ACP-204 in Adults With Alzheimer's Disease Psychosis

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 are no plans to change living arrangements * Has a designated study partner/caregiver * Able to complete all study visits with a study partner/caregiver * Must be on a stable dose of cholinesterase inhibitor or memantine, if applicable Exclusion Criteria: * Requires treatment with a medication prohibited by the protocol * Is in hospice and receiving end-of-life palliative care, or has become bedridden * Requires skilled nursing care * Psychotic symptoms that are primarily attributable to delirium, substance abuse, or a medical or psychiatric condition other than dementia * Known history of cerebral amyloid angiopathy, epilepsy, central nervous system neoplasm, or unexplained syncope * Atrial fibrillation * Symptomatic orthostatic hypotension * Protocol-defined exclusionary clinical laboratory findings * Treatment with anti-tau therapy or donanemab within 2 months prior to Screening Additional inclusion/exclusion criteria apply. Subjects will be evaluated at screening to ensure that all criteria for study participation are met.