P1139Switching from ustekinumab originator to biosimilar: No adverse impact on inflammatory bowel disease control and well tolerated by patients in a UK multicentre study

Background Ustekinumab is an effective treatment for patients with Crohn’s disease (CD) and ulcerative colitis (UC). The availability of biosimilar ustekinumab in 2024 and potential healthcare savings drove a national agenda to use ustekinumab biosimilars for licensed indications. In the UK, pharmacists predominantly oversaw the switch. We aimed to assess the effectiveness, safety and tolerability of biosimilar ustekinumab when switching from ustekinumab originator in inflammatory bowel disease (IBD). Methods Patients with IBD established on originator ustekinumab across 12 UK sites and undergoing a switch to biosimilar ustekinumab were included. Each site determined the specific biosimilar to be used for their patient cohort according to local medicines governance protocols. A retrospective review of prospectively collected records was performed 12 to 24 weeks after the switch. Baseline data included C-reactive protein (CRP), faecal calprotectin (FCP), clinical disease activity indices (Harvey-Bradshaw Index (HBI) for CD and Simple Clinical Colitis Activity Index (SCCAI) for UC) and a baseline physician’s global assessment (PGA). Demographic data, treatment history and adverse drug reactions (ADR) were recorded. Statistical method Wilcoxon signed rank test was used to compare pre- and post- switch variables via GraphPad Prism 10.6.1. Results We included 545 patients (293, 54% female) of whom 461 (85%) had CD and 84 (15%) had UC. Three biosimilars were used; Wezenla 423 (77%) patients, Pyzchiva 80 (15%) patients and Uzpruvo 42 (8%) patients. Prior treatment exposure was anti-tumour necrosis factor agents (anti-TNF) in 440 (81%) patients, vedolizumab in 89 (16%) patients and both anti-TNF and vedolizumab in 65 (12%) patients. 14 (3%) patients received steroids at the time of switch. Between baseline and week 12-24 there were no statistically significant differences in biochemical or clinical markers (Table 1), except PGA scores increased significantly post switch (p = 0.0001). However, the absolute change in mean PGA values was small (0.31 to 0.51) and median difference was zero. There was treatment persistence with ustekinumab biosimilar in 495 (91%) patients. Of the remaining 50 (9%) patients, 39 (7%) were switched to another treatment and 11 (2%) switched back to the originator. 32 (6%) patients experienced an ADR (Table 2); 5 (0.9%) patients reported an injection site reaction. Conclusion We observed high treatment persistence rates and stable clinical disease activity and biomarkers with ustekinumab biosimilars. Biosimilar ustekinumab was well tolerated and appears to be safe. Biosimilar evaluation will continue with the 12-month review of this cohort. Conflict of interest: Mrs. Sharma, Esha: I have received speaking and/or advisory fees from the following pharmaceutical companies: Bristol Meyers-Squibb, Eli Lilly and Company, AbbVie, Dr Falk Pharma, Galapagos, Takeda, Janssen, Pfizer and Pharmacosmos Allah-Ditta, Mohammed: I have been paid honorarium from Abbvie, Takeda, Dr Falk, Sandoz, Ferring Pharma, Tillots, Eli Lilly Povlsen, Sebastian: No conflict of interest Greenwood, Joshua: No conflict of interest Shinh, Sunayna: No conflict of interest Omrani, Fatima: Speaker fees from AbbVie and Takeda Raftis, Katherine: No conflict of interest Leason, Georgina: No conflict of interest Rousseau, Camille: No conflict of interest Cattermull, Mark: None Leung, Natalie: No conflict of interest Sonwalkar, Sunil: No conflict of interest Toft, Jennifer: Have done speaking for Abbvie and Takeda Rees, Fiona: Speaker fees: J&J, Dr Falk, Gilead, Intercept, Ferring, Pfizer, Takeda, Abbvie, Lilly Support for conference attendance and training: Pharmacosmos, Dr Falk, Ferring, Intercept Conference attendance support: I do not know how this is different from above Consultation fees: Celltrion, BMS, Takeda, Violicom Other (please specify): Volunteer for BSG, CCUK, IBD-UK and UKCPA Aslam, Aneela: No conflict of interest Rashid, Zara: Sponsorship from Abbvie to attend ECCO 2024 Sponsorship for J&J to attend ECCO 2025 Speaker fees from Abbvie 2024 Rudling, Ruth: Speaker fees for event paid by Ferring Conference attendance fee (plus travel etc) funded by AbbVie and Ferring Advisory board fee by Takeda Activate course (completed 2024) paid by Takeda Kwok, Jon: Speaker fees, advisory board, education events and conference sponsorship: Abbvie, Bristol Myers Squibb, Dr Falk Pharma, Eli Lilly and Company, Ferring, Johnson & Johnson, Pharmacosmos, Takeda Pharmaceutical Company, Tillotts Pharma, UCB Pharma Tavangari, Yasmin: No conflict of interest Kirkbride, Matthew: No conflict of interest Chau, Wai-Ling: Feb 2023: I have received a course and accommodation fee from Takeada to attend activate Takaeda pharmacist and development programme. Cripps, Sarah: Consultancy fees: Abbvie, Advanz, Dr Falk, Galapagos, Pfizer, Lilly, SALTs healthcare, Sandoz, Takeda Sponsorship: Abbvie, BMS, Celltrion, Gilead, Lilly, Tillots Bailey, Jon: AbbVie - speaker Galen - clinical consultation Lee, Hean Yeung: No conflict of interest Garcia Fuertes, Fernando: No conflict of interest Travers, Katie: Honorarium from Morph Consultancy Sponsorship from Tillotts Pharma UK to attend BSG Live 2025 Sponsorship from Abbvie to attend IBDistinction Roadshow 2025 Sponsorship from Dr Falk to attend SW and Wales Pharmacist Network Meeting 2024 Taherzadeh, Nina: Takeda - paid panel session for IBD study day Bell, Iona: No conflict of interest Blaker, Paul Andrew: Received sponsorship to attend meetings from Celltrion, Jansen and Takeda. I have received speaker fees from Abbvie to provide educational meetings. Limdi, Jimmy: Speaker and Consultancy fees: Abbvie, Arena, AlfaSigma, BioHit, Bristol Myers Squibb, Celltrion, Eli Lilly, Ferring, Galapagos, Johnson & Johnson, MSD, Pfizer, Tillotts Samaan, Mark: Advisory fees: Janssen, Takeda, Sandoz, Samsung Bioepis, Galapagos, AbbVie, Pfizer, STADA, Bristol-Myers Squibb, MSD, Sanofi, Tillotts, MSD Lecture fees: Bristol-Myers Squibb, Janssen, Takeda, MSD, Falk, AbbVie, Galapagos, Lilly, Advanz