Fumarate-based MS therapies have equal benefit for different races
After a year, ARRs were significantly reduced across all ethnic groups
Fumarate-based therapies like Tecfidera (dimethyl fumarate) and Vumerity (diroximel fumarate) are equally effective among Black, Hispanic, Asian, and white adults with relapsing forms of multiple sclerosis (MS) in the U.S., the largest real-world study of its kind shows.
“The findings of this study suggest that fumarate medicines work well for people with MS regardless of their racial or ethnic background,” researchers wrote in the healthcare claims analysis, “Real-World Treatment Outcomes in Black, Hispanic, Asian, and White People with Multiple Sclerosis Treated with Fumarates in the USA,” published in Neurology and Therapy.
In MS, the immune system mistakenly attacks the myelin sheath, a protective coating around nerve fibers, damaging nerve cells in the brain and spinal cord.
Studies suggest a higher incidence of MS in Black people compared with white people, and a lower incidence among Asians and Hispanics. Black MS patients also tend to have a more severe disease course, more frequent relapses, and faster disability progression.
However, “there is limited research on MS in minority populations, primarily due to their underrepresentation in clinical trials,” wrote the researchers, who said this result “poses a significant challenge to understanding the differential impact of MS therapies across diverse populations.”
Tecfidera and Vumerity, both marketed by Biogen, are oral fumarate disease-modifying therapies (DMTs) approved for relapsing forms of MS. Once inside the body, both medicines are converted into their active form, monomethyl fumarate, which is thought to reduce MS-driving inflammation by altering immune cell activity. Vumerity is the next-generation option that delivers a comparable amount of monomethyl fumarate as Tecfidera, but with fewer gastrointestinal side effects.
Effectiveness of fumarate-based DMTs for patients of different races
In the study, which was sponsored by Biogen, researchers evaluated the real-world effectiveness of Tecfidera and Vumerity among Black, Hispanic, Asian, and white MS patients using data from the Komodo Health claims database. They identified 6,800 adults with MS in the U.S. who’d received fumarate medicines between 2017 and 2022: 4,650 self-reported as white, 1,241 as Black, 777 as Hispanic, and 132 as Asian.
“This is the largest analysis to date of the treatment effects of any individual class of DMT in Black and Hispanic [people with MS],” they wrote.
Before treatment, Black patients had more severe MS and a higher prevalence of coexisting conditions like chronic lung disease, congestive heart failure, and diabetes than other groups. They were also more likely to live in states with higher poverty levels, as were Hispanics, and less likely to have commercial insurance.
The mean exposure to fumarates was lowest among Black patients (449 days) compared with Hispanic (488), white (554), and Asian (559) patients.
“This could suggest potential disparities in access to treatments, but it is also possible that other factors contributed to the lower exposure, such as differences in patient preferences, or healthcare provider perceptions,” the researchers wrote.
After a year of treatment, annualized relapse rates (ARRs) were significantly reduced across all the ethnic groups. The ARR dropped from 0.338 to 0.252 for Black patients, 0.311 to 0.185 for Hispanic patients, 0.295 to 0.163 for Asian patients, and 0.299 to 0.214 for white patients. There were no significant differences in ARRs between ethnic groups after adjusting for disease activity and coexisting conditions.
The proportions of MS patients who remained free of relapses at two years were also similar: Black (77%), Hispanic (75.4%), Asian (81.7%), and white (80.5%).
At one year, the decline in the absolute lymphocyte count (ALC), that is, the number of immune lymphocytes, was smaller in Black patients (10.3%) than in Hispanic (20.1%) and white (20.4%) patients. The reduction in ALC between Black and white patients was statistically significant, but not between Hispanic and white patients. There wasn’t enough ALC data to analyze the Asian group.
“The relationship between lymphocyte counts and treatment effectiveness is not necessarily causal, and caution should be used when interpreting these ALC results, as they may be independent of efficacy outcomes,” the researchers wrote.
The mean annualized usage of healthcare resources and healthcare costs (per patient per year) were similar across all the groups.
“This large, real-world, claims-based analysis confirmed the benefit of fumarates treatment in 2,150 [people with MS] who self-reported being in a racial/ethnic minority group,” the researchers wrote. “The effectiveness of fumarates was similar across all racial/ethnic groups in this analysis.”
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