Overview

Researchers want to learn if giving MK-1167 (the study medicine) along with acetylcholinesterase inhibitor (AChEI) therapy can improve symptoms of Alzheimer's disease dementia (AD dementia), such as memory and mental activity. AD dementia is the most common type of dementia. AChEI therapy is the standard treatment for AD dementia.

The goals of this study are to learn:

• If at least one dose level (amount) of MK-1167 works to improve a person's memory and thinking compared to a placebo
• About the safety of MK-1167 and if people tolerate it

Eligibility

Inclusion Criteria:

• Has mild to moderate Alzheimer's Disease (AD) dementia (ie, Stage 4 or Stage 5 AD) based on the Alzheimer's Association Revised Criteria for Diagnosis and Staging of Alzheimer's Disease
• Has a Mini-Mental State Examination (MMSE) score of 12 to 24 (inclusive)
• Is using acetylcholinesterase inhibitors (AChEI) therapy for management of AD dementia
• Has a designated study partner who can fulfill the requirements of this study. The study partner will need to spend sufficient time with the participant to be familiar with their overall function and behavior and be able to provide adequate information about the participant needed for the study including, knowledge of functional and basic activities of daily life, work/educational history, cognitive performance, emotional/psychological state, and general health status

Exclusion Criteria:

• Has a known history of stroke or cerebrovascular disease
• Has diagnosis of a clinically relevant central nervous system (CNS) disease other than AD dementia or other condition that negatively impacts cognition or cognitive status chronically
• Has structural brain disease
• Has a history of seizures or epilepsy
• Has any other major CNS trauma, or infections that affect brain function (eg, Human immunodeficiency virus (HIV), syphilis, and/or neurological sequelae of Coronavirus disease caused by severe acute respiratory syndrome coronavirus 2 (COVID-19), including impact on cognition)
• Has major medical illness or unstable medical condition
• Has a history of malignancy
• Resides in a nursing home or assisted care facility with need for direct continuous medical care and nursing supervision (with protocol-specified exceptions)
• Has liver disease, including but not limited to chronic viral hepatitis, nonviral hepatitis, cirrhosis, malignancies, autoimmune liver diseases