Gefitinib, as a member of the ‘‘small molecule’’ tyrosinekinase inhibitors (TKI),16,17is a standard first-line treat-ment for NSCLC patients with EGFR mutation. Severalrandomized phase III trials demonstrated that gefiti-nib prolonged progression-free survival and improvedquality of life compared with platinum-based doubletchemotherapy.4—6However, the development of secondaryresistance inevitably leads to treatment failure (in the mostrecent studies for up to 10—14 months).10The most com-mon molecular mechanisms of secondary resistance arehreonine-to-methionine amino acid change at position 790(T790M) of the EGFR kinase domain (found in 50% of cases)and MET amplification (found in up to 20% cases).18,19Someagents were designed to overcome the secondary resis-tance, such as afatinib, which is an irreversible inhibitoragainst all EGFR family members and T790M mutation,20hasalso demonstrated to be superior to chemotherapy in EGFR