It is intended to provide a medicament and a method for treating cancer comprising a compound having MDM2 inhibiting activity and a compound having FLT3 inhibiting activity in combination. The present invention provides a medicament comprising (3′R,4′S,5′R)—N-[(3R,6S)-6-carbamoyltetrahydro-2H-pyran-3-yl]-6″-chloro-4′-(2-chloro-3-fluoropyridin-4-yl)-4,4-dimethyl-2″-oxo-1″,2″-dihydrodispiro[cyclohexane-1,2′-pyrrolidine-3′,3″-indole]-5′-carboxamide or a pharmaceutically acceptable salt thereof and N-(5-tert-butyl-isoxazol-3-yl)-N′-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl}urea or a pharmaceutically acceptable salt thereof in combination, and a treatment method using these compounds or salts in combination.
