mg, 110mg, 120mg, 130mg, 140mg, 150mg, 160mg, 170mg, 180mg, 190mg, 200mg, 210mg, 220mg, 230mg, 240mg, 250mg, 260mg, 2 70mg, 280mg, 290mg, 300mg, 350mg, 400mg, 450mg, 500mg, 550mg, 600mg, 650mg, 700mg, 750mg, 800mg, 850mg, 900mg, 950mg, 1000mg.

In a further preferred embodiment, the dose of the androgen receptor antagonist is selected from 20 mg to 500 mg, further preferably 50 mg to 300 mg, more preferably 100 mg to 300 mg, and further preferably 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg, 200 mg, 210 mg, 220 mg, 230 mg, 240 mg, 250 mg, 260 mg, 270 mg, 280 mg, 290 mg, and 300 mg.

In alternative embodiments, the androgen receptor antagonist is administered once every three days, once every two days, once a day, twice a day, or three times a day.

In a preferred embodiment, the dosage of the androgen receptor antagonist is 160 mg, and the administration frequency is once a day.

In an optional embodiment, the cancer is selected from at least one of the following: prostate cancer, lung cancer, stomach cancer, liver cancer, kidney cancer, breast cancer, pancreatic cancer, ovarian cancer, bladder cancer, esophageal cancer, salivary gland cancer, head and neck cancer, skin cancer, pharyngeal cancer, laryngeal cancer, gallbladder cancer, bile duct cancer, thyroid cancer, uterine cancer, vulvar cancer, penile cancer, testicular cancer, urothelial cancer, urethral cancer, colon cancer, rectal cancer, colorectal cancer, esophageal gastric junction cancer, gastrointestinal stromal tumor, squamous cell carcinoma, peritoneal cancer, leukemia, malignant lymphoma, plasmacytoma, myeloma, neuroepithelial tissue tumor, nerve sheath tumor, mesothelioma, Paget's disease and sarcoma.

Further, the prostate cancer is selected from castration-resistant prostate cancer, metastatic prostate cancer, hormone-sensitive prostate cancer, metastatic hormone-sensitive prostate cancer or metastatic castration-resistant prostate cancer.

Furthermore, metastatic castration-resistant prostate cancer is metastatic castration-resistant prostate cancer that has failed or is intolerant to at least one line of treatment or metastatic castration-resistant prostate cancer that has not received treatment at the metastatic stage.

The present disclosure also provides a pharmaceutical composition comprising the above-mentioned antibody-drug conjugate and an androgen receptor antagonist, and one or more pharmaceutically acceptable carriers, excipients, and diluents.

The present disclosure also provides a method for treating cancer, comprising administering the above-mentioned antibody drug conjugate and an androgen receptor antagonist in combination to a subject in need thereof.

In an optional embodiment, the cancer is selected from at least one of the following: prostate cancer, lung cancer, stomach cancer, liver cancer, kidney cancer, breast cancer, pancreatic cancer, ovarian cancer, bladder cancer, esophageal cancer, salivary gland cancer, head and neck cancer, skin cancer, pharyngeal cancer, laryngeal cancer, gallbladder cancer, bile duct cancer, thyroid cancer, uterine cancer, vulvar cancer, penile cancer, testicular cancer, urothelial cancer, urethral cancer, colon cancer, rectal cancer, colorectal cancer, esophageal gastric junction cancer, gastrointestinal stromal tumor, squamous cell carcinoma, peritoneal cancer, leukemia, malignant lymphoma, plasmacytoma, myeloma, neuroepithelial tissue tumor, nerve sheath tumor, mesothelioma, Paget's disease and sarcoma.

In an optional embodiment, the above-mentioned prostate cancer is selected from castration-resistant prostate cancer, metastatic prostate cancer, hormone-sensitive prostate cancer, metastatic hormone-sensitive prostate cancer or metastatic castration-resistant prostate cancer.

In an optional embodiment, the above-mentioned metastatic castration-resistant prostate cancer is selected from metastatic castration-resistant prostate cancer that has failed or is intolerant to at least one line of treatment or metastatic castration-resistant prostate cancer that has not received treatment at the metastatic stage.

Another aspect of the present disclosure provides the aforementioned anti-B7H3 antibody-drug conjugate for use in treating cancer, wherein the anti-B7H3 antibody-drug conjugate is used in combination with the aforementioned androgen receptor antagonist.

Another aspect of the present disclosure provides the aforementioned androgen receptor antagonist for use in treating cancer, wherein the androgen receptor antagonist is used in combination with an anti-B7H3 antibody drug conjugate.

In this disclosure, the term "combination" refers to a mode of administration that includes the sequential or simultaneous administration of two or more drugs. Simultaneous administration, independently formulated and co-administered, and independently formulated and sequentially administered administration all fall within the scope of combined administration described in this disclosure.

"Concurrently" refers to administering at least one dose of an androgen receptor antagonist and an anti-B7H3 antibody-drug conjugate within a specific timeframe. The specific timeframe can include administering two or more drugs within 3 days, 2 days, 1 day, 12 hours, 6 hours, 1 hour, or 30 minutes, where both drugs exhibit a pharmacological effect.

"Sequential" administration includes the administration of an androgen receptor antagonist and an anti-B7H3 antibody-drug conjugate within different dosing cycles. The time period can be within a single dosing cycle, optionally within 4 weeks, 3 weeks, 2 weeks, or 1 week. This time period includes treatments in which the androgen receptor antagonist and the anti-B7H3 antibody-drug conjugate are administered via the same or different routes of administration.

the term

In order to make the present disclosure more easily understood, certain technical and scientific terms are specifically defined below. Unless otherwise explicitly defined herein, all other technical and scientific terms used herein have the meanings commonly understood by those skilled in the art to which the present disclosure belongs.

The present disclosure incorporates all the contents of application WO2020063673 into the present application.

The term "antibody drug conjugate" refers to an antibody linked to a biologically active drug via a stable linker. In the present disclosure, "antibody drug conjugate" refers to a monoclonal antibody or antibody fragment linked to a biologically active toxic drug via a stable linker.

The term "antibody" refers to immunoglobulins, which are tetrapeptide chains composed of two identical heavy chains and two identical light chains connected by interchain disulfide bonds. The amino acid composition and order of the constant region of immunoglobulins' heavy chains vary, resulting in different antigenicity. Consequently, immunoglobulins can be divided into five classes, or isotypes, namely IgM, IgD, IgG, IgA, and IgE, with their corresponding heavy chains being μ, δ, γ, α, and ε, respectively. Within the same class, Igs are further divided into subclasses based on the amino acid composition of their hinge regions and the number and location of heavy chain disulfide bonds. For example, IgG can be divided into IgG1, IgG2, IgG3, and IgG4. Light chains are classified as either kappa or lambda chains based on differences in their constant regions. Each of the five Ig classes can have either kappa or lambda chains.

The approximately 110 amino acids near the N-terminus of an antibody's heavy and light chains vary greatly in sequence, forming the variable region (Fv region); the remaining amino acid sequences near the C-terminus are relatively stable, forming the constant region. The variable region comprises three hypervariable regions (HVRs) and four framework regions (FRs), whose sequences are relatively conserved. These three hypervariable regions determine the antibody's specificity and are also known as complementarity-determining regions (CDRs). Each light chain variable region (LCVR) and heavy chain variable region (HCVR) consists of three CDR regions and four FR regions, arranged in the following order from amino to carboxyl terminus: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The three CDR regions of the light chain are LCDR1, LCDR2, and LCDR3; the three CDR regions of the heavy chain are HCDR1, HCDR2, and HCDR3.

In the present disclosure, the amino acid sequences of the above CDRs are shown in accordance with the Kabat definition rules. However, it is well known to those skilled in the art that the CDRs of antibodies can be defined in the art by a variety of methods, such as Chothia based on the three-dimensional structure of the antibody and the topology of the CDR loop (Chothia et al. (1989) Nature 342:877-883, Al-Lazikani et al., "Standard conformations for the canonical structures of immunoglobulins", Journal of Molecular Biology, 273, 927-948 (1997)), Kabat based on the variability of antibody sequences (Kabat et al., Sequences of Proteins of Immunological Interest, 4th edition, U.S. Department of Health and Human Services, National Institutes of Health (1987)), AbM (University of Bath), Contact (University College London), the International ImMunoGeneTics database (IMGT) (world wide web imgt.cines.fr/), and the North CDR definition based on affinity propagation clustering using a large number of crystal structures. It will be understood by those skilled in the art that, unless otherwise specified, the terms "CDR" and "complementarity determining region" of a given antibody or region thereof (e.g., variable region) should be understood to cover the complementarity determining region defined by any of the above-mentioned known schemes described by the present invention. Although the scope of protection claimed in the present invention is based on the sequences shown in the Kabat definition rules, amino acid sequences corresponding to the definition rules of other CDRs should also fall within the scope of protection of the present invention.

The term "antigen-binding fragment" refers to one or more fragments of an antibody that retain the ability to specifically bind to an antigen. It has been shown that fragments of a full-length antibody can be used to perform the antigen-binding function of an antibody. Examples of binding fragments included in "antigen-binding fragments" include (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL, and CH1 domains; (ii) a F(ab') ₂ fragment, a bivalent fragment comprising two Fab fragments connected by a disulfide bridge on the hinge region; (iii) a Fd fragment consisting of the VH and CH1 domains; (iv) a Fv fragment consisting of the VH and VL domains of a single arm of an antibody; (v) a single domain or dAb fragment (Ward et al., (1989) Nature 341: 544-546), which consists of a VH domain; and (vi) an isolated complementarity determining region (CDR) or (vii) a combination of two or more isolated CDRs, optionally connected by a synthetic linker.

The term "drug loading" refers to the average number of cytotoxic drugs loaded per ligand in a molecule of Formula (I), and can also be expressed as the ratio of the amount of drug to the amount of antibody. The drug loading can range from 0 to 12, preferably 1 to 10, cytotoxic drugs (D) attached per antibody (Pc). In the embodiments of the present disclosure, the drug loading is expressed as n, also known as the DAR value, and exemplary values are 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. The average number of drug products per ADC molecule after the conjugation reaction can be determined by conventional methods such as UV/visible spectroscopy, mass spectrometry, ELISA assays, and HPLC characterization.

The term "pharmaceutical composition" is a product comprising one or more active ingredients (e.g., antibodies, ADCs) in optionally specified amounts, as well as any product produced directly or indirectly by combining one or more active ingredients in optionally specified amounts. The different active ingredients in the pharmaceutical composition can be administered independently in separate formulations, including administration simultaneously or at different time points for combined synergistic effect. In the present disclosure, "pharmaceutical composition" and "formulation" are not mutually exclusive.

The term "treating" means administering an internal or external therapeutic agent, such as a composition comprising any of the binding compounds of the present disclosure, to a patient who has one or more symptoms of a disease for which the therapeutic agent is known to have a therapeutic effect. Typically, the therapeutic agent is administered in an amount effective to alleviate one or more symptoms of the disease in the treated patient or population to induce regression of such symptoms or inhibit the development of such symptoms to any clinically measurable degree. The amount of a therapeutic agent effective to alleviate any specific disease symptom (also referred to as a "therapeutically effective amount") can vary according to a variety of factors, such as the patient's disease state, age, and weight, and the ability of the drug to produce the desired therapeutic effect in the patient. Whether the symptoms of the disease have been alleviated can be assessed by any clinical test method commonly used by a physician or other health care professional to assess the severity or progression of the symptoms. Although embodiments of the present disclosure (e.g., methods of treatment or articles of manufacture) may not be effective in alleviating every symptom of the target disease, they should alleviate the target disease symptoms in a statistically significant number of patients as determined by any statistical test known in the art, such as the Student's t-test, chi-square test, U test according to Mann and Whitney, Kruskal-Wallis test (H test), Jonckheere-Terpstra test, and Wilcoxon test.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1. Efficacy of drug A combined with drug B on LNCaP clone FGC human prostate cancer xenografts

Figure 2 Effects of drug A combined with drug B on body weight of LNCaP clone FGC tumor-bearing mice

DETAILED DESCRIPTION

The present application will be explained in more detail below with reference to the embodiments. The embodiments of the present application are only used to illustrate the technical solutions of the present application and are not intended to limit the essence and scope of the present application.

Example 1. Preparation of anti-B7H3 antibody drug conjugates

According to the production method described in WO2020063673, h1702DS (anti-B7H3 antibody) and an isotecan analog were used to prepare the anti-B7H3 antibody-drug conjugate shown in the following structure. The average value calculated by the HIC method was n = 4.1, i.e., FADC-2. The h1702DS heavy chain sequence is shown in SEQ ID NO: 09, and the light chain sequence is shown in SEQ ID NO: 10.

Example 2. In vivo inhibitory effect of an anti-B7H3 antibody-drug conjugate combined with an androgen receptor antagonist on LNCaP clone FGC human prostate cancer cell transplants in mice

1. Experimental Materials

Human prostate cancer LNCaP clone FGC cells were cultured as monolayers in RPMI 1640 medium supplemented with 10% fetal bovine serum, 100 U/mL penicillin, and 100 μg/mL streptomycin in a 37°C, 5% CO2 incubator. Twice weekly, cells were routinely digested with trypsin-EDTA and passaged. Cells were harvested and counted when cell saturation reached 80%-90% and the desired number was reached.

NOD SCID mice, male, weighing 20-24 g, were purchased from Zhejiang Weitonglihua Experimental Animal Technology Co., Ltd.

Drug A: Prepared using the method described in WO2020063673, the drug was diluted with normal saline;

Drug B: Enzalutamide was prepared using the method described in WO2006124118, CAS: 915087-33-1, with the following structural formula. The drug was prepared using 10% DMSO + 30% PEG400 + 60% (20% HP-β-CD);

2. Experimental Methods

LNCaP clone FGC cells were resuspended in PBS at a density of 1× ^10⁻¹ cells/mL. The resuspended cells were mixed with an equal volume of Matrigel and inoculated subcutaneously on the right side of the back of each mouse, with 0.2 mL (1× ^10⁷ cells/animal) inoculated. Groups were assigned when the average tumor volume reached 100-150 ^mm³ (Day 0). Dosing began on the same day of grouping. Drug A was administered via tail vein injection (iv) as a single dose; drug B was administered via oral gavage (po) once daily; the dosing volume for both groups was 10 mL/kg. The solvent group received the same volume of "solvent." Specific dosing schedules are shown in Table 1. Tumor volume was measured, mice were weighed, and data were recorded.

The experimental indicators are to examine the effect of drugs on tumor growth, and the specific indicators are ΔT/ΔC (%) or tumor inhibition rate TGI (%).

Tumor diameter was measured with a vernier caliper twice a week, and tumor volume (V) was calculated as follows:

V = 1/2 × a × b ² where a and b represent length and width respectively.

ΔT/ΔC (%)=(TT ₀ )/(CC ₀ )′100, wherein T and C are the tumor volumes at the end point of the experiment, and T ₀ and C ₀ are the tumor volumes at the beginning of the experiment.
TGI (%) = 100 - ΔT/ΔC (%)

When tumor regression occurs, TGI (%) = 100-(TT ₀ )/T ₀ '100

If the tumor is smaller than its initial volume, that is, T<T ₀ or C<C ₀ , it is defined as partial tumor regression (PR); if the tumor disappears completely, it is defined as complete tumor regression (CR).

At the end of the experiment, when the experimental endpoint was reached, or when the average tumor volume reached 2,000 mm ³ , the animals were sacrificed under CO ₂ anesthesia, and the tumors were subsequently dissected and photographed.

Experimental data were analyzed and graphed using GraphPad Prism 9.0.0. Two-way ANOVA was used to analyze tumor volume data at different time points within each group and assess intergroup differences. A p value of < 0.05 was considered statistically significant.

Table 1 Dosing regimen of drug A combined with drug B in the LNCaP clone FGC model

3. Experimental Results

The growth inhibitory effects of drug A combined with drug B on the LNCaP clone FGC model are shown in Table 2 and Figure 1. The body weight changes of animals in each group in the LNCaP clone FGC model are shown in Figure 2.

Table 2. Growth inhibitory effects of drug A combined with drug B on the LNCaP clone FGC model

Note:

p-value: Values obtained by Dunnett analysis using two-way ANOVA based on tumor volume in each group, with the vehicle group as the control. Additionally, Fisher's LSD method was used for analysis using two-way ANOVA. #: p-value 0.0252 for the comparison between the drug A plus drug B group and the drug A alone group; &: p-value < 0.0001 for the comparison between the drug A plus drug B group and the drug B alone group.

At the end of the experiment (Day 20), the mean tumor volumes in the Drug A, Drug B, and Drug A combined with Drug B groups were 423 mm ³ , 649 mm ³ , and 272 mm ³ , respectively, with tumor inhibition rates of 78.76%, 60.65%, and 90.90%, respectively, all significantly different from the vehicle group (p < 0.05). The Drug A combined with Drug B group demonstrated a significantly higher tumor inhibition rate compared to both the Drug A alone and Drug B alone groups (p < 0.05). Throughout the experiment, the body weights of the tumor-bearing mice in the drug-treated groups fluctuated slightly, and the combined dose was well tolerated.

4. Experimental Conclusion

In the LNCaP clone FGC human prostate cancer transplant mouse model, drug A combined with drug B showed stronger and significantly different anti-tumor effects compared with drug A alone and drug B alone, and did not show obvious toxic side effects.

Example 3. Clinical trial of anti-B7H3 antibody drug conjugate combined with androgen receptor antagonist for the treatment of prostate cancer

This study is used to evaluate the safety, tolerability, and efficacy of the combination therapy of an anti-B7H3 antibody-drug conjugate and an androgen receptor antagonist in patients with prostate cancer. The study endpoints include but are not limited to: the MTD or maximum applicable dose (MAD) of the anti-B7H3 antibody-drug conjugate administered by intravenous infusion in the combination therapy, ORR, DCR, DoR and radiographic progression-free survival (rPFS) assessed by the investigator according to RECIST 1.1 (for evaluation of soft tissue lesions) and PCWG3 (for evaluation of bone lesions) criteria, time to PSA progression (TTPP) and PSA50 response rate, time to first subsequent treatment (TFST), OS, pharmacokinetic characteristics of the anti-B7H3 antibody-drug conjugate administered by intravenous infusion in the combination therapy, and immunogenicity of the anti-B7H3 antibody-drug conjugate in the combination therapy.

1. Name of investigational drug:

(1) Anti-B7H3 Antibody Drug Conjugates

Dosage form: Injection (lyophilized powder), Specification: 100 mg/bottle, packaged in 20 mL borosilicate glass tube injection bottle, Manufacturer: Shanghai Hansoh Biopharmaceutical Technology Co., Ltd.

(2) Androgen receptor antagonist enzalutamide

Dosage form: soft capsule, specification: 40mg, aluminum-plastic packaging, outer composite film bag, manufacturer: Jiangsu Hausen Pharmaceutical Group Co., Ltd.

2. Target group:

Dose escalation population: Metastatic castration-resistant prostate cancer that has failed or is intolerant to at least one line of treatment. It is required that the disease progresses after receiving at most one previously approved new endocrine therapy (NHA, such as abiraterone, enzalutamide or apalutamide, etc.) in the mCRPC stage; if the subject is intolerant to NHA, refuses, or is unable to receive the treatment for other reasons, the disease progresses after receiving at most one systemic chemotherapy. First-generation anti-androgen therapy (such as bicalutamide, flutamide, nilutamide) is not considered as a new endocrine therapy or a chemotherapy regimen. Subjects taking first-generation anti-androgen therapy drugs must wash out for at least 28 days before enrollment;

Expanded population: Advanced, previously untreated, metastatic castration-resistant prostate cancer. The requirement for metastatic disease is radiographically documented metastatic lesions, excluding subjects with only pelvic lymph node metastasis or local recurrence (bladder or rectum). Subjects who have previously received first-generation anti-androgen therapy (e.g., bicalutamide, flutamide, nilutamide) are eligible for enrollment, provided they have undergone a washout period of at least 28 days prior to enrollment.

3. Dosage regimen:

Recommended dosing priority: Administer enzalutamide orally first, followed by administration of anti-B7H3 antibody-drug conjugate therapy at least 30 minutes after the completion of enzalutamide administration.

Enzalutamide, 160 mg, orally (regardless of feeding status), once daily (QD), continued until objective disease progression (excluding donations) or other protocol-specified criteria for discontinuation of study treatment are met. If the subject fails to take the medication on time, they should make up the missed dose as soon as possible; if they miss a full day, they should continue taking the medication at their usual daily dose the next day. If the subject vomits after taking the medication, they will not receive a supplemental dose and should take the next scheduled dose at the next scheduled time. Anti-B7H3 antibody-drug conjugates are administered at a pre-set dose of 8.0 mg/kg by intravenous infusion, Q3W, until objective disease progression (excluding donations) or other protocol-specified criteria for discontinuation of study treatment are met.

Claims (19)

The use of an antibody drug conjugate and an androgen receptor antagonist in combination in the preparation of a drug for treating cancer, wherein the structure of the antibody drug conjugate is shown in formula (I): in: n is 1 to 10, preferably 2 to 8, more preferably 3 to 8, and n is a decimal or an integer; Pc is an anti-B7H3 antibody or an antigen-binding fragment thereof. The use according to claim 1, wherein the anti-B7H3 antibody or its antigen-binding fragment comprises: heavy chain HCDR1, HCDR2, HCDR3 as shown in SEQ ID NO: 01, 02 and 03 amino acid sequences, respectively, and light chain LCDR1, LCDR2 and LCDR3 as shown in SEQ ID NO: 04, 05 and 06 amino acid sequences, respectively. The use according to claim 1 or 2, wherein the anti-B7H3 antibody or antigen-binding fragment thereof is selected from a humanized antibody or a fragment thereof. The use according to claim 3, wherein the anti-B7H3 antibody or antigen-binding fragment thereof comprises a heavy chain constant region of human IgG1, IgG2, IgG3 or IgG4 isotype, and a light chain constant region comprising κ or λ; preferably, the anti-B7H3 antibody or antigen-binding fragment thereof comprises a heavy chain constant region of IgG1 or IgG4 isotype. The use according to claim 3, wherein the heavy chain variable region sequence of the anti-B7H3 antibody or its antigen-binding fragment is such as the sequence shown in SEQ ID NO: 07 or its variant, and the light chain variable region sequence is such as the sequence shown in SEQ ID NO: 08 or its variant. The use according to any one of claims 1 to 5, wherein the heavy chain sequence of the anti-B7H3 antibody or its antigen-binding fragment is such as the sequence shown in SEQ ID NO: 09 or a variant thereof, and the light chain sequence is such as the sequence shown in SEQ ID NO: 10 or a variant thereof. [Corrected 16.04.2025 in accordance with Article 91]
The use according to any one of claims 1 to 6, wherein the androgen receptor antagonist is enzalutamide, rezvilutamide, proxalutamide, darolutamide, apalutamide, bicalutamide, flutamide, nilutamide, deuterated enzalutamide, pyrilutamide, dimethylcurcumin, APC-100, CB-03-01, TRC-253, INO-464, Liproca Depot, IONIS-AR-2.5Rx; preferably enzalutamide. [Corrected 16.04.2025 in accordance with Article 91]
The use according to any one of claims 1 to 7, wherein the antibody drug conjugate and the androgen receptor antagonist are respectively contained in different preparations as active ingredients and are administered simultaneously or at different times. [Corrected 16.04.2025 in accordance with Article 91]
The use according to any one of claims 1 to 7, wherein the antibody drug conjugate and the androgen receptor antagonist are contained in a single preparation as active ingredients and administered. [Corrected 16.04.2025 in accordance with Article 91]
The use according to any one of claims 1 to 9, wherein the dose of the antibody drug conjugate is 1.0 mg/kg to 20.0 mg/kg, preferably 1.0 mg/kg to 12.0 mg/kg, and the administration frequency is once a week, once every two weeks, once every three weeks or once every four weeks. [Corrected 16.04.2025 in accordance with Article 91]
The use according to any one of claims 1 to 9, wherein the dose of the androgen receptor antagonist is 1 mg to 1000 mg, preferably 20 mg to 500 mg, further preferably 50 mg to 300 mg, more preferably 100 mg to 300 mg; the administration frequency is once every three days, once every two days, once a day, twice a day or three times a day. [Corrected 16.04.2025 in accordance with Article 91]
The method according to any one of claims 1 to 11, wherein the cancer is selected from at least one of the following: prostate cancer, lung cancer, stomach cancer, liver cancer, kidney cancer, breast cancer, pancreatic cancer, ovarian cancer, bladder cancer, esophageal cancer, salivary gland cancer, head and neck cancer, skin cancer, pharyngeal cancer, laryngeal cancer, gallbladder cancer, bile duct cancer, thyroid cancer, uterine cancer, vulvar cancer, penile cancer, testicular cancer, urothelial cancer, urethral cancer, colon cancer, rectal cancer, colorectal cancer, esophageal gastric junction cancer, gastrointestinal stromal tumor, squamous cell carcinoma, peritoneal cancer, leukemia, malignant lymphoma, plasmacytoma, myeloma, neuroepithelial tissue tumor, nerve sheath tumor, mesothelioma, Paget's disease and sarcoma. [Corrected 16.04.2025 in accordance with Article 91]
The use according to claim 12, wherein the prostate cancer is selected from castration-resistant prostate cancer, metastatic prostate cancer, hormone-sensitive prostate cancer, metastatic hormone-sensitive prostate cancer or metastatic castration-resistant prostate cancer. [Corrected 16.04.2025 in accordance with Article 91]
The use according to claim 13, wherein the metastatic castration-resistant prostate cancer is selected from metastatic castration-resistant prostate cancer that has failed or is intolerant to at least one line of treatment or metastatic castration-resistant prostate cancer that has not received treatment at the metastatic stage. [Corrected 16.04.2025 in accordance with Article 91]
A pharmaceutical composition comprising the antibody-drug conjugate according to any one of claims 1 to 14 and an androgen receptor antagonist, and one or more pharmaceutically acceptable carriers, excipients, and diluents. [Corrected 16.04.2025 in accordance with Article 91]
A method for treating cancer, comprising administering to a subject in need thereof an antibody drug conjugate according to any one of claims 1 to 14 and an androgen receptor antagonist in combination, wherein the combined administration can be simultaneous or at different time points. [Corrected 16.04.2025 in accordance with Article 91]
The method of claim 16, wherein the cancer is selected from at least one of the following: prostate cancer, lung cancer, stomach cancer, liver cancer, kidney cancer, breast cancer, pancreatic cancer, ovarian cancer, bladder cancer, esophageal cancer, salivary gland cancer, head and neck cancer, skin cancer, pharyngeal cancer, laryngeal cancer, gallbladder cancer, bile duct cancer, thyroid cancer, uterine cancer, vulvar cancer, penile cancer, testicular cancer, urothelial cancer, urethral cancer, colon cancer, rectal cancer, colorectal cancer, esophageal gastric junction cancer, gastrointestinal stromal tumor, squamous cell carcinoma, peritoneal cancer, leukemia, malignant lymphoma, plasmacytoma, myeloma, neuroepithelial tissue tumor, nerve sheath tumor, mesothelioma, Paget's disease and sarcoma. The method of claim 17, wherein the prostate cancer is selected from castration-resistant prostate cancer, metastatic prostate cancer, hormone-sensitive prostate cancer, metastatic hormone-sensitive prostate cancer or metastatic castration-resistant prostate cancer. The method according to claim 18, wherein the metastatic castration-resistant prostate cancer is selected from metastatic castration-resistant prostate cancer that has failed or is intolerant to at least one line of treatment or metastatic castration-resistant prostate cancer that has not received treatment at the metastatic stage.