The present invention provides a pharmaceutical composition for the prevention and / or treatment of diseases associated with pulmonary fibrosis.The present invention provides a pharmaceutical composition containing 3- [2- (5 - {[1 - (5-ethoxypyrimidin-2-yl) -2-isopropyl-6-oxo-4-propyl-1,6-dihydropyrimidin- methyl} pyridin-2-yl) phenyl] -1,2,4-oxadiazol-5 (4H) -one or a salt thereof or a solvate thereof as an active ingredient for the prevention and / or treatment of diseases associated with pulmonary fibrosis.本發明之課題係提供一種用於預防及/或治療肺纖維化相關疾病的醫藥組成物。本發明所提供之用於預防及/或治療肺纖維化相關疾病的醫藥組成物，係以3-[2-(5-{[1-(5-乙氧基嘧啶-2-基)-2-異丙基-6-側氧基-4-丙基-1,6-二氫嘧啶-5-基]甲基}吡啶-2-基)苯基]-1,2,4-噁二唑-5(4H)-酮或其鹽或者該化合物之溶媒化物作為有效成分。
