Xarelto is facing regulatory scrutiny in Europe and the U.S., after a testing device used on some participants in an important blood thinner study was found to be defective.
The study in question was known as the ROCKET AF trial, and compared the performance of Xarelto and warfarin for the prevention of stroke and systemic embolisms in patients with non-valvular atrial fibrillation. The results, which were published in The New England Journal of Medicine in 2011, indicated that Xarelto was non-inferior to warfarin in reducing those risks without significantly increasing the risk of bleeding,. The study played an important role in Xarelto’s regulatory approval, both in the U.S. and abroad.
According to The British Medical Journal, a device called INRatio was among a number of testing devices utilized during the ROCKET AF trial to determine how quickly blood was clotting in subjects treated with warfarin. The INRatio device was recalled in December 2014, following reports of 19,000 malfunctions that resulted in faulty test results. The U.S. Food & Drug Administration (FDA) granted Class I status to the INRatio recall, which is the agency’s most serious category.
“Due to the defect it is now thought that the INR (international normalized ratio) device may have impacted the clotting results in some patients in the warfarin group,” the European Medicines Agency (EMA) said in a statement. The EMA will now be reanalyzing those results, and plans to publish the findings when its investigation is complete.
Officials from the FDA told Reuters that the agency was “aware of concerns regarding the INR device and its use in the Rocket AF trial and is reviewing relevant data.”
News of this investigation comes as thousands of Xarelto lawsuits continue to progress in federal and state courts around the U.S. The product liability claims were filed on behalf of patients who allegedly experienced uncontrollable internal bleeding and other serious complications related to their use of the novel anticoagulant.
Xarelto was granted FDA approval in 2011. In October, Bayer reported that the medication had a 34% share of the global market for anticoagulants. Since its approval, the drug has been heavily promoted as a superior alternative for warfarin, as its use does not require patients to undergo regular blood monitoring.
Xarelto lawsuit plaintiffs allege that marketing claims touting the drug as an improvement over warfarin were misleading. Their complaints point out that there currently exists no approved antidote for reversing Xarelto’s anticoagulant effects should patients experience serious internal bleeding. Similar bleeding associated with warfarin can be stopped via the administration of vitamin K. Plaintiffs also assert that Xarelto users would actually benefit from regular blood tests to ensure appropriate dosing.