Mesalazine Modified-Release Tablet in the Treatment of Ulcerative Colitis in the Remission Phase: A Chinese, Multicenter, Single-Blind, Randomized Controlled Study

Introduction: This study aimed to compare the efficacy and safety of two mesalazine formulations in the treatment of Chinese patients with ulcerative colitis (UC) in the remission phase. Methods: In this multicenter, single-blind, randomized controlled study conducted from November 2010 to August 2012, 251 patients with UC from 18 hospitals were enrolled. The patients were randomized to treatment with mesalazine modified-release tablets (MR group, n = 126) or other enteric-coated tablets (EC group, n = 125), at 800 mg three-times daily for 48 weeks. The primary efficacy parameter was the rate of non-emergence of bloody stool. If the lower limit of the 95% confidence interval (CI) of the primary efficacy measure was over -10%, the modified-release tablets were considered non-inferior to the enteric-coated tablets. The secondary efficacy parameters included the period of non-emergence of bloody stool and the period of non-recurrence of UC. The incidences of adverse events and adverse drug reactions were compared between the two groups. Results: At 48 weeks of maintenance treatment, the rates of non-emergence of bloody stool were 82.99% (95% CI 73.53-92.45%) and 73.30% (95% CI 64.04-82.56%) in the MR and EC groups, respectively, and the difference between the two groups was 9.69% (95% CI -1.15-20.53%). There was no significant difference in the period of non-emergence of bloody stool and the period of non-recurrence of UC between the two groups (P> 0.05). The incidences of adverse events were 48.78% (60/123) and 48.00% (60/125) in the MR and EC groups, respectively (P = 0.902). The incidences of adverse drug reactions were 16.26% (20/123) and 13.60% (17/125) in the MR and EC groups, respectively (P = 0.556). Conclusion: Mesalazine modified-release tablets were non-inferior to the enteric-coated tablets and may be considered an effective and safe treatment alternative for the maintenance of remission in Chinese patients with UC.