Race, Ethnicity May Affect DMT Response and Tolerability in Multiple Sclerosis

Investigators found that Hispanic and African American patients had an increased risk of developing ambulatory disability, when compared to Caucasian patients with MS.

Data presented at the 37th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), October 13-15, showed varying tolerability and response to disease modifying therapies (DMTs), depending on race and ethnicity for patients with multiple sclerosis (MS). 

Study authors Carlos A. Pérez, MD, assistant professor, neurology, Baylor College of Medicine; director, Multiple Sclerosis regional Program, Neurology Care Line, Michael E. DeBakey VA Medical Center; and John A. Lincoln, MD, PhD, associate professor, neurology; and director, MRI Analysis Center, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), conducted a retrospective review of 300 age and gender-matched patients with MS, including 100 Hispanic patients, 100 African American patients, and 100 Caucasian patients, all followed at UTHealth over the course of 20 years. 

Data showed that both Hispanic and African American patients with MS had a higher risk of ambulatory disability, with an HR of 8.1 (95% CI, 3.2-16.8; P <.001) and an HR of 9.2 (95% CI, 4.1-19.6; P <.001), respectively, when compared to Caucasian patients with MS.

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Investigators confirmed findings despite similar baseline characteristics, sociodemographic profiles, as well as patterns of DMT exposure, noting glatiramer acetate as the most prevalent firstline DMT prescribed and patients who were taking ocrelizumab (Ocrevus; Genentech) were less likely to switch treatment methods. 

Results further showed that of patients required escalation of therapy, African Americans accounted for the majority (40.5%), while also being less likely to respond to interferon-ß when used as a first-line treatment (63.2%). Further, African American patients had the highest rate of adverse events (AEs) in response to treatment, specifically to interferons, with AEs occurring in 46.0% of cases.

Data showed that Hispanic patients were more likely to discontinue treatment with DMTs in general (12.0%), and Caucasian patients were less likely to tolerate glatiramer acetate (42.5%). DMTs included in the review were interferons (n = 101; 35.4%), glatiramer acetate (n = 125; 43.9%), teriflunomide (Aubagio; Biogen)(n = 11; 3.9%), sphingosine phosphate 1 inhibitors (n = 16; 5.6%), fumarates (n = 10; 3.5%), natalizumab (Tysabri; Biogen) (n = 8; 2.8%), and CD20 inhibitors (n = 11; 3.9%). Cladribine (Mavenclad; EMD Serono), adrenocorticotropic hormone, and mitoxantrone were excluded due to low number of patients taking them.

“Hispanic/Latino and African American patients with MS have a greater risk for poor outcome compared to their Caucasian counterparts,” Pérez and Lincoln wrote on the presentation poster. “There is growing concern about differential responses to treatment by race/ethnicity. Evidence-based approaches to therapy in MS are largely based on data from phase 3 studies with suboptimal racial/ethnic representation, which limits generalizability of therapeutic approaches to underrepresented populations.”

Caucasian patients had a median age of 43.6 years (standard deviation [SD], 11.2), Hispanic patients had a median of 42.8 years (SD, 11.2), and Black patients had a median of 42.9 years (SD, 11.2). Each group had approximately 77 women (77%). Patients stopped or switched DMTs due to inefficiency, intolerance, nonadherence, inconvenience, insurance, or pregnancy. 

Future research should incorporate real-world data into currently underrepresented clinical studies, investigators noted, to better inform efforts in precision medicine and enhance standard-of-care practices for minority groups with MS, effectively improving outcomes. 

Another recent narrative review concluded that racial and ethnic health disparities and care inequities in MS and neuromyelitis optica spectrum disorder put Black, Hispanic, and Latinx individuals at a disadvantage in receiving adequate care in the US compared with White individuals. Investigators from the study noted research is necessitated to investigate how social determinants of health mechanisms and structures contribute to these inequities for underrepresented populations, primarily lower rates of education, income, and access to specialty care.

For more coverage of ECTRIMS 2021, click here.

REFERENCE
Pérez C, Lincoln JA. Real-world influence of race/ethnicity on response and tolerability of multiple sclerosis treatment: a 20-year comparative study. Presented at: ECTRIMS 2021; October 13-15; Virtual. Poster P682.