Azathioprine versus Mycophenolate Mofetil in combination with anti-TNF alpha agents in the management of Crohn's Disease

Background: Combination therapy of biologics and immunomodulators is sometimes necessary in chronically active Crohn's disease to achieve remission and prevent further complications. Treatment escalation in patients who are intolerant to thiopurines can be very challenging as there are few alternative immunosuppressive agents. In this study we evaluate mycophenolate mofetil in combination with an anti-TNF alpha agent in patients who are intolerant to azathioprine. Methods: 17 patients under double immunosuppression (mycophenolate mofetil + biologic) were compared to 29 randomly chosen patients with an azathioprine-based combination therapy. The indication for treatment escalation was chronically active Crohn's disease. Treatment response was compared between both groups, defined by a drop of Crohn's diseases activity index (CDAI) of 70 and 100 points, respectively. Results: The median follow up time for all patients was 12 months. In the mycophenolate mofetil group five patients (29.4%) discontinued due to adverse events. Eight patients (47.1%; CDAI -70) and four patients (23.5%; CDAI -100) achieved treatment response, respectively. In the azathioprine group two patients (6.7%) discontinued treatment due to lack of improvement. 11 patients (37.9%; CDAI -70) and 8 patients (27.6%; CDAI -100) had a response to the double immunosuppression, respectively. Treatment response for both groups (CDAI -70, p = 0.757; CDAI -100, p = 1) was comparable. Conclusion: Mycophenolate mofetil could be a treatment option in combination with biologics in patients with chronically active Crohn's disease who are intolerant to thiopurines.