Advanced Malignant Pleural Mesothelioma Research Articles

Final analysis of the BIMES trial, a phase II single arm study assessing efficacy and safety of bintrafusp alfa in previously treated advanced malignant pleural mesothelioma (GECP 20/09).

8084 Background: Transforming growth factor β (TGF-β) is involved in tumor immune evasion and epithelial–mesenchymal transition (EMT). As TGF-β upregulation and EMT are associated with resistance to anti-PD1 therapy, we evaluated the efficacy of bintrafusp alfa, a bifunctional fusion protein targeting TGF-β and PD-L1, in malignant pleural mesothelioma (MPM). Methods: Patients with advanced MPM who were previously treated with platinum-based chemotherapy were enrolled and received bintrafusp alfa 1200mg/m2 every 2 weeks until progression or for a maximum of two years. The primary objective was to determine the progression-free survival (PFS) by modified RECIST v1.1. assessed by the investigators. The expected median PFS was 4.5 months. Secondary objectives were overall response rate, duration of response, overall survival (OS) and safety. Results: Between October 2021 to March 2023, 47 patients were enrolled. Mean age was 70 years (41-84) and 36 (78.3%) were males. Most patients had epithelioid histology (82.9%) and had received only 1 prior line of therapy (84.8%). With a median follow-up of 11.5 months, 43 patients had disease progression and 24 patients died. The median number of doses administered was 4 (1-21) and reasons for treatment discontinuation were disease progression (82.6%), toxicity (6.5%), investigator decision (4.4%) and death (6.5%) by tumor progression. The median PFS was 1.9 months (95% CI 1.7 – 5.4) and the 6 month-PFS rate was 15.9%. Disease control rate was 34.8% (95% CI 22.2-49.9) consisting of 2 patients with partial response and 13 patients with stable disease as best response. The median OS was 11.9 months (95% CI 4.4 – not reached) and 6, 12 and 18-month OS rate was 65.3%, 46.5% and 26.6%, respectively. No significant differences in OS and PFS were observed based on MPM histological subtype. Grade 3-4 treatment-related adverse events occurred in 16 (34%) patients, anemia being the most common (n = 5); skin toxicity (n = 3); colitis (n = 2); adrenal insufficiency, acute kidney injury, allergic reaction, lipase, and amylase increased (n = 1 each). Conclusions: Bintrafusp alfa did not reach the expected efficacy in patients with advanced malignant pleural mesothelioma previously treated with platinum-based chemotherapy. Clinical trial information: NCT05005429 .

Emerging New Targets in Systemic Therapy for Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is a heterogeneous cancer composed of distinct molecular and pathologic subtypes. Unfortunately, MPM is aggressive, and current therapies for advanced, unresectable disease remain limited to cytotoxic chemotherapy and immunotherapy. Our understanding of the genomic landscape of MPM is steadily growing, while the discovery of effective targeted therapies in MPM has advanced more slowly than in other solid tumors. Given the prevalence of alterations in tumor suppressor genes in MPM, it has been challenging to identify actionable targets. However, efforts to characterize the genetic signatures in MPM over the last decade have led to a range of novel targeted therapeutics entering early-phase clinical trials. In this review, we discuss the advancements made thus far in targeted systemic therapies in MPM and the future direction of targeted strategies in patients with advanced MPM.

Antipodoplanin antibody enhances the antitumor effects of CTLA-4 blockade against malignant mesothelioma by natural killer cells.

Combination immunotherapy with multiple immune checkpoint inhibitors (ICIs) has been approved for various types of malignancies, including malignant pleural mesothelioma (MPM). Podoplanin (PDPN), a transmembrane sialomucin-like glycoprotein, has been investigated as a diagnostic marker and therapeutic target for MPM. We previously generated and developed a PDPN-targeting Ab reagent with high Ab-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). However, the effects of anti-PDPN Abs on various tumor-infiltrating immune cells and their synergistic effects with ICIs have remained unclear. In the present study, we established a novel rat-mouse chimeric anti-mouse PDPN IgG2a mAb (PMab-1-mG2a ) and its core-fucose-deficient Ab (PMab-1-mG2a -f) to address these limitations. We identified the ADCC and CDC activity of PMab-1-mG2a -f against the PDPN-expressing mesothelioma cell line AB1-HA. The antitumor effect of monotherapy with PMab-1-mG2a -f was not sufficient to overcome tumor progression in AB1-HA-bearing immunocompetent mice. However, PMab-1-mG2a -f enhanced the antitumor effects of CTLA-4 blockade. Combination therapy with anti-PDPN Ab and anti-CTLA-4 Ab increased tumor-infiltrating natural killer (NK) cells. The depletion of NK cells inhibited the synergistic effects of PMab-1-mG2a -f and CTLA-4 blockade invivo. These findings indicated the essential role of NK cells in novel combination immunotherapy targeting PDPN and shed light on the therapeutic strategy in advanced MPM.

Efficacy and safety profile of combining antiangiogenic agents with chemotherapy in patients with advanced malignant pleural mesothelioma: A systematic review and meta-analysis of randomized controlled trials.

Several prospective trials had been reported on chemotherapy with or without antiangiogenic agents in patients with advanced malignant pleural mesothelioma (MPM), with diverse results. We performed this systematic review and meta-analysis to evaluate the efficacy and safety of the combination regimen. We systematically identified trials in several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ASCO Abstracts and ESMO Abstracts. All the randomized controlled trials (RCTs) about chemotherapy combined with antiangiogenic agents in advanced MPM were identified. Overall survival (OS) was the primary outcome, while progression-free survival (PFS), overall response rate (ORR) and serious toxicities were the secondary outcomes. Review Manager 5.3 was used to perform the statistical analyses. Stata 12.0 was used to assess the publication bias of egger's test. 5 randomized controlled trials containing 1250 patients were finally included in this analysis. Statistical analyses showed that the addition of antiangiogenic agents to chemotherapy could prolong OS [HR 0.79 (0.71-0.89), p<0.0001] and PFS [HR 0.75 (0.68-0.84), p<0.00001] in advanced MPM, especially in the epithelioid subgroup, with a tolerable toxicity profile. No significant difference was found in the analysis of ORR [HR 1.13 (0.95-1.35), p = 0.18]. Heterogeneity was found in the analyses of PFS and ORR, which might be caused by the limitation in uniform evaluation of tumor response. The combination of antiangiogenic agents with chemotherapy showed superior over chemotherapy alone in patients with advanced MPM. More prospective trials should be warranted to identify patients who would most likely benefit from the combination regimen.

PD-L1 expression complements CALGB prognostic scoring system in malignant pleural mesothelioma.

Programmed death ligand-1 (PD-L1) expression is a predictive biomarker in patients with lung cancer, but its role in malignant pleural mesothelioma (MPM) remains unclear. Evidence suggests that higher PD-L1 expression is correlated with worse survival. CALGB is the main scoring system used to predict the benefit of chemotherapy treatment. This study aimed to determine the prognostic value of PD-L1 expression and its addition to CALGB scoring system in patients with MPM. In this retrospective analysis, we evaluated samples with confirmed locally advanced or metastatic MPM. PD-L1 Tumor Proportional Score (TPS) was determined by immunohistochemistry at diagnosis. 73 patients were included in this study. A cutoff value of 15 was set for a high or low PD-L1 TPS. In total, 71.2% (n=52) and 28.8% (n=21) of individuals harbored low or high PD-L1 expression, respectively. PD-L1High was associated with worse median progression-free Survival (mPFS) [4.9 vs. 10.8 months; HR 2.724, 95% CI (1.44-5.14); p = 0.002] and Overall Survival (OS) [6.0 vs. 20.9 months; HR 6.87, 95% CI (3.4-8.7); p<0.001] compared to patients with PD-L1Low. Multivariate analysis confirmed that PD-L1 expression was an independent factor for PFS and OS in patients with MPM and CALGB score of 5-6. PD-L1 addition to CALGB scale improves its prognostic estimation of MPM survival and should be considered in future research.

Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma.

To assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery. Consecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As asecondary endpoint, reported toxicity was assessed. Atotal of 34localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31patients. Grade3 side effects were experienced by 26.7% of patients and there were no grade4 or 5events observed. Median PFS was 19months. Median OS was 20months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008). IMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as acomponent of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.

Salvage pleurectomy/decortication following immunotherapy for malignant pleural mesothelioma.

Salvage surgery following immunotherapy is a promising treatment option for advanced malignant tumour. However, only a few cases of salvage surgery for malignant pleural mesothelioma (MPM) have been reported. This retrospective study was conducted to assess the feasibility of salvage surgery following immunotherapy for initially unresectabele MPM. Among 61 patients who received pleurectomy/decortication (P/D) for MPM, 7 patients received salvage P/D after immunotherapy. Surgical indication of salvage P/D was conversion to resectability in 5 patients and local relapse in 2 patients, and macroscopic complete resection was achieved in all patients. Although salvage P/D was associated with longer operation time (median, 507 min), higher intraoperative blood loss (median, 2573 mL) and higher morbidity (≥ grade 3, 29%), no patient died after surgery. Radiographic response to immunotherapy was well correlated with pathologic response, as all 4 patients with partial response showed significant pathologic response (viable cells, ≤50%). With the median postoperative follow-up duration of 9.0 months, all patients were alive mostly without tumour recurrence as local recurrence developed in 1 patient. To conclude, salvage P/D after immunotherapy may be a feasible treatment option for selected patients with advanced MPM, which should be validated in future multi-institutional studies. In addition, a long-term follow-up is essential to reveal the clinical benefit achieved with salvage P/D following immunotherapy.

2192P Quality of life (QoL) of patients (pts) with advanced malignant pleural mesothelioma (aMPM) treated in a real-world setting

2192P Quality of life (QoL) of patients (pts) with advanced malignant pleural mesothelioma (aMPM) treated in a real-world setting

Impact of BAP1 mutational status on immunotherapy outcomes in advanced malignant pleural mesothelioma: A single institution experience.

e20537 Background: Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor of mesothelial cells usually diagnosed at advanced stages with dismal prognosis. Most patients progress after 1st line systemic chemotherapy. In the last decade, single or dual agent immune checkpoint inhibitor (ICI) therapy has emerged as a therapeutic option. BAP1 is a commonly mutated tumor suppressor gene in MPM that has been shown to correlate negatively with survival in other solid tumors. We sought to determine the impact of BAP1 mutation on outcomes with ICIs when used as second line systemic therapy. Methods: We retrospectively reviewed a cohort of MPM patients who received ICIs at the Cleveland Clinic foundation between 2017-2022. Patients must have progressed after 1st line systemic chemotherapy prior to ICI. We then compared oncologic outcomes of ICI therapy based on BAP1 mutational status on Next-Generation Sequencing (NGS). End points of interest were overall response rate (ORR) and progression free survival (PFS) while on ICIs. Results: There were a total of 43 MPM patients who received ICIs following progression on pemetrexed/carboplatin (Median age 74 years, IQR 66-81, range 57-92) with a male predominance (M:F ratio 39:4). Histologies included- 58% epithelioid, 28% sarcomatoid and 14% mixed/biphasic histology. Single agent ICI therapy with nivolumab or pembrolizumab was used in 65%. Median follow up was 3 months. BAP1 mutation on NGS was detected in 16%. Other mutated genes included CDKN2A- 7%, BRAF- 5%, MTAP 2% and PTEN 2%. We compared baseline characteristics and outcomes between BAP1 wild type (WT) and BAP1 mutated (MT) groups. Median age at mesothelioma diagnosis were similar 74 vs 70 years (0.3347) with no significant differences in either asbestos or smoking exposure (Table 1). An analysis of outcomes revealed an ORR to ICI of 33% (36% vs 29% respectively [p = 0.9]). PFS was similar between both groups - 4 months [95% CI, 3-NA] for BAP1 WT vs 4 months [95% CI, 2-18] for BAP1 MT group. Conclusions: BAP1 mutation had no prognostic significance on either response rates or disease progression while on ICI therapy in our cohort of advanced MPM patients. The identification of predictive biomarkers for immunotherapy of MPM is an area of unmet clinical need. [Table: see text]

Association of tertiary lymphoid structures with outcomes from PD-1 inhibition in advanced malignant pleural mesothelioma.

e20545 Background: Predictive biomarkers of benefit form immunotherapy in malignant mesothelioma patients remain poorly defined. The 9-15 PROMISE-MESO study (NCT02991482) of the European Thoracic Oncology Platform (ETOP) evaluated second-line pembrolizumab against chemotherapy. Pembrolizumab led to an increased response rate compared to chemotherapy, which did not translate to survival benefits. We evaluated if the presence of tertiary lymphoid structures (TLSs) with different compositions or LRRC15+ immune suppressive fibroblasts could predict the clinical benefit from pembrolizumab. Methods: We performed multiplex immune histochemistry analysis on tumor tissues. 144 patients were included in the clinical trial, from whom, 112 had available tumor tissue for analysis: 55 patients in the chemotherapy arm, and 57 patients in the immune therapy arm. We performed the following panel: calretinin or WT1 (mesothelioma cells), CD20, CD23, CD11c, LRRC15, aSMA, and DAPI. We used the Akoya Vectra Polaris platform for analysis. The IFQuant analytical pipeline developed at the Swiss Institute for Bioinformatics (SIB) was used for analyses. Results: We defined three categories of TLSs: general CD20+ TLSs independent of other markers. CD20/CD23 double-positive as mature TLSs (mTLS), and TLSs with dendritic cells (CD11c+, cTLS). Immune suppressive CAFs were defined as LRRC15+ cells/mm2. CD20+ TLSs were identified in 84% of patients' stroma, with a median of 21 TLSs/tumor tissue and 2 TLSs/mm2. mTLSs were rare, only detected in 10 of the 112 patients (9%). cTLSs with dendritic cells were more frequent and present in 45% of all patients (50/112), and roughly half of the TLS+ patients (53%) had CD11c+ cells detected in TLSs. LRRC15+ cancer-associated fibroblasts (CAFs) were detected in 85% of patients, with a median density of 61 cells/mm2. LRRC15- tumors also contained TLSs but had significantly fewer than LRRC15+ tumors (p = 0.0079). We did not find any significant association between the responses or PFS with TLS, mTLS, and LRRC15+ CAFs. We found inverse association between cTLS levels and response to immune therapy (p = 0.037) but not for PFS. Conclusions: Our data shows that advanced malignant mesotheliomas frequently harbor TLSs, but these TLSs are mostly not activated/mature. The absence of antigen-presenting cells in TLSs, like CD11c dendritic cells, is unexpectedly associated with increased response to pembrolizumab. The high prevalence of immune suppressive LRRC15+ CAFs might explain the low response rate to pembrolizumab and could be linked to the absence of maturation of TLSs. Clinical trial information: EudraCT number: 2016-002062-31 .

Establishment and validation of nomograms to predict survival probability of advanced malignant pleural mesothelioma based on the SEER database and a Chinese medical institution.

The purpose of this study was to build nomograms for predicting the survival of individual advanced pleural mesothelioma (MPM) patients using the Surveillance, Epidemiology, and End Results (SEER) database. The 1251 patients enrolled from the SEER database were randomized (in a 7:3 ratio) to a training cohort and an internal validation cohort. Eighty patients were enrolled from the Harbin Medical University Cancer Hospital as the external validation cohort. Nomograms were constructed from variables screened by univariate or multivariate Cox regression analyses and evaluated by consistency indices (C-index), calibration plots, and receiver operating characteristic (ROC) curves. Patients from the SEER database who received chemotherapy alone and chemoradiotherapy were statistically paired using propensity score matching of the two groups and performed subgroup analysis in the screened variables. The nomograms are well-structured and well-validated prognostic maps constructed from four variables: gender, histology, AJCC stage, and treatment. All individuals were allocated into high-risk versus low-risk groups based on the median risk score of the training cohort, with the high-risk group having worse OS and CSS in all three cohorts (P<0.05). The outcomes of the subgroup analysis indicated that the advanced MPM patients receiving chemotherapy with or without local radiotherapy do not affect OS or CSS. The accurate nomograms to predict the survival of patients with advanced MPM were built and validated based on an analysis of the SEER database with an external validation cohort. The study suggests that the additional local radiotherapy to chemotherapy does not increase the survival benefit of patients.

Abstract 1371: Tumor treating fields exposure causes an imbalance of reactive oxygen homeostasis likely through the cytosolic function of the fanconi′s anemia genes

Abstract The use of Tumor Treating Fields (TTFields) has been shown to significantly benefit patients with non-resectable locally advanced or metastatic glioblastoma and malignant pleural mesothelioma. Although the disruption of mitosis that was initially attributed as the mechanism of tumor cell killing, in subsequent studies, it has been shown that TTFields inhibits DNA damage repair by downregulating DNA repair genes and proteins, including those associated with Fanconi's Anemia (FA). As a result, radiation-induced DNA damage repair is reduced and DNA replication fork protection is impaired, leading to replication stress and replication fork collapse. As the FA genes play a critical role in multiple repair pathways, TTFields is likely to increase susceptibility to other chemo agents besides radiation that cause DNA damage which is repaired by FA-dependent DNA repair and replication fork maintenance pathways in nuclei. In addition to their nuclear role, the FA proteins also regulate mitophagy in the cytosol. Using a panel of non-small cell lung cancer cell lines, it was found that TTFields exposure disrupted the clearance of damaged mitochondria despite the presence of a well-defined membrane markers for autophagosomal destruction of damaged mitochondria, that being PINK1 and parkin. Analysis of electron micrographs revealed disrupted mitochondrial cristae, while radical oxygen metabolism studies identified an imbalance leading to the production of reactive oxygen species (ROS) and ultimately, cell death. The downregulation of key mitochondrial genes including DAPIT, OSCP1, ATP5S, ATP5B and COXIV that are related to electron transport and mitochondrial integrity was confirmed by gene expression analysis. The small molecule dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase, changes the metabolic state of cancer cells from cytoplasmic glycolysis to mitochondrial glucose oxidation, resulting in a decrease in mitochondrial membrane potential and an increase in ROS production in cancer cells. A combination of DCA with TTFields is therefore being investigated as a means of exploiting mitochondrial dysfunction caused by TTFields. The inhibition of mitophagy suggests a new mechanism of action for TTFields exposure tied to the downregulation of the FA pathway genes, the result being both nuclear and cytosolic perturbations in cell homeostasis. This study offers an evidence-based rationale for combining TTFields with various chemotherapy agents that may cause DNA damage, induce replication stress, and expose cells to radical oxygen byproducts of disrupting electron transport chains and the disruption of mitochondrial integrity. Citation Format: Narasimha Kumar Karanam, Michael Story. Tumor treating fields exposure causes an imbalance of reactive oxygen homeostasis likely through the cytosolic function of the fanconi′s anemia genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1371.

The Predictive Value of ERCC1, RRM1, and Thymidylate Synthase in Advanced Malignant Pleural Mesothelioma Patients Treated with Platinum-Based Chemotherapy.

A rare yet severe neoplasia called malignant pleural mesothelioma (MPM) typically manifests itself in advanced stages. Despite some improvements in the treatment of patients with MPM, this malignancy continues to have a detrimental prognosis . The primary goal of the present study was to assess the associatin between ERCC1, RRM1, and thymidylate synthase (TS) expression and disease outcome in patients with malignant pleural mesothelioma (MPM) treated with either pemetrexed plus cisplatin or gemcitabine plus cisplatin. This prospective cohort study was done on ninety-one advanced MPM patients. The patients received either pemetrexed plus platinum (55 of 91) or gemcitabine plus platinum chemotherapy (36 of 91). Tissue biopsy was taken at time of diagnosis. Immunohistochemistry was used to assess the levels of ERCC1, RRM1, and TS transcription in tissue biopsies (paraffin embedded). Based on the findings, 70% of patients with low expression of TS had low expression of ERCC1, and 68% of patients with high expression of TS had high expression of ERCC1, suggesting a significat association between ERCC1 expression and TS expression (p=0.005). However, there was no relation between ERCC1 and RRM1 expression patterns (p= 0.296). In patients underwen platinum-based theraphy (n 91), a significant correlation was detected between low ERCC1 median High-scoring and longer progression time (TTP;9.6 v 5.3 months;P< .001) or overall survival (OS) (OS;18.1 v 9.1 months; P<0.001). A significant correlation was found between low TS protein expression and longer time progression (TTP; 11.8 v 5.4 months; P< .001) or OS (OS; 19.8 v 8.5 months; P <0.001) in patients undergoing pemetrexed plus platinum chemotherapy (n 55). Low RRM1 expression was accompanied by high progression free survival (TTP; 10.6 v 3.8 months) and OS (OS; 20.6 v 8.6 months) in patients receiving gemcitabine plus platinum chemotherapy. Based on the multivariate test results, the independent variables significantly affecting OS were tumor stage (HR: 2.3; 95% CI: 1.1-4.9; p= 0.021) and ERCC1 (HR: 2.7; 95% CI: 1.7-4.3; p < 0.001). Decreased TS protein expression can be indicative of greater responsivness to pemtrexed and of longer TTP and OS in individuals with advanced MPM (locally progressed or metastatic) who are receiving pemetrexed-based chemotheraphy. Low ERCC1 expressions in individuals with advanced MPM can predict increased PFS and OS, as well as a better responsivness to platinum-based chemotherapy. In patients with progressed MPM receiving gemcitabine plus cisplatin chemotherapy, lower RRM1 expression was associated with a better prognosis, longer PFS, and longer OS.

11P Association of VISTA-expressing CD66b-positive neutrophils, with response and survival benefit from pembrolizumab in advanced malignant pleural mesothelioma

V-domain Ig suppressor of T cell activation, VISTA, is a type I transmembrane protein that functions as an immune checkpoint. VISTA can be expressed by a wide range of cell types. Malignant pleural mesothelioma (MPM) is a tumor type with the highest levels of VISTA expression. However, it remains unclear if VISTA could be a predictive or prognostic marker in MPM following PD-1 blockade.

Final results of DIADEM, a phase II study to investigate the efficacy and safety of durvalumab in advanced pretreated malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a cancer with a high mortality rate and few therapeutic options. After platinum-pemetrexed combination, no further promising drug seems to be effective. Immune checkpoint inhibitors may have some activity in pretreated patients and no data are available in this population about durvalumab. DIADEM was a multicenter, open-label, single-arm, phase II trial aimed at evaluating the efficacy and safety of durvalumab. Patients with locally advanced/metastatic MPM who progressed after platinum-pemetrexed chemotherapy were enrolled to receive durvalumab (1500 mg, intravenously Q4W) for 12 months or until evidence of disease progression or unacceptable toxicity. The primary endpoint was the proportion of patients alive and free from progression at 16 weeks (PFS16wks) calculated from treatment initiation. Secondary endpoints were progression-free survival, overall survival, overall response rate, and safety. Sixty-nine patients with a median age of 69 years (range 44-82 years) were enrolled; 62 patients (89.9%) had epithelioid histotype. As first-line treatment, all patients received platinum derivatives-pemetrexed combination (60.9% with carboplatin and 39.1% with cisplatin). As of March 2021, the median follow-up was 9.2 months (interquartile range 5.2-11.1 months). Six patients (8.7%) completed the 12-month treatment; 60 patients discontinued, of whom 42 for progressive disease, and 4 died. Seventeen patients (28.3%; 95% confidence interval 17.5% to 41.4%) were alive or free from progression at 16 weeks. Eleven patients (18.6%) had a grade 3 or 4 treatment-related adverse event (AE), and one (1.4%) had a grade ≥3 immune-related, treatment-related AE. There was one drug-related death. Durvalumab alone in pretreated non-selected MPM did not reach a meaningful clinical activity, showing any new major safety issue signals.

1641TiP Adjuvant nivolumab with chemotherapy in pleural mesothelioma: The NICITA trial

Recently, a dual immunotherapy was approved in unresectable Malignant pleural mesothelioma (MPM). There is, however, no approved standard therapy for the treatment of early-stage MPM. A multimodal therapy, consisting of extended pleurectomy/decortication (eP/D) together with inductive or adjuvant chemotherapy is generally recommended. Considering the immunogenic effects of chemotherapy on the tumor microenvironment, synergistic effects are expected when such a treatment is combined with immune checkpoint inhibitor, as already shown by recent clinical data in patients with advanced MPM.

Cost-effectiveness of nivolumab plus ipilimumab as first-line treatment for American patients with unresectable malignant pleural mesothelioma.

BackgroundThe treatment paradigm of unresectable malignant pleural mesothelioma (MPM) has changed in recent years. Checkmate 743 demonstrate that nivolumab plus ipilimumab showed good clinical benefits compared with chemotherapy in the treatment of MPM. The study is aim to evaluate the cost-effectiveness of Nivolumab plus ipilimumab vs. platinum plus chemotherapy for the first-line treatment of unresectable MPM.MethodsA Markov model was developed to compare the cost and quality-adjusted life-year (QALY) of nivolumab plus ipilimumab and chemotherapy over a 10-year time horizon. Clinical efficacy and safety data were extracted from the CheckMate 743 trials. Health state utilities were obtained from published literature. Costs were collected from an US payer perspective. One-way and probabilistic sensitivity analyses were conducted to explore the impact of uncertainties on the cost-effectiveness's results.ResultsIn the base case analysis, the incremental healthcare costs and QALYs for Nivolumab plus Ipilimumab vs. chemotherapy are $196,604.22 and 0.53, respectively, resulting an incremental cost-effectiveness ratio (ICER) of $372,414.28/QALYs for the model cohort of patients with locally advanced or metastatic MPM. However, Probabilistic sensitivity analysis showed that there was no probability that Nivolumab plus ipilimumab was cost-effective within the fluctuation range of other model parameters in first-line in unresectable MPM. The results of one-way sensitivity analysis showed that the cost of Nivolumab was the most sensitive parameter.ConclusionsThe ICER of Nivolumab plus ipilimumab is above the theoretical willingness-to-pay threshold in the U.S, which suggests that first-line nivolumab plus ipilimumab for unresectable MPM may be not a cost-effective choice.

DREAM3R: Durvalumab with chemotherapy as first-line treatment in advanced pleural mesothelioma—A phase 3 randomized trial.

TPS8599 Background: Combination PD1/CTLA4 immune checkpoint blockade and platinum-pemetrexed (CP) chemotherapy are standard first-line options for the treatment of unresectable malignant pleural mesothelioma (MPM). Two recent, single-arm, phase 2 trials (DREAM and PrE0505) combining the PD-L1 inhibitor durvalumab and standard first line CP both exceeded pre-specified efficacy criteria. The Phase 3 DREAM3R trial aims to determine the effectiveness of including durvalumab with first line CP chemotherapy in advanced MPM. Methods: Treatment-naïve patients with advanced MPM will be randomized (2:1) to either durvalumab 1500 mg every 3 weeks plus chemotherapy (cisplatin 75 mg/m2 or carboplatin AUC 5 and pemetrexed 500 mg/m2) every 3 weeks for 4-6 cycles (Arm A), followed by durvalumab 1500 mg every 4 weeks until disease progression, unacceptable toxicity or patient withdrawal, versus doublet chemotherapy alone for 4-6 cycles with all patients monitored for progression. The target sample size is 480 patients recruited over 27 months, with follow up for an additional 24 months. This provides over 85% power if the true hazard ratio for overall survival (OS) is 0.70, with 2-sided alpha of 0.05, assuming a median OS of 15 months in the control group. Key eligibility criteria include: MPM of any histological subtype; measurable disease per RECIST 1.1 modified for mesothelioma (mRECIST 1.1); ECOG PS 0-1; and adequate hematologic, renal, and liver function. Exclusions: Prior systemic anticancer treatment for MPM, diagnosis based solely on cytology or fine needle aspiration biopsy, contraindication to immunotherapy or conditions requiring immunosuppressive agents or corticosteroids. Patients will be further stratified at randomization by: Age (18-70 years vs. &gt; 70), sex, histology (epithelioid vs. non-epithelioid), planned platinum (cisplatin vs. carboplatin) and geographic region (USA vs. ANZ). The primary endpoint is OS. Secondary endpoints include progression-free survival; objective tumor response; adverse events; health-related quality of life; and healthcare resource use in ANZ. Tertiary correlative objectives aim to further explore and validate potential prognostic and/or predictive biomarkers (including those identified in the DREAM and PrE0505 studies, PD-L1 expression, tumor mutation burden, genomic characteristics, and HLA subtypes) via tissue and serial blood samples. An imaging databank will be assembled for validation of radiological measures of response, and studies of possible radiomic biomarkers in mesothelioma. The study is active and enrolling in both ANZ and in the US. Clinical trial information: NCT04334759 and ACTRN 12620001199909.

Immunotherapy in malignant pleural mesothelioma: a long story ended in success

Malignant pleural mesothelioma (MPM) is an aggressive and rare disease, mainly due to asbestos exposure, characterized by a poor prognosis. For almost two decades, platinum-based chemotherapy has been the only approved therapeutic regimen for first-line MPM, with an overall survival of 12 months. In the last years, the therapeutic scenario of different tumor types, including MPM, has dramatically changed due to immune checkpoint inhibition. The promising results of this approach have promoted new efforts into clinical research, and many trials investigating novel therapeutic combinations are currently ongoing. The aim of the present review is to provide a comprehensive overview of the most promising immunotherapeutic-based strategies currently under investigation for advanced MPM.

Treatment patterns and outcomes in older patients with advanced malignant pleural mesothelioma: Analyses of Surveillance, Epidemiology, and End Results-Medicare data.

BackgroundMalignant mesothelioma is a rare neoplasm associated with asbestos exposure. Characterizing treatment patterns and outcomes of older patients with advanced malignant pleural mesothelioma (MPM) is important to understand the unmet needs of this population.AimTo evaluate the demographic and clinical characteristics, treatment patterns, and outcomes among older patients diagnosed with advanced MPM in the United States between 2007 and 2013.MethodsThis was a retrospective cohort study using Surveillance, Epidemiology, and End Results (SEER) data linked with Medicare claims. We included patients who were age 66 or older at the time of their primary MPM diagnosis between 2007 and 2013 and followed them through 2014. Treated patients who received first‐line chemotherapy with pemetrexed and platinum within 90 days of diagnosis, second‐line, or third‐line therapy were identified for evaluation of outcomes.ResultsThere were 666 older patients with advanced MPM, of whom 82% were male, 87% White, 78% stage IV, and 70% had no mobility limitation indicators at diagnosis. There were 262 patients who received first‐line chemotherapy for advanced MPM, most of whom (80%; n = 209) received pemetrexed‐platinum. Of these 209 patients, 41% (n = 86) initiated second‐line therapy, and 26% (n = 22) initiated third‐line therapy. Median overall survival for the cohort of 209 patients was 7.2 months. Patients with epithelioid histology had better median overall survival (12.2 months) compared with other histologies (4.4–5.6 months). Within 90 days of diagnosis of advanced MPM, 78% of patients were hospitalized, 52% visited an emergency department, and 21% had hospice care. The 2‐year cost of care was over $100 000 for all patients with advanced MPM treated with first‐line pemetrexed‐platinum.ConclusionsAlthough first‐line systemic anticancer treatment was generally consistent with guidelines (e.g., pemetrexed‐platinum), poor patient outcomes highlight the need for effective treatment options for older patients with advanced MPM.