Maridebart Cafraglutide in Heart Failure With Preserved or Mildly Reduced Ejection Fraction and Obesity

Inclusion Criteria: * Age ≥ 18 years at the time of informed consent. * BMI ≥ 30.0 kg/m\^2 at the time of randomization. * HF diagnosed for at least 30 days with New York Heart Association (NYHA) Class II-IV at the time of informed consent. * Managed with HF standard of care therapies. * Left ventricular ejection fraction (LVEF) of \> 40% within 12 months from the beginning of screening. * Elevated NT-proBNP. * Participants must have at least one of the following: 1. Structural heart disease within 12 months prior to screening OR 2. Documented hospitalization with a primary diagnosis of decompensated HF which required IV loop diuretic treatment \> 30 days and \< 12 months prior to randomization OR 3. Evidence of elevated filling pressures within 12 months before randomization. Exclusion Criteria: * History of any of the following within 60 days prior to or during screening: Type I (spontaneous) MI, valvular replacement or repair, coronary revascularization, coronary artery bypass graft surgery or other major cardiovascular surgery, stroke. * HF due to: hypertrophic cardiomyopathy, infiltrative cardiomyopathy, active myocarditis, constrictive pericarditis, cardiac tamponade, arrhythmogenic right ventricular or left ventricular cardiomyopathy/dysplasia, uncorrected primary valvular heart disease, clinically significant congenital heart disease. * Any lifetime history of LVEF ≤ 40%. * Hospitalized with acute decompensated HF at the time of or during the screening period. * Type 1 diabetes mellitus, or any type of diabetes with the exception of T2DM or history of gestational diabetes. * For participants with a prior diagnosis of T2DM (including those diagnosed during screening): 1. HbA1c \> 10.0% (86 mmol/mol) at screening 2. Uncontrolled diabetes requiring immediate therapy 3. History of diabetic ketoacidosis or hyperosmolar state/coma within 12 months before randomization 4. One or more episodes of severe hypoglycemia within 6 months before randomization and/or history of hypoglycemia unawareness 5. History or presence of either proliferative diabetic retinopathy, or diabetic maculopathy, or severe non-proliferative diabetic retinopathy; or currently receiving or planning to receive treatment for diabetic retinopathy and/or macular edema. * SBP ≥ 180 mmHg during the screening period, or on three or more blood pressure-lowering drugs with a SBP \> 160 mmHg during the screening period. * History of chronic pancreatitis or acute pancreatitis in the 180 days before screening or during the screening period. * Any personal lifetime history of, or family history(first-degree relative\[s\]) of medullary thyroid carcinoma or MEN-2. * eGFR \< 20 mL/min/1.73 m\^2 (CKD-EPI creatinine (Cr)-cystatin C equation) or receiving dialysis at screening. * Calcitonin ≥ 50 ng/L (pg/mL) at screening. * Acute or chronic hepatitis. * Any of the following psychiatric history: 1. History of unstable major depressive disorder or other severe psychiatric disorder within 2 years prior to screening or during the screening period 2. Lifetime history of suicide attempt 3. History of non-suicidal self-injury within 5 years prior to screening or during the screening period. * History of any other condition that, in the opinion of the investigator, may preclude the participant from following the protocol and completing the trial. * Use of any glucagon-like peptide 1 receptor agonist (GLP-1 RA), glucose-dependent insulinotropic polypeptide (GIP) agonists or antagonists, or amylin analogs within 90 days prior to or during the screening period or planned use during the conduct of the trial.