Dimethyl fumarate for relapsing MS.

Dimethyl fumarate (DMF) is the latest oral therapy approved for relapsing-remitting multiple sclerosis (RRMS). In 2 placebo-controlled phase III trials, twice daily DMF demonstrated a 44%-53% reduction in annualized relapse rate and 71%-90% reduction in new MRI lesions. In one trial, DMF slowed the accumulation of disability, but not in the other trial. The main side effects of DMF include gastrointestinal symptoms (nausea, abdominal pain, vomiting, and diarrhea) and skin flushing, which peak at treatment initiation. There was no increased risk of opportunistic infections. Recommended safety monitoring includes complete blood count prior to treatment and annually while on treatment. Appealing aspects of DMF include potent efficacy, oral administration, and good safety and tolerability profiles. Altogether, DMF is an attractive option for first-line treatment, breakthrough disease activity, intolerance to other therapies, and possibly natalizumab-treated patients with positive JC virus serology.