Controlled trial of oral 5-aminosalicyclic acid for the prevention of early relapse in Crohn's disease

Background: Recent data indicate that 5-aminosalicylic acid (5-ASA) is most effective in preventing relapse of Crohn's disease in patients with a short duration of remission before enrolment. Aim: To evaluate the efficacy of oral 5-ASA treatment, started immediately after achieving steroid-induced remission, in preventing clinical relapses of Crohn's disease. Methods: Patients with active Crohn's disease, achieving remission on steroids, were randomized to oral 5-ASA 3 g/day or placebo, while steroids were tapered over 6 weeks. The trial was terminated after interim analysis showed a slightly higher relapse rate in the 5-ASA group, and the calculated probability of seeing a statistically significant difference by completing the study was minimal. Results: Final analysis included 117 patients (58 taking 5-ASA and 59 taking placebo; follow-up 9.2 +/- 6.5 months). Cumulative relapse rates at 6 and 12 months were 34% and 58% in 5-ASA patients and 31% and 52% in placebo patients, respectively (rate difference + 0.095; 95% CI = -0.085 to +0.274). Subgroups analysis showed that 5-ASA was equally ineffective in patients with ileal, colonic or ileocolonic disease. Conclusions: Contrary to previous results, in our study early introduction of treatment with oral 5-ASA did not prevent relapse in Crohn's disease patients treated with steroids to induce remission.