This phase 1b/2 study will be in 2 parts. Study Part 1 will involve subjects with prodromal Alzheimer's disease. Study Part 2 will involve subjects with Down syndrome.
The purpose of this study is to assess the safety, tolerability, immunogenicity and pharmacodynamic effects of ACI-24.060 in subjects with prodromal Alzheimer's disease and in non-demented adults with Down syndrome.