Eligible patients were on DMF/FTY at enrollment in MS Partners Advancing Technology and Health Solutions (MS PATHS) network with ≥1y follow-up. Sensitivity analysis included a sub-group who initiated DMF/FTY ≤2y before MS PATHS. Propensity score weighting (PSW) covariates included age, sex, race, education, MS duration, prior therapy, cardiovascular disease, diabetes, and time since DMF/FTY initiation (sensitivity analysis). Generalized estimating equation models assessed differences in means and 1-year change in processing speed test (PST).

702 DMF and 600 FTY patients were eligible; 632 and 541 had PST assessments, respectively. Mean time (SD) since treatment initiation was 2.3 (1.7) [DMF] and 2.7 (2.1) years [FTY]. Mean number (SD) of follow-up assessments was the same between groups (2.3 [0.9]). At first MS PATHS visit, 324 (46%) [DMF] and 236 (39%) [FTY] had cardiovascular disease (p=0.01); mean (SD) PST was 49 (13) [DMF] and 51 (12) [FTY] for overall patients (p=0.007) and 51 (13) [DMF] and 52 (12) [FTY] without cardiovascular comorbidities (p=0.10). Following PSW (DMF as reference), difference in mean PST (-0.63, p=0.4) and slope of change in PST (0.06, p=0.88) during 1-year follow-up was not significant. Sensitivity analyses, including 135 and 134 patients with mean time (SD) since DMF/FTY initiation of 11.2 (7.2) and 10.1 (6.9) months, showed similar findings.