Avastin Breast Cancer Benefits Questioned by FDA

FDA drug reviewers are questioning the benefits of Avastin, a cancer drug by Roche, saying that studies show it does not extend lives of breast cancer patients and does not reduce tumors as much as previously thought. 

The FDA’s Avastin findings were included in a briefing document submitted to the agency’s Oncologic Drugs Advisory Committee, which will meet on Tuesday to make recommendations on whether Avastin breast cancer use should continue or whether there should be an Avastin recall for that approved treatment. In the briefing document, FDA reviewers said that not only were benefits in question, but the side effects of Avastin were more severe than with other, similar, drugs.

Avastin (bevacizumab) was approved by the FDA in 2004 for treatment of non-small cell lung cancer and colorectal cancer when combined with chemotherapy. It was then was granted accelerated approval for use with paclitaxel to treat breast cancer patients by FDA in February 2008. The drug prevents the formation of new blood vessels in tumors, starving them and inhibiting their growth.

The approval of Avastin for breast cancer treatment was based on a clinical trial finding that it slowed the growth of breast cancer tumors, at odds with the usual requirement that breast cancer treatment drugs show that they actually extend the lives of patients. As part of the accelerated approval process, Genentech, a subsidiary of Roche, had to continue two more drug trials and then submit their findings to FDA.

Now the FDA is indicating that follow-up studies seem to indicate that the drug does not extend patient lives, and also point out that the studies do not show the same amount of tumor growth reduction as the first trials. The new trials found that the most common of the severe Avastin side effects were hypertension, gastrointestinal bleeding and febrile neutropenia.

Avastin has also been tied to increased risk of blood clots and has been linked to reports of serious eye inflammation from Avastin when used off-label to treat wet macular degeneration.