Background and Aims: Thiopurines are commonly used for treating ulcerative colitis (UC), despite the fact that controlled evidence supporting their efficacy is limited. The aim of this study was to evaluate the long-term outcome of thiopurines as maintenance therapy in a large cohort of UC patients.
Methods: All UC patients receiving thiopurine monotherapy at three tertiary IBD centers from 1995 to 2015 were identified. The primary endpoint was steroid-free clinical remission. Secondary endpoints were mucosal healing (MH), defined as Mayo endoscopic subscore 0, long-term safety, and predictors of sustained clinical remission.
Results: We identified 192 patients, contributing a total of 747 person-years of follow-up (median follow-up 36 months, range 1-210 months). Steroid dependency was the most common indication for thiopurine treatment (58%). Steroid-free remission occurred in 45.3% of patients; 36.3% stopped thiopurines because of treatment failure and 18.2% for adverse events or intolerance. The cumulative probability of maintaining steroid-free remission while on thiopurine treatment was 87%, 76%, 67.6%, and 53.4% at 12, 24, 36, and 60 months, respectively. MH occurred in 57.9% of patients after a median of 18 months (range 5-96). No independent predictors of sustained clinical remission could be identified.
Conclusions: Thiopurines represent an effective and safe long-term maintenance therapy for UC patients.