The purpose of this study is to determine the effects of CNP520 on cognition, global clinical status, and underlying AD pathology, as well as the safety of CNP520, in people at risk for the onset of clinical symptoms of AD based on their age, APOE genotype and elevated amyloid.
Inclusion Criteria: * consent to receive disclosure of their risk estimates to develop clinical symptoms of AD based on their APOE genotype and, if Heterozygotes, evidence of elevated brain amyloid. * Male or female, age 60 to 75 years inclusive. Females must be considered post-menopausal and not of child bearing potential * Cognitively unimpaired as evaluated by memory tests performed at screening. * Participant's willingness to have a study partner. * Carrier of at least one APOE4 gene if Heterozygotes, elevated brain amyloid (as measured by CSF Abeta or amyloid PET imaging). Exclusion Criteria: * Any disability that could have prevented the participants from completing all study requirements. - * Current medical or neurological condition that could have impacted cognition or performance on cognitive assessments. * Advanced, severe progressive or unstable disease that could have interfered with the safety, tolerability and study assessments, or put the participant at special risk. * History of malignancy of any organ system, treated or untreated, within the past 60 months. * Indication for, or current treatment with ChEIs and/or another AD treatment (e.g. memantine). * Contraindication or intolerance to MRI. * Brain MRI results showing findings unrelated to AD that, in the opinion of the Investigator might be a leading cause to future cognitive decline, could have posed a risk to the participant, or could have prevented a satisfactory MRI assessment for safety monitoring. * Suicidal Ideation in the past six months, or Suicidal Behavior in the past two years. * A positive drug screen at Screening, if, in the Investigator's opinion, was is due to drug abuse. * Significantly abnormal laboratory results at Screening, not as a result of a temporary condition. * Current clinically significant ECG findings. * Clinically relevant depigmenting or hypopigmenting conditions (e.g. albinism, vitiligo) or active / history of chronic urticaria in the past year.