On March 27, the FDA approved dimethyl fumarate (Tecfidera; Biogen) to treat adults with relapsing-remitting multiple sclerosis (MS). The exact mechanism of action for dimethyl fumarate is unknown, but researchers believe it affects multiple sclerosis by activating the Nrf2 pathway, the primary cellular defense against the cytotoxic effects of oxidative stress.
The approval is based on results of two phase 3 clinical trials—DEFINE and CONFIRM—that showed that patients taking dimethyl fumarate had a significantly reduced rate of annualized relapse compared with patients taking placebo (DEFINE, 53% reduction, P<.0001; CONFIRM, 44% reduction, P<.0001).
The most common side effects reported during the trails were flushing and GI disturbance (nausea, vomiting, diarrhea), particularly at the start of therapy. These side effects may decrease over time. Dimethyl fumarate reduces lymphocytes and so the FDA recommends that patients be assessed before starting treatment with the drug, and annually thereafter.
The FDA new release is available here.