Sequential ctDNA whole-exome sequencing in advanced lung adenocarcinoma with initial durable tumor response on immune checkpoint inhibitor and late progression.

BACKGROUND: Despite prolonged tumor response to immune checkpoint inhibitors (ICIs) for a subset of patients with advanced non-small cell lung cancer (NSCLC), a secondary resistance will occur for a majority of these patients. The understanding of late progression mechanisms with ICIs is important to improve future treatment strategies. METHODS: We performed whole-exome sequencing (WES) on circulating tumor DNA and compared molecular profiles between the beginning of ICI treatment and tumor progression in patients with advanced NSCLC treated with ICIs and who had initial and prolonged tumor response with secondary progression, after at least 6 months of treatment. RESULTS: We identified eight patients who experienced initial and durable tumor response, and secondary tumor progression after 6 months of treatment, with available paired blood samples (diagnosis and progression). All had lung adenocarcinoma, three had programmed-death ligand-1 expression ≥50% in immunohistochemistry and all presented low blood tumor mutational burden (bTMB). Seven patients received nivolumab in second-line or more, and one received pembrolizumab as first-line treatment. WES at progression showed clonal selection with molecular alterations of Wnt pathway-related genes, increase of copy number aberrations in cancer-related genes and loss of tumor-suppressor genes (such as PTEN) or of genes associated with immune response (such as B2M). No difference in term of bTMB was observed at progression. CONCLUSIONS: This is the first study describing putative molecular mechanisms associated with late progression under ICI in lung cancer. Studies on treatment strategies adapted to these mechanisms are needed.

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.