A Study of Donanemab (LY3002813) in Participants With Early Alzheimer's Disease (TRAILBLAZER-ALZ 2)

The reason for this study is to see how safe and effective the study drug donanemab is in participants with early Alzheimer's disease. Additional participants will be enrolled to an addendum safety cohort. The participants will be administered open-label donanemab. Trial participants who were dosed with donanemab in the main study will be enrolled to a 3-year follow up addendum. No study drug will be administered during this follow up.

TRAILBLAZER-ALZ 2 is a Phase 3, double-blind, placebo-controlled study to evaluate the safety and efficacy of N3pG antibody (donanemab) in participants with early symptomatic AD (prodromal AD and mild dementia due to AD) with the presence of brain amyloid and tau pathology. Following the double-blind 76-week main study period, a double-blind 78-week long-term extension period is added to further evaluate donanemab efficacy and safety over time. Participants from the addendum safety cohort are not eligible for the extension period. Participants previously dosed with donanemab in the main study will be monitored to track re-accumulation of amyloid plaque for 3 years.

Inclusion Criteria: * Gradual and progressive change in memory function reported by participants or informants for ≥ 6 months * MMSE score of 20 to 28 (inclusive) at baseline * Meet 18F flortaucipir PET scan (central read) criteria - does not apply to safety cohort * Meet 18F florbetapir PET scan (central read) criteria * Have a study partner who will provide written informed consent to participate Exclusion Criteria: * Contraindication to MRI or PET scans * Current treatment with immunoglobulin G (IgG) therapy