NEW YORK (GenomeWeb News) - The US Food and Drug Administration this week cleared the first test to detect gene variants in patients that are sensitive to the anticoagulant warfarin. The test is made by Northbrook, Ill.-based Nanosphere.
"Today’s action offers physicians the first FDA cleared genetic test for warfarin sensitivity, which is another step in our commitment to personalized medicine,” said Daniel Schultz, director of FDA’s Center for Devices and Radiological Health, in a statement. “With this test, physicians may be able to use genetic information along with other clinical information to treat their patients.”
Warfarin, marketed as Coumadin by Bristol-Myers Squibb, is used to prevent potentially fatal clots in blood vessels. However, too much or too little of the drug in patients can cause serious, life-threatening bleeding or blood clots. Variability to warfarin response has been linked to mutations in two genes: CYP2C9 and VKORC1.
Nanosphere’s Verigene Warfarin Metabolism Nucleic Acid Test, which runs on the company’s Verigene platform, “detects some variants of both genes,” the FDA said in a statement.
The agency cleared the test based on results of a study conducted by Nanosphere of “hundreds of DNA samples as well as on a broad range of published literature.” In a three-site study, the test was “accurate in all cases where the test yielded a result,” the FDA said. However, approximately 8 percent of the tests could not identify which genetic variants were present.
In August, FDA updated labeling for warfarin with information explaining that people with variations of the genes CYP2C9 and VKORC1 may respond differently to the drug.
The agency, however, stopped short of requiring physicians in the label to genetically test their patients, noting that additional outcomes studies needed to be done.
“The Nanosphere test is not intended to be a stand-alone tool to determine optimum drug dosage, but should be used along with clinical evaluation and other tools, including [International Normalized Ratio], to determine the best treatment for patients,” the FDA said.
While Nanosphere is the first company to receive FDA approval for a warfarin test, it is not the only company with a product in this area. Kimball Genetics last year launched a warfarin sensitivity DNA test for research purposes, while Nanogen, Genelex, AutoGenomics, and Clinical Data each market home-brew warfarin tests of their own. Other companies, such as Osmetech and ParagonDx, have announced plans to develop their own tests in this area.
Nanosphere recently filed for an initial public offering, through which it hopes to raise at least $90 million.