Objectives Mycophenolate mofetil (MMF) is an immunosuppressive agent, sometimes used as a disease-modifying therapy for multiple sclerosis (MS). Several studies have reported the relative safety of this treatment but, to date, its efficacy has rarely been described. We performed a retrospective study to assess the safety and efficacy of MMF in patients with MS.

Methodology Three French MS centres included all of their patients treated by MMF. The main outcome criterion was annualised relapse rate (ARR) in the 1 year period after onset of MMF compared with the 1 year control period. Treatment with another immunosuppressive drug, such as mitoxantrone or cyclophosphamide, in the 2 years preceding initiation of MMF was included in a subgroup analysis. MMF safety and progression of the Expanded Disability Status Scale (EDSS) score were also assessed.

Results 344 patients were included; 149 patients were previously treated with another immunosuppressant (IS group). Mean MMF treatment duration was 25.3±1.1 months. During the 1 year control period, ARR was 1.11±0.08, and for the 1 year treatment period, ARR was reduced significantly to 0.35±0.05 (p<0.0001, Wilcoxon paired test). Adverse events (occurring in 11% of patients) were mainly digestive disorders, benign infections, asthenia and transitory lymphopenia. Concerning the progression of disability, in the subgroup of patients without previous immunosuppressant treatment, EDSS remained stable between initiation and 1 year after the beginning of MMF.

Interpretation Our results suggest that MMF can improve or stabilise MS patients and can be used as an alternative therapy.