Alere to Withdraw Anticoagulation Monitors From US Market

Megan Brooks


July 13, 2016

Alere Inc will be initiating a voluntary withdrawal of the Alere INRatio and INRatio2 prothrombin time/international normalized ratio (PT/INR) monitoring system because of the potential for the monitors to give inaccurate INR results, the US Food and Drug Administration (FDA) said in a safety alert posted on its website yesterday.

The withdrawal is the latest chapter in an ongoing controversy regarding INR readings obtained in the ROCKET AF trial, which had concluded that rivaroxaban (Xarelto, Bayer/Johnson & Johnson) is noninferior to warfarin for the prevention of stroke or major embolism in patients with nonvalvular atrial fibrillation. It had been alleged that the INR monitors used in the study, the same as or similar to those referenced in the current Alere announcement, had been inaccurate in a way that made warfarin therapy seem less effective.

"We are collaborating with the FDA and other global regulatory authorities to establish the detailed process for product withdrawal and discontinuation," Jackie Lustig, Alere's senior director for corporate communications, told Medscape Medical News by email.

She said the company has not disclosed publicly how many of these monitors are still being used in the United States or if any are being used outside the United States.

In December 2014, Alere initiated a voluntary "urgent correction" to alert users of the Alere INRatio and INRatio2 systems of certain medical conditions that should not be tested with the systems, which they detailed in a press release.

"In certain cases an Alere INRatio PT/INR Monitor system may provide an INR result that is clinically significantly lower than a result obtained using a reference INR system (laboratory method)," the company said in the release.

Alere proactively reported the problems to the FDA, launched an investigation, and developed software enhancements to address the issues.

But the FDA has concluded that 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," the agency said in the July 12 safety alert.

Going forward, Alere said it will provide a timeline to discontinue the product line and will provide further information to help ensure "orderly transition" for patients requiring anticoagulation monitoring. In the interim, they are advising patients to speak with their healthcare providers before making any changes to their current PT/INR monitoring practices.

Healthcare providers are encouraged to report adverse events or side effects related to the use of these products to the FDA's MedWatch Safety Information and Adverse Event Reporting Program.

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