Mycophenolate mofetil for Crohn's disease: short-term efficacy and long-term outcome

To assess the long-term efficacy of the antimetabolite agent mycophenolate mofetil in patients with Crohn's disease.

Twenty patients with complicated Crohn's disease were treated with mycophenolate mofetil, 1 g b.d., for up to 7 years. Twelve patients were intolerant to azathioprine, seven were resistant to azathioprine and one had a history of mesalazine-induced pancreatitis. The response to mycophenolate mofetil was determined by calculation of the Harvey-Bradshaw index, the ability to taper steroids and the grading of fistula activity.

After 6 months, 11 of the 20 patients had responded. Seven of the 11 responders relapsed after a median of 18 months, three have an ongoing response at month 17, 19 and 82, and one discontinued mycophenolate mofetil owing to toxicity. After initial treatment failure, mycophenolate mofetil was continued in 12 of 17 patients for a further 2-41 months without inducing a stable remission. Mycophenolate mofetil was of benefit in nine of the 12 patients intolerant to azathioprine and in two of the seven patients resistant to azathioprine. Perianal fistulas improved in seven of eight patients; five of the seven subsequently deteriorated, but only one due to reactivated perianal disease.

Mycophenolate mofetil was initially effective in a sizeable fraction of patients with complicated Crohn's disease, but relapse within 18 months was common. Nevertheless, mycophenolate mofetil could be a useful alternative in patients intolerant to azathioprine.