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

APCC is a composite score derived from the specific scores from the Repeatable Battery for the Assessment of Neurological Status (RBANS), Mini-Mental State Examination (MMSE) and the Raven's Progressive Matrices. The APCC score is a weighted score with ranges from from 0 to 100 where higher scores correspond to better cognitive performance.

Time frame: CI = Baseline to Weeks 26, 52,78 104 and Baseline to last assessment; CII = Baseline to Weeks 26, 52, 78, 104 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

Event was defined as the first confirmed diagnosis of MCI due to Alzheimer's disease (AD) or dementia due to AD (whichever occurred first) after adjudication by the progression adjudication committee (PAC) as triggered either by an investigator diagnosis or an increase in the Clinical Dementia Rating (CDR) global score. An event had to be confirmed by the PAC at two consecutive visits. In case no confirmed event was observed for a participant, the observation was censored, and the censoring date was defined as the last date where the diagnostic classification was assessed. The Study was terminated and only confirmed events collected up to the data cut-off point were counted. Due to the early termination of the study only a small number of events were observed and time-to-event could not be analyzed. Kaplan-Meyer (KM) estimates were provided to estimate probability that a subject would have an event prior to the specified visit.

Time frame: Baseline to end of exposure for a maximum of 1455 days for CI and 907 days for CII

Population: n=number of participants at risk to experience an event at the time-point

Annualized % change from baseline in volume of specific brain regions of interest (ROIs): whole brain (WB), hippocampus (Hip), and lateral ventricles (LV). Annualized percentage change was calculated as (percentage per participant / time interval (in days)) x 365.25. Time interval (in days) was derived as date of current MRI assessment on study drug - date of baseline MRI assessment + 1.

Time frame: CI = Baseline to Weeks 26, 52 and Baseline to last assessment; CII = Baseline to Weeks 26, 52 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Safety analysis set - only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

Alzheimer's Disease-related biomarkers analyzed in cerebrospinal fluid (CSF): Amyloid Beta 40 (Aβ40)

Time frame: Baseline to last assessment

Population: No lumbar punctures for CSF collection were performed due to early termination of trial

Alzheimer's Disease-related biomarkers analyzed in cerebrospinal fluid (CSF): Amyloid Beta 42 (Aβ42)

Time frame: Baseline to last assessment

Population: No lumbar punctures for CSF collection were performed due to early termination of trial

Alzheimer's Disease-related biomarkers analyzed in cerebrospinal fluid (CSF): total tau protein and phosphorylated tau protein levels

Time frame: Baseline to last assessment

Population: No lumbar punctures for CSF collection were performed due to early termination of trial

The CDR was obtained through semi-structured interviews of participants and informants, and cognitive functioning was rated on a 5-point scale of functioning in six domains: memory, orientation, judgement and problem solving, community affairs, home and hobbies, and personal care. The CDR global score ranged from zero to three, while the CDR-SOB was the sum of the ratings from the six domains, ranging from 0 to 18 with a minimum increment of 0.5. Higher scores indicated greater disease severity.

Time frame: CI = Baseline to Weeks 26, 52,78 104 and Baseline to last assessment; CII = Baseline to Weeks 26, 52, 78, 104 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

To demonstrate the effects of CNP520 vs placebo on tau pathology in the brain

Time frame: Baseline to last assessment

Population: No post baseline data collected

Alzheimer's Disease-related biomarkers analyzed in blood serum: light chain neurofilaments (NfL)

Time frame: Baseline to Week 26 and week 52, CI baseline to last assessment. CII baseline to last on-treatment and to last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. CI last post-baseline assessment. CII Last on-treatment is the last assessment before or at last day on study drug + 31 days.

Everyday Cognition Scale (ECog) measures cognitively-relevant everyday abilities comprised of 39 items covering 6 cognitively-relevant domains: Everyday Memory, Everyday Language, Everyday Visuospatial Abilities, Everyday Planning, Everyday Organization, and Everyday Divided Attention. The questionnaire is a self-reported measure completed by both participant and study partner (informant). The total score for the 39 items ranges from 39 to 195, with greater scores indicating worse daily function. Cohort I=C I and Cohort II=C II.

Time frame: CI = Baseline to Weeks 26, 52 and Baseline to last assessment; CII = Baseline to Weeks 26, 52 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

Everyday Cognition Scale (ECog) measures cognitively-relevant everyday abilities comprised of 39 items covering 6 cognitively-relevant domains: Everyday Memory, Everyday Language, Everyday Visuospatial Abilities, Everyday Planning, Everyday Organization, and Everyday Divided Attention. The questionnaire is a self-reported measure completed by both participant and study partner (informant). The total score for the 39 items ranges from 39 to 195, with greater scores indicating worse daily function.

Time frame: CI = Baseline to Weeks 26, 52 and Baseline to last assessment; CII = Baseline to Weeks 26, 52 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

Repeatable Battery for the Assessment of Neurological Status (RBANS) is a clinical tool designed to detect and characterize the earliest neurocognitive changes associated with dementia. The RBANS generates age-adjusted index scores for five neurocognitive domains: Immediate Memory, Visuospatial/Constructional, Language, Attention and Delayed Memory, which are used to calculate a Total Scale Index score. Index scores and total score range from 40 to 160 and a higher score indicates better cognitive functioning.

Time frame: CI = Baseline to Weeks 26, 52 and Baseline to last assessment; CII = Baseline to Weeks 26, 52 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

Repeatable Battery for the Assessment of Neurological Status (RBANS) is a clinical tool designed to detect and characterize the earliest neurocognitive changes associated with dementia. The RBANS generates age-adjusted index scores for five neurocognitive domains: Immediate Memory, Visuospatial/Constructional, Language, Attention and Delayed Memory, which are used to calculate a Total Scale Index score. Index scores and total score range from 40 to 160 and a higher score indicates better cognitive functioning.

Time frame: CI = Baseline to Weeks 26, 52,78 104 and Baseline to last assessment; CII = Baseline to Weeks 26, 52, 78, 104 and Baseline to Last on-treatment and Baseline to Last off-treatment

Population: Only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

To demonstrate the effects of CAD106 vs placebo on Alzheimer's Disease-related biomarkers

Time frame: Baseline up to approximately Week 104

Population: Only available for Cohort I. For Cohort II, no post-baseline (year 2) amyloid PET scans could be obtained due to the early trial termination

AUC is calculated based on 'on treatment' visit only.(missing values for peak visits were linearly interpolated for calculation; missing values for trough visits were imputed by average of non-missing trough values.).

Time frame: Week 9, 13, 15, 26 and quarterly thereafter (trough values)

Population: Safety population

Time frame: Month 6 to Month 60

Population: No analysis performed due to early termination, no month 60 data

Cmax is the maximum Titer Concentration of any post-baseline 'on treatment' visit. A visit is considered as 'on treatment' if visit date is within {last injection + 180 days}. \- Geometric mean and CI's are back-transformed from the estimates for Log mean and CI's.

Time frame: Week 9, 13, 15, 26 and quarterly thereafter (trough values)

Population: Safety population

Safety MRI included sequences necessary for ascertainment of possible ARIA-E (Amyloid Related Imaging Abnormality-Edema), ARIA-H (Amyloid Related Imaging Abnormality- Hemorrhage, including superficial siderosis and microhemorrhages), assessment of recent infarcts and white matter integrity examination (White matter disease worsening since baseline) and a general assessment of brain abnormalities. Assessment of cerebral amyloid angiopathy (CAA) is included in the overall safety MRI findings results.

Time frame: Baseline to end of exposure for a maximum of 1455 days for CI and 907 days for CII

Population: Safety analysis set - only participants with a value at both Baseline and that visit are included. For CI: last post-baseline assessment collected during the study. For CII: Last on-treatment is the last assessment before or at last day on study drug + 31 days. Last off-treatment is the last assessment after last day on study drug + 31 days.

Prospective suicidality assessment was performed with the use of Columbia-Suicide Severity Rating Scale (C-SSRS), a questionnaire using a detailed branched logic algorithm evaluating participant's suicidality ideation and behavior. Answer yes on item 4 or 5 of the Suicidal Ideation section or yes on any item of the Suicidal Behavior section was considered positive.

Time frame: Baseline to end of exposure for a maximum of 1455 days for CI and 907 days for CII

Population: Safety analysis set which includes only participants with events