Time course of clinical and neuroradiological effects of delayed-release dimethyl fumarate in multiple sclerosis

BACKGROUND AND PURPOSE: Delayed-release dimethyl fumarate (DMF, also known as gastro-resistant DMF), demonstrated efficacy and safety in relapsing−remitting multiple sclerosis in the 2-year, randomized, placebo-controlled, phase 3 DEFINE and CONFIRM trials. A post hoc analysis of integrated data from DEFINE and CONFIRM was conducted to determine the temporal profile of the clinical and neuroradiological effects of DMF. METHODS: Eligible patients were randomized to receive placebo, DMF 240 mg twice (BID) or three times (TID) daily or glatiramer acetate (GA; reference comparator; CONFIRM only) for up to 96 weeks. Patients in the GA group were excluded from this analysis. RESULTS: A total of 2301 patients were randomized and received treatment with placebo (n = 771) or DMF BID (n = 769) or TID (n = 761). DMF significantly reduced the annualized relapse rate beginning in weeks 0–12 (BID, P = 0.0159; TID, P = 0.0314); the proportion of patients relapsed beginning at week 10 (BID, P = 0.0427) and week 12 (TID, P = 0.0451); and the proportion of patients with 12-week confirmed disability progression beginning at week 62 (BID, P = 0.0454) and week 72 (TID, P = 0.0399), compared with placebo. These effects were sustained throughout the 2-year study period. DMF significantly reduced the odds of having a higher number of gadolinium-enhancing lesions by 88% (BID) and 75% (TID) and the mean number of new or enlarging T2 lesions by 72% (BID) and 67% (TID), from the first post-baseline magnetic resonance imaging assessment at 24 weeks (all P < 0.0001 versus placebo). CONCLUSIONS: In phase 3 clinical trials, DMF demonstrated rapid and sustained clinical and neuroradiological efficacy in relapsing−remitting multiple sclerosis.