A selective inhibitor of Aurora A kinase for use in treating cancer, by administration in combination with a MEK inhibitor, wherein the selective inhibitor of Aurora A kinase is 4-{[9-chloro-7-(2-fluoro-6-methoxyphenyl)-5 H -pyrimido[5,4- d] benzazepin-2-yl]amino}-2-methoxybenzoic acid, or a pharmaceutically acceptable salt thereof, and the MEK inhibitor is a compound selected from the group consisting of: I-1: 5-(2-Fluoro-4-iodophenylamino)-3,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione I-2: 5-(2-Fluoro-4-iodophenylamino)-3-(2-hydroxyethyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione I-3 Methyl 2-(5-(2-fluoro-4-iodophenylamino)-8-methyl-4,7-dioxo-7,8-dihydropyrido [2,3 -d]pyrimidin-3 -yl)acetate I-4 5-(2-Fluoro-4-iodophenylamino)-3,6,8-trimethylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione I-5 -3-(2,3-Dihydroxypropyl)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido [2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-6 -3-(2,3-Dihydroxypropyl)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido [2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-7 -6-Chloro-3-(2,3-dihydroxypropyl)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido [2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-8 -3-(2,3-Dihydroxypropyl)-5-(2-fluoro-4-iodophenylamino)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-9 -5-(4-Bromo-2-fluorophenylamino)-3-(2,3-dihydroxypropyl)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-10 -5-(4-Bromo-2-fluorophenylamino)-3-(2, 3 -dihydroxypropyl)-6, 8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-11 5-(4-Bromo-2-fluorophenylamino)-3-(2-hydroxyethyl)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-13 -3-(2,3-Dihydroxypropyl)-5-(2-fluoro-4-iodophenylamino)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-14 5-(2-Fluoro-4-iodophenylamino)-3-(2-hydroxyethyl)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-15 5-(2-Fluorophenylamino)-3-(2-hydroxyethyl)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-16 -3-(2,3-Dihydroxypropyl)-5-(4-ethynyl-2-fluorophenylamino)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-17 6-Fluoro-5-(2-fluoro-4-iodophenylamino)-3-(2-hydroxyethyl)-8-methylpyrido [2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-18 -3-(2,3-Dihydroxypropyl)-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-19 -3-(2,3-Dihydroxypropyl)-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-20 -5-(4-Bromo-2-fluorophenylamino)-3-(2,3-dihydroxypropyl)-6-fluoro-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-21 -3-(2,3-Dihydroxypropyl)-5-(4-ethynyl-2-fluorophenylamino)-6-fluoro-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-22 -3-(2,3-dihydroxypropyl)-5-(4-ethynyl-2-fluorophenylamino)-6-fluoro-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-23 - N -(4-(3-(2,3-Dihydroxypropyl)-6- fluoro-8-methyl-4, 7 -dioxo-3,4, 7,8-tetrahydropyrido[2,3-d]pyrimidin-5-ylamino)-3-fluorophenyl)methanesulfonamide I-24 3-(1,3-Dihydroxypropan-2-yl)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-25 3-(1,3-Dihydroxypropan-2-yl)-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-26 5-(2-Fluoro-4-iodophenylamino)-3-(2-hydroxyethoxy)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-27 -3-(2,3-Dihydroxypropoxy)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-28 -3-(2,3-Dihydroxypropoxy)-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-29 -5-(4-Bromo-2-fluorophenylamino)-6-chloro-3-(2,3-dihydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-30 6-Chloro-5-(2-fluoro-4-iodophenylamino)-3-(2-hydroxyethyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-31 5-(2-Fluoro-4-iodophenylamino)-3-(3-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-32 6-Chloro-5-(2-fluoro-4-iodophenylamino)-3-(3-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-33 5-(4-Bromo-2-fluorophenylamino)-3-(3-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-34 5-(4-Bromo-2-fluorophenylamino)-6-chloro-3-(3-hydroxypropyl)-8-methylpyrido [2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-35 5-(4-Bromo-2-chlorophenylamino)-3-(3-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-36 5-(4-Bromo-2-chlorophenylamino)-6-chloro-3-(3-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-37 3-(2-(Dimethylamino)ethyl)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-38 5-(2-Fluoro-4-iodophenylamino)-3-(2-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-39 -3-(2,4-Dihydroxybutyl)-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-40 6-Chloro-5-(2-fluoro-4-iodophenylamino)-3-(2-hydroxypropyl)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-41 -5-(4-Bromo-2-fluorophenylamino)-3-(2,3-dihydroxypropyl)-6-fluoro-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-42 3-Benzyl-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-43 3-(1,3-Dihydroxypropan-2-yl)-5-(2-fluoro-4-iodophenylamino)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione I-44 -3-(2,3-Dihydroxypropyl)-5-(4-ethynyl-2-fluorophenylamino)-6,8-dimethylpyrido[2,3-d]pyrimidine-4,7(3 H,8 H)-dione or a pharmaceutically acceptable salt thereof.