WALTHAM, Mass.--(BUSINESS WIRE)--ImmunoGen, Inc. (Nasdaq: IMGN), a biotechnology company that develops antibody-based anticancer products using its Targeted Antibody Payload (TAP) technology, today announced the initiation of a randomized Phase I/II clinical trial to evaluate its proprietary product candidate, IMGN901 (lorvotuzumab mertansine), for first-line treatment of small-cell lung cancer (SCLC) in patients with extensive disease.