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

This study will assess the effects of each of the two therapies given separately, both
targeting amyloid, on cognition, global clinical status, and underlying pathology in
participants at risk for the onset of clinical symptoms of Alzheimer's disease (AD).
Cognitively unimpaired individuals with two APOE4 genes and age 60 to 75 years, inclusive,
are selected as they represent a population at particularly high risk of progression to Mild
Cognitive Impairment and/or dementia due to Alzheimer's disease.

The study follows a randomized, double-blind, placebo-controlled, two-cohort, parallel group
design in which participants receive one of the investigational treatments or their matching
placebo for at least 60 months up to a maximum of 96 months and no longer than when the
target number of events for the TTE endpoint has been observed and confirmed in either
cohort.

An unbalanced randomization (active: placebo) of 5:3 ratio in Cohort I (430 CAD106 :260
Placebo) and 3:2 ratio in Cohort II (390 CNP520 : 260 Placebo) will be applied. Randomization
will be stratified by age group (60-64 years, 65-75 years) and region (North America/Other ,
Europe).

Participants who meet study entry requirements will be required to undergo at least one PET
scan during the course of the study. Additional PET scans, blood and CSF collection will be
voluntary. The study (also known as the Generation Study 1) is conducted as part of the
Alzheimer's Prevention Initiative (API) program.

Key Inclusion Criteria:

- Consent to receive disclosure of their risk estimates to develop clinical symptoms of
AD based on their APOE genotype.

- Male or female, age 60 to 75 years inclusive. Females must be considered
post-menopausal and not of child bearing potential.

- Mini-Mental State Examination (MMSE) total score ≥ 24 (at screening or in previous 3
months) and cognitively unimpaired as evaluated by memory tests performed at
screening.

- Homozygous APOE4 genotype.

- Participant's willingness to have a study partner.

Key Exclusion Criteria:

- Any disability that may prevent the participants from completing all study
requirements.

- Current medical or neurological condition that might impact cognition or performance
on cognitive assessments.

- Advanced, severe progressive or unstable disease that may interfere 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.

- History of hypersensitivity to any of the investigational drugs or their excipients /
adjuvant or to drugs of similar chemical classes.

- Indication for, or current treatment with ChEIs and/or another AD treatment (e.g.
memantine).

- Contraindication or intolerance to MRI or PET investigations (with fluorinated radio
ligands).

- Brain MRI results showing findings unrelated to AD that, in the opinion of the
Investigator might be a leading cause to future cognitive decline, might pose a risk
to the participant, or might prevent 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, this is due to
drug abuse.

- Significantly abnormal laboratory results at Screening, or infection not as a result
of a temporary condition.

- Current clinically significant ECG findings. For Cohort - I only: Participants with
previous organ transplantation or stem cell transplantation, or indication for
treatment 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.