Persist or resist: Immune checkpoint inhibitors in EGFR-mutated NSCLC

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), especially third-generation TKIs, have significantly improved the progression-free survival and overall survival of non-small cell lung cancer (NSCLC) patients with EGFR mutation, TKI resistance is inevitable for most patients. Over the past few years, immune checkpoint inhibitors (ICIs) have significantly improved the survival for EGFR-wild type NSCLC patients. However, no significantly improved benefits were observed with ICI monotherapy in EGFR-mutated patients. EGFR-mutated NSCLC shows more heterogeneity in tumor mutational burden (TMB), programmed cell death-ligand 1 (PD-L1), and immune microenvironment characteristics. Whether ICIs are suitable for EGFR-mutated NSCLC patients remains to be elucidated. In this review, we summarized clinical trials of ICIs or combined therapy in EGFR-mutated NSCLC patients. We further discussed the factors determining the efficacy of ICIs in EGFR-mutated NSCLC patients, the mutation subtypes and microenvironment characteristics of potential responders. More importantly, we provided insights into areas worth further investigation in the future.