The Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU) has completed the first stage of participant enrollment in the first Alzheimer’s prevention trial for autosomal dominant Alzheimer’s disease (ADAD), also referred to as early-onset Alzheimer’s disease. The goal of the first stage of the study is to determine the biomarker and cognitive effects of two different drugs targeting amyloid beta. With this enrollment milestone, first biomarker results may be available at the end of 2016 with the final cognitive endpoint data expected in late 2019.