Therapy For High-grade Glioma Research Articles

Oxime Linked Doxorubicin Glycoconjugates Improve the Specific Targeting of Glioblastoma in High-Grade Glioma Therapy

Oxime Linked Doxorubicin Glycoconjugates Improve the Specific Targeting of Glioblastoma in High-Grade Glioma Therapy

M6A RNA METHYLATION AS A THERAPEUTIC TARGET IN HIGH GRADE GLIOMA

Abstract AIMS High grade glioma (HGG) is a devastating brain cancer that has poor prognostic outcomes. Very recently, the field of epitranscriptome has emerged as a novel druggable target for multiple diseases, including cancers. In the present study, we sought to investigate the functional importance of N6-methyladenosine (m6A) RNA methylation in the pathogenesis and drug resistance of paediatric and adult high grade glioma. METHOD To identify the expression of key m6A effectors, RT-qPCR and immunofluorescence were undertaken in patient derived HGG cell lines, primary low passage HGG cells and human tissues. The expression of these effectors was modified using siRNA-mediated knockdown and small molecules to identify their effects on key transcription factors. The consequences of modification on the ability of the cells to form neurospheres and invade was also assessed. Developing chemotherapy-resistant cell lines is undertaking to assess the effect of m6A RNA levels on the ability of HGG cells to adapt to environmental changes. Measuring the level of m6A-modified transcripts were achieved by developing LC-MS/MS and MeRIP (methylated RNA immunoprecipitation) qPCR techniques. RESULTS We found that key m6A effectors such as methyltransferase like 3 (METTL3), Wilms tumor 1-associating protein (WTAP) and fat mass and obesity-associated (FTO) are expressed at significantly higher level in paediatric and adult HGG models than in control at both gene and protein levels. Furthermore, these effectors regulate the expression of key transcription factors in self-renewal, cell cycle regulation and tumorigenesis. siRNA-mediated depletion of m6A effectors and inhibition of METTL3 using small molecules such as STM2457 and STM3006 reduce the capacity of cells to form neurospheres and invade as well as improving the sensitivity of HGG cells to chemotherapeutic agents. CONCLUSION Our findings suggest that m6A effectors are potential pro-oncogenic factors that, if druggable, will represent an advanced avenue in HGG therapy.

Advancements and challenges: immunotherapy therapy in high-grade glioma- a meta-analysis of randomized clinical trials.

High-grade gliomas (HGG)are the most aggressive primary brain tumors with poor prognoses despite conventional treatments. Immunotherapy has emerged as a promising avenue due to its potential to elicit a targeted immune response against tumor cells. This meta-analysis aimed to evaluate the efficacy and safety of various immunotherapeutic strategies, including immune checkpoint inhibitors (ICI), virotherapy, and dendritic cell vaccines (DCV) in treating HGG. Following the PRISMA framework, we searched PubMed, Cochrane, and Embase for studies reporting outcomes of HGG patients treated with immunotherapy. Key metrics included overall survival, progression-free survival, and treatment-related adverse events. We reviewed 47 studies, analyzing data from 3674 HGG patients treated with immunotherapy. The mean overall survival for patients treated with ICI was 11.05months, with virotherapy at 11.79months and notably longer for DCV at 24.11months. The mean progression-free survival (PFS) for ICIs was 3.65months. Virotherapy demonstrated a PFS favoring the control group, indicating minimal impact, while DCV showed substantial PFS improvementwith a median of 0.43 times lower hazard compared to controls (95% CI: 29-64%). Adverse events were primarily Grade 1 or 2 for ICI, included a Grade 5 event for virotherapy, and were predominantly Grade 1 or 2 for DCV, indicating a favorable safety profile. Immunotherapy holds potential as an effective treatment for HGG, especially DCV. However, results vary significantly with the type of therapy and individual patient profiles. Further randomized controlled trials are necessary to establish robust clinical guidelines and optimize treatment protocols.

A Cross-Sectional Analysis of Interventional Clinical Trials in High-Grade Glioma Therapy.

High-grade glioma is the most frequent and lethal primary tumor of the central nervous system. Despite advances in surgical, pharmacological, and cell-directed therapies, there have been no updates to the standard of care in over a decade. This cross-sectional study analyzes patient and trial data from 201 interventional trials completed between 2010 and 2023, encompassing 18,563 participants. Although we found that all trials reported participant age and sex, only 52% of trials reported participant demographics, resulting in 51% of total participant demographics being unreported. The majority of studies did not report ethnicity, with approximately 60% of participants unreported. Additionally, males were significantly underrepresented in trials, comprising 60% of participants despite representing 75% of glioblastoma patients. Improved demographic reporting has been observed since 2011; however, it is inconsistent. Furthermore, we cataloged the geographic diversity of trials across the United States and found significant coverage deserts in relatively rural, but highly affected, areas such as Montana and Maine. We found a wider distribution of trials in both urban and wealthier regions, which indicates extensive coverage gaps and decreased access to participation for patients of a lower socioeconomic status.

Endovascular Applications for the Management of High-Grade Gliomas in the Modern Era.

High-grade gliomas (HGGs) have a poor prognosis and are difficult to treat. This review examines the evolving landscape of endovascular therapies for HGGs. Recent advances in endovascular catheter technology and delivery methods allow for super-selective intra-arterial cerebral infusion (SSIACI) with increasing precision. This treatment modality may offer the ability to deliver anti-tumoral therapies directly to tumor regions while minimizing systemic toxicity. However, challenges persist, including blood-brain barrier (BBB) penetration, hemodynamic complexities, and drug-tumor residence time. Innovative adjunct techniques, such as focused ultrasound (FUS) and hyperosmotic disruption, may facilitate BBB disruption and enhance drug penetration. However, hemodynamic factors that limit drug residence time remain a limitation. Expanding therapeutic options beyond chemotherapy, including radiotherapy and immunobiologics, may motivate future investigations. While preclinical and clinical studies demonstrate moderate efficacy, larger randomized trials are needed to validate the clinical benefits. Additionally, future directions may involve endovascular sampling for peri-tumoral surveillance; changes in drug formulations to prolong residence time; and the exploration of non-pharmaceutical therapies, like radioembolization and photodynamic therapy. Endovascular strategies hold immense potential in reshaping HGG treatment paradigms, offering targeted and minimally invasive approaches. However, overcoming technical challenges and validating clinical efficacy remain paramount for translating these advancements into clinical care.

Abstract A017: Cell-specific photodynamic therapy for high grade gliomas

Abstract A017: Cell-specific photodynamic therapy for high grade gliomas

Adoptive cell therapy for high grade gliomas using simultaneous temozolomide and intracranial mgmt-modified γδ t cells following standard post-resection chemotherapy and radiotherapy: current strategy and future directions.

Cellular therapies, including chimeric antigen receptor T cell therapies (CAR-T), while generally successful in hematologic malignancies, face substantial challenges against solid tumors such as glioblastoma (GBM) due to rapid growth, antigen heterogeneity, and inadequate depth of response to cytoreductive and immune therapies, We have previously shown that GBM constitutively express stress associated NKG2D ligands (NKG2DL) recognized by gamma delta (γδ) T cells, a minor lymphocyte subset that innately recognize target molecules via the γδ T cell receptor (TCR), NKG2D, and multiple other mechanisms. Given that NKG2DL expression is often insufficient on GBM cells to elicit a meaningful response to γδ T cell immunotherapy, we then demonstrated that NKG2DL expression can be transiently upregulated by activation of the DNA damage response (DDR) pathway using alkylating agents such as Temozolomide (TMZ). TMZ, however, is also toxic to γδ T cells. Using a p140K/MGMT lentivector, which confers resistance to TMZ by expression of O(6)-methylguanine-DNA-methyltransferase (MGMT), we genetically engineered γδ T cells that maintain full effector function in the presence of therapeutic doses of TMZ. We then validated a therapeutic system that we termed Drug Resistance Immunotherapy (DRI) that combines a standard regimen of TMZ concomitantly with simultaneous intracranial infusion of TMZ-resistant γδ T cells in a first-in-human Phase I clinical trial (NCT04165941). This manuscript will discuss DRI as a rational therapeutic approach to newly diagnosed GBM and the importance of repeated administration of DRI in combination with the standard-of-care Stupp regimen in patients with stable minimal residual disease.

Differential Expression of SRY-Related HMG-Box Transcription Factor 2, Oligodendrocyte Lineage Transcription Factor 2, and Zinc Finger E-Box Binding Homeobox 1 in Serum-Derived Extracellular Vesicles: Implications for Mithramycin Sensitivity and Targeted Therapy in High-Grade Glioma.

Glioblastoma multiforme (GBM) is the most aggressive type of glioma and is often resistant to traditional therapies. Evidence suggests that glioma stem cells (GSCs) contribute to this resistance. Mithramycin (Mit-A) targets GSCs and exhibits antitumor activity in GBM by affecting transcriptional targets such as SRY-related HMG-box transcription factor 2 (SOX2), oligodendrocyte lineage transcription factor 2 (OLIG2), and zinc finger E-box binding homeobox 1 (ZEB1). However, its clinical use has been limited by toxicity. This study explored the diagnostic potential of serum extracellular vesicles (EVs) to identify Mit-A responders. Serum EVs were isolated from 70 glioma patients, and targeted gene expression was analyzed using qRT-PCR. Using chemosensitivity assay, we identified 8 Mit-A responders and 17 nonresponders among 25 glioma patients. The M-score showed a significant correlation (p = 0.045) with isocitrate dehydrogenase 1 mutation but not other clinical variables. The genes SOX2 (p = 0.005), OLIG2 (p = 0.003), and ZEB1 (p = 0.0281) were found to be upregulated in the responder EVs. SOX2 had the highest diagnostic potential (AUC = 0.875), followed by OLIG2 (AUC = 0.772) and ZEB1 (AUC = 0.632).The combined gene panel showed significant diagnostic efficacy (AUC = 0.956) through logistic regression analysis. The gene panel was further validated in the serum EVs of 45 glioma patients. These findings highlight the potential of Mit-A as a targeted therapy for high-grade glioma based on differential gene expression in serum EVs. The gene panel could serve as a diagnostic tool to predict Mit-A sensitivity, offering a promising approach for personalized treatment strategies and emphasizing the role of GSCs in therapeutic resistance.

P02.17.A FEATURES OF METABOLIC PSEUDO-PROGRESSION VISUALIZATION OF GRADE 3-4 GLIOMAS AFTER COMBINATION THERAPY. CORRELATION WITH MRI

Abstract BACKGROUND Follow-ap assessment of post-therapeutic changes in gliomas of 3-4 raids revealed the phenomen of metabolic pseudoprogression. This feature was manifested in a transistor increase in the capture of the radiopharmaceutical. This "anomaly" requires study for a correct differential diagnosis between progression and pseudoprogression MATERIAL AND METHODS For the period from 2019 to 2023, 27 patients aged 24-72 years (average age 55 years) with the phenomena of metabolic pseudoprogression of 3-4 grades gliomas after combination therapy participated in the study. The studies were carried out using PET-CT and 1.5T, 3.0T MR scanners using T2, T2 flair, T13D before and after contrast, T2* perfusion. Postprocessing was carried out using a workstation SINGO.VIA using technological processes: neuro3d, MM oncology, MR neurology. RESULTS It was found that in all cases of transient increase in radiopharmaceuticals capture after radiotherapy in terms from 9 months to 36 months, the values of radiopharmaceuticals accumulation were determined in the range of 1.8-3.5 and were they were divided into two groups according to MRI data: group A (n=17) with structural changes, group B (n=10) with a stable MR pattern. According to MRI data in group A, there was an increase in the pathological zone, these changes involved white matter with more pronounced changes in the periventricular regions. In group B, the changes concerned gray matter. In addition, changes in group B were accompanied by manifestations of vasculopathy of the SMART type (Stroke-Like Migraine Attacks After Radiation Therapy). In subsequent observations, these changes in both groups were reduced, both according to PET and MRI CONCLUSION A temporary increase in the values of the capture of radiopharmaceuticals after combination therapy for high grade gliomas can be determined both in the white and gray matter of the brain. This may correspond to the manifestations of a post-radiation reaction. Compared with the MRI data, there is a difference in morphological manifestations at the level of gray and white matter, which is probably due to their different radioresistance. These newly discovered factors may be of key importance for further treatment of patients

P07.03.A COMPLETE LONG-LASTING RESPONSE TO MULTIMODAL THIRD LINE TREATMENT WITH NEUROSURGICAL RESECTION, CARMUSTINE WAFER IMPLANTATION AND DABRAFENIB PLUS TRAMETINIB IN A BRAFV600E MUTATED HIGH-GRADE GLIOMA

Abstract BACKGROUND BRAF mutations are drivers of oncogenesis in a variety of tumors and they can be successfully targeted with small molecule inhibitors. In primary central nervous system tumors, BRAFV600E mutations are most frequently found in pleomorphic xanthoastrocytoma, ganglioglioma, pilocytic astrocytoma and epithelioid glioblastoma. Dabrafenib is a potent and selective inhibitor of BRAF-mutant kinase that was approved, as monotherapy or in combination with trametinib (mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor), for unresectable or metastatic BRAF-mutated melanoma, advanced non-small cell lung cancer and anaplastic thyroid cancer harboring BRAFV600E mutation. MATERIAL AND METHODS In February 2016, a 21-year-old female was admitted to our Unit for seizures. A brain magnetic resonance imaging (MRI) revealed a frontal contrast enhanced lesion. Neurosurgical resection was performed. The histological analysis diagnosed anaplastic pleomorphic xanthoastrocytoma (PXA) WHO grade III. A volumetric modulated radiotherapy course was delivered for a total dose of 59,4 Gy in 33 fractions with concomitant and adjuvant temozolomide therapy (Stupp protocol). In October 2017, a brain MRI showed relapsing disease. Six courses of chemotherapy with procarbazine, lomustine and vincristine (PCV) were administered, and then neurosurgical partial removal and carmustine wafer implantation were performed. The histological analysis confirmed BRAF V600E mutated anaplastic PXA. RESULTS In April 2019 the 24-year-old female patient with BRAF mutated anaplastic PXA started her third-line therapy with dabrafenib. The well-known tumor residue was less evident on the subsequent MRIs performed every three/four months. Given the literature data of the most effectiveness and the best control of the side effects, in August 2020 the patient was put on combined treatment with dabrafenib plus trametinib. Since December 2021 the residual tumor has not been longer visible. Last MRI evaluation, performed on January 26th 2023, showed no recurrence of the disease, four years after BRAF inhibitor treatment beginning. CONCLUSION Dabrafenib plus trametinib is a promising new therapy for patients affected by BRAFV600E-mutant glioma, with high overall response and manageable toxicity. Due to very poor prognosis, there are a few described cases of high-grade glioma (HGG) patients in third-line therapy, showing complete response and for such a long time. The emergence of optimized sequencing strategies and targeted agents, including multimodal treatment and systemic therapy with dabrafenib plus trametinib, will continue to broaden personalized therapy in HGG and to improve patient outcomes.

Ozone therapy for high-grade glioma: an overview.

High-grade gliomas (grades III and IV) are highly malignant and aggressive brain tumors that present significant treatment challenges. Despite advances in surgery, chemotherapy, and radiation therapy, the prognosis for patients with glioma remains poor, with a median overall survival (mOS) range of 9-12 months. Therefore, exploring new and effective therapeutic strategies to improve glioma prognosis is of utmost importance and ozone therapy is a viable option. Ozone therapy has been used in various cancers, such as colon, breast, and lung, yielding significant results in preclinical studies and clinical trials. Only a few studies have been conducted on gliomas. Furthermore, since the metabolism of brain cells involves aerobic glycolysis, ozone therapy may improve the oxygen condition and enhance glioma radiation treatment. However, understanding the correct ozone dosage and optimal time of administration remains challenging. Herein, we hypothesize that ozone therapy should be more effective in gliomas compared with other tumors. This study provides an overview of the use of ozone therapy in high-grade glioma, including mechanisms of action, preclinical data, and clinical evidence.

Abstract LB290: Intracranial, intratumoral drug-releasing microdevices in patients with high grade gliomas may identify biomarkers of drug activity and predict tumor response to systemic chemotherapy

Abstract The lack of reliable predictive biomarkers to guide effective therapy is a major obstacle for the advancement of therapy for high grade gliomas (HGG), and particularly glioblastoma (GBM), one of the few cancers whose prognosis has not improved over the past several decades. With this pilot clinical trial we provide first in human evidence that drug-releasing intratumoral microdevices (IMD) can be safely and effectively used to obtain patient-specific, high throughput molecular and histopathological data to inform selection of drugs based on their observed antitumor effect in situ. The use of IMD is seamlessly integrated in standard surgical practice during tumor resection. None of the six enrolled patients experienced adverse events related to the IMD, and the retrieved tissue was usable for downstream analysis for 11 out of 12 retrieved specimens. Molecular analysis of the specimens provided, for the first time in humans, preliminary evidence of the robustness of the readout, with strong correlation between IMD analysis and clinic-radiological responses to temozolomide. We also identified novel transcriptomic and metabolomic biomarkers of response and resistance to a range of targeted and cytotoxic agents used on the IMD. From an investigational aspect, the amount of information obtained with IMD allows unprecedented characterization of tissue effects of any drugs of interest, within the physiological context of the intact tumor. Citation Format: Oliver Jonas, Pier Paolo Peruzzi. Intracranial, intratumoral drug-releasing microdevices in patients with high grade gliomas may identify biomarkers of drug activity and predict tumor response to systemic chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB290.

Upregulated Immunogenic Cell-Death-Associated Gene Signature Predicts Reduced Responsiveness to Immune-Checkpoint-Blockade Therapy and Poor Prognosis in High-Grade Gliomas.

Background: Immunogenic cell death (ICD) has emerged as a potential mechanism mediating adaptive immune response and tumor immunity in anti-cancer treatment. However, the signature of ICD in high-grade gliomas (HGGs) remains largely unknown, and its relevance to immunotherapies is still undetermined. The purpose of this study is to identify ICD-associated genotypes in order to explore their relevance to tumor immunity, patient prognosis and therapeutic efficacy of immune checkpoint blockade (ICB) therapy in HGGs. Methods: Bulk RNA-seq data and clinical information on 169 and 297 patients were obtained from the Cancer Genome Atlas (TCGA) and China Glioma Genome Atlas (CGGA), respectively. The functional enrichment and characterization of ICD genotyping were detected, and the ICD prognostic signature prediction model was constructed using least absolute shrinkage and selection operator (LASSO) regression. The responsiveness to immunotherapy was predicted according to the scoring of the ICD prognostic signature. Results: The HGG patients with high ICD gene signature (C1) showed poor outcomes, increased activity of immune modulation and immune escape, high levels of immune-checkpoint markers, and HLA-related genes, which may explain their reduced response to ICB immunotherapy. A gene set of the ICD signature, composing FOXP3, IL6 LY96, MYD88 and PDIA3, showed an independent prognostic value in both the TCGA and the CGGA HGG cohort. Conclusions: Our in silico analyses identified the ICD gene signature in HGGs with potential implications for predicting the responsiveness to ICB immune therapy and patient outcomes.

CTNI-11. DEEP PHENOTYPING OF MULTI DRUG RESPONSES IN PATIENTS WITH GLIOMAS USING TUMOR-EMBEDDED MICRODEVICES

Abstract The lack of reliable predictive biomarkers to guide effective therapy is a major obstacle for the advancement of therapy for high grade gliomas (HGG), and particularly glioblastoma (GBM), one of the few cancers whose prognosis has not improved over the past several decades. With this pilot clinical trial we provide first in human evidence that drug-releasing intratumoral microdevices (IMD) can be safely and effectively used to obtain patient-specific, high throughput molecular and histopathological data to inform selection of drugs based on their observed antitumor effect in situ. The use of IMD is seamlessly integrated in standard surgical practice during tumor resection. None of the six enrolled patients experienced adverse events related to the IMD, and the retrieved tissue was usable for downstream analysis for 11 out of 12 retrieved specimens. Molecular analysis of the specimens provided, for the first time in humans, preliminary evidence of the robustness of the readout, with strong correlation between IMD analysis and clinic-radiological responses to temozolomide. From an investigational aspect, the amount of information obtained with IMD allows unprecedented characterization of tissue effects of any drugs of interest, within the physiological context of the intact tumor.

Abstract CT142: A Phase I clinical trial of dose-escalated metabolic therapy combined with concomitant radiation therapy in high-grade glioma

Abstract Background Animal brain-tumor models have demonstrated a synergistic interaction between radiation therapy and a ketogenic diet (KD). Metformin has in-vitro anti-cancer activity, through AMPK activation and mTOR inhibition. We hypothesized that metabolic stress (moderate hypoglycemia) would enhance the anti-tumor efficacy of concurrent DNA damage. We further hypothesized that concurrent metformin would decrease insulin resistance and consequently elevate ketone blood level. We performed a formal prospective phase I dose-escalation trial to assess the tolerability and feasibility of this approach. Methods A prospective single-institution phase I clinical trial of combined metabolic therapy and radiotherapy. Radiotherapy was either 60Gy over six weeks or 35Gy over two weeks for newly diagnosed and recurrent gliomas, respectively. The dietary intervention consisted of a KD supplemented with medium chain triglycerides (MCT). There were three cohorts 1) dietary intervention alone, 2) low-dose metformin (850mg twice-daily) combined with dietary intervention and 3) high-dose metformin (850mg three-times daily) combined with dietary intervention. Statistics: The prediction of blood ketones levels was performed using a mixed-model univariate analysis methodology. Clinicaltrials.gov NCT02149459. Results A total of 13 patients were accrued, median age 61 years, of whom 6 had newly diagnosed and 7 with recurrent disease. All completed radiation therapy; 5 patients stopped the metabolic intervention early. Metformin 850mg three-times daily was poorly tolerated. There were no grade 4/5 adverse events. Median levels of β-hydroxybutyrate increased from 0.09 mmol/l at baseline to 0.59 mmol/l during the trial (p=0.006). Ketone levels were associated with dietary factors (ketogenic ratio, p < 0.001), use of metformin (p = 0.02) and low insulin levels (p = 0.002). Median progression free survival was 10 months for newly diagnosed disease and 4 months for recurrent disease.Conclusions The intervention was fairly well tolerated. Metformin use and dietary intake were associated with higher serum ketone levels. The recommended phase II dose is the 8 weeks of a KD combined with 850mg metformin twice daily. The trial was supported by the EU FP7 Marie Curie program FP7-MC-CIG 303795, and the Rosetrees Trust. The MCT oil was provided by Nutricia, Netherlands. Citation Format: Yaacov R. Lawrence, Keren Porper, Yael Shpatz, Luba Plotkin, Ronit Pechthold, Alisa Talianski, Zvi Symon, uri Amit, Zvi Cohen, Hili Gnessin, Yair Anikster, Yael Mardor, Leor Zach. A Phase I clinical trial of dose-escalated metabolic therapy combined with concomitant radiation therapy in high-grade glioma [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 CT142.

Abstract PO-004: A phase I clinical trial of dose-escalated metabolic therapy combined with concomitant radiation therapy in high-grade glioma

Abstract Background Animal brain-tumor models have demonstrated a synergistic interaction between radiation therapy and a ketogenic diet (KD). Metformin has in-vitro anti-cancer activity, through AMPK activation and mTOR inhibition. We hypothesized that metabolic stress (moderate hypoglycemia) would enhance the anti-tumor efficacy of concurrent DNA damage. We further hypothesized that concurrent metformin would decrease insulin resistance and consequently elevate ketone blood level. We performed a formal prospective phase I dose-escalation trial to assess the tolerability and feasibility of this approach. Methods A prospective single-institution phase I clinical trial of combined metabolic therapy and radiotherapy. Radiotherapy was either 60Gy over six weeks or 35Gy over two weeks for newly diagnosed and recurrent gliomas, respectively. The dietary intervention consisted of a KD supplemented with medium chain triglycerides (MCT). There were three cohorts 1) dietary intervention alone, 2) low-dose metformin (850mg twice-daily) combined with dietary intervention and 3) high-dose metformin (850mg three-times daily) combined with dietary intervention. Statistics: The prediction of blood ketones levels was performed using a mixed-model univariate analysis methodology. Clinicaltrials.gov NCT02149459. Results A total of 13 patients were accrued, median age 61 years, of whom 6 had newly diagnosed and 7 with recurrent disease. All completed radiation therapy; 5 patients stopped the metabolic intervention early. Metformin 850mg three-times daily was poorly tolerated. There were no grade 4/5 adverse events. Median levels of β-hydroxybutyrate increased from 0.09 mmol/l at baseline to 0.59 mmol/l during the trial (p=0.006). Ketone levels were associated with dietary factors (ketogenic ratio, p < 0.001), use of metformin (p = 0.02) and low insulin levels (p = 0.002). Median progression free survival was 10 months for newly diagnosed disease and 4 months for recurrent disease. Conclusions The intervention was fairly well tolerated. Metformin use and dietary intake were associated with higher serum ketone levels. The recommended phase II dose is the 8 weeks of a KD combined with 850mg metformin twice daily. The trial was supported by the EU FP7 Marie Curie program FP7-MC-CIG 303795, and the Rosetrees Trust. The MCT oil was provided by Nutricia, Netherlands. Citation Format: Yaacov Lawrence, Keren Porper, Yael Shpatz, Uri Amit, Zvi Symon, Leor Zach. A phase I clinical trial of dose-escalated metabolic therapy combined with concomitant radiation therapy in high-grade glioma [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-004.

Assessment of Isocitrate Dehydrogenase 1 Mutation by Immunohistochemistry in Egyptian Patients with High-grade Gliomas

BACKGROUND: At present, the classification of central nervous system tumors relies on molecular factors in addition to histologic features to identify many tumor types. This should subsequently results in more accurate diagnosis as well as addressing specific markers of potential prognostic and predictive value. AIM: This study was conducted to emphasize the importance of including isocitrate dehydrogenase 1 (IDH1) evaluation as a crucial part of the diagnosis and categorization of high-grade glioma cases. This also may help to individualize the treatment of high-grade glioma patients. MATERIALS AND METHODS: The current study included 60 cases of high-grade gliomas, studied histologically and immunohistochemically for the detection of IDH1 mutation. The results were correlated with different clinicopathologic variables and course of the disease. RESULTS: IDH1 immunohistochemical expression was positive in 46.67% of the studied high-grade glioma cases. A statistically significant relationship was detected between IDH1 expression and tumor histologic grade as 100% of Grade III anaplastic oligodendroglioma cases and 80% of the Grade III anaplastic astrocytoma cases were IDH1 positive while only 40.4% of Grade IV glioblastoma cases were IDH1 positive (p = 0.03). In addition, patients who were IDH1 mutant were in a better category of response to radiotherapy (p = 0.019) and also to chemotherapy (p < 0.001). Moreover, patients who expressed IDH1 had prolonged overall survival (OS) and progression-free survival than those who showed negative IDH1expression (p < 0.001). On the other hand, no statistically significant relationship was detected between IDH1 expression and patients age, sex, tumor site, tumor size, motor symptoms, sensory symptoms, and increased intracranial tension (p > 0.05). CONCLUSIONS: It is suggested that IDH1 is a good prognostic marker for gliomas and is a good predictive marker for response to treatment. IDH1 is a promising target for therapy in high-grade gliomas through the emerging IDH1 inhibitors. Immunohistochemical testing for IDH1 is a practical and cost-effective method that should be applied in all glioma cases. Further study on a larger sample size is recommended to validate the current results. Moreover, applying molecular analysis to detect IDH1 mutation is recommended to be able to precisely detect the IDH1 wild-type tumor

Cerebral venous sinus thrombosis with venous hemorrhagic infarct in a patient with high-grade glioma of the left thalamus

Cerebral venous sinus thrombosis (CVST) is an uncommon type of venous thromboembolism whose diagnosis is often difficult due to its vague and non-specific clinical findings. Sometimes, the diagnosis is delayed as the symptoms were considered to be attributable to the underlying etiology, especially in patients with brain tumors such as high-grade glioma (HGG). We described the case of a 60-year-old male patient who presented with headache, generalized seizures, and right hemiparesis soon after receiving brain radiation and temozolomide therapy for HGG of the left thalamus. Initially, his symptoms were considered to be due to his underlying tumor but the subsequent imaging revealed left transverse, left sigmoid, and superior sagittal sinus thrombosis with venous hemorrhagic infarct of the left occipitoparietal lobe. The patient was started on anticoagulant therapy and symptoms resolved completely within a month. Clinicians should always consider CVST in the differential diagnosis of non-specific neurological symptoms, especially in patients with underlying brain tumors.

Prophylactic anticonvulsant therapy in high-grade glioma: A systematic review and meta-analysis of longitudinal studies

IntroductionIt is common practice to prescribe prophylactic antiepileptic drugs (AED) to high-grade glioma (HGG) patients without a history of seizures, yet with limited evidence supporting its use. Ideally, the effectiveness of prophylactic anticonvulsants must outweigh the occurrence of adverse effects and interactions related to AED. The authors conducted a systematic review and metanalysis of longitudinal studies regarding the effectiveness of prophylactic AED in seizure-naïve HGG patients. Materials and methodsPubMed/MEDLINE, Cochrane Central Register of Controlled trials, Embase and clinicaltrials.gov databases were systematically searched. Of the initial 1773 studies identified, 15 were finally selected for data extraction and analysis. Heterogeneity among studies, pooled hazard ratios, publication bias and sensitivity analyses were performed separately for a 15-study group (HGG patients within larger series of brain tumors) and a 6-study group (exclusively HGG patients). ResultsAED prophylaxis did not significantly reduce the incidence of postoperative seizures compared with controls, both in the 15-study group (Mantel-Haenszel random-effects pooled OR 1.08, 95% CI 0.82–1.43, 2123 patients) and in the 6-study group (pooled OR 1.22, 95% CI 0.77–1.92, 540 patients). However, some issues (paucity of prospective trials, overall moderate-risk of bias, and few studies addressing HGG patients exclusively) preclude firm conclusions against routine prophylactic AED prescription. Reported adverse effects attributable to AED were acceptable in the majority of studies. ConclusionsWithin the limitations of this review, the results of this metanalysis do not support the routine administration of prophylactic AED to HGG patients without a history of seizures.

Isocaloric Ketogenic Diet in Adults with High-Grade Gliomas: A Prospective Metabolic Study

The use of the ketogenic diet (KD) as an adjuvant therapy in high-grade gliomas (HGG) is supported by preclinical studies, but clinical data on its effects on metabolism are currently lacking. In this study, we describe the effects of a KD on glucose profile, ketonemia, energy metabolism, and nutritional status, in adults affected by HGG. This was a single-arm prospective study. An isocaloric 3:1 KD was administered for 1 mo. Glucose profile was assessed by using fasting glycemia, insulin, and glycated hemoglobin. To evaluate ketonemia changes, a hand-held ketone meter was used from home. Energy metabolism was assessed by indirect calorimetry. Nutritional status was evaluated through changes in body composition and in lipid and hepatic profile. No changes in fasting glycemia were observed; however, insulinemia dropped to half of baseline levels. The KD shifted the metabolism, rising ketonemia and decreasing glucose oxidation rate to a quarter of the initial values. Moreover, the KD was generally safe. One-month intervention with the KD was able to act upon key metabolic substrates potentially involved in HGG metabolism. The lack of a significant reduction in fasting glycemia should be investigated in future studies.