The purpose of this randomised, double-blind, placebo-controlled, multicenter study is to evaluate the efficacy and safety of concomitant use of eplontersen and ALXN2220 compared with eplontersen and placebo in adult participants with Transthyretin-mediated amyloid cardiomyopathy (ATTR-CM).
Participant must be ≥ 18 years to ≤ 85 years at the time of signing the informed consent.
Endomyocardial biopsy with confirmatory TTR amyloid typing OR
Grade 2 or 3 cardiac uptake on 99mTc scintigraphy in the absence of monoclonal gammopathy OR
Grade 2 or 3 cardiac uptake on 99mTc scintigraphy AND confirmatory TTR amyloid typing in the presence of monoclonal gammopathy.
Known leptomeningeal amyloidosis.
Known light chain (AL) or secondary (amyloid A) amyloidosis, or any other form of systemic amyloidosis.
Cardiomyopathy not primarily caused by ATTR-CM, for example, cardiomyopathy primarily due to hypertension, valvular heart disease, or ischaemic heart disease per Investigator's assessment.
Acute coronary syndrome, unstable angina, stroke, transient ischaemic attack, coronary revascularisation, cardiac device implantation, cardiac valve repair, or major surgery within 12 weeks of Screening.