Moderate or severe stage Alzheimer's disease (AD) or significant cognitive impairment (CI)

Has a history of previous clinical intracerebral hemorrhage (ICH) with onset less than 90 days prior to anticipated randomization in the study

Has alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \>3×upper limit of normal (ULN) at Screening

Has estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73m\^2 at Screening

Has recently received an investigational agent

Has had treatment with amyloid-targeting antibody

A Phase 2 Trial of ALN-APP in Patients With Cerebral Amyloid Angiopathy