Real-World Comparison of Adherence and Persistence Among African-Americans with Multiple Sclerosis Treated with Fingolimod Versus Glatiramer Acetate
Studies examining real-world adherence and persistence on disease-modifying therapies (DMTs) among African-American patients diagnosed with multiple sclerosis (MS) are scarce.
To compare adherence, persistence, and discontinuation between African-American patients with MS initiating therapy on fingolimod (FTY) versus glatiramer acetate (GA).
This retrospective study used medical and pharmacy claims data and enrollment information from a large national United States health plan. African-American patients ≥18 years old initiating treatment on FTY or GA from 9/1/2010-6/30/2014 were included. The first FTY or GA claim determined the index date; patients were assigned to the FTY or GA cohort according to index DMT. Patients had continuous health plan enrollment during 6 months pre-index and 12 months post-index, ≥1 MS diagnosis (ICD-9 code 340) in the pre-index period or in the first 6 months post-index, and <25 days per hospital stay during post-index period. Outcomes were measured over the 12-month post-index period, and included adherence measured with proportion of days covered (PDC), discontinuation (≥60-day gap in index DMT), and persistence (days to first discontinuation). Outcomes were reported by DMT cohort.
Of 210 patients, 71 were in the FTY cohort and 139 in the GA cohort. FTY and GA cohorts, respectively, had similar age (mean [standard deviation (SD)]: 43.7 [10.3] vs. 42.6 [12.0] years), gender (81.7 vs. 87.8% female), ≥1 pre-index period MS relapse (31.0 vs. 31.7%), geographic region, insurance type, and index year. FTY vs. GA patients were less likely to be treatment-naïve (52.1 vs. 79.9%, respectively). The FTY cohort had greater adherence compared with GA, with mean PDC of 0.78 (95% confidence interval [CI] 0.72, 0.83) vs. 0.67 (CI: 0.63, 0.72) and 63.4% with PDC ≥0.80 (CI: 51.1, 74.5) vs. 46.0% (CI: 37.6, 54.7). FTY patients had twice the odds of PDC ≥0.80 (unadjusted odds ratio: 2.03, CI: 1.13, 3.65). The percentage discontinuing their index DMT was 28.2% for FTY and 39.6% for GA. FTY patients were persistent for mean (SD) 298.5 (109.4) days vs. GA patients (266.7 [124.1] days); the difference in mean persistence between cohorts was 31.8 days (CI: -2.6, 66.1).
Similar to trends in the general MS population, African-American MS patients were significantly more adherent to FTY versus GA treatment in the real-world setting, which should be considered when discussing MS treatment options.