Saida T, et al. - The APEX study is a randomized phase 3 study conducted in two parts: a 24-week, double-blind, placebo-controlled portion (part I, which is complete), and an open-label extension (part II, which is ongoing. In part 1, the effectiveness and safety of delayed-release dimethyl fumarate (DMF) 240 mg twice daily or placebo were evaluated in relapsing-remitting multiple sclerosis (RRMS) patients. Study participants included 225 patients, 142 of which were East Asian. Key criteria for exclusion included a neuromyelitis optica spectrum disorder diagnosis. The study was completed by 213 patients (95.1%). The results obtained from this phase 3 study indicate that the robust effectiveness and favorable benefit-risk profile of DMF encompasses Japanese and, more widely, East Asian RRMS patients. Symptoms associated with flushing and gastrointestinal events were adverse events related to DMF treatment.