Nivolumab in pre-treated malignant pleural mesothelioma: real-world data from the Dutch expanded access program

Real-world safety of nivolumab in patients with malignant pleural mesothelioma in Japan: post-marketing surveillance study

OBJECTIVE

This post-marketing surveillance (PMS) was conducted to evaluate the incidence of adverse events with nivolumab in patients with unresectable, advanced or recurrent malignant pleural mesothelioma (MPM) that had progressed after first-line chemotherapy and to identify factors that potentially affected its safety in real-world clinical practice.

METHODS

Patients who had not received nivolumab previously were registered between November 2018 and February 2021. Nivolumab was given intravenously 240 mg every 2 weeks or 480 mg every 4 weeks. Patients were followed up for 6 months after treatment initiation. Information on patient characteristics, treatment status, and adverse events was collected.

RESULTS

This PMS enrolled 124 patients, involving 48 sites across Japan. At 6 months, nivolumab therapy was ongoing in 35.5% of patients (44/124) and had been discontinued in 64.5% (80/124). The overall incidence of treatment-related adverse events (TRAEs) was 40.3%; the incidence of Grade 3 or higher TRAEs was 12.9%. The pattern of TRAEs based on System Organ Class categories was generally consistent with those seen in the Japanese phase II MERIT study. The most common Grade 3 or higher TRAEs were interstitial lung disease (2.4%), lung disorder, and diarrhea (each 1.6%). The incidence of TRAEs was significantly higher in inpatients or patients who had good PS, high bodyweight, high body mass index, or autoimmune diseases than in those without these characteristics.

CONCLUSION

The post-marketing incidence of TRAEs with nivolumab in patients with MPM has been evaluated, and no new safety signals were identified compared to the phase II clinical trial in Japan.

Safety and efficacy of PD-1/PD-L1 immune checkpoint inhibitors in patients with pre-treated advanced stage malignant mesothelioma: a systematic review and meta-analysis

BACKGROUND

Malignant mesothelioma is an aggressive cancer with poor prognosis. Programmed cell death protein-1 (PD-1) and its ligand 1 (PD-L1) immune checkpoint inhibitors (ICIs) have recently presented as a viable option in some first line but primarily as a second-line treatment of advanced-stage malignant mesothelioma (asMM). Therefore, this systematic review and meta-analysis aims to assess the safety and efficacy of PD-1/L-1 ICIs in advanced-stage malignant mesothelioma.

METHODS

PubMed, Scopus, and Cochrane databases were searched for all studies assessing the safety and efficacy of anti PD-1/PD-L1 agents. Primary outcomes were objective response rate (ORR) and disease control rate (DCR). Secondary outcomes were median progression free (mPFS) and overall survival (mOS). Safety outcomes were treatment- (TRAEs) and immune-related adverse events (IRAEs). A random-effects meta-analysis was performed to pool medians and to derive event rates.

RESULTS

A total of 15 studies were included with total of 1064 asMM patients. ORR and DCR were 16% and 57%, respectively. A pooled mPFS was 4.53 (CI: 3.40-5.65) and mOS was 10.51 (CI: 9.03-12.00). Overall TRAEs had an event rate of 0.69 (0.50-0.83) whereas IRAEs had an event rate of 0.28 (0.15-0.46). There were no significant differences between pembrolizumab, nivolumab primarily, and avelumab subgroups for all the outcomes. Additionally, meta-regression found no covariate to be a significant factor in ORR and DCR.

CONCLUSION

In this meta-analysis we found that anti-PD1/PD-L1 treatment could be useful in pretreated asMM as they had at least comparable or greater mPFS, mOS, ORR, and DCR than other second-line agents currently being used.

REGISTRATION NUMBER

This systematic review was registered at PROSPERO prior to the literature search, CRD42023442350.

Nivolumab in pretreated pleural mesothelioma: Results from an observational real-world study of patients treated within the AIFA 5% Fund

BACKGROUND

Pleural mesothelioma is a rare cancer with a dismal prognosis and few therapeutic options, especially in the pretreated setting. Immunotherapy with checkpoint inhibitors as single agents yielded interesting results in refractory pleural mesothelioma, achieving a response rate between 10-20%, median progression-free survival of 2-5 months and median overall survival of 7-13 months.

PATIENTS AND METHODS

A retrospective, multi-institutional study of pleural mesothelioma patients treated with nivolumab in second and further line was performed. The endpoints of the study are response rate, disease control rate, progression free survival and overall survival.

RESULTS

Sixty-five patients with pleural mesothelioma treated with nivolumab in second and further line were enrolled at seven Italian institutions. The response rate was 8%, disease control rate was 37%, median progression free survival was 5.7 months (95% CI: 2.9-9.0) and median overall survival was 11.1 (95% CI 6.2-19.9) months. A higher neutrophils and neutrophils to lymphocytes ratio at baseline were associated with worse prognosis.

CONCLUSION

Nivolumab as a single agent is fairly active in a cohort of unselected pretreated pleural mesothelioma patients. Further investigations on clinical and translational factors are needed to define which patient might benefit most from nivolumab treatment in pleural mesothelioma.

Improvements in Systemic Therapies for Advanced Malignant Mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignancy associated with poor prognosis and a 5-year survival rate of 12%. Many drugs have been tested over the years with conflicting results. The aim of this review is to provide an overview of current therapies in MPM and how to best interpret the data available on these drugs. Furthermore, we focused on promising treatments under investigation, such as immunotherapy with targets different from anti-PD-1/PD-L1 inhibitors, vaccines, target therapies, and metabolism-based strategies.

High density and proximity of CD8+ T cells to tumor cells are correlated with better response to nivolumab treatment in metastatic pleural mesothelioma

BACKGROUND

The efficacy of immune checkpoint inhibitors (ICIs) in pleural mesothelioma has recently been established. The response to ICIs can be predicted by quantitative analysis of cells and their spatial distribution in the tumor microenvironment (TME). However, the detailed composition of the TME in pleural mesothelioma has not been reported. We evaluated the association between the TME and response to ICIs in this cancer.

METHODS

A retrospective analysis of 22 pleural mesothelioma patients treated with nivolumab in different centers was performed using surgical specimens. Four patients had a partial response to nivolumab (response group) and 18 patients had stable or progressive disease (nonresponse group). The number of CD4, CD8, FoxP3, CK, and PD-L1 positive cells, cell density, and cell-to-cell distance were analyzed by multiplex immunofluorescence.

RESULTS

PD-L1 expression did not differ significantly between the response and nonresponse groups. The density of total T cells and of CD8⁺ T cells was significantly higher in the response than in the nonresponse group. CD8⁺ T cells were more clustered and located closer to tumor cells, whereas regulatory T cells were located further from tumor cells in the response than in the nonresponse group.

CONCLUSIONS

High density and spatial proximity of CD8⁺ T cells to tumor cells were associated with better response to nivolumab, whereas the proximity of regulatory T cells to tumor cells was associated with worse response, suggesting that the distinct landscape of the TME could be a potential predictor of ICI efficacy in pleural mesothelioma.

ATG5 as biomarker for early detection of malignant mesothelioma

OBJECTIVES

Malignant pleural mesothelioma (MPM) is an aggressive disease with grim prognosis due to lack of effective treatment options. Disease prediction in association with early diagnosis may both contribute to improved MPM survival. Inflammation and autophagy are two processes associated with asbestos-induced transformation. We evaluated the level of two autophagic factors ATG5 and HMGB1, microRNAs (miRNAs) such as miR-126 and miR-222, and the specific biomarker of MPM, soluble mesothelin related proteins (Mesothelin) in asbestos-exposed individuals, MPM patients, and healthy subjects. The performance of these markers in detecting MPM was investigated in pre-diagnostic samples of asbestos-subjects who developed MPM during the follow-up and compared for the three groups.

RESULTS

The ATG5 best distinguished the asbestos-exposed subjects with and without MPM, while miR-126 and Mesothelin were found as a significant prognostic biomarker for MPM. ATG5 has been identified as an asbestos-related biomarker that can help to detect MPM with high sensitivity and specificity in pre-diagnostic samples for up to two years before diagnosis. To utilize this approach practically, higher number of cases has to be tested in order to give the combination of the two markers sufficient statistical power. Performance of the biomarkers should be confirmed by testing their combination in an independent cohort with pre-diagnostic samples.

Combination of PD-1/PD-L1 checkpoint inhibition and dendritic cell therapy in mice models and in patients with mesothelioma

Immunotherapy with anti-PD1/PD-L1 is effective in only a subgroup of patients with malignant pleural mesothelioma (MPM). We investigated the efficacy of a combination of anti-PD1/PD-L1 and dendritic cell (DC) therapy to optimally induce effective anti-tumor immunity in MPM in both humans and mice. Data of nine MPM patients treated with DC therapy and sequential anti-PD1 treatment were collected and analyzed for progression-free survival (PFS) and overall survival (OS). Survival and T-cell responses were monitored in AC29 mesothelioma-bearing mice treated concurrently with the combination therapy; additionally, the role of the tumor-draining lymph node (TDLN) was investigated. The combination therapy resulted in a median OS and PFS of 17.7 and 8.0 months, respectively. Grade 3 to 4 treatment-related adverse events had not been reported. Survival of the mesothelioma-bearing mice treated with the combination therapy was longer than that of untreated mice, and coincided with improved T-cell activation in peripheral blood and less T-cell exhaustion in end stage tumors. Comparable results were obtained when solely the TDLN was targeted. We concluded that this combination therapy is safe and shows promising OS and PFS. The murine data support that PD-L1 treatment may reinvigorate the T-cell responses induced by DC therapy, which may primarily be the result of TDLN targeting.

Immunotherapy vs. Chemotherapy in Subsequent Treatment of Malignant Pleural Mesothelioma: Which Is Better?

(1) Background: Malignant pleural mesothelioma (MPM) is a rare but aggressive tumor arising from the pleural surface. For relapsed MPM, there is no accepted standard of- are for subsequent treatment. Thus, we aimed to compare the efficacy of chemotherapy, targeting drugs, and immune-checkpoint inhibitors (ICIs) as subsequent therapy for relapsed MPM. (2) Methods: The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched several acknowledged databases. Primary outcomes were defined as overall median progressive survival (mPFS) and median overall survival (mOS) in different treatment groups. Secondary outcomes were defined as objective response rate (ORR), the proportion of stable disease (SD), and progressive disease (PD). (3) Results: Ultimately, 43 articles were selected for the meta-analysis. According to the results of a pooled analysis of single-arm studies, ICIs showed a slight advantage in mOS, while chemotherapy showed a slight advantage in mPFS (mOS: 11.2 m vs. 10.39 m and mPFS: 4.42 m vs. 5.08 m for ICIs group and chemotherapy group, respectively). We identified only a few studies that directly compared the efficacy of ICIs with that of chemotherapy, and ICIs did not show significant benefits over chemotherapy based on mOS. (4) Conclusions: Based on current evidence, we considered that immunotherapy might not be superior to chemotherapy as a subsequent therapy for relapsed MPM. Although several studies investigated the efficacy of ICIs, targeting drugs, and chemotherapy in relapsed MPM, there was still no standard of care. Further randomized control trials with consistent criteria and outcomes are recommended to guide subsequent therapy in relapsed MPM and identify patients with certain characteristics that might benefit from such subsequent therapy.

The association between albumin levels and survival in patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

Background: The albumin levels may potentially be used as a prognostic biomarker in patients with cancertreated with immune checkpoint inhibitors (ICIs) due to its close relationship with nutritional and inflammatory status. However, the available data is limited with heterogeneous patient cohorts, sample sizes and variable cut-offs. Therefore, we conducted a systematic review and meta-analysis to evaluate the association between survival outcomes and albumin levels in patients treated with ICIs. Methods: We conducted a systematic review using the PubMed, Web of Science, and Embase databases to filter the published studies up to 1 June 2022. The meta-analyses were performed with the generic inverse-variance method with a random-effects model due to the high degree of heterogeneity. The primary outcome measure was hazard ratio (HR) with 95% confidence intervals (CI). The study protocol was registered with the PROSPERO registry (Registration Number: CRD42022337746). Results: Thirty-six studies encompassing 8406 cancer patients with advanced disease were included in the meta-analyses. Almost half of the studies were conducted in NSCLC cohorts (n = 15), and 3.5 gr/dL was the most frequently used albumin cut-off in the included studies (n = 20). Patients with lower albumin levels had a significantly increased risk of death (HR: 1.65, 95% CI: 1.52-1.80, p < 0.0001) than patients with higher albumin levels. Subgroup analyses for study location, sample size, tumor type and albumin cut-off were demonstrated consistent results. Furthermore, in the subgroup analysis of eight studies using albumin levels as a continuous prognostic factor, every 1 gr/dL decrease in albumin levels was associated with significantly increased risk of death by a factor of 10% (HR: 1.10, 95% CI: 1.05-1.16, p = 0.0002). Similar to analyses with overall survival, the patients with lower albumin levels had an increased risk of progression or death compared to patients with higher albumin levels (HR: 1.76, 95% CI: 1.40-2.21, p < 0.001). Conclusion: The available evidence demonstrates that albumin levels may be a prognostic biomarker in advanced cancer patients treated with ICIs. Further research is needed to delineate the role of albumin levels in patients treated with ICIs in the adjuvant setting, as well as the possible benefit of therapeutic approaches to improve hypoalbuminemia.

Nivolumab plus ipilimumab in malignant pleural mesothelioma

INTRODUCTION

Unresectable pleural mesothelioma is a poor prognosis disease. Improvement in overall survival (OS) has been shown with PEMETREXED combined to CISPLATIN. BEVACIZUMAB combined with chemotherapy is associated with an improvement in OS, compared to chemotherapy alone, but is not supported by health insurance everywhere.

AREAS COVERED

Immune Checkpoint Inhibition (ICI) monotherapy seemed to be promising, but is controversial. ICI combination showed significant results. NIVOLUMAB, an anti-Programmed-Death-receptor 1, associated to IPILIMUMAB, an anti-Cytotoxic-T-Lymphocyte-Associated-protein 4, was evaluated in two phase II trials and a phase III trial, recently published. This combination led to a significant benefit in survival in first line compared to chemotherapy (OS 18.1 months (95%CI(16.8-21.4)) vs 14.1 (95%CI(12.4-16.2) HR 0.74 (95%CI 0.6-0.91) p=0.002).

EXPERT OPINION

These results represent a big step in unresectable pleural mesothelioma. The benefit in non-epithelioid subtype is impressive (OS 18.1 months (95%CI 12.2-22.8) vs 8.8 months 95%CI (7.4-10.2) HR 0.46 (95%CI(0.31-0.68)). Benefit in epithelioid subtype (OS 18.7 months 95%CI(16.9-22) vs 16.5 95%CI(14.9-20.5) HR 0.86 95%CI(0.69-1.08)) is similar to the benefit of the combination of BEVACIZUMAB and chemotherapy. Identification of predictive biomarkers is needed to identify patients who are most likely to benefit from each therapeutic strategy.

Lurbinectedin shows clinical activity and immune-modulatory functions in patients with pre-treated small cell lung cancer and malignant pleural mesothelioma

PURPOSE

Lurbinectedin is a promising new drug being investigated in pre-treated patients with small cell lung cancer (SCLC) or malignant pleural mesothelioma (MPM). Its clinical activity in the real-world setting has not been investigated yet.

PATIENTS AND METHODS

Clinical data of patients with SCLC and MPM who were treated with lurbinectedin were prospectively collected. Comprehensive immune cell profiling by flow cytometry was performed on screening and treating peripheral blood samples.

RESULTS

A total of 95 patients (43 SCLC and 52 MPM) were treated, mostly as ≥3-line of therapy. In the SCLC cohort, a median progression-free survival (mPFS) was 1.5 months (95% CI: 1.4-3.0), and median overall survival was 7.0 months (95% CI: 4.7-not reached). Objective radiological response and disease control rate after 12 weeks were 16% and 28%, respectively. In the MPM cohort, median progression-free survival was 2.8 months (95% CI: 1.4-4.2), and median overall survival was 7.2 months (95% CI: 5.9-not reached). Disease control rate after 12 weeks was 29%, whereas no partial responses were registered. No new safety signals were observed. Lurbinectedin treatment was significantly associated with the depletion of circulating classical monocytes, which correlated with a better PFS in patients with SCLC. Lurbinectedin increased the proliferation of CD4⁺ and CD8⁺ T cells (SCLC) and natural killer and natural killer T cells (SCLC and MPM) and altered co-stimulatory and co-inhibitory receptor expression on circulating lymphocytes.

CONCLUSION

Lurbinectedin has a manageable safety profile and shows clinical activity in pre-treated patients with SCLC and MPM. Its immune-modulatory functions make lurbinectedin a potential platform for immunotherapy combinations.

The Predictive and Prognostic Nature of Programmed Death-Ligand 1 in Malignant Pleural Mesothelioma: A Systematic Literature Review

Introduction

Given the emergence of combination of programmed cell death protein-1 and CTLA4 pathway blockade as effective treatment options in malignant pleural mesothelioma (MPM), there is interest in the extent to which programmed death-ligand 1 (PD-L1) expression may be prognostic of clinical outcomes and predictive of response to anti-programmed death (ligand) 1 (PD-[L]1) therapies.

Methods

MEDLINE and EMBASE electronic databases were searched until November 4, 2020. English-language randomized trials and observational studies that reported clinical outcomes and PD-L1 expression in adult patients (>18 or >20 y) with MPM were included. Forest plots were used to descriptively summarize clinical outcome data across studies.

Results

A total of 29 publications were identified providing data on the research question. Among the studies in which anti-PD-(L)1 therapies were not specified to have been used, 63% (10 of 16) found patients with tumors expressing PD-L1 (typically >1%) to have poorer survival than those with tumors expressing lower levels of PD-L1. Among the studies in which anti-PD-(L)1 therapies were used, 83% (five of six) did not reveal an association between survival and PD-L1 tumor expression. The single study directly comparing outcomes between those treated and untreated with anti-PD-(L)1 therapies across different PD-L1 cutoffs did not identify any differences between the groups.

Conclusions

The quality and consistency of the existing evidence base are currently insufficient to draw conclusions regarding a prognostic or predictive role of PD-L1 in MPM. Furthermore, high-quality studies on this topic are required to support the use of PD-L1 as a biomarker in MPM.

HDAC Inhibition with Valproate Improves Direct Cytotoxicity of Monocytes against Mesothelioma Tumor Cells

Simple Summary

Tumor-associated macrophages and monocyte myeloid-derived immunosuppressive cells are associated with bad prognosis in malignant pleural mesothelioma (MPM). This study shows that peripheral blood monocytes can, nevertheless, be cytotoxic for MPM tumor cells. This cytotoxic activity that involves direct cell-to-cell contact can be improved with a lysine deacetylase inhibitor (VPA), opening new prospects for further improvement of still unsatisfactory MPM therapies.

Abstract

The composition of the tumor microenvironment (TME) mediates the outcome of chemo- and immunotherapies in malignant pleural mesothelioma (MPM). Tumor-associated macrophages (TAMs) and monocyte myeloid-derived immunosuppressive cells (M-MDSCs) constitute a major fraction of the TME. As central cells of the innate immune system, monocytes exert well-characterized functions of phagocytosis, cytokine production, and antibody-dependent cell-mediated cytotoxicity (ADCC). The objective of this study was to evaluate the ability of monocytes to exert a direct cytotoxicity by cell-to-cell contact with MPM cells. The experimental model is based on cocultures between human blood-derived monocytes sorted by negative selection and mesothelioma cell lines. Data show (i) that blood-derived human monocytes induce tumor cell death by direct cell-to-cell contact, (ii) that VPA is a pharmacological enhancer of this cytotoxic activity, (iii) that VPA increases monocyte migration and their aggregation with MPM cells, and (iv) that the molecular mechanisms behind VPA modulation of monocytes involve a downregulation of the membrane receptors associated with the M2 phenotype, i.e., CD163, CD206, and CD209. These conclusions, thus, broaden our understanding about the molecular mechanisms involved in immunosurveillance of the tumor microenvironment and open new prospects for further improvement of still unsatisfactory MPM therapies

Immune-Checkpoint Inhibitors for Malignant Pleural Mesothelioma: A French, Multicenter, Retrospective Real-World Study

Backgrounds: Malignant pleural mesothelioma (MPM) is a cancer with poor prognosis. Second-line and onward therapy has many options, including immune-checkpoint inhibitors with demonstrated efficacy: 10−25% objective response rate (ORR) and 40−70% disease-control rate (DCR) in clinical trials on selected patients. This study evaluated real-life 2L+ nivolumab efficacy in MPM patients and looked for factors predictive of response. Methods: This retrospective study included (September 2017−July 2021) all MPM patients managed in 11 French centers. Results: The 109 enrolled patients’ characteristics were: median age: 69 years; 67.9% men; 82.6% epithelioid subtype. Strictly, second-line nivolumab was given to 51.4%. Median PFS and OS were 3.8 (3.2−5.9) and 12.8 (9.2−16.4) months. ORR was 17/109 (15.6%); 34/109 patients had a stabilized disease (DCR 46.8%). Univariable analysis identified several parameters as significantly (p < 0.05) prognostic of OS [HR (95% CI)]: biphasic subtype: 3.3 (1.52−7.0), intermediate Lung Immune Prognostic Index score: 0.46 (0.22−0.99), progression on the line preceding nivolumab: 2.1 (1.11−3.9) and age > 70 years: 2.5 (1.5−4.0). Multivariable analyses retained only biphasic subtype: 3.57 (1.08−11.8) and albumin < 25 g/L: 10.28 (1.5−70.7) as significant and independent predictors. Conclusions: Second-line and onward nivolumab is effective against MPM in real life but with less effectiveness in >70 years. Ancillary studies are needed to identify the predictive factors.

Immunotherapy for mesothelioma: Moving beyond single immune check point inhibition

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm with low survival rates. Platinum-based chemotherapy has represented the cornerstone of treatment for over a decade, prompting the investigation of new therapeutic strategies both in the early stage of the disease and in the advanced setting. The advent of immune check-point inhibitors (ICIs) has recently revamped the enthusiasm for using immunotherapy also in MPM. However, results from first clinical trials using single immune check-point inhibition have been conflicting, and this may be mainly attributed to the lack of specific biomarkers as well as to intra- and inter- patient heterogeneity. The phase III Checkmate743 firstly demonstrated the superiority of an ICI combination (nivolumab plus ipilimumab) over chemotherapy in the first-line treatment of unresectable MPM, leading to FDA approval of this regimen and showing that moving beyond single immune check point inhibition might be a successful strategy to overcome resistance in the majority of MPM patients. In this review, we describe the emerging immunotherapy strategies for the treatment of MPM. We also discuss how refining the approach in pre-clinical studies towards a more holistic perspective (which takes into account not only genetic but also pathophysiological vulnerabilities) and strengthening multi-institutional collaboration in clinical trials is finally helping the clinical development of immunotherapy in MPM.

The efficacy of immune checkpoint inhibitors in thoracic malignancies

The advent of immune checkpoint inhibitors (ICIs) has rapidly transformed the treatment paradigm for multiple cancer types, including thoracic malignancies. In advanced non-small cell lung cancer (NSCLC), ICIs have shifted treatment paradigm and improved overall survival reaching almost one-third of patients alive at 5 years. ICIs therapies have also modified the therapeutic strategy in first-line setting in metastatic small-cell lung cancer (SCLC) patients as well as in malignant pleural mesothelioma (MPM) improving the overall survival compared with standard treatment. This phenomenon is of huge relevance as both SCLC and MPM were considered orphan diseases without any significant improvement in the therapeutic strategy in the first-line setting during the last 15 years. In this review, we aim to review the efficacy of ICI in thoracic malignancies either in monotherapy or in combination, according to predictive biomarkers, and to the US Food and Drug Administration and the European Medicines Agency approvals of treatment strategies. We address the efficacy of these agents, especially in NSCLC according to PD-L1 expression and histologic subtype.

BRCA-associated protein 1 (BAP1) and miR-31 combination predicts outcomes in epithelioid malignant pleural mesothelioma

Background

Malignant pleural mesothelioma (MPM) is an aggressive disease, with few available treatment options. Identification of novel prognostic and predictive biomarkers is a priority. In MPM patients, BRCA-associated protein 1 (BAP1) alterations are detected in about 60% of cases and miR-31 seems to be involved in BAP1 regulation at post-transcriptional level. The aim of this study was to evaluate the interaction between BAP1 and miR-31 in MPM and their prognostic role in MPM.

Methods

The expression of BAP1 and miR-31 was analyzed in tissues of 55 MPM patients treated with first-line chemotherapy. Overall survival (OS) and progression-free survival (PFS) were assessed by Kaplan-Meier method and Log-rank test was used to investigate differences among subgroups. Multivariate Cox regression analysis was used to evaluate independent predictors of survival.

Results

In the whole cohort, loss of BAP1 was associated with a significant improvement in OS, but not in PFS. Lower miR-31 levels were detected in epithelioid MPM (e-MPM) compared to the non-epithelioid subtypes and resulted associated with BAP1 loss. By looking at the e-MPM subgroup, loss of BAP1 was not able to predict clinical outcome. Conversely, miR-31 levels were significantly associated with PFS (P=0.028), but not with OS (P=0.059). By combining the two biomarkers, e-MPM patients with BAP1 loss/low miR-31 levels showed a better prognosis compared to the ones with BAP1 retained/high miR-31 levels (median OS 22.6 vs. 17.0 months, P=0.017 and median PFS 8.7 vs. 5.1 months, P=0.020). The BAP1 and miR-31 combination was confirmed at multivariate analysis as an independent prognostic factor for e-MPM patients.

Conclusions

In this preliminary study, we found that the prognostic stratification of e-MPM patients may be improved by simultaneously assessing of BAP1 status and miR-31 levels. The two-biomarker score is useful to identify a subgroup of e-MPM tumors characterized by BAP1 retained and high miR-31 levels with worse clinical outcome.

Immune checkpoint inhibitors a new player in the therapeutic game of mesothelioma: New reality with new challenges

Malignant pleural mesothelioma (MPM) is a rare and orphan thoracic malignancy, with a poor prognosis as the majority of patients are diagnosed with unresectable MPM, with no significant improvements in the therapeutic strategy for over a decade. However, the recent approval of immune checkpoint inhibitors (ICI) in treatment-naïve patients with unresectable MPM marks a significant step forward and hope for the treatment of this disease. In this narrative review, we discuss the biological rationale to use ICI in the treatment of MPM. We summarize the current evidence for the efficacy of ICI in MPM and discuss several unresolved challenges regarding the use of ICI in this disease, such as the best upfront immune approach in MPM (ICI versus ICI plus chemotherapy), the optimal sequential treatment strategy according to the first-line treatment, and the potential role of predictive biomarkers.

Emerging avenues in immunotherapy for the management of malignant pleural mesothelioma

BACKGROUND

The role of immunotherapy in cancer is now well-established, and therapeutic options such as checkpoint inhibitors are increasingly being approved in many cancers such as non-small cell lung cancer (NSCLC). Malignant pleural mesothelioma (MPM) is a rare orphan disease associated with prior exposure to asbestos, with a dismal prognosis. Evidence from clinical trials of checkpoint inhibitors in this rare disease, suggest that such therapies may play a role as a treatment option for a proportion of patients with this cancer.

MAIN TEXT

While the majority of studies currently focus on the established checkpoint inhibitors (CTLA4 and PD1/PDL1), there are many other potential checkpoints that could also be targeted. In this review I provide a synopsis of current clinical trials of immunotherapies in MPM, explore potential candidate new avenues that may become future targets for immunotherapy and discuss aspects of immunotherapy that may affect the clinical outcomes of such therapies in this cancer.

CONCLUSIONS

The current situation regarding checkpoint inhibitors in the management of MPM whilst encouraging, despite impressive durable responses, immune checkpoint inhibitors do not provide a long-term benefit to the majority of patients with cancer. Additional studies are therefore required to further delineate and improve our understanding of both checkpoint inhibitors and the immune system in MPM. Moreover, many new potential checkpoints have yet to be studied for their therapeutic potential in MPM. All these plus the existing checkpoint inhibitors will require the development of new biomarkers for patient stratification, response and also for predicting or monitoring the emergence of resistance to these agents in MPM patients. Other potential therapeutic avenues such CAR-T therapy or treatments like oncolytic viruses or agents that target the interferon pathway designed to recruit more immune cells to the tumor also hold great promise in this hard to treat cancer.

Malignant pleural mesothelioma: clinical experience and prognostic value of derived neutrophil-to-lymphocyte ratio and PD-L1 expression

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor, with a poor prognosis. MPM needs to find prognostic factors of survival. We provided the management of patients with MPM and sought to determine whether pre-treatment levels of derived neutrophil-to-lymphocyte ratio (dNLR) as well as PD-L1 expression were reliable prognostic factors of survival.

METHODS

We conducted a single-institution retrospective study, including all patients with MPM treated at La Paz University Hospital between December 2009 and March 2018. Baseline disease, demographics, clinical data, treatment characteristics and complete blood cell counts were collected. We examined dNLR at baseline and data for PD-L1 expression were analyzed in tumor cells by immunohistochemistry.

RESULTS

We included 25 patients. The median overall survival (OS) was 15.7 months (95% CI 11.3-20.0). 5 patients had a dNLR greater than 3 (20%). Patients with a dNLR greater than 3 had shorter median OS (8.5 months), than patients with a dNLR less than 3 (17.0 months), with statistically significant differences (p = 0.038). Ten patients (40%) had positive PD-L1 expression (≥ 1%). Patients with positive PD-L1 expression had shorter median OS (8.5 months) than patients with negative PDL1 expression (15.7 months), but without statistically significant association (p = 0.319).

CONCLUSION

The survival data obtained in our sample are consistent with those previously reported. Pretreatment levels of dNLR greater than 3 and positive PD-L1 expression could be significant prognostic factors for poor survival in patients with MPM. Further and prospective studies are needed to explore this relationship and to derive definitive conclusions.

The Gustave Roussy Immune (GRIm)-Score Variation Is an Early-on-Treatment Biomarker of Outcome in Advanced Non-Small Cell Lung Cancer (NSCLC) Patients Treated with First-Line Pembrolizumab

Background: The Gustave Roussy Immune (GRIm)-Score takes into account neutrophil-to-lymphocyte ratio (NLR), serum albumin concentration and lactate dehydrogenase (LDH) and its prognostic value has been investigated in patients treated with immune check-point inhibitors (ICIs). To further assess the prognostic and predictive value of baseline GRIm-Score (GRImT0) in advanced non-small cell lung cancer (aNSCLC) patients, we separately investigated two cohorts of patients treated with first-line pembrolizumab or chemotherapy. We also investigated whether GRIm-Score at 45 days since treatment initiation (GRImT1) and GRIm-Score difference between the two timepoints may better predict clinical outcomes (GRImΔ = GRImT0 − GRImT1). Methods: We retrospectively evaluated 222 aNSCLC patients: 135 treated with pembrolizumab and 87 treated with chemotherapy as the first-line regimen. NLR, serum albumin and LDH concentrations were assessed at T0 and at T1. According to the GRIm-Score, patients were assigned 1 point if they had NLR > 6, LDH > upper limit normal or albumin < 3.5 g/dL. Patients with a GRIm-Score < 2 were considered as having a low Score. Results: In both cohorts, no difference in terms of overall survival (OS) between patients with low and high GRImT0 was found. Otherwise, median OS and progression free survival (PFS) of the low GRImT1 group were significantly longer than those of the high GRImT1 group in pembrolizumab-treated patients, but not in the CHT cohort (pembrolizumab cohort: low vs. high; median OS not reached vs. 9.2 months, p = 0.004; median PFS 10.8 vs. 2.3 months, p = 0.002). Patients receiving pembrolizumab with stable/positive GRImΔ had better OS (median OS not reached vs. 12.0 months, p < 0.001), PFS (median PFS 20.6 vs. 2.6 months, p < 0.001) and objective response rate (58.2% vs. 7.6%, p = 0.003) compared to patients with negative GRImΔ. Conclusion: Our data shown that GRImT1 and GRImΔ are more reliable peripheral blood biomarkers of outcome compared to GRImT0 in aNSCLC patients treated with pembrolizumab and might represent useful biomarkers to drive clinical decisions in this setting.

Old but gold: the role of drug combinations in improving response to immune check-point inhibitors in thoracic malignancies beyond NSCLC

The introduction of immune checkpoint inhibitors (ICIs) in non-oncogene addicted non-small cell lung cancer (NSCLC) has revolutionized the treatment scenario and led to a meaningful improvement in patient prognosis. Disappointingly, the success of ICI therapy in NSCLC has not been fully replicated in other thoracic malignancies as small cell lung cancer (SCLC), malignant pleural mesothelioma (MPM), and thymic epithelial tumors (TETs), due to the peculiar biological features of these disease and to the difficulties in the conduction of well-designed, biomarker-driven clinical trials. Therefore, combination strategies of ICIs plus conventional therapies (either chemotherapy, alternative ICIs or targeted agents) have been implemented. Although first approvals of ICI therapy have been recently granted in SCLC and MPM (in combination with chemotherapy and different ICIs), results remain somewhat modest and limited to a small proportion of patients. This work reviews the trial results of ICI therapy in mesothelioma, SCLC, and TETs and discusses the potential of combining ICIs with old drugs.

The Influence of Systemic Inflammation Response Index on Survival Outcomes of Limited-Stage Small-Cell Lung Cancer Patients Treated with Concurrent Chemoradiotherapy

Background

Recent studies have indicated that the systemic inflammation response index (SIRI) can efficiently predict survival outcomes in various tumor types. Thusly, in absence of comparable investigations in limited-stage small-cell lung cancers (LS-SCLCs), we aimed to retrospectively evaluate the prognostic utility of SIRI in LS-SCLC patients treated with concurrent chemoradiotherapy (CRT). Patients and Methods. Present multi-institutional retrospective analysis incorporated LS-SCLC patients treated with CRT at three academic radiation oncology centers between January 2007 and December 2018. The SIRI was calculated by using the peripheral blood neutrophil (N), monocyte (M), and lymphocyte (L) counts acquired in the last ≤7 days before the commencement of the CRT: SIRI = N × M/L. Accessibility of pretreatment SIRI cutoff that may stratify the study population into two gatherings with distinctive overall survival (OS) results was evaluated by utilizing the receiver operating characteristic (ROC) curve analysis. Primary objective was the association between the SIRI values and the OS results.

Results

Search for the availability of an ideal SIRI cutoff that may stratify the entire patients' population into two particular groups with distinctive OS outcomes identified the 1.93 value (area under the curve (AUC): 72.9%; sensitivity: 74.6%; specificity: 70.1%): Group 1: SIRI <1.93 (N = 71) and Group 2: SIRI ≥1.93 (N = 110), respectively. At a median follow-up of 17.9 (95% CI: 13.2-22.6) months, 47 (26.0%) patients were still alive (47.9% for SIRI <1.93 versus 18.3% for SIRI ≥1.93; p < 0.001). Kaplan-Meier comparisons between the two SIRI groups showed that the SIRI <1.93 cohort had significantly longer median OS (40.5 versus 14.2 months; p < 0.001) than the SIRI ≥1.93 cohort. Similarly, the 3- (54% versus 12.6%) and 5-year (33% versus 9.9%) OS rates were also numerically superior in the SIRI <1.93 cohort. Results of the multivariate analyses uncovered that the prognostic significance of the SIRI on OS outcomes was independent of the other confounding variables.

Conclusions

The results of this retrospective multi-institutional cohort analysis suggested that a pre-CRT SIRI was a strong and independent prognostic biomarker that reliably stratified LS-SCLC patients into two cohorts with significantly different OS outcomes.

Establishment and Characterization of Patient-Derived Xenografts (PDXs) of Different Histology from Malignant Pleural Mesothelioma Patients

Simple Summary

Malignant pleural mesothelioma (MPM) is a rare tumor with unfavorable prognosis for which new therapeutic interventions are urgently needed. The aim of our study was to develop a preclinical model representative of the different histotypes found in human tumors that can be used as models for the discovery of new treatments and combinations. We successfully generated patient-derived xenografts (PDXs) from MPM, which strongly resembled the tumors of origin in terms of morphology and immunohistochemistry. These tumors, when growing in mice, poorly respond to cisplatin, a finding that aligned with the clinical results. From one of the PDXs, we generated 2D and 3D cultures maintaining the phenotypical characteristics of human tumors and PDXs. Altogether, these preclinical models represent a useful tool for the discovery of new targets and drug combinations.

Abstract

Background: Malignant pleural mesothelioma (MPM) is a very aggressive tumor originating from mesothelial cells. Although several etiological factors were reported to contribute to MPM onset, environmental exposure to asbestos is certainly a major risk factor. The latency between asbestos (or asbestos-like fibers) exposure and MPM onset is very long. MPM continues to be a tumor with poor prognosis despite the introduction of new therapies including immunotherapy. One of the major problems is the low number of preclinical models able to recapitulate the features of human tumors. This impacts the possible discovery of new treatments and combinations. Methods: In this work, we aimed to generate patient-derived xenografts (PDXs) from MPM patients covering the three major histotypes (epithelioid, sarcomatoid, and mixed) occurring in the clinic. To do this, we obtained fresh tumors from biopsies or pleurectomies, and samples were subcutaneously implanted in immunodeficient mice within 24 h. Results: We successfully isolated different PDXs and particularly concentrated our efforts on three covering the three histotypes. The tumors that grew in mice compared well histologically with the tumors of origin, and showed stable growth in mice and a low response to cisplatin, as was observed in the clinic. Conclusions: These models are helpful in testing new drugs and combinations that, if successful, could rapidly translate to the clinical setting.

High-intensity statins are associated with improved clinical activity of PD-1 inhibitors in malignant pleural mesothelioma and advanced non-small cell lung cancer patients

BACKGROUND

In preclinical models, statins showed vaccine adjuvant activities and synergized with PD-1 inhibitors. We analyzed the impact of statin treatment on clinical outcome in thoracic cancer patients treated with PD-1 inhibitors.

METHODS

A total of 82 malignant pleural mesothelioma (MPM) and 179 advanced non-small cell lung cancer (aNSCLC) patients treated with PD-1 inhibitors as second or further line treatment were examined. Seventy-seven MPM patients treated with standard chemotherapy were analyzed as control cohort. Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were calculated.

RESULTS

Among 253 patients with available data, statin use was associated with increased ORR (32% versus 18%, P = .02), PFS (median 6.7 versus 2.9 months, hazard ratio [HR] 0.57, 95% CI 0.39-0.83, P < .01), and OS (median 13.1 versus 8.7 months, HR 0.67, 95% CI 0.45-1.00, P = .05). In the control MPM cohort treated with chemotherapy (n = 77), no association was found. MPM patients who used statins showed improved ORR (22% versus 6%, P = .05), PFS (median 6.7 versus 2.4 months, P < .01), and OS (median not reached versus 6.0 months, P = .01). In aNSCLC patients, statin use was associated with improved ORR (40% versus 22%, P = .04) and PFS (median 7.8 versus 3.6 months, P = .03), but no significant difference in OS was found (median 13.1 versus 10.1 months, P = .30). Multivariable analysis confirmed the correlation between statin use and better PFS and OS in MPM and better PFS in aNSCLC. In the whole cohort, high but not low/moderate-intensity statins were associated with better OS compared to no user (P = .02 and P = .59, respectively).

CONCLUSIONS

Our study showed that statins are associated with better clinical outcome in MPM and aNSCLC patients treated with PD-1 inhibitors in an intensity-dependent manner.