Medicare fails to ‘keep up with’ Medicaid, private market on infliximab biosimilar uptake
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Key takeaways:
- Medicare uptake of infliximab biosimilars remains low, prescribed to only 23% of patients.
- Medicaid and private insurance report significantly greater and faster uptake of infliximab biosimilars.
SAN DIEGO — Compared with Medicaid and private insurance, Medicare has lagged significantly in adopting infliximab biosimilars despite the multiple options now available, according to data presented at ACR Convergence 2023.
“The United States spends more on prescription drugs than any other country in the world, [and] more than $4 billion was spent on infliximab [Remicade, Janssen] in 2020,” Eric Roberts, PhD, MPH, a research statistical analyst at University of California, San Francisco, told Healio. “Biosimilars were meant to drive down drug costs by increasing marketplace competition. However, compared to other biosimilar drugs that have been introduced in the U.S., infliximab has had the slowest uptake. Moreover, biosimilar infliximab uptake has lagged behind many European countries.”
He added: “The biggest difference between the U.S. and Europe in terms of drug pricing is our multiplicity of health insurance coverages and reduced ability to negotiate drug prices.”
To investigate the varying rates of infliximab biosimilar adoption among the three major U.S. health insurance programs — Medicare, Medicaid and private insurance — Roberts and colleagues examined data from the RISE registry and compared the rates of biosimilar uptake following each biosimilar infliximab approval from 2016 to 2022.
The researchers evaluated all bio-originator and biosimilar infliximab recipients aged older than 18 years following the release of infliximab-dyyb (Inflectra, Celltrion/Pfizer) in November 2016 through March 2022, categorizing patients by coverage type — Medicare, Medicaid or private insurance. Patients who had both Medicare and Medicaid were assigned to the Medicaid group.
Roberts and colleagues created a model to assess the likelihood of patients receiving a biosimilar by insurance type over time, while adjusting for age, sex, race/ethnicity and socioeconomic status.
According to the researchers, among the 422,388 administrations of infliximab products between November 2016 and March 2022, 9.6% were for a biosimilar. Following the market launch of infliximab-dyyb in 2016, the researchers observed that biosimilar uptake was low across all insurance types, used among fewer than 5% of patients.
“With the infliximab-abda [Renflexis, Samsung and Merck] market launch in July 2017, Medicaid was the only insurance to show a rapid increase in uptake reaching 17% over 3 years — a 5.7-fold increase — compared to 12% and 10% for Medicare and private insurance, respectively,” Roberts said.
However, after infliximab-axxq (Avsola, Amgen) launched in July 2020, the researchers observed that biosimilar uptake surged for both Medicaid (44%) and private insurance (38%), while Medicare uptake was relatively modest (23%).
“These results demonstrate that the Medicare program, the largest federal insurance program in the U.S., has not supported robust biosimilar uptake and competition, and has not kept up with private insurers or Medicaid in terms of biosimilar infliximab uptake,” Roberts told Healio.
The researchers noted that significant patient savings could be gained through the use of biosimilars without risks to patient health — benefits that Medicare has been more reluctant to take advantage of.
“The next step is to understand the poor uptake of biosimilar infliximab for Medicare patients particularly compared to the greater and quicker uptake among Medicaid patients,” Roberts told Healio. “This likely is related to manufacturer rebates and financial incentives to switch. Pricing systems are the result of political decisions; understanding how we can ensure fair pricing for all patients can help ensure the health of patients.”