A Study of the Safety and Efficacy of Pimavanserin in Patients With Parkinson's Disease Psychosis

Inclusion Criteria:

- A clinical diagnosis of Parkinson's disease with a minimum duration of 1 year

- Presence of visual and/or auditory hallucinations, and/or delusions, occurring during
the four weeks prior to study screening

- Psychotic symptoms must have developed after Parkinson's disease diagnosis was
established

- Subjects that are on anti-Parkinson's medication must be on a stable dose for 1 month
prior to Study Day 1 (Baseline) and during the trial

- Subject that has received stereotaxic surgery for subthalamic nucleus deep brain
stimulation must be at least 6 months post surgery and the stimulator settings must
have been stable for at least 1 month prior to Study Day 1 (Baseline) and must remain
stable during the trial

- The subject is willing and able to provide consent

- Caregiver is willing and able to accompany the subject to all visits

- Subject and caregiver are willing and able to adequately communicate in English for
the purposes of the primary assessment

Exclusion Criteria:

- Subject has a history of significant psychotic disorders prior to or concomitantly
with the diagnosis of Parkinson's disease including, but not limited to,
schizophrenia or bipolar disorder

- Subject has received previous ablative stereotaxic surgery (i.e., pallidotomy and
thalamotomy) to treat Parkinson's disease

- Subject has current evidence of a serious and or unstable cardiovascular,
respiratory, gastrointestinal, renal, hematologic or other medical disorder

- Subject has had a myocardial infarction in last six months

- Subject has any surgery planned during the screening, treatment or follow-up periods

Patients will be evaluated at screening to ensure that all criteria for study
participation are met. These evaluations will include specific measures of psychosis
severity, delirium, dementia, cardiovascular condition, and pregnancy status. Patients may
be excluded from the study based on these assessments (and specifically if it is
determined that their baseline health and psychiatric condition do not meet all
protocol-specified entry criteria).