**A Clinical Trial of Trontinemab for Alzheimer's Disease** This study is testing a new drug, *trontinemab*, to see if it helps people with early symptoms of Alzheimer's disease, a brain disorder that affects memory and thinking. Participants must be able to complete tasks and tests, possibly with help from a "study partner." The study checks for Alzheimer's using a special brain scan called *amyloid PET* or a test of spinal fluid. People with other brain issues or serious health problems can't join. **Key Points:** - The study requires multiple visits for tests like MRI scans and memory assessments. - Participants need to have a "study partner" to help with the study requirements. - Safety is important, so people with unstable health conditions can't join. Participants should have a history of gradual memory decline over the past year and a specific score on memory tests. This study is for people who are still in the early stages of Alzheimer’s, not for those with other brain conditions.