Clinical trial: Ulcerative colitis maintenance treatment with 5-ASA – a 1-year, randomized multicentre study comparing MMX with Asacol.Prantera C, Kohn A, Campieri M, Caprilli R, Cottone M, Pallone F, Savarino V, Sturniolo GC, Vecchi M, Ardia A, Bellinvia S. Aliment Pharmacol Ther. 2009 Aug 12. [Epub ahead of print] Background: 5-ASA-MMX((R)) (1.2g/tablet) is a 5-aminosalicylic acid formulation, designed for once-daily dosing in the treatment of ulcerative colitis. Aim: in this double-blind, double-dummy, parallel-group, randomized, comparator study of 5-ASA, we evaluate the efficacy and safety of 5-ASA-MMx (2.4g/day, once daily), compared with Asacol((R)) (2.4g/day, twice daily) in the maintenance of left-sided UC. Methods: 331 patients with UC were randomized to receive either 5-ASA-MMx 2.4g/day, once daily, or Asacol 2.4g/day, twice daily for 12 months. All patients were in remission for >/=1 month prior to the trial, with >/=1 documented relapse in the previous year. The co-primary endpoints of this study were the proportion of patients in clinical, and clinical and endoscopic remission following 12 months’ treatment. Results: in the intent-to-treat population, excluding those with major protocol deviations, 68.0 and 65.9% patients in the 5-ASA-MMx and Asacol groups, respectively, were in clinical remission (P = 0.69), and 60.9 and 61.7% of patients, respectively, were in clinical and endoscopic remission (P = 0.89). Diary card data revealed statistically significant, treatment differences favoring 5-ASA-MMx. Both treatments were similarly tolerated. Conclusions: once-daily 5-ASA-MMx is similarly effective with a comparable safety profile to Asacol administered twice daily, for the maintenance treatment of ulcerative colitis.