Leflunomide Treatment of Crohn's Disease Patients Intolerant to Standard Immunomodulator Therapy

BACKGROUNDImmunomodulator therapy with the purine analogs azathioprine and 6-mercaptopurine (6-MP), is efficacious in the treatment of moderate to severe Crohn's disease (CD), but is not tolerated by a significant minority of patients. The pyrimidine analog, leflunomide, has demonstrated efficacy in the treatment of rheumatoid arthritis (RA) patients. Because established RA immunomodulator agents may demonstrate success in the treatment of CD, we reviewed our clinical open-label experience with leflunomide in a refractory CD population. GOALSAssess the effect of leflunomide 20 mg daily, on disease activity, steroid requirement and serologic measures of inflammatory activity in our series of CD patients intolerant to azathioprine/6-MP. STUDYCD patients intolerant of azathioprine/6-MP were offered leflunomide treatment. The Harvey-Bradshaw (H-B) disease activity index, global assessment, serologic parameters and ability to taper corticosteroids of those who accepted were retrospectively assessed. RESULTSLeflunomide was well tolerated and resulted in a significant reduction in the H-B score, global assessment and serologic parameters in 8/12 patients. Average follow-up was 38 weeks and a majority of steroid-dependent patients were able to successfully taper following leflunomide initiation. CONCLUSIONSOur case series demonstrates that the pyrimidine analog leflunomide may be effective for treating moderate to severe CD patients intolerant to standard immunomodulator therapy and warrants further investigation in a randomized controlled trial.