FDA Advisory Panel Backs Xarelto to Prevent Strokes

Sept. 8, 2011 -- An FDA advisory panel has voted to recommend approval of a new blood thinner to prevent strokes and dangerous blood clots in patients with the heart rhythm disorder atrial fibrillation.

In a vote of nine to two, with one member abstaining, the panel said Xarelto (rivaroxaban) was at least as safe and effective as the older drug warfarin.

Warfarin is also sold under the brand names Coumadin and Jantoven.

The vote puts the panel at odds with the FDA's own reviewers, who recommended against approval in a 388-page report released in advance of the meeting.

The FDA is not required to follow the panel's recommendation, but often does.

"Having treated thousands of patients with atrial fibrillation and dealt with the tremendous problems of using warfarin and patients having issues with warfarin, I think there's a tremendous unmet medical need for new therapies," says panel member Philip Sager, MD, in explaining his vote for approval. Sager is a pharmaceutical consultant and chair of the scientific programs committee of the Cardiac Safety Research Consortium in San Francisco.

Others said they felt "fatal flaws" in the way the drug was studied and lingering questions about the safest way to give it were reasons to vote no.

"When you deal with a morbid, mortal complication like [stroke], we owe patients the best therapy we can get," says panel member Steven Nissen, MD, chair of the department of cardiovascular medicine at the Cleveland Clinic. "It makes me concerned that this may be a step back, rather than a step forward."

The vote was a boost for the drug's developers, Johnson & Johnson and partner Bayer Healthcare. The drugmakers see Xarelto as a potential blockbuster treatment for atrial fibrillation, a condition that's becoming more common in an aging population.

Xarelto was approved in July to prevent blood clots in people having hip and knee replacement surgery.

As many as 2.2 million Americans have atrial fibrillation, a condition that causes the heart to beat in an irregular and uncoordinated way. When that happens, blood may pool and clot in the heart's upper chambers. Those blood clots can then break free and travel to the brain, causing strokes and other dangerous complications.

Studies have shown that people with atrial fibrillation have an increased risk of having a stroke compared to people without the condition.

Questions About Study Design

The panel's discussion centered on the findings of the company-sponsored ROCKET-AF study. The results of that study were published last month in The New England Journal of Medicine.

Panel members say they were particularly concerned that many of the patients in the study who were taking warfarin didn't seem to have been getting optimal doses of that drug.

As a result, FDA reviewers said, Xarelto may have looked more effective in the study than it actually was.