The US Food and Drug Administration announced today that it would be revoking the agency’s approval of Avastin (bevacizumab) for first-line treatment of metastatic breast cancer. The FDA concluded from several studies and a public hearing held in June that the Genentech drug — a monoclonal antibody that inhibits vascular endothelial growth factor — was not safe or effective for women with breast cancer.
“Women risk life-threatening side effects… from taking Avastin and these can be justified only if there was good evidence that use of the drug would benefit the patient,” said FDA commissioner Margaret Hamburg in a media briefing this morning. “After reviewing the available studies, it is clear that there is no proof of a benefit in breast cancer patients.”
The side effects of Avastin include severe bleeding, high blood pressure and heart attacks. Nonetheless, the drug will remain on the market for other types of cancer — including colon, lung, kidney and brain — for which the efficacy outweighs the risks.
The FDA conditionally approved Avastin in 2008 under an accelerated approval process, after positive results from a single study showed almost a half year average increase in progression-free survival in people taking the drug. After two consequent trials by Genentech failed to confirm the original benefits seen, an FDA advisory committee voted 12-1 in July 2010 to revoke Avastin’s approval for this indication. Genentech contested the FDA’s position, requesting a public hearing this summer, but a second, six-member panel unanimously stood by the original decision. Today’s announcement by Hamburg puts a final chapter on this saga.
The National Breast Cancer Coalition (NBCC), based out of Washington, DC, expressed approval of the FDA decision. “If evidence shows an approved drug has little or no benefit and harms patients, approval must be revoked,” Fran Visco, president of the NBCC, wrote in a statement.
But Gary Lyman of the Duke University Medical Center in Durham, North Carolina disagrees. “As a breast cancer oncologist, I feel strongly that Avastin works, we just don’t know who to give it to,” he says. The missing link, according to Lyman, is a biomarker or test to tell which subgroup of patients benefits from the drug. “I would have preferred that the FDA extended conditional approval of the drug until more data could answer all the questions,” says Lyman, who sat on earlier advisory committees regarding the drug.
Ultimately, Lyman strongly believes the drug will be back. “I don’t think this is the final word,” he says.