P698 Effectiveness and Safety of Ustekinumab for Ulcerative Colitis: A Brazilian Multicentre Real-World Observational Study

Background Real-world data on the effectiveness and safety of ustekinumab (UST) in ulcerative colitis (UC) are lacking in Latin America. In this study, we aimed to describe the effectiveness and safety of UST in a real-world multicentre cohort of Brazilian patients with UC. Methods We conducted a multicentre retrospective observational cohort study, including patients with moderate to severe UC (Total Mayo score 6-12, with an endoscopic subscore of 2 or 3) who received UST. The co-primary endpoints were clinical remission, defined as a total Mayo score ≤2 at 1 year, with a combined rectal bleeding and stool frequency subscore of ≤1, and endoscopic remission (endoscopic Mayo subscore of zero) within one year from baseline. Secondary endpoints included clinical response between weeks 12-16, endoscopic response within one year of starting UST, steroid-free clinical remission at week 52, and biochemical remission at week 52. We also evaluated UST treatment persistence and safety. Results A total of 50 patients were included (female, n=36, 72.0%), with a median disease duration of 9.2 years (1-27). Most patients had extensive colitis (n=38, 76.0%), and 43 (86.0%) were steroid-dependent at baseline. Forty patients (80.0%) were previously exposed to biologics (anti-TNF drugs, n=31; vedolizumab [VDZ], n=27). The co-primary endpoints of clinical remission and endoscopic remission at 1 year were achieved by 50.0% and 36.0% of patients, respectively. Clinical response at weeks 12-16 was 56.0%, endoscopic response, steroid-free clinical remission, and biochemical remission at week 52 were 68.0%, 67.4%, and 50.0%, respectively. The UST treatment persistence rates at 24 months was 73.7%. During the follow-up, 10 patients (20.0%) were hospitalized, mostly due to disease progression, and three patients required colectomy. Nine patients (18.0%) discontinued the drug mainly due to a lack of effectiveness. Twenty-six adverse events (AEs) were reported, 15 of which were considered as serious AEs. Conclusion This is the first real-world experience study to report the effectiveness and safety of UST specifically in a Latin American population. In this real-world cohort of difficult-to-treat UC patients, UST was associated with improvements in clinical, biochemical, and endoscopic outcomes. The safety profile was favorable, consistent with the known profile of UST.