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

Inclusion Criteria (sporadic CAA patients):

• Is 50 years or older

• Has probable CAA per the Boston Criteria Version 2.0

Inclusion Criteria (Dutch-type CAA patients):

• Is 30 years or older

• Has known E693Q amyloid precursor protein (APP) gene mutation for Dutch-type CAA

Exclusion Criteria:

• Moderate or severe stage Alzheimer's disease (AD) or significant cognitiveimpairment (CI)

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

• Has alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >3×upperlimit 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

Note: other protocol defined inclusion / exclusion criteria apply