FDA denies accelerated approval for ImmunoGen, Genentech potential breast cancer treatment

FDA denies accelerated approval for cancer drug

WALTHAM, Mass. — Federal regulators have ruled that a potential breast cancer treatment from ImmunoGen failed to meet the standard for accelerated approval, the company said Friday.

The Waltham company saw its share price sink 35 percent after it said its fiscal 2011 financial guidance is no longer applicable.

The Food and Drug Administration ruled that all available treatment choices for metastatic breast cancer had not been exhausted in the study population for the drug, T-DM1, the company said.

The agency reviews a limited number of drugs for accelerated approval status, usually for limited release, to treat serious illnesses with few or no other options.

T-DM1 is composed of the breast cancer drug trastuzumab, which is marketed as Herceptin by Genentech, and a cell-killing agent developed by ImmunoGen.

Genentech, a unit of Swiss drug developer Roche, has been testing the drug and submitted a biologic license application last month seeking accelerated approval.

The application was based on a mid-stage study that showed T-DM1 reduced tumors in some women with a form of advanced breast cancer who had received, on average, seven prior medicines.

But Genentech received a “refuse to file” letter from the FDA, ImmunoGen said.

Genentech will continue its late-stage trial of the potential treatment and expects to submit a new application in mid 2012, according to ImmunoGen.

Updated financial guidance from ImmunoGen is being developed.

Shares of ImmunoGen Inc. fell $2.95 to $5.44 in Friday afternoon trading.

(This version CORRECTS the description of the relationship between the companies regarding the drug’s development)