Aim: To investigate potential associations between clinical and standard peripheral blood biomarkers and clinical outcome in patients with non-small cell lung cancer (NSCLC) treated with nivolumab. Patients and Methods: A total of 120 patients with advanced NSCLC treated at seven comprehensive cancer care centers were analyzed in this national retrospective study. Survival statistics were evaluated using the Kaplan-Meier method and Cox analysis. Results: Among clinical parameters, histology was significantly associated with progression-free survival. Univariate Cox-proportional hazards model indicated prognostic and predictive role of a panel of laboratory parameters reflecting chronic inflammatory pattern (elevated neutrophil count, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, C-reactive protein and decrease in hemoglobin and albumin). Higher serum calcium concentration was also associated with nivolumab treatment effect. Conclusion: Tumor histology was the only clinical parameter predicting the outcome of nivolumab treatment.Among the laboratory parameters, our analysis identified a laboratory panel reflecting chronic inflammation as a potential predictive marker of nivolumab treatment.Nivolumab is a human monoclonal anti-programed cell death 1 (PD-1) therapy that represents a new therapeutic option in the second-line treatment of advanced non-small cell lung cancer (NSCLC). Improved efficacy and a more favorable adverse event profile have been documented for nivolumab compared to docetaxel in phase III studies. However, the objective response rate on nivolumab monotherapy is only about 20%, with the disease control rate reaching approximately 50% (1, 2). Therefore, many patients do not benefit from nivolumab treatment and, taking into account the cost/efficacy ratio, identification of predictive parameters that would aid identification of the most suitable candidates for this therapy remains a topic of high unmet medical need. Much effort has been made to demonstrate that programmed death-ligand 1 (PD-L1) expression on tumor cells represent, a potential biomarker of response to anti-PD1 therapy (3, 4). However, for nivolumab, this seems to hold true in nonsquamous NSCLC only, although data for other drugs, e.g. pembrolizumab, have demonstrated the predictive role of PD-L1 expression even in patients with squamous histology (5). For various reasons, PD-L1 expression is still not an ideal biomarker (6). Therefore, the search for other predictive biomarkers should continue. Several approaches 6771