Comprehensive serum biomarker analysis reveals IL-8 changes as the only predictor of the effectiveness of immune checkpoint inhibitors for patients with advanced non-small cell lung cancer.

OBJECTIVES

Programmed cell death ligand 1 (PD-L1) expression is widely used to predict the effectiveness of PD-(L)1 inhibitors despite its imperfection. Previous studies suggested the utilization of various serum biomarkers; nonetheless, findings are inconclusive because of limited sample sizes or the focus on a single biomarker in many of these studies. This study analyzed multiplex serum biomarkers to explore their predictive ability in a large cohort of patients with advanced non-small-cell lung cancer (NSCLC) treated with a PD-L1 inhibitor in a real-world setting.

MATERIALS AND METHODS

This was a sub-study of J-TAIL, a prospective observational study of atezolizumab monotherapy in pre-treated patients with advanced NSCLC. From April to October 2019, 262 patients were enrolled from 73 sites in Japan. Serum samples were collected at baseline and at the second dose of atezolizumab. Quantification of the 51 serum cytokines, chemokines, growth factors, and vascular endothelial growth factors was performed using the Luminex platform. Baseline values and fold changes of the time of the second dose to the baseline were examined in association with the effectiveness of atezolizumab.

RESULTS

Among the 51 proteins assessed, a higher baseline interleukin (IL)-12 level, a higher soluble CD40 ligand fold change, a lower IL-8 fold change were associated with higher objective response rate (ORR). Of these, only the lower IL-8 fold change was associated with better progression-free survival (PFS) (adjusted hazard ratio, 1.98; 95 % confidence interval, 1.45-2.70; P < 0.01). Multivariate analysis demonstrated that the lower IL-8 fold change was an independent factor for both the ORR and PFS. The IL-8 fold change was independent of the neutrophil/lymphocyte ratio, and durable PFS was observed in patients with both low.

CONCLUSION

Comprehensive serum biomarker analysis revealed that a lower fold change in serum IL-8 was associated with better outcomes in pre-treated patients with advanced NSCLC receiving atezolizumab.