Patent ID: 8822648

Claim:
A fusion protein comprising: a single chain variable fragment (scFv) specific for both carcinoembryonic antigen (CEA) and CEA related Cell Adhesion Molecule 1 (CEACAM1), and a leader sequence, said leader sequence comprising all, or substantially all, of the E. coli Pel B leader sequence, a linker sequence being optionally present between said leader sequence and said scFv, wherein: the V H and the V L portion of the scFv are as shown in SEQ ID NO: 2, the V H and the V L portion of the scFv are as shown in SEQ ID NO: 2 with the Pro at position 200 mutated to Leu, the V H and the V L portion of the scFv are as shown in SEQ ID NO: 2 with the Pro at position 200 of SEQ ID NO: 2 mutated to Leu and the Cys at position 242 of SEQ ID NO: 2 mutated to Trp, the V H and the V L portion of the scFv are as shown in SEQ ID NO: 2 with the Trp at position 208 of SEQ ID NO: 2 mutated to Arg, the V H and the V L portion of the scFv are as shown in SEQ ID NO: 2 with the Trp at position 208 of SEQ ID NO: 2 mutated to Arg and the Cys at position 242 of SEQ ID NO: 2 mutated to Trp, or the V H and the V L portion of the scFv are as shown in SEQ ID NO: 2 with the Cys at position 242 of SEQ ID NO: 2 mutated to Trp.