Background:

BAY-678 is an orally active, potent and selective inhibitor of human neutrophil elastase (HNE) [1][2].

Human neutrophil elastase (HNE) is a member of the chymotrypsin-like family of serine proteases and is stored in the neutrophil cytoplasm. HNE is a key protease for matrix degradation and high HNE activity is occured in inflammatory diseases. So HNE is a potential target for the treatment of pulmonary diseases such as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), bronchiectasis (BE), and pulmonary hypertension (PH) [1].

BAY-678 is an orally active, potent and selective inhibitor of human neutrophil elastase (HNE). BAY-678 inhibited HNE reversibly with IC50 value of 20 nM and Ki value of 15 nM. BAY-678 showed no inhibition against 21 related serine proteases, up to a concentration of 30 μM [1].

In rats, BAY-678 showed medium clearance with t1/2 of 1.3h [1].

参考文献:
[1].  von Nussbaum F, Li VM, Allerheiligen S, et al. Freezing the Bioactive Conformation to Boost Potency: The Identification of BAY 85-8501, a Selective and Potent Inhibitor of Human Neutrophil Elastase for Pulmonary Diseases. ChemMedChem. 2015 Jul;10(7):1163-73.
[2].  von Nussbaum F, Li VM, Meibom D, et al. Potent and Selective Human Neutrophil Elastase Inhibitors with Novel Equatorial Ring Topology: in vivo Efficacy of the Polar Pyrimidopyridazine BAY-8040 in a Pulmonary Arterial Hypertension Rat Model. ChemMedChem. 2016 Jan 19;11(2):199-206.