Optimization of antibodies that bind lymphocyte activation gene-3 (lag-3), and uses thereof

Abstract

The present invention provides isolated monoclonal antibodies that specifically bind LAG-3, and have optimized functional properties compared to previously described anti-LAG-3 antibodies, such as antibody 25F7 (US 2011/0150892 A1). These properties include reduced deamidation sites, while still retaining high affinity binding to human LAG-3, and physical (i.e., thermal and chemical) stability. Nucleic acid molecules encoding the antibodies of the invention, expression vectors, host cells and methods for expressing the antibodies of the invention are also provided, as well as immunoconjugates, bispecific molecules and pharmaceutical compositions comprising the antibodies. The present invention also provides methods for detecting LAG-3, as well as methods for treating stimulating immune responses using an anti-LAG-3 antibody of the invention. Combination therapy, in which the antibodies are co-administered with at least one additional immunostimulatory antibody, is also provided.

What is claimed: 
     
         1 . An isolated monoclonal antibody, or an antigen-binding portion thereof, that binds human LAG-3, comprising heavy and light chain variable regions, wherein the heavy chain variable region comprises the CDR1, CDR2, and CDR3 regions from the heavy chain variable region of SEQ ID NO: 12 and the light chain variable region comprises the CDR1, CDR2, and CDR3 regions from the light chain variable region of SEQ ID NO: 14. 
     
     
         2 . An isolated monoclonal antibody, or an antigen-binding portion thereof, that binds human LAG-3, comprising heavy and light chain CDR1, CDR2, and CDR3 regions, comprising the amino acid sequences of SEQ ID NOs: 15, 16, 17, and SEQ ID NOs: 18, 19, and 20, respectively. 
     
     
         3 . An isolated monoclonal antibody, or an antigen-binding portion thereof, that binds human LAG-3, comprising heavy and light chain variable regions, comprising the amino acid sequences of SEQ ID NOs: 12 and 14, respectively. 
     
     
         4 . The antibody, or antigen-binding portion thereof, of  claim 1 , which stimulates an immune response. 
     
     
         5 . The antibody, or antigen-binding portion thereof, of  claim 1 , which binds an epitope of human LAG-3 comprising the amino acid sequence PGHPLAPG (SEQ ID NO: 21), HPAAPSSW (SEQ ID NO: 22), or PAAPSSWG (SEQ ID NO: 23). 
     
     
         6 . The antibody, or antigen-binding portion thereof, of  claim 1 , which binds to human LAG-3 with a K D  of 0.27×10 −9  M or less. 
     
     
         7 . The antibody, or antigen-binding portion thereof, of  claim 1 , which is a human, humanized, or chimeric antibody. 
     
     
         8 . The antibody, or antigen-binding portion thereof, of  claim 7 , which comprises a mutation in the hinge region. 
     
     
         9 . The antibody, or antigen-binding portion thereof, of  claim 8 , which comprises a serine to proline mutation. 
     
     
         10 . The antibody, or antigen-binding portion thereof, of  claim 1 , which is an IgG1, IgG2 or IgG4 isotype. 
     
     
         11 . The antibody, or antigen-binding portion thereof, of  claim 1 , which is an antibody fragment or a single chain antibody. 
     
     
         12 . A bispecific molecule comprising the antibody, or antigen-binding portion thereof, of  claim 1 , and a second antibody or antigen-binding portion thereof. 
     
     
         13 . An immunoconjugate comprising the antibody, or antigen-binding portion thereof, of  claim 1 , linked to a therapeutic agent. 
     
     
         14 . A composition comprising the antibody, or antigen-binding portion thereof, of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         15 . A composition comprising the bispecific molecule of  claim 11  and a pharmaceutically acceptable carrier. 
     
     
         16 . A composition comprising the immunoconjugate of  claim 13 , and a pharmaceutically acceptable carrier. 
     
     
         17 . The composition of  claim 14 , further comprising an anti-cancer agent. 
     
     
         18 . The composition of  claim 17 , wherein the agent is an antibody or a chemotherapeutic agent. 
     
     
         19 . An isolated nucleic acid encoding the heavy and/or light chain variable region of the antibody, or antigen-binding portion thereof, of  claim 3 . 
     
     
         20 . A method of stimulating an immune response in a subject comprising administering the antibody, or antigen-binding portion thereof, of  claim 1 , to the subject, such that an immune response in the subject is stimulated. 
     
     
         21 . The method of  claim 20 , wherein the subject is a tumor-bearing subject and an immune response against the tumor is stimulated. 
     
     
         22 . The method of  claim 20 , wherein the subject is a virus-bearing subject and an immune response against the virus is stimulated. 
     
     
         23 . The method of  claim 20 , wherein the immune response is an antigen-specific T cell response, such that an antigen-specific T cell response is stimulated. 
     
     
         24 . The method of  claim 23 , wherein interleukin-2 production by the antigen-specific T cell is stimulated. 
     
     
         25 . A method for inhibiting growth of tumor cells in a subject comprising administering to the subject the antibody, or antigen-binding portion thereof, of  claim 1 , such that growth of the tumor is inhibited in the subject. 
     
     
         26 . A method for treating viral infection in a subject comprising administering to the subject the antibody, or antigen-binding portion thereof, of  claim 1 , such that the viral infection is treated in the subject. 
     
     
         27 . The method of  claim 20 , further comprising administration of at least one additional immunostimulatory antibody. 
     
     
         28 . The method of  claim 27 , wherein the at least one immunostimulatory additional antibody is an anti-PD-1 antibody. 
     
     
         29 . The method of  claim 27 , wherein the at least one additional immunostimulatory antibody is an anti-PD-L1 antibody. 
     
     
         30 . The method of  claim 27 , wherein the at least one additional immunostimulatory antibody is an anti-CTLA-4 antibody.