FDA’s announcement Wednesday came three months after Alere withdrew its INRatio and INRatio2 PT/INR monitor systems, which were used to monitor warfarin in the ROCKET-AF trial. Results of that study, which compared warfarin to Xarelto, supported the agency’s approval of Xarelto in July 2011.
When reports surfaced that the INRatio monitors could provide inaccurate results, FDA conducted three separate reviews (clinical, statistical and clinical pharmacology) to determine whether the devices affected ROCKET-AF study findings. The agency said in a news release that “effects on strokes or bleeding, including bleeding in the head, were minimal.”
Xarelto is approved to reduce the risk of stroke and systemic embolism in patients with nonvalvular a-fib. FDA said no labeling changes or other regulatory action would be required due to issues with the INRatio monitoring systems.