"The FDA's approval of Avastin will give many women an additional option in the treatment of a serious disease," said Otis Brawley, MD, chief medical officer, American Cancer Society, when the approval was announced.

Avastin, manufactured by Genentech, is also approved to treat colon cancer and lung cancer. Studies have shown that Avastin helps patients with these cancers live longer. Some doctors have been prescribing the drug "off label" for breast cancer treatment, but the drug is expensive, and insurance reimbursement has been an issue.

A recent study showed that women who took Avastin in combination with the chemotherapy drug Taxol (paclitaxel) stayed in remission longer than women who took Taxol by itself; however, the combination did not improve overall survival rates. Before the FDA grants full approval, it will review data from two ongoing phase III clinical trials using the drug.

"The FDA has almost always required that drugs be shown to extend life in order to be approved, which makes them much more likely to be covered by insurers. The FDA's approval process for Avastin tells us that regulators are now making quality of life issues an important of their decision-making," said Brawley.

"It will be important for future clinical trials of similar treatments to carefully measure not only the clinical response of the cancer under study, but also demonstrate clearly that a new drug can improve the quality of life for the patients who respond."