← Back to Search


Pimavanserin vs. Quetiapine for Psychosis in Parkinson's Disease (C-SAPP Trial)

Phase 4
Research Sponsored by VA Office of Research and Development
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Age 40 years or older
Diagnosis of Parkinson's Disease consistent with UK Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria
Must not have
Deep brain stimulation (DBS) surgery occurring within 6 months prior or has had stimulator adjustments in the previous month
Suspected atypical parkinsonian disorder or dementia with Lewy bodies (DLB)
Screening 2 days
Treatment 4 months
Follow Up 2 weeks
Awards & highlights


This trial will compare the safety and effectiveness of Quetiapine and Pimavanserin in Veterans with Parkinson's disease psychosis.

Who is the study for?
This trial is for Veterans with Parkinson's Disease who are experiencing psychosis, such as hallucinations or delusions. Participants must be English-speaking adults over 40 years old, have regular contact with a caregiver, and not live in a nursing home. They can't have used certain antipsychotics recently, have heart rhythm problems, severe dementia or other disqualifying conditions.Check my eligibility
What is being tested?
The study compares the safety and effectiveness of two antipsychotic drugs: Quetiapine (commonly used but not FDA-approved for PD psychosis) versus Pimavanserin (newer and FDA-approved specifically for PD psychosis). The goal is to determine which drug works best for treating psychosis in Parkinson's patients.See study design
What are the potential side effects?
Potential side effects may include changes in mood or behavior, dizziness or lightheadedness due to low blood pressure, nausea or digestive issues, abnormal heart rhythms (QT prolongation), sleepiness during the day and trouble sleeping at night.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
I am 40 years old or older.
I have been diagnosed with Parkinson's Disease.
I experience strong hallucinations or delusions.
My caregiver is over 18, agrees to the study terms, and spends significant time with me daily.
I am 18 years old or older.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
I had DBS surgery less than 6 months ago or adjusted my stimulator last month.
I might have an unusual form of Parkinson's or dementia with Lewy bodies.
My psychosis is due to a toxic or metabolic disorder.
I have a history of long QT syndrome.
I have a history of irregular heartbeats that are not under control.
I am currently on medication that affects how my body processes drugs.
I am taking medication that affects my heart's electrical cycle.
I couldn't tolerate quetiapine or pimavanserin.
I am currently living in a nursing home or will be during the study.
I am not pregnant and willing to use contraception if I can have children.


Screening ~ 2 days
Treatment ~ 4 months
Follow Up ~2 weeks
This trial's timeline: 2 days for screening, 4 months for treatment, and 2 weeks for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Psychotic Disorders
Secondary outcome measures
CGI-I Parkinsonism
+1 more

Trial Design

2Treatment groups
Active Control
Group I: QuetiapineActive Control1 Intervention
Quetiapine extended release will be titrated as shown in the following table. During the 8-week treatment phase, there is a maximum of 6 weeks for titration. Titration Schedule Visit/call Quetiapine Dose (Flexible)Quetiapine Notes Baseline visit (Visit 00)25 mg IR QHSAll participants must be up-titrated to at least 50 mg/day at week 1 Week 1 call (Visit 01)50 mg XR QHSUp-titration Week 3 visit (Visit 03)100 mg XR QHS (requiring two 50-mg quetiapine XR capsules)Up- or down-titration as appropriate based on psychosis symptoms and tolerability Week 5 visit (Visit 05)150 mg quetiapine XR QHSUp- or down-titration as appropriate based on psychosis symptoms and tolerability Week 6 call (Visit 06)200 mg quetiapine XR QHSUp- or down-titration as appropriate based on psychosis symptoms and tolerability
Group II: Pimavanserin 34mgActive Control1 Intervention
All participants assigned to pimavanserin will receive the FDA-approved dose of 34mg (equivalent to 40 mg pimavanserin tartrate) daily without titration; however, because pimavanserin is blinded to quetiapine, participants will undergo sham titration based on tolerability.

Find a Location

Who is running the clinical trial?

VA Office of Research and DevelopmentLead Sponsor
1,628 Previous Clinical Trials
3,325,621 Total Patients Enrolled
Daniel Weintraub, MDStudy ChairCorporal Michael J. Crescenz VA Medical Center, Philadelphia, PA
4 Previous Clinical Trials
319 Total Patients Enrolled

Media Library

Pimavanserin (Antipsychotic) Clinical Trial Eligibility Overview. Trial Name: NCT04373317 — Phase 4
Parkinson's Disease Research Study Groups: Quetiapine, Pimavanserin 34mg
Parkinson's Disease Clinical Trial 2023: Pimavanserin Highlights & Side Effects. Trial Name: NCT04373317 — Phase 4
Pimavanserin (Antipsychotic) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04373317 — Phase 4
~149 spots leftby Oct 2025