British Columbia (BC) first province Implement a mandatory non-medical switch policy from infliximab (Remicade) to biosimilars in Canada. Phase 1 of the biosimilar program began on May 27, 2019, focusing on rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis and plaque psoriasis. The province’s drug program has since approved infliximab biosimilars for these conditions only, and requires all patients taking the reference product to switch within a six-month transition period.
A recent study, published in CMAJ Open, designed to examine any impact on health service utilization in the first year of British Columbia’s biosimilars program to inform policymakers. Patients and physicians are concerned about non-medical switching “despite evidence that switching is not associated with negative health effects,” and mandatory switching policies must be closely monitored “to provide early data on the safety of these policies,” the researchers wrote.
Using the British Columbia Department of Health database, the authors constructed three historical cohorts between 2016 and 2018 and one policy cohort of infliximab-treated patients with inflammatory arthritis or psoriasis in 2019. They followed each cohort for 1 year starting May 27, using data on drug and health service utilization outcomes as indicators of patient health. Notably, patients with inflammatory bowel disease (IBD) were not included in the first phase of the policy change, nor were they included in the study.
A total of 572 unique patients were included: 520 in the 2016 cohort, 461 in the 2017 cohort, 423 in the 2018 cohort, and 377 in the policy cohort. Many patients were in multiple cohorts, and 335 (58.6%) were included in all 4 cohorts. The 2016-2018 historical cohort reflects healthcare utilization prior to the policy shift.
In all cohorts, approximately half of the patients (50.4% to 53.5%) had rheumatoid arthritis. Psoriasis was the least common diagnosis (3.3% to 4.0% of patients). Patients in the policy cohort used fewer synthetic anti-inflammatory drugs than those in the historical cohort, but the researchers found no other differences in baseline characteristics between the cohorts.
In the policy cohort, 233 patients (61.8%) switched to infliximab biosimilar products after a 6-month transition period. Within 1 year of the policy taking effect, 329 (87.3%) had switched.
In the entire cohort, most patients refilled their infliximab prescriptions at least 4 times during the 1-year follow-up period. Although the first 3 refills were similar between cohorts, there were approximately 7.2% fewer patients in the policy cohort who were prescribed a fourth refill from January 14 to February 25 (2020) compared with the historical cohort.
The authors explained this “transient small reduction” in infliximab supplementation as a delay in the fourth refill for patients in the policy cohort. They speculate that this reduction may represent an attempt to stop treatment after remission, then flare up and restart treatment. However, they said, “in the absence of clinical data, we could not confirm this explanation.” The researchers said that since they did not observe an increase in switching to a different biologic during this period, and the decrease was temporary , so “both are encouraging signs in terms of safety.”
Overall, there was no increase in the use of other anti-inflammatory drugs in the policy cohort compared with the historical cohort. Compared with the historical cohort, the policy cohort showed less use of synthetic disease-modifying antirheumatic drugs (DMARDs) and NSAIDs, but similar use of oral corticosteroids. “We see this as a positive sign; that is, fewer patients in the policy cohort had symptoms while receiving biosimilars,” the authors wrote.
health service utilization
The first emergency department visit and first discharge were similar between the policy cohort and the historical cohort. While outpatient visits to any physician were similar between the different cohorts, the first visit occurred at an earlier time in the policy cohort, and about 15% of patients in the policy cohort had multiple visits to specialists compared to the historical cohort.
The researchers anticipated increased visits to rheumatology and dermatology specialists by patients in the policy cohort “as patients may discuss switching with their specialists.” A similar increase was observed in previous studies, they noted.
Monitoring “did not detect signals negatively impacting health service use”
Aside from a brief reduction in the fourth infliximab refill and an expected increase in specialist visits, the researchers said they “did not observe a negative impact of infliximab policy on health service utilization during the first year of follow-up. Signal.”
In conclusion, they said, there was no increase in switching to a different biologic or DMARD, no increase in other anti-inflammatory drugs, and no increase in emergency department visits or hospitalizations. They also noted that during the months analyzed in 2020, COVID-19 “had no discernible impact on health service utilization for these patients.”
Their findings “support the safety of the biosimilar program for infliximab users,” but say that “detailed, long-term cohort studies and hypothesis-testing approaches could provide additional assurance about the policy’s safety.” “
Fisher A, Kim JD, Dormuth CR. Mandatory nonmedical switching from innovator to biosimilar infliximab in British Columbia patients with inflammatory arthritis and psoriasis: a cohort study. CMAJ Open. 2022;10(1):E109-E118. doi:10.9778/cmajo.20200319