IMPORTANCE After multiple sclerosis (MS) relapse while a patient is receiving an injectable disease-modifying drug, many physicians advocate therapy switch, but the relative effectiveness of different switch decisions is often uncertain.OBJECTIVE To compare the effect of the oral immunomodulator fingolimod with that of all injectable immunomodulators (interferons or glatiramer acetate) on relapse rate, disability, and treatment persistence in patients with activeMS. DESIGN, SETTING, AND PARTICIPANTS Matched retrospective analysis of data collected prospectively from MSBase, an international, observational cohort study. The MSBase cohort represents a population of patients with MS monitored at large MS centers. The analyzed
data were collected between July 1996 and April 2014. Participants included patients with relapsing-remittingMS who were switching therapy to fingolimod or injectable immunomodulators up to 12 months after on-treatment clinical disease activity (relapse or progression of disability), matched on demographic and clinical variables. Median follow-up
duration was 13.1 months (range, 3-80). Indication and attrition bias were controlled with propensity score matching and pairwise censoring, respectively. Head-to-head analyses of relapse and disability outcomes used paired, weighted, negative binomial models or frailty
proportional hazards models adjusted formagnetic resonance imaging variables. Sensitivity analyses were conducted. EXPOSURES Patients had received fingolimod, interferon beta, or glatiramer acetate for a
minimum of 3 months following a switch of immunomodulatory therapy.