P661 Ustekinumab in Crohn’s disease: A three-year multicentre prospective study from Hungary - Assessing efficacy, drug sustainability, and safety

Background While randomized controlled trials have shown ustekinumab (UST) as an effective therapeutic option for Crohn’s disease (CD), there is a lack of long-term observational data in real-world CD patient settings. This prospective study seeks to evaluate the clinical effectiveness, sustainability, and safety of UST in a nationwide multicentre cohort of CD patients over three years. The aim is to bridge the gap in our understanding of UST's real-world implications for long-term CD management. Methods CD patients undergoing ustekinumab (UST) treatment were consecutively enrolled at nine Hungarian Inflammatory Bowel Disease centers from January 2019 to May 2020. Over a three-year period, comprehensive data on patient demographics, disease characteristics, treatment history, clinical disease activity (measured by the Harvey Bradshaw Index (HBI)), biomarkers, and endoscopic activity (evaluated using the Simple Endoscopic Score for Crohn’s Disease (SES-CD)) were systematically collected. Results Involving 148 patients, the cohort comprised 48.9% with complex behavior of CD and 97.2% with previous anti-TNF exposure. Pre-induction remission rates were observed at 12.2% (HBI) and 5.1% (SES-CD). Clinical remission rates (HBI) at the end of the first, second, and third years were 52.2%, 55.6%, and 50.9%, respectively. Criteria for endoscopic remission were met in 14.3%, 27.5%, and 35.3% of subjects at the end of the first, second, and third years. Dose intensification was notable, with 84.0% of patients on an 8-weekly and 29.9% on a 4-weekly regimen by the end of year 3. Throughout the follow-up period, drug sustainability stood at 76.9%, and no serious adverse events were observed. Conclusion Our study confirms that ustekinumab is a sustainable, effective, and safe long-term treatment for Crohn's disease patients with a severe disease phenotype and a history of high anti-TNF failure, with the need for frequent dose adjustments.