Fc variants with altered binding to FcRn
The present application relates to optimized IgG immunoglobulin variants, engineering methods for their generation, and their application, particularly for therapeutic purposes.
1. A polypeptide comprising a variant Fc region comprising amino acid substitutions at residues 259 and 308, wherein said amino acid substitutions are an isoleucine that is not the wild-type amino acid at position 259 and a phenylalanine that is not the wild-type amino acid at position 308, wherein said polypeptide is an antibody or an immunoadhesin and wherein numbering is according to the EU Index in Kabat et al.
2. A polypeptide according to claim 1 which is an antibody.
3. A polypeptide according to claim 2 wherein said antibody is selected from the group consisting of a chimeric antibody, a humanized antibody, a monoclonal antibody or a human antibody.
4. A composition comprising the polypeptide of claim 1 and a carrier.