Comparison of Single Agent Check-Point Inhibitors as First-Line Treatment in NSCLC Patients with High PD-L1-Expression

Abstract Background: Three antibodies directed against programmed cell death receptor 1 (PD-1) or its ligand 1 (PD-L1) are approved for the first-line therapy of metastatic non-small cell lung cancer (NSCLC), but no direct comparison has been performed. Methods: The clinicopathological features of 161 locally advanced NSCLC patients with unresectable tumor disease and being unfit to undergo definitive chemo-/radiotherapy or metastatic NSCLC patients, who received atezolizumab, cemiplimab or pembrolizumab as single-agent, first-line, palliative checkpoint-inhibitor (CPI) therapy in a certified German lung cancer center, were analyzed. Results: High PD-L1-positive immune cells scores (= 10%) were found in 33 patients (23.8%) with available values. Partial response occurred in 54.4%, stable disease in 21.6% and progressive disease in 24.0% of the assessable 127 patients with significant differences between the treatment groups in the univariate analysis. Median progression-free survival (PFS) and overall survival (OS) of the entire cohort were 10.5 and 15.0 months. There was no difference between the treatment groups. Patients receiving pembrolizumab instead of atezolizumab tended to have a longer PFS (13.0 vs. 9.1 months, p=0.063). In patients with stage IV at initial diagnosis, median PFS and OS were 10.5 and 12.0 months, resp., with a similar trend of a prolonged PFS and OS for treatment with pembrolizumab (PFS: 11.0 vs. 9.1 months, p=0.058; OS: 14.2 vs. 8.7 months, p=0.065). But the differences were not statistically significant. Conclusion: Different PD-1/PD-L1 inhibitors as first-line palliative treatment for locally advanced or metastatic NSCLC show a similar effectiveness.