EGFR and non-small cell lung carcinoma: However, IPASS [15] and OPTIMAL [16] clinical trials suggested that patients with NSCLC received EGFR-TKIs alone failed to prolonged progression-free survival (PFS), and showed secondary resistance after 10-13 months in 10-13 months with objective response rate (ORR) of 43% in IPASS and 83% in OPTIMAL.