Under Medicare Part D drug benefits, the biosimilar infliximab-dyyb was only 18% less expensive than the infliximab reference product, exceeding $14,000 annually, according to a research letter published in JAMA.
The researchers noted that without biosimilar gap discounts, annual out-of-pocket costs for beneficiaries would actually be higher for infliximab-dyyb (Inflectra, Celltrion/Pfizer) than infliximab (Remicade, Janssen).
Although Congress empowered the FDA to approve biosimilars to foster competition and lower costs, “for the more than 43 million beneficiaries with Medicare Part D drug benefits, it is unclear whether biosimilars lower out-of-pocket costs given Part D’s complex cost-sharing structure,” Jinoos Yazdany, MD, MPH, associate professor at the University of California, San Francisco School of Medicine, and colleagues wrote. “Currently, beneficiaries receive a 50% manufacturer discount during the gap for brand-name drugs and biologics, but not for biosimilars.”
To determine how the recent Bipartisan Budget Act, which requires gap discounts for biosimilars beginning in 2019, is expected to impact patients’ out-of-pocket costs, the researchers assessed coverage and cost-sharing for infliximab-dyyb, the second biosimilar to be approved in the United States, compared with its reference product, infliximab.
To assess mean total cost and out-of-pocket requirements for infliximab-dyyb and infliximab, Yazdany and colleagues examined benefit design data for all Part D plans from the June 2017 Medicare Prescription Drug Plan Formulary, Pharmacy Network and Pricing Information Files, assuming each patient adhered to a standard 8-week dosing regimen or 6.5 prescriptions annually.
The researchers then used these national means to extrapolate maximum annual out-of-pocket costs if Medicare beneficiaries used each drug under a standard 2017 Part D benefit, which included a $400 deductible, coverage gap beginning at $3,700 in drug costs, as well as catastrophic coverage when out-of-pocket costs exceeded $4,950.
According to the researchers, infliximab-dyyb exhibited moderately lower mean total cost compared with infliximab, for both 8-week ($2,185 vs. $2,667) and yearly ($14,202 vs. $17,335) prescriptions. However, all Part D plans required coinsurance cost-sharing for infliximab-dyyb, and set coinsurance rates comparable to infliximab (26.6% vs. 28.4% of drug cost). Yazdany and colleagues noted that without the coverage gap discounts, projected annual out-of-pocket costs were, in fact, higher for infliximab-dyyb than infliximab ($5,118 vs. $3,432).
In addition, among the 2,547 Part D plans examined by the researchers, significantly fewer plans covered infliximab-dyyb (10%) than infliximab (96%).
“Without biosimilar gap discounts in 2017, beneficiaries would have paid more than $5,100 for infliximab-dyyb or nearly $1,700 more in projected out-of-pocket costs than infliximab,” Yazdany and colleagues wrote. “Although biosimilar gap discounts begin in 2019, infliximab-dyyb may still not significantly reduce Part D beneficiaries’ out-of-pocket costs given its high price and coinsurance cost-sharing similar to infliximab. Further policies are needed to address affordability and access to specialty drugs.”– by Robert Stott
Disclosure: Yazdany reports receiving an independent investigator award from Pfizer. The other authors report no relevant financial disclosures.