Real-world data survival outcomes of first line immunotherapy with pembrolizumab in high expressers with stage IV non-small cell lung cancer.

BACKGROUND: Pembrolizumab monotherapy is standard of care in first line treatment of patients with stage IV lung cancer and programmed death ligand 1 (PD-L1) expression ≥ 50%. Whether the higher levels of PD-L1 expression predict higher benefit from the treatment with pembrolizumab is still debatable. PATIENTS AND METHODS: This trial analyzed clinical and pathological characteristics, overall response rate (ORR), and survival outcomes in patients with non-small cell lung cancer (NSCLC) and PD-L1 expression of ≥ 50% who received front line treatment with pembrolizumab in real-world setting. The aim was to evaluate does the level of expression influence survival endpoints. RESULTS: Fifty-one consecutive patients were evaluated in this study. The median PFS for patients in this study was 12.0 months (95% CI, 7.7-16.2 months), and the median OS was 21.0 months (95% CI, 9.6-32.3 months). Based on PD-L1 status patients were divided into two groups. First one with PD-L1 expression of 50%-79%, and the second with expression over 80%. Gender distribution between the two groups (p = 0.029) and difference in stage of the disease (p = 0.039) were statistically significant. There was no significant difference in progression free survival (p = 0.548) and overall survival (p = 0.153) between two groups. CONCLUSIONS: This trial did not confirm relation between higher expression of PD-L1 and better survival outcomes. However, the pitfall of the trial was relatively small number of patients, so with the expansion of this real-world data (RWD) dataset future results might differ.