Treating patients with the new blood thinning medication dabigatran (Pradaxa®), instead of warfarin results in significantly higher per patient costs and higher net costs per stroke avoided, according to a new study by pharmacy benefit manager Prime Therapeutics (Prime).The study will be presented today at the Academy of Managed Care Pharmacy's Educational Conference in Atlanta, Ga.
Dabigatran is a type of blood-thinning medication used to reduce the risk of stroke and blood clots in patients with non-valvular atrial fibrillation, a common heart arrhythmia. The pivotal FDA approval study (RE-LY) (1) found dabigatran may be safer than warfarin for some patients and may reduce the risk of stroke more than warfarin. Unlike warfarin, which has been available for more than 50 years, dabigatran does not require monthly blood tests to monitor the drug's effectiveness.
However, according to Prime's analysis, the reduction in regular lab tests doesn't outweigh significantly higher costs of dabigatran. The RE-LY study showed the number needed to treat (NNT) with dabigatran to prevent one stroke compared to warfarin was 137 patients. Based on the per patient per year (PPPY) costs, this means treating 137 patients with dabigatran instead of warfarin would result in additional medical and pharmacy costs of $279,617 to avoid one stroke at a cost of $26,407 (based on Medicare figures). Total net cost to avoid one stroke would be $253,210.
To determine these differences in cost, researchers from Prime, and the Health Care Service Corporation in Chicago, Ill., reviewed pharmacy and medical claims from two million commercial members. They identified 13,337 individuals continuously enrolled in 2009 who had a warfarin claim in January 2009, cumulative warfarin supply of at least 270 days, and at least one medical claim indicating warfarin management/monitoring.
Of the continuously enrolled members, 2,975 patients met warfarin monitoring criteria and the PPPY total warfarin management costs were $544 ($496 medical plus $48 pharmacy) while the total dabigatran PPPY costs were $2,585 ($118 medical for an estimated two office visits and $2,467 pharmacy).
"Dabigatran is attractive to patients because of its convenience and potential clinical benefit, but its convenience comes at a high cost," said Patrick Gleason, PharmD, director of clinical outcomes assessment at Prime. "Even when we consider the savings from fewer blood tests, there is a substantial increase in cost to treat patients with dabigatran compared to warfarin to prevent one stroke. Health plans should weigh the benefits and added costs when making decisions about where dabigatran should be placed on a formulary."
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