By Shobha Dhadda, SVP, Global Head, Biostatistics & Clinical Development Operations, ADBH, Eisai





June 15, 2023

An estimated 6.5 million Americans age 65 and older were living with some form of Alzheimer's disease (AD) in 2022. As the pharmaceutical and biotech industry continues to make strides in AD research and development, we must focus on addressing a historically overlooked issue: ensuring the demographics of the people studied in AD clinical trials are reflective of the population affected by this devastating disease.

Many clinical trials across disease areas have failed to adequately represent the ethnic diversity of the world we live in, and trials exploring investigational agents for people living with AD and dementia have followed the same pattern. This becomes increasingly concerning when we look at who is most likely to be diagnosed with these devastating diseases.

Approximately 13% of Hispanic Americans 65 or older are living with AD or another dementia.1 Among Black Americans ages 70 and older, 21.3% are living with AD.2 An analysis of over 100 clinical trials in AD found that only 12% of participants were of racial minorities (according to the USC Keck School of Medicine), despite a higher prevalence of AD in Black and Hispanic populations.3

At Eisai, we have a responsibility to conduct clinical trials that better represent the demographics of the people that suffer from the diseases we aim to treat. This mindset was at the core of our approach to developing the Phase 3 Clarity AD clinical trial for Alzheimer's disease.

Ensuring ethnic diversity in clinical trials is not only a matter of equity – people of different ages, races, and ethnicities may react differently to investigational agents, and as we search for solutions in research, it is vital to recruit participants that accurately represent the population that would ultimately be treated with the therapy.

Before Eisai’s Clarity AD Phase 3 trial was initiated, we selected sites and investigators working within ethnically diverse communities, implemented outreach activities with local community centers and churches, and engaged with patient advocacy groups and community leaders, all with the purpose of prioritizing an ethnically diverse population base for that study. We implemented decentralizing clinical trial activities (i.e., creating options for patient participation beyond traditional research sites) to reduce burden on participants.

The result for our Phase 3 Clarity AD study was a trial population where 22.5% of participants were Hispanic and 4.5% were African American, compared to the median 5.3% of all minority participants in Alzheimer’s disease clinical trials historically.4 Eisai understands that there is tremendous work to be done, especially amongst the African American community, to ensure clinical trials reflect the ethnic diversity of our global community.

Significant innovations in the preclinical Alzheimer’s disease, AHEAD study, for diverse participant recruitment and enrollment are ongoing.

Of course, diversity should not stop with clinical trials. If we are to make progress in providing relief for not only people living with AD, but with other diseases as well, the entire industry must shift toward an evolved, more equitable approach to health and research. Eisai will continue to work with the patient community and advocates, as well as building new relationships with people and organizations that can help develop and implement strategies to address health disparities. Our hope is that the ethnic diversity represented in the Clarity AD trial can provide a roadmap for researchers to build on this result so that it can be replicated to eligible patients in the real-world.

This article was written and approved by Eisai Inc.


1. Alzheimer’s Association. 2022 Alzheimer’s Disease Facts and Figures. Alzheimer's & Dementia: The Journal of the Alzheimer's Association. 2022 Mar; 18(4): 700–789. https://doi.org/10.1002/alz.12638

2. Alzheimer’s Association. “Hispanic American More Likely to Develop Dementia. Why?” Retrieved April 17, 2023 from https://www.alz.org/news/2022/hispanic-americans-more-likely-to-developdementia#:~:text=Approximately%2013%25%20of%20Hispanics%2065,support%20for%20Hispanic%20community%20members

3. Alzheimer’s Association. “Black Americans and Alzheimer’s” Retrieved April 17, 2023 from https://www.alz.org/help-support/resources/black-americans-and-alzheimers

4. Hamashige, Hope. “Ensuring diverse participation in Alzheimer’s clinical trial participants” Retrieved from https://keck.usc.edu/ensuring-diverse-participation-in-alzheimers-clinical-trial-participants/

5. Sanne, Franzen, et al. Diversity in Alzheimer’s disease drug trials: The importance of eligibility criteria. Alzheimer's & Dementia: The Journal of the Alzheimer's Association. 2022 Mar; 18(4): 810–823. https://doi.org/10.1002/alz.12433