Bisspecific antibody to EGFR / C-MET and its application

Claims

1. A bispecific antibody comprising an antigen-binding arm A that specifically binds to the human epidermal growth factor receptor (EGFR) and antagonizes the binding of epidermal growth factor (EGF) to EGFR, and an antigen-binding arm B that specifically binds to the hepatocyte growth factor receptor (c-Met) and antagonizes the binding of hepatocyte growth factor (HGF) to c-Met, wherein the binding arm A comprises a light chain A (LCA) and a heavy chain A (HCA), and the binding arm B comprises a light chain B (LCB) and a heavy chain B (HCB), wherein LCA, HCA, LCB and HCB comprise the amino acid sequences presented in SEQ ID NO: 1, 2, 3 and 4, respectively.

2. A bispecific antibody according to claim 1, having one or more of the following functions: (1) the ability to inhibit EGF ligand-mediated EGFR autophosphorylation and HGF ligand-mediated c-Met autophosphorylation; (2) the ability to inhibit the growth and proliferation of dual EGFR- and / or c-Met-positive human tumor cells, wherein the effect of said inhibition of proliferation of dual EGFR- and c-Met-positive tumor cells is stronger than that of a combination of a monoclonal antibody to EGFR and a monoclonal antibody to c-Met; (3) the ability to mediate antibody-dependent cytotoxicity (ADCC); (4) stimulation of internalization of the target protein, wherein the level of internalization mediated by the bispecific antibody is higher than the level of internalization mediated by the c-Met-specific binding arm B or the EGFR-specific binding arm A; (5) the ability to inhibit the proliferation of cell lines with acquired resistance to osimertinib.

3. A bispecific antibody according to claim 1 or 2, having a significantly higher affinity for c-Met than for EGFR.

4. The bispecific antibody of any one of claims 1 to 3, wherein the binding arm A comprises a variable light chain region A (VLA) and a variable heavy chain region A (VHA), and the binding arm B comprises a variable light chain region B (VLB) and a variable heavy chain region B (VHB), wherein the VHA and VLA of the binding arm A are derived from an IgG polypeptide A (IgG(A)) containing a homodimeric structure of VHA and VLA, and the VHB and VLB of the binding arm B are derived from an IgG polypeptide B (IgG(B)) containing a homodimeric structure of VHB and VLB;wherein VHA comprises VHA complementarity determining region 1 (CDR1), VHA CDR2 and VHA CDR3 of the amino acid sequences presented in SEQ ID NOs: 19, 20 and 21, respectively, VLA comprises VLA CDR1, VLA CDR2 and VLA CDR3 of the amino acid sequences presented in SEQ ID NOs: 22, 23 and 24, respectively, VHB comprises VHB CDR1, VHB CDR2 and VHB CDR3 of the amino acid sequences presented in SEQ ID NOs: 25, 26 and 27, respectively, and VLB comprises VLB CDR1, VLB CDR2 and VLB CDR3 of the amino acid sequences presented in SEQ ID NOs: 28, 29 and 30, respectively.

5. The bispecific antibody of claim 4, wherein VHA, VLA, VHB and VLB comprise the amino acid sequences shown in SEQ ID NO: 5, 6, 7 and 8, respectively.

6. The bispecific antibody of any one of claims 1 to 5, wherein the binding arm A further comprises a heavy chain constant region A (CHA) and a light chain constant region A (CLA), and the binding arm B further comprises a heavy chain constant region B (CHB) and a light chain constant region B (CLB), wherein both CHA and CHB are heavy chain constant regions of the IgG1 isotype.

7. The bispecific antibody of any one of claims 1 to 6, wherein CHA comprises an Fc(A) region, the Fc(A) region comprises a CH3(A) region; CHB comprises an Fc(B) region, the Fc(B) region comprises a CH3(B) region, the CH3(A) region and the CH3(B) region can form a heterodimer through an interaction, wherein the heterodimer interaction is stronger than each of the homodimer interactions of the CH3(A) region and the CH3(B) region, or optionally both of the CH3(A) antigen-binding arm A and the CH3(B) antigen-binding arm B contain amino acid mutations that enhance and facilitate the formation of a heterodimer; or optionally, CH3(A) comprises an amino acid mutation as shown in F405L and CH3(B) comprises an amino acid mutation as shown in K409R; or further optionally, both Fc(A) and Fc(B) comprise a combination of amino acid mutations that reduce immunogenicity.

8. The bispecific antibody of any one of claims 1 to 7, wherein Fc(A) comprises the amino acid sequence presented in SEQ ID NO: 9, and Fc(B) comprises the amino acid sequence presented in SEQ ID NO:

10.

9. The bispecific antibody of any one of claims 1 to 8, wherein CHA, CLA, CHB and CLB comprise the amino acid sequences shown in SEQ ID NO: 11, 12, 13 and 14, respectively.

10. A coding nucleic acid composition comprising the polynucleotide sequences presented in SEQ ID NO: 15, 16, 17 and 18, capable of respectively encoding HCA, HCB, LCA and LCB of the bispecific antibody according to claim 1.

11. A pharmaceutical composition comprising a bispecific antibody according to any one of claims 1-9 and a pharmaceutically acceptable carrier or diluent.

12. The pharmaceutical composition of claim 11, further comprising a second therapeutic agent or therapeutic regimen, wherein the second therapeutic agent or therapeutic regimen comprises chemotherapeutic drugs, DNA alkylating agents, immunomodulators, proteasome inhibitors, histone deacetylase inhibitors, radiation therapy, stem cell transplantation, variant bispecific antibodies that interact with various tumor cell surface antigens and T cell or immune cell antigens, antibody-drug conjugates, bispecific antibodies conjugated to an antitumor agent, PD-1, PD-L1 or CTLA-4 checkpoint inhibitors, or a combination thereof.

13. The bispecific antibody of any one of claims 1 to 9 or the pharmaceutical composition of claim 11 or claim 12 for use in the treatment of a disease or tumor comprising EGFR- and c-Met-abnormal cells, and / or inhibiting the growth or metastasis of tumor or cancer cells expressing EGFR and / or c-Met in a patient, and / or treating a disease resistant to osimertinib; wherein the EGFR- and c-Met-abnormal cells contain an activating EGFR mutation, EGFR gene amplification, increased HGF expression, an activating c-Met mutation, c-Met gene amplification, or a KRAS mutation.

14. A bispecific antibody or pharmaceutical composition for use according to claim 13, wherein the tumor or cancer is one of epithelial cell cancer, breast cancer, ovarian cancer, lung adenocarcinoma, small cell lung cancer, colorectal cancer, anal cancer, prostate cancer, bladder cancer, pharyngeal cancer, nasal cavity cancer, pancreatic cancer, skin cancer, tongue cancer, esophageal cancer, vaginal cancer, cervical cancer, spleen cancer, testicular cancer, gastric cancer, thymus cancer, thyroid cancer, hepatocellular carcinoma, or sporadic or hereditary papillary renal cell carcinoma; or optionally the cancer is one of non-small cell lung cancer, pancreatic cancer, gastric cancer, colon cancer, and liver cancer.

15. A method for treating a disease or tumor comprising EGFR- and c-Met-abnormal cells, and / or inhibiting the growth or metastasis of tumor or cancer cells expressing EGFR and / or c-Met in a patient, and / or treating a disease resistant to osimertinib; wherein the method comprises administering a bispecific antibody according to any one of claims 1 to 9 or a pharmaceutical composition comprising a bispecific antibody according to claim 11 or 12; wherein the EGFR- and c-Met-abnormal cells contain an activating mutation of EGFR, amplification of the EGFR gene, increased expression of HGF, an activating mutation of c-Met, amplification of the c-Met gene, or a KRAS mutation; and / or the tumor or cancer is one of epithelial cell cancer, breast cancer, ovarian cancer, lung adenocarcinoma, small cell lung cancer, colorectal cancer, anal cancer, prostate cancer, bladder cancer, pharyngeal cancer, nasal cavity cancer, pancreatic cancer, skin cancer, tongue cancer, esophageal cancer, vaginal cancer, cervical cancer, spleen cancer, testicular cancer, gastric cancer, thymus cancer, thyroid cancer, hepatocellular carcinoma, or sporadic or hereditary papillary renal cell carcinoma; or optionally, the cancer is one of non-small cell lung cancer, pancreatic cancer, gastric cancer, colon cancer, and liver cancer.