Data and Code for: AI-guided patient stratification improves outcomes and efficiency of Alzheimer’s Disease clinical trial. Data from a clinical trial on Alzheimer's disease (for details on the data collection and trial protocol, see: Wessels, A. M. et al. Efficacy and Safety of Lanabecestat for Treatment of Early and Mild Alzheimer Disease: The AMARANTH and DAYBREAK-ALZ Randomized Clinical Trials. JAMA Neurol 77, 199–209, 2020) were re-analysed using machine learning tools. More precise patient stratification based on biomarker data at baseline showed differences in primary outcomes (cognitive tests) between patient groups.