It is intended to provide a medicament and a method for treating cancer, comprising a compound having MDM2 inhibiting activity and a DNA methyltransferase inhibitor 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 a DNA methyltransferase inhibitor in combination, and a treatment method using the compound or a salt thereof and a DNA methyltransferase inhibitor in combination.
