Roche-ImmunoGen to Start T-DM1 Trials

WALTHAM, Mass. (TheStreet) -- ImmunoGen(IMGN) is expected to announce Monday a commitment by its partner Roche to begin new late-stage clinical trials of the experimental breast cancer drug T-DM1.

The overall goal of this new clinical trial program will be to determine whether T-DM1, which is still not approved for use, can one day replace Roche's Herceptin as the leading treatment for women with certain breast cancers.

Herceptin global sales totaled $3.8 billion in the first nine months of 2009 and $4.7 billion in sales in 2008, according to Roche.

The Genentech unit of Roche will start a phase III study of T-DM1 in first-line breast cancer in May 2010. Additionally, a clinical trial designed to evaluate T-DM1 in the post-surgical, or adjuvant, setting is also in the planning stages, Immunogen will announce.

T-DM1 is a second-generation version of Roche's Herceptin. It consists of Herceptin (also known as trastuzumab) linked to a tumor-killing chemotherapy payload developed by ImmunoGen.

Roche's new commitment to advance T-DM1 comes as the drug maker plans to meet with the U.S. Food and Drug Administration to discuss seeking approval for T-DM1 as a third-line treatment for breast cancer patients.

On Saturday, researchers presented new clinical data from a phase II study showing that T-DM1 shrank tumors in 33% of critically ill breast cancer patients. The 110 patients in this study were essentially out of medical options because their breast cancer was no longer responding to treatment with Herceptin or GlaxoSmithKline's(GSK) Tykerb.