Design, synthesis and biological activity of original pyrazolo-pyrido-diazepine, -pyrazine and -oxazine dione derivatives as novel dual Nox4/Nox1 inhibitors.

Pyrazolo-pyrido-diazepine, -pyrazine and -oxazine dione derivatives are new chemical entities with good and attractive druglikeness properties. A series of pyrazolo-pyrido-diazepine dione analogs demonstrated to be particularly amenable to lead optimization through a couple of cycles in order to improve specificity for isoforms Nox4 and Nox1 and had excellent pharmacokinetic parameters by oral route. Several molecules such as compound 7c proved to be highly potent in in vitro assays on human lung fibroblasts differentiation as well as in curative murine models of bleomycin-induced pulmonary fibrosis with superior efficiency over Pirfenidone. Pyrazolo-pyrido-diazepine dione derivatives targeting Nox4 and Nox1 isoforms appear highly promising therapeutics for the treatment of idiopathic pulmonary fibrosis.

First in class, potent, and orally bioavailable NADPH oxidase isoform 4 (Nox4) inhibitors for the treatment of idiopathic pulmonary fibrosis.

We describe the design, synthesis, and optimization of first-in-class series of inhibitors of NADPH oxidase isoform 4 (Nox4), an enzyme implicated in several pathologies, in particular idiopathic pulmonary fibrosis, a life-threatening and orphan disease. Initially, several moderately potent pyrazolopyridine dione derivatives were found during a high-throughput screening campaign. SAR investigation around the pyrazolopyridine dione core led to the discovery of several double-digit nanomolar inhibitors in cell free assays of reactive oxygen species (ROS) production, showing high potency on Nox4 and Nox1. The compounds have little affinity for Nox2 isoform and are selective for Nox4/1 isoforms. The specificity of these compounds was confirmed in an extensive in vitro pharmacological profile, as well as in a counterscreening assay for potential ROS scavenging. Concomitant benefits are good oral bioavailability and high plasma concentrations in vivo, allowing further clinical trials for the potential treatment of fibrotic diseases, cancers, and cardiovascular and metabolic diseases.