EGFR and non-small cell lung carcinoma: Osimertinib is a new oral, irreversible, third-generation EGFR-TKI that is designed to selectively target inhibition of both EGFR sensitizing and T790M resistance mutations and also has therapeutic effects on NSCLC central nervous system (CNS) metastasis (Mok et al., 2017; Yang et al., 2017; Goss et al., 2018).