INS1033

INS1033 is an investigational, oral, small molecule inhibitor of cathepsin C (CatC), also known as dipeptidyl peptidase 1 (DPP1), developed by Insmed Incorporated. CatC is a lysosomal cysteine protease that plays a critical role in the activation of neutrophil serine proteases (NSPs)—such as neutrophil elastase, proteinase 3, and cathepsin G—during neutrophil maturation in the bone marrow. By inhibiting CatC, INS1033 prevents the activation of these NSPs, which are key mediators of inflammation and tissue destruction in various chronic inflammatory diseases. INS1033 is being developed as a potential treatment for neutrophil-mediated inflammatory conditions, including bronchiectasis, following the development of Insmed's lead CatC inhibitor, brensocatib. It is currently undergoing Phase 1 clinical evaluation for safety, tolerability, and pharmacokinetics in healthy volunteers.