Cathepsin C-IN-5 (compound SF38) is a potent, selective and orally active Cathepsin C inhibitor with IC50s of 59.9 nM, 4.26 µM, >5 µM, >5 µM, >5 µM for Cat C, Cat L, Cat S, Cat B, Cat K, respectively. Cathepsin C-IN-5 inhibits the Cat C activity in bone marrow and blood. Cathepsin C-IN-5 decreases the activation of NSPs (neutrophil serine proteases). Cathepsin C-IN-5 shows anti-inflammatory activity.