Sacubitril hemicalcium salt (AHU377 calcium salt) is a potent NEP inhibitor with an IC50 of 5 nM. Sacubitril hemicalcium salt is a component of the heart failure medicine LCZ696. Sacubitril hemicalcium salt is a prodrug of LBQ657, which is an inhibitor of the zinc metallopeptidase neprilysin. Neprilysin degrades a variety of vasoactive peptides such as atrial and brain natriuretic peptide, bradykinin, adrenomedullin, and endothelin-1. Inhibition of neprilysin leads to an increased level of these peptides and, thus, antihypertensive effects. Formulations containing AHU377 in combination with the angiotensin II receptor antagonist valsartan are used to treat hypertension and heart failure.

NEP:5 nM

AHU377 is converted by enzymatic cleavage of the ethyl ester into the active neprilysin inhibiting metabolite LBQ657. The inactive NEPi precursor, AHU377, does not inhibit collagen accumulation in fibroblasts nor cardiac myocyte hypertrophy. In cardiac fibroblasts, the active NEPi LBQ657 had no discernible effects. In contrast, LBQ657 modestly inhibits cardiac myocyte hypertrophy.

In humans, AHU377 (tmax 0.5-1.1 h) are absorbed quickly. AHU377 is converted rapidly into LBQ657 with its tmax being reached in 1.9-3.5 h. Mean t1/2 values for the biologically active LBQ657 is 9.9-11.1 h.In vehicle-treated dogs, ANF increases urinary sodium excretion from 17.3±3.6 to 199.5±18.4 pequivkglmin. This effect is potentiated significantly in animals which receive AHU377.