Introduction: Compared with the non-Hispanic/non-Latino population, Hispanic/Latino patients with multiple sclerosis (MS) are reported to exhibit greater disease severity. Geographical location and genetics play a role in differences observed across Hispanic/Latino subpopulations. We evaluated real-world safety and effectiveness of dimethyl fumarate (DMF) on MS disease activity in Hispanic/Latino patients.
Methods: ESTEEM is an ongoing, 5-year, multinational, prospective study evaluating long-term safety and effectiveness of DMF in patients with MS. This interim analysis included patients newly prescribed DMF in routine practice at 394 sites globally.
Results: Overall, 4986 non-Hispanic/non-Latino and 98 Hispanic/Latino patients were analyzed; median (range) follow-up was 18 (2-37) months. Unadjusted annualized relapse rates (ARRs) for 12 months before DMF initiation versus 36 months post DMF initiation, respectively, were: non-Hispanic/non-Latino patients, 0.82 (95% CI 0.80-0.84) versus 0.10 (95% CI 0.09-0.10), 88% lower ARR (P < 0.0001); Hispanic/Latino patients, 0.80 (95% CI 0.65-1.00) versus 0.09 (95% CI 0.06-0.14), 89% lower ARR (P < 0.0001). In total, 28 (29%) Hispanic/Latino patients reported adverse events leading to treatment discontinuation; gastrointestinal (GI) disorders (n = 10, 10%) were the most common, consistent with the non-Hispanic/non-Latino population (8%). Median lymphocyte counts decreased by approximately 24% in the first year (vs 36% decrease in non-Hispanic/non-Latino patients) then remained stable and above the lower limit of normal in most patients.
Conclusions: Relapse rates remained low in Hispanic/Latino patients, consistent with non-Hispanic/non-Latino patients. The safety profile of DMF in Hispanic/Latino patients was consistent with safety findings from the non-Hispanic/non-Latino ESTEEM population, demonstrating the real-world treatment benefit of DMF in the Hispanic/Latino patient cohort.
Keywords: Dimethyl fumarate; Multiple sclerosis; Safety and effectiveness.