Ustekinumab in Ulcerative Colitis: A Real-Life Effectiveness Study Across Multiple Belgian Centers (SULTAN).

Background/Objectives: Ustekinumab (UST) has shown to be effective and safe in patients with moderate-to-severe UC in the UNIFI trials. However, real-life data on its effectiveness, particularly for histological remission, are still limited. To assess the real-world effectiveness and safety of UST in refractory UC patients. Methodology: This multicentric, retrospective cohort study included UC patients treated with UST from September 2020 to June 2023. The primary endpoint was steroid-free clinical remission (partial Mayo score of ≤2 with no subscore > 1) at week 16. Secondary endpoints included clinical, endoscopic, histological response and remission. Results: 120 patients with moderate-severe UC were included across 16 centers. Median disease duration was 11 years (1-74 y), and 81 (68%) patients had previously failed ≥2 biological therapies. At week 16, steroid-free clinical remission was achieved in 34% (41/120) of patients, with endoscopic and histological remission in, respectively, 19% (23/120) and 8% (3/37). By week 52, 44% (38/85) of patients were in steroid-free clinical remission, with endoscopic and histological remission, respectively, in 25% (13/52) and 11% (5/45). Active smoking was a negative predictor for steroid-free remission (OR 0.412, p = 0.011). UST drug persistence by week 52 was 70.8%. Active smoking (aOR 3.058, p = 0.02), prior vedolizumab non-response (OR 2.592, p = 0.03) and a high Nancy baseline score (OR 2.46, p = 0.04) were associated with early UST failure. No new safety signals were observed. Conclusions: In this real-life cohort, UST shows acceptable remission rates and high treatment persistence in refractory UC patients, with a favorable safety profile.