A Study of Different Donanemab (LY3002813) Dosing Regimens in Adults With Early Alzheimer's Disease (TRAILBLAZER-ALZ 6)

This study will investigate different donanemab dosing regimens and their effect on the frequency and severity of ARIA-E in adults with early symptomatic Alzheimer's disease (AD) and explore participant characteristics that might predict risk of ARIA. Approximately 375 additional participants will be enrolled in addendum 2. Addendum 3 includes a subset of participants from the main study to receive a single dose. The study will last approximately 91 weeks and include up to 26 visits in the main study.

Inclusion Criteria: * Gradual and progressive change in memory function reported by the participant or informant for ≥6 months. * A mini mental state examination (MMSE) score of 20 to 28 (inclusive) at screening. * Have an amyloid PET scan result from central read, consistent with the presence of amyloid pathology. Exclusion Criteria: * Have significant neurological disease affecting the central nervous system other than AD, that may affect cognition or ability to complete the study, including but not limited to, other dementias, serious infection of the brain, Parkinson's disease, multiple concussions, or epilepsy or recurrent seizures, except febrile childhood seizures. * Has current serious or unstable illnesses including cardiovascular, hepatic, renal, gastroenterologic, respiratory, endocrinologic, neurologic (other than AD), psychiatric, immunologic, or hematologic disease and other conditions that, in the investigator's opinion, could interfere with the analyses in this study. * A life expectancy of \