Efficacy and safety of a novel high-dose mesalazine tablet in mild to moderate active ulcerative colitis: a double-blind, multicentre, randomised trial

Background: Adherence to mesalazine treatment is essential for the successful treatment of ulcerative colitis. Objective: The objective of this study was to compare the efficacy, safety and preference of a novel high-dose 1000 mg mesalazine tablet versus conventional treatment for ulcerative colitis remission. Methods: This pivotal phase III trial compared one 1000 mg mesalazine tablet (M1000 group) versus two registered 500 mg mesalazine tablets (M2x500 group), both taken three times daily, in patients with mild to moderately active ulcerative colitis. The primary efficacy variable was clinical remission at week 8. Results: A total of 306 patients were considered for intent-to-treat analysis. Clinical remission was achieved in 45.0% of the patients in the M1000 group versus 41.9% in the M2x500 group (P<0.001 for non-inferiority). Mucosal healing was achieved by 68.9% of the patients in the M1000 group and 68.4% in the M2x500 group. The majority of patients preferred the intake of one high-dose tablet (47.7%) over two low-dose tablets (10.5%). Oral treatment with high-dose 1000 mg mesalazine tablets was well tolerated without new safety signals. Conclusions: The novel high-dose 1000 mg mesalazine tablet is effective, non-inferior to the registered 500 mg mesalazine tablet, and safe for ulcerative colitis treatment. It was preferred by a majority of patients and may improve ulcerative colitis treatment adherence.