Eph receptor Fc variants with enhanced antibody dependent cell-mediated cytotoxicity activity
The present invention relates to novel Fc variants that immuno-specifically bind to an Eph receptor. The Fc variants comprise a binding region that immunospecifically binds to an Eph receptor and an Fc region that further comprises at least one novel amino acid residue which may provide for enhanced effector function. More specifically, this invention provides Fc variants that have modified binding affinity to one or more Fc ligand (e.g., FcγR, C1q). Additionally, the Fc variants have altered antibody-dependent cell-mediated cytotoxicity (ADCC) and/or complement dependent cytotoxicity (CDC) activity. The invention further provides methods and protocols for the application of said Fc variants that immunospecifically bind to an Eph receptor, particularly for therapeutic purposes.
1. An antibody that binds and agonizes at least the Erythropoeitin-Producing human Hepatocellular (Eph) receptor A2, wherein said antibody comprises a heavy chain variable domain which comprises a VH CDR1 having SEQ ID NO:70, a VH CDR2 having SEQ ID NO:71, and a VH CDR3 having SEQ ID NO:72 and a light chain variable domain which comprises a VL CDR1 having SEQ ID NO:73, a VL CDR2 having SEQ ID NO:74, and a VL CDR3 having SEQ ID NO:75.
2. The antibody of claim 1 , wherein said antibody comprises an IgG1 Fc region, wherein the Fc region comprises the high effector function amino acid residues 239D, 330L and 332E, as numbered by the EU index as set forth in Kabat, said antibody has an increased binding affinity for FcγRIIIA as compared to the same antibody not comprising the high effector function amino acid residues and wherein said increased affinity for FcγRIIIA results in an enhanced ADCC activity.
3. The antibody of claim 1 , wherein said antibody is humanized, CDR-grafted, or chimeric.
4. The antibody of claim 1 , wherein said antibody is conjugated to a detectable agent, therapeutic agent or drug.
5. A formulation comprising the antibody of claim 1 in a pharmaceutically-acceptable excipient.
6. The antibody of claim 1 , wherein said antibody comprises a variable heavy chain and a variable light chain, wherein said heavy chain has a sequence comprising SEQ ID NO:68, and wherein said light chain has a sequence comprising SEQ ID NO:69.
7. The antibody of claim 6 , wherein said antibody comprises an IgG1 Fc region, wherein the Fc region comprises the high effector function amino acid residues 239D, 330L and 332L, as numbered by the EU index as set forth in Kabat, said antibody has an increased binding affinity for FcγRIIIA as compared to the same antibody not comprising the high effector function amino acid residues and wherein said increased affinity for FcγRIIIA results in an enhanced ADCC activity.
8. The antibody of claim 7 , wherein said antibody is conjugated to a detectable agent, therapeutic agent or drug.
9. A formulation comprising the antibody of claim 7 in a pharmaceutically-acceptable excipient.
10. The antibody of claim 2 , wherein said antibody is humanized, CDR-grafted, or chimeric.
11. The antibody of claim 2 , wherein said antibody is conjugated to a detectable agent, therapeutic agent or drug.
12. A formulation comprising the antibody of claim 2 in a pharmaceutically acceptable excipient.
13. The antibody of claim 6 , wherein said antibody is conjugated to a detectable agent, therapeutic agent or drug.
14. A formulation comprising of the antibody of claim 6 in a pharmaceutically-acceptable excipient.