Pirfenidone is a medication used for the treatment of idiopathic pulmonary fibrosis. It works by reducing lung fibrosis through downregulation of the production of growth factors and procollagens I and II.
It was first approved in Japan for the treatment of patients with idiopathic pulmonary fibrosis after clinical trials, under the trade name of Pirespa by Shionogi, in 2008. It was approved for use in the European Union in 2011, in Canada in 2012, and in the United States in October 2014. There is also a topical form created for the treatment of abnormal wound healing processes.