A Phase 2/3 interventional study of ACP-204 and Placebo in Alzheimer's Disease Psychosis, sponsored by ACADIA Pharmaceuticals Inc.. Recruiting at 150 sites in 12 countries. Open to participants aged 55 Years to 95 Years. Per ClinicalTrials.gov, last updated 2026-09-25.
Sponsored by ACADIA Pharmaceuticals Inc. · Phase 2/3, Interventional, and Treatment
This is a master protocol for 3 independent, seamlessly enrolling, multicenter, randomized, double-blind, placebo-controlled, parallel-group studies in patients with ADP
All 3 substudies will be analyzed independently of each other.
Each substudy individually will consist of a screening period (up to 49 days); a double-blind treatment period (6 weeks); a safety follow-up period (30 days) for patients not rolling over into an open-label extension study; and vital status follow-up (for patients who terminated their substudy early).
Exclusion Criteria:
Additional inclusion/exclusion criteria apply. Subjects will be evaluated at screening to ensure that all criteria for study participation are met.
Administration once daily at approximately the same time of day, with or without food
Drug: ACP-204
Administration once daily at approximately the same time of day, with or without food
Drug: ACP-204
Administration once daily at approximately the same time of day, with or without food
Drug: Placebo
ACP-204 is a potent and selective antagonist/inverse agonist of 5-hydroxytryptamine (serotonin) receptor subtype 2A.
ACP-204 matching placebo
Scale for the Assessment of Positive Symptoms-Hallucinations and Delusions subscales (SAPS-H+D) total score change from baseline (Substudies 1, 2A, 2B)
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.
Time frame: From baseline to Week 6
Clinical Global Impression-Severity in the ADP context (CGI-S-ADP) score
The CGI-S scale is a clinician-rated, 7-point scale that is designed to rate the severity of the subject's symptoms at the time of assessment using the Investigator's judgment and past experience with subjects who have the same disorder. The CGI-S-ADP scale is the CGI-S scale applied in the ADP context, in which hallucinations and delusions are the symptoms of interest.
Time frame: Baseline to Week 6
Showing the first 100 of 150 sites across 12 countries.
Plan to share: No
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ACADIA Pharmaceuticals Inc.