Two-year real-life efficacy, tolerability and safety of dimethyl fumarate in an Italian multicentre study

Background Dimethyl-fumarate (DMF) demonstrated efficacy and safety in relapsing-remitting multiple sclerosis (MS) in randomized clinical trials. Objectives To track and evaluate post-market DMF profile in real-world setting. Materials and methods Patients receiving DMF referred to Italian MS centres were enrolled and prospectively followed, collecting demographic clinical and radiological data. Results Among the 735 included patients, 45.4% were naive to disease-modifying therapies, 17.8% switched to DMF because of tolerance, 27.4% switched to DMF because of lack of efficacy, and 9.4% switched to DMF because of safety concerns. Median DMF exposure was 17 months (0-33). DMF reduced the annual relapse rate (ARR) by 63.2%. At 12 and 24 months, 85 and 76% of patients were relapse-free. NEDA-3 status after 12 months of DMF treatment was maintained by 47.5% of patients. 89 and 70% of patients at 12 and 24 months regularly continued DMF. Most frequent adverse events (AEs) were flushing (37.2%) and gastro-enteric AEs (31.1%). Conclusion Our post-market study corroborated that DMF is a safe and effective drug. Additionally, the study suggested that naive patients strongly benefit from DMF and that DMF improved ARR also in patients who were horizontally switched from injectable therapies due to tolerability and efficacy issues.