Predictors Of Benefits To Chemoimmunotherapy (Cit) In Stage Iv Non-Small-Cell Lung Cancer (Nsclc): A Meta-Analysis.

e20595 Background: Immune checkpoint inhibitors (ICIs) have changed the landscape of NSCLC therapy. In previous study, gender, smoking history, and PD-L1 status were found to influence the efficacy of ICI monotherapy in NSCLC. This meta-analysis evaluated the clinical and molecular factors predictive of benefit from the addition of ICIs to first-line (1L) chemotherapy in metastatic NSCLC. Methods: Using the random effect model, we computed and compared the pooled hazard ratio (HR) of progression-free survival (PFS) and overall survival (OS) among the selected subgroups. The correlation between PD-L1 expression level and outcome was analyzed by meta-regression. Results: 7 phase III randomized trials comparing CIT vs. chemo in the 1L treatment of stage 4 NSCLC were included. CIT evenly improved the PFS irrespective of age, gender, histology, smoking history and ECOG performance status (PS). While patients (pts) with liver metastasis or ALK/EGFR aberration had greater PFS with the addition of ICI to Bevacizumab (BEV) based chemo regimen, the derived benefit was no longer statistically significant among pts treated with non-BEV-based regimens. Whereas the PFS superiority conferred by CIT was noticed across all PD-L1 expression subgroups, the benefit correlated with PD-L1 level and was more pronounced in the “PD-L1 high” subset. Except for pts with EGFR/ALK abnormalities, squamous histology or liver metastasis, CIT yielded a consistent amelioration of OS across the other selected subgroups. Conclusions: Survival advantage associated with 1L CIT in metastatic NSCLC was observed in different pts population including those for which single-agent ICI has limited therapeutic benefit. Our findings support the role of chemo +/- VEGF blockade as enhancer of ICIs activity even in “less immunogenic” context. [Table: see text]