* Trastuzumab-DM1 filed based on positive mid-stage trails
* Roche has said drug could be launched in 2011 if approved
(adds details, background)
ZURICH, July 7 Swiss drugmaker Roche Holding AG ROG.VX has submitted a new breast cancer drug for approval with U.S. health regulators, the group said on Wednesday, taking the innovative treatment a step closer towards the market.
Roche said it filed trastuzumab-DM1 (T-DM1) for approval with the U.S. Food and Drug Administration (FDA) for people with advanced HER2-positive breast cancer who had previously received other treatments.
A mid-stage phase II study showed that the drug shrank tumours in one-third of women who had received on average seven prior medicines for advanced HER2-positive breast cancer, Roche said.
Roche has said the new drug could eventually rake in sales of over 2 billion Swiss francs ($1.88 billion).
The news is also a boost for ImmunoGen (IMGN.O) as the drug comprises ImmunoGen's DM1 cancer-cell killing agent linked to the HER2-targeting antibody trastuzumab, or Herceptin, and would be the first product developed by ImmunoGen filed for approval.
Breast cancer is the second-leading cause of cancer death among women in the U.S. and approximately 15 to 30 percent of breast cancers are HER2-positive, Roche said.
When HER2-positive breast cancer is advanced, the disease has spread to other parts of the body, most commonly to the lungs, bones, liver and brain.
Roche had already said it aimed to file T-DMI1 for approval after phase II, adding the drug's launch could take place in the beginning of 2011, if approved.
Roche will still conduct Phase III studies. Drugmakers usually file for approval after final trial outcomes.
The success of new drugs is key for the world's largest maker of cancer drugs, as competitors work on rival products to some of Roche's best-selling medicines.
In addition, Roche's blockbusters MabThera and Herceptin could become vulnerable to so-called biosimilar drugs as they lose their patent protection in a several European countries in 2014 and 2015. (Reporting by Sven Egenter; Editing by Hans Peters) ($1=1.063 Swiss Franc)