FDA looks at Avastin risks

By Dr. Ananya Mandal, MDJun 29 2011

The US Food and Drug Administration is holding a two-day hearing that pits the FDA's Center for Drug Evaluation and Research against Genentech, that manufactures breast cancer drug Avastin. A handful of breast cancer patients testified Tuesday that Avastin helped in treating their metastatic breast cancer but a review of studies conducted by the FDA's Center for Drug Evaluation and Research suggests the risks outweigh the benefits of Avastin for treating breast cancer, FDA officials said at the hearing.

The FDA had granted an accelerated conditional approval for Avastin in February 2008 to treat late-stage breast cancer patients. Avastin, or bevacizumab, is an injected medication thought to slow cancer by choking off the blood vessels that feed tumor growth. The drug blocks a protein important for forming such vessels, according to the FDA.

But results from four trials that enrolled more than 3,000 women found no significant reduction in progression of the disease or improvement of death rates among those who took Avastin and underwent chemotherapy.

Dr. Richard Pazdur, director of the FDA's Office of Oncology Drug Products, said at the hearing Tuesday, “The decision must be based on the totality of evidence in all clinical trials. The totality of data submitted to FDA shows it's not safe and effective [for treating] breast cancer.”

This hearing heralds the beginning of recommendations for regulatory withdrawal of the drug for use on breast cancer patients. Some cancer specialists said the decision could hold huge implications for the way their patients will be treated. “This decision [could] remove an option for patients,” said Dr. Edith Perez, clinical oncologist at the Mayo Clinic.

The panel asked whether the FDA's experts who testified believed that some patients could benefit from Avastin. “No, we do not agree,” Dr. Patricia Keegan, director of the FDA's Division of Biologic Oncology Products in the Office of Oncology Drug Products, said. “Despite the hopes of everyone inside and outside this room there is no evidence that Avastin saves or extends lives,” she said.