Survival and soluble immune mediators of immune checkpoint inhibitor-induced interstitial lung disease in patients with non-small cell lung cancer.

ABSTRACT

BACKGROUND: Immune checkpoint inhibitor-related interstitial lung disease (ICI-ILD) is a serious adverse event frequently observed in patients with non-small cell lung cancer (NSCLC). We investigated the clinical effects and mechanism of action of ICI-ILD in NSCLC patients treated with ICI. METHODS: We retrospectively screened patients with advanced or recurrent NSCLC who received PD-1/PD-L1 inhibitor monotherapy and examined the prognostic impact of ICI-ILD. In addition, we analyzed the levels of 72 different soluble immune mediators in pre-treatment plasma to explore possible mechanisms associated with the development of ICI-ILD. Furthermore, the relationships between soluble immune mediators associated with ICI-ILD development and survival were analyzed. RESULTS: Of 141 patients with NSCLC, 25 (17.7%) developed ICI-ILD. Logistic regression analysis revealed that pre-treatment CXCL9, MMP-1, IL-6, and IL-19 levels were associated with ICI-ILD development. There were no significant differences in progression-free survival (PFS) and overall survival (OS) between patients with or without ICI-ILD. In patients with ICI-ILD, patients with lower grade ICI-ILD had better OS than those with higher-grade ICI-ILD. In ICI-ILD patients, there was a trend for patients with lower-grade ICI-ILD to have better PFS and OS than those with higher-grade ICI-ILD. Among four soluble immune mediators associated with ICI-ILD, a high level of IL-19 was significantly correlated with worse OS and PFS. CONCLUSION: The identified soluble immune mediators, including CXCL9, MMP-1, IL-6, and IL-19, may be useful as biomarkers to associate with ICI-ILD development. Although we did not detect significant differences in PFS and OS between patients with and without ICI-ILD, PFS and OS were longer in those with lower-grade ICI-ILD than in patients with higher-grade ICI-ILD. Among biomarkers, IL-19 may be a causal and prognostic factor for ICI-ILD.