The Centers for Medicare & Medicaid Services (CMS) has decided that current evidence does not demonstrate that pharmacogenomic testing to predict warfarin responsiveness improves health outcomes in Medicare beneficiaries, and has suggested that coverage with evidence development (CED) is appropriate.

As a result, it is proposing that pharmacogenomic testing to predict warfarin responsiveness is covered only when provided to Medicare beneficiaries who are candidates for anticoagulation therapy with warfarin, and only then in the context of a prospective, randomized, controlled clinical study when that study meets these standards: A study seeking Medicare payment for pharmacogenomic testing to predict warfarin responsiveness provided to the beneficiary pursuant to CED must address one or more aspects of the following question.

Physicians currently base the dosage on several factors, including age and weight, and then every few days test whether a patient's blood is clotting properly and adjust the dosage accordingly. According to the New York Times, finding the best dose of warfarin, or Coumadin, is "notoriously tricky."

A dosage that is too small could be ineffective at preventing blood clots, while a dosage that is too large could cause internal bleeding. The NY Times reported that tens of thousands of patients visit hospitals each year because of complications from the drug. The tests cost between $50 and $500.

Prospectively, in Medicare-aged subjects whose warfarin therapy management includes pharmacogenomic testing to predict warfarin response, the agency is seeking answers about the frequency and severity of the following outcomes, compared with subjects whose warfarin therapy management does not include pharmacogenomic testing:

• Major hemorrhage;
• Minor hemorrhage;
• Thromboembolism related to the primary indication for anticoagulation;
• Other thromboembolic event; and
• Mortality.

CMS is soliciting public comments for the next month on this proposed decision pursuant to the Social Security Act.