Health Canada approved biosimilars Brenzys and Erelzi in August 2016 and April 2017, respectively. The study tracked effects of the first phase of the British Columbia Ministry of Health’s Biosimilar Initiative, which required patients to switch to biosimilars starting in May 2019.
Requiring patients to switch from originator etanercept (Enbrel) to etanercept biosimilars caused no permanent, unintended changes in patterns of health care use, suggesting the change did not harm patient health and may have even reduced disease severity, according to a Canadian study.
Health Canada approved the biosimilar products Brenzys (etanercept injection) and Erelzi (etanercept-szzs) in August 2016 and April 2017, respectively. This new study, by researchers at the University of British Columbia, tracked the effects of the first phase of the British Columbia Ministry of Health’s Biosimilar Initiative, which required patients to switch to biosimilars starting in May 2019.
Investigators used administrative data on prescriptions, diagnoses, hospital admissions and other events for 2655 individuals in the provincial health plan. They compared health services utilizations in the 3 years before the switch and during the policy implementation period. The most common diagnosis among patients in the study was rheumatoid arthritis (58.8%–63.1%), followed by psoriatic arthritis (12.6%–17.7%), juvenile rheumatoid arthritis, ankylosing spondylitis, and undetermined conditions.
During a 6-month transition period, the percentage of prescriptions for biosimilars among all etanercept refills covered by the provincial drug plan rose from 17.3% (349 of 2016 prescriptions) in May 2019 to 96.9% (1887 of 1948 prescriptions) in December 2019.
Among other results, the study authors found that the average quantity of etanercept dispensed and average number of days on other types of drugs were similar or lower in the policy cohort compared to the historical cohort.
“The direction of the change in utilization suggested a possible benefit,” they wrote. “Specifically, patients in the policy cohort had fewer days on [conventional synthetic disease-modifying antirheumatic drugs,] csDMARDS, oral steroids, and [nonsteroidal anti-inflammatory drugs], which may suggest better control of disease severity.”
The historical and policy groups also switched to different biologic DMARDs at similar rates, at 8.2%-9.7% for the historical cohorts and 9.6% for the policy cohort.
The authors observed anticipated changes during the transition, such as a transient increase of up to +0.9% in the cumulative incidence difference in first visits to physicians, and a transient increase of up to 1.7% in second visits. No difference was detected in third visits, while fourth visits had a transient increase of up to 2.6%.
For visits to rheumatologists specifically, the maximal cumulative incidence difference was an increase of 12.8% for first visits and an increase of 12.7% for second visits. No difference was observed in the cumulative incidence of emergency department visits or hospital admissions.
Other changes were minor or transient, including a transient increase (up to 3%) in first and second refills of etanercept during followup. There was no difference in third and fourth refills. By the end of the transition, 65.1% (1102) of the patients in the policy cohort had switched to a biosimilar, and 88.1% (1493) had done so by the end of a 1-year followup period.
The investigators noted different findings on health services use in similar studies of non-medical switches to biosimilars, many of which focused on treatment discontinuation. A Danish study found that the use and costs of outpatient services increased after switching to biosimilar etanercept, while costs of admissions and drugs decreased.
Studies of switches to biosimilar infliximab have found increased visits to physicians, including an 83% increase to rheumatologists and other specialists in an Italian study, and significantly higher health services costs in outpatient settings in a Turkish study.
“An increase in visits after switching…may have indicated unintended negative impacts of a policy. Further research with a design similar to the Danish studies could provide a better understanding of this change in British Columbia,” the authors wrote.
Fisher A, Kim JD, Carney G, Dormuth C. Rapid monitoring of health services use following a policy to switch patients from originator to biosimilar etanercept-a cohort study in British Columbia. BMC Rheumatol. 2022;6(1):5. Published January 27, 2022. doi:10.1186/s41927-021-00235-x.