Search

Background: Previous studies showed opposite effects of NOTCH1 and NOTCH2 on mesothelioma cell survival under hypoxia. Mechanisms underlying these effects are not still clear and this pathway plays a key role in angiogenesis and cancer stem cells (CSCs) self-renewal processes., Purpose: In this study we evaluated whether NOTCH1, NOTCH2 copy number alterations (CNAs) might predict prognosis of patients with pleural mesothelioma (PM) and if the modulation of this pathway might target CSCs, potentiating pemetrexed activity, also in hypoxic conditions., Methods: Recurrent CNAs were determined by high-resolution whole-genome sequencing from paraffin-embedded samples of a "discovery cohort" (26 patients treated with pemetrexed-based chemotherapy). Prognostic CNAs were validated by PCR gene copy-number and expression analyses in the "discovery" and in two independent "validation" cohorts of pemetrexed-treated and untreated patients (N = 45 and N = 40). Functional analyses of emerging genes were performed through siRNA in different subpopulation of PM cells, growing under hypoxia., Results: A copy number gain of NOTCH2 was observed in 50% of patients with progressive disease and its overexpression correlated with a worse prognosis in both pemetrexed-treated and untreated-patients' cohorts. Conversely, losses of PTP4A3 correlated with clinical benefit, while patients with overexpression of both NOTCH2 and PTP4A3 had the worse prognosis. Moreover, NOTCH2 silencing through siRNA in vitro reduced migration, enhancing apoptosis of PM cells, while the PTP4A3 inhibitor BR-1 overcame pemetrexed resistance in PM cells characterized by high NOTCH2/PTP4A3 expression., Conclusions: NOTCH2 and PTP4A3 alterations are associated with clinical outcomes in pemetrexed-treated PM patients. The inhibition of NOTCH pathway may be exploited to eradicate CSCs and improve patients' survival., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Pleural mesothelioma (PM) is an aggressive cancer with limited treatment options. In particular, the frequent loss of tumor suppressors, a key oncogenic driver of the disease that is therapeutically intractable, has hampered the development of targeted cancer therapies. Here, we interrogate the PM genome using CRISPR-mediated gene editing to systematically uncover PM cell susceptibilities and provide an evidence-based rationale for targeted cancer drug discovery. This analysis has allowed us to identify with high confidence numerous known and novel gene dependencies that are surprisingly highly enriched for non-oncogenic pathways involved in response to various stress stimuli, in particular DNA damage and transcriptional dysregulation. By integrating genomic analysis with a series of in vitro and in vivo functional studies, we validate and prioritize several non-oncogene addictions conferred by CDK7, CHK1, HDAC3, RAD51, TPX2, and UBA1 as targetable vulnerabilities, revealing previously unappreciated aspects of PM biology. Our findings support the growing consensus that stress-responsive non-oncogenic signaling plays a key role in the initiation and progression of PM and provide a functional blueprint for the development of unprecedented targeted therapies to combat this formidable disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: First-line standard-of-care for unresectable, pleural mesothelioma (PM) changed with the phase 3 CheckMate 743 study results, showing that nivolumab plus ipilimumab (Nivo + Ipi) significantly extended overall survival (OS) versus platinum + pemetrexed chemotherapy for PM (median OS 18.1 versus 14.1 months; hazard ratio: 0.74; p = 0.002). Efficacy and safety data in real-world (rw) settings are needed to confirm these results., Methods: This French multicenter, retrospective cohort study was undertaken to assess the outcomes of treatment-naïve PM patients given Nivo + Ipi via an early-access program (EAP). The primary objective was investigator-assessed real world -progression-free survival (PFS). The secondary objectives were the combination's -overall survival (OS) and safety., Results: From 1 April 2021 to 15 Feb 2022, the analysis included 201 of the 305 EAP-enrolled patients treated in 63 centers (79.6 % men; median age: 75 years; 91.8 % Eastern Cooperative Oncology Group performance status (ECOG-PS) 0/1; 74.5 % epithelioid histology). With median (95 % CI) follow-up for all patients of 18.4 (17.7-19.2) months, -PFS and OS were 6.3 (5.3-7.5) and 18.9 (17.6-not reached (NR)) months, with 1-year OS at 66.4 % (60.1-73.3 %). Median OS and 1-year survival rates were 21.0 (18.7-NR) and 70.8 % (63.9 %-780.6 %), and 14.1 (10.9-21.0) months and 54.9 % (42.8 %-70.4 %) for epithelioid and non-epithelioid PM subgroups, respectively. PFS was equal between the two subgroups. Grade 3-4 adverse events occurred in 23.3 % of patients and three deaths were treatment-related., Conclusions: For this unselected PM population, efficacy and safety outcomes compared favorably with CheckMate 743 trial results., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: Pleural mesothelioma is a cancer arising in the cells that line the lungs and chest wall with poor survival and poor response to first-line therapy. Organoid models of cancer can faithfully recapitulate the genetic and histopathological characteristics of individualized tumors and have potential to be used for precision medicine, however methods of establishing patient-derived mesothelioma organoids have not been well established in the published literature., Materials and Methods: Long-term mesothelioma patient-derived organoids were established from ten malignant pleural effusion fluids. Mesothelioma patient-derived organoids were compared to the corresponding biopsy tissue specimens using immunohistochemistry labelling for select diagnostic markers and the TruSight Oncology-500 sequencing assay. Cell viability in response to the chemotherapeutic drug cisplatin was assessed., Results: We established five mesothelioma patient-derived organoid cultures from ten malignant pleural effusion fluids collected from nine individuals with pleural mesothelioma. Mesothelioma patient-derived organoids typically reflected the histopathological and genomic features of patients' matched biopsy specimens and displayed cytotoxic sensitivity to cisplatin in vitro., Conclusion: This is the first study of its kind to establish long-term mesothelioma organoid cultures from malignant pleural effusions and report on their utility to test individuals' chemotherapeutic sensitivities ex vivo., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: Nivolumab (anti-PD-1) plus ipilimumab (anti-CTLA-4) is a new first-line treatment combination for patients with pleural mesothelioma. Nivolumab-ipilimumab improved the survival, however, 30.3% of the patients suffered from grade 3-4 treatment related adverse events (TRAE's) and TRAE's led to discontinuation in 23.0% of all patients. Here, we present the first real-world data of nivolumab plus ipilimumab in patients with malignant mesothelioma treated in two mesothelioma expert centers., Methods: Clinical data of patients with mesothelioma treated with nivolumab and ipilimumab were prospectively collected. Clinical parameters were obtained every visit, CT scans were evaluated every 12 weeks and adverse events were assessed continuously during the treatment. Data on grade 2-5 TRAE's and activity (overall response rate (ORR), duration of response (DOR), disease control rate (DCR), median progression-free survival (mPFS) and median overall survival (mOS) were reported., Results: Between January 2021 and August 2022, 184 patients were treated with nivolumab plus ipilimumab. The median follow-up was 12.1 months (95 %CI 11.1 - 13.1). Grade 3-4 TRAEs were seen in 27.7 % of the patients and 25.0 % discontinued immunotherapy treatment early because of TRAE's. ORR was 21.7 % (95 % CI 15.7-27.7), median DOR was 5.7 months (IQR 3.2-8.7) and DCR at 12 weeks 56.0 % (95 % CI 48.8-63.2). The mPFS was 5.5 months (95 %CI 4.1-6.9), mOS was 14.1 months (95 % CI 11.1-18.2)., Conclusions: Nivolumab plus ipilimumab had an equal efficacy in a real-world comparable population but also a high risk of TRAE's, leading to discontinuation of treatment in 25% of the patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: VEGF/VEGFR autocrine loop is a hallmark of pleural mesothelioma (PM). We thus assayed the prognostic and predictive values of VEGFR-2 [vascular endothelial growth factor receptor 2 or Flk-1] and CD34, a marker of endothelial cells, in samples from patients accrued in the Mesothelioma Avastin Cisplatin Pemetrexed Study ('MAPS', NCT00651456)., Materials and Methods: VEGFR2 and CD34 expression were assayed using immunohistochemistry in 333 MAPS patients (74.3%), and their prognostic value was evaluated in terms of overall survival (OS) and progression-free survival (PFS) in univariate and multivariate analyses, before validation by bootstrap methodology., Results: Positive VEGFR2 or CD34 staining was observed in 234/333 (70.2%) and 322/323 (99.6%) of tested specimens, respectively. VEGFR2 and CD34 staining correlated weakly, yet significantly, with each other (r = 0.36, p < 0.001). High VEGFR2 expression or high CD34 levels were associated with longer OS in PM patients in multivariate analysis (VEGFR2: adjusted [adj.] hazard ratio [HR]: 0.91, 95% confidence interval [CI] [0.88; 0.95], p < 0.001; CD34: adj. HR: 0.86, 95 %CI [0.76; 0.96], p = 0.010), with only high VEGFR2 expression resulting in significantly longer PFS (VEGFR2: adj. HR: 0.96, 95 %CI [0.92; 0.996], p = 0.032). Stability of these results was confirmed using bootstrap procedure. Nevertheless, VEGFR2 expression failed to specifically predict longer survival in bevacizumab-chemotherapy combination trial arm, regardless of whether the VEGFR2 score was combined or not with serum VEGF concentrations., Conclusion: VEGFR2 overexpression independently correlated with longer OS or PFS in PM patients, such biomarker deserving prospective evaluation as stratification variable in future clinical trials., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Franck Morin reports financial support was provided by Roche-France (2013). Solenn Brosseau reports financial support was provided by CHU de Caen (APRI 2012). Gerard Zalcman reports financial support was provided by League against Cancer (2012). Guenaelle Levallet reports financial support was provided by Fond de Recherche en Santé Respiratoire (FRSR 2012)., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Malignant pleural mesothelioma (MPM) is an asbestos-related fatal malignant neoplasm. Although there has been no reliable chemotherapeutic regimen other than combination therapy of cisplatin and pemetrexed for two decades, combination of ipilimumab plus nivolumab brought about a better outcome in patients with MPM. Thus, cancer immunotherapy using immune checkpoint inhibitor (ICI) is expected to play a central role in the treatment of MPM. To maximize the antitumor effect of ICI, we evaluated whether nintedanib, an antiangiogenic agent, could augment the antitumor effect of anti-programmed cell death 1 (PD-1) antibody (Ab). Although nintedanib could not inhibit the proliferation of mesothelioma cells in vitro, it significantly suppressed the growth of mesothelioma allografts in mice. Moreover, combination therapy with anti-PD-1 Ab plus nintedanib reduced tumor burden more dramatically compared with nintedanib monotherapy via inducing remarkable necrosis in MPM allografts. Nintedanib did not promote the infiltration of CD8 +  T cells within the tumor when used alone or in combination with anti-PD-1 Ab but it independently decreased the infiltration of tumor-associated macrophages (TAMs). Moreover, immunohistochemical analysis and ex vivo study using bone marrow-derived macrophages (BMDMs) showed that nintedanib could polarize TAMs from M2 to M1 phenotype. These results indicated that nintedanib had a potential to suppress protumor activity of TAMs both numerically and functionally. On the other hand, ex vivo study revealed that nintedanib upregulated the expression of PD-1 and PD-ligand 1 (PD-L1) in BMDMs and mesothelioma cells, respectively, and exhibited the impairment of phagocytic activity of BMDMs against mesothelioma cells. Co-administration of anti-PD-1 Ab may reactivate phagocytic activity of BMDMs by disrupting nintedanib-induced immunosuppressive signal via binding between PD-1 on BMDMs and PD-L1 on mesothelioma cells. Collectively, combination therapy of anti-PD-1 Ab plus nintedanib enhances the antitumor activity compared with respective monotherapy and can become a novel therapeutic option for patients with MPM., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: Pleural mesothelioma (PM) is an aggressive malignancy with limited treatment options. The first-line therapy has remained unchanged for two decades and consists of pemetrexed in combination with cisplatin. Immune-checkpoint inhibitors (nivolumab plus ipilimumab) have high response rates, resulting in recent updates in treatment recommendations by the U.S. Food and Drug Administration. However, the overall benefits of combination treatment are modest, suggesting that other targeted therapy options should be investigated., Materials and Methods: We employed high-throughput drug sensitivity and resistance testing on five established PM cell lines using 527 cancer drugs in a 2D setting. Drugs of the greatest potential (n = 19) were selected for further testing in primary cell models derived from pleural effusions of seven PM patients., Results: All established and primary patient-derived PM cell models were sensitive to the mTOR inhibitor AZD8055. Furthermore, another mTOR inhibitor (temsirolimus) showed efficacy in most of the primary patient-derived cells, although a less robust effect was observed when compared with the established cell lines. Most of the established cell lines and all patient-derived primary cells exhibited sensitivity to the PI3K/mTOR/DNA-PK inhibitor LY3023414. The Chk1 inhibitor prexasertib showed activity in 4/5 (80%) of the established cell lines and in 2/7 (29%) of the patient-derived primary cell lines. The BET family inhibitor JQ1 showed activity in four patient-derived cell models and in one established cell line., Conclusion: mTOR and Chk1 pathways had promising results with established mesothelioma cell lines in an ex vivo setting. In patient-derived primary cells, drugs targeting mTOR pathway in particular showed efficacy. These findings may inform novel treatment strategies for PM., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Objectives: Malignant pleural mesothelioma (MPM) is an aggressive cancer which at large is not amenable to curative surgery. Despite the recent approval of immune checkpoint inhibitor therapy, the response rates and survival following systemic therapy is still limited. Sacituzumab govitecan is an antibody-drug conjugate targeting the topoisomerase I inhibitor SN38 to trophoblast cell-surface antigen 2 (TROP-2)-positive cells. Here we have explored the therapeutic potential of sacituzumab govitecan in MPM models., Materials and Methods: TROP2 expression was analyzed in a panel of two well established and 15 pleural effusion derived novel lines by RT-QPCR and immunoblotting, TROP2 membrane-localization was studied by flow cytometry and immunohistochemistry. Cultured mesothelial cells and pneumothorax pleura served as controls. The sensitivity of MPM cell lines to irinotecan and SN38 was studied using cell viability, cell cycle, apoptosis and DNA damage assays. Drug sensitivity of cell lines was correlated with RNA expression of DNA repair genes. Drug sensitivity was defined as an IC50 below 5 nM in the cell viability assay., Results: TROP2 expression was detected at RNA and protein level in 6 of the 17 MPM cell lines, but not in in cultured mesothelial control cells or in the mesothelial layer of the pleura. TROP2 was detectable on the cell membrane in 5 MPM lines and was present in the nucleus in 6 cell models. Ten of 17 MPM cell lines showed sensitivity to SN38 treatment, among those 4 expressed TROP2. High AURKA RNA expression and high proliferation rate correlated with sensitivity to SN38-induced cell death, DNA damage response, cell cycle arrest and cell death. Sacituzumab govitecan treatment effectively induced cell cycle arrest and cell death in TROP2-positive MPM cells., Conclusion: TROP2 expression and sensitivity to SN38 in MPM cell lines support biomarker-selected clinical exploration of sacituzumab govitecan in patients with MPM., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Objectives: Second-line chemotherapy is not a standard of care in patients with malignant pleural mesothelioma (MPM) that progresses after first-line treatment with cisplatin and pemetrexed. In pre-clinical models, the combination of gemcitabine (GEM) and imatinib mesylate (IM), compared with GEM alone, led to a further tumor growth inhibition and improved survival. This phase II study evaluates the antitumor activity of a combination of IM and GEM in platinum-pemetrexed-pretreated MPM patients expressing PDGFR-β and/or cKIT by immunohistochemistry (IHC)., Patients and Methods: GEM (1000 mg/m 2 ) was given on days 3 and 10; IM (400 mg) was taken orally on days 1-5 and 8-12 of a 21-day cycle. The primary endpoint was the 3-month progression-free survival (PFS) rate. The study follows the optimal two-stage design of Simon. A 3-month PFS target of 75 % was required. With a probability error α = 10 % and a power of 80 %, the calculated sample size was 22 patients. In particular, in the first step, six out of nine patients and globally 14/22 patients free from progressive disease at 3 months were required. Secondary endpoints included response rate, duration of response, toxicity and overall survival (OS)., Results: In total, 23 patients were enrolled (ECOG PS 0-1/2: 9/13; one previous line/≥two previous lines: 10/13). Partial response was achieved in four patients (17.4 %) and stable disease in 11 (47.8 %) with a disease control rate of 65.3 %. After a median follow-up of 34.5 months, median PFS and OS were 2.8 and 5.7 months, respectively. The 3-month PFS rate was 39.1 % (9/23 patients). All-grade drug-related adverse events occurred in 17 (73.9 %) patients. Grade 3 treatment-related adverse events were observed in four (17 %) patients., Conclusions: The combination of IM and GEM is well tolerated in platinum-pemetrexed-pretreated MPM patients expressing PDGFR-β and/or cKIT by IHC, but it does not show a significant PFS benefit., Competing Interests: Declaration of Competing Interest All the authors declare no competing interests. None of the authors have received funding for this work., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: Currently, there is no optimal salvage therapy for patients with malignant pleural mesothelioma (MPM) who relapse after treatment with first-line chemotherapy. In line with the strong preclinical rationale for targeting fibroblast growth factor receptor (FGFR) signalling in malignant mesothelioma, we conducted a phase II study assessing the efficacy of AZD4547, an oral tyrosine multi-kinase FGFR 1-3 inhibitor, as a second or third-line treatment., Materials and Methods: We conducted a single-center, open-label, single-arm phase II study of AZD4547 in eligible patients with confirmed, measurable MPM and radiological progression after first or second-line systemic chemotherapy. Patients received continuous, twice-daily oral AZD4547 on a 3-weekly cycle. The primary end point was 6-month progression free survival (PFS6). Response was assessed with CT scan every 6 weeks according to the modified RECIST criteria for mesothelioma (mRECIST) and toxicities were also assessed. The study used a Simon's two-stage design: 26 patients would be recruited to the first stage and more than 7 (27 %) of 26 patients were required to achieve PFS6 to continue to stage two, for a potential total cohort of 55 patients., Results: 3 of 24 patients (12 %) were progression-free at 6 months. Hence, the study fulfilled stopping criteria regardless of further recruitment and warranted discontinuation. The most common toxicities (across all grades) were hyperphosphatemia, xerostomia, mucositis, retinopathy, dysgeusia, and fatigue. Maximum toxicities were grade 2 or below for all patients across all cycles. There was no association between tumour BAP1 protein loss and clinical outcomes., Conclusions: The FGFR 1-3 inhibitor AZD4547 did not demonstrate efficacy in patients with MPM who had progressed after first line treatment with platinum-based chemotherapy., (Copyright © 2020 Elsevier B.V. All rights reserved.)