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MK-7622 in People with Alzheimer's Disease Taking Donepezil


This trial will test the efficacy and safety of MK-7622 as an add-on therapy to donepezil in people with mild to moderate Alzheimer's disease.

Minimum Age Maximum Age Gender Healthy Volunteers
55 Years 85 Years Both No
October 2013
May 2017

  • Diagnosis of probable mild to moderate Alzheimer's disease based on both the National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision criteria for AD
  • Clear history of cognitive and functional decline during at least 1 year that is either documented in medical records or history from an informant who knows the participant well
  • Taking a stable dose of 10 mg donepezil daily for at least 3 months before screening; willing to remain on the same dose for the duration of the trial
  • Ability to read at a 6th grade level or equivalent; history of academic achievement and/or employment sufficient to exclude mental retardation
  • Reliable, competent trial partner/caregiver who has a close relationship with the participant

  • Neurological disorder other than probable Alzheimer's disease
  • Clinically relevant or unstable psychiatric disorder, excluding major depression in remission for more than 2 years
  • Major surgery within the past 3 months
  • At imminent risk of self-harm or harm to others
  • History of stroke, seizures or epilepsy within the last 5 years, alcoholism or drug dependency/abuse within the past 5 years, or hepatitis or liver disease that has been active within the past 6 months
  • Inability to undergo a magnetic resonance imaging scan
  • Recent or ongoing uncontrolled, clinically significant medical condition within the past 3 months (such as diabetes, hypertension, thyroid or endocrine disease, congestive heart failure, angina, cardiac or gastrointestinal disease, dialysis, or abnormal renal function) such that participation in the trial would pose a significant medical risk; controlled co-morbid conditions are not exclusionary if stable
  • History or current evidence of long QT syndrome, corrected QT (QTc) interval 470 milliseconds or more (for male subjects) or 80 milliseconds or more (for female subjects), or torsades de pointes
  • History of cancer within the past 5 years, except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or localized prostate carcinoma that has been treated with potentially curative therapy, with no evidence of recurrence for at least 3 years
  • Clinically significant vitamin B12 deficiency or increased thyroid-stimulating hormone level in the past 6 months.

This Phase II trial will test the experimental drug MK-7622 to see if it improves cognition in people with mild to moderate Alzheimer's disease. The trial consists of two stages. Participants in Stage 1 will be randomized to receive either the test drug or a placebo, a capsule taken once daily, for 26 weeks. Based on the results, the trial may continue into Stage 2, in which a separate group of participants will be randomized to receive either the test drug (5, 15, or 45 mg) or a placebo, taken once daily, for 26 weeks. All participants will receive a placebo at some point during the trial. The primary hypothesis are that MK-7622 is superior to placebo in improving cognition in participants after 12 weeks.


Central Contact: 1-888-577-8839


Name Phone Email
Merck 1-888-577-8839


A Seamless Phase IIa/IIb, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel Group Trial to Evaluate the Efficacy and Safety of MK-7622 as an Adjunctive Therapy to Donepezil for Symptomatic Treatment in Subjects With Alzheimer's Dise