P0940Dose reduction of escalated dose ustekinumab or vedolizumab can be effective in selected patients with Inflammatory Bowel Disease

Abstract Background Advanced therapies are effective treatments to achieve induction and maintain remission in patients with Inflammatory Bowel Disease (IBD), although there are associated costs. Some patients lose response over time, and dose escalation (DE) may be required to regain effect. It is unclear whether patients on DE of ustekinumab or vedolizumab require DE for a short period or a different therapy entirely. Our aim is to assess the outcomes of ustekinumab and vedolizumab dose reduction (DR) in patients with IBD. Methods We retrospectively assessed IBD patients who were on DE of ustekinumab or vedolizumab at the Western General Hospital between March 2023 and March 2025. Patients were followed up for 2-years. DE of ustekinumab was 4 or 6-weekly treatment and vedolizumab was 4-weekly. Patients on DE ustekinumab or vedolizumab were followed up in a virtual biologic clinic or a routine outpatient clinic. Those on DE with clinical and biochemical remission for 1-year were considered for a DR. Clinical disease activity, blood tests and faecal calprotectin were used to assess response. Successful DR was defined as continuing DR with clinical and biochemical remission for 1-year. Results 66 patients on DE ustekinumab were assessed. There were 42(63.6%) males and 57(83.4%) had Crohn’s Disease (CD). At 1-year, 10 had achieved a DR, 34 patients continued on DE as they did not meet criteria for DR, and 22 patients switched therapies. At 2-years, of those 10 that had a DR, 2 patients switched, 1 re-escalated, and 7(70%) remained on DR. 17 of the 34 patients who continued DE ustekinumab remained on DE, 8 patients switched therapy, and 8 had achieved a DR. 25 patients on DE vedolizumab were assessed. There were 13(52%) males and 12(48%) had CD. At 1-year, 5 had achieved a DR, 7 switched therapies, and 11 continued on DE. At 2-years, all 5(100%) that initially achieved a DR were maintained on their new reduced dose. Of those 11 that remained on DE, 5 switched therapies, 4 remained on DE, and 2 had achieved a DR. Conclusion This preliminary data demonstrates that in our cohort, 70% of those with ustekinumab and 100% of those with vedolizumab who had a DR at 1-year continued a reduced dose at 2-years, i.e., 13 patients had a successful DR. A further 8 patients with ustekinumab and 2 patients with vedolizumab had achieved a DR by 2-years and they have been stable on these doses for 1-year. Although further data is needed, this study suggests that DR of escalated doses of ustekinumab or vedolizumab may be a clinically and cost-effective strategy for those with stable IBD. Conflict of interest: Dr. Nicholls, Jack: No conflict of interest O’hare, Claire: No conflict of interest Cassidy, Eimear: No conflict of interest Watson, Eleanor: No conflict of interest Lees, Charlie: Consultancy and lecture fees: Abbvie, Oshi Health, Gilead, Pfizer, Takeda, Janssen, Shire, Samsung Bioepis, Dr Falk, GSK, Galapagos, Trellus Health, Iterative Scopes, Fresnius Kabi Plevris, Nikolas: Speaker fees / travel support from Abbvie, Pfizer, Janssen, Lilly, Ferring Arnott, Ian: Personal Fees: Takeda, Vifor, Tillots, alfasigma, Johnson & Johnson, Eli Lilly and Company