*8.1. Treatment of Patients Harboring a Driver Mutation*

ICIs are clearly less effective among patients harboring driver mutations. Among other EGFR mutations, exon del19 is reported to result in a lower PFS than L858R on ICI treatment (del19 HR 0.449 *p* < 0.001, L858R HR 0.578 *p* = 0.001) [52]. Among these, the PFS, among patients harboring these mutations, was significantly higher when the PD-L1 expression rate was compared between the negative group (0%) and the positive group (≥1%) (2.8 mo vs. 1.7 mo) results [52], suggesting that PD-L1 expression rate may be related to the efficacy of ICIs, even among patients harboring driver mutations. Regimens combining atezolizumab with CBDCA+PTX+BEV in the IMpower150 trial were also effective among patients harboring driver mutations upon subgroup analysis [19], and we believe that they hold promise as second-line treatment candidates upon using molecular-targeted agents. WJCOG8515L trial (UMIN000021133) have compared nivolumab with CBDCA+PEM in EGFR-TKI post-treatment NSCLC resistant cases through mechanisms other than T790M, and we believe that use of ICI for patients harboring driver mutations would be a future challenge.
