Biomarker substudies
Participants were assigned to either a tau PET substudy (based on the geographical availability of the tau PET radioligand) or a CSF substudy. Participants assigned to the tau PET substudy were provided the option to also participate in the CSF substudy (participants enrolled in both substudies were considered enrolled in the tau PET substudy for randomization purposes).PET imaging was performed using [Participants in the tau PET substudy underwent tau PET scans at baseline, 52 weeks and 78 weeks. Participants in the CSF substudy had CSF samples collected at baseline, 48 weeks and 76 weeks. A small subset of participants (