Binding domain-immunoglobulin fusion proteins

Abstract

The invention relates to novel binding domain-immunoglobulin fusion proteins that feature a binding domain for a cognate structure such as an antigen, a counterreceptor or the like, a wild-type lgG1, IGA or IgE hinge region polypeptide or a mutant IgG1 hinge region polypeptide having either zero, one or two cysteine residues, and immunoglobulin CH2 and CH3 domains, and that are capable of ADCC and/or CDC while occurring predominantly as polypeptides that are compromised in their ability to form disulfide-linked multimers. The fusion proteins can be recombinantly produced at high express levels. Also provided are related compositions and methods, including cell surface forms of the fusion proteins and immunotherapeutic applications of the fusion proteins and of polynucleotides encoding such fusion proteins.

1 .- 61 . (canceled) 
     
     
         62 . A method for treating a disease involving a B cell disorder, wherein the disease involving B cell disorder is a malignancy or immune system disorder, comprising administering to a subject in need thereof a therapeutically effective amount of a single chain binding domain-immunoglobulin fusion protein that binds human CD20 and comprises from N-terminus to C-terminus:
 (a) a binding domain polypeptide that binds human CD20, wherein the binding domain polypeptide comprises amino acids 23-265 of SEQ ID NO:397 except that leucine at position 155 of SEQ ID NO:397 is substituted with a serine,   (b) a human IgG1 hinge peptide comprising a mutated core sequence as set forth in amino acids 279-282 of SEQ ID NO:397, 398 or 582,   (c) an immunoglobulin heavy chain CH2 constant region polypeptide as set forth in amino acids 284-393 of SEQ ID NO:397, and   (d) an immunoglobulin heavy chain CH3 constant region polypeptide as set forth in amino acids 394-500 of SEQ ID NO:397,   wherein the single chain binding domain-immunoglobulin fusion protein promotes antibody dependent cell-mediated cytotoxicity, complement fixation, or both.   
     
     
         63 . The method of  claim 62 , wherein the disease involving a B cell disorder is an immune system disorder, and wherein the immune system disorder is psoriasis, systemic lupus erythematosus, type 1 diabetes mellitus, multiple sclerosis, inflammatory bowel disease, Crohn's disease, or ulcerative colitis. 
     
     
         64 . The method of  claim 62 , wherein the disease involving a B cell disorder is an immune system disorder, and wherein the immune system disorder is rheumatoid arthritis. 
     
     
         65 . The method of  claim 62 , wherein the disease involving a B cell disorder is a malignancy, wherein the malignancy is chronic lymphocytic leukemia. 
     
     
         66 . The method according to any one of  claims 62 - 65 , wherein the human IgG1 hinge peptide of the single chain binding domain-immunoglobulin fusion protein comprises amino acids 279-282 of SEQ ID NO:397. 
     
     
         67 . The method according to any one of  claims 62 - 65 , wherein the human IgG1 hinge peptide of the single chain binding domain-immunoglobulin fusion protein comprises amino acids 279-282 of SEQ ID NO:398. 
     
     
         68 . The method according to any one of  claims 62 - 65 , wherein the human IgG1 hinge peptide of the single chain binding domain-immunoglobulin fusion protein comprises amino acids 279-282 of SEQ ID NO:582. 
     
     
         69 . A method for treating a disease involving a B cell disorder, wherein the disease involving B cell disorder is a malignancy or immune system disorder, comprising administering to a subject in need thereof a therapeutically effective amount of a single chain binding domain-immunoglobulin fusion protein that binds human CD20 and comprises from N-terminus to C-terminus:
 (a) a binding domain polypeptide that binds human CD20, wherein the binding domain comprises an immunoglobulin light chain variable region comprising complementary determining regions of amino acids 46-55, 71-76, and 110-118 of SEQ ID NO:397 fused via a linker polypeptide to an immunoglobulin heavy chain variable region comprising complementary determining regions of amino acids 175-179, 194-210, and 243-255 of SEQ ID NO:397, wherein the linker polypeptide comprises amino acids 129-144 of SEQ ID NO:397,   (b) a human IgG1 hinge peptide comprising a mutated core sequence as set forth in amino acids 279-282 of SEQ ID NO:397,   (c) an immunoglobulin heavy chain CH2 constant region polypeptide as set forth in amino acids 284-393 of SEQ ID NO:397, and   (d) an immunoglobulin heavy chain CH3 constant region polypeptide as set forth in amino acids 394-500 of SEQ ID NO:397,   wherein the single chain binding domain-immunoglobulin fusion protein promotes antibody dependent cell-mediated cytotoxicity, complement fixation, or both.   
     
     
         70 . The method of  claim 69 , wherein the disease involving a B cell disorder is an immune system disorder, and wherein the immune system disorder is psoriasis, systemic lupus erythematosus, type 1 diabetes mellitus, multiple sclerosis, inflammatory bowel disease, Crohn's disease, or ulcerative colitis. 
     
     
         71 . The method of  claim 69 , wherein the disease involving a B cell disorder is an immune system disorder, and wherein the immune system disorder is rheumatoid arthritis. 
     
     
         72 . The method of  claim 68 , wherein the disease involving a B cell disorder is a malignancy, and wherein the malignancy is chronic lymphocytic leukemia. 
     
     
         73 . The method according to any one of  claims 69 - 72 , wherein the binding domain polypeptide has a serine at position 11 in the immunoglobulin heavy chain variable region polypeptide of the single chain binding domain-immunoglobulin fusion protein.