Tufts Study: Most Payers Don't Give Preference to Biosimilars

Biosimilars are gaining traction in the United states, but the majority of payers are putting them on an equal footing with reference drugs when it comes to coverage decisions, according to a new study.

US health plans granted preferred status to biosimilars in just 14% of coverage decisions, according to a survey of decisions issued by 17 of the largest US commercial health plans, representing approximately 60% of commercially covered patients. By contrast, the reference product was given preferred status in 33% of decisions, and in 53% of decisions, neither the biosimilar nor the reference product was preferred.

The study was conducted by investigators from the Center for the Evaluation of Value and Risk in Health at Tufts Medical Center in Boston, Massachusetts. They evaluated 535 coverage decisions for biosimilars available in the United States in August 2019.

Investigators treated a biosimilar brand and an indication for that biosimilar as an individual coverage decision. For example, there were 5 potential coverage decisions a payer could make for Mvasi, a bevacizumab biosimilar indicated for 5 types of cancer.

There was variation in how payers covered biosimilars. Just 2 of the plans covered biosimilars as preferred products in ≥ 50% of their decisions. Two health plans always covered biosimilars and reference products with no preferences in each decision.

There was also variation in decisions regarding types of biosimilars. For example, 51% of plans gave the Zarxio filgrastim biosimilar preferred status, but 65% and 59% of plans preferred the reference product over the Renflexis and Inflectra infliximab biosimilars, respectively.

“Reasons for this variation are unknown, but may include more successful negotiation of rebates at some plans than others,” the authors wrote. They said rebates are not publicly disclosed, which makes it difficult to verify this hypothesis.

The authors concluded that their findings may help to further elucidate why uptake of biosimilars may be lagging in the United States.

“The slow uptake of biosimilars in the US has been attributed to factors such as patent disputes and reference product manufacturer tactics to delay biosimilar market entry. This study suggests that a lack of preferred coverage among health plans may also be delaying uptake,” they wrote.

Earlier this year, Health New England said that it had saved $1.7 million over a year's span by using prior authorization to spur use of biosimilar infliximab, achieving 93% utilization.

Reference

Chambers JD, Lai RC, Margaretos NM, Panzer AD, Cohen JT, Neumann PJ. Coverage for biosimilars vs reference products among US commercial health plans. JAMA. 2020;19;323(19):1972-1973. doi:10.1001/jama.2020.2229