Overview

Researchers want to know if the study treatment called MK-2214 works to slow certain changes in the brains of people with Alzheimer's disease (AD). AD is a type of dementia that can cause loss of memory, communication (such as speech), and decision-making skills. It can limit a person's ability to do daily tasks. MK-2214 is a study treatment designed to slow down AD.

The goals of the study are to learn:

• If MK-2214 slows the spread of tau in the brain compared to placebo. Tau is a protein that accumulates in AD & damages brain cells. A placebo looks like the study treatment but has no study treatment in it. Using a placebo helps researchers better understand the effects of a study treatment.
• About the safety of MK-2214 and if people tolerate it

Eligibility

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

• Has mild cognitive impairment (MCI) or mild dementia due to Alzheimer's Disease (AD)
• Has a designated study partner who can fulfill the requirements of this study
• If on an approved AD therapy for symptomatic AD, the dosing regimen must have been stable for 3 months prior to screening

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

• Has a known history of stroke or cerebrovascular disease
• Has diagnosis of a clinically relevant central nervous system disease other than AD or other condition that negatively impacts cognition or cognitive status chronically
• Has structural brain disease
• Has a history of seizures or epilepsy within 5 years before screening
• Has any other major central nervous system trauma, or infections that affect brain function
• Has major medical illness or unstable medical condition within 3 months before screening
• Has a severe, acute, or chronic medical or psychiatric condition or laboratory abnormality
• Has any immunological disease, which is not adequately controlled, or which requires treatment with biologics and/or immunosuppressants during the study
• Has a bleeding disorder that is not under adequate control
• Has a history of malignancy occurring within 5 years of screening
• Has a risk factor for corrected QT interval (QTc) prolongation
• Has liver disease
• Is unwilling or unable to undergo computed tomography (CT), positron emission tomography (PET), or magnetic resonance imaging (MRI) scan
• Resides in a nursing home or assisted care facility with need for direct continuous medical care and nursing supervision