A Phase 3 Study To Evaluate The Safety And Tolerability Of Dimebon Patients With Mild To Moderate Alzheimer's Disease

Inclusion Criteria:

- Diagnosis of Alzheimer's Disease.

- MMSE 12-26 inclusive.

- If on existing anti-dementia therapy, have been on a stable dose of anti-dementia
therapy (cholinesterase inhibitors and/or memantine) for at least 60 days prior to
dosing in study.

- If not taking existing anti-dementia therapy, have not received therapy with
cholinesterase inhibitors and/or memantine within 60 days prior to dosing in this
study.

Exclusion Criteria:

- Have major structural brain disease (e.g., ischemic infarcts, subdural hematoma,
hemorrhage, hydrocephalus, brain tumors, multiple subcortical ischemic lesions, or a
single lesion in a critical region [e.g., thalamus, hippocampus]).

- Have any major medical illness or unstable medical condition within six months of
screening that may interfere with the patient's ability to comply with study
procedures and abide by study restrictions.

- Have not been on a stable dose of anti-dementia therapy for at least 60 days prior to
dosing or intend to start anti-dementia therapy during the double blind portion of the
study.

- Reside in a nursing home or assisted care facility with need for 24-hour care and
supervision.