A majority of Food and Drug Administration panelists voted against a new use for Johnson & Johnson's blood thinner Xarelto to reduce life-threatening blood clots.
The FDA's panel of experts voted 6-4 Wednesday against the new use for the pill, saying too much information was missing from company studies to accurately gauge the drug's benefit. One panel member abstained.
The FDA is not required to follow the group's advice, though it often does. A final decision is expected by June 29.
J&J already markets the pill for two patient groups: those with irregular heartbeat and those undergoing hip or knee replacement surgery.
The New Brunswick, N.J.-based company is now asking the FDA to approve it as a preventive measure against life-threatening blood clots in patients with acute coronary artery disease. That's a condition in which a narrowed blood vessel reduces flow to the heart muscle, increasing the risk of heart attack and other catastrophic problems.
The FDA's lead reviewer for the drug recommended approving the indication, based on a 15,500-patient J&J study showing Xarelto significantly reduced a combination of fatal heart problems, stroke and heart attack.
Panelists said the trial appeared successful, but they worried that the large number of patients who dropped out may have exaggerated the drug's effect. More than 2,400 patients, or 15.5 percent of the total study population, dropped out before completion. J&J argued that this drop-out rate is not unusual for a large, long-term drug study.
Panelists also worried about bleeding side effects linked to the pill. Patients taking Xarelto were three times more likely to have major internal bleeding, compared with patients taking traditional blood thinners like aspirin and Plavix. Xarelto would be used as an add-on drug, in addition to those older blood thinners. Panelists said they were skeptical about creating a new standard where patients would take three drugs to prevent blood clots.
Xarelto is part of a new group of blood thinners intended to supplant the longtime standard treatment, warfarin, which is cheap but requires frequent blood tests to get dosing right and can interact with numerous foods and other medicines. J&J markets Xarelto in the U.S., and Bayer HealthCare sells it in other regions. It was first approved in July.
Other new blood thinners include Pradaxa from Boehringer Ingelheim, which was approved in October 2010.
J&J shares fell 25 cents to close at $63.27.