A Longitudinal Evaluation of a Radiotracer for Use in Tau Tracking

Phase 2

Completed

Conditions: Alzheimer Disease
Mild Cognitive Impairment

Interventions: Drug: All Subjects

Registration Number: NCT03919669

Lead Sponsor: University of Wisconsin, Madison

Brief Summary: This is a longitudinal, observational study evaluating the imaging characteristics of the tau PET radioligand \[18F\]MK-6240 in Alzheimer's disease (AD), Mild Cognitive Impairment (MCI) and Healthy Volunteer (HV) subjects. Up to 42 subjects, including approximately 28 MCI/mild AD subjects, up to 5 moderate AD subjects, and 9 similarly aged HV subjects will be consented and screened. Imaging procedures include \[11C\]PiB to evaluate amyloid deposition, \[18F\]MK-6240 PET, and structural MRI. All subjects complete an evaluable baseline \[18F\]MK-6240 PET scan, as well as scans at 6, 12 and 24 months post-baseline. If unable to complete the 6 month, 12 month, or 24 month visit, an 18 month and/or 30 month visit may instead be scheduled, totaling a maximum of four time points.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 27

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
All Subjects	All Subjects	All subjects will complete PET imaging sessions evaluating the tau PET radioligand \[18F\]MK-6240 at baseline, as well as at 6, 12 and 24 months post-baseline. If unable to complete the 6 month, 12 month, or 24 month visit, an 18 month and/or 30 month visit may instead be scheduled, totaling a maximum of four time points.

Primary Outcome Measures

Name	Time	Method
Change in [18F]MK-6240 Standard Uptake Value Ratio (SUVR) Uptake	Baseline to 12 months	Composite mean SUVR across standard regions including: numerator was the entorhinal, amygdala, fusiform, inferior temporal, middle temporal cortex; denominator was the inferior cerebellum cortex. The SUVR is a ratio and has a theoretic interpretable minimum of 1.0. This primary outcome is reported by the three primary groups: Healthy Volunteers, Mild Cognitive Impairment, and Dementia.

Secondary Outcome Measures

Name	Time	Method
Correlate the Changes in [18F]MK-6240 Uptake and Changes in Clinical Cognitive Assessments by Mini-Mental Status Exam (MMSE)	Baseline to 12 months	This outcome is correlational and therefore the arms/groups are collapsed to All Subjects so that we can assess the overall pattern of relationship between cognition and tau signal across the entire continuum of Alzheimer's disease. The MMSE is a sensitive, valid and reliable 30-point questionnaire that is used extensively in clinical and research settings to measure cognitive impairment. It is commonly used as screening tool for dementia. It is also used to estimate the severity and progression of cognitive impairment and to follow the course of cognitive changes in an individual over time; thus, making it an effective way to document an individual's response to treatment. The range is 0-30 with higher scores indicating better cognitive functioning.
Change in [18F]MK-6240 Standard Uptake Value Ratio (SUVR) Uptake	Baseline to 6 months	Composite mean SUVR across standard regions including: numerator was the entorhinal, amygdala, fusiform, inferior temporal, middle temporal cortex; denominator was the inferior cerebellum cortex. The SUVR is a ratio and has a theoretic interpretable minimum of 1.0. This primary outcome is reported by the three primary groups: Healthy Volunteers, Mild Cognitive Impairment, and Dementia.
The Correlation Between the Change in [18F]MK-6240 Uptake and the Change in the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-cog) Using Items 1-11	Baseline to 12 months	This outcome is correlational and therefore the arms/groups are collapsed to All Subjects so that we can assess the overall pattern of relationship between cognition and tau signal across the entire continuum of Alzheimer's disease. The ADAS-cog is one of the most frequently used tests to measure cognition in clinical trials in AD. The first 11 items of the ADAS-cog were used for this outcome. The ADAS was developed as a two-part scale: one that measured cognitive functions and one that measured non-cognitive functions such as mood and behavior. Most current research, including this study, uses the ADAS-Cog, which is the sub-scale that measures cognitive ability. The ADAS-cog score is based on incorrect items or errors and has a range of 0-50, where lower scores indicate better cognitive functioning.
Correlate the Changes in [18F]MK-6240 Uptake and Changes in Clinical Cognitive Assessments by Clinical Dementia Rating Scale (CDR).	Baseline to 12 months	This outcome is correlational and therefore the arms/groups are collapsed to All Subjects so that we can assess the overall pattern of relationship between cognition and tau signal across the entire continuum of Alzheimer's disease. The CDR was developed primarily for use in persons with dementia of the Alzheimer type. The six domains of CDR are: Memory, Orientation, Judgment and Problem-solving, Community Affairs, Home and Hobbies, and Personal Care. Each domain is rated on a 5-point scale of functioning: 0 no impairment; 0.5 questionable impairment; 1 mild impairment; 2 moderate impairment; and 3 severe impairment. The Sum of Boxes is the score used which is simply the sum of the 6 Domain Box Scores. The range is 0-18 with lower scores indicating better cognitive function.