NCT06159673 · ACADIA Pharmaceuticals Inc.
ACP-204 in Adults With Alzheimer's Disease Psychosis
What this study is about
This is a master protocol for 3 independent, seamlessly enrolling, conducted at multiple hospitals, randomly assigned, where neither patients nor doctors know which treatment is given, compared against an inactive treatment, parallel-group studies in patients with ADP * Substudy 1 (Phase 2) will evaluate effectiveness and dose response of ACP-204 30 and 60 mg vs placebo.
View original scientific description
This is a master protocol for 3 independent, seamlessly enrolling, multicenter, randomized, double-blind, placebo-controlled, parallel-group studies in patients with ADP * Substudy 1 (Phase 2) will evaluate efficacy and dose response of ACP-204 30 and 60 mg vs placebo. This substudy will be initiated first. * Substudies 2A and 2B (both: Phase 3) will be confirmatory studies of either both doses (ACP-204 30 and 60 mg, respectively) or a single dose from Part 1 vs placebo.
Interventions
DRUG
ACP-204
ACP-204 is a potent and selective antagonist/inverse agonist of 5-hydroxytryptamine (serotonin) receptor subtype 2A.
DRUG
Placebo
ACP-204 matching placebo
Primary outcome measures
Scale for the Assessment of Positive Symptoms-Hallucinations and Delusions subscales (SAPS-H+D) total score change from baseline (Substudies 1, 2A, 2B)
Time frame: From baseline to Week 6
The SAPS-H+D subscales are a measure of two psychotic symptoms: hallucinations and delusions. The SAPS-H+D total score is the sum of the scores of the Hallucinations and Delusions subscales. The hallucinations domain score (SAPS-H) is the sum of the 7 hallucinations item scores, and the delusions domain core (SAPS-D) is the sum of the 13 delusions item scores.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Is male or female and ≥55 and ≤95 years of age living in the community or in an institutionalized setting
- Meets clinical criteria for possible or probable AD based on the 2011 National Institute on Aging-Alzheimer Association (NIA-AA) criteria
- Meets the revised criteria for psychosis in major or mild neurocognitive disorder established by the International Psychogeriatrics Association (IPA)
- Has either blood-based biomarker or documented evidence (e.g. positron emission tomography, cerebrospinal fluid biomarker) indicating amyloid plaque deposition and neuropathologic change consistent with AD
- Has a prior magnetic resonance imaging or computed tomography scan of the brain that is consistent with the diagnosis of AD
- Meets revised criteria for psychosis in major or mild neurocognitive disorder as per International Psychogeriatrics Association
- MMSE score ≥6 and ≤24
- Psychotic symptoms for at least 2 months
- Lives in a stable place of residence and there
Where
- Chandler, Arizona
- Scottsdale, Arizona
- Anaheim, California
- Costa Mesa, California
- Fresno, California
- Garden Grove, California
- Aventura, Florida
- Daytona Beach, Florida
- Doral, Florida
- Hialeah, Florida
- Miami, Florida
- Miami Beach, Florida
And 20 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 16, 2026 · Source of record for eligibility and locations