P360 Safety and clinical efficacy of double switch from originator infliximab to biosimilars CT-P13 and SB2 in patients with inflammatory bowel diseases (SCESICS): A multicentre study

Abstract Background Since infliximab (IFX) patent expiry in 2015, several IFX biosimilars have been licensed in EU for all indications, including inflammatory bowel diseases (IBD). IFX biosimilars currently available in Italy include CT-P13 and SB2, both of which demonstrated comparable efficacy, safety and immunogenicity with IFX originator in IBD patients. Safety and clinical efficacy of single switch from originator IFX to CT-P13 have also been confirmed in a prospective clinical trial. On the contrary, data regarding multiple therapeutic switching of IFX originator with CT-P13 and SB2 are currently lacking. Methods This study was aimed to evaluate the safety and efficacy of double switch from IFX originator to CT-P13 and subsequently to SB2 in patients with IBD. From November 2018 to May 2019, patients undergoing IFX double switch in 8 Centres in Lombardy were retrospectively analysed. The overall rate of IFX discontinuation, incidence and type of adverse events (AE) and proportion of patients on clinical remission over time were recorded. Data were compared with a control group of 66 IBD patients single switched from IFX originator to CT-P13. Results Fifty-two double-switched IBD patients were enrolled (63% M, mean age 41 years, 75% Crohn’s disease, 25% ulcerative colitis). Main indications for IFX therapy were moderate to severe disease (50%) and steroid-dependent disease (25%). The overall 24- and 48-week IFX discontinuation rates following second switch (CTP13->SB2) were 2% (95% CI 0–6%) and 14% (95% CI 3–25%), respectively. During a median follow-up of 40 weeks (18–48), 4 patients (12%) experienced a total of 6 AE (2 cutaneous, 2 infectious, 1 articular and 1 immunological), leading to IFX discontinuation in 3 cases (6%). No infusion reactions were observed. At week 24 following second switch, 49 (94%) patients were in clinical remission, the remaining 3 patients not being in remission already at the time of second switch. Only one patient lost response after week 24, 48 (92%) of patients being in clinical remission at the end of follow-up. No differences in IFX discontinuation, AE and clinical remission rates were found between double-switched and single-switched patients. No clinical parameters were found to predict safety and efficacy outcomes. Conclusion The study supports both safety and efficacy of the double switch from IFX originator to CT-P13 and SB2 in patients with IBD, and demonstrates its non-inferiority to a single switch strategy, with potential cost implications.