Patent ID: 8524231

Claim:
A chimeric antigen binding polypeptide that specifically binds to a target antigen, the polypeptide comprising a VH domain and a VL domain, said VH domain comprising hypervariable loops H1, H2 and H3, wherein said VH domain polypeptide is paired with a VL domain comprising hypervariable loops L1, L2 and L3, wherein said VH domain and said VL domain are each fused to one or more IgG constant domains of a human antibody, wherein at least the H3 hypervariable loop is obtained from a conventional antibody of a species in the family Camelidae, and wherein said conventional antibody is a heterotetrameric IgG antibody composed of two identical light chains and two identical heavy chains, wherein at least one of the hypervariable loops H1, H2, L1, L2 and L3 exhibits a predicted or actual canonical fold structure which is identical or substantially identical to a canonical fold structure of a corresponding H1, H2, L1, L2 or L3 hypervariable loop which occurs in human antibodies.