P565 Comparison of the efficacy of adalimumab and ustekinumab for prevention of intestinal fibrosis in bio-naive Crohn's Disease patients

Abstract Background Adalimumab (ADA) and ustekinumab (UST) are effective and efficient therapeutic options for patients with luminal Crohn's disease (CD). However, data evaluating treatment efficacy in stricturing CD are lacking. The aim of this study was to compare real-life efficacy of ADA and UST in prevention of development and/or progression of preexisting bowel stenosis in bio-naive CD patients. Secondary aim was to identify potential factors affecting treatment success. Methods A single-center, non interventional, retrospective chart review (January 2015 – April 2022) ofadult bio-naive CD patients treated with ADA or UST for a minimum of 6 months was performed. Fibrotic intestinal stricture was defined as stenosis with a prestenotic small bowel or colon dilatation seen on magnetic resonance enterography or intestinal ultrasound or as a small bowel or colon obstruction impassable for an endoscope. Continuous variables were compared using Mann-Whitney test, and categorical variables using X2 Fisher exact test when appropriate. Categorical variables were presented as numbers and valid percentages. Logistic regression was performed to determine potential predictors for stenosis development or progression. Results Total of 63 CD patients were included, with in ADA group (69.8%). Patients characteristics were similar in both observed groups regarding median disease duration prior to induction of biologic (57 (20-132) months on ADA, 57 (20-161) months on UST) and median treatment persistence (21 (10-38) months on ADA, 20 (14-53) on UST). Patients on UST were significantly older (ADA mean 37 y vs UST mean 51 y; p<0.05). Combotherapy was used in 35.1% of patients in ADA group. After average of 20 months of treatment duration 9.1% people in ADA group and 5.3% in UST group developed new symptomatic bowel stenosis. At the time of biologic introduction, 4 people in ADA (9.1%) and 1 in UST group (5.3%) had preexisting bowel stenosis - out of those patients, 3 in ADA group (6.8%), had a worsening of stenosis which required treatment discontinuation. Surgery was performed in 2 patients, both in ADA group (4.5%). Statistically significant difference wasn’t observed between ADA and UST group in stenosis development or progression (p=0.52). Combotherapy had no influence on primary aim in ADA group (p=0.59)Age, gender, biologic therapy, combotherapy as well as disease and therapy duration don't seem to be connected with stenosis development or progression Conclusion These real world data suggest that longterm treatment with both ADA and/or UST provide comparable efficiency for prevention of intestinal bowel fibrostenosis occurrence or progression. Larger, prospective studies should be conducted