Evaluation of Flortaucipir PET Signal and Cognitive Change in Early Alzheimer's Disease

Study Overview
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Brief Summary
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This study will evaluate whether visual interpretation of flortaucipir-PET (positron emission tomography) scans, examining patterns of tracer uptake at baseline, can predict the rate of clinically-meaningful cognitive decline due to AD after 18 months. All scans are acquired from cohorts of a previously completed study, I8D-MC-AZES (NCT02245737, lanabecestat, Eli Lilly and Company sponsor).

Official Title
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Evaluation of the Relationship Between Baseline Flortaucipir PET Signal and Cognitive Change in Subjects With Early Alzheimer's Disease Participating in the I8D-MC-AZES Protocol Addendum D5010C00009 (2.1) (Tau Imaging)

Conditions
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Alzheimer Disease

Intervention / Treatment
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* Drug: flortaucipir F18
* Procedure: Brain PET Scan


Participation Criteria
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Eligibility Criteria
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Scan Reader Criteria (5 total readers): Board-certified in radiology or nuclear medicine Professional experience interpreting PET scans Scan Criteria (205 total scans): Former enrollment in AZES Study Flortaucipir scan at baseline clinical dementia rating - sum of boxes (CDR-SB) assessment at 18 months Scan Study Population (AZES Study): 55 to 85 years MCI due to AD or probable AD by National Institute on Aging-Alzheimer's Association criteria (Albert 2011 mini-mental status exam (MMSE) of 20 to 30 inclusive CDR global score of 0.5 (MCI), or 0.5 or 1 (AD) with a memory box score ≥ 0.5, and a score of ≤85 on the Delayed Memory Index of the Repeatable Battery for the Assessment of Neuropsychological Status. Amyloid positive status confirmed by florbetapir PET or lumbar puncture

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Physician PET scan readers are participants, blinded to demographic and clinical data from the source PET scans.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Flortaucipir PET Scan<br>No study drug will be administered. Scans previously acquired from Study I8D-MC-AZES (NCT02245737, Eli Lilly and Company sponsor) will be read by independent, blinded readers. | Drug: flortaucipir F18<br>* No study drug will be administered. Scans previously acquired from Study I8D-MC-AZES (NCT02245737, Eli Lilly and Company sponsor) at baseline will be read by independent, blinded readers. IV injection, 240 megabecquerel (MBq) (6.5 mCi), single dose in AZES<br>* Other names: LY3191748;Procedure: Brain PET Scan<br>* positron emission tomography (PET) scan of the brain<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Risk Ratio for AD Symptom Progression on CDR-SB | Baseline flortaucipir F 18 PET imaging results were determined by majority read (see Baseline Characteristics for description). Clinically meaningful deterioration (CMD) was defined for the primary endpoint as a worsening of the Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) score of one point or more. The clinical dementia rating (CDR) examines 6 categories of cognitive functioning domains. Each domain is scored on a scale ranging from 0 to 3 (including 0.5). A CDR-SB was generated as the sum of the values in each of the 6 domains. The CDR-SB sum scores range from 0 to 18, with higher scores indicating greater cognitive impairment and a 1 point worsening is considered a clinically significant symptom change. | Within 18 months of scan | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Risk Ratio for AD Symptom Progression on Various Clinical Measures | Baseline flortaucipir F 18 PET imaging results were determined by majority read (see Baseline Characteristics for description). Clinically meaningful deterioration (CMD) was defined for the cognitive endpoints as follows: mini-mental status exam (MMSE) worsening of 3 points or greater, Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog11) worsening of 4 points or greater, Pfeffer's Functional Activities Questionnaire (FAQ) worsening of 3 points or greater, CDR global worsening of greater than 0 points. MMSE scores range from 0 to 30 with lower scores indicating worsening cognitive function. ADAS-Cog11 scores range from 0 to 70 with higher scores indicating worsening cognitive function. FAQ scores range from 0 to 30 with higher scores indicating worsening cognitive function. CDR global is scored on a 5 point scale (0, 0.5, 1, 2, 3) with higher scores indicating worsening cognitive function. | Within 18 months of scan | 
| Mean Change in Cognitive/Functional Assessments | Mean change in cognitive/functional measures baseline between τAD++ and non-τAD++ (determined by baseline tau status), calculated by Mixed Model Repeat Measures (MMRM). CDR-SB scores range from 0 to 18, with higher scores indicating worsening cognitive impairment. MMSE scores range from 0 to 30 with lower scores indicating worsening cognitive function. ADAS-Cog11 scores range from 0 to 70 with higher scores indicating worsening cognitive function. FAQ scores range from 0 to 30 with higher scores indicating worsening cognitive function. | baseline and 18 months | 
| Inter-Reader Reliability of Reader Interpretation of Flortaucipir F 18 PET Imaging | As measured by Fleiss' Kappa across all scans read. Fleiss' kappa is a statistical measure for assessing the reliability of agreement between a fixed number of raters when assigning categorical ratings to a number of items or classifying items. Fleiss' kappa can range from -1 to 1 with 1 indicating perfect agreement between the readers. Read results binarized as τAD++ or non-τAD++. | baseline scan |