PROBLEM TO BE SOLVED: To provide pyrimidinediamine compounds useful for inhibiting kinase activity, including activity of polo-like kinase 1 (PLK1).SOLUTION: There is provided a compound represented by the formula (I), or a pharmaceutically acceptable salt, solvate, N-oxide or prodrug thereof. [Y1 is O or S; Z1 is CH or N; A is phenyl or 6-membered heteroaryl; and R1 to R10 are H or the like.]COPYRIGHT: (C)2015,JPO&INPIT【課題】ポロ様キナーゼ1(PLK1)の活性を含む、キナーゼ活性を阻害するために有用なピリミジンジアミン化合物の提供。【解決手段】式(I)で示される化合物又は薬学的に許容される塩、溶媒和物、N-酸化物、又はプロドラッグ。[Y1はO又はS;Z1はCH又はN;Aはフェニル又は6員のヘテロアリール;R1~R10はH等]【選択図】なし