AHEAD Plasma Extension (APEX) study

Abstract In order to move closer to primary prevention of Alzheimer’s disease, that is the prevention of amyloid and tau accumulation, efficient, relatively low cost, non-invasive, and reliable methods are needed to identify individuals most likely to develop AD pathology. With the advent of blood-based biomarkers, we have the opportunity to track cognitively unimpaired individuals over time and investigate rates of change in both amyloid and tau plasma markers. The AHEAD 3-45 Study is screening cognitively unimpaired individuals ages 55-80 for a secondary prevention trial testing lecanemab funded by a public-private-philanthropic partnership. We implemented plasma screening in the AHEAD study and have many individuals who underwent plasma screening but did not ultimately meet the amyloid PET eligibility for inclusion into the A3 or A45 trials. This group is a particularly valuable cohort of individuals on whom we already have substantial information and who have already expressed interest in AD prevention research. The Alzheimer Plasma Extension (APEX) Study will enroll a subset of these individuals for longitudinal assessments of plasma biomarkers, cognition, and function.