P0730Clinical outcomes and drug sustainability after non-medical switch from ustekinumab originator to biosimilars in Inflammatory Bowel Disease

Abstract Background Biologic therapies have transformed the management of inflammatory bowel disease (IBD), yet their high cost poses substantial challenges for healthcare systems. Biosimilars offer a cost-effective alternative, with extensive evidence supporting the safety and efficacy of non-medical switching for infliximab and adalimumab. However, real-world data on ustekinumab biosimilars in IBD remain limited. Given increasing mandates for non-medical switches in Canada, evaluating clinical outcomes is critical to ensure patient safety and treatment sustainability. We hypothesized that switching from originator ustekinumab to a biosimilar would preserve clinical efficacy, safety, and drug persistence in patients with IBD. Methods To evaluate clinical efficacy, drug sustainability, biomarker activity and adverse events (AEs) in inflammatory bowel disease (IBD) patients who underwent non-medical biosimilar switching from ustekinumab originator to a biosimilar. Results 81 patients were included 85.2% had Crohn’s disease (CD), the median age at inclusion: 42 years (IQR 29-61). Previous biological exposure was 82.7% and a dose optimization of the originator ustekinumab was performed in 63% before the switch. Drug sustainability at 12 and 24 weeks of switch was 96.3% and 95%, regardless of disease type or phenotype. The discontinuation rate was 4.9%. There was no significant difference in the rates of clinical remission at week 8 before switch, baseline, week 12, and 24 after switch: 87%, 85.9%, 84.3%, and 92.7%, p = NS. The biomarker activity was not significantly different for CRP, hemoglobin, albumin and fecal calprotectin (p = NS). All patients who stopped therapy after the non-medical switch needed a dose optimisation of the originator ustekinumab and had previous biological therapy prior to starting the ustekinumab originator. Conclusion Despite prior biologic exposure and frequent dose escalation, switching to ustekinumab biosimilar showed stable efficacy, unchanged biomarkers, and high drug sustainability. References: 1. Wetwittayakhlang P, Karkout K, Wongcha-Um A, et al. Clinical efficacy and nocebo effect following non-medical biosimilar switch in patients with inflammatory bowel disease: A prospective observational study. Dig Liver Dis. 2024;56(1):35-42. doi:10.1016/j.dld.2023.06.022 2. Hoang TT, Reid J, Galorport C, Bressler B, Leung Y, Rosenfeld G. Outcomes of a mandatory non-medical switch of infliximab to a biosimilar for inflammatory bowel disease in British Columbia, Canada. J Can Assoc Gastroenterol. 2024;7(4):299-305. Published 2024 Mar 23. doi:10.1093/jcag/gwae011 3. Lichtenstein GR, Soonasra A, Latymer M, Singh S, Feagan BG. Systematic review: effectiveness and safety of switching between originator infliximab and biosimilar infliximab in patients with inflammatory bowel disease. Expert Opin Biol Ther. 2024;24(7):691-708. doi:10.1080/14712598.2024.2378090 Conflict of interest: Dr. Kritzinger, Justin: No conflict of interest Candel, Ivanna: i dont have conflict of interest Kotrri, Gynter: No conflict of interest Nadeem, Huzaifa: No conflict of interest Bitton, Alain: No conflict of interest Afif, Waqqas: Grant: Abbvie, Takeda, Pfizer, Janssen Personal Fees: Advisory Boards: Abbvie, Amgen, Arena Pharmaceuticals, Dynacare, Frenenius Kabi, Janssen, Merck, Novartis, Pfizer, Takeda Wild, Gary: No conflict of interest Bessissow, Talat: No conflict of interest Lakatos, Péter Laszlo: Personal Fees: Amgen, Bristol Myers Squibb, Celltrion, Fresenius Kabi, Gilead, Johnson & Johnson, Eli Lilly, Merck, Organon, Pendopharm, Pfizer, Roche, Sandoz, Sanofi and Takeda Other: Gilead, Pfizer and Takeda