The role of the gut microbiome on radiation therapy efficacy and gastrointestinal complications: A systematic review

Radiation therapy (RT) is an essential component of therapy either curative or palliative armamentarium in oncology, but its efficacy varies considerably among patients through many extrinsic and intrinsic mechanisms of the tumour, which are beginning to be better understood. Recent studies have shown that the gut microbiome represents a key factor in the modulation of the systemic immune response and consequently on patients' outcome. Moreover, the emergence of biomarkers that are derived from the gut microbiota has fuelled the development of adjuvant strategies for patients treated with immunotherapy in combination or not with RT. Despite progress in development of more precise radiotherapy techniques, almost all patients undergoing RT to the abdomen, pelvis, or rectum develop acute adverse events as a consequence of several dose-limiting parameters such as the location of irradiation that may subsequently damage normal tissue including the intestinal epithelium. Several lines of evidence in preclinical models identified that vancomycin improves RT-induced gastrointestinal toxicities such as diarrhea and oral mucositis. In order to gain further insight into this rapidly evolving field, we have systematically reviewed the studies that have described how the gut microbiome may directly or indirectly modulate RT efficacy and its gastro-intestinal toxicities. Lastly, we outline current knowledge gaps and discuss potentially more satisfactory therapeutic options to restore the functionality of the gut microbiome of patients treated with RT.

[Checkpoint inhibitors for cancer therapy]

In recent years, a breakthrough in tumor therapy was achieved with the development of checkpoint inhibitors. Checkpoint inhibitors activate the immune defense against tumors by overcoming the inhibitory effect of specific cell surface proteins acting as control points, the so-called checkpoints. This article provides an overview of the mode of action of approved checkpoint inhibitors and the status of current clinical development.The previously approved checkpoint inhibitors, monoclonal antibodies directed against the checkpoints CTLA‑4 and PD-1/PD-L1, are used in various tumor entities (including lung, kidney, and urothelial carcinoma; head and neck cancer; melanoma; and Hodgkin lymphoma). For the first time, long-term survival has been achieved in some of these patients with advanced tumors. Unfortunately, this efficacy can be observed only in a small proportion of the treated patients, depending on the tumor indication. Improved efficacy is envisioned by patient selection via predictive biomarkers and the development of combination therapies. Mandatory testing of the expression level of the predictive PD-L1 biomarker is already required in some indications to select patients with an enhanced benefit/risk relationship.

Immunogenicity and antitumor efficacy of a novel human PD-1 B-cell vaccine (PD1-Vaxx) and combination immunotherapy with dual trastuzumab/pertuzumab-like HER-2 B-cell epitope vaccines (B-Vaxx) in a syngeneic mouse model

Therapeutic blockade of PD-1/PD-L1 signaling with monoclonal antibodies (mAbs) has shown clinical success and activity across a broad set of cancer subtypes. However, monotherapy with PD-1/PD-L1 inhibitors are only effective in a subset of patients and ongoing studies show efficacy of treatment depends on a combinatorial approach. Contrary to mAbs chimeric B-cell cancer vaccines incorporating a “promiscuous” T-cell epitope have the advantage of producing a polyclonal B-cell antibody that can potentially induce memory B- and T-cell responses, while reducing immune evasion and suppression. Here, we describe a novel PD-1 B-cell peptide epitope vaccine (amino acid 92–110; PD1-Vaxx) linked to a measles virus fusion peptide (MVF) amino acid 288–302 via a four amino acid residue (GPSL) emulsified in Montanide ISA 720VG that aims to induce the production of polyclonal antibodies that block PD-1 signaling and thus trigger anticancer effects similar to nivolumab. In preclinical studies, the PD1-Vaxx outperformed the standard anti-mouse PD-1 antibody (mAb 29F.1A12) in a mouse model of human HER-2 expressing colon carcinoma. Furthermore, the combination of PD1-Vaxx with combo HER-2 peptide vaccine (B-Vaxx) showed enhanced inhibition of tumor growth in colon carcinoma BALB/c model challenged with CT26/HER-2 cells. The PD-1 or combined vaccines were safe with no evidence of toxicity or autoimmunity.

Liquid Biopsies to Evaluate Immunogenicity of Gynecological/Breast Tumors: On the Way to Blood-Based Biomarkers for Immunotherapies

BACKGROUND

Despite the assumption of breast cancer (BC) as a cold, non-immunogenic tumor, immune checkpoint inhibitor (ICI) therapy is favorable for a subgroup of patients. Immunohistochemical assessment of the programmed cell death ligand 1 (PD-L1) is the only approved companion diagnostic for anti-PD-L1 therapy in metastatic triple-negative BC; however, challenges regarding the standardization of PD-L1 scoring in tumor tissue still remain. Consequently, to select patients most likely to respond to ICI, blood-based biomarkers are urgently needed.

SUMMARY AND KEY MESSAGES

Liquid biopsy, comprising circulating immune cells, circulating tumor cells and extracellular vesicles, as well as their surface proteins, is of high potential, and these analytes were already shown to be molecular correlates or regulators of the evasion from antitumoral immune reaction. Liquid biopsy, also enabling the evaluation of tumor mutational burden (TMB), microsatellite instability, and the T-cell receptor repertoire, allows serial sampling for monitoring purposes and reflects intra-tumoral heterogeneity which qualifies as marker for immunogenicity. Only a very few studies have already elucidated the potential of these analytes as biomarkers under ICI therapy. Nonetheless, the topic is of growing interest and has high relevance for the future. However, for clinical implementation, these multifarious analytes first need to pass robust standardization and validation procedures.

Identifying and characterising the impact of excitability in a mathematical model of tumour-immune interactions

We study a five-compartment mathematical model originally proposed by Kuznetsov et al. (1994) to investigate the effect of nonlinear interactions between tumour and immune cells in the tumour microenvironment, whereby immune cells may induce tumour cell death, and tumour cells may inactivate immune cells. Exploiting a separation of timescales in the model, we use the method of matched asymptotics to derive a new two-dimensional, long-timescale, approximation of the full model, which differs from the quasi-steady-state approximation introduced by Kuznetsov et al. (1994), but is validated against numerical solutions of the full model. Through a phase-plane analysis, we show that our reduced model is excitable, a feature not traditionally associated with tumour-immune dynamics. Through a systematic parameter sensitivity analysis, we demonstrate that excitability generates complex bifurcating dynamics in the model. These are consistent with a variety of clinically observed phenomena, and suggest that excitability may underpin tumour-immune interactions. The model exhibits the three stages of immunoediting - elimination, equilibrium, and escape, via stable steady states with different tumour cell concentrations. Such heterogeneity in tumour cell numbers can stem from variability in initial conditions and/or model parameters that control the properties of the immune system and its response to the tumour. We identify different biophysical parameter targets that could be manipulated with immunotherapy in order to control tumour size, and we find that preferred strategies may differ between patients depending on the strength of their immune systems, as determined by patient-specific values of associated model parameters.

TEPI-2 and UBI: designs for optimal immuno-oncology and cell therapy dose finding with toxicity and efficacy

Conventional dose finding designs in oncology drug development target on the identification of the maximum tolerated dose (MTD), with the assumption that the MTD has the most potential of clinical activity among those identified tolerable dose levels. However, immuno-oncology (I-O) and cell therapy area, may lack dose-efficacy monotonicity, posing significant challenges in the statistical designs for dose finding trials. A desirable design should empower the trial to identify the right dose level with tolerable toxicity and acceptable efficacy. Such dose is called as optimal biological dose (OBD), which is more appropriate to be considered as the primary objective of the first-in-human trial in I-O and cell therapy than MTD. We propose two model-assisted designs in this setting: the toxicity and efficacy probability interval-2 (TEPI-2) design and the utility-based interval (UBI) design that incorporate the toxicity and efficacy outcomes simultaneously and identify a dose that has high probability of acceptable efficacy with manageable toxicity. The proposed designs can generate decision tables before trial starts to facilitate practical and easy-to-implement applications. Through simulation studies, our proposed novel designs demonstrate superior performance in accuracy, efficiency, and safety. Additionally, they can reduce the number of patients and shorten clinical development timeline. We also illustrate the advantages of proposed methods by redesigning a CAR T-cell therapy phase I clinical trial for multiple myeloma and summarize our recommendations in the discussion section.

Biotech and Breakthroughs in Immuno-Oncology

The age of immuno-oncology has ushered in a rush within the biopharmaceutical industry. This intense focus has been characterized as a frenzy or overhyped, but represents a substantial investment in new products that hope to harness the immune system against cancer. Such agents include next-generation checkpoint antagonists, immune costimulatory agonists, and a diverse array of novel mechanisms of action and therapeutic modalities targeting immune cell types and the interplay of the host and tumor at the immune synapse. This article surveys the clinical development and investment activity with Immuno-Oncology, specifically prostate, kidney, and bladder cancers.

Clinical development of cell therapies for cancer: The regulators' perspective

Novel cell therapies for haematological malignancies and solid tumours address pressing clinical need while offering potentially paradigm shifts in efficacy. However, innovative development risks outflanking information on statutory frameworks, regulatory guidelines and their working application. Meeting this challenge, regulators offer wide-ranging expertise and experience in confidential scientific and regulatory advice. We advocate early incorporation of regulatory perspectives to support strategic development of clinical programmes. We examine critical issues and key advances in clinical oncology trials to highlight practical approaches to optimising the clinical development of cell therapies. We recommend early consideration of collaborative networks, early-access schemes, reducing bias in single-arm trials, adaptive trials, clinical end-points supporting risk/benefit and cost/benefit analyses, companion diagnostics, real-world data and common technical issues. This symbiotic approach between developers and regulators should reduce development risk, safely expedite marketing authorisation, and promote early, wider availability of potentially transformative cell therapies for cancer.

Biology of the Triple-Negative Breast Cancer: Immunohistochemical, RNA, and DNA Features

Background

The triple-negative breast cancer (TNBC) constitutes a heterogeneous disease with an aggressive behavior and a poor prognosis. A better understanding of its biology is required to identify new biomarkers and improve clinical outcomes.

Summary

To date, the definition and classification of TNBC depends on a multiomic approach including immunohistochemistry (IHC), genomic, and transcriptomic features, and the tumor immune landscape. The development of new technologies has allowed us to sequence the whole cancer genome. The Cancer Genome Atlas (TCGA) and next-generation sequencing have led to a greater knowledge of DNA alterations such as TP53 or BRCA mutations, copy number variations, and DNA methylations. In addition, gene expression profiling has allowed to define a molecular intrinsic classification of TNBC based on mRNA. IHC and genomic profiling are also necessary to identify new immune biomarkers such as the presence of tumor-infiltrating lymphocytes and the expression of immune checkpoint molecules.

Key Messages

This review aimed to provide recent knowledge of TNBC biology and classification focused on IHC, transcriptomics, genomic features, and the new immune biomarkers.

Current Status and Future Perspectives of Immunotherapy in Middle-Income Countries: A Single-Center Early Experience

Background

Immunotherapy agents offer novel treatment options in advanced cancers. However, their use is limited in developing countries lacking unifying guidelines and can be followed by a financial burden. In this study, we aimed to provide an overview regarding the use of immunotherapy and the overall response to treatment in patients with metastatic disease in relation to cost-effectiveness.

Methods

This was a retrospective study involving adult metastatic cancer patients, treated with programmed cell death-1 (PD-1) inhibitors at American University of Beirut Medical Center (AUBMC), a tertiary cancer center in Lebanon. Study enrollment began on January 1, 2014 and ended on January 12, 2016. Baseline demographics, epidemiological and clinical data were collected from the patients’ records.

Results

Our study consisted of 34 patients. Fifteen patients self-financed the treatment. The patients were prescribed immunotherapy without programmed cell death-ligand 1 (PD-L1) testing as it was not part of the guidelines at the time. Twenty-two patients were treated with nivolumab and 12 patients with pembrolizumab. Thirteen patients showed partial response or stable disease, while 21 patients showed progression.

Conclusion

Improvement in terms of overall survival and progression-free survival has been undercut by the lack of availability of these drugs and their cost. Considering that a large percentage of patients do not respond to immunotherapy, there is a need to use guidelines such as a preset PD-L1 level that ensure cost-effectiveness and prevent resource waste.

[Immunotherapy in bladder cancer-quo vadis? Update on current trials and developments]

BACKGROUND

Great advances have been made for the treatment of urothelial carcinoma by the introduction of checkpoint inhibitors (CPI). Single-agent immunotherapy with CPIs has been approved for patients with metastatic or locally advanced inoperable urothelial carcinoma who have either progressed during or after platinum-based chemotherapy or who are cisplatin-ineligible. For cisplatin-ineligible patients, approval is restricted to patients with high programmed cell death ligand 1 (PD-L1) expression. For patients with nonmuscle invasive bladder cancer (NMIBC) or patients with muscle invasive bladder cancer (MIBC) who receive curative therapy, no CPIs have received approval in Germany.

OBJECTIVES

To provide an overview of the current landscape of immunotherapy in patients with urothelial carcinoma.

METHODS

Summary of the therapeutic landscape and resulting challenges based on currently published data using a PubMed search.

RESULTS

In the treatment of metastatic or inoperable urothelial carcinoma, CPIs represent standard treatment. Depending on the results of currently performed trials, an extension of its use to the perioperative setting (neoadjuvant/adjuvant) and to patients with Bacillus Calmette Guérin (BCG) unresponsive NMIBC in the near future is currently being discussed.

CONCLUSIONS

Immuno-oncologic treatment using CPIs has become an integral part of the management of patients with advanced bladder cancer. For biomarker-based patient selection and combination therapies, there is an urgent need for further investigations within clinical trial protocols.

IConMHC: a deep learning convolutional neural network model to predict peptide and MHC-I binding affinity

Tumor-specific neoantigens are mutated self-peptides presented by tumor cell major histocompatibility complex (MHC) molecules and are necessary to elicit host's anti-cancer cytotoxic T cell responses. It could be specifically recognized by neoantigen-specific T cell receptors (TCRs). However, current wet-lab assays for identifying peptide MHC binding are too expensive and time-consuming to meet the clinical needs. In this study, we developed an in silico method with a deep convolutional neural network (CNN) model, iConMHC, to predict peptide MHC binding affinity. Unlike other in silico methods that only learn from properties of amino acid in neoantigen peptides alone and/or MHCs alone, iConMHC learns from physical and chemical interaction properties between pairwise amino acids from the two molecules. These properties, such as contact potentials and distances in folded proteins, directly affect neoantigen-MHC binding affinity. In addition, IConMHC is a pan-allele model that is capable of making predictions for all the MHC alleles. Even for those rare MHC alleles without training data, iConMHC can make predictions with reasonable accuracy. We benchmarked iConMHC with other commonly used MHC-I binding predictors and found our model performs better than most of the pan-allele models.

A phase 1 trial of the safety, tolerability and biological effects of intravenous Enadenotucirev, a novel oncolytic virus, in combination with chemoradiotherapy in locally advanced rectal cancer (CEDAR)

BACKGROUND

Chemoradiotherapy remains the standard of care for locally advanced rectal cancer. Efforts to intensify treatment and increase response rates have yet to yield practice changing results due to increased toxicity and/or absence of increased radiosensitization. Enadenotucirev (EnAd) is a tumour selective, oncolytic adenovirus which can be given intravenously. Pre-clinical evidence of synergy with radiation warrants further clinical testing and assessment of safety with radiation.

METHODS

Eligibility include histology confirmed locally advanced rectal cancer that require chemoradiation. The trial will use a Time-to-Event Continual Reassessment Model-based (TiTE-CRM) approach using toxicity and efficacy as co-primary endpoints to recommend the optimal dose and treatment schedule 30 patients will be recruited. Secondary endpoints include pathological complete response the neoadjuvant rectal score. A translational program will be based on a mandatory biopsy during the second week of treatment for 'proof-of-concept' and exploration of mechanism. The trial opened to recruitment in July 2019, at an expected rate of 1 per month for up to 4 years.

DISCUSSION

Chemoradiation with Enadenotucirev as a radiosensitiser in locally Advanced Rectal cancer (CEDAR) is a prospective multicentre study testing a new paradigm in radiosensitization in rectal cancer. The unique ability of EnAd to selectively infect tumour cells following intravenous delivery is an exciting opportunity with a clear translational goal. The novel statistical design will make efficient use of both toxicity and efficacy data to inform subsequent studies.

TRIAL REGISTRATION

ClinicalTrial.gov, NCT03916510. Registered 16th April 2019.

Phase 1b study of a small molecule antagonist of human chemokine (C-C motif) receptor 2 (PF-04136309) in combination with nab-paclitaxel/gemcitabine in first-line treatment of metastatic pancreatic ductal adenocarcinoma

Background In pancreatic ductal adenocarcinoma (PDAC), the chemokine (C-C motif) ligand 2 (CCL2)/chemokine (C-C motif) receptor 2 (CCR2) axis plays a key role in immunosuppressive properties of the tumor microenvironment, patient prognosis, and chemoresistance. This phase Ib study assessed the effects of the orally administered CCR2 inhibitor PF-04136309 in combination with nab-paclitaxel and gemcitabine in patients with previously untreated metastatic PDAC. Methods Patients received PF-04136309 twice daily (BID) continuously plus nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2) administered on days 1, 8, and 15 of each 28-day cycle. The primary objectives were to evaluate safety and tolerability, characterize dose-limiting toxicities (DLTs), and determine the recommended phase II dose (RP2D) of PF-04136309. Results In all, 21 patients received PF-04136309 at a starting dose of 500 mg or 750 mg BID. The RP2D was identified to be 500 mg BID. Of 17 patients treated at the 500 mg BID starting dose, three (17.6%) experienced a total of four DLTs, including grade 3 dysesthesia, diarrhea, and hypokalemia and one event of grade 4 hypoxia. Relative to the small number of patients (n = 21), a high incidence (24%) of pulmonary toxicity was observed in this study. The objective response rate for 21 patients was 23.8% (95% confidence interval: 8.2-47.2%). Levels of CD14 + CCR2+ inflammatory monocytes (IM) decreased in the peripheral blood, but did not accumulate in the bone marrow. Conclusions PF-04136309 in combination with nab-paclitaxel plus gemcitabine had a safety profile that raises concern for synergistic pulmonary toxicity and did not show an efficacy signal above nab-paclitaxel and gemcitabine. ClinicalTrials.gov identifier: NCT02732938.

Sequential Systemic Treatment in Advanced Hepatocellular Carcinoma Is Able to Prolong Median Survival to More than 3 Years in a Selected Real-World Cohort

Introduction

The number of efficacious systemic agents for advanced hepatocellular carcinoma (HCC) has rapidly increased over the past 3 years. However, guidance for optimal sequential systemic treatment in patients with advanced disease and experience with outcome and safety profiles are lacking.

Objective

We aimed to assess efficacy and tolerability of sequential systemic therapy of advanced HCC.

Methods

Our single-center study prospectively followed 14 patients who received multiple, sequential systemic therapies after progression or intolerance to sorafenib. Endpoints were overall and progression-free survival (OS, PFS), objective response rate (ORR), and treatment-emergent adverse events (TEAE).

Results

Patients had well-compensated liver function and good performance status at start of each systemic therapy. Agents included sorafenib (n = 14), regorafenib (n = 10), immunotherapy with nivolumab or pembrolizumab (n = 10), lenvatinib (n = 3), ramucirumab (n = 2), and others, with a median of 3 lines of systemic therapy per patient. Median OS was 37.4 months from initiation of first-line therapy with sorafenib. PFS and ORR for sorafenib, regorafenib, and immunotherapy were 6.6, 5.3, and 6.6 months, and 15.4, 11.1, and 22.2%, respectively. TEAE were frequent (46-80%), but mostly manageable during tyrosine kinase inhibitor therapy and without the need for termination in most patients. However, TEAE due to immunotherapy (60%) led to cessation of treatment in 40% of the patients.

Conclusions

Sequential systemic therapy is able to prolong median OS in selected patients with advanced HCC to more than 3 years. TEAE are frequent, but manageable, and the quality of adverse events depends on the respective agent. Further investigation of potential predictive biomarkers for treatment allocation is needed.

Rational targeting of immunosuppressive neutrophils in cancer

Neutrophils, the most abundant circulating leukocytes in human, play an indispensable role in the innate immune response to microbial infections. However, the contribution of tumor-associated neutrophils (TANs) to cancer progression and tumor immunity has been a matter of debate for decades. A higher neutrophil-to-lymphocyte ratio is associated with adverse overall survival in many solid tumors. Preclinical evidence exists to support both anti-tumor and pro-tumor activities of TANs, and TANs employ diverse mechanisms to influence tumor progression and metastasis. Here, we focus our review on the immunosuppressive mechanism of TANs and highlight how neutrophils can operate to dampen both innate and adaptive immunity to promote tumorigenesis. Here we discuss the intriguing and sometimes controversial connection between TANs and granulocytic/polymorphonuclear myeloid-derived suppressor cells (G/PMN-MDSCs). The molecular mechanisms underlying neutrophils' role in immunosuppression provide potential therapeutic targets for cancer treatment, either as monotherapies or as a part of combinatorial regimens. Therefore, we also highlight a number of neutrophil-targeting approaches that may improve the efficacy of current anticancer therapies, especially cancer immunotherapy. Currently interest is surging in the understanding and targeting of immunosuppressive neutrophils, with the goal of developing novel therapeutic strategies in the battle against cancer.

Real-World Outcomes for Advanced Non-Small Cell Lung Cancer Patients Treated With a PD-L1 Inhibitor Beyond Progression

BACKGROUND

Clinical trials of anti-programmed cell death ligand 1 (PD-L1) inhibitor to treat advanced non-small-cell lung cancer (aNSCLC) have permitted treatment beyond progression (TBP). However, the outcomes of patients receiving TBP in routine clinical care are unknown.

MATERIALS AND METHODS

The present retrospective, observational, multicenter analysis evaluated de-identified electronic health record-derived data from community-based clinics in the United States. The patients had confirmed aNSCLC, had started anti-PD-L1 inhibitor therapy (nivolumab, pembrolizumab, or atezolizumab) before October 1, 2018, and had experienced a real-world progression (rwP) event. The study period ended March 31, 2019. The primary objective was to compare the overall survival (OS) of patients who had discontinued immunotherapy ≤ 30 days (non-TBP) compared with > 30 days after rwP (TBP). Descriptive analyses were performed. The Kaplan-Meier method and log-rank test were conducted for OS. An adjusted multivariable Cox proportional hazards regression model was also used.

RESULTS

Overall, the data from 4223 patients were analyzed; 2555 (60.5%) and 1668 (39.5%) in the non-TBP and TBP cohorts, respectively. The median treatment duration for the non-TBP and TBP patients was 2.8 and 9.1 months (log-rank test, P < .001), respectively. The TBP group experienced longer unadjusted OS compared with the non-TBP group (11.5 vs. 5.1 months; log-rank test, P < .001). After adjusting for clinically relevant patient characteristics, the TBP OS benefit persisted (adjusted hazard ratio, 0.69; P < .001).

CONCLUSIONS

TBP with PD-L1 inhibitor therapy is common in aNSCLC routine care and is potentially effective. These results support clinical trial observations likely to affect practice patterns.

Targeting tumor-associated macrophages in head and neck squamous cell carcinoma

In head and neck squamous cell carcinoma (HNSCC), tumor-associated macrophages (TAMs) are associated with a poorer prognosis. TAMs, derived from inflammatory monocyte, play a critical role in regulating tumor progression. Generally, TAMs promote tumor progression and suppress immune response via both innate and adaptive immune mechanisms. However, as the double-blade sword, TAMs retain the potential pro-inflammatory ability to inhibit tumor progression. By depleting the immunosuppressive function or evoking anti-tumor ability, therapeutic strategies targeting TAMs show promising preclinical and clinical effects. Now, macrophage-centered therapeutic approaches are entering the clinical arena. In this review, we discuss the immunosuppressive role of TAMs in the tumor microenvironment and the therapeutic approaches targeting macrophages which offer promise in improving HNSCC outcome.

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.

Immuno-oncology-the new paradigm of lung cancer treatment

Systemic therapy is an essential part of treatment for all patients with small-cell lung cancer (sclc) and for most patients with non-small-cell lung cancer (nsclc). Standards of care have evolved dramatically since 2009, especially in the setting of incurable or advanced nsclc. Part of that evolution has been the incorporation of immuno-oncology drugs, especially immune checkpoint inhibitors (icis) into multiple therapeutic scenarios. In the present review, we discuss the role of the immune system in lung cancer and the previous failures of immunotherapy for patients with lung cancer. We then provide an overview of the existing evidence for the use of icis in patients with advanced nsclc that is either treatment-naïve or pretreated, for consolidative treatment after chemoradiotherapy in stage iii nsclc, and for palliative therapy in patients with sclc. Finally, we discuss duration of treatment, special populations, and the future of immuno-oncology for patients with lung cancer. Overall, we provide an evidence-based snapshot of immuno-oncology agents in the treatment of lung cancer up to early 2019.

Targeting T cell activation in immuno-oncology

The years since 2009 have seen tremendous progress in unlocking the curative potential of the immune system for the treatment of cancer. Much of that revolution in immuno-oncology has been fueled by the clinical success of immune checkpoint inhibitors, particularly those targeting the PD-1 axis. Unfortunately, many patients still fail to benefit from checkpoint blockade or other immunotherapies. An inability to fully activate antitumour T cells contributes in part to the failure of those therapies. Here, we review the basic biology of T cell activation, with particular emphasis on the essential role of the dendritic cell and the innate immune system in T cell activation. The current understanding of the multiple factors that govern T cell activation and how they impinge on tumour immunotherapy are also discussed. Lastly, treatment strategies to potentially overcome barriers to T cell activation and to enhance the efficacy of immunotherapy are addressed.

First-line Treatment of Metastatic Renal Cell Carcinoma in the Immuno-oncology Era: Systematic Review and Network Meta-analysis

Combination treatments with immuno-oncology (IO) agents and IO agents plus a vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) have been approved for first-line treatment of patients with metastatic renal cell carcinoma (mRCC). No direct comparisons have been performed among these treatment options. We performed a systematic review and network meta-analysis to compare and rank the available regimens for first-line treatment in terms of survival benefit and efficacy. In accordance with the Preferred Reporting Items for Systematic Review statement, a systematic search of reported studies was performed in MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE up to May 31, 2019. Network meta-analysis models were adjusted using the Bayesian method. Four randomized clinical trials, with a total of 3758 patients, met the inclusion criteria. Considering systemic therapy, 1880 patients had received sunitinib and 550, 432, 442, and 454 patients had received ipilimumab plus nivolumab (ipi + nivo), pembrolizumab plus axitinib (pembro + axi), avelumab plus axitinib (avelu + axi), and atezolizumab plus bevacizumab (atezo + bev). No difference was found in overall survival between ipi + nivo and pembro + axi for the intention to treat population (hazard ratio [HR], 1.34; 95% credible interval [CrI], 0.92-1.97). No difference was found in progression-free survival among the treatments. The overall response rate (ORR) was superior with pembro + axi and avelu + axi compared with the ORR with the other treatments (atezo + bev vs. pembro + axi: HR, 0.66; 95% CrI, 0.52-0.84; ipi + nivo vs. pembro + axi: HR, 0.73; 95% CrI, 0.59-0.90; atezo + bev vs. avelu + axi: HR, 0.55; 95% CrI, 0.43-0.71; avelu + axi vs. ipi + nivo: HR, 1.66; 95% CrI, 1.31-2.12), with no differences across them (HR, 1.21; 95% CrI, 0.95-1.53). In the present indirect comparison, for an intention to treat population, we found no survival differences between pembro + axi and ipi + nivo. All treatments showed better progression-free survival compared with sunitinib that was similar among them. The combination of an IO agent (pembrolizumab or avelumab) and axitinib seemed to be the most effective therapy for the ORR.

Harmonization and Standardization of Panel-Based Tumor Mutational Burden Measurement: Real-World Results and Recommendations of the Quality in Pathology Study

INTRODUCTION

Tumor mutational burden (TMB) is a quantitative assessment of the number of somatic mutations within a tumor genome. Immunotherapy benefit has been associated with TMB assessed by whole-exome sequencing (wesTMB) and gene panel sequencing (psTMB). The initiatives of Quality in Pathology (QuIP) and Friends of Cancer Research have jointly addressed the need for harmonization among TMB testing options in tissues. This QuIP study identifies critical sources of variation in psTMB assessment.

METHODS

A total of 20 samples from three tumor types (lung adenocarcinoma, head and neck squamous cell carcinoma, and colon adenocarcinoma) with available WES data were analyzed for psTMB using six panels across 15 testing centers. Interlaboratory and interplatform variation, including agreement on variant calling and TMB classification, were investigated. Bridging factors to transform psTMB to wesTMB values were empirically derived. The impact of germline filtering was evaluated.

RESULTS

Sixteen samples had low interlaboratory and interpanel psTMB variation, with 87.7% of pairwise comparisons revealing a Spearman's ρ greater than 0.6. A wesTMB cut point of 199 missense mutations projected to psTMB cut points between 7.8 and 12.6 mutations per megabase pair; the corresponding psTMB and wesTMB classifications agreed in 74.9% of cases. For three-tier classification with cut points of 100 and 300 mutations, agreement was observed in 76.7%, weak misclassification in 21.8%, and strong misclassification in 1.5% of cases. Confounders of psTMB estimation included fixation artifacts, DNA input, sequencing depth, genome coverage, and variant allele frequency cut points.

CONCLUSIONS

This study provides real-world evidence that all evaluated panels can be used to estimate TMB in a routine diagnostic setting and identifies important parameters for reliable tissue TMB assessment that require careful control. As complex or composite biomarkers beyond TMB are likely playing an increasing role in therapy prediction, the efforts by QuIP and Friends of Cancer Research also delineate a general framework and blueprint for the evaluation of such assays.

Immunogenomic pathways associated with cytotoxic lymphocyte infiltration and survival in colorectal cancer

Background

Colorectal cancer (CRC) is the second leading cancer killer in the US today and patients with metastatic disease have only a 14% 5-year survival. One of the most impactful recent advances in cancer therapy, immune checkpoint inhibition, has not been shown to be effective for the majority of these patients. In this study, we use The Cancer Genome Atlas (TCGA) and recently developed informatic-based tools to identify targets for immune based therapy in colorectal cancer patients.

Methods

Open access, pre-processed (level 3) mRNA data and clinical data from colorectal patients from the TCGA was downloaded from FireCloud. Using the Microenvironment Cell Populations-Counter method (MCP-Counter), cytotoxic lymphocyte scores were calculated for all patients. Patients were then grouped by cytotoxic lymphocyte score (High vs Low), pathologic stage, and location to identify differentially expressed genes. Pathway enrichment analysis was performed using Reactome to determine differentially expressed genes associated with immune pathways. Survival analysis was performed with identified differentially expressed genes.

Results

In the TCGA dataset, there are 461 colon and 172 rectal cancer patients. After stratifying patients by cytotoxic lymphocyte score, anatomical location, and stage, we found a significant number of differentially expressed genes. We identified one pathway, “immunoregulatory interactions between a lymphoid and non-lymphoid cell”, that was highly enriched and included in all tumor locations and stages. Survival analysis performed with differentially expressed genes in this pathway identified 21 different genes associated with survival and cytotoxic lymphocyte infiltration, with ~ 70% of these genes occurring in the metastatic right-sided CRC group. Specifically, all genes associated with survival in the metastatic right-sided colorectal cancer group with low cytotoxic lymphocyte scores positively impacted survival.

Conclusions

Utilizing the TCGA, a publicly available dataset, and informatics-based analyses, we identified potential targets to improve immune based therapy in colorectal cancer. Additionally, we note the most targets in metastatic right-sided CRC patients, the patient group with the worst predicted survival. The results from this study demonstrate the ability of informatics-based analytic techniques to identify new therapeutic targets as well as improve patient selection for intervention, helping us to achieve the goals of precision-based oncology.

[Role of immunotherapy in locally advanced non-small cell lung cancer]

Concomitant radiochemotherapy has been the standard of care for unresectable stage III non-small cell lung cancer (NSCLC), irrespective of histological sub-type or molecular characteristics. Currently, only 15-30 % of patients are alive five years after radiochemotherapy, and this figure remains largely unchanged despite multiple phase III randomised trials. In recent years, immune-checkpoint blockades with anti-PD-(L)1 have revolutionised the care of metastatic NSCLC, becoming the standard front- and second-line strategy. Several preclinical studies reported an increased tumour antigen release, improved antigen presentation, and T-cell infiltration in irradiated tumours. Immunotherapy has therefore recently been evaluated for patients with locally advanced stage III NSCLC. Following the PACIFIC trial, the anti-PD-L1 durvalumab antibody has emerged as a new standard consolidative treatment for patients with unresectable stage III NSCLC whose disease has not progressed following concomitant platinum-based chemoradiotherapy. Immunoradiotherapy therefore appears to be a promising association in patients with localised NSCLC. Many trials are currently evaluating the value of concomitant immunotherapy and chemoradiotherapy and/or consolidative chemotherapy with immunotherapy in patients with locally advanced unresectable NSCLC.