Relapse Prevention Study of Pimavanserin in Dementia-related Psychosis

Inclusion Criteria:

1. Meets criteria for All-cause Dementia according to NIA-AA guidelines

2. Meets clinical criteria for one of the following disorders: Dementia associated with
Parkinson's disease, Dementia with Lewy bodies, Possible or probable Alzheimer's
disease, Frontotemporal degeneration spectrum disorders, Vascular dementia

3. Has an MMSE score ≥6 and ≤24

4. Has had psychotic symptoms for at least 2 months

5. Must be on a stable does of cholinesterase inhibitor or memantine, if applicable

6. If the subject is female, she must not be pregnant or breastfeeding. She must also be
of non-childbearing potential or must agree to use a clinically acceptable method of
contraception for the duration of the study

Exclusion Criteria:

1. Has psychotic symptoms that are primarily attributable to a condition other than
dementia

2. Has had a recent major depressive episode

3. Has experienced suicidal ideation or behavior within 3 months prior to study
enrollment

4. Has evidence of a non-neurologic medical comorbidity or medication use that could
substantially impair cognition

5. Has a history of ischemic stroke within the last 12 months or any evidence of
hemorrhagic stroke

6. Has a known history of cerebral amyloid angiopathy (CAA), epilepsy, CNS neoplasm, or
unexplained syncope

7. Has any of the following: greater than New York Heart Association (NYHA) Class 2
congestive heart failure, Grade 2 or greater angina pectoris, sustained ventricular
tachycardia, ventricular fibrillation, torsade de pointes, syncope due to an
arrhythmia, an implantable cardiac defibrillator

8. Had a myocardial infarction within the last 6 months

9. Has a known personal or family history or symptoms of long QT syndrome

10. Has a significant unstable medical condition that could interfere with subject's
ability to complete the study or comply with study procedures

11. Requires treatment with a medication or other substance that is prohibited by the
protocol

Additional inclusion/exclusion criteria apply. Subjects will be evaluated at screening to
ensure that all criteria for study participation are met.