Immunotherapy for advanced and recurrent malignant pleural mesothelioma.

OBJECTIVES: This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects of immune checkpoint inhibitors (single-agent or combination therapy) in people with advanced malignant pleural mesothelioma in a first-line or salvage setting.

Use of agent-based modeling to analyze potential non-occupational exposures to asbestos of the general population of Sibaté (Colombia).

Previous studies conducted in the municipality of Sibaté (Colombia) have revealed alarming findings regarding asbestos exposure in the region, as it is the site of the country's first mesothelioma cluster. Non-occupational asbestos exposure events were identified in this population, and the young age of the mesothelioma cases at the time of diagnosis suggests that asbestos exposure occurred during their childhood. The creation of landfilled zones in the 1980s and 1990s, utilizing friable asbestos among other disposed materials, may have been a significant asbestos exposure event contributing to the elevated number of mesothelioma cases. The objective of this study was to model various historical exposure scenarios related to the creation and interaction of the population with asbestos-contaminated landfilled zones, in light of the absence of asbestos monitoring in the region. The models utilized a multi-agent simulation process, focusing on a 10-year period (1986-1995). Various relevant variables were incorporated into the modeling process, including, for example, the number of children playing in the landfilled zones and the percentage of children carrying asbestos fibers on their clothes to their homes. A range of values for input data for the models were utilized, spanning from very conservative numbers to exposure-promoting values. The average number of exposed individuals estimated over 750 simulation runs, considering all scenarios, was 571, with a range between 31 and 3800 exposed individuals. The use of multi-agent simulation models can assist the understanding of past asbestos exposure events, especially when there is a lack of environmental surveillance data.

Trends in Asbestos Exposure and Malignant Mesothelioma Incidence in Emilia-Romagna Italy: A Retrospective Study 1996-2023.

Malignant mesothelioma (MM) is a rare but lethal cancer strongly associated with asbestos exposure. This retrospective study examines trends in asbestos exposure in Emilia-Romagna, Northern Italy. Between 1996 and 2023, 3,513 cases of MM were recorded, predominantly in males (72%) and in older than 65 years (79%). Occupational exposure accounted for 82% of cases, with a significant increase observed over time from 71% to 88% in the most recent period. A greater definition of professional exposure indicates that certain exposure has gone from 49% in the first period to 62% and 58% in the last two periods; probable exposure showed a decrease from 21% to 16% while possible exposure decreased from 16% to 13%. Familiar exposure remained relatively constant at around 8%, environmental exposure showed a slight decrease from 4% to 2%, while non-occupational exposure remained stable at 2%. Among patients with exclusively occupational exposure (1,826 cases), 87% were male and aged between 65 and 75 years (36%) and 75+ (41%). The exposure rates for the province of residence see the province of Reggio Emilia with the highest occupational exposure rate (2.5 x 100,000 residents), followed by Ravenna (2.3 x 100,000 residents) and Parma and Piacenza which have similar exposure rates with 2.2 x 100,000 residents. Professional sectors such as construction, railway maintenance and metalworking are identified as high-risk industries. Despite efforts to mitigate exposure, non-occupational and environmental exposures persist. The study highlights the importance of continuous surveillance and exposure monitoring to guide effective interventions and legal recognition of MM.

A gut microbiota rheostat forecasts responsiveness to PD-L1 and VEGF blockade in mesothelioma.

Malignant mesothelioma is a rare tumour caused by asbestos exposure that originates mainly from the pleural lining or the peritoneum. Treatment options are limited, and the prognosis is dismal. Although immune checkpoint blockade (ICB) can improve survival outcomes, the determinants of responsiveness remain elusive. Here, we report the outcomes of a multi-centre phase II clinical trial (MiST4, NCT03654833) evaluating atezolizumab and bevacizumab (AtzBev) in patients with relapsed mesothelioma. We also use tumour tissue and gut microbiome sequencing, as well as tumour spatial immunophenotyping to identify factors associated with treatment response. MIST4 met its primary endpoint with 50% 12-week disease control, and the treatment was tolerable. Aneuploidy, notably uniparental disomy (UPD), homologous recombination deficiency (HRD), epithelial-mesenchymal transition and inflammation with CD68+ monocytes were identified as tumour-intrinsic resistance factors. The log-ratio of gut-resident microbial genera positively correlated with radiological response to AtzBev and CD8+ T cell infiltration, but was inversely correlated with UPD, HRD and tumour infiltration by CD68+ monocytes. In summary, a model is proposed in which both intrinsic and extrinsic determinants in mesothelioma cooperate to modify the tumour microenvironment and confer clinical sensitivity to AtzBev. Gut microbiota represent a potentially modifiable factor with potential to improve immunotherapy outcomes for individuals with this cancer of unmet need.

Mesothelioma: molecular pathology and biomarkers.

Diffuse mesotheliomas are characterized by recurrent genomic alterations involving tumor suppressors and epigenetic regulators such as BAP1, CDKN2A, MTAP, and NF2. Depending on the differential diagnosis as informed by histologic assessment, one can apply the appropriate immunohistochemical and/or molecular panels to reach the correct pathologic diagnosis, sometimes even in cases with limited tissues. Biomarkers aid in the diagnosis of mesothelioma in the following scenarios: 1) For a tumor that is overtly malignant, how can one distinguish mesothelioma from other tumors? 2) For a mesothelial proliferation, how can one distinguish mesothelioma from a reactive process? To distinguish mesotheliomas from carcinomas, at least two positive and two negative markers are currently recommended. To distinguish sarcomatoid mesothelioma from pleomorphic carcinoma, even more markers-and sometimes molecular testing-are needed. To distinguish mesothelioma from reactive mesothelial conditions, useful immunohistochemical biomarkers include BAP1, MTAP, and merlin, which serve as surrogates for the corresponding gene mutation status. In patients with unusual clinical history, for tumors with a peculiar microscopic appearance, and/or in cases with an equivocal immunophenotypic profile, molecular testing can help to exclude mimics and to confirm the pathologic diagnosis.

[Erionite, an exposure factor linked to pleural mesothelioma]. / L'érionite, un facteur expositionnel lié au mésothéliome pleural.

Mesotheliomas are neoplasia developed from the mesothelium, a layer covering the viscera (visceral layer) and the cavity where the organs are (parietal layer). The best known, and the most frequently encountered is the pleural mesothelioma. This disease has a close link with exposure to asbestos, a mineral fibre now banned in several countries. However, other exposure factors have also been incriminated, including another one recognised as a certain carcinogenic agent for several years now : erionite. We present the case of a patient with pleural mesothelioma whose exposure to erionite could be demonstrated. The presentation of this clinical case will be complemented by a literature review on this less known and mostly environmental exposure, contrary to asbestos which is mostly professional.

Les mésothéliomes sont des néoplasies se développant à partir du mésothélium, feuillet recouvrant, d'une part, les viscères (feuillet viscéral) et, d'autre part, la cavité où se trouvent les organes (feuillet pariétal). Le plus connu, et le plus fréquemment rencontré, est le mésothéliome pleural. Cette maladie a un lien étroit avec l'exposition à l'amiante, fibre minérale maintenant interdite dans plusieurs pays. Cependant, d'autres facteurs expositionnels ont également été incriminés, dont un autre reconnu comme cancérogène certain depuis plusieurs années : l'érionite. Nous présentons le cas d'un patient atteint d'un mésothéliome pleural pour lequel une exposition à l'érionite a pu être étayée. La présentation du cas clinique sera complétée d'une revue de la littérature sur cette exposition particulière moins connue et majoritairement environnementale, contrairement à l'amiante dont l'exposition est majoritairement professionnelle.

[Malignant mesothelioma of the vaginal testis: diagnostic and therapeutic considerations]. / Le mésothéliome malin de la vaginale testiculaire : aspects diagnostiques et thérapeutiques.

Mesothelioma of the testicular vagina is a rare malignant tumour, most often discovered by chance. The rarity of this type of tumour has not led to the development of specific guidelines. Median survival is estimated at 30 months. The lack of data and official recommendations makes surgical and medical management and follow-up difficult. Men who have not undergone radical orchiectomy die very rapidly after diagnosis. The remission rate at 1 year post-orchidectomy is 47 %, the recurrence rate at 1 year is 53 % and 92 % of relapses occur within 5 years post-operatively. The treatment option of hemiscrotectomy in the first instance has rarely been used; a second-look resection with negative margins may be proposed. The usefulness of adjuvant chemotherapy and/or radiotherapy has not been clearly demonstrated. Local recurrence is accompanied by metastasis in 85 % of cases. In the case of metastatic cancer (15 %), the retro-peritoneal, inguinal and iliac lymph nodes may be invaded. Follow-up by injected thoraco-abdomino-pelvic CT scan is recommended every 3 months for 2 years, then once a year for 3 years, for a total of 5 years of close follow-up. The long-term recurrence rate is 3 %.

Le mésothéliome de la vaginale testiculaire est une tumeur maligne rare et souvent de découverte fortuite. Sa rareté d'apparition n'a pas permis de développer des recommandations spécifiques. La survie médiane est estimée à 30 mois. Le manque de recommandations officielles rend sa prise en charge chirurgicale, médicale et son suivi difficiles. Les hommes n'ayant pas bénéficié d'orchidectomie radicale décèdent très rapidement après le diagnostic. Le taux de rémission à 1 an post-orchidectomie est de 47 %, le taux de récurrence à 1 an est de 53 % et 92 % des rechutes se font endéans les 5 ans post-opératoires. L'option thérapeutique par hémi-scrotectomie en première intention a rarement été pratiquée, une résection de «second look¼ en marges saines peut être proposée. L'utilité d'une chimiothérapie et/ou d'une radiothérapie adjuvante n'a pas été clairement démontrée. Une rechute locale est accompagnée de métastases dans 85 % des cas. En cas de cancer d'emblée métastatique (15 %), les relais ganglionnaires rétro-péritonéaux, inguinaux et iliaques peuvent être envahis. Un suivi par scanner thoraco-abdomino-pelvien injecté est recommandé tous les 3 mois pendant 2 ans, puis 1 fois par an pendant 3 ans pour un total de 5 ans. Le taux de récidive au long cours est de 3 %.

Enhancing the immunogenicity of Wilms tumor 1 epitope in mesothelioma cells with immunoproteasome inhibitors.

The immunogenicity of cancer cells is influenced by several factors, including the expression of the major histocompatibility complex class I (MHC-I), antigen expression, and the repertoire of proteasome-produced epitope peptides. The malignant pleural mesothelioma cell line ACC-MEOS-4 (MESO-4) expresses high levels of MHC-I and Wilms tumor 1 (WT1) tumor antigens. Using a functional T cell reporter assay specific for the HLA-A*24:02 restricted WT1 epitope (WT1235, CMTWNQMNL), we searched for factors that augmented the immunogenicity of MESO-4, focusing on proteasomes, which have a central role in the antigen processing machinery. ONX-0914, a selective inhibitor of the immunoproteasome subunit ß5i, enhanced immunogenicity dose-dependently at low concentrations without cytotoxicity. In addition, CD8+ T lymphocytes recognizing WT1 showed greater cytotoxicity against MESO-4 pre-treated with ONX-0914. MESO-4 expresses a standard proteasome (SP) and immunoproteasome (IP). Notably, IP has distinct catalytic activity from SP, favoring the generation of antigenic peptides with high affinity for MHC-I in antigen-presenting cells and cancer cells. In vitro, immunoproteasome digestion assay and mass spectrometry analysis showed that IP cleaved WT1235 internally after the hydrophobic residues. Importantly, this internal cleavage of the WT1235 epitope was mitigated by ONX-0914. These results suggest that ONX-0914 prevents the internal destructive cleavage of WT1235 by IP, thereby promoting the specific presentation of the WT1 epitope by MESO-4. In conclusion, selective IP inhibitors might offer a means to modulate cancer cell immunogenicity by directing the presentation of particular tumor epitopes.

Randomized trial of anetumab ravtansine and pembrolizumab compared to pembrolizumab for mesothelioma.

PURPOSE: The mesothelin-targeting antibody-drug conjugate anetumab ravtansine was evaluated in combination with the programmed cell death-1 (PD-1) inhibitor pembrolizumab based on the common expression of mesothelin and reports of activity in mesothelioma. PATIENTS AND METHODS: A phase 1 safety run-in of the combination of anetumab ravtansine (6.5 mg/kg iv q3weeks) and pembrolizumab (200 mg, IV q3weeks) was conducted, followed by a phase 2 randomization to the combination or pembrolizumab alone at medical centers across the United States and Canada in the National Cancer Institute's Experimental Therapeutics Clinical Trials Network. Patients with pleural mesothelioma that expressed mesothelin and had previously received platinum-based therapy were eligible. RESULTS: In phase 1 (n = 12) only one dose limiting toxicity was observed and the rules for dose reduction were not met. In phase 2, there was no difference in the confirmed response rates between the combination group (n = 18, 2 partial responses [PR], 11 %) and the pembrolizumab group (n = 17, 1 PR, 6 %; z = -0.5523, p = 0.29116). The median PFS was 12.2 months (95 % CI 5.1-not evaluable [NE]) for the combination, and 3.9 months for pembrolizumab (95 % CI 2.1-NE)(HR=0.55, p = 0.20). Patients with high baseline levels of soluble mesothelin who received anetumab ravtansine had a median PFS of 5 months. CONCLUSIONS: The numeric difference in PFS between treatment groups was not statistically significant, likely related to a smaller than planned sample size. High levels of soluble mesothelin should potentially be considered to select against the use of mesothelin-targeting therapies in development that are neutralized by soluble mesothelin.

Asbestos Surveillance Program Aachen (ASPA): Cancer mortality among asbestos exposed power industry workers.

BACKGROUND: The time between initial asbestos exposure and asbestos-related disease can span several decades. The Asbestos Surveillance Program aims to detect early asbestos-related diseases in a cohort of 8,565 power industry workers formerly exposed to asbestos. RESEARCH QUESTION: How does asbestos exposure patterns affect cancer mortality and the duration of latency until death? METHODS: A mortality follow-up was conducted with available vital status for 8,476 participants (99 %) and available death certificates for 89.9 % of deceased participants. Standardised mortality ratios (SMR) were calculated for asbestos-related cancers. The SMR of mesothelioma and lung cancer were stratified by exposure duration, cumulative asbestos exposure and smoking. The effect of age at first exposure, cumulative asbestos exposure and smoking on the duration of latency until death was examined using multiple linear regression analysis. RESULTS: The mortality risk of mesothelioma (n = 104) increased with cumulative asbestos exposure but not with exposure duration; the highest mortality (SMR: 23.20; 95 % CI: 17.62-29.99) was observed in participants who performed activities with short extremely high exposures (steam turbine revisions). Lung cancer mortality (n = 215) was not increased (SMR: 1.03; 95 % CI: 0.89-1.17). Median latency until death was 46 (15-63) years for mesothelioma and 44 (15-70) years for lung cancer and deaths occurred between age 64 and 82 years. Latency until death was not influenced by age at first exposure, cumulative exposure, or smoking. CONCLUSION: Cumulative dose seems to be more appropriate than exposure duration for estimating the risk of mesothelioma death. Additionally, exposure with high cumulative doses in short time should be considered. Since only lung cancer mortality, not incidence, was recorded in this study, lung cancer risk associated with asbestos exposure could not be assessed and the lung cancer mortality was lower than expected probably due to screening effects and improved treatments. The critical time window of death from asbestos-related cancer is between the seventh and ninth decade of life. Future studies should further explore the concept of latency, especially since large ranges are reported throughout the literature.

Unleashing precision: A review of targeted approaches in pleural mesothelioma.

This review delves into the intricate landscape of pleural mesothelioma (PM), emphasizing the need for nuanced therapeutic strategies. While platinum-based chemotherapy remains a cornerstone, the advent of immune checkpoint inhibitors (ICIs), notably through the Checkmate 743 trial, has reshaped treatment paradigms. Challenges persist due to patient heterogeneity and a lack of specific biomarkers. Targeting genotypic and phenotypic alterations emerges as a promising avenue, demanding precision oncology in this rare disease. CDKN2A loss, prevalent in PM, may respond to CDK4/6 inhibitors. Defects in MMR and HR suggest tailored approaches with ICI or PARP inhibitors, respectively. Ongoing trials explore novel inhibitors and promising targets like mesothelin. Implementing these strategies requires overcoming challenges in patient selection, combination therapies, biomarker identification, and cost considerations. Collaboration is crucial for transforming these insights into impactful clinical interventions, heralding the era of personalized and precision medicine for PM.

Volatile organic compound analysis of malignant pleural mesothelioma chorioallantoic membrane xenografts.

Malignant pleural mesothelioma (MPM) is an aggressive cancer associated with asbestos exposure. MPM is often diagnosed late, at a point where limited treatment options are available, but early intervention could improve the chances of successful treatment for MPM patients. Biomarkers to detect MPM in at-risk individuals are needed to implement early diagnosis technologies. Volatile organic compounds (VOCs) have previously shown diagnostic potential as biomarkers when analysed in MPM patient breath. In this study, chorioallantoic membrane (CAM) xenografts of MPM cell lines were used as models of MPM tumour development for VOC biomarker discovery with the aim of generating targets for investigation in breath, biopsies or other complex matrices. VOC headspace analysis of biphasic or epithelioid MPM CAM xenografts was performed using solid-phase microextraction and gas chromatography-mass spectrometry. We successfully demonstrated the capture, analysis and separation of VOC signatures from CAM xenografts and controls. A panel of VOCs was identified that showed discrimination between MPM xenografts generated from biphasic and epithelioid cells and CAM controls. This is the first application of the CAM xenograft model for the discovery of VOC biomarkers associated with MPM histological subtypes. These findings support the potential utility of non-invasive VOC profiling from breath or headspace analysis of tissues for detection and monitoring of MPM.

Chemotherapy increases CDA expression and sensitizes malignant pleural mesothelioma cells to capecitabine treatment.

The combination of cisplatin and pemetrexed remains the gold standard chemotherapy for malignant pleural mesothelioma (MPM), although resistance and poor response pose a significant challenge. Cytidine deaminase (CDA) is a key enzyme in the nucleotide salvage pathway and is involved in the adaptive stress response to chemotherapy. The cytidine analog capecitabine and its metabolite 5'-deoxy-5-fluorocytidine (5'-DFCR) are converted via CDA to 5-fluorouracil, which affects DNA and RNA metabolism. This study investigated a schedule-dependent treatment strategy, proposing that initial chemotherapy induces CDA expression, sensitizing cells to subsequent capecitabine treatment. Basal CDA protein expression was low in different mesothelioma cell lines but increased in the corresponding xenografts. Standard chemotherapy increased CDA protein levels in MPM cells in vitro and in vivo in a schedule-dependent manner. This was associated with epithelial-to-mesenchymal transition and with HIF-1alpha expression at the transcriptional level. In addition, pretreatment with cisplatin and pemetrexed in combination sensitized MPM xenografts to capecitabine. Analysis of a tissue microarray (TMA) consisting of samples from 98 human MPM patients revealed that most human MPM samples had negative CDA expression. While survival curves based on CDA expression in matched samples clearly separated, significance was not reached due to the limited sample size. In non-matched samples, CDA expression before but not after neoadjuvant therapy was significantly associated with worse overall survival. In conclusion, chemotherapy increases CDA expression in xenografts, which is consistent with our in vitro results in MPM and lung cancer. A subset of matched patient samples showed increased CDA expression after therapy, suggesting that a schedule-dependent treatment strategy based on chemotherapy and capecitabine may benefit a selected MPM patient population.

Clinical investigation of former workers exposed to asbestos: the health surveillance experience of an Italian University Hospital.

Background: The need for health surveillance of former workers exposed to asbestos was provided by law in Italy after the asbestos ban in 1992. Objectives: We describe the results of the health surveillance of former workers exposed to asbestos, conducted over 27 years, from 1994 to 2020, at the Operative Unit of Occupational Medicine of the University Hospital of Bari. Materials and methods: We adopted the health surveillance protocol, which was validated at the national level in 2018. Results: A total of 1,405 former workers exposed to asbestos were examined. We proceeded with diagnosing pathologies in 339 cases (24% of the cohort subjected to surveillance), with diagnoses of some cases involving multiple pathologies. Specifically, pleural plaques were diagnosed in 49.2% of the 339 cases, asbestosis in 35.9%, malignant pleural mesothelioma (MPM) in 20.3%, mesothelioma of the vaginal tunic of the testis (MTVT) in 9.1%, lung cancer in 5.8%, and laryngeal cancer in 0.8%. Conclusion: Despite the 1992 asbestos ban, asbestos-related diseases remain a serious public health issue. It is important to establish criteria that ensure the health surveillance of formerly exposed workers minimizes costs, reduces the number of invasive examinations, and optimizes achievable results.

Living with mesothelioma: a systematic review of mental health and well-being impacts and interventions for patients and their informal carers.

OBJECTIVES: Mesothelioma is an aggressive cancer predominantly affecting the lung and abdominal linings. It can have a unique impact on mental health and well-being (MHWB) due to its incurability, poor prognosis and asbestos-exposure causation. This review's aims were to identify/synthesise international evidence on mesothelioma's MHWB impacts; explore MHWB interventions used by patients and carers; and identify evidence of their effectiveness. DESIGN: Systematic review. DATA SOURCES: Databases, searched March 2022 and March 2024, were MEDLINE; CINAHL; PsycINFO; Cochrane Library; ASSIA. ELIGIBILITY CRITERIA: We included study designs focusing on psychological impacts of living with mesothelioma and MHWB interventions used by patients and informal carers, published in English since January 2002. DATA EXTRACTION AND SYNTHESIS: A team of reviewers screened included studies using standardised methods. Quality was assessed using validated tools: Mixed-Methods Appraisal tool for primary research and Joanna Briggs Institute Critical Appraisal Checklist for Systematic Reviews. RESULTS: Forty-eight studies met the inclusion criteria: 20 qualitative, 16 quantitative, nine reviews, two mixed-methods, one combined systematic review/qualitative study. UK studies predominated. Many MHWB impacts were reported, including traumatic stress, depression, anxiety and guilt. These were influenced by mesothelioma's causation, communication issues and carer-patient relational interactions. Participants used wide-ranging MHWB interventions, including religious/spiritual practice; talking to mental-health professionals; meaning-making. Some strategies were presented as unhelpful, for example, denial. Participants reported lack of access to support. CONCLUSIONS: Most qualitative studies were rated high quality. The quality of the quantitative studies and reviews varied. The sparse literature regarding MHWB in mesothelioma means more research is needed into impacts on patients and carers, including trauma. To enable access to evidence-based support, research is recommended concerning MHWB interventions' effectiveness in mesothelioma. PROSPERO REGISTRATION NUMBER: CRD42022302187.

Incidental Diagnosis of Malignant Peritoneal Mesothelioma During Liver Transplantation Surgery: A Case Report.

BACKGROUND Malignant peritoneal mesothelioma (MPM) is a rare, lethal tumor of serous membranes. The most common factor reported in association with MPM is asbestos exposure, while viral infections, genetic predisposition, paraneoplastic syndrome, and altered immunity have been described as well. The diagnosis can be challenging among those with lower tumor burden as well as nonspecific symptoms, and it is not unusual to discover the diagnosis incidentally. CASE REPORT A middle-aged woman with decompensated cirrhosis underwent extensive pre-transplant workup, showing no evidence of malignancy. She had a personal history of asbestos exposure and family history of MPM in the extended family. During transplant surgery, a few peritoneal nodules were noted, leading to termination of the procedure. Pathological analysis confirmed malignant MPM. A multidisciplinary discussion led to following a conservative treatment approach without any intervention, due to higher risk of worsening hepatic decompensation associated with peritonectomy and intraperitoneal chemotherapy. The patient's hepatic decompensation resolved 6 months after the aborted liver transplant operation. Since the diagnosis of MPM, positron emission tomography scans have shown no recurrence of MPM for 3 consecutive years. CONCLUSIONS This is the first case of MPM diagnosed incidentally during a liver transplantation surgery. This case highlights the challenges in the diagnosis and management of MPM in a patient with decompensated liver disease. A multidisciplinary approach and following a consensus decision led to prolonged survival in the described patient.

Real-World efficacy and safety of combination nivolumab plus ipilimumab for Untreated, Unresectable, pleural Mesothelioma: The Meso-Immune (GFPC 04-2021) trial.

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.