Drug Development in Alzheimer’s Disease—The Role of Default Mode Network Assessment in Phase II

A lzheimer’s disease (AD) is rapidly becoming more common as the global population ages. New treatments are needed and new approaches to drug development are warranted. The phase II challenge for AD treatment development programs is how to provide proof-of-concept (POC) of the candidate agent without a large long trial equivalent to phase III. We propose that the available data support measures of the default mode network (DMN) using functional magnetic resonance imaging (fMRI) as demonstrating the effect of treatment on cognitive circuits critical to human cognition. Improved DMN function with symptomatic cognitive enhancing agents or decreased deterioration of DMN function compared to placebo in trials of disease-modifying agents would support POC and allow progression to phase III with greater confidence.