The invention provides a method of treating a subject with cancer, particularly leukemia, lymphoma, solid cancer such as colorectal cancer, gastric cancer, bladder cancer, non-small cell lung cancer, and breast cancer, comprising administering to the subject a compound of formulae (I) 40 or (Ia) in combination with an antimetabolite such as methotrexate, pemetrexed, cytarabine or nelarabine, or 5-fluorouracil, or capecitabine or their derivatives.
