Use of bevacizumab in recurrent glioblastoma

Altered Mental Status in Cancer

Patients with cancer experience high rates of alterations in mental status. The mechanisms for altered mental status (AMS) in this population are manifold. The cancer itself may cause AMS through direct invasion of the central nervous system or as metastatic leptomeningeal spread. However, cancer patients are also vulnerable to tumor-associated complications such as seizures, cerebral edema, strokes, or cancer treatment-related complications such as infections, direct neural injury from radiation or chemotherapy, edema, or dysregulated autoimmune response from immunotherapies. Both during treatment and as sequelae, patients may suffer neurocognitive complications from chemotherapy and radiation, medications or opportunistic infections, as well as toxic-metabolic, nutritional, and endocrine complications. In this review, we describe a clinical approach to the cancer patient presenting with AMS and discuss the differential drivers of AMS in this patient population. While common etiologies of AMS in noncancer patients (toxic-metabolic or infectious encephalopathy, delirium) are also applicable to cancer patients, we additionally provide a cancer-specific differential diagnosis that warrants special consideration in the cancer patient with AMS.

Hypofractionated re-irradiation with bevacizumab for relapsed chemorefractory glioblastoma after prior high dose radiotherapy: a feasible option for patients with large-volume relapse

PURPOSE

There remains no standard of care for patients with recurrent and chemorefractory glioblastoma. Re-irradiation (reRT) provides an additional management option. However, published series predominantly focus on small reRT volumes utilizing stereotactic hypofractionated regimens. Concerns regarding toxicity have limited utilisation of reRT for larger recurrences, however this may be mitigated with use of bevacizumab (BEV).

METHODS AND MATERIALS

A prospective database of patients managed with the EORTC-NCIC (Stupp) protocol 60 Gy chemoradiotherapy protocol for glioblastoma between 2007 and 2021 was reviewed for those patients receiving reRT for chemorefractory relapse. Serial MRI and PET were used to establish true progression and exclude patients with pseudoprogression or radionecrosis from reRT. The primary endpoint was overall survival (OS) from date of reRT. Prognostic factors were also assessed.

RESULTS

447 patients managed for glioblastoma under the Stupp protocol were identified, of which 372 had relapsed and were thus eligible for reRT. 71 patients underwent reRT. Median relapse-free survival from diagnosis for the reRT and overall cohorts were similar at 11.6 months (95%CI:9.4-14.2) and 11.8 months (95%CI:9.4-14.2) respectively. 60/71 (85%) reRT patients had received BEV prior to reRT and continued concurrent BEV during reRT. Of the 11 patients not managed with BEV during reRT, 10 required subsequent salvage BEV. ReRT patients were younger (median 53 vs. 59 years, p < 0.001), had better performance status (86% vs. 69% ECOG 0-1, p = 0.002) and more commonly had MGMT promoter-methylated tumours (54% vs. 40%, p = 0.083) compared to non-reRT patients. Median reRT PTV volume was 135cm3 (IQR: 69-207cm3). Median OS from reRT to death was 7.1 months (95%CI:6.3-7.9). Patients aged < 50, 50-70 and > 70 years had post-reRT median OS of 7.7, 6.4 and 6.0 months respectively (p = 0.021). Median post-reRT survival was longer for patients with ECOG performance status 0-1 compared to 2-3 (8.1 vs. 6.3 months, p = 0.039). PTV volume, site of relapse, MGMT promoter-methylation status and extent of initial surgical resection were not associated with post-reRT survival. ReRT was well-tolerated. Out of the 6 patients (8%) admitted to hospital after reRT, only one was for reRT toxicity. This was a CTCAE grade 3 radiation necrosis event in a patient managed without prior BEV.

CONCLUSION

Patients with recurrent glioblastoma who have been previously treated with 60 Gy radiotherapy have a meaningful survival benefit from large volume re-irradiation which is well tolerated. ReRT should not be ignored as a salvage treatment option in patients with chemorefractory progressive disease.

Engineered smart materials for RNA based molecular therapy to treat Glioblastoma

Glioblastoma (GBM) is an aggressive malignancy of the central nervous system (CNS) that remains incurable despite the multitude of improvements in cancer therapeutics. The conventional chemo and radiotherapy post-surgery have only been able to improve the prognosis slightly; however, the development of resistance and/or tumor recurrence is almost inevitable. There is a pressing need for adjuvant molecular therapies that can successfully and efficiently block tumor progression. During the last few decades, non-coding RNAs (ncRNAs) have emerged as key players in regulating various hallmarks of cancer including that of GBM. The levels of many ncRNAs are dysregulated in cancer, and ectopic modulation of their levels by delivering antagonists or overexpression constructs could serve as an attractive option for cancer therapy. The therapeutic potential of several types of ncRNAs, including miRNAs, lncRNAs, and circRNAs, has been validated in both in vitro and in vivo models of GBM. However, the delivery of these RNA-based therapeutics is highly challenging, especially to the tumors of the brain as the blood-brain barrier (BBB) poses as a major obstacle, among others. Also, since RNA is extremely fragile in nature, careful considerations must be met while designing a delivery agent. In this review we have shed light on how ncRNA therapy can overcome the limitations of its predecessor conventional therapy with an emphasis on smart nanomaterials that can aide in the safe and targeted delivery of nucleic acids to treat GBM. Additionally, critical gaps that currently exist for successful transition from viral to non-viral vector delivery systems have been identified. Finally, we have provided a perspective on the future directions, potential pathways, and target areas for achieving rapid clinical translation of, RNA-based macromolecular therapy to advance the effective treatment of GBM and other related diseases.

Bispecific antibody shuttles targeting CD98hc mediate efficient and long-lived brain delivery of IgGs

The inability of antibodies to penetrate the blood-brain barrier (BBB) is a key limitation to their use in diverse applications. One promising strategy is to deliver IgGs using a bispecific BBB shuttle, which involves fusing an IgG to a second affinity ligand that engages a cerebrovascular endothelial target and facilitates transport across the BBB. Nearly all prior efforts have focused on shuttles that target transferrin receptor (TfR-1) despite inherent delivery and safety challenges. Here, we report bispecific antibody shuttles that engage CD98hc, the heavy chain of the large neutral amino acid transporter (LAT1), and efficiently transport IgGs into the brain. Notably, CD98hc shuttles lead to much longer-lived brain retention of IgGs than TfR-1 shuttles while enabling more specific targeting due to limited CD98hc engagement in the brain parenchyma, which we demonstrate for IgGs that either agonize a neuronal receptor (TrkB) or target other endogenous cell-surface proteins on neurons and astrocytes.

Efficacy of Anti-VEGF Drugs Based Combination Therapies in Recurrent Glioblastoma: Systematic Review and Meta-Analysis

BACKGROUND

Recurrent glioblastoma multiforme (rGBM) has a grim prognosis, with current therapies offering no survival benefit. Several combination therapies involving anti-VEGF agents have been studied with mixed results.

METHODS

A systematic search was performed using five electronic databases: PubMed, Scopus, ISI, Embase, and the Cochrane Library, without language limitations. The primary outcome of interest was progression-free survival (PFS). Secondary outcomes were overall survival (OS), objective response ratio (ORR), and grade ≥ 3 adverse events. Estimates for PFS and OS were calculated as random effects hazard ratio (HR) with 95% confidence intervals (CIs) using the generic inverse variance method. Estimates for ORR and grade ≥ 3 adverse events were calculated using a random-effects risk ratio (RR) with 95% confidence intervals (CIs) using the Mantel-Haenszel method.

RESULTS

Thirteen studies met the inclusion criteria and a total of 1994 patients were included in the analysis. There was no statistically significant improvement in PFS (HR 0.84; 95% CI (0.68, 1.03); I2=81%), OS (HR 0.99; 95% CI (0.88, 1.12); I2=0%), and ORR (RR 1.36; 95% CI (0.96, 1.92); I2=61%) in the combination therapy group when compared to the control group. Significantly higher grade ≥ 3 adverse events (RR 1.30; 95% CI (1.14, 1.48); I2=47%) were seen in the combination therapy when compared to the control group.

CONCLUSION

Our analysis showed that the use of combination therapy with anti-VEGF agents did not offer any benefit in PFS, OS, or ORR. In contrast, it had significantly higher grade 3-5 adverse events. Further studies are needed to identify effective therapies in rGBM that can improve survival.

Bispecific antibody shuttles targeting CD98hc mediate efficient and long-lived brain delivery of IgGs

The inability of antibodies and other biologics to penetrate the blood-brain barrier (BBB) is a key limitation to their use in diagnostic, imaging, and therapeutic applications. One promising strategy is to deliver IgGs using a bispecific BBB shuttle, which involves fusing an IgG with a second affinity ligand that engages a cerebrovascular endothelial target and facilitates transport across the BBB. Nearly all prior efforts have focused on the transferrin receptor (TfR-1) as the prototypical endothelial target despite inherent delivery and safety challenges. Here we report bispecific antibody shuttles that engage CD98hc (also known as 4F2 and SLC3A2), the heavy chain of the large neutral amino acid transporter (LAT1), and efficiently transport IgGs into the brain parenchyma. Notably, CD98hc shuttles lead to much longer-lived brain retention of IgGs than TfR-1 shuttles while enabling more specific brain targeting due to limited CD98hc engagement in the brain parenchyma. We demonstrate the broad utility of the CD98hc shuttles by reformatting three existing IgGs as CD98hc bispecific shuttles and delivering them to the mouse brain parenchyma that either agonize a neuronal receptor (TrkB) or target other endogenous antigens on specific types of brain cells (neurons and astrocytes).

Adenosine Targeting as a New Strategy to Decrease Glioblastoma Aggressiveness

Simple Summary

Given the rising mortality rate caused by GBM, current therapies do not appear to be effective in counteracting tumor progression. The role of adenosine and its interaction with specific receptor subtypes in various physiological functions has been studied for years. Only recently, adenosine has been defined as a tumor-protective target because of its accumulation in the tumor microenvironment. Current knowledge of the adenosine pathway and its involvement in brain tumors would support research in the development of adenosine receptor antagonists that could represent alternative treatments for glioblastoma, used either alone and/or in combination with chemotherapy, immunotherapy, or both.

Abstract

Glioblastoma is the most commonly malignant and aggressive brain tumor, with a high mortality rate. The role of the purine nucleotide adenosine and its interaction with its four subtypes receptors coupled to the different G proteins, A1, A2A, A2B, and A3, and its different physiological functions in different systems and organs, depending on the active receptor subtype, has been studied for years. Recently, several works have defined extracellular adenosine as a tumoral protector because of its accumulation in the tumor microenvironment. Its presence is due to both the interaction with the A2A receptor subtype and the increase in CD39 and CD73 gene expression induced by the hypoxic state. This fact has fueled preclinical and clinical research into the development of efficacious molecules acting on the adenosine pathway and blocking its accumulation. Given the success of anti-cancer immunotherapy, the new strategy is to develop selective A2A receptor antagonists that could competitively inhibit binding to its endogenous ligand, making them reliable candidates for the therapeutic management of brain tumors. Here, we focused on the efficacy of adenosine receptor antagonists and their enhancement in anti-cancer immunotherapy.

Metachronous Osseous Metastases From Gliobliostoma Mutiforme: An Unusual Presentation

Metastasis occurs very rarely in glioblastoma cases. Diagnosing metastatic glioblastoma has to follow a strict protocol to avoid misdiagnosis. Weiss’s 1955 criteria, which is in prevalence, needs to be modified to include current standards of investigation. We report an interesting case of metachronous osseous metastasis from a primary glioblastoma with a complete response at a local site. We also suggest modifications to Weiss’ criteria, which may improve its utility in establishing the diagnosis of metastatic glioblastoma.

The Monoterpenoid Perillyl Alcohol: Anticancer Agent and Medium to Overcome Biological Barriers

Perillyl alcohol (POH) is a naturally occurring monoterpenoid related to limonene that is present in the essential oils of various plants. It has diverse applications and can be found in household items, including foods, cosmetics, and cleaning supplies. Over the past three decades, it has also been investigated for its potential anticancer activity. Clinical trials with an oral POH formulation administered to cancer patients failed to realize therapeutic expectations, although an intra-nasal POH formulation yielded encouraging results in malignant glioma patients. Based on its amphipathic nature, POH revealed the ability to overcome biological barriers, primarily the blood–brain barrier (BBB), but also the cytoplasmic membrane and the skin, which appear to be characteristics that critically contribute to POH’s value for drug development and delivery. In this review, we present the physicochemical properties of POH that underlie its ability to overcome the obstacles placed by different types of biological barriers and consequently shape its multifaceted promise for cancer therapy and applications in drug development. We summarized and appraised the great variety of preclinical and clinical studies that investigated the use of POH for intranasal delivery and nose-to-brain drug transport, its intra-arterial delivery for BBB opening, and its permeation-enhancing function in hybrid molecules, where POH is combined with or conjugated to other therapeutic pharmacologic agents, yielding new chemical entities with novel mechanisms of action and applications.

A tale of two multi-focal therapies for glioblastoma: An antibody targeting ELTD1 and nitrone-based OKN-007

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. Despite a multimodal treatment response, survival for GBM patients remains between 12 and 15 months. Anti‐ELTD1 antibody therapy is effective in decreasing tumour volumes and increasing animal survival in an orthotopic GBM xenograft. OKN‐007 is a promising chemotherapeutic agent that is effective in various GBM animal models and is currently in two clinical trials. In this study, we sought to compare anti‐ELTD1 and OKN‐007 therapies, as single agents and combined, against bevacizumab, a commonly used therapeutic agent against GBM, in a human G55 xenograft mouse model. MRI was used to monitor tumour growth, and immunohistochemistry (IHC) was used to assess tumour markers for angiogenesis, cell migration and proliferation in the various treatment groups. OKN and anti‐ELTD1 treatments significantly increased animal survival, reduced tumour volumes and normalized the vasculature. Additionally, anti‐ELTD1 was also shown to significantly affect other pro‐angiogenic factors such as Notch1 and VEGFR2. Unlike bevacizumab, anti‐ELTD1 and OKN treatments did not induce a pro‐migratory phenotype within the tumours. Anti‐ELTD1 treatment was shown to be as effective as OKN therapy. Both OKN and anti‐ELTD1 therapies show promise as potential single‐agent multi‐focal therapies for GBM patients.

Transmembrane Protein TMEM230, a Target of Glioblastoma Therapy

Glioblastomas (GBM) are the most aggressive tumors originating in the brain. Histopathologic features include circuitous, disorganized, and highly permeable blood vessels with intermittent blood flow. These features contribute to the inability to direct therapeutic agents to tumor cells. Known targets for anti-angiogenic therapies provide minimal or no effect in overall survival of 12–15 months following diagnosis. Identification of novel targets therefore remains an important goal for effective treatment of highly vascularized tumors such as GBM. We previously demonstrated in zebrafish that a balanced level of expression of the transmembrane protein TMEM230/C20ORF30 was required to maintain normal blood vessel structural integrity and promote proper vessel network formation. To investigate whether TMEM230 has a role in the pathogenesis of GBM, we analyzed its prognostic value in patient tumor gene expression datasets and performed cell functional analysis. TMEM230 was found necessary for growth of U87-MG cells, a model of human GBM. Downregulation of TMEM230 resulted in loss of U87 migration, substratum adhesion, and re-passaging capacity. Conditioned media from U87 expressing endogenous TMEM230 induced sprouting and tubule-like structure formation of HUVECs. Moreover, TMEM230 promoted vascular mimicry-like behavior of U87 cells. Gene expression analysis of 702 patients identified that TMEM230 expression levels distinguished high from low grade gliomas. Transcriptomic analysis of patients with gliomas revealed molecular pathways consistent with properties observed in U87 cell assays. Within low grade gliomas, elevated TMEM230 expression levels correlated with reduced overall survival independent from tumor subtype. Highest level of TMEM230 correlated with glioblastoma and ATP-dependent microtubule kinesin motor activity, providing a direction for future therapeutic intervention. Our studies support that TMEM230 has both glial tumor and endothelial cell intracellular and extracellular functions. Elevated levels of TMEM230 promote glial tumor cell migration, extracellular scaffold remodeling, and hypervascularization and abnormal formation of blood vessels. Downregulation of TMEM230 expression may inhibit both low grade glioma and glioblastoma tumor progression and promote normalization of abnormally formed blood vessels. TMEM230 therefore is both a promising anticancer and antiangiogenic therapeutic target for inhibiting GBM tumor cells and tumor-driven angiogenesis.

Clinical study of apatinib plus temozolomide for the treatment of recurrent high-grade gliomas

OBJECTIVES

Recurrent high-grade glioma, a malignant tumor of the brain or spinal cord associated with poor prognosis with a median survival of <6 months. Recurrent high-grade glioma does not have standard treatment even if some strategies have some effect in recurrent gliomas. Apatinib, as a tyrosine kinase inhibitor shown to be effective in treating the lung and gastric cancer. The present study investigated the efficacy and safety of apatinib in combination with dose-dense regimens of temozolomide for treating recurrent glioma.

PATIENTS AND METHODS

Eighteen patients with recurrent high-grade glioma were enrolled and treated with apatinib (500 mg/day) and TMZ (50 mg/m²/day). Patients who achieved partial response or stable disease continued treatment. Administration of drug was terminated for patients with progressive disease, who could not tolerate toxicity, and who required discontinuation due to other medical conditions.

RESULTS

From the 18 cases, only 17 were included in the evaluation of the curative effect of the drug and in that four showed partial responses, ten had stable disease, remaining three exhibited progressive disease. The disease control rate was 82.3% (14/17). Progression-free and overall survival was found to be 4 months and 9.1 months, respectively. Three patients became transiently capable of self-care (Karnofsky performance status >70). Cognition and quality of life improved after treatment and from the safety perspective, three most common adverse reactions included epilepsy (24.1%), hypertension (20.7%), and fatigue (17.2%).

CONCLUSION

Apatinib and TMZ may represent an alternative treatment option for patients with recurrent high-gradeglioma, especially those with a low Karnofsky performance status. However, studies using a larger sample size are required to confirm these findings.

Phase I trial of intranasal NEO100, highly purified perillyl alcohol, in adult patients with recurrent glioblastoma

Background

Better treatments for glioblastoma (GBM) patients, in particular in the recurrent setting, are urgently needed. Clinical trials performed in Brazil indicated that intranasal delivery of perillyl alcohol (POH) might be effective in this patient group. NEO100, a highly purified version of POH, was current good manufacturing practice (cGMP) manufactured to evaluate the safety and efficacy of this novel approach in a Phase I/IIa clinical trial in the United States.

Methods

A total of 12 patients with recurrent GBM were enrolled into Phase I of this trial. NEO100 was administered by intranasal delivery using a nebulizer and nasal mask. Dosing was 4 times a day, every day. Four cohorts of 3 patients received the following dosages: 96 mg/dose (384 mg/day), 144 mg/dose (576 mg/day), 192 mg/dose (768 mg/day), and 288 mg/dose (1152 mg/day). Completion of 28 days of treatment was recorded as 1 cycle. Adverse events were documented, and radiographic response via Response Assessment in Neuro-Oncology (RANO) criteria was evaluated every 2 months. Progression-free and overall survival were determined after 6 and 12 months, respectively (progression-free survival-6 [PFS-6], overall survival-12 [OS-12]).

Results

Intranasal NEO100 was well tolerated at all dose levels and no severe adverse events were reported. PFS-6 was 33%, OS-12 was 55%, and median OS was 15 months. Four patients (33%), all of them with isocitrate dehydrogenase 1 (IDH1)-mutant tumors, survived >24 months.

Conclusion

Intranasal glioma therapy with NEO100 was well tolerated. It correlated with improved survival when compared to historical controls, pointing to the possibility that this novel intranasal approach could become useful for the treatment of recurrent GBM.

ELTD1 as a multi-focal target for malignant gliomas: preclinical studies

BACKGROUND

Glioblastoma (GBM) is the most aggressive malignant primary brain tumor in adults. These high-grade gliomas undergo unregulated vascular angiogenesis, migration and cell proliferation allowing the tumor cells to evade cell-cycle checkpoints and apoptotic pathways. The Epidermal growth factor, latrophilin, and seven transmembrane domain-containing 1 on chromosome 1 (ELTD1) is an angiogenic biomarker that is highly expressed in malignant gliomas. Novel treatments targeting ELTD1 with monovalent monoclonal (mmAb) and single chain variable fragment (scFv) antibodies were effective in increasing animal survival, decreasing tumor volume and normalizing the vasculature. Due to the success of our antibody treatments on angiogenesis, this study sought to determine if our anti-ELTD1 treatments affected other aspects of tumorigenesis (cell proliferation, migration, and apoptosis) in a G55 glioma xenograft preclinical mouse model.

METHODS

Tumor tissue from untreated, mmAb and scFv anti-ELTD1 treated animals was used to quantify the positivity levels of human mitochondrial antibody, c-MET and Ki-67 for cellular proliferation, migratory markers CD44v6, TRPM8, and BMP2, and cleaved caspase 3 to assess apoptotic activity.

RESULTS

This approach demonstrated that our anti-ELTD1 treatments directly affected and decreased the human tumor cells within the tumor region. Additionally, there was a significant decrease in both cellular proliferation and migration due to anti-ETLD1 therapy. Lastly, anti-ELTD1 treatments successfully increased apoptotic activity within the tumor region.

CONCLUSION

Our data suggest that anti-ELTD1 therapies would be effective against malignant gliomas by having a multi-focal effect and targeting all four aspects of tumorigenesis.

Disentangling the therapeutic tactics in GBM: From bench to bedside and beyond

Glioblastoma multiforme (GBM) is one of the most common and malignant form of adult brain tumor with a high mortality rate and dismal prognosis. The present standard treatment comprising surgical resection followed by radiation and chemotherapy using temozolomide can broaden patient's survival to some extent. However, the advantages are not palliative due to the development of resistance to the drug and tumor recurrence following the multimodal treatment approaches due to both intra- and intertumoral heterogeneity of GBM. One of the major contributors to temozolomide resistance is O⁶ -methylguanine-DNA methyltransferase. Furthermore, deficiency of mismatch repair, base excision repair, and cytoprotective autophagy adds to temozolomide obstruction. Rising proof additionally showed that a small population of cells displaying certain stem cell markers, known as glioma stem cells, adds on to the resistance and tumor progression. Collectively, these findings necessitate the discovery of novel therapeutic avenues for treating glioblastoma. As of late, after understanding the pathophysiology and biology of GBM, some novel therapeutic discoveries, such as drug repurposing, targeted molecules, immunotherapies, antimitotic therapies, and microRNAs, have been developed as new potential treatments for glioblastoma. To help illustrate, "what are the mechanisms of resistance to temozolomide" and "what kind of alternative therapeutics can be suggested" with this fatal disease, a detailed history of these has been discussed in this review article, all with a hope to develop an effective treatment strategy for GBM.

Chimeric Antigen Receptor T-Cell Therapy in Glioblastoma: Current and Future

Glioblastoma (GBM) is a highly aggressive glioma with an extremely poor prognosis after conventional treatment. Recent advances in immunotherapy offer hope for these patients with incurable GBM. Our present review aimed to provide an overview of immunotherapy for GBM, especially chimeric antigen receptor T-cell (CAR T) therapy. CAR T-cell immunotherapy, which involves the engineering of T cells to kill tumors by targeting cell surface-specific antigens, has been successful in eliminating B-cell leukemia by targeting CD19. IL-13Rα2, EGFRvIII, and HER2-targeted CAR T cells have shown significant clinical efficacy and safety in phase 1 or 2 clinical trials conducted in patients with GBM; these findings support the need for further studies to examine if this therapy can ultimately benefit this patient group. However, local physical barriers, high tumor heterogeneity, and antigen escape make the use of CAR T therapy, as a treatment for GBM, challenging. The potential directions for improving the efficacy of CAR T in GBM are to combine the existing traditional therapies and the construction of multi-target CAR T cells.

Treatment of recurrent glioblastoma: state-of-the-art and future perspectives

BACKGROUND

Almost all patients affected by glioblastoma experience recurrence of the disease.

AREAS COVERED

Management of recurrent glioblastoma is a clinical challenge, and several elements should be taken into consideration when making treatment choice. Loco-regional treatments may be the best treatment approach in selected cases while systemic therapies or supportive care alone are necessary for other patients. Unfortunately, few drugs have shown clinical in this setting. This lack of effective treatments has made recurrent glioblastoma a disease orphan of an effective approach.

EXPERT OPINION

Results of recent clinical trials offer interesting perspectives and may controvert this axiom.

Vesiclemia: counting on extracellular vesicles for glioblastoma patients

Although rare, glioblastoma is a devastating tumor of the central nervous system characterized by a poor survival and an extremely dark prognosis, making its diagnosis, treatment, and monitoring highly challenging. Numerous studies have highlighted extracellular vesicles (EVs) as key players of tumor growth, invasiveness, and resistance, as they carry oncogenic material. Moreover, EVs have been shown to communicate locally in a paracrine way but also at remote throughout the organism. Indeed, recent reports demonstrated the presence of brain tumor-derived EVs into body fluids such as plasma and cerebrospinal fluid. Fluid-associated EVs have indeed been suspected to reflect quantitative and qualitative information about the status and fate of the tumor and can potentially act as a resource for noninvasive biomarkers that might assist in diagnosis, treatment, and follow-up of glioblastoma patients. Here, we coined the name vesiclemia to define the concentration of plasmatic EVs, an intuitive term to be directly transposed in the clinical jargon.

Rechallenging Recurrent Glioblastoma with Intra-Arterial Bevacizumab with Blood Brain-Barrier Disruption Results in Radiographic Response

BACKGROUND

High-dose bevacizumab delivered via super selective intra-arterial cerebral infusion (SIACI) is one promising clinical trial combination for patients with glioblastoma (GBM). Although both continuous intravenous and intra-arterial administration of bevacizumab, and rechallenge with intravenous bevacizumab, have demonstrated improved survival, this is the first description of rechallenging GBM with SIACI of bevacizumab.

CASE DESCRIPTION

We report a case of a 43-year-old woman with recurrent GBM who had received treatment from 3 clinical trials, including a rechallenge with SIACI of bevacizumab. First, she enrolled into a phase I/II trial for patients newly diagnosed with GBM (NCT01811498) and received 3 doses of SIACI bevacizumab over 180 days in addition to standard of care chemotherapy and radiation. Following progression, as indicated on her magnetic resonance imaging scan, she consented for a separate clinical trial for her disease and received 2 cycles of temozolomide with an investigational agent. The patient was removed from the study on tumor progression. Subsequently, she was rechallenged with SIACI of bevacizumab via a third clinical trial (NCT01269853) and then completed 3 intravenous infusions. After completing the third trial, her magnetic resonance imaging scan demonstrated improvement based on Response Assessment In Neuro-Oncology criteria.

CONCLUSIONS

This is the first report to highlight the effect of rechallenging a patient with SIACI of bevacizumab following disease progression after initial bevacizumab treatment and subsequent alternate clinical trial failure. There is a need to conduct further clinical trials to evaluate the benefits of rechallenge with SIACI versus intravenous bevacizumab for GBM and further explore theories of bevacizumab resistance.

Genetic variants of vascular endothelial growth factor predict risk and survival of gliomas

The vascular endothelial growth factor regulates angiogenesis that is increased in glioma. VEGF polymorphisms are thought to modulate vascular endothelial growth factor plasma levels and therefore may be implicated in glioma risk. We aimed to clarify the role of VEGF and von Willebrand factor polymorphisms in glioma susceptibility and prognosis. A case-control study of 126 glioma patients and 180 cancer-free controls was performed. Using Sequenom MassARRAY platform, 11 VEGF and 1 VWF polymorphisms were genotyped. Unconditional multivariate logistic regression models were used to calculate odds ratios and 95% confidence intervals. The associations between polymorphisms and survival were evaluated using a Cox regression model. Bonferroni's adjustment was used to correct for multiple testing. The VEGF polymorphism rs833061 was strongly associated with increased risk for glioma (odds ratio = 164.85) and glioblastoma (odds ratio = 155.66), confirmed after Bonferroni correction. Also, the VEGF polymorphisms rs3024994, rs2010963, and particularly the homozygous carriers of rs1005230 were associated with a worse prognosis for glioma and glioblastoma. Our data support a role of VEGF and VWF polymorphisms as glioma biomarkers, with additional potential relevance for molecular stratification of patients for anti-angiogenic therapies.

Prognostic significance of epidermal growth factor receptor expression in glioma patients

Purpose

There is a great controversy regarding the prognostic significance of epidermal growth factor receptor (EGFR) in glioma patients. The current meta-analysis was conducted to evaluate the effect of abnormal EGFR expression on overall survival in glioma patients.

Materials and methods

A comprehensive literature search of PubMed, EMBASE, Google Scholar, Web of Science, and Cochrane Library was conducted. The combined hazard ratio (HR) and its 95% confidence intervals (CIs) were used to evaluate the association between EGFR expression and survival in glioma.

Results

A total of 476 articles were screened, and 17 articles containing 1,458 patients were selected. The quality assessment of the included studies was performed by the Newcastle-Ottawa Scale. Overexpression of EGFR was found to be an indicator of poor prognosis in overall survival in glioma patients (HR =1.72, 95% CI 1.32-2.25, P=0.000, random effect) and glioblastoma multiforme patients (HR =1.57, 95% CI 1.15-2.14, P=0.004, random effect). Subgroup analysis was conducted to explore the source of high heterogeneity.

Conclusion

This meta-analysis indicated that high expression of EGFR may serve as a biomarker for poor prognosis in glioma patients.

Phase II Study of Bevacizumab and Vorinostat for Patients with Recurrent World Health Organization Grade 4 Malignant Glioma

LESSONS LEARNED

Combination regimen with bevacizumab (BEV) and vorinostat is well tolerated in patients with recurrent glioblastoma.Treatment of recurrent glioblastoma remains challenging as this study and others attempt to improve progression-free survival and overall survival with BEV-containing regimens.

BACKGROUND

Recurrent glioblastoma (GBM; World Health Organization grade 4) continues to have a very poor prognosis. Bevacizumab (BEV) has been shown to improve progression-free survival (PFS) in recurrent GBM and is approved by the U.S. Food and Drug Administration for the treatment of recurrent GBM. Combination regimens have been explored, and in this phase II nonrandomized trial, we evaluated the efficacy of BEV combined with histone deacetylase inhibitor vorinostat (VOR) in recurrent GBM.

MATERIALS AND METHODS

In this phase II, single-center, nonrandomized study, subjects with recurrent GBM received BEV 10 mg/kg intravenously (IV) every 2 weeks combined with VOR 400 mg p.o. daily for 7 days on, 7 days off, in a 28-day cycle. The primary endpoint was 6-month PFS (PFS6).

RESULTS

Forty patients with recurrent GBM were enrolled and evaluated. PFS6 was 30.0% (95% confidence interval [CI] 16.8%-44.4%). Median overall survival (OS) was 10.4 months (95% CI 7.6-12.8 months). Overall radiographic response rate was 22.5% based on 9 partial responses. The most common grade 2 and above treatment-related adverse events were lymphopenia (55%), leukopenia (45%), neutropenia (35%), and hypertension (33%). Grade 4 adverse events were leukopenia (3%), neutropenia (3%), sinus bradycardia (3%), and venous thromboembolism (3%). Two deaths occurred in this study, with one due to tumor progression and another possibly related as death not otherwise specified.

CONCLUSION

Combination treatment of BEV and VOR was well tolerated. This combination therapy for this study population did not improve PFS6 or median OS when compared with BEV monotherapy.

Combined EGFR- and notch inhibition display additive inhibitory effect on glioblastoma cell viability and glioblastoma-induced endothelial cell sprouting in vitro

Background

For Glioblastoma (GBM) patients, a number of anti-neoplastic strategies using specifically targeting drugs have been tested; however, the effects on survival have been limited. One explanation could be treatment resistance due to redundant signaling pathways, which substantiates the need for combination therapies. In GBM, both the epidermal growth factor receptor (EGFR) and the notch signaling pathways are often deregulated and linked to cellular growth, invasion and angiogenesis. Several studies have confirmed cross-talk and co-dependence of these pathways. Therefore, this study aimed at testing a combination treatment strategy using inhibitors targeting the notch and EGFR pathways.

Methods

For evaluation of cell viability a standard MTT assay was used. Western blotting (WB) and Q-RT-PCR were employed in order to assess the protein- and mRNA expression levels, respectively. In order to determine angiogenic processes, we used an endothelial spheroid sprouting assay. For assessment of secreted VEGF from GBM cells we performed a VEGF-quantikine ELISA.

Results

GBM cells were confirmed to express EGFR and Notch and to have the capacity to induce endothelial cell sprouting. Inhibition of EGFR and Notch signaling was achieved using either Iressa (gefitinib) or the gamma-secretase inhibitor DAPT. Our data showed that DAPT combined with Iressa treatment displayed increased inhibitory effect on cell viability and abrogated expression and activation of major pro-survival pathways. Similarly, the combinational treatment significantly increased abrogation of GBM-induced endothelial cell sprouting suggesting reduced GBM angiogenesis.

Conclusion

This study finds that simultaneous targeting of notch and EGFR signaling leads to enhanced inhibitory effects on GBM-induced angiogenesis and cell viability, thereby stressing the importance of further evaluation of this targeting approach in a clinical setting.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-016-0309-2) contains supplementary material, which is available to authorized users.

The Role of a Single Angiogenesis Inhibitor in the Treatment of Recurrent Glioblastoma Multiforme: A Meta-Analysis and Systematic Review

BACKGROUND

Currently, the standard treatment for newly diagnosed glioblastoma multiforme (GBM) is maximal safe surgical resection followed by radiation therapy with concurrent and adjuvant temozolomide. However, disease recurs in almost all patients, and the optimal salvage treatment for recurrent GBM remains unclear. We conducted a systematic review and meta-analysis of published clinical trials to assess the efficacy and toxicities of angiogenesis inhibitors alone as salvage treatment in these patients.

METHODS

Trials published between 1994 and 2015 were identified by an electronic search of public databases (MEDLINE, EMBASE, Cochrane library). Demographic data, treatment regimens, objective response rate (ORR), median progression-free survival (PFS), median overall survival (OS), 6-months PFS rate, 1-year OS and grade 3/4 toxicities were extracted. We also compared the main outcomes of interest between bevacizumab and other angiogenesis inhibitors. All analyses were performed using Comprehensive Meta Analysis software (Version 2.0).

RESULTS

A total of 842 patients were included for analysis: 343 patients were treated with bevacizumab, 386 with other angiogenesis inhibitors and 81 with thalidomide. The pooled ORR, 6-months PFS, and 1-year OS for recurrent GBM patients receiving angiogenesis inhibitors was 20.1%, 19.5% and 29.3%, respectively. The use of single agent bevacizumab in recurrent GBM significantly improved ORR and 6-months PFS when compared to other angiogenesis inhibitors [relative risk (RR) 2.93, 95% CI 1.38-6.21; p = 0.025; and RR 2.36 95% CI 1.46-3.82; p<0.001, respectively], while no significant difference in 1-year OS was found between the two groups (p = 0.07). when compared to thalidomide, bevacizumab treatment in recurrent GBM significantly improved ORR (RR 6.8, 95%CI: 2.64-17.6, p<0.001), but not for 6-months PFS (p = 0.07) and 1-year OS (p = 0.31). As for grade 3/4 toxicities, the common toxicity was hypertension with pooled incidence of 12.1%, while high-grade thromboembolic events (2.2%), hemorrhage (5.1%) and GI perforation (2.8%) associated with angiogenesis inhibitors were relatively low.

CONCLUSIONS

In comparison with other angiogenesis inhibitors and thalidomide, the use of single agent bevacizumab as salvage treatment for recurrent GBM patients improve ORR and 6-months PFS, but not for 1-year OS.