Clinical and patient determinants of changing therapy in relapsing-remitting multiple sclerosis (SWITCH study)

clinical factors and frequency of disease-modifying therapy (DMT) changes/interruptions in relapsing-remitting multiple sclerosis (RRMS) patients have not been well defined. The aim of this study was to describe reasons of MS treatment modifications in a large cohort of Italian MS patients.

this multicenter, cross-sectional non interventional study (SWITCH) conducted at 28 Italian MS centers, screened, by visit/telephone contact between June 2016 and June 2017, all RRMS patients receiving stable DMT treatment and enrolled patients with change in DMT treatment.

out of 13,657 recorded in the log, 409 (3%) changed therapy. Of these, 336 (2.5%), met the study criteria and were considered eligible. Among 303 (90.2% of 336) patients switching, the most common reason was "lack of efficacy" (58.4% of 303). Among 30 (8.9%) patients who interrupted treatment temporarily, the most common reason was pregnancy (40.0% of 30). Out of 3 (0.9%) patients who discontinued treatment permanently, 2 (66.7%) had as first reason as "patient decision". Multivariate analysis showed that EDSS was the only variable with statistically significant effect on changing treatments (r = 8.33; p-value of Type III Sum of Squares = 0.016).

in our study, 303 (90.2% of eligible patients) switched treatment, 30 (8.9%) interrupted treatment temporarily, and 3 (0.9%) discontinued treatment permanently. Efficacy remains the main driving force behind switching behavior, as the primary aim of treatment is to be disease free or reduce disease activity.