The instant invention provides a method of treating a cancer, selected from the group consisting of breast cancer, melanoma, colorectal cancer, non-small cell lung cancer and ovarian cancer, by administering a combination of a WEE1 inhibitor and a CHK1 inhibitor, wherein the WEE1 inhibitor is MK-1775 or a pharmaceutically acceptable salt thereof, or MK-3652 or a pharmaceutically acceptable salt thereof, and the CHK1 inhibitor is MK-8776 or a pharmaceutically acceptable salt thereof, or SCH900444 or a pharmaceutically acceptable salt thereof.