A bibliometric analysis of oncolytic virotherapy combined with immunotherapy

Oncolytic virotherapy in combination with immunotherapy has demonstrated significant survival benefits in some types of cancer. Here, we summarized the development, research hotpots and potential trends of the combination therapy using visual bibliometric analysis. A total of 712 articles were retrieved on June 21, 2023. The USA was the top contributors of any country (325, 45.65%), and the Rluk Research Libraries UK ranked first (43, 6.03%) of any institutions. The Journal for ImmunoTherapy of Cancer was with the largest publications (60, 8.43%). 'Tumor microenvironment' and 'delivery' were citation keywords with the strongest ongoing bursts. Research fronts in the future may focus on the methods of virus delivery and tumor microenvironment modulation. Futhermore, the most extensively studied cancer were melanoma, glioma and hepatocellular carcinoma.

The critical role of tumor microbiome in cancer immunotherapy

In recent years, the microbiome has shown an integral role in cancer immunotherapy and has become a prominent and widely studied topic. A full understanding of the interactions between the tumor microbiome and various immunotherapies offers opportunities for immunotherapy of cancer. This review scrutinizes the composition of the tumor microbiome, the mechanism of microbial immune regulation, the influence of tumor microorganisms on tumor metastasis, and the interaction between tumor microorganisms and immunotherapy. In addition, this review also summarizes the challenges and opportunities of immunotherapy through tumor microbes, as well as the prospects and directions for future related research. In conclusion, the potential of microbial immunotherapy to enhance treatment outcomes for cancer patients should not be underestimated. Through this review, it is hoped that more research on tumor microbial immunotherapy will be done to better solve the treatment problems of cancer patients.

Prospects and challenges of neoantigen applications in oncology

Neoantigen, unique peptides resulting from tumor-specific mutations, represent a promising frontier in oncology for personalized cancer immunotherapy. Their unique features allow for the development of highly specific and effective cancer treatments, which can potentially overcome the limitations of conventional therapies. This paper explores the current prospects and challenges associated with the application of neoantigens in oncology. We examine the latest advances in neoantigen identification, vaccine development, and adoptive T cell therapy. Additionally, we discuss the obstacles related to neoantigen heterogeneity, immunogenicity prediction, and the tumor microenvironment. Through a comprehensive analysis of current research and clinical trials, this paper aims to provide a detailed overview of how neoantigens could revolutionize cancer treatment and the hurdles that must be overcome to realize their full potential.

The current therapeutic cancer vaccines landscape in non-small cell lung cancer

Currently, conventional immunotherapies for the treatment of non-small cell lung cancer (NSCLC) have low response rates and benefit only a minority of patients, particularly those with advanced disease, so novel therapeutic strategies are urgent deeded. Therapeutic cancer vaccines, a form of active immunotherapy, harness potential to activate the adaptive immune system against tumor cells via antigen cross-presentation. Cancer vaccines can establish enduring immune memory and guard against recurrences. Vaccine-induced tumor cell death prompts antigen epitope spreading, activating functional T cells and thereby sustaining a cancer-immunity cycle. The success of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rendered cancer vaccines a promising avenue, especially when combined with immunotherapy or chemoradiotherapy for NSCLC. This review delves into the intricate antitumor immune mechanisms underlying therapeutic cancer vaccines, enumerates the tumor antigen spectrum of NSCLC, discusses different cancer vaccines progress and summarizes relevant clinical trials. Additionally, we analyze the combination strategies, current limitations, and future prospects of cancer vaccines in NSCLC treatment, aiming to offer fresh insights for their clinical application in managing NSCLC. Overall, cancer vaccines offer promising potential for NSCLC treatment, particularly combining with chemoradiotherapy or immunotherapy could further improve survival in advanced patients. Exploring inhaled vaccines or prophylactic vaccines represents a crucial research avenue.

Current progress of anti‑PD‑1/PDL1 immunotherapy for glioblastoma (Review)

Glioblastoma (GBM) is the most common central nervous system malignancy in adults. GBM may be classified as grade IV diffuse astrocytoma according to the 2021 World Health Organization revised classification of central nervous system tumors, which means it is the most aggressive, invasive, undifferentiated type of tumor. Immune checkpoint blockade (ICB), particularly anti‑programmed cell death protein‑1 (PD‑1)/PD‑1 ligand‑1 immunotherapy, has been confirmed to be successful across several tumor types. However, in GBM, this treatment is still uncommon and the efficacy is unpredictable, and <10% of patients show long‑term responses. Recently, numerous studies have been conducted to explore what factors may indicate or affect the ICB response rate in GBM, including molecular alterations, immune expression signatures and immune infiltration. The present review aimed to summarize the current progress to improve the understanding of immunotherapy for GBM.

An optimal promoter regulating cytokine transgene expression is crucial for safe and effective oncolytic virus immunotherapy

In general, ensuring safety is the top priority of a new modality. Although oncolytic virus armed with an immune stimulatory transgene (OVI) showed some promise, the strategic concept of simultaneously achieving maximum effectiveness and minimizing side effects has not been fully explored. We generated a variety of survivin-responsive "conditionally replicating adenoviruses that can target and treat cancer cells with multiple factors (m-CRAs)" (Surv.m-CRAs) armed with the granulocyte-macrophage colony-stimulating factor (GM-CSF) transgene downstream of various promoters using our m-CRA platform technology. We carefully analyzed both therapeutic and adverse effects of them in the in vivo syngeneic Syrian hamster cancer models. Surprisingly, an intratumor injection of a conventional OVI, which expresses the GM-CSF gene under the constitutively and strongly active "cytomegalovirus enhancer and β-actin promoter", provoked systemic and lethal GM-CSF circulation and shortened overall survival (OS). In contrast, a new conceptual type of OVI, which expressed GM-CSF under the cancer-predominant and mildly active E2F promoter or the moderately active "Rous sarcoma virus long terminal repeat", not only abolished lethal adverse events but also prolonged OS and systemic anti-cancer immunity. Our study revealed a novel concept that optimal expression levels of an immune stimulatory transgene regulated by a suitable upstream promoter is crucial for achieving high safety and maximal therapeutic effects simultaneously in OVI therapy. These results pave the way for successful development of the next-generation OVI and alert researchers about possible problems with ongoing clinical trials.

The landscape of combining immune checkpoint inhibitors with novel Therapies: Secret alliances against breast cancer

This review focuses on the immune checkpoint inhibitors (ICIs) in the context of breast cancer (BC) management. These innovative treatments, by targeting proteins expressed on both tumor and immune cells, aim to overcome tumor-induced immune suppression and reactivate the immune system. The potential of this approach is the subject of numerous clinical studies. Here, we explore the key studies and emerging therapies related to ICIs providing a detailed analysis of their specific and combined use in BC treatment.

Current and emerging intralesional immunotherapies in cutaneous oncology

Immunotherapies have revolutionized the management of advanced cutaneous malignancies. However, some patients fail to respond to these therapies, others are ineligible because of comorbidities, and a minority of patients experience treatment-limiting systemic immune-related adverse events. To address these issues and expand treatment options for patients with early-stage disease, a variety of immunotherapies are being developed for direct intratumoral administration. Agents including oncolytic viruses, monoclonal antibodies, cytokines, peptides, and pattern-recognition receptor agonists have been engineered to evoke a local immune response while minimizing systemic toxicity and have shown favorable results in preclinical and early clinical testing. This review covers the current landscape of intratumoral immunotherapies for the treatment of cutaneous melanoma, squamous cell carcinoma, and basal cell carcinoma, highlighting the diverse array of agents being explored and their potential benefits and challenges.

Exosome-based immunotherapy as an innovative therapeutic approach in melanoma

The malignant form of melanoma is one of the deadliest human cancers that accounts for almost all of the skin tumor-related fatalities in its later stages. Achieving an exhaustive understanding of reliable cancer-specific markers and molecular pathways can provide numerous practical techniques and direct the way toward the development of rational curative medicines to increase the lifespan of patients. Immunotherapy has significantly enhanced the treatment of metastatic and late-stage melanoma, resulting in an incredible increase in positive responses to therapy. Despite the increasing occurrence of melanoma, the median survival rate for patients with advanced, inoperable terminal disease has increased from around six months to almost six years. The current knowledge of the tumor microenvironment (TME) and its interaction with the immune system has resulted in the swift growth of innovative immunotherapy treatments. Exosomes are small extracellular vesicles (EVs), ranging from 30 to 150 nm in size, that the majority of cells released them. Exosomes possess natural advantages such as high compatibility with living organisms and low potential for causing immune reactions, making them practical for delivering therapeutic agents like chemotherapy drugs, nucleic acids, and proteins. This review highlights recent advancements in using exosomes as an approach to providing medications for the treatment of melanoma.

Ultrasound-guided intra-tumoral administration of directly-injected therapies: a review of the technical and logistical considerations

BACKGROUND

Directly-injected therapies (DIT) include a broad range of agents within a developing research field in cancer immunotherapy, with encouraging clinical trial results in various tumour subtypes. Currently, the majority of such therapies are only available within clinical trials; however, more recently, talimogene laherparepvec (T-VEC, Imlygic) has been approved as the first oncolytic virus therapy in the USA and Europe. Our institution contributes to multiple different trials exploring the efficacy of DIT, the majority of which are performed by oncologists in clinic. However, specific, challenging cases - mainly neck tumours - require image-guided administration.

MAIN BODY

This review article addresses the technical and logistical factors relevant to the incorporation of image-guided DIT into an established ultrasound service. Image-guidance (usually with ultrasound) is frequently needed for certain targets that cannot be palpated or are in high-risk locations, e.g. adjacent to blood vessels. A multi-disciplinary approach is essential to facilitate a safe and efficient service, including careful case-selection. Certain protocols and guidance need to be followed when incorporating such a service into an established ultrasound practice to enhance efficiency and optimise safety. Key learning points are drawn from the literature and from our early experience at a tertiary cancer centre following image guided DIT for an initial cohort of 22 patients (including 11 with a neck mass), addressing trial protocols, pre-procedure work-up, organisation, planning, consent, technical aspects, procedure tolerability, technical success, and post-procedure considerations.

CONCLUSION

With appropriate planning and coordination, and application of the learning points discussed herein, image-guided administration of DIT can be safely and efficiently incorporated into an established procedural ultrasound list. This has relevance to cancer centres, radiology departments, individual radiologists, and other team members with a future role in meeting the emerging need for these procedures. This paper provides advice on developing such an imaging service, and offers certain insights into the evolving remit of radiologists within cancer care in the near future.

Extracellular vesicles reshape the tumor microenvironment to improve cancer immunotherapy: Current knowledge and future prospects

Tumor immunotherapy has revolutionized cancer treatment, but limitations remain, including low response rates and immune complications. Extracellular vesicles (EVs) are emerging as a new class of therapeutic agents for various diseases. Recent research shows that changes in the amount and composition of EVs can reshape the tumor microenvironment (TME), potentially improving the effectiveness of immunotherapy. This exciting discovery has sparked clinical interest in using EVs to enhance the immune system's response to cancer. In this Review, we delve into the world of EVs, exploring their origins, how they're generated, and their complex interactions within the TME. We also discuss the crucial role EVs play in reshaping the TME during tumor development. Specifically, we examine how their cargo, including molecules like PD-1 and non-coding RNA, influences the behavior of key immune cells within the TME. Additionally, we explore the current applications of EVs in various cancer therapies, the latest advancements in engineering EVs for improved immunotherapy, and the challenges faced in translating this research into clinical practice. By gaining a deeper understanding of how EVs impact the TME, we can potentially uncover new therapeutic vulnerabilities and significantly enhance the effectiveness of existing cancer immunotherapies.

Tumour Immunotherapy and Applications of Immunological Products: A Review of Literature

Malignant tumors, characterized by uncontrolled cell proliferation, are a leading global health challenge, responsible for over 9.7 million deaths in 2022, with new cases expected to rise to 35 million annually by 2050. Immunotherapy is preferred to other cancer therapies, offering precise targeting of malignant cells while simultaneously strengthening the immune system's complex responses. Advances in this novel field of science have been closely linked to a deeper knowledge of tumor biology, particularly the intricate interplay between tumor cells, the immune system, and the tumor microenvironment (TME), which are central to cancer progression and immune evasion. This review offers a comprehensive analysis of the molecular mechanisms that govern these interactions, emphasizing their critical role in the development of effective immunotherapeutic products. We critically evaluate the current immunotherapy approaches, including cancer vaccines, adoptive T cell therapies, and cytokine-based treatments, highlighting their efficacy and safety. We also explore the latest advancements in combination therapies, which synergistically integrate multiple immunotherapeutic strategies to overcome resistance and enhance therapeutic outcomes. This review offers key insights into the future of cancer immunotherapy with a focus on advancing more effective and personalized treatment strategies.

HSV-1-induced N6-methyladenosine reprogramming via ICP0-mediated suppression of METTL14 potentiates oncolytic activity in glioma

Upon infection with herpes simplex virus 1 (HSV-1), the virus deploys multiple strategies to evade the host's innate immune response. However, the mechanisms governing this phenomenon remain elusive. Here, we find that HSV-1 leads to a decrease in overall m6A levels by selectively reducing METTL14 protein during early infection in glioma cells. Specifically, the HSV-1-encoded immediate-early protein ICP0 interacts with METTL14 within ND10 bodies and serves as an E3 ubiquitin protein ligase, targeting and ubiquitinating METTL14 at the lysine 156 and 162 sites. Subsequently, METTL14 undergoes proteasomal degradation. Furthermore, METTL14 stabilizes ISG15 mRNA mediated by IGF2BP3 to promote antiviral effects. Notably, METTL14 suppression significantly enhances the anti-tumor effect of oncolytic HSV-1 (oHSV-1) in mice bearing glioma xenografts. Collectively, these findings establish that ICP0-guided m6A modification controls the antiviral immune response and suggest that targeting METTL14/ISG15 represents a potential strategy to enhance the oncolytic activity of oHSV-1 in glioma treatment.

Expression of c-erb-B2 oncoprotein as a neoantigen strategy to repurpose anti-neu antibody therapy in a model of melanoma

In this study, we tested a novel approach of "repurposing" a biomarker typically associated with breast cancer for use in melanoma. HER2/neu is a well characterized biomarker in breast cancer for which effective anti-HER2/neu therapies are readily available. We constructed a lentivirus encoding c-erb-B2, an animal (rat) homolog to HER2/neu. This was used to transfect B16 melanoma in vitro for use in an orthotopic preclinical mouse model, which resulted in expression of rat c-erb-B2 as a neoantigen target for anti-c-erb-B2 monoclonal antibody (7.16.4). The c-erb-B2-expressing melanoma was designated B16/neu. 7.16.4 produced statistically significant in vivo anti-tumor responses against B16/neu. This effect was mediated by NK-cell antibody-dependent cell-mediated cytotoxicity. To further model human melanoma (which expresses < 5% HER2/neu), our c-erb-B2 encoding lentivirus was used to inoculate naïve (wild-type) B16 tumors in vivo, resulting in successful c-erb-B2 expression. When combined with 7.16.4, anti-tumor responses were again demonstrated where approximately 40% of mice treated with c-erb-B2 lentivirus and 7.16.4 achieved complete clinical response and long-term survival. For the first time, we demonstrated a novel strategy to repurpose c-erb-B2 as a neoantigen target for melanoma. Our findings are particularly significant in the contemporary setting where newer anti-HER2/neu antibody-drug therapies have shown increased efficacy.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Oncolytic Viruses as Reliable Adjuvants in CAR-T Cell Therapy for Solid Tumors

Although impactful scientific advancements have recently been made in cancer therapy, there remains an opportunity for future improvements. Immunotherapy is perhaps one of the most cutting-edge categories of therapies demonstrating potential in the clinical setting. Genetically engineered T cells express chimeric antigen receptors (CARs), which can detect signals expressed by the molecules present on the surface of cancer cells, also called tumor-associated antigens (TAAs). Their effectiveness has been extensively demonstrated in hematological cancers; therefore, these results can establish the groundwork for their applications on a wide range of requirements. However, the application of CAR-T cell technology for solid tumors has several challenges, such as the existence of an immune-suppressing tumor microenvironment and/or inadequate tumor infiltration. Consequently, combining therapies such as CAR-T cell technology with other approaches has been proposed. The effectiveness of combining CAR-T cell with oncolytic virus therapy, with either genetically altered or naturally occurring viruses, to target tumor cells is currently under investigation, with several clinical trials being conducted. This narrative review summarizes the current advancements, opportunities, benefits, and limitations in using each therapy alone and their combination. The use of oncolytic viruses offers an opportunity to address the existing challenges of CAR-T cell therapy, which appear in the process of trying to overcome solid tumors, through the combination of their strengths. Additionally, utilizing oncolytic viruses allows researchers to modify the virus, thus enabling the targeted delivery of specific therapeutic agents within the tumor environment. This, in turn, can potentially enhance the cytotoxic effect and therapeutic potential of CAR-T cell technology on solid malignancies, with impactful results in the clinical setting.

Cytokine-armed vaccinia virus promotes cytotoxicity toward pancreatic carcinoma cells via activation of human intermediary CD56dimCD16dim natural killer cells

Pancreatic ductal adenocarcinoma (PDAC) remains a particularly aggressive disease with few effective treatments. The PDAC tumor immune microenvironment (TIME) is known to be immune suppressive. Oncolytic viruses can increase tumor immunogenicity via immunogenic cell death (ICD). We focused on tumor-selective (vvDD) and cytokine-armed Western-reserve vaccinia viruses (vvDD-IL2 and vvDD-IL15) and infected carcinoma cell lines as well as patient-derived primary PDAC cells. In co-culture experiments, we investigated the cytotoxic response and the activation of human natural killer (NK). Infection and virus replication were assessed by measuring virus encoded YFP. We then analyzed intracellular signaling processes and oncolysis via in-depth proteomic analysis, immunoblotting and TUNEL assay. Following the co-culture of mock or virus infected carcinoma cell lines with allogenic PBMCs or NK cell lines, CD56+ NK cells were analyzed with respect to their activation, cytotoxicity and effector function. Both, dose- and time-dependent release of danger signals following infection were measured. Viruses effectively entered PDAC cells, emitted YFP signals and resulted in concomitant oncolysis. The proteome showed reprogramming of normally active core signaling pathways in PDAC (e.g., MAPK-ERK signaling). Danger-associated molecular patterns were released upon infection and stimulated co-cultured NK cells for enhanced effector cytotoxicity. NK cell subtyping revealed enhanced numbers and activation of a rare CD56dimCD16dim population. Tumor cell killing was primarily triggered via Fas ligands rather than granule release, resulting in marked apoptosis. Overall, the cytokine-armed vaccinia viruses induced NK cell activation and enhanced cytotoxicity toward human PDAC cells in vitro. We could show that cytokine-armed virus targets the carcinoma cells and thus has great potential to modulate the TIME in PDAC.

Oncolytic virotherapy against lung cancer: key receptors and signaling pathways of viral entry

Lung cancer accounts for the highest cancer-related mortality worldwide. While immunotherapies targeting anti-tumor immune responses have demonstrated efficacy in clinical practice, the demand for novel treatment modalities remains urgent. Oncolytic viruses (OVs), which selectively kill tumor cells while stimulating an anti-tumor immune response, represent a potential breakthrough in lung cancer therapy. The induction of anti-tumor immunity by OVs is central to their overall therapeutic effectiveness. Many natural receptors on the surface of cancer cells are dysregulated, providing potential entry points for OVs. Furthermore, the inherent dysregulation of some key signaling pathways in lung cancer cells promotes proliferation, progression and metastasis, which may facilitate selective viral replication. In this review, we explore the application of OVs in lung cancer by analyzing several major OVs and their corresponding entry receptors. Then, we also examine the key signaling pathways and molecules with the potential to synergize with OVs in modulating the immune tumor microenvironment. Finally, we discuss the combination and administration strategies that warrant further clinical trials for validation. Despite certain limitations, the tolerability of OVs positions virotherapy as a promising avenue in the future of lung cancer treatment.

Advances in Adjuvant and Neoadjuvant Therapy for Melanoma

Melanoma remains one of the most common cancers diagnosed in the United States, yet there have been substantial advancements in the treatment of resectable disease. Adjuvant therapy with immune checkpoint blockade (ICB) and targeted therapy with BRAF/MEK inhibitors (BRAF/MEKi) have now become standard of care for resectable stage IIIB-IV melanoma. In this article, the authors discuss recent scientific developments pertinent to the treatment of resectable melanoma including ICB, targeted therapy with BRAF/MEKi, oncolytic viruses, tumor-infiltrating lymphocyte therapy, and cancer vaccines.

Small extracellular vesicles carrying reovirus, tumor antigens, interferon-β, and damage-associated molecular patterns for efficient tumor treatment

Small extracellular vesicles (SEV) have attracted much attention both as mediators of intercellular communication and as drug delivery systems. In addition, recent studies have shown that SEV containing virus components and virus particles are released from virus-infected cells. Oncolytic viruses, which efficiently kill tumor cells by tumor cell-specific replication, have been actively studied as novel anticancer agents in clinical and preclinical studies. However, it remains to be fully elucidated whether SEV released from oncolytic virus-infected cells are involved in the antitumor effects of oncolytic viruses. In this study, we examined the tumor cell killing efficiencies and innate immune responses following treatment with SEV released from oncolytic reovirus-infected tumor cells in vitro and in vivo. Reovirus-infected B16 cells secreted SEV associated with or containing reovirus particles (Reo-SEV) with a diameter of approximately 130 nm and a zeta potential of -17 mV, although death of reovirus-infected B16 cells was not observed. The secreted Reo-SEV also contained interferon (IFN)-β, tumor antigens, and damage-associated molecular patterns (DAMPs), including heat shock proteins (HSPs). Reo-SEV were secreted from the tumor tissues of reovirus-injected mice. Inhibition of the SEV secretion pathway using GW4869, which is a neutral sphingomyelinase inhibitor, resulted in significant reduction in the infectious titers of reovirus in the culture supernatants, suggesting that the cells released progeny virus via the SEV secretion pathway. Reo-SEV more efficiently killed mouse tumor cells and induced innate immune responses in mouse bone marrow-derived dendritic cells than reovirus. Reovirus and Reo-SEV mediated efficient and comparable levels of growth suppression of B16 subcutaneous tumors and induction of tumor infiltration of CD8+ T cells following intravenous administration. These results indicate that Reo-SEV are a promising oncolytic agent and that SEV are an effective delivery vehicle for oncolytic virus.

Effects of intratumoral microbiota on tumorigenesis, anti-tumor immunity, and microbe-based cancer therapy

Intratumoral microbiota (IM) has emerged as a significant component of the previously thought sterile tumor microenvironment (TME), exerting diverse functions in tumorigenesis and immune modulation. This review outlines the historical background, classification, and diversity of IM, elucidating its pivotal roles in oncogenicity, cancer development, and progression, alongside its influence on anti-tumor immunity. The signaling pathways through which IM impacts tumorigenesis and immunity, including reactive oxygen species (ROS), β-catenin, stimulator of interferon genes (STING), and other pathways [NF-κB, Toll-like receptor (TLR), complement, RhoA/ROCK, PKR-like ER kinase (PERK)], are discussed comprehensively. Furthermore, we briefly introduce the clinical implications of IM, emphasizing its potential as a target for novel cancer therapies, diagnostic biomarkers, and prognostic indicators. Notably, microbe-based therapeutic strategies such as fecal microbiome transplantation (FMT), probiotics regulation, bacteriotherapy, bacteriophage therapy, and oncolytic virotherapy are highlighted. These strategies hold promise for enhancing the efficacy of current cancer treatments and warrant further exploration in clinical settings.

Progression of oncolytic virus in liver cancer treatment

The liver plays a crucrial role in detoxification, metabolism, and nutrient storage. Because liver cancer ranks among the top three leading causes of death globally, there is an urgent need for developing treatment strategies for liver cancer. Although traditional approaches such as radiation, chemotherapy, surgical removal, and transplantation are widely practiced, the number of patients with liver cancer continues to increase rapidly each year. Some novel therapeutics for liver cancer have been studied for many years. In the past decade, oncolytic therapy has emerged, in which viruses selectively infect and destroy cancer cells while sparing normal cells. However, oncolytic virotherapy for liver cancer remains relatively obscure due to the aggressive nature of the disease and the limited effectiveness of treatment. To keep pace with the latest developments in oncolytic tumor therapy for liver cancer, this review summarizes basic science studies and clinical trials conducted within 5 years, focusing on the efficacy and safety profiles of the five most commonly used oncolytic viruses: herpes simplex virus, adenovirus, influenza virus, vaccinia virus, and coxsackievirus.

Advancing Lung Cancer Treatment with Combined c-Met Promoter-Driven Oncolytic Adenovirus and Rapamycin

Lung cancer remains a formidable health challenge due to its high mortality and morbidity rates. Non-small cell lung cancer (NSCLC) constitutes approximately 85% of all lung cancer cases, with small cell lung cancer (SCLC) accounting for the remainder. Both NSCLC and SCLC cells express receptor tyrosine kinases, which may be overexpressed or mutated in lung cancer, leading to increased activation. The c-Met receptor tyrosine kinase, crucial for cell transformation and tumor growth, invasion, and metastasis, became the focus of our study. We used an E1B55KD-deleted, replication-selective oncolytic adenovirus (Ad.What), driven by the c-Met promoter, targeting lung cancer cells with c-Met overexpression, thus sparing normal cells. Previous studies have shown the enhanced antitumor efficacy of oncolytic adenoviruses when combined with chemotherapeutic agents. We explored combining rapamycin, a selective mTOR inhibitor with promising clinical trial outcomes for various cancers, with Ad.What. This combination increased infectivity by augmenting the expression of coxsackievirus and adenovirus receptors and αV integrin on cancer cells and induced autophagy. Our findings suggest that combining a c-Met promoter-driven oncolytic adenovirus with rapamycin could be an effective lung cancer treatment strategy, offering a targeted approach to exploit lung cancer cells' vulnerabilities, potentially marking a significant advancement in managing this deadly disease.

Advances in the management of regionally metastatic melanoma

Despite numerous developments in systemic therapy, the prognosis for patients with locoregionally advanced melanoma remains poor. By delivering therapy directly to the targeted area via intralesional injections or intra-arterial isolated infusions, systemic side effects are minimized and oncolytic agents are delivered more directly and effectively to the melanoma. There has been significant progress in recent years with intralesional agents such as Talimogene laherparepvec (T-VEC), PV-10 and TAVOkinase/electrocorporation as well as advances in infusional therapies such as percutaneous hepatic perfusion (PHP) for hepatic metastasis of ocular melanoma. This review evaluates advances in intralesional and infusional therapies for melanoma while limiting discussion to those therapies currently approved and on trial.

Translation of oncolytic viruses in sarcoma

Sarcomas are a rare and highly diverse group of malignancies of mesenchymal origin. While sarcomas are generally considered resistant to immunotherapy, recent studies indicate subtype-specific differences in clinical response to checkpoint inhibitors (CPIs) that are associated with distinct immune phenotypes present in sarcoma subtypes. Oncolytic viruses (OVs) are designed to selectively infect and kill tumor cells and induce intratumoral immune infiltration, enhancing immunogenicity and thereby sensitizing tumors to immunotherapy. Herein we review the accumulated clinical data evaluating OVs in sarcoma. Small numbers of patients with sarcoma were enrolled in early-stage OV trials as part of larger solid tumor cohorts demonstrating safety but providing limited insight into the biological effects due to the low patient numbers and lack of histologic grouping. Several recent studies have investigated talimogene laherparepvec (T-VEC), an approved oncolytic herpes simplex virus (HSV-1), in combination therapy regimens in sarcoma patient cohorts. These studies have shown promising responses in heavily pre-treated and immunotherapy-resistant patients associated with increased intratumoral immune infiltration. As new and more potent OVs enter the clinical arena, prospective evaluation in subtype-specific cohorts with correlative studies to define biomarkers of response will be critical to advancing this promising approach for sarcoma therapy.

Deletion of the RGD motif from the penton base in oncolytic adenoviruses enhances antitumor efficacy of combined CAR T cell therapy

Oncolytic viruses often face challenges in achieving optimal antitumor immunity as standalone therapies. The penton base RGD-integrin interactions play a significant role in wild-type adenovirus-induced innate immune responses. To modify these responses, we present ISC301, a novel oncolytic adenovirus engineered by deleting the natural RGD motifs in the penton base while incorporating artificial RGD motifs in the fiber knobs. ISC301 demonstrated comparable in vitro infectivity, cytotoxic effects, and signaling profiles across various cell types to its parental ICOVIR-5, which retains the penton base RGD motif. In immunodeficient and immunocompetent mouse models, ISC301 exhibited similar in vivo antitumor efficacy to ICOVIR-5. However, ISC301 induced higher intratumoral inflammation through NF-κB activation, leading to increased levels of tumor-infiltrating leukocytes and higher proportion of cytotoxic CD8+ T cells. In addition, ISC301 elicits a heightened pro-inflammatory response in peripheral blood. Importantly, when combined with CAR T cell therapy, ISC301 exhibited superior antitumor efficacy, surpassing monotherapy outcomes. These findings emphasize the impact of adenoviral modifications on antitumor immune responses. The deletion of penton base RGD motifs enhances ISC301's pro-inflammatory profile and boosts CAR T cell therapy efficacy. This study enhances understanding of oncolytic virus engineering strategies, positioning ISC301 as a promising candidate for combined immunotherapeutic approaches in cancer treatment.

Novel insights into the regulation of exosomal PD-L1 in cancer: From generation to clinical application

Programmed cell death ligand 1 (PD-L1) interacts with programmed cell death 1 (PD-1), leading to T cell exhaustion and promoting tumor cell survival, ultimately mediating immunosuppression. While FDA-approved monoclonal antibodies targeting the PD-1/PD-L1 interaction have shown success in cancer treatment, some patients experience limited and short-lived therapeutic outcomes. Recent studies have identified PD-L1 expression not only on tumor cell surfaces but also on exosomes, with secretion pathways including both conventional and unconventional endocytosis routes, presenting a unique therapeutic opportunity. Emerging evidence suggests that exosomal PD-L1 contributes to systemic immunosuppression, potentially counteracting the effects of anti-PD-1 checkpoint therapies. However, the significance of exosomal PD-L1 in clinical cancer patients unresponsive to anti-PD-1/PD-L1 immunotherapy, as well as the factors regulating its generation, remain unclear. Moreover, the mechanisms underlying PD-L1 expression on exosomes and its regulation in cancer are yet to be fully elucidated. This review primarily focuses on the mechanisms modulating exosomal PD-L1 generation in cancer, while also outlining its involvement in immunosuppression, tumor proliferation, and response to cancer immunotherapy. Additionally, we explore the potential of exosomal PD-L1 as a cancer biomarker and therapeutic target, aiming to provide a comprehensive overview of this emerging field and its implications for cancer treatment and diagnosis.

Optimizing Pancreatic Cancer Therapy: The Promise of Immune Stimulatory Oncolytic Viruses

Pancreatic cancer presents formidable challenges due to rapid progression and resistance to conventional treatments. Oncolytic viruses (OVs) selectively infect cancer cells and cause cancer cells to lyse, releasing molecules that can be identified by the host's immune system. Moreover, OV can carry immune-stimulatory payloads such as interleukin-12, which when delivered locally can enhance immune system-mediated tumor killing. OVs are very well tolerated by cancer patients due to their ability to selectively target tumors without affecting surrounding normal tissues. OVs have recently been combined with other therapies, including chemotherapy and immunotherapy, to improve clinical outcomes. Several OVs including adenovirus, herpes simplex viruses (HSVs), vaccinia virus, parvovirus, reovirus, and measles virus have been evaluated in preclinical and clinical settings for the treatment of pancreatic cancer. We evaluated the safety and tolerability of a replication-competent oncolytic adenoviral vector carrying two suicide genes (thymidine kinase, TK; and cytosine deaminase, CD) and human interleukin-12 (hIL12) in metastatic pancreatic cancer patients in a phase 1 trial. This vector was found to be safe and well-tolerated at the highest doses tested without causing any significant adverse events (SAEs). Moreover, long-term follow-up studies indicated an increase in the overall survival (OS) in subjects receiving the highest dose of the OV. Our encouraging long-term survival data provide hope for patients with advanced pancreatic cancer, a disease that has not seen a meaningful increase in OS in the last five decades. In this review article, we highlight several preclinical and clinical studies and discuss future directions for optimizing OV therapy in pancreatic cancer. We envision OV-based gene therapy to be a game changer in the near future with the advent of newer generation OVs that have higher specificity and selectivity combined with personalized treatment plans developed under AI guidance.

Tumor-Localized Interleukin-2 and Interleukin-12 Combine with Radiation Therapy to Safely Potentiate Regression of Advanced Malignant Melanoma in Pet Dogs

PURPOSE

Cytokines IL2 and IL12 exhibit potent anticancer activity but suffer a narrow therapeutic window due to off-tumor immune cell activation. Engineering cytokines with the ability to bind and associate with tumor collagen after intratumoral injection potentiated response without toxicity in mice and was previously safe in pet dogs with sarcoma. Here, we sought to test the efficacy of this approach in dogs with advanced melanoma.

PATIENTS AND METHODS

This study examined 15 client-owned dogs with histologically or cytologically confirmed malignant melanoma that received a single 9-Gy fraction of radiotherapy, followed by six cycles of combined collagen-anchored IL2 and IL12 therapy every 2 weeks. Cytokine dosing followed a 3 + 3 dose escalation design, with the initial cytokine dose chosen from prior evaluation in canine sarcomas. No exclusion criteria for tumor stage or metastatic burden, age, weight, or neuter status were applied for this trial.

RESULTS

Median survival regardless of the tumor stage or dose level was 256 days, and 10/13 (76.9%) dogs that completed treatment had CT-measured tumor regression at the treated lesion. In dogs with metastatic disease, 8/13 (61.5%) had partial responses across their combined lesions, which is evidence of locoregional response. Profiling by NanoString of treatment-resistant dogs revealed that B2m loss was predictive of poor response to this therapy.

CONCLUSIONS

Collectively, these results confirm the ability of locally administered tumor-anchored cytokines to potentiate responses at regional disease sites when combined with radiation. This evidence supports the clinical translation of this approach and highlights the utility of comparative investigation in canine cancers.

Breaking Barriers: Animal viruses as oncolytic and immunotherapeutic agents for human cancers

Oncolytic viruses, defined as viruses capable of lysing cancer cells, emerged as a groundbreaking class of therapeutic entities poised to revolutionize cancer treatment. Their mode of action encompasses both direct tumor cell lysis and the indirect enhancement of anti-tumor immune responses. Notably, four leading contenders in this domain, Rigvir® in Latvia, T-VEC in the United States, H101 in China and Teserpaturev (DELYTACT®) in Japan, have earned approval for treating metastatic melanoma (Rigvir and T-VEC), nasopharyngeal carcinoma and malignant glioma, respectively. Despite these notable advancements, the integration of oncolytic viruses into cancer therapy encounters several challenges. Foremost among these hurdles is the considerable variability observed in clinical responses to oncolytic virus interventions. Moreover, the adaptive immune system may inadvertently target the oncolytic viruses themselves, diverting immune resources away from tumor antigens and undermining therapeutic efficacy. Another significant limitation arises from the presence of preexisting immunity against oncolytic viruses in certain patient populations, hampering treatment outcomes. To circumvent this obstacle, researchers are investigating the utilization of animal viruses, for which humans lack preexisting immunity, as a compelling alternative to human-derived counterparts. In our comprehensive review, we delve into the intricate nuances of oncolytic virotherapy, elucidating the multifaceted mechanisms through which these viruses exert their anti-cancer effects. Furthermore, we provide a thorough examination of animal-derived oncolytic viruses, highlighting their respective strengths and limitations. Lastly, we explore the promising potential of leveraging animal viruses as potent oncolytic agents, offering new avenues for enhancing the efficacy and reach of human cancer therapeutics.

Gene therapy for polygenic or complex diseases

Gene therapy utilizes nucleic acid drugs to treat diseases, encompassing gene supplementation, gene replacement, gene silencing, and gene editing. It represents a distinct therapeutic approach from traditional medications and introduces novel strategies for genetic disorders. Over the past two decades, significant advancements have been made in the field of gene therapy, leading to the approval of various gene therapy drugs. Gene therapy was initially employed for treating genetic diseases and cancers, particularly monogenic conditions classified as orphan diseases due to their low prevalence rates; however, polygenic or complex diseases exhibit higher incidence rates within populations. Extensive research on the etiology of polygenic diseases has unveiled new therapeutic targets that offer fresh opportunities for their treatment. Building upon the progress achieved in gene therapy for monogenic diseases and cancers, extending its application to polygenic or complex diseases would enable targeting a broader range of patient populations. This review aims to discuss the strategies of gene therapy, methods of gene editing (mainly CRISPR-CAS9), and carriers utilized in gene therapy, and highlight the applications of gene therapy in polygenic or complex diseases focused on applications that have either entered clinical stages or are currently undergoing clinical trials.

Safety, Efficacy, and Biological Data of T-Cell-Enabling Oncolytic Adenovirus TILT-123 in Advanced Solid Cancers from the TUNIMO Monotherapy Phase I Trial

PURPOSE

TILT-123 (igrelimogene litadenorepvec) is an oncolytic adenovirus armed with TNFa and IL2, designed to induce T-cell infiltration and cytotoxicity in solid tumors.

PATIENTS AND METHODS

TUNIMO (NCT04695327) was a single-arm, multicenter phase I dose-escalation trial designed to assess the safety of TILT-123 in advanced solid cancers refractory to standard therapy. Patients received intravenous and intratumoral TILT-123. The primary endpoint was safety by adverse events (AE), laboratory values, vital signs, and electrocardiograms. Secondary endpoints included tumor response, pharmacokinetics, and predictive biomarkers.

RESULTS

Twenty patients were enrolled, with a median age of 58 years. Most prevalent cancer types included sarcomas (35%), melanomas (15%) and ovarian cancers (15%). No dose-limiting toxicities were observed. The most frequent treatment-related AEs included fever (16.7%), chills (13.0%), and fatigue (9.3%). Ten patients were evaluable for response on day 78 with RECIST 1.1, iRECIST or PET-based evaluation. The disease control rate by PET was 6/10 (60% of evaluable patients) and 2/10 by RECIST 1.1 and iRECIST(20%of evaluable patients). Tumor size reductions occurred in both injected and non-injected lesions. TILT-123 was detected in injected and non-injected tumors, and virus was observed in blood after intravenous and intratumoral injections. Treatment resulted in reduction of lymphocytes in blood, with concurrent lymphocyte increases in tumors, findings compatible with trafficking.

CONCLUSIONS

TILT-123 was safe and able to produce antitumor effects in local and distant lesions in heavily pre-treated patients. Good tolerability of TILT-123 facilitates combination studies, several of which are ongoing (NCT04217473, NCT05271318, NCT05222932, and NCT06125197). See related commentary by Silva-Pilipich and Smerdou, p. 3649.

Dose Considerations for Vaccinia Oncolytic Virus Based on Retrospective Reanalysis of Early and Late Clinical Trials

Over the past decade, oncolytic viruses (OVs) have been developed as a promising treatment alone or in combination in immuno-oncology but have faced challenges in late-stage clinical trials. Our retrospective reanalysis of vaccinia oncolytic virus (VOV) clinical trials indicates that lower doses-rather than the maximum tolerated dose (MTD)-are associated with better tumor response rates. Patients who responded well to lower doses generally had prolonged survival rates in the early phase clinical trial. The association between poor outcomes and an increase in OV-induced neutrophils (OV-N) but not baseline neutrophil counts suggests the need for a comprehensive characterization of OV-N. Although this reanalysis is limited by patient heterogeneity-including differences in cancer type and stage, treatment schedules, and administration routes-it remains informative given the complexities of translational studies in the tumor-bearing mouse models of vaccinia oncolytic viruses. Notably, while OV-N increases with higher viral doses, the immune state shaped by tumor progression likely amplifies this tendency. These findings highlight the importance of OV-N immune modulation as well as dose optimization for the successful clinical development of VOV.

Intralesional Talimogene Laherparepvec Immunotherapy for Melanoma: A Case Study

Melanoma, characterized by its aggressive nature and tendency for metastasis, presents a significant challenge in clinical management. While surgical excision remains the gold standard for localized disease, therapeutic advancements for advanced stages are crucial. Oncolytic virotherapy, exemplified by Talimogene laherparepvec (T-VEC), offers a potential approach. Here, we present a 79-year-old male with advanced melanoma on the left distal thumb who opted for T-VEC therapy over surgical excision. Over 18 sessions, T-VEC demonstrated efficacy, resulting in lesion regression and no evidence of recurrence upon long-term monitoring. This case emphasizes the potential of T-VEC in advanced melanoma management, leveraging its dual mechanism targeting primary and metastatic lesions while harnessing immune response. Safety considerations and further investigations into potential interactions with other immunotherapies are warranted to optimize treatment strategies and ensure patient well-being. As oncolytic virotherapy continues to evolve, T-VEC stands as a potential option for the treatment of advanced melanoma.

oHSV2-mGM repolarizes TAMs and cooperates with αPD1 to reprogram the immune microenvironment of residual cancer after radiofrequency ablation

BACKGROUND

Due to the size and location of the tumor, incomplete radiofrequency ablation (iRFA) of the target tumor inhibits tumor immunity. In this study, a murine herpes simplex virus (oHSV2-mGM) armed with granulocyte-macrophage colony-stimulating factor (GM-CSF) was constructed to explore its effect on innate and adaptive immunity during iRFA, and the inhibitory effect of programmed cell death-1 (PD1) on tumor.

METHODS

We verified the polarization and activation of RAW264.7 cells mediated by oHSV2-mGM in vitro. Subsequently, we evaluated the efficacy of oHSV2-mGM alone and in combination with αPD1 in the treatment of residual tumors after iRFA in two mouse models. RNA-seq was used to characterize the changes of tumor microenvironment.

RESULTS

oHSV2-mGM lysate effectively stimulated RAW264.7 cells to polarize into M1 cells and activated M1 phenotypic function. In the macrophage clearance experiment, oHSV2-mGM activated the immune response of tumor in mice. The results in vivo showed that oHSV2-mGM showed better anti-tumor effect in several mouse tumor models. Finally, oHSV2-mGM combined with PD1 antibody can further enhance the anti-tumor effect of oHSV2-mGM and improve the complete remission rate of tumor in mice.

CONCLUSION

The application of oHSV2-mGM leads to the profound remodeling of the immune microenvironment of residual tumors. oHSV2-mGM also works in synergy with PD1 antibody to achieve complete remission of tumors that do not respond well to monotherapy at immune checkpoints. Our results support the feasibility of recombinant oncolytic virus in the treatment of residual tumors after iRFA, and propose a new strategy for oncolytic virus treatment of tumors.

Synergistic effects of herpes oncolytic virus and cyclophosphamide for recurrent malignant glioma: a narrative review

Gliomas, comprising nearly 80% of brain malignancies, present a formidable challenge with glioblastomas being the most aggressive subtype. Despite multidisciplinary care, including surgery and chemoradiotherapy, the prognosis remains grim, emphasizing the need for innovative treatment strategies. The blood-brain barrier complicates drug access, and the diverse histopathology hinders targeted therapies. Oncolytic herpes viruses (oHSVs), particularly HSV1716, G207, and rQNestin34.5v, show promise in glioma treatment by selectively replicating in tumor cells. Preclinical and clinical studies demonstrate the safety and efficacy of oHSVs, with T-Vec being FDA-approved. However, challenges like viral delivery limitations and antiviral responses persist. The combination of oHSVs and combining cyclophosphamide (CPA) addresses these challenges, demonstrating increased transgene expression and viral activity. The immunosuppressive properties of CPA, particularly in metronomic schedules, enhance oHSV efficacy, supporting the development of this combination for recurrent malignant gliomas. CPA with oHSVs enhances viral oncolysis and extends survival. CPA's immunomodulatory effects, suppressing regulatory T cells, improve oHSV efficiency. While obstacles remain, this synergistic approach offers hope for improved outcomes, necessitating further research and clinical validation.

Gene and cell therapy of human genetic diseases: Recent advances and future directions

Disruptions in normal development and the emergence of health conditions often result from the malfunction of vital genes in the human body. Decades of scientific research have focused on techniques to modify or substitute defective genes with healthy alternatives, marking a new era in disease treatment, prevention and cure. Recent strides in science and technology have reshaped our understanding of disorders, medication development and treatment recommendations, with human gene and cell therapy at the forefront of this transformative shift. Its primary objective is the modification of genes or adjustment of cell behaviour for therapeutic purposes. In this review, we focus on the latest advances in gene and cell therapy for treating human genetic diseases, with a particular emphasis on FDA and EMA-approved therapies and the evolving landscape of genome editing. We examine the current state of innovative gene editing technologies, particularly the CRISPR-Cas systems. As we explore the progress, ethical considerations and prospects of these innovations, we gain insight into their potential to revolutionize the treatment of genetic diseases, along with a discussion of the challenges associated with their regulatory pathways. This review traces the origins and evolution of these therapies, from conceptual ideas to practical clinical applications, marking a significant milestone in the field of medical science.

The long-term effectiveness and mechanism of oncolytic virotherapy combined with anti-PD-L1 antibody in colorectal cancer patient

Colorectal cancer (CRC) is known to be resistant to immunotherapy. In our phase-I clinical trial, one patient achieved a 313-day prolonged response during the combined treatment of oncolytic virotherapy and immunotherapy. To gain a deeper understanding of the potential molecular mechanisms, we performed a comprehensive multi-omics analysis on this patient and three non-responders. Our investigation unveiled that, initially, the tumor microenvironment (TME) of this responder presented minimal infiltration of T cells and natural killer cells, along with a relatively higher presence of macrophages compared to non-responders. Remarkably, during treatment, there was a progressive increase in CD4+ T cells, CD8+ T cells, and B cells in the responder's tumor tissue. This was accompanied by a significant upregulation of transcription factors associated with T-cell activation and cytotoxicity, including GATA3, EOMES, and RUNX3. Furthermore, dynamic monitoring of peripheral blood samples from the responder revealed a rapid decrease in circulating tumor DNA (ctDNA), suggesting its potential as an early blood biomarker of treatment efficacy. Collectively, our findings demonstrate the effectiveness of combined oncolytic virotherapy and immunotherapy in certain CRC patients and provide molecular evidence that virotherapy can potentially transform a "cold" TME into a "hot" one, thereby improving sensitivity to immunotherapy.

Beyond the Scalpel: Advancing Strategic Approaches and Targeted Therapies in Nonexcisable Melanomas

Melanoma in challenging anatomical locations such as the face, acral surfaces, and mucosal areas presents unique hurdles for surgical excision. This review examines alternative nonsurgical treatment modalities in the context of these complexities, addressing the gaps in current guidelines and the varied efficacy of existing therapies. A comprehensive literature search was conducted using PubMed, Embase, and Web of Science databases. The review focuses on peer-reviewed articles discussing nonsurgical treatment options for melanoma in complex anatomical locations. Articles were screened by three independent researchers, ensuring a broad analysis of topical agents, immunotherapies, radiotherapies, and targeted therapies. The review highlights significant advancements in localized treatments such as imiquimod and intralesional therapy with talimogene laherparepvec (T-VEC), which show promise in managing nonexcisable melanomas. BRAF and MEK inhibitors, as well as checkpoint inhibitors targeting CTLA-4 and PD-1/PD-L1 pathways, demonstrate improved survival rates but pose challenges with resistance and systemic side effects. Radiotherapy serves as an adjunctive strategy due to melanoma's inherent radioresistant properties. Despite advancements, there is a notable absence of comprehensive, evidence-based protocols to guide the treatment of melanoma in these critical areas. This paper underscores the need for standardized treatment guidelines that account for the efficacy, side effects, and psychosocial impacts of therapies. Future research should focus on refining existing treatments and exploring innovative modalities to enhance patient outcomes in the management of nonexcisable melanomas. Comprehensive guidelines and long-term efficacy studies are essential to optimize care and improve the quality of life for patients afflicted with melanoma in challenging anatomical locations.

Advances in Immunomodulatory Mesoporous Silica Nanoparticles for Inflammatory and Cancer Therapies

In recent decades, immunotherapy has been considered a promising treatment approach. The modulatable enhancement or attenuation of the body's immune response can effectively suppress tumors. However, challenges persist in clinical applications due to the lack of precision in antigen presentation to immune cells, immune escape mechanisms, and immunotherapy-mediated side effects. As a potential delivery system for drugs and immunomodulators, mesoporous silica has attracted extensive attention recently. Mesoporous silica nanoparticles (MSNs) possess high porosity, a large specific surface area, excellent biocompatibility, and facile surface modifiability, making them suitable as multifunctional carriers in immunotherapy. This article summarizes the latest advancements in the application of MSNs as carriers in cancer immunotherapy, aiming to stimulate further exploration of the immunomodulatory mechanisms and the development of immunotherapeutics based on MSNs.

Nanomedicine-based cancer immunotherapy: a bibliometric analysis of research progress and prospects

Despite the increasing number of studies on nanomedicine-based cancer immunotherapy, the overall research trends in this field remain inadequately characterized. This study aims to evaluate the research trends and hotspots in nanomedicine-based cancer immunotherapy through a bibliometric analysis. As of March 31, 2024, relevant publications were retrieved from the Web of Science Core Collection. Analytical tools including VOSviewer, CiteSpace, and an online bibliometric analysis platform were employed. A total of 5,180 publications were analyzed. The study reveals geographical disparities in research output, with China and the United States being the leading contributors. Institutionally, the Chinese Academy of Sciences, University of Chinese Academy of Sciences, and Sichuan University are prominent contributors. Authorship analysis identifies key researchers, with Liu Zhuang being the most prolific author. "ACS Nano" and the "Journal of Controlled Release and Biomaterials" are identified as the leading journals in the field. Frequently occurring keywords include "cancer immunotherapy" and "drug delivery." Emerging frontiers in the field, such as "mRNA vaccine," "sonodynamic therapy," "oral squamous cell carcinoma," "STING pathway,"and "cGAS-STING pathway," are experiencing rapid growth. This study aims to provide new insights to advance scientific research and clinical applications in nanomedicine-based cancer immunotherapy.

Biomaterial-Based Sustained-Release Drug Formulations for Localized Cancer Immunotherapy

Cancer immunotherapy has revolutionized clinical cancer treatments by taking advantage of the immune system to selectively and effectively target and kill cancer cells. However, clinical cancer immunotherapy treatments often have limited efficacy and/or present severe adverse effects associated primarily with their systemic administration. Localized immunotherapy has emerged to overcome these limitations by directly targeting accessible tumors via local administration, reducing potential systemic drug distribution that hampers drug efficacy and safety. Sustained-release formulations can prolong drug activity at target sites, which maximizes the benefits of localized immunotherapy to increase the therapeutic window using smaller dosages than those used for systemic injection, avoiding complications of frequent dosing. The performance of sustained-release formulations for localized cancer immunotherapy has been validated preclinically using various implantable and injectable scaffold platforms. This review introduces the sustained-release formulations developed for localized cancer immunotherapy and highlights their biomaterial-based platforms for representative classes, including inorganic scaffolds, natural hydrogels, synthetic hydrogels, and microneedle patches. The design rationale and other considerations are summarized for further development of biomaterials for the construction of optimal sustained-release formulations.

Intradermal vaccination with a phytoglycogen nanoparticle and STING agonist induces cytotoxic T lymphocyte-mediated antitumor immunity

A critical aspect of cancer vaccine development is the formulation with effective adjuvants. This study evaluated whether combining a cationic plant-derived nanoparticle adjuvant (Nano-11) with the clinically tested STING agonist ADU-S100 (MIW815) could stimulate anticancer immunity by intradermal vaccination. Nano-11 combined with ADU-S100 (NanoST) synergistically activated antigen-presenting cells, facilitating protein antigen cross-presentation in vitro and in vivo. Intradermal vaccination using ovalbumin (OVA) as a tumor antigen and combined with Nano-11 or NanoST prevented the development of murine B16-OVA melanoma and E.G7-OVA lymphoma tumors. The antitumor immunity was abolished by CD8+ T cell depletion but not by CD4+ T cell depletion. Therapeutic vaccination with NanoST increased mouse survival by inhibiting B16-OVA tumor growth, and this effect was further enhanced by PD-1 checkpoint blockade. Our study provides a strong rationale for developing NanoST as an adjuvant for intradermal vaccination and next-generation preventative and therapeutic cancer vaccines by STING-targeted activation.

Oncolytic Tanapoxvirus Variants Expressing mIL-2 and mCCL-2 Regress Human Pancreatic Cancer Xenografts in Nude Mice

Pancreatic ductal adenocarcinoma (PDAC) is the fifth leading cause of cancer-related death and presents the lowest 5-year survival rate of any form of cancer in the US. Only 20% of PDAC patients are suitable for surgical resection and adjuvant chemotherapy, which remains the only curative treatment. Chemotherapeutic and gene therapy treatments are associated with adverse effects and lack specificity/efficacy. In this study, we assess the oncolytic potential of immuno-oncolytic tanapoxvirus (TPV) recombinants expressing mouse monocyte chemoattractant protein (mMCP-1 or mCCL2) and mouse interleukin (mIL)-2 in human pancreatic BxPc-3 cells using immunocompromised and CD-3+ T-cell-reconstituted mice. Intratumoral treatment with TPV/∆66R/mCCL2 and TPV/∆66R/mIL-2 resulted in a regression in BxPc-3 xenograft volume compared to control in immunocompromised mice; mCCL-2 expressing TPV OV resulted in a significant difference from control at p < 0.05. Histological analysis of immunocompromised mice treated with TPV/∆66R/mCCL2 or TPV/∆66R/mIL-2 demonstrated multiple biomarkers indicative of increased severity of chronic, active inflammation compared to controls. In conclusion, TPV recombinants expressing mCCL2 and mIL-2 demonstrated a therapeutic effect via regression in BxPc-3 tumor xenografts. Considering the enhanced oncolytic potency of TPV recombinants demonstrated against PDAC in this study, further investigation as an alternative or combination treatment option for human PDAC may be warranted.

Proliferating Cell Nuclear Antigen in the Era of Oncolytic Virotherapy

Proliferating cell nuclear antigen (PCNA) is a well-documented accessory protein of DNA repair and replication. It belongs to the sliding clamp family of proteins that encircle DNA and acts as a mobile docking platform for interacting proteins to mount and perform their metabolic tasks. PCNA presence is ubiquitous to all cells, and when located in the nucleus it plays a role in DNA replication and repair, cell cycle control and apoptosis in proliferating cells. It also plays a crucial role in the infectivity of some viruses, such as herpes simplex viruses (HSVs). However, more recently it has been found in the cytoplasm of immune cells such as neutrophils and macrophages where it has been shown to be involved in the development of a pro-inflammatory state. PCNA is also expressed on the surface of certain cancer cells and can play a role in preventing immune cells from killing tumours, as well as being associated with cancer virulence. Given the growing interest in oncolytic viruses (OVs) as a novel cancer therapeutic, this review considers the role of PCNA in healthy, cancerous, and immune cells to gain an understanding of how PCNA targeted therapy and oncolytic virotherapy may interact in the future.

Leveraging the intratumoral microbiota to treat human cancer: are engineered exosomes an effective strategy?

Cancer remains a leading cause of global mortality. The tumor microbiota has increasingly been recognized as a key regulator of cancer onset and progression, in addition to shaping tumor responses to immunotherapy. Microbes, including viruses, bacteria, fungi, and other eukaryotic species can impact the internal homeostasis and health of humans. Research focused on the gut microflora and the intratumoral microbiome has revolutionized the current understanding of how tumors grow, progress, and resist therapeutic interventions. Even with this research, however, there remains relatively little that is known with respect to the abundance of microbes and their effects on tumors and the tumor microenvironment. Engineered exosomes are a class of artificial extracellular nanovesicles that can actively transport small molecule drugs and nucleic acids, which have the broad prospects of tumor cell therapy. The present review offers an overview of recent progress and challenges associated with the intratumoral microbiome and engineered exosomes in the context of cancer research. These discussions are used to inform the construction of a novel framework for engineered exosome-mediated targeted drug delivery, taking advantage of intratumoral microbiota diversity as a strategic asset and thereby providing new opportunities to more effectively treat and manage cancer in the clinic.

Advancements in Melanoma Therapies: From Surgery to Immunotherapy

OPINION STATEMENT

Melanoma is defined as the most aggressive and deadly form of skin cancer. The treatment of melanoma depends on the disease stage, tumor location, and extent of its spread from its point of origin. Melanoma treatment has made significant advances, notably in the context of targeted and immunotherapies. Surgical resection is the main therapeutic option for earlystage melanoma, and it provides favourable outcomes. With disease metastasis, systemic treatments such as immunotherapy and targeted therapy become increasingly important. The identification of mutations that lead to melanoma has influenced treatment strategies. Targeted therapies focusing on these mutations offer improved response rates and fewer toxicities than conventional chemotherapy. Furthermore, developing immunotherapies, including checkpoint inhibitors and tumor-infiltrating lymphocyte (TIL) therapies, has demonstrated encouraging outcomes in effectively combating cancer cells. These therapeutic agents demonstrate superior effectiveness and a more tolerable side-effect profile, improving the quality of life for patients receiving treatment. The future of melanoma treatment may involve a multimodal approach consisting of a combination of surgery, targeted therapy, and immunotherapy adapted to each patient's profile. This approach may improve survival rates and health outcomes.

The Oncolytic virus VT1092M and an Anti-PD-L1 antibody synergize to induce systemic antitumor immunity in a murine bilateral tumor model

This study investigated the synergistic potential of an oncolytic herpes simplex virus armed with interleukin 12 (VT1092M) in combination with immune checkpoint inhibitors for enhancing antitumor responses. The potential of this combination treatment to induce systemic antitumor immunity was assessed using bilateral subcutaneous tumor and tumor re-challenge mouse models. The antitumor efficacy of various OV and ICI treatment combinations and the underlying mechanisms were explored through diverse analytical techniques, including flow cytometry and RNA sequencing. Using VT1092M, either alone or in combination with an anti-PD-L1 antibody, significantly reduced the sizes of both the injected and untreated abscopal tumors in a bilateral tumor mouse model. The combination therapy demonstrated superior antitumor efficacy to the other treatment conditions tested, which was accompanied by an increase in T cell numbers and CD8+T cell activation. Results from the survival and tumor re-challenge experiments showed that the combination therapy elicited long-term, tumor-specific immune responses, which were associated with tumor clearance and prolonged survival. Immune cell depletion assays identified CD8+T cells as the crucial mediators of systemic antitumor immunity during combination therapy. In conclusion, the combination of VT1092M and PD-L1 blockade emerged as a potent inducer of antitumor immune responses, surpassing the efficacy of each monotherapy. This synergistic approach holds promise for achieving robust and sustained antitumor immunity, with potential implications for preventing tumor metastasis in patients with cancer.

Oncolytic intralesional therapy for metastatic melanoma

In-transit metastasis (ITM) develop in approximately 1 in 10 patients with melanoma and the disease course can vary widely. Surgical resection is the gold-standard treatment; however, ITM are often surgically unresectable due to size, distribution, and/or anatomic involvement. Oncolytic viral therapies are one category of non-surgical treatment options available for ITM. They induce tumor cell lysis and systemic anti-tumor activity through selective infection of tumor cells by naturally occurring or genetically modified factors. While there are numerous oncolytic viral therapies in various stages of development for the treatment of ITM, this discussion focuses on the mechanism and available literature for the two most established herpes virus-based therapies.

Open-label, phase II study of talimogene laherparepvec plus pembrolizumab for the treatment of advanced melanoma that progressed on prior anti-PD-1 therapy: MASTERKEY-115

BACKGROUND

Treatment options for immunotherapy-refractory melanoma are an unmet need. The MASTERKEY-115 phase II, open-label, multicenter trial evaluated talimogene laherparepvec (T-VEC) plus pembrolizumab in advanced melanoma that progressed on prior programmed cell death protein-1 (PD-1) inhibitors.

METHODS

Cohorts 1 and 2 comprised patients (unresectable/metastatic melanoma) who had primary or acquired resistance, respectively, and disease progression within 12 weeks of their last anti-PD-1 dose. Cohorts 3 and 4 comprised patients (resectable disease) who underwent complete surgery, received adjuvant anti-PD-1, and experienced recurrence. Cohort 3 were disease-free for < 6 months and cohort 4 for ≥ 6 months after starting the adjuvant anti-PD-1 therapy and before confirmed recurrence. The primary endpoint was objective response rate (ORR) per RECIST v1.1. Secondary endpoints included complete response rate (CRR), disease control rate (DCR) and progression-free survival (PFS) per RECIST v1.1 and irRC-RECIST, and safety.

RESULTS

Of the 72 enrolled patients, 71 were treated. The ORR (95% CI) was 0%, 6.7% (0.2-32.0), 40.0% (16.3-67.7), and 46.7% (21.3-73.4) in cohorts 1-4, respectively; iORR was 3.8% (0.1-19.6), 6.7% (0.2-32.0), 53.3% (26.6-78.7), and 46.7% (21.3-73.4). iCRR was 0%, 0%, 13.3%, and 13.3%. Median iPFS (months) was 5.5, 8.2, not estimable [NE], and NE for cohorts 1-4, respectively; iDCR was 50.0%, 40.0%, 73.3%, and 86.7%. Treatment-related adverse events (TRAEs), grade ≥ 3 TRAEs, serious AEs, and fatal AEs occurred in 54 (76.1%), 9 (12.7%), 24 (33.8%), and 10 (14.1%) patients, respectively.

CONCLUSION

T-VEC-pembrolizumab demonstrated antitumor activity and tolerability in PD-1-refractory melanoma, specifically in patients with disease recurrence on or after adjuvant anti-PD-1.

TRIAL REGISTRATION

ClinicalTrials.gov identifier - NCT04068181.