The present invention relates to a pharmaceutical composition for preventing or treating metastatic ovarian cancer, endometrial cancer or breast cancer, which comprises the compound of formula 1 or a pharmaceutically acceptable salt thereof. [Selection diagram] Fig. 3本発明は、化学式1の化合物またはその薬学的に許容可能な塩を含む転移性卵巣癌、子宮内膜癌もしくは乳癌の予防または治療用の薬学的組成物に関する。【選択図】図3