An Interim Analysis of 2 Years of Continuous Ozanimod Treatment From the True North OpenLabel Extension Study

Background: The phase 3 True North (TN) study demonstrated the efficacy and safety of oral ozanimod 0.92 mg once daily (equivalent to ozanimod HCl 1 mg) in patients with moderately to severely active ulcerative colitis (UC). The ongoing TN open-label extension (OLE) study is exploring longer-term efficacy and safety of ozanimod in the treatment of UC. This interim analysis of the TN OLE evaluated the efficacy and safety of ozanimod in patients who received 98 weeks of continuous ozanimod treatment. Methods: Patients in clinical response after 52 weeks of continuous ozanimod therapy during TN who rolled over into the OLE were included (data cutoff: September 30, 2020). Endoscopy was performed annually throughout the OLE and was scored by Mayo endoscopic score. Efficacy data (clinical remission, clinical response, endoscopic improvement, and corticosteroid-free remission) were analyzed using observed cases (OC) and nonresponder imputation (NRI). Safety data were also recorded. Results: Of 131 patients in clinical response at TN Week 52, 83 (63%) were in clinical remission and 48 (37%) were in clinical response only (but not clinical remission) upon entry to the OLE. Nearly 73% of the overall population of clinical responders, including 69% of patients who achieved clinical remission and 79% of patients who achieved clinical response only, completed Week 46 of the OLE (ie, Week 98 of continuous ozanimod therapy) at the time of data cutoff when outcomes were measured (NRI group). Baseline demographic and clinical characteristics were similar for patients in clinical remission and in clinical response only, except more patients with clinical response only at OLE entry were exposed to prior immunomodulators or tumor necrosis factor inhibitors at TN baseline. A high proportion of the overall population sustained clinical remission (67%), clinical response (97%), endoscopic improvement (74%), and corticosteroid-free remission (63%) on ozanimod at OLE Week 46 (OC analysis); NRI values were 44%, 64%, 58%, and 42%, respectively. There were higher rates of clinical remission (73% vs 55%), endoscopic improvement (82% vs 58%), and corticosteroid-free remission (71% vs 50%) among patients entering the OLE in clinical remission versus clinical response only (OC analysis). In the overall population of clinical responders, the mean partial Mayo score stabilized by Week 18 (mean, 1.3 points; range, 0-6 points) of the maintenance period and was maintained through OLE Week 46 (mean, 0.9 points; range, 0-4 points) in patients treated with continuous ozanimod. No new safety findings emerged from this extended analysis; 1 sudden death occurred during the OLE and was determined to be unrelated to ozanimod. Conclusion(s): This interim analysis of the TN OLE found that patients who achieved clinical response or clinical remission after 52 weeks of ozanimod had a high rate of sustaining clinical response, clinical remission, and endoscopic improvement for another year with continued use of ozanimod. Patients who were in clinical response after 52 weeks of ozanimod could achieve clinical remission with continued ozanimod therapy. No additional safety signals were observed.