PROBLEM TO BE SOLVED: To provide a novel pharmaceutical composition or novel combination drug for the treatment of cancer with reduced adverse side effects.SOLUTION: A pharmaceutical composition or combination drug contains, as active ingredients, (a) a coordination compound composed of a block copolymer represented by the following formula I and cisplatin, and (b) gemcitabine hydrochloride.【課題】副作用を軽減した新規がん治療用の医薬組成物又は組合せ剤の提供。【解決手段】有効成分として、(a)下記Iで表されるブロック共重合体とシスプラチンからなる配位化合物及び(b)塩酸ゲムシタビン;を含んでなる、医薬組成物又は組合せ剤。【選択図】なし