Therapeutic misunderstandings in modern research.

Clinical trials play a crucial role in generating evidence about healthcare interventions and improving outcomes for current and future patients. For individual trial participants, however, there are inevitably trade-offs involved in clinical trial participation, given that trials have traditionally been designed to benefit future patient populations rather than to offer personalised care. Failure to understand the distinction between research and clinical care and the likelihood of benefit from participation in clinical trials has been termed the 'therapeutic misconception'. The evolution of the clinical trials landscape, including greater integration of clinical trials into healthcare and development of novel trial methodologies, may reinforce the significance of the therapeutic misconception and other forms of misunderstanding while at the same time (paradoxically) challenging its salience. Using cancer clinical trials as an exemplar, we describe how methodological changes in early- and late-phase clinical trial designs, as well as changes in the design and delivery of healthcare, impact upon the therapeutic misconception. We suggest that this provides an impetus to re-examine the ethics of clinical research, particularly in relation to trial access, participant selection, communication and consent, and role delineation.

Predicting response to immune checkpoint blockade in NSCLC with tumour-only RNA-seq.

BACKGROUND: Targeted RNA sequencing (RNA-seq) from FFPE specimens is used clinically in cancer for its ability to estimate gene expression and to detect fusions. Using a cohort of NSCLC patients, we sought to determine whether targeted RNA-seq could be used to measure tumour mutational burden (TMB) and the expression of immune-cell-restricted genes from FFPE specimens and whether these could predict response to immune checkpoint blockade. METHODS: Using The Cancer Genome Atlas LUAD dataset, we developed a method for determining TMB from tumour-only RNA-seq and showed a correlation with DNA sequencing derived TMB calculated from tumour/normal sample pairs (Spearman correlation = 0.79, 95% CI [0.73, 0.83]. We applied this method to targeted sequencing data from our patient cohort and validated these results against TMB estimates obtained using an orthogonal assay (Spearman correlation = 0.49, 95% CI [0.24, 0.68]). RESULTS: We observed that the RNA measure of TMB was significantly higher in responders to immune blockade treatment (P = 0.028) and that it was predictive of response (AUC = 0.640 with 95% CI [0.493, 0.786]). By contrast, the expression of immune-cell-restricted genes was uncorrelated with patient outcome. CONCLUSION: TMB calculated from targeted RNA sequencing has a similar diagnostic ability to TMB generated from targeted DNA sequencing.

When research becomes practice: the concept of the therapeutic misconception and challenges to consent in clinical trials.

Many factors influence patients' decisions to participate in clinical trials. For many, the primary motivation is the possibility that they might derive some benefit from participation. This is particularly true for patients with limited treatment options, such as patients with advanced cancer. While this is not surprising, it is potentially problematic if patients fail to recognise the distinction between research and clinical care (a phenomenon known as the 'therapeutic misconception'). This is becoming increasingly problematic as clinical trial designs become more complex, as clinical trials become more embedded in routine clinical care, and as trials are increasingly used by patients and clinicians to access new diagnostic platforms and therapies. We outline some of these recent trends, focusing on the cancer clinical trials landscape as this provides a good case study of the phenomenon. We conclude by making preliminary suggestions that changes to the consent process, perhaps using 'dynamic consent' platforms, might help to mitigate the therapeutic misconception and note the need for further research to guide strategies for improving communication and decision-making.

Assessing Tumor-infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method From the International Immunooncology Biomarkers Working Group: Part 1: Assessing the Host Immune Response, TILs in Invasive Breast Carcinoma and Ductal Carcinoma In Situ, Metastatic Tumor Deposits and Areas for Further Research.

Assessment of tumor-infiltrating lymphocytes (TILs) in histopathologic specimens can provide important prognostic information in diverse solid tumor types, and may also be of value in predicting response to treatments. However, implementation as a routine clinical biomarker has not yet been achieved. As successful use of immune checkpoint inhibitors and other forms of immunotherapy become a clinical reality, the need for widely applicable, accessible, and reliable immunooncology biomarkers is clear. In part 1 of this review we briefly discuss the host immune response to tumors and different approaches to TIL assessment. We propose a standardized methodology to assess TILs in solid tumors on hematoxylin and eosin sections, in both primary and metastatic settings, based on the International Immuno-Oncology Biomarker Working Group guidelines for TIL assessment in invasive breast carcinoma. A review of the literature regarding the value of TIL assessment in different solid tumor types follows in part 2. The method we propose is reproducible, affordable, easily applied, and has demonstrated prognostic and predictive significance in invasive breast carcinoma. This standardized methodology may be used as a reference against which other methods are compared, and should be evaluated for clinical validity and utility. Standardization of TIL assessment will help to improve consistency and reproducibility in this field, enrich both the quality and quantity of comparable evidence, and help to thoroughly evaluate the utility of TILs assessment in this era of immunotherapy.

Assessing Tumor-Infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method from the International Immuno-Oncology Biomarkers Working Group: Part 2: TILs in Melanoma, Gastrointestinal Tract Carcinomas, Non-Small Cell Lung Carcinoma and Mesothelioma, Endometrial and Ovarian Carcinomas, Squamous Cell Carcinoma of the Head and Neck, Genitourinary Carcinomas, and Primary Brain Tumors.

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

The impact of pre-treatment smoking status on survival after chemoradiotherapy for locally advanced non-small-cell lung cancer.

INTRODUCTION: Smoking is a risk factor for the development of lung cancer and reduces life expectancy within the general population. Retrospective studies suggest that non-smokers have better outcomes after treatment for lung cancer. We used a prospective database to investigate relationships between pre-treatment smoking status and survival for a cohort of patients with stage III non-small-cell lung cancer (NSCLC) treated with curative-intent concurrent chemoradiotherapy (CRT). METHODS: All patients treated with CRT for stage III NSCLC at a major metropolitan cancer centre were prospectively registered to a database. A detailed smoking history was routinely obtained at baseline. Kaplan-Meier statistics were used to assess overall survival and progression-free survival in never versus former versus current smokers. RESULTS: Median overall survival for 265 eligible patients was 2.21 years (95 % Confidence Interval 1.78, 2.84). It was 5.5 years (95 % CI 2.1, not reached) for 25 never-smokers versus 1.9 years (95 % CI 1.5, 2.7) for 182 former smokers and 2.2 years (95 % CI 1.3, 2.7) for 58 current smokers. Hazard ratio for death was 2.43 (95 % CI 1.32-4.50) for former smokers and 2.75 (95 % CI 1.40, 5.40) for current smokers, p = 0.006. Actionable tumour mutations (EGFR, ALK, ROS1) were present in more never smokers (14/25) than former (9/182) or current (3/58) smokers. TKI use was also higher in never smokers but this was not significantly associated with superior survival (Hazard ratio 0.71, 95 % CI 0.41, 1.26). CONCLUSIONS: Never smokers have substantially better overall survival than former or current smokers after undergoing CRT for NSCLC.

Longitudinal Analyses of Circulating Tumor DNA for the Detection of EGFR Mutation-Positive Advanced NSCLC Progression During Treatment: Data From FLAURA and AURA3.

INTRODUCTION: EGFR tyrosine kinase inhibitor (EGFR-TKI)-sensitizing and -resistance mutations may be detected in plasma through circulating tumor DNA (ctDNA). Circulating tumor DNA level changes reflect alterations in tumor burden and could be a dynamic indicator of treatment effect. This analysis aimed to determine whether longitudinal EGFR-mutation ctDNA testing could detect progressive disease (PD) before radiologic detection. METHODS: This was a retrospective, exploratory ctDNA analysis in two phase 3 trials (FLAURA, NCT02296125; AURA3, NCT02151981). Patients had treatment-naïve (FLAURA) or EGFR-TKI pre-treated (AURA3) advanced NSCLC with EGFR mutations and on-study PD (RECIST [Response Evaluation Criteria in Solid Tumors]), with a baseline ctDNA result and EGFR-mutation ctDNA monitoring beyond Cycle 3 Day 1. Patients received osimertinib versus comparator EGFR-TKIs (FLAURA) or chemotherapy (AURA3). Outcomes included time from ctDNA PD to RECIST PD and the first subsequent treatment (FLAURA only). RESULTS: Circulating tumor DNA PD preceded or co-occurred with RECIST-defined PD in 93 out of 146 patients (64%) in FLAURA and 82 out of 146 patients (56%) in AURA3. Median time from ctDNA PD to RECIST-defined PD (mo) was 3.4 and 2.6 in the osimertinib and comparator EGFR-TKI arms (FLAURA) and 2.8 and 1.5 in the osimertinib and chemotherapy arms (AURA3). In FLAURA, the median time from ctDNA PD to the first subsequent treatment (mo) was 6.0 and 4.7 in the osimertinib (n = 51) and comparator EGFR-TKI arms (n = 70). CONCLUSIONS: Among patients with EGFR mutation-positive advanced NSCLC receiving EGFR-TKI or chemotherapy with ctDNA data and RECIST-defined PD, ctDNA PD preceded/co-occurred with RECIST-defined PD in approximately 60% of cases. Longitudinal ctDNA monitoring may detect PD before radiologic PD.

Experience of the first adult-focussed undiagnosed disease program in Australia (AHA-UDP): solving rare and puzzling genetic disorders is ageless.

BACKGROUND: Significant recent efforts have facilitated increased access to clinical genetics assessment and genomic sequencing for children with rare diseases in many centres, but there remains a service gap for adults. The Austin Health Adult Undiagnosed Disease Program (AHA-UDP) was designed to complement existing UDP programs that focus on paediatric rare diseases and address an area of unmet diagnostic need for adults with undiagnosed rare conditions in Victoria, Australia. It was conducted at a large Victorian hospital to demonstrate the benefits of bringing genomic techniques currently used predominantly in a research setting into hospital clinical practice, and identify the benefits of enrolling adults with undiagnosed rare diseases into a UDP program. The main objectives were to identify the causal mutation for a variety of diseases of individuals and families enrolled, and to discover novel disease genes. METHODS: Unsolved patients in whom standard genomic diagnostic techniques such as targeted gene panel, exome-wide next generation sequencing, and/or chromosomal microarray, had already been performed were recruited. Genome sequencing and enhanced genomic analysis from the research setting were applied to aid novel gene discovery. RESULTS: In total, 16/50 (32%) families/cases were solved. One or more candidate variants of uncertain significance were detected in 18/50 (36%) families. No candidate variants were identified in 16/50 (32%) families. Two novel disease genes (TOP3B, PRKACB) and two novel genotype-phenotype correlations (NARS, and KMT2C genes) were identified. Three out of eight patients with suspected mosaic tuberous sclerosis complex had their diagnosis confirmed which provided reproductive options for two patients. The utility of confirming diagnoses for patients with mosaic conditions (using high read depth sequencing and ddPCR) was not specifically envisaged at the onset of the project, but the flexibility to offer recruitment and analyses on an as-needed basis proved to be a strength of the AHA-UDP. CONCLUSION: AHA-UDP demonstrates the utility of a UDP approach applying genome sequencing approaches in diagnosing adults with rare diseases who have had uninformative conventional genetic analysis, informing clinical management, recurrence risk, and recommendations for relatives.

Microfluidic based immunosensor for detection and purification of carbonylated proteins.

A microchip has been developed on the basis of immno-precipitation approach for fast and sensitive enrichment of low abundant carbonylated proteins. This microfluidic method could enrich molecular biomarkers, which could be further analyzed in the proteomic study of age-related diseases and therapeutic development. In this study, an immunoaffinity-based PDMS micro-device was designed, fabricated, and chemically modified to specifically trap DNP-labeled PTM proteins of low abundance from a complex protein mixture. Carbonylated protein is selected as a representative PTM protein to illustrate the wide application of this immuno-based microchip for other PTMs which could be readily labeled by different antibody groups. Surface characterization methods such as atomic force microscopy and fluorescence microscopy were used to evaluate the construction of glutaraldehyde- and antibody- terminated PDMS substrates in the device fabrication. Quantitative study was also applied to study the target protein capture and elution efficiency of the device. In a testing mixture consisting of smaller amount of test model-In Vitro oxidized cytochrome c and large blocking protein BSA, a high sensitivity and specificity for only carbonylated protein biomarkers was demonstrated using this on-chip immnuoaffinity based extraction/enrichment. For this highly dense 193-post arrays µ-chip, a low abundance of 159 ng of standard in vitro test model- cytochrome c was enriched at flow speed of 5 µL/min within 110 min. We demonstrated that this nascent micro-immunoprecipitation (µ-IP) method is capable for enrichment of biomarkers in protein post-translation modification related diseases and promise great advance in early disease detection.

Rehabilitation outcomes for people with lung cancer (UNITE): protocol for the development of a core outcome set.

INTRODUCTION: With treatment-related improvements in survival, rehabilitation is essential to improve function and health-related quality of life and manage the high symptom burden associated with lung cancer. Despite this, significant heterogeneity exists in the outcomes and instruments used to evaluate lung cancer rehabilitation programme impact. This study aims to develop a core set of clinically relevant lung cancer rehabilitation outcomes for use in clinical practice. METHODS AND ANALYSIS: An international Delphi consensus study involving consumer, healthcare professional and researcher stakeholders to determine which outcomes to include and how to measure these. Stage 1 (preliminary): mixed methods to develop the potential list of outcomes (1) overview of systematic reviews of lung cancer exercise interventions and (2) focus groups and individual interviews with people with lung cancer. Stage 2: outcomes were grouped according to the International Classification of Functioning, Disability and Health domains. Stage 3: to determine priority outcomes for core outcome set (COS) inclusion participants will rate each outcome's importance (one-nine-point Likert scale) over two-three survey rounds. Stage 4: following review by the steering committee, a consensus meeting will be held if agreement on the COS has not been reached.Stage 5: recommendations will be made regarding a single instrument for measuring each COS outcome by reviewing existing resources where consensus has already been reached. Where resources do not exist the quality and feasibility of potential measurement instruments will be appraised, and the Delphi consensus survey and meeting process outlined in stages 3-4 will be repeated.This protocol adheres to the COS-Standardised Protocol statement and will be conducted and reported according to the COS-Standards for Development recommendations and the COS-Standards for Reporting. ETHICS AND DISSEMINATION: Ethics approval (20/9/22, University of Melbourne ID 2022-24839-32231-3). Dissemination in peer-reviewed journals and conference presentations.

Family carer needs in advanced disease: systematic review of reviews.

BACKGROUND: Family carers are vital in the management and delivery of home-based palliative care. Decision-makers need to know what the most commonly expressed unmet needs of family carers are to target available support services. AIM: To identify the most commonly expressed needs of family carers of people with an advanced disease, assess the quality of current evidence, and set an agenda for future research and clinical practice. DESIGN: A systematic review of reviews, prospectively registered on PROSPERO. Study quality was assessed using the Joanna Briggs Institute critical appraisal checklist for systematic reviews and research syntheses. DATA SOURCES: MEDLINE, Embase, Emcare, PsycINFO, CINAHL, Informit and Cochrane Library were searched for reviews about the needs of carers looking after patients with advanced disease from 2010 to 2020. RESULTS: Findings from 21 reviews identified emotional support, disease-specific knowledge, carer role responsibilities, self-care and general practical support as the most commonly expressed needs expressed by family carers. Additionally, access to professional services, formal education opportunities and communication with health professionals were identified as caregivers' preferred ways of having these needs met. Extraction of carer-specific needs was challenging at times as results were often combined with patient results in reviews. CONCLUSION: Practical difficulties exist in effectively resourcing services to meet the needs of family carers. Information regarding the most commonly expressed needs shared by caregivers and their preferred delivery source can provide an opportunity to focus available support services to achieve the highest possible impact for carers of patients with advanced disease. PROSPERO REGISTRATION NUMBER: CRD42018088678.

A Multi-Center Real-World Experience of IMpower150 in Oncogene Driven Tumors and CNS Metastases.

BACKGROUND: There are limited real world data on the IMpower150 regimen in oncogene driven tumors and central nervous system metastases; this study aims to address this gap. MATERIALS AND METHODS: Retrospective analysis of patients with advanced non-small cell lung cancer treated with the IMpower150 regimen across 12 Australian sites between July 2018 and April 2021. Clinicopathologic and treatment parameters were correlated with efficacy and toxicity. RESULTS: A total of 106 patients identified with median follow up of 8 months (range 0-72). Median age was 61 years (range 33-83), 34% Asian and 58% never-smokers. An oncogene was reported in 94 (89%) patients, EGFR in 72 (68%). At treatment commencement, 50 (47%) patients had brain metastases, 21 (20%) leptomeningeal disease (LMD) and 47 (44%) liver metastases. 27% were treatment-naïve and pemetrexed was substituted for paclitaxel in 44 (42%). The overall response rate was 51% for all patients; 52% in patients with EGFR mutations. Patients with untreated brain metastases prior to commencing IMpower150 had a similar intracranial response as those with treated brain metastases (55% vs. 53%). The median time to treatment failure and overall survival from commencement of IMpower150 was 5.7 and 11.4 months respectively for the entire cohort and 5.2 and 10.5 months in those with an EGFR sensitizing mutation. Overall survival in patients with liver, brain metastases and LMD was 11.0, 11.4, and 7.1 months respectively. No new safety signals seen. CONCLUSION: In this largely oncogene positive, pre-treated population the IMpower150 regimen demonstrated clinically-meaningful responses, including in patients with CNS disease.

Egg-Derived Anti-SARS-CoV-2 Immunoglobulin Y (IgY) With Broad Variant Activity as Intranasal Prophylaxis Against COVID-19.

COVID-19 emergency use authorizations and approvals for vaccines were achieved in record time. However, there remains a need to develop additional safe, effective, easy-to-produce, and inexpensive prevention to reduce the risk of acquiring SARS-CoV-2 infection. This need is due to difficulties in vaccine manufacturing and distribution, vaccine hesitancy, and, critically, the increased prevalence of SARS-CoV-2 variants with greater contagiousness or reduced sensitivity to immunity. Antibodies from eggs of hens (immunoglobulin Y; IgY) that were administered the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein were developed for use as nasal drops to capture the virus on the nasal mucosa. Although initially raised against the 2019 novel coronavirus index strain (2019-nCoV), these anti-SARS-CoV-2 RBD IgY surprisingly had indistinguishable enzyme-linked immunosorbent assay binding against variants of concern that have emerged, including Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529). This is different from sera of immunized or convalescent patients. Culture neutralization titers against available Alpha, Beta, and Delta were also indistinguishable from the index SARS-CoV-2 strain. Efforts to develop these IgY for clinical use demonstrated that the intranasal anti-SARS-CoV-2 RBD IgY preparation showed no binding (cross-reactivity) to a variety of human tissues and had an excellent safety profile in rats following 28-day intranasal delivery of the formulated IgY. A double-blind, randomized, placebo-controlled phase 1 study evaluating single-ascending and multiple doses of anti-SARS-CoV-2 RBD IgY administered intranasally for 14 days in 48 healthy adults also demonstrated an excellent safety and tolerability profile, and no evidence of systemic absorption. As these antiviral IgY have broad selectivity against many variants of concern, are fast to produce, and are a low-cost product, their use as prophylaxis to reduce SARS-CoV-2 viral transmission warrants further evaluation. Clinical Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT04567810, identifier NCT04567810.

Thermal ablation in non-small cell lung cancer: a review of treatment modalities and the evidence for combination with immune checkpoint inhibitors.

Lung cancer is the leading cause of cancer death worldwide, with approximately 1.6 million cancer related deaths each year. Prognosis is best in patients with early stage disease, though even then five-year survival is only 55% in some groups. Median survival for advanced non-small cell lung cancer (NSCLC) is 8-12 months with conventional treatment. Immune checkpoint inhibitor (ICI) therapy has revolutionised the treatment of NSCLC with significant long-term improvements in survival demonstrated in some patients with advanced NSCLC. However, only a small proportion of patients respond to ICI, suggesting the need for further techniques to harness the potential of ICI therapy. Thermal ablation utilizes the extremes of temperature to cause tumour destruction. Commonly used modalities are radiofrequency ablation (RFA), cryoablation and microwave ablation (MWA). At present thermal ablation is reserved for curative-intent therapy in patients with localized NSCLC who are unable to undergo surgical resection or stereotactic ablative body radiotherapy (SABR). Limited evidence suggests that thermal ablative modalities can upregulate an anticancer immune response in NSCLC. It is postulated that thermal ablation can increase tumour antigen release, which would initiate and upregulated steps in the cancer immunity cycle required to elicit an anticancer immune response. This article will review the current thermal ablative techniques and their ability to modulate an anti-cancer immune response with a view of using thermal ablation in conjunction with ICI therapy.

Impact of Radiotherapy on the Efficacy and Toxicity of anti-PD-1 Inhibitors in Metastatic NSCLC.

BACKGROUND: The impact of radiotherapy (RT) on the efficacy and toxicity of immune checkpoint inhibitors (ICIs) in patients with metastatic non-small-cell lung cancer (NSCLC) is unclear. MATERIALS AND METHODS: We identified patients with metastatic NSCLC treated with the anti-programmed death 1 antibodies nivolumab or pembrolizumab between January 2016 and May 2019 at 3 tertiary centers, who were also treated with palliative RT either during or within 3 months of starting anti-programmed death 1 treatment. Patient demographics, tumor characteristics, and treatment history were collected. Response rates, progression-free survival (PFS), and overall survival (OS) were analyzed and correlated with RT use. RESULTS: A total of 269 patients were identified, with a median follow-up of 19.4 months. The median age was 70 years (range, 35-90 years), and they were 63% male, 60% smokers, and 65% had adenocarcinoma histology. At the commencement of ICI treatment, the majority (86%) had ≥ 1 line of prior therapy and 34% had brain metastases. A total of 102 (38%) patients received RT within 3 months of starting ICI or subsequently during ICI treatment. Of patients that received RT, 86 (84%) received conventional hypofractionated RT, and, in the majority, 81 (79%) the intent of RT was symptom control. The use of RT did not increase grade 3/4 immune-related adverse events. The overall median PFS was 2.0 months (95% confidence interval, 1.3-2.6 months) and the median OS was 9.0 months (95% confidence interval, 6.4-9.5 months). There were no significant differences in median PFS (3.0 vs. 2.0 months; P = .515) and median OS (9.0 vs. 9.0 months; P = .917) in the patients who received RT versus those that did not. CONCLUSIONS: In patients with metastatic NSCLC, the addition of RT to ICI was not associated with increased toxicity or improved survival.

Transcriptional perturbation of protein arginine methyltransferase-5 exhibits MTAP-selective oncosuppression.

We hypothesized that small molecule transcriptional perturbation could be harnessed to target a cellular dependency involving protein arginine methyltransferase 5 (PRMT5) in the context of methylthioadenosine phosphorylase (MTAP) deletion, seen frequently in malignant pleural mesothelioma (MPM). Here we show, that MTAP deletion is negatively prognostic in MPM. In vitro, the off-patent antibiotic Quinacrine efficiently suppressed PRMT5 transcription, causing chromatin remodelling with reduced global histone H4 symmetrical demethylation. Quinacrine phenocopied PRMT5 RNA interference and small molecule PRMT5 inhibition, reducing clonogenicity in an MTAP-dependent manner. This activity required a functional PRMT5 methyltransferase as MTAP negative cells were rescued by exogenous wild type PRMT5, but not a PRMT5E444Q methyltransferase-dead mutant. We identified c-jun as an essential PRMT5 transcription factor and a probable target for Quinacrine. Our results therefore suggest that small molecule-based transcriptional perturbation of PRMT5 can leverage a mutation-selective vulnerability, that is therapeutically tractable, and has relevance to 9p21 deleted cancers including MPM.

Plasma pre-treatment T790M relative allelic frequency in patients with advanced EGFR-mutated non-small cell lung cancer predicts treatment response to subsequent-line osimertinib.

BACKGROUND: Approximately half of all patients with advanced EGFR-mutant NSCLC will develop acquired resistance to first or second-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs) with a T790M mutation. In the AURA3 trial, patients with a T790M mutation had a response rate of 71% to osimertinib, a third-generation EGFR-TKI. The response to osimertinib may vary according to plasma T790M mutation frequency. Our aim was to determine the effect of plasma T790M mutation load on treatment response to osimertinib in an Australian multi-institutional cohort. METHODS: We performed a retrospective study on patients treated with osimertinib in the second-line setting and beyond between 2016-2018 from ten centres in Australia, who had T790M mutations detected in tumour or plasma. The primary objective was to investigate if there was a difference in disease control rate (DCR) between patients with high vs. low T790M relative allelic frequency (RAF) as detected in plasma, using a 0.3 RAF cut-off, as determined by ddPCR or BEAMing PCR. Secondary objective was to determine the survival outcomes according to high versus low plasma T790M RAF. Additional analyses were performed to investigate the survival outcome for patients with plasma versus tissue T790M positivity. RESULTS: A total of 139 patients were included in this study. Patients with higher RAF demonstrated higher DCR (74% vs. 36%, P=0.02), however there was no statistically significant difference in survival outcomes in the two groups. Exploratory analysis showed that patients with tissue T790M+ had improved DCR compared with those with plasma T790M+ (89% vs. 68%, P=0.01) and longer progression free survival (median 15.4 vs. 9.7 months; HR 0.51, 95% CI: 0.34 to 0.77, P=0.003) and overall survival (median not reached, HR 0.51, 95% CI: 0.30 to 0.86, P=0.02). Patients who were tissue T790M+ demonstrated superior survival compared to plasma T790M+ after correcting for confounding variables in a multivariate model. CONCLUSIONS: DCR was superior in patients with higher plasma T790M mutation load versus lower plasma T790M mutational load, without significant survival benefit. Plasma T790M RAF is a potential predictive biomarker which should be investigated and validated in larger prospective studies.

Immunotherapy for malignant mesothelioma: reality check.

INTRODUCTION: Initial data of immune based therapy showed promise for improving malignant mesothelioma (MM) treatment. However, the results of such treatments have neither been predictable nor consistent and recent clinical studies of immune checkpoint inhibitors in MM have dampened initial enthusiasm. Areas covered: We comprehensively discuss the basis, modalities and updated results of immunotherapy in MM. An online search was conducted for relevant literature and abstracts of recent meetings. Expert commentary: Although initial studies have demonstrated proof of principle that manipulating the immune checkpoint axis holds promise in MM, results of some recent large studies using checkpoint inhibitors have been disappointing. This is not surprising given the low mutational load in MM and suggests that single agent immunotherapy has limited benefit in this disease. We believe that in order to demonstrate durable survival benefits, they will need to be used in combination approaches with other immunotherapies, vaccines or chemotherapy.

Clinical Utility of Patient-Derived Xenografts to Determine Biomarkers of Prognosis and Map Resistance Pathways in EGFR-Mutant Lung Adenocarcinoma.

PURPOSE: Although epidermal growth factor receptor (EGFR) -mutated adenocarcinomas initially have high response rates to EGFR tyrosine kinase inhibitors (TKIs), most patients eventually develop resistance. Patient-derived xenografts (PDXs) are considered preferred preclinical models to study the biology of patient tumors. EGFR-mutant PDX models may be valuable tools to study the biology of these tumors and to elucidate mechanisms of resistance to EGFR-targeted therapies. METHODS: Surgically resected early-stage non-small-cell lung carcinoma (NSCLC) tumors were implanted into nonobese diabetic severe combined immune deficient (NOD-SCID) mice. EGFR TKI treatment was initiated at tumor volumes of 150 µL. Gene expression analysis was performed using a microarray platform. RESULTS: Of 33 lung adenocarcinomas with EGFR activating mutations, only 6 (18%) engrafted and could be propagated beyond passage one. Engraftment was associated with upregulation of genes involved in mitotic checkpoint and cell proliferation. A differentially expressed gene set between engrafting and nonengrafting patients could identify patients harboring EGFR-mutant tumor with significantly different prognoses in The Cancer Genome Atlas Lung Adenocarcinoma datasets. The PDXs included models with variable sensitivity to first- and second-generation EGFR TKIs and the monoclonal antibody cetuximab. All EGFR-mutant NSCLC PDXs studied closely recapitulated their corresponding patient tumor phenotype and clinical course, including response pattern to EGFR TKIs. CONCLUSION: PDX models closely recapitulate primary tumor biology and clinical outcome. They may serve as important laboratory models to investigate mechanisms of resistance to targeted therapies, and for preclinical testing of novel treatment strategies.