Dimethyl fumarate (DMF) is an oral therapy in development for multiple sclerosis (MS). Fumaric acids were first studied in MS in a Phase 1, open-label, baseline-controlled trial using the combination fumaric acid ester preparation Fumaderm. Based upon the encouraging Phase 1 results, Fumapharm partnered with Biogen Idec to conduct a Phase 2 trial of DMF in relapsing-remitting multiple sclerosis (RRMS). The use of DMF in autoimmune diseases arose from a personal view of the immune system, whereby autoimmunity is caused by disruption in the Krebs's cycle. The Phase 2 trial found that 720 mg/d of BG00012 reduced active inflammation. The Phase 3 trials provide pivotal and definitive evidence regarding the safety and efficacy of BG00012 in MS. Ongoing laboratory studies and advanced imaging studies in the Phase 3 trials are evaluating the neuroprotective effects of BG00012. Fumaric acids such as BG00012 are an exciting new class of potential MS treatment.