Topics:

T-DM1 (trastuzumab emtansine) – Top 10 Late-Stage Cancer Drugs – 2012

Tools

Developer: Roche/Genentech
Partner: ImmunoGen
Lead indication: Breast cancer
Key date: BLA expected later this year

Previously snubbed by U.S. regulators in 2010, T-DM1 appears to be an odds-on favorite to win FDA approval in its second try with the agency. Roche ($RHHBY) has gathered the late-stage trial data that it needs to seek the agency's nod, and the drugmaker plans to send its applications for U.S. and European approval of the blockbuster hopeful later this year.

Roche's Genentech unit has developed T-DM1, which is a formulation of Herceptin linked to the chemo drug DM1, to provide a new edge in the battle against HER2-positive breast tumors. The company now markets Herceptin, which is the targeted antibody ingredient in T-DM1. Results from a Phase III trial dubbed EMILIA revealed in March that patients on T-DM1 lived longer without their cancer getting worse than people who took the breast cancer drug lapatinib and the chemo pill Xeloda.

Roche aims to get T-DM1 to market as swiftly as possible. The new drug could shore up the company's leading position in treating breast cancers in which human epidermal growth factor receptor 2 (HER2) drives the growth of cancer cells. More drugs for targeting such tumors, which represent 15% to 20% of breast cancers, are expected to hit the market in the coming years, including a cheaper Herceptin biosimilar.

Despite the competition, analysts expect T-DM1 to surpass $1 billion in global annual sales if approved. JPMorgan biotech analyst Cory Kasimov, for instance, projects peak sales of the drug to reach about $3.5 billion and gives the experimental treatment an 85% shot at approval. These are good numbers for Roche, the world's biggest cancer drugmaker, and ImmunoGen ($IMGN), the biotech outfit that provides the linker tech and the DM1 chemo for the treatment.