Provided are methods for overcoming resistance to an ErbB pathway inhibitor, such as an EGFR inhibitor or a HER2 inhibitor. The resistance may be acquired resistance to an EGFR inhibitor, such as acquired resistance to gefitinib. In the methods provided, a subject exhibiting resistance to an ErbB pathway inhibitor is selected and both an ErbB 3 inhibitor and a second ErbB pathway inhibitor are administered to the subject, such as an EGFR inhibitor or a HER2 inhibitor. Also provided are methods for inhibiting the growth of a tumor comprising a T790M EGFR mutation by contacting the tumor with an ErbB3 inhibitor and an EGFR inhibitor. Compositions for overcoming resistance to an ErbB pathway inhibitor, comprising both an ErbB 3 inhibitor and a second ErbB pathway inhibitor, such as an EGFR inhibitor or a HER2 inhibitor, are also provided.ＥＧＦＲ阻害剤またはＨＥＲ２阻害剤などのＥｒｂＢ経路阻害剤に対する耐性を克服するための方法を提供する。耐性は、ゲフィチニブに対する獲得耐性などの、ＥＧＦＲ阻害剤に対する獲得耐性であり得る。提供する方法において、ＥｒｂＢ経路阻害剤に対する耐性を示す対象を選択し、ＥｒｂＢ３阻害剤と、ＥＧＦＲ阻害剤またはＨＥＲ２阻害剤などの第２のＥｒｂＢ経路阻害剤との両方を対象に投与する。Ｔ７９０Ｍ ＥＧＦＲ変異を含む腫瘍をＥｒｂＢ３阻害剤およびＥＧＦＲ阻害剤と接触させることによって、腫瘍の成長を阻害する方法も提供する。ＥｒｂＢ３阻害剤と、ＥＧＦＲ阻害剤またはＨＥＲ２阻害剤などの第２のＥｒｂＢ経路阻害剤との両方を含むＥｒｂＢ経路阻害剤に対する耐性を克服するための組成物も提供する。
