Could a drug clear Alzheimer's plaques in people with down syndrome?

This study tests whether donanemab, given as an IV infusion every 4 weeks, can safely lower amyloid plaques in the brains of 60 adults aged 35–50 with Down syndrome. Participants receive either donanemab or a placebo for 12 months, followed by a 12-month extension where everyone gets the real drug if needed. The goal is to see if reducing amyloid can slow memory decline, but this is not a cure—ongoing management is expected.