Introduction: Malignant pleural mesothelioma (MPM) is a malignant disease of the pleura which recently can be treated with immune checkpoint inhibitors (ICI). To optimize this treatment, a better... Show moreIntroduction: Malignant pleural mesothelioma (MPM) is a malignant disease of the pleura which recently can be treated with immune checkpoint inhibitors (ICI). To optimize this treatment, a better understanding of the tumor micro environment is needed. We investigated subgroups of immune cells in subsequent tumor biopsies of patients treated with ICI. Methods: Biopsies from MPM patients included in two clinical ICI trials (nivolumab alone and an ipilimumab/nivolumab combination) were examined. At baseline and after 6 weeks of treatment, pleural biopsies were taken to examine the tumor microenvironment (CD20+, CD4+, CD8+, FoxP3+ and PD-1+ ). Cell density was defined as the number of marker positive cells per mm(2). Radiological responses were evaluated as partial response, stable disease or progressive disease according to modified RECIST criteria. Results: Thirty-four and 36 patients were included in the nivolumab and ipiliumumab/nivolumab trial respectively. In the nivolumab trial, no significant differences in cell densities were seen in baseline biopsies of patients with partial response versus progressive disease. In contrast, in the ipilimumab/nivolumab trial, a higher cell density of CD4+, CD8+, FoxP3+ and PD-1+ cells at baseline was significantly correlated with partial responses. On-treatment biopsies of both trials did not show significant changes when compared to baseline biopsies. Conclusion: Biopsies from patients responding to nivolumab plus ipilimumab treatment show a significant higher cell density of CD4+, CD8+, FoxP3+ and PD-1+ cells, without a change after 6 weeks of treatment. This observation is a first step in exploring the tumor microenvironment as predictor of response in ICI treatment in MPM. Show less
Objectives: Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer with a poor prognosis and limited treatment options. This study assessed the characteristics, treatment patterns,... Show moreObjectives: Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer with a poor prognosis and limited treatment options. This study assessed the characteristics, treatment patterns, and outcomes for patients diagnosed with MPM in England. Materials and methods: As part of I-O Optimise, this retrospective cohort study analyzed data recorded in the Cancer Analysis System in England for all adult patients newly diagnosed with MPM between 2013 and 2017, with follow-up to March 2018 or death, whichever occurred first. Overall survival (OS) was estimated using Kaplan-Meier methods. A Cox regression model was used to describe the impact of sociodemographic and clinical characteristics at diagnosis on OS. Results: 9458 patients diagnosed with MPM were analyzed. Median age at diagnosis was 75 years; 83.4% were male. Eastern Cooperative Oncology Group performance status (ECOG PS) was 0-1 for 44.5%; 2 for 11.5%; 2 for 9.1%; and missing for 34.9% of patients. TNM stage was missing for 60.4%. A majority of patients had epithelioid histology (36.4%) or not otherwise specified (NOS) MPM (43.3%). After diagnosis, 48.7% of all patients received best supportive care (BSC; no surgery, radiotherapy, SACT); 11.4% received palliative radiotherapy alone; 6.5% underwent surgery; 33.4% received systemic anticancer therapy (SACT) as initial treatment. Platinum plus pemetrexed was the main SACT regimen used in both first and second line. Median OS (8.3 months) varied by histopathology and ranged from 4.3 to 13.3 months for sarcomatoid and epithelioid MPM, respectively. After adjusting for age, sex, and ECOG PS, sarcomatoid, biphasic, and NOS MPM remained significantly associated with worse OS than epithelioid MPM (all p < 0.001). Median OS varied from 4.6 to 17.0 months for patients receiving BSC/palliative radiotherapy, and patients receiving surgery, respectively. Conclusion: Outcomes for patients with MPM in England remain poor. Future studies will investigate the impact of newer therapies on the treatment patterns and survival of MPM patients. Show less
Mankor, J.M.; Disselhorst, M.J.; Poncin, M.; Baas, P.; Aerts, J.G.J.V.; Vroman, H. 2020
Background: Combined immune checkpoint inhibitor (ICI) treatment targeting PD-1 and CTLA-4 was suggested to yield clinical benefit over chemotherapy in malignant pleural mesothelioma (MPM), whereas... Show moreBackground: Combined immune checkpoint inhibitor (ICI) treatment targeting PD-1 and CTLA-4 was suggested to yield clinical benefit over chemotherapy in malignant pleural mesothelioma (MPM), whereas aPD-1 monotherapy failed to provide benefit in phase-Ill trials. Success of ICI depends on the presence and activation of tumor-specific T cells. Therefore, we investigated whether T-cell characteristics are underlying clinical efficacy of ICI treatment in MPM.Methods: Comprehensive immune cell profiling was performed on screening and on treatment peripheral blood samples of mesothelioma patients treated with nivolumab (aPD-1) monotherapy (NCT02497508), or a combination of nivolumab and ipilimumab (aCTLA-4) (NCT03048474).Findings: aPD-1 /aCTLA-4 combination treatment induced a profound increase in proliferation and activation of T cells, which was not observed upon aPD-1 monotherapy. Moreover, patients that responded to combination treatment had low frequencies of naive CDS T cells and high frequencies of effector memory CDS T cells that re-expressed RA (TEMRA) at screening. The frequency of Granzyme-B and Interferon-y producing TEM-RAs was also higher in responding patients.Interpretation: High proportions of TEMRAs and cytokine production by TEMRAs before treatment, was associated with a better clinical outcome. TEMRAs, which likely comprise tumor-specific T cells, tend to require blockage of both aPD-1 and aCTLA-4 to be reactivated. In conclusion, peripheral blood TEMRAs can play a key role in explaining and predicting clinical benefit upon aPD-1/aCTLA-4 combination treatment. (C) 2020 Published by Elsevier B.V. Show less
Malignant pleural mesothelioma (MPM) is an aggressive tumor of the mesothelial cells lining the pleura. The poor prognosis of patients indicates the importance to find more effective treatments.... Show moreMalignant pleural mesothelioma (MPM) is an aggressive tumor of the mesothelial cells lining the pleura. The poor prognosis of patients indicates the importance to find more effective treatments. Therefore, this thesis focused on finding new treatment strategies for MPM. We present a method in which primary MPM cultures were chemically profiled to determine second-line treatment for patients. With this personalized treatment strategy we were able to predict individual patient responses to selected drugs. Based on the chemical profiles of all tumor cultures, these cultures could be divided in three groups. Transcriptomic analysis of these groups identified a unique genetic profile separating these groups and identifying the fibroblast growth factor receptor (FGFR) as a new target for the treatment of MPM. The cultures sensitive to FGFR inhibitors were dependent on FGFR3 mediated signaling which was regulated by BAP1, indicating BAP1 can serve as a biomarker for this treatment. Another target explored in this thesis was 5T4. We showed that 5T4 was only expressed in the tumor cells and that antibody-drug conjugates effectively kill high 5T4 expressing MPM cells. Altogether we present different promising novel strategies in the treatment of MPM, which could improve the survival outcome of these patients. Show less
Schunselaar, L.M.; Monkhorst, K.; Noort, V. van der; Wijdeven, R.; Peters, D.; Zwart, W.; ... ; Baas, P. 2018
