Overview

• Citing AHEAD 3-45 data from 6,437 cognitively unimpaired adults across 75 U.S. sites, Keck researchers report lower p-tau217–defined amyloid prevalence in African American, Hispanic and Asian participants, limiting entry into lecanemab prevention trials.
• Among participants who met the p-tau217 cutoff, all racial and ethnic groups were equally likely to meet amyloid PET criteria, suggesting the threshold identifies early pathology consistently across groups.
• The study team has invited screen-failed participants into the APEX follow-up and plans to expand analyses to more than 20,000 individuals to track biomarker trajectories and refine eligibility rules.
• A separate UC San Diego analysis of 5,712 Hispanic and Latino adults links higher blood NfL and GFAP—and, for memory, p-tau181—to greater self-reported cognitive decline, while Aβ42/40 shows no association.
• Researchers say blood assays could offer faster, less-invasive screening than PET, though the FDA-cleared Lumipulse pTau217/Aβ42 test remains costly and limited to specialized settings, underscoring the need for validation in diverse populations.