Patent ID: 8835607
Filing Date: 2014-09-16
Classification: C07K

Abstract:
1. A chimeric antibody which specifically binds a target antigen, the chimeric antibody comprising a VH domain comprising HCDR1, HCDR2, and HCDR3 region amino acid sequences and a VL domain comprising LCDR1, LCDR2, and LCDR3 region sequences, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 region sequences are obtained from a conventional camelid antibody, wherein the conventional camelid antibody is a heterotetrameric IgG antibody composed of two identical light chains and two identical heavy chains, wherein the heavy chains comprise a camelid VH domain paired with a camelid VL domain of said light chains, wherein the camelid VH domain has a sequence identity of 90% or more to a human VH domain germline sequence across the framework regions FR1, FR2, FR3 and FR4, wherein the VH domain amino acid sequence of the chimeric antibody is obtained by substituting one or more amino acid residues of the camelid VH domain at one or more positions selected from the group consisting of H1, H5, H7, H11, H12, H13, H14, H29, H30, H37, H40, H48, H67, H68, H69, H71, H74, H77, H78, H80, H81, H82b, H83, H84, H85, H86, H89, H93, H94 and H108, according to Kabat, with amino acids that are found at the corresponding positions in the human germline VH domain sequence, wherein the VH domain and the VL domain of the chimeric antibody are each fused to one or more IgG constant domains of a human antibody, and and wherein the HCDR1 and HCDR2 or the LCDR1 and LCDR2 of the conventional camelid antibody exhibit a combination of canonical fold structures which is identical or substantially identical to a combination of canonical fold structures for HCDR1 and HCDR2 or LCDR1 and LCDR2 of a human antibody.