UV1 telomerase vaccine with ipilimumab and nivolumab as second line treatment for pleural mesothelioma - A phase II randomised trial

PURPOSE

The NIPU-trial investigates the effect of adding the telomerase vaccine UV1 to treatment with ipilimumab and nivolumab for patients with pleural mesothelioma (PM).

METHODS

In this phase 2 open-label trial, patients with PM progressing after first-line chemotherapy were randomised to receive ipilimumab and nivolumab alone (arm B) or combined with UV1 (arm A). The primary endpoint was progression-free survival (PFS) as determined by BICR. It was estimated that 69 PFS events were needed to detect a hazard ratio (HR) of 0.60 with 80% power and a one-sided alpha level of 0.10.

RESULTS

118 patients were randomised. The median PFS determined by blinded independent central review (BICR) was 4.2 months (95%CI 2.9-9.8) in arm A and 4.7 months (95%CI 3.9-7.0) in arm B (HR 1.01, 80%CI 0.75-1.36 P = 0.979), after a median follow-up of 12.5 months (95%CI 9.7-15.6). The investigator-determined median PFS was 4.3 months (95%CI 3.0-6.8) in arm A and 2.9 months (95%CI 2.4-5.5) in arm B (HR 0.60, 80%CI 0.45-0.81 P = 0.025). Confirmed objective response rate (ORR) by BICR was 31% in arm A and 16% in arm B (odds ratio 2.44 80%CI 1.35-4.49 P = 0.056). After a median follow-up time of 17.3 months (95%CI 15.8-22.9), the OS was 15.4 months (95%CI 11.1-22.6) in arm A and 11.1 months (95%CI 8.8-18.1) in arm B, (HR 0.73, 80%CI 0.53-1.0, P = 0.197).

CONCLUSION

The primary endpoint was not met. Predefined analyses of response rates are in favour of adding the vaccine.

Current State-of-the-Art Therapy for Malignant Pleural Mesothelioma and Future Options Centered on Immunotherapy

Malignant pleural mesothelioma (MPM) is a locally aggressive disease related to asbestos exposure with a median survival for untreated patients of 4-8 months. The combination of chemotherapy based on platinum and antifolate is the standard treatment, and the addition of bevacizumab adds two months to median survival. Recently, in first-line treatment, immunotherapy combining nivolumab with ipilimumab has been shown to be superior to chemotherapy in the CheckMate-743 study in terms of overall survival (18.1 months), leading to its approval by the FDA and EMA. The positive results of this study represent a new standard of treatment for patients with MPM; however, not all patients will benefit from immunotherapy treatment. In an effort to improve the selection of patient candidates for immunotherapy for different tumors, biomarkers that have been associated with a greater possibility of response to treatment have been described. MPM is a type of tumor with low mutational load and neo-antigens, making it a relatively non-immunogenic tumor for T cells and possibly less susceptible to responding to immunotherapy. Different retrospective studies have shown that PD-L1 expression occurs in 20-40% of patients and is associated with a poor prognosis; however, the predictive value of PD-L1 in response to immunotherapy has not been confirmed. The purpose of this work is to review the state of the art of MPM treatment in the year 2023, focusing on the efficacy results of first-line or subsequent immunotherapy studies on patients with MPM and possible chemo-immunotherapy combination strategies. Additionally, potential biomarkers of response to immunotherapy will be reviewed, such as histology, PD-L1, lymphocyte populations, and TMB.

Expression of TILs and Patterns of Gene Expression from Paired Samples of Malignant Pleural Mesothelioma (MPM) Patients

MPM is an aggressive disease with an immunosuppressive tumor microenvironment, and interest in exploring immunotherapy in this disease has been increasing. In the first line of treatment, the combination of nivolumab and ipilimumab demonstrated an improvement in survival over chemotherapy. The presence of TILs has been recognized as a marker of antitumor immune response to chemotherapy in solid tumors. The aim of our study is to identify the effect of treatment on immune cells and the immune gene profile in MPM. We investigated the changes in expression of TILs in 10 human MPM paired tumor tissues using immunohistochemistry and gene expression analysis from paired untreated and treated samples. In this small series, we demonstrated that during the evolution of disease without any treatment there was an increase in the inflammatory component in tumor samples. After systemic treatment there was a decrease in the number of TILs. We observed that after systemic treatment or disease progression immune gene signatures were suppressed. Our integrated analysis of paired samples with immune profile and genomic changes on MPM suggested that during the evolution of the disease the immune system tends to switch, turning off with treatment.

Efficacy and safety of nivolumab for patients with pre-treated type B3 thymoma and thymic carcinoma: results from the EORTC-ETOP NIVOTHYM phase II trial

BACKGROUND

Thymic malignancies are rare intrathoracic tumors, which may be aggressive and difficult to treat. They represent a therapeutic challenge in the advanced/metastatic setting, with limited treatment options after the failure of first-line platinum-based chemotherapy. They are frequently associated with autoimmune disorders that also impact oncological management.

MATERIALS AND METHODS

NIVOTHYM is an international, multicenter, phase II, two-cohort, single-arm trial evaluating the activity and safety of nivolumab [240 mg intravenously (i.v.) q2 weeks] alone or with ipilimumab (1 mg /kg i.v. q6 weeks) in patients with advanced/relapsed type B3 thymoma or thymic carcinoma, after exposure to platinum-based chemotherapy. The primary endpoint is progression-free survival rate at 6 months (PFSR-6) based on RECIST 1.1 as per independent radiological review.

RESULTS

From April 2018 to February 2020, 55 patients were enrolled in 15 centers from 5 countries. Ten patients (18%) had type B3 thymoma and 43 (78%) had thymic carcinoma. The majority were male (64%), and the median age was 58 years. Among the 49 eligible patients who started treatment, PFSR-6 by central review was 35% [95% confidence interval (CI) 22% to 50%]. The overall response rate and disease control rate were 12% (95% CI 5% to 25%) and 63% (95% CI 48% to 77%), respectively. Using the Kaplan-Meier method, median progression-free survival and overall survival by local assessment were 6.0 (95% CI 3.1-10.4) months and 21.3 (95% CI 11.6-not estimable) months, respectively. In the safety population of 54 patients, adverse events (AEs) of grade 1/2 were observed in 22 (41%) patients and grade 3/4 in 31 (57%) patients. Treatment-related AEs of grade 4 included one case of neutropenia, one case of immune-mediated transaminitis, and two cases of myocarditis.

CONCLUSIONS

Nivolumab monotherapy demonstrated an acceptable safety profile and objective activity, although it has been insufficient to meet its primary objective. The second cohort of NIVOTHYM is currently ongoing to assess the combination of nivolumab plus ipilimumab.

Overview of Checkpoint Inhibitors Mechanism of Action: Role of Immune-Related Adverse Events and Their Treatment on Progression of Underlying Cancer

In recent years, immunotherapy-based regimens have been included into the treatment's algorithm of several cancer types. Programmed death-1 (PD-1) and cytotoxic T lymphocyte antigen-4 (CTLA-4) interact with their ligands found on the surface of antigen presenting cells (APC) or tumor cells (PD-L1/2 and CD80/86). Through these interactions, stimulatory or inhibitory signals are established. Immune checkpoint inhibitors (ICIs), block these interactions, and when administered not only as monotherapy but also as part of combination regimens, have shown to improve survival results in multiple advanced cancers leading to an increasing number of patients treated with ICI and, as a consequence, a rise in the number of patients developing immune-related adverse events (irAEs). Presence of irAEs has been associated with greater benefit from treatment, especially when blocking PD-L1. Recent data suggests that treatment benefit persists after discontinuation of ICIs due to a treatment related adverse event, regardless of the grade. Patients experiencing grade 3-4 irAEs are at risk of toxicity recurrence after reintroducing immunotherapy and therefore, the decision to resume the treatment is challenging. In these cases, a multidisciplinary approach is always needed and several factors should be considered. Management of severe toxicities may require systemic corticosteroids which can impact on T-cell function. Due to their immunosuppressive properties, it is necessary to deeper determine how corticosteroids influence responses. In terms of overall survival (OS), the use of steroids as therapy for irAEs seems not to reduce OS and several studies have reported durable responses in patients experiencing autoimmune toxicities treated with corticosteroids.

High levels of chromosomal aberrations negatively associate with benefit to checkpoint inhibition in NSCLC

BACKGROUND

Immune checkpoint inhibitors (ICIs) targeting the programmed cell death 1/programmed death-ligand 1 axis have transformed the management of advanced non-small cell lung cancer (NSCLC). However, many patients do not benefit from this type of treatment, and thus several molecular biomarkers of benefit have been explored. The value of somatic copy number alterations (SCNAs) burden remains elusive.

PATIENTS AND METHODS

We assembled a cohort of 109 patients with NSCLC treated with ICIs and available tumor samples. We performed shallow whole-genome sequencing on 89 patients to determine genome-wide SCNAs and targeted gene expression analysis on 63 patients to study immune infiltration. We analyzed SCNAs burden in different ways (ie, the fraction of the genome altered or number of events) and studied their association with ICIs benefit based on survival analysis. We correlated SCNAs burden and immune infiltration on 35 patients of our cohort and on patients with lung adenocarcinoma from The Cancer Genome Atlas (TCGA).

RESULTS

High SCNAs burden, computed in diverse ways, is negatively associated with ICIs progression-free survival (PFS), with the fraction of the genome altered (FGA) by arm and chromosome events showing the strongest association with PFS (p=0.002) (n=77). Nevertheless, we found differences in SCNAs across some clinicopathological features (sample site origin). A multivariate analysis adjusted for relevant characteristics showed that the FGA of arm and chromosome alterations was strongly associated with PFS (HR=2.21, p=3.3 x 10^-5). Finally, we confirmed that SCNAs burden negatively correlates with tumor immune infiltration (n=35), although this correlation was not found for the males studied. Similar results were observed in the TCGA cohort.

CONCLUSIONS

SCNAs burden is a potential biomarker of benefit to ICIs in patients with NSCLC, although there appear to be some nuances worth consideration. Further studies will be needed to establish its role as a biomarker of benefit to ICIs.

462 A randomised open-label phase I/II study adding ONCOS-102 to pemetrexed/cisplatin in patients with unresectable malignant pleural mesothelioma – 24 month survival data

Background

Malignant pleural mesothelioma (MPM) is an aggressive malignancy without curative treatment. Standard of care (SOC) include pemetrexed/cisplatin and nivolumab/ipilimumab with median overall survival in unresectable disease of 12.1 months and 18.1 months respectively.1 2 ONCOS-102 is a granulocyte-macrophage colony stimulating factor (GM-CSF) expressing oncolytic adenovirus (Ad5/3-D24-GMCSF) with a unique ability to both prime and boost immune responses. The aim of the study was to assess efficacy and safety of ONCOS-102 in combination with SOC chemotherapy in 1st and 2nd line unresectable MPM.

Methods

Twenty patients (experimental arm) were allocated to receive ONCOS-102 given intratumorally under CT or US guidance at a dose of 3 x 1011 VP on Day 1, 4, 8, 36, 78 and 120 plus six cycles of SOC starting on Day 22. Eleven patients (control group) received SOC. Imaging was done at baseline, Day 43–64 and 127–148 with regular monitoring of blood and biopsy based immune markers. Primary objective was safety and tolerability. Secondary objectives were ORR, PFS and OS as well as immunological activation. An analysis of 24 month survival data compared randomised only patients excluding six patients in the single-arm safety lead-in.

Results

24-month survival rate for 1st line pts was 50% in the experimental group and 0% in the control group with mOS of 25.0 months and 13.5 months respectively (N.S). Based on censoring, mOS in the experimental group will be within 21.9 – 25.0 months range. mOS across both 1st and 2nd line was 19.3 and 18.3 months for experimental and control patients (N.S). mPFS was 9.8 months in the experimental group and 7.6 in the control group (N.S.).

Conclusions

The survival rate of patients receiving ONCOS-102 in combination with SOC was seen to be numerically higher than previously reported for SOC or nivolumab/ipilimumab. Improved survival was associated with ONCOS-102 induced immune activation with a favourable TME modulation providing scientific rationale for combination with check point inhibition.

Trial Registration

ClinicalTrials.

gov NCT02879669

References

Vogelzang, et al, Phase III study of pemetrexed in combination with cisplatin versus cisplatin alone in patients with malignant pleural mesothelioma. J Clin Oncol 2003;21: 2636–44.

Baas P, et al, First-line nivolumab plus ipilimumab in unresectable pleural mesothelioma (CheckMate 743): a multicentre, randomised, open-label, phase 3 trial. The Lancet 2021; 397: 375–386.

Ethics Approval

This study was approved by the IRBs of all the participating sites in Madrid, Barcelona, Rennes and Poitiers.

Efficacy of chemotherapy for malignant pleural mesothelioma according to histology in a real-world cohort

CheckMate 743 trial demonstrated survival benefit of immunotherapy in first line in MPM with some differences in the efficacy of chemotherapy according to histology. The objective of this study is to characterize the impact of chemotherapy according to histology in patients diagnosed with MPM at our institution. Clinical records of all MPM patients diagnosed at Vall d'Hebron University Hospital between November 2002 and April 2020 were reviewed. Associations between clinical variables and outcomes were assessed with Cox regression models. Survival data were calculated by the Kaplan-Meier method. 189 patients were included with 76% of tumors classified as epithelioid subtype. First line chemotherapy was offered to 85% of patients. Median survival in overall population was 21.3 months (95% CI 17.2-24.3). We found that patients with epithelioid tumors had better overall survival (OS) and progression free survival (PFS). Median OS of epithelioid patients treated with first line chemotherapy was 26.7 months versus 15.0 months in non-epithelioid patients (HR 2.25 CI 95% 1.4-3.4; p < 0.001). Median PFS for patients with epithelioid tumors treated with chemotherapy was 4.8 months versus 3.6 months in non-epithelioid (HR 1.5 CI 95% 1.0-2.3; p = 0.03). The improvement of outcomes in patients with epithelioid histology was detected in patients treated with cisplatin or carboplatin. Histology was not a predictive factor for the platinum agent sensitivity (p of interaction PFS = 0.09, p of interaction OS = 0.65). In our series, patients with non-epithelioid tumors presented worse prognosis. Although epithelioid tumors exposed to cisplatin had higher PFS, histology was not a clear predictor of chemotherapy efficacy.

A randomized, phase 2 study of deoxyuridine triphosphatase inhibitor, TAS-114, in combination with S-1 versus S-1 alone in patients with advanced non-small-cell lung cancer

Introduction TAS-114 is a potent inhibitor of deoxyuridine triphosphatase, which is a gatekeeper protein preventing uracil and 5-fluorouracil (5-FU) misincorporation into DNA. TAS-114 has been suggested to enhance the antitumor activity of 5-FU. This randomized, phase 2 study investigated TAS-114 plus S-1 (TAS-114/S-1) vs. S-1 in non-small-cell lung cancer (NSCLC) patients. Methods Patients with advanced NSCLC, previously treated with ≥ 2 regimens, were randomized 1:1 to receive TAS-114 (400 mg)/S-1 (30 mg/m²) or S-1 (30 mg/m²). Progression-free survival (PFS, independent central review) was the primary endpoint. Secondary endpoints included disease control rate (DCR), overall survival (OS), overall response rate (ORR), and safety. Results In total, 127 patients received treatment. Median PFS was 3.65 and 4.17 months in the TAS-114/S-1 and S-1 groups, respectively (hazard ratio [HR] 1.16, 95% confidence interval [CI] 0.71–1.88; P = 0.2744). DCR was similar between groups (TAS-114/S-1 80.3%, S-1 75.9%) and median OS was 7.92 and 9.82 months for the TAS-114/S-1 and S-1 groups, respectively (HR 1.31, 95% CI 0.80–2.14; P = 0.1431). The ORR was higher in the TAS-114/S-1 group than the S-1 group (19.7% vs. 10.3%), and more patients with tumor shrinkage were observed in the TAS-114/S-1 group. Incidence rates of anemia, skin toxicities, and Grade ≥ 3 treatment-related adverse events were higher in the TAS-114/S-1 group compared with the monotherapy group. Conclusions Although the TAS-114/S-1 combination improved the response rate, this did not translate into improvements in PFS. Clinical Trial Registration No. NCT02855125 (ClinicalTrials.gov) registered on 4 August 2016.

Tumour Treating Fields in combination with pemetrexed and cisplatin or carboplatin as first-line treatment for unresectable malignant pleural mesothelioma (STELLAR): a multicentre, single-arm phase 2 trial

BACKGROUND

Tumour Treating Fields (TTFields) are a regional, antimitotic treatment for solid tumours, which is based on the delivery of low-intensity alternating electric fields. The aim of the STELLAR study was to test the activity of TTFields delivered to the thorax in combination with systemic chemotherapy for the front-line treatment of patients with unresectable malignant pleural mesothelioma.

METHODS

STELLAR was a prospective, single-arm, phase 2 trial done at 12 European academic and non-academic sites (five in Italy, three in Poland, one in France, one in Belgium, one in Spain, and one in the Netherlands) for treatment-naive patients with histologically confirmed unresectable malignant pleural mesothelioma. Patients were aged at least 18 years, had an Eastern Cooperative Oncology Group performance status of 0-1, and at least one measurable or evaluable lesion according to modified Response Evaluation Criteria in Solid Tumors for mesothelioma. Patients received continuous TTFields at a frequency of 150 kHz to the thorax and concomitant chemotherapy with intravenous pemetrexed (500 mg/m² on day 1) plus intravenous platinum (either cisplatin 75 mg/m² on day 1 or carboplatin area under the curve 5 on day 1) every 21 days for up to six cycles. Patients not progressing after completion of chemotherapy received TTFields as maintenance treatment until progression, patient or physician decision, or unacceptable toxic effects. The primary endpoint of the trial was overall survival. Survival analyses were done in the intention-to-treat population, and safety analyses were done in all patients who received at least 1 day of TTFields treatment. This trial is registered with ClinicalTrials.gov, NCT02397928.

FINDINGS

Between Feb 9, 2015 and March 21, 2017, 80 patients were enrolled in the study. Median follow-up was 12·5 months (IQR 7·4-16·6). Median overall survival was 18·2 months (95% CI 12·1-25·8). The most common grade 3 or worse adverse events were anaemia (nine [11%] patients), neutropenia (seven [9%]), and thrombocytopenia (four [5%]). Skin reaction was the only adverse event associated with TTFields and was reported as grade 1-2 in 53 (66%) patients, and as grade 3 in four (5%) patients. No treatment-related deaths were observed.

INTERPRETATION

The trial showed encouraging overall survival results, with no increase in systemic toxicity. TTFields (150 kHz) delivered to the thorax concomitant with pemetrexed and platinum was an active and safe combination for front-line treatment of unresectable malignant pleural mesothelioma. Further investigation in a randomised trial is warranted.

FUNDING

Novocure.

Abstract CT201: Final results of Phase II STELLAR trial: TTFields with chemotherapy in unresectable malignant pleural mesothelioma

Background Tumor Treating Fields (TTFields) are an anti-mitotic, regional treatment modality, utilizing low intensity alternating electric fields delivered non-invasively to the tumor using a portable device. In-vitro, human mesothelioma cells were highly susceptible to TTFields. TTFields plus chemotherapy have significantly extended survival in glioblastoma.

Method Patients (n= 80) with unresectable, previously untreated mesothelioma were treated with continuous 150 kHz TTFields (&gt;18h/day) in combination with pemetrexed and cisplatin or carboplatin. Inclusion criteria: ECOG PS 0-1, pathologically proven mesothelioma and at least one measurable lesion per modified RECIST criteria. The primary endpoint was overall survival (OS) and secondary endpoints were response rate, progression free survival (PFS) and toxicity. EOCG status and cancer-related pain were assessed until disease progression using a visual analog scale. This prospective, single arm study assumed an historical control with a median survival of 12.1 months (Vogelzang, JCO. 2003). The sample size provides 80% power with a two-sided alpha of 0.05 to detect an increase in median OS of 5.5 months.

Result All 80 patients had a minimum follow up of 12 months. Median age was 67 (range 27-78), 84% were male and 44% (35 patients) had an ECOG PS of 1. 66% (53 patients) had epithelioid histology, similar to the Vogelzang study. Median OS was 18.2 months (95% CI 12.1-25.8) versus 12.1 months in the historical control. The 1-year survival rate was 62.2% (95% CI 50.3-72.0). Median OS for epithelioid patients was 21.2 months (95% CI 13.2-25.8). Clinical benefit (PR+SD) was seen in 97.2% of patients. ECOG score was stable during the first year of follow up. Compliance with TTFields was 68% (16.3 hours/day) during the first 3 months of therapy. 63% (50 patients) received carboplatin. Median time to deterioration in performance status was 13.1 months. Average pain score was lower compared to baseline during the first 7 months of treatment and higher later with a median time to a clinical significant 33% increase in pain of 8.4 months. No device-related serious adverse events (AEs) were reported. Expected TTFields-related dermatitis was reported in 46% (37 patients). Four patients (5%) had grade 3 dermatitis. Grade 3-4 systemic AEs were reported in &gt;3% of patients: hematological AEs (15%) and fatigue (4%).

Conclusion The study met its primary endpoint of significant extension of survival in previously untreated mesothelioma patients. Secondary efficacy endpoints were also improved compared to historical control. The study demonstrated no safety concerns for TTFields plus standard chemotherapy to the thorax. The use of the TTFields was not associated with a decrease in performance status or an increase in pain. TTFields in combination with chemotherapy are efficacious in malignant pleural mesothelioma vs chemotherapy alone in historical data.

Citation Format: Giovanni Luca Ceresoli, Joachim Aerts, Jaroslaw Madrzak, Rafal Dziadziuszko, Rodryg Ramlau, Susana Cedres, Birgitta Hiddinga, Jan VanMeerbeeck, Manlio Mencoboni, David Planchard, Antonio Chella, Lucio Crino, Maciej Krzakowski, Federica Grosso. Final results of Phase II STELLAR trial: TTFields with chemotherapy in unresectable malignant pleural mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT201.

Whole exome sequencing (WES) of non-small cell lung cancer (NSCLC) for tumor mutational burden (TMB) analysis and long-term benefit to immune checkpoint inhibitors (ICIs)

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Background: ICIs have significantly changed the therapeutic landscape of advanced NSCLC. As such, characterizing predictive markers of long-term clinical benefit is a critical objective. TMB quantification using targeted gene panels associates with long-term response to ICIs in NSCLC patients (Rizvi H ASCO 18). Although TMB quantified by targeted NGS correlates with that of WES, caution may be needed when using smaller panels. Methods: Here we analyzed WES of tumors and matched normal tissue from 67 NSCLC patients including 42 treated with ICIs. We correlated TMB with clinico-pathological features and outcomes. TMB was categorized as high vs. low according to the upper quartile of cohort distribution. Results: The median TMB was 2.68 non-synonymous variants (nSNVs)/Mb, ranging from 0 to 15.6 nSNVs/Mb, with upper quartile at 5.42 nSNVs/Mb. TMB was higher for smoker/current smoker (median 3.51) compared to never smokers (median 0.94, p = 0.0048) but no differences were seen in elderly ( > 70 years) vs. young patients or across histologies (squamous, adeno and other) and stages at diagnosis. In patients treated with ICIs, median TMB was 5.44 for those achieving complete response, 3.87 for patients with partial response and 2.42 for patients with progressive disease (PD) (p = 0.04). Moreover, improved clinical outcomes were associated with higher TMB (Table). In patients treated with ICIs, TMB as continuous variable had an impact on progression free survival (PFS) (p = 0.03). Median PFS was 22.3 months (mo) (14-not reached) for those with high TMB and 6.4 mo (3-16) for those with low TMB (HR 0.34, 0.13-0.9, p = 0.03). Median overall survival was not reached for those patients with high TMB and 32 mo (22-43) for those with low TMB (HR 0.29, 0.1-0.86, p = 0.02). Conclusions: High TMB correlates with long-term ICI benefit in NSCLC patients. Mutations in individual genes potentially linked to long-term benefit or resistance to ICIs will be presented. [Table: see text]

Analysis of mismatch repair (MMR) proteins expression in a series of malignant pleural mesothelioma (MPM) patients

e20062

Background: The increasing incidence and poor outcome associated with MPM demand identification of effective treatment options. Promising results have been reported with immunotherapy (IO) in a small proportion of MPM patients (p). MMR deficiency (dMMR) has been well described in several malignancies and was recently approved as a tumor biomarker for IO with anti-PD-1 checkpoint inhibitor. Next generation sequencing (NGS) data demonstrated that 2% of MPM harbor microsatellite instability. The aim of this study is to characterize MMR by immunohistochemistry (IHC) in a series of MPM p. Methods: Tumors of 159 MPM p from Vall d´Hebron University Hospital and October 12th University Hospital diagnosed between 2002 and 2017 were reviewed. Formalin-fixed, paraffin-embedded tissue was stained for MLH1, MSH2, MSH6 and PMS2 and tumors were classified as dMMR when any MMR protein expression was negative and MMR intact when all MMR proteins were positively expressed. Associations between clinical variables and outcome were assessed with Cox regression models and survival data were calculated by the Kaplan-Meier method. Results: P characteristics: median age: 69 years (29-88 years), males: 71%, performance status (PS) 1:69%, asbestos exposure: 52%, stage III at diagnosis: 42%, epithelial subtype: 65%, systemic treatment 81% (57% chemotherapy with cisplatin plus pemetrexed in first line), 50% received second line and 28% third line. MMR protein expression was analyzed in 158 samples with enough tissue and was positive in all of the cases. The median overall survival (mOS) in all population was 15 months (m) (13.5-18.8m). In a multivariate model factors associated to improved mOS were PS 0 vs PS2 (13 v 2 m, HR 12.8, p < 0.01), neutrophil-lymphocyte ratio (NLR) < 5 (18 v 9 m in NLR ≥5,HR 1.5, p < 0.05) and epitheliod vs sarcomatoid histology (18 vs 4 m HR 4.7, p < 0.01). Thirteen p received IO with anti-CTLA4 or anti-PD-1 blockade in clinical trials, 58% had a response or stable disease for more than 6 m, with median progression-free survival (PFS) of 5.7 m (2.1-26.1m). Conclusions: In our series we were unable to identify any MPM patient with dMMR by IHC. Further studies are needed to elucidate novel predictive biomarkers benefit from IO in MPM.

The IASLC Mesothelioma Staging Project: Proposals for the M Descriptors and for Revision of the TNM Stage Groupings in the Forthcoming (Eighth) Edition of the TNM Classification for Mesothelioma

INTRODUCTION

The M component and TNM stage groupings for malignant pleural mesothelioma (MPM) have been empirical. The International Association for the Study of Lung Cancer developed a multinational database to propose evidence-based revisions for the eighth edition of the TNM classification of MPM.

METHODS

Data from 29 centers were submitted either electronically or by transfer of existing institutional databases. The M component as it currently stands was validated by confirming sufficient discrimination (by Kaplan-Meier analysis) with respect to overall survival (OS) between the clinical M0 (cM0) and cM1 categories. Candidate stage groups were developed by using a recursive partitioning and amalgamation algorithm applied to all cM0 cases.

RESULTS

Of 3519 submitted cases, 2414 were analyzable and 84 were cM1 cases. Median OS for cM1 cases was 9.7 months versus 13.4 months (p = 0.0013) for the locally advanced (T4 or N3) cM0 cases, supporting inclusion of only cM1 in the stage IV group. Exploratory analyses suggest a possible difference in OS for single- versus multiple-site cM1 cases. A recursive partitioning and amalgamation-generated survival tree on the OS outcomes restricted to cM0 cases with the newly proposed (eighth edition) T and N components indicates that optimal stage groupings for the eighth edition will be as follows: stage IA (T1N0), stage IB (T2-3N0), stage II (T1-2N1), stage IIIA (T3N1), stage IIIB (T1-3N2 or any T4), and stage IV (any M1).

CONCLUSIONS

This first evidence-based revision of the TNM classification for MPM leads to substantial changes in the T and N components and the stage groupings.

The IASLC Mesothelioma Staging Project: Proposals for Revisions of the T Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma

INTRODUCTION

The current T component for malignant pleural mesothelioma (MPM) has been predominantly informed by surgical data sets and consensus. The International Association for the Study of Lung Cancer undertook revision of the seventh edition of the staging system for MPM with the goal of developing recommendations for the eighth edition.

METHODS

Data elements including detailed T descriptors were developed by consensus. Tumor thickness at three pleural levels was also recorded. An electronic data capture system was established to facilitate data submission.

RESULTS

A total of 3519 cases were submitted to the database. Of those eligible for T-component analysis, 509 cases had only clinical staging, 836 cases had only surgical staging, and 642 cases had both available. Survival was examined for T categories according to the current seventh edition staging system. There was clear separation between all clinically staged categories except T1a versus T1b (hazard ratio = 0.99, p = 0.95) and T3 versus T4 (hazard ratio = 1.22, p = 0.09), although the numbers of T4 cases were small. Pathological staging failed to demonstrate a survival difference between adjacent categories with the exception of T3 versus T4. Performance improved with collapse of T1a and T1b into a single T1 category; no current descriptors were shifted or eliminated. Tumor thickness and nodular or rindlike morphology were significantly associated with survival.

CONCLUSIONS

A recommendation to collapse both clinical and pathological T1a and T1b into a T1 classification will be made for the eighth edition staging system. Simple measurement of pleural thickness has prognostic significance and should be examined further with a view to incorporation into future staging.

Abstract B187: Prevalence of MET copy number variation, MET expression and MET related genomic alterations in all solid tumors pre-screening program. VHIO experience

Background: Aberrant MET activation occurs in many types of malignancies and includes protein overexpression, increased gene copy number, amplifications, mutations and deletions. The frequency of genomic alterations in MET varies widely among solid tumors. The criteria for MET amplification and MET overexpression have not been established as well as the relationship between MET amplification, MET expression and additional genomic alterations known to be important in tumor biology. Previous and current phase 1 clinical trials have selected patients without matching MET criterion.

Materials and Methods: From Dec/2012 to Dec/2014, 203 formalin fixed paraffin embedded tumor samples from 197 patients consented to undergo targeted MET analysis. Samples were 117 primary and 86 metastatic tumors. Tumor types included colorectal, gastric, lung, glioblastoma, and breast. Samples were analyzed by fluorescence in situ hybridization (FISH) for MET gene amplification (MET/CEN-7 FISH Zytolight SPEC assay Z-2087, Zytovision), and by immunohistochemistry (IHC) for MET protein expression [Met (D1C2) XP® Rabbit mAb #8198, Cell signaling]. Mutations in key oncogenes were determined using Sequenom (Mass Array) and Amplicon-Mi Seq (Illumina) Cancer Panel.

Results: MET gene copy number variation (&gt;5copies) was found in 11 of 203 samples (5%) and MET gene amplification (based on the definition of MET/CEN-7 ≥2.2) was found in 6 of 203 samples (3%). Eleven (5%) samples had ≥4 or ≤5 copies of MET gene. KRAS mutation was found in 28 of 167 samples (17%) and PIK3CA mutation in 6 of 167 samples (4%). Both mutations were observed in tumor samples with &lt; 4 copies of MET gene. MET IHC positive (≥ 50% positive cells 3+) was found in 11 of 203 samples (5%). Seven of 203 samples (3%) had MET IHC positive (≥ 50% positive cells 3+ and 2+). MET protein expression showed statistical association with MET gene copy number (P&lt;0.001). There was a statistically significant increased expression of MET in metastatic samples compared with primary tumor specimens (P = 0.001).

Conclusion: MET expression is higher in metastatic than primary tumor samples. There is a significant association between MET expression and gene copy number. High MET copy number was more frequent in tumors without KRAS and PIK3CA mutation. Quantitative MET protein expression data will be presented.

MET IHCMET FISH≥ 50% cells 3+≥ 50% cells 3+ and 2+&lt; 50% cells 3+and 2+&lt; 2 copies01 (0.7%)40 (28.2%)2- &lt;4 copies4 (2.8%)3 (2.1%)79 (55.6%)4-5 copies1 (0.7%)1 (0.7%)4 (2.8%)&gt;5 copies5 (3.5%)04 (2.8%)

Citation Format: Analía Azaro, Guillem Argilés, María Alsina, Elena Elez, Teresa Macarulla, Cristina Cruz, Donatella Marino, Cinta Hierro, Susana Cedres, Alejandro Navarro, María Ochoa de Olza, Irene Braña, Juan Martín-Liberal, Marta Vilaró, Debora Moreno, Paola Martínez, María Díaz, Ana Vivancos, Jordi Rodón, Josep Tabernero, Ludmila Prudkin, Paolo Nuciforo. Prevalence of MET copy number variation, MET expression and MET related genomic alterations in all solid tumors pre-screening program. VHIO experience. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B187.

Whole-exome sequencing in tumor samples from sequenom-wild-type, ALK negative stage IV lung adenocarcinoma (ADC) patients (p)

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Background: The majority of lung ADC tumors are characterized by specific genetic features with KRAS mutations (mut) seen in 20-30%, EGFR mut in 15%, EML4-ALK translocations in 5%, and ERBB2 mut in 2%, among others. Some of these genetic alterations are already being used for selecting targeted therapies. However, identification of additional genomic alterations is required. Methods: In the present ongoing study we perform whole-exome sequencing in paraffin-embedded tumor samples from OncoCarta v1.0 panel wild-type (no mut in hotspots of KRAS, EGFR, ERBB2, AKT1, BRAF, PIK3CA genes) and ALK negative (by FISH) stage IV ADC lung cancer p, and in their matched normal tissue samples. Results: To date, a total of 7 tumors and matched normal tissues have been successfully analyzed. We have detected mut in previously identified ADC genes, such as ERBB2, CTNNB1, TP53, SMAD4 or APC. Interestingly, mut were found in genes belonging to the proposed new cancer hallmark ‘epigenetic and RNA regulation’, such as BRD3, EPC1, PHF1 in almost every p included in our study. Regarding alterations that could be considered relevant for lung tumor pathogenesis/growth or as potential targets for treatment therapies, we were able to identify candidates in 4 of the 7 p. In one p, a case of a transmembrane domain ERBB2mut in exon 20 (p.E770delinsEAYVM) not previously detected by the OncoCarta v1.0 panel (that interrogates L755P, G776S/L/V/C, A775_G776insYVMA, P780_Y781insGSP, S779_P780insVGS mut) was found. In another p, three somatic mut in the BRCA1/2 genes were detected. Additionally, one p had an ALK point mut (p.P336K), for which no functional information is available, together with an APC mutation. In the remaining p, a non-hotspot mutation (although previously detected in a colorectal tumor) was found in CTNNB1. Conclusions: In this limited experience of whole-exome sequencing of a subgroup of stage IV lung ADC p, potentially targetable alterations not formerly detected by other techniques were found. We believe that genomic approaches to detecting alterations may be useful in clinical practice and will hopefully provide assistance in making treatment decisions.

Amplification of fibroblast growth factor receptor type 1 gene (FGFR1) in samples from 101 NSCLC patients (pts) with squamous cell carcinoma (SCC) histology

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Background: The FGFR1 gene is located in the chromosomal region 8p12 and encodes a transmembrane receptor tyrosine kinase. Amplification of FGFR1 has been reported in lung cancer, predominantly in SCC (in up to ~ 20%) and has been considered a potential target for treatment with anti-FGFR1 agents. Different methods and cutoff levels to determine FGFR1 amplification have been reported but as yet no consensus has been reached on standard method. The aim of this study is to assess FGFR1 amplification determined by FISH analysis in a set of samples from 101SCC pts and to explore their clinical features. Methods: Tumor samples from 101SCC pts diagnosed at our institution from August 2007 to August 2011 were screened for FGFR1 amplification by FISH using the ZytoLight SPEC FGFR1/CEN8 probe. FGFR1 was considered FISH positive with a ratio > 2.2 and FISH FGFR1 was polysomic with 3 or more signals in ≥30% of tumor cells, any other result was considered as negative. For exploratory analyses FGFR1 amplification was considered positive if a median of 6 or more gene copies were identified and FISH were polysomic with more than 2 gene copies but less than 6. Results: Pts characteristics: median age 76 yrs (range 45-80), 91% male, 33% current smokers, 67% former smokers, stage: 8% IA/ 15% IB/ 11% IIA/ 11% IIB/ 24% IIIA, 12% IIIB/ 19% IV. With a median follow up of 48 months, the median overall survival was 18 months. FISH FGFR1 was positive (ratio > 2.2) in 7 (6.9%) pts: 6 were male, 4 former smokers. FISH FGFR1 was considered negative but polysomic (3 or more signals in ≥30% of tumor cells) in 43/94 (45%) pts. If we use for FISH positivity a cutoff of 6 or more copies only 3 patients were considered as positive for FGFR1 amplification (2 were also FISH positive by ratio>2.2). All those 5 patients considered FISH negative by gen copy number (but positive by ratio) were polysomic. Conclusions: In our experience FGFR1 amplification detected by FISH isrelatively uncommon in SCC, although a relevant proportion of FGFR1 FISH negative tumors had polysomy. Standarization of methods to determine FGFR1 amplification and the potential clinical significance of the presence of FGFR1 polysomy are needed.