FILE PHOTO: The logo of Swiss pharmaceutical company Roche is seen outside their headquarters in Basel January 30, 2014. REUTERS/Ruben Sprich/File Photo

ZURICH (Reuters) - Swiss drugmaker Roche said on Tuesday its Tecentriq medicine will get a speedy review by U.S. regulators in a tough-to-treat form of breast cancer, as it seeks to be the first company to have its immunotherapy win approval in this indication.

Roche said the U.S. Food and Drug Administration (FDA) gave priority review to Tecentriq with the chemotherapy Abraxane for initial treatment of people with metastatic triple-negative breast cancer whose tumors test positive for a protein, called PD-L1, that helps them avoid immune system detection.

With the accelerated review, Roche expects a decision by March 12.

“People need more options for this type of breast cancer, which is particularly difficult to treat,” said Sandra Horning, Roche’s chief medical officer, in a statement.

With sales of Tecentriq trailing immunotherapies from Merck and Bristol-Myers Squibb in the main form of lung cancer, Roche is seeking to be first-to-market in smaller but still-lucrative treatment areas.

Triple-negative tumors, which affect 15 percent of breast cancer patients, offer just such an opportunity, though Roche has won the FDA’s priority review in just a subset of patients - the roughly 40 percent of patients in its study whose tumors had high levels of PD-L1.

For them, interim overall survival data released at a medical conference in Germany last month showed they lived a median of 25 months, compared to just 15.5 months for the patients getting only chemotherapy.

For all 902 patients in Roche’s study - including those whose tumors did not express high levels of PD-L1 - the benefit was less-pronounced: Those getting the Tecentriq cocktail lived a median 21.3 months, so far, compared to 17.6 months for those on chemotherapy, Roche reported.