Disclosed herein are embodiments of a method and pharmaceutical composition for treating acute myeloid leukemia (AML). In particular, the method embodiments comprise treating AML with 6-((5-fluoro-2-((3,4,5-trimethoxyphenyl)amino)pyrimidin-4-yl)amino)-2,2-dimethyl-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one, or a prodrug thereof, alone or in combination with one or more therapeutic agents that themselves are effective for treating AML. Also disclosed are embodiments of a pharmaceutical composition comprising 6-((5-fluoro-2-((3,4,5-trimethoxyphenyl)amino)pyrimidin-4-yl)amino)-2,2-dimethyl-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one, or a prodrug thereof, either as the sole therapeutic agent or in combination with one or more therapeutic agents effective for treating AML.