Safety and Tolerability Study of Flexible Dosing of Brexpiprazole in the Treatment of Subjects With Agitation Associated With Dementia of the Alzheimer's Type

Inclusion Criteria: * Male and female subjects 55 to 90 years of age, inclusive, at the time of informed consent. * Subjects who are residing at their current location for at least 14 days before screening and are expected to remain at the same location for the duration of the trial. * Subjects with diagnosis of probable Alzheimer's disease according to NINCDS-ADRDA criteria. * Subjects with a MMSE score of 5 to 22, inclusive, at screening and baseline visits. * Subjects with onset of symptoms of agitation at least 2 weeks prior to the screening visit. * Subjects with a total score greater than or equal to 4 on the agitation aggression item of the NPI-NH or NPI/NPI-NH at the screening and baseline visits. * Subjects who require pharmacotherapy for the treatment of agitation per the investigator's judgement, after an evaluation of reversible factors (eg, pain, infection, polypharmacy) and a trial of nonpharmacological interventions. * Subjects must have a previous MRI or CT scan of the brain, which was performed after the onset of symptoms of dementia, with findings consistent with the diagnosis of Alzheimer's disease. Exclusion Criteria: * Subjects with dementia or other memory impairment not due to Alzheimer's disease. * Subjects with history of stroke, well-documented transient ischemic attack, or pulmonary or cerebral embolism. * Subjects who currently have clinically significant neurological, hepatic, renal, metabolic, hematological, immunological, cardiovascular, pulmonary, gastrointestinal, or psychiatric disorders. * Subjects who have been diagnosed with an Axis I disorder (DSM-IV-TR criteria). * Subjects with uncontrolled hypertension. * Subjects with uncontrolled insulin-dependent diabetes mellitus (IDDM) * Subjects with epilepsy or a history of seizures. * Subjects considered in poor general health based on the investigator's judgment.