• Male or female subjects aged ≥18 and ≤80 years old at the time of signing informed consent.

• Diagnosis of transthyretin cardiac amyloidosis (ATTR-CM) based on the 2021 Chinese Expert Consensus on the Diagnosis and Treatment of Transthyretin Cardiac Amyloidosis, the 2021 European Society of Cardiology (ESC) guidelines, and the 2023 American College of Cardiology (ACC) guidelines, including hereditary ATTR cardiac amyloidosis (ATTRv-CM) and wild-type ATTR cardiac amyloidosis (ATTRwt-CM); and relevant indicators meet the following criteria:

‣ 1 New York Heart Association (NYHA) functional classification of I to III; 2.2 6-minute walk test (6-MWT) ≥ 150 meters at screening; 2.3 Echocardiogram evidence of cardiac involvement: left ventricular wall thickness (interventricular septum and/or posterior wall thickness ≥12 mm); 2.4 Brain natriuretic peptide N-terminal prohormone (NT-proBNP) \< 2000 pg/mL at screening; 2.5 Receiving stable and standardized cardiovascular medication treatment.

• Body weight must not be less than 40 kg at screening.

• Subjects must meet the following laboratory criteria at screening:

‣ 1 Aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (except for Gilbert's syndrome), International Normalized Ratio (INR) \< upper limit of normal (ULN); 4.2 Subjects with a history of Gilbert's syndrome have a total bilirubin not exceeding twice the upper limit of normal (ULN) during the screening period; 4.3 Estimated glomerular filtration rate (eGFR) \> 45 mL/min/1.73m\^2 at screening; 4.4 Platelet count ≥ 100 × 10\^9/L; 4.5 Coagulation function at screening: fibrinogen, activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) are all within the normal range; 4.6 Low-density lipoprotein (LDL) cholesterol \< 200 mg/dL; 4.7 Vitamin A level ≥ lower limit of normal (LLN); 4.8 Vitamin B12 level ≥ lower limit of normal (LLN).

• Acceptance of ATTR-CM medication treatment:

‣ 1 Unable to receive existing ATTR-CM-related medication due to regional medical resources, health policies, personal financial capacity, or drug intolerance; 5.2 Despite receiving at least 6 months of ATTR-CM medication treatment, the subject's ATTR-CM condition still progresses (meeting at least one of the following): Increased hospitalizations related to heart failure; Worsening of NYHA classification; 6-MWT decrease of at least 30 meters; NT-proBNP increase by 30%; Troponin increase by 30%; Echocardiogram indicates: increase in left ventricular wall thickness by 2 mm, or decrease in left ventricular ejection fraction by ≥5%, or decrease in global longitudinal strain by ≥1%, or decrease in stroke volume by ≥5%, or worsening diastolic function; New conduction block on electrocardiogram.

• No intake of alcohol from the start of the screening period to 28 days after receiving the trial treatment medication.

• Female subjects must be postmenopausal for at least one year, or have undergone hysterectomy.

• Male subjects and their partners must use highly effective contraceptive measures recognized by the doctor throughout the trial process and for at least 5 months after the trial ends.

• Male subjects must not donate sperm within 84 days after receiving study medication.

⁃ Voluntary signing of informed consent.