Scientists recommend 'black box' for Avastin

A report released in the new issue of the Journal of the American Medical Association said that Genentech's blockbuster cancer drug, Avastin, could raise the risk of blood clots by about 12 percent, which means a risk of blood clots that is about 33 percent higher than that of patients not on the therapy. The increased risk of blood clots is especially problematic for cancer patients, because increased clotting is a major cause if illness--and even death--for them. However, the study found that while 6.3 percent of the clots required treatment, few of the clots were fatal.

Earlier studies were too small to base recommendations upon, but that the new review of 15 studies and close to 8,000 patients is strong, said study author, Shenhong Wu of Stony Brook University in New York.

Approximately 350,000 cancer patients across the globe have been treated with Avastin since it was approved for use in 2004. It can cost as much as $55,000 per year, with sales reaching $2 billion this year alone.

According to the JAMA review, the drug should receive the FDA's strongest warning, but a spokesperson for Genentech said that all cancer patients are at increased risk for blood clots and that the label already warns patients about the risk.

- check out the USA Today report