Study: Branded Direct Oral Anticoagulants Raised Medicare Part D Spending

Competition among branded products did not substantially curb annual spending increases.

Since 2011, Medicare spending on oral anticoagulants has increased 16-fold to more than $7 billion annually, accounting for 5.9% of Part D spending in 2019, according to a research letter published July 23, 2021, in JAMA Health Forum.

Spending growth was driven by rising Part D enrollment, increased oral anticoagulant use, a shift from warfarin to direct oral anticoagulants (DOACs), and rising costs.

The 2019, the three most commonly used medications were Eliquis (apixaban) accounting for 41.4% of prescriptions and 59.5% of spending. Generic warfarin accounted for 29.6% of prescriptions; 1.6% of spending. Xarelto (rivaroxaban) accounted for 21.6% of prescriptions and 33.2% of spending.

Eliquis and Xarelto exhibited nearly identical cost growth, with average annual increases of 9.3% for Eliquis and 9.5% for Xarelto. For generic warfarin, annual estimated costs decreased by 27.6% over the study period.

Investigators found that competition among branded direct oral anticoagulants did not substantially curb annual spending increases, and they say this suggests a lack of price competition. The exception was Pradaxa (dabigatran), which faces a disadvantage because it requires multiple doses a day, investigators said the price of Praxada fell slightly from 2017.

Investigators used the Medicare Part D Prescription Drug Event file, which includes annual aggregate data for all Medicare Advantage and stand-alone Part D plans, to study oral anticoagulant use between 2011 and 2019.

They suggest that generic DOACs can help ensure competition prevents unsustainable Medicare drug spending. The first generic for Eliquis was approved by the FDA in December 2019. But the product has not become available because of patent litigation with Eliquis’ developers Bristol-Myers Squibb and Pfizer.

There is no generic approved for Xarelto.