Immunoconjugates Comprising Anti-HER2 Antibodies and Pyrrolobenzodiazepines

Abstract

The invention provides immunoconjugates comprising anti-HER2 antibodies and methods of using the same.

1 . An immunoconjugate comprising an antibody and a cytotoxic agent, wherein the immunoconjugate has the formula Ab-(L-D)p, wherein:
 (a) Ab is the antibody;   (b) L is a linker;   (c) D is a cytotoxic agent; and   (d) p ranges from 1-8;   
       and wherein D is a pyrrolobenzodiazepine and L-D comprises the structure: 
       
         
           
           
               
               
           
         
       
       wherein:
 Y has the formula: 
 
       
         
           
           
               
               
           
         
         G is a linker connected to the antibody; 
         n is an integer selected in the range of 0 to 48; 
       
       and wherein the antibody is a humanized monoclonal antibody that binds HER2 comprising (a) HVR-H1 comprising the amino acid sequence of SEQ ID NO: 15; (b) HVR-H2 comprising the amino acid sequence of SEQ ID NO: 16; (c) HVR-H3 comprising the amino acid sequence of SEQ ID NO: 17; (d) HVR-L1 comprising the amino acid sequence of SEQ ID NO: 12; (e) HVR-L2 comprising the amino acid sequence of SEQ ID NO: 13; and (f) HVR-L3 comprising the amino acid sequence of SEQ ID NO:14. 
     
     
         2 . The immunoconjugate of  claim 1 , wherein the antibody comprises a heavy chain variable region comprising the sequence of SEQ ID NO: 11 and a light chain variable region comprising the sequence of SEQ ID NO: 10. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The immunoconjugate of  claim 1 , which is an antibody fragment that binds HER2. 
     
     
         6 . The immunoconjugate of  claim 1 , wherein HER2 is human HER2 comprising amino acids 23 to 1255 of SEQ ID NO: 1. 
     
     
         7 . The immunoconjugate of an  claim 1 , wherein the antibody binds to extracellular domain I of HER2. 
     
     
         8 . The immunoconjugate of  claim 7 , wherein extracellular domain I of HER2 has the sequence of SEQ ID NO: 35. 
     
     
         9 . The immunoconjugate of  claim 4 , which is an IgG1, IgG2a or IgG2b antibody. 
     
     
         10 . The immunoconjugate of  claim 1 , wherein the antibody comprises one or more engineered free cysteine amino acids residues. 
     
     
         11 . The immunoconjugate of  claim 10 , wherein the one or more engineered free cysteine amino acids residues are located in the heavy chain. 
     
     
         12 . The immunoconjugate of  claim 10 , wherein the one or more engineered free cysteine amino acids residues are located in the light chain. 
     
     
         13 . The immunoconjugate of  claim 11 , wherein the antibody comprises at least one mutation in the heavy chain constant region selected from A118C and S400C. 
     
     
         14 . The immunoconjugate of  claim 12 , wherein the antibody comprises at least one mutation in the light chain constant region selected from K149C and V205C. 
     
     
         15 . The immunoconjugate of  claim 1 , wherein the antibody comprises:
 a) a heavy chain comprising the sequence of SEQ ID NO: 19 and a light chain comprising the sequence of SEQ ID NO: 18; or   b) a heavy chain comprising the sequence of SEQ ID NO: 19 and a light chain comprising the sequence of SEQ ID NO: 23; or   c) a heavy chain comprising the sequence of SEQ ID NO: 24 and a light chain comprising the sequence of SEQ ID NO: 18.   
     
     
         16 . The immunoconjugate of  claim 1 , wherein the antibody comprises the heavy chain constant region of SEQ ID NO: 28. 
     
     
         17 . The immunoconjugate of  claim 1 , wherein the antibody comprises the light chain constant region of SEQ ID NO: 25. 
     
     
         18 .- 32 . (canceled) 
     
     
         33 . The immunoconjugate of  claim 1 , comprising the structure: 
       
         
           
           
               
               
           
         
       
     
     
         34 . The immunoconjugate of  claim 1 , wherein p ranges from 1.3-2 or from 2-5. 
     
     
         35 . A pharmaceutical formulation comprising the immunoconjugate of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         36 . The pharmaceutical formulation of  claim 35 , further comprising an additional therapeutic agent. 
     
     
         37 . The pharmaceutical formulation of  claim 36 , wherein the additional therapeutic agent is an antibody or immunoconjugate that binds HER2. 
     
     
         38 . The pharmaceutical formulation of  claim 37 , wherein the additional therapeutic agent is (i) an antibody or immunoconjugate that binds to domain II of HER2, and/or (ii) an antibody or immunoconjugate that binds to domain IV or HER2. 
     
     
         39 . The pharmaceutical formulation of  claim 38 , wherein the additional therapeutic agent is (i) an antibody or immunoconjugate that binds to epitope 2C4, and/or (ii) an antibody or immunoconjugate that binds to epitope 4D5. 
     
     
         40 . The pharmaceutical formulation of  claim 36 , wherein the additional therapeutic agent is trastuzumab, trastuzumab-MCC-DM1 (T-DM1), and/or pertuzumab. 
     
     
         41 . The pharmaceutical formulation of  claim 36 , further comprising (1) trastuzumab or T-DM1, and (2) pertuzumab. 
     
     
         42 . A method of treating an individual having a HER2-positive cancer, the method comprising administering to the individual an effective amount of the immunoconjugate of  claim 1 . 
     
     
         43 . The method of  claim 42 , wherein the HER2-positive cancer is breast cancer or gastric cancer. 
     
     
         44 . The method of  claim 43 , wherein the HER2-positive breast cancer is early-stage breast cancer. 
     
     
         45 . The method of  claim 43 , wherein the HER2-positive breast cancer is metastatic breast cancer. 
     
     
         46 . The method of  claim 42 , further comprising administering an additional therapeutic agent to the individual. 
     
     
         47 . A method of treating an individual having a HER2-positive cancer, the method comprising administering to the individual an effective amount of the immunoconjugate of  claim 1  and at least one additional therapeutic agent to the individual. 
     
     
         48 . The method of  claim 47 , wherein the additional therapeutic agent is an antibody or immunoconjugate that binds HER2. 
     
     
         49 . The method of  claim 48 , wherein the additional therapeutic agent is (i) an antibody or immunoconjugate that binds to domain II of HER2, and/or (ii) an antibody or immunoconjugate that binds to domain IV or HER2. 
     
     
         50 . The method of  claim 49 , wherein the additional therapeutic agent is (i) an antibody or immunoconjugate that binds to epitope 2C4, and/or (ii) an antibody or immunoconjugate that binds to epitope 4D5. 
     
     
         51 . The method of  claim 47 , wherein the additional therapeutic agent is selected from trastuzumab, trastuzumab-MCC-DM1 (T-DM1), and pertuzumab. 
     
     
         52 . The method of  claim 47 , wherein the additional therapeutic agents are (1) trastuzumab or T-DM1, and (2) pertuzumab. 
     
     
         53 . The method of  claim 47 , wherein the HER2-positive cancer is breast cancer or gastric cancer. 
     
     
         54 . The method of  claim 53 , wherein the HER2-positive breast cancer is metastatic breast cancer. 
     
     
         55 . The method of  claim 53 , wherein the HER2-positive breast cancer is early-stage breast cancer. 
     
     
         56 . The method of  claim 42 , wherein the HER2-positive cancer is recurrent cancer. 
     
     
         57 . The method of  claim 56 , wherein the recurrent cancer is locally recurrent cancer. 
     
     
         58 . The method of  claim 42 , wherein the HER2-positive cancer is advanced cancer. 
     
     
         59 . The method of  claim 42 , wherein the HER2-positive cancer is non-resectable. 
     
     
         60 . A method of treating an individual having a HER2-positive cancer, comprising:
 a) subjecting the individual to neoadjuvant treatment with the immunoconjugate  claim 1 ,   b) removing the cancer by definitive surgery, and   c) subjecting the individual to adjuvant treatment with the immunoconjugate of  claim 1 .   
     
     
         61 . The method of  claim 60 , wherein the HER2-positive cancer is breast cancer or gastric cancer. 
     
     
         62 . The method of  claim 61 , wherein the HER2-positive cancer is breast cancer. 
     
     
         63 . A method of inhibiting proliferation of a HER2-positive cell, the method comprising exposing the cell to the immunoconjugate of  claim 1  under conditions permissive for binding of the immunoconjugate to HER2 on the surface of the cell, thereby inhibiting proliferation of the cell. 
     
     
         64 . The method of  claim 63 , wherein the cell is a breast cancer cell or a gastric cancer cell.