Core Phase: Change From Baseline up to Month 24 in Alzheimer's Disease Composite Score (ADCOMS)
ADCOMS is a weighted linear combination of 12 items from three existing clinical scales: the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), the Mini Mental State Examination (MMSE), and the CDR. Four items are from the ADAS-cog (A4 [Delayed Word Recall], A7 [Orientation], A8 [Word Recognition], A11 [Word Finding]); 2 items are from the MMSE (M1 [Orientation Time], M7 [Drawing]); 6 items are from the CDR (C1 [Personal Care], C2 [Community Affairs], C3 [Home and Hobbies], C4 [Judgment and Problem Solving], C5 [Memory], C6 [Orientation]). Composite score is derived from the variables from the 12 items, and ranges from 0 to 1.97, where higher score indicates worse performance.
Core Phase: Change From Baseline up to Month 24 in Amyloid Positron Emission Tomography (PET) Standardized Uptake Value Ratio (SUVR)
Amyloid PET scan assesses cerebral amyloid load using 3 tracers (florbetapir, florbetaben and flutemetamol) which is standardized into centiloids for evaluation of AD. Centiloid values on centiloid scale is based on mean composite SUVR in cingulate, frontal, parietal and temporal cortexes using whole cerebellum as reference region. SUVR is ratio of tracer uptake in each of cingulate, frontal, parietal and temporal cortexes relative to cerebellum. The centiloid scale anchor points are 0 and 100, where 0 represents a high-certainty amyloid negative scan and 100 represents the amount of global amyloid deposition found in a typical AD scans.
Core Phase: Change From Baseline up to Month 24 in the CDR-SB Score for Participants Enriched by Baseline Amyloid PET SUVR Between 1.2 and 1.6
The CDR scale is a clinical global rating scale that requires interviewing both the participant and an informant who knows and has contact with the participant. The CDR scale is a clinician directed assessment of both cognition and function, and is intended to capture the state and therefore the disease stage of the participant. The CDR scale assesses 6 domains of participant function (memory, orientation, judgement and problem solving, community affairs, home and hobbies and personal care) on a 5-point scale in which no impairment=0, questionable impairment=0.5, mild impairment=1, moderate impairment=2 and severe impairment=3. The CDR-SB is a sum of the individual domain scores and ranges from 0 to 18. Higher score indicates more impairment. Amyloid PET scans allow in vivo assessment of cerebral amyloid load. SUVR indicates the ratio of tracer uptake in the frontal cortex relative to the cerebellum or the ratio of tracer uptake in the whole brain relative to the cerebellum.
Core Phase: Change From Baseline up to Month 24 in the ADCOMS for Participants Enriched by Baseline Amyloid PET SUVR Between 1.2 and 1.6
ADCOMS is a weighted linear combination of 12 items from three existing clinical scales: the ADAS-cog, the MMSE, and the CDR. Four items are from the ADAS-cog (A4 [Delayed Word Recall], A7 [Orientation], A8 [Word Recognition], A11 [Word Finding]); 2 items are from the MMSE (M1 [Orientation Time], M7 [Drawing]); 6 items are from the CDR (C1 [Personal Care], C2 [Community Affairs], C3 [Home and Hobbies], C4 [Judgment and Problem Solving], C5 [Memory], C6 [Orientation]). Composite score is derived from the variables from the 12 items, and ranges from 0 to 1.97, where higher score indicates worse performance. Amyloid PET scans allow in vivo assessment of cerebral amyloid load. SUVR indicates the ratio of tracer uptake in the frontal cortex relative to the cerebellum or the ratio of tracer uptake in the whole brain relative to the cerebellum.
Core Phase: Change Per Year (Mean Slope) in CDR-SB Score up to Month 24
The CDR scale is a clinical global rating scale that requires interviewing both the participant and an informant who knows and has contact with the participant. The CDR scale is a clinician directed assessment of both cognition and function, and is intended to capture the state and therefore the disease stage of the participant. The CDR scale assesses 6 domains of participant function (memory, orientation, judgement and problem solving, community affairs, home and hobbies and personal care) on a 5-point scale in which no impairment=0, questionable impairment=0.5, mild impairment=1, moderate impairment=2 and severe impairment=3. The CDR-SB is a sum of the individual domain scores and ranges from 0 to 18. Higher score indicates more impairment. In this outcome measure, change per year (mean slope) in CDR-SB score was calculated up to month 24, where higher change indicated more impairment and lower change indicated less impairment.
Core Phase: Time to Worsening of CDR Score up to Month 24
The CDR scale is a clinical global rating scale that requires interviewing both the participant and an informant who knows and has contact with the participant. The CDR scale is a clinician directed assessment of both cognition and function, and is intended to capture the state and therefore the disease stage of the participant. The CDR scale assesses 6 domains of participant function (memory, orientation, judgement and problem solving, community affairs, home and hobbies and personal care) on a 5-point scale in which no impairment=0, questionable impairment=0.5, mild impairment=1, moderate impairment=2 and severe impairment=3. The global CDR score is computed via an algorithm and ranges from 0 to 3. Higher score indicates more impairment. In this outcome measure, time (in months) to worsening of CDR score (that is, an increase from baseline by at least 0.5 points on the global CDR scale on 2 consecutive scheduled visits) up to month 24 was calculated.
Core Phase: Time to Conversion to Dementia for Participants Who Were Not Clinically Staged as Having Dementia at the Core Phase Baseline up to Month 24
Time (in months) to conversion to dementia for participants who were not clinically staged as having dementia at the core phase baseline (that is time from randomization to conversion to dementia in clinical diagnosis).
Core Phase: Change From Baseline up to Month 24 in the Alzheimer's Disease Assessment Scale-cognition14 (ADAS-Cog14) Score
ADAS-cog14 is a psychometric instrument that evaluates 14-items (Immediate Word-recall [0-10], Commands [0-5], Constructional Praxis [0-5], Delayed Word-recall [0-10], Naming Objects/Fingers [0-5], Ideational Praxis [0-5], Orientation[0-8], Word Recognition [0-12], Remembering Test Instructions [0-5], Comprehension[0-5], Word Finding Difficulty [0-5], Spoken Language Ability [0-5], Executive Function [0-5], and Number Cancellation [0-5] test). It is considered to be more sensitive for less impaired populations such as MCI/Prodromal and mild AD participants. The total score ranges from 0 to 90. Higher score indicates more impairment.
Core Phase: Change From Baseline up to Month 24 in the MMSE Score
The MMSE is a cognitive instrument commonly used for screening purposes, for staging of disease severity and is often measured longitudinally in AD clinical studies to follow disease progression and treatment effects. MMSE is composed of 30 questions grouped into domains (Orientation to Time [0-5], Orientation to Place [0-5], Registration [0-3], Attention and Calculation [0-5], Recall [0-3], Naming [0-2], Repetition [0-1], Comprehension [0-3], Reading [0-1], Writing [0-1], Drawing [0-1]). For each of the MMSE domains, six items are computed (Orientation to Time [0-5], Orientation to Place [0-5], Registration [0-3], Attention and Calculation [0-5], Recall [0-3], Language: Naming, Repetition, Comprehension, Reading, Writing, and Drawing [0-9]). The MMSE Total Score is the sum of the six domains and ranges from 0 to 30. If any domain score was missing then the total score was missing. Higher score indicates better function.
Core Phase: Change From Baseline up to Month 24 in the Functional Assessment Questionnaire (FAQ) Score
FAQ scores 10 items & measures activities of daily living (paying bills/balancing checkbook, assembling tax records, shopping alone for clothes or groceries, playing game of skill such as bridge or chess/working on a hobby, heating water & turning off stove, preparing balanced meal, keeping track of current events, paying attention & understanding television program, remembering appointments, driving or traveling out of neighborhood). Each item is rated as follows: 0=Normal, 1=Has difficulty but does by self, 2=Requires assistance, 3=Dependent, or 8=Not Applicable. The total score is the sum of all 10 items & ranges from 0 to 30. Higher score indicates more impairment. If any activity was missed, then the total score was missed. Activities rated as "Not Applicable" were not used in the computation of the total score. To account for "Not Applicable" activity, the total score was weighted as:Total Score=Total Score*30/(30 minus 3 times the number of activities marked"Not Applicable").
Core Phase: Change From Baseline up to Month 24 in the ADAS-cog14 Word List (Immediate Recall and Delayed Recall) Score
The ADAS-cog14 Word List is a summation of two items: "Immediate Word-recall" and "Delayed Word-recall". Immediate Word-recall test: Participants are asked to recall words and the number of "No" responses for each trial (total 3 trials) are summed. Subscore: sum of scores from 3 trials, divided by 3. Score ranges from 0 to 10. Delayed Word-recall: Participants used to recall words after a delay and the number of "No" responses are summed. Score ranges from 0 to 10. The Total Score ranges from 0 to 20. Higher score indicates more impairment.
Core Phase: Change From Baseline up to Month 24 in the Alzheimer's Disease Assessment Scale-cognition11 (ADAS-Cog11) Score
ADAS-cog11 is a psychometric instrument that evaluates 11-items (Immediate Word-recall [0 to 10], Commands [0-5], Constructional Praxis [0-5], Naming Objects/Fingers [0-5], Ideational Praxis [0-5], Orientation[0-8], Word Recognition [0-12], Remembering Test Instructions [0-5], Comprehension[0-5], Word Finding Difficulty [0-5], Spoken Language Ability [0-5] test) and is considered more sensitive for less impaired populations such as MCI/Prodromal and mild AD participants. The Total score ranges from 0 to 70. Higher score indicates more impairment.
Core Phase: Change From Last Dose in the CDR-SB Score
The CDR scale is a clinical global rating scale that requires interviewing both the participant and an informant who knows and has contact with the participant. The CDR scale is a clinician directed assessment of both cognition and function, and is intended to capture the state and therefore the disease stage of the participant. The CDR scale assesses 6 domains of participant function (memory, orientation, judgement and problem solving, community affairs, home and hobbies and personal care) on a 5-point scale in which no impairment=0, questionable impairment=0.5, mild impairment=1, moderate impairment=2 and severe impairment=3. The CDR-SB is a sum of the individual domain scores and ranges from 0 to 18. Higher score indicates more impairment.
Core Phase: Change From Last Dose in the ADCOMS
ADCOMS is a weighted linear combination of 12 items from three existing clinical scales: the ADAS-cog, the MMSE, and the CDR. Four items are from the ADAS-cog (A4 [Delayed Word Recall], A7 [Orientation], A8 [Word Recognition], A11 [Word Finding]); 2 items are from the MMSE (M1 [Orientation Time], M7 [Drawing]); 6 items are from the CDR (C1 [Personal Care], C2 [Community Affairs], C3 [Home and Hobbies], C4 [Judgment and Problem Solving], C5 [Memory], C6 [Orientation]). Composite score is derived from the variables from the 12 items, and ranges from 0 to 1.97, where higher score indicates worse performance.
Core Phase: Change From Last Dose in the ADAS-cog11 Score
ADAS-cog11 is a psychometric instrument that evaluates 11-items (Immediate Word-recall [0 to 10], Commands [0-5], Constructional Praxis [0-5], Naming Objects/Fingers [0-5], Ideational Praxis [0-5], Orientation[0-8], Word Recognition [0-12], Remembering Test Instructions [0-5], Comprehension[0-5], Word Finding Difficulty [0-5], Spoken Language Ability [0-5] test) and is considered more sensitive for less impaired populations such as MCI/Prodromal and mild AD participants. The Total score ranges from 0 to 70. Higher score indicates more impairment.
Core Phase: Change From Last Dose in the ADAS-cog14 Score
ADAS-cog14 is a psychometric instrument that evaluates 14-items (Immediate Word-recall [0 to 10], Commands [0-5], Constructional Praxis [0-5], Delayed Word-recall [0-10], Naming Objects/Fingers [0-5], Ideational Praxis [0-5], Orientation[0-8], Word Recognition [0-12], Remembering Test Instructions [0-5], Comprehension[0-5], Word Finding Difficulty [0-5], Spoken Language Ability [0-5], Executive Function [0-5], and Number Cancellation [0-5] test). It is considered to be more sensitive for less impaired populations such as MCI/Prodromal and mild AD participants. The Total Score ranges from 0 to 90. Higher score indicates more impairment.
Core Phase: Change From Last Dose in the MMSE Score
The MMSE is a cognitive instrument commonly used for screening purposes, for staging of disease severity and is often measured longitudinally in AD clinical studies to follow disease progression and treatment effects. MMSE is composed of 30 questions grouped into domains (Orientation to Time [0-5], Orientation to Place [0-5], Registration [0-3], Attention and Calculation [0-5], Recall [0-3], Naming [0-2], Repetition [0-1], Comprehension [0-3], Reading [0-1], Writing [0-1], Drawing [0-1]). For each of the MMSE domains, six items are computed (Orientation to Time [0-5], Orientation to Place [0-5], Registration [0-3], Attention and Calculation [0-5], Recall [0-3], Language: Naming, Repetition, Comprehension, Reading, Writing, and Drawing [0-9]). The MMSE Total Score is the sum of the six domains and ranges from 0 to 30. If any domain score was missing then the total score was missing. Higher score indicates better function.
Core Phase: Change From Last Dose in the ADAS-cog14 Word List (Immediate Recall and Delayed Recall) Score
The ADAS-cog14 Word List is a summation of two items: "Immediate Word-recall" and "Delayed Word-recall". Immediate Word-recall test: Participants are asked to recall words and the number of "No" responses for each trial (total 3 trials) are summed. Subscore: sum of scores from 3 trials, divided by 3. Score ranges from 0 to 10. Delayed Word-recall: Participants used to recall words after a delay and the number of "No" responses are summed. Score ranges from 0 to 10. The Total Score ranges from 0 to 20. Higher score indicates more impairment.
Extension Phase: Change From Core Phase Baseline up to Month 12 of the Extension Phase in CDR-SB Score
The CDR scale is a clinical global rating scale that requires interviewing both the participant and an informant who knows and has contact with the participant. The CDR scale is a clinician directed assessment of both cognition and function, and is intended to capture the state and therefore the disease stage of the participant. The CDR scale assesses 6 domains of participant function (memory, orientation, judgement and problem solving, community affairs, home and hobbies and personal care) on a 5-point scale in which no impairment=0, questionable impairment=0.5, mild impairment=1, moderate impairment=2 and severe impairment=3. The CDR-SB is a sum of the individual domain scores and ranges from 0 to 18. Higher score indicates more impairment.
Extension Phase: Change From Core Phase Baseline up to Month 12 of the Extension Phase in ADCOMS
ADCOMS is a weighted linear combination of 12 items from three existing clinical scales: the ADAS-cog, the MMSE, and the CDR. Four items are from the ADAS-cog (A4 [Delayed Word Recall], A7 [Orientation], A8 [Word Recognition], A11 [Word Finding]); 2 items are from the MMSE (M1 [Orientation Time], M7 [Drawing]); 6 items are from the CDR (C1 [Personal Care], C2 [Community Affairs], C3 [Home and Hobbies], C4 [Judgment and Problem Solving], C5 [Memory], C6 [Orientation]). Composite score is derived from the variables from the 12 items, and ranges from 0 to 1.97, where higher score indicates worse performance.
Extension Phase: Change From Core Phase Baseline up to Month 12 of the Extension Phase in MMSE Score
The MMSE is a cognitive instrument commonly used for screening purposes, for staging of disease severity and is often measured longitudinally in AD clinical studies to follow disease progression and treatment effects. MMSE is composed of 30 questions grouped into domains (Orientation to Time [0-5], Orientation to Place [0-5], Registration [0-3], Attention and Calculation [0-5], Recall [0-3], Naming [0-2], Repetition [0-1], Comprehension [0-3], Reading [0-1], Writing [0-1], Drawing [0-1]). For each of the MMSE domains, six items are computed (Orientation to Time [0-5], Orientation to Place [0-5], Registration [0-3], Attention and Calculation [0-5], Recall [0-3], Language: Naming, Repetition, Comprehension, Reading, Writing, and Drawing [0-9]). The MMSE Total Score is the sum of the six domains and ranges from 0 to 30. If any domain score is missing then the total score is missing. Higher score indicates better function.
Extension Phase: Change From Core Phase Baseline up to Month 12 of the Extension Phase in FAQ Score
FAQ scores 10 items & measures activities of daily living (paying bills/balancing checkbook, assembling tax records, shopping alone for clothes or groceries, playing game of skill such as bridge or chess/working on a hobby, heating water & turning off stove, preparing balanced meal, keeping track of current events, paying attention & understanding television program, remembering appointments, driving or traveling out of neighborhood). Each item is rated as follows: 0=Normal, 1=Has difficulty but does by self, 2=Requires assistance, 3=Dependent, or 8=Not Applicable. The total score is the sum of all 10 items & ranges from 0 to 30. Higher score indicates more impairment. If any activity was missed, then the total score was missed. Activities rated as "Not Applicable" were not used in the computation of the total score. To account for "Not Applicable" activity, the total score was weighted as:Total Score=Total Score*30/(30 minus 3 times the number of activities marked"Not Applicable").
Extension Phase: Change From Core Phase Baseline up to Month 12 of the Extension Phase in ADAS-cog14 Score
ADAS-cog14 is a psychometric instrument that evaluates 14-items (Immediate Word-recall [0 to 10], Commands [0-5], Constructional Praxis [0-5], Delayed Word-recall [0-10], Naming Objects/Fingers [0-5], Ideational Praxis [0-5], Orientation[0-8], Word Recognition [0-12], Remembering Test Instructions [0-5], Comprehension[0-5], Word Finding Difficulty [0-5], Spoken Language Ability [0-5], Executive Function [0-5], and Number Cancellation [0-5] test). It is considered to be more sensitive for less impaired populations such as MCI/Prodromal and mild AD participants. The total score ranges from 0 to 90. Higher score indicates more impairment.
Extension Phase: Change From Core Phase Baseline up to Month 12 of the Extension Phase in ADAS-cog14 Word List (Immediate Recall and Delayed Recall) Score
The ADAS-cog14 Word List is a summation of two items: "Immediate Word-recall" and "Delayed Word-recall". Immediate Word-recall test: Participants are asked to recall words and the number of "No" responses for each trial (total 3 trials) are summed. Subscore: sum of scores from 3 trials, divided by 3. Score ranges from 0 to 10. Delayed Word-recall: Participants used to recall words after a delay and the number of "No" responses are summed. Score ranges from 0 to 10. The Total Score ranges from 0 to 20. Higher score indicates more impairment.
Extension Phase: Time to Conversion to Dementia for Participants Who Were Not Clinically Staged as Having Dementia at the Core Phase Baseline up to Month 12 of the Extension Phase
Time (in months) to conversion to dementia for participants who were not clinically staged as having dementia at the core phase baseline (that is time from randomization to conversion to dementia in clinical diagnosis).