A phase I/II clinical trial investigating the adverse and therapeutic effects of a postoperative autologous dendritic cell tumor vaccine in patients with malignant glioma

Autologous tumor lysate-loaded dendritic cell vaccination in glioblastoma patients: a systematic review of literature

Glioblastoma (GBM) is one of the most common primary malignant brain tumors. Annually, there are about six instances recorded per 100,000 inhabitants. Treatment for GB has not advanced all that much. Novel medications have been investigated recently for the management of newly diagnosed and recurring instances of GBM. For GBM, surgery, radiation therapy, and alkylating chemotherapy are often used therapies. Immunotherapies, which use the patient's immune reaction against tumors, have long been seen as a potential cancer treatment. One such treatment is the dendritic cell (DC) vaccine. This cell-based vaccination works by stimulating the patient's own dendritic cells' antigenic repertoire, therefore inducing a polyclonal T-cell response. Systematic retrieval of information was performed on PubMed, Embase, and Google Scholar. Specified keywords were used to search, and the articles published in peer-reviewed scientific journals were associated with brain GBM, cancer, and Autologous Tumor Lysate-Loaded Dendritic Cell Vaccination. Selected 90 articles were used in this manuscript, of which 30 articles were clinical trials. Compared to shared tumor antigen peptide vaccines, autologous cancer DCs have a greater ability to stimulate the immune system, which is why dendritic cell fusion vaccines have shown early promise in several clinical studies. Survival rates for vaccinated patients were notably better compared to matched or historical controls. For newly diagnosed patients, the median overall survival (mOS) ranged from 15 to 41.4 months, while the progression-free survival (PFS) ranged from 6 to 25.3 months. We discovered through this analysis that autologous multiomics analysis of DC vaccines showed enhanced antitumor immunity with a focus on using activated, antigen-loaded donor DCs to trigger T-cell responses against cancer, particularly in glioblastoma. It also showed improved patient survival, especially when combined with standard chemoradiotherapy. DC vaccines show promise in treating GBM by enhancing survival and reducing tumor recurrence. However, challenges in vaccine production, antigen selection, and tumor heterogeneity highlight the need for continued research and optimization to improve efficacy and patient outcomes.

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

BACKGROUND

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.

OBJECTIVE

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.

METHODS

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.

RESULTS

We reviewed 47 studies, analyzing data from 3674 HGG patients treated with immunotherapy. The mean overall survival for patients treated with ICI was 11.05 months, with virotherapy at 11.79 months and notably longer for DCV at 24.11 months. The mean progression-free survival (PFS) for ICIs was 3.65 months. Virotherapy demonstrated a PFS favoring the control group, indicating minimal impact, while DCV showed substantial PFS improvement with 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.

CONCLUSION

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.

The clinical utility of autologous tumor lysate-loaded dendritic cell vaccination for patients with glioma: A systematic review and meta-analysis

BACKGROUND

Dendritic cell (DC) vaccines show promise for glioma treatment, but optimal use remains uncertain. This meta-analysis examined DC vaccine efficacy and safety for gliomas.

METHODS

This systematic review and meta-analysis study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. From the date of inception to October 23, 2023, electronic databases PubMed, Embase, Web of Science, and Scopus have been thoroughly evaluated.

RESULTS

A total of 12 studies with 998 patients and a mean age ranging from 40.2 to 56 years were included. Across 12 articles, DC vaccine 6-month overall survival (OS) was 100% [95% confidence interval {95%CI}: 100%-100%]. Respectively, 12-month OS reported 75% [95%CI: 65%-85%] but declined to 32% [95%CI: 20%-43%] for 24-month OS. 6- and 12-month progression-free survival reached 49% [95%CI: 21%-77%] and 19% [95%CI:8%-30%]. Studying radiological outcomes shows that complete response and partial response rates were 13% [95%CI: 17%-42%], and 26% [95%CI: 10%-42%], though stable disease reached 33% [95%CI: 15%-51%], suggesting predominant antineoplastic effects. The progressive disease rate also was 24% [95%CI: 9%-57%].

CONCLUSIONS

In gliomas, DC vaccinations show a temporary efficacy; stability is more prevalent than regression. Impacts favor decreased resistance to early disease. Enhancing efficacy remains critical. Early therapy can be enhanced by appropriate supplementary therapy integration.

Dendritic cell vaccine for glioblastoma: an updated meta-analysis and trial sequential analysis

BACKGROUND

Dendritic cell (DC) vaccine is an emerging immunotherapy that could potentially improve glioblastoma survival. The first phase III clinical trial of DC vaccine was recently published. This meta-analysis aims to update and reappraise existing evidence on the efficacy of DC vaccine in patients with glioblastoma.

METHODS

We searched PubMed, Embase, and Cochrane Library for clinical trials of DC vaccine for glioblastoma. The quality of the studies was assessed using the RoB 2.0 and ROBINS-I tools. The results of overall survival (OS) and progression-free survival (PFS) were pooled using hazard ratios (HRs) with corresponding 95% confidence intervals (CI). Summary effects were evaluated using random effects models. Trial sequential analysis (TSA) was performed.

RESULTS

Seven clinical trials involving 3,619 patients were included. DC vaccine plus standard care was associated with significantly improved OS (HR = 0.71; 95% CI, 0.57 - 0.88) and PFS (HR = 0.65; 95% CI, 0.43 - 0.98). In the subgroup of newly diagnosed glioblastoma, DC vaccine was associated with improved PFS (HR = 0.59; 95% CI, 0.39 - 0.90). TSA of OS showed that the cumulative z-score line for the DC vaccine crossed the benefit boundary and reached the required sample size. TSA of PFS and subgroup analysis of newly diagnosed glioblastoma showed that the required sample size was not reached.

CONCLUSIONS

This updated meta-analysis, which included the first phase III trial of a DC vaccine for glioblastoma, demonstrated that the DC vaccine was associated with improved OS. Moreover, TSA showed that the required sample size was reached, indicating a true-positive result. Future studies are required for patient subgroups with newly diagnosed and recurrent glioblastoma.

Immunotherapeutic advances in glioma management: The rise of vaccine-based approaches

BACKGROUND

Gliomas, particularly glioblastoma multiforme (GBM), are highly aggressive brain tumors that present significant challenges in oncology due to their rapid progression and resistance to conventional therapies. Despite advancements in treatment, the prognosis for patients with GBM remains poor, necessitating the exploration of novel therapeutic approaches. One such emerging strategy is the development of glioma vaccines, which aim to stimulate the immune system to target and destroy tumor cells.

AIMS

This review aims to provide a comprehensive evaluation of the current landscape of glioma vaccine development, analyzing the types of vaccines under investigation, the outcomes of clinical trials, and the challenges and opportunities associated with their implementation. The goal is to highlight the potential of glioma vaccines in advancing more effective and personalized treatments for glioma patients.

MATERIALS AND METHODS

This narrative review systematically assessed the role of glioma vaccines by including full-text articles published between 2000 and 2024 in English. Databases such as PubMed/MEDLINE, EMBASE, the Cochrane Library, and Scopus were searched using key terms like "glioma," "brain tumor," "glioblastoma," "vaccine," and "immunotherapy." The review incorporated both pre-clinical and clinical studies, including descriptive studies, animal-model studies, cohort studies, and observational studies. Exclusion criteria were applied to omit abstracts, case reports, posters, and non-peer-reviewed studies, ensuring the inclusion of high-quality evidence.

RESULTS

Clinical trials investigating various glioma vaccines, including peptide-based, DNA/RNA-based, whole-cell, and dendritic-cell vaccines, have shown promising results. These vaccines demonstrated potential in extending survival rates and managing adverse events in glioma patients. However, significant challenges remain, such as therapeutic resistance due to tumor heterogeneity and immune evasion mechanisms. Moreover, the lack of standardized guidelines for evaluating vaccine responses and issues related to ethical considerations, regulatory hurdles, and vaccine acceptance among patients further complicate the implementation of glioma vaccines.

DISCUSSION

Addressing the challenges associated with glioma vaccines involves exploring combination therapies, targeted approaches, and personalized medicine. Combining vaccines with traditional therapies like radiotherapy or chemotherapy may enhance efficacy by boosting the immune system's ability to fight tumor cells. Personalized vaccines tailored to individual patient profiles present an opportunity for improved outcomes. Furthermore, global collaboration and equitable distribution are critical for ensuring access to glioma vaccines, especially in low- and middle-income countries with limited healthcare resources CONCLUSION: Glioma vaccines represent a promising avenue in the fight against gliomas, offering hope for improving patient outcomes in a disease that is notoriously difficult to treat. Despite the challenges, continued research and the development of innovative strategies, including combination therapies and personalized approaches, are essential for overcoming current barriers and transforming the treatment landscape for glioma patients.

State-of-the-Art and New Treatment Approaches for Spinal Cord Tumors

Spinal cord tumors, though rare, present formidable challenges in clinical management due to their intricate nature. Traditional treatment modalities like surgery, radiation therapy, and chemotherapy have been the mainstay for managing these tumors. However, despite significant advancements, challenges persist, including the limitations of surgical resection and the potential side effects associated with radiation therapy. In response to these limitations, a wave of innovative approaches is reshaping the treatment landscape for spinal cord tumors. Advancements in gene therapy, immunotherapy, and targeted therapy are offering groundbreaking possibilities. Gene therapy holds the potential to modify the genes responsible for tumor growth, while immunotherapy harnesses the body's own immune system to fight cancer cells. Targeted therapy aims to strike a specific vulnerability within the tumor cells, offering a more precise and potentially less toxic approach. Additionally, novel surgical adjuncts are being explored to improve visualization and minimize damage to surrounding healthy tissue during tumor removal. These developments pave the way for a future of personalized medicine for spinal cord tumors. By delving deeper into the molecular makeup of individual tumors, doctors can tailor treatment strategies to target specific mutations and vulnerabilities. This personalized approach offers the potential for more effective interventions with fewer side effects, ultimately leading to improved patient outcomes and a better quality of life. This evolving landscape of spinal cord tumor management signifies the crucial integration of established and innovative strategies to create a brighter future for patients battling this complex condition.

A systematic review of immunotherapy in high-grade glioma: learning from the past to shape future perspectives

High-grade gliomas (HGGs) constitute the most common malignant primary brain tumor with a poor prognosis despite the standard multimodal therapy. In recent years, immunotherapy has changed the prognosis of many cancers, increasing the hope for HGG therapy. We conducted a comprehensive search on PubMed, Scopus, Embase, and Web of Science databases to include relevant studies. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Fifty-two papers were finally included (44 phase II and eight phase III clinical trials) and further divided into four different subgroups: 14 peptide vaccine trials, 15 dendritic cell vaccination (DCV) trials, six immune checkpoint inhibitor (ICI) trials, and 17 miscellaneous group trials that included both "active" and "passive" immunotherapies. In the last decade, immunotherapy created great hope to increase the survival of patients affected by HGGs; however, it has yielded mostly dismal results in the setting of phase III clinical trials. An in-depth analysis of these clinical results provides clues about common patterns that have led to failures at the clinical level and helps shape the perspective for the next generation of immunotherapies in neuro-oncology.

Efficacy and Safety of Vaccines After Conventional Treatments for Survival of Gliomas: A Systematic Review and Meta-Analysis

Background

Malignant gliomas are known with poor prognosis and low rate of survival among brain tumors. Resection surgery is followed by chemotherapy and radiotherapy in treatment of gliomas which is known as the conventional treatment. However, this treatment method results in low survival rate. Vaccination has been suggested as a type of immunotherapy to increase survival rate of glioma patients. Different types of vaccines have been developed that are mainly classified in two groups including peptide vaccines and cell-based vaccines. However, there are still conflicts about which type of vaccines is more efficient for malignant glioma treatment.

Methods

Phase Ⅰ/Ⅱ clinical trials which compared the efficacy and safety of various vaccines with conventional treatments were searched in databases through November 2022. Overall survival (OS) rate, progression free survival (PFS), and OS duration were used for calculation of pooled risk ratio (RR). In addition, fatigue, headache, nausea, diarrhea, and flu-like syndrome were used for evaluating the safety of vaccines therapy in glioma patients.

Results

A total of twelve articles were included in the present meta-analysis. Comparison of OS rate between vaccinated groups and control groups who underwent only conventional treatments showed a significant increase in OS rate in vaccinated patients (I2 = 0%, RR = 11.17, 95% CI: 2.460-50.225). PFS rate was better in vaccinated glioma patients (I2 = 83%, RR = 2.87, 95% CI: 1.63-5.03). Assessment of safety demonstrated that skin reaction (I2 = 0.0%, RR = 3.654; 95% CI: 1.711-7.801, p-value = 0.0058) and flu-like syndrome were significantly more frequent adverse effects win vaccinated groups compared to the control group. Subgroup analysis also showed that vaccination leads to better OS duration in recurrent gliomas than primary gliomas, and in LGG than HGG (p-value = 0). On the other hand, personalized vaccines showed better OS duration than non-personalized vaccines (p-value = 0).

Conclusion

Vaccination is a type of immunotherapy which shows promising efficacy in treatment of malignant glioma patients in terms of OS, PFS and duration of survival. In addition, AFTV, peptide, and dendritic cell-based vaccines are among the most efficient vaccines for gliomas. Personalized vaccines also showed considerable efficacy for glioma treatments.

Dendritic cells as orchestrators of anticancer immunity and immunotherapy

Dendritic cells (DCs) are a heterogeneous group of antigen-presenting innate immune cells that regulate adaptive immunity, including against cancer. Therefore, understanding the precise activities of DCs in tumours and patients with cancer is important. The classification of DC subsets has historically been based on ontogeny; however, single-cell analyses are now additionally revealing a diversity of functional states of DCs in cancer. DCs can promote the activation of potent antitumour T cells and immune responses via numerous mechanisms, although they can also be hijacked by tumour-mediated factors to contribute to immune tolerance and cancer progression. Consequently, DC activities are often key determinants of the efficacy of immunotherapies, including immune-checkpoint inhibitors. Potentiating the antitumour functions of DCs or using them as tools to orchestrate short-term and long-term anticancer immunity has immense but as-yet underexploited therapeutic potential. In this Review, we outline the nature and emerging complexity of DC states as well as their functions in regulating adaptive immunity across different cancer types. We also describe how DCs are required for the success of current immunotherapies and explore the inherent potential of targeting DCs for cancer therapy. We focus on novel insights on DCs derived from patients with different cancers, single-cell studies of DCs and their relevance to therapeutic strategies.

Nanomedicine facilitated cell signaling blockade: difficulties and strategies to overcome glioblastoma

Glioblastoma (GBM) is a highly aggressive and lethal type of brain tumor with complex and diverse molecular signaling pathways involved that are in its development and progression. Despite numerous attempts to develop effective treatments, the survival rate remains low. Therefore, understanding the molecular mechanisms of these pathways can aid in the development of targeted therapies for the treatment of glioblastoma. Nanomedicines have shown potential in targeting and blocking signaling pathways involved in glioblastoma. Nanomedicines can be engineered to specifically target tumor sites, bypass the blood-brain barrier (BBB), and release drugs over an extended period. However, current nanomedicine strategies also face limitations, including poor stability, toxicity, and low therapeutic efficacy. Therefore, novel and advanced nanomedicine-based strategies must be developed for enhanced drug delivery. In this review, we highlight risk factors and chemotherapeutics for the treatment of glioblastoma. Further, we discuss different nanoformulations fabricated using synthetic and natural materials for treatment and diagnosis to selectively target signaling pathways involved in GBM. Furthermore, we discuss current clinical strategies and the role of artificial intelligence in the field of nanomedicine for targeting GBM.

Therapeutic cell-based vaccines for glioblastoma multiforme

Glioblastoma multiforme (GBM), a highly aggressive tumor, poses significant challenges in achieving successful treatment outcomes. Conventional therapeutic modalities including surgery, radiation, and chemotherapy have demonstrated limited efficacy, primarily attributed to the complexities associated with drug delivery to the tumor site and tumor heterogeneity. To address this critical need for innovative therapies, the potential of cancer vaccines utilizing tumor cells and dendritic cells has been explored for GBM treatment. This article provides a comprehensive review of therapeutic vaccinations employing cell-based vaccine strategies for the management of GBM. A meticulous evaluation of 45 clinical trials involving more than 1500 participants revealed that cell-based vaccinations have exhibited favorable safety profiles with minimal toxicity. Moreover, these vaccines have demonstrated modest improvements in overall survival and progression-free survival among patients. However, certain limitations still persist. Notably, there is a need for advancements in the development of potent antigens to evoke immune responses, as well as the optimization of dosage regimens. Consequently, while cell-based vaccinations show promise as a potential therapeutic approach for GBM, further research is imperative to overcome the current limitations. The ultimate objective is to surmount these obstacles and establish cell-based vaccinations as a standard therapeutic modality for GBM.

Methods behind oncolytic virus-based DC vaccines in cancer: Toward a multiphase combined treatment strategy for Glioblastoma (GBM) patients

Glioblastoma (GBM) remains an orphan cancer disease with poor outcome. Novel treatment strategies are needed. Immunotherapy has several modes of action. The addition of active specific immunotherapy with dendritic cell vaccines resulted in improved overall survival of patients. Integration of DC vaccination within the first-line combined treatment became a challenge, and immunogenic cell death immunotherapy during chemotherapy was introduced. We used a retrospective analysis using real world data to evaluate the complex combined treatment, which included individualized multimodal immunotherapy during and after standard of care, and which required adaptations during treatment, and found a further improvement of overall survival. We also discuss the use of real world data as evidence. Novel strategies to move the field of individualized multimodal immunotherapy forward for GBM patients are reviewed.

Whole tumour cell-based vaccines: tuning the instruments to orchestrate an optimal antitumour immune response

Immunotherapy, particularly those based on immune checkpoint inhibitors (ICIs), has become a useful approach for many neoplastic diseases. Despite the improvements of ICIs in supporting tumour regression and prolonging survival, many patients do not respond or develop resistance to treatment. Thus, therapies that enhance antitumour immunity, such as anticancer vaccines, constitute a feasible and promising therapeutic strategy. Whole tumour cell (WTC) vaccines have been extensively tested in clinical studies as intact or genetically modified cells or tumour lysates, injected directly or loaded on DCs with distinct adjuvants. The essential requirements of WTC vaccines include the optimal delivery of a broad battery of tumour-associated antigens, the presence of tumour cell-derived molecular danger signals, and adequate adjuvants. These factors trigger an early and robust local innate inflammatory response that orchestrates an antigen-specific and proinflammatory adaptive antitumour response capable of controlling tumour growth by several mechanisms. In this review, the strengths and weaknesses of our own and others' experiences in studying WTC vaccines are revised to discuss the essential elements required to increase anticancer vaccine effectiveness.

A Holistic Approach to Hard-to-Treat Cancers: The Future of Immunotherapy for Glioblastoma, Triple Negative Breast Cancer, and Advanced Prostate Cancer

Immunotherapy represents an attractive avenue for cancer therapy due to its tumour specificity and relatively low frequency of adverse effects compared to other treatment modalities. Despite many advances being made in the field of cancer immunotherapy, very few immunotherapeutic treatments have been approved for difficult-to-treat solid tumours such as triple negative breast cancer (TNBC), glioblastoma multiforme (GBM), and advanced prostate cancer (PCa). The anatomical location of some of these cancers may also make them more difficult to treat. Many trials focus solely on immunotherapy and have failed to consider or manipulate, prior to the immunotherapeutic intervention, important factors such as the microbiota, which itself is directly linked to lifestyle factors, diet, stress, social support, exercise, sleep, and oral hygiene. This review summarises the most recent treatments for hard-to-treat cancers whilst factoring in the less conventional interventions which could tilt the balance of treatment in favour of success for these malignancies.

Application of injectable hydrogels in cancer immunotherapy

Immunotherapy is a revolutionary and promising approach to cancer treatment. However, traditional cancer immunotherapy often has the disadvantages of limited immune response rate, poor targeting, and low treatment index due to systemic administration. Hydrogels are drug carriers with many advantages. They can be loaded and transported with immunotherapeutic agents, chemical anticancer drugs, radiopharmaceuticals, photothermal agents, photosensitizers, and other therapeutic agents to achieve controlled release of drugs, extend the retention time of drugs, and thus successfully trigger anti-tumor effects and maintain long-term therapeutic effects after administration. This paper reviews recent advances in injectable hydrogel-based cancer immunotherapy, including immunotherapy alone, immunotherapy with combination chemotherapy, radiotherapy, phototherapy, and DNA hydrogel-based immunotherapy. Finally, we review the potential and limitations of injectable hydrogels in cancer immunotherapy.

Characterization and Treatment of Spinal Tumors

The prevalence of spinal tumors is rare in comparison to brain tumors which encompass most central nervous system tumors. Tumors of the spine can be divided into primary and metastatic tumors with the latter being the most common presentation. Primary tumors are subdivided based on their location on the spinal column and in the spinal cord into intramedullary, intradural extramedullary, and primary bone tumors. Back pain is a common presentation in spine cancer patients; however, other radicular pain may be present. Magnetic resonance imaging (MRI) is the imaging modality of choice for intradural extramedullary and intramedullary tumors. Plain radiographs are used in the initial diagnosis of primary bone tumors while Computed tomography (CT) and MRI may often be necessary for further characterization. Complete surgical resection is the treatment of choice for spinal tumors and may be curative for well circumscribed lesions. However, intralesional resection along with adjuvant radiation and chemotherapy can be indicated for patients that would experience increased morbidity from damage to nearby neurological structures caused by resection with wide margins. Even with the current treatment options, the prognosis for aggressive spinal cancer remains poor. Advances in novel treatments including molecular targeting, immunotherapy and stem cell therapy provide the potential for greater control of malignant and metastatic tumors of the spine.

Recent Advances in Glioma Cancer Treatment: Conventional and Epigenetic Realms

Glioblastoma (GBM) is the most typical and aggressive form of primary brain tumor in adults, with a poor prognosis. Successful glioma treatment is hampered by ineffective medication distribution across the blood-brain barrier (BBB) and the emergence of drug resistance. Although a few FDA-approved multimodal treatments are available for glioblastoma, most patients still have poor prognoses. Targeting epigenetic variables, immunotherapy, gene therapy, and different vaccine- and peptide-based treatments are some innovative approaches to improve anti-glioma treatment efficacy. Following the identification of lymphatics in the central nervous system, immunotherapy offers a potential method with the potency to permeate the blood-brain barrier. This review will discuss the rationale, tactics, benefits, and drawbacks of current glioma therapy options in clinical and preclinical investigations.

Emerging immune-based technologies for high-grade gliomas

INTRODUCTION

The selection of a tailored and successful strategy for high-grade gliomas (HGGs) treatment is still a concern. The abundance of aberrant mutations within the heterogenic genetic landscape of glioblastoma strongly influences cell expansion, proliferation, and therapeutic resistance. Identification of immune evasion pathways opens the way to novel immune-based strategies. This review intends to explore the emerging immunotherapies for HGGs. The immunosuppressive mechanisms related to the tumor microenvironment and future perspectives to overcome glioma immunity barriers are also debated.

AREAS COVERED

An extensive literature review was performed on the PubMed/Medline and ClinicalTrials.gov databases. Only highly relevant articles in English and published in the last 20 years were selected. Data about immunotherapies coming from preclinical and clinical trials were summarized.

EXPERT OPINION

The overall level of evidence about the efficacy and safety of immunotherapies for HGGs is noteworthy. Monoclonal antibodies have been approved as second-line treatment, while peptide vaccines, viral gene strategies, and adoptive technologies proved to boost a vivid antitumor immunization. Malignant brain tumor-treating fields are ever-changing in the upcoming years. Constant refinements and development of new routes of drug administration will permit to design of novel immune-based treatment algorithms thus improving the overall survival.

Congress of Neurological Surgeons systematic review and evidence-based guidelines update on the role of targeted therapies and immunotherapies in the management of progressive glioblastoma

The following questions and recommendations are pertinent to the following: TARGET POPULATION: These recommendations apply to adults with progressive GBM who have undergone standard primary treatment with surgery and/or chemoradiation. QUESTION 1: In adults with progressive glioblastoma is the use of bevacizumab as monotherapy superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

Level III: Treatment with bevacizumab is suggested in the treatment of progressive GBM, as it provides improved disease control compared to historical controls as measured by best imaging response and progression free survival at 6 months, while not providing evidence for improvement in overall survival. QUESTION 2: In adults with progressive glioblastoma is the use of bevacizumab as combination therapy with cytotoxic agents superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

Level III: There is insufficient evidence to show benefit or harm of bevacizumab in combination with cytotoxic therapies in progressive glioblastoma due to a lack of evidence supporting a clearly defined benefit without significant toxicity. QUESTION 3: In adults with progressive glioblastoma is the use of bevacizumab as a combination therapy with targeted agents superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

There is insufficient evidence to support a recommendation regarding this question. QUESTION 4: In adults with progressive glioblastoma is the use of targeted agents as monotherapy superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

There is insufficient evidence to support a recommendation regarding this question. QUESTION 5: In adults with progressive glioblastoma is the use of targeted agents in combination with cytotoxic therapies superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

There is insufficient evidence to support a recommendation regarding this question. QUESTION 6: In adults with progressive glioblastoma is the use of immunotherapy monotherapy superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

There is insufficient evidence to support a recommendation regarding this question. QUESTION 7: In adults with progressive glioblastoma is the use of immunotherapy in combination with targeted agents superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

There is insufficient evidence to support a recommendation regarding this question. QUESTION 8: In adults with progressive glioblastoma is the use of immunotherapy in combination with bevacizumab superior to standard salvage cytotoxic chemotherapy as measured by progression free survival and overall survival?

RECOMMENDATION

There is insufficient evidence to support a recommendation regarding this question.

“Security Dilemma”: Active Immunotherapy before Versus after Radiation Therapy Alone or Chemo-Radiotherapy for Newly Diagnosed Glioblastoma

Management of glioblastoma should be aggressive and personalised to increase the quality of life. Many new therapies, such as active immunotherapy, increase the overall survival, yet they result in complications which render the search for the optimal treatment stra-tegy challenging.

In order to answer whether the available treatment options should be administered in a specific row, we performed a literature search and meta-analysis. The results show that overall survival among the different treatment groups was equal, while the rates of complications were unequal. After surgery, when active immunotherapy was administered before radiation, radiation and chemotherapy, complication rates were lower.

For newly diagnosed glioblastoma in adults, applying active immunotherapy after total resection but before the other complementary treatment options is associated with lower complication rates.

Review: Neurological Complications From Therapies for Pediatric Brain Tumors

Surgery, chemotherapy and radiation have been the mainstay of pediatric brain tumor treatment over the past decades. Recently, new treatment modalities have emerged for the management of pediatric brain tumors. These therapies range from novel radiotherapy techniques and targeted immunotherapies to checkpoint inhibitors and T cell transfer therapies. These treatments are currently investigated with the goal of improving survival and decreasing morbidity. However, compared to traditional therapies, these novel modalities are not as well elucidated and similarly has the potential to cause significant short and long-term sequelae, impacting quality of life. Treatment complications are commonly mediated through direct drug toxicity or vascular, infectious, or autoimmune mechanisms, ranging from immune effector cell associated neurotoxicity syndrome with CART-cells to neuropathy with checkpoint inhibitors. Addressing treatment-induced complications is the focus of new trials, specifically improving neurocognitive outcomes. The aim of this review is to explore the pathophysiology underlying treatment related neurologic side effects, highlight associated complications, and describe the future direction of brain tumor protocols. Increasing awareness of these neurologic complications from novel therapies underscores the need for quality-of-life metrics and considerations in clinical trials to decrease associated treatment-induced morbidity.

Cell‑based immunotherapy of glioblastoma multiforme (Review)

Glioblastoma multiforme (GBM) is the most aggressive and lethal primary glial brain tumor. It has an unfavorable prognosis and relatively ineffective treatment protocols, with the median survival of patients being ~15 months. Tumor resistance to treatment is associated with its cancer stem cells (CSCs). At present, there is no medication or technologies that have the ability to completely eradicate CSCs, and immunotherapy (IT) is only able to prolong the patient's life. The present review aimed to investigate systemic solutions for issues associated with immunosuppression, such as ineffective IT and the creation of optimal conditions for CSCs to fulfill their lethal potential. The present review also investigated the main methods involved in local immunosuppression treatment, and highlighted the associated disadvantages. In addition, novel treatment options and targets for the elimination and regulation of CSCs with adaptive and active IT are discussed. Antagonists of TGF-β inhibitors, immune checkpoints and other targeted medication are also summarized. The role of normal hematopoietic stem cells (HSCs) in the mechanisms underlying systemic immune suppression development in cases of GBM is analyzed, and the potential reprogramming of HSCs during their interaction with cancer cells is discussed. Moreover, the present review emphasizes the importance of the aforementioned interactions in the development of immune tolerance and the inactivation of the immune system in neoplastic processes. The possibility of solving the problem of systemic immunosuppression during transplantation of donor HSCs is discussed.

Delayed Effect of Dendritic Cells Vaccination on Survival in Glioblastoma: A Systematic Review and Meta-Analysis

Background: Dendritic cell vaccination (DCV) strategies, thanks to a complex immune response, may flare tumor regression and improve patients’ long-term survival. This meta-analysis aims to assess the efficacy of DCV for newly diagnosed glioblastoma patients in clinical trials. Methods: The study databases, including PubMed, Web of Knowledge, Google Scholar, Scopus, and Cochrane, were searched by two blinded investigators considering eligible studies based on the following keywords: “glioblastoma multiforme”, “dendritic cell”, “vaccination”, “immunotherapy”, “immune system”, “immune response”, “chemotherapy”, “recurrence”, and “temozolomide”. Among the 157 screened, only 15 articles were eligible for the final analysis. Results: Regimens including DCV showed no effect on 6-month progression-free survival (PFS, HR = 1.385, 95% CI: 0.822–2.335, p = 0.673) or on 6-month overall survival (OS, HR = 1.408, 95% CI: 0.882–2.248, p = 0.754). In contrast, DCV led to significantly longer 1-year OS (HR = 1.936, 95% CI: 1.396–2.85, p = 0.001) and longer 2-year OS (HR = 3.670, 95% CI: 2.291–5.879, p = 0.001) versus control groups. Hence, introducing DCV could lead to increased 1 and 2-year survival of patients by 1.9 and 3.6 times, respectively. Conclusion: Antitumor regimens including DCV can effectively improve mid-term survival in patients suffering glioblastoma multiforme (GBM), but its impact emerges only after one year from vaccination. These data indicate the need for more time to achieve an anti-GBM immune response and suggest additional therapeutics, such as checkpoint inhibitors, to empower an earlier DCV action in patients affected by a very poor prognosis.

The multifaceted mechanisms of malignant glioblastoma progression and clinical implications

With the application of high throughput sequencing technologies at single-cell resolution, studies of the tumor microenvironment in glioblastoma, one of the most aggressive and invasive of all cancers, have revealed immense cellular and tissue heterogeneity. A unique extracellular scaffold system adapts to and supports progressive infiltration and migration of tumor cells, which is characterized by altered composition, effector delivery, and mechanical properties. The spatiotemporal interactions between malignant and immune cells generate an immunosuppressive microenvironment, contributing to the failure of effective anti-tumor immune attack. Among the heterogeneous tumor cell subpopulations of glioblastoma, glioma stem cells (GSCs), which exhibit tumorigenic properties and strong invasive capacity, are critical for tumor growth and are believed to contribute to therapeutic resistance and tumor recurrence. Here we discuss the role of extracellular matrix and immune cell populations, major components of the tumor ecosystem in glioblastoma, as well as signaling pathways that regulate GSC maintenance and invasion. We also highlight emerging advances in therapeutic targeting of these components.

Immunotherapy Resistance in Glioblastoma

Glioblastoma is the most common malignant primary brain tumor in adults. Despite treatment consisting of surgical resection followed by radiotherapy and adjuvant chemotherapy, survival remains poor at a rate of 26.5% at 2 years. Recent successes in using immunotherapies to treat a number of solid and hematologic cancers have led to a growing interest in harnessing the immune system to target glioblastoma. Several studies have examined the efficacy of various immunotherapies, including checkpoint inhibitors, vaccines, adoptive transfer of lymphocytes, and oncolytic virotherapy in both pre-clinical and clinical settings. However, these therapies have yielded mixed results at best when applied to glioblastoma. While the initial failures of immunotherapy were thought to reflect the immunoprivileged environment of the brain, more recent studies have revealed immune escape mechanisms created by the tumor itself and adaptive resistance acquired in response to therapy. Several of these resistance mechanisms hijack key signaling pathways within the immune system to create a protumoral microenvironment. In this review, we discuss immunotherapies that have been trialed in glioblastoma, mechanisms of tumor resistance, and strategies to sensitize these tumors to immunotherapies. Insights gained from the studies summarized here may help pave the way for novel therapies to overcome barriers that have thus far limited the success of immunotherapy in glioblastoma.

Glioblastoma pharmacotherapy: A multifaceted perspective of conventional and emerging treatments (Review)

Due to its localisation, rapid onset, high relapse rate and resistance to most currently available treatment methods, glioblastoma multiforme (GBM) is considered to be the deadliest type of all gliomas. Although surgical resection, chemotherapy and radiotherapy are among the therapeutic strategies used for the treatment of GBM, the survival rates achieved are not satisfactory, and there is an urgent need for novel effective therapeutic options. In addition to single-target therapy, multi-target therapies are currently under development. Furthermore, drugs are being optimised to improve their ability to cross the blood-brain barrier. In the present review, the main strategies applied for GBM treatment in terms of the most recent therapeutic agents and approaches that are currently under pre-clinical and clinical testing were discussed. In addition, the most recently reported experimental data following the testing of novel therapies, including stem cell therapy, immunotherapy, gene therapy, genomic correction and precision medicine, were reviewed, and their advantages and drawbacks were also summarised.

Dendritic Cell Vaccination of Glioblastoma: Road to Success or Dead End

Glioblastomas (GBM) are the most frequent and aggressive malignant primary brain tumor and remains a therapeutic challenge: even after multimodal therapy, median survival of patients is only 15 months. Dendritic cell vaccination (DCV) is an active immunotherapy that aims at inducing an antitumoral immune response. Numerous DCV trials have been performed, vaccinating hundreds of GBM patients and confirming feasibility and safety. Many of these studies reported induction of an antitumoral immune response and indicated improved survival after DCV. However, two controlled randomized trials failed to detect a survival benefit. This raises the question of whether the promising concept of DCV may not hold true or whether we are not yet realizing the full potential of this therapeutic approach. Here, we discuss the results of recent vaccination trials, relevant parameters of the vaccines themselves and of their application, and possible synergies between DCV and other therapeutic approaches targeting the immunosuppressive microenvironment of GBM.

The Efficacy of Dendritic Cell Vaccine for Newly Diagnosed Glioblastoma: A Meta-analysis of Randomized Controlled Studies

ABSTRACT

The efficacy of dendritic cell vaccine for newly diagnosed glioblastoma remains controversial. We conduct a systematic review and meta-analysis to explore the influence of dendritic cell vaccine on treatment efficacy for newly diagnosed glioblastoma. We search PubMed, EMBASE, Web of science, EBSCO, and Cochrane library databases through December 2019 for randomized controlled trials assessing the efficacy and safety of dendritic cell vaccine for newly diagnosed glioblastoma. This meta-analysis is performed using the random effect model. Three randomized controlled trials are included in the meta-analysis. Overall, compared with control group for newly diagnosed glioblastoma, dendritic cell vaccine shows no substantial effect on median overall survival [standard mean difference, 0.11; 95% confidence interval (CI), -0.18 to 0.41; P = 0.45], median progression-free survival (standard mean difference, 0.12; 95% CI, -0.24 to 0.48; P = 0.50), progression-free survival rate [risk ratio (RR), 1.29; 95% CI, 0.82-2.04; P = 0.27], overall survival rate (RR, 1.29; 95% CI, 0.61-2.72; P = 0.50), or nervous system disorders (RR, 0.80; 95% CI, 0.59-1.08; P = 0.14). Dendritic cell vaccine may provide no obvious benefits for the newly diagnosed glioblastoma.

Oncolytic Viruses for Malignant Glioma: On the Verge of Success?

Glioblastoma is one of the most difficult tumor types to treat with conventional therapy options like tumor debulking and chemo- and radiotherapy. Immunotherapeutic agents like oncolytic viruses, immune checkpoint inhibitors, and chimeric antigen receptor T cells have revolutionized cancer therapy, but their success in glioblastoma remains limited and further optimization of immunotherapies is needed. Several oncolytic viruses have demonstrated the ability to infect tumors and trigger anti-tumor immune responses in malignant glioma patients. Leading the pack, oncolytic herpesvirus, first in its class, awaits an approval for treating malignant glioma from MHLW, the federal authority of Japan. Nevertheless, some major hurdles like the blood–brain barrier, the immunosuppressive tumor microenvironment, and tumor heterogeneity can engender suboptimal efficacy in malignant glioma. In this review, we discuss the current status of malignant glioma therapies with a focus on oncolytic viruses in clinical trials. Furthermore, we discuss the obstacles faced by oncolytic viruses in malignant glioma patients and strategies that are being used to overcome these limitations to (1) optimize delivery of oncolytic viruses beyond the blood–brain barrier; (2) trigger inflammatory immune responses in and around tumors; and (3) use multimodal therapies in combination to tackle tumor heterogeneity, with an end goal of optimizing the therapeutic outcome of oncolytic virotherapy.

Immunotherapy and radiation for high-grade glioma: a narrative review

Glioblastoma and other high-grade gliomas (HGGs) are the most common and deadly primary brain tumors. Due to recent advances in immunotherapy and improved clinical outcomes in other disease sites, the study of immunotherapy in HGG has increased significantly. Herein, we summarize and evaluate existing evidence and ongoing clinical trials investigating the use of immunotherapy in the treatment of HGG, including therapeutic vaccination, immune checkpoint inhibition, adoptive lymphocyte transfer, and combinatorial approaches utilizing radiation and multiple modalities of immunotherapy. Special attention is given to the mechanisms by which radiation may improve immunogenicity in HGG, why this motivates the study of radiation in combination with immunotherapy, and how to determine optimal dosing and scheduling of radiation. Though larger randomized controlled trials have not consistently shown improvements in clinical outcomes, this area of research is still in its early stages and a number of important lessons can be taken away from the studies that have been completed to date. Many studies found a subset of patients who experienced durable responses, and analysis of their immune cells and tumor cells can be used to identify biomarkers that predict therapeutic response, as well as additional glioma-specific targets that can enhance therapeutic efficacy in a challenging tumor type.

The efficacy of dendritic cell vaccine for newly diagnosed glioblastoma: A meta-analysis of randomized controlled studies

INTRODUCTION

The efficacy of dendritic cell vaccine to treat glioblastoma remained elusive and therefore we conducted a meta-analysis to explore the influence of dendritic cell vaccine on treatment efficacy of glioblastoma.

METHODS

PubMed, EMbase, Web of science, EBSCO and Cochrane library databases have been searched through October 2020, and we included randomized controlled trials (RCTs) assessing the efficacy of dendritic cell vaccine for glioblastoma.

RESULTS

Four RCTs and 267 patients were included in the meta-analysis. Compared to control group for glioblastoma, dendritic cell vaccine demonstrated no obvious impact on overall survival (HR=0.59; 95% CI=0.34 to 1.04; P=0.07), progression-free survival (PFS, HR=0.72; 95% CI=0.52 to 1.00; P=0.05), nervous system disorders (OR=0.61; 95% CI=0.29 to 1.29; P=0.20), or adverse events (OR=1.44; 95% CI=0.82 to 2.50; P=0.20).

CONCLUSIONS

Dendritic cell vaccine may be not effective to treat glioblastoma.

Application of New Radiosensitizer Based on Nano-Biotechnology in the Treatment of Glioma

Glioma is the most common intracranial malignant tumor, and its specific pathogenesis has been unclear, which has always been an unresolved clinical problem due to the limited therapeutic window of glioma. As we all know, surgical resection, chemotherapy, and radiotherapy are the main treatment methods for glioma. With the development of clinical trials and traditional treatment techniques, radiotherapy for glioma has increasingly exposed defects in the treatment effect. In order to improve the bottleneck of radiotherapy for glioma, people have done a lot of work; among this, nano-radiosensitizers have offered a novel and potential treatment method. Compared with conventional radiotherapy, nanotechnology can overcome the blood–brain barrier and improve the sensitivity of glioma to radiotherapy. This paper focuses on the research progress of nano-radiosensitizers in radiotherapy for glioma.

Decipher the Glioblastoma Microenvironment: The First Milestone for New Groundbreaking Therapeutic Strategies

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. Despite the combination of novel therapeutical approaches, it remains a deadly malignancy with an abysmal prognosis. GBM is a polymorphic tumour from both molecular and histological points of view. It consists of different malignant cells and various stromal cells, contributing to tumour initiation, progression, and treatment response. GBM’s microenvironment is multifaceted and is made up of soluble factors, extracellular matrix components, tissue-resident cell types (e.g., neurons, astrocytes, endothelial cells, pericytes, and fibroblasts) together with resident (e.g., microglia) or recruited (e.g., bone marrow-derived macrophages) immune cells. These latter constitute the so-called immune microenvironment, accounting for a substantial GBM’s tumour volume. Despite the abundance of immune cells, an intense state of tumour immunosuppression is promoted and developed; this represents the significant challenge for cancer cells’ immune-mediated destruction. Though literature data suggest that distinct GBM’s subtypes harbour differences in their microenvironment, its role in treatment response remains obscure. However, an in-depth investigation of GBM’s microenvironment may lead to novel therapeutic opportunities to improve patients’ outcomes. This review will elucidate the GBM’s microenvironment composition, highlighting the current state of the art in immunotherapy approaches. We will focus on novel strategies of active and passive immunotherapies, including vaccination, gene therapy, checkpoint blockade, and adoptive T-cell therapies.

Immunotherapy for recurrent glioblastoma: practical insights and challenging prospects

Glioblastoma (GB) is the most common high-grade intracranial malignant tumor with highly malignant biological behavior and a high recurrence rate. Although anti-PD-1/PD-L1 antibodies have achieved significant survival benefits in several kinds of solid tumors, the phase III clinical trial Checkmate 143 demonstrated that nivolumab, which targets PD-1, did not achieve survival benefits compared with bevacizumab in recurrent glioblastoma (rGB) patients. Nevertheless, neoadjuvant anti-PD-1 therapy followed by surgery and adjuvant anti-PD-1 therapy could effectively activate local and systemic immune responses and significantly improve the OS of rGB patients. Furthermore, several studies have also confirmed the progress made in applying tumor-specific peptide vaccination or chimeric antigen receptor-T (CAR-T) cell therapy to treat rGB patients, and successes with antibodies targeting other inhibitory checkpoints or costimulatory molecules have also been reported. These successes inspired us to explore candidate combination treatments based on anti-PD-1/PD-L1 antibodies. However, effective predictive biomarkers for clinical efficacy are urgently needed to avoid economic waste and treatment delay. Attempts to prolong the CAR-T cell lifespan and increase T cell infiltration through engineering techniques are addressing the challenge of strengthening T cell function. In this review, we describe the immunosuppressive molecular characteristics of rGB; clinical trials exploring anti-PD-1/PD-L1 therapy, tumor-specific peptide vaccination, and CAR-T cell therapy; candidate combination strategies; and issues related to strengthening T cell function.

Current Immunotherapies for Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive malignant tumor found in the central nervous system. Currently, standard treatments in the clinic include maximal safe surgical resection, radiation, and chemotherapy and are mostly limited by low therapeutic efficiency correlated with poor prognosis. Immunotherapy, which predominantly focuses on peptide vaccines, dendritic cell vaccines, chimeric antigen receptor T cells, checkpoint inhibitor therapy, and oncolytic virotherapy, have achieved some promising results in both preclinical and clinical trials. The future of immune therapy for GBM requires an integrated effort with rational combinations of vaccine therapy, cell therapy, and radio- and chemotherapy as well as molecule therapy targeting the tumor microenvironment.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.

Recurrent Glioblastoma: From Molecular Landscape to New Treatment Perspectives

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.

Randomized Controlled Immunotherapy Clinical Trials for GBM Challenged

Simple Summary

Although multiple meta-analyses on active specific immunotherapy treatment for glioblastoma multiforme (GBM) have demonstrated a significant prolongation of overall survival, no single research group has succeeded in demonstrating the efficacy of this type of treatment in a prospective, double-blind, placebo-controlled, randomized clinical trial. In this paper, we explain how the complexity of the tumor biology and tumor–host interactions make proper stratification of a control group impossible. The individualized characteristics of advanced therapy medicinal products for immunotherapy contribute to heterogeneity within an experimental group. The dynamics of each tumor and in each patient aggravate comparative stable patient groups. Finally, combinations of immunotherapy strategies should be integrated with first-line treatment. We illustrate the complexity of a combined first-line treatment with individualized multimodal immunotherapy in a group of 70 adults with GBM and demonstrate that the integration of immunogenic cell death treatment within maintenance chemotherapy followed by dendritic cell vaccines and maintenance immunotherapy might provide a step towards improving the overall survival rate of GBM patients.

Abstract

Immunotherapies represent a promising strategy for glioblastoma multiforme (GBM) treatment. Different immunotherapies include the use of checkpoint inhibitors, adoptive cell therapies such as chimeric antigen receptor (CAR) T cells, and vaccines such as dendritic cell vaccines. Antibodies have also been used as toxin or radioactive particle delivery vehicles to eliminate target cells in the treatment of GBM. Oncolytic viral therapy and other immunogenic cell death-inducing treatments bridge the antitumor strategy with immunization and installation of immune control over the disease. These strategies should be included in the standard treatment protocol for GBM. Some immunotherapies are individualized in terms of the medicinal product, the immune target, and the immune tumor–host contact. Current individualized immunotherapy strategies focus on combinations of approaches. Standardization appears to be impossible in the face of complex controlled trial designs. To define appropriate control groups, stratification according to the Recursive Partitioning Analysis classification, MGMT promotor methylation, epigenetic GBM sub-typing, tumor microenvironment, systemic immune functioning before and after radiochemotherapy, and the need for/type of symptom-relieving drugs is required. Moreover, maintenance of a fixed treatment protocol for a dynamic, deadly cancer disease in a permanently changing tumor–host immune context might be inappropriate. This complexity is illustrated using our own data on individualized multimodal immunotherapies for GBM. Individualized medicines, including multimodal immunotherapies, are a rational and optimal yet also flexible approach to induce long-term tumor control. However, innovative methods are needed to assess the efficacy of complex individualized treatments and implement them more quickly into the general health system.

Clinical implication of cellular vaccine in glioma: current advances and future prospects

Gliomas, especially glioblastomas, represent one of the most aggressive and difficult-to-treat human brain tumors. In the last few decades, clinical immunotherapy has been developed and has provided exceptional achievements in checkpoint inhibitors and vaccines for cancer treatment. Immunization with cellular vaccines has the advantage of containing specific antigens and acceptable safety to potentially improve cancer therapy. Based on T cells, dendritic cells (DC), tumor cells and natural killer cells, the safety and feasibility of cellular vaccines have been validated in clinical trials for glioma treatment. For TAA engineered T cells, therapy mainly uses chimeric antigen receptors (IL13Rα2, EGFRvIII and HER2) and DNA methylation-induced technology (CT antigen) to activate the immune response. Autologous dendritic cells/tumor antigen vaccine (ADCTA) pulsed with tumor lysate and peptides elicit antigen-specific and cytotoxic T cell responses in patients with malignant gliomas, while its pro-survival effect is biased. Vaccinations using autologous tumor cells modified with TAAs or fusion with fibroblast cells are characterized by both effective humoral and cell-mediated immunity. Even though few therapeutic effects have been observed, most of this therapy showed safety and feasibility, asking for larger cohort studies and better guidelines to optimize cellular vaccine efficiency in anti-glioma therapy.

Congress of neurological surgeons systematic review and evidence-based guidelines update on the role of emerging developments in the management of newly diagnosed glioblastoma

TARGET POPULATION

These recommendations apply to adult patients with newly diagnosed or suspected glioblastoma.

IMAGING

Question What imaging modalities are in development that may be able to provide improvements in diagnosis, and therapeutic guidance for individuals with newly diagnosed glioblastoma?

RECOMMENDATION

Level III: It is suggested that techniques utilizing magnetic resonance imaging for diffusion weighted imaging, and to measure cerebral blood and magnetic spectroscopic resonance imaging of N-acetyl aspartate, choline and the choline to N-acetyl aspartate index to assist in diagnosis and treatment planning in patients with newly diagnosed or suspected glioblastoma.

SURGERY

Question What new surgical techniques can be used to provide improved tumor definition and resectability to yield better tumor control and prognosis for individuals with newly diagnosed glioblastoma?

RECOMMENDATIONS

Level II: The use of 5-aminolevulinic acid is recommended to improve extent of tumor resection in patients with newly diagnosed glioblastoma. Level II: The use of 5-aminolevulinic acid is recommended to improve median survival and 2 year survival in newly diagnosed glioblastoma patients with clinical characteristics suggesting poor prognosis. Level III: It is suggested that, when available, patients be enrolled in properly designed clinical trials assessing the value of diffusion tensor imaging in improving the safety of patients with newly diagnosed glioblastoma undergoing surgery.

NEUROPATHOLOGY

Question What new pathology techniques and measurement of biomarkers in tumor tissue can be used to provide improved diagnostic ability, and determination of therapeutic responsiveness and prognosis for patients with newly diagnosed glioblastomas?

RECOMMENDATIONS

Level II: Assessment of tumor MGMT promoter methylation status is recommended as a significant predictor of a longer progression free survival and overall survival in patients with newly diagnosed with glioblastoma. Level II: Measurement of tumor expression of neuron-glia-2, neurofilament protein, glutamine synthetase and phosphorylated STAT3 is recommended as a predictor of overall survival in patients with newly diagnosed with glioblastoma. Level III: Assessment of tumor IDH1 mutation status is suggested as a predictor of longer progression free survival and overall survival in patients with newly diagnosed with glioblastoma. Level III: Evaluation of tumor expression of Phosphorylated Mitogen-Activated Protein Kinase protein, EGFR protein, and Insulin-like Growth Factor-Binding Protein-3 is suggested as a predictor of overall survival in patients with newly diagnosed with glioblastoma.

RADIATION

Question What radiation therapy techniques are in development that may be used to provide improved tumor control and prognosis for individuals with newly diagnosed glioblastomas?

RECOMMENDATIONS

Level III: It is suggested that patients with newly diagnosed glioblastoma undergo pretreatment radio-labeled amino acid tracer positron emission tomography to assess areas at risk for tumor recurrence to assist in radiation treatment planning. Level III: It is suggested that, when available, patients be with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of radiation dose escalation, altered fractionation, or new radiation delivery techniques.

CHEMOTHERAPY

Question What emerging chemotherapeutic agents or techniques are available to provide better tumor control and prognosis for patients with newly diagnosed glioblastomas?

RECOMMENDATION

Level III: As no emerging chemotherapeutic agents or techniques were identified in this review that improved tumor control and prognosis it is suggested that, when available, patients with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of chemotherapy.

MOLECULAR AND TARGETED THERAPY

Question What new targeted therapy agents are available to provide better tumor control and prognosis for individuals with newly diagnosed glioblastomas?

RECOMMENDATION

Level III: As no new molecular and targeted therapies have clearly provided better tumor control and prognosis it is suggested that, when available, patients with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of molecular and targeted therapies IMMUNOTHERAPY: Question What emerging immunotherapeutic agents or techniques are available to provide better tumor control and prognosis for patients with newly diagnosed glioblastomas?

RECOMMENDATION

Level III: As no immunotherapeutic agents have clearly provided better tumor control and prognosis it is suggested that, when available, patients with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of immunologically-based therapies.

NOVEL THERAPIES

Question What novel therapies or techniques are in development to provide better tumor control and prognosis for individuals with newly diagnosed glioblastomas?

RECOMMENDATIONS

Level II: The use of tumor-treating fields is recommended for patients with newly diagnosed glioblastoma who have undergone surgical debulking and completed concurrent chemoradiation without progression of disease at the time of tumor-treating field therapy initiation. Level II: It is suggested that, when available, enrollment in properly designed studies of vector containing herpes simplex thymidine kinase gene and prodrug therapies be considered in patients with newly diagnosed glioblastoma.

[Dendritic cell vaccines in neurological oncology]

Dendritic cell-based vaccines are an intensively studied active immunotherapy technology. Aim of this article is to review the results of the key clinical studies of such vaccines in the treatment of neuro-oncological diseases. Their effectiveness was studied most widely in the treatment of malignant glial tumors, the study went from experimental work to phase III clinical studies, preliminary results of which indicate some positive results of this immunotherapy method in adults. Currently, emphasis is also being placed on the identification of clinical and immunological correlates of the patient's response to therapy and on the search for new antigens for sensitization of dendritic cells Studies of dendritic cell vaccines also include a number of other neuro-oncological diseases. A separate part of this article is devoted to the treatment of intracerebral tumors in children, for example, medulloblastomas and gliomas of the pons. In addition, the potential use of dendritic cell vaccines for intracerebral metastases is considered.

Immunotherapy for glioma: Current management and future application

Gliomas are intrinsic brain tumors that originate from neuroglial progenitor cells. Conventional therapies, including surgery, chemotherapy, and radiotherapy, have achieved limited improvements in the prognosis of glioma patients. Immunotherapy, a revolution in cancer treatment, has become a promising strategy with the ability to penetrate the blood-brain barrier since the pioneering discovery of lymphatics in the central nervous system. Here we detail the current management of gliomas and previous studies assessing different immunotherapies in gliomas, despite the fact that the associated clinical trials have not been completed yet. Moreover, several drugs that have undergone clinical trials are listed as novel strategies for future application; however, these clinical trials have indicated limited efficacy in glioma. Therefore, additional studies are warranted to evaluate novel therapeutic approaches in glioma treatment.

Challenging the indiscriminate use of temozolomide in pediatric high-grade gliomas: A review of past, current, and emerging therapies

Pediatric high-grade gliomas (pHGG) constitute 8% to 12% of primary brain tumors in childhood. The most widely utilized treatment encompasses surgical resection followed by focal radiotherapy and temozolomide. However, experiences over past decades have not demonstrated improved outcomes. pHGG have been classified into different molecular subgroups defined by mutations in histone 3, IDH gene, MAPK pathway, and others, thereby providing a rationale for various targeted therapies. Additionally, immunotherapy and drug repurposing have also become attractive adjunctive treatments. This review focuses on past, present, and emerging treatments for pHGG integrating molecular research with the mainstream pediatric drug development in Europe and the United States to sketch a way forward in the development of novel therapeutic approaches. The implementation of randomized clinical trials with adaptive designs, underpinned by a robust biological rationale, and harnessing collaboration between the pharmaceutical industry, academia, regulators and patients/parents organizations will be essential to improve the outcomes for these children.

Novel therapeutic strategies for spinal osteosarcomas

At the dawn of the third millennium, cancer has become the bane of twenty-first century man, and remains a predominant public health burden, affecting welfare and life expectancy globally. Spinal osteogenic sarcoma, a primary spinal malignant tumor, is a rare and challenging neoplastic disease to treat. After the conventional therapeutic modalities of chemotherapy, radiation and surgery have been exhausted, there is currently no available alternative therapy in managing cases of spinal osteosarcoma. The defining signatures of tumor survival are characterised by cancer cell ability to stonewall immunogenic attrition and apoptosis by various means. Some of these biomarkers, namely immune-checkpoints, have recently been exploited as druggable targets in osteosarcoma and many other different cancers. These promising strides made by the use of reinvigorated immunotherapeutic approaches may lead to significant reduction in spinal osteosarcoma disease burden and corresponding reciprocity in increase of survival rates. In this review, we provide the background to spinal osteosarcoma, and proceed to elaborate on contribution of the complex ecology within tumor microenvironment giving arise to cancerous immune escape, which is currently receiving considerable attention. We follow this section on the tumor microenvironment by a brief history of cancer immunity. Also, we draw on the current knowledge of treatment gained from incidences of osteosarcoma at other locations of the skeleton (long bones of the extremities in close proximity to the metaphyseal growth plates) to make a case for application of immunity-based tools, such as immune-checkpoint inhibitors and vaccines, and draw attention to adverse upshots of immune-checkpoint blockers as well. Finally, we describe the novel biotechnique of CRISPR/Cas9 that will assist in treatment approaches for personalized medication.

A Characterization of Dendritic Cells and Their Role in Immunotherapy in Glioblastoma: From Preclinical Studies to Clinical Trials

Glioblastoma (GBM) is the most common and fatal primary central nervous system malignancy in adults with a median survival of less than 15 months. Surgery, radiation, and chemotherapy are the standard of care and provide modest benefits in survival, but tumor recurrence is inevitable. The poor prognosis of GBM has made the development of novel therapies targeting GBM of paramount importance. Immunotherapy via dendritic cells (DCs) has garnered attention and research as a potential strategy to boost anti-tumor immunity in recent years. As the “professional” antigen processing and presenting cells, DCs play a key role in the initiation of anti-tumor immune responses. Pre-clinical studies in GBM have shown long-term tumor survival and immunological memory in murine models with stimulation of DC activity with various antigens and costimulatory molecules. Phase I and II clinical trials of DC vaccines in GBM have demonstrated some efficacy in improving the median overall survival with minimal to no toxicity with promising initial results from the first Phase III trial. However, there remains no standardization of vaccines in terms of which antigens are used to pulse DCs ex vivo, sites of DC injection, and optimal adjuvant therapies. Future work with DC vaccines aims to elucidate the efficacy of DC-based therapy alone or in combination with other immunotherapy adjuvants in additional Phase III trials.

Immunotherapy for High Grade Gliomas: A Clinical Update and Practical Considerations for Neurosurgeons

The current standard of care for patients with high grade gliomas includes surgical resection, chemotherapy, and radiation; but even still the majority of patients experience disease progression and succumb to their illness within a few years of diagnosis. Immunotherapy, which stimulates an anti-tumor immune response, has been revolutionary in the treatment of some hematological and solid malignancies, generating substantial excitement for its potential for patients with glioblastoma. The most commonly used immunotherapies include dendritic cell and peptide vaccines, checkpoint inhibitors, and adoptive T cell therapy. However, to date, the preclinical success of these approaches against high-grade glioma models has not been replicated in human clinical trials. Moreover, the complex response to these biologically active treatments can complicate management decisions, and the neurosurgical oncology community needs to be actively involved in and up to date on the use of these agents in high grade glioma patients. In this review, we discuss the challenges immunotherapy faces for high grade gliomas, the completed and ongoing clinical trials for the major immunotherapies, and the nuances in management for patients being actively treated with one of these agents.

Oncolytic adenovirus: A tool for cancer therapy in combination with other therapeutic approaches

Cancer therapy using oncolytic viruses is an emerging area, in which viruses are engineered to selectively propagate in tumor tissues without affecting healthy cells. Because of the advantages that adenoviruses (Ads) have over other viruses, they are more considered. To achieve tumor selectivity, two main modifications on Ads genome have been applied: small deletions and insertion of tissue- or tumor-specific promoters. Despite oncolytic adenoviruses ability in tumor cell lysis and immune responses stimulation, to further increase their antitumor effects, genomic modifications have been carried out including insertion of checkpoint inhibitors and antigenic or immunostimulatory molecules into the adenovirus genome and combination with dendritic cells and chemotherapeutic agents. This study reviews oncolytic adenoviruses structures, their antitumor efficacy in combination with other therapeutic strategies, and finally challenges around this treatment approach.

Assessment of efficacy of dendritic cell therapy and viral therapy in high grade glioma clinical trials. A meta-analytic review

In recent years, immunotherapy has raised the interest of many studies and provided different perspectives for the therapeutic management of high grade glioma. Our meta-analysis focused on the effectiveness of dendritic cell (DC) therapy and viral therapy (VT) in clinical trials. Fourteen eligible studies have been evaluated and the results suggest the improvement of both OS (HR = 0.65) (p < 0.0001) and PFS (HR = 0.59) (p = 0.01) for patients receiving DC therapy. The data for VT showed a slight improvement in terms of OS (HR = 0.81), while PFS was similar to the control arms (HR = 1.06) (p = 0.41).