WASHINGTON (AP) -- Federal regulators have denied Johnson & Johnson's request to expand approval of its blood thinner Xarelto for a new use to prevent life-threatening blood clots in high-risk patients.
J&J said Thursday that the Food and Drug Administration responded to the company's request with additional questions about the proposed new use.
"We will continue to work with the FDA to fully address their questions as quickly as possible," Paul Burton, vice president of J&J's Janssen division, said in a statement.
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 asked the FDA in December to approve Xarelto as a preventive measure against 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.
Last month, an FDA panel of experts voted 6-4 against expanding use of the pill, saying too much information was missing from company studies to accurately gauge the drug's benefit. The FDA is not required to follow the advice of the group, which is composed of outside experts.
Panelists also expressed concerns 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 a supplemental drug 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.