This extension study begins after completion of the previous study called AG10-501 (also known as ACT-EARLY). Entry into this extension study must occur within 60 days of finishing the previous study.

Before any procedures begin, a signed informed consent form must be provided, confirming the willingness to participate in this extension study.

The diagnosis of transthyretin amyloid cardiomyopathy (a condition where abnormal protein deposits affect the heart) must have been confirmed during the previous study.

If female and capable of becoming pregnant, a highly effective method of contraception must be used starting from the first day of the study and continuing for 30 days after the last dose of the study medication.

If male and sexually active with a female partner of childbearing potential, a double-barrier method of birth control must be used during the study and for 30 days after the last dose of the study medication. Sperm donation must be avoided for at least 30 days after the last dose.

The study medication is called acoramidis (also referred to as AG10). The active ingredient is acoramidis hydrochloride.

The medication is provided as a tablet that is taken by mouth.

The study is designed as an open-label study, which means both the patient and the medical team will know that acoramidis is being administered.

The specific dosage, frequency, and exact duration of treatment are determined by the study protocol and will be explained by the study team.

Throughout the study, regular visits will be scheduled to monitor safety and how well the medication is tolerated.

During these visits, physical examinations will be performed to check for any abnormal findings that may be clinically relevant.

Vital signs (such as blood pressure, heart rate, and temperature) will be measured and reviewed for any abnormal changes.

Electrocardiograms (ECG, a test that records the electrical activity of the heart) will be performed to detect any abnormal heart rhythm or conduction problems.

Laboratory tests will be conducted using blood samples to check for changes in safety parameters that may require attention.

Any adverse events (unwanted or harmful reactions) and serious adverse events (severe reactions that may require hospitalization or are life-threatening) will be recorded and evaluated.

Echocardiography (an ultrasound test of the heart) will be performed at scheduled intervals to measure changes in the structure and function of the heart muscle.

Strain parameters (measurements that show how well the heart muscle is contracting) will also be assessed during these imaging tests.

Blood tests will measure levels of NT-proBNP (a substance released when the heart is under stress) and high-sensitivity troponin I (a marker of heart muscle damage). Changes in these levels from the beginning of the study will be tracked.

The development of symptomatic disease (when symptoms of the heart condition become noticeable) will be monitored throughout the study.

Any episodes of heart failure will be recorded, including hospitalizations or unplanned visits related to worsening heart function.

New heart rhythm problems (arrhythmias) will be monitored, including new occurrences of irregular heartbeats such as atrial fibrillation or atrial flutter, dangerous fast heartbeats from the lower chambers of the heart, or problems with the heart’s electrical conduction that may require a pacemaker.

New diagnoses or surgeries related to conditions that may be associated with the disease will be tracked. These include carpal tunnel syndrome (compression of a nerve in the wrist), tendon ruptures, spinal narrowing, joint problems in the hips or knees, finger stiffness, or shoulder joint issues.

Hospitalizations related to heart and blood vessel problems, as well as deaths from any cause or from heart-related causes, will be recorded.

The extension study is planned to continue until approximately April 2032.

Participation may be discontinued earlier if adverse events occur that require stopping the medication, or if withdrawal from the study is requested.

After the last dose of study medication, contraception requirements must continue for an additional 30 days.