This trial was a randomized, double-blind, placebo-controlled, parallel group, adaptive design with variable treatment duration planned in cognitively unimpaired participants aged 60 to 75 years, with at least one apolipoprotein E allele (APOE4), (homozygotes (HMs) or heterozygotes (HTs)) and, if HTs, with evidence of elevated brain amyloid. The participants were randomized to either CNP520 50 mg, CNP520 15 mg or placebo a 2:1:2 ratio and was stratified based on amyloid status. The planned treatment period of 5 to 8 years was not achieved due to early study termination.