A Study to Evaluate Mivelsiran in Adult Participants With Early-Stage Down Syndrome-Associated Alzheimer's Disease (DS-AD)

The purpose of the study is to evaluate the effect of mivelsiran in adult participants with early-stage DS-AD and to characterize the safety, tolerability, and pharmacodynamics (PD) of mivelsiran. The study will be conducted over 2 periods: a 24-month double-blind period and an optional 12-month open-label treatment extension (OLE) period. The estimated duration of study participation, inclusive of screening, treatment, and additional safety follow-up, is up to 39 months.

NCT Number	NCT07636811
Lead Sponsor	Alnylam Pharmaceuticals
Conditions	Down Syndrome-Associated Alzheimer's Disease (DS-AD)
Enrollment	58 participants
Start Date	2026-07-01
Primary Completion	2030-05-18 (estimated)
Study Completion	2031-07-23 (estimated)
Updated on ClinicalTrials.gov	2026-06-09