Gefitinib with pemetrexed as first-line therapy in patients with advanced nonsquamous non-small cell lung cancer with activating epidermal growth factor receptor mutations

While lung cancer is the most common cause of cancer death worldwide, epidermal growth factor receptor (EGFR) is the most common type of actionable mutation. Improved outcome with EGFR tyrosine kinase inhibitor (TKI) compared with conventional chemotherapy was the beginning of precision medicine for non-small cell lung cancer (NSCLC) (1). And the testing of EGFR became routine especially in adenocarcinoma of the lung. However, most patients will develop disease progression following successful treatment with EGFR TKIs. In the pooled analysis of 54 studies, gefitinib produced 9.4 months (95% CI, 9.0–9.8) of progression-free survival (PFS) (2). The most common mechanism of resistance is secondary mutation of T790M (3). So, improving PFS of patients with EGFR mutated tumor treated with EGFR TKI remains a critical therapeutic challenge.