A pharmaceutical composition comprising a Cdc7 inhibitor and an M phase promoter. In particular, the pharmaceutical composition wherein the Cdc7 inhibitor is a furanone derivative represented by the following formula (I) or a pharmaceutically acceptable salt thereof. (In the formula, A represents —COOR1 or a hydrogen atom, R1 represents a hydrogen atom, a hydrocarbon group which may have a substituent, or a heterocyclic ring which may have a substituent； R2 and R3； May be the same or different, have a hydrogen atom, a hydrocarbon group that may have a substituent, a phenyl group that may have a substituent, a heterocyclic ring that may have a substituent, and a substituent. Represents an optionally substituted heterocyclic ring, or an optionally substituted amino group, or R2 and R3 together with the nitrogen atom to which they are bonded, an optionally substituted heterocyclic ring Or a heterocyclic condensed ring which may have a substituent, and R4 represents a hydrogen atom or a halogen atom, provided that when A represents -COOR1, R2 and R3 are substituted at the same time. In the case where A is a hydrogen atom, R3 is hydrogen. Representing a child.)Ｃｄｃ７阻害剤とＭ期促進剤とを含む薬剤組成物。特に、Ｃｄｃ７阻害剤が、下式（Ｉ）で示されるフラノン誘導体又はその薬学的に許容される塩である薬剤組成物。（式中、Ａは、－ＣＯＯＲ１又は水素原子を表し、Ｒ１は、水素原子、置換基を有してもよい炭化水素基、又は置換基を有してもよい複素環を表し、Ｒ２及びＲ３は同一又は異なってもよく、水素原子、置換基を有してもよい炭化水素基、置換基を有してもよいフェニル基、置換基を有してもよい複素環、置換基を有してもよい複素環式縮合環、又は置換基を有してもよいアミノ基を表す。あるいは、Ｒ２及びＲ３は、これらが結合している窒素原子と共に、置換基を有してもよい複素環又は置換基を有してもよい複素環式縮合環を形成してもよい。Ｒ４は、水素原子又はハロゲン原子を表す。ただし、Ａが－ＣＯＯＲ１を表す場合は、Ｒ２及びＲ３は同時に置換基を有してもよいアミノ基にならず、Ａが水素原子を表す場合は、Ｒ３は水素原子を表す。）
