The subject of present invention is to provide a novel compound or salts thereof, or their crystals, which are useful for inhibiting Ax1 and treatment of diseases caused by Ax1 hyperfunction, treatment of diseases associated with Ax1 hyperfunction, and/or treatment of diseases accompanying with Ax1 hyperfunction. The solution of present invention is to provide a pyridone derivative or salts thereof having various substituents represented by the following formula (1), wherein R1, R2, R3, R5, R6, A, W, X and n of formula (1) are each defined as same as the definitions in the specification.本發明之課題係提供一種新穎化合物或其鹽、或彼等之結晶，其有用於阻礙Ax1，而治療以Ax1之機能亢進作為原因的疾病、治療與Ax1之機能亢進有關的疾病、以及/或治療伴隨Ax1之機能亢進的疾病。本發明之解決手段係提供一種具有各種取代基的下述式(1)所表示的吡啶酮衍生物或其鹽、或彼等之結晶(其中，式(1)中之R1、R2、R3、R5、R6、A、W、X以及n係各自與說明書中之定義同義)。
