Tioxaprofen is a sulfidopeptide leukotriene receptor antagonist. It is an orally bioavailable anti-inflammatory agent, originated by Kyorin Pharmaceutical, which is being developed in clinical trials by the US company MediciNova for the treatment of interstitial cystitis and asthma. The actions of the drug are described by MediciNova as consisting of eosinophil migration inhibition, leukotriene antagonism, and phosphodiesterase IV inhibition. Other mechanisms described for Tioxaprofen include the inhibition of phosphodiesterases III, 5-lipoxygenase, phospholipase C as well as thromboxane A2. Tioxaprofen in doses of 1 and 5 mg/kg inhibits bronchoconstriction induced by inhalation of antigen and propranolol in a dose-dependent manner. Tioxaprofen was in phase III clinical trial for the treatment of asthma. However, this development was discontinued. It is under investigation for the treatment of idiopathic pulmonary fibrosis and Non-alcoholic steatohepatitis.