Glioblastomas are the most common form of malignant primary brain tumor and an important cause of morbidity and mortality. In recent years there have been important advances in understanding the molecular pathogenesis and biology of these tumors, but this has not translated into significantly improved outcomes for patients. In this consensus review from the Society for Neuro-Oncology (SNO) and the European Association of Neuro-Oncology (EANO), the current management of isocitrate dehydrogenase wildtype (IDHwt) glioblastomas will be discussed. In addition, novel therapies such as targeted molecular therapies, agents targeting DNA damage response and metabolism, immunotherapies, and viral therapies will be reviewed, as well as the current challenges and future directions for research.

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Glioblastoma in adults: a Society for Neuro-Oncology (SNO) and European Society of Neuro-Oncology (EANO) consensus review on current management and future directions

Vascular endothelial growth factor (VEGF) is an attractive target of antiangiogenic therapy in glioblastomas. Bevacizumab (Bev), a humanized anti-VEGF antibody, is associated with the improvement of progression-free survival and performance status in patients with glioblastoma. However, randomized trials uniformly suggest that these favorable clinical effects of Bev do not translate into an overall survival benefit. The mechanisms of action of Bev appear to include the inhibition of tumor angiogenesis, as well as indirect effects such as the depletion of niches for glioma stem cells and stimulation of antitumor immunity. Although several molecules/pathways have been reported to mediate adaptation and resistance to Bev, including the activation of alternative pro-angiogenic pathways, the resistance mechanisms have not been fully elucidated; for example, the mechanism that reinduces tumor hypoxia remains unclarified. The identification of imaging characteristics or biomarkers predicting the response to Bev, as well as the better understanding of the mechanisms of action and resistance, is crucial to improve the overall clinical outcome and optimize individual therapy. In this article, the authors review the results of important clinical trials/studies, the current understanding of the mechanisms of action and resistance, and the knowledge of imaging characteristics and biomarkers predicting the response to Bev.

Bevacizumab for malignant gliomas: current indications, mechanisms of action and resistance, and markers of response.

Glioblastoma is the most frequent and aggressive form among malignant central nervous system primary tumors in adults. Standard treatment for newly diagnosed glioblastoma consists in maximal safe resection, if feasible, followed by radiochemotherapy and adjuvant chemotherapy with temozolomide; despite this multimodal treatment, virtually all glioblastomas relapse. Once tumors progress after first-line therapy, treatment options are limited and management of recurrent glioblastoma remains challenging. Loco-regional therapy with re-surgery or re-irradiation may be evaluated in selected cases, while traditional systemic therapy with nitrosoureas and temozolomide rechallenge showed limited efficacy. In recent years, new clinical trials using, for example, regorafenib or a combination of tyrosine kinase inhibitors and immunotherapy were performed with promising results. In particular, molecular targeted therapy could show efficacy in selected patients with specific gene mutations. Nonetheless, some molecular characteristics and genetic alterations could change during tumor progression, thus affecting the efficacy of precision medicine. We therefore reviewed the molecular and genomic landscape of recurrent glioblastoma, the strategy for clinical management and the major phase I-III clinical trials analyzing recent drugs and combination regimens in these patients.

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Recurrent Glioblastoma: From Molecular Landscape to New Treatment Perspectives.

Glioblastoma (GBM) is the most common malignant primary brain tumor, and the available treatment options are limited. This article reviews the recent preclinical and clinical investigations that seek to expand the repertoire of effective medical and radiotherapy options for GBM. Recent phase III trials evaluating checkpoint inhibition did not result in significant survival benefit. Select vaccine strategies have yielded promising results in early phase clinical studies and warrant further validation. Various targeted therapies are being explored but have yet to see breakthrough results. In addition, novel radiotherapy approaches are in development to maximize safe dose delivery. A multitude of preclinical and clinical studies in GBM explore promising immunotherapies, targeted agents, and novel radiation modalities. Recent phase III trial failures have once more highlighted the profound tumor heterogeneity and diverse resistance mechanisms of glioblastoma. This calls for the development of biomarker-driven and personalized treatment approaches.

Novel Therapies for Glioblastoma

Author(s): Cloughesy, Timothy F; Brenner, Andrew; de Groot, John F; Butowski, Nicholas A; Zach, Leor; Campian, Jian L; Ellingson, Benjamin M; Freedman, Laurence S; Cohen, Yael C; Lowenton-Spier, Noa; Rachmilewitz Minei, Tamar; Fain Shmueli, Shifra; GLOBE Study Investigators; Wen, Patrick Y | Abstract: BackgroundOfranergene obadenovec (VB-111) is an anticancer viral therapy that demonstrated in a phase II study a survival benefit for patients with recurrent glioblastoma (rGBM) who were primed with VB-111 monotherapy that was continued after progression with concomitant bevacizumab.MethodsThis pivotal phase III randomized, controlled trial compared the efficacy and safety of upfront combination of VB-111 and bevacizumab versus bevacizumab monotherapy. Patients were randomized 1:1 to receive VB-111 1013 viral particles every 8 weeks in combination with bevacizumab 10 mg/kg every 2 weeks (combination arm) or bevacizumab monotherapy (control arm). The primary endpoint was overall survival (OS), and secondary endpoints were objective response rate (ORR) by Response Assessment in Neuro-Oncology (RANO) criteria and progression-free survival (PFS).ResultsEnrolled were 256 patients at 57 sites. Median exposure to VB-111 was 4 months. The study did not meet its primary or secondary goals. Median OS was 6.8 versus 7.9 months in the combination versus control arm (hazard ratio, 1.20; 95% CI: 0.91-1.59; P = 0.19) and ORR was 27.3% versus 21.9% (P = 0.26). A higher rate of grades 3-5 adverse events was reported in the combination arm (67% vs 40%), mainly attributed to a higher rate of CNS and flu-like/fever events. Trends for improved survival with combination treatment were seen in the subgroup of patients with smaller tumors and in patients who had a posttreatment febrile reaction.ConclusionsIn this study, upfront concomitant administration of VB-111 and bevacizumab failed to improve outcomes in rGBM. Change of treatment regimen, with the lack of VB-111 monotherapy priming, may explain the differences from the favorable phase II results.Clinical trials registrationNCT02511405.

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A randomized controlled phase III study of VB-111 combined with bevacizumab vs bevacizumab monotherapy in patients with recurrent glioblastoma (GLOBE).

Author(s): Brenner, Andrew J; Peters, Katherine B; Vredenburgh, James; Bokstein, Felix; Blumenthal, Deborah T; Yust-Katz, Shlomit; Peretz, Idit; Oberman, Bernice; Freedman, Laurence S; Ellingson, Benjamin M; Cloughesy, Timothy F; Sher, Naamit; Cohen, Yael C; Lowenton-Spier, Noa; Rachmilewitz Minei, Tamar; Yakov, Niva; Mendel, Itzhak; Breitbart, Eyal; Wen, Patrick Y | Abstract: BackgroundVB-111 is a non-replicating adenovirus carrying a Fas-chimera transgene, leading to targeted apoptosis of tumor vascular endothelium and induction of a tumor-specific immune response. This phase I/II study evaluated the safety, tolerability, and efficacy of VB-111 with and without bevacizumab in recurrent glioblastoma (rGBM).MethodsPatients with rGBM (n = 72) received VB-111 in 4 treatment groups: subtherapeutic (VB-111 dose escalation), limited exposure (LE; VB-111 monotherapy until progression), primed combination (VB-111 monotherapy continued upon progression with combination of bevacizumab), and unprimed combination (upfront combination of VB-111 and bevacizumab). The primary endpoint was median overall survival (OS). Secondary endpoints were safety, overall response rate, and progression-free survival (PFS).ResultsVB-111 was well tolerated. The most common adverse event was transient mild-moderate fever. Median OS time was significantly longer in the primed combination group compared with both LE (414 vs 223 days; hazard ratio [HR], 0.48; P = 0.043) and unprimed combination (414 vs 141.5 days; HR, 0.24; P = 0.0056). Patients in the combination phase of the primed combination group had a median PFS time of 90 days compared with 60 in the LE group (HR, 0.36; P = 0.032), and 63 in the unprimed combination group (P = 0.72). Radiographic responders to VB-111 exhibited characteristic, expansive areas of necrosis in the areas of initial enhancing disease.ConclusionsPatients with rGBM who were primed with VB-111 monotherapy that continued after progression with the addition of bevacizumab showed significant survival and PFS advantage, as well as specific imaging characteristics related to VB-111 mechanism of action. These results warrant further assessment in a randomized controlled study.

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Safety and efficacy of VB-111, an anticancer gene therapy, in patients with recurrent glioblastoma: results of a phase I/II study.

The present invention, in some embodiments thereof, relates to methods of producing adenoviruses such as pro- and anti-angiogenic adenovirus vectors and preparations generated thereby. Particularly, in some embodiments, the viral vectors comprise a heterologous pro- or anti-angiogenic gene under the transcriptional control of the murine pre-proendothelin promoter (e.g. PPE-1-3X), for targeted expression of in angiogenic endothelium.

Methods of Producing Adenovirus Vectors and Viral Preparations Generated Thereby

Anti-angiogenic adenovirus vectors, and therapeutic use thereof are provided, and more particularly, but not exclusively, clinical protocols for treatment of solid tumors in patients with an Ad5-PPE-1-3X-fas-chimera adenovirus vector

Methods for use of a specific anti-angiogenic adenoviral agent

Unit dosage forms comprising between 1 mg and 100 mg VB-201 and a pharmaceutically acceptable carrier, and formulated for oral administration, are disclosed herein, as well as treatment regimens comprising oral administration of VB-201 once or twice daily for treating an inflammatory disease or disorder.

Treatment with vb-201

The invention provides methods of inducing or improving responsiveness to a VEGF antagonist to a subject or a subject population comprising administering an adenovirus comprising a nucleic acid construct comprising a FAS-chimera gene operably linked to an endothelial cell-specific promoter and administering the VEGF antagonist.

Naamit Sher

Papers

Safety and efficacy of VB-111, an anticancer gene therapy, in patients with recurrent glioblastoma: results of a phase I/II study.

Methods of Producing Adenovirus Vectors and Viral Preparations Generated Thereby

Methods for use of a specific anti-angiogenic adenoviral agent

Treatment with vb-201

Methods of inducing responsiveness to anti-angiogenic agent