Weigh Roche cancer drug toxicity, say FDA staff

WASHINGTON, Dec 3 (Reuters) - The benefits of Roche Holding AG's (ROG.VX) cancer drug Avastin in breast cancer should be weighed against some toxic side effects including the potential for death, U.S. regulatory staffers said in documents released on Monday.

The U.S. Food and Drug Administration staff review comes ahead of a Wednesday advisory panel on a bid by Roche and U.S. partner Genentech Inc DNA.N to extend use of Avastin, already approved to treat lung and colon cancer, to patients with breast cancer.

The expert panel will give advice to the FDA on broadening use of the drug as a first-line treatment for patients with breast cancer whose disease has spread.

In a key trial, the drug failed to extend overall survival, although it did meet its primary goal of "progression-free survival," the probability that a patient will remain alive, without the disease getting worse.

A 5-1/2-month improvement in progression-free survival "must be weighted against the increased toxicity, including deaths associated" with the drug, FDA staffers wrote in a review posted on the FDA's Web site. (Reporting by Kim Dixon; Editing by Tim Dobbyn)