Major success for T-DM1
02.10.2012 - Roche's trastuzumab emtansine (T-DM1) appears to keep its promises. The armed antibody significantly extended overall survival in breast cancer patients.
Roche presented the latest big pack of Phase III data for T-DM1 at the ESMO conference currently being held in Vienna. The EMILIA study has shown that people with previously treated HER2-positive metastatic breast cancer survived significantly longer when treated with T-DM1 compared to those who received the standard-of-care, a combination of lapatinib and capecitabine. Results showed the risk of death was reduced by 32% for people who received the antibody-drug conjugate compared to those who received lapatinib plus Xeloda (HR=0.68; P=0.0006). People in the study treated with trastuzumab emtansine survived a median of 5.8 months longer than those who received lapatinib and Xeloda (median overall survival: 30.9 months vs. 25.1 months). No new safety signals were observed and adverse events (AEs) were consistent with those seen in previous studies, with fewer people who received trastuzumab emtansine experiencing Grade 3 or higher (severe) adverse events than those who received lapatinib plus Xeloda (40.8 percent vs. 57.0 percent).
Representatives from Roche and industry experts were "extremely pleased" with the results. "Roche is moving away from Herceptin, with successors that are not just an inch better, but much, much better," said Andrew Weiss from Vontobel. Simos Simeonidis from SG Cowen has laid out a bullish marketing scenario, expecting that T-DM1 could earn more than its predecessor Herceptin (US$5.4bn) last year. "And since it will probably be priced at a meaningful premium to Herceptin, we think T-DM1 could end up as one of the biggest biotech drugs", Simeonidis said.
Genentech Inc., a Roche subsidiary situated in San Francisco (USA), is the developer of T-DM1. The company has already filed a marketing application for the drug to the Food and Drug Administration (FDA) in the US. The development was accomplished under an agreement with ImmunoGen, Inc. from Waltham (USA). The company from Massachusetts provides the linker chemistry and the compound drug's cancer killing agent, which is targeted by the antibody (trastuzumab) to Her2neu tumour cell receptors. ImmunoGen calls its technology TAP, Targeted Antibody Payload. The cytotoxic agent is a derivative of maytansine that inhibits the assembly of microtubules. Maytansines are potent toxins that naturally occur in the shrubs and trees of the Genus Maytenus spp.