AHEAD 3-45 Study: A Study to Evaluate Efficacy and Safety of Treatment With Lecanemab in Participants With Preclinical Alzheimer's Disease and Elevated Amyloid and Also in Participants With Early Preclinical Alzheimer's Disease and Intermediate Amyloid

This study is looking at how well a drug called lecanemab works to help people with early signs of Alzheimer's, a brain disease affecting memory. Alzheimer's involves an increase in a protein called amyloid in the brain, making it hard for people to remember things. In this study, lecanemab is compared to a placebo, which is a harmless pill that doesn't affect the body. Scientists want to see if lecanemab can improve memory and reduce amyloid over about 4 years (216 weeks). Participants must be between 55 and 80 years old and have certain levels of amyloid in their brains. They need a study partner, like a friend or family member, to help them during the study. People who are pregnant, have certain health issues, or take certain medicines cannot participate. The study has an extension phase for those who completed the initial phase.

• Study lasts for 4 years with regular check-ups.
• Participants will not know if they receive lecanemab or placebo.
• Potential side effects and risks are involved.