Cediranib in patients with malignant mesothelioma: a phase II trial of the University of Chicago Phase II Consortium

Posterior Reversible Encephalopathy Syndrome after Lenvatinib Therapy in a Patient with Olfactory Neuroblastoma

Posterior reversible encephalopathy syndrome (PRES) is a rare but severe neurological syndrome that may stem from the use of some medications. Although its mechanism is not well-known, hypertension and endothelial dysfunction have been mentioned in previous literature as being related. Lenvatinib serves as a neoplastic agent that inhibits the tyrosine kinase of vascular endothelial growth factor receptors (VEGFR). VEGFR inhibitors result in endothelial dysfunction and consequent hypertension by nitric oxide pathway suppression and endothelin (ET)-1 stimulation. We hypothesized that VEGFR inhibitors would cause PRES. Herein, we report the case of a 40-year-old man with olfactory neuroblastoma who developed PRES while undergoing treatment with lenvatinib, 7 months after initiation. The symptoms included loss of consciousness and seizures. Fortunately, the symptoms and presence of PRES in imaging resolved, 7 days and 1 month, respectively, after cessation of lenvatinib.

Venous Thromboembolism in Cancer Patients Undergoing Chemotherapy: A Systematic Review and Meta-Analysis

Objective: Venous thromboembolism (VTE) is a life-threatening complication that may exacerbate cancer prognosis. Whilst some studies indicate an increased risk of VTE in cancer patients undergoing chemotherapy, the prevalence estimates on the pooled prevalence of VTE in cancer patients undergoing chemotherapy are not known. This study aims to calculate the pooled prevalence of VTE in chemotherapy-treated cancer patients. Methods: Studies on VTE occurrence in cancer patients undergoing chemotherapy were retrieved after database search. The terms used included “cancer”, “chemotherapy”, and “venous thromboembolism”. A random-effects meta-analysis was conducted to obtain a pooled estimate of VTE prevalence in cancer patients undergoing chemotherapy. Results: A total of 102 eligible studies involving 30,671 patients (1773 with VTE, 28,898 without) were included in the meta-analysis. The pooled estimate of VTE prevalence was found to be 6%, ranging from 6% to 7% (ES 6%; 95% CI 6−7%; z = 18.53; p < 0.001). Conclusions: The estimated pooled prevalence rate of VTEs was 6% in cancer patients undergoing CRT, which was higher than the overall crude prevalence rate (5.78%). Comprehensive cancer care should consider stratified VTE risk assessment based on cancer phenotype, given that certain phenotypes of cancer such as bladder, gastric and ovarian posing particularly high risks of VTE.

A Glimpse in the Future of Malignant Mesothelioma Treatment

Malignant mesothelioma (MMe) is a rare neoplasm with few therapeutic options available. The landscape of effective therapy for this disease remained unchanged in the last two decades. Recently, however, the introduction of Immune Checkpoint Inhibitors (ICIs) led to small, but nevertheless, promising improvements. However, many efforts are still needed to radically improve the prognosis of MMe. In this review, we analyze all those therapeutic strategies for MMe that are still in a preclinical or early clinical phase of development. In particular, we focus on novel antiangiogenic drugs and their possible combination with immunotherapy. Furthermore, we describe also more complex strategies such as microRNA-loaded vectors, oncolytic viruses, and engineered lymphocytes.

Novel and Promising Systemic Treatment Approaches in Mesothelioma

OPINION STATEMENT

There was limited progress in the development of novel systemic approaches in the treatment of advanced malignant mesothelioma for years following the publication of the pivotal phase III trial of Vogelzang et al. that established the cisplatin/pemetrexed regimen as a standard 1st-line systemic therapy. Since then, over the last several years, a significant step forward has been made, with incorporation of immune checkpoint inhibitors and anti-angiogenic agents. In addition, better appreciation of mesothelioma biology has allowed detection of novelmolecular therapeutic targets. All the above-mentioned strategies, along with the additional promising approaches represented by adoptive T cell therapy, dendritic cell therapy, cancer vaccines, oncoviral therapy, and agents targeting mesothelin are discussed in this review. The clinical research to identify effective biologic targets and treatment combinations in malignant mesothelioma is ongoing.

Pleural mesothelioma (PM) - The status of systemic therapy

Pleural mesothelioma (PM) remains a malignancy with poor prognosis. Despite initial disappointing response rates to single-agent chemotherapy, upfront platinum and anti-folate-based combination chemotherapy has remained the backbone of treatment for PM for the last three decades. The role of maintenance chemotherapy remains unclear; switch-maintenance gemcitabine has shown improvements in progression-free but not overall survival. The addition of antiangiogenic agents to chemotherapy yielded modest improvements in survival, both upfront in combination with platinum-pemetrexed, and in the relapsed setting. Immunotherapy, particularly PD-(L)1 inhibitors, has shown important but variable effectiveness in relapsed PM when used as monotherapy, and is an important salvage treatment after first-line chemotherapy. Furthermore, the randomized phase 3 trial of ipilimumab-nivolumab versus platinum-pemetrexed chemotherapy demonstrated improved overall survival favouring ipilimumab-nivolumab (HR 0.74, 96.6% CI 0.60-0.91; p = 0.0020), establishing this regimen as the new standard first-line treatment for PM, particularly in those with non-epithelioid histology. Increased interest in PM genomics has led to development of novel personalized therapeutics, such as those targeting DNA repair and EZH2 pathways, however with variable outcomes in trials. Targeting the membrane glycoprotein mesothelin and arginine deprivation are other important strategies under ongoing investigation. The field of PM is changing and new treatments bring hope to a largely lethal and poor prognostic malignancy. Despite these developments, current challenges include understanding the role of combination and multimodality treatments, drivers of resistance to treatment, and establishing predictive biomarkers to improve patient selection and treatment sequencing.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pretherapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasize that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pre-therapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

Antiangiogeneic Strategies in Mesothelioma

There is a strong rationale for inhibiting angiogenesis in mesothelioma. Vascular endothelial growth factor (VEGF) is an autocrine growth factor in mesothelioma and a potent mitogen for mesothelial cells. Further, the abnormal tumor vasculature promotes raised interstitial pressure and hypoxia, which may be detrimental to both penetration and efficacy of anticancer agents. Antiangiogenic agents have been trialed in mesothelioma for close to two decades, with early phase clinical trials testing vascular targeting agents, the VEGF-A targeting monoclonal antibody bevacizumab, and numerous tyrosine kinase inhibitors, many with multiple targets. None of these have shown efficacy which has warranted further development as single agents in any line of therapy. Whilst a randomized phase II trial combining the multitargeted tyrosine kinase inhibitor nintedanib with platinum/pemetrexed chemotherapy was positive, these results were not confirmed in a subsequent phase III study. The combination of cisplatin and pemetrexed with bevacizumab, in appropriately selected patients, remains the only anti-angiogenic combination showing efficacy in mesothelioma. Extensive efforts to identify biomarkers of response have not yet been successful.

Chemotherapy options versus "novel" therapies: how should we treat patients with malignant pleural mesothelioma

Today there are several options for the treatment of patients with malignant pleural mesothelioma (MPM). The therapeutic arsenal has expanded from only chemotherapy with or without surgery in selected cases to a variety of new compounds that target the malignant cell or its micro-environment. Immunotherapy has been the latest achievement and now single arm and randomized studies are being presented. A renewed interest has occurred in the combination of surgery, chemotherapy and radiation therapy. In this review we present the available data on previous and running studies and try to give a recommendation how to select the best patient for the most optimal therapy.

Malignant Pleural Mesothelioma: State-of-the-Art on Current Therapies and Promises for the Future

Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer of the pleural surface associated with asbestos exposure. The median survival of MPM patients is a mere 8-14 months, and there are few biomarkers and no cure available. It is hoped that, eventually, the incidence of MPM will drop and remain low and constant, given that most nations have banned the use of asbestos, but in the meantime, the incidence in Europe is still growing. The exact molecular mechanisms that explain the carcinogenicity of asbestos are not known. Standard therapeutic strategies for MPM include surgery, often coupled with chemotherapy and/or radiotherapy, in a small percentage of eligible patients and chemotherapy in tumors considered unresectable with or without adjuvant radiotherapy. In recent years, several new therapeutic avenues are being explored. These include angiogenesis inhibitors, synthetic lethal treatment, miRNA replacement, oncoviral therapies, and the fast-growing field of immunotherapy alone or in combination with chemotherapy. Of particular promise are the multiple options offered by immunotherapy: immune checkpoint inhibitors, tumor vaccines, and therapies taking advantage of tumor-specific antigens, such as specific therapeutic antibodies or advanced cell-based therapies exemplified by the CAR-T cells. This review comprehensively presents both old and new therapeutic options in MPM, focusing on the results of the numerous recent and on-going clinical trials in the field, including the latest data presented at international meetings (AACR, ASCO, and ESMO) this year, and concludes that more work has to be done in the framework of tailored therapies to identify reliable targets and novel biomarkers to impact MPM management.

Emerging therapies in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare cancer of the pleural surfaces frequently related to asbestos exposure. It is characterized by a poor prognosis even for patients treated with trimodality therapy, including surgery, chemotherapy and radiotherapy. Moreover, the majority of patients are not candidates for surgery due to disease advanced stage or medical comorbidities. For these patients, the survival rate is even lower and few therapeutic options are currently available. Nevertheless, many interesting novel approaches are under investigation, among which immunotherapy represents one of the most promising emerging strategies. In this review, we will discuss the role of new therapeutic options, particularly immunotherapy, and present the results of the most important and promising clinical trials.

What can independent research for mesothelioma achieve to treat this orphan disease?

Introduction: Malignant pleural mesothelioma (MPM) is a rare neoplasm with a poor prognosis, as current therapies are ineffective. Despite the increased understanding of the molecular biology of mesothelioma, there is still a lack of drugs that dramatically enhance patient survival. Area Covered: This review discusses recent and complete clinical trials supported by the NIH, other U.S. Federal agencies, universities and organizations found on clinicaltrials.gov. Firstly, chemotherapy-based trials are described, followed by immunotherapy and multitargeted therapy. Then we introduce drug repositioning and the use of drug docking as tools to find new interesting molecules. Finally, we highlight potential molecular pathways that may play a role in mesothelioma biology and therapy. Expert Opinion: Numerous biases are present in the clinical trials due to a restricted number of cases, inappropriate endpoints and inaccurate stratification of patients which delay the finding of a treatment for MPM. The most crucial issue of independent research for MPM is the lack of more substantive funding to translate these findings to the clinical setting. However, this approach is not necessarily scientific given the low mutational load of mesothelioma relative to other cancers, and therefore patients need a more solid rationale to have a good chance of successful treatment.

Targeting angiogenesis for patients with unresectable malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a global health issue, the principal cause of which is exposure to asbestos. The prevalence is anticipated to rise over the next 2 decades, particularly in developing countries, due to the 30-50-year latency period between exposure to asbestos and carcinogenic development. Unresectable MPM has a poor prognosis and limited treatment options and, as such, there is a broad range of therapeutic targets of interest, including angiogenesis, immune checkpoints, mesothelin, as well as chemotherapeutic agents. Recently, the results of several randomized trials in the first-line setting combining antiangiogenic agents with chemotherapy have been reported. This review examines the scientific rationale for targeting angiogenesis in the treatment of unresectable MPM and analyzes recent clinical results with antiangiogenic agents in development (bevacizumab, nintedanib, and cediranib) for the management of MPM.

Malignant Pleural Mesothelioma: Is Tailoring the Second-Line Therapy Really "Raising the Bar?"

OPINION STATEMENT

Unresectable or relapsed malignant pleural mesothelioma (MPM) has dismal prognosis. First-line combination therapy with pemetrexed and a platinum analog allows a modest survival benefit, while no clear therapeutic options exist for the second-line therapy. In this setting, pemetrexed seems to be the most active drug; however, the inclusion in front-line treatment limits its use in further lines. Nevertheless, rechallenge with one or both drugs used in first-line remains a feasible strategy for responder patients. Alternatively, only few cytotoxic drugs have demonstrated a mild activity in refractory MPM. Among other options, targeted therapy has unfortunately produced disappointing results as salvage treatment probably due to the lack of a clear understanding of the tumor biology. In contrast, recent data suggest moderate efficacy and mild toxicity of immunotherapy also for the treatment of MPM. The combination of checkpoint inhibitors with chemotherapy or other immunological agents seems promising and could really "raise the bar" in this setting.

Current and Future Management of Malignant Mesothelioma: A Consensus Report from the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation

On March 28- 29, 2017, the National Cancer Institute (NCI) Thoracic Malignacy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation convened the NCI-International Association for the Study of Lung Cancer- Mesothelioma Applied Research Foundation Mesothelioma Clinical Trials Planning Meeting in Bethesda, Maryland. The goal of the meeting was to bring together lead academicians, clinicians, scientists, and the U.S. Food and Drug Administration to focus on the development of clinical trials for patients in whom malignant pleural mesothelioma has been diagnosed. In light of the discovery of new cancer targets affecting the clinical development of novel agents and immunotherapies in malignant mesothelioma, the objective of this meeting was to assemble a consensus on at least two or three practice-changing multimodality clinical trials to be conducted through NCI's National Clinical Trials Network.

A systematic review and meta-analysis of second-line therapies for treatment of mesothelioma

INTRODUCTION

Advanced malignant pleural mesothelioma (MPM) is generally treated with platinum/pemetrexed-based first-line therapy. Once the disease progresses, evidence for the efficacy of palliative treatments is lacking, and platinum re-challenge or single-agent chemotherapy are commonly used. To assess the effects of cytostatic or targeted therapy for treating MPM, we performed a systematic review and meta-analysis.

MATERIAL AND METHODS

PubMed, the Cochrane Library, and Embase databases were searched to identify published articles on second-line treatments for recurrent or advanced mesothelioma. Inclusion criteria were publication in the English language, describing clinical trials with 20 or more patients, and evaluability for efficacy and for receiving second-line systemic therapies. Data were pooled using number of events/number of evaluable patients, median overall survival (OS) and progression-free survival (PFS), according to a fixed or random effect model. Pooled median OS was the primary endpoint.

RESULTS

A total of 49 eligible studies (n = 3938 patients; range, 12-400) were identified. Median progression-free survival (PFS) was 3.4 months (95%CI 2.87-3.93). Median pooled OS was 7.86 (95%CI 7.01-8.72). The pooled overall response rate (ORR) was 8.63% (95%CI 6-11.26), and the pooled disease control rate (DCR) was 54.8% (95%CI 48.9-60.6). Median pooled OS with platinum- and pemetrexed-based chemotherapy were 7.93 and 7.78 months, respectively.

CONCLUSIONS

There remains uncertainty about the ideal second-line agent for MPM. Based on this meta-analysis, palliative chemotherapy or other experimental agents can be considered for patients with MPM who desire further treatment after their disease has progressed, during or after first-line therapy.

Posterior reversible encephalopathy syndrome and takotsubo cardiomyopathy associated with lenvatinib therapy for thyroid cancer: a case report and review

As immunotherapies including tyrosine kinase inhibitors become more widely used for the treatment of a variety of malignancies, it is important for prescribers and patients to understand the potential adverse effects associated with these drugs. It is especially important to understand the potentially fatal side effects associated with these drugs to further determine risk factors for their development. The review presents a case of posterior reversible encephalopathy syndrome with concomitant Takotsubo cardiomyopathy, associated with use of lenvatinib therapy for thyroid cancer. It discusses the interventions performed and outcome. Potential mechanisms for development of these rare adverse effects, as well as cases in which these adverse effects are seen with use of other tyrosine-kinase inhibitors will be presented. It is important to continue to report these side effects, and further studies are needed to elucidate potential risk factors for their development, as well as to determine prognosis after development.

Targeting the Hippo Pathway Is a New Potential Therapeutic Modality for Malignant Mesothelioma

Malignant mesothelioma (MM) constitutes a very aggressive tumor that arises from the pleural or peritoneal cavities and is highly refractory to conventional therapies. Several key genetic alterations are associated with the development and progression of MM including mutations of the CDKN2A/ARF, NF2, and BAP1 tumor-suppressor genes. Notably, activating oncogene mutations are very rare; thus, it is difficult to develop effective inhibitors to treat MM. The NF2 gene encodes merlin, a protein that regulates multiple cell-signaling cascades including the Hippo pathway. MMs also exhibit inactivation of Hippo pathway components including LATS1/2, strongly suggesting that merlin-Hippo pathway dysregulation plays a key role in the development and progression of MM. Furthermore, Hippo pathway inactivation has been shown to result in constitutive activation of the YAP1/TAZ transcriptional coactivators, thereby conferring malignant phenotypes to mesothelial cells. Critical YAP1/TAZ target genes, including prooncogenic CCDN1 and CTGF, have also been shown to enhance the malignant phenotypes of MM cells. Together, these data indicate the Hippo pathway as a therapeutic target for the treatment of MM, and support the development of new strategies to effectively target the activation status of YAP1/TAZ as a promising therapeutic modality for this formidable disease.

Anti-Angiogenic Tyrosine Kinase Inhibitors and Reversible Posterior Leukoencephalopathy Syndrome: Could Hypomagnesaemia Be the Trigger?

Reversible posterior leukoencephalopathy syndrome (RPLS), also known frequently as posterior reversible encephalopathy syndrome (PRES), is a characteristic acute neuro-radiology syndrome with clinical presentation that typically includes acute hypertension, seizures and other neurological symptoms and signs. Many patients with RPLS have (a history of) pre-existing hypertension and in receipt of diuretics. It is being diagnosed more frequently and in association with an increasing number of morbidities and medications. Drugs most frequently implicated are immunosuppressant drugs and anticancer agents, including a number of anti-angiogenic tyrosine kinase inhibitors (TKIs). Hypomagnesaemia is a frequent finding at presentation in RPLS patients, which is known to lead to or aggravate hypertension. Pre-eclampsia, a variant of RPLS, responds effectively to intravenous magnesium. Cyclosporin, tacrolimus and some TKIs that induce RPLS are also known to give rise to both hypertension and hypomagnesaemia. This raises an interesting hypothesis that hypomagnesaemia may play a contributory role in triggering RPLS in some patients by acutely raising the blood pressure further. Additional systematic studies are required to test this hypothesis. If the hypothesis is confirmed, hypomagnesaemia offers an effective target for risk mitigation and prevention of RPLS in patients identified at risk.

Gremlin-1 is a key regulator of the invasive cell phenotype in mesothelioma

Malignant mesothelioma originates from mesothelial cells and is a cancer type that aggressively invades into the surrounding tissue, has poor prognosis and no effective treatment. Gremlin-1 is a cysteine knot protein that functions by inhibiting BMP-pathway activity during development. BMP-independent functions have also been described for gremlin-1. We have previously shown high gremlin-1 expression in mesothelioma tumor tissue. Here, we investigated the functions of gremlin-1 in mesothelioma cell migration and invasive growth. Gremlin-1 promoted mesothelioma cell sprouting and invasion into three dimensional collagen and Matrigel matrices. The expression level of gremlin-1 was linked to changes in the expression of SNAI2, integrins, matrix metalloproteinases (MMP) and TGF-β family signaling - all previously associated with a mesenchymal invasive phenotype. Small molecule inhibitors of MMPs completely blocked mesothelioma cell invasive growth. In addition, inhibitors of TGF-β receptors significantly reduced invasive growth. This was associated with reduced expression of MMP2 but not SNAI2, indicating that gremlin-1 has both TGF-β pathway dependent and independent mechanisms of action. Results of in vivo mesothelioma xenograft experiments indicated that gremlin-1 overexpressing tumors were more vascular and had a tendency to send metastases. This suggests that by inducing a mesenchymal invasive cell phenotype together with enhanced tumor vascularization, gremlin-1 drives mesothelioma invasion and metastasis. These data identify gremlin-1 as a potential therapeutic target in mesothelioma.

A review of bevacizumab in the treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive cancer with poor prognosis. Systemic chemotherapy is the primary treatment modality for the majority of patients. VEGF plays a key mitogen for MPM cells physiopathology. Bevacizumab, a monoclonal anti-VEGF antibody, was a rational approach to be tested in MPM. Based on the results of the Phase III IFCT-0701 mesothelioma avastin cisplatin pemetrexed study, cisplatin-pemetrexed-bevacizumab is now the accepted standard in France. The National Comprehensive Cancer Network guidelines have also included this combination as an option for standard front-line therapy. This review summarized the efficacy and safety data of bevacizumab in the treatment of patients with MPM.

A pilot study of zoledronic acid in the treatment of patients with advanced malignant pleural mesothelioma

Purpose

Malignant pleural mesothelioma (MPM) is a rare malignancy with a dismal median survival of <12 months with current therapy. Single and combination chemotherapy regimens have shown only modest clinical benefit. In preclinical studies, nitrogen-containing bisphosphonates (zoledronic acid) inhibit growth of mesothelioma cells by different mechanisms: inhibition of mevalonate pathway, inhibition of angiogenesis, activation of apoptosis through caspase activation, and alteration in activity of matrix metalloproteinases, thereby affecting invasiveness of cancer cells.

Patients and methods

We investigated the role of zoledronic acid in a pilot, single-arm trial of MPM patients with Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0–2 who had progressed on prior treatments or had not received systemic therapy due to poor PS. Primary end point was composite response rate by modified response evaluation criteria in solid tumors and/or metabolic response by 2-deoxy-2-[fluorine-18]fluoro-d-glucose (¹⁸F-FDG) positron emission tomography criteria. Secondary end points were progression-free survival (PFS) and overall survival (OS). Exploratory end points include the effect of zoledronic acid therapy on vascular endothelial growth factor (VEGF), basic fibroblast growth factor, interleukin 8, transforming growth factor beta, mesothelin, and osteopontin levels.

Results

Eight male patients (median age of 62 years) with the following clinical characteristics were treated; ECOG PS was 0–2, 75% with epithelioid type, and 62% had prior chemotherapy Overall composite response rate was 12.5% and the clinical benefit rate (response + stable disease) was 37.5%. Median PFS was 2 months (0.5–21 months) and median OS was 7 months (0.8–28 months). No treatment-related toxicities were observed. Lower VEGF levels were predictive of favorable response and mesothelin levels correlated with disease course.

Conclusion

Zoledronic acid shows modest clinical activity without significant toxicity in patients with advanced MPM.

Novel systemic therapy against malignant pleural mesothelioma

Malignant pleural mesothelioma is an aggressive tumor of the pleura with an overall poor prognosis. Even with surgical resection, for which only a subset of patients are eligible, long term disease free survival is rare. Standard first-line systemic treatment consists of a platinum analog, an anti-metabolite, and sometimes anti-angiogenic therapy, but there is currently no well-established standard therapy for refractory or relapsed disease. This review focuses on efforts to develop improved systemic therapy for the treatment of malignant pleural mesothelioma (MPM) including cytotoxic systemic therapy, a variety of tyrosine kinase inhibitors and their downstream effector pathways, pharmacologic targeting of the epigenome, novel approaches to target proteins expressed on mesothelioma cells (such as mesothelin), arginine depletion therapy, and the emerging role of immunotherapy. Overall, these studies demonstrate the challenges of improving systemic therapy for MPM and highlight the need to develop therapeutic strategies to control this disease.

Spotlight on bevacizumab and its potential in the treatment of malignant pleural mesothelioma: the evidence to date

Malignant pleural mesothelioma (MPM) is a rare, but aggressive cancer. Surgery and radiation offer limited benefit, and systemic chemotherapy remains the primary treatment modality for the majority of patients. Vascular endothelial growth factor (VEGF) and its receptor have been recognized as important players in the biology of this disease. Bevacizumab is a monoclonal antibody that binds VEGF and blocks its interaction with the VEGF receptor. Recent studies have shown benefit with the addition of bevacizumab to the combination of cisplatin and pemetrexed in MPM. This combination is now included in the National Comprehensive Cancer Network guidelines (with a category 2A recommendation) as a possible first-line treatment for unresectable MPM in appropriately selected patients. This review discusses the rationale behind the use of bevacizumab in MPM, as well as summarizes the pharmacology, efficacy, safety, and toxicity of bevacizumab across multiple trials. The use of small-molecule inhibitors of angiogenesis in the treatment of MPM is also discussed.

A phase II trial of dovitinib in previously-treated advanced pleural mesothelioma: The Ontario Clinical Oncology Group

OBJECTIVES

Following failure of a platinum-antifolate combination regimen, there is no standard therapy for advanced malignant pleural mesothelioma (MPM). The fibroblast growth factor receptor (FGFR) signaling pathways may be a relevant target in MPM. Dovitinib inhibits multiple tyrosine receptor kinases, predominantly the vascular endothelial growth factor receptors (VEGFR), but also FGFRs, and could be active in MPM.

METHODS

This open-label multicentre phase II trial [NCT01769547] enrolled fit, consenting adult patients with advanced MPM who had previously received platinum-antifolate combination chemotherapy and up to one additional line of systemic therapy. Dovitinib was administered orally at 500mg/day for 5days on, 2days off, in 28-day cycles. Response was assessed every 2 cycles using RECIST 1.1 criteria modified for MPM. Correlative studies included FGFR-1 amplification on archival tumour and serum samples for circulating angiogenesis factors. The primary end-point was the proportion of patients progression-free at 3 months (PF3) using a two-stage design.

RESULTS

12 patients (10 males, median age 67) were enrolled. The median number of cycles administered was 2.5 (range 1-8). One unconfirmed partial response was observed. PF3 was 50% (95% confidence interval 28.4% to 88.0%); although the criterion for proceeding to stage II accrual was met, the trial was halted due to a combination of minimal activity with several early progression events and poor tolerability in this patient population. One of 12 tumour specimens had low amplification of FGFR-1.

CONCLUSIONS

Dovitinib has minimal activity in previously-treated MPM. The role of the FGFR pathway in MPM remains unclear.

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.

Hypertension in cancer patients treated with anti-angiogenic based regimens

New anti-cancer drugs that inhibit the vascular endothelial growth factor (VEGF) signaling pathway are highly effective in the treatment of solid tumors, however concerns remain regarding their cardiovascular safety. The most common side effect of VEGF signaling pathway (VSP) inhibition is the development of systemic hypertension. We review the incidence, possible mechanisms, significance and management of hypertension in patients treated with VSP inhibitors.

Systemic Approach to Malignant Pleural Mesothelioma: What News of Chemotherapy, Targeted Agents and Immunotherapy?

Malignant pleural mesothelioma is a rare cancer with a cause-effect relationship to asbestos exposure. The prognosis is poor and chemotherapy seems the best treatment option. In the last two decades a deeper understanding of mesothelioma carcinogenesis and invasiveness mechanisms has prompted research efforts to test new agents in patients with malignant pleural mesothelioma, but the results have been modest. Attractive preclinical data disappointed in subsequent experimental phases. Other promising agents failed to improve patient outcomes due to high toxicity. Interesting suggestions have come from preliminary data on immunotherapy. Several trials are ongoing and the results are eagerly awaited. The aim of this review is to discuss the most recent news on systemic therapy for advanced malignant pleural mesothelioma.

Latest developments in our understanding of the pathogenesis of mesothelioma and the design of targeted therapies

Malignant mesothelioma is an aggressive cancer whose pathogenesis is causally linked to occupational exposure to asbestos. Familial clusters of mesotheliomas have been observed in settings of genetic predisposition. Mesothelioma incidence is anticipated to increase worldwide in the next two decades. Novel treatments are needed, as current treatment modalities may improve the quality of life, but have shown modest effects in improving overall survival. Increasing knowledge on the molecular characteristics of mesothelioma has led to the development of novel potential therapeutic strategies, including: molecular targeted approaches, that is the inhibition of vascular endothelial growth factor with bevacizumab; immunotherapy with chimeric monoclonal antibody, immunotoxin, antibody drug conjugate, vaccine and viruses; inhibition of asbestos-induced inflammation, that is aspirin inhibition of HMGB1 activity may decrease or delay mesothelioma onset and/or growth. We elaborate on the rationale behind new therapeutic strategies, and summarize available preclinical and clinical results, as well as efforts still ongoing.

Mesothelioma treatment: Are we on target? A review

Targeted treatment is a therapy directed at a specific molecular target close to a hallmark of cancer. The target should be measurable with a biomarker and measurement of the target should correlate with clinical outcome when targeted treatment is administered. Current clinical guidelines do not recommend targeted or biological therapy in MPM. However, since these recommendations came out, new agents have been investigated in MPM. This review updates the use of targeted and biological treatment in patients with mesothelioma.

Receptor tyrosine kinase inhibitors: Are they real tumor killers?

Inhibiting tumor growth by targeting the tumor vasculature was first proposed by Judah Folkman almost 40 years ago. Since then, different approaches and numerous drugs and agents have been developed to achieve this goal, either with the aim of inhibiting tumor neoangiogenesis or normalizing the tumor vasculature. Among the most promising therapeutic targets are receptor tyrosine kinases (RTKs), some of which are predominantly expressed on tumor endothelial cells, although they are sometimes also present on tumor cells. The majority of RTK inhibitors investigated over the past two decades competes with ATP at the active site of the kinase and therefore block the phosphorylation of intracellular targets. Some of these drugs have been approved for therapy, whereas others are still in clinical trials. Here, we discuss the scientific basis, current status, problems and future prospects of RTK inhibition in anti-tumor therapy.

New and emerging therapeutic options for malignant pleural mesothelioma: review of early clinical trials

Malignant pleural mesothelioma (MPM) is a rare tumor that is challenging to control. Despite some benefit from using the multimodality-approach (surgery, combination chemotherapy and radiation), survival remains poor. However, current research produced a list of potential therapies. Here, we summarize significant new preclinical and early clinical developments in treatment of MPM, which include mesothelin specific antibody and toxin therapies, interleukin-4 (IL-4) receptor toxins, dendritic cell vaccines, immune checkpoint inhibitors, and gene-based therapies. In addition, several local modalities such as photodynamic therapy, postoperative lavage using betadine, and cryotherapy for local recurrence, have also shown to be effective for local control of disease.

Malignant pleural mesothelioma: new hope in the horizon with novel therapeutic strategies

Malignant pleural mesothelioma (MPM) is a rare but aggressive malignancy of the pleura, with a strong causal link to asbestos exposure. MPM incidence has been increasing in recent years and it is not expected to fall off in the next two decades. Prognosis of MPM patients is modest since the vast majority of patients are diagnosed at advanced stage and because platinum-based chemotherapy remains the cornerstone of treatment, with no standard second line treatment. Most current efforts to improve outcomes are based on a better understanding of the stromal compartment and deregulated pathways leading ultimately to the design of clinical trials based on novel therapeutic approaches such as immunotherapy or molecular-directed compounds. This review seeks to update the last clinical trials investigating novel agents in unresectable MPM.

Systemic treatment of malignant pleural mesothelioma: new agents in clinical trials raise hope of relevant improvements

PURPOSE OF REVIEW

Malignant pleural mesothelioma (MPM) is a rare malignancy with limited therapeutic options and its incidence is still increasing in both Europe and the developing nations. Prognosis of MPM patients is poor even if the median survival durations have been slightly improved after the introduction of the up-to-date chemotherapy combination with pemetrexed and cisplatin. There is a continuing unmet need to develop better systemic treatment for this disease, but the rarity of the tumor type creates formidable challenges in clinical trial research.

RECENT FINDINGS

Better understanding of the molecular machinery of MPM leads to the design and synthesis of novel compounds targeted against pathways identified as crucial for MPM cell proliferation and metastasis. Most efforts aim at improving standard first-line therapy, or developing effective second-line treatments. Several classes of drugs are currently being explored either in combination with cisplatin and pemetrexed or as single agent for relapsed or progressive MPM.

SUMMARY

This review focuses on several ongoing or recently completed clinical trials investigating novel, promising agents as first-line or second-line therapy for advanced MPM.

Systematic review of response rates of sarcomatoid malignant pleural mesotheliomas in clinical trials

RATIONALE

Malignant pleural mesothelioma is an almost universally fatal malignancy primarily related to asbestos exposure. Based on the differences in immunologic markers and gene expression between histologic subtypes of mesothelioma, and our clinical impression that response rates vary by histology, we decided to examine the reported response rates of mesothelioma subtypes.

OBJECTIVES

Our objective was to compare the response rates of sarcomatoid mesotheliomas to the overall response rates in published clinical trials.

METHODS

We searched PubMed for "mesothelioma" with the clinical trials filter selected. We included articles published between January 1, 2000 and March 20, 2014 in which subjects received first or second line systemic therapy for malignant pleural mesothelioma. Studies investigating multi-modality therapy including surgery were excluded. Response rates [including 95% confidence intervals (95% CI)] were estimated for the entire patient cohort and then separately for subjects with sarcomatoid tumors.

MEASUREMENTS AND MAIN RESULTS

We reviewed 544 publications of which 41 trials met our inclusion criteria. Eleven of these trials did not include patients with sarcomatoid mesothelioma (27% of eligible studies). The remaining 30 publications included 1475 subjects, 1011 with epithelioid tumors (68.5%), 203 with biphasic tumors (13.8%), 137 with sarcomatoid tumors (9.3%) and 124 with unknown subtypes (8.4%). In total, there were 323 responses (21.9%, complete and partial responses, 95% CI: 16.3, 28.8) to systemic therapy across all histological subtypes. In patients with sarcomatoid tumors (n=137) 19 responses were observed. This accounted for 5.9% of all responses and yields a 13.9% (95% CI: 8.6, 21.6) response rate for patients with sarcomatoid tumors. Multiple biases likely affected this systematic review.

CONCLUSION

Response rates for different histological subtypes of malignant pleural mesothelioma are infrequently reported. Partial and complete responses to systemic therapies appear to be less common among patients with sarcomatoid tumors.

Risks of proteinuria associated with vascular endothelial growth factor receptor tyrosine kinase inhibitors in cancer patients: a systematic review and meta-analysis

BACKGROUND

Vascular endothelial growth factor tyrosine-kinase inhibitors (VEGFR-TKIs) have emerged as an effective targeted therapy in the treatment of cancer patients, the overall incidence and risk of proteinuria associated these drugs is unclear. We performed a systematic review and meta-analysis of published clinical trials to quantify the incidence and risk of proteinuria associated with VEGFR-TKIs.

METHODOLOGY

Databases from PubMed, Web of Science and abstracts presented at ASCO meeting up to May 31, 2013 were searched to identify relevant studies. Eligible studies included prospective phase II and III trials evaluating VEGFR-TKIs in cancer patients with adequate data on proteinuria. Statistical analyses were conducted to calculate the summary incidence, Odds ratio (OR) and 95% confidence intervals (CIs) by using either random effects or fixed effect models according to the heterogeneity of included studies.

PRINCIPAL FINDINGS

A total of 6,882 patients with a variety of solid tumors from 33 clinical trials were included in our analysis. The incidence of all-grade and high-grade (grade 3 or higher) proteinuria was 18.7% (95% CI, 13.3%-25.6%) and 2.4% (95% CI, 1.6%-3.7%), respectively. Patients treated with VEGFR-TKIs had a significantly increased risk of all-grade (OR 2.92, 95%CI: 1.09-7.82, p = 0.033) and high-grade proteinuria (OR 1.97, 95%CI: 1.01-3.84, p = 0.046) when compared to patients treated with control medication. No evidence of publication bias was observed.

CONCLUSIONS

The use of VEGFR-TKIs is associated with a significant increased risk of developing proteinuria. Physicians should be aware of this adverse effect and should monitor cancer patients receiving VEGFR-TKIs.

A phase I study of the combination of ro4929097 and cediranib in patients with advanced solid tumours (PJC-004/NCI 8503)

Background:

The Notch signalling pathway has been implicated in tumour initiation, progression, angiogenesis and development of resistance to vascular endothelial growth factor (VEGF) targeting, providing a rationale for the combination of RO4929097, a γ-secretase inhibitor, and cediranib, a VEGF receptor tyrosine kinase inhibitor.

Methods:

Patients received escalating doses of RO4929097 (on a 3 days-on and 4 days-off schedule) in combination with cediranib (once daily). Cycle 1 was 42 days long with RO4929097 given alone for the first 3 weeks followed by the co-administration of both RO4929097 and cediranib starting from day 22. Cycle 2 and onwards were 21 days long. Soluble markers of angiogenesis were measured in plasma samples. Archival tumour specimens were assessed for expression of three different components of Notch signalling pathway and genotyping.

Results:

In total, 20 patients were treated in three dose levels (DLs). The recommended phase II dose was defined as 20 mg for RO4929097 on 3 days-on and 4 days-off schedule and 30 mg daily for cediranib. The most frequent treatment-related adverse events (AEs) were diarrhoea, hypertension, fatigue and nausea. Eleven patients had a best response of stable disease and one patient achieved partial response. We did not detect any correlation between tested biomarkers of angiogenesis or the Notch pathway and treatment effect. There was no correlation between mutational status and time to treatment failure.

Conclusion:

RO4929097 in combination with cediranib is generally well tolerated at the DLs tested. Preliminary evidence of antitumour efficacy with prolonged disease stabilisation in some patients with progressive malignancies warrants further clinical investigation of this treatment strategy.