The present invention relates to combination comprising (i) an ErbB inhibitor; and (ii) a CDK inhibitor, or a pharmaceutically acceptable salt thereof, selected from: (a) roscovitine; (b) 3-{9-isopropyl-6-[(pyridin-3-ylmethyl)-amino]-9H-purin-2-ylamino}-2-methyl-pentan-2-ol; (c) 3-{9-isopropyl-6-[(pyridin-3-ylmethyl)-amino]-9H-purin-2-ylamino}-pentan-2-ol; and (d) (2R,3S-3-(6-((4,6-dimethylpyridin-3-ylmethylamino)-9-isopropyl-9H-purin-2-ylamino)pentan-2-ol.Further aspects of the invention relate to pharmaceutical products and pharmaceutical compositions comprising combinations according to the invention, and methods of treatment using the same.