Relapsing–Remitting Multiple Sclerosis: Patterns of Response to Disease-Modifying Therapies and Associated Factors: A National Survey

INTRODUCTION Current treatments for relapsing-remitting multiple sclerosis (RRMS) are only partially effective. The objective of this study was to characterize treatment response in RRMS patients in Portugal to 12-month therapy with first-line disease-modifying therapies. METHODS In this retrospective study, neurologists at participating centers completed survey questionnaires using records of patients with RRMS who had received first-line treatment with one of five European Medicine Agency-approved agents in the 12 months prior to inclusion in the survey. Sub-optimal responders included patients treated for at least 1 year, and who had ≥1 relapse(s) or an increase of 1.5 points on the Expanded Disability Status Scale (EDSS; if baseline EDSS was 0) or an increase of ≥0.5 points (baseline EDSS ≥1). Optimal responders included patients treated for at least 1 year without relapse and who had an increase of <1.5 points on EDSS (if baseline EDSS was 0) or no increase in EDSS (baseline EDSS ≥1). RESULTS Data for 1,131 patients from 15 centers were analyzed. Twenty-six percent (95% confidence interval 23-28%) of patients had sub-optimal treatment response. Duration of therapy (P < 0.001), age at the start of therapy (P = 0.03), and baseline EDSS score (P < 0.001), were significantly different among treatments. Sub-optimal treatment response appeared to be related only to a more severe EDSS score at baseline and did not differ among therapies. CONCLUSION Neurologists should closely monitor patients to optimize treatment strategies and better control disease, improving prognosis.