BMS-599626 (60-240 mg/kg; p.o.; daily for 14 days) results in a dose-dependent inhibition of Sal2 tumor growth. BMS599626 treatment results in the inhibition of GEO xenograft tumor growth when given once daily for 14 days. In addition to efficacy in the Sal2, GEO, and KPL4 models, BMS-599626 has similar antitumor activity in other HER2 amplified xenograft models including the BT474 breast and N87 gastric tumors, as well as other HER1-overexpressing non-small-cell lung tumors (A549 and L2987). BMS599626 given before and during irradiation improved the radioresponse of HN5 tumors in vivo.