No sign of harmful impacts related to the mandatory biosimilar switching policy for patients with inflammatory bowel diseases treated with infliximab was observed in the cohort study.
British Columbia’s Biosimilars Initiative policy, launched in September 2019, was designed for nonmedical switching from infliximab to a biosimilar for patients with inflammatory bowel diseases (IBDs). The switch was not linked to harmful impacts on either medications and health services use during the first year of the policy, according to a study published in Gastroenterology Research and Practice.1 Dose escalation increase, defined as a 25% or greater increase in daily dose, was associated with an improvement in health status proxies.
Overall spending on medications account for 44-76% of patients’ annual healthcare expenses, making biologic medications the main “cost driver.”2 To reduce these costs and reduce premiums, nonmedical switching from the biologic to lower-priced biosimilars have been encouraged.
“Recent interventional and observational studies and systematic literature reviews found similar benefits and harms related to the biosimilar infliximab compared with the originator in adult and pediatric patients with IBD,” Anat Fisher, MD, MHA, PhD, and a team of investigators, noted. “However, data on the impact of policies for a nonmedical switch are lacking, and in patients with IBDs, the surveillance to date has been limited to switching rates.”
Administrative health data from the British Columbia Minsitry of Health and the Canadian Institute for Health Information was utilized to create 3 historical cohorts during 6-month identification periods in 2016, 2017, and 2018, and 1 policy cohort of patients with IBD who were previously treated with the infliximab originator in the population-based cohort study. Information included medication records from pharmacies, outpatient visits, inpatient hospitalizations, and patient characteristics.
Investigators evaluated the incidence of medication and health services. Primary medication endpoints were the dispensation of infliximab, dose escalation, receiving a different biologic medication, antibiotic medication prescriptions for IBD-related conditions, and the new use of prednisone. Health services endpoints included outpatient visits to a physician or gastroenterologist, emergency admissions, and discharges from a hospital. Differences between the historical cohorts and the policy cohort were calculated using log-likelihood ratios.
The number of patients in the cohorts ranged between 1839 in the policy cohort and 1994-2368 in the historical cohorts. Patients were aged between 4 and 90 years, with a mean age of 43 years. Within the year following the policy launch, 92.3% of users were switched to the biosimilar. During the follow-up period, there was a 0.9% increase in the first dispensation of infliximab, either biosimilar or biologic. There was also a 16.2% increase in dose escalation, a 2.4% decrease in antibiotics, and a 2.6% decrease in new prednisone use. A 4% decrease in discharges from a hospital occurred, coupled with a 2.9% decrease in emergency admissions. A 24.0% anticipated increase in clinic visits to manage switching to biosimilars occurred.
The lack of a control group hindered differentiation between the policy’s effect and other concurrent events, including clinical guidelines or the COVID-19 pandemic, which resulted in decreased clinical visits and changes in the frequency of medication dispensation due to panic buying and manufacturing disruption. Additionally, investigators were unable to obtain records of over-the-counter medications or medications used in hospitals.
“During the first year of the British Columbia Biosimilars Initiative, we found no signal of unintended or harmful impacts of the mandatory switching policy that targeted patients with IBDs who were using infliximab,” investigators concluded. “Our results support previous findings of minimal or no harmful effects of switching to a biosimilar on patient health.”