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The Alere INRatio and INRatio2 PT/INR Monitoring System are being pulled from the market.
Alere, the manufacturer of the devices, which are used by people taking warfarin (Coumadin) to monitor their INR, said that the action follows a "collaborative process" with the FDA. The company said it "is working with the FDA to determine the most appropriate timing for product discontinuation and will provide guidance on transitioning patients to an alternate solution to allow them to continue anti-coagulation monitoring in the least disruptive manner possible."
The portable monitoring systems were relatively obscure until last year, when the findings of the pivotal ROCKET AF trial were called into question after it was revealed that the Alere device used to monitor and calibrate warfarin usage in the trial had been defective and the subject of a serious FDA recall.
Since then the FDA, the European Medicines Agency, and the trial investigators have sought to confirm the findings of ROCKET AF, which compared rivaroxaban (Xarelto) with warfarin in patients with atrial fibrillation. Recently the trial investigators published a letter in the New England Journal of Medicine comparing readings from the Alere device with stored blood samples taken during the trial. The trial investigators found that there were potentially important differences between the two methods, but that the main findings of the trial did not appear to have been compromised.
In December 2014, Alere issued the first alert informing users that the devices should not be used by patients with certain medical conditions. Alere said that, at the end of 2015, it submitted software enhancements to the FDA that corrected the earlier problems, but "the FDA notified the company that it believes the company's studies do not adequately demonstrate the effectiveness of the software modification and advised Alere to submit a proposed plan to voluntarily remove the INRatio device from the market."
In February, Abbott agreed to purchase Alere for $5.85 billion. It has since tried to back away from the deal because of a U.S. investigation into Alere's foreign operation, according to a report in Bloomberg.