Safety and Efficacy of Pimavanserin in Adults With Parkinson's Disease and Depression

An Open-label, 8-Week Study of Safety and Efficacy of Pimavanserin Treatment in Adults With Parkinson's Disease and Depression

The purpose of this study is to assess the efficacy of pimavanserin for the treatment of depression in adults with Parkinson's disease.

Inclusion Criteria:

1. Can understand and provide signed informed consent, request for medical records and/or subject privacy form if applicable according to local regulations

2. Has a clinical diagnosis of idiopathic Parkinson's disease with a minimum duration of 1 year, defined as the presence of at least three of the following cardinal features, in the absence of alternative explanations or atypical features:

   1. rest tremor
   2. rigidity
   3. bradykinesia and/or akinesia
   4. postural and gait abnormalities

3. Meets clinical criteria for depression with Parkinson's disease as listed in the NINDS/NIMH Guidelines

4. If currently taking an anti-depressant, is being treated with only one SSRI or SNRI antidepressant at a dose within the US FDA-approved dose range. Subjects who are currently taking a second antidepressant or antidepressant augmentation agent at a sub-therapeutic dose or for an inadequate duration at Screening, and can be discontinued from this agent before the Baseline visit (in the opinion of the Investigator), may be eligible for the study.

5. Is on a stable dose of anti-Parkinson's medication for 1 month prior to Screening

6. If the subject is female, she must be of non-childbearing potential or agree to use two methods of clinically acceptable contraception

Exclusion Criteria:

1. Use of an antipsychotic within 3 weeks or 5 half-lives of Baseline (whichever is longer)
2. Had a myocardial infarction within the 6 months prior to Screening
3. Has a known personal or family history or symptoms of long QT syndrome
4. Evidence of severe or medically significant hepatic or renal impairment on laboratory tests as assessed by the Investigator or Medical Monitor
5. Has a history of PD psychosis, schizophrenia, or other psychotic disorder, or bipolar I or II disorder.
6. Actively suicidal at Visit 1 (Screening) or Visit 2 (Baseline)
7. Is pregnant or breastfeeding
8. Has previously been treated with pimavanserin or is currently taking pimavanserin
9. Has a sensitivity to pimavanserin or its excipients
10. Is judged by the Investigator or the Medical Monitor to be inappropriate for the study

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