Cardiac Magnetic Resonance and Echocardiography Study With Acoramidis

An Open-Label Study to Investigate the Long-Term Effects of Acoramidis on Cardiac Function, Structure and Cardiac Amyloid Burden in Participants With Transthyretin Amyloid Cardiomyopathy (ATTR-CM)

The study aims to evaluate the effect of acoramidis on cardiac functional and structural improvement in participants with ATTR-CM.

Study AG10-404 is an open-label study to investigate the long-term effects of acoramidis on cardiac functional and structural improvement, and the effects on cardiac amyloid burden in participants with ATTR-CM using two types of imaging, cardiac MRI and echocardiograms to track changes in heart structure and amyloid buildup over time.

Up to approximately 150 participants (ages 18-80) will be enrolled. Participants will receive study drug (712 mg equivalent to 800 mg of acoramidis hydrochloride) orally twice daily from Day 1 through Month 36. The study duration for an individual participant is approximately 38 months, including up to 45 days for screening, 36 months for open-label treatment and 1 month follow-up after the last dose of study drug. In-clinic visits will occur at Day 1, Day 28, Month 6, and every 6 months up to Month 36. Phone visits will occur at Month 3 and every 6 months thereafter up to Month 33. Participants will be followed throughout their participation in this study and for 30 days (+7 days) after the last dose of study drug.

Key Inclusion Criteria:

• Participants aged 18 to 80
• Confirmed diagnosis of ATTR-CM requiring targeted therapy
• At screening: New York Heart Association (NYHA) Class I/II; estimated glomerular filtration rate (eGFR) ≥40 mL/min/1.73m2; left ventricular ejection fraction (LVEF) >35%; left ventricular (LV) wall thickness ≥12 mm.
• Heart failure condition has been clinically stable for at least 6 weeks prior to screening.

Key Exclusion Criteria:

• Current or planned implantation of a cardiac implantable electronic device (eg, pacemaker, implantable cardiac defibrillator).
• Acute myocardial infarction, acute coronary syndrome or coronary revascularization, or experienced stroke or transient ischemic attack within 90 days prior to screening.
• Hemodynamic instability.
• Likely to undergo heart transplantation within 12 months from screening.
• Confirmed diagnosis of AL amyloidosis at screening.
• At screening: NYHA Class III/IV; National Amyloidosis Center (NAC) Stage 3.
• Prior or current treatment with acoramidis.