Clinicopathological and molecular landscape of 5-year IDH-wild-type glioblastoma survivors: A multicentric retrospective study

Five-year glioblastoma (GBM) survivors (LTS) are the minority of the isocitrate dehydrogenase (IDH)-wild-type GBM patients, and their molecular fingerprint is still largely unexplored. This multicenter retrospective study analyzed a large LTS-GBM cohort from nine Italian institutions and molecularly characterized a subgroup of patients by mutation, DNA methylation (DNAm) and copy number variation (CNV) profiling, comparing it to standard survival GBM. Mutation scan allowed the identification of pathogenic variants in most cases, showing a similar mutational spectrum in both groups, and highlighted TP53 as the most commonly mutated gene in the LTS group. We confirmed DNAm as a valuable tool for GBM classification with a diagnostic refinement by using brain tumor classifier v12.5. LTS were more heterogeneous with more cases classified as diffuse pediatric high-grade glioma subtypes and having peculiar CNVs. We observed a global higher methylation in CpG islands and in gene promoters of LTS with methylation levels of distinct gene promoters correlating with prognosis.

Response assessment of GBM during immunotherapy by delayed contrast treatment response assessment maps

Introduction

Assessing the treatment response of glioblastoma multiforme during immunotherapy (IT) is an open issue. Treatment response assessment maps (TRAMs) might help distinguish true tumor progression (TTP) and pseudoprogression (PsP) in this setting.

Methods

We recruited 16 naïve glioblastoma patients enrolled in a phase II trial consisting of the Stupp protocol (a standardized treatment for glioblastoma involving combined radiotherapy and chemotherapy with temozolomide, followed by adjuvant temozolomide) plus IT with dendritic cells. Patients were followed up till progression or death; seven underwent a second surgery for suspected progression. Clinical, immunological, and MRI data were collected from all patients and histology in case of second surgery. Patients were classified as responders (progression-free survival, PFS > 12 months), and non-responders (PFS ≤ 12), HIGH-NK (natural killer cells, i.e., immunological responders), and LOW-NK (immunological non-responders) based on immune cell counts in peripheral blood. TRAMs differentiate contrast-enhancing lesions with different washout dynamics into hypothesized tumoral (conventionally blue-colored) vs. treatment-related (red-colored).

Results

Using receiver operating characteristic (ROC) curves, a threshold of -0.066 in VBlue/VCE (volume of the blue portion of tumoral area/volume of contrast enhancement) variation between values obtained in the MRI performed before PsP/TTP and at TTP/PSP allowed to discriminate TTP from PsP with a sensitivity of 71.4% and a specificity of 100%. Among HIGH-NK patients, at month 6 there was a significant reduction compared to baseline and month 2 in median "blue" volumes.

Discussion

In conclusion, in our pilot study TRAMs support the discrimination between tumoral and treatment-related enhancing features in immunological responders vs. non-responders, the distinction between PsP and TTP, and might provide surrogate markers of immunological response.

Development of A Radiomic Model for MGMT Promoter Methylation Detection in Glioblastoma Using Conventional MRI

The methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter is a molecular marker associated with a better response to chemotherapy in patients with glioblastoma (GB). Standard pre-operative magnetic resonance imaging (MRI) analysis is not adequate to detect MGMT promoter methylation. This study aims to evaluate whether the radiomic features extracted from multiple tumor subregions using multiparametric MRI can predict MGMT promoter methylation status in GB patients. This retrospective single-institution study included a cohort of 277 GB patients whose 3D post-contrast T1-weighted images and 3D fluid-attenuated inversion recovery (FLAIR) images were acquired using two MRI scanners. Three separate regions of interest (ROIs) showing tumor enhancement, necrosis, and FLAIR hyperintensities were manually segmented for each patient. Two machine learning algorithms (support vector machine (SVM) and random forest) were built for MGMT promoter methylation prediction from a training cohort (196 patients) and tested on a separate validation cohort (81 patients), based on a set of automatically selected radiomic features, with and without demographic variables (i.e., patients' age and sex). In the training set, SVM based on the selected radiomic features of the three separate ROIs achieved the best performances, with an average of 83.0% (standard deviation: 5.7%) for accuracy and 0.894 (0.056) for the area under the curve (AUC) computed through cross-validation. In the test set, all classification performances dropped: the best was obtained by SVM based on the selected features extracted from the whole tumor lesion constructed by merging the three ROIs, with 64.2% (95% confidence interval: 52.8-74.6%) accuracy and 0.572 (0.439-0.705) for AUC. The performances did not change when the patients' age and sex were included with the radiomic features into the models. Our study confirms the presence of a subtle association between imaging characteristics and MGMT promoter methylation status. However, further verification of the strength of this association is needed, as the low diagnostic performance obtained in this validation cohort is not sufficiently robust to allow clinically meaningful predictions.

Case report: Multiple brain intravascular papillary endothelial hyperplasia: incidence, diagnostic challenges, and management approach

Multiple hemorrhagic brain lesions are mainly diagnosed based on clinico-radiological features integrated with histological data. Intravascular papillary endothelial hyperplasia (IPEH), or Masson's tumor, is a very rare entity, particularly when localized in the brain. In this study, we describe a case of multiple recurrent brain IPEHs and provide details on the diagnostic phase, therapeutic approaches, and related challenges. A 55-year-old woman presented with a relapsing neurological deficit. Brain magnetic resonance imaging (MRI) revealed a hemorrhagic right frontal-parietal lesion. When new neurological symptoms occurred, subsequent MRI scans detected more bleeding cerebral lesions. She underwent a series of single hemorrhagic lesion debulking. For any samples that underwent histopathological examination, the first results were not informative; the second and the third results revealed hemangioendothelioma (HE); and the fourth results led to the IPEH diagnosis. Interferon alpha (IFN-α) and subsequently sirolimus were prescribed. Both were well tolerated. Clinical and radiological features remained stable 43 months after starting sirolimus therapy and 132 months after the first diagnosis. To date, 45 cases of intracranial IPEH have been reported, mostly as single lesions without parenchymal location. They are usually treated by surgery and sometimes by radiotherapy upon recurrence. Our case is notable for two main reasons: because of the consecutive recurrent multifocal exclusively cerebral lesions and the therapeutic approach we used. Based on multifocal brain recurrence and good performance, we propose pharmacological therapy, including IFN-α and sirolimus, to stabilize IPEH.

Towards an Established Intraoperative Oncological Favorable Tool: Results of Fluorescein-Guided Resection from a Monocentric, Prospective Series of 93 Primary Glioblastoma Patients

It is commonly reported that maximizing surgical resection of contrast-enhancing regions in patients with glioblastoma improves overall survival. Efforts to achieve an improved rate of resection have included several tools: among those, the recent widespread of fluorophores. Sodium fluorescein is an unspecific, vascular dye which tends to accumulate in areas with an altered blood-brain barrier. In this retrospective analysis of patients prospectively enrolled in the FLUOCERTUM study, we aimed to assess the role of fluorescein-guided surgery on surgical radicality, survival, and morbidity. A retrospective review based on 93 consecutively and prospectively enrolled IDH wild-type glioblastoma patients (2016-2022) was performed; fluorescence characteristics, rate of resection, clinical outcome, and survival were analyzed. No side effect related to fluorescein occurred; all of the tumors presented a strong yellow-green enhancement and fluorescein was judged fundamental in distinguishing tumors from viable tissue in all cases. Gross total resection was achieved in 77 cases out of 93 patients (82.8%). After a mean follow-up time of 17.4 months (3-78 months), the median progression-free survival was 12 months, with a PFS-6 and PFS-12 of 94.2% and 50%, respectively, whereas median overall survival was estimated to be 16 months; survival at 6, 12, and 24 months was 91.8%, 72.3%, and 30.1%, respectively. Based on these results, we can assert that the fluorescein-guided technique is a safe and valuable method for patients harboring a newly diagnosed, untreated glioblastoma.

EPCO-02. GENOME-WIDE DNA METHYLATION PROFILING AND GENETIC CHARACTERIZATION OF LONG-TERM SURVIVAL IDH WILD-TYPE GLIOBLASTOMA PATIENTS

Glioblastoma multiforme (GBM) has a dismal outcome of approximately 12 months. Less than 5% of patients (long-term survivors-LTS) survives more than 5-years, including IDH-mutant gliomas. Nevertheless, the molecular fingerprint of LTS remains largely uncharted. DNA methylation (DNAm) is an epigenetic modification, altered in cancer and used to classify brain tumors. In this multicentric study sponsored by Alleanza Contro il Cancro (ACC) network, we aimed to molecularly characterize LTS vs standard survival GBM (CTR) by DNAm/Copy Number Variation (CNV) and mutation profiling. We analyzed 51 IDHwt GBM samples (27LTS/24CTR) by Illumina EPIC beadChip and AmpliSeq Comprehensive Cancer Panel. We ran methylation data through the brain tumor classifiers v11b4 and v12.5, performed multidimensional scaling analysis and investigated differentially methylated regions (DMR) correlating them with survival. According to v11b4, cases were classified as: 43 GBM IDHwt (22LTS/21CTR), 27 with a calibrated score >0.84 (16LTS); Plexus Tumor with low scores (2LTS/3CTR); 3 LTS samples did not match. A diagnostic refinement was observed by the v12.5, with 48 cases classifying as GBM IDHwt (25LTS/23CTR) and 35 (19LTS) with optimal score. The LTS group was more heterogeneous, with 4 cases matching in the pedHGG subtypes, including 2 cases in young adults, one with high tumor mutational burden and MSH6 mutation. No specific DNAm genomic profile was observed for LTS patients but we identified 18 significant DMRs, 4 associated with survival probability. At CNV analysis, most cases showed classical alterations (Chr7 gain with or w/o EGFR amplification, 9p21 loss, Chr10 loss) while pedHGG were associated with PDGFRA amplification, 1q gain, 13q loss. NGS identified at least 1 pathogenic variant in 40 cases (22CTR/18LTS) and showed a higher prevalence of mutation negative cases among LTS. No significant difference between the 2 groups was observed in terms of prevalence of mutated genes or number of VUS per sample.

P11.04.A Observational, prospective multicenter study on the role of body mass index (BMI) in the development of thrombotic complications in cancer patients with PICC: preliminary results

Background

Peripherally inserted central catheters (PICC) became widespread and changed substantially the approach to the patients venous system. They guarantee, both in hospital and at home, a stable and safe vascular access to administer irritants or vesicants therapies. However, the benefit provided may occasionally be affected by relevant thrombotic complications especially in patients with hypercoagulability such as oncological patients. Among the identification of independent risk factors, the role of a BMI>25 kg/m2 is now emerging in literature with conflicting results.

Material and Methods

Oncological patients with PICC were included in this multicenter prospective study. We evaluated clinical data, BMI, KPS, steroid therapies and anticoagulants at the time of PICC positioning and at regular intervals.

Results

A total of 51 patients were analyzed. The median KPS was 90 (range 80-100), and the median ECOG was 1 (range 0-3). The most common tumors were represented by: lymphomas both Hodgkin and non-Hodgkin (38%), lymphatic and myeloid leukemia (35%), neurooncological tumors including glioblastoma, primary central nervous system lymphoma, anaplastic astrocytoma and meningioma (15%), other solid cancer (breast, gastroesophageal, rectal cancer) (12%).55% patients were at first diagnoses, 12% were at the first recurrence, and the remaining were at the second or third recurrence. No malpositioning were registered. 18% of patients were on anticoagulant/antiplatelet therapy, 67% were treated with steroids. Concerning BMI, 39% was normal weight, 43% overweight and 10% obese, only 2% was considered underweight. Overall, 8% of patients developed PICC related thrombosis within a median time of 68 days (49-87) after PICC implantation mainly occurred in upper right extremity insertion sites. We therefore assessed the incidence of PICC related thromboembolic events in the groups, with 4% of event registered in the cohort of patients overweight/obese, and 14% of events in the cohort of patients with normal weight/underweight.

Conclusion

Preliminary analysis does not allow to draw firm conclusions. It will therefore be necessary to reach the sample size for achieve generalizable results and confirm the risk of developing thromboembolic events in overweight/obese patients. Meanwhile, an accurate anamnesis and a physical evaluation with particular attention to the presence of malnutrition, both over nutrition and undernutrition, could help to identify potential oncological patients at risk of developing PICC related thrombosis.

KS02.5.A COVID19 impact on the neuro-oncological population. evaluation of critical issues and resources of patients and caregivers

Background

The COVID-19 pandemic has inferred on patients (PTS) with cancer regarding disease evolution as well as the emotional and social functioning. The assessment of the needs and perceptions of PTS and their caregivers, is a priority to ensure an adequate standard in taking care and to promote the compliance to the treatments.

The aim of this study is to understand how COVID-19 affects the emotional state and medical relationship in neuro-oncology.

Material and Methods

From Apr 2020 to Dec 2021 a prospective study was conducted on neuro-oncological PTS and their caregivers, including a 41-question and 16-question survey respectively.

Results

162 PTS and 66 caregivers completed the questionnaire. 57.5% of PTS perceived grater risk , 37.5% the same risk and 5% lower risk of contracting the COVID-19 disease compared to the general population. 9.6% of PTS got SARS-CoV2 infection.Using a scale 0-10 for the assessment of anxiety, PTS experienced 5.8 (standard deviation, sd 2.6) as anxiety level related to tumor and 4.6 (sd 2.5) level about COVID-19 risk. For the most part there was no change in the treatment of cancer (81.5%). Due to the COVID-19 pandemic, 9.2% of PTS decided to delay anti-tumoral therapeutic schedule and 27.9% referred to be worried about going to hospital for consultation. Overall, 93.5% of PTS was satisfied with the treatments received. 52.6% of PTS felt different perception of the future during COVID-19, mostly referred like more uncertain. Caregivers experienced 7.7 (sd 2.1) anxiety level about tumor and 5.5 (sd 2.4) about COVID-19 risk. In 67.7% of caregivers the perception of the future has been changed, mostly towards greater insecurity. 75.0% of PTS described at least good Quality of Life (QoL), 65.4% of PTS declared to have sufficient resources to deal with the situation. There was a correlation between QoL and resources (P = 0.000). 77.3% of caregivers defined their care burden increased during the pandemic and 73.4% defined their QoL at least as good. We found a correlation between COVID-19 anxiety and anxiety for tumor diagnosis (ρ=0.53%, P = 0.000) as well as with future perception (Mann Whitney U test between PTS with different versus unchanged future perception, P = 0.001) in the PTS population.

Conclusion

The WHO definition of health refers to the biopsychosocial model. This model attributes the outcome of disease, as well as health, to the intricate and variable interaction of biological, psychological factors and social factors. In line with this model, it is essential to guarantee and improve the standard of care, also based to the real needs perceived by PTS and caregivers and to historical and social context. This is especially important in a pandemic period like COVID-19 is in which the good QoL can be compromised. An appropriate health-system organization and a special attention to patient doctor communication can make the different on QoL and the future perception.

CLRM-08 TARGETING IMMUNE-PAYLOAD TO THE GLIOBLASTOMA TUMOR MICROENVIRONMENT USING A MACROPHAGE-BASED TREATMENT RELYING ON AUTOLOGOUS, GENETICALLY MODIFIED, HEMATOPOIETIC STEM CELL-BASED THERAPY: THE TEM-GBM STUDY (NCT03866109)

We developed an autologous hematopoietic stem cell-based platform designed to deliver IFNa, by a transcriptional and post-transcriptional control mechanism mediated by miRNA target sequences, specifically into the tumor microenvironment (TME) via Tie-2 expressing monocytes (Temferon). As of Feb 2022, 3 escalating doses of Temferon (0.5-2.0x106/kg) were tested across 15 newly diagnosed, unmethylated MGMT GBM patients assigned to 5 cohorts. Follow-up from surgery is 6–28mo (2–25mo after Temferon). To date, no DLTs have been identified. As expected, 1mo after the administration of the highest tested dose, the hematopoietic system of Temferon-treated patients was composed of up to 30% of CD14+ modified cells. Temferon-derived progeny persisted, albeit at lower levels, up to 18mo (longest time of analysis). Despite the substantial proportion of engineered cells, very low concentrations of IFNα were detected in the plasma and in the CSF, indicating tight regulation of transgene expression. SAEs were mostly attributed to conditioning chemotherapy (infections) or disease progression (seizures). 1SUSAR (persistent GGT elevation) occurred. Median OS is 15mo from surgery. Homing of transduced cells to the tumor was demonstrated by the presence of gene-marked cells in the 2nd surgery specimens of 3 out 4 pts belonging to low dose cohorts. Single-cell RNA seq of the TME highlighted a Temferon signature associated with the induction IFNa responsive genes and macrophage repolarization. Potential long-term benefit with Temferon was identified in a patient from cohort 3, who had PD at D+120 with two distant enhancing lesions, and increased tumor necrosis. 1y following Temferon, with no 2nd-line therapy added, there was approximately 40% reduction in enhancing tumor volume compared to D+180 with a stable clinical and imaging picture thereafter. The results provide initial evidence of Temferon’s potential to modulate the TME of GBM patients, and anecdotal evidence for long lasting effects of Temferon in prevention of disease progression.

Abstract 5213: Genetically modified Tie-2 expressing monocytes target IFN-α2 to the glioblastoma tumor microenvironment (TME): Preliminary data from the TEM-GBM Phase 1/2a study

Increasing clinical use of immune checkpoint inhibitors testifies to the importance of modulating the immune TME to obtain meaningful anti-tumor immune responses. Acting only on T lymphocytes may, however, not be sufficient, e.g. in immunologically-cold tumors or due to de novo or acquired resistance. Moreover, immune-related AEs remain hurdles of T cell therapies. To overcome these limitations and to awaken the immune system in an agnostic way against the tumor, we have developed a genetically modified cell-based autologous hematopoietic stem cell platform (Temferon) delivering immunotherapeutic payloads into the TME through Tie-2 expressing monocytes (TEMs), a subset of tumor infiltrating macrophages. TEM-GBM is an ongoing open-label, Phase 1/2a dose-escalating study evaluating the safety & efficacy of Temferon in up to 21 newly diagnosed patients with glioblastoma & unmethylated MGMT promoter assigned to 7 different cohorts (3 pts each) differing by Temferon dose (0.5-4.0x106/kg) and conditioning regimen (BCNU+ or Busulfan+Thiotepa). By Oct 15th, 2021, 15 pts (cohort 1-5) had received escalating doses of Temferon with a median follow up of 267 days (range: 60-749). Rapid engraftment and hematological recovery from nonmyeloablative conditioning occurred in all pts. Temferon-derived differentiated cells, as determined by the presence of vector genomes in the DNA, were found at increasing proportions in PB and BM, reaching up to 30% at 1 month for the highest cohorts tested (2.0x106/kg) and persisting up to 18 months, albeit at lower levels. Despite the significant proportion of engineered cells, only very low median concentrations of IFNα were detected in the plasma (D+30, 5.9; D+90, 8.8pg/mL) and in the cerebrospinal fluid (D+30, 1.5; D+90, 2.4pg/mL), indicating tight regulation of vector expression. SAEs were mostly attributed to conditioning chemotherapy (e.g. infections) or disease progression (e.g. seizures). 1 SUSAR (persistent GGT elevation) has occurred. Median OS is 14 mth from surgery (11 mth post Temferon). Four pts from the low dose cohorts underwent 2nd surgery. These recurrent tumors contained gene-marked cells and expressed IFN-responsive genes, indicative of local IFNα release by TEMs. In 1 pt, a stable lesion (as defined by MRI) had a higher proportion of T cells & TEMs, an increased IFN-response signature and myeloid re-programming revealed by scRNAseq, as compared to a synchronous, progressing tumor. TCR sequencing of blood and tumor samples showed a post-treatment increase in the cumulative frequency of tumor-associated T cell clones identified in 1st and 2nd surgery specimens (up to 4 out of 9 subjects). These results provide initial evidence for on-target activity of Temferon in GBM, to be consolidated with longer follow up in the higher dose cohorts.

Citation Format: Bernhard Gentner, Gaetano Finocchiaro, Francesca Farina, Marica Eoli, Alessia Capotondo, Elena Anghileri, Matteo Barcella, Maria Grazia Bruzzone, Matteo Giovanni Carrabba, Valeria Cuccarini, Giorgio D'Alessandris, Francesco Di Meco, Valeria Ferla, Paolo Ferroli, Filippo Gagliardi, Federico Legnani, Pietro Mortini, Matteo Maria Naldini, Alessandro Olivi, Roberto Pallini, Monica Patanè, Rosina Paterra, Bianca Pollo, Marco Saini, Silvia Snider, Valentina Brambilla, Stefania Mazzoleni, Andrew Zambanini, Carlo Russo, Luigi Naldini, Fabio Ciceri. Genetically modified Tie-2 expressing monocytes target IFN-α2 to the glioblastoma tumor microenvironment (TME): Preliminary data from the TEM-GBM Phase 1/2a study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5213.

Harnessing genetically engineered hematopoietic progenitor cells to redirect the tumor immune microenvironment against glioblastoma (TEM-GBM Study)

2040

Background: Immunotherapies represent powerful tools that are transforming the treatment of many cancers. However, immune dysfunction in cancer is multifactorial requiring multiple points of action, especially in immunologically-cold tumors. Methods: We have developed a genetically modified, autologous hematopoietic stem cell-based platform designed to deliver Interferon-alpha (IFNa) specifically into the tumor microenvironment through Tie-2 expressing monocytes (Temferon), in order to activate the immune system in an agnostic way against the tumor and re-establish immunosurveillance. Results: As of Jan 2022, 3 escalating doses of Temferon (from 0.5 to 2.0x106/kg) were tested across 15 patients assigned to 5 cohorts affected by newly diagnosed, unmethylated MGMT glioblastoma (GBM). The follow-up range from surgery is 5 – 27 mo (3 – 24 mo after Temferon). In all patients, we observed rapid engraftment of gene modified progenitors and fast recovery from sub-myeloablative conditioning (median engraftment across all the cohorts: Neu D+13, PLT D+14). Temferon-derived differentiated cells, as determined by the presence of vector genomes in the DNA, were found at increasing proportions in blood and bone marrow, reaching up to 30% at 1 mo for the highest dose cohorts tested and persisting up to 18 mo, albeit at lower levels. Despite the significant proportion of engineered cells, only very low median concentrations of IFNα were detected in the plasma (D+30, 5.9; D+90, 8.8pg/mL) and in the CSF (D+30, 1.5; D+90, 2.4pg/mL), indicating tight regulation of vector expression. SAEs were mostly attributed to conditioning chemotherapy (e.g. infections) or disease progression (e.g. seizures). 1 SUSAR (persistent GGT elevation) has occurred. Median OS is 14 mo from surgery (10 mo post Temferon). A patient from cohort 3, had at D+120 disease progression with two distant enhancing lesions, and increased tumor necrosis. One year following Temferon, with no 2nd line therapy added, there was approximately 40% reduction in enhancing tumor volume compared to D+180. Four pts from the low dose cohorts underwent 2nd surgery. Vector genomes were detectable in tumor biopsies. Single cell RNA seq performed on CD45+ cells purified from the GBM TME highlighted the presence of an Interferon gene signature in all patients, resulting in macrophage repolarization in some of them. Conclusions: Our interim results show that Temferon is well tolerated, with no dose limiting toxicities identified to date. The results provide initial evidence of Temferon’s potential to modulate the TME of GBM patients. Clinical trial information: NCT03866109.

Deciphering the Labyrinthine System of the Immune Microenvironment in Recurrent Glioblastoma: Recent Original Advances and Lessons from Clinical Immunotherapeutic Approaches

The interpretation of the presence and function of immune infiltration in glioblastoma (GBM) is still debated. Over the years, GBM has been considered a cold tumor that is less infiltrated by effector cells and characterized by a high proportion of immunosuppressive innate immune cells, including GBM-associated microglia/macrophages (GAMs). In this context, the failure of checkpoint inhibitors, particularly in recurrent GBM (rGBM), caused us to look beyond the clinical results and consider the point of view of immune cells. The tumor microenvironment in rGBM can be particularly hostile, even when exposed to standard immunomodulatory therapies, and tumor-infiltrating lymphocytes (TILs), when present, are either dysfunctional or terminally exhausted. However, after checkpoint blockade therapy, it was possible to observe specific recruitment of adaptive immune cells and an efficient systemic immune response. In this review article, we attempt to address current knowledge regarding the tumor and immune microenvironment in rGBM. Furthermore, immunosuppression induced by GAMs and TIL dysfunction was revisited to account for genetic defects that can determine resistance to therapies and manipulate the immune microenvironment upon recurrence. Accordingly, we reevaluated the microenvironment of some of our rGBM patients treated with dendritic cell immunotherapy, with the goal of identifying predictive immune indicators of better treatment response.

Carcinomatosis under control by osimertinib in EGFR and TP53 mutated lung adenocarcinoma

INTRODUCTION

Approximately 25%-30% of patients with non-small cell lung cancer (NSCLC) develop central nervous system (CNS) metastases during the course of the disease; this percentage is higher in patients with epidermal growth factor receptor (EGFR) mutations. Leptomeningeal metastases, infrequent in the advanced setting, have a particularly dismal prognosis. Osimertinib, a third-generation EGFR inhibitor, can provide effective and durable response in this setting.

CASE DESCRIPTION

We present a 62-year-old man with progressive vomiting, headache, short-term memory impairment, and left lower limb hyposthenia. Computed tomography (CT) showed bilateral lung nodules, multiple lymphadenopathies, liver and bone metastases, and CNS and leptomeningeal dissemination, including multiple parenchymal nodules located at supra- and infratentorial brain. Bone needle biopsy documented TTF1+ lung adenocarcinoma. Whole brain radiotherapy (WBRT) and symptomatic treatments were started. Next-generation sequencing reported deletion of exon 19 of EGFR and mutation 8 of TP53. Osimertinib 80 mg was promptly started and WBRT interrupted. Some days after the patient experienced repetitive seizures and neurologic worsening, antiepileptic drugs and dexamethasone were implemented, with gradual improvement. Radiologic evaluation, including brain MRI and thorax-abdominal CT, showed partial response on CNS as well as extracranial sites, which was sustained.

CONCLUSIONS

First-line treatment with osimertinib can be safe and effective in EGFR-mutated NSCLC even in presence of multiple negative predictive factors (poor Performance Status, diffuse leptomeningeal involvement, TP53 comutation), suggesting that deferring local treatments can be feasible in this setting, allowing the patient to maintain a good quality of life.

IMMU-01. TEM-GBM: AN OPEN-LABEL, PHASE I/IIA DOSE-ESCALATION STUDY EVALUATING THE SAFETY AND EFFICACY OF GENETICALLY MODIFIED TIE-2 EXPRESSING MONOCYTES TO DELIVER IFN-A WITHIN GLIOBLASTOMA TUMOR MICROENVIRONMENT

Temferon is a macrophage-based treatment relying on ex-vivo transduction of autologous HSPCs to express immune-payloads within the TME. Temferon targets the immune-modulatory molecule IFN-a, to a subset of tumor infiltrating macrophages known as Tie-2 expressing macrophages (TEMs) due to the Tie2 promoter and a post-transcriptional regulation layer represented by miRNA-126 target sequences. As of 31st May 2021, 15-patients received Temferon (D+0) with follow-up of 3 – 693 days. After conditioning neutrophil and platelet engraftment occurred at D+13 and D+13.5, respectively. Temferon-derived differentiated cells, as determined be the number of vector copy per genome, were found within 14 days post treatment and persisted albeit at lower levels up to 18-months. Very low concentrations of IFN-a in the plasma (8.7 pg/ml-D+30) and in the CSF (1.6 pg/ml-D+30) were detected, suggesting tight regulation of transgene expression. Five-deaths occurred at D+322, +340, +402, +478 and +646 due to PD, and one at D+60 due to complications following the conditioning regimen. Eight-patients had progressive disease (range: D-11 to +239) as expected for this tumor type. SAEs include GGT elevation (possibly related to Temferon) and infections, venous thromboembolism, brain abscess, hemiparesis, seizures, anemia and general physical condition deterioration, compatible with ASCT, concomitant medications and PD. Four-patients underwent 2ndsurgery. Recurrent tumors had gene-marked cells and increased expression of ISGs compared to first surgery, indicative of local IFNa release by TEMs. In one patient, a stable lesion had a higher proportion of T cells and TEMs within the myeloid infiltrate and an increased ISGs than in the progressing lesion, detected in the same patient. Tumor-associated clones expanded in the periphery. TME characterization by scRNA and TCR-sequencing is ongoing. To date, Temferon is well tolerated, with no DLTs identified. The results provide initial evidence of Temferon potential to activate the immune system of GBM patients, as predicted by preclinical studies.

P12.04 Body Mass Index: a possible PICC-related complications risk factor in neuro oncological patients

BACKGROUND

The use of central venous catheter with peripheral insertion (PICC) has increased rapidly in recent years particularly in cancer patients because they represent a stable and safe vascular access to administer irritants or vesicants therapies. However, the benefit provided may occasionally be affected by severe complications. An observational study conducted at our Institute, showed a significant increase of thromboembolic risk in neuro-oncological patients compared to general cancer population (16.3% vs 6.7% respectively). For this reason, it is essential to identify independent risk factors in order to avoid preventable harm.

MATERIAL AND METHODS

Neuro-oncological patients with PICC that developed a thromboembolic event were retrospectively analyzed. We evaluated clinical data, BMI, KPS, steroid therapies and anticoagulants at the time of positioning of the PICC and at the onset of the thrombotic event.

RESULTS

A total of 90 neuro-oncological patients have been analyzed. The most common histology was represented by glioblastoma, followed by anaplastic astrocytoma, primary central nervous system lymphoma, grade II glioma. 17.6% of patients were at first diagnoses, 41.6% were at the first recurrence, and the remaining patients were at the second or third recurrence. The median KPS was 90 (range 80–100), and the median ECOG was 0 (range 0–2). Overall, 14% patients developed thromboembolic events within a median time of 34.5 days (range 5–146) after PICC implantation. Among these, 64% of patients was considered overweight. No patients were on anticoagulant therapy but all were treated with a median dose of 5.5 mg of steroids (range 3,5-12), stable between PICC insertion and onset of adverse event.

CONCLUSION

64% of patients who developed a thromboembolic event had BMI >28 at the time of PICC insertion, suggesting a possible trend towards a risk of developing PICC related thrombosis in overweight/obese patients. Other independent risk factors for PICC associated complications seems to be amount of previous chemotherapies administered: 82% of patients who developed thrombotic complications had already undergone at least one line of chemotherapy before PICC placement, suggesting this condition as a possible risk factor for the onset of the event. Also failed positioning attempts could damage vascular endothelium, contributing to the onset of thrombotic complications. An accurate anamnesis and a physical evaluation with particular attention to the presence of malnutrition could help in the in the early identification of independent risk factors that could farther negatively influence the outcome of neuro-oncological patients.

Abstract CT180: Changes in immunologic responses and in the tumor microenvironment in patients with glioblastoma multiforme treated with IFN-a immune cell and gene therapy (TEM-GBM_001 Study)

Genetically modified cell-based therapies are of increasing relevance in immuno-oncology due to their potential for tumor specificity, long term efficacy & limiting off-target effects. We have developed a genetically modified cell-based platform, with ex-vivo transduction of autologous hematopoietic stem & progenitor cells with a lentiviral vector expressing the IFN-α transgene (Temferon) & delivery by autologous stem cell transplantation (ASCT). Specific control mechanisms restrict transgene expression to Tie-2 expressing macrophages (TEMs) thanks to a specific Tie-2 promoter & a post-transcriptional regulation layer represented by miRNA target sequences.

TEM-GBM is an ongoing open-label, Phase I/IIa dose-escalation study evaluating safety & efficacy of Temferon in newly diagnosed patients with glioblastoma & unmethylated MGMT promoter. Part A includes 15 patients to optimize the dose & conditioning regimen (completion expected end of Q2/21), & Part B includes 6 patients.

By 10th Nov 2020, 13 patients had enrolled; 8 received Temferon with a median follow up of 298 days (53-491). One patient died from progressive disease (PD) at D+403. PD occurred in 6 patients after a median 123 days (83-229) from treatment, within expectations for this tumor type. 4 patients underwent second surgery. Temferon was well tolerated, with median neutrophil & platelet engraftment occurring at D+13 & D+12, respectively, post submyeloablative BCNU + Thiotepa conditioning, & without dose-limiting toxicities. SAEs attributed to ASCT, concomitant medications & GBM progression included febrile neutropenia & other infectious complications, venous thromboembolism, poor performance status, liver enzyme elevation, brain abscess & hemiparesis. Temferon-derived differentiated cells, as determined by the presence of vector genomes in peripheral blood & bone marrow, were evident within 14 days from treatment & persisted, albeit at lower levels, in the long term (up to 1 year). The built-in transgene expression control mechanism was effective as suggested by the very low concentrations of IFN-α detected in the plasma & cerebrospinal fluid. The T-cell immune repertoire changed after treatment, with evidence for expansion of tumor-associated clones in peripheral blood. Preliminary data on tumor specimens from second surgery confirmed the presence of TEMs & increased expression of IFN-responsive gene signatures compared to diagnosis indicative of local IFN-α release. Biopsies of a stable as compared to a progressing lesion in 1 patient had a higher proportion of T cells & TEMs within the myeloid infiltrate & a markedly increased IFN-response signature. Comprehensive characterization of the tumor microenvironment by scRNA sequencing is ongoing. The results provide initial evidence of the biological effects of Temferon in patients with GBM.

Citation Format: Bernhard Gentner, Gaetano Finocchiaro, Francesca Farina, Alessia Capotondo, Marica Eoli, Elena Anghileri, Maya Ganzetti, Matteo Carabba, Valeria Cuccarini, Francesco Di Meco, Federico Legnani, Bianca Pollo, Maria Grazia Bruzzone, Marco Saini, Paolo Ferroli, Roberto Pallini, Alessandro Olivi, Rosina Paterra, Mariagrazia Garramone, Stefania Mazzoleni, Valentina Brambilla, Tiziana Magnani, Gabriele Antonarelli, Matteo Naldini, Matteo Barcella, Carlo Russo, Luigi Naldini, Fabio Ciceri. Changes in immunologic responses and in the tumor microenvironment in patients with glioblastoma multiforme treated with IFN-a immune cell and gene therapy (TEM-GBM_001 Study) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT180.

A phase I-IIa study of genetically modified Tie-2 expressing monocytes in patients with glioblastoma multiforme (TEM-GBM Study)

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Background: Genetically modified cell-based therapies are relevant in immuno-oncology due to their potential for tumor specificity & potential durability. We developed a cell-based treatment, Temferon, relying on ex-vivo transduction of autologous HSPCs to express therapeutic payloads within the tumor microenvironment. Temferon targets IFNa to Tie-2 expressing macrophages (TEMs). Methods: TEM-GBM is an open-label, Phase I/IIa dose-escalation study evaluating safety & efficacy of Temferon in up to 21 newly diagnosed patients with glioblastoma & unmethylated MGMT promoter. Autologous HSPCs are transduced ex-vivo with a lentiviral vector encoding for IFNa. The transgene expression is confined to TEMs due to the Tie2 promoter & the post-transcriptional regulation by miRNA-126. Results: As of January 17 2021, 15 patients have been enrolled; 9 received Temferon (D+0) with follow-up of 61 – 559 days. There was rapid engraftment & hematological recovery after the conditioning regimen. Median neutrophil & platelet engraftment occurred at D+13 & D+12, respectively. Temferon-derived differentiated cells, as determined by the presence of vector genomes in the DNA of peripheral blood & bone marrow cells, were found within 14 days post treatment & persisted subsequently, albeit at lower levels (up to 18 months). We also detected very low concentrations of IFNa in the plasma (median 5pg/ml at D+30; baseline < LLOQ) & in the cerebrospinal fluid, suggesting tight regulation of transgene expression. Three deaths occurred: two at D+343 & +402 after Temferon administration due to disease progression, & one at D+60 due to complications following the conditioning regimen. Seven patients had progressive disease (PD; range D+27-239) as expected for this tumor type. SAEs include infections, venous thromboembolism, brain abscess, hemiparesis, GGT elevation & poor performance status compatible with autologous stem cell transplantation, concomitant medications & PD. Four patients underwent second surgery. These recurrent tumors had gene-marked cells present & increased expression of IFN-responsive gene signatures compared to diagnosis, indicative of local IFNa release by TEMs. In one patient a stable lesion (as defined by MRI) had a higher proportion of T cells & TEMs within the myeloid infiltrate & an increased IFN-response signature than in a progressing lesion. The T-cell immune repertoire changed with evidence for expansion of tumor-associated clones. Tumor microenvironment characterization by scRNA & TCR sequencing is ongoing. Conclusions: Our interim results show that Temferon is well tolerated by patients, with no dose limiting toxicities identified to date. The results provide initial evidence of Temferon potential to modulate the TME of GBM patients, as predicted by preclinical studies. Clinical trial information: NCT03866109.

Neuro-telehealth for fragile patients in a tertiary referral neurological institute during the COVID-19 pandemic in Milan, Lombardy

Background

Lombardy was severely hit by the COVID-19 pandemic since February 2020 and the Health System underwent rapid reorganization. Outpatient clinics were stopped for non-urgent patients: it became a priority to manage hundreds of fragile neurological patients who suddenly had less reference points. In Italy, before the pandemic, Televisits were neither recognized nor priced.

Methods

At the Fondazione IRCCS Istituto Neurologico C. Besta, we reorganized outpatient clinics to deliver Neuro-telemedicine services, including Televisits and Teleneurorehabilitation, since March 2020. A dedicated Working Group prepared the procedure, tested the system, and designed satisfaction questionnaires for adults and children.

Results

After a pilot phase, we prepared a procedure for Telemedicine outpatient clinics which was approved by hospital directions. It included prescription, booking, consenting, privacy and data protection, secure connection with patients (Teams Microsoft 365), electronic report preparation and delivery, reporting, and accountability of the services. During the March–September 2020 period, we delivered 3167 Telemedicine services, including 1618 Televisits, to 1694 patients (972 adults, 722 children) with a wide range of chronic neurological disorders. We successfully administered different clinical assessment and scales. Satisfaction among patients and caregivers was very high.

Conclusions

During the dramatic emergency, we were able to take care of more than 1600 patients by organizing Neuro-telehealth in a few weeks, lessening the impact of the pandemic on fragile patients with chronic neurological disorders; this strategy is now stably embedded in our care pathways. In Italy, Telehealth is at present recognized and priced and is becoming a stable pillar of the health system.

MYD88 L265P mutation and interleukin-10 detection in cerebrospinal fluid are highly specific discriminating markers in patients with primary central nervous system lymphoma: results from a prospective study

Reliable biomarkers are needed to avoid diagnostic delay and its devastating effects in patients with primary central nervous system (CNS) lymphoma (PCNSL). We analysed the discriminating sensitivity and specificity of myeloid differentiation primary response (88) (MYD88) L265P mutation (mut-MYD88) and interleukin-10 (IL-10) in cerebrospinal fluid (CSF) of both patients with newly diagnosed (n = 36) and relapsed (n = 27) PCNSL and 162 controls (118 CNS disorders and 44 extra-CNS lymphomas). The concordance of MYD88 mutational status between tumour tissue and CSF sample and the source of ILs in PCNSL tissues were also investigated. Mut-MYD88 was assessed by TaqMan-based polymerase chain reaction. IL-6 and IL-10 messenger RNA (mRNA) was assessed on PCNSL biopsies using RNAscope technology. IL levels in CSF were assessed by enzyme-linked immunosorbent assay. Mut-MYD88 was detected in 15/17 (88%) PCNSL biopsies, with an 82% concordance in paired tissue-CSF samples. IL-10 mRNA was detected in lymphomatous B cells in most PCNSL; expression of IL-6 transcripts was negligible. In CSF samples, mut-MYD88 and high IL-10 levels were detected, respectively, in 72% and 88% of patients with newly diagnosed PCNSL and in 1% of controls; conversely, IL-6 showed a low discriminating sensitivity and specificity. Combined analysis of MYD88 and IL-10 exhibits a sensitivity and specificity to distinguish PCNSL of 94% and 98% respectively. Similar figures were recorded in patients with relapsed PCNSL. In conclusion, high detection rates of mut-MYD88 and IL-10 in CSF reflect, respectively, the MYD88 mutational status and synthesis of this IL in PCNSL tissue. These biomarkers exhibit a very high sensitivity and specificity in detecting PCNSL both at initial diagnosis and relapse. Implications of these findings in patients with lesions unsuitable for biopsy deserve to be investigated.

Adjuvant chemotherapy after severe myelotoxicity during chemoradiation phase in malignant gliomas. Is it feasibile? Results from AINO study (Italian Association for Neuro-Oncology)

BACKGROUND

Malignant gliomas (MG) are aggressive brain tumours in adults. The standard of care is concurrent radiation plus temozolomide (TMZ) [chemo-radiotherapy (CRT)] followed by TMZ maintenance up to 6 months. TMZ is considered to have a low toxicity profile, but several studies reported occurrence of severe myelosuppression, especially during the concomitant phase. Toxicity may be prolonged, thus treatment should be discontinued.

PURPOSE

To evaluate the risk of recurrente myelotoxicity during adjuvant chemotherapy (CT) in patients who recovered from severe myelotoxicity during CRT.

METHODS

We retrospectively collected data on patients with MG who developed and recovered from severe myelotoxicity during CRT from eight Italian neuro-oncology centers.

RESULTS

We included 87 patients. Histology was Glioblastoma (GBM) in 78 patients (89.7%); 60% of patients were female. After myelotoxicity recovery, 54 (62%) received treatment. The majority of them (82%, n = 44) received adjuvant TMZ and 18% (n = 10) others treatments. Out of 44 patients who received adjuvant TMZ, 34% experienced the re-occurrence of grade 3-4 myelotoxicity which required permanent CT discontinuation in 6 (13%) cases. Patients who received TMZ or other treatments had longer overall (OS) (adjusted HR 0.46, p = 0.008) and progression free survival (PFS) (adjusted HR 0.57, p = 0.034) than those who remained untreated.

CONCLUSION

Our study suggests that after severe myelotoxicity the majority of patients received treatment, particularly with TMZ. Only a fraction of patients experienced toxicity recurrence, suggesting that TMZ is well tolerated and had an impact on PFS and OS.

CTIM-24. AUTOLOGOUS CD34+ ENRICHED HEMATOPOIETIC PROGENITOR CELLS GENETICALLY MODIFIED FOR HUMAN INTERFERON-α2, ARE WELL TOLERATED & RAPIDLY ENGRAFT IN PATIENTS WITH GLIOBLASTOMA MULTIFORME (TEM-GBM_001 STUDY)

GBM with an unmethylated MGMT gene promoter is associated with very poor prognosis. A subset of tumor associated macrophages expressing the angiopoietin receptor Tie2 (TEMs) can be genetically modified for local & tumor restricted release of interferon-α2 (IFN). IFN has antitumor effects, inhibits angiogenesis & modulates the immune system. Temferon consists of autologous HSPCs transduced ex-vivo with an LVV encoding an IFN gene & expression control sequences for TEMs. TEM-GBM is an open-label, Phase I/IIa study (Part A: 3x3x3 dose escalation; Part B: n=12), & Temferon (single dose) is given to patients with first diagnosis of GBM & unmethylated MGMT promoter. Part A 3rd cohort is ongoing & completes dosing in September 2020. Eight patients completed screening; one patient died (disease progression) before Temferon was administered. Six patients received Temferon (3 women, 3 men, mean age 52.3 years). Cohort 1 received Temferon 0.5x106 cells/kg & Cohort 2, 1x106 cells/kg. Neutropenia & thrombocytopenia occurred as expected following conditioning & hematologic recovery (HR) occurred median D+13. Transduced PBMCs were identified by vector copy number (VCN) on myeloid cells at HR & at later timepoints. In general, a dose-ordered increase in VCN was observed (mean VCN D+30 CD14+ Cohort 1: 0.094, cohort 2: 0.125); 1 patient in each cohort had low VCNs. VCN remained detectable up to recent follow up visits (≤ D+180). No dose-limiting toxicities have been reported. Four SAEs occurred in 3 patients who received Temferon (pneumonia, pulmonary embolism, febrile neutropenia, fatigue) but these events were not attributed to Temferon, resolved, & may have been related to the conditioning regimen (carmustine & thiotepa). Disease progression has been confirmed in 3 patients who received Temferon. These preliminary results indicate feasibility of engrafting a pre-determined fraction of Temferon cells in the bone marrow of GBM patients without, so far, causing dose-limiting toxicity.

Medulloblastoma of the adult: results from a multicenter retrospective study by AINO (Italian Association of Neuro-Oncology) and SIN (Italian Society of Neurology)

INTRODUCTION

Medulloblastoma (MB) is the most common primary malignant intracranial tumor in childhood, but it is very rare in adults, and for this reason, the optimal treatment has not yet been defined. We designed a multicentric study in order to define relevant outcome measures for future prospective studies.

MATERIALS AND METHODS

The project involved 10 Italian centers. The database shared among the centers contains epidemiological, diagnostic (radiological and histological/molecular), therapeutic, recurrence information, and survival data.

RESULTS

A total of 152 patients (102 males and 50 females, median age 32) were included in the study. Twenty-three of 152 patients had a diagnosis of classic medulloblastoma, 52/152 had desmoplastic/extensive nodularity, 2/152 had large-cell anaplastic medulloblastoma, and the remaining had diagnoses not otherwise specified. Almost all patients underwent craniospinal irradiation after surgery; in 85.5% of patients, adjuvant chemotherapy, mainly platinum- and etoposide-based chemotherapy, was performed immediately after RT. Upon recurrence, most patients were retreated with various chemotherapy regimens, including intrathecal chemotherapy in patients with leptomeningeal dissemination. The overall survival (OS) rate at 5 years was 73.3% (95% CI, 65.0-80.0%). The median OS for the whole group of patients was 112 months.

CONCLUSIONS

The data collected were mainly consistent with the literature. A limitation of this study was the large number of patients lost to follow-up and the lack of molecular data for most patients diagnosed until 2010. An important challenge for the future will be MB biologic characterization in adults, with the identification of specific genetic patterns. It will be important to have more national and international collaborations to provide evidence-based management strategies that attempt to obtain a standard of care.

Advanced MRI Assessment during Dendritic Cell Immunotherapy Added to Standard Treatment Against Glioblastoma

Evaluating changes induced by immunotherapies (IT) on conventional magnetic resonance imaging (MRI) is difficult because those treatments may produce inflammatory responses. To explore the potential contribution of advanced MRI to distinguish pseudoprogression (PsP) and true tumor progression (TTP), and to identify patients obtaining therapeutic benefit from IT, we examined aMRI findings in newly diagnosed glioblastoma treated with dendritic cell IT added to standard treatment. We analyzed longitudinal MRIs obtained in 22 patients enrolled in the EUDRACT N° 2008-005035-15 trial. According to RANO criteria, we observed 18 TTP and 8 PsP. Comparing MRI performed at the time of TTP/PsP with the previous exam performed two months before, a difference in cerebral blood volume ΔrCBV_max ≥ 0.47 distinguished TTP from PsP with a sensitivity of 67% and specificity of 75% (p = 0.004). A decrease in minimal apparent diffusion coefficient rADC_min (1.15 vs. 1.01, p = 0.003) was observed after four vaccinations only in patients with a persistent increase of natural killer cells (response effectors during IT) in peripheral blood. Basal rADC_min > 1 was independent predictor of longer progression free (16.1 vs. 9 months, p = 0.0001) and overall survival (32.8 vs. 17.5 months, p = 0.0005). In conclusion, rADC predicted response to immunotherapy and survival; Apparent Diffusion Coefficient (ADC) and Cerebral Blood Volume (CBV) modifications over time help differentiating PsP from TTP at onset.

Prospective observational study on the complications and tolerability of a peripherally inserted central catheter (PICC) in neuro-oncological patients

PURPOSE

The use of central venous catheters with peripheral insertion (PICC) has increased rapidly in recent years, particularly in cancer patients. The benefits provided may occasionally be affected by relevant complications, such as infections and thrombotic events, especially in neuro-oncological patients. To date, the risk of PICC-related complications in this subset of patients is unknown, as is tolerability. As a primary objective, this study aimed to collect complications related to PICCs in primary neuro-oncological patients. As a secondary objective, the study aimed to evaluate PICC tolerability.

METHODS

Neuro-oncological patients with PICCs that were placed as part of normal clinical practice at IRCCS Neurologico C. Besta were consecutively enrolled in the study. PICC-related complications were recorded immediately (during the procedure), early (within 1 week after PICC insertion), and late (1-3-5 months after PICC placement). At the same time points, all patients were also evaluated for tolerability through interviews with semi-structured, open-ended questions.

RESULTS

Sixty patients were enrolled (41 males and 19 females, with a median age of 56.2 years). Excluding loss to follow-up, 33/49 patients developed at least one complication related to the PICC. Immediate complications mainly included hematoma (8), accidental arterial puncture (4), and primary malpositioning (3). Regarding early and late complications, 3 device-related infections, 8 thrombotic events, and 20 mechanical complications were registered. Semi-structured interviews revealed an overall positive experience with the device. The most negative impact was on hygiene habits, with 34 patients becoming caregiver-dependent. Over time, almost all patients became used to the device and perceived greater security during chemotherapy. A strongly negative issue was the difficulty of relying on competently trained healthcare personnel in outpatient setting.

CONCLUSION

The results showed a nonnegligible increased thromboembolic risk in neuro-oncological patients with PICCs, almost double that in historical oncological populations. It is essential to extend the study to a greater number of patients to achieve reliable results and to identify patients at high risk. The device seems to be positively accepted by the majority of patients, without affecting activities of daily living.

P14.64 Primary Central Nervous System Lymphoma (PCNSL) with HD- MTX based chemotherapy: tolerability and results

BACKGROUND

Primary Central nervous system (CNS) lymphomas (PCNSL) are extranodal, malignant non- Hodgkin lymphomas of the diff use large B-cell type, confined to CNS. It accounts for up to 1% of all lymphomas and about 3% of all CNS tumours. The incidence continues to rise in immuno- competent elderly patients.Although the prognosis of PCNSL remains poor, it has improved in the past two decades as a result of better treatment strategies. However, treatment recommendations still result mainly from retrospective series or single-arm phase 2 studies and a few three completed randomised trials. We described a series of patients with newly diagnosis of PCNSL treated with modified-schedula published by Omuro

MATERIAL AND METHODS

Patients was treated with HD-MTX, procarbazine, vincristine, received four 28-day cycles of chemotherapy, on schedule: HD-MTX (3·5 g/m²) days 1 and 15; Procarbazine (100 mg/m²) on days 1–7. Vincristine (1·4 mg/m²) on days 1 and 15. Toxicity was assessed with Common Terminology Criteria for Adverse Events version 4. The International PCNSL Collaborative Group Response Criteria were used for response assessment. Endpoints include overall survival (OS) and adverse events (AE).

RESULTS

21 immunocompetent patients (12 females and 9 males) were retrospectively studied, among 2014 to 2019. Median age at diagnosis 61 years (range 41–76). Median KPS at diagnosis was 70 (range 40–100). Clinical and radiological data and treatment related toxicity were described

CONCLUSION

Present combination regimen is effective; however, AE incidence is high, and often induces schedule modification

P14.74 Remarkable response to Combined BRAF and MEK Inhibitors in two Adults with leptomeningeal carcinomatosis secondary to Pleomorphic Xantoastrocytoma grade II with BRAFv600E mutation

BACKGROUND

Several cancers with the BRAF V600E mutations have been successfully treated with targeted therapy. Pleomorphic xanthoastrocytoma (PXA) is a rare brain tumor, with an incidence of 0.07cases per 100,000. The BRAFV600 mutation is present in 38–60% of PXA. Typical treatment is gross total resection, followed by radiotherapy and cytotoxic chemotherapy at recurrence

MATERIAL AND METHODS

Two cases are described.

RESULTS

The first case is a 37 old man with a left temporal lobe lesion who underwent a craniotomy with total tumor resection. Histological diagnosis was PXA WHO grade 2with BRAF V600E mutation.Five months after, MR imaging of his brain and spine showed tumor progression with extensive leptomeningeal disease. The patient received adjuvant brain and spinal radiotherapy Two weeks after, due to rapid clinical worsening he had a new brain and spinal MRI showing hydrocephalus and progression of the pachymeningeal-based masses and received an emergency ventricular -peritoneal shunt. Given the genetic analysis, the extent of disease and rapidity of the progression, BRAF and MEK inhibitors, dabrafenib (150 mg, twice daily) and trametinib (2 mg, daily) were started. Remarkably, within 2 week of initiating dual-targeted therapy, the patient experienced a dramatic improvement in consciousness and overall strength; brainand spinal MRI revealed initial reduction of the leptomenigeal enhacement and no evidence of progression of the intraparenchymal disease. The therapy was well-tolerated. Currently, after sixteen months,the patient remains on treatment with a consistent functional status improvement and no radiological evidence of disease progression. The second case is a 51 old women who developed leptomeningeal carcinomatosis seven year after resection of a frontal left PXA WHO grade 2 with BRAFv600E mutation. The patient had received brain radiotherapy five years after diagnosis and Cyber Knife for tumor progression. Ten months later MR imaging of his brain and spine showed tumor progression with extensive leptomeningeal disease, she was treated with temozolomide for 8 after clinical and radiological worsening she had a second surgery with resection of recurrent frontale left lesion Histopathology PXA WHO grade 2 with BRAF V600E mutation. She developed hydrocephalus, received an emergency ventricular -peritoneal shunt. BRAF and MEK inhibitors, dabrafenib (150 mg, twice daily) and trametinib (2 mg, daily) were started three months ago with initial clinical benefit

CONCLUSION

All patients with PXA should be tested for the BRAFV600 mutation, since, in these cases, targeted therapy with BRAF and MEK inhibitors seems to be a useful option for salvage treatment.

Expansion of effector and memory T cells is associated with increased survival in recurrent glioblastomas treated with dendritic cell immunotherapy

Background

The efficacy of dendritic cell (DC) immunotherapy as a single therapeutic modality for the treatment of glioblastoma (GBM) patients remains limited. In this study, we evaluated in patients with GBM recurrence the immune-mediated effects of DC loaded with autologous tumor lysate combined with temozolomide (TMZ) or tetanus toxoid (TT).

Methods

In the phase I-II clinical study DENDR2, 12 patients were treated with 5 DC vaccinations combined with dose-dense TMZ. Subsequently, in eight patients, here defined as Variant (V)-DENDR2, the vaccine site was preconditioned with TT 24 hours before DC vaccination and TMZ was avoided. As a survival endpoint for these studies, we considered overall survival 9 months (OS9) after second surgery. Patients were analyzed for the generation of effector, memory, and T helper immune response.

Results

Four of 12 DENDR2 patients reached OS9, but all failed to show an immunological response. Five of eight V-DENDR2 patients (62%) reached OS9, and one patient is still alive (OS >30 months). A robust CD8⁺ T-cell activation and memory T-cell formation were observed in V-DENDR2 OS>9. Only in these patients, the vaccine-specific CD4⁺ T-cell activation (CD38⁺/HLA-DR⁺) was paralleled by an increase in TT-induced CD4⁺/CD38^low/CD127^high memory T cells. Only V-DENDR2 patients showed the formation of a nodule at the DC injection site infiltrated by CCL3-expressing CD4⁺ T cells.

Conclusions

TT preconditioning of the vaccine site and lack of TMZ could contribute to the efficacy of DC immunotherapy by inducing an effector response, memory, and helper T-cell generation.

Survival gain in glioblastoma patients treated with dendritic cell immunotherapy is associated with increased NK but not CD8+ T cell activation in the presence of adjuvant temozolomide

In a two-stage phase II study, 24 patients with first diagnosis of glioblastoma (GBM) were treated with dendritic cell (DC) immunotherapy associated to standard radiochemotherapy with temozolomide (TMZ) followed by adjuvant TMZ.

Three intradermal injections of mature DC loaded with autologous GBM lysate were administered before adjuvant TMZ, while 4 injections were performed during adjuvant TMZ. According to a two-stage Simon design, to proceed to the second stage progression-free survival (PFS) 12 months after surgery was expected in at least 8 cases enrolled in the first stage. Evidence of immune response and interaction with chemotherapy were investigated. After a median follow up of 17.4 months, 9 patients reached PFS12. In these patients (responders, 37.5%), DC vaccination induced a significant, persistent activation of NK cells, whose increased response was significantly associated with prolonged survival. CD8⁺ T cells underwent rapid expansion and priming but, after the first administration of adjuvant TMZ, failed to generate a memory status. Resistance to TMZ was associated with robust expression of the multidrug resistance protein ABCC3 in NK but not CD8⁺ T cells. The negative effect of TMZ on the formation of T cell-associated antitumor memory deserves consideration in future clinical trials including immunotherapy.

Fluorescein-Guided Surgery for Resection of High-Grade Gliomas: A Multicentric Prospective Phase II Study (FLUOGLIO)

Purpose: Sodium fluorescein is a dye that, intravenously injected, selectively accumulates in high-grade glioma (HGG) tissue through a damaged blood-brain barrier. In this article, the final results of a multicentric prospective phase II trial (FLUOGLIO) on fluorescein-guided HGG resection through a dedicated filter on the surgical microscope were reported.Methods: Patients with suspected HGGs considered suitable for removal were eligible to participate in this trial. Fluorescein was intravenously injected at a dose of 5 to 10 mg/kg. The primary endpoint was the percentage of patients with histologically confirmed HGGs, without contrast-enhancing tumor at the immediate postoperative MRI. Secondary endpoints were PFS, residual tumor on postoperative MRI, overall survival, neurologic deficits, and fluorescein-related toxicity. The sensitivity and specificity of fluorescein in identifying tumor tissue were estimated by fluorescent and nonfluorescent biopsies at the tumor margin. The study was registered on the European Regulatory Authorities website (EudraCT 2011-002527-18).Results: Fifty-seven patients aged 45 to 75 years were screened for participation, and 46 were considered for primary and secondary endpoints. Mean preoperative tumor volume was 28.75 cm³ (range, 1.3-87.8 cm³). Thirty-eight patients (82.6%) underwent a complete tumor removal. Median follow-up was 11 months. PFS-6 and PFS-12 were 56.6% and 15.2%. Median survival was 12 months. No adverse reaction related to SF administration was recorded. The sensitivity and specificity of fluorescein in identifying tumor tissue were respectively 80.8% and 79.1%.Conclusions: Fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and enables a high percentage of contrast-enhancing tumor in patients with HGGs. Clin Cancer Res; 24(1); 52-61. ©2017 AACR.

Diffuse glioblastoma resembling acute hemorrhagic leukoencephalitis

We report the case of a young man with sudden onset of diplopia after an upper respiratory tract infection. Based on the first radiological findings acute hemorrhagic leukoencephalitis, a variant of acute disseminated encephalomyelitis, was suspected and treatment with high dose intravenous dexamethasone was started but it was stopped for intolerance. The patient clinically worsened, developing gait instability, ataxia and ophthalmoplegia; brain MRI performed 20 days later showed severe progression of the disease with subependymal dissemination. After brain biopsy of the right temporal lesion the histological diagnosis was glioblastoma. These findings suggest that MRI features of acute hemorrhagic leukoencephalitis may dissimulate the diagnosis of diffuse glioma/glioblastoma. This case underscores the importance of considering diffuse glioma in the differential diagnosis of atypical signs and symptoms of acute hemorrhagic leukoencephalitis and underlines the relevant role of integrating neuroradiologic findings with neuropathology.

Apparent diffusion coefficient (ADC) decrease to predict longer survival in glioblastoma patients treated by dendritic cell immunotherapy plus standard of care

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Background: The MRI follow –up of patients affected by glioblastoma (GBM) and treated with immunotherapy may be difficult, as immune responses may mimic tumor progression. To explore the potential contribution of quantitative MRI to the identification of patients with clinical benefit benefit, we used advanced MRI to study GBM patients treated with dendritic cell (DC) immunotherapy added to standard treatment (surgery, radiotherapy with concomitant temozolomide (TMZ) followed by adjuvant TMZ; DENDR1 trial, EUDRACT N° 2008-005035-15). Methods: A retrospective analysis was performed on longitudinal MRIs obtained soon after radiotherapy, within two days before the first vaccination (basal MRI) and every two months, in 22 patients enrolled in DENDR1. The following parameters were collected: tumor volume of contrast–enhanced lesions, mean rCBV, maximal rCBV, mean ADC, minimal ADC, ADC skewness. Receiver Operating Characteristic (ROC) curves were used to determine optimal sensitivity and specificity in differentiating patients as responder or not responder. Association with PFS (as per RANO criteria) and OS was analyzed using log-rank test and Cox regression. Results: Ten patients with PFS > 12 months were defined as responders Their basal mean ADC was significantly higher than in non responders (1.34 ± 0.17 vs 1.14 ± 0.34, p = 0.03). After four DC vaccinations mean ADC significantly decreased in responders only from 1.34 ± 0.17 to 1.23 ±0.23 (p = 0.028); the decrease persisted during immunotherapy. A basal mean ADC value ≥ 1.07 and a decrease in mean ADC value ≥ 0.13 were significant predictors of longer PFS (15.4 vs 9 m p = 0.0006; 17.2 vs 10.2 p = 0.04) and OS (29 vs 12.5 mo p = 0.002; 33 vs 19.9 p = 0.04 No significant correlations between the other parameters and the outcome were observed. Conclusions: Association with prolonged survival may suggest that in DENDR1responders decreased ADC is partly contributed by immune cells infiltrating the tumor.

Needs of neuro-oncological patients and their caregivers during the hospitalization and after discharge: results from a longitudinal study

PURPOSE

The aims of this study are to identify neuro-oncological patients' and their caregivers' needs during hospitalization (T0) and at 4 months after discharge (T1); to analyze the longitudinal changes in patients' and caregivers' needs and burden; to identify correlations between patients' needs and caregivers' burden and needs.

METHODS

A pilot observational longitudinal study was conducted on 94 neuro-oncological patients and their caregivers using NEQ to evaluate patients' needs, CNA, and FSQ for caregivers' needs and burden at T0 and T1. Descriptive statistics were performed to illustrate the distribution of questionnaires' scores. The longitudinal change of NEQ, FSQ, and CNA scores were investigated using Wilcoxon test. Spearman's correlation was used to measure the relation between NEQ and FSQ and CNA scores.

RESULTS

The most frequent patients and caregivers' needs were material and informative. Needs tend to decrease over time; in particular FSQ factor "need for knowledge about the disease", CNA factor "Information/communication needs" and CNA total score significantly decreased (p < 0.001). NEQ total score significantly correlated with FSQ factors "emotional burden" and "need for knowledge about the disease" and CNA total and factors scores at T0 and T1. At T0, NEQ correlated significantly with FSQ factor "thoughts about death", while at T1, it correlated with FSQ factor "problems in social involvement".

CONCLUSIONS

It is crucial to plan an assessment of patients' and caregivers' needs from the very beginning, in order to identify those individuals potentially at risk of developing high level of distress and to provide information and support following the illness trajectory of the brain tumor.

Anti-GD2-like IgM autoreactivity in multiple sclerosis patients

Seric IgM autoreactivity in 100 multiple sclerosis (MS) and 106 control (70 of whom had other neurological diseases) patients was assessed either by immunohistochemistry on normal human CNS tissue or to GD2, GD1a, GD3 by ELISA and thin layer chromatography (TLC) techniques. By double immunohistochemistry, we found that 44% of the total MS population showed seric IgM reactivity to oligodendrocytes and myelin, this finding being particularly frequent in patients with secondary progressive MS. In the non-MS cohort, positive signals were seen only in one patient. In all cases, extraction of lipids from CNS sections abolished the immunoreactivity. Among the gangliosides investigated by ELISA, anti-GD2-like IgM autoantibodies were detected in the serum of 30% of MS patients, a subgroup of whom (below 10%) reacted also with GD1a and/or GD3. More than 85% of MS cases with anti-GD2-like IgM immunoreactivity by ELISA showed also IgM anti-oligodendrocyte/myelin staining by immunohistochemistry. However, no immunostaining in MS sera was observed when gangliosides were resolved by TLC. A positive correlation with neurological disability was observed, as the Expanded Disability Status Scale of MS patients with anti-GD2-like IgM autoreactivity by ELISA was significantly worse than seronegative MS cases. The results of the present study enforce the role of glycolipids as potential autoantigens and of IgM autoantibodies in MS pathogenesis.

Is fluorescein-guided technique able to help in resection of high-grade gliomas?

OBJECT

Fluorescein, a dye that is widely used as a fluorescent tracer, accumulates in cerebral areas where the blood-brain barrier is damaged. This quality makes it an ideal dye for the intraoperative visualization of high-grade gliomas (HGGs). The authors report their experience with a new fluorescein-guided technique for the resection of HGGs using a dedicated filter on the surgical microscope.

METHODS

The authors initiated a prospective Phase II trial (FLUOGLIO) in September 2011 with the objective of evaluating the safety of fluorescein-guided surgery for HGGs and obtaining preliminary evidence regarding its efficacy for this purpose. To be eligible for participation in the study, a patient had to have suspected HGG amenable to complete resection of the contrast-enhancing area. The present report is based on the analysis of the short- and long-term results in 20 consecutive patients with HGGs (age range 45-74 years), enrolled in the study since September 2011. In all cases fluorescein (5-10 mg/kg) was injected intravenously after intubation. Tumor resection was performed with microsurgical technique and fluorescence visualization by means of BLUE 400 or YELLOW 560 filters on a Pentero microscope.

RESULTS

The median preoperative tumor volume was 30.3 cm(3) (range 2.4-87.8 cm(3)). There were no adverse reactions related to fluorescein administration. Complete removal of contrast-enhanced tumor was achieved in 80% of the patients. The median duration of follow-up was 10 months. The 6-months progression-free survival rate was 71.4% and the median survival was 11 months.

CONCLUSIONS

Analysis of these 20 cases suggested that fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and allows a high rate of complete resection of contrast-enhanced tumor as determined on early postoperative MRI. Clinical trial registration no.: 2011-002527-18 (EudraCT).

The natural killer cell response and tumor debulking are associated with prolonged survival in recurrent glioblastoma patients receiving dendritic cells loaded with autologous tumor lysates

Recurrent glioblastomas (GBs) are highly aggressive tumors associated with a 6–8 mo survival rate. In this study, we evaluated the possible benefits of an immunotherapeutic strategy based on mature dendritic cells (DCs) loaded with autologous tumor-cell lysates in 15 patients affected by recurrent GB. The median progression-free survival (PFS) of this patient cohort was 4.4 mo, and the median overall survival (OS) was 8.0 mo. Patients with small tumors at the time of the first vaccination (< 20 cm³; n = 8) had significantly longer PFS and OS than the other patients (6.0 vs. 3.0 mo, p = 0.01; and 16.5 vs. 7.0 mo, p = 0.003, respectively). CD8⁺ T cells, CD56⁺ natural killer (NK) cells and other immune parameters, such as the levels of transforming growth factor β, vascular endothelial growth factor, interleukin-12 and interferon γ (IFNγ), were measured in the peripheral blood and serum of patients before and after immunization, which enabled us to obtain a vaccination/baseline ratio (V/B ratio). An increased V/B ratio for NK cells, but not CD8⁺ T cells, was significantly associated with prolonged PFS and OS. Patients exhibiting NK-cell responses were characterized by high levels of circulating IFNγ and E4BP4, an NK-cell transcription factor. Furthermore, the NK cell V/B ratio was inversely correlated with the TGFβ2 and VEGF V/B ratios. These results suggest that tumor-loaded DCs may increase the survival rate of patients with recurrent GB after effective tumor debulking, and emphasize the role of the NK-cell response in this therapeutic setting.