Efficacy of dimethyl fumarate in Japanese multiple sclerosis patients: interim analysis of randomized, double-blind APEX study and its open-label extension.

Abstract

BackgroundCurrent data for the use of dimethyl fumarate (DMF) in Japanese patients with relapsing–remitting multiple sclerosis (RRMS) is limited.ObjectivesTo assess the efficacy of DMF in Japanese patients with RRMS.MethodsThe phase 3, multinational APEX study (ClinicalTrials.gov identifier: NCT01838668) consisted of two parts: a 24-week double-blind part where subjects were randomized to receive DMF 240 mg or placebo twice daily in East Asian and Eastern European countries, and an open-label extension part where all subjects received DMF. The primary endpoint was the total number of new gadolinium-enhancing lesions in Weeks 12–24. In this interim analysis, we report efficacy data in the Japanese subgroup (DMF n = 56; placebo n = 58) over 72 weeks, including an extension phase.ResultsDMF reduced the total number of new gadolinium-enhancing lesions in Weeks 12–24 by 85% versus placebo (p < 0.0001). At Week 24, the annualized relapse rate was also reduced by 48% with DMF, versus placebo. DMF reduced the probability of relapse from Week 8 and was sustained. The number of gadolinium-enhancing lesions was maintained through 72 weeks.ConclusionsDMF demonstrated sustained efficacy in this Japanese subgroup. The results were consistent with those observed in studies of DMF enrolling primarily Caucasian patients.