BAY-85-8501

BAY-85-8501 is a selective, reversible and potent inhibitor of Human Neutrophil Elastase (HNE), with an IC₅₀ of 65 pM. IC50 & Target: IC50: 65 pM (HNE)^[1]. In Vivo: In this model the exogenous HNE noxa is the primary cause of injury and lung hemorrhage. Based on picomolar potency against HNE as well as single digit potency versus MNE, BAY-85-8501 (29) completely prevents the development of lung injury and subsequent inflammation when administered 1 h prior to the HNE noxa. In the 0.01 mg/kg dose group, hemoglobin concentration is already significantly decreased. At a dose of 0.1 mg/kg, a significant effect on neutrophil count is observed. In this setup, efficacy is predominantly driven by potency against HNE (K_i=0.08 nM). As the highly HNE-selective inhibitor BAY 85-8501 has no effect on PPE, BAY-85-8501 could not prevent the primary lung injury in this setup. Nevertheless, BAY-85-8501 could inhibit MNE, the endogenous driver of inflammation and secondary injury, although with decreased potency. Consequently, the effects of BAY-85-8501 on inflammation and secondary injury are weaker at this point, and only observed at 30-fold higher doses. Efficacy is predominantly driven by potency against MNE (K_i=6 nM) in this second setup^[1].