Retrospective study for clinical biomarkers to guide post-EGFR-TKI treatment strategies in EGFR-mutant NSCLC

Background: In patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations, the combination of atezolizumab, bevacizumab, carboplatin, and paclitaxel (ABCP) has demonstrated encouraging efficacy following prior treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, real-world evidence comparing ABCP with standard platinum-based chemotherapy remains unclear. Methods: We conducted a multicenter retrospective study including 408 patients with advanced or recurrent EGFR-mutant NSCLC who received either platinum-based chemotherapy (with or without bevacizumab) or ABCP after EGFR-TKI treatment at 20 institutions in Japan. Clinical outcomes were evaluated using propensity score matching to adjust for baseline characteristics. Results: After propensity score matching, there were no significant differences in progression-free survival (PFS) or overall survival (OS) between the Chemo/Chemo + BEV and ABCP groups (median PFS, p = 0.44; median OS, p = 0.84). In the subgroup of patients with programmed death-ligand 1 (PD-L1) expression ≥50%, the ABCP group exhibited significantly longer PFS compared with the Chemo/Chemo + BEV group ( p = 0.02). Conclusions: Among patients with EGFR-mutant NSCLC previously treated with EGFR-TKIs, those with high PD-L1 expression may derive greater benefit from ABCP therapy compared with platinum-based chemotherapy, suggesting that ABCP could represent a more promising treatment option in this subgroup.