Circulating NEP and NEP Inhibition Study in Heart Failure With Preserved Ejection Fraction

This is a proof of concept single arm study in which 40 subjects with HFpEF will be assigned
to Entresto™ 49/51 mg (sacubitril/valsartan) twice-daily for a total duration of up to 5
weeks of treatment. Blood will be drawn prior to and at completion of treatment. The primary
endpoint measured is change in biomarkers with Entresto™ administration that reflect NEP
activity and myocardial stress (NT pro-ANP, -BNP, -CNP) and drug action (cGMP). This endpoint
has been well validated as a measure of Entresto™ drug response.

Inclusion Criteria

1. Age ≥ 50 years

2. LVEF ≥ 45% assessed by echocardiography, nuclear scan, MRI or left ventriculogram
within the past 24 months

3. Current New York Heart Association (NYHA) class 2-4 symptoms of heart failure (HF)

4. Stable medical therapy for 30 days as defined by:

1. No addition or removal of ACE, ARB, beta-blockers, calcium channel blockers
(CCBs) or aldosterone antagonists

2. No change in dosage of ACE, ARBs, beta-blockers, CCBs or aldosterone antagonists
of more than 100%

5. One of the following within the last 12 months

1. Previous hospitalization for HF with radiographic evidence of pulmonary
congestion (pulmonary venous hypertension, vascular congestion, interstitial
edema, pleural effusion) or

2. Catheterization documented elevated filling pressures at rest (LVEDP≥15 or
PCWP≥20) or with exercise (PCWP≥25) or

3. Elevated NT-proBNP (> 400 pg/ml) or BNP (> 200 pg/ml) or

4. Echo evidence of diastolic dysfunction / elevated filling pressures (at least
two)

i. E/A > 1.5 + decrease in E/A of > 0.5 with valsalva

ii. Deceleration time ≤ 140 ms

iii. Pulmonary vein velocity in systole < diastole (PVs
iv. E/e'≥15

v. Left atrial enlargement (≥ moderate)

vi. Pulmonary artery systolic pressure > 40 mmHg

vii. Evidence of left ventricular hypertrophy

1. LV mass/BSA ≥ 96 (♀) or ≥ 116 (♂) g/m2

2. Relative wall thickness ≥ 0.43 (♂ or ♀) [(IVS+PW)/LVEDD]

3. Posterior wall thickness ≥ 0.9 (♀) or 1.0 (♂) cm

Exclusion Criteria

1. History of hypersensitivity or allergy to ACE inhibitors (ACEIs), ARBs, or NEP
inhibitors

2. Known history of angioedema

3. Previous LVEF < 40% at any time

4. Systolic blood pressure < 100 mmHg or > 180 mmHg

5. Current acute decompensated HF (exacerbation of chronic HF manifested by signs and
symptoms that may require intravenous therapy)

6. Unstable angina, myocardial infarction, stroke, transient ischemic attack, or
cardiovascular surgery or urgent percutaneous coronary intervention (PCI) within 3
months of screening or elective PCI within 30 days of entry

7. Significant valvular stenosis or regurgitation (greater than moderate in severity),
hypertrophic, restrictive or obstructive cardiomyopathy including amyloidosis,
constrictive pericarditis, primary pulmonary hypertension, or biopsy proven active
myocarditis

8. Severe congenital heart disease

9. History of heart transplant or with LV assist device

10. Evidence of severe hepatic disease as determined by any one of the following: history
of hepatic encephalopathy, history of esophageal varices, or history of porto-caval
shunt.

11. Glomerular filtration rate < 20 ml/min/1.73 m2 on most recent clinical laboratories*

12. Serum potassium of > 5.5 mEq/dL on most recent clinical laboratories*

13. Concomitant use of aliskiren in patients with diabetes

14. Currently receiving an investigational drug

15. Inability to comply with planned study procedures

16. Female subject who is pregnant or breastfeeding

- Performed within 90 days of enrollment