Initial treatment strategy and clinical outcomes in Finnish MS patients: a propensity-matched study

Background The optimal treatment strategy with disease-modifying therapies (DMTs) in relapsing-remitting multiple sclerosis (RRMS) remains uncertain. Objective To compare outcomes of initial treatment with infusion therapies and starting therapy with medium efficacy therapy in a propensity-matched cohort of Finnish RRMS patients. Methods A total of 154 RRMS patients initiating natalizumab, alemtuzumab, ocrelizumab or rituximab as first DMT (high efficacy DMT, heDMT group) and 1771 patients initially treated with injectable therapies, teriflunomide or dimethylfumarate and escalated based on disease activity (moderate efficacy DMT, meDMT group) were identified from the Finnish MS registry. Nearest neighbor propensity matching (1:1, caliper 0.1) was performed for age, sex, baseline Expanded Disability Status Scale (EDSS), annual relapse rate (ARR) one year prior DMT and time since MS symptom onset. Primary outcome was time to 6-month confirmed EDSS progression and the secondary outcome time to first relapse. Results In the propensity-matched group comparisons, the probability of 6-month confirmed disability progression (CDP) at 5 years after DMT start was 28.4% (95% CI 15.7-39.3) in the heDMT group (n = 66) and 47.0% (95% CI 33.1-58.1) in meDMT group (n = 66), p = 0.013. Probability of relapse at 5 years was 34.6% (95% CI 24.1-43.6) for heDMT (n = 105) and 47.2% (95% CI 36.6-56.1) for meDMT (n = 105), p = 0.019. Conclusions Initiating MS-therapy with heDMT significantly reduced the risk of 5-year disability progression and relapse compared to using meDMT as first DMT choice in propensity-matched groups of Finnish MS-patients.