In light of clinical trials suggesting no benefit from the medication among breast cancer patients, U.S. Food and Drug Administration advisory panel voted yesterday in favor of withdrawing approval of the cancer drug Avastin (bevacizumab) for treatment of breast cancer. Avastin, which is manufactured by Roche, was originally granted “accelerated approval” for treatment of breast cancer in February 2008 after preliminary trials showed that the drug slowed tumor growth. As the L.A. Times explains:
“The initial approval was based on a clinical trial in which Avastin … was combined with the breast cancer drug paclitaxel in women with metastatic breast cancer. That trial showed that Avastin plus paclitaxel increased the time during which the therapy prevented progression of the disease — known as progression-free survival — by a little over five months compared with paclitaxel alone. The combination did not increase overall survival by a significant amount, however.”
Yet, while expedited approval can be given for drugs that target potentially fatal diseases, manufacturers are required to complete additional trials to confirm the drug’s safety and efficacy. Findings from two such trials, released earlier this month, suggest that Avastin does not improve survival compared with chemotherapy treatment on its own. What’s more, the follow-up trials also found no evidence that the drug impaired tumor growth, as the initial study found. The Associated Press sums up the trial findings:
“… FDA reviewers said two follow-up studies recently submitted by Roche failed to show that Avastin significantly extended lives compared to chemotherapy alone. Additionally, the FDA said more recent data did not confirm the tumor shrinkage seen in earlier studies. Patients taking Avastin showed significantly more side effects, including high blood pressure, fatigue and abnormal white blood cell levels.”
Based on the trial results, the FDA advisory committee voted yesterday 13 to 0 that the new trials failed to confirm the earlier findings, and 12 to 1 in favor of removing approval of Avastin as a treatment for breast cancer. Should the FDA follow the panel recommendation, withdrawal of Avastin as a breast cancer treatment would not impact its approval for treating other types of cancer — including lung, colon, brain and kidney cancers.
The FDA is expected to make a decision on the drug by September 17. According to the Wall Street Journal, Avastin is a top-selling cancer drug worldwide, with nearly $6 billion in sales in 2009 — some $1 billion of which were for breast cancer treatment.