A149 REAL WORLD OUTCOMES OF NON-MEDICAL SWITCHING OF INFLIXIMAB BIOSIMILAR IN BRITISH COLUMBIA FOR THE TREATMENT OF INFLAMMATORY BOWEL DISEASE (IBD)

Abstract

Abstract Background A mandated non-medical switch to the infliximab biosimilars was launched in British Columbia in 2019. British Columbia was the first province in Canada to mandate the switch from the originator infliximab (RemicadeTM) to one of the 2 approved biosimilars (InflectraTM or RenflexisTM). There is limited data for mandatory non-medical switching in IBD as was undertaken in BC. Aims This study aimed to obtain real-world evidence evaluating the clinical outcomes of nonmedical switch from Remicade to the infliximab biosimilars. Methods This is a retrospective observational study from the IBD Centre of BC (a tertiary care referral centre in Vancouver, BC). Patients on infliximab at the time of the mandated switch were identified through search of the electronic medical record. The primary outcome was drug continuation at 12 months post switch. Secondary outcomes included flare of disease, adverse events, and number of doctor visits within the first 12 months post switch. A comparison group included patients maintained on originator infliximab. Results A total of 235 patients were evaluated; 175 patients in the biosimilar switch group, and 60 patients in the control group. Baseline characteristics of the groups were similar. Discontinuation of infliximab occurred in 22 patients (17 in biosimilar switch group and 5 in the control group. There was no difference in the rate of discontinuation of infliximab between the biosimilar group (9.7%) and the originator molecule group (8.3%); chi squared (1, N=235) = 0.1004, p = .75. The most common reason for discontinuation was flare of disease in 6 patients in the biosimilar group and 4 patients in the control group. An additional 4 patients in the biosimilar group and 3 patients in the control group had a flare of symptoms but were maintained on therapy with an escalation of dosage or course of corticosteroids. Two patients had active disease at the time of switch and discontinued therapy. Adverse events accounted for discontinuation in 5 patients on biosimilar and 1 in the control group. These included joint pain, epigastric symptoms, drug intolerance, drug induced lupus, and drug induced pulmonary nodules in the biosimilar group, and drug induced vasculitis in the control group. Two patients in the biosimilar group discontinued due to antibody formation. Two patients in the biosimilar group discontinued therapy due to preference. Conclusions In this small subset of the BC IBD population undergoing a non-medical biosimilar switch of infliximab, there was no difference in the discontinuation rate between the biosimilars or the originator infliximab molecule. These findings are consistent with the existing real-world evidence. Funding Agencies None