Compound-19

Compound-19 (also known as Com-19 or TZ-L19) is a selective small molecule inhibitor of NADPH oxidase (NOX) isoforms 1, 2, and 4. Developed by Tiiz Therapeutics, the drug is designed to target the tumor microenvironment (TME) by modulating the activity of cancer-associated fibroblasts (CAFs). CAFs contribute to tumor progression and immunotherapy resistance through extracellular matrix remodeling and the secretion of immunosuppressive cytokines. By inhibiting NOX1, NOX2, and NOX4, Compound-19 reduces CAF activation, suppresses tumor fibrosis, and decreases the expression of immune-suppressive factors. Preclinical studies in pancreatic and colorectal cancer models have demonstrated that Compound-19 increases intratumoral CD8+ T cell infiltration and resensitizes tumors to immune checkpoint inhibitors (ICIs) like pembrolizumab. It is currently entering Phase 1 clinical development for the treatment of advanced solid tumors.