Solid tumors residing in tissues and organs leave footprints in circulation through circulating tumor cells (CTCs) and circulating tumor DNAs (ctDNA). Characterization of the ctDNA portraits and comparison with tumor DNA mutational portraits may reveal clinically actionable information on solid tumors that is traditionally achieved through more invasive approaches. We isolated ctDNAs from plasma of patients of 103 lung cancer and 74 other solid tumors of different tissue origins. Deep sequencing using the Guardant360 test was performed to identify mutations in 73 clinically actionable genes, and the results were associated with clinical characteristics of the patient. The mutation profiles of 37 lung cancer cases with paired ctDNA and tumor genomic DNA sequencing were used to evaluate clonal representation of tumor in circulation. Five lung cancer cases with longitudinal ctDNA sampling were monitored for cancer progression or response to treatments. Mutations in TP53, EGFR, and KRAS genes are most prevalent in our cohort. Mutation rates of ctDNA are similar in early (I and II) and late stage (III and IV) cancers. Mutation in DNA repair genes BRCA1, BRCA2, and ATM are found in 18.1% (32/177) of cases. Patients with higher mutation rates had significantly higher mortality rates. Lung cancer of never smokers exhibited significantly higher ctDNA mutation rates as well as higher EGFR and ERBB2 mutations than ever smokers. Comparative analysis of ctDNA and tumor DNA mutation data from the same patients showed that key driver mutations could be detected in plasma even when they were present at a minor clonal population in the tumor. Mutations of key genes found in the tumor tissue could remain in circulation even after frontline radiotherapy and chemotherapy suggesting these mutations represented resistance mechanisms. Longitudinal sampling of five lung cancer cases showed distinct changes in ctDNA mutation portraits that are consistent with cancer progression or response to EGFR drug treatment. This study demonstrates that ctDNA mutation rates in the key tumor-associated genes are clinical parameters relevant to smoking status and mortality. Mutations in ctDNA may serve as an early detection tool for cancer. This study quantitatively confirms the hypothesis that ctDNAs in circulation is the result of dissemination of aggressive tumor clones and survival of resistant clones. This study supports the use of ctDNA profiling as a less-invasive approach to monitor cancer progression and selection of appropriate drugs during cancer evolution.

Veliparib is a potent poly(ADP)-ribose polymerase (PARP) 1 and 2 inhibitor that impedes repair of DNA damage induced by cytotoxic and radiation therapies. This phase 1 study evaluated veliparib in combination with chemoradiotherapy in patients with unresectable stage III non-small cell lung cancer (NSCLC). Patients received veliparib orally twice daily (BID) in escalating doses (60-240 mg, Day -3 to 1 day after last dose of radiation) combined with weekly carboplatin (area under the curve [AUC] 2 mg/mL/min), paclitaxel (45 mg/m²), and daily radiation therapy (60 Gy in 30 fractions), followed by two cycles of veliparib (120-240 mg BID, Days -2 through 5 of each 21-day cycle), carboplatin (AUC 6 mg/mL/min, Day 1 of each cycle), and paclitaxel (200 mg/m², Day 1 of each cycle) consolidation. Endpoints included veliparib maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), pharmacokinetics, safety, and efficacy. Forty-eight patients were enrolled. The MTD/RP2D of veliparib was 240 mg BID with chemoradiotherapy followed by 120 mg BID with consolidation. The most common any-grade adverse events (AEs) in this cohort for the whole treatment period were nausea (83%), esophagitis (75%), neutropenia (75%), and thrombocytopenia (75%). Dose-proportional pharmacokinetics of veliparib were observed. Median progression-free survival (mPFS) was 19.6 months (95% CI: 9.7-32.6). Median overall survival was estimated to be 32.6 months (95% CI: 15.0-not reached). In patients treated with the RP2D, mPFS was 19.6 months (95% CI: 3.0-not reached). When combined with standard concurrent chemoradiotherapy and consolidation chemotherapy in patients with stage III NSCLC, veliparib demonstrated an acceptable safety profile and antitumor activity with an mPFS of 19.6 months.

This phase II study investigated dose-intense erlotinib maintenance after dose-dense chemotherapy for patients with metastatic non-small cell lung cancer and examined two cell cycle biomarkers. Patients with newly diagnosed metastatic non-small cell lung cancer received docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) on day 1 and pegfilgrastim on day 2 every 14 days for four cycles. Patients then received erlotinib with initial doses based on smoking status. Doses were increased in 75 mg increments every two weeks depending on toxicities until each patient's maximal tolerable dose (MTD) was achieved. Cyclin D1 and D3 biomarkers were measured by immunohistochemistry. The objectives of the study were to evaluate time to progression (TTP) and overall survival (OS) for the entire population and biomarker subgroups. Forty-five patients were enrolled. Intra-patient erlotinib MTD ranged from 0 to 525 mg. Median MTD achieved in smokers was higher than in non-smokers (300 vs. 150 mg; P=0.019). TTP for the entire cohort was not significantly improved compared to historical controls. Patients with high cyclin D1 expressing tumors demonstrated improved TTP on erlotinib (8.2 vs. 4.7 months; hazard ratio, 4.1; 95% CI, 1.6-0.6; P=0.003) and improved OS (20.5 vs. 8.0 months; hazard ratio 2.8; 95% CI, 1.2-6.3; P=0.016). Intratumoral cyclin D3 expression did not impact clinical outcomes. Current smokers but not former smokers exhibit a higher erlotinib MTD. High cyclin D1 expression was associated with favorable TTP and OS.

Background/Objectives: No prior studies have attempted to identify a biomarker for initial brain metastasis velocity (iBMV), with limited studies attempting to correlate genomic data with the development of brain metastases. Methods: Patients with non-small-cell lung cancer (NSCLC) who underwent next-generation sequencing (NGS) were identified in our departmental database. iBMV was calculated by dividing the number of BMs by the interval of time between primary cancer and BM diagnosis. Two-sample t-testing was used to identify mutations statistically associated with iBMV (p < 0.1). A value of +1 was assigned to each mutation with a positive association (“deleterious genes”), and a value of −1 to each with an inverse association (“protective genes”). The sum of these values was calculated to define iBMV risk scores of −1, 0 and 1. Pearson correlation test was used to determine the association between iBMV risk score and calculated iBMV, and a competing risk analysis assessed for death as a competing risk to the development of BMs. Results: A total of 312 patients were included in the analysis, 218 of whom (70%) developed brain metastases. “Deleterious genes” included ARID1A, BRAF, CDK4, GNAQ, MLH1, MSH6, PALB2, RAD51D, RB1 and TSC1; “protective genes” included ARAF, IDH1, MYC, and PTPN11. iBMV risk scores of 1, 0 and −1, predicted an 88%, 61% and 65% likelihood of developing a BM (p < 0.01). A competing risk analysis found a significant association between iBMV risk scores of 1 vs. 0 and 1 vs. −1, and the likelihood of developing a BM using death as a competing risk. Overall survival (OS) at 1 and 2 years for patients with iBMV risk scores of 1, 0 and −1 was 72% vs. 84% vs. 85% and 46% vs. 69% vs. 70% (p < 0.02). Conclusions: Development of a genomic signature for iBMV via non-invasive liquid biopsy appears feasible in NSCLC patients. Patients with a positive iBMV risk score were more likely to develop brain metastases. Validation of this signature could lead to a biomarker with the potential to guide treatment recommendations and surveillance schedules.

Clinical perspective on PROSE: does VeriStrat testing improve selection of second-line treatment for patients with non-small cell lung cancer?

9047 Background: Unselected patients with stage 4 lung cancer who receive front line platinum based chemotherapy and maintenance chemotherapy have demonstrated a PFS less than 6 months with very few patients alive at 5 years. Patients with a small number of metastatic lesions may have a different biology, and aggressive local treatment of oligometastases is an active area of investigation. Methods: Patients were required to have stable disease or response after 3-6 cycles of platinum based chemotherapy and PS 0-2. Oligometastatic disease was defined as a maximum number of 5 metastatic lesions for all disease sites including no more than 3 active extracranial metastatic lesions. Limited mediastinal lymph node involvement was allowed. Results: 29 patients were enrolled between 10/2010 and 10/2015. 3 patients were excluded from analysis due to concerns regarding eligibility/treatment response. Despite closing early due to slow accrual, the study met its primary endpoint for success which was PFS greater than 6 months. The median PFS (95% CI) was 11.0 months (7.4-15.9 months) and the median OS was 22.2 months (13.3-45.7 months). The 1-year, 3-year, and 5-year OS were 73%, 35%, and 29%. Conclusions: Patients with oligometastatic NSCLC who received platinum based chemotherapy followed by oligometastatic consolidative radiation without maintenance chemotherapy demonstrated prolonged disease control and overall survival. Clinical trial information: nct01185639.