Clinical Outcomes for Plasma-Based Comprehensive Genomic Profiling Versus Standard-of-Care Tissue Testing in Advanced Non-Small Cell Lung Cancer.

BACKGROUND: Somatic genomic testing is recommended by numerous expert guidelines to inform targeted therapy treatment for patients with advanced nonsquamous non-small cell lung cancer (aNSCLC). The NILE study was a prospective observational study that demonstrated noninferiority of cell-free circulating tumor DNA (cfDNA)-based tumor genotyping compared to tissue-based genotyping to find targetable genomic alterations in patients with newly diagnosed nonsquamous aNSCLC. As the cohort has matured, clinical outcomes data can now be analyzed. METHODS: This prospective, multicenter North American study enrolled patients with previously untreated nonsquamous aNSCLC who had standard of care (SOC) tissue genotyping performed and concurrent comprehensive cfDNA analysis (Guardant360). Patients with targetable genomic alterations, as defined by NCCN guidelines, who were treated with physician's choice of therapy had objective response rates, disease control rate, and time to treatment collected and compared to published outcomes. RESULTS: Among 282 patients, 89 (31.6%) had an actionable biomarker, as defined by NCCN, detected by tissue (21.3%) and/or cfDNA (27.3%) analysis. Sixty-one (68.5%) of these were treated with an FDA-approved targeted therapy guided by somatic genotyping results (EGFR, ALK, ROS1). Thirty-three patients were eligible for clinical response evaluation and demonstrated an objective response rate of 58% and disease control rate of 94%. Twenty-five (76%) and 17 (52%) achieved a durable response > 6 months and 12 months, respectively. The time to treatment (TtT) was significantly faster for cfDNA-informed biomarker detection as compared to tissue genotyping (18 vs. 31 days, respectively; P = .0008). CONCLUSIONS: cfDNA detects guideline-recommended biomarkers at a rate similar to tissue genotyping, and therapeutic outcomes based on plasma-based comprehensive genomic profiling are comparable to published targeted therapy outcomes with tissue profiling, even in community-based centers.

Clinical Utility of Comprehensive Cell-free DNA Analysis to Identify Genomic Biomarkers in Patients with Newly Diagnosed Metastatic Non-small Cell Lung Cancer.

PURPOSE: Complete and timely tissue genotyping is challenging, leading to significant numbers of patients with newly diagnosed metastatic non-small cell lung cancer (mNSCLC) being undergenotyped for all eight genomic biomarkers recommended by professional guidelines. We aimed to demonstrate noninferiority of comprehensive cell-free DNA (cfDNA) relative to physician discretion standard-of-care (SOC) tissue genotyping to identify guideline-recommended biomarkers in patients with mNSCLC. PATIENTS AND METHODS: Prospectively enrolled patients with previously untreated mNSCLC undergoing physician discretion SOC tissue genotyping submitted a pretreatment blood sample for comprehensive cfDNA analysis (Guardant360). RESULTS: Among 282 patients, physician discretion SOC tissue genotyping identified a guideline-recommended biomarker in 60 patients versus 77 cfDNA identified patients (21.3% vs. 27.3%; P < 0.0001 for noninferiority). In tissue-positive patients, the biomarker was identified alone (12/60) or concordant with cfDNA (48/60), an 80% cfDNA clinical sensitivity for any guideline-recommended biomarker. For FDA-approved targets (EGFR, ALK, ROS1, BRAF) concordance was >98.2% with 100% positive predictive value for cfDNA versus tissue (34/34 EGFR-, ALK-, or BRAF-positive patients). Utilizing cfDNA, in addition to tissue, increased detection by 48%, from 60 to 89 patients, including those with negative, not assessed, or insufficient tissue results. cfDNA median turnaround time was significantly faster than tissue (9 vs. 15 days; P < 0.0001). Guideline-complete genotyping was significantly more likely (268 vs. 51; P < 0.0001). CONCLUSIONS: In the largest cfDNA study in previously untreated mNSCLC, a validated comprehensive cfDNA test identifies guideline-recommended biomarkers at a rate at least as high as SOC tissue genotyping, with high tissue concordance, more rapidly and completely than tissue-based genotyping.See related commentary by Meador and Oxnard, p. 4583.

Analytical and Clinical Validation of a Digital Sequencing Panel for Quantitative, Highly Accurate Evaluation of Cell-Free Circulating Tumor DNA.

Next-generation sequencing of cell-free circulating solid tumor DNA addresses two challenges in contemporary cancer care. First this method of massively parallel and deep sequencing enables assessment of a comprehensive panel of genomic targets from a single sample, and second, it obviates the need for repeat invasive tissue biopsies. Digital Sequencing™ is a novel method for high-quality sequencing of circulating tumor DNA simultaneously across a comprehensive panel of over 50 cancer-related genes with a simple blood test. Here we report the analytic and clinical validation of the gene panel. Analytic sensitivity down to 0.1% mutant allele fraction is demonstrated via serial dilution studies of known samples. Near-perfect analytic specificity (> 99.9999%) enables complete coverage of many genes without the false positives typically seen with traditional sequencing assays at mutant allele frequencies or fractions below 5%. We compared digital sequencing of plasma-derived cell-free DNA to tissue-based sequencing on 165 consecutive matched samples from five outside centers in patients with stage III-IV solid tumor cancers. Clinical sensitivity of plasma-derived NGS was 85.0%, comparable to 80.7% sensitivity for tissue. The assay success rate on 1,000 consecutive samples in clinical practice was 99.8%. Digital sequencing of plasma-derived DNA is indicated in advanced cancer patients to prevent repeated invasive biopsies when the initial biopsy is inadequate, unobtainable for genomic testing, or uninformative, or when the patient's cancer has progressed despite treatment. Its clinical utility is derived from reduction in the costs, complications and delays associated with invasive tissue biopsies for genomic testing.

Phase I/IIa study of cisplatin and gemcitabine as induction chemotherapy followed by concurrent chemoradiotherapy with gemcitabine and paclitaxel for locally advanced non-small-cell lung cancer.

PURPOSE: This is a phase I/IIa study to assess tolerance of gemcitabine and paclitaxel with radiotherapy in locally advanced non-small-cell lung cancer after induction chemotherapy. PATIENTS AND METHODS: Fifty-seven patients with stage III non-small-cell lung cancer were treated with cisplatin 80 mg/m2 on days 1 and 22 and gemcitabine 1,250 mg/m2 on days 1, 8, 22, and 28. Chemoradiotherapy began on day 43 as follows: cohort 1 (n = 9), gemcitabine 300 mg/m2 and paclitaxel 35 mg/m2 weekly (except week 9); cohort 2 (n = 9), gemcitabine 150 mg/m2 and paclitaxel 35 mg/m2 weekly (except week 9); cohort 3 (n = 10) and the 25 phase IIa patients, gemcitabine 300 mg/m2 and paclitaxel 135 mg/m2 every 21 days. Patients were treated with three-dimensional thoracic radiotherapy concurrently to 60 Gy. RESULTS: Weekly chemotherapy resulted in grade 4 esophageal and grade 3 or higher pulmonary toxicities. Reduction in dose density (cohort 3) led to a tolerable toxicity profile and was chosen as the phase IIa regimen. The response rate to induction was 49%, with stable disease in 40% of the patients. The response rate after consolidation therapy was 75% (94% for weekly chemotherapy v 82% for every 3 weeks). Median survival was 23 months, and 3-year survival was 45% for eligible patients. Local relapse occurred in 20% of the patients. Performance status of more than 1 predicted for poor outcome, but baseline pulmonary function did not. Dosimetric parameters including V15, V20, V30 (percent lung volume receiving > or = 15, > or = 20, and > or = 30 Gy, respectively), and mean lung dose correlated with pulmonary toxicity. CONCLUSION: Additional investigation with the 3-week schedule is warranted in patients with a good performance status based on the safety profile and preliminary efficacy data observed in this study.