Study of the Effect of SR57667B in Patients With Alzheimer's Disease

Inclusion Criteria: Male / female outpatients. Age > 50 years at screening. Dementia of Alzheimer's Type (DSM-IV 290.0) according to DSM-IV criteria, Probable AD according to NINCDS-ADRDA criteria, Mini-Mental State Examination score > 12 and < 26. Untreated or treated for a minimum of 6 months before randomization with a stable dose of the cholinesterase inhibitors Generally healthy and ambulatory or ambulatory-aided (i.e., walker or cane). Presence of a reliable caregiver. Patient, identified caregiver and, if applicable, patient surrogate (primary relative, legal guardian, medical proxy) have given their informed written consent and are capable of following study procedures Exclusion Criteria: Any cause of dementia not due to Alzheimer's disease, Delusions, delirium, psychosis, depression, or other significant psychiatric disorder. Treatment with any registered or putative cognitive enhancer or disease modifier other than donepezil, rivastigmine or galantamine. Females who are pregnant or breast-feeding. Females of child bearing potential (premenopausal female biologically capable of becoming pregnant) must have a confirmed negative serum b-HCG pregnancy test at the screening visit, and must use an acceptable method of birth control. Severe or unstable cardiovascular, respiratory, renal, hematological, endocrinological, neurological or other somatic disease. Use of CYP3A4 strong inhibitors Evidence (detected by history, physical examination and / or laboratory / ECG tests) of any clinically significant or unstable medical disorder that could interfere with the subject's participation in the clinical trial; interfere with the absorption, metabolism or excretion of the study medication; or interfere with the evaluation of the study drug. Alterations of laboratory tests or ECG findings of potential clinical significance.