Switching to natalizumab or fingolimod in multiple sclerosis: Comparative effectiveness and effect of pre-switch disease activity

Background: Patients with relapsing-remitting multiple sclerosis (RRMS) who experience relapses on a first-line therapy (interferon, glatiramer acetate, dimethyl fumarate, or teriflunomide; collectively, "BRACETD") often switch to another therapy, including natalizumab or fingolimod. Here we compare the effectiveness of switching from a first-line therapy to natalizumab or fingolimod after >= 1 relapse. Methods: Data collected prospectively in the MSBase Registry, a global, longitudinal, observational registry, were extracted on February 6, 2018. Included patients were adults with RRMS with >= 1 relapse on BRACETD therapy in the year before switching to natalizumab or fingolimod. Included patients received natalizumab or fingolimod for >= 3 months after the switch.Results: Following 1:1 propensity score matching, 1000 natalizumab patients were matched to 1000 fingolimod patients. Mean (standard deviation) follow-up time was 3.02 (2.06) years after switching to natalizumab and 2.58 (1.64) years after switching to fingolimod. Natalizumab recipients had significantly lower annualized relapse rate (relative risk=0.66; 95% confidence interval [CI], 0.59-0.74), lower risk of first relapse (hazard ratio [HR]=0.69; 95% CI, 0.60-0.80), and higher confirmed disability improvement (HR=1.27; 95% CI, 1.03-1.57) than fingolimod recipients. No difference in confirmed disability worsening was observed.Conclusions: Patients with RRMS switching from BRACETD demonstrated better outcomes with natalizumab than with fingolimod.