Exploratory Study Evaluating the Relevance of [68Ga]Ga-FAPI-46 for Staging and Identifying Progressing Patients With Transthyretin Cardiac Amyloidosis

Inclusion criteria

• Men or women ≥ 18 years
• Definite ATTR-CM diagnosis based on the 2021 ESC expert consensus
• Written and signed informed consent (obtained on the screening day at the latest and before any investigation)
• Affiliation with French social security system or beneficiary from such system
• Women must meet one of the following criteria at the time of inclusion:

• present a negative pregnancy test (blood test) before the injection of [68Ga]Ga-FAPI-46 and use highly1 effective contraceptive measures for a duration of 6 months after the PET with [68Ga]Ga-FAPI-46;
• or be post-menopausal (aged over 50 with amenorrhea for at least 12 months after stopping all exogenous hormone treatments);
• or (if under 50 years of age) have been in amenorrhea for at least 12 months after stopping exogenous hormone treatments and with luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels corresponding to post-menopausal levels;
• or have undergone irreversible surgical sterilization by hysterectomy, bilateral oophorectomy or bilateral salpingectomy (this operation must be documented);
• Male patients will be required to use male contraception (condoms) for a duration of 3 months after the PET;
• Women partners will be required to use an acceptable2 contraceptive measure (as they will not receive the trial drug) for a duration of 3 months after the PET;
• Male partners will be required to use male contraception (condoms) for a duration of 6 months after the PET.

Exclusion criteria

• History of Myocardial infarction or myocarditis
• Severe aortic stenosis
• Current or prior participation in a clinical trial evaluating a TTR-targeted gene-silencing therapy (TTR= transthyretin) or an amyloid-depleting treatment for cardiac transthyretin amyloidosis (ATTR-CM).
• Any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule
• Women who are pregnant or breastfeeding. A serum pregnancy test will be performed at the start of the study and within 48 hours prior to PET for all female subjects of childbearing potential.
• Patient under guardianship or trusteeship.
• Patient under judicial protection.
• Patient unable to understand spoken or written French
• Known hypersensitivity to gallium-68, to any excipient or derivative