Patients with Parkinson's disease (PD) sometimes experience symptoms affecting their movement, such as slowness, tremor, stiffness, and balance or walking problems. Many patients also have other symptoms not related to movement, called non-motor symptoms, which may affect one's mood or emotions, memory or thinking, or cause one to see or hear things that aren't real (hallucinations) or believe things that aren't true (delusions). Hallucinations or delusions, together called psychosis, occur in up to 60% of PD patients at some point in time. Parkinson's disease psychosis can sometimes be associated with decreased quality of life, increased nursing home placement, increased rate of death, and greater caregiver burden. There are approximately 50,000 Veterans with Parkinson's disease receiving care in the VA, and up to 30,000 (60%) of them will experience psychosis at some point in time.

Quetiapine is an antipsychotic drug approved by the Food and Drug Administration (FDA) that is the most commonly used medication to treat PD psychosis, but more studies are needed to determine if it works for this condition and is also well tolerated and safe. Pimavanserin is a newer antipsychotic drug approved by the Food and Drug Administration (FDA) specifically to treat PD psychosis, but more studies are needed to determine if it works and its safety.

The purpose of this research is to gather additional information on the safety and effectiveness of both Quetiapine and Pimavanserin. By doing this study, the investigators hope to learn which of these medications is the most effective course of treatment for people with PD psychosis.

Enrollment is open to Veterans nationwide, see your VA provider about the possibility of being referred to one of the study's Hub sites. This can be done through contact from your provider to the study's NSC (Tamara Boney at 267-303-9829).

CSP #2015 - C-SAPP is a randomized, intent-to-treat, double-blind, two-arm, parallel design, multicenter comparator study. A total of up to approximately 24 Department of Veterans Affairs Medical Centers (VAMCs) will be invited to participate in the study. Veterans age 40 years and older with PD and symptoms of psychosis will be pre-screened for enrollment (consent) using established inclusion/exclusion criteria. Enrolled participants meeting eligibility will be randomized in a blinded fashion to one of two arms (fixed-dose pimavanserin or flexible-dose quetiapine), stratified by cognitive impairment [per the Montreal Cognitive Assessment (MoCA)]. Assessments will be collected at multiple time points - baseline, week 3, week 5, and at week 8 after randomization. Assessments of psychosis (CGI-I psychosis), PDP symptoms (SAPS-PD), and nighttime sleep/daytime sleepiness [per Scales for Outcomes in PD-Sleep Scale nighttime subscale (SCOPA-S NS)/Epworth Sleepiness Scale (ESS)] will be completed at each in-person visit, while caregiver burden (ZBI), functioning and well-being [per the Parkinson's Disease Questionnaire-8 (PDQ-8)] will be assessed at baseline and treatment visits of weeks 5 and 8, parkinsonism (CGI-I parkinsonism) and motor abilities (MDS-UPDRS III) at baseline and week 8, and cognition (MoCA) at screening and week 8. Additional contact by phone/video will occur at weeks 1 and 6. PD medications and side-effects will also be collected. SAEs, and AEs using the Treatment Emergent Symptom Scale (TESS) for guidance, will be continuously monitored at each participant contact (in-person and phone/video). A quality by design (QbD) approach was utilized focusing on its key principles to help prospectively identify important errors that could jeopardize the reliability of the data and safety of study participants.

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

In order to facilitate titrations, study drug will be provided in blister cards with a sufficient number of over-encapsulated drug to bridge participants to their next titration step. Each blister card will contain a one-week supply of study drug. Because dosing will be nightly, and the study will use a combination of quetiapine strengths for all protocol-specified quetiapine doses, participants in both treatment groups will take two identical capsules both of which containing the protocol-specified nightly dose. For example, if a participant is randomized to quetiapine and is up-titrated from 50 to 100 mg ER, this participant will take 2 identical capsules, each containing 50 mg of ER quetiapine. Similarly, participants randomized to pimavanserin will take two capsules every night, one containing a placebo capsule, and the other containing 34 mg of pimavanserin.