Mycophenolate Mofetil Appears Effective for the Treatment of Patients With Refractory Crohn's Disease.

Background: Medically refractory Crohn's disease (CD) is associated with a high risk of complications. Mycophenolate mofetil (MMF), a small molecule immunosuppressant, has limited data in patients with CD, and objective endoscopic response to MMF has not been reported.

Aims: We evaluated the safety and clinical, endoscopic, and biochemical effectiveness of off-label MMF for refractory CD as monotherapy or in combination with a biologic in patients with CD.

Methods: We retrospectively assessed adverse events (AEs), clinical response (Harvey-Bradshaw index), endoscopic response (simple endoscopic score in Crohn's disease), and physician global assessment at an academic medical center and county hospital.

Results: 60 patients received MMF as monotherapy (n = 40) or in combination with a biologic (n = 20) between 2008 and 2021 at a dose ranging from 1000 to 4000 mg daily. Median age was 39 years and median disease duration was 12 years. All patients previously failed ≥ 1 advanced therapy (median = 4). The median MMF therapy duration was 27 weeks. 54% achieved clinical response and 19% achieved clinical remission after a mean of 19.5 weeks (SD 14.5). Endoscopic response occurred in 32%, endoscopic remission in 16%, and endoscopic healing in 4% after a mean of 46.6 weeks (SD 31.0). 48% of patients experienced AEs, most commonly mild infection, nausea/vomiting, and headache. One serious AE occurred, which was assessed as unrelated to MMF.

Conclusions: MMF resulted in clinical, endoscopic, and biochemical benefits in some patients with refractory CD, and was tolerated by most patients. Further randomized controlled trials are needed to define optimal dosing and long-term efficacy and safety.