Postoperative maintenance of Crohn's disease remission with 6-mercaptopurine, mesalamine, or placebo: a 2-year trial

BACKGROUND & AIMS: No therapy has been shown to reliably prevent the evolution of postoperative recurrence of Crohn's disease. The aim of the current trial was to compare 6-mercaptopurine (6-MP) and mesalamine with placebo for the prevention of clinical, endoscopic, and radiographic recurrence of Crohn's disease after resection and ileocolic anastomosis. METHODS: Five centers randomized 131 patients to receive 6-MP (50 mg), mesalamine (3 g), or placebo daily in a double-blind, double-dummy trial. Patients had clinical assessments at 7 weeks and then every 3 months; colonoscopy at 6, 12, and 24 months; and small bowel series at 12 and 24 months. End points were clinical, endoscopic, and radiographic recurrence rates at 24 months. RESULTS: Clinical recurrence rates (intent to treat) by life-table analysis at 24 months were 50% (95% confidence interval [CI], 34%-68%), 58% (95% CI, 41%-75%), and 77% (95% CI, 61%-91%) in patients receiving 6-MP, mesalamine, and placebo, respectively. Endoscopic recurrence rates were 43% (95% CI, 28%-63%), 63% (95% CI, 47%-79%), and 64% (95% CI, 46%-81%), and radiographic recurrence rates were 33% (95% CI, 19%-54%), 46% (95% CI, 29%-66%), and 49% (95% CI, 30%-72%), respectively. 6-MP was more effective than placebo ( P < 0.05) at preventing clinical and endoscopic recurrence over 2 years. Patient withdrawals resulted in 69% of the study population evaluable for the clinical recurrence end point. CONCLUSIONS: 6-MP, 50 mg daily, was more effective than placebo at preventing postoperative recurrence of Crohn's disease and should be considered as a maintenance therapy after ileocolic resection.