Dimethyl fumarate beneficial treatment for Black, Hispanic/Latino patients with MS
Dimethyl fumarate was safe and lowered relapse rates for up to 5 years in Black and Hispanic/Latino patients with relapsing-remitting multiple sclerosis, according to a poster at the Consortium of Multiple Sclerosis Centers annual meeting.
“Evidence suggests that clinical course and disability outcomes associated with multiple sclerosis may vary according to ethnicity and race,” Mitzi J. Williams, MD, of the Joi Life Wellness Group MS Center in Smyrna, Ga., told Healio. “Dimethyl fumarate was previously shown to be efficacious in a small sample of Black and Hispanic/Latino patients in the DEFINE/CONFIRM studies and a retrospective chart review.”
While dimethyl fumarate (DMF) was shown to be effective over 3 years in this patient population, Williams and colleagues sought to evaluate the drug’s long-term efficacy and safety in Black, non-Black, Hispanic/Latino and non-Hispanic/non-Latino patients with relapsing-remitting multiple sclerosis.
Researchers included 10,502 individuals (220 Black, 5,031 non-Black, 105 Hispanic/Latino and 5,146 non-Hispanic/non-Latino) who received at least one newly prescribed dose of DMF at approximately 390 clinical practice sites across the globe and were monitored for 5 years.
Outcomes of interest included incidence of serious adverse events and the effectiveness and safety of DMF, which were evaluated in a post hoc subgroup analysis in Black, non-Black, Hispanic/Latino and non-Hispanic/non-Latino participants. Researchers assessed annualized relapse rates (ARRs) by negative binomial model.
Results showed the following unadjusted ARRs up to 5 years — Black = 0.054 (95% CI, 0.038-0.078), non-Black = 0.077 (95% CI, 0.072-0.081), Hispanic/Latino = 0.069 (95% CI, 0.043-0.112) and non-Hispanic/non-Latino = 0.076 (95% CI, 0.072-0.081). Compared with AARs obtained 12 months before study inclusion, these values represent reductions ranging from 90.6% to 92.1% for all subgroups. The percentage of patients without relapse at 5 years was 80% to 85%.
Median lymphocyte counts also decreased in the first year, with researchers reporting a decline of 24.4% in Black patients, 35.8% in non-Black, 28.2% in Hispanic/Latino and 35.6% in non-Hispanic/non-Latino, and then remained stable.
The most common reason for treatment discontinuation in Black and Hispanic/Latino subgroups was gastrointestinal disorders.
“These data provide insights into the real-world treatment benefit of dimethyl fumarate in Black and Hispanic/Latino patients,” Williams told Healio. “Specifically, the annualized relapse rate was significantly lower up to 5 years after initiation with dimethyl fumarate compared with the 12 months prior to dimethyl fumarate initiation, and the safety profile in these subgroups was consistent with the overall ESTEEM population.”