Phase 2, Efficacy and Safety Study of ACP-204 in Lewy Body Dementia Psychosis

May 27, 2026 updated by: ACADIA Pharmaceuticals Inc.

A Double-Blind, Placebo-Controlled, Phase 2, Efficacy and Safety Study of ACP-204 in Adults With Lewy Body Dementia Psychosis (LBDP)

Multicenter, randomized, 6-week, double-blind, placebo-controlled, parallel-group, Phase 2 study in subjects with LBDP.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Study Website: https://illumerastudy.com/

Study Type

Interventional

Enrollment (Estimated)

180

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Bulgaria
      • Cherven Bryag, Bulgaria, 5980
        • Recruiting
        • Ambulatory for Individual Practice for Specialized Medical Care in Psychiatry - Dr Ivo Natsov
      • Plovdiv, Bulgaria, 4002
        • Recruiting
        • UMHAT Sv Georgi EAD
      • Sofia, Bulgaria, 1408
        • Recruiting
        • DCC "Sv. Vrach and Sv. Sv. Kuzma and Damyan", OOD
      • Sofia, Bulgaria, 1431
        • Recruiting
        • UMHAT "Alexandrovska" EAD
      • Sofia, Bulgaria, 1113
        • Recruiting
        • Medical Center SV.Naum
      • Sofia, Bulgaria, 1618
        • Recruiting
        • Medical Center Detsko Zdrave Branch Maestro Kanev
      • Varna, Bulgaria, 9000
        • Recruiting
        • DCC Mladost M- Varna, OOD
  • Czechia
      • Brno, Czechia, 656 91
        • Recruiting
        • Fakultni nemocnice u sv. Anny v Brne
      • Choceň, Czechia, 56501
        • Recruiting
        • NEUROHK s.r.o. Poliklinika Chocen a.s.
      • Prague, Czechia, 12808
        • Recruiting
        • Všeobecná fakultní nemocnice v Praze
      • Prague, Czechia, 16000
        • Recruiting
        • Neuropsychiatrie s.r.o.
      • Rychnov nad Kněžnou, Czechia, 51601
        • Recruiting
        • Vestra Clinics s.r.o
  • France
      • Bron, France, 69677
        • Recruiting
        • Hopital Neurologique Bron
      • Paris, France, 75013
        • Recruiting
        • Hôpital Broca
      • Strasbourg, France, 67000
        • Recruiting
        • CHU Strasbourg-Hopital Hautepierre
      • Tours, France, 37044
        • Recruiting
        • CHRU de Tours- Hopital Bretonneau
      • Vandœuvre-lès-Nancy, France, 54511
        • Recruiting
        • CHRU de Nancy- Hospital de Brabois
    • Cedex 9
      • Toulouse, Cedex 9, France, 31059
        • Recruiting
        • CHU de Toulouse- Hopital Purpan
      • Toulouse, Cedex 9, France, 31059
        • Recruiting
        • Gérontopôle Centre de Recherche Clinique
    • Nord
      • Lille, Nord, France, 59037
        • Recruiting
        • Hopital Roger Salengro - CHU Lille
    • Paris
      • Paris, Paris, France, 75010
        • Recruiting
        • Hôpital Lariboisière, Histologie et CMRR
    • Rhone
      • Villeurbanne, Rhone, France, 69100
        • Recruiting
        • Hôpital des Chapennes
  • Italy
      • Brescia, Italy, 25123
        • Recruiting
        • Azieda Socio Sanitaria Territoriale degli Spedali Civili di Brescia
      • Roma, Italy, 128
        • Recruiting
        • Università Campus Bio-Medico di Roma
      • Roma, Italy, 185
        • Recruiting
        • Azienda Ospedaliera Universitaria Policlinico Umberto I - Università di Roma La Sapienza, UOI Day Hospital di Neurologia
    • Napoli
      • Naples, Napoli, Italy, 80138
        • Recruiting
        • Azienda Ospedaliera Univerrsitaria
  • Serbia
      • Belgrade, Serbia, 11000
        • Recruiting
        • University Clinical Center of Serbia
      • Belgrade, Serbia, 11000
        • Recruiting
        • Institute of Mental Health
      • Belgrade, Serbia, 11000
        • Recruiting
        • University Clinical Hospital Center Zvezdara
      • Kragujevac, Serbia, 34000
        • Recruiting
        • University Clinical Center Kragujevac
  • United States
    • California
      • Irvine, California, United States, 92612
        • Recruiting
        • ATP Clinical Research Inc.
        • Contact:
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20057
        • Recruiting
        • Georgetown University
    • Florida
      • Aventura, Florida, United States, 33180
        • Recruiting
        • Humanity Clinical Research, Corp
      • Boca Raton, Florida, United States, 33486
        • Recruiting
        • Parkinson's Disease and Movement Disorders Center of Boca Raton
      • Clermont, Florida, United States, 34711
        • Recruiting
        • K2 Medical Research Winter Garden LLC
      • Gainesville, Florida, United States, 32608
        • Recruiting
        • University of Florida - Shands
      • Lady Lake, Florida, United States, 32159
        • Recruiting
        • K2 Summit Research
      • Maitland, Florida, United States, 32751
        • Recruiting
        • Neurology Associates, P. A.
      • Miami, Florida, United States, 33032
      • Miami, Florida, United States, 33122
        • Recruiting
        • Premier Clinical Research Institute, Inc.
      • Miami, Florida, United States, 33165
        • Recruiting
        • MediClear Medical & Research Center, Inc.
      • Miami, Florida, United States, 33135
        • Recruiting
        • Advanced Clinical Research Network, Corp
      • West Palm Beach, Florida, United States, 33407
        • Recruiting
        • Health Synergy Clinical Research, LLC
    • Hawaii
      • Honolulu, Hawaii, United States, 96817
        • Recruiting
        • Hawaii Pacific Neuroscience
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • Recruiting
        • University of Kansas Medical Center Research Institute Inc.
    • New York
      • Commack, New York, United States, 11725
        • Recruiting
        • Parkinson's Disease and Movement Disorders Center of Boca Raton d/b/a Parkinson's Research Center of America-Long Island
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27517
        • Recruiting
        • UNC Hospitals
    • Ohio
      • Columbus, Ohio, United States, 43210
        • Recruiting
        • The Ohio State University, Energy Advancement and Innovation Center
    • Oklahoma
      • Tulsa, Oklahoma, United States, 74136
        • Recruiting
        • The Movement Disorder Clinic of Oklahoma
    • Pennsylvania
      • Abington, Pennsylvania, United States, 19001
        • Suspended
        • Abington Neurological Associates, LTD
    • Texas
      • Cypress, Texas, United States, 77429
        • Recruiting
        • Horizon Clinical Research Group
      • Houston, Texas, United States, 77054
        • Recruiting
        • Prolato Clinical Research Center
      • San Antonio, Texas, United States, 78229
        • Recruiting
        • The University of Texas Health Science Center San Antonio
      • Stafford, Texas, United States, 77477
        • Recruiting
        • R and H Clinical Research
    • Virginia
      • Richmond, Virginia, United States, 23219
        • Recruiting
        • Virginia Commonwealth University (a public institution of higher education)
    • Washington
      • Kirkland, Washington, United States, 98034
        • Recruiting
        • EvergreenHealth

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male or female ≥55 years to <85 years of age at the Screening visit living in the community or, if permitted by local regulations, in an institutionalized setting

  • Can provide written informed consent. If the subject is deemed not competent to provide informed consent, the following requirements for consent must be met:

    1. The subject's LAR must provide written informed consent.
    2. The subject must provide written (if capable) informed assent per local regulations.
  • Meets either the clinical criteria for Parkinson's disease with dementia as defined by the Movement Disorder Society's Task Force or the revised clinical criteria for probable dementia with Lewy bodies (DLB) by consensus criteria (Fourth consensus report of the DLB Consortium).
  • Meets the revised criteria for psychosis in major or mild neurocognitive disorder established by the International Psychogeriatrics Association

Exclusion Criteria:

  • Is in hospice, is receiving end-of-life palliative care, or is bedridden
  • Has psychotic symptoms that are primarily attributable to delirium, substance abuse, or a medical or psychiatric condition (e.g. schizophrenia, bipolar disorder, delusional disorder) other than dementia
  • Is actively suicidal at Visit 1 (Screening) or Visit 2 (Baseline)
  • Has a history or current evidence of a serious and/or significant unstable cardiovascular, respiratory, endocrine, gastrointestinal, renal, hepatic, hematologic, immunologic, genitourinary, psychiatric or neurologic (including stroke, chronic seizures, or clinically significant head injury) abnormality or disease or other medical disorder, including cancer or malignancies that could interfere with subject's ability to complete the study or comply with study procedures
  • Has other clinically significant CNS abnormalities that are most likely contributing to the dementia or findings on MRI or CT

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Placebo once daily
Drug: Placebo
Provided as 1 capsule, to be taken orally once daily
Experimental: ACP-204 30 mg
ACP-204 dose of 30 mg once daily
Drug: ACP-204
Provided as 1 capsule, to be taken orally once daily
Experimental: ACP-204 60 mg
ACP-204 dose of 60 mg once daily
Drug: ACP-204
Provided as 1 capsule, to be taken orally once daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from Baseline in SAPS-LBDP total score at Week 6
Time Frame: 6 weeks
Change from Baseline in Scale for the Assessment of Positive Symptoms- Lewy Body Dementia Psychosis (SAPS-LBDP) total score at Week 6
6 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

ACADIA Pharmaceuticals Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 6, 2025

Primary Completion (Estimated)

February 1, 2028

Study Completion (Estimated)

March 1, 2028

Study Registration Dates

First Submitted

June 12, 2025

First Submitted That Met QC Criteria

June 12, 2025

First Posted (Actual)

June 19, 2025

Study Record Updates

Last Update Posted (Actual)

May 29, 2026

Last Update Submitted That Met QC Criteria

May 27, 2026

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ACP-204-012
  • 2025-521710-25-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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