As clinical trials move to earlier stages of disease and focus on cognitively normal (CN) individuals with positive biomarkers of Alzheimer disease (AD) (eg, β-amyloid [Aβ]), it is critical to determine the relationship between these biomarkers and cognitive change. It is especially important to determine whether this cognitive change varies by biomarker status and whether sufficient cognitive change occurs to provide clinically meaningful outcomes during short follow-up intervals. For example, the recently initiated Anti-Amyloid Treatment in Asymptomatic Alzheimer’s Disease trial1 is enrolling individuals who are CN but amyloid positive to assess the efficacy of an antiamyloid therapy on cognitive trajectories during a 3-year follow-up period.
Resnick SM. Preclinical Biomarkers in Alzheimer DiseaseA Sum Greater Than the Parts. JAMA Neurol. 2014;71(11):1357-1358. doi:10.1001/jamaneurol.2014.2462