A Study of CAD106 and CNP520 Versus Placebo in Participants at Risk for the Onset of Clinical Symptoms of Alzheimer's Disease

Key Inclusion Criteria:

• Consented to receive disclosure of their risk estimates to develop clinical symptomsof AD based on their APOE genotype.
• Male or female, age 60 to 75 years inclusive. Females were to be post-menopausal.
• Mini-Mental State Examination (MMSE) total score ≥ 24 and cognitively unimpaired asevaluated by memory tests
• Homozygous APOE4 genotype.
• Participant willing to have a study partner.

Key Exclusion Criteria:

• Any disability that prevented the participant from completing all study requirements.
• Current medical or neurological condition that could have impacted cognition orperformance on cognitive assessments.
• Advanced, severe progressive or unstable disease that may have interfered with thesafety, tolerability and study assessments, or put the participant at special risk.
• History of malignancy of any organ system, treated or untreated, within 60 monthsprior to screening.
• History of hypersensitivity to any of the investigational drugs or their excipients /adjuvant or to drugs of similar chemical classes.
• Indication or on current treatment with ChEIs and/or another AD treatment (e.g.memantine).
• Contraindication or intolerance to MRI or PET investigations (with fluorinated radioligands).
• Brain MRI results showing findings unrelated to AD that, in the opinion of theInvestigator could have been a leading cause to future cognitive decline, pose a riskto the participant, or prevent a satisfactory MRI assessment for safety monitoring.
• Suicidal Ideation in the past six months or Suicidal Behavior in the past two years,prior to screening.
• A positive drug screen at Screening, if, in the Investigator's opinion, this was dueto drug abuse.
• Significantly abnormal laboratory results at Screening, or infection not as a resultof a temporary condition.
• Current clinically significant ECG findings. For Cohort - I only: Participants withprevious organ transplantation or stem cell transplantation, or indication fortreatment with anti-coagulants. For Cohort - II only: Participants with depigmenting or hypopigmenting conditions (e.g.albinism vitiligo) or active / history of chronic urticarial in the past year.