AHU-377 is an inhibitor of neprilysin with IC50 value of 5nM [1].

AHU-377 and the angiotensin II AT1 receptor antagonist valsartan compose LCZ696 in a 1:1 molar ratio. LCZ696 is an angiotensin receptor neprilysin inhibitor. It can reduce blood pressure and may be a novel drug for the treatment of heart failure. AHU-377 is a prodrug, it can be converted by enzymatic cleavage of the ethyl ester into the active form LBQ657. It is reported that AHU-377(30 and 100 mg/kg, PO) can cause antihypertensive effect in a dose-dependent manner in Dahl-SS rats. But in the DOCA-salt hypertensive rats, it shows a weak reduction [2, 3].

References:
[1] Ksander GM, Ghai RD, deJesus R, Diefenbacher CG, Yuan A, Berry C, Sakane Y, Trapani A. Dicarboxylic acid dipeptide neutral endopeptidase inhibitors. J Med Chem. 1995 May 12;38(10):1689-700.
[2] Voors AA, Dorhout B, van der Meer P. The potential role of valsartan + AHU377 ( LCZ696 ) in the treatment of heart failure. Expert Opin Investig Drugs. 2013 Aug;22(8):1041-7.
[3] Laxminarayan G Hegde, Cecile Yu, Cheruvu Madhavi et al. Comparative efficacy of AHU-377, a potent neprilysin inhibitor, in two rat models of volume-dependent hypertension. BMC Pharmacology 2011, 11(Suppl 1):P33.