To follow-up on the safety of subjects who were previously treated in a double-blind trial of brexpiprazole.

Behavioral symptoms, such as agitation, are core features in subjects with Alzheimer's disease and related dementias, and develop in the majority of dementia subjects. The presence of agitation in subjects with Alzheimer's disease places a significant burden not only on subjects and their caregivers but also on the healthcare system.

This is a trial designed to assess the ongoing safety of subjects with agitation associated with dementia of the Alzheimer's type after completing a 12-week double-blind trial of brexpiprazole or placebo; drug and placebo are discontinued prior to subjects enrolling in the safety follow-up trial. The trial consists of a continuous 2 month observation period. The trial population will include male and female subjects with a diagnosis of probable Alzheimer's disease.

Inclusion Criteria:

• The investigator must assess the capacity of the subject to provide informed consent prior to enrollment and throughout the trial.
• Male and female subjects who completed both the 12-week double-blind treatment period and the 30-day safety follow-up visit of the previous brexpiprazole trial.
• Subject has an identified caregiver who is usually assigned to care for the subject on a regular basis, has sufficient contact to describe the subject's symptoms, and has direct observation of the subject's behavior.
• Subject is able to comply with the protocol requirements.

Exclusion Criterion:

• Subjects who, in the opinion of the investigator, medical monitor, or sponsor should not participate in the trial.

Subjects must have completed a previous double-blind trial of brexpiprazole or placebo; neither drug or placebo will be administered in the trial