Studies find uneven uptake of biosimilars as availability increases

As biosimilars become increasingly available, they are creating a competitive market with originator products, but uptake of biosimilars among patients is varied and depends on factors like patient demographics, geography, site of care, prescriber specialty, and insurance type, according to two recent studies published in the journal Health Affairs.

Molly Beinfeld, of Tufts University, told Regulatory Focus in an interview that she and her colleagues are “somewhat optimistic” about the biosimilar market.

“Seven years of data tells us that biosimilars are gaining market share, net prices are declining, payers are prioritizing biosimilars and the biologics market is competitive,” she said.

In their study, Beinfeld and colleagues evaluated seven originator products and 20 biosimilars, using data from the Tufts Medical Center Specialty Drug Evidence and Coverage Database to identify coverage, US commercial payers claims data from the IQVIA Longitudinal Access and Adjudicated Data Set for analyzing market share, and data from the Centers for Medicare and Medicaid Services to examine average sales price quarterly payment from 2017-2022.

The researchers performed an analysis of coverage for originator drugs in relation to biosimilars for the same indication that included the proportion of a payer’s coverage with regard to preferred coverage, co-preferred coverage, and non-preferred coverage. They also analyzed market share for originator and biosimilar drugs based on the launch date of the first biosimilar, and analyzed the market share since the first biosimilar launch for an originator drug.

Overall, the results showed preference for covering a single originator or biosimilar decreased from 70% to 24% between August 2017 and August 2022, while originator preference decreased from 55% to 8%, and preference for covering multiple products increased from 30% to 76%. There was a large variation (3%-89%) in whether payers covered originator products in 2022, but nearly all payers had co-preferred coverage for products in a given indication, with 55% of policies having two co-preferred products as a first-line option, 24% having one preferred product, and 21% having three products or more.

“Market share for any individual biosimilar was around 20% on average, suggesting a very competitive market for biosimilars,” Beinfeld said.

There was also a decrease in the market share of originators after a biosimilar was introduced, with average sales price of the originator-biosimilar market decreasing to 63% at 4 years after a biosimilar was introduced, and a 91% reduction in mean wholesale acquisition after a biosimilar’s introduction. “[W]e found that it took an average of 3 years for the market share of biosimilars to exceed that of originators,” Beinfeld explained.

The studies come as benefits managers are choosing to move away from originator biologics, choosing instead to recommend biosimilar versions of the medicines. UnitedHealth Group recently decided it would remove the rheumatoid arthritis drug Humira (adalimumab) from its list of preferred drugs in 2025, following similar announcements by Cigna and Caremark earlier this year.

“We are encouraged to see large payers shift their formularies away from Humira,” Beinfeld told Focus. “[T]his is a leading indicator of how prices and market share will change over time. We believe this steady shift is consistent with the historical trends we observed in our study.”

Beinfeld said the group will continue to monitor trends in the biosimilar market, in particular the biosimilars for Humira and Stelara, and examine how the Inflation Reduction Act impacts incentives for biosimilars.

Biosimilar adoption depends varies based on patient, location, clinical factors

Uptake of biosimilars is also on the rise, but varies based on the demographics of patients, where they live, where they receive care, and their prescriber’s specialty. In a recent study, researchers from the Program on Regulation, Therapeutics, and Law (PORTAL) at Brigham and Women’s Hospital and Harvard Medical School analyzed the rates of biosimilar adoption in 196,766 patients who had commercial insurance or Medicare Advantage between 2013 and 2022.

Overall, they found biosimilar use increased from 1% in 2013 to 34% in 2022, and 52,936 patients (27%) in the study initiated a biosimilar. Patients had a mean age of 68.8 years, and a majority were white (69%) women (58%) enrolled in Medicare Advantage (74%). In contrast, patients under 18 years old significantly less likely to use biosimilars compared with patients 65 years and older (adjusted odds ratio, 0.33; 95% CI, 0.29-0.39; P < .001).

“This lower uptake in pediatric populations can be explained by several factors, such as biosimilars having pediatric indications carved out of their labels due to ongoing patents or FDA-granted exclusivity, or the unavailability of pediatric dosage forms for certain biosimilars,” Dongzhe Hong, PhD, a postdoctoral research fellow with PORTAL, told Focus.

There was also a difference in uptake based on biosimilar type, with biosimilar versions of filgrastim, trastuzumab, infliximab, rituximab, and epoetin alfa being more popular in 2022 than biosimilar versions of pegfilgrastim and bevacizumab.

Patients were less likely to initiate a biosimilar if it was administered in a physician office compared with a hospital outpatient setting (adjusted OR = 0.65; 95% CI, 95% CI, 0.62-0.67; P < .001), were more likely to initiate a biosimilar if they lived in the US South (adjusted OR = 1.26; 95% CI, 1.21-1.32; P < .001) and US West (adjusted OR = 1.36; 95% CI, 1.30-1.43; P < .001) compared to the US Northeast, and were more likely to initiate a biosimilar if it was prescribed by a generalist physician compared to a specialist (adjusted OR = 1.17; 95% CI, 1.11-1.24; P < .001).

“Lower biosimilar initiation in office settings compared with hospital outpatient settings may be partially attributed to different drug pricing programs and reimbursement policies between hospitals and physician offices,” Hong told Focus. “Paradoxically, provider organizations can be financially incentivized to use higher-priced drugs to maximize revenue, particularly if they can purchase them at discounted prices through the 340B program.”

The researchers said their findings may be relevant for policymakers who want to lower prescription drug spending and increase affordability of medications. Hong proposed three area where policymakers could focus their efforts: streamlining the FDA approval pathway, addressing patient thickets, and increasing educational efforts.

Regarding the FDA approval pathway, “simplifying and expediting the regulatory process for biosimilars, particularly through fast-track designations in high-need therapeutic areas, would encourage faster market entry,” Hong said.

Another area of focus is in reducing patent protections on biologics, reducing the exclusivity period for originator biologics to 7 years instead of 12 years, and introducing step therapy with biologics in formularies before moving on to a reference biologic.

“As biosimilars gain more visibility and are integrated into formularies, the competition they generate can reduce costs and expand access to these therapies. However, achieving larger market potential will also depend on the FDA granting interchangeability designations, which allow for substitution without prescriber intervention,” Hong explained. “These moves are in line with our study’s findings, which emphasize that payer-driven initiatives and regulatory support are essential to accelerating biosimilar adoption.”

Education is also important, including “educational efforts directed at reducing biosimilar skepticism among health care providers and patients,” Hong said.

While their study examined biosimilars in healthcare provider settings, Hong noted future research should look at self-administered biologics like insulin “to understand the broader implications of biosimilar adoption across different medication types.”

Health Aff Beinfeld et al.
Health Aff Hong et al.

Studies find uneven uptake of biosimilars as availability increases

Related topics

Recommended content

Welcome to the new RAPS Digital Experience