Gene expression profile of high PD-L1 non-small cell lung cancers refractory to pembrolizumab.

BACKGROUND: Despite high expression of PD-L1, around half of advanced non-small cell lung cancer (NSCLC) will not experience tumor response with pembrolizumab. There is an need for a better understanding of the resistance mechanisms in this setting. METHODS: This bi-centric retrospective study included all consecutive patients with PDL1 ≥ 50% advanced NSCLC treated with pembrolizumab in first-line treatment between 2016 and 2020. We compared the clinical characteristics of patients with early progression (refractory) vs others. We performed a comprehensive gene expression profile screening by RNAseq capture on tumor samples. RESULTS: We included 46 patients. Twenty-two patients were refractory to pembrolizumab, mainly women, with poor performance status and lower albumin concentration. RNAseq analysis was performed on 19 samples. Hierarchical clustering allowed the identification of 3 clusters with various proportion of refractory tumors: intermediate (C1: 57%), high (C2: 71%) and low proportion (C3: 40%). Comparative analysis between C2 and C3 allowed the identification of overexpressed (n = 137) and underexpressed (n = 40) genes. Among the genes of interest, C2 exhibits higher activation of pathways associated with stemness phenotype (Hedgehog, Notch and Hippo pathways) and pathways associated with loss of PTEN and JAK2. In C2, genes associated with PD-1, toll-like receptor-9 (TLR-9), major histocompatibility complex (MHC) and interferon-γ pathways were underexpressed. CONCLUSION: This study gives an overview of activated and downregulated pathways in high PD-L1 NSCLC refractory to pembrolizumab. These tumors showed activation of pathways associated with cancer stem cells, loss of PTEN and JAK2, and inhibition of both priming and effector phases of the immune response.

Baseline Hedgehog Pathway Activation and Increase of Plasma Wnt1 Protein Are Associated with Resistance to Immune Checkpoint Inhibitors in Advanced Non-Small-Cell Lung Cancer.

Hedgehog (Hh) and Wingless-type (Wnt) pathways are associated with resistance to immune checkpoint inhibitors (ICIs) in preclinical studies. This study aimed to assess the association between expression and activation levels of Wnt and Sonic Hedgehog (Shh) pathways and resistance to ICIs in advanced NSCLC patients treated with ICI. Hh and Wnt pathways activation was assessed by immunohistochemistry (Gli1 and beta-catenin) on corresponding tumor tissues, and by plasma concentrations of Shh and Wnt (Wnt1, Wnt2 and Wnt3) at ICI introduction and at the first clinical evaluation. Sixty-three patients were included, with 36 patients (57.1%) with available tissue. Response rate was lower in Gli1+ NSCLC (20.0%) compared to Gli1 negative (Gli-) NSCLC (55.6%) (p = 0.015). Rate of primary resistance was 69.8%, vs. 31.2%, respectively (p = 0.04), and median progression-free survival (PFS) was 1.9 months (interquartile range (IQR) 1.2-5.7) vs. 6.1 months (1.6-26.0), respectively (p = 0.08). Median PFS and overall survival were shorter in case of increase of Wnt1 concentration during ICI treatment compared to other patients: 3.9 months vs. 11.2 months (p = 0.008), and 15.3 months vs. not reached (p = 0.003). In conclusion, baseline activation of Hh pathway and increase of Wnt1 concentrations during ICI treatment were associated with poor outcome in NSCLC patients treated with ICIs.

Plasma Biomarkers Screening by Multiplex ELISA Assay in Patients with Advanced Non-Small Cell Lung Cancer Treated with Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). An unmet need remains for new biomarkers associated with ICIs. In this study, consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab were included. Plasma at ICIs initiation was prospectively collected and a multiplex ELISA assay testing 48 cytokines and growth factors was performed. Exploratory endpoints were the association between plasma biomarkers with outcome and grade III-IV immune related adverse events (irAEs). Thirty-five patients were included. Patients without clinical benefit (n = 22) had higher pre-ICI soluble Hepatocyte Growth Factor (sHGF) (210.9 vs. 155.8 pg/mL, p = 0.010), lower pre-ICI soluble Fibroblast Growth Factor (sFGF) (4.0 vs. 4.8 pg/mL, p = 0.043) and lower pre-ICI interleukine-12 (IL-12) (1.3 vs. 2.2 pg/mL, p = 0.043) concentrations. Patients with early progression (n = 23) had higher pre-ICIs sHGF (206.2 vs. 155.8 pg/mL, p = 0.025) concentrations. Patients with low sHGF levels at ICIs initiation had longer progression-free survival and overall survival than those with high sHGF levels: respectively 2.5 vs. 8.0 months (p = 0.002), and 5.5 vs. 35.0 months (p = 0.001). TNF-α, IL-16, IL-12p40 and MCP3 were associated with high grade irAEs. This study shows the potential association between several plasma biomarkers with outcome and grade 3-4 IrAEs in advanced NSCLC treated with ICIs.