Abstracts presented at EULAR 2023 highlighted the impact that a mandatory switching policy had on biosimilar uptake in British Columbia, Canada, and the lack of uptake when no such policy was in place in the United States.
Mandatory switching policies can help accelerate biosimilar uptake. Two posters presented at EULAR 2023, the annual European congress of rheumatology, analyzed uptake in Canada after a mandatory switch policy was implemented and uptake in the United States, where there is no such policy.
In one abstract, researchers sought to evaluate the impact of the Biosimilars Initiative in British Columbia, Canada, on uptake and spending for infliximab, etanercept, and adalimumab biosimilars.1 In 2019, British Columbia was the first jurisdiction in Canada to implement a mandatory switch policy for patients with inflammatory arthritis. The Biosimilars Initiative initially covered infliximab and etanercept and was expanded to adalimumab in 2021.
Through the initiative, patients must switch to biosimilars in order to maintain public insurance coverage, although coverage of the reference products was allowed if medically necessary.
Using administrative claims data from January 2013 to March 2023, the researchers evaluated 2 groups affected by policy interventions: (1) patients who were required to start on the biosimilar versions when they initiated treatment (new start policy) and (2) patients who were already receiving reference products and were required to switch to a biosimilar to maintain coverage (mandatory switching). The new start policy was implemented between February 2016 and July 2017 and the mandatory switching policy was implemented between May and November 2019 for infliximab and etanercept and between April and October 2021 for adalimumab.
The study included 208,984 residents of British Columbia 18 years or older who were treated with etanercept or infliximab. There was only a small gradual increase of 0.65% in the proportion of biosimilar etanercept prescriptions dispensed after the new start policy was implemented.
However, there was a marked immediate and sustained impact on uptake when the mandatory switch policy was implemented. Under the mandatory policy, there was a sustained increase of 76.98% and 58.43% in the proportion of biosimilar etanercept and infliximab, respectively, prescriptions dispensed. Spending increased 78.22% for biosimilar etanercept and 71.23% for biosimilar infliximab. The results for adalimumab, which started switching later, were similar.
“Further analysis will examine changes in other health utilization, and long-term impact on prescribing patterns,” the authors concluded. “These findings may be particularly relevant to areas with a more concentrated insurance system where mandatory switching policies could lead to greater savings.”
Meanwhile, in the United States, where there is no mandatory switch policy, uptake of infliximab biosimilars has been slow over the last 6 years, according to a second abstract.2 There are currently 3 infliximab biosimilars on the market in the United States.
The researchers used the RISE registry to study physician prescribing and evaluate uptake between 2016, when the first infliximab biosimilar launched in the United States, and 2022. During the study period, 32,916 individuals used the reference product, 3999 used infliximab-dybb, 1369 used infliximab-abda, and 1099 used infliximab-axxq.
The authors found that the introduction of new biosimilar formulations in 2017 and 2020 had a minimal impact on increasing the uptake of infliximab biosimilars, which is below 20%.
Among 102 rheumatology practices studied:
With only small differences in patient characteristics when comparing users of the reference product and the biosimilars, the authors concluded that prescribing differences were not driven by patient characteristics, geographical region, diagnosis, and insurance.
“These findings suggest that in the absence of mandatory switching policies or other incentives, the U.S. has largely failed to achieve a robust biosimilars market, stymieing efforts to increase competition and reduce cost,” they wrote.
1. Mcclean A, Harrison M, Cheng L, et al. The impact of biosimilar switching policies in inflammatory arthritis on uptake and spending in British Columbia, Canada. Presented at: EULAR 2023 Congress; May 31-June 3, 2023; Milan, Italy. Abstract POS0564.
2. Yazdany J, Li J, Roberts E, Stovall R, Schmajuk G. Uptake of infliximab biosimilars among U.S. rheumatology practices through 2022. Presented at: EULAR 2023 Congress; May 31-June 3, 2023; Milan, Italy. Abstract POS0823.