Disclosed herein is the use of 1-ethyl-7-(2-methyl-6-(1H-1,2,4-triazol-3-yl)pyridin-3-yl)-3,4-dihydropyrazino[2,3-b]pyrazin-2(1H)-one, a TOR kinase inhibitor, in combination with an effective amount of a histone deacetylase inhibitor for treating or preventing a cancer, wherein the cancer is a cancer of the head, neck, eye, mouth, throat, esophagus, bronchus, larynx, pharynx, chest, bone, lung, colon, rectum, stomach, prostate, urinary bladder, uterine, cervix, breast, ovaries, testicles or other reproductive organs, skin, thyroid, blood, lymph nodes, kidney, liver, pancreas, and brain or central nervous system, and wherein the histone deacetylase inhibitor may be selected from Belinostat, MS-275 and Romidepsin.
