Sacubitril is a prodrug neprilysin inhibitor used in combination with valsartan (sold under the brand name Entresto among others) to reduce the risk of cardiovascular events in patients with chronic heart failure (NYHA Class II-IV) and reduced ejection fraction. It was approved under the FDA's priority review process for use in heart failure on July 7, 2015. Sacubitril's active metabolite, LBQ657 inhibits neprilysin, a neutral endopeptidase that would typically cleave natiuretic peptides such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and c-type natriuretic peptide (CNP). ANP and BNP are released under atrial and ventricle stress, which activate downstream receptors leading to vasodilation, natriuresis and diuresis. Under normal conditions, neprilysin breaks down other vasodilating peptides and also vasoconstrictors such as angiotensin I and II, endothelin-1 and peptide amyloid beta-protein. Inhibition of neprilysin therefore leads to reduced breakdown and increased concentration of endogenous natriuretic peptides in addition to increased levels of vasoconstricting hormones such as angiotensin II.