SwissTecLive: effectiveness and safety of dimethyl fumarate in the treatment of RRMS in the Swiss clinical practice setting

Abstract Background Delayed-released dimethyl fumarate (DMF) is an oral disease-modifying therapy (DMT) approved for treating patients with multiple sclerosis (MS). This post-marketing study aimed at collecting real-world data on the safety, effectiveness, and tolerability of DMF in patients with relapsing remitting multiple sclerosis (RRMS). Methods 1-year post-marketing survey of patients prescribed DMF followed-up quarterly in hospital setting and private neurological practices in Switzerland from January 2015 to January 2018. Data on relapses, Expanded disability status scale (EDSS) score change, safety, tolerability, treatment adherence as judged by the treating neurologist and satisfaction were collected. Patients could refer to a patient support program. Results Of the 158 patients, 67 (42.4%) were treatment naive, 91 (57.6%) switched from a prior MS DMT to DMF, 131 (82.9%) were treatment adherent, 108 (68.4%) used the support program, and 45 (28.5%) discontinued the therapy. Insufficient tolerability and insufficient effectiveness were the main reasons for discontinuation. 134 (84.8%) patients remained relapse free, 97 (61.4%) had stable or decreased EDSS score after 12 months. 74 (46.8%) patients reported adverse events; of these, 28 (17.7%) discontinued DMF treatment. Physicians and patients rated treatment satisfaction similarly (median score 8.0 of 10). Conclusions The results obtained from this real-world observation are consistent with the efficacy and safety findings reported in pivotal and larger observational trials evaluating DMF treatment. Most side effects were experienced early after therapy initiation reflecting the timing of therapy discontinuation.