By Charles R. Babcock and David Hilzenrath
The FDA is asking for help addressing the “safety and effectiveness” of portable devices used to perform blood tests on patients taking the widely used blood thinner warfarin.
The agency said it will hold a public workshop about the devices on January 25 “to seek and identify potential solutions” to what it described as “scientific and regulatory challenges.” The blood tests are meant to make sure patients are not prescribed too much or too little of the drug, which would put them at heightened risk of bleeding or stroke.
An FDA notice about the meeting was dated Dec. 7, a few weeks after the Project On Government Oversight spotlighted a series of problems spanning several years involving testing devices marketed under the name “INRatio.” Those have been the subject of FDA warning letters and recalls. A 2014 recall said affected devices could produce false readings and cause “severe or life-threatening injuries, including death.”
A new POGO review of FDA records found recalls in recent years involving other brands of devices made for the same purpose.
A clinical trial of the blood thinner Xarelto relied on INRatio devices, POGO reported in November. Based on the clinical trial, which compared Xarelto to warfarin, in 2011 the FDA approved Xarelto for use in patients with atrial fibrillation, a cardiac condition that can cause clots and strokes and afflicts millions of people in the United States. President Obama’s FDA commissioner nominee, former Duke University researcher Robert Califf, was a leader of that Xarelto trial and shared responsibility for its design and oversight.
The December 2014 INRatio recall was a Class I, the most serious type. However, the agency did not require that the products, produced by Alere of San Diego, be retrieved from doctors or patients, company spokeswoman Jackie Lustig told POGO last month. They remain in use, and Alere is still trying to develop a software upgrade to “address the potential for inaccuracies,” Lustig said.
An Alere representative will make a presentation at the FDA workshop, Lustig said last week.
A European regulatory agency has opened an investigation into whether INRatio devices yielded inaccurate readings in the Xarelto trial, thereby compromising the trial results. The FDA has said it is “reviewing relevant data.” The companies that market Xarelto—Bayer and Janssen, a subsidiary of Johnson & Johnson—have said their analyses confirm the trial results. The Duke Clinical Research Institute, which Califf formerly headed, posted a statement saying that results of a new analysis were consistent with the results from original trial. The Duke institute coordinated the original trial and was essentially reviewing its own work.
The testing devices are used to determine how fast patients’ blood is clotting—whether it is too thick or too thin—and how if at all their warfarin dosing should be adjusted. They are known as PT/INR devices after two measures of clotting time.
Clotting time can be measured using portable devices or by taking blood samples and sending them to laboratories for analysis. The FDA workshop is focused on the portable “point of care” devices, which are used in doctors’ offices and, on a do-it-yourself basis, in patients’ homes.
FDA spokeswoman Deborah Kotz declined to say what prompted the FDA to schedule the upcoming public meeting or what problems it is meant to address.
The POGO search of FDA databases found recalls involving other brands of point of care PT/INR devices. Those were class II and III recalls, meaning they were less serious. For example, according to the FDA website, a Class II recall applies when a product “may cause temporary or medically reversible adverse health consequences or where the probability of serious adverse health consequences is remote.”
For example, in May 2013, Roche Diagnostics Operations Inc. of Indianapolis issued an “Urgent Medical Device Correction” letter after it “confirmed the potential for an undetected elevated INR test result” with its CoaguChek XS meters. Some drug combinations with warfarin “could potentially lead to an extremely high test result,” the company said.
In October 2013, Abbott Point of Care Inc. of Princeton, N.J., issued an “Urgent Recall Notice” after it determined that some of its i-Stat PT/INR cartridges “have the potential to exhibit incorrectly elevated INR.”
In March 2012, Abbott had issued an “URGENT RECALL NOTICE” after finding other i-Stat PT/INR cartridges had the same potential problem.
Roche executives did not respond to requests for comment. Abbott spokeswoman Darcy Ross said she was looking into the recalls.
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