Comparative discontinuation, effectiveness, and switching practices of dimethyl fumarate and fingolimod at 36-month follow-up

Background: Dimethyl fumarate (DMF) and fingolimod (FTY) are approved oral disease modifying therapies (DMTs) for relapsing multiple sclerosis (MS). There are currently no known head-to-head studies comparing DMF and FTY over 36 months, which leaves their relative effectiveness unknown. Objective: To assess real-world discontinuation, effectiveness, and switching practices of DMF and FTY over 36 months along with disease activity after switching DMT. Methods: Patients prescribed DMF (n = 737) and FTY (n 535) from two academic MS centers were retrospectively reviewed. Discontinuation and effectiveness outcomes were assessed using propensity score (PS) weighting. PS model covariates included sociodemographics and clinical and MRI characteristics. Results: Discontinuation was more common in DMF (58.3%) versus FTY (45.2%) over 36 months [OR = 1.81, 95% CI (1.41-2.31), p < .001], largely driven by intolerance [OR = 1.63, 95% CI (1.18-1.73), p < .001]. There were no differences in clinical relapses [OR = 1.27, 95% CI (0.90-1.79), p = .17], gadolinium-enhancing (GdE) lesions [OR = 1.25, 95% CI (0.85-1.84), p = .26], or new T2-hyperintense lesions [OR = 0.99, 95% CI (0.74-1.32), p = .93]. Within 12 months of DMF/FTY discontinuation, switchers to highly effective therapy (HET) versus other DMTs (injectables/orals) had fewer relapses (DMF/HET, 5.9% versus DMF/Other, 14.2%, p = .03; FTY/HET, 11.6% versus FTY/Other, 18.0%, p = .04) and fewer GdE lesions post-FTY (DMF/HET, 10.3% versus DMF/Other, 14.3%, p = .36; FTY/HET, 11.9% versus FTY/Other, 21.5%, p = .04). Conclusion: This combined analysis showed similar effectiveness for DMF and FTY over 36 months with higher DMF discontinuations. Disease activity was lower in switchers to HET versus injectable/oral therapies after DMF/FTY cessation.