Is maintenance therapy always necessary for patients with ulcerative colitis in remission?

Background: The efficacy of sulphasalazine and mesalazine in preventing relapse in patients with ulcerative colitis is well known. It is less clear how long such maintenance should be continued, and if the duration of disease remission is a factor that affects the risk of recurrence. Aim: To determine whether the duration of disease remission affects the relapse rate, by comparing the efficacy of a delayed-release mesalazine (Asacol, Bracco S.p.A., Milan, Italy) against placebo in patients with ulcerative colitis with short- and long-duration of disease remission. Methods: 112 patients (66 male, 46 female, mean age 35 years), with intermittent chronic ulcerative colitis in clinical, endoscopic and histological remission with sulphasalazine or mesalazine for at least 1 year, were included in the study. Assuming that a lower duration of remission might be associated with a higher relapse rate, the patients were stratified according to the length of their disease remission, prior to randomization into Group A (Asacol 26, placebo 35) in remission from 1 to 2 years, or Group B (Asacol 28, placebo 23) in remission for over 2 years, median 4 years. Patients were treated daily with oral Asacol 1.2 g vs, placebo, for a follow-up period of 1 year. Results: We employed an intention-to-treat analysis. In Group A, whilst no difference was found between the two treatments after 6 months, mesalazine was significantly more effective than placebo in preventing relapse at 12 months [Asacol 6/26 (23%), placebo 17/35 (49%), P = 0.035, 95% CI: 48-2.3%]. In contrast, in Group B no statistically significant difference was observed between the two treatments, either at 6 or 12 months [Asacol 5/28 (18%), placebo 6/23 (26%), P = 0.35, 95% CI: 31-14%] of follow-up, Patients in group B were older, and had the disease and remission duration for longer, than those in Group A. Conclusions: Mesalazine prophylaxis is necessary for the prevention of relapse by patients with ulcerative colitis in remission for less than 2 pears, but this study casts doubt over whether continuous maintenance treatment is necessary in patients with prolonged clinical, endoscopic and histological remission, who are at very low risk of relapse.