Placebo effect in subjects with cognitive impairment.

Understanding both the placebo response and the underlying disease progression is crucial to designing clinical trials and interpreting results in Alzheimer's disease (AD) research. The disease severity at different stage of disease (e.g., mild cognitive impairment (MCI), early or late AD) is related to the rate of disease progression, which make it even difficult for AD researchers to understand the clinical trial results. A model-based meta-analysis approach using all available historical data provides quantitative understanding of placebo effect and disease progression in AD and offers a useful tool to aid in both trial design and trial interpretation. The Critical Path Institute (C-Path) is a nonprofit organization founded in 2005 as a vehicle to develop tools to accelerate drug development. The drug development tool (DDT) with AD is the first-ever quantitative DDT to be endorsed by FDA and EMA, and is publicly available to researchers through C-Path's website: https://c-path.org/ad-cts-tool-request/.