Personalized Medicine Watch by John Russell
September 9, 2008 | Payers, physicians, and the pharmaceutical industry are closely watching CMS deliberations over whether or not to pay for a genetic-based test that provides guidance on Warfarin dosing. The FDA, which approved the test, says it’s an important tool, but the CMS isn’t so sure and opened a National Coverage Analysis (NCA) on the subject in August.
This is an important first test for personalized medicine (PM). Achieving the right dosing for the anticoagulant Warfarin is notoriously tricky. Something like half a million patients begin taking Warfarin each year and adverse affects (bleeding) are not uncommon. The test in question determines a patient’s haplotype for CYP2C, a key protein in Warfarin metabolism.
A study published in the New England Journal of Medicine earlier this year (link to abstract below) suggested genotyping for a different protein, VKORC1, was actually a better indicator and cast doubt on the CYP2C test. In any case, the initial deadline for public comment to NCA passed last week, and observers are now anxiously awaiting CMS’ decision, which will have a significant affect on patient access to these PM tests.
These are early days for personalized medicine and clearly many significant science and funding questions will arise, such as those surround the Warfarin genotyping test. Stay tuned.
Genetic Determinants of Response to Warfarin during Initial Anticoagulation, NEJM
NCA Tracking Sheet for Pharmacogenomic Testing for Warfarin Response (CAG-00400N)
Warfarin DNA Testing Reimbursement Public Comment DEADLINE Wednesday 9/3/08