Programmed Cell Death Protein 1 Inhibitors and MET Targeted Therapies in NSCLC With MET Exon 14 Skipping Mutations: Efficacy and Toxicity as Sequential Therapies

Introduction

NSCLC with MET exon 14 skipping mutation (METex14) is associated with poor outcomes. Integration of novel targeted therapies is challenging because of barriers in testing and drug access. We, therefore, sought to characterize the treatment patterns, outcomes, and emerging issues of treatment sequencing in patients with METex14-mutant NSCLC.

Methods

We reviewed all NSCLC cases with METex14 alterations between 2014 and 2020 across four Canadian cancer centers. Demographics, disease characteristics, systemic therapy, overall response rates (ORRs), survival, and toxicity were summarized.

Results

Among 64 patients with METex14-mutant NSCLC, the median overall survival was 23.1 months: 127.0 months in stage 1, 27.3 months in resected stage 2 and 3, and 16.6 months in unresectable stage 3 or 4 disease, respectively. In patients with advanced disease, 22% were too unwell for systemic treatment. MET tyrosine kinase inhibitors (TKIs) were administered to 28 patients with an ORR of 33%, median progression-free survival of 2.7 months, and 3.8 months for selective TKIs. Programmed cell death protein-1 (PD-1) inhibitors were given to 25 patients-the ORR was 44% and progression-free survival was 10.6 months. No responses were seen with subsequent MET TKIs after initial TKI treatment. Grade 3 or higher toxicities occurred in 64% of patients who received MET TKI after PD-1 inhibitors versus 8% in those who did not receive PD-1 inhibitors.

Conclusions

Many patients with advanced METex14 NSCLC were too unwell to receive treatment. PD-1 inhibitors seem effective as an initial treatment, although greater toxicity was seen with subsequent MET TKIs. Thus, timely testing for METex14 skipping and initial therapy are imperative to improving patient survival.

Consensus Recommendations to Optimize the Detection and Reporting of NTRK Gene Fusions by RNA-Based Next-Generation Sequencing

The detection of gene fusions by RNA-based next-generation sequencing (NGS) is an emerging method in clinical genetic laboratories for oncology biomarker testing to direct targeted therapy selections. A recent Canadian study (CANTRK study) comparing the detection of NTRK gene fusions on different NGS assays to determine subjects’ eligibility for tyrosine kinase TRK inhibitor therapy identified the need for recommendations for best practices for laboratory testing to optimize RNA-based NGS gene fusion detection. To develop consensus recommendations, representatives from 17 Canadian genetic laboratories participated in working group discussions and the completion of survey questions about RNA-based NGS. Consensus recommendations are presented for pre-analytic, analytic and reporting aspects of gene fusion detection by RNA-based NGS.

The NRF2 antagonist ML385 inhibits PI3K-mTOR signaling and growth of lung squamous cell carcinoma cells

BACKGROUND

Lung squamous cell carcinoma (LUSC) currently has limited therapeutic options because of the relatively few validated targets and the lack of clinical drugs for some of these targets. Although NRF2/NFE2L2 pathway activation commonly occurs in LUSC, NRF2 has predominantly been studied in other cancer models. Here, we investigated the function of NRF2 in LUSC, including in organoid models, and we explored the activity of a small molecule NRF2 inhibitor ML385, which has not previously been investigated in LUSC.

METHODS

We first explored the role of NRF2 signaling in LUSC cancer cell line and organoid proliferation through NRF2 knockdown or ML385 treatment, both in vivo and in vitro. Next, we performed Western blot and immunofluorescence assays to determine the effect of NRF2 inhibition on PI3K-mTOR signaling. Finally, we used cell viability and clonogenic assays to explore whether ML385 could sensitize LUSC cancer cells to PI3K inhibitors.

RESULTS

We find that downregulation of NRF2 signaling inhibited proliferation of LUSC cancer cell lines and organoids, both in vivo and in vitro. We also demonstrate that inhibition of NRF2 reduces PI3K-mTOR signaling, with two potential mechanisms being involved. Although NRF2 promotes AKT phosphorylation, it also acts downstream of AKT to increase RagD protein expression and recruitment of mTOR to lysosomes after amino acid stimulation. We also find that ML385 potentiates LUSC growth inhibition by a pan-PI3K inhibitor, which correlates with stronger inhibition of PI3K-mTOR signaling.

CONCLUSIONS

Our data provide additional support for NRF2 promoting LUSC growth through PI3K-mTOR activation and support development of NRF2 inhibitors for the treatment of LUSC.

CANTRK: A Canadian Ring Study to Optimize Detection of NTRK Gene Fusions by Next-Generation RNA Sequencing

The Canadian NTRK (CANTRK) study is an interlaboratory comparison ring study to optimize testing for neurotrophic receptor tyrosine kinase (NTRK) fusions in Canadian laboratories. Sixteen diagnostic laboratories used next-generation sequencing (NGS) for NTRK1, NTRK2, or NTRK3 fusions. Each laboratory received 12 formalin-fixed, paraffin-embedded tumor samples with unique NTRK fusions and two control non-NTRK fusion samples (one ALK and one ROS1). Laboratories used validated protocols for NGS fusion detection. Panels included Oncomine Comprehensive Assay v3, Oncomine Focus Assay, Oncomine Precision Assay, AmpliSeq for Illumina Focus, TruSight RNA Pan-Cancer Panel, FusionPlex Lung, and QIAseq Multimodal Lung. One sample was withdrawn from analysis because of sample quality issues. Of the remaining 13 samples, 6 of 11 NTRK fusions and both control fusions were detected by all laboratories. Two fusions, WNK2::NTRK2 and STRN3::NTRK2, were not detected by 10 laboratories using the Oncomine Comprehensive or Focus panels, due to absence of WNK2 and STRN3 in panel designs. Two fusions, TPM3::NTRK1 and LMNA::NTRK1, were challenging to detect on the AmpliSeq for Illumina Focus panel because of bioinformatics issues. One ETV6::NTRK3 fusion at low levels was not detected by two laboratories using the TruSight Pan-Cancer Panel. Panels detecting all fusions included FusionPlex Lung, Oncomine Precision, and QIAseq Multimodal Lung. The CANTRK study showed competency in detection of NTRK fusions by NGS across different panels in 16 Canadian laboratories and identified key test issues as targets for improvements.

Predictive Biomarkers for Immunotherapy in Lung Cancer: Perspective from the IASLC Pathology Committee

Immunotherapy including immune checkpoint inhibitors (ICIs) has become the backbone of treatment for the majority of lung cancers with advanced or metastatic disease. In addition, they have increasingly been used for early-stage tumors in neoadjuvant and adjuvant settings. Unfortunately, however, only a subset of patients experiences meaningful response to ICIs. While PD-L1 protein expression by immunohistochemistry (IHC) has played a role as the principle predictive biomarker for immunotherapy, its performance may not be optimal, and it suffers multiple practical issues with different companion diagnostic assays approved. Similarly, tumor mutation burden (TMB) has multiple technical issues as a predictive biomarker for ICIs. Now, ongoing research on tumor and host immune-specific factors has identified immunotherapy biomarkers that may provide better response and prognosis prediction, in particular in a multimodal approach. This review by the IASLC Pathology Committee provides an overview of various immunotherapy biomarkers including updated data on PD-L1 IHC and TMB, and assesssments of neoantigens, genetic and epigenetic signatures, immune microenvironment by IHC and transcriptomics, as well as microbiome and pathological response to neoadjuvant immunotherapies. The aim of this review is to underline the efficacy of new individual or combined predictive biomarkers beyond PD-L1 IHC and TMB.

Plasma-first: accelerating lung cancer diagnosis and molecular profiling through liquid biopsy

Introduction:

Molecular profiling of tumor tissue is the gold standard for treatment decision-making in advanced non-small cell lung cancer (NSCLC). Results may be delayed or unavailable due to insufficient tissue, prolonged wait times for biopsy, pathology assessment and testing. We piloted the use of plasma testing in the initial diagnostic workup for patients with suspected advanced lung cancer.

Methods:

Patients with ⩽15 pack-year smoking history and suspected advanced lung cancer referred to the lung cancer rapid diagnostic program underwent plasma circulating-tumor DNA testing using a DNA-based mutation panel. Tissue testing was performed per standard of care, including comprehensive next-generation sequencing (NGS). The primary endpoint was time from diagnostic program referral to cancer treatment in stage IV NSCLC patients (Cohort A) compared to a contemporary cohort not enrolled in the study (Cohort B) and an historical pre-COVID cohort referred to the program between 2018 and 2019 (Cohort C).

Results:

From January to June 2021, 20 patients were enrolled in Cohort A; median age was 70.5 years (range 33–87), 70% were female, 55% Caucasian, 85% never smokers, and 75% were diagnosed with NSCLC. Seven had actionable alterations detected in plasma or tissue (4/7 concordant). Fusions, not tested in plasma, were identified by immunohistochemistry for three patients. Mean result turnaround time was 17.8 days for plasma NGS and 23.6 days for tissue (p = 0.10). Mean time from referral to treatment initiation was significantly shorter in cohort A at 32.6 days (SD 13.1) versus 62.2 days (SD 31.2) in cohort B and 61.5 days (SD 29.1) in cohort C, both p < 0.0001.

Conclusion:

Liquid biopsy in the initial diagnostic workup of patients with suspected advanced NSCLC can lead to faster molecular results and shorten time to treatment even with smaller DNA panels. An expansion study using comprehensive NGS plasma testing with faster turnaround time is ongoing (NCT04862924).

Plasma first: Accelerating lung cancer diagnosis through liquid biopsy

3039

Background: Molecular profiling of tumor tissue is the gold standard for treatment decision making in advanced non-small cell lung cancer. Results may be delayed or unavailable due to insufficient tissue samples or prolonged wait times for biopsy, pathology assessment and testing. We piloted the use of plasma molecular testing as part of the initial diagnostic work-up for patients with suspected advanced lung cancer (NCT04863924). Methods: Patients with radiologic evidence of advanced lung cancer referred to the lung rapid diagnostic program underwent plasma circulating tumor DNA (ctDNA) testing using InVisionFirst-Lung, a next-generation sequencing (NGS) assay targeting 37 genes. Standard tissue testing was performed with comprehensive NGS (Oncomine). The primary endpoint was time to treatment in stage IV NSCLC patients compared to an historical pre-COVID-19 cohort (2018-9). Secondary endpoints included actionable targets identified in plasma, % of patients starting targeted therapy based on liquid biopsy and result turnaround time (TAT). Results: Between July 1 to December 31, 2021, 60 patients were enrolled. Median age was 70 years (range 33-91), 52% were female, 57% Caucasian, 48% never smokers. Of these, 73% had NSCLC, 12% small cell, 10% non-lung pathology and 5% declined tissue biopsy. Of 44 NSCLC patients, 5 (11%) had early-stage disease and underwent curative therapy. Most stage IV patients (79%) had systemic treatment. Median time to treatment initiation in the study cohort was 34 days (n = 31, range 10-90) versus 62 days (n = 101, range 13-159) in the historical cohort (p<0.0001). Two thirds (N = 23) of stage IV NSCLC patients had actionable alterations identified, (30% in current/ex-smokers); 18 started targeted therapy including 10 based on plasma results before tissue results were available. Median TAT was 7 days for plasma from blood draw to reporting (range 4-14) and 26 days for tissue molecular testing (range 11-42), p<0.0001. Concordance was high between plasma and tissue testing (70%). Liquid biopsy identified actionable alterations for 3 patients not identified by tissue NGS. In 4 cases, plasma testing failed to identify actionable alterations detected in tissue, due to undetectable plasma ctDNA. Conclusions: Liquid biopsy in the initial diagnostic workup of patients with suspected advanced NSCLC leads to faster molecular results and shortens time to treatment compared to tissue testing alone. Supplementing the current standard of tissue molecular testing with a plasma-first approach during the diagnostic work up of patients with suspected advanced lung cancer may increase access to precision medicine and improve patient outcomes. Clinical trial information: NCT04863924. [Table: see text]

Molecular testing and patterns of treatment in patients with NSCLC: An IASLC analysis of ASCO CancerLinQ Discovery Data

9128

Background: Precision medicine has resulted in improved outcomes for non-small cell lung cancer (NSCLC); while molecular testing is considered critical for guiding treatment decisions for advanced stage NSCLC, adoption of testing in routine practice is variable. We analyzed the factors contributing to molecular testing and treatment patterns in patients with lung cancer. Methods: The ASCO CancerLinQ Discovery dataset was queried to identify patients diagnosed with lung cancer between the years 2010-2018. Data on demographics, tumor stage, histology and treatments were extracted, and receipt of molecular testing was investigated as the primary outcome. Univariate association of each clinicopathological variable with molecular testing outcome was performed using chi-square test for categorical variables and ANOVA test for numerical variables. A multivariable logistic regression analysis with backward selection at an alpha of 0.05 was reported. All analyses were conducted using SAS 9.4. Results: A total of 37,925 NSCLC patients with stage IV disease were analyzed. Patient characteristics: median age 65 years, 51% male, 68% white, 33.5% adenocarcinoma. Approximately 22% of all NSCLC patients had molecular testing results. In adenocarcinoma patients, 49% had molecular testing results available. In the stage IV group, 47% were treated with chemotherapy, 16% with immunotherapy and 3% with targeted therapy. On multivariable analysis, females were more likely to have molecular testing compared to males [(OR: 1.29 (1.22-1.37); p < 0.001]. Compared to White patients, Black patients were less likely to have molecular testing [OR: 0.89 (0.81-0.97); p = 0.009] and Asians were more likely to undergo testing [OR: 2.22 (1.79-2.75); p < 0.001]. Hispanic patients were more likely to undergo molecular testing compared to non-Hispanics [OR:1.24 (1.02-1.52); p = 0.03]. Additionally, treatment with immunotherapy [OR: 1.86 (1.72-2.01); p < 0.001] and targeted therapy [OR: 2.29 (2.00-2.64); p < 0.001] were associated with significantly higher likelihood of having molecular testing. These results were also confirmed on a subgroup analysis of adenocarcinoma patients. Conclusions: In this analysis of a US-based real-world dataset of stage IV NSCLC patients, White race and female sex are associated with higher likelihood of having molecular test performed. The percentage of patients undergoing testing remains sub-optimal.

Immune Resistance Interrogation Study (IRIS): A prospective comprehensive multi-omic analysis in patients with intrinsic and acquired resistance to immunotherapy

TPS2679

Background: Immune checkpoint inhibitors (ICI) have demonstrated efficacy in a wide variety of cancers. Nevertheless, only a small proportion of patients derive a durable benefit. Mechanisms underlying primary and acquired resistance are still incompletely understood. They comprise tumor-intrinsic factors such as genomic and transcriptomic changes; upregulation of immunosuppressive subsets; T cell exhaustion; and promotion of an immune-tolerant tumor microenvironment. The collection of tumor biopsy at disease progression (PD) is challenging both in clinical and research settings as this often occurs at the time of treatment discontinuation. However, the analysis of these samples can lead to novel strategies to prevent or reverse immune resistance. Thus, the current approach to begin a profiling study with patients at the time of PD on ICI enables access and interrogation of such samples. Methods: IRIS is a prospective, investigator-initiated trial at the Princess Margaret Cancer Centre that aims to extensively characterize the genomic, transcriptomic, epigenetic and immunophenotypic profiles of tumors with primary versus acquired resistance to ICI-based therapy. Primary resistance is defined as PD at the first on-treatment imaging, whereas acquired resistance is defined as PD occurring after an initial partial or complete response or following disease stability lasting ≥6 months. Additional objectives include the evaluation of radiomic parameters on standard radiological imaging, investigation of fecal microbiome, generation of patient-derived organoids and facilitation of data and sample sharing with the research community. The planned samples size is 100 patients. A one-time fresh tumor biopsy, blood and stool samples and archival tissue (when available) are collected at the time of PD on ICI (baseline) from all the participants. Longitudinal blood samples are obtained every 2-3 months (around the time of tumor imaging) until PD in patients receiving a subsequent treatment. Subjects who are not amenable for therapy undergo blood collections at the time of further PD. Molecular characterization of tumor samples includes: DNA/RNA sequencing, Assay of Transposase Accessible Chromatin (ATAC)-sequencing, Cellular Indexing of Transcriptomes and Epitopes (CITE)-sequencing, multiplexed immunohistochemistry and flow cytometry. Results of NGS performed on the first biopsy core are returned to patient and physician. Key eligibility criteria include diagnosis of solid tumor, progression to ICI as the most recent line of treatment and disease amenable to core needle biopsy. The IRIS trial, activated in October 2020, is currently open to enrollment. As of January 2021, 21 patients have been enrolled and a total of 92 tissue cores, 42 blood and 20 stool samples have been collected. Clinical trial information: NCT04243720.

Sequencing of systemic therapies in advanced NSCLC with MET exon 14 skipping mutation: A multicenter experience

e21123

Background: The treatment landscape for patients with metastatic non-small cell lung cancer (mNSCLC) with a MET exon 14 skipping mutation ( MET ex14) is rapidly changing, with recent approvals of MET selective tyrosine kinase inhibitors (TKIs) and reports of durable response to immune checkpoint inhibitors (ICI), particularly among those with sarcomatoid histology. Currently there are no published data that inform the sequencing of TKIs and ICI regimens. We sought to characterize treatment patterns and outcomes in this population at 3 Ontario cancer centres. Methods: We reviewed all mNSCLC patients with MET ex14 identified by tissue or plasma NGS in the last 4 years. Patients with EGFR co-mutation or MET amplification alone were excluded. All systemic therapies and outcomes of overall response (ORR), progression free survival (PFS), overall survival (OS), and adverse events (AEs) were captured. Results: We identified 43 patients with MET alterations, of whom 29 had MET ex14: median age 73 years (54-92), 66% female, 79% non-smokers. Tumor histology was adenocarcinoma in 76%, pleomorphic/sarcomatoid in 21% and adenosquamous in 3% of patients. 69% of patients had PD-L1 ≥50%. At presentation, 20% of patients had high disease burden and ECOG ≥2. Among 15 patients who received ICI, ORR with ICI monotherapy was 45% (10/11 had PD-L1 ≥50%) and ORR with ICI plus chemotherapy was 75% (4/4 had PD-L1 0-49%). Responses were seen in 50% of non-smokers (7/12 had PD-L1 ≥50%). The median PFS with ICI was 10.6 months (1.7-NR). MET TKIs were received by 18 patients (16 crizotinib, 1 capmatinib, 1 cabozantinib), with an ORR of 28% (30% amongst those who received crizotinib first line). The median PFS with TKIs was 2.6 months (1.2-8.9). Median OS for the entire cohort was 24.4 months (10.1-48.3). Patients who received initial ICI (n = 13) compared to those who received initial TKI (n = 11) had significantly longer OS (48.3 vs 13.6 months; p = 0.005), not controlled for prognostic factors. All patients who progressed after ICI (9/13) received further treatment while only 50% of patients who progressed after TKI (8/11) received subsequent therapy. 7 patients received TKI therapy after ICI with a median time to TKI of 35 days (24-181). 6 patients (85.7%) experienced an early grade ≥3 AE (4 transaminitis, 2 pneumonitis) resulting in permanent discontinuation of TKI in half of patients. There were no treatment-related deaths. Conclusions: Patients with MET ex14 NSCLC benefit from ICI irrespective of PD-L1 expression and smoking history. ORR and PFS with earlier generation TKIs (crizotinib) were poor. Increased toxicity is seen when a TKI is used after ICI and careful monitoring is necessary. Future studies focusing on the optimal sequencing of TKIs and ICI-containing therapy should be prioritized, as well as broader access to newer generation MET TKIs with greater activity.

The value of defining molecular resistance in patients with progressive EGFR and ALK-driven lung cancer in a public system

3126

Background: Repeat molecular profiling, except to detect EGFR T790M, is not routinely performed in Canadian patients with lung cancer progressing on EGFR tyrosine kinase inhibitors (TKIs). We performed genomic profiling on post-progression biopsies in patients with stage IV non-small cell lung cancer (NSCLC) and known EGFR/ ALK aberrations treated with TKIs to identify resistance mechanisms, evaluate options for subsequent treatment, and to assess clinical trial eligibility and costs. Methods: From Feb 2018-Aug 2020, post-progression tumour biopsies from consenting patients at a major cancer centre underwent genomic profiling (ThermoFisher OCA v3.0 including hotspots, fusions, and copy number variations in 161 cancer-associated genes). Outcomes of interest were the identification of resistance mutations, actionable targets, clinical trial eligibility (per clinicaltrials.gov), and costs. Results: Thirty-two patients consented to the study. Most, 84% (n = 27), had successful testing completed while 16% (n = 5) had insufficient tissue. Median age of the cohort was 56 yrs, 59% (n = 16) were female, 74% (n = 20) were never-smokers, 81% (n = 22) had ECOG performance status 0-1, and 67% (n = 18) were Asian. The majority, 81% (n = 22) had EGFR mutated NSCLC, and had progressed on EGFR TKIs (15 with previously identified T790M had progressed on osimertinib), and 19% (n = 5) had ALK fusions. Patients had received a median of 2 prior lines of targeted therapy prior to re-biopsy (IQR 1.5,3). One patient had evidence of small cell transformation and associated TP53 and RB1 mutations, 11% (n = 3) had acquired EGFR C797S mutations, and 11% (n = 3) had acquired ALK resistance point mutations (G1202R n = 2, I1171N n = 1). Genomic profiling identified additional actionable targets in 19% of patients (n = 5: MET exon 14 skip mutation n = 1, MET amplification n = 2, BRAF V600E n = 2). Overall, 33% (n = 9) patients had management-changing resistance mechanisms identified (small cell transformation n = 1, actionable targets n = 5, ALK inhibitor resistance = 3). New clinical trial options based on genomic profiling results were identified for 67% (n = 18) of patients. Incremental costs for repeat genomic profiling were approximately $880 CAD per case. Conclusions: Molecular profiling upon development of resistance to targeted therapy in our cohort revealed actionable resistance mechanisms for over a third of patients and clinical trial options for 67%. These incremental benefits for patients highlight the importance of routine molecular profiling in the setting of acquired TKI resistance in lung cancer.

Elderly patients with unresectable stage 3 NSCLC treated with definitive chemoradiation with or without durvalumab: Safety and outcomes

8547

Background: Recently, it has been demonstrated that the addition of durvalumab after chemoradiation (CRT) in unresectable stage 3 non-small cell lung cancer (NSCLC) significantly improves overall survival (OS). The benefit of CRT in elderly patients is considered controversial given its increased toxicity. As such, CRT followed by durvalumab in elderly patients may be underutilized despite its demonstrated superiority. The practice pattern at our center is to offer curative treatment unless clearly contraindicated. We sought to investigate the outcomes of elderly patients treated with CRT +/- durvalumab at our center. Methods: We conducted a review of all stage 3 NSCLC patients treated with CRT between 2018 and 2020. Patients were analyzed based on age: < 70 years, ≥70 years. Endpoints evaluated were treatment patterns, toxicity, progression free survival (PFS) and overall survival (OS). Results: We identified 115 stage 3 patients: 44 patients ≥70 years (70-89) and 71 patients < 70 years (34-69). Patients were fit: ECOG 0-1 (98%/97%), mean Charlson comorbidity index (CCI) (1.1/0.9) in elderly vs young patients; p > 0.05. All other baseline characteristics including PD-L1 expression were similar. The chemotherapy regimens (platinum in combination with etoposide, paclitaxel or pemetrexed), dose intensity (97% vs 97%) and percentage of planned cycles received (91% vs 96%) were similar. There were 2 treatment related deaths from CRT among the younger cohort and none in the elderly patients. At the completion of CRT, 75% of elderly and 72% of young patients received durvalumab. Clinician/patient preference was the most common reason for not receiving consolidation durvalumab in older patients (55% vs 25%). The median time to starting durvalumab was 43 days in the elderly and 37 days in young patients (p = 0.19). Durvalumab was well tolerated in the elderly and incidence of grade ≥3 immune-related adverse events was 9% compared to 6% in young patients; p = 0.68. The durvalumab completion rates were 30% in elderly and 24% in young patients; p = 0.22. Median PFS was similar between elderly and young patients (17.9 vs 10.6 months respectively; p = 0.07), even after adjusting for the CCI (HR 0.60; p = 0.07). The 24- and OS rates are also similar (p = 0.93): 77% in elderly and 77% in young patients. Conclusions: Definitive CRT followed by durvalumab can be safely delivered in elderly patients ≥70 years with comparable outcomes. The non-significant trend towards better PFS in elderly patients suggests that only select fit patients are being referred for treatment. In conclusion, all patients should undergo comprehensive oncologic assessment to determine if curative intent treatment can be delivered to avoid undertreatment of elderly patients.

Impact of KRAS mutational variant on response to immunotherapy in metastatic NSCLC

e21127

Background: KRAS alterations constitute the most common driver mutations in metastatic non-small cell lung cancers (mNSCLC) and occur in approximately 30% of patients. KRAS mutational subtype as well as the presence of co-mutations has been associated with altered activation of downstream signaling pathways in preclinical models. We hypothesize that different KRAS G12C mutational subsets will be associated with variable clinical outcome and response to therapy. To this end, we have performed a retrospective analysis of survival and treatment outcomes by KRAS mutation subtype (G12C vs non-G12C). Methods: A review of KRAS-mutated mNSCLC patients treated with immunotherapy between 2013 and 2020 was conducted. Patient demographics, smoking status, KRAS mutational subtype, co-mutations and PD-L1 status were collected. Overall response rate (ORR) and progression-free survival (PFS) were analyzed in each subgroup. Results: 98 KRAS mutant mNSCLC patients were treated with immune checkpoint inhibitors (ICI): 37% with a KRAS G12C mutation, 62% with a non-G12C mutation. Patients with a G12C mutation were more likely to be of Caucasian ancestry (86% vs 56%; p = 0.01) whereas all other characteristics were similar between the groups including smoking history, PD-L1 expression ≥50% (61% vs 40%) and the presence of a TP53 co-mutation (48% vs. 54%); all p > 0.05. Treatment patterns were similar between the groups, with PD-1 inhibitor monotherapy given in 86% vs 79% of KRAS G12C and non-G12C patients. Overall response rate was 51% vs 27% in G12C vs non-G12C (p = 0.03). PFS was superior in G12C mutants (19.6 months vs 4.0 months), even after adjusting for smoking history, TP53 co-mutation status and PD-L1 expression (adjusted HR 0.51; p = 0.02). In subgroup analyses, the superiority in PFS was driven by the G12C mutants with high PD-L1 expression (n = 19): 26.8 months in G12C, PD-L1 high vs 4.7 months in G12C, PD-L1 low vs. 4.7 months in KRAS transversion mutations, PD-L1 high vs 4.0 months in transversion mutations, PD-L1 low vs. 3.0 months in transition mutations; p < 0.001. Conclusions: The presence of a KRAS G12C mutation is associated with improved ORR and PFS after treatment with ICI compared to non-G12C mutations in mNSCLC. The greatest benefit in PFS was observed in the subgroup with G12C mutation and high PD-L1 expression. Differential activation of downstream signaling associated with specific KRAS codon 12 mutation variants may modulate the composition of the tumor immune microenvironment thereby contributing to the variable response to immunotherapy. Further understanding on these molecular mechanisms may direct the development of new treatment strategies in KRAS mutant lung cancers.

Durability of CNS disease control in NSCLC patients with brain metastases treated with immune checkpoint inhibitors plus cranial radiotherapy

BACKGROUND

Immune checkpoint inhibitors (ICIs) have excellent systemic activity and are standard first line treatment in EGFR/ALK wild type metastatic non-small cell lung cancer (NSCLC). However, their role in patients with brain metastases, which affects over 20% of patients and cause significant morbidity, is less clear.

METHODS

We reviewed patients with EGFR/ALK wild-type mNSCLC with CNS metastases. Serial MRIs were reviewed to determine the time to intracranial progression (iPFS). Multivariate regression was performed to adjust for the disease-specific graded prognostic score (ds-GPA).

RESULTS

We identified 36 ICI- and 33 chemotherapy-treated patients with baseline CNS metastases and available serial MRIs (average frequency:3.5 months). Baseline radiation was given except for 2 chemotherapy-treated patients with asymptomatic solitary metastasis. The CNS burden of disease was higher in the ICI-treated group (ICI:22% vs. chemotherapy:0% had >10 lesions; p = 0.02), but the utilization of WBRT was not (ICI:31% vs. chemotherapy:45%; p = 0.09). At the time of progression, CNS involvement was identified in 30 % of ICI-treated patients compared to 64 % of chemotherapy controls (p = 0.02). ICI-treated patients had superior iPFS (13.5 vs 8.4 months) that remained significant in multivariate analysis (HR 1.9; 95%CI 1.1--3.4). Superior CNS outcomes in ICI-treated patients were driven by the PD-L1 high subgroup where the 12-month cumulative incidence rate of CNS progression was 19% in ICI-treated PD-L1 ≥ 50%, 50% in ICI-treated PD-L1 < 50% and 58% in chemotherapy-treated patients (p = 0.03).

CONCLUSIONS

Remarkable CNS disease control is seen with baseline RT plus ICIs in patients with PD-L1 ≥ 50%. Strategies for delaying WBRT should be investigated in this subgroup of patients.

The International Association for the Study of Lung Cancer Global Survey on Programmed Death-Ligand 1 Testing for NSCLC

INTRODUCTION

Programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) is required to determine the eligibility for pembrolizumab monotherapy in advanced NSCLC worldwide and for several other indications depending on the country. Four assays have been approved/ Communauté Européene-In vitro Diagnostic (CV-IVD)-marked, but PD-L1 IHC seems diversely implemented across regions and laboratories with the application of laboratory-developed tests (LDTs).

METHOD

To assess the practice of PD-L1 IHC and identify issues and disparities, the International Association for the Study of Lung Cancer Pathology Committee conducted a global survey for pathologists from January to May 2019, comprising multiple questions on preanalytical, analytical, and postanalytical conditions.

RESULT

A total of 344 pathologists from 64 countries participated with 41% from Europe, 24% from North America, and 18% from Asia. Besides biopsies and resections, cellblocks were used by 75% of the participants and smears by 11%. The clone 22C3 was most often used (69%) followed by SP263 (51%). They were applied as an LDT by 40% and 30% of the users, respectively, and 76% of the participants developed at least one LDT. Half of the participants reported a turnaround time of less than or equal to 2 days, whereas 13% reported that of greater than or equal to 5 days. In addition, quality assurance (QA), formal training for scoring, and standardized reporting were not implemented by 18%, 16%, and 14% of the participants, respectively.

CONCLUSIONS

Heterogeneity in PD-L1 testing is marked across regions and laboratories in terms of antibody clones, IHC assays, samples, turnaround times, and QA measures. The lack of QA, formal training, and standardized reporting stated by a considerable minority identifies a need for additional QA measures and training opportunities.

Subtypes of EGFR- and HER2-Mutant Metastatic NSCLC Influence Response to Immune Checkpoint Inhibitors

INTRODUCTION

The efficacy of immune checkpoint inhibitors (ICIs) is low among EGFR-mutated non-small-cell lung cancer (NSCLC), although prolonged responses have occasionally been reported. We investigated the association between mutation subtypes and ICI outcomes among HER2- and EGFR-mutated NSCLC.

PATIENTS AND METHODS

This retrospective single-center study analyzed patients with EGFR- and HER2-mutated advanced NSCLC who received at least 1 cycle of ICI between 2013 and 2019. Patient characteristics, mutation subtype, and ICI outcomes.

RESULTS

Among 48 patients with advanced NSCLC, 14 (29%) had HER2 mutations and 34 (71%) had EGFR mutations. EGFR mutations included 16 (47%) exon 19 deletion, 7 (21%) L858R, 5 (15%) uncommon, and 6 (18%) exon 20 insertion. Compared to EGFR-sensitizing mutations (ESMs), HER2 and EGFR exon 20 mutations were associated with a trend toward better response (respectively, ESM, HER2, and EGFR exon 20: 11%, 29%, and 50%; P = .07) and significantly better disease control rates (respectively, 18%, 57%, and 67%; P = .008). Compared to ESM, HER2 mutations (adjusted hazard ratio, 0.35; P = .02) and EGFR exon 20 mutations (adjusted hazard ratio, 0.37; P = .10 trend) were also associated with improved PFS. Programmed death ligand 1 (PD-L1) expression remained an independent predictor of PFS (adjusted hazard ratio, 0.42; 95% confidence interval, 0.23-0.76; P = .004). The 6-month PFS rates were 29% (HER2), 33% (EGFR exon 20), and 4% (ESM). ICIs were generally well tolerated in this population. Importantly, no immune-related toxicity was observed in 10 patients who received a tyrosine kinase inhibitor (TKI) as the immediate next line treatment after ICI.

CONCLUSION

HER2 and EGFR exon 20 mutations derive greater benefit from ICIs with comparable PFS to wild-type historical second/third-line unselected cohorts. ICIs remain a treatment option for this genomic subgroup, given the absence of approved targeted therapies for these rare mutations.

Diagnostic patterns of non-small-cell lung cancer at Princess Margaret Cancer Centre

Background

Accurate classification of lung cancer subtypes has become critical in tailoring lung cancer treatment. Our study aimed to evaluate changes in diagnostic testing and pathologic subtyping of advanced non-small-cell lung cancer (nsclc) over time at a major cancer centre.

Methods

In a review of patients diagnosed with advanced nsclc at Princess Margaret Cancer Centre between 2007-2009 and 2013-2015, diagnostic method, sample type and site, pathologic subtype, and use of immunohistochemistry (ihc) staining and molecular testing were abstracted.

Results

The review identified 238 patients in 2007-2009 and 283 patients in 2013-2015. Over time, the proportion of patients diagnosed with adenocarcinoma increased to 73.1% from 60.9%, and diagnoses of nsclc not otherwise specified (nos) decreased to 6.4% from 18.9%, p < 0.0001. Use of diagnostic bronchoscopy decreased (26.9% vs. 18.4%), and mediastinal sampling procedures, including endobronchial ultrasonography, increased (9.2% vs. 20.5%, p = 0.0001). Use of ihc increased over time to 76.3% from 41.6% (p < 0.0001). Larger surgical or core biopsy samples and those for which ihc was performed were more likely to undergo biomarker testing (both p < 0.01).

Conclusions

Customizing treatment based on pathologic subtype and molecular genotype has become key in treating patients with advanced lung cancer. Greater accuracy of pathology diagnosis is being achieved, including through the routine use of ihc.

Minimalist approaches to cancer tissue-of-origin classification by DNA methylation

Classification of cancers by tissue-of-origin is fundamental to diagnostic pathology. While the combination of clinical data, tissue histology, and immunohistochemistry is usually sufficient, there remains a small but not insignificant proportion of difficult-to-classify cases. These challenging cases provide justification for ancillary molecular testing, including high-throughput DNA methylation array profiling, which promises cell-of-origin information and compatibility with formalin-fixed specimens. While diagnostically powerful, methylation profiling platforms are costly and technically challenging to implement, particularly for less well-resourced laboratories. To address this, we simulated the performance of "minimalist" methylation-based tests for cancer classification using publicly-available and internal institutional profiling data. These analyses showed that small and focused sets of the most informative CpG biomarkers from the arrays are sufficient for accurate diagnoses. As an illustrative example, one classifier, using information from just 53 out of about 450,000 available CpG probes, achieved an accuracy of 94.5% on 2575 fresh primary validation cases across 28 cancer types from The Cancer Genome Atlas Network. By training minimalist classifiers on formalin-fixed primary and metastatic cases, generally high accuracies were also achieved on additional datasets. These results support the potential of minimalist methylation testing, possibly via quantitative PCR and targeted next-generation sequencing platforms, in cancer classification.

A phase III randomized trial of pleurectomy/decortication plus chemotherapy with or without adjuvant hemithoracic intensity-modulated pleural radiation therapy (IMPRINT) for malignant pleural mesothelioma (MPM) (NRG LU-006)

TPS9079

Background: Pleurectomy/Decortication (P/D) with neoadjuvant or adjuvant chemotherapy has become a common lung-sparing surgical approach for MPM. Adjuvant hemithoracic IMPRINT was developed at Memorial Sloan Kettering Cancer Center and safe in a multi-institutional phase II study, with promising survival outcomes. The National Cancer Institute (NCI) sponsored this phase III randomized cooperative group trial to test the efficacy of this lung-sparing trimodality approach for resectable MPM. Methods: Patients with newly diagnosed MPM amenable to P/D are enrolled and undergo P/D followed by adjuvant platinum/pemetrexed (preferred) or neoadjuvant chemotherapy followed by P/D. Patients are stratified by histologic subtype, resection status (R0/1 vs. R2), and center patient volume (≤10 vs. > 10 P/Ds per year). Within 8 weeks after completion of the second modality patients are randomized 1:1 to undergo hemithoracic IMPRINT vs. no further therapy. All IMPRINT contours and treatment plans will be centrally reviewed. A contouring atlas and treatment planning constraints for target structures and organs at risk including acceptable and unacceptable variations and deviations were developed. Photon and proton therapy are permitted. The primary endpoint of the study is overall survival. Secondary endpoints include local failure-free, distant-metastases-free and progression-free survival, treatment-related toxicities (CTCAE v5.0) and change in quality-of-life (EORTC QLQ-C30 mean score changes at 9 months post randomization). The target accrual is 150 patients. This study was activated on January 29, 2020. Over 20 institutions have already committed to opening the study which is open to all National Clinical Trials Network (NCTN) sites. Treatment planning guidelines and helpful hints for photon and proton therapy will be presented. Conclusions: NRG LU-006 (clinicaltrials.gov: NCT04158141 ) is open to accrual. This is the first NRG Oncology randomized phase III trial on MPM and evaluates the use of IMPRINT following lung-sparing P/D and chemotherapy. This project was supported by grants U10CA180868 (NRG Oncology Operations), U10CA180822 (NRG Oncology SDMC), U24CA180803 (IROC) from the National Cancer Institute (NCI). Clinical trial information: NCT04158141.

Genomic analysis of driver-negative lung adenocarcinoma (LA) in lifetime never smokers

3571

Background: Genomic events giving rise to driver negative LA in never smokers remain elusive. Here we report results of whole exome sequencing (WES) and targeted RNA sequencing in NS who had no mutation drivers found on routine clinical testing by targeted next generation sequencing (NGS). Methods: The cohort of never smokers with EGFR/ALK negative LA by clinical biomarker testing at Princess Margaret Cancer Centre, were first subjected to various clinical NGS profiling platforms (table). Where tissue was available, those negative for potential drivers in the clinical NGS then underwent WES (mean coverage > 200x) and Oncomine comprehensive v.3 RNA sequencing. We analyzed mutational signatures (MS) of the driver negative cohort based on the COSMIC catalog and assessed the median tumor mutation burden (mTMB mut/Mb -Megabase) in cases without a smoking MS, to avoid confounders. Results: Of 159 never smokers profiled with clinical NGS, potential drivers were found in 86 (54%): 75 (87%) with mutations in known LA driver genes and 11 (13%) with fusions. Among the remaining never smokers that tested negative by clinical NGS, 35 (48%) had available tissue for further testing. The Oncomine panel identified 9 cases (25%) with fusions or MET exon14 mutation (n = 7). Within the driver negative group, 24 (92%) underwent WES. Three tumors had WES base substitution patterns that were consistent with a smoking-related MS (MS4). Twenty-one patients exhibited signatures found common across all cancer types (MS 5), associated with DNA mismatch repair (MS 6, MS 20) or APOBEC over-activation (MS 2, MS13). In the driver-negative group, we identified 7 pts with somatic mutations in the KMT2 family (4 KMT2C, 4 KMT2A, 1 KMT2D), known for putative tumor suppressors and histone methyltransferases. mTMB on the driver negative group was 1.92, while one outlier with APOBEC MS and KMT2C/A mutations had a TMB of 16.8. Conclusions: Never smokers with driver negative LA are a heterogeneous group, with different MS and a wide TMB range. Mutations on KMT2 family are frequently found in driver negative LA in never smokers and warrant further investigations. [Table: see text]

CCTG BR.34: A randomized trial of durvalumab and tremelimumab +/- platinum-based chemotherapy in patients with metastatic (Stage IV) squamous or nonsquamous non-small cell lung cancer (NSCLC)

9502

Background: First-line therapy for advanced NSCLC includes PD-1 checkpoint inhibitor (ICI) monotherapy, and in combination with chemotherapy. Combination ICI have also demonstrated better survival compared to chemotherapy (CM-227). In CCTG BR.34, we compared overall survival (OS) in patients with advanced NSCLC receiving first-line durvalumab plus tremelimumab (DT) with or without platinum doublet chemotherapy (CT). Methods: This international, open-label, randomized trial accrued 301 participants from Canada and Australia, with stage IV NSCLC, EGFR/ALK wildtype, ECOG PS 0/1. Patients were randomized to DT for 4 cycles or DT+CT (pemetrexed- or gemcitabine-platinum), with ongoing D or D + pemetrexed (non-squamous) maintenance until disease progression. Stratification factors included histology, stage IVA v. IVB and smoking status. The primary endpoint was OS; secondary endpoints included progression-free survival (PFS), objective response rate (ORR = CR + PR) and adverse events (AEs). Results: At a median follow up of 16.6 months, no significant difference in OS was seen between the two treatment arms, with a median OS of 16.6 months with DT+CT v. 14.1 months with DT, (estimated HR 0.88, 90% CI 0.67-1.16). PFS was significantly improved in the DT+CT arm (stratified HR 0.67, 95% CI 0.52-0.88; medians 7.7 v. 3.2 months). ORR was higher in the DT+CT arm, 28% v. 14%, (odds ratio 2.1, p=0.001). Preplanned subgroup analysis demonstrated no significant differences in treatment outcomes by plasma TMB (<20 v. ≥20 mut/Mb, Guardant OMNI), age, sex, or smoking status. There was a trend to improved OS with DT+CT in the subgroup with PD-L1 TPS≥50%, (HR 0.64, 95% CI 0.40-1.04, p=0.07). Plasma TMB<20 mut/Mb was associated with shorter survival in both treatment groups (HR 1.99, 95% 1.3-3.1). Toxicity was greater in the DT+CT arm, with grade≥3 adverse events in 82% v. 70%, (p=0.02), most commonly dyspnea, nausea and cough. The incidence of immune-related adverse events was similar between arms (colitis 11%, pneumonitis 6%, endocrinopathy 21%). Grade 5 events occurred in 2.7%, (5 with DT+CT, 3 with DT). Conclusions: The addition of CT to first-line DT did not improve OS in advanced NSCLC. CT+DT improved ORR and PFS, and was associated with greater toxicity. No differential effects were seen by PD-L1 TPS nor bTMB. These data suggest that adding chemotherapy to ICI may be beneficial in those with PD-L1 TPS >=50%, and warrant further analysis in independent datasets. Clinical trial information: NCT03057106 .

Canadian Multicenter Project on Standardization of Programmed Death-Ligand 1 Immunohistochemistry 22C3 Laboratory-Developed Tests for Pembrolizumab Therapy in NSCLC

INTRODUCTION

The programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) assay is used to select patients for first or second-line pembrolizumab monotherapy in NSCLC. The PD-L1 IHC 22C3 pharmDx assay requires an Autostainer Link 48 instrument. Laboratories without this stainer have the option to develop a highly accurate 22C3 IHC laboratory-developed test (LDT) on other instruments. The Canadian 22C3 IHC LDT validation project was initiated to harmonize the quality of PD-L1 22C3 IHC LDT protocols across 20 Canadian pathology laboratories.

METHODS

Centrally optimized 22C3 LDT protocols were distributed to participating laboratories. The LDT results were assessed against results using reference PD-L1 IHC 22C3 pharmDx. Analytical sensitivity and specificity were assessed using cell lines with varying PD-L1 expression levels (phase 1) and IHC critical assay performance controls (phase 2B). Diagnostic sensitivity and specificity were assessed using whole sections of 50 NSCLC cases (phase 2A) and tissue microarrays with an additional 50 NSCLC cases (phase 2C).

RESULTS

In phase 1, 80% of participants reached acceptance criteria for analytical performance in the first attempt with disseminated protocols. However, in phase 2A, only 40% of participants reached the desired diagnostic accuracy for both 1% and 50% tumor proportion score cutoff. In phase 2B, further protocol modifications were conducted, which increased the number of successful laboratories to 75% in phase 2C.

CONCLUSIONS

It is possible to harmonize highly accurate 22C3 LDTs for both 1% and 50% tumor proportion score in NSCLC across many laboratories with different platforms. However, despite a centralized approach, diagnostic validation of predictive IHC LDTs can be challenging and not always successful.

Crizotinib inhibition of ROS1-positive tumours in advanced non-small-cell lung cancer: a Canadian perspective

The ros1 kinase is an oncogenic driver in non-small-cell lung cancer (nsclc). Fusion events involving the ROS1 gene are found in 1%-2% of nsclc patients and lead to deregulation of a tyrosine kinase-mediated multi-use intracellular signalling pathway, which then promotes the growth, proliferation, and progression of tumour cells. ROS1 fusion is a distinct molecular subtype of nsclc, found independently of other recognized driver mutations, and it is predominantly identified in younger patients (<50 years of age), women, never-smokers, and patients with adenocarcinoma histology. Targeted inhibition of the aberrant ros1 kinase with crizotinib is associated with increased progression-free survival (pfs) and improved quality-of-life measures. As the sole approved treatment for ROS1-rearranged nsclc, crizotinib has been demonstrated, through a variety of clinical trials and retrospective analyses, to be a safe, effective, well-tolerated, and appropriate treatment for patients having the ROS1 rearrangement. Canadian physicians endorse current guidelines which recommend that all patients with nonsquamous advanced nsclc, regardless of clinical characteristics, be tested for ROS1 rearrangement. Future integration of multigene testing panels into the standard of care could allow for efficient and cost-effective comprehensive testing of all patients with advanced nsclc. If a ROS1 rearrangement is found, treatment with crizotinib, preferably in the first-line setting, constitutes the standard of care, with other treatment options being investigated, as appropriate, should resistance to crizotinib develop.

Clinical, pathological and genetic predictors of patient-derived xenograft (PDX) engraftment in EGFR-mutated lung adenocarcinoma (LUAD)

3110

Background: PDX are useful preclinical models to study drug response and resistance. Different specimen types have been used to generate PDX models including histological (surgery and CT-guided biopsy) and cytological preparations (EBUS and pleural effusions). We hypothesize that engraftment is not stochastic and is affected by many factors including sample type and tumor pathological and molecular properties. To improve sample selection and cost-effectiveness of PDX experiments, we investigated clinical, histological and genetic correlates of engraftment in EGFR-mutated LUAD. Methods: We assessed PDX engraftment from 96 surgical resections, 13 CT-guided biopsies, 21 EBUS and 14 pleural effusions of EGFR-mutated LUAD. Sixty-five samples, including 6 engrafted (XG) and 54 non-engrafted (noXG) were evaluated by exome sequencing. Results: Engraftment was successful in 9/96 (9%) surgical resections, 6/13 (46%) CT-guided biopsies, and 0/35 cytological samples. Biopsies taken at time of treatment failure (compared to treatment naive biopsies) correlated with greater engraftment (p=0.007, AUC = 0.68). Multivariable regression analysis of clinical variables at the time of sampling identified advanced (vs early) stage (p = 0.003) and histological (vs cytological) preparations (p < 0.001) as the strongest predictors of engraftment (AUC = 0.79). Among tumor histologic features, solid (vs lepidic, acinar and papillary) pattern was associated with greater engraftment (p < 0.001). Presence of EGFR-T790M (p = 0.004) and TP53 (p = 0.009) mutations were associated with greater engraftment; all XG samples carried TP53 mutations. EGFR-Ex19del (p = 0.076) showed a trend towards engraftment whereas EGFR-L858R (p = 0.086) trended towards non-engraftment. Conclusions: Advanced stage, post-therapy tumors, T790M+ and TP53+ EGFR-mutated LUAD samples obtained for histological processing are more likely to engraft as PDXs. Despite low engraftment rates, these models are useful to study novel therapeutic strategy and elucidation of resistance mechanisms.

Quantifying EpCAM heterogeneity of circulating-tumor-cells (CTCs) from small cell lung cancer (SCLC) patients

e20091

Background: Tumor heterogeneity and evolution of SCLC is poorly defined. Serial longitudinal interrogation of tumor heterogeneity from CTCs detected in peripheral blood patient (pt) samples is a potential strategy to address this gap in knowledge. However, existing technology is generally limited to the capture and enumeration of CTCs, without a high-throughput method to quantify phenotypic properties. Here, we evaluated a novel nanotechnology platform – nanoparticle-mediated magnetic ranking cytometry (MagRC) to profile SCLC CTCs by EpCAM protein expression. Methods: Blood samples from 20 SCLC pts were processed through the MagRC platform. Magnetic nanoparticles conjugated with anti-EpCAM antibodies were incubated with whole blood samples then introduced into the MagRC device where CTCs are sorted by differently sized nickel micromagnets within microfluidic channels. Captured CTCs are ranked into 8 zones that correlate with EpCAM expression levels (zone 1 = highest to 8 = lowest). For 8 pts, all samples were processed at a 1mL/hr flow rate (fr), and for 12 pts, a 0.5mL/hr fr was also studied; 66% of all chips were processed at a 1ml/hr fr and 34% at a 0.5ml/hr fr. The average zone for each chip was compared to the flow rate, age, and stage (extensive-stage (ES) vs limited-stage (LS)). The differences were tested using the Wald test within the linear mixed effects model. Results: Among 20 pts, 11 were ES; 9 were LS. Median age at diagnosis was 69 years old (yo); 65% were male. We detected CTCs in 12 of 20 pts (60%), similar to other studies. When comparing the MagRC-ranked EpCAM zone, the 0.5mL/hr fr demonstrated a lower median zone (4.3 vs 6.5; p < 0.001) as compared to the 1mL/hr rate. Interestingly, pts > 65 yo had a higher median zone (6.2 vs. 3.5; p = 0.019) compared to those ≤65 yo. The effect remained significant after controlling for flow rate (p = 0.002). No EpCAM zone difference was detected between ES and LS. Conclusions: We demonstrate the ability of MagRC to quantify EpCAM expression levels of CTCs from SCLC pts. We observed a higher MagRC zone (i.e. lower EpCAM expression) from pts > 65 yo. This observation requires validation in larger datasets along with continued investigation into the biology of SCLC CTCs.

Bone metastases as predictors of treatment response and rapidly progressive disease in NSCLC patients on PD-1/PD-L1 immune checkpoint inhibitors (ICI)

e20667

Background: The tissue microenvironment associated with specific organ metastases potentially influences the efficacy of checkpoint inhibitors. The presence of liver metastases is a predictor of poor response and survival in melanoma and is correlated with reduced CD8+ T cell infiltration. Our study examined clinicopathologic characteristics, focusing on sites of metastatic disease, that are associated with poor outcomes. Methods: Advanced NSCLC patients treated with ≥1 cycle of ICI were reviewed. Baseline age, sex, histology, stage, smoking status, ethnicity, PD-L1 expression and sites of metastases were recorded. Best overall response (BOR) was determined by clinical imaging response and categorized ordinally as shrinkage, stable, or progression, adapted from RECIST for CR/PR, SD, PD. A rapidly progressive phenotype (RPP) was defined as BOR of progression and ICI use of ≤2 months. The association between sites of metastases and clinical outcomes were investigated using logistic and cox regression models. Results: Among 219 eligible patients, bone was the most common metastatic site (34.7%), followed by brain (21.5%), adrenals (14.2%), and liver (13.7%). Bone metastases (OR 0.45, p = 0.004) were associated with a worse BOR, while only a trend was observed for liver metastases (OR 0.47, p = 0.06). Adrenal metastases were associated with a better BOR (OR 2.08, p = 0.04). But thorax limited disease did not associate with BOR (OR 1.08, p = 0.76). In a multivariate model, bone was the only metastatic site associated with a worse BOR (OR 0.50, p = 0.01). Further, bone metastases were associated with RPP (adjusted OR 1.91, p = 0.04). Both bone (adjusted hazard ratio/aHR 1.61, p = 0.01) and liver metastases (aHR 1.80, p = 0.02) were associated with a shorter time-to-treatment-failure. The presence of liver (aHR 2.63, p < 0.001) but not bone (aHR 1.04, p = 0.86) metastases was a significant predictor of poor OS. Conclusions: We report a novel finding that the presence of bone metastases was associated with a worse clinical overall response on ICI and a rapidly progressive phenotype. Further investigations into the mechanisms of RPP in the presence of bone metastases are needed.

Methylation profiling of EGFR mutant primary and metastatic lung cancer with brain metastasis

e20574

Background: EGFR-mutant lung cancer is a key molecular subtype of lung cancer. In recent years there is clear recognition in the value of using methylation signature of cancer for improving diagnosis and predicting outcome as well as understanding the biology of cancer progression. Methods: In this study we chose to characterize the methylome signature of early stage surgically resected EGFR-mutant lung adenocarcinomas in the primary lung tumor. 90 NSCLC cases and 7 matched metastatic brain samples were profiled using Illumina Infinium MethylationEPIC Beadchip. We compared methylation profiles of 1) smokers versus lifetime non-smokers and 2) matched primary lung versus brain metastasis to identify methylation biomarkers. We performed supervised analysis and unsupervised clustering of the methylation data. Results: Unsupervised clustering of all lung and brain samples based on 10K most variable probes showed a similar methylation signature between metastatic brain samples and lung samples. The 7-matched brain and lung samples formed close cluster groups based on matching pairs for the most variable probes from 2.5K to 10K, reflecting the same cell of origin. Supervised analysis of smokers versus lifetime non-smokers did not show any significant methylation differences between the two groups, while unsupervised analysis did not create clusters of smokers and non-smokers based on various number of probe sets we analyzed. Conclusions: Lung tumors that metastasized to the brain share similar methylation features with primary lung tumors. Comprehensive methylation profiling demonstrated no difference between EGFR mutant tumors in smokers versus non-smokers, suggesting that the EGFR mutation is a stronger determinant of outcome independent of smoking.

Myeloid immunosuppressive state as a predictor of rapidly progressive phenotype and poor survival in advanced non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 inhibitors

e20594

Background: Immune subpopulations within the tumor microenvironment (TME) play a central role in determining response to checkpoint inhibitors. Myeloid derived suppressor cells, a heterogeneous population of immature myeloid cells, have a predominantly immunosuppressive role by stimulating T regulatory cells. We hypothesize that elevated myeloid-to-lymphocyte measures in the peripheral blood predict for greater numbers of myeloid derived suppressor cells in the TME and worse outcomes. Methods: In advanced NSCLC patients who received immunotherapy between 2010-2018, baseline characteristics collected retrospectively included age, sex, histology, stage, smoking status, ethnicity, PD-L1 expression and tumor genotype. Pre-treatment neutrophil/lymphocyte (NLR) and monocyte/lymphocyte ratios (MLR) were log transformed and analyzed using cox and logistic regression models. Results: Among 219 eligible patients, a high NLR was associated with shorter time-to-treatment-failure (HR 1.38, 95%CI 1.09-1.75, p = 0.008) and poorer OS (HR 1.62, 95%CI 1.23-2.14, p < 0.001), independent of PD-L1 levels. Disproportionate increases in NLR and MLR were highly correlated (Spearman’s rho = 0.78). Further, higher NLR (p = 0.09) or MLR (p = 0.06) tended to associate with best overall response (BOR) to immunotherapy, with higher rates of progressive disease (PD) and lower rates of clinical response. A high NLR (p = 0.01) and MLR (p = 0.02) were associated with a rapidly progressive phenotype defined by PD as the BOR and duration of therapy ≤2 months. This remained significant after adjusting for confounders in a multivariate model (p = 0.03 for NLR and p = 0.03 for MLR). No associations were observed between high myeloid counts and other clinical prognostic factors such as liver metastases. Conclusions: A myeloid immunosuppressive state characterized by a disproportionate increase in peripheral immune myeloid populations is significantly associated with primary refractory disease, rapidly progressive phenotype, and poorer survival. Further investigation into myeloid mediated mechanisms of resistance is warranted.

Non-small cell lung cancer (NSCLC) next generation sequencing (NGS) using the Oncomine Comprehensive Assay (OCA) v3: Integrating expanded genomic sequencing into the Canadian publicly funded health care model

2620

Background: Standard of care (SOC) molecular diagnostics for stage IV NSCLC patients in Ontario, Canada includes publicly reimbursed EGFR/ ALK, and selected BRAF and ROS-1 testing. Other genomic alterations are not tested routinely; however, enhanced molecular testing may broaden treatment options for patients. This study evaluated costs, identified actionable targets, and determined clinical trial eligibility as a result of using the OCAv3 NGS in stage IV NSCLC patients. Methods: In a prospective study of stage IV NSCLC out-patients at Princess Margaret Cancer Centre (Toronto) without EGFR/ALK/KRAS/BRAF alteration (unless failure of prior targeted therapy), diagnostic samples were tested by OCAv3 (ThermoFisher; 161 genes: hotspots, fusions, and copy number variations). Primary endpoints were incremental actionable targets and clinical trial opportunities as a result of broader OCAv3 testing. Secondary endpoints include feasibility and cost from the Canadian public healthcare perspective, and treatment outcomes. Results: Of 65 enrolled patients (Feb 2018-Jan 2019; 40 (62%) completed/14 (21%) screen fail/ 11 (17%) pending), median age of completed cohort was 65, 60% (N = 24) female, never/light smokers 68% (N = 27), Asian 38% (N = 15), previously treated 33% (N = 13). Actionable targets beyond SOC were identified in 33% (N = 13): ERBB2 (N = 8), BRAFV600 (N = 3), NRG fusion (N = 1), MET exon 14 (N = 1). New clinical trial options were identified in 70%. Failure of NGS was secondary to insufficient tissue [91% (N = 10) of screen failures; usually due to tissue exhaustion from prior SOC molecular testing]. Incremental costs per case beyond EGFR/ALK are estimated at $540 CAD. If ROS-1 and BRAF testing were publicly reimbursed at current rates, the incremental profiling cost with OCAv3 would be $90 CAD per case. Conclusions: Although a key barrier to implementation is lack of funding for NGS in the Canadian publicly funded system, the OCAv3 consolidates genomic testing, identifies additional actionable targets, and substantially increases clinical trial eligibility for patients at a small incremental cost. Clinical trial information: NCT03558165.

Canadian consensus: oligoprogressive, pseudoprogressive, and oligometastatic non-small-cell lung cancer

Background

Little evidence has been generated for how best to manage patients with non-small-cell lung cancer (nsclc) presenting with rarer clinical scenarios, including oligometastases, oligoprogression, and pseudoprogression. In each of those scenarios, oncologists have to consider how best to balance efficacy with quality of life, while maximizing the duration of each line of therapy and ensuring that patients are still eligible for later options, including clinical trial enrolment.

Methods

An expert panel was convened to define the clinical questions. Using case-based presentations, consensus practice recommendations for each clinical scenario were generated through focused, evidence-based discussions.

Results

Treatment strategies and best-practice or consensus recommendations are presented, with areas of consensus and areas of uncertainty identified.

Conclusions

In each situation, treatment has to be tailored to suit the individual patient, but with the intent of extending and maximizing the use of each line of treatment, while keeping treatment options in reserve for later lines of therapy. Patient participation in clinical trials examining these issues should be encouraged.

Canadian perspectives: update on inhibition of ALK-positive tumours in advanced non-small-cell lung cancer

Background

Inhibition of the anaplastic lymphoma kinase (alk) oncogenic driver in advanced non-small-cell lung carcinoma (nsclc) improves survival. In 2015, Canadian thoracic oncology specialists published a consensus guideline about the identification and treatment of ALK-positive patients, recommending use of the alk inhibitor crizotinib in the first line. New scientific literature warrants a consensus update.

Methods

Clinical trials of alk inhibitor were reviewed to assess benefits, risks, and implications relative to current Canadian guidance in patients with ALK-positive nsclc.

Results

Randomized phase iii trials have demonstrated clinical benefit for single-agent alectinib and ceritinib used in treatment-naïve patients and as second-line therapy after crizotinib. Phase ii trials have demonstrated activity for single-agent brigatinib and lorlatinib in further lines of therapy. Improved responses in brain metastases were observed for all second- and next/third-generation alk tyrosine kinase inhibitors in patients progressing on crizotinib. Canadian recommendations are therefore revised as follows:■ Patients with advanced nonsquamous nsclc have to be tested for the presence of an ALK rearrangement.■ Treatment-naïve patients with ALK-positive disease should initially be offered single-agent alectinib or ceritinib, or both sequentially.■ Crizotinib-refractory patients should be treated with single-agent alectinib or ceritinib, or both sequentially.■ Further treatments could include single-agent brigatinib or lorlatinib, or both sequentially.■ Patients progressing on alk tyrosine kinase inhibitors should be considered for pemetrexed-based chemotherapy.■ Other systemic therapies should be exhausted before immunotherapy is considered.

Summary

Multiple lines of alk inhibition are now recommended for patients with advanced nsclc with an ALK rearrangement.

Refined RIP-seq protocol for epitranscriptome analysis with low input materials

N6-Methyladenosine (m⁶A) accounts for approximately 0.2% to 0.6% of all adenosine in mammalian mRNA, representing the most abundant internal mRNA modifications. m⁶A RNA immunoprecipitation followed by high-throughput sequencing (MeRIP-seq) is a powerful technique to map the m⁶A location transcriptome-wide. However, this method typically requires 300 μg of total RNA, which limits its application to patient tumors. In this study, we present a refined m⁶A MeRIP-seq protocol and analysis pipeline that can be applied to profile low-input RNA samples from patient tumors. We optimized the key parameters of m⁶A MeRIP-seq, including the starting amount of RNA, RNA fragmentation, antibody selection, MeRIP washing/elution conditions, methods for RNA library construction, and the bioinformatics analysis pipeline. With the optimized immunoprecipitation (IP) conditions and a postamplification rRNA depletion strategy, we were able to profile the m⁶A epitranscriptome using 500 ng of total RNA. We identified approximately 12,000 m⁶A peaks with a high signal-to-noise (S/N) ratio from 2 lung adenocarcinoma (ADC) patient tumors. Through integrative analysis of the transcriptome, m⁶A epitranscriptome, and proteome data in the same patient tumors, we identified dynamics at the m⁶A level that account for the discordance between mRNA and protein levels in these tumors. The refined m⁶A MeRIP-seq method is suitable for m⁶A epitranscriptome profiling in a limited amount of patient tumors, setting the ground for unraveling the dynamics of the m⁶A epitranscriptome and the underlying mechanisms in clinical settings.

N6-Methyladenosine (m⁶A) is one of the most abundant and conserved mRNA modifications. It has been reported to influence multiple steps of RNA life cycle and play an important role in the initiation and progression of human cancers. m⁶A RNA immunoprecipitation followed by high-throughput sequencing (MeRIP-seq) is a powerful technique to map the m⁶A location transcriptome-wide. However, this method typically requires 300 μg of total RNA, which limits its application to patient tumors. In this study, we presented an optimized MeRIP-seq protocol that allows us to profile m⁶A epitranscriptiome using as low as 500 ng of total RNA. By applying our refined protocol to 2 lung cancer patient tumors and integrating with proteomic data, we identified dynamics at the m⁶A level that account for the discordance between mRNA and protein levels in these tumors.

Circulating tumour DNA in EGFR-mutant non-small-cell lung cancer

The advent of targeted therapy in non-small-cell lung cancer (nsclc) has made the routine molecular diagnosis of EGFR mutations crucial for optimal patient management. Obtaining tumour tissue for biomarker testing, especially in the setting of re-biopsy, can present many challenges. A potential alternative source of tumour dna is circulating cell-free tumour-derived dna (ctdna). Although ctdna is present in low quantities in plasma, the convenience of sample acquisition and the increasing reliability of detection methods make this approach a promising one. The various performance characteristics of both digital and nondigital platforms are still variable, and a standardized approach is needed that will make those platforms reliable clinical tools for the detection of EGFR sensitizing mutations and resistance mutations, including the T790M resistance mutation. Information derived from ctdna can be used to assess tumour burden, to identify genomic-based resistance mechanisms, and to track dynamic changes during therapy.

PD-L1 Immunohistochemistry Comparability Study in Real-Life Clinical Samples: Results of Blueprint Phase 2 Project

OBJECTIVES

The Blueprint (BP) Programmed Death Ligand 1 (PD-L1) Immunohistochemistry Comparability Project is a pivotal academic/professional society and industrial collaboration to assess the feasibility of harmonizing the clinical use of five independently developed commercial PD-L1 immunohistochemistry assays. The goal of BP phase 2 (BP2) was to validate the results obtained in BP phase 1 by using real-world clinical lung cancer samples.

METHODS

BP2 were conducted using 81 lung cancer specimens of various histological and sample types, stained with all five trial-validated PD-L1 assays (22C3, 28-8, SP142, SP263, and 73-10); the slides were evaluated by an international panel of pathologists. BP2 also assessed the reliability of PD-L1 scoring by using digital images, and samples prepared for cytological examination. PD-L1 expression was assessed for percentage (tumor proportional score) of tumor cell (TC) and immune cell areas showing PD-L1 staining, with TCs scored continuously or categorically with the cutoffs used in checkpoint inhibitor trials.

RESULTS

The BP2 results showed highly comparable staining by the 22C3, 28-8 and SP263 assays; less sensitivity with the SP142 assay; and higher sensitivity with the 73-10 assay to detect PD-L1 expression on TCs. Glass slide and digital image scorings were highly concordant (Pearson correlation >0.96). There was very strong reliability among pathologists in TC PD-L1 scoring with all assays (overall intraclass correlation coefficient [ICC] = 0.86-0.93), poor reliability in IC PD-L1 scoring (overall ICC = 0.18-0.19), and good agreement in assessing PD-L1 status on cytological cell block materials (ICC = 0.78-0.85).

CONCLUSION

BP2 consolidates the analytical evidence for interchangeability of the 22C3, 28-8, and SP263 assays and lower sensitivity of the SP142 assay for determining tumor proportion score on TCs and demonstrates greater sensitivity of the 73-10 assay compared with that of the other assays.

Evidence-based best practices for EGFR T790M testing in lung cancer in Canada

Epidermal growth factor receptor (egfr) tyrosine kinase inhibitors (tkis) are recommended as first-line systemic therapy for patients with non-small-cell lung cancer (nsclc) having mutations in the EGFR gene. Resistance to tkis eventually occurs in all nsclc patients treated with such drugs. In patients with resistance to tkis caused by the EGFR T790M mutation, the third-generation tki osimertinib is now the standard of care. For optimal patient management, accurate EGFR T790M testing is required. A multidisciplinary working group of pathologists, laboratory medicine specialists, medical oncologists, a respirologist, and a thoracic radiologist from across Canada was convened to discuss best practices for EGFR T790M mutation testing in Canada. The group made recommendations in the areas of the testing algorithm and the pre-analytic, analytic, and post-analytic aspects of clinical testing for both tissue testing and liquid biopsy circulating tumour dna testing. The recommendations aim to improve EGFR T790M testing in Canada and to thereby improve patient care.

Immunohistochemistry of Pulmonary Biomarkers: A Perspective From Members of the Pulmonary Pathology Society

The use of immunohistochemistry for the determination of pulmonary carcinoma biomarkers is a well-established and powerful technique. Immunohistochemisty is readily available in pathology laboratories, is relatively easy to perform and assess, can provide clinically meaningful results very quickly, and is relatively inexpensive. Pulmonary predictive biomarkers provide results essential for timely and accurate therapeutic decision making; for patients with metastatic non-small cell lung cancer, predictive immunohistochemistry includes ALK and programmed death ligand-1 (PD-L1) (ROS1, EGFR in Europe) testing. Handling along proper methodologic lines is needed to ensure patients receive the most accurate and representative test outcomes.

Use of a marketing plan for recruitment to a lung cancer screening study

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Background: Recruitment to clinic trials is typically poor. Among barriers to recruitment may be the limited knowledge of trialists with respect to marketing techniques. Improvements in marketing could decrease recruitment time and shorten the time to access new interventions. We hypothesized that a marketing plan would improve recruitment to a lung cancer screening study. Methods: The Pan-Canadian Early Detection of Lung Cancer Trial recruited subjects from 8 centres to a screening study of low-dose CT scan and autofluorescence bronchoscopy. Recruitment processes were undertaken independently at each centre. One centre (M) used marketing expertise and a marketing plan, including surveying study candidates for motivators, resulting in specific newsprint advertisements. Screened trial candidates provided demographic and tobacco use data and indicated how they had heard about the study (bus, friend/family, MD, mail, newsprint, radio, TV, other). No site paid for radio or TV time. We used regression analyses to assess whether newsprint advertisements were more effective for recruitment at site M compared with all other sites. Results: From 2008 to 2010, 7059 candidates contacted all centres for eligibility screening, including 779 at centre M. Overall, 50.2% were female; median age was 59 yrs. Compared with other centres, candidates at centre M had less education (p < 0.001), a higher median 3-year lung cancer risk (2.3 vs 2.0%, p < 0.001), but were more likely to have learned of the study by newsprint (58.8 vs 53.3%, chi-squared p = 0.004), and were more likely to be recruited (44.0 vs 34.9%, p < 0.001). It was more likely that newsprint was the driver for screening contact among candidates with higher education level (OR 1.05/level), higher age (OR 1.03 / yr) and contact at site M (OR 1.31) (all < 0.001). Recruitment after eligibility screening was higher when newsprint was the driver for contact on univariable but not multivariable analysis. Conclusions: The effectiveness of newsprint advertising in motivating study contact may be improved by the formal use of marketing expertise. Newsprint advertising may improve the likelihood of recruitment after study screening, possibly through improved initial self-screening by the candidate. Clinical trial information: NCT00751660.

Evaluation of stored liquid biopsies for molecular profiling in patients with non-small cell lung cancer (NSCLC)

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Background: Molecular profiling is often limited by access to sufficient tumour tissue for comprehensive analysis and due to tumour heterogeneity, the complete range of tumor DNA abnormalities may not be represented nor accurately reflect the clinical evolution of disease. Circulating tumour DNA (ctDNA) can be used as a liquid biopsy for molecular abnormalities detection, quantification and monitoring for personalised treatment strategies. Methods: Plasma was collected at baseline (BL) and during study therapy from advanced NSCLC patients (pts) enrolled in a placebo controlled phase III trial of a novel irrerversible EGFR inhibitor; all patients had received standard therapy with chemotherapy and gefitinib or erlotinib. Archival tissue was collected when available but biopsy was not required prior to enrolment. BL Plasma ( < 3ml), stored for ~8 years was used to extract DNA and analysed using InVision (enhanced tagged-amplicon sequencing). Results: BL plasma from 387 pts was tested; 289 pts had available tissue results (from archival tissue collected at diagnosis) for EGFR (174WT/115Mut) and 243 for KRAS (205WT/38Mut). Despite age of plasma samples, ctDNA analysis detected cancer mutations in 310 pts (82%): TP53 (45%), KRAS (15%), and EGFR (43%; 56% were EGFR del19 and 29% L858R); T790M was detected in 80 patients. EGFR mutations were identified in 29 patients and KRAS in 10 patients with unknown tissue status. Also of note, STK11 (32 pts, 12 with KRAS), BRAF (5pts, 3 with V600E), MET(7 pts, 4 with METamp), ERBB2 (16pts, 10 with ERBB2amp) were identified in ctDNA analysis. Median time and median number of lines of systemic therapy between tissue biopsy and blood was 714 days and 3 lines respectively. Further analyses of ctDNA analyses in context of patient and trial outcomes are in progress. Conclusions: Liquid biopsies provide opportunity to evaluate molecular mutation profile in NSCLC patients. We demonstrate a highly sensitive method for ctDNA analysis which is complementary to tissue molecular analysis.

Phase II clinical and molecular trial of oral ENMD-2076 in clear cell ovarian cancer (CCOC): A study of the Princess Margaret phase II consortium

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Background: CCOC is a rare chemoresistant subtype of OC. ENMD-2076 is an oral multi-target kinase inhibitor with antiangiogenic/antiproliferative profile; selective activity against the mitotic kinase Aurora A and VEGFRs, FGFRs. Methods: This is a multi-center Phase II study of ENMD-2076 in pts with recurrent CCOC and prior platinum. Primary endpoints were ORR and 6-m PFS rate. Correlative analyses include ARID1A, PTEN expression by IHC and genome sequencing by custom capture library of 555 genes. Results: Completed study enrolled 40 pts – 37 evaluable, median age of 54 (39-78). 12 pts (31%) received prior radiation and 24 (62%), 11 (28%), 4 (10%) had 1, 2 or 3 lines of chemotherapy. Archival tissue was available for 36/37 pts. Best response was PR for 2 pts (1 unconfirmed), SD for 25 (68%) and PD for 10 (26%) pts. Median PFS was 3.7 months (m) (95%CI: 3.4-4.4). ENMD was well tolerated with main related AE: hypertension (21 pts - 8 G3), nausea (18 pts -1 G3) and diarrhea (17 pts - 4 G3). By IHC, median PFS (95%CI) in ARID1A loss (19 pts) was 4.1m (3.5-10.3) vs 3.6m (1.7-3.9) in ARID1A positive (17 pts) (p = 0.024). Whilst, by IHC, PTEN was loss in 20 pts; intact in 10 and heterogeneous in 6 pts; no difference in PFS was observed. By PI3KCA mutation status, median PFS (95%CI) in wild-type (WT) (12 pts) was 5m (3.4-19.3) vs 3.7m (167-4.4) in mutated group (20 pts) (p = 0.038). Molecular profiling showed variants in PI3KCA (27%), ARID1A (26%), TP53 (7%), BRIP1 (7%), ATM (11%), BRCA1 (5%), BRCA2 (3%), RAD50 (3%), PABL2 (1%), RAD51C (1%), FANCA (1%), CTNNB1 (3%).The patient with the longest treatment duration (22m) was PTEN WT, diploid PTEN, putative bi-allelic inactivation of ARID1A. Conclusions: The PFS at 6 months was 20% for the evaluable patients, 31% in ARID1A loss and 12% in ARID1A positive patients. Loss of ARID1A, a known negative prognostic factor, was correlated with better PFS on ENMD-2076. Additional molecular profiling of the baseline biopsy material is underway. Clinical trial information: NCT01914510.

Improving molecular testing and personalized medicine in non-small-cell lung cancer in Ontario

BACKGROUND

Although molecular testing has become standard in managing advanced nonsquamous non-small-cell lung cancer (nsclc), most patients undergo minimally invasive procedures, and the diagnostic tumour specimens available for testing are usually limited. A knowledge translation initiative to educate diagnostic specialists about sampling techniques and laboratory processes was undertaken to improve the uptake and application of molecular testing in advanced lung cancer.

METHODS

A multidisciplinary panel of physician experts including pathologists, respirologists, interventional thoracic radiologists, thoracic surgeons, medical oncologists, and radiation oncologists developed a specialty-specific education program, adapting international clinical guidelines to the local Ontario context. Expert recommendations from the program are reported here.

RESULTS

Panel experts agreed that specialists procuring samples for lung cancer diagnosis should choose biopsy techniques that maximize tumour cellularity, and that conservation strategies to maximize tissue for molecular testing should be used in tissue processing. The timeliness of molecular reporting can be improved by pathologist-initiated reflex testing upon confirmation of nonsquamous nsclc and by prompt transportation of specimens to designated molecular diagnostic centres. To coordinate timely molecular testing and optimal treatment, collaboration and communication between all clinicians involved in diagnosing patients with advanced lung cancer are mandatory.

CONCLUSIONS

Knowledge transfer to diagnostic lung cancer specialists could potentially improve molecular testing and treatment for advanced lung cancer patients.

Management of EGFR-mutated non-small-cell lung cancer: practical implications from a clinical and pathology perspective

Starting in the early 2000s, non-small-cell lung cancer (nsclc) subtypes have evolved from being histologically described to molecularly defined. Management of lung adenocarcinomas now generally requires multiple molecular tests at baseline to define the optimal treatment strategy. More recently, second biopsies performed at progression in patients treated with tyrosine kinase inhibitors (tkis) have further defined the continued use of molecularly targeted therapy. In the present article, we focus on one molecular subtype: EGFR-mutated nsclc. For that patient population, multiple lines of tki therapy are now available either clinically or in clinical trials. Each line of treatment is guided by the specific mutations (for example, L858R, T790M, C797S) identified in EGFR. We first describe the various mechanisms of acquired resistance to EGFR tki treatment. We then focus on strategies that clinicians and pathologists can both use during tissue acquisition and handling to optimize patient results. We also discuss future directions for the molecular characterization of lung cancers with driver mutations, including liquid biopsies. Finally, we provide an algorithm to guide treating physicians managing patients with EGFR-mutated nsclc. The same framework can also be applied to other molecularly defined nsclc subgroups as resistance patterns are elucidated and additional lines of treatment are developed.

A preclinical trial to evaluate therapies for BRCA-associated pancreatic cancer

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Background: Pancreatic ductal adenocarcinoma (PDAC) associated with germline BRCA1 or BRCA2mutations may have selective sensitivity to agents that exploit homologous recombination DNA repair defects. We hypothesized that cisplatin, a DNA-crosslinking agent, and talazoparib, a poly(ADP-ribose) polymerase (PARP) inhibitor, monotherapies are efficacious in BRCA-associated PDAC, while combination therapies with these agents have enhanced efficacy. Methods: A preclinical trial was performed in subcutaneous patient-derived tumor xenograft (PDX) mouse models with (n = 5) and without (n = 2) germline BRCA1 or BRCA2mutations. Mice harboring PDX tumors were treated with vehicle, talazoparib, cisplatin, gemcitabine, talazoparib with cisplatin (TC), talazoparib with gemcitabine (TG), or cisplatin with gemcitabine (CG). Twelve tumors were randomized into each trial arm, treated for 28 days, and then monitored without further treatment to assess tumor regrowth. Results: Treatment with cisplatin and talazoparib monotherapies resulted in 89.8% and 88.2% tumor growth inhibition (GI) in BRCA-associated cases versus 34.0% and 34.7% GI in the cases without germline BRCAmutations, respectively. Gemcitabine-based combinations were more effective than monotherapies in BRCA-associated cases (p < 0.001), with CG and TG resulting in tumor regression in five and three BRCA-associated cases, respectively. Although we also observed the treatment effect with these combinations in non-BRCA cases, it paralleled the gemcitabine monotherapy effect in these cases (p = 0.322). Following cessation of treatment, we observed heterogeneity in tumor regrowth. CG and TG demonstrated sustained responses across all BRCA-associated cases, however, TG had greater toxicity than CG. Conclusions: Our preclinical data suggest that targeted therapy with CG is efficacious with a sustained response and less toxicity than TG in BRCA-associated PDAC.