A 16-Week Open-Label Study of the Effects of Treatment With Pimavanserin on Activities of Daily Living in Subjects With Parkinson’s Disease Psychosis

1. Male or female subjects at least 40 years of age

2. Has a Mini-Mental State Examination (MMSE) score ≥21 at Screening

3. Does not meet the criteria for all-cause dementia

4. Has a diagnosis of idiopathic Parkinson’s disease (PD)

5. Has psychotic symptoms severe enough to warrant treatment with an antipsychotic agent

6. Psychotic symptoms developed after the diagnosis of PD was established

7. If the subject is female, she must not be pregnant or breastfeeding. She must also be
of non-childbearing potential (defined as either surgically sterilized or at least 1
year postmenopausal) OR must agree to use TWO clinically acceptable methods of
contraception.

Exclusion Criteria:

1. Has atypical parkinsonism (Parkinson’s plus, multiple system atrophy [MSA],
progressive supranuclear palsy [PSP]), or secondary parkinsonism variants such as
tardive or medication induced parkinsonism

2. Has current evidence of an unstable neurological, cardiovascular, respiratory,
gastrointestinal, renal, hepatic, hematologic, or other medical or psychiatric
disorder, including cancer or malignancies that, in the judgment of the Investigator,
would jeopardize the safe participation of the subject in the study or significantly
interfere with the conduct or interpretation of the study

3. Has a history of myocardial infarction, unstable angina, acute coronary syndrome, or
cerebrovascular accident within the last 6 months prior to Screening

4. Has any of the following:

1. greater than New York Heart Association (NYHA) Class 2 congestive heart failure

2. Grade 2 or greater angina pectoris (by Canadian Cardiovascular Society Angina
Grading Scale)

3. sustained ventricular tachycardia

4. ventricular fibrillation

5. torsades de pointes

6. syncope due to an arrhythmia

7. an implantable cardiac defibrillator

5. Has a known personal or family history of long QT syndrome or family history of sudden
cardiac death

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

7. Has a body mass index (BMI) <18.5 kg/m2 or >35 kg/m2 at Screening or Baseline or known
unintentional clinically significant weight loss (i.e., ≥7%) over past 6 months

8. Is suicidal at Screening or Baseline

9. Has a history of a significant psychotic disorder prior to or concomitantly with the
onset of PD including, but not limited to, schizophrenia or bipolar disorder

10. Had dementia prior to or concomitantly with the onset of motor symptoms of PD

11. Is judged by the Investigator or the Medical Monitor to be inappropriate for the study
for any reason

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