The inability to stop or prevent the progression of Alzheimer's Disease (AD) has been well been documented, expensive, and frustrating. It has, however, bred collaboration and innovation rarely seen in industry. To facilitate trial optimization, a coalition (CAMD) provided placebo-arm patient level data for 6500 patients over 24 clinical trials of AD and MCI (the CODR database) and funded development of a clinical trial simulation tool (R::adsim). A disease-drug-trial model for Alzheimer's Disease was developed based on joint modeling of literature meta-data and CODR, summarizing available evidence with regard to rates of natural progression, placebo effects, and drug effects for marketed therapeutics [Rogers et al., 2012]. The adsim package implement the model to simulate longitudinal ADAS-cog data based upon patient baseline information. Hypothesized drug effects may be specified in a flexible manner, potentially including disease modifying components that are expressed relative to progression rates. Simulation of ADAS-cog trial results is then straightforward for a variety of designs that are typically of interest in stages of development ranging from phase 2a to phase 3.