Immune‐inflammatory markers and clinical characteristics as predictors of the depth of response and prognosis of patients with PD‐L1 ≥50% metastatic non‐small cell lung cancer receiving first‐line immunotherapy

Abstract Background Patients with programmed cell death‐ligand 1 (PD‐L1) ≥50% metastatic non‐small cell lung cancer (NSCLC) treated with first‐line immunotherapy showed heterogeneous tumor responses. In this study, we investigated the clinical and immune‐inflammatory markers distinguishing patients with metastatic NSCLC achieving high depth of tumor response (HDPR) from those with non‐high depth of response (NHDPR). The impact of clinical features on the prognosis of patients with PD‐L1 ≥50% were further clarified. Methods The clinical characteristics and immune‐inflammatory markers of 17 patients with PD‐L1 ≥50% metastatic NSCLC at Beijing Tiantan Hospital between July 2020 and December 2023 were retrospectively analyzed. Results Among the 17 patients, seven (41.2%) patients achieved HDPR (range: −50%, −72%) and 10 (58.8%) patients achieved NHDPR (range: −13%, −45%). Below normal CD4 + T lymphocytes/CD8 + T lymphocytes (CD4/CD8) ratio (p = 0.01) and oncogenes and/or tumor suppressor gene mutations (TP53/KRAS/EGFR) (p = 0.001) were found enriched for NHDPR compared with HDPR. With a median follow‐up of 26.0 months (range: 17.2–34.8 months), the median progression‐free survival (PFS) following first‐line immunotherapy and overall survival (OS) were 9.0 months (95% CI: 5.0–13.0) and not reached (NR), respectively. The neutrophil‐to‐lymphocyte ratio (NLR) was identified as an independent prognostic factor on first‐line PFS. Patients with an NLR ≥4 exhibited a shorter median PFS (7.0 months vs. NR; p = 0.033; 95% CI: 1.2–80.2) than those with an NLR