Patent ID: 8883981

Claim:
A recombinant antibody composition comprising recombinant antibodies, said recombinant antibodies having greater complement-dependent cytotoxic activity than human IgG1 and human IgG3 antibodies of the same binding specificity under the same conditions, said recombinant antibodies comprising a region containing a CH1, a hinge, a CH2 and a CH3 domain, said region comprising the amino acid sequence of SEQ ID NO: 76 in which at least the first 110 amino acids commencing at residue 114 of SEQ ID NO: 76 are replaced with the corresponding residues from SEQ ID NO: 78, and in which residues 1-113 of SEQ ID NO: 76 in said region are not replaced with the corresponding residues from SEQ ID NO: 78.