Final survival outcomes and immune biomarker analysis of a randomized, open-label, phase I/II study combining oncolytic adenovirus ONCOS-102 with pemetrexed/cisplatin (P/C) in patients with unresectable malignant pleural mesothelioma (MPM)

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Background: MPM is an aggressive malignancy without curative treatment. ONCOS-102 is an oncolytic adenovirus expressing GM-CSF (Ad5/3-D24-GMCSF) with a clinically documented ability to stimulate local and systemic immune responses and re-modulate the tumor microenvironment, both as a monotherapy and in combination with anti-PD1 blockade. The study objectives included determining safety and tolerability, efficacy and immunological activation in repeat tumor biopsies, and correlations with clinical outcomes. Methods: Following a safety run-in of n = 6 pts, 25 patients were randomized to receive ONCOS-102 intratumorally under CT or US guidance at a dose of 3 x 1011 Virus Particles on Day 1, 4, 8, 36, 78 and 120, plus six cycles of P/C starting on Day 22, or control comprising six cycles of P/C only. Both treatment-naïve (1L) and previously treated patients (2L) were enrolled. Imaging was done at baseline, Day 43-64 and 127-148 and tumor biopsy were collected at baseline and at Day 36. Final survival analysis (n = 25) was performed after 30 mo follow up. Multiplex immunofluorescence for immune cell subsets, RNASeq and qPCR was performed on repeat tumor samples. Results: The most frequent adverse events were anaemia, neutropenia and asthenia reported by > 50% in both groups with more frequent reports of pyrexia and nausea in the experimental (exp) group. No difference in the rate of severe events (Gr 3/4 acc to NCI CTCAE vs 4.0) were observed. 30-month survival rate (n = 25) was 34.3 % vs 18.2 % (NS) with mOS of 19.3 mo (95% CI: 4.6, NA) vs 18.3 mo (95% CI: 3.1, 28.9) in the exp group vs control. For patients treated in the 1L setting, 30 mo survival was 33.3 % in the exp group (n = 8) and 0% in the control group (n = 6) with mOS of 25.0 months and 13.5 months, respectively (NS). mPFS was unchanged from prior cut-offs; 9.8 months in the exp group and 7.6 in the control (NS). ONCOS-102 + P/C induced a pronounced increase in tumor infiltration by CD4+, CD8+ and granzyme B expressing CD8+ T-cells as well as M1:M2 macrophage polarization in patients with disease control (n = 13) vs progressing patients (n = 3). The data from RNAseq and qPCR analysis will be presented. Conclusions: The addition of ONCOS-102 to P/C was well tolerated by MPM patients and resulted in numerically improved 30-month survival rate in the overall population, and improved mOS in chemotherapy-naïve patients, albeit not statistically significant. Substantial immunological activation in tumor associated with ONCOS-102 was demonstrated, correlating with clinical benefit. Further exploration of ONCOS-102 as a treatment option in MPM is warranted Clinical trial information: NCT02879669.

T-cell infiltration in matched samples from malignant pleural mesothelioma (MPM) during evolution of disease

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Background: MPM is an aggressive cancer associated with asbestos exposure. Chemotherapy has been a mainstay of therapy and recently immunotherapy has been associated with survival improvements. Chemotherapy and immunotherapy influence the tumor microenvironment and some reports have shown increased of TIL after chemotherapy in MPM. The purpose of this study was to determine dynamic changes in the tumor immune environment during mesothelioma evolution and after systemic therapies in paired samples. Methods: We examined 20 matched formalin-fixed paraffin embedded tissue samples from 10 patients (p) with MPM taken at diagnosis and at disease progression (follow-up), including untreated and treated with chemotherapy or immunotherapy. Tissue densities (number of cells/mm2) of key immune effector cells such as total lymphocytes (CD3), cytotoxic T cells (CD8), regulatory T cells (FOXP3) and monocytes/macrophages (CD163) were quantified by image analysis using multiplexed immunohistochemistry (IHC). PD-L1 expression in both tumor cells and immune cells was analysed by singleplex IHC and quantified using the CPS score. Results: Median age was 62 years (range 53-84), 7 p were male and all p presented epithelioid histology. Three matched samples belong to patients that did not receive any systemic treatment between biopsies and the other 7 pair of samples belong to patients treated with chemotherapy +/- immunotherapy. The median interval between paired biopsies was 12 m (3-33 m). Median overall survival was 27.8 months (1 m-NR). Median densities of T cells and macrophages in diagnostic and matched follow-up samples were: CD3+:982 vs 712; CD8+:422 vs 334, FOXP3+: 22 vs 25 and CD163+: 2086 vs 1706. Median PD-L1 CPS was 2.5 and 4 in diagnostic and follow-up samples, respectively. In p receiving treatment between sample pairs, the median densities in diagnostic and follow-up matched samples were: CD3+:979 vs 407; CD8+:467 vs 225, FOXP3+: 25 vs 15, CD163+: 1583 vs 1508, and PD-L1: 2 and 1. In p without any systemic treatment between sample pairs, the median densities were CD3+:1645 vs 2397; CD8+:376 vs 1605, FOXP3+: 19 vs 121, CD163+: 2102 vs 2377, and PD-L1: 3 vs 25. Conclusions: In our small series with paired samples from MPM p, we observed immune cells infiltration changes during MPM evolution with a trend towards a decrease after systemic therapy. Further investigation in tumor microenvironment in MPM to define the most appropriate time for immunotherapy is needed.

Analysis of chemotherapy efficacy according to histology in malignant pleural mesothelioma (MPM) patients (p)

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Background: MPM is a highly aggressive pleural tumor associated with asbestos exposure and with limited survival despite systemic therapy. Histology is a prognostic factor and recently CheckMate 743 trial demonstrated survival benefit of immunotherapy in first line with some differences in the efficacy of chemotherapy according to histology. However, randomized trials who led to the approval of antifolate in mesothelioma did not include analysis of outcomes by histology. The objective of this study is to characterize the impact of chemotherapy according to histology in p with MPM at our institution. Methods: We review 189 MPM p diagnosed at Vall d´Hebron University Hospital between November 2002 and April 2020. Associations between clinical variables and outcome were assessed with Cox regression models and survival data were calculated by the Kaplan-Meier method. Results: Patient’s characteristics: median age 68 years (y) (45-88 y), males: 70%, performance status (PS)1: 69%, asbestos exposure: 75%, epithelioid subtype: 76%. First line chemotherapy was offered to 85% of p (66% cisplatin-pemetrexed and 27% carboplatin-pemetrexed). Median overall survival (OS) in overall population was 21.3 m (95%CI17.2-24.3). Epithelioid histology, PS 0, neutrophil-lymphocyte ratio <5 and treatment with cisplatin vs carboplatin were associated with significant improvements in OS (p<0.001). When we analyzed the survival of patients who received first line chemotherapy according to histology, we found that patients with epithelioid tumors had better PFS and OS. Median PFS for p with epithelioid tumors treated with chemotherapy in first line was 4.8 m versus 3.6 months non-epithelioid (HR1.5 CI95% 1.1-2.3; p=0.03). OS of epithelioid p treated with first line chemotherapy was 26.7 m versus 15.0 m non-epithelioid patients (HR2.25 CI95% 1.4-3.4; p<0.001). We analyzed if the differences in survival according to histology were due to type of systemic treatment received (Table). Conclusions: In our series, p with non-epithelioid tumors presented worse prognosis. We confirmed histology is a prognostic factor with better OS for p with epithelioid tumors. Moreover, we demonstrated better efficacy of chemotherapy in epithelioid tumors, although histology is not a predictive factor for the platinum agent sensitivity (p of interaction PFS=0.09, p of interaction OS= 0.65).[Table: see text]

Genomic alterations profiling by liquid biopsy and their association to immune checkpoints inhibitors (ICI) response in a cohort of non-small cell lung cancer (NSCLC) patients

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Background: In metastatic NSCLC, identification of biomarkers of response to immune checkpoint inhibitors (ICI) is still an unmet need. Liquid biopsy, including the detection of circulating tumor DNA (ctDNA) in patients’ bloodstream, is an emerging tool for detecting and monitoring genetic alterations. Mutations in specific genes as KRAS or STK11, in combination with PDL1, have been suggested as potential biomarkers to select responders to ICI. Methods: Digital NGS of ctDNA was analyzed by Guardant360 in samples from 89 patients with advanced NSCLC treated with ICI between 2017 to 2019. Plasma samples after progression to ICI were obteined from 40 patients and we focus in this subgroup to explore mutations of genes commonly alterated in lung cancer and correlate them with clinical outcomes. Results: Forty patients were included in the analysis with a median age of 64.5 years and 62.5% were diagnosed with adenocarcinoma. Fourteen patients were treated with single agent ICI as first line, 19 patients as second line and 7 in third line. A median of 4 mutations per patient were detected (range 0-13). Mutations (mut) in TP53 were found in 85% of the patients, KRAS in 34%, STK11 in 22% and both genes KRAS and STK11 were alterated in 12.5% of the patients. Globally, median PFS (mPFS) of the patients treated with ICI was 7.5 months. mPFS in patients harboring KRAS mutations was 4.9 m ( vs 10.1 m in patients without KRASmut, logrank test p-value = 0.031) and 4.1 m in those patients with STK11 mutations (vs 9.5 m in patients without STK11mut, logrank test p-value = 0.034). Additionally, mutations in both genes were also associated to statistically significant shorter mPFS 3.9 m vs 9.5 m (logrank test p-value < 0.01). Conclusions: Our results support the idea that tumor alterations identified by liquid biopsy panels can potentially contribute as biomarkers of response to ICI in NSCLC. When analyzing the mutational panorama after ICI treatment, we find that those patients exhibiting KRAS and/or STK11 mutations in their ctDNA have a shorter PFS.

Immune checkpoint inhibitors (ICI) response in metastatic non-small cell lung cancer (NSCLC) patients with WNT pathway mutations (APC/CTNNB1)

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Background: APC and CTNNB1 mutations (mut) lead to an aberrant activation of the WNT pathway which has been linked to lack of benefit of immunotherapy in patients (pts) with lung cancer. Our aim is to describe the pts’ characteristics of a NSCLC cohort with APC or CTNNB1 mut and their association with outcomes (Overall survival [OS] and Progression-Free-Survival [PFS]) when treated with ICI. Methods: We selected NSCLC pts with mut in APC or CTNNB1 by targeted NGS (tissue), whole exome sequencing (tissue) or Guardant 360(plasma) between January 2014 and October 2019. Functionality of mut and β-catenin protein expression by immunohistochemistry (IHC) were correlated with outcome. Results: We identified a total of 37 patients with 44 mutually-exclusive mutations in APC (31) or CTNNB1 (6), 25 adenocarcinomas (68%). Of APC mut cohort, 16 had pathogenic mut (52%) and 15 of unknown significance (48%). All 6 CTN NB1 mut were known pathogenic. Median OS (mOS) in metastatic setting was 21.6 months (m) (CI95% 14.9-NR), without differences between APC and CTNNB1 groups (HR 1.5, p = 0.4) or when stratified by mut functionality (HR 1.1, p = 0.8). Globally, 21 pts received treatment with ICI (57%, 19 APC, 2 CTNNB1), median PFS (mPFS) was 5.43m (1.8-21.7), with trend for shorter mPFS in CTNNB1 mut (mPFS 1.7m) vs. APC mut (mPFS 6.6m, HR 1.5, p = 0.1). Among patients treated with ICI, 8 (38%) had coexisting driver targetable alterations ( EGFR, ERBB2 or MET) and 13 (62%) other functional mut were found ( TP53, KRAS, STK11, BRCA2, ATM). mPFS was 3.9m (1.8-NR) in the subgroup with driver mut vs. 6.6m (1.4-NR) for remaining pts (HR 1.36, p = 0.5). In 15 pts β-catenin IHC was performed, being positive in 7 cases (47%), 4 of them received ICI with a mPFS 12.1m. Conclusions: In our experience, benefit with ICI is not influenced by the presence of APC mut, and small numbers of CTNNB1 cohort limit conclusive statements. Additional studies are required to assess WNT pathway activation on top of genomics and correlate with the ICI efficacy.

Outcome of EGFR mutant patirnts included in a clinical trial after progression on EGFR TKI

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Background: EGFR mutant(EGFRm) NSCLC patients develop adquired resistance after 12 months on EGFR TKI. Acquired T790mutation(T790M) is the most common mechanism of resistance in around 60% of patients, followed by MET amplification in 20% of cases. Inclusion in a clinical trials at progression may have an impact in patients’ outcome. Methods: We retrospectively assessed the overall survival in EGFRm patients according to post-progression treatment on 1st/2nd generation EGFR TKI: standard vs. experimental (clinical trial). Also, we assessed the survival in the cohort of acquired T790M NSCLC patients(p). X2 test and long rank test P values are described. OS was defined since progression 1st/2nd generation EGFR TKI to death or last follow up Results: 42p EGFRm were enrolled. According to EGFRm subtype (24 p EGFR del19, 14p EGFR L858R, 1p EGFR exon18, 1 EGFR exon20 ,2p unknown). Median age was 58 (33-83) and 27 (64%) females. First-line EGFR TKI was 30% gefitinib / 58 % erlotinib /10 % afatinib/2% dacotinib At PD, in 51 biopsies (b) were performed,11p were biopsy twice.Tumor tissue for molecular determinations was available in in 86% of cases. Druggable molecular alterations were detected in 57% of cases: 20 acquired T790M and 4 MET amplification. According to these results all 24 p were enrolled in a clinical trial (NCT02108964,NCT01802632,NCT02147990,NCT02335944, NCT02151981), and 18p were screening failure; 8p (45%) of them due to abscense of adquired resistance mechanisms. 10 received platinum-based chemotherapy and 6 only received best supportive care. OS metastatic disease was 51 months for patients included in a clinical trial vs 22 months for those on standard treatment (p < 0.001; 95%CI: 14.4-47). OS was: 34 months vs 10 months for those included in a clinical trial vs standard, respectively (p < 0.001; 95%CI: 8.88-25). For T790M tumours, OS post-progression was 25 months Conclusions: Enrolling patients in clinical trials may allow personalised treatment according to mechanisms of resistance improving survival after 1st/2nd generation EGFR TK progression disease.

Outcome of KRAS mutated (m) non-small cell lung cancer (NSCLC) patients (pts) treated with immune checkpoint inhibitors (immuneCI)

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Background: The most frequent genetic alteration in advanced NSCLC is KRASm in ~25% of tumors. This event associates with smoking pattern and high mutational burden, which correlate with the efficacy of CI in NSCLC. There is in silico evidence that coexisting KRASm and TP53m positively impact immuneCI benefit , but this association needs clinical validation. Methods: We retrospectively assess the efficacy of PD-1/PDL-1 CI (atezolizumab, pembrolizumab, nivolumab or durvalumab) in a cohort of NSCLC patients whose tumors were KRASm (with or without coexisting TP53m) as assessed by a next-generation sequencing test. Endpoints were clinical benefit rate (CBR), defined as partial response or stable disease > 4 months (m), and time to progression (TTP) on immuneCI. Fisher-exact test and log-rank test P values are described. Results: 25 pacients were identified, 68% female, median age 54 y (33-75), 95% former/current smoker; 95% adenocarcinoma; 59% with 2 or more metastatic sites; 36% immuneCI as third-line or beyond (median time from first-line to immuneCI of 7.5 m). 20 tumors had KRASm in codon 12, 3 codon 13 and 2 in codon 61. Overall, CBR was 36% (CI95% 19%-57%) and median TTP was 3.7 m (CI95% 2.2-NA). Coexisting KRASm/ TP53m (n = 11) did not associate with higher CB (27% vs 50%, p = 0.56). A trend for lower TTP in the KRASm/ TP53m vs TP53 wild-type was observed (2.1 vs 5.6 m, HR 0.3; p = 0.11). Conclusions: NSCLC patients whose tumors are KRASm can have substantial benefit with immuneCI. In our series, the population with KRASm/ TP53m tumors did not derive higher clinical benefit from this therapeutic intervention

Molecular sequencing and gene fusion detection in non-small cell lung cancer (NSCLC) patients: Impact of co-existing alterations

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Background: There is a growing need for accurate molecular diagnostics for proper targeted therapeutics selection in NSCLC patients (pts). We assess whether next generation techniques increase the identification of alterations in a prospective cohort of NSCLC pts, and evaluate prognostic value of different molecular alterations. Methods: Next generation sequencing (Amplicon-seq, 60 genes) and NanoString Gene fusion (20 genes) testing were conducted in NSCLC pts treated in a single center from November 2014 to May 2016. Overall survival (OS) according to the molecular profile was analysed by Kaplan-Meier method and Cox models. Results: Molecular tests were performed in 73advanced NSCLC pts.Median age was 54 year, 50% were women. Histology: 73% adenocarcinoma; 7% squamous, 20% others (Neuroendocrine, NOS). Tests were performed in biopsies from metastatic sites in 55% of pts.These techniques identified molecular alterations in 89% of cases: TP53 mutation (mut) 37/73 (51%); KRASmut 21/73 (29%); EGFRmut 11/73 (15%) ; CDKN2mut 7/73 (9%); BRAFmut (pG469R), ERBB2mut and METexon14mut in (1/73) 1.3%, respectively; ALKfusion (fus) 2/73 (2.7%); ROS1fus 1/73 (1.3%) , and RET fus 3/73 (4%). Concomitant mutations were identified in 32% of pts mainly with TP53 (TP53/EGFR: (5/11) 45% and TP53/KRAS: (7/21) 33%). Matched targeted treatment was offered in 17/73 (23%), mostly tyrosine kinase inhibitors (TKI); anti-EGFR in 11/17 (65%) and ALK/ROS TKI in 3/17 (17.5%). Three pts (17.5%) received anti-MET or anti-HER2 TKI. OS in this whole population treated with target therapies (n = 17) was 45.7 months (m) (CI95% 26.8-NA). The KRASmut group had median OS of 10 m (CI95% 7.5-NA), while the remaining population with wild type (WT) for all driver alterations had median OS of 23 m (CI95% 20-NA), (HR 1.71 for KRASmut vs WT pts, p = 0.18). The presence of coexisting TP53mut did not negatively impact on OS in the cohorts with EGFRmut and KRASmut (p > 0.1) in a multivariate model. Conclusions: Combined next generation techniques for molecular profile in NSCLC pts identifies molecular alterations that have clinically relevant impact in survival. Coexisting TP53mut alteration shows no detrimental effect in OS.

Ex Vivo Modeling of Multidomain Peptide Hydrogels with Intact Dental Pulp

Preservation of a vital dental pulp is a central goal of restorative dentistry. Currently, there is significant interest in the development of tissue engineering scaffolds that can serve as biocompatible and bioactive pulp-capping materials, driving dentin bridge formation without causing cytotoxic effects. Our earlier in vitro studies described the biocompatibility of multidomain peptide (MDP) hydrogel scaffolds with dental pulp-derived cells but were limited in their ability to model contact with intact 3-dimensional pulp tissues. Here, we utilize an established ex vivo mandible organ culture model to model these complex interactions. MDP hydrogel scaffolds were injected either at the interface of the odontoblasts and the dentin or into the pulp core of mandible slices and subsequently cultured for up to 10 d. Histology reveals minimal disruption of tissue architecture adjacent to MDP scaffolds injected into the pulp core or odontoblast space. Additionally, the odontoblast layer is structurally preserved in apposition to the MDP scaffold, despite being separated from the dentin. Alizarin red staining suggests mineralization at the periphery of MDP scaffolds injected into the odontoblast space. Immunohistochemistry reveals deposition of dentin sialophosphoprotein by odontoblasts into the adjacent MDP hydrogel, indicating continued functionality. In contrast, no mineralization or dentin sialophosphoprotein deposition is evident around MDP scaffolds injected into the pulp core. Collagen III expression is seen in apposition to gels at all experimental time points. Matrix metalloproteinase 2 expression is observed associated with centrally injected MDP scaffolds at early time points, indicating proteolytic digestion of scaffolds. Thus, MDP scaffolds delivered centrally and peripherally within whole dental pulp tissue are shown to be biocompatible, preserving local tissue architecture. Additionally, odontoblast function and pulp vitality are sustained when MDP scaffolds are intercalated between dentin and the odontoblast region, a finding that has significant implications when considering these materials as pulp-capping agents.

Water uptake, priming, drying and storage effects in Cassia excelsa Schrad seeds

The aims of this study were to evaluate the effects of osmotic potential on the water uptake curve in Cassia excelsa seeds and use the results to analyze the effects of dehydration and storage on primed seed germination. Seeds were imbibed in distilled water and polyethylene glicol (PEG 6000) osmotic solutions at -0.2, -0.4, and -0.6 MPa, at 20 degrees C. The radicle emergence and seed moisture content were evaluated at 6-hour intervals during 240 hours. Afterwards, seeds were primed in distilled water and PEG 6000 solutions at -0.2, -0.4, and -0.6 MPa for 48, 72, 96, and 168 hours at 20 degrees C, followed by air drying and storage for 15 days at 5 degrees C. The lower the osmotic potential, the higher the time required for priming. The osmoconditioning yields benefits with PEG solutions at 0.0 and -0.2 MPa; seed improvements were maintained during storage for 15 days at 5 degrees C, but were reverted by seed drying.