Disclosed is a therapeutic or prophylactic agent for leukemia. The therapeutic or prophylactic agent comprises a glycine derivative having a specific structure such as a compound represented by the formula below [(E)-2-(2,6-dichlorobenzamide)-5-[4-(isopropyl-pyrimidin-2-ylamino)phenyl]pent-4-enoic acid] or a pharmacologically acceptable salt thereof as an active ingredient. The therapeutic or prophylactic agent shows excellent absorption properties and stability upon being orally administered and has a significant therapeutic or prophylactic effect.
