Xarelto Study Not Affected By Faulty Monitoring Device, FDA Says

Federal regulators say they do not believe a potentially defective blood monitoring device used during Xarelto clinical trials influenced the decision to approve the new-generation anticoagulant. 

This week, the FDA issued a re-analysis of the phase III ROCKET AF clinical trials (PDF), which was the basis for the agency’s decision to approve Xarelto. The study has come under fire by a number of critics in recent years, raising concerns that potential problems with the Alere INRatio device, which was used during the trials, but later recalled due to potentially inaccuracies.

In March, the New York Times reported that editors at the New England Journal of Medicine had expressed concerns that they had been lied to by researchers out of Duke University, who ran the ROCKET AF trials. The report indicated that the editors felt they had been misled about the existence of data on the INRatio which would have raised questions about the accuracy of the trial’s results.

An Alere InRation recall was announced by the FDA in July 2016, after the agency found that the manufacturer of the device failed to fix inaccuracies with the blood thinner monitor in 2014, following 19,000 reports of incorrect results by consumers and health care professionals, 14 of which resulted in serious injuries.

The Xarelto blood testing problems in the clinical trial were first reported in the medical journal The BMJ in December, with researchers warning that the device may have led to an underestimation of the rate of Xarelto bleeding complications in comparison to warfarin.

The ROCKET-AF clinical trials compared the rate of bleeding events between Xarelto (rivaroxaban) and Coumadin (warfarin). The Alere INRatio was used to measure the levels of warfarin in patients’ blood and was used to adjust their dosage. The FDA announced it would review the trial results in light of concerns over the Alere INRatio recall. According to the findings, the agency determined that the device did not affect the trial results.

“The Agency has determined that effects on strokes or bleeding, including bleeding in the head, were minimal,” the FDA concluded. “The FDA concludes that Xarelto is a safe and effective alternative to warfarin in patients with atrial fibrillation.”

The agency said it conducted a variety of analyses to reach its conclusions, however, some have already cast doubts on the FDA’s positions on Xarelto since the new commissioner, Dr. Robert Cardiff, led the Xarelto clinical trials before he was appointed to head the agency.

Xarelto Lawsuits Over Bleeding Problems

Xarelto (rivaroxaban) is part of a new class of blood thinners introduced in recent years as a replacement for warfarin, which had been the go-to anticoagulation treatment for decades. Since it was approved in 2011, this new-generation treatment has been commonly prescribed instead of warfarin for reduction of the risk of blood clots and strokes among patients with atrial fibrillation, or following hip or knee replacement surgery.

Amid allegations that the drug makers failed to adequately warn about the risk of bleeding, nearly 11,000 Xarelto lawsuits have been filed in courts throughout the U.S., each raising similar allegations that plaintiffs suffered severe and sometimes fatal injuries due to uncontrollable bleeding while on the medication.

While users of warfarin can be given a dose of vitamin K to reduce the blood thinning effects of the medication, there were no similar reversal agents available for Xarelto at the time it was introduced, placing doctors in a position where they were unable to control many bleeding problems.

Lawsuits also allege that the drug makers provided false and misleading information about the importance of blood monitoring on Xarelto, marketing the drug as easier to use and indicating that it does not require close testing like warfarin. However, independent studies published after the medication was introduced have suggested that Xarelto monitoring may help identify patients at greater risk of bleeds.

As part of the coordinated proceedings in the federal Xarelto litigation, a small group of “bellwether” cases are being prepared for early trial dates, which are expected to begin early next year to help gauge how juries may respond to certain evidence that has been obtained during the discovery process.

While the outcome of these early bellwether trials will not be binding in other cases, they may facilitate Xarelto settlement negotiations that will avoid the need for thousands of individual cases to go to trial nationwide.