The TOMMORROW Study: Design of an Alzheimer's Disease Delay-of-Onset Clinical Trial

This article describes the study design of a dual-objective, Phase III clinical trial in individuals presymptomatic for Alzheimer’s disease. It addresses the particular challenges for delay and prevention studies. These include:

• Ensuring that the trial population, cognitively normal at outset, contains a sufficient number of participants at increased risk of cognitive impairment onset during the trial time frame to avoid prohibitive trial size and duration.
• Finding appropriate measures to detect the earliest signs of disease and track cognitive decline.
• Building in procedural flexibility to retain participants through the long duration of delay and prevention trials.

Burns DK, Chiang C, Welsh-Bohmer KA, et al. The TOMMORROW study: Design of an Alzheimer's disease delay-of-onset clinical trial. Alzheimer’s & Dementia 2019;5:661–670.