Clinical Course of Bio Naive Ulcerative Colitis Patients Five Years After Initiation of Adalimumab in a Nationwide Cohort.

Background: There is limited data on the long-term clinical outcomes of bio-naïve ulcerative colitis (UC) patients who are initiated on adalimumab (ADA). Our study aims to evaluate the clinical course of a nationwide cohort of bio naïve UC patients who were started on ADA, and then followed for 5 years after initiation of the drug. Methods: We conducted a retrospective cohort study using the US Veteran Affairs Healthcare System (VAHS). Bio naïve UC patients were followed for 5 years after initiation of ADA. The primary outcome was to determine the time to discontinuation of ADA and if patients achieved endoscopic remission by the end of follow-up. Results: A total of 387 patients were included among whom 193 (49.87%) had pancolitis. The highest rate of ADA discontinuation was within the first year, with the elderly having a higher rate of discontinuation (HR 1.67, 95% CI: 1.14-2.45) and those on concomitant immunomodulators having a lower rate of discontinuation (HR 0.70, 95% CI: 0.48-1.03). In total, 125 (32.30%) patients remained on ADA at the end of their maximum follow-up. 54 (43.90%) achieved endoscopic remission. Conclusion: Among bio-naive UC patients who were started on ADA, a third were still on the drug at the end of 5 years and half had endoscopic remission. The rate of discontinuation was highest within the first year of initiation, but patients continued to stop the drug over the course of follow-up.