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Comparing Pimavanserin and Quetiapine for Parkinson's Psychosis

CSP #2015 - Multicenter, Randomized, Double-blind Comparator Study of Antipsychotics Pimavanserin and Quetiapine for Parkinson''s Disease Psychosis (C-SAPP)

Phase 4 Interventional VA Office of Research and Development · NCT04373317

This study is testing whether Pimavanserin or Quetiapine works better to help veterans with Parkinson's disease who have hallucinations or delusions.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment358 (estimated)
Ages40 Years and up
SexAll
SponsorVA Office of Research and Development Federal
Locations24 sites (Tucson, Arizona and 23 other locations)
Trial IDNCT04373317 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to compare the effectiveness of Pimavanserin and Quetiapine in treating psychosis symptoms in veterans with Parkinson's disease. It focuses on patients who experience hallucinations or delusions, which can significantly impact their quality of life. Participants must be stable on their Parkinson's medications and have a caregiver who can provide support throughout the study. The trial is conducted across multiple VA health care systems in California and Arizona.

Who should consider this trial

Good fit: Ideal candidates include veterans aged 40 and older diagnosed with Parkinson's disease who experience significant psychosis symptoms.

Not a fit: Patients without Parkinson's disease or those who do not experience psychosis symptoms may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a more effective treatment option for managing psychosis in patients with Parkinson's disease.

How similar studies have performed: Previous studies have shown promise in treating Parkinson's psychosis with similar medications, but this specific comparison is novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Veteran
* Age 40 years or older
* Diagnosis of Parkinson's Disease consistent with UK Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria
* Psychosis \[with Neuropsychiatric Inventory (NPI) hallucinations (B) or delusions (A) score 4 or greater\]
* Stable dose of PD medications for at least 2 weeks
* If on an acetylcholinesterase inhibitor (AChEI) initially prescribed at least 3 months prior and stable dose (no dose or medication change) for past month
* Informed other must provide informed consent and agree to attend all study visits. The informed other must be at least 18 years of age and have regular contact with the patient (on average at least 4 days per week and at least 2 hours per day, or at least 3 days per week and at least 4 hours per day, that is with patient) via in-person, video, or telephone
* English-speaking

INFORMED OTHER

* Age 18 years or older
* Must have regular contact with the patient (on average at least 4 days per week, and at least 2 hours per day, or at least 3 days per week and at least 4 hours pr day, that is with patient) via in-person, video, or telephone
* Agree to attend all study visits
* Be able to provide informed consent
* English-speaking

Exclusion Criteria:

* Psychosis symptoms severe enough to preclude enrollment in a clinical trial and require prompt clinical care instead
* Treatment with quetiapine \>50 mg/day or pimavanserin in the past 3 months, or quetiapine 50 mg/day or another antipsychotic in the past week prior to study randomization
* Deep brain stimulation (DBS) surgery within 3 months or has had stimulator adjustments in the previous 2 weeks
* History of a psychotic disorder prior to PD, including bipolar disorder, schizophrenia, schizoaffective disorder, and major depressive disorder with psychotic features, if it is thought to be the cause of the current psychosis symptoms
* Suspected atypical parkinsonian disorder or dementia with Lewy bodies (DLB)
* Psychosis secondary to other toxic or metabolic disorder
* History of long QT syndrome
* Documented chart evidence indicating persistent hypoglycemia, hypokalemia, hypomagnesemia that would put patient at increased risk for QTc prolongation.
* History of ventricular arrhythmias, except when treated with an implantable cardioverter defibrillator (ICD) or pacemaker, or untreated or unstable atrial fibrillation/flutter
* Currently taking medications that are moderate or strong CYP3A4 inducers or strong CYP3A4 inhibitors
* Concomitant use of drugs that prolong the QTc interval with a known risk of Torsades de Pointes
* Comorbid medical condition determined too severe by Site Investigator to allow participation in clinical trial
* Failure to tolerate quetiapine or pimavanserin previously
* Severe cognitive impairment (MoCA score \<5)
* Nursing home placement at screening or planned placement during the study, unless approved by study Co-Chairs. Approval will depend upon nursing facility agreement to receive, return, and administer medications or allow participant to self-administer study medications; appropriate IO availability; and transportation availability for study visits.
* Currently enrolled in another therapeutic or interventional study
* Pregnant, or a female of child-bearing potential who is unwilling to use a reliable form of contraception

Where this trial is running

Tucson, Arizona and 23 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Parkinson's Disease PsychosisPimavanserinQuetiapine
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.