An Open-Label Extension Study of Fazirsiran

You likely can't join if

• 1. The participant is likely to require major surgery. Major surgery typically requires at least 1 night in the hospital. Examples include laparoscopic surgery (except cholecystectomy and tubal ligation); GI tract surgery including 1 or more segments of the colon or terminal ileum; open resection of organs; large joint replacements; mastectomy with reconstruction; and spine, thoracic, vascular, or intracranial surgery. Note: participants who are awaiting a liver transplant may roll over into this study and receive treatment until the last regularly scheduled study visit, or 4 weeks before the procedure, whichever occurs later. In an urgent situation, a transplant should not be withheld due to timing of last dose. 2. The participant has evidence of other forms of chronic liver diseases, including viral hepatitis B or C, primary biliary cholangitis, primary sclerosing cholangitis, Wilson disease, alcoholic hepatitis, hemochromatosis, liver cancer, history of biliary diversion, or autoimmune hepatitis. 3. The participant has abnormal finding(s) of clinical relevance during the evaluation before the first study dosing that, in the opinion of the investigator, could adversely impact participant safety during the study or adversely impact study results. 4. The participant had major protocol deviation(s) (as determined by the sponsor) in AROAAT2001 or AROAAT2002 that would affect the conduct of this study. 5. The participant permanently discontinued investigational product because of an AE, adjudicated as related to the study intervention, in AROAAT2001 or AROAAT2002. 6. Female participants who became pregnant during Study AROAAT2001 or AROAAT2002, female participants who are lactating or planning to become pregnant during the study period; or males or female participants of childbearing potential not agreeing to continue using appropriate contraception methods (that is, highly effective methods for female and medically appropriate methods for male study participants) through the conclusion of study participation.