An Extension Study to Assess Long-Term Safety of Eplontersen in Adults With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM)

To join this study, you must be an adult, aged 18 years or older, and have already successfully completed a previous study involving eplontersen (either the ION-682884-CS2 study or the ISIS 420915-CS101 study). Your doctor must also agree that this study is suitable for you and be willing to treat you with eplontersen as part of the study.

You also need to be willing to take vitamin A supplements every day, as instructed by the study team. Both your doctor and the study organisers need to agree that you are a good fit for the study and that participating won't be harmful to your health.

You cannot join this study if you stopped taking the study medication permanently during the previous study you were in. Also, if you have any new health problems, or if an existing condition has gotten worse, and your doctor thinks this would make the study unsuitable or difficult for you, then you wouldn't be able to take part.

If you join this study, you will receive doses of eplontersen once every four weeks. You will also need to take recommended daily doses of vitamin A supplements. This treatment will continue for up to three years (36 months), or until eplontersen becomes available as a standard treatment in your country, whichever happens first.

Throughout the study, you will have regular visits with the study team. These visits will involve various tests and checks to monitor your health and how you are responding to the medication. These might include physical examinations, blood tests, and other assessments to track the safety and effects of eplontersen. The study team will tell you exactly how often these visits will be and what they will involve. They will also let you know about any follow-up appointments after you finish taking the medication.