[18F]MK-6240 Positron Emission Tomography (PET) Tracer First-in-Human Validation Study (MK-6240-001)

This 2-part, open-label study was designed to investigate the safety, tolerability, and efficacy of \[18F\]MK-6240, a Positron Emission Tomography (PET) imaging agent, for the quantification of neurofibrillary tangle (NFT) deposition in the brain. Brain NFT deposition is a pathologic finding in Alzheimer's Disease (AD), with brain NFT density shown to correlate with the severity of cognitive impairment in AD. The objectives of the study include performing the following with respect to \[18F\]MK-6240 administered as a PET imaging agent: 1) assess safety and tolerability; 2) determine radiation safety profile; 3) determine optimal imaging protocol parameters for quantification of brain NFTs in AD; 4) compare tracer binding in brain PET scans from participants with AD, participants with amnestic mild cognitive impairment (MCI) and healthy elderly participants; and 5) evaluate intra-subject test-retest (T-RT) variability of tracer uptake in brain regions of interest.