Study to Evaluate Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of LCZ696 Followed by a 52-week Study of LCZ696 Compared With Enalapril in Pediatric Patients With Heart Failure

Key Inclusion Criteria:

- Chronic heart failure resulting from left ventricular systolic dysfunction, and
receiving chronic HF therapy (if not newly diagnosed)

- NYHA classification II-IV (older children: 6 to <18 years old) or Ross CHF
classification II-IV (younger children: < 6 years old)

- Systemic left ventricular ejection fraction ≤ 40% or fractional shortening ≤20%

- For Part 1 study: Patients must be treated with an ACEI or ARB prior to screening.
Patients in Group 1 and 2 must be currently treated with the dose equivalent of at
least enalapril 0.2 mg/kg prior to the LCZ696 3.1 mg/kg administration. Group 3
patients will participate in LCZ696 0.8 mg/kg and not LCZ696 3.1 mg/kg.

- Biventricular physiology with systemic left ventricle

Key Exclusion Criteria:

- Patient with single ventricle or systemic right ventricle

- Patients listed for heart transplantation (as United Network for Organ Sharing status
1A) or hospitalized waiting for transplant (while on inotropes or with ventricular
assist device)

- Sustained or symptomatic dysrhythmias uncontrolled with drug or device therapy

- Patients that have had cardiovascular surgery or percutaneous intervention to palliate
or correct congenital cardiovascular malformations within 3 months of the screening
visit. Patients anticipated to undergo corrective heart surgery during the 12 months
after entry into Part 2

- Patients with unoperated obstructive or severe regurgitant valvular (aortic,
pulmonary, or tricuspid) disease, or significant systemic ventricular outflow
obstruction or aortic arch obstruction

- Patients with restrictive or hypertrophic cardiomyopathy

- Active myocarditis

- Renal vascular hypertension (including renal artery stenosis)

- Moderate-to severe obstructive pulmonary disease

- Serum potassium > 5.3 mmol/L

- History of angioedema

- Allergy or hypersensitivity to ACEI / ARB