Patent ID: 11879004
Assignee: GENZYME CORPORATION
Field: Pharmaceuticals (Chemistry)
Classification: CPC A  C | IPC A  C

Claim 0:
1. An antigen-binding protein or an antigen-binding fragment thereof, comprising an antigen-binding domain and an antibody heavy chain constant (CH) domain comprising a double-engineered cysteine reactive amino acid residue at positions selected from the group consisting of: K274C and A339C, K274C and K360C, K274C and N384C, K274C and G385C, K274C and V422C, and K274C and S440C, according to the numbering of the EU index of Kabat, wherein the cysteine reactive amino acid residue is conjugated to a ligand via a linker, wherein the ligand comprises polyethylene glycol (PEG), a diagnostic agent, or a drug, and wherein the antigen-binding protein comprises a ligand to antibody ratio (LAR) of at least 3.0.