Study investigates how effective multiple sclerosis medications are across racial and ethnic groups

For people with relapsing-remitting multiple sclerosis (MS), a new study has found that the drug ofatumumab is more effective than teriflunomide at helping people across racial and ethnic groups reach a period of no disease activity. The study is published in the July 17, 2024, online issue of Neurology. Ofatumumab, a monoclonal antibody, is a newer drug for treating MS. Teriflunomide, an immunomodulatory agent, has been available for over a decade.

MS is a disease in which the body's immune system attacks myelin, the fatty white substance that insulates and protects the nerves. Symptoms may include fatigue, numbness, tingling or difficulty walking. Relapsing-remitting MS is the most common stage of the disease, marked by symptom flare-ups followed by periods of remission.

"Ethnically diverse groups, including Black and African American, Hispanic and Latino, and Asian individuals, are consistently underrepresented in clinical trials, limiting the data available to help make the best treatment decisions for people in these groups," said study author Mitzi Joi Williams, MD, of Joi Life Wellness MS Center in Atlanta and a Fellow of the American Academy of Neurology. "Our study examined the efficacy and safety of ofatumumab in diverse populations. We found overall the drug was effective and safe across racial and ethnic groups."

The study was a post hoc analysis of two previous studies, meaning the researchers looked back at data already collected to more closely examine racial and ethnic differences.

The study involved 1,882 participants, of which 3% self-identified as non-Hispanic Black, 4% as non-Hispanic Asian, 8% as Hispanic/Latino and 82% as non-Hispanic white. The remaining participants were classified as "other/unknown."

One half of participants received 20 milligrams (mg) ofatumumab every four weeks. The other half received 14 mg of teriflunomide once daily. Participants were followed for two years.

Researchers examined disease activity. No disease activity meant participants had no new relapses with symptom flare-ups, no change in disability and no new lesions in the brain or spine detected with an MRI scan.

Over the study, 33% of the non-Hispanic Black participants taking ofatumumab had no disease activity compared to 3% taking teriflunomide. Among non-Hispanic Asian participants, the percentages were 43% and 22% respectively. For Hispanic/Latino participants, 37% and 19%, and for non-Hispanic white participants, 37% and 17%. The proportion of people treated with ofatumumab who had no disease activity was consistent among all race and ethnicity groups.

Rates of experiencing side effects were similar for all groups.

"Determining whether there are differences in how people respond to MS therapies is of great importance so that ultimately, each person is given the most effective treatment for them," said Williams. "Underrepresentation of diverse populations continues to be an issue in research. Future studies should strive to enroll racially and ethnically diverse groups to better inform treatment decisions."

A limitation was that the original studies examined in this analysis were not designed to examine the efficacy and safety of the drugs based on race and ethnicity.