A Study of MP-101 in Dementia-Related Psychosis and/or Agitation and Aggression

Inclusion Criteria: * Females must be of non-childbearing potential, defined as women greater than or equal to (≥) 60 years of age, postmenopausal women ≥50 and less than (\<) 60 years of age who have had a cessation of menses for at least 12 months, or women who are congenitally or surgically sterile * Males must agree to use 2 forms of highly effective birth control with female partners of childbearing potential while enrolled in the study, and for at least 28 days following the last dose * Ambulatory (with or without walking device) with a stable gait * Have a Mini-Mental State Examination (MMSE) score of 10 to 24 * Meet clinical criteria for one of the following disorders: dementia associated with Parkinson's disease, dementia with Lewy bodies, possible or probable Alzheimer's disease, frontotemporal degeneration spectrum disorders, vascular dementia * Able to communicate verbally * Have an NPI score of ≥4 on either individual item (delusions or hallucinations) or ≥6 on the Psychosis Subscale (combined delusions and hallucinations), or an NPI score of ≥4 on agitation/aggression domain * Have a reliable caregiver who provides written informed consent to participate and who is in frequent contact with the patient (defined as spending at least 4 hours/day at least 4 days/week with the patient and who is knowledgeable about the patient's daytime and nighttime behaviors). The caregiver must be able to communicate with site personnel, and opinion of the investigator, must unde…