Clinical predictors of Dimethyl Fumarate response in multiple sclerosis: a real life multicentre study

•In real life, DMF reduced the annualized relapse rate (ARR) by 75% respect to the pre-treatment ARR.•Age of onset of MS was related with rate or relapses, with younger age being protective.•De-escalating from second-line therapies was associated to higher risk of relapsing.•Disease duration was associated with higher rate of NEDA-3 failure.•Higher pre-treatment EDSS was associated with DMF discontinuation. Dimethyl-fumarate (DMF) was effective and safe in relapsing–remitting multiple sclerosis (MS) in randomized clinical trials. We aimed to evaluate the efficacy and safety of DMF and factors related to drug response in real-life setting. We analysed prospectively collected demographic and clinical data for patients treated with DMF in six multiple sclerosis (MS) centers from 2015 to 2017 in Campania region, Italy. We performed univariate and multivariate analyses to assess relationships between baseline parameters and DMF efficacy outcomes, Annualized Relapse Rate (ARR), Expanded Disability Status Scale (EDSS) progression and No Evidence of Disease Activity (NEDA-3) status. we analyzed data of 456 patients (67% female subjects, mean age 40 ± 12 years, mean disease duration 9 ± 9 years, mean treatment duration 18 ± 11 months, median EDSS 2.5, 0–8). Proportion of Naïve versus pretreated with other DMTs patients was 149/307 (32.7%), with 122 patients switching to DMF for disease activity (26.7%) and 185 for safety and tolerability issues (40.6%). During treatment with DMF, the annualized relapse rate was reduced by 75% respect to the pre-treatment ARR [incidence-rate-ratio (IRR) = 0.25, p