This blinded analysis demonstrates the ability of amplicon-based plasma NGS to detect a full range of targetable genotypes in NSCLC, including fusion genes, with high accuracy. The ability of plasma NGS to detect a range of preexisting and acquired resistance mechanisms highlights its potential value as an alternative to single mutation digital PCR-based plasma assays for personalizing treatment of TKI resistance in lung cancer.
PURPOSE Guidelines advocate molecular profiling in the evaluation of advanced non–small-cell lung cancer (NSCLC) and support the use of plasma circulating tumor DNA (ctDNA)-based profiling for patients with insufficient tissue. Thorough prospective clinical validation studies of next-generation sequencing (NGS)-based ctDNA assays are lacking. We report the multicentered prospective clinical validation of the InVision ctDNA assay in patients with advanced untreated NSCLC. METHODS A total of 264 patients with untreated advanced NSCLC were prospectively recruited, and their plasma was analyzed using a ctDNA NGS assay for detection of genomic alterations in 36 commonly mutated genes. Tumor tissue was available in 178 patients for molecular profiling for comparison with plasma profiling. The remaining 86 patients were included to compare ctDNA profiles in patients with and without tissue for profiling. RESULTS Concordance of InVisionFirst with matched tissue profiling was 97.8%, with 82.9% positive predictive value, 98.5% negative predictive value, 70.6% sensitivity, and 99.2% specificity. Considering specific alterations in eight genes that most influence patient management, the positive predictive value was 97.8%, with 97.1% negative predictive value, 73.9% sensitivity, and 99.8% specificity. Across the entire study, 48 patients with actionable alterations were identified by ctDNA testing compared with only 38 by tissue testing. ctDNA NGS reported either an actionable alteration or an alteration generally considered mutually exclusive for such actionable changes in 53% of patients. CONCLUSION The liquid biopsy NGS assay demonstrated excellent concordance with tissue profiling in this multicenter, prospective, clinical validation study, with sensitivity and specificity equivalent to Food and Drug Administration–approved single-gene ctDNA assays. The use of plasma-based molecular profiling using NGS led to the detection of 26% more actionable alterations compared with standard-of-care tissue testing in this study.
Background: We assessed whether serial ctDNA monitoring of plasma and saliva predicts response and resistance to osimertinib in EGFR-mutant lung adenocarcinoma. Three ctDNA technologies—blood-based droplet-digital PCR (ddPCR), next-generation sequencing (NGS), and saliva-based EFIRM liquid biopsy (eLB)—were employed to investigate their complementary roles. Methods: Plasma and saliva samples were collected from patients enrolled in a prospective clinical trial of osimertinib and local ablative therapy upon progression (NCT02759835). Plasma was analyzed by ddPCR and NGS. Saliva was analyzed by eLB. Results: A total of 25 patients were included. We analyzed 534 samples by ddPCR (n = 25), 256 samples by NGS (n = 24) and 371 samples by eLB (n = 22). Among 20 patients who progressed, ctDNA progression predated RECIST 1.1 progression by a median of 118 days (range: 61–272 days) in 11 (55%) patients. Of nine patients without ctDNA progression by ddPCR, two patients had an increase in mutant EGFR by eLB and two patients were found to have ctDNA progression by NGS. Levels of ctDNA measured by ddPCR and NGS at early time points, but not volumetric tumor burden, were associated with PFS. EGFR/ERBB2/MET/KRAS amplifications, EGFR C797S, PIK3CA E545K, PTEN V9del, and CTNNB1 S45P were key resistance mechanisms identified by NGS. Conclusion: Serial assessment of ctDNA in plasma and saliva predicts response and resistance to osimertinib, with each assay having supplementary roles.
A quantitative sandwich ELISA for lipoprotein(a) [Lp(a)], utilizing a monoclonal capture antibody that recognizes human and rhesus monkey apolipoprotein(a) [apo(a)] isoforms in combination with a polyclonal anti-apolipoprotein B-peroxidase conjugate was developed. This assay generates a linear calibration curve from 31.2 to 1000 mg/L, is highly reproducible (intra- and interassay CV of < 5% and < or = 12%, respectively), and shows no interference from plasminogen (1 g/L), low-density lipoprotein (6.00 g/L), triglycerides (27.00 g/L from chylomicrons and 10.00 g/L from very-low-density lipoprotein), hemoglobin (5 g/L), or bilirubin (30 mg/L). This assay format quantifies the concentration of Lp(a) on an equal molar basis regardless of apo(a) isoform. In contrast, a commercially available ELISA [Macra Lp(a)] method with a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apo(a) conjugate was found to underestimate the Lp(a) concentrations of individuals with lower-M(r) apo(a) isoforms--whether quantifying the Lp(a) in plasma or the purified lipoprotein. This demonstrates the importance of assay format selection in quantifying Lp(a).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.