Performing a therapeutic switch in MS is still a matter of debate. Objective of our study is to compare switching to another first-line therapy with switching to a second-line therapy in persons with relapsing-remitting multiple sclerosis (pwRRMS). A retrospective analysis of data prospectively collected was performed. PwRRMS experiencing on-treatment disease activity were included. No clinical relapse, no sustained disability progression by the Expanded Disability Status Scale (EDSS), and no radiological activity (new T2 and/or gadolinium-enhanced brain lesions) were used as indicators of no disease activity (NEDA 3). Time to reach the first relapse after switch and time to reach an EDSS of 4.0 were also evaluated. Ninety-one pwRRMS were enrolled. Forty-eight (52.7 %) were on lateral switch, and 43 (47.3 %) on escalation switch. At baseline, the two groups differed for T2 and T1 brain lesions number (higher in the escalation group, p < 0.005). The proportion of pwRRMS who were NEDA 3 after 24 months from the switch was similar in the two groups (20.8 % in lateral group and 18.6 % in escalation group). No difference in timing to reach the first relapse after switch and an EDSS of 4.0 were found. Therefore, in selected pwRRMS, lateral and escalation strategies showed similar efficacy in delaying MS progression.
Keywords: Escalation; Lateral; Multiple sclerosis; Switch; Therapy failure.