(AP) -- Drugmaker Roche said Friday that U.S. health regulators will take more time to review its drug Avastin for breast cancer, a use that has generated vigorous debate among cancer specialists and patients.
The company said in a statement that the Food and Drug Administration extended its review of the drug by 90 days, or until Dec. 17.
The FDA granted Avastin accelerated approval for breast cancer in 2008 based on a study suggesting it halted the progression of breast cancer for more than five months. That study paired Avastin with the chemotherapy drug paclitaxel.
Roche submitted two additional studies last year designed to win full approval for the drug, combining Avastin with four other chemotherapies. However, those studies showed a delay in cancer progression of one to three months.
Because of those disappointing results, the FDA is now considering whether to revoke the drug's approval for breast cancer.
The agency's outside panel voted 12-1 in favor of that action in July, arguing that the drug's performance didn't offer a "clinically meaningful" benefit for patients.
But more than 6,000 people have signed a petition urging the agency to keep the drug approved for breast cancer patients who respond well.
Avastin is a blockbuster drug approved for a half dozen forms of cancer, including colon, lung, kidney and brain cancer. The FDA's current review only applies to the drug's use in recurring breast cancer.
Avastin was Roche's top-selling cancer drug last year with sales of $5.9 billion.
If the FDA does revoke Avastin's approval, doctors would still have the option to prescribe it "off-label," for breast cancer but many insurers do not reimburse drugs that don't have the FDA's stamp of approval. Without insurance coverage, Avastin's enormous cost would put the treatment out of reach for most patients. Roche sells the drug at a wholesale price of $7,700 a month.
FDA rules bar the agency from considering cost when making drug approval decisions.
Breast cancer is the second most-common cause of cancer death among U.S. women, according to the Centers for Disease Control and Prevention. Last year more than 40,000 deaths in the U.S. were attributed to the disease.
Roche is headquartered in Basel, Switzerland. Last year the company acquired South San Francisco-based Genentech, which makes Avastin and several other leading cancer therapies.