FDA clears blood thinner for irregular heartbeat

[November 05, 2011]  WASHINGTON (AP) -- More than 2 million new U.S. patients will be eligible to receive a next-generation blood thinner drug called Xarelto, after the Food and Drug Administration approved the medication to treat a common heart problem that can lead to stroke.

Federal health officials approved the drug from Johnson & Johnson and Bayer to prevent strokes in patients with atrial fibrillation, a condition that causes the heart's upper chambers beat chaotically and ineffectively. The irregular heartbeats can cause blood clots which travel to the brain, blocking blood flow and occasionally causing a stroke.

"This approval gives doctors and patients another treatment option for a condition that must be managed carefully," said Dr. Norman Stockbridge, director of FDA's cardiovascular and renal products division.

The once-a-day pill was first approved in July to prevent strokes in patients receiving hip and knee replacements. Today's approval expands the drug's indication to the much larger group of roughly 2.2 million Americans with atrial fibrillation.

For more than half a century, atrial fibrillation patients have relied on the tough-to-use blood thinner warfarin, sold under the brand name Coumadin. Doctors often have trouble gauging the right dose of the drug for each patient. Too much warfarin can cause dangerous internal bleeding, and too little can result in strokes.

In a setback for the drugs' developers, the FDA did not approve a manufacturer-requested claim that Xarelto was superior at preventing stroke and blood clots when compared with warfarin. Instead the FDA states that the companies' 14,000-patient study showed Xarelto and warfarin were about the same in preventing stroke.

Also, the FDA added a boxed safety warning, the most serious kind, stating that patients should not stop taking Xarelto without notifying their doctors first. Discontinuing the drug can increase the risk of stroke.

Numerous drugmakers have been working to develop an updated alternative to warfarin, one of the most widely-used medications in the U.S. Last year U.S. pharmacies filled 32 million prescriptions for warfarin, according to data tracker IMS Health.

Last October, the FDA approved the first alternative to warfarin for atrial fibrillation -- Pradaxa, known chemically as dabigatran, made by the German company Boehringer Ingelheim. That drug's label states that the daily pill "significantly reduced" stroke and blood clots in a study of 18,000 patients.

In September a panel of outside advisers to the FDA voted 9-2 to recommend approval for use in atrial fibrillation. The panel's recommendation came despite questions from FDA scientists about the reliability of some data submitted on Xarelto.

Xarelto is the first in a new class of blood thinning drugs that work by blocking a clotting protein called factor Xa. Older blood thinners, including warfarin, work by preventing blood platelets from sticking together.

Known chemically as rivaroxaban, Xarelto was discovered by German drugmaker Bayer and co-developed with New Brunswick, N.J.-based J&J. J&J holds U.S. marketing rights to the drug while Bayer markets the drug in the rest of the world.

[Associated Press]

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