Pharmacokinetics and safety of cavosonstat (N91115) in healthy and cystic fibrosis adults homozygous for F508DEL-CFTR

Background: Cavosonstat (N91115), an orally bioavailable inhibitor of S-nitrosoglutathione reductase, promotes cystic fibrosis transmembrane conductance regulator (CFTR) maturation and plasma membrane stability, with a mechanism of action complementary to CFTR correctors and potentiators. Methods: A Phase I program evaluated pharmacokinetics, drug-drug interactions and safety of cavosonstat in healthy and cystic fibrosis (CF) subjects homozygous for F508de1-CFTR. Exploratory outcomes included changes in sweat chloride in CF subjects. Results: Cavosonstat was rapidly absorbed and demonstrated linear and predictable pharmacokinetics. Exposure was unaffected by a high-fat meal or rifampin-mediated effects on drug metabolism and transport. Cavosonstat was well tolerated, with no dose-limiting toxicities or significant safety findings. At the highest dose, significant reductions from baseline in sweat chloride were observed (-4.1 mmol/L; P = 0.032) at day 28. Conclusions: The favorable safety and clinical profile warrant further study of cavosonstat in CF. (C) 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.