George Hartman; Paul Humphries; Robert Hughes; Andrew Ho; Rusty Montgomery; Aditi Deshpande; Maitriyee Mahanta; Sarah Tronnes; Samantha Cowdin; Xu He; Fangchao Liu; Lifang Zhang; Chuan Liu; Dengfeng Dou; Jin Li; Aleksander Spasic; Rebecca Coll; Michael Marleaux; Inga V. Hochheiser; Matthias Geyer; Paul Rubin; Kristen Fortney; Kevin Wilhelmsen
Bioorg. Med. Chem. Lett., 2024, 102, 129675
https://doi.org/10.1016/j.bmcl.2024.129675

Abstract

NLRP3 is an intracellular sensor protein that detects a broad range of danger signals and environmental insults. Its activation results in a protective pro-inflammatory response designed to impair pathogens and repair tissue damage via the formation of the NLRP3 inflammasome. Assembly of the NLRP3 inflammasome leads to caspase 1-dependent secretory release of the pro-inflammatory cytokines IL-1β and IL-18 as well as to gasdermin d-mediated pyroptotic cell death. Herein, we describe the discovery of a novel indazole series of high affinity, reversible inhibitors of NLRP3 activation through screening of DNA-encoded libraries and the potent lead compound 3 (BAL-0028, IC50 = 25 nM) that was identified directly from the screen. SPR studies showed that compound 3 binds tightly (KD range 104–123 nM) to the NACHT domain of NLRP3. A CADD analysis of the interaction of compound 3 with the NLRP3 NACHT domain proposes a binding site that is distinct from those of ADP and MCC950 and includes specific site interactions. We anticipate that compound 3 (BAL-0028) and other members of this novel indazole class of neutral inhibitors will demonstrate significantly different physical, biochemical, and biological properties compared to NLRP3 inhibitors previously identified.