Efficacy and Safety of Ozanimod in Ulcerative Colitis: A Real-World Pan-Hellenic Study

Background and Objectives: Ozanimod is approved for the treatment of ulcerative colitis (UC). The aim of the present study was to evaluate the clinical, biochemical, and endoscopic outcomes. Materials and Methods: This was a retrospective, multicenter, cohort study. Clinical, biochemical, endoscopic, and safety data were collected from medical records. Τhe primary outcome was clinical response at week 12. Secondary outcomes included clinical remission, endoscopic improvement and remission, biochemical outcomes, treatment persistence, and safety. Clinical outcomes were assessed at weeks 12 and 48, while treatment persistence was evaluated over the complete 48-week follow-up period, using Kaplan-Meier analysis. Clinical response was defined as a ≥30% reduction in partial Mayo score and remission as a partial Mayo score < 3, with no individual sub-score > 1 and a rectal bleeding sub-score of 0. Clinical response and remission were primarily assessed using an observed-case approach, with an additional sensitivity analysis classifying discontinuations due to lack of efficacy as treatment failures. Results: A total of 79 patients were included (62.0% male; median age 44 years, IQR 31-56). Prior biologic exposure was recorded in 29.1%, and 64.6% were previously exposed to oral corticosteroids. Among patients with available clinical assessment at week 12 (n = 62), clinical response and clinical remission were achieved in 77.4% and 71.0%, respectively. Among patients with available data at week 12 (n = 32), endoscopic improvement was observed in 65.6%, while endoscopic remission was achieved in 15.6%. At week 48, among 26 evaluable patients, clinical response and remission rates were 96.2% and 84.6%, respectively; when discontinuations due to lack of efficacy were considered treatment failures, the corresponding rates were 52.1% and 45.8%. Treatment persistence did not differ significantly according to overall prior biologic exposure, whereas previous vedolizumab exposure was associated with lower treatment persistence over the week 48 follow-up (log-rank p = 0.037). In multivariable Cox regression, previous vedolizumab exposure remained associated with an increased hazard of treatment discontinuation (adjusted HR 3.07, 95% CI 1.23-7.67; p = 0.016). Adverse events were reported in 13.9% of patients. Conclusions: Ozanimod demonstrated good efficacy and a favorable safety profile in patients with moderate UC.