Primary tumor xenografts (PTXG) established directly from patients' primary tumors in immunosuppressed animals might represent the spectrum of histologic complexity of lung cancers better than ...xenografts derived from established cell lines. These models are important in the study of aberrant biological pathways in cancers and as preclinical models for testing new therapeutic agents. However, not all primary tumors engraft when implanted into immunosuppressed mice. We have investigated factors that may influence the ability of primary non-small cell lung cancer (NSCLC) to form xenografts and their association with clinical outcome.
Tumor fragments from patients undergoing curative surgery were implanted into NOD-SCID (nonobese diabetic-severely combined immunodeficient) mice within 24 hours of surgery. Patient characteristics for tumors that engrafted (XG) and did not engraft (no-XG) were compared. Patient tumor DNA was profiled for the presence of 238 known mutations in 19 cancer-associated genes by using the MassARRAY platform.
Xenografts were established and passaged successfully from 63 of 157 (40%) implanted NSCLCs. Tumor factors associated with engraftment included squamous histology, poor differentiation, and larger tumor size. Significantly fewer EGFR (epidermal growth factor receptor)-mutated tumors engrafted (P = 0.03); conversely, more K-RAS-mutated tumors engrafted (P = 0.05). In multivariate analysis including age, sex, stage, and mutation, patients with XG tumors had significantly shorter disease-free survival compared with no-XG patients (hazard ratio: 7.0, 95% CI: 3.1-15.81; P < 0.000003).
PTXGs closely mirror the histology and molecular profiles of primary tumors and therefore may serve as important preclinical models. Tumors that engraft are biologically more aggressive and may be more representative of cancers with a higher propensity to relapse after surgery.
A greater understanding of non–small-cell lung cancer at a molecular level has led to the identification of an increasing number of driver mutations. Extensive research of the KRAS gene as well as ...specific mutations has established its role in tumorigenesis. Nevertheless, the role of KRAS oncogene in non–small-cell lung cancer remains unclear. Recent studies indicated that mutant KRAS could be predictive of lack of response to chemotherapy, but large pooled analysis failed to confirm this result. The predictive value of KRAS mutation and EGFR-TKI treatment is more ambiguous with some recent evidence suggesting that it may be a negative predictive biomarker. This review provides an overview of RAS biology, assesses the utility of KRAS as a prognostic marker, and evaluates its role as a predictive marker for response to chemotherapy and EGFR-TKIs. In addition, we review some current studies that are targeting the KRAS pathway.
Checkpoint inhibitors targeting programmed cell death 1 or its ligand (PD-L1) as monotherapies or in combination with anti-cytotoxic T-lymphocyte-associated antigen 4 have shown clinical activity in ...patients with metastatic non-small cell lung cancer.
To compare durvalumab, with or without tremelimumab, with chemotherapy as a first-line treatment for patients with metastatic non-small cell lung cancer.
This open-label, phase 3 randomized clinical trial (MYSTIC) was conducted at 203 cancer treatment centers in 17 countries. Patients with treatment-naive, metastatic non-small cell lung cancer who had no sensitizing EGFR or ALK genetic alterations were randomized to receive treatment with durvalumab, durvalumab plus tremelimumab, or chemotherapy. Data were collected from July 21, 2015, to October 30, 2018.
Patients were randomized (1:1:1) to receive treatment with durvalumab (20 mg/kg every 4 weeks), durvalumab (20 mg/kg every 4 weeks) plus tremelimumab (1 mg/kg every 4 weeks, up to 4 doses), or platinum-based doublet chemotherapy.
The primary end points, assessed in patients with ≥25% of tumor cells expressing PD-L1, were overall survival (OS) for durvalumab vs chemotherapy, and OS and progression-free survival (PFS) for durvalumab plus tremelimumab vs chemotherapy. Analysis of blood tumor mutational burden (bTMB) was exploratory.
Between July 21, 2015, and June 8, 2016, 1118 patients were randomized. Baseline demographic and disease characteristics were balanced between treatment groups. Among 488 patients with ≥25% of tumor cells expressing PD-L1, median OS was 16.3 months (95% CI, 12.2-20.8) with durvalumab vs 12.9 months (95% CI, 10.5-15.0) with chemotherapy (hazard ratio HR, 0.76; 97.54% CI, 0.56-1.02; P = .04 nonsignificant). Median OS was 11.9 months (95% CI, 9.0-17.7) with durvalumab plus tremelimumab (HR vs chemotherapy, 0.85; 98.77% CI, 0.61-1.17; P = .20). Median PFS was 3.9 months (95% CI, 2.8-5.0) with durvalumab plus tremelimumab vs 5.4 months (95% CI, 4.6-5.8) with chemotherapy (HR, 1.05; 99.5% CI, 0.72-1.53; P = .71). Among 809 patients with evaluable bTMB, those with a bTMB ≥20 mutations per megabase showed improved OS for durvalumab plus tremelimumab vs chemotherapy (median OS, 21.9 months 95% CI, 11.4-32.8 vs 10.0 months 95% CI, 8.1-11.7; HR, 0.49; 95% CI, 0.32-0.74). Treatment-related adverse events of grade 3 or higher occurred in 55 (14.9%) of 369 patients who received treatment with durvalumab, 85 (22.9%) of 371 patients who received treatment with durvalumab plus tremelimumab, and 119 (33.8%) of 352 patients who received treatment with chemotherapy. These adverse events led to death in 2 (0.5%), 6 (1.6%), and 3 (0.9%) patients, respectively.
The phase 3 MYSTIC study did not meet its primary end points of improved OS with durvalumab vs chemotherapy or improved OS or PFS with durvalumab plus tremelimumab vs chemotherapy in patients with ≥25% of tumor cells expressing PD-L1. Exploratory analyses identified a bTMB threshold of ≥20 mutations per megabase for optimal OS benefit with durvalumab plus tremelimumab.
ClinicalT rials.gov Identifier: NCT02453282.
Background
Osimertinib is a third‐generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that is selective for both EGFR‐TKI–sensitizing and T790M (threonine‐to‐methionine ...substitution at codon 790)‐resistance mutations. The authors present long‐term follow‐up data from a preplanned, pooled analysis of phase 2 studies, the AZD9291 First Time in Patients Ascending Dose Study (AURA) extension trial (clincialtrials.gov identifier NCT01802632) and the AURA2 trial (NCT02094261).
Methods
Patients with centrally confirmed, T790M mutation‐positive, advanced non‐small cell lung cancer received osimertinib 80 mg once daily until disease progression or study discontinuation. Response was assessed by a blinded, independent, central review using Response Evaluation Criteria in Solid Tumors, version 1.1. The primary endpoint was the objective response rate.
Results
In total, 411 patients received osimertinib (second line, 129 patients; third line or later, 282 patients). At the data cutoff date of November 1, 2016, the median treatment exposure was 16.4 months (range, 0‐29.7 months), the objective response rate was 66% (95% confidence interval CI, 61%‐70%), the median response duration was 12.3 months (95% CI, 11.1‐13.8 months), and the median progression‐free survival was 9.9 months (95% CI, 9.5‐12.3 months). At the data cutoff date of May 1, 2018, 271 patients (66%) had died, and 140 patients (34%) had discontinued before death. The median overall survival was 26.8 months (95% CI, 24.0‐29.1 months); and the 12‐month, 24‐month, and 36‐month survival rates were 80%, 55%, and 37%, respectively. Grade ≥3 possibly causally related (investigator assessed) adverse events were reported in 65 patients (16%), and the most common were rash (grouped terms; 42%; grade ≥3, 1%) and diarrhea (39%; <1%).
Conclusions
This pooled analysis represents the most mature clinical trial data for osimertinib in patients with pretreated, T790M‐positive, advanced non‐small cell lung cancer, further establishing osimertinib as a standard of care for this patient population.
This preplanned, long‐term follow‐up, pooled analysis of the phase 2 AURA extension (NCT01802632) and AURA2 (NCT02094261) studies represents the most mature clinical trial data for osimertinib in patients with pretreated, T790M‐positive, advanced non–small cell lung cancer. Osimertinib (80 mg once daily) demonstrates a high response rate, with clinically meaningful progression‐free and overall survival, and a well characterized, manageable safety profile, which further establishes osimertinib as a standard of care for this patient population.
•In EGFR-mutated NSCLC, TP53 co-mutation is not a strong prognostic marker.•TP53 missense mutations might be predictive of lower ORR and shorter PFS on TKIs.•Larger datasets are required to validate ...these observations.
TP53 mutations are common in non-small cell lung cancer (NSCLC) and have been reported as prognostic of poor outcome. The impact of TP53 co-mutations in epidermal growth factor receptor (EGFR)-mutated NSCLC is unclear.
Tissue from 105 patients with EGFR-mutated NSCLC at Princess Margaret Cancer Centre was analyzed by next-generation or Sanger sequencing to determine TP53 mutational status. Associations between TP53 status and baseline patient and tumor characteristics, treatments and outcomes (relapse-free survival RFS after surgical resection, overall survival OS, overall response rate ORR and progression-free survival PFS on EGFR tyrosine kinase inhibitors TKIs), were investigated.
Dual TP53/EGFR mutations were found in 43/105 patients (41%). Among 76 patients who underwent surgical resection, neither RFS (HR 0.99, CI 0.56–1.75, p=0.96) nor OS (HR 1.39, CI 0.70–2.77; p=0.35) was associated with TP53 status. Sixty patients (24 TP53 MUT; 36 TP53 WT) received first-generation EGFR TKIs for advanced disease. ORR was not significantly different (TP53 MUT 54%, WT 66%, p=0.42). There was a non-significant trend towards shorter PFS on EGFR TKIs with TP53 mutation (HR 1.74, CI 0.98–3.10, p=0.06). When limited to TP53 missense mutations (n=17), PFS was significantly shorter (HR 1.91, CI 1.01–3.60, p=0.04). Among 11 evaluable patients treated with T790M inhibitors, ORR was not significantly different (TP53 MUT 3/3 100%, WT 7/8 88%).
Patients with dual TP53/EGFR mutations, especially missense mutations, had marginally lower response rates and shorter PFS when treated with EGFR TKI therapy. Larger datasets are required to validate these observations.
PURPOSE Adjuvant cisplatin-based chemotherapy (ACT) is now an accepted standard for completely resected stage II and III A non-small-cell lung cancer (NSCLC). Long-term follow-up is important to ...document persistent benefit and late toxicity. We report here updated overall survival (OS) and disease-specific survival (DSS) data. PATIENTS AND METHODS Patients with completely resected stage IB (T2N0, n = 219) or II (T1-2N1, n = 263) NSCLC were randomly assigned to receive 4 cycles of vinorelbine/cisplatin or observation. All efficacy analyses were performed on an intention-to-treat basis. Results Median follow-up was 9.3 years (range, 5.8 to 13.8; 33 lost to follow-up); there were 271 deaths in 482 randomly assigned patients. ACT continues to show a benefit (hazard ratio HR, 0.78; 95% CI, 0.61 to 0.99; P = .04). There was a trend for interaction with disease stage (P = .09; HR for stage II, 0.68; 95% CI, 0.5 to 0.92; P = .01; stage IB, HR, 1.03; 95% CI, 0.7 to 1.52; P = .87). ACT resulted in significantly prolonged DSS (HR, 0.73; 95% CI, 0.55 to 0.97; P = .03). Observation was associated with significantly higher risk of death from lung cancer (P = .02), with no difference in rates of death from other causes or second primary malignancies between the arms. CONCLUSION Prolonged follow-up of patients from the JBR.10 trial continues to show a benefit in survival for adjuvant chemotherapy. This benefit appears to be confined to N1 patients. There was no increase in death from other causes in the chemotherapy arm.
To compare the efficacy of aflibercept (ziv-aflibercept), a recombinant human fusion protein targeting the vascular endothelial growth factor (VEGF) pathway, with or without docetaxel in ...platinum-pretreated patients with advanced or metastatic nonsquamous non-small-cell lung cancer.
In this international, double-blind, placebo-controlled phase III trial, 913 patients were randomly assigned to (ziv-)aflibercept 6 mg/kg intravenous (IV; n = 456) or IV placebo (n = 457), both administered every 3 weeks and in combination with docetaxel 75 mg/m(2). The primary end point was overall survival (OS). Other efficacy outcomes, safety, and immunogenicity were also assessed.
Patient characteristics were balanced between arms; 12.3% of patients had received prior bevacizumab. (Ziv-)Aflibercept did not improve OS (hazard ratio HR, 1.01; 95% CI, 0.87 to 1.17; stratified log-rank P = .90). The median OS was 10.1 months (95% CI, 9.2 to 11.6 months) for (ziv-)aflibercept and 10.4 months (95% CI, 9.2 to 11.9 months) for placebo. In exploratory analyses, median progression-free survival was 5.2 months (95% CI, 4.4 to 5.6 months) for (ziv-)aflibercept versus 4.1 months (95% CI, 3.5 to 4.3 months) for placebo (HR, 0.82; 95% CI, 0.72 to 0.94; P = .0035); overall response rate was 23.3% of evaluable patients (95% CI, 19.1% to 27.4%) in the (ziv-)aflibercept arm versus 8.9% (95% CI, 6.1% to 11.6%; P < .001) in the placebo arm. Grade ≥ 3 adverse events occurring more frequently in the (ziv-)aflibercept arm versus the placebo arm were neutropenia (28.0% v 21.1%, respectively), fatigue (11.1% v 4.2%, respectively), stomatitis (8.8% v 0.7%, respectively), and hypertension (7.3% v 0.9%, respectively).
The addition of (ziv-)aflibercept to standard docetaxel therapy did not improve OS. In exploratory analyses, secondary efficacy end points did seem to be improved in the (ziv-)aflibercept arm. The study regimen was associated with increased toxicities, consistent with known anti-VEGF and chemotherapy-induced events.
National Cancer Institute of Canada Clinical Trials Group Study BR.21 established erlotinib as a standard of care in patients with non-small-cell lung cancer (NSCLC) after failure of first- or ...second-line chemotherapy. The current study analyzes the influence of age on outcomes in BR.21.
BR.21 was a double-blind phase III trial that randomly assigned 731 patients to erlotinib 150 mg daily or placebo. End points included progression-free survival and overall survival (OS), response, quality of life (QOL), drug exposure, and toxicity, which are analyzed in this retrospective study by the following two age groups: >or= 70 years (elderly) or less than 70 years (young).
There were 163 elderly patients (112 on erlotinib, 51 on placebo) and 568 young patients (376 on erlotinib, 192 on placebo). There was no significant difference between age groups randomly assigned to erlotinib or placebo in progression-free survival (elderly: 3.0 v 2.1 months; hazard ratio HR = 0.63; 95% CI, 0.44 to 0.90; P = .009; young: 2.1 v 1.8 months; HR = 0.64; 95% CI, 0.53 to 0.76; P < .0001; interaction, P = .77) or OS (elderly: 7.6 v 5.0 months; HR = 0.92; 95% CI, 0.64 to 1.34; P = .67; young: 6.4 v 4.7 months; HR = 0.73; 95% CI, 0.61 to 0.89; P = .0014; interaction, P = .31). Response rates were similar between age groups. Elderly patients, compared with young patients, had significantly more overall and severe (grade 3 and 4) toxicity (35% v 18%; P < .001), were more likely to discontinue treatment as a result of treatment-related toxicity (12% v 3%; P < .0001), and had lower relative dose-intensity (64% v 82% received > 90% planned dose; P < .001).
Elderly patients treated with erlotinib gain similar survival and QOL benefits as younger patients but experience greater toxicity.
Small cell lung cancer (SCLC) is usually classified using the limited and extensive definition. The tumor, node, metastasis (TNM) classification should also be applicable to SCLC, but it has only ...been reported in small surgical series. The current analysis looks to the impact of the TNM system on the clinical staging of SCLC and of the new International Association for the study of Lung Cancer (IASLC) proposals.
Using the IASLC database, survival analyses were performed for clinically staged patients. Prognostic groups were compared, and the new IASLC TNM proposals were applied to this population and to the Surveillance, Epidemiology, and End Results (SEER) database.
The IASLC database contained 12,620 eligible cases of small cell histology. TNM staging was available for 8088 patients. Survival was directly correlated to both T and N category. Differences were more pronounced in patients without mediastinal or supraclavicular nodal involvement. Stage grouping using the sixth edition of TNM also differentiates survival except between IA and IB. Patients with pleural effusion regardless of the cytology have an intermediate prognosis between limited and extensive disease. The IASLC proposals for the seventh edition of the TNM classification also apply to this series of SCLC and to the SEER database.
TNM staging is recommended for SCLC, and stratification by stage I-III should be incorporated in clinical trials of early-stage disease. Further studies are needed to clarify the impact of pleural effusion and the extent of N3 disease.
Targeted therapies require life-long treatment, as drug discontinuation invariably leads to tumor recurrence. Recurrence is mainly driven by minor subpopulations of drug-tolerant persister (DTP) ...cells that survive the cytotoxic drug effect. In lung cancer, DTP studies have mainly been conducted with cell line models.
We conducted an in vivo DTP study using a lung adenocarcinoma patient-derived xenograft tumor driven by an EGFR mutation. Daily treatment of tumor-bearing mice for 5 to 6 weeks with the EGFR inhibitor erlotinib markedly shrunk tumors and generated DTPs, which were analyzed by whole exome, bulk population transcriptome, and single-cell RNA sequencing.
The DTP tumors maintained the genomic clonal architecture of untreated baseline (BL) tumors but had reduced proliferation. Single-cell RNA sequencing identified a rare (approximately 4%) subpopulation of BL cells (DTP-like) with transcriptomic similarity to DTP cells and intermediate activity of pathways that are up-regulated in DTPs. Furthermore, the predominant transforming growth factor-β activated cancer-associated fibroblast (CAF) population in BL tumors was replaced by a CAF population enriched for IL6 production. In vitro experiments indicate that these populations interconvert depending on the levels of transforming growth factor-β versus NF-κB signaling, which is modulated by tyrosine kinase inhibitor presence. The DTPs had signs of increased NF-κB and STAT3 signaling, which may promote their survival.
The DTPs may arise from a specific preexisting subpopulation of cancer cells with partial activation of specific drug resistance pathways. Tyrosine kinase inhibitor treatment induces DTPs revealing greater activation of these pathways while converting the major preexisting CAF population into a new state that may further promote DTP survival.
PDF
