Patent ID: 8394926

Claim:
A bispecific single chain antibody which comprises (a) a first binding domain specifically binding to human CD3, and (b) a second binding domain specifically binding to human CEA, wherein said second binding domain comprises a variable light chain (V L ) region and a variable heavy chain (V H ) region: wherein said V L comprises a CDR-L1 having the amino acid sequence “TLRRGINVGAYSIY” (SEQ ID NO. 73); a CDR-L2 having the amino acid sequence “YKSDSDKQQGS” (SEQ ID NO. 72); and a CDR-L3 having the amino acid sequence “MIWHSGASAV” (SEQ ID NO. 71); and wherein said V H comprises a CDR-H1 having the amino acid sequence “SYWMH” (SEQ ID NO. 68); a CDR-H2 having the amino acid sequence “FIRNKANGGTTEYAASVKG” (SEQ ID NO. 67); and a CDR-H3 having the amino acid sequence “DRGLRFYFDY” (SEQ ID NO. 66).