Identification and engineering of antibodies with variant Fc regions and methods of using same
The present invention relates to molecules, particularly polypeptides, more particularly immunoglobulins (e.g., antibodies), comprising a variant Fc region, wherein said variant Fc region comprises at least one amino acid modification relative to a wild-type Fc region, which variant Fc region binds FcγRIIIA and/or FcγRIIA with a greater affinity, relative to a comparable molecule comprising the wild-type Fc region. The molecules of the invention are particularly useful in preventing, treating, or ameliorating one or more symptoms associated with a disease, disorder, or infection. The molecules of the invention are particularly useful for the treatment or prevention of a disease or disorder where an enhanced efficacy of effector cell function (e.g., ADCC) mediated by FcγR is desired, e.g., cancer, infectious disease, and in enhancing the therapeutic efficacy of therapeutic antibodies the effect of which is mediated by ADCC.
1. A method of enhancing antibody-dependent cell mediated cytotoxicity (ADCC) in a patient having a cancer characterized by a cancer antigen, said method comprising administering to said patient a therapeutically effective amount of a polypeptide having a variant Fc region, wherein said variant Fc region:
(A) contains a CH2 domain and a CH3 domain; and
(B) possesses an amino acid sequence that differs from the amino acid sequence of a wild-type Fc region by comprising amino acid modifications R292P and V3051, relative to said wild-type Fc region, wherein said numbering is that of the EU index as in Kabat.
2. The method of claim 1 , wherein said amino acid modifications additionally comprise the modification F243L.
3. The method of claim 1 , wherein said amino acid modifications cause said variant Fc region to bind FcγRII with an altered affinity relative to that of said wild-type Fc region.
4. The method of claim 3 , wherein said altered FcγRII affinity is an enhanced FcγRIIA binding affinity.
5. The method of claim 3 , wherein said altered FcγRII affinity is a decreased FcγRIIB binding affinity.
6. The method of claim 1 , wherein said amino acid modifications cause said variant Fc region to bind FcγRIII with an altered affinity relative to that of said wild-type Fc region.
7. The method of claim 6 , wherein said altered affinity for an FcγRIII is an increased affinity.
8. The method of claim 6 , wherein said FcγRIII is FcγRIIIA.
9. The method of claim 6 , wherein said variant Fc region also binds FcγRIIB with decreased affinity relative to that of a wild-type Fc region.
10. The method of claim 6 , wherein said variant Fc region also binds FcγRIIA with increased affinity relative to that of a wild-type Fc region.
11. The method of claim 1 , wherein said variant Fc region additionally comprises a modification that enhances C1q binding, said modification being:
(1) P247L and N421K;
(2) R255L and P396L;
(3) K370E and P396L;
(4) K392T and P396L;
(5) P396L and V240A; or
(6) P396L and Q419H.
12. The method of claim 1 , wherein said variant Fc region additionally comprises a modification at position 297.
13. The method of claim 1 , wherein said polypeptide is an antibody that contains said variant Fc region.
14. The method of claim 13 , wherein said antibody is antibody produced by hybridoma clone: 1D5 (ATCC accession number PTA-5958), 1F2 (ATCC accession number PTA-5959), 2D11 (ATCC accession number PTA-5960), 2E1 (ATCC accession number PTA-5961) or 2H9 (ATCC accession number PTA-5962).
15. The method of claim 1 , wherein said cancer antigen is selected from the group consisting of MAGE-1, MAGE-3, BAGE, GAGE-1, GAGE-2, N-acetylglucosaminyltransferase, p15, beta-catenin, MUM-1, CDK4, HER-2/neu, human papillomavirus-E6, human papillomavirus-E7, or MUC-1.