Background And Objectives: Isolated value of MRI metrics in relapsing multiple sclerosis (RMS) as a surrogate marker of response to disease-modifying treatment (DMT) and, thus, as decision criteria for DMT escalation in the absence of clinical signs of disease activity is still a matter of debate. The aim of this study was to investigate whether DMT escalation based on isolated MRI activity affects clinical outcome.
Methods: Combining data from 5 MS centers in Austria and Switzerland, we included patients with RMS aged at least 18 years who (1) had initiated first-line, low-to-moderate-efficacy DMT (interferon β, glatiramer acetate, teriflunomide, or dimethyl fumarate) continued for ≥12 months, (2) were clinically stable (no relapses or disability progression) on DMT for 12 months, (3) had MRI at baseline and after 12 months on DMT, and (4) had available clinical follow-up for ≥2 years after the second MRI.