70P Efficacy of PD-1 blockade plus chemotherapy in patients with oncogenic-driven non-small cell lung cancer

Background: PD-1 blockade combined with chemotherapy has become the standard of care for patients with advanced non-small-cell lung cancer (NSCLC) without oncogenic drivers.Oncogenic-driven advanced NSCLC showed limited response to PD-1 blockade monotherapy or chemotherapy alone.Whether NSCLC patients with oncogenic drivers showed response to PD-1 blockade plus chemotherapy remains undetermined.Methods: 329 patients with at least one oncogenic driver alteration NSCLC receiving PD-1 plus chemotherapy or each monotherapy were retrospectively identified.Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were used to evaluate the therapeutic outcomes differences among patients with different oncogenic drivers.Results: Totally, 176 patients received PD-1 blockade plus chemotherapy, 60 patients received PD-1 blockade monotherapy and 93 patients received chemotherapy alone were included.Oncogenic drivers including KRAS (31.0%),EGFR (30.4%),HER2 (14.6%),BRAF (10.3%),RET (7.0%) and other mutations (6.7%) were identified.Compared with PD-1 and chemo mono-treatment, patients with oncogenic drivers received PD-1 blockade plus chemotherapy showed significantly better objective response rate (48% vs 22% and 26%; P < 0.001), progression-free survival (median 9.5 vs 3.8 and 5.6 months; P < 0.001) and overall survival (median 25.3 vs 16.8 and 17.0 months; P < 0.001).Multivariate cox regression analysis revealed that PD-1 blockade plus chemotherapy showed dramatically improved benefits both in PFS and OS.Conclusions: PD-1 blockade plus chemotherapy showed superior efficacy than PD-1 blockade monotherapy or chemotherapy alone in patients with oncogenic-driven advanced NSCLC, particularly in KRAS, EGFR and BRAF subgroup, indicating that PD-1 blockade plus chemotherapy could be considered as optional treatments when these patients without available targeted therapy.Legal entity responsible for the study: The authors.