Intratumoral Therapy Research Articles

Optimization of multi-electrode implant configurations and programming for the delivery of non-ablative electric fields in intratumoral modulation therapy.

Application of low intensity electric fields to interfere with tumor growth is being increasingly recognized as a promising new cancer treatment modality. Intratumoral modulation therapy (IMT) is a developing technology that uses multiple electrodes implanted within or adjacent tumor regions to deliver electric fields to treat cancer. In this study, the determination of optimal IMT parameters was cast as a mathematical optimization problem, and electrode configurations, programming, optimization, and maximum treatable tumor size were evaluated in the simplest and easiest to understand spherical tumor model. The establishment of electrode placement and programming rules to maximize electric field tumor coverage designed specifically for IMT is the first step in developing an effective IMT treatment planning system. Finite element method electric field computer simulations for tumor models with 2 to 7 implanted electrodes were performed to quantify the electric field over time with various parameters, including number of electrodes (2 to 7), number of contacts per electrode (1 to 3), location within tumor volume, and input waveform with relative phase shift between 0 and 2π radians. Homogeneous tissue specific conductivity and dielectric values were assigned to the spherical tumor and surrounding tissue volume. In order to achieve the goal of covering the tumor volume with a uniform threshold of 1V/cm electric field, a custom least square objective function was used to maximize the tumor volume covered by 1V/cm time averaged field, while maximizing the electric field in voxels receiving less than this threshold. An additional term in the objective function was investigated with a weighted tissue sparing term, to minimize the field to surrounding tissues. The positions of the electrodes were also optimized to maximize target coverage with the fewest number of electrodes. The complexity of this optimization problem including its non-convexity, the presence of many local minima, and the computational load associated with these stochastic based optimizations led to the use of a custom pattern search algorithm. Optimization parameters were bounded between 0 and 2π radians for phase shift, and anywhere within the tumor volume for location. The robustness of the pattern search method was then evaluated with 50 random initial parameter values. The optimization algorithm was successfully implemented, and for 2 to 4 electrodes, equally spaced relative phase shifts and electrodes placed equidistant from each other was optimal. For 5 electrodes, up to 2.5cm diameter tumors with 2.0V, and 4.1cm with 4.0V could be treated with the optimal configuration of a centrally placed electrode and 4 surrounding electrodes. The use of 7 electrodes allow for 3.4cm diameter coverage at 2.0V and 5.5cm at 4.0V. The evaluation of the optimization method using 50 random initial parameter values found the method to be robust in finding the optimal solution. This study has established a robust optimization method for temporally optimizing electric field tumor coverage for IMT, with the adaptability to optimize a variety of parameters including geometrical and relative phase shift configurations.

Tumor-responsive copper-activated disulfiram for synergetic nanocatalytic tumor therapy

Exploring alternative biomedical use of traditional drugs in different disease models is highly important as it can reduce the cost of drug development and overcome several critical issues of traditional chemodrugs such as low chemotherapeutic efficiency, severe side effect, and drug resistance. Disulfiram (DSF), a clinically approved alcohol-aversion drug, was recently demonstrated to feature tumor-growth suppression effect along with the co-administration of Cu2+ species, but direct Cu2+ administration mode might cause severe toxicity originating from low Cu2+ accumulation into the tumor and nonspecific Cu2+ distribution-induced cytotoxicity. Based on the intriguing drug-delivery performance of nanoscale metal-organic frameworks (MOFs), we herein construct HKUST nMOFs as the Cu2+ self-supplying nanocarriers for efficient delivery of the DSF drug. The mildly acidic condition of tumor microenvironment initially triggered the release of Cu ions from HKUST nMOFs, which further reacted with the encapsulated DSF to form toxic Cu(DDTC)2 (activation) for tumor chemotherapy. Especially, during the Cu(DDTC)2 complexation, Cu+ species were formed concomitantly, triggering the intratumoral nanocatalytic therapy for the generation of reactive oxygen species to synergistically destroying the tumor cells/tissue. As a result, synergetic tumor-responsive chemotherapy and nanocatalytic therapy are enabled by DSF@HKUST nanodrugs, as demonstrated by the dominant anticancer efficacy with satisfied biocompatibility both in vitro and in vivo. The present work offers a sophisticated strategy for tumor-responsive nontoxic-to-toxic therapeutic with high biocompatibility.

Constructing a Biomaterial to Simulate Extracellular Drug Transport in Solid Tumors.

Designing an in vitro model of the tumor extracellular microenvironment to screen intratumoral drugs is an active challenge. As recent clinical successes of human intratumoral therapies stimulate research on intratumoral delivery, a need for a 3D tumor model to screen intratumoral therapies arises. When injecting the drug formulation directly into the tumor, the biophysics affecting intratumoral retention must be considered; especially for biologic therapies, which may be dominated by extracellular transport mechanisms. Fibrotic regions in solid tumors are typically rich in collagen I fibers. Using shear rheology, head and neck tumors with higher collagen density show a higher stiffness. Similarly, the stiffness of the hyaluronic acid (HA) hydrogel models is increased by adding collagen fibers to model the bulk biomechanical properties of solid tumors. HA hydrogels are then used as intratumoral injection site simulators to model in vitro the retention of glatiramer acetate (GA) and polyethylene glycol (PEG) administered intratumorally. Both compounds are also injected in murine tumors and retention is studied ex vivo for comparison. Retention of GA in the hydrogels is significantly longer than PEG, analogous to the solid tumors, suggesting the utility of HA hydrogels with collagen I fibers for screening extracellular drug transport after intratumoral administration.

Nanoscale Metal-Organic Frameworks for Cancer Immunotherapy.

Cancer immunotherapy, particularly checkpoint blockade immunotherapy (CBI), has revolutionized the treatment of some cancers by reactivating the antitumor immunity of hosts with durable response and manageable toxicity. However, many cancer patients with low tumor antigen exposure and immunosuppressive tumor microenvironments do not respond to CBI. A variety of methods have been investigated to reverse immunosuppressive tumor microenvironments and turn "cold" tumors "hot" with the goal of extending the therapeutic benefits of CBI to a broader population of cancer patients. Immunostimulatory adjuvant treatments, such as cancer vaccines, photodynamic therapy (PDT), radiotherapy (RT), radiotherapy-radiodynamic therapy (RT-RDT), and chemodynamic therapy (CDT), promote antigen presentation and T cell priming and, when used in combination with CBI, reactivate and sustain systemic antitumor immunity. Cancer vaccines directly provide tumor antigens, while immunoadjuvant therapies such as PDT, RT, RT-RDT, and CDT kill cancer cells in an immunogenic fashion to release tumor antigens in situ. Direct administration of tumor antigens or indirect intratumoral immunoadjuvant therapies as in situ cancer vaccines initiate the immuno-oncology cycle for antitumor immune response.With the rapid growth of cancer nanotechnology in the past two decades, a large number of nanoparticle platforms have been studied, and some nanomedicines have been translated into clinical trials. Nanomedicine provides a promising strategy to enhance the efficacy of immunoadjuvant therapies to potentiate cancer immunotherapy. Among these nanoparticle platforms, nanoscale metal-organic frameworks (nMOFs) have emerged as a unique class of porous hybrid nanomaterials with metal cluster secondary building units and organic linkers. With molecular modularity, structural tunability, intrinsic porosity, tunable stability, and biocompatibility, nMOFs are ideally suited for biomedical applications, particularly cancer treatments.In this Account, we present recent breakthroughs in the design of nMOFs as nanocarriers for cancer vaccine delivery and as nanosensitizers for PDT, CDT, RT, and RT-RDT. The versatility of nMOFs allows them to be fine-tuned to effectively load tumor antigens and immunoadjuvants as cancer vaccines and significantly enhance the local antitumor efficacy of PDT, RT, RT-RDT, and CDT via generation of reactive oxygen species (ROS) for in situ cancer vaccination. These nMOF-based treatments are further combined with cancer immunotherapies to elicit systemic antitumor immunity. We discuss novel strategies to enhance light tissue penetration and overcome tumor hypoxia in PDT, to increase energy deposition and ROS diffusion in RT, to combine the advantages of PDT and RT to enable RT-RDT, and to trigger CDT by hijacking aberrant metabolic processes in tumors. Loading nMOFs with small-molecule drugs such as an indoleamine 2,3-dioxygenase inhibitor, the toll-like receptor agonist imiquimod, and biomacromolecules such as CpG oligodeoxynucleotides and anti-CD47 antibody synergizes with nMOF-based radical therapies to enhance their immunotherapeutic effects. Further combination with immune checkpoint inhibitors activates systemic antitumor immune responses and elicits abscopal effects. With structural and compositional tunability, nMOFs are poised to provide a new clinically deployable nanotechnology platform to promote immunostimulatory tumor microenvironments by delivering cancer vaccines, mediating PDT, enhancing RT, enabling RT-RDT, and catalyzing CDT and potentiate cancer immunotherapy.

Abstract 902: Augmentation of anti-melanoma response by combining radiation-based in situ vaccination with GIFT4 B cell therapy

Abstract We have recently demonstrated the effectiveness of combining external beam radiation therapy (RT), intratumoral immunocytokine (IT-IC), and anti-CTLA4 (αCTLA4) in eliminating large (500mm3) B78 melanomas (MEL), prolonging survival and invoking T cell immune memory in mice. This highly translational therapy is currently being investigated in a phase I clinical trial. Despite the success of this regimen against large single subcutaneous MEL tumors, many mice with large tumors and intravenously (IV) injected metastatic MEL, receiving this same regimen, still die from metastatic disease. A recent report has shown that fusokine GIFT4, a recombinant chimera of GMCSF and IL4 programs B cells (GIFT4BC) to acquire a unique phenotype with augmented capacity for antigen presentation and anti-MEL activity. Herein, we report the preliminary results of studies combining RT+IC+αCTLA4 with intratumoral (IT) GIFT4BCs therapy. We hypothesized that GIFT4BCs enhance the anti-tumor and anti-metastatic efficacy of RT+IC+αCTLA4. C57BL/6 mice were engrafted with 2 × 106 B78 MEL intradermally in the flank. At a tumor volume of ~250mm3, mice were intravenously injected with 3.5 × 105 B16 MEL (a metastatic parental line of B78 MEL) to induce metastases. Mice were treated with 12 Gy RT on day 1 (D1), 1 × 107 IT- GIFT4BC on D4, IC (IT, 50ug) on D6-D10, and αCTLA4 (ip, 200ug) on D3, 6, and 9 (designated RT+IC+αCTLA4+GIFT4BC). Control groups received no treatment, GIFT4BCs alone, or RT+IC+αCTLA4. Tumor growth and survival were monitored. At the time of euthanasia for tumor burden or illness, necropsy was performed to quantify metastases. A pre-determined cohort of mice from each treatment group were euthanized on D12. From these, tumor-draining lymph nodes were fixed for histology and tumors were harvested for qPCR, histology, and flow cytometry. Preliminary results indicate that the addition of GIFT4BCs to RT+IC+αCTLA4 improves survival. Lungs from treated mice showed reduced metastatic burden in RT+IC+αCTLA4+GIFT4BC mice compared to controls. GIFT4BCs were identified in the tumor-draining lymph nodes using confocal microscopy in RT+IC+αCTLA4+GIFT4BC mice. qPCR analysis of tumor samples revealed an upregulation of interferon gamma (Ifny) in RT+IC+αCTLA4+GIFT4BC mice compared to control groups. Flow cytometry analysis show increased CD45+ tumor infiltrating lymphocytes in RT+IC+αCTLA4+GIFT4BC compared to RT+IC+αCTLA4 groups. Combination of RT+IC+αCTLA4+GIFT4BC displays anti-MEL activity that reduces metastatic burden and prolongs survival in murine MEL models. These preliminary findings support published hypotheses which postulate that GIFT4BC-mediated mechanisms may augment the T cell response through B cell antigen presentation and chemotactic cytokine production in vivo. Future studies will elucidate the mechanisms of anti-tumor efficacy of RT+IC+αCTLA4+GIFT4BC. Citation Format: Elizabeth G. Sumiec, Claire C. Baniel, Amber M. Bates, Sarah Emma, Erin Nystuen, Alexander L. Rakhmilevich, Amy K. Erbe, Pradyut Paul, Jacques Galipeau, Paul M. Sondel, Zachary S. Morris. Augmentation of anti-melanoma response by combining radiation-based in situ vaccination with GIFT4 B cell therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 902.

Nanoformulation of CCL21 greatly increases its effectiveness as an immunotherapy for neuroblastoma

Neuroblastoma is the most commonly diagnosed extracranial solid tumor in children. The patients with aggressive metastatic disease or refractory/relapsed neuroblastoma currently face a dismally low chance of survival. Thus, there is a great need for more effective therapies for this illness. In previous studies, we, as well as others, showed that the immune cell chemoattractant C-C motif chemokine ligand 21 (CCL21) is effective as an intratumoral therapy able to slow the growth of cancers. In this current study, we developed and tested an injectable, slow-release, uniform, and optimally loaded alginate nanoformulation of CCL21 as a means to provide prolonged intratumoral treatment. The alginate-nanoformulated CCL21, when injected intratumorally into mice bearing neuroblastoma lesions, significantly prolonged survival and decreased the tumor growth rate compared to CCL21 alone, empty nanoparticles, or buffer. Notably, we also observed complete tumor clearance and subsequent full protection against tumor rechallenge in 33% of nanoformulated CCL21-treated mice. Greater intratumoral presence of nanoformulated CCL21, compared to free CCL21, at days 1 and 2 after treatment ended was confirmed through fluorescent labeling and tracking. Nanoformulated CCL21-treated tumors exhibited a general pattern of prolonged increases in anti-tumor cytokines and relatively lower levels of pro-tumor cytokines in comparison to tumors treated with CCL21 alone or buffer only. Thus, this novel nanoformulation of CCL21 is an effective treatment for neuroblastoma, and may have potential for the delivery of CCL21 to other types of solid tumors in the future and as a slow-release delivery modality for other immunotherapies

Abstract IA19: Immunotherapy in ovarian cancer: Challenges and novel opportunities

Abstract IA19: Immunotherapy in ovarian cancer: Challenges and novel opportunities

Bronchoscopic intratumoural therapies for non-small cell lung cancer.

The past decade has brought remarkable improvements in the treatment of non-small cell lung cancer (NSCLC) with novel therapies, such as immune checkpoint inhibitors, although response rates remain suboptimal. Direct intratumoural injection of therapeutic agents via bronchoscopic approaches poses the unique ability to directly target the tumour microenvironment and offers several theoretical advantages over systemic delivery including decreased toxicity. Increases in understanding of the tumour microenvironment and cancer immunology have identified many potential options for intratumoural therapy, especially combination immunotherapies. Herein, we review advances in the development of novel bronchoscopic treatments for NSCLC over the past decade with a focus on the potential of intratumoural immunotherapy alone or in combination with systemic treatments.

Effect of UV-curable and injectable dendrimer matrix on tumor pharmacokinetics and survival in a hepatocellular carcinoma mouse model using interstitial photodynamic therapy.

e15598 Background: Intratumoral drug delivery in cancer treatment has shown to increase drug accumulation in tumors and decrease adverse effects of systemic therapies. The active agent is typically required to stay in contact with the tumor and thus attachment directly into the tumor or to the surrounding tissue is warranted. In addition, a long-acting release of the active drug is vital. Dendrimers are nano-sized, radially symmetric molecules with homogeneous and monodisperse structures, which can used to encapsulate drug molecules for controlled release with the aid of external stimuli at physiological pH. Methods: We prepared a dendrimeric drug delivery matrix based on a PEG-core. The model drug (5-fluorouracil or doxorubicin) was covalently bonded to the core. The release of the drug was observed up to 29 days in vitro. The outer shell of the matrix was partially modified to obtain a fast UV-curing and subsequent attachment to the tumor tissue utilizing interstitial photodynamic therapy. We compared the pharmacokinetics, tissue distribution and antitumor efficacy of conventional systemic therapy and the intratumoral therapy in xenograft-bearing mice. In addition, we monitored blood parameters and body weight of the animals for adverse effects. Results: The dendrimer matrix caused significantly greater inhibition of human hepatocellular carcinoma xenograft tumor growth when compared with systemic therapy, without increasing toxicity. The matrix enabled a significant increase in drug accumulation in tumors, and markedly extended the survival of mice compared with systemic treatments. A larger decrease in blood parameters as well as spleen weight was observed in the systemic therapy group especially when using 5-fluorouracil. Conclusions: Our study shows that the intratumoral treatment strategy based on a novel UV-curable dendrimer hydrogel matrix enhances antitumor activity by improving pharmacokinetics and drug accumulation and increases efficacy in comparison to conventional systemic therapy. These results highlight the potential use of dendrimer hydrogels in the treatment of hepatocellular carcinoma.

Cytokine-Enhanced Vaccine and Suicide Non-Viral Gene Therapy in Advanced Metastatic Melanoma Patients: Two Case Reports

The prognostic for metastatic melanoma is very poor when treated with standard cytotoxic chemotherapies and it is often refractory to check point inhibitors and/or molecular targets. In this context the development of new treatments with better efficacy and safety profiles is highly desirable. Based on our successful experience applying suicide and immune gene therapy in a veterinary clinical setting, we are proposing its translation to human patients. We are presenting here the first-in-human safety assay of this approach. We report two cases of refractory metastatic melanoma. The first-one was a 27-years-old pharyngeal mucosal melanoma patient with a primary tumor in his left tonsil. Despite transient slowing down, the disease successively progressed to radiotherapy, radical surgery, ipilimumab, nivolumab, imatinib and temozolomide. The second-one was a 72-years-old malignant melanoma patient with a primary tumor in his left hallux. Despite transient slowing down, the disease successively progressed to hallux amputation, inguinal lymphadenectomy, radiotherapy, interferon-alpha, ipilimumab, pembrolizumab and temozolomide. The proposed treatment included local intratumoral suicide gene therapy concomitant with a subcutaneous vaccine composed by allogeneic tumor extracts and liposomes with plasmids bearing IL-2 and GM-CSF genes. The treatment was safe: the only side effects were from mild to moderate and manageable: pyrexia, swelling of the injected tumor and partial hair loss (alopecia). Due to disease progression both patients were withdrawn from the study before completing the complete series of interventions. These preliminary data encourage the completion of further clinical trials to establish the possible clinical benefit of the proposed approach.

Custom 3D Brain Cancer Model to Test a Novel Anti‐Cancer Electrotherapy

IntroductionHigh‐Grade Gliomas (HGG) are primary malignant brain tumors with dismal treatment outcomes. Our team has been pioneering a novel implantable biotechnology called Intratumoral modulation therapy (IMT) that distributes non‐ablative electric fields across tumor‐affected brain regions to induce tumor cell death. A systematic means to define the mechanism and optimal treatment parameters for various forms of HGG is needed to advance this promising technology towards clinical application. The aim of this study was to develop a custom, high throughput, patient‐derived 3D HGG model to investigate the therapeutic effects of IMT.MethodsPrimary patient HGG cells (1×104) were implanted into wells of a 96‐well plate containing 200 uL of Matrigel®. The resultant tumor spheroids were characterized over 14 days by observing growth, invasion and viability with MTT assays, confocal microscopy and bioluminescence imaging (BLI). The culture plates were custom adapted to house implantable IMT devices to broadly distribute IMT fields across HGG tumors. Computer‐generated IMT field modeling was performed using COMSOL software to predict field strength and distribution, and to reconstruct IMT fields in the 3D system. Spheroids received 72‐hours of IMT using a spectrum of treatment parameters based upon a continuous, low amplitude sinusoidal waveform.ResultsPatient‐derived HGG spheroids exhibited multi‐layered, progressive growth and invasion of peritumoral matrix over the 14‐day study period. Computer simulation predicted electric field distribution and intensity across patient HGG spheroids for a spectrum of defined IMT parameters. Using the simulation plans to guide treatment settings, IMT produced a significant reduction (>60%) of metabolic viability in HGG spheroids treated with IMT compared to sham conditions. This data was corroborated by BLI which revealed >65% signal loss associated with IMT.ConclusionIMT is a highly promising innovation designed to combat HGGs, the most devastating of primary brain cancers. Our custom in vitro IMT model permits high throughput testing of treatment parameters in 3D patient HGG spheroids. This innovative preclinical strategy will be instrumental in defining the potential and optimizing treatment response across a spectrum of high fatality HGG cancers.Support or Funding InformationThis work was supported by the Cancer Research Society and preformed at Schulich School of Medicine and Dentistry and Lawson Health Research Institute.

Intratumor Heterogeneity and Therapy Resistance: Contributions of Dormancy, Apoptosis Reversal (Anastasis) and Cell Fusion to Disease Recurrence.

A major challenge in treating cancer is posed by intratumor heterogeneity, with different sub-populations of cancer cells within the same tumor exhibiting therapy resistance through different biological processes. These include therapy-induced dormancy (durable proliferation arrest through, e.g., polyploidy, multinucleation, or senescence), apoptosis reversal (anastasis), and cell fusion. Unfortunately, such responses are often overlooked or misinterpreted as “death” in commonly used preclinical assays, including the in vitro colony-forming assay and multiwell plate “viability” or “cytotoxicity” assays. Although these assays predominantly determine the ability of a test agent to convert dangerous (proliferating) cancer cells to potentially even more dangerous (dormant) cancer cells, the results are often assumed to reflect loss of cancer cell viability (death). In this article we briefly discuss the dark sides of dormancy, apoptosis, and cell fusion in cancer therapy, and underscore the danger of relying on short-term preclinical assays that generate population-based data averaged over a large number of cells. Unveiling the molecular events that underlie intratumor heterogeneity together with more appropriate experimental design and data interpretation will hopefully lead to clinically relevant strategies for treating recurrent/metastatic disease, which remains a major global health issue despite extensive research over the past half century.

In situ antitumor vaccination: Targeting the tumor microenvironment.

Tumor microenvironment is known to play important roles in tumor progression. Many therapies, targeting the tumor microenvironment, are designed and applied in the clinic. One of these approaches is in situ antitumor therapy. This way, bacteria, antibodies, plasmid DNA, viruses, and cells are intratumorally delivered into the tumor site as "in-situ antitumor vaccine," which seeks to enhance immunogenicity and generate systemic T cell responses. In addition, this intratumoral therapy can alter the tumor microenvironment from immunosuppressive to immunostimulatory while limiting the risk of systemic exposure and associated toxicity. Contemporarily, promising preclinical results and some initial success in clinical trials have been obtained after intratumoral therapy.

Molecular imaging-monitored radiofrequency hyperthermia-enhanced intratumoral herpes simplex virus-thymidine kinase gene therapy for rat orthotopic ovarian cancer

Objective To establish the technique of intratumoral combination therapy of radiofrequency hyperthermia (RFH) with herpes simplex virus-thymidine kinase/ganciclovir (HSV-TK/GCV) gene therapy for rat ovarian cancers. Material and methods This study consisted of three parts: (1) in vitro experiments to establish the ‘proof of principal’ that combination of RFH and HSV-TK gene therapy has the synergistic effect on human ovarian cancer cells; (2) creation of bioluminescence imaging-detectable rat ovarian cancer model; and (3) in vivo experiments using this rat model to validate the technical feasibility of the combination therapy. Cells and nude rats were divided into four groups: (i) combination therapy (HSV-TK/GCV + RFH); (ii) RFH; (iii) HSV-TK/GCV; and (iv) phosphate-buffered saline (PBS). Data were analyzed using Dunnett t-test or Kruskal–Wallis test. Results Cell proliferation assay demonstrated significantly greater reduction in viable cells with the combination therapy [0.52 (0.43, 0.61)] compared to other treatments [RFH 0.90 (0.84, 0.96), HSV-TK/GCV 0.71 (0.53, 0.88), PBS 1 (1, 1); p < .05]. For 24 rat models with bioluminescence imaging-detectable orthotopic ovarian cancer (n = 6 per group), optical imaging demonstrated significantly decreased relative bioluminescence signal with the combination therapy [0.81 (0.52, 1.08)] compared to other treatments [RFH 3.60 (2.34, 4.86), HSV-TK/GCV 2.21 (1.71, 2.71), PBS 3.74 (3.19, 4.29); p < .001]. Ultrasound imaging demonstrated the smallest relative tumor volume with the combination therapy [0.78 (0.45, 1.11) versus 3.50 (2.67, 4.33), 2.10 (0.83, 3.37), 3.70 (1.79, 5.61); p < .05]. Conclusion The feasibility of intratumoral RFH-enhanced HSV-TK/GCV gene therapy was established on a unique rat model with molecular imaging-detectable orthotopic ovarian cancer.

A polymeric paste for intratumoural therapy.

A polymeric paste for intratumoural therapy.

Genetic Hallmarks and Heterogeneity of Glioblastoma in the Single-Cell Omics Era.

Glioblastoma multiforme is the most common and aggressive malignant primary brain tumor. As implied by its name, the disease displays impressive intrinsic heterogeneity. Among other complications, inter- and intratumoral diversity hamper glioblastoma research and therapy, typically leaving patients with little hope for long-term survival. Extensive genetic analyses, including omics, characterize several recurrent mutations. However, confounding factors mask crucial aspects of the pathology to conventional bulk approaches. In recent years, single-cell omics have made their first appearance in cancer research, and the methodology is about to reach its full potential for glioblastoma too. Here, recent glioblastoma single-cell omics investigations are reviewed, and most promising routes toward less grim prognoses and more efficient therapeutics are discussed.

Intratumoral Immunotherapy-Update 2019.

Intratumoral immunotherapies aim to trigger local and systemic immunologic responses via direct injection of immunostimulatory agents with the goal of tumor cell lysis, followed by release of tumor‐derived antigens and subsequent activation of tumor‐specific effector T cells. In 2019, a multitude of intratumoral immunotherapies with varied mechanisms of action, including nononcolytic viral therapies such as PV‐10 and toll‐like receptor 9 agonists and oncolytic viral therapies such as CAVATAK, Pexa‐Vec, and HF10, have been extensively evaluated in clinical trials and demonstrated promising antitumor activity with tolerable toxicities in melanoma and other solid tumor types. Talimogene laherparepvec (T‐VEC), a genetically modified herpes simplex virus type 1–based oncolytic immunotherapy, is the first oncolytic virus approved by the U.S. Food and Drug Administration for the treatment of unresectable melanoma recurrent after initial surgery. In patients with unresectable metastatic melanoma, T‐VEC demonstrated a superior durable response rate (continuous complete response or partial response lasting ≥6 months) over subcutaneous GM‐CSF (16.3% vs. 2.1%; p < .001). Responses were seen in both injected and uninjected lesions including visceral lesions, suggesting a systemic antitumor response. When combined with immune checkpoint inhibitors, T‐VEC significantly improved response rates compared with single agent; similar results were seen with combinations of checkpoint inhibitors and other intratumoral therapies such as CAVATAK, HF10, and TLR9 agonists. In this review, we highlight recent results from clinical trials of key intratumoral immunotherapies that are being evaluated in the clinic, with a focus on T‐VEC in the treatment of advanced melanoma as a model for future solid tumor indications.Implications for PracticeThis review provides oncologists with the latest information on the development of key intratumoral immunotherapies, particularly oncolytic viruses. Currently, T‐VEC is the only U.S. Food and Drug Administration (FDA)‐approved oncolytic immunotherapy. This article highlights the efficacy and safety data from clinical trials of T‐VEC both as monotherapy and in combination with immune checkpoint inhibitors. This review summarizes current knowledge on intratumoral therapies, a novel modality with increased utility in cancer treatment, and T‐VEC, the only U.S. FDA‐approved oncolytic viral therapy, for medical oncologists. This review evaluates approaches to incorporate T‐VEC into daily practice to offer the possibility of response in selected melanoma patients with manageable adverse events as compared with other available immunotherapies.

Biological intratumoral therapy for the high-grade glioma part I: intratumoral delivery and immunotoxins

Management of high-grade gliomas remains a complex challenge. Standard of care consists of microsurgical resection, chemotherapy and radiation, but despite these aggressive multimodality therapies the overall prognosis remains poor. A major focus of ongoing translational research studies is to develop novel therapeutic strategies that can maximize tumor cell eradication while minimizing collateral side effects. Particularly, biological intratumoral therapies have been the focus of new translational research efforts due to their inherent potential to be both dynamically adaptive and target specific. This two-part review will provide an overview of biological intratumoral therapies and summarize key advances and remaining challenges in intratumoral biological therapies for high-grade glioma. Part I focuses on discussion of the concepts of intratumoral delivery and immunotoxin therapies.

Biological intratumoral therapy for the high-grade glioma part II: vector- and cell-based therapies and radioimmunotherapy.

Management of high-grade gliomas (HGGs) remains a complex challenge with an overall poor prognosis despite aggressive multimodal treatment. New translational research has focused on maximizing tumor cell eradication through improved tumor cell targeting while minimizing collateral systemic side effects. In particular, biological intratumoral therapies have been the focus of novel translational research efforts due to their inherent potential to be both dynamically adaptive and target specific. This two part review will provide an overview of biological intratumoral therapies that have been evaluated in human clinical trials in HGGs, and summarize key advances and remaining challenges in the development of these therapies as a potential new paradigm in the management of HGGs. Part II discusses vector-based therapies, cell-based therapies and radioimmunotherapy.

Intratumoral IL-12 Gene Therapy Inhibits Tumor Growth In A HCC-Hu-PBL-NOD/SCID Murine Model.

PurposeThis study aimed to evaluate the efficacy and safety of intratumoral IL-12 gene therapy in an HCC-hu-PBL-NOD/SCID mouse model.Materials and methodsThe HCC murine model was generated in NOD/SCID mice, and mice with grafted tumors were injected intraperitoneally with 2 × 107 human peripheral blood lymphocytes 14 days after modeling. After 4 days, mice were randomly divided into the 9597/IL-12 group, the 9597/plasmid group and the PBS group. The changes of tumor volume were measured and mouse peripheral blood was sampled post-treatment for ELISA and CBA analyses, and the grafted tumors were collected 28 days post-treatment for immunohistochemistry, ELISA, CBA and detection of cell cycle and apoptosis.ResultsThe tumor volume was smaller in the 9597/IL-12 group than in the 9597/plasmid and PBS groups on days 7, 14, 21, and 28 post-treatment (P < 0.05). Higher IL-12 levels were detected in the peripheral blood and the supernatants of grafted tumor homogenates in the 9597/IL-12 group than in the 9597/plasmid and PBS groups 7, 14, 21 and 28 days post-treatment (P < 0.05). IHC revealed higher counts of CD3+T cells, CD4+T helper cells, IFN-γ Th1 cells+ and S-100 protein positive dentric cells and lower MVD in the 9597/IL-12 group than in the 9597/plasmid and PBS groups (P < 0.05). Flow cytometry showed a significantly higher proportion of HCC cells at the G0/G1 phase and a significantly lower proportion of HCC cells at the S phase in the 9597/IL-12 group than in the PBS group (P < 0.05) and a greater apoptotic rate of HCC cells in the 9597/IL-12 group than in the 9597/plasmid and PBS groups (P < 0.05).ConclusionIntratumoral IL-12 gene therapy may inhibit tumorigenesis with mild adverse effects in a HCC-hu-PBL-NOD/SCID murine model through inhibiting angiogenesis, arresting cells in G0/G1 phase and inducing apoptosis.