Study Overview

Design: A global Phase 3, double-blind, placebo-controlled safety and efficacy study of oral Dimebon in patients with mild to moderate Alzheimer’s disease.

Locations:

Approximately 100 centers located in North America, South America, and Europe. View site locations.

Primary objectives:

• Determine the effect of Dimebon on cognition and memory
• Determine the effect of Dimebon on global function

Secondary objectives:

• Determine the effect of Dimebon on self-care and daily function
• Determine the effect of Dimebon on behavior
• Determine the safety of treatment with Dimebon

Study design:

• Randomized, double-blind, 26-week study of 2 doses of oral Dimebon (5 mg TID and 20 mg TID)
• 525 patients randomized into 3 equal groups
  • Dimebon 5 mg TID
  • Dimebon 10 mg TID for 7 days, then 20 mg for remainder
  • Placebo
• Patients are required to participate in the study with a caregiver who can assist at least 5 days a week for 3 hours a day
• Efficacy assessments will be performed at baseline, week 6, week 12, week 18, and week 26
• Patients will receive 26 weeks of treatment; those who complete the 26-week study (placebo and treatment groups) may then choose to continue receiving Dimebon by participating in an extension study

Inclusion criteria:

• Male or female ≥50 years of age
• Diagnosis of probable Alzheimer’s disease according to the following criteria:
  • Diagnostic and Statistical Manual of Mental Disorders-IV Text Revision (DSM-IV)
  • National Institute of Neurological and Communicative Disorders and Stroke—Alzheimer’s disease and Related Disorders Association’s
    Criteria (NINCDS-ADRDA) for probable Alzheimer’s disease
  • Mini-Mental State Examination (MMSE) score between 10 and 24, inclusive
  • Modified Hachinski ischemic score ≤4
• Brain imaging within 3 months of enrollment
• At least 8 years of education, with pre-Alzheimer’s capability of reading, writing, and communicating effectively
• Able to cooperate with study drug administration and study procedures and to abide by study restrictions
• Ability to give informed consent, or to have a legally authorized representative provide consent
• A guardian or caregiver who: provides assistance at least 5 days per week for at least 3 hours per day; can accompany the participant to all study visits; and can supervise administration of the study drug (guardian must be able to read, write, and be capable of providing responses to the CIBIC-plus, ADCS-ADL, NPI, and RUD-Lite assessment tools)
• Participants may be living in an assisted-care facility, if living independently (not requiring 24-hour care and supervision)
• Females must be surgically sterile or postmenopausal (for at least 2 years) or must agree to use a double-barrier method of birth control; males must agree to use a double-barrier method of birth control during the study and for at least 30 days following the last dose of study drug

Exclusion criteria:

• Major structural brain disease (eg, ischemic infarcts, subdural hematoma, hemorrhage, hydrocephalus, brain tumors, multiple subcortical lesions, or a single lesion in a critical area
• Any major medical illness or unstable medical condition within 6 months of screening that may interfere with the patient’s ability to comply with study procedures and abide by study restrictions
• Residence in a nursing home or assisted-living facility with a need for 24-hour care and supervision
• A history of hypersensitivity to Dimebon or other antihistamines
• HIV, AIDS, or a history of hepatitis B or hepatitis C
• Certain laboratory abnormalities apparent at screening visit
• Use of cholinesterase inhibitors, memantine, or certain other medications within 90 days prior to enrollment
• Participation in an Alzheimer’s disease investigational drug study within 90 days prior to study entry