US Food and Drug Administration (FDA) Commissioner Margaret Hamburg handed down in November the final decision to revoke approval of Genentech's Avastin (bevacizumab) in metastatic breast cancer. Avastin, which binds to vascular endothelial growth factor, received accelerated approval in 2008 obligating the S. San Francisco–based company to confirm promising data in post-marketing studies, but two confirmatory trials failed to support the 5.5-month improvement of progression-free survival seen in the pivotal study. Citing a poor benefit-to-risk profile, FDA's Center for Drug Evaluation and Research (CDER) proposed withdrawing approval due to serious hypertension and kidney toxicity side effects, but the Roche unit challenged the move—the first time a drugmaker has ever done so—requesting a two-day hearing last summer. Following the hearing, the FDA's Oncologic Drugs Advisory Committee supported CDER's recommendation, as did Hamburg, but Genentech has not given up. It is launching a new phase 3 trial of Avastin with paclitaxel, evaluating a potential biomarker to help identify metastatic breast cancer patients who benefit the most. Hamburg says she will reconsider her decision if Genentech is able to identify super-responders. “FDA will work with Genentech on the design of trials to explore whether such a subset of patients exists,” says FDA spokesperson Karen Riley, “and if so, develop ways to identify such patients for whom Avastin treatment is safe and effective. But while these studies are going on, the breast cancer indication should not remain on the drug's labeling.” Avastin is approved for colon, lung, kidney and brain cancers.