Apratastat is an orally active, potent, and reversible dual inhibitor of tumor necrosis factor-α converting enzyme (TACE) and matrix metalloproteinases (MMPs) . Apratastat can potently inhibit the release of TNF-α in vitro, ex vivo, and in vivo with IC50s of 144 ng/mL in vitro and 81.7 ng/mL ex vivo, respectively.