Efficacy and safety of an intensified schedule of tremelimumab for chemotherapy-resistant malignant mesothelioma: an open-label, single-arm, phase 2 study

CTLA-4: a moving target in immunotherapy

CD28 and CTLA-4 are members of a family of immunoglobulin-related receptors that are responsible for various aspects of T-cell immune regulation. The family includes CD28, CTLA-4, and ICOS as well as other proteins, including PD-1, BTLA, and TIGIT. These receptors have both stimulatory (CD28, ICOS) and inhibitory roles (CTLA-4, PD-1, BTLA, and TIGIT) in T-cell function. Increasingly, these pathways are targeted as part of immune modulatory strategies to treat cancers, referred to generically as immune checkpoint blockade, and conversely to treat autoimmunity and CTLA-4 deficiency. Here, we focus on the biology of the CD28/CTLA-4 pathway as a framework for understanding the impacts of therapeutic manipulation of this pathway.

Medical treatment of malignant pleural mesothelioma relapses

There are not established treatments for patients with advanced malignant pleural mesothelioma that progressed after first-line chemotherapy with cisplatin and pemetrexed. Retrospective analyses suggest a possible role for rechallenge with pemetrexed for selected patients. Phase II trials demonstrate a modest efficacy of vinorelbine monotherapy with a response rate ranging between 0% and 18% and a tolerable toxicity profile. Combination schedules, despite an increased toxicity, fail to demonstrate an improved efficacy. To date, genome wide analyses did not show molecular targets suitable for therapy and biological drugs did not exert a significant efficacy in clinical trials. Immunotherapy has given a hint of efficacy in early clinical trials but definitive evaluations are still ongoing.

Cancer immunotherapy-induced endocrinopathies: Clinical behavior and therapeutic approach

Cancer immunotherapy has proven to be effective in a wide variety of tumors. The use of immune checkpoint blocking monoclonal antibodies has become a standard treatment regimen in some of them as advanced melanoma. However, given the mechanism of action, its use may be associated with immune-related adverse events that may complicate the clinical course and prognosis of patients. Among these are autoimmune endocrine adverse effects, such as hypophysitis, hypo and hyperthyroidism, and adrenal insufficiency. This review focuses on the most relevant and new aspects related to the incidence, clinical presentation, diagnosis and treatment of these adverse effects associated with different types of immune checkpoint inhibitors in cancer immunotherapy.

New horizons from immunotherapy in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive disease with a severe prognosis. Medical treatment for MPM unresectable patients is still unsatisfactory; therefore novel therapeutic approaches are urgently needed. Immunotherapy represents a promising treatment for MPM patients. Here, we'll discuss the most promising immunotherapeutic treatments currently under active investigation for this still dreadful disease.

Mesothelioma in Australia: a review

The incidence of malignant mesothelioma in Australia is among the highest in the world as a result of widespread use of asbestos by industry and in construction throughout the 20th century. The risk of developing malignant mesothelioma after asbestos exposure is dose-related; a transient, low dose exposure confers a correspondingly very low risk of disease. Malignant mesothelioma is a heterogeneous disease, partly explaining the limited role of biomarkers in screening and diagnosis. The prognosis remains poor, and early advice on medico-legal compensation and a collaborative team approach to managing malignant mesothelioma are both essential. Chemotherapy can have a modest treatment effect in some people. New therapies, such as immunotherapy, do not yet have a defined role in the treatment of malignant mesothelioma. As treatment options for malignant mesothelioma are limited and no cure is available, there is no established role for early detection or screening of at risk populations. A multidisciplinary approach to caring for patients with malignant mesothelioma and their carers is vital.

Endocrine dysfunction following immune checkpoint inhibitor therapy

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICI) represent an important milestone in the modern era of antineoplastic therapy and have ushered optimism amongst oncologists and patients alike. These agents, however, are associated with significant potential toxicities, the importance of which cannot be overstated. The clinical presentation, diagnosis, and management strategies of immune-related endocrinopathies associated with ICI use are described in this case-based review.

RECENT FINDINGS

An increasing number of ICI have shown promise in the management of various malignancies in the recent years. These include cytotoxic T lymphocyte antigen-4 inhibitors, programmed cell death 1 (PD-1) antibodies, and PD-ligand 1 (PD-L1) antibodies. Several endocrinopathies, including hypophysitis, thyroid dysfunction, hyperglycemia, and primary adrenal insufficiency, have been associated with the use of these agents. Toxicities may range from mild transient laboratory abnormalities to potentially life-threatening ones, warranting immediate therapeutic intervention. Combination ICI therapies may be associated with a greater risk of endocrine dysfunction when compared with monotherapy. The clinical presentation and laboratory assessment of these patients often pose a diagnostic challenge as they may be confused by the symptoms related to their underlying malignancy or potential associated acute illnesses.

SUMMARY

ICI use is associated with serious endocrinopathies that may have a nonspecific initial presentation. A constant eye for these symptoms and a systematic approach to diagnosis are essential for prompt initiation of therapy and prevention of significant complications.

Trial watch: Immune checkpoint blockers for cancer therapy

Immune checkpoint blockers (ICBs) are literally revolutionizing the clinical management of an ever more diversified panel of oncological indications. Although considerable attention persists around the inhibition of cytotoxic T lymphocyte-associated protein 4 (CTLA4) and programmed cell death 1 (PDCD1, best known as PD-1) signaling, several other co-inhibitory T-cell receptors are being evaluated as potential targets for the development of novel ICBs. Moreover, substantial efforts are being devoted to the identification of biomarkers that reliably predict the likelihood of each patient to obtain clinical benefits from ICBs in the absence of severe toxicity. Tailoring the delivery of specific ICBs or combinations thereof to selected patient populations in the context of precision medicine programs constitutes indeed a major objective of the future of ICB-based immunotherapy. Here, we discuss recent preclinical and clinical advances on the development of ICBs for oncological indications.

Immunotherapy advances for mesothelioma treatment

INTRODUCTION

Mesothelioma is a rare type of cancer that is strongly tied to asbestos exposure. Despite application of different modalities such as chemotherapy, radiotherapy and surgery, patient prognosis remains very poor and therapies are ineffective. Much research currently focuses on the application of novel approaches such as immunotherapy towards this disease. Areas covered: The types, stages and aetiology of mesothelioma are detailed, followed by a discussion of the current treatment options such as radiotherapy, surgery, and chemotherapy. A description of innate and adaptive immunity and the principles and justification of immunotherapy is also included. Clinical trials for different immunotherapeutic modalities are described, and lastly the article closes with an expert commentary and five-year view, the former of which is summarised below. Expert commentary: Current efforts for novel mesothelioma therapies have been limited by attempting to apply treatments from other cancers, an approach which is not based on a solid understanding of mesothelioma biology. In our view, the influence of the hostile, hypoxic microenvironment and the gene expression and metabolic changes that resultantly occur should be characterised to improve therapies. Lastly, clinical trials should focus on overall survival rather than surrogate endpoints to avoid bias and inaccurate reflections of treatment effects.

Anti-CTLA-4 therapy for malignant mesothelioma

Immunotherapy is an emerging therapeutic strategy with a promising clinical outcome in some solid tumors, particularly metastatic melanoma. One approach to immunotherapy is immune checkpoint inhibitors, such as blockage of CTLA-4 and PD-1/PD-L1. This special report aims to describe the state of clinical trials of tremelimumab in patients with unresectable malignant mesothelioma (MM) in particular with regard to the clinical efficacy, safety and tolerability. Criticism and perspective of this treatment are also discussed. Biological and clinical considerations rule out the use of tremelimumab as single agent for MM and, more generally, the use of immune checkpoint inhibitors for MM is still largely questionable and not supported by evidences.

Tremelimumab as second-line or third-line treatment in relapsed malignant mesothelioma (DETERMINE): a multicentre, international, randomised, double-blind, placebo-controlled phase 2b trial

BACKGROUND

New therapeutic strategies for malignant mesothelioma are urgently needed. In the DETERMINE study, we investigated the effects of the cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibody tremelimumab in patients with previously treated advanced malignant mesothelioma.

METHODS

DETERMINE was a double-blind, placebo-controlled, phase 2b trial done at 105 study centres across 19 countries in patients with unresectable pleural or peritoneal malignant mesothelioma who had progressed after one or two previous systemic treatments for advanced disease. Eligible patients were aged 18 years or older with Eastern Cooperative Oncology Group performance status of 0 or 1 and measurable disease as defined in the modified Response Evaluation Criteria In Solid Tumors (RECIST) version 1.0 for pleural mesothelioma or RECIST version 1.1 for peritoneal mesothelioma. Patients were randomly assigned (2:1) in blocks of three, stratified by European Organisation for Research and Treatment of Cancer status (low risk vs high risk), line of therapy (second line vs third line), and anatomic site (pleural vs peritoneal), by use of an interactive voice or web system, to receive intravenous tremelimumab (10 mg/kg) or placebo every 4 weeks for 7 doses and every 12 weeks thereafter until a treatment discontinuation criterion was met. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study drug. The trial is ongoing but no longer recruiting participants, and is registered with ClinicalTrials.gov, number NCT01843374.

FINDINGS

Between May 17, 2013, and Dec 4, 2014, 571 patients were randomly assigned to receive tremelimumab (n=382) or placebo (n=189), of whom 569 patients received treatment (two patients in the tremelimumab group were excluded from the safety population because they did not receive treatment). At the data cutoff date (Jan 24, 2016), 307 (80%) of 382 patients had died in the tremelimumab group and 154 (81%) of 189 patients had died in the placebo group. Median overall survival in the intention-to-treat population did not differ between the treatment groups: 7·7 months (95% CI 6·8-8·9) in the tremelimumab group and 7·3 months (5·9-8·7) in the placebo group (hazard ratio 0·92 [95% CI 0·76-1·12], p=0·41). Treatment-emergent adverse events of grade 3 or worse occurred in 246 (65%) of 380 patients in the tremelimumab group and 91 (48%) of 189 patients in the placebo group; the most common were dyspnoea (34 [9%] patients in the tremelimumab group vs 27 [14%] patients in the placebo group), diarrhoea (58 [15%] vs one [<1%]), and colitis (26 [7%] vs none). The most common serious adverse events were diarrhoea (69 [18%] patients in the tremelimumab group vs one [<1%] patient in the placebo group), dyspnoea (29 [8%] vs 24 [13%]), and colitis (24 [6%] vs none). Treatment-emergent events leading to death occurred in 36 (9%) of 380 patients in the tremelimumab group and 12 (6%) of 189 in the placebo group; those leading to the death of more than one patient were mesothelioma (three [1%] patients in the tremelimumab group vs two [1%] in the placebo group), dyspnoea (three [1%] vs two [1%]); respiratory failure (one [<1%] vs three [2%]), myocardial infarction (three [1%] vs none), lung infection (three [1%] patients vs none), cardiac failure (one [<1%] vs one [<1%]), and colitis (two [<1%] vs none). Treatment-related adverse events leading to death occurred in five (1%) patients in the tremelimumab group and none in the placebo group. The causes of death were lung infection in one patient, intestinal perforation and small intestinal obstruction in one patient; colitis in two patients, and neuritis and skin ulcer in one patient.

INTERPRETATION

Tremelimumab did not significantly prolong overall survival compared with placebo in patients with previously treated malignant mesothelioma. The safety profile of tremelimumab was consistent with the known safety profile of CTLA-4 inhibitors. Investigations into whether immunotherapy combination regimens can provide greater efficacy than monotherapies in malignant mesothelioma are ongoing.

FUNDING

AstraZeneca.

Promising investigational drug candidates in phase I and phase II clinical trials for mesothelioma

INTRODUCTION

Malignant mesothelioma is a rare and lethal malignancy primarily affecting the pleura and peritoneum. Mesothelioma incidence is expected to increase worldwide and current treatments remain ineffective, leading to poor prognosis. Within this article potential targets to improve the quality of life of the patients and assessment of further avenues for research are discussed. Areas covered: This review highlights emerging therapies currently under investigation for malignant mesothelioma with a specific focus on phase I and phase II clinical trials. Three main areas are discussed: immunotherapy (immune checkpoint blockade and cancer vaccines, among others), multitargeted therapy (such as targeting pro-angiogenic genes) and gene therapy (such as suicide gene therapy). For each, clinical trials are described to detail the current or past investigations at phase I and II. Expert opinion: The approach of applying existing treatments from other cancers does not show significant benefit, with the most promising outcome being an increase in survival of 2.7 months following combination of chemotherapy with bevacizumab. It is our opinion that the hypoxic microenvironment, the role of the stroma, and the metabolic status of mesothelioma should all be assessed and characterised to aid in the development of new treatments to improve patient outcomes.

Immune checkpoint therapy of mesothelioma: Pre-clinical bases and clinical evidences

Treatment with immune-checkpoint blocking monoclonal antibody (mAb) is demonstrating a significant efficacy in different tumor types. Here, we discuss the impact of this promising approach in malignant mesothelioma (MM), a still dreadful disease in which medical treatment has been set on platinum based chemotherapy for decades with unsatisfactory results.

Novel immunotherapy clinical trials in malignant pleural mesothelioma

In this article, we review ongoing novel clinical trials currently investigating immunotherapeutic approaches for patients with malignant pleural mesothelioma (MPM). There is a dearth of effective therapeutic options for patients diagnosed with MPM and metastatic cancers of the pleura; these diseases have an estimated annual incidence of 150,000. Modulating the immune microenvironment to promote antitumor immune responses by systemically and regionally delivered therapeutic agents is an active area of investigation. We have conducted a review of the clinical trials database for clinical trials actively recruiting MPM patients. We focused on novel therapeutic agents administered either systemically or intrapleurally to modulate the tumor immune microenvironment. Herein, we have summarized the published results of early phase clinical trials. A total of 43 clinical trials met our inclusion criteria. These trials are investigating immunologic agents (n=20) and antibody directed therapies (n=23). The regional intrapleural delivery technique (6 trials) is used to administer chemotherapy agents (3 of 6 trials) and immunotherapy agents (3 of 6 trials), including chimeric antigen receptor T cells (1 of 6 trials). Current clinical trials modulating the MPM immune microenvironment and the combination of these novel agents with standard of care therapy provide a promising area of investigation for MPM therapy.

Pseudoprogression in microsatellite instability-high colorectal cancer during treatment with combination T cell mediated immunotherapy: a case report and literature review

Evading tumor-mediated immunosuppression through antibodies to immune checkpoints has shown clinical benefit in patients with select solid tumors. There is a heterogeneity of responses in patients receiving immunotherapy, including pseudoprogression in which the tumor burden increases initially before decreasing to reach disease control. The characteristics and basis of pseudoprogression, however, remains poorly understood. We hereby report a case of microsatellite instability (MSI)-high metastatic colorectal cancer treated with combination of OX40 agonist and programmed death ligand-1 (PD-L1) antagonist that demonstrated pseudoprogression reaching 163% increase from baseline tumor burden. Tumor regression was subsequently observed and patient has remained in stable disease. Despite the substantial radiological progression, the symptomatic improvement reported by the patient led us to the decision of treatment continuation based on the suspicion of pseudoprogression, illustrating the importance of clinical evaluation in medical decision making while managing patients on immunotherapy. Additionally, the patient's MSI-high status contributes to his good, maintained response to PD-L1 blockade. Our case provides a frame of reference for fluctuation in tumor burden associated with pseudoprogression. Here we also evaluate the incidence and scale of pseudoprogression across solid tumor types.

Immunotherapy for malignant pleural mesothelioma: current status and future directions

Malignant pleural mesothelioma (MPM) has been marked historically by poor prognosis. Current standard of care for this deadly disease results in sub-optimal improvements in overall survival (OS), which has prompted researchers to explore innovative treatment alternatives. Immunotherapy is an emerging therapeutic modality that harnesses the power of the human immune system. In this review, we summarize the different methods of immunotherapy for malignant pleural mesothelioma. Using ClinicalTrials.gov we searched the terms "immunotherapy" and "immune therapy" combined with "pleural mesothelioma". Our search yielded 75 trials, among which 37 trials met our specific criteria. Our search identified immune checkpoint blockade, immunotoxin therapy, anticancer vaccines, oncolytic viral therapy, and adoptive cell therapy as the most common and pertinent methods of immunotherapy currently being assessed in clinical trials. We have reviewed the most up-to-date clinical trials involving immunotherapeutic approaches for the treatment of malignant pleural mesothelioma. In addition to highlighting some of the successes of immunotherapy, we also have identified limitations that must be overcome to improve the efficacy of these therapies.

Autologous hematopoietic stem cell transplantation following high-dose chemotherapy for nonrhabdomyosarcoma soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) are a highly heterogeneous group of rare malignant solid tumors. Nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) comprise all STS except rhabdomyosarcoma. In people with advanced local or metastatic disease, autologous hematopoietic stem cell transplantation (HSCT) applied after high-dose chemotherapy (HDCT) is a planned rescue therapy for HDCT-related severe hematologic toxicity. The rationale for this update is to determine whether any randomized controlled trials (RCTs) have been conducted and to clarify whether HDCT followed by autologous HSCT has a survival advantage.

OBJECTIVES

To assess the efficacy and safety of high-dose chemotherapy (HDCT) followed by autologous hematopoietic stem cell transplantation (HSCT) for all stages of nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) in children and adults.

SEARCH METHODS

For this update, we revised the search strategy to improve the precision and reduce the number of irrelevant hits. We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), PubMed from 2012 to 6 September 2016, and Embase from 2012 to 26 September 2016. We searched online trial registries and congress proceedings from 2012 to 26 September 2016.

SELECTION CRITERIA

Terms representing STS and autologous HSCT were required in the title or abstract. We restricted the study design to RCTs. We included studies if at least 80% of participants had a diagnosis listed in any version of the World Health Organization (WHO) classification and classified as malignant. The search included children and adults with no age limits.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane. The primary outcomes were overall survival and treatment-related mortality.

MAIN RESULTS

We identified 1549 records; 85 items from electronic databases, 45 from study registries, and 1419 from congress proceedings. The revised search strategy did not identify any additional RCTs. In the previous version of the review, we identified one RCT comparing HDCT followed by autologous HSCT versus standard-dose chemotherapy (SDCT). The trial randomized 87 participants who were considerably heterogeneous with respect to 19 different tumor entities. The data from 83 participants were available for analysis.In the single included trial, overall survival at three years was 32.7% in the HDCT arm versus 49.4% in the SDCT arm and there was no difference between the treatment groups (hazard ratio (HR) 1.26, 95% confidence interval (CI) 0.70 to 2.29, P = 0.44; 1 study, 83 participants; high quality evidence). In a subgroup of participants who had a complete response before HDCT, overall survival was higher in both treatment groups and overall survival at three years was 42.8% in the HDCT arm versus 83.9% in the SDCT arm and favored the SDCT group (HR 2.92, 95% CI 1.1 to 7.6, P = 0.028; 1 study, 39 participants).In the single included trial, the authors reported one treatment-related leukemia death two years after HDCT. They also evaluated severe adverse events WHO grade 3 to 4 in 22 participants in the HDCT arm and in 51 participants in the SDCT arm. The authors reported 11 events concerning digestive-, infection-, pain-, or asthenia-related toxicity in the HDCT arm and one event in the SDCT arm (moderate quality evidence). The development of secondary neoplasia was not addressed. We judged the study to have an overall unclear risk of bias as three of seven items had unclear and four items had low risk of bias. For GRADE, we judged three items as high quality and three items were not reported.

AUTHORS' CONCLUSIONS

The limited data of a single RCT with an unclear risk of bias and moderate to high quality evidence showed no survival advantage for HDCT. If this treatment is offered it should only be given after careful consideration on an individual person basis and possibly only as part of a well-designed RCT.

Immune-related ocular toxicities in solid tumor patients treated with immune checkpoint inhibitors: a systematic review

INTRODUCTION

Immune-related ocular toxicities are uncommon but serious adverse events that may be associated with the use of immune checkpoint inhibitors. The objective of this review is to assess the incidence and risk of ocular toxicities which are potentially immune-related and occur with immune checkpoint treatment of solid tumors. Areas covered: PubMed database has been searched till June 2016. Prospective clinical trials reporting the occurrence of immune-related ocular toxicities in solid tumor patients treated with immune checkpoint inhibitors were included. Eleven trials with 4965 participants were included. These studies included one study for ipilimumab and tremelimumab, three studies for nivolumab, five studies for pembrolizumab and one study comparing pembrolizumab to ipilimumab. No atezolizumab studies were included. The most common ocular toxicities reported with these agents included uveitis and dry eyes. Pooled analysis for odds ratio of all-grade immune-related ocular toxicities is 3.40 [95% CI: 1.32-8.71; P = 0.01]. Expert commentary: Despite being uncommon, immune-related ocular toxicities (particularly uveitis and dry eyes) occur with a higher frequency in cancer patients treated immune checkpoint inhibitors compared to those treated with control regimens.

Current Diagnosis and Management of Immune Related Adverse Events (irAEs) Induced by Immune Checkpoint Inhibitor Therapy

The indications of immune checkpoint inhibitors (ICIs) are set to rise further with the approval of newer agent like atezolimumab for use in patients with advanced stage urothelial carcinoma. More frequent use of ICIs has improved our understanding of their unique side effects, which are known as immune-related adverse events (irAEs). The spectrum of irAEs has expanded beyond more common manifestations such as dermatological, gastrointestinal and endocrine effects to rarer presentations involving nervous, hematopoietic and urinary systems. There are new safety data accumulating on ICIs in patients with previously diagnosed autoimmune conditions. It is challenging for clinicians to continuously update their working knowledge to diagnose and manage these events successfully. If diagnosed timely, the majority of events are completely reversible, and temporary immunosuppression with glucocorticoids, infliximab or other agents is warranted only in the most severe grade illnesses. The same principles of management will possibly apply as newer anti- cytotoxic T lymphocytes-associated antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1/PD-L1) antibodies are introduced. The current focus of research is for prophylaxis and for biomarkers to predict the onset of these toxicities. In this review we summarize the irAEs of ICIs and emphasize their growing spectrum and their management algorithms, to update oncology practitioners.

T cell exhaustion: from pathophysiological basics to tumor immunotherapy

The immune system is capable of distinguishing between danger- and non-danger signals, thus inducing either an appropriate immune response against pathogens and cancer or inducing self-tolerance to avoid autoimmunity and immunopathology. One of the mechanisms that have evolved to prevent destruction by the immune system, is to functionally silence effector T cells, termed T cell exhaustion, which is also exploited by viruses and cancers for immune escape In this review, we discuss some of the phenotypic markers associated with T cell exhaustion and we summarize current strategies to reinvigorate exhausted T cells by blocking these surface marker using monoclonal antibodies.

Immune-Checkpoint Inhibitors in the Era of Precision Medicine: What Radiologists Should Know

Over the past five years immune-checkpoint inhibitors have dramatically changed the therapeutic landscape of advanced solid and hematologic malignancies. The currently approved immune-checkpoint inhibitors include antibodies to cytotoxic T-lymphocyte antigen-4, programmed cell death (PD-1), and programmed cell death ligand (PD-L1 and PD-L2). Response to immune-checkpoint inhibitors is evaluated on imaging using the immune-related response criteria. Activation of immune system results in a unique toxicity profile termed immune-related adverse events. This article will review the molecular mechanism, clinical applications, imaging of immune-related response patterns and adverse events associated with immune-checkpoint inhibitors.

Neurological adverse events associated with immune checkpoint inhibitors: Review of the literature

Immune checkpoint inhibitors (ICIs) targeting CTLA4 and PD1 constitute a promising class of cancer treatment but are associated with several immune-related disorders. We here review the literature reporting neurological adverse events (nAEs) associated with ICIs. A systematic search of literature, up to February 2016, mentioning nAEs in patients treated with ICIs was conducted. Eligible studies included case reports and prospective trials. One case seen in our ward was also added. Within the 59 clinical trials (totalling 9208 patients) analysed, the overall incidence of nAEs was 3.8% with anti-CTLA4 antibodies, 6.1% with anti-PD1 antibodies, and 12.0% with the combination of both. The clinical spectrum of neurological disorders was highly heterogeneous. Most of these nAEs were grade 1-2 and consisted of non-specific symptoms such as headache (55%). The incidence of high grade nAEs was below 1% for all types of treatment. Headaches, encephalopathies and meningitis were the most commonly reported (21%, 19% and 15%, respectively). Among the 27 case reports, the most common nAEs were encephalopathies, meningoradiculoneuritis, Guillain-Barré like syndromes and myasthenic syndromes. The median time of nAEs onset was 6 weeks. In most cases, drug interruption and steroids led to neurological recovery, even in conditions where steroids are not usually recommended such as Guillain-Barré syndrome.

Malignant pleural mesothelioma: an update on investigation, diagnosis and treatment

Malignant pleural mesothelioma is an aggressive malignancy of the pleural surface, predominantly caused by prior asbestos exposure. There is a global epidemic of malignant pleural mesothelioma underway, and incidence rates are predicted to peak in the next few years.This article summarises the epidemiology and pathogenesis of malignant pleural mesothelioma, before describing some key factors in the patient experience and outlining common symptoms. Diagnostic approaches are reviewed, including imaging techniques and the role of various biomarkers. Treatment options are summarised, including the importance of palliative care and methods of controlling pleural effusions. The evidence for chemotherapy, radiotherapy and surgery is reviewed, both in the palliative setting and in the context of trimodality treatment. An algorithm for managing malignant pleural effusion in malignant pleural mesothelioma patients is presented. Finally new treatment developments and novel therapeutic approaches are summarised.

Management of recurrence after initial surgery for malignant pleural mesothelioma: a mini-review

Recurrence after surgery in the multimodality therapy for malignant pleural mesothelioma is a common problem. As the majority of patients experience not only local but also distant metastases, a systemic treatment strategy in addition to local control measures remains necessary. Nevertheless, none of the chemotherapy regimens have achieved clinical success. Local management modalities such as stereotaxic treatments, cryoablation and redo surgery on the other hand have promising results, but provide palliative outcomes.

The resistance related to targeted therapy in malignant pleural mesothelioma: Why has not the target been hit yet?

Malignant pleural mesothelioma (MPM) is an aggressive tumor of the pleura with a poor prognosis. The most active first-line regimens are platinum compounds and pemetrexed. There is no standard second-line treatment in MPM. Advances in the understanding of tumor molecular biology have led to the development of several targeted treatments, which have been evaluated in clinical trials. Unfortunately none of the explored targeted treatments can currently be recommended as routine treatment in MPM. We reviewed the biological pathways involved in MPM, the clinical trials about targeted therapy, and possible related mechanisms of resistance. We suggest that specific genetic markers are needed as targets of selective therapy. By this way the selection of patients based on the molecular profile may facilitate a therapeutic strategy that allows the use of the most appropriate drug for each patient.

Molecular Pathways: At the Crossroads of Cancer Epigenetics and Immunotherapy

Epigenetic regulation allows heritably modulating gene expression profiles without modifying the primary sequence of gDNA. Under physiologic conditions, epigenetic patterns determine tissue-specific gene expression landscapes, gene imprinting, inactivation of chromosome X, and preservation of genomic stability. The most characterized mediators of epigenetic inheritance are gDNA methylation and histone posttranslational modifications that cooperate to alter chromatin state and genome transcription. According to these notions, it is not surprising that cancer cells invariantly deploy epigenetic alterations to achieve gene expression patterns required for neoplastic transformation and tumor progression. In this context, the recently uncovered use of epigenetic alterations by cancer cells to become stealth from the host's immune recognition has significant immunobiologic relevance in tumor progression, and it appears to have potential clinical usefulness. Indeed, immune evasion is among the major obstacles to further improve the efficacy of cancer immunotherapies and to increase long-lasting disease control. Luckily, different "epigenetic drugs" able to revert these "epimutations" are available, some of which have already been approved for clinical use. Here, we summarize the immunomodulatory activities of epigenetic drugs that lead to improved immune recognition of cancer cells and focus on the potential of this class of agents in improving the anticancer activity of novel immunotherapies through combinatorial epigenetic immunotherapy approaches.

CTLA-4 in mesothelioma patients: tissue expression, body fluid levels and possible relevance as a prognostic factor

CTLA-4 function as a negative regulator of T cell-mediated immune response is well established, whereas much less is known about the immunoregulatory role of its soluble isoform (sCTLA-4). No data are available on CTLA-4 expression and prognostic impact in malignant pleural mesothelioma (MPM). We investigated, by immunohistochemistry, CTLA-4 expression in tumor tissues and, by ELISA, sCTLA-4 levels in sera and matched pleural effusions from 45 MPM patients. Prognostic effect of CTLA-4 expression on overall survival (OS) was assessed through Cox regression and prognostic significance expressed as death rate ratio (HR). We found that 56.0 % of MPM tissues expressed CTLA-4 with variable intensity and percentage of positive cells estimated by the immunoreactive score. sCTLA-4 levels were significantly higher in sera (S-sCTLA-4) than in pleural effusions (PE-sCTLA-4) (geometric mean ratio = 2.70, P value = 0.020). CTLA-4 expression at the tissue level was higher in the epithelioid histological subtype than in the sarcomatoid, whereas at the serum level, it was higher in the sarcomatoid subtype. A homogeneous favorable prognostic effect was found for CTLA-4 overexpression in tissue, serum and pleural effusion. Interestingly, only the PE-sCTLA-4 was found to be a statistically significant positive prognostic factor (HR = 0.37, 95 % CI = 0.18-0.77, P value = 0.007). Indeed, PE-sCTLA-4 correlated with CTLA-4 expression in tissues, whereas this latter expression showed a weak association with OS. To confirm our findings, further experimental evidences obtained from a larger cohort of MPM patients are required. However, our results would indicate a positive correlation of PE-sCTLA-4 levels and OS in MPM patients.

Management of malignant pleural mesothelioma-part 2: therapeutic approaches : Consensus of the Austrian Mesothelioma Interest Group (AMIG)

Treatment of malignant pleural mesothelioma (MPM) depends on performance status of the patient, tumor stage, and histological differentiation. Chemotherapy (CHT) can be administered as first- and second-line treatment in unresectable MPM or as neoadjuvant or adjuvant treatment before or after surgery. A combination of an antifolate and platinum-based CHT is the only approved standard of care. Several targeted and immunotherapies are in evaluation and further studies are warranted to determine the therapeutic value of these new treatment options. Radiotherapy (RT) can be considered either as adjuvant treatment after surgery or for palliation of pain-related tumor growth. Recent data support the use of RT in a neoadjuvant setting. Macroscopic complete resection by pleurectomy/decortication (P/D) or extrapleural pneumonectomy (EPP) is indicated in selected patients with good performance status. Surgery should only be applied as part of a multimodality treatment (MMT) in combination with chemo- and/or radiotherapy. In a large number of cases, palliative attempts are needed to improve quality of life and to achieve symptom control.

New therapeutic strategies for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignant disease affecting the mesothelium, commonly associated to asbestos exposure. Therapeutic actions are limited due to the late stage at which most patients are diagnosed and the intrinsic chemo-resistance of the tumor. The recommended systemic therapy for MPM is cisplatin/pemetrexed regimen with a mean overall survival of about 12months and a median progression free survival of less than 6months. Considering that the incidence of this tumor is expected to increase in the next decade and that its prognosis is poor, novel therapeutic approaches are urgently needed. For some tumors, such as lung cancer and breast cancer, druggable oncogenic alterations have been identified and targeted therapy is an important option for these patients. For MPM, clinical guidelines do not recommend biological targeted therapy, mainly because of poor target definition or inappropriate trial design. Further studies are required for a full comprehension of the molecular pathogenesis of MPM and for the development of new target agents. This review updates pre-clinical and clinical data on the efficacy of targeted therapy and immune checkpoint inhibition in the treatment of mesothelioma. Finally, future perspectives in this deadly disease are also discussed.

Moving Immune Checkpoint Blockade in Thoracic Tumors beyond NSCLC

SCLC and malignant pleural mesothelioma (MPM) are historically characterized by a disappointing lack of significant therapeutic breakthroughs for novel agents, and both malignancies represent true unmet medical needs. Given the promising results of anti-cytotoxic T-lymphocyte associated protein-4 and anti-programmed cell death-1/programmed death ligand-1 antibodies in the treatment of advanced NSCLCs, these immune checkpoint inhibitors are now also under investigation in SCLC and MPM, as well as in thymic epithelial tumors (TETs). Here, we review the biological and clinical rationale for immune checkpoint inhibition in SCLC, MPM, and TETs and present preliminary clinical results with available antibodies. Immunotherapeutic perspectives for these malignancies in terms of novel agents currently under evaluation or anticipated in the near future are also discussed. Current immune checkpoint blockers targeting cytotoxic T-lymphocyte associated protein-4 and the programmed cell death-1/programmed death ligand-1 axis, administered alone or in combination and as multimodality treatment, are likely to be a valuable addition to the therapeutic array for managing SCLC and MPM; studies in TETs, which are currently in their infancy, are merited. Close attention to potential toxicities will be important to the success of such strategies in these settings.

Modern management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a deadly disease that produces a significant worldwide health care burden. The majority of cases are associated with prior asbestos exposure, but recent studies have identified a possible genetic predisposition in a minority of patients. Historically, obtaining a pathologic diagnosis of MPM was challenging, but with current pathological techniques, a secure diagnosis is possible in the majority of patients. Curative therapy for MPM remains elusive, and the primary treatment option for fit patients is platinum-based chemotherapy. Encouraging recent reports suggest that there may be a benefit to the addition of bevacizumab to standard chemotherapy as well as with the use of immune checkpoint inhibitors in MPM. Selected patients may be considered for aggressive surgical approaches, but there is considerable controversy regarding the true benefit of surgery and multimodality therapy in this disease.

Immunotherapy for lung cancer

Treatment of lung cancer remains a challenge, and lung cancer is still the leading cause of cancer-related mortality. Immunotherapy has previously failed in lung cancer but has recently emerged as a very effective new therapy, and there is now growing worldwide enthusiasm in cancer immunotherapy. We summarize why immune checkpoint blockade therapies have generated efficacious and durable responses in clinical trials and why this has reignited interest in this field. Cancer vaccines have also been explored in the past with marginal success. Identification of optimal candidate neoantigens may improve cancer vaccine efficacy and may pave the way to personalized immunotherapy, alone or in combination with other immunotherapy such as immune checkpoint blockade. Understanding the steps in immune recognition and eradication of cancer cells is vital to understanding why previous immunotherapies failed and how current therapies can be used optimally. We hold an optimistic view for the future prospect in lung cancer immunotherapy.

Immune checkpoint inhibition in ovarian cancer

Recent studies have shown that tumor cells acquire escape mechanisms to evade host immunity in the tumor microenvironment. Two key immune checkpoint pathways mediated by immunosuppressive co-signaling, the first via programmed cell death 1 (PD-1) and PD-1 ligand 1 (PD-1/PD-L1) and the second via CTLA-4 and B7 (CTLA-4/B7), have been previously described. Several clinical trials have revealed an outstanding anti-tumor efficacy of immune checkpoint inhibitors (anti-CTLA-4 antibody, anti-PD-1 antibody and/or anti-PD-L1 antibody) in patients with various types of solid malignancies, including non-small cell lung cancer, melanoma, renal cell cancer and ovarian cancer. In this review, we examine pre-clinical studies that described the local immune status and immune checkpoint signals in ovarian cancer, highlight recent clinical trials that evaluated immune checkpoint inhibitors against ovarian cancer and discuss the clinical issues regarding immune checkpoint inhibitors.

Tremelimumab: research and clinical development

The immune checkpoint therapy is a relatively recent strategy that aims to tweak the immune system to effectively attack cancer cells. The understanding of the immune responses and their regulation at the intracellular level and the development of fully humanized monoclonal antibodies are the pillars of an approach that could elicit durable clinical responses and even remission in some patients with cancer. Most of the immune checkpoints that regulate the T-cell responses (activation and inhibition) operate through proteins present on the cytoplasmic membrane of the immune cells. Therefore, specific antibodies capable of blocking the inhibitory signals should lead to unrestrained immune responses that supersede the inhibitory mechanisms, which are naturally present in the tumor microenviroment. The best-known and most successful targets for immune checkpoint therapy are the cytotoxic T-lymphocyte antigen-4 and programmed cell death-1 coreceptors. Tremelimumab (CP-675,206) is a fully humanized monoclonal antibody specific for cytotoxic T-lymphocyte antigen-4, which has been successfully used to treat patients with metastatic melanoma and some other cancers. Although still a work in progress, the use of tremelimumab as an immune checkpoint therapeutic agent is a promising approach alone or in combination with other anticancer drugs. Here, we review the use of this antibody in a number of clinical trials against solid tumors.

Malignant pleural mesothelioma: an update on diagnosis and treatment options

Malignant pleural mesothelioma (MPM) represents a significant diagnostic and therapeutic challenge and is almost always a fatal disease. Imaging abnormalities are common, but have a limited role in distinguishing mesothelioma from metastatic pleural disease. Similarly, minimally invasive biomarkers have shown promise but also have limitations in the diagnosis of mesothelioma. In experienced centers, cytology and immunohistochemistry are now sufficient to diagnose the epithelioid subtype of mesothelioma, which can reduce the need for more invasive diagnostic investigations. Prognosis of MPM is modestly impacted by oncological treatments. Chemotherapy with cisplatin and pemetrexed is considered the standard of care, though the addition of bevacizumab to the platinum doublet may be the new standard of care. New targeted therapies have demonstrated some promise and are being addressed in clinical trials. This review focuses on the current data on the diagnostic and therapeutic issues of MPM.

Management of toxicities of immune checkpoint inhibitors

Immune checkpoint inhibition with the anti-CTLA-4 antibody ipilimumab and the anti-PD-1 antibodies nivolumab and pembrolizumab has improved survival in metastatic melanoma, lung cancer and renal cancer. Use of these agents holds promise in other malignancies. The augmented immune response enabled by these agents has led to a particular group of side effects called immune-related adverse events (irAEs). The main irAEs include diarrhea, colitis, hepatitis, skin toxicities and endocrinopathies such as hypophysitis and thyroid dysfunction. The anti-PD-1 antibodies have a different toxicity profile to ipilimumab with fewer high grade events. This article identifies the rates of common and uncommon irAEs associated with each immune checkpoint inhibitor (ICPI) and their timing of onset, focusing mainly on the experience in melanoma and lung cancer. An approach to management for each class of irAE is provided.

New directions in mesothelioma treatment

For most patients with mesothelioma, symptom control and palliative chemotherapy are mainstays of care. First-line cisplatin/pemetrexed chemotherapy has demonstrated survival and quality-of-life benefits. A randomized controlled trial adding bevacizumab to cisplatin and pemetrexed recently reported improved survival and time to progression, and may constitute a new standard of care where economically viable. Immunotherapy is under active investigation and positive results have been reported from single-arm studies of the anti-CTLA4 antibody tremelimumab; the anti-PD-1 antibody pembrolizumab; and mesothelin-targeting strategies. Symptom control remains critical for patient well-being, and includes management of pleural effusion, analgesia, treatment of symptomatic masses and management of systemic symptoms. There is increasing evidence that tunneled pleural catheters are preferred over talc pleurodesis for recurrent pleural effusion.

Tremelimumab-associated tumor regression following after initial progression: two case reports

The human IgG2 monoclonal antibody tremelimumab is an immune checkpoint inhibitor that blocks cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). The therapeutic response of anti-CTLA-4 monoclonal antibodies possess unique kinetics, in that antitumor responses are often observed after initial short-term disease progression, in some cases as long as 6-12 months after anti-CTLA-4 treatment initiation. Here, we report two cases: one of bile duct cancer and the other of squamous cell carcinoma of unknown primary, both of which demonstrated initial rapid disease progression followed by dramatic tumor shrinkage after one or two doses of tremelimumab, without any immune-related adverse events. This delayed, yet dramatic antitumor response suggests that tremelimumab may hold promise in the treatment of solid tumors.

Novel insights into the pathophysiology and treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma is an aggressive, treatment-resistant tumor, which continues to increase in frequency throughout the world because the causative agent, asbestos, has high economic importance, particularly in developing countries. Patients typically present with breathlessness and chest pain with pleural effusions. Median survival is around 12 months from diagnosis. Palliative chemotherapy is beneficial for mesothelioma patients with high performance status. The role of aggressive surgery remains controversial. This review will outline some of the recent advances in the development of novel therapies for malignant pleural mesothelioma, with a focus on immunological approaches.