A Study to Assess the Efficacy and Safety of ITI-1284 in the Treatment of Agitation Associated With Alzheimer's Dementia

Inclusion Criteria: * Can understand the nature of the trial and protocol requirements and provide signed informed consent, if in the judgement of the Investigator is deemed competent to provide consent or if patient is deemed not competent to provide informed consent, with the patient's assent (if capable), consent may be provided by an appropriate person (eg, patient's Legally Authorized Representative \[LAR\]) before the initiation of any study-specific procedures in accordance with local regulations; * Meets clinical criteria for Alzheimer's disease based on 2011 National Institute of Aging-Alzheimer's Association (NIA-AA) dementia criteria and biomarker criteria and either: * Has a high likelihood for amyloid pathology consistent with Alzheimer's disease, as confirmed by blood-based biomarker at Screening; or * Has historical documentation of cerebrospinal fluid (CSF) biomarker or amyloid positron emission tomography (PET) brain scan; * Meets all criteria for agitation according to the International Psychogeriatric Association (IPA) consensus definition * Has clinically meaningful agitation defined as a Neuropsychiatric Inventory-Agitation/Aggression (NPI-AA) domain total score of ≥ 4 at both Screening and Baseline; * CGI-S score ≥ 4 at Screening and Baseline; * Has Mini-Mental State Examination, 2nd Edition™: Standard Version (MMSE-2®:SV) score of 6 to 24 at Screening; Exclusion Criteria: * Agitation symptoms are attributable to concomitant medications, adverse environmental conditions, substance abuse, or active medical or psychiatric conditions as per Investigator's judgment; * Has been diagnosed with one or more of the following psychiatric conditions: * Schizophrenia, schizoaffective disorder, or other psychotic disorder that is not related to Alzheimer's dementia; * Bipolar disorder; * Major depressive disorder, unless it is considered stable and treated for at least 8 weeks prior to Screening; * Has a significant risk for suicidal behavior during the course of their participation in the study, or is considered to be an imminent danger to themselves or others, in the opinion of the investigator, and/or as assessed by Columbia Suicide Severity Rating Scale (C-SSRS); or the patient has had 1 or more suicide attempts within the 2 years prior to Screening; * The patient has known hypersensitivity or intolerance to ITI-1284 or lumateperone, or to any of their excipients.