Detection and Monitoring of Tumor-Derived Mutations in Circulating Tumor DNA Using the UltraSEEK Lung Panel on the MassARRAY System in Metastatic Non-Small Cell Lung Cancer Patients

Analysis of circulating tumor DNA (ctDNA) is a potential minimally invasive molecular tool to guide treatment decision-making and disease monitoring. A suitable diagnostic-grade platform is required for the detection of tumor-specific mutations with high sensitivity in the circulating cell-free DNA (ccfDNA) of cancer patients. In this multicenter study, the ccfDNA of 72 patients treated for advanced-stage non-small cell lung cancer (NSCLC) was evaluated using the UltraSEEK® Lung Panel on the MassARRAY® System, covering 73 hotspot mutations in EGFR, KRAS, BRAF, ERBB2, and PIK3CA against mutation-specific droplet digital PCR (ddPCR) and routine tumor tissue NGS. Variant detection accuracy at primary diagnosis and during disease progression, and ctDNA dynamics as a marker of treatment efficacy, were analyzed. A multicenter evaluation using reference material demonstrated an overall detection rate of over 90% for variant allele frequencies (VAFs) > 0.5%, irrespective of ccfDNA input. A comparison of UltraSEEK® and ddPCR analyses revealed a 90% concordance. An 80% concordance between therapeutically targetable mutations detected in tumor tissue NGS and ccfDNA UltraSEEK® analysis at baseline was observed. Nine of 84 (11%) tumor tissue mutations were not covered by UltraSEEK®. A decrease in ctDNA levels at 4-6 weeks after treatment initiation detected with UltraSEEK® correlated with prolonged median PFS (46 vs. 6 weeks; p < 0.05) and OS (145 vs. 30 weeks; p < 0.01). Using plasma-derived ccfDNA, the UltraSEEK® Lung Panel with a mid-density set of the most common predictive markers for NSCLC is an alternative tool to detect mutations both at diagnosis and during disease progression and to monitor treatment response.

Abstract 3411: Detection and monitoring of tumor-derived mutations in ctDNA using the UltraSEEK Lung Panel on the MassARRAY System in metastatic NSCLC patients

Background: The analysis of circulating tumor DNA (ctDNA) is a potential minimally invasive molecular tool to guide treatment decision making and disease monitoring. A suitable diagnostic-grade platform is required for detection of tumor-specific mutations with high sensitivity in circulating cell-free DNA (ccfDNA) of cancer patients.

Methods: In an international multicenter study conducted by three laboratories participating in the CANCER-ID consortium, a cohort containing 177 cell-free plasma samples at baseline, follow-up or disease progression derived from 72 patients treated for advanced-stage non-small cell lung cancer (NSCLC), relevant mutations were tested using the UltraSEEK® Lung Panel on the MassARRAY® System covering 73 hotspot mutations in EGFR, KRAS, BRAF, ERBB2 and PIK3CA, and compared against mutation-specific droplet digital PCR (ddPCR) and tumor tissue next-generation sequencing (NGS) performed in routine diagnostics. Variant detection accuracy at primary diagnosis and during disease progression, and ctDNA dynamics as a marker of treatment efficacy were analyzed.

Results: The UltraSEEK® Lung Panel revealed an overall detection rate of 87.2% irrespective of ccfDNA input, and a specificity of &gt;99.5% using the reference material. When comparing the 131 variants identified in the patient-derived cell-free plasma using UltraSEEK® with mutation-specific ddPCR analyses, a concordance of 90% was found. The 77 diagnostically or clinically relevant variants identified in 66 pretreatment tumor tissue showed an overall concordance with UltraSEEK® of 73% at baseline with a false-negative rate of 3%. When restricting to therapeutically targetable mutations, the concordance elevated to 85%. A decrease in ctDNA levels at 4-6 weeks after start of treatment detected with UltraSEEK® correlated with a prolonged median PFS (46 vs 11 weeks; P&lt;0.05) and OS (145 vs 39 weeks; P&lt;0.001). In four out of thirteen NSCLC patients treated with targeted therapy, resistance mutations were identified using UltraSEEK® at disease progression, implicating the requirement of a therapy switch.

Conclusion: Using plasma-derived ccfDNA, the UltraSEEK® Lung Panel with a mid-density set of the most common predictive markers for NSCLC is an alternative tool to detect both mutations at diagnosis and disease progression, and to monitor treatment response.

Citation Format: Paul van der Leest, Melanie Janning, Naomi Rifaela, Maria L. Aguirre Azpurua, Jolanthe Kropidlowski, Sonja Loges, Nicholas Lozano, Alexander Sartori, Darryl Irwin, Pierre-Jean Lamy, T. Jeroen N. Hiltermann, Harry J. Groen, Klaus Pantel, Léon C. van Kempen, Harriet Wikman, Ed Schuuring. Detection and monitoring of tumor-derived mutations in ctDNA using the UltraSEEK Lung Panel on the MassARRAY System in metastatic NSCLC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3411.

Circulating tumor DNA as a biomarker for monitoring early treatment responses of patients with advanced lung adenocarcinoma receiving immune checkpoint inhibitors

Immunotherapy for metastasized non-small-cell lung cancer (NSCLC) can show long-lasting clinical responses. Selection of patients based on programmed death-ligand 1 (PD-L1) expression shows limited predictive value for durable clinical benefit (DCB). We investigated whether early treatment effects as measured by a change in circulating tumor DNA (ctDNA) level is a proxy of early tumor response to immunotherapy according to response evaluation criteria in solid tumors v1.1 criteria, progression-free survival (PFS), DCB, and overall survival (OS). To this aim, blood tubes were collected from advanced-stage lung adenocarcinoma patients (n = 100) receiving immune checkpoint inhibitors (ICI) at baseline (t0 ) and prior to first treatment evaluation (4-6 weeks; t1 ). Nontargetable (driver) mutations detected in the pretreatment tumor biopsy were used to quantify tumor-specific ctDNA levels using droplet digital PCR. We found that changes in ctDNA levels were strongly associated with tumor response. A > 30% decrease in ctDNA at t1 correlated with a longer PFS and OS. In total, 80% of patients with a DCB of ≥ 26 weeks displayed a > 30% decrease in ctDNA levels. For patients with a PD-L1 tumor proportion score of ≥ 1%, decreasing ctDNA levels were associated with a higher frequency a DCB (80%) and a prolonged median PFS (85 weeks) and OS (101 weeks) compared with patients with no decrease in ctDNA (34%; 11 and 39 weeks, respectively). This study shows that monitoring of ctDNA dynamics is an easy-to-use and promising tool for assessing PFS, DCB, and OS for ICI-treated NSCLC patients.

Mass Spectrometry as a Highly Sensitive Method for Specific Circulating Tumor DNA Analysis in NSCLC: A Comparison Study

Simple Summary

We compared the UltraSEEK™ Lung Panel on the MassARRAY^® System (Agena Bioscience) with the FDA-approved Cobas^® EGFR Mutation Test v2 for the detection of EGFR mutations in liquid biopsies of NSCLC patients, accompanied with preanalytical sample assessment using the novel Liquid IQ^® Panel. For the detection of relevant predictive mutations using the UltraSEEK™ Lung Panel, an input of over 10 ng showed 100% concordance with Cobas^® EGFR Mutation Test v2 and detection of all tissue confirmed mutations. In case of lower ccfDNA input, the risk of missing clinically relevant mutations should be considered. The use of a preanalytical ccfDNA quality control assay such as the Liquid IQ^® Panel is recommended to confidently interpret results, avoiding bias induced by non-specific genomic DNA and low input of specific tumoral ccfDNA fragments.

Abstract

Plasma-based tumor mutational profiling is arising as a reliable approach to detect primary and therapy-induced resistance mutations required for accurate treatment decision making. Here, we compared the FDA-approved Cobas^® EGFR Mutation Test v2 with the UltraSEEK™ Lung Panel on the MassARRAY^® System on detection of EGFR mutations, accompanied with preanalytical sample assessment using the novel Liquid IQ^® Panel. 137 cancer patient-derived cell-free plasma samples were analyzed with the Cobas^® and UltraSEEK™ tests. Liquid IQ^® analysis was initially validated (n = 84) and used to determine ccfDNA input for all samples. Subsequently, Liquid IQ^® results were applied to harmonize ccfDNA input for the Cobas^® and UltraSEEK™ tests for 63 NSCLC patients. The overall concordance between the Cobas^® and UltraSEEK™ tests was 86%. The Cobas^® test detected more EGFR exon19 deletions and L858R mutations, while the UltraSEEK™ test detected more T790M mutations. A 100% concordance in both the clinical (n = 137) and harmonized (n = 63) cohorts was observed when >10 ng of ccfDNA was used as determined by the Liquid IQ^® Panel. The Cobas^® and UltraSEEK™ tests showed similar sensitivity in EGFR mutation detection, particularly when ccfDNA input was sufficient. It is recommended to preanalytically determine the ccfDNA concentration accurately to ensure sufficient input for reliable interpretation and treatment decision making.