Three-Year Effectiveness of Dimethyl Fumarate in Multiple Sclerosis: A Prospective Multicenter Real-World Study.

BACKGROUND: Dimethyl fumarate (DMF) has demonstrated efficacy in phase III studies. However, real-world data are still limited. OBJECTIVE: The objective of this study was to describe the profile of patients who receive DMF and to assess the effectiveness of DMF regarding relapses, disability progression, magnetic resonance imaging activity, and NEDA (No Evidence Disease Activity)-3 status in a Spanish population in a real-world setting. METHODS: We conducted a multicenter prospective study of patients who started DMF between 2014 and 2019 in Spain. Three subgroups were considered: naïve, switch to DMF because of inefficacy, and switch to DMF because of adverse effects. The effects of DMF on clinical and radiological measures were evaluated. RESULTS: Among 886 patients, 25.3% were naïve, 28.8% switched because of adverse effects, and 45.9% because of inefficacy. Median follow-up was 38.9 (interquartile range 22.6-41.8) months. Annualized relapse rates were 0.15, 0.10, and 0.10 at 12, 24, and 36 months respectively, and 77.7% of patients were relapse free at month 42. At 12, 24, and 42 months, 96.1%, 87.4%, and 79.7% of patients were progression free, respectively. The number of T1 gadolinium-enhancement (T1Gd+) lesions was 0.19, 0.14, and 0.18 at 12, 24, and 36 months. NEDA-3 status at month 42 was maintained by 49.8% of patients. Relapsing was associated with higher annualized relapse rates the year before (hazard ratio 1.34, p < 0.001) and to the inefficacy switch vs naïve group (hazard ratio 1.76, p = 0.003). A higher baseline Expanded Disability Status Scale score was associated with disability progression (hazard ratio 1.15, p = 0.003) and more T1Gd+ lesions (hazard ratio 1.07, p < 0.001) with radiological progression. A higher baseline Expanded Disability Status Scale score, a larger number of T1Gd+ lesions, and a switch because of inefficacy (vs adverse events) were all risk factors for losing NEDA-3 status. DMF was discontinued in 29.9% of patients, in 13.5% because of inefficacy. CONCLUSIONS: Our findings confirm the sustained effectiveness of DMF on the clinical and radiological activity of multiple sclerosis in a real-world setting, both in naïve patients and in those switching from other multiple sclerosis therapies.

Tolerability and safety of dimethyl fumarate in relapsing multiple sclerosis: a prospective observational multicenter study in a real-life Spanish population.

BACKGROUND: Dimethyl fumarate (DMF) tolerability and safety in multiple sclerosis (MS) has been analyzed in randomized clinical trials. Real-life studies are needed to assess possible harms of this therapy in a wider MS population. OBJECTIVE: To evaluate DMF tolerability, safety and persistence in MS in a real-world setting. METHODS: We conducted a multicenter prospective study of patients who started DMF, attended in 16 public hospitals of Spain. A specific database was elaborated to collect data on most frequent adverse events (AE). Regression models were used to analyze the effect of demographic and clinical characteristics on risk of AEs and DMF discontinuation. RESULTS: We collected data of 886 patients (2681 patients/years-exposition) with median 39.5 (IQR 23, 51.5) months on DMF exposure; 25.3% were treatment naïve and 74.7% switched to DMF from other disease-modifying therapies. DMF was discontinued in 29.9% of patients, in 13.2% due to AEs and in 13.5% to inefficacy. AEs were experienced by 71.2%, being flushing the most frequent (44.1%), 5.4% developed grade III lymphopenia, without cases of grade IV. Females showed a higher risk of flushing and gastroenteric symptoms (OR 1.49, p = 0.011; OR 1.69, p = 0.001, respectively); lymphopenia was associated with older age (OR 1.04, p < 0.001), and a higher EDSS with lymphopenia (OR 1.10, p = 0.035) and DMF withdrawal (HR 1.43, p = 0.012). No safety problems were reported. CONCLUSIONS: Our findings confirm good tolerability and safety of DMF in real-world setting and suggest that women have an increased risk of AEs and higher baseline disability involves greater risk of drug discontinuation.