A Study of ONO-2020 in Patients With Agitation Associated With Alzheimer's Disease Dementia

Inclusion Criteria:

• Diagnosis of probable AD according to the diagnostic criteria for AD dementia (NIA-AA 2011)

• Mini-Mental State Examination (MMSE) score ≥ 5 to ≤ 22 at the start of the treatmentperiod

• Symptoms of agitation defined by the IPA from at least 14 days before the start ofthe screening period

• Neuropsychiatric Inventory-Nursing Home version (NPI-NH) Agitation/Aggression domain (NPI-NH-A/A) score ≥ 4 at the start of the treatment period.

• Patients who can participate in the study under hospitalization from 21 days beforethe start of the treatment period to throughout the treatment period

Exclusion Criteria:

• Diagnosis of dementia not due to AD or any other disorder with memory impairment,such as mixed dementia, vascular dementia, Lewy body dementia, dementia associatedwith Parkinson's disease, frontotemporal dementia, drug-induced dementia, dementiaassociated with human immunodeficiency virus (HIV) infection, traumatic braininjury, normal pressure hydrocephalus, or other non-AD dementia

• Any MRI or CT scan of the brain performed after the onset of dementia with findingsconsistent with clinically relevant CNS disease other than AD, such as vascularchanges (eg, cortical cerebral infarction, multiple cerebral infarctions),space-occupying lesions (eg, tumors), or any other major structural brain disease

• Delirium within 30 days before the start of the screening period or a history ofdelirium

• At risk of suicide according to the Columbia-Suicide Severity Rating Scale (C-SSRS) (answers "yes" to Question 4 or 5 of the suicidal ideation section of the C-SSRS) orany suicide attempt within 6 months before the start of the screening period, or atserious risk of suicide in the opinion of the investigator or subinvestigator

• Prior or current treatment with anti-amyloid beta antibodies