Black, Asian, and Hispanic individuals may be less likely than Whites to be included in clinical trials for treatment of Alzheimer’s Disease (AD), according to a report in JAMA Network Open. Increasing the diversity of participants in AD trials is essential to developing treatments and ultimately minimizing disparities in disease burden.
Rema Raman, Ph.D., of the Alzheimer’s Therapeutic Research Institute at the University of Southern California and colleagues analyzed screening data from 5,945 candidates for the Anti-Amyloid in Asymptomatic AD (A4) trial. This study is an ongoing 240-week, placebo-controlled, randomized phase 3 trial of an anti-Aβ monoclonal antibody in older adults with preclinical AD. Specifically, the researchers looked at the recruiting and screening processes for 5,107 White candidates, 323 Black candidates, 261 Hispanic candidates, 112 Asian candidates, and 142 candidates who reported race or ethnicity as “other.”
While multiple strategies were used to recruit candidates for the trial (including community outreach, referrals by trial investigators, paid advertisements, and more), White candidates were more likely to report referrals from a variety of sources, while Black, Hispanic, and Asian candidates were more likely to report being recruited by the study sites.
The screening process for the AD4 trial included five visits completed within 90 days. A total of 1,683 participants were excluded based on their initial screening visit, which included cognitive testing and other assessments. Non-White participants were excluded more frequently at an initial screening than were White participants: 30.7% of Black participants, 26.8% of Asian participants, and 26.1% Hispanic participants were excluded from the trial during an initial screening compared with 16.2% of White participants. Non-Whites were also more likely to be excluded when amyloid was assessed.
“The current results suggest that, even among the relatively small number of Hispanic and non-White participants recruited to the A4 trial, participants differed in their recruitment sources, their demographic and clinical characteristics, the reasons that they were excluded from participation, and their overall likelihood of being eligible for randomization,” Raman and colleagues wrote. “To the extent that the A4 Study is an accurate model of recruitment results for future preclinical AD trials, addressing each of these elements may be necessary to conduct truly inclusive studies of representative and generalizable samples.”
In an accompanying editorial, Jennifer J. Manly, Ph.D., of the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain at Columbia University Irving Medical Center and colleagues said the study reveals the need to change recruiting protocols. “[W]e need to consider the lasting implications of engaging underrepresented communities to recruit for a research trial and then deeming most willing people ineligible,” they wrote. “To learn from each other, narrow widespread disparities in AD, and accelerate toward our 2025 goal of reducing the impact of AD in the United States, harmonization and standardization of recruitment data are needed, but if the foundation of that standard continues to be Whiteness, AD research will continue to be dramatically less inclusive than the disease itself.”