The Alere INRatio® and INRatio®2 PT/INR Monitoring Systems are being withdrawn from the US market because they may provide inaccurate international normalized ratio (INR) results.
These handheld blood coagulation systems, which consist of a small monitor and disposable test strips, are used to monitor patients taking warfarin.
The manufacturer of these systems, Alere Inc., said it is working with the US Food and Drug Administration (FDA) to determine the most appropriate timing for product discontinuation.
The company also said it will provide guidance on transitioning patients using the INRatio systems to an alternate solution to allow them to continue anticoagulation monitoring in the least disruptive manner possible.
Background on the withdrawal
In December 2014, Alere initiated a voluntary correction to inform users of the INRatio® and INRatio®2 PT/INR Monitoring Systems that patients with certain medical conditions should not be tested with the systems.
The company found that, in certain cases, the systems provided an INR result that was clinically significantly lower than a result obtained using a reference INR system (laboratory method).
In fact, there has been speculation that this issue may have affected the results of the ROCKET AF trial, a comparison of rivaroxaban and warfarin in which INRs were measured with the INRatio systems.
The FDA is currently investigating this possibility, although the European Medicines Agency has said the study’s overall results were not affected by the issue.
After Alere reported the issue with the INRatio systems to the FDA, the company began conducting its own investigation.
Over the past 2 years, Alere invested in the research and development of software enhancements to address the potential of the INRatio systems to deliver results that differ from laboratory INR measurement.
Alere said it is confident the software enhancements it developed and submitted to the FDA at the end of 2015 effectively address this issue.
However, the FDA said the company’s studies do not adequately demonstrate the effectiveness of the software modification. The agency therefore advised Alere to submit a proposed plan to voluntarily remove the INRatio systems from the market.
The company decided to follow this recommendation and plans to provide a timeline to discontinue the product line. Alere said it will provide further information on patient transition to patients and healthcare providers.
For more information regarding this product discontinuation, visit http://www.inr-care.com.
