Novel Clinical Trials and Approaches in the Management of Glioblastoma.

PURPOSE OF REVIEW: The purpose of this review is to discuss a wide variety of novel therapies recently studied or actively undergoing study in patients with glioblastoma. This review also discusses current and future strategies for improving clinical trial design in patients with glioblastoma to maximize efficacy in discovering effective treatments. RECENT FINDINGS: Over the years, there has been significant expansion in therapy modalities studied in patients with glioblastoma. These therapies include, but are not limited to, targeted molecular therapies, DNA repair pathway targeted therapies, immunotherapies, vaccine therapies, and surgically targeted radiotherapies. Glioblastoma is the most common malignant primary brain tumor in adults and unfortunately remains with poor overall survival following the current standard of care. Given the dismal prognosis, significant clinical and research efforts are ongoing with the goal of improving patient outcomes and enhancing quality and quantity of life utilizing a wide variety of novel therapies.

Cerebrospinal Fluid Liquid Biopsies in the Evaluation of Adult Gliomas.

PURPOSE OF REVIEW: This review aims to discuss recent research regarding the biomolecules explored in liquid biopsies and their potential clinical uses for adult-type diffuse gliomas. RECENT FINDINGS: Evaluation of tumor biomolecules via cerebrospinal fluid (CSF) is an emerging technology in neuro-oncology. Studies to date have already identified various circulating tumor DNA, extracellular vesicle, micro-messenger RNA and protein biomarkers of interest. These biomarkers show potential to assist in multiple avenues of central nervous system (CNS) tumor evaluation, including tumor differentiation and diagnosis, treatment selection, response assessment, detection of tumor progression, and prognosis. In addition, CSF liquid biopsies have the potential to better characterize tumor heterogeneity compared to conventional tissue collection and CNS imaging. Current imaging modalities are not sufficient to establish a definitive glioma diagnosis and repeated tissue sampling via conventional biopsy is risky, therefore, there is a great need to improve non-invasive and minimally invasive sampling methods. CSF liquid biopsies represent a promising, minimally invasive adjunct to current approaches which can provide diagnostic and prognostic information as well as aid in response assessment.

Intracranial intraoperative radiotherapy (IORT): evaluation of electrocorticography and peri-operative seizure risk.

BACKGROUND: Intra-operative radiotherapy (IORT) for brain metastases (BMs) and primary brain tumors has emerged as an adjuvant radiation modality that allows for consolidation of care into a single anesthetic episode with surgical resection. Yet, there is a paucity of data regarding the impact that IORT may have on peri-operative and long-term seizure risk. METHODS: A retrospective analysis of patients receiving IORT during tumor resection was performed via registry including data regarding peri-operative anti-seizure medications and anesthetic agents. Intra-operative neuromonitoring was performed using electrocorticography (ECoG) captured before-, during-, and after-IORT then analyzed for evidence of seizure or significant baseline changes. Kaplan-Meir estimations were used for overall survival analysis relative to documented clinical seizure incidence post-IORT. RESULTS: Of the 24 consecutive patients treated with IORT during tumor resection included, 18 (75%) patients were diagnosed with BMs while 6 (25%) had newly-diagnosed glioblastoma. Mean and median survival times were 487 and 372 days, respectively. Clinical seizures occurred in 3 patients post-IORT, 2 BMs patients within 9 months and 1 glioblastoma patient at 14 months. IORT time represented 9.5% of anesthetic time. ECoG recordings were available for 5 patients (4 BMs; 1 glioblastoma), with mean recording durations of 13% of the total anesthetic time and no evidence of high-frequency oscillations or seizure activity. CONCLUSIONS: IORT is an option for delivery of definitive radiation in surgically resected brain tumors without increasing the peri-operative or long-term risk of seizure. ECoG data during the delivery of radiation fail to demonstrate any electrophysiological changes in response to ionizing radiation.

Belzutifan in adults with VHL-associated central nervous system hemangioblastoma: a single-center experience.

PURPOSE: Belzutifan is a selective inhibitor of hypoxia-inducible factor 2 alpha (HIF-2a) that has emerged as a targeted therapy option for Von Hippel-Lindau (VHL) syndrome-associated tumors with recent FDA approval. There is limited real-world evidence regarding safety and efficacy in CNS hemangioblastoma. Our objective was to report on our clinical experience with belzutifan in adult patients with VHL-associated CNS hemangioblastoma. METHODS: We retrospectively reviewed our institutional experience of belzutifan in adult patients (> 18 years of age at time of therapy) with VHL and craniospinal CNS hemangioblastomas not amenable to surgical resection. The period for study review was October 2021 to March 2023. RESULTS: 4 patients (all female) with a median age of 36 years at time of belzutifan initiation were included. Median duration of therapy at last follow-up was 11 months (6-17 months). All patients had radiographic response to therapy after a median of 3 months (2-5 months), with maximal response to therapy after a median of 8 months (3-17 months). Therapy was well tolerated, with the most common adverse effect being anemia. No patients had treatment pauses or dose adjustments due to belzutifan-related toxicity. No patients experienced hypoxia. CONCLUSION: We showed that belzutifan is safe and well-tolerated with strong disease response for CNS hemangioblastoma in adults with VHL, supporting continued use of belzutifan in this patient population. Future studies should assess duration of treatment, effects of cessation after long-term use, and markers of therapeutic response.

Safety of intravenous thrombolysis for ischemic stroke in patients with hematologic malignancies: A single institution experience.

BACKGROUND: Data on safety of thrombolysis for acute ischemic stroke (AIS) in patients with hematologic malignancy is not well established. We report our single institution experience with thrombolysis in this patient population. METHODS: We identified patients with pathology-confirmed hematologic malignancy from 2000-2022. Primary exposure was presence of AIS and receipt of intravenous (IV) thrombolysis. Primary outcome was safety of IV thrombolysis in this patient population. Safety was measured through imaging review for hemorrhagic transformation, post-stroke mortality, and modified Rankin Scale (mRS) at 90 days. RESULTS: Among 45,894 patients with hematologic malignancy, 1,099 (2.4%) were identified as having a suspected AIS. Twenty (1.8%) received IV tissue plasminogen activator (tPA) for AIS, three underwent endovascular intervention, and 17 had AIS confirmed on MRI. Two patients with confirmed AIS experienced hemorrhagic transformation, one of which was symptomatic. Most patients (n=10, 59%) were functionally independent (mRS 0-2) at 90 days post-stroke, including all patients with active hematologic malignancy at the time of stroke (n=3). Four patients died within 90 days of AIS. None of these deaths were patients with active hematologic malignancy at the time of stroke. CONCLUSIONS: Without other contraindications, IV alteplase should be considered for management of AIS in patients with hematologic malignancy. The safety profile of tPA administration in this patient population may be similar to the general population, whether underlying hematologic malignancy is active or in remission.

Routine use of low-dose glucarpidase following high-dose methotrexate in adult patients with CNS lymphoma: an open-label, multi-center phase I study.

BACKGROUND: High-dose methotrexate (HD-MTX) has broad use in the treatment of central nervous system (CNS) malignancies but confers significant toxicity without inpatient hydration and monitoring. Glucarpidase is a bacterial recombinant enzyme dosed at 50 units (u)/kg, resulting in rapid systemic MTX clearance. The aim of this study was to demonstrate feasibility of low-dose glucarpidase to facilitate MTX clearance in patients with CNS lymphoma (CNSL). METHODS: Eight CNSL patients received HD-MTX 3 or 6 g/m2 and glucarpidase 2000 or 1000u 24 h later. Treatments repeated every 2 weeks up to 8 cycles. RESULTS: Fifty-five treatments were administered. Glucarpidase 2000u yielded > 95% reduction in plasma MTX within 15 min following 33/34 doses (97.1%) and glucarpidase 1000u yielded > 95% reduction following 15/20 doses (75%). Anti-glucarpidase antibodies developed in 4 patients and were associated with MTX rebound. In CSF, glucarpidase was not detected and MTX levels remained cytotoxic after 1 (3299.5 nmol/L, n = 8) and 6 h (1254.7 nmol/L, n = 7). Treatment was safe and well-tolerated. Radiographic responses in 6 of 8 patients (75%) were as expected following MTX-based therapy. CONCLUSIONS: This study demonstrates feasibility of planned-use low-dose glucarpidase for MTX clearance and supports the hypothesis that glucarpidase does not impact MTX efficacy in the CNS. CLINICAL TRIAL REGISTRATION: NCT03684980 (Registration date 26/09/2018).

Clinical experience and outcomes in patients with pineal parenchymal tumor of intermediate differentiation (PPTID): a single-institution analysis.

PURPOSE: Pineal parenchymal tumor of intermediate differentiation (PPTID) is a neoplasm of pinealocyte origin and of intermediate differentiation (WHO grade 2 or 3). Treatment selection and prognostication is challenging for this rare, recently characterized tumor. In this single study, we review our clinical experience in patients with PPTID as well as pooled data from two other institutions. METHODS: This is a retrospective analysis of patients seen at Mayo Clinic, with additional data pooled from two similar studies at outside institutions for comparison and further analysis. RESULTS: Ten adult patients (6 male) were identified. Median age at diagnosis was 36 years (range 13-73 years). Patients were followed between 3 and 88 months with no reported deaths. The most common presenting symptom was headache, followed by nausea. Nine patients had local disease without neuroaxial dissemination at diagnosis, one of which had tumor recurrence at 36 months. Two patients underwent gross total resection (GTR) without adjuvant radiation without recurrence (PFS 4 and 46 months). In our combined analysis, we reviewed 36 patients from three different institutions. Four patients presented with disseminated disease. GTR was achieved for 16 patients. Twenty-eight patients received adjuvant radiation therapy and 16 patients experienced disease recurrence. Median overall survival was 44 months. CONCLUSION: Our single institution experience and combined multi-institution analysis suggest GTR is associated with improved outcomes. The role of adjuvant radiation therapy and utility of CSI compared to focal RT is less unclear. Prospective study is required to identify optimal adjuvant therapy selection.

Immunotherapy in Glioblastoma: Current Approaches and Future Perspectives.

Glioblastoma (GBM) is the most common malignant brain tumor. Despite multimodality treatment with surgical resection, radiation therapy, chemotherapy, and tumor treating fields, recurrence is universal, median observed survival is low at 8 months and 5-year overall survival is poor at 7%. Immunotherapy aims to generate a tumor-specific immune response to selectively eliminate tumor cells. In treatment of GBM, immunotherapy approaches including use of checkpoint inhibitors, chimeric antigen receptor (CAR) T-Cell therapy, vaccine-based approaches, viral vector therapies, and cytokine-based treatment has been studied. While there have been no major breakthroughs to date and broad implementation of immunotherapy for GBM remains elusive, multiple studies are underway. In this review, we discuss immunotherapy approaches to GBM with an emphasis on molecularly informed approaches.

Neurocutaneous melanocytosis-associated malignant melanoma presenting with peritoneal seeding.

Neurocutaneous melanocytosis (NCM) is characterized by melanocyte deposition in the leptomeninges and brain parenchyma, primarily occurring in children with large or giant congenital melanocytic nevi (LCMN) or multiple congenital melanocytic nevi. Patients with NCM may develop hydrocephalus and increased intracranial pressure, which can be managed with ventriculoperitoneal (VP) shunting. We present the case of a 16-month-old girl who developed peritoneal carcinomatosis and malignant ascites following VP shunting for hydrocephalus secondary to NCM to increase awareness of this rare, but serious, complication of cerebrospinal fluid diversion.

Needle electromyography and histopathologic correlation in myopathies.

INTRODUCTION: Needle electromyography (EMG) findings help confirm myopathy and may indicate specific pathologic changes on muscle biopsy. METHODS: We conducted a retrospective chart review of 218 consecutive patients referred for muscle biopsy. Presence of specific needle EMG findings was correlated with pathologic findings of inflammation, necrosis, splitting, and vacuolar changes. Sensitivity, specificity, and positive and negative predictive values of specific EMG findings for pathologic changes were calculated. RESULTS: Short-duration motor unit potentials (MUP) were sensitive (83%-94%) but not specific (34%-49%) for pathologic changes. Fibrillation potentials were 65%-74% sensitive and 58%-81% specific for inflammation, necrosis, splitting, or vacuolar changes. The absence of fibrillation potentials had high negative predictive value (82%-93%) for inflammation, splitting, or vacuolar changes. DISCUSSION: Fibrillation potentials and short-duration MUPs predict pathologic changes of muscle fiber necrosis, splitting, and/or vacuolar changes (as seen with inflammatory myopathies and muscular dystrophies). Absence of fibrillation potentials suggests other myopathologic changes (e.g., congenital myopathy). Muscle Nerve 59:315-320, 2019.

Do medical student stress, health, or quality of life foretell step 1 scores? A comparison of students in traditional and revised preclinical curricula.

THEORY: We explored the theory that measures of medical students' well-being and stress from different types of preclinical curricula are linked with performance on standardized assessment. HYPOTHESES: Self-reported stress and quality of life among sophomore medical students having different types of preclinical curricula will vary in their relationships to USMLE Step 1 scores. METHOD: Voluntary surveys in 2010 and 2011 compared self-reported stress, physical and mental health, and quality of life with Step 1 scores for beginning sophomore students in the final year of a traditional, discipline-based curriculum and the 1st year of a revised, systems-based curriculum with changed grading system. Wilcoxon rank sum tests and Spearman rank correlations were used to analyze data, significant at p <.05. RESULTS: New curriculum students reported worse physical health, subjective feelings, leisure activities, social relationships and morale, and more depressive symptoms and life stress than traditional curriculum students. However, among curriculum-related stressors, few differences emerged; revised curriculum sophomores reported less stress working with real and standardized patients than traditional students. There were no class differences in respondents' Step 1 scores. Among emotional and physical health measures, only feelings of morale correlated negatively with Step 1 performance. Revised curriculum students' Step 1 scores correlated negatively with stress from difficulty of coursework. CONCLUSIONS: Although revised curriculum students reported worse quality of life, general stress, and health and less stress from patient interactions than traditional students, few measures were associated with performance differences on Step 1. Moreover, curriculum type did not appear to either hinder or help students' Step 1 performance. To identify and help students at risk for academic problems, future assessments of correlates of Step 1 performance should be repeated after the new curriculum is well established, relating them also to performance on other standardized assessments of communication skills, professionalism, and later clinical evaluations in clerkships or internships.

Antiangiogenic exclusion rules in glioma trials: Historical perspectives and guidance for future trial design.

Background: Despite the lack of proven therapies for recurrent high-grade glioma (HGG), only 8%-11% of patients with glioblastoma participate in clinical trials, partly due to stringent eligibility criteria. Prior bevacizumab treatment is a frequent exclusion criterion, due to difficulty with response assessment and concerns for rebound edema following antiangiogenic discontinuation. There are no standardized trial eligibility rules related to prior antiangiogenic use. Methods: We reviewed ClinicalTrials.gov listings for glioma studies starting between May 2009 and July 2022 for eligibility rules related to antiangiogenics. We also reviewed the literature pertaining to bevacizumab withdrawal. Results: Two hundred and ninety-seven studies for patients with recurrent glioma were reviewed. Most were phase 1 (n = 145, 49%), non-randomized (n = 257, 87%), evaluated a drug-only intervention (n = 223, 75%), and had a safety and tolerability primary objective (n = 181, 61%). Fifty-one (17%) excluded participants who received any antiangiogenic, one (0.3%) excluded participants who received any non-temozolomide systemic therapy. Fifty-nine (20%) outlined washout rules for bevacizumab (range 2-24 weeks, 4-week washout n = 35, 12% most common). Seventy-eight required a systemic therapy washout (range 1-6 weeks, 4-week washout n = 34, 11% most common). Nine permitted prior bevacizumab use with limitations, 18 (6%) permitted any prior bevacizumab, 5 (2%) were for bevacizumab-refractory disease, and 76 (26%) had no rules regarding antiangiogenic use. A literature review is then presented to define standardized eligibility criteria with a 6-week washout period proposed for future trial design. Conclusions: Interventional clinical trials for patients with HGG have substantial heterogeneity regarding eligibility criteria pertaining to bevacizumab use, demonstrating a need for standardizing clinical trial design.

Isocitrate Dehydrogenase Inhibitors in Glioma: From Bench to Bedside.

Isocitrate dehydrogenase (IDH) mutant gliomas are a primary malignancy of the central nervous system (CNS) malignancies, most commonly affecting adults under the age of 55. Standard of care therapy for IDH-mutant gliomas involves maximal safe resection, radiotherapy, and chemotherapy. However, despite good initial responses to multimodality treatment, recurrence is virtually universal. IDH-mutant gliomas represent a life-limiting prognosis. For this reason, there is a great need for novel treatments that can prolong survival. Uniquely for IDH-mutant gliomas, the IDH mutation is the direct driver of oncogenesis through its oncometabolite 2-hydroxygluterate. Inhibition of this mutated IDH with a corresponding reduction in 2-hydroxygluterate offers an attractive treatment target. Researchers have tested several IDH inhibitors in glioma through preclinical and early clinical trials. A phase III clinical trial of an IDH1 and IDH2 inhibitor vorasidenib yielded promising results among patients with low-grade IDH-mutant gliomas who had undergone initial surgery and no radiation or chemotherapy. However, many questions remain regarding optimal use of IDH inhibitors in clinical practice. In this review, we discuss the importance of IDH mutations in oncogenesis of adult-type diffuse gliomas and current evidence supporting the use of IDH inhibitors as therapeutic agents for glioma treatment. We also examine unresolved questions and propose potential directions for future research.

Immune Checkpoint Inhibitors and Glioblastoma: A Review on Current State and Future Directions.

Glioblastoma (GBM) is the most prevalent malignant tumor of the central nervous system. The prognosis of GBM is grim, with a median overall survival of 14.6 months and only 6.9% of patients surviving 5 years after the initial diagnosis. Despite poor outcomes, standard therapy of surgical resection, radiotherapy, chemotherapy, and tumor-treating fields has remained largely unchanged. The introduction of immune checkpoint inhibitors (ICI) has been a paradigm shift in oncology, with efficacy across a broad spectrum of cancer types. Nonetheless, investigations of ICIs in both newly diagnosed and recurrent GBM have thus far been disappointing. This lack of clinical benefit has been largely attributed to the highly immunosuppressive nature of GBM. However, immunotherapy still holds promise for the treatment of GBM, with combinatorial strategies offering hope for potentially overcoming these current limitations. In this review, we discuss the outcomes of clinical trials employing ICIs in patients with GBM. Afterward, we review ICI combination strategies and how these combinations may overcome the immunosuppressive microenvironment of GBM in the context of preclinical/clinical evidence and ongoing clinical trials.

Spinal Meningeal Mass Lesion: A Rare Presentation of Primary Dural Follicular Lymphoma.

INTRODUCTION: The differential diagnosis of a spinal intradural extramedullary mass lesion is broad and includes meningioma, schwannoma, neurofibroma, leptomeningeal metastasis, and myxopapillary ependymoma. Though rare, lymphoma should be included in the differential diagnosis of a dural mass lesion. CASE REPORT: A 38-year-old man presented with back pain that progressed over 1 month with associated focal tenderness over his mid to lower thoracic spine. He developed intermittent numbness of the bilateral lower extremities, nuchal rigidity, difficulty sleeping, and night sweats. A magnetic resonance imaging of the thoracic spine demonstrated a dorsal intradural extramedullary enhancing lesion from T7 to T10 extending outside the spinal canal. Dural thickening across the entire circumference of the spinal cord was noted. Computed tomography (CT)-guided biopsy of the thoracic lesion was performed, and pathology was consistent with follicular lymphoma. Fluorodeoxyglucose positron emission tomography:CT demonstrated no systemic disease. Bone marrow biopsy was negative for malignancy. Symptoms resolved with dexamethasone therapy. He was treated with bendamustine and rituximab with follow-up positron emission tomography:CT 2 months later demonstrating a complete response. CONCLUSIONS: Lymphoma can rarely present as an isolated dural lesion and should be considered in the differential diagnosis of intradural extramedullary spinal mass lesions. Prompt diagnosis and initiation of treatment can lead to complete response and resolution of symptoms.

A case series of osseous metastases in patients with glioblastoma.

BACKGROUND: Extracranial metastases occur in <2% of cases of glioblastoma (GBM). When metastases do occur, bone is the most common destination. Herein, we review clinical characteristics of GBM patients with osseous metastases and evaluate both potential risk factors and prognostic significance. METHODS: Using an institutional database, we identified and retrospectively analyzed 6 patients with both GBM and osseous metastases. We collected data on patient demographics, tumor genetics, clinical courses, and outcomes. Given the rarity of metastatic GBM, we conducted historical comparisons using previously published literature. RESULTS: Five patients with osseous metastases (83%) were male, with a median age of 46 years at GBM diagnosis (range: 20-84). All patients had IDH-wildtype, MGMT promoter unmethylated GBM and 5 (83%) had alterations in TP53. All patients underwent surgical resection for GBM followed by radiation with concurrent and adjuvant temozolomide. Four patients (67%) received bevacizumab prior to bone metastasis diagnosis. Bone metastases were discovered at a median of 12.2 months (range: 5.3-35.2) after GBM diagnosis and 4.8 months after starting bevacizumab (range: 3.5-13.2). Three patients (50%) received immunotherapy. After osseous metastasis diagnosis, the median survival was 25 days (range: 13-225). CONCLUSION: In our cohort, most patients were male and young at the time of GBM diagnosis. All patients had IDH-wildtype, MGMT promoter unmethylated GBM, and most had alterations in TP53, which may be important for osseous metastasis. Most patients received bevacizumab, which has been associated with earlier metastasis. Osseous metastases of GBM occur and portend a dismal prognosis in an already aggressive malignancy.

Osimertinib is associated with improved outcomes in pre-treated non-small cell lung cancer leptomeningeal metastases: A systematic review and meta-analysiss.

Purpose: Leptomeningeal metastasis (LM) is a severe complication of non-small cell lung cancer (NSCLC). In patients with NSCLC LM harboring epidermal growth factor receptor (EGFR) mutations, osimertinib is favored over alternative EGFR tyrosine kinase inhibitors (TKIs). However, the efficacy of osimertinib relative to other EGFR-TKIs is not well established for patients with LM. We aimed to compare the efficacy of EGFR-TKIs in EGFR-mutated NSCLC LM. Methods: This systematic review and meta-analysis performed according to PRISMA guidelines included studies of adult patients with EGFR-mutated NSCLC and a diagnosis of LM who received an EGFR-TKI for the treatment of LM. We searched Medline ALL, Embase, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science Core Collection. The evaluation of biases was done by using the Ottawa-Newscastle scale. The hazard ratio was used as the parameter of interest for overall survival (OS) and central nervous system-specific progression-free survival (PFS). Results: 128 publications were included with 243 patients and 282 lines of EGFR-TKI for NSCLC LM that met inclusion criteria. The median PFS in patients receiving any EGFR-TKI was 9.1 months, and the median OS was 14.5 months. In univariate analyses of the entire cohort, osimertinib treatment demonstrated significantly prolonged PFS, but not OS, compared to other EGFR-TKIs. Osimertinib demonstrated significantly prolonged PFS and OS in the subset of patients who were previously treated with EGFR-TKIs, but not in EGFR-TKI naïve patients. Conclusion: Osimertinib is associated with improved outcomes compared to other EGFR-TKIs, particularly in patients previously treated with EGFR-TKIs. An important limitation is that most patients were derived from retrospective reports. These results highlight the need for prospective studies for this difficult-to-treat patient population.