["alzheimer's disease"]
['placebo', 'idalopirdine']

        Inclusion Criteria:

          -  The patient has a knowledgeable and reliable caregiver.

          -  The patient is an outpatient.

          -  The patient has probable AD.

          -  The patient has mild to moderate AD.

          -  Stable treatment with donepezil.

          -  The patient, if a woman, must have had her last natural menstruation ≥24 months prior
             to baseline, OR be surgically sterile.

          -  The patient, if a man, agrees to protocol-defined use of effective contraception if
             his female partner is of childbearing potential, OR must have been surgically
             sterilised prior to the screening visit.

        Exclusion Criteria:

          -  The patient has evidence of any clinically significant neurodegenerative disease, or
             other serious neurological disorders other than AD.

          -  The patient has a Diagnostic and Statistical Manual of Mental Disorders, 4th edition,
             Text Revision (DSM-IV-TR) Axis I disorder other than AD.

          -  The patient has evidence of clinically significant disease.

          -  The patient's donepezil therapy is likely to be interrupted or discontinued during the
             study.

          -  The patient is currently receiving memantine or has taken memantine within 2 months
             prior to screening.

        Other inclusion and exclusion criteria may apply.
      