Clinical Trials

Inclusion Criteria:

- Male or female.

- Age greater than or equal to (≥) 18 to less than (<) 85 years at the time of signing
informed consent.

- Have an established diagnosis of Transthyretin amyloid cardiomyopathy (ATTR CM) with
either wild-type transhyretin (TTR) or hereditary transthyretin (TTR) genotype as per
local standards.

- Expected to be on stable doses of cardiovascular medical therapy 6 weeks prior to the
randomisation visit.

- Known end-diastolic interventricular septal wall thickness greater than or equal to
(≥) 12 millimeters (mm).

- Presently classified as New York Heart Association (NYHA) Class II-III.

- N-terminal-pro brain natriuretic peptide (NT-proBNP) concentration greater than or
equal to (≥) 650 picograms per milliliter (pg/mL) in sinus cardiac rhythm and greater
than (>) 1000 pg/mL in atrial fibrillation at screening.

- Completed greater than or equal to (≥) 150 meters to less than or equal to (≤) 450
meters on the 6-minute walk test (MWT) at screening.

- Estimated glomerular filtration rate (eGFR) greater than or equal to (≥) 25
milliliter per minute per 1.73 meter square (mL/min/1.73 m^2) at screening.

Exclusion Criteria:

- Cardiomyopathy not primarily caused by transthyretin amyloid cardiomyopathy
transthyretin amyloid cardiomyopathy (ATTR CM), for example, cardiomyopathy due to
hypertension, valvular heart disease, or ischemic heart disease.

- A prior solid organ transplant.

- Planned solid organ transplant during the study.

- Presence or history of malignant neoplasm (other than basal or squamous cell skin
cancer, insitu carcinomas of the cervix, or in-situ/high grade prostatic
intraepithelial neoplasia (PIN) or low-grade prostate cancer) within 5 years before
screening.

- Current treatment with calcium channel blockers with conduction system effects
(example [e.g.], verapamil, diltiazem). The use of dihydropyridine calcium channel
blockers is allowed. The use of digoxin will only be allowed if required for
management of atrial fibrillation with rapid ventricular response.

- Acute coronary syndrome, unstable angina, stroke, transient ischemic attack (TIA),
coronary revascularization, cardiac valve repair, or major surgery within 3 months of
screening.

- Body weight > 120 kilogram (kg) (264.6 pounds [lb]) at screening.

- History of contrast allergy or adverse reactions to gadolinium-containing agents.

Eligibility last updated 7/14/22. Questions regarding updates should be directed to the study team contact.