Abstract
Background/Aims: The introduction of anti-tumor necrosis factor-α antibodies transformed the landscape of inflammatory bowel disease (IBD) treatment. Because biologics are associated with increased medical costs, the use of biosimilars (BS) is recommended. However, high-quality evidence on the efficacy of BS in Japan remains limited. Therefore, this study aimed to evaluate the efficacy and safety of BS in patients with IBD.Methods: Patients with IBD who underwent a non-medical switch (NMS) from infliximab originator (IFX-O) to IFX-BS at Fukuoka University Chikushi Hospital were prospectively evaluated. The observation period was up to 56 weeks after the NMS, and the rate of continuation, clinical remission at 56 weeks, safety, and changes in trough concentration were analyzed. Moreover, a questionnaire survey regarding BS and NMS was conducted.Results: A total of 167 patients were included in this study. The continuation rate for IFX-BS therapy after NMS was high (95.6%). The remission maintenance rate at 56 weeks was 85.7% for patients with Crohn’s disease and 77.8% for patients with ulcerative colitis. Adverse events were observed in 22.8% of patients. However, only 2 severe adverse events were recorded. The ratios of trough concentrations at 8, 24, and 56 weeks to that at week 0 were 115.6%, 101.2%, and 123.5%, respectively, indicating statistical non-inferiority. In a questionnaire survey, only 6.2% of the patients were aware of BS, however, more than half of them agreed with the NMS recommendation.Conclusions: The efficacy and safety of IFX-BS after NMS are high. In addition, its trough concentration is serologically non-inferior to baseline values.