Baseline circulating myeloid-derived suppressor cells subpopulations, neutrophils/lymphocytes ratio, and response to PD-1/PD-L1 inhibitor in non-small cell lung cancer patients.

e15042 Background: Inhibitors of immune checkpoint PD-1/PD-L1 (ICI) have become a care standard in non-small cell lung cancer (NSCLC). Despite promising results, some patients cannot take advantage of immunotherapy effects. Nowadays, neither predictive nor prognostic circulating biomarkers have been found in order to select patients or to predict response to ICI. Myeloid-derived suppressor cells (MDSC) are potent immunity suppressors and may represent both a potential prognostic and a predictive biomarker. We aimed to assess the role of pretreatment circulating MDSC subpopulations on ICI outcomes in NSCLC patients. Methods: 86 NSCLC patients treated with ICI and 10 healthy donors in 3 cent…