AG13909

AG13909 (also known as Lu AG13909) is a potent and selective small molecule inhibitor of the enzyme 11β-hydroxylase (CYP11B1), which was developed by Lundbeck for the treatment of Cushing's disease. CYP11B1 is a cytochrome P450 enzyme in the adrenal cortex that catalyzes the final step of cortisol biosynthesis. By inhibiting this enzyme, AG13909 aimed to normalize the excessive cortisol production that characterizes Cushing's disease. The compound was designed to be highly selective for CYP11B1 over the closely related enzyme aldosterone synthase (CYP11B2) to avoid potential mineralocorticoid-related side effects. AG13909 reached Phase I clinical development, where its safety, tolerability, and pharmacokinetics were evaluated. However, in 2019, Lundbeck announced the termination of the AG13909 program following a strategic review of its research and development portfolio.