Peripheral Blood Markers Identify Risk of Immune-Related Toxicity in Advanced Non-Small Cell Lung Cancer Treated with Immune-Checkpoint Inhibitors.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) are now standard of care for advanced non-small cell lung cancer (NSCLC). Unfortunately, many patients experience immune-related adverse events (irAEs), which are usually mild and reversible, but they require timely management and may be life threatening. No predictive markers of irAEs are available.

MATERIALS AND METHODS: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were evaluated in patients with NSCLC consecutively treated with ICIs. Prespecified cutoff values of NLR and PLR were used and related to outcome and onset of irAEs. A control group of patients with advanced NSCLC not receiving ICIs was included.

RESULTS: The study included 184 patients: 26 (14.1%) received pembrolizumab upfront, and 142 (77%) received ICIs (pembrolizumab, nivolumab or atezolizumab) after one or more lines of chemotherapy. The median number of ICIs cycles was six (range, 1-61). The median progression-free survival and overall survival were 4.8 (95% CI, 3.4-6.3) and 20.6 (95% CI, 14.7-26.5) months, respectively. Sixty patients (32.6%) developed irAEs, mainly grade 1-2 (65.0%), causing ICI interruption in 46 cases (25.0%). Low NLR and low PLR at baseline were significantly associated with the development of irAEs (odds ratio [OR], 2.2; p = .018 and OR, 2.8; p = .003, respectively). Multivariate analyses confirmed PLR as independent predictive marker of irAEs (OR, 2.3; p = .020).

CONCLUSION: NLR and PLR may predict the appearance of irAEs in non-oncogene-addicted aNSCLC, although this conclusion warrants prospective validation.

IMPLICATIONS FOR PRACTICE: This study was designed to investigate the role of blood biomarkers in predicting the occurrence of immune-related adverse events (irAEs) in patients with advanced non-small cell lung cancer receiving immunotherapy. The results of the study suggest a potential predictive role of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as markers for irAE development in this category of patients. These data provide rationale for an easy and feasible application to be validated in clinical practice.