MAGNITUDE: A Phase 3 Study of NTLA-2001 in Participants With Transthyretin Amyloidosis With Cardiomyopathy (ATTR-CM)

Inclusion Criteria:

• Documented diagnosis of ATTR amyloidosis with cardiomyopathy

• Medical history of heart failure (HF)

• Symptoms of HF are optimally managed and clinically stable within 28 days prior toadministration of study intervention

• Screening NT-proBNP, a blood marker of HF severity, greater than or equal to 600pg/mL and less than 10,000 pg/mL

Exclusion Criteria:

• New York Heart Association (NYHA) Class IV HF

• Polyneuropathy Disability score of IV (confined to wheelchair or bed)

• Has hepatitis B, hepatitis C or human immunodeficiency virus (HIV) infection

• History of active malignancy within 3 years prior to screening

• RNA silencer therapy (patisiran, inotersen and/or eplontersen) within 12 monthsprior to dosing. Any prior vutrisiran use is not allowed

• Initiation of tafamidis or acoramidis within 56 days prior to study dosing

• Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73m^2

• Liver failure

• Uncontrolled blood pressure

• Unable or unwilling to take vitamin A supplementation for the duration of the study