Technology evaluation: C242-DM1, ImmunoGen Inc.

C242-DM1 is a tumor-activated immunotoxin under development by GlaxoSmithKline plc (formerly SmithKline Beecham plc), under licence from ImmunoGen Inc, as a potential treatment for colon tumor. It consists of a colon cancer-specific humanized antibody, C242, conjugated to the maytansine derivative DM1. In preclinical studies, C242-DM1 caused complete tumor regression in animal models of both human pancreatic and non-small cell lung cancer (NSCLC) at non-toxic doses. C242-DM1 has also been evaluated in an immunoconjugate combination with J-591 (Cornell University). The J591-DM1 immunoconjugate demonstrated effective, antigen-specific delivery of a highly cytotoxic drug to PSMA-positive Pca cells in vitro and in vivo with low systemic toxicity. Results from studies in monkeys showed that C242-DM1 had no significant toxicity or side effects, when administered at doses higher than those that were previously shown to completely eradicate human colon tumors in mice [271420]. ImmunoGen acquired the right to evaluate, and an option to license, technology related to maytansines from Takeda. In February 1999, ImmunoGen and SmithKline Beecham signed a US $45 million development and commercialization agreement for C242-DM1 [313493]. In August 1997, Immunogen received an SBIR grant to advance development of huC242-DM1 [258356]. EP-00425235, held by ImmunoGen, covers conjugated forms of ansamitocin (maytansine) derivatives. Takeda holds several patents for the production of ansamitocin and its analogs, the first one being JP-53124692.