Adam Fleisher, MD, MAS, Eli Lilly and Company, Indianapolis, IN, explains the importance of moving towards pathologically defined cohorts in Alzheimer’s disease clinical trials. Alzheimer’s disease is a highly heterogeneous disorder, with substantial variability in etiology, genotype, clinical presentation, and pathological patterns. While the long-term goal is to develop efficacious treatments for patients across this spectrum, refining populations is of critical importance in early stages of drug development. Pathologically defined cohorts focus in on patients that are most likely to benefit from experimental therapies and increase the power of a trial to gather the proof-of-concept evidence necessary for continued drug development. This interview took place at the AD/PD™ 2022 Conference in Barcelona, Spain.