Alzheimer's disease is a large and growing unmet medical need. Clinical trial designs need to assess disease-related outcomes earlier to accelerate the development of better treatments for Alzheimer's disease. ACU193 is a monoclonal antibody that selectively targets amyloid β oligomers, thought to be the most toxic species of Aβ that accumulates early in AD and contributes to downstream pathological effects. Nonclinical data indicate that ACU193 can reduce the toxic effects of amyloid β oligomers. ACU193 is currently being investigated in a phase 1 clinical trial designed with the properties described in this report. This phase 1 trial is designed to provide data to enable a go/no-go decision regarding the initiation of a subsequent phase 2/3 study.