Patent ID: 8618252

Claim:
An IgG Fc-containing polypeptide comprising an altered Fc region, wherein said Fc-containing polypeptide comprises at least one mutation within the Fc region as compared to a starting Fc-containing polypeptide and wherein the at least one mutation is a substitution at EU amino acid position 304 with aspartate or glutamate in combination with a second mutation selected from the group consisting of: a substitution at EU amino acid position 284 with aspartate or glutamate; a substitution at EU amino acid position 285 with aspartate or glutamate; a substitution at EU amino acid position 286 with aspartate or glutamate; a substitution at EU amino acid position 288 with a aspartate or glutamate; a substitution at EU amino acid position 290 with aspartate or glutamate; and a substitution at EU amino acid position 305 with aspartate or glutamate, wherein the IgG Fc-containing polypeptide binds FcRn with different binding affinity compared to the starting polypeptide that does not contain the mutations.