High levels of chromosomal aberrations negatively associate with benefit to checkpoint inhibition in NSCLC

Immunotherapy; Lung neoplasms; Tumor biomarkersImmunoteràpia; Càncer de pulmó; Biomarcadors tumoralsInmunoterapia; Cáncer de pulmón; Biomarcadores tumoralesBackground Immune checkpoint inhibitors (ICIs) targeting the programmed cell death 1/programmed death-ligand 1 axis have transformed the management of advanced non-small cell lung cancer (NSCLC). However, many patients do not benefit from this type of treatment, and thus several molecular biomarkers of benefit have been explored. The value of somatic copy number alterations (SCNAs) burden remains elusive. Patients and methods We assembled a cohort of 109 patients with NSCLC treated with ICIs and available tumor samples. We performed shallow whole-genome sequencing on 89 patients to determine genome-wide SCNAs and targeted gene expression analysis on 63 patients to study immune infiltration. We analyzed SCNAs burden in different ways (ie, the fraction of the genome altered or number of events) and studied their association with ICIs benefit based on survival analysis. We correlated SCNAs burden and immune infiltration on 35 patients of our cohort and on patients with lung adenocarcinoma from The Cancer Genome Atlas (TCGA). Results High SCNAs burden, computed in diverse ways, is negatively associated with ICIs progression-free survival (PFS), with the fraction of the genome altered (FGA) by arm and chromosome events showing the strongest association with PFS (p=0.002) (n=77). Nevertheless, we found differences in SCNAs across some clinicopathological features (sample site origin). A multivariate analysis adjusted for relevant characteristics showed that the FGA of arm and chromosome alterations was strongly associated with PFS (HR=2.21, p=3.3 x 10−5). Finally, we confirmed that SCNAs burden negatively correlates with tumor immune infiltration (n=35), although this correlation was not found for the males studied. Similar results were observed in the TCGA cohort. Conclusions SCNAs burden is a potential biomarker of benefit to ICIs in patients with NSCLC, although there appear to be some nuances worth consideration. Further studies will be needed to establish its role as a biomarker of benefit to ICIs.This work was supported by Merck Healthcare KGaA, Darmstadt, Germany (Grant for Oncology Innovation to the Vall d’Hebron Institute of Oncology (VHIO), Barcelona, Spain), Fundación Cientifica Asociación Española Contra el Cancer-AECC (grant number GCB14142170 to EF); the Catalan Government/AGAUR (2017–SGR–1738 to EF). Merck Healthcare KGaA reviewed the manuscript for medical accuracy only before journal submission

Dynamic changes in circulating tumor DNA assessed by shallow whole‐genome sequencing associate with clinical efficacy of checkpoint inhibitors in NSCLC

Immune checkpoint inhibitors (ICIs) targeting the PD‐1/PD‐L1 axis are the main therapeutic option for patients with advanced non‐small cell lung cancer (NSCLC) without a druggable oncogenic alteration. Nevertheless, only a portion of patients benefit from this type of treatment. Here, we assessed the value of shallow whole‐genome sequencing (sWGS) on plasma samples to monitor ICI benefit. We applied sWGS on cell‐free DNA (cfDNA) extracted from plasma samples of 45 patients with metastatic NSCLC treated with ICIs. Over 150 samples were obtained before ICI treatment initiation and at several time points throughout treatment. From sWGS data, we computed the tumor fraction (TFx) and somatic copy number alteration (SCNA) burden and associated them with ICI benefit and clinical features. TFx at baseline correlated with metastatic lesions at the bone and the liver, and high TFx (≥ 10%) associated with ICI benefit. Moreover, its assessment in on‐treatment samples was able to better predict clinical efficacy, regardless of the TFx levels at baseline. Finally, for a subset of patients for whom SCNA burden could be computed, increased burden correlated with diminished benefit following ICI treatment. Thus, our data indicate that the analysis of cfDNA by sWGS enables the monitoring of two potential biomarkers—TFx and SCNA burden—of ICI benefit in a cost‐effective manner, facilitating multiple serial‐sample analyses. Larger cohorts will be needed to establish its clinical potential