Avastin may be linked to fatal side effects, study says

Avastin, a popular cancer drug that slows the growth of some types of tumors, may also be linked to an increased risk of death, new research suggests.

A study published Tuesday in the Journal of the American Medical Assn. reviewed randomized controlled clinical trials from 1966 to 2010 with a total of 10,217 patients.

FOR THE RECORD: An earlier version of this post said the FDA withdrew approval of Avastin for breast cancer patients in December. In fact, the FDA moved to begin the process of withdrawing approval. Genentech has requested a hearing appealing this proposed withdrawal, a spokeswoman for the company said in an e-mail.

The rate of death, or “fatal adverse event” in researcher-speak, hit 2.5% for patients who took Avastin, known generically as bevacizumab, and a chemotherapy drug. That compared to 1.5% for those who took chemotherapy drugs alone. The most common causes of death were hemorrhage, neutropenia and gastorintestinal tract perforation. Here’s the study abstract.

And by definition, “fatal adverse event” means the death was probably caused by a drug.

Avastin made news in December when the Food and Drug Administration moved to begin the process of withdrawing approval of Avastin as a treatment for breast cancer because the federal agency found no evidence that it extended the lives of women who had the disease. Drug maker Genentech requested a hearing appealing this proposed withdrawal. In that action, the drug was still approved for kidney, brain and lung cancers.

The researchers write in conclusion: “It is important for physicians and patients to recognize the risks as well as the benefits associated with bevacizumab treatment and to monitor closely to identify and treat serious adverse effects.”

It’s likely we’ll be hearing more about this apparent connection in the months and years to come.