Infusion Reaction Incidence after Switching All Patients to an Infliximab Biosimilar in an Australian Hospital

To date, two infliximab biosimilar brands have been approved for use in Australia. In 2020, Queensland Health encouraged biosimilar use by removing the infliximab originator from their state formulary and left only one infliximab biosimilar (Renflexis (R); Samsung Bioepis, Sydney, NSW, Australia). The aim was to conduct a quality assurance study examining the incidence of infusion reactions after switching all patients to the one approved biosimilar brand of infliximab. This was a retrospective study of medical charts of all patients who received an infliximab dose at a tertiary hospital between 10 June to 30 September 2020. The number of infusion reactions to the first dose of Renflexis (R) (Samsung Bioepis) was compared to the two doses immediately prior to the switch with an alternative brand. The study received ethics exemption (2020100904CM). A total of 370 doses of infliximab were dispensed to 139 patients, of which 320 doses (86.5%) were Renflexis (R) (Samsung Bioepis). There were three patients excluded from the study. A total of 119 patients (88%) were switched to the Renflexis (R) (Samsung Bioepis) brand and two of these patients (1.7%) experienced a true infusion reaction. When compared to doses prior to the switch, three of 116 patients (2.6%) with data available experienced an infusion reaction for the dose immediately prior, and one of 113 patients (0.9%) for two doses prior. No treatment-naive patients (n = 17) initiated on Renflexis (R) (Samsung Bioepis) experienced an infusion reaction. The use of a biosimilar infliximab, in both treatment-naive patients and those and switching from alternative brands, does not appear to have an increased incidence of infusion reactions.