ClinicalTrials.gg
RecruitingNCT05590637CAMELOTUpdated Sep 9, 2025

Comparing Antipsychotic Medications in LBD Over Time

A Phase 4 interventional study of Pimavanserin and Quetiapine in Parkinson's Disease Psychosis and Dementia With Lewy Bodies, sponsored by The University of Texas Health Science Center at San Antonio. Recruiting at 2 sites in United States. Per ClinicalTrials.gov, last updated 2025-09-09.

Sponsored by The University of Texas Health Science Center at San Antonio · Phase 4, Interventional, and Treatment

From the registry’s dates

  • Primary completion was expected by Aug 2026, 3 months ago, but the record still lists the study as recruiting.
  • Registered 5 months after the study started (first participant enrolled Apr 2022, registered Oct 2022).
  • Started Apr 2022; still recruiting 4 years 6 months later.
Phase
Phase 4
Study type
Interventional
Enrollment
94
Allocation
Randomized
Sex
All
01

Study summary

The primary objective of this study is to determine whether treatment with pimavanserin or quetiapine is associated with a greater improvement in psychosis when used in a routine clinical setting to treat hallucinations and/or delusions due to Parkinson's disease (PD) or dementia with Lewy bodies (DLB) - collectively referred to as Lewy body disease (LBD).

Read the detailed description

Psychosis (hallucinations and delusions) is a common problem in Parkinson's disease (PD) and dementia with Lewy bodies (DLB). PD is a common neurodegenerative disorder that causes movement, cognitive, and psychiatric symptoms. DLB is a similar disorder, though causes more severe cognitive and psychiatric problems. Psychosis is highly prevalent among people with PD and DLB, often manifesting as visual hallucinations or paranoid delusions. Up to 60% of people with PD will experience psychosis over the course of their disease. Psychosis is associated with increased mortality, caregiver burden, and poorer quality of life.

More study is needed to determine the best way to treat psychosis in PD and DLB. Currently, both quetiapine and pimavanserin are used in clinical practice for psychosis in PD and DLB. However, few comparison studies have been done and it is unclear if one medication is superior to the other. This will be a clinical trial comparing quetiapine and pimavanserin among patients with psychosis due to PD or DLB requiring initiation of a medication. Patients will be randomized to quetiapine or pimavanserin and improvement in psychosis at 6 months will be compared between the groups.

02

Conditions studied

  • Parkinson's Disease Psychosis
  • Dementia With Lewy Bodies

Keywords

  • quetiapine
  • pimavanserin
  • psychosis
  • hallucinations
  • delusions
03

In context

Lewy Body Disease

239 studies on the registry are indexed under Lewy Body Disease; 89 are open to participants now.

This study's planned enrollment of 94 is close to the median of 89 across 152 interventional studies indexed under Lewy Body Disease.

Browse Lewy Body Disease studies →

Lead sponsor

The University of Texas Health Science Center at San Antonio is the lead sponsor of 445 studies on the registry; 89 are open to participants now.

Of its 65 completed or terminated interventional studies of FDA-regulated products, 35 (54%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Patients seen in the neurology clinic at UT Health San Antonio
  • Diagnosed with psychosis due to PD or DLB
  • Requiring initiation of an antipsychotic medication
  • Clinical equipoise between quetiapine and pimavanserin must exist
  • The prescribing provider must be comfortable prescribing and managing both quetiapine and pimavanserin

Exclusion criteria

Exclusion Criteria:

  • Medical to either medication
  • Caregiver unavailable to complete NPI-Q
  • Currently taking an antipsychotic medication
  • Prescribing provider unwilling to manage either medication
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

05

Study design

Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
94 participants (estimated)

Study arms

  • Active comparator
    quetiapine

    Elderly patients with dementia-related psychosis will be treated with quetiapine, an atypical antipsychotic indicated for the treeatment of: schizophrenia, bipolar I manic episodes and bipolar depressive episodes.

    Drug: Quetiapine

  • Active comparator
    pimavanserin

    Elderly patients with dementia-related psychosis will be treated with pimavanserin, an atypical antipsychotic indicated for treatment of hallucinations and delusions associated with Parkinson's disease.

    Drug: Pimavanserin

Interventions

  • Dosage choice and further medication management will be at the discretion of the treating clinician, per routine clinical practice.

    Also known as: Nuplazid

  • Dosage choice and further medication management will be at the discretion of the treating clinician, per routine clinical practice.

    Also known as: Seroquel

06

What researchers measure

Primary outcomes

  1. Neuropsychiatry Inventory Questionnaire (NPI-Q), Hallucinations + Delusions (H+D)

    Change in the Hallucinations + Delusions sub-score of the neuropsychiatric inventory questionnaire. Each NPI-Q item is scored by severity (1-3), and distress to caregiver (0-5), then added together (range 0-8) with a higher score indicating greater severity.

    Time frame: Baseline to 6 months

Secondary outcomes

  1. Neuropsychiatry Inventory Questionnaire (NPI-Q) total score

    Change in the total neuropsychiatric inventory questionnaire score, which includes 12 items, each scored from 0-8 with a higher score indicating more severe symptoms.

    Time frame: Baseline to 6 months

  2. Neuropsychiatry Inventory Questionnaire (NPI-Q) (anxiety)

    Change in the neuropsychiatric inventory questionnaire item for anxiety, scored from 0-8 with a higher score indicating more severe anxiety.

    Time frame: Baseline to 6 months

  3. Neuropsychiatry Inventory Questionnaire (NPI-Q) (agitation)

    Change in the neuropsychiatric inventory questionnaire for agitation, scored from 0-8 with a higher score indicating more severe agitation.

    Time frame: Baseline to 6 months

  4. Neuropsychiatry Inventory Questionnaire (NPI-Q) (nighttime behaviors)

    Change in the neuropsychiatric inventory questionnaire for sleep disturbance, scored from 0-8 with a higher score indicating more severe sleep disturbances.

    Time frame: Baseline to 6 months

  5. Mortality

    Number of subjects who survived until the 6 month study assessment visit

    Time frame: 6 months

  6. Time to discontinuation of per-protocol medication

    Will examine whether participants continued the chosen medication until study completion or if they either discontinued the study medication or added the other study medication.

    Time frame: Baseline to 6 months

  7. MDS-UPDRS part 3

    Unified Parkinson's Disease Rating Scale, motor score. The motor examination scale consists of 33 items graded 0-4 points with an overall possible score of 0-132 points. A higher score indicates a higher burden of motor symptoms.

    Time frame: Baseline to 6 months

  8. CGIC, PGIC, CGI-C:CVR

    Clinician, patient, and caregiver global impressions of change. Each is a single item assessment rated from 1 (very much improved) to 7 (very much worse). A higher score indicates worsening symptoms.

    Time frame: Baseline to 6 months

Other outcomes

  1. Medication out-of-pocket cost

    Amount of out of pocket costs spent on medications during the study

    Time frame: Baseline to 6 months

  2. NPI-Q caregiver portion

    Change in the total of the caregiver distress items of the neuropsychiatric inventory. The scale contains 12 items, each scored from 0-5 (least to most distress). Possible scores Range from 0-60 with a lower score indicating less caregiver distress

    Time frame: Baseline to 6 months

  3. Patient contact

    Number of between visit patient encounters (phone, EMR messages)

    Time frame: Baseline to 6 months

07

Study locations

2 of 2 sites recruiting
08

References and documents

Publications

  • Tran N, Wang CP, Seshadri S, Coss P, Vaou OE, Saadatpour L, Paiz C, Solis D, Grimaldo J, Erskine S, Horn S. Pragmatic trial design enhances diversity and retention among research participants with Lewy body diseases. NPJ Dement. 2026;2(1):10. doi: 10.1038/s44400-026-00059-x. Epub 2026 Feb 2. PubMed 41640857 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 9, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05590637
Collaborators
Alzheimer's Association
Responsible party
Sponsor
First posted
Oct 21, 2022
Start date
Apr 22, 2022
Primary completion
Aug 2026 (estimated)
Completion
Feb 2027 (estimated)
Last update
Sep 9, 2025

Study contacts

Carolyn Paiz, BS
Contact
paizc@uthscsa.edu
210-450-8830
Sarah Horn, MD
principal investigator · The University of Texas Health Science Center at San Antonio

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drugs tested here: Pimavanserin · Quetiapine

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