Dose-Finding Study To Evaluate Safety, Tolerability, and Efficacy of E2609 in Participants With Mild Cognitive Impairment Due to Alzheimer's Disease (Prodromal Alzheimer's Disease) and Mild to Moderate Dementia Due to Alzheimer's Disease

Each participant will receive 2 tablets, which when combined will make up the required doses of E2609 or placebo, to be administered orally once per day (QD) with food.

Each participant will receive 2 tablets, which when combined will make up the required doses of E2609 or placebo, to be administered orally once per day (QD) with food.