Selective myeloperoxidase (MPO) inhibitor (IC50 = 1.5 μM in LPS-stimulated human whole blood). Selective for MPO over a panel of 50 receptors, enzymes, ion channels and transporters, including thyroid peroxidase. Inhibits MPO activity in peritoneal lavage and plasma in a murine peritonitis model. Also reduces lung edema in a murine pulmonary immune complex vasculitis model. Orally bioavailable. Purity 98%. MW (observed): 321.35