Oncolytic virotherapy evolved into the fourth generation as tumor immunotherapy.

BACKGROUND: Oncolytic virotherapy (OVT) is a promising anti-tumor modality that utilizes oncolytic viruses (OVs) to preferentially attack cancers rather than normal tissues. With the understanding particularly in the characteristics of viruses and tumor cells, numerous innovative OVs have been engineered to conquer cancers, such as Talimogene Laherparepvec (T-VEC) and tasadenoturev (DNX-2401). However, the therapeutic safety and efficacy must be further optimized and balanced to ensure the superior safe and efficient OVT in clinics, and reasonable combination therapy strategies are also important challenges worthy to be explored. MAIN BODY: Here we provided a critical review of the development history and status of OVT, emphasizing the mechanisms of enhancing both safety and efficacy. We propose that oncolytic virotherapy has evolved into the fourth generation as tumor immunotherapy. Particularly, to arouse T cells by designing OVs expressing bi-specific T cell activator (BiTA) is a promising strategy of killing two birds with one stone. Amazing combination of therapeutic strategies of OVs and immune cells confers immense potential for managing cancers. Moreover, the attractive preclinical OVT addressed recently, and the OVT in clinical trials were systematically reviewed. CONCLUSION: OVs, which are advancing into clinical trials, are being envisioned as the frontier clinical anti-tumor agents coming soon.

Immunotherapy for keratinocyte cancers. Part II: Identification and management of cutaneous side effects of immunotherapy treatments.

Keratinocytic cancers (KCs), specifically cutaneous squamous cell and basal cell carcinomas, can respond to topical, intralesional, or systemic immunotherapies, but cutaneous adverse events (CAEs) may occur. Understanding these risks, early recognition of these CAEs, and effective treatment may enable patients to continue their anticancer immunotherapies without dose impact. Immune checkpoint inhibitor-related CAEs after KCs can have multiple clinical presentations, with specific observed types including psoriasis and bullous pemphigoid. Cutaneous toxicities can require biopsies to confirm the diagnosis, especially in patients who are not responsive to topical or oral steroids, since the selection of biologic drugs depends on accurate diagnosis. Different types of CAEs from immune checkpoint inhibitors have been associated with different oncologic outcomes in various primary cancer types, and this remains to be determined for KC patients. CAE characterization and management after immune checkpoint inhibitors in KC patients is a rapidly growing field that needs specific and prospective studies.

Role of Virus-Directed Therapy in Soft Tissue Sarcoma.

OPINION STATEMENT: Bone and soft tissue sarcoma are rare cancers of mesenchymal origin with the characteristics of heterogeneity and diversity that account for less than 1% of solid malignant cancers. Conventional chemotherapy remains standard of care with response rates of 10-15% that are usually dependent on histologic subtype as some subtypes are chemotherapy resistant. There remains a large unmet clinical need for new and novel options promoting the development of promising therapeutic options such as immunotherapy. With more than 80 different subtypes, the heterogeneity of sarcoma requires thoughtful clinical trial design. In the sarcoma field, recent breakthroughs have occurred in the context of histology-specific approach based on underlying tumor biology. To that end, immunotherapy approaches will need to take a similar approach. Oncolytic viruses (OVs) have emerged as a promising treatment for many solid tumors and shown encouraging results in sarcoma. This review mainly focuses on collective clinical data highlighting the role of OVs as immunotherapy being used in soft tissue sarcoma (STS) and bone sarcomas. Combining OVs with T cell-activating checkpoint inhibition, adoptive cell therapy or targeted therapies may yield increased potency, improve antitumor efficacy of oncolytic virotherapy, and offer a new prospect for the treatment of sarcoma.

False positive FDG uptake in melanoma patients treated with talimogene laherparepvec (T-VEC).

Talimogene laherparepvec (T-VEC) is a genetically modified herpes simplex virus-1-based oncolytic immunotherapy and has been approved for the local treatment of unresectable (stage IIIB/C and IVM1a) cutaneous melanoma. During T-VEC treatment, tumor response is often evaluated using [18F]2-fluoro-2-deoxy- d-glucose(FDG) positron emission tomography/computed tomography (PET/CT). In a Dutch cohort (n = 173), almost one-third of patients developed new-onset FDG uptake in uninjected locoregional lymph nodes during T-VEC. In 36 out of 53 (68%) patients with new nodal FDG uptake, nuclear medicine physicians classified this FDG uptake as "suspected metastases" without clinical or pathological confirmation in the majority of patients. These false positive results indicate that new-onset FDG uptake in locoregional lymph nodes during T-VEC treatment does not necessarily reflect progressive disease, but may be associated with immune infiltration. In current clinical practice, physicians should be aware of the high false positive rate of FDG uptake during treatment with T-VEC in patients with melanoma. Therefore, pathological examination of lymph node lesions with new FDG uptake is recommended to differentiate between progressive disease and immune infiltration after treatment with T-VEC.

Review of talimogene laherparepvec: A first-in-class oncolytic viral treatment of advanced melanoma.

Talimogene laherparepvec (T-VEC) is an oncolytic virus based on herpes simplex virus type 1 approved for intralesional treatment of advanced melanoma. In this article, we review the clinical literature on T-VEC for advanced melanoma and provide a practical approach to using T-VEC in the dermatologic surgery and oncology clinic. PubMed was used to conduct a systematic literature review of articles describing the structure, basic science, and clinical and therapeutic properties of T-VEC. The national clinical trials database was also searched for T-VEC clinical trials. Phase I to III clinical trials and early real-world experience have shown the efficacy of T-VEC in advanced melanoma as single or combination therapy with tolerable adverse effects. We conclude that with a standardized clinical approach and training, dermatologists can pave the way in using T-VEC and future oncolytic virus therapies in appropriate clinical scenarios.

Treatment Options for Advanced Melanoma After Anti-PD-1 Therapy.

PURPOSE OF REVIEW: While anti-PD-1 antibodies have been a breakthrough in the treatment of patients with advanced melanoma, a substantial proportion of patients are still refractory to or progress after treatment with anti-PD-1 immunotherapy. Here, we review the post anti-PD-1 therapy alternatives that may be possible for patients with unresectable or metastatic stage 3 or 4 melanoma. RECENT FINDINGS: Currently available treatment options include BRAF-targeted and MEK inhibitor-targeted therapies for those with BRAFV600 mutant melanoma, while for patients with BRAF-WT melanoma or those who have already received prior BRAF-targeted therapy, options include anti-CTLA-4 therapy, alone or in combination with anti-PD-1 therapy, or for selected patients, clinical trials that may incorporate other immune checkpoint inhibitors or co-stimulatory agonists, oncolytic virotherapies, adoptive cellular therapies, or other novel agents. Participation in clinical trials is critical in order to delineate what more effective treatment options are and which group of patients after receiving prior anti-PD-1 therapy.

Real-world use of talimogene laherparepvec in Germany: a retrospective observational study using a prescription database.

Aim: There is a growing body of data on real-world use of talimogene laherparepvec (T-VEC). We aimed to characterize real-world T-VEC use using a nationally representative German prescription database covering 60% of prescriptions reimbursed. Patients & methods: A retrospective analysis was conducted using the German IMS® LRx prescription database, analyzing patients aged ≥18 years with an initial T-VEC prescription at 106 plaque-forming units (PFU)/ml and ≥1 subsequent prescription at 108 PFU/ml. Median time on T-VEC treatment, patient characteristics and patterns of T-VEC use were described. Results: Of 127 patients prescribed T-VEC, 72 patients (57%) met study criteria. About two-thirds of these patients initiated T-VEC in 2017. Median age at T-VEC initiation was 74 years (range: 44 to 91). Most prescriptions (88%) were dispensed from hospitals. At study end, 26 (36%) patients remained on T-VEC; 46 (64%) had ended treatment. Median duration of T-VEC treatment for all patients was 18.7 weeks (95% CI: 15.3-26.9) and was longer among those who initiated treatment in 2017 versus 2016 (26.7 vs 15.6 weeks, respectively). Median volume administered for the first 106 PFU/ml and second 108 PFU/ml was 4 ml; the volume decreased for subsequent administrations (2 ml by the eighth administration and 1 ml by the 16th administration). Conclusion: This real-world prescription database study showed that patients who initiated treatment in 2017 had a treatment duration in clinical practice that corresponded with the European Summary of Product Characteristics guideline of continuing T-VEC for ≥6 months. Additional long-term data linking drug use with clinical outcomes are needed.

Overcoming Immune Evasion in Melanoma.

Melanoma is the most aggressive and dangerous form of skin cancer that develops from transformed melanocytes. It is crucial to identify melanoma at its early stages, in situ, as it is "curable" at this stage. However, after metastasis, it is difficult to treat and the five-year survival is only 25%. In recent years, a better understanding of the etiology of melanoma and its progression has made it possible for the development of targeted therapeutics, such as vemurafenib and immunotherapies, to treat advanced melanomas. In this review, we focus on the molecular mechanisms that mediate melanoma development and progression, with a special focus on the immune evasion strategies utilized by melanomas, to evade host immune surveillances. The proposed mechanism of action and the roles of immunotherapeutic agents, ipilimumab, nivolumab, pembrolizumab, and atezolizumab, adoptive T- cell therapy plus T-VEC in the treatment of advanced melanoma are discussed. In this review, we implore that a better understanding of the steps that mediate melanoma onset and progression, immune evasion strategies exploited by these tumor cells, and the identification of biomarkers to predict treatment response are critical in the design of improved strategies to improve clinical outcomes for patients with this deadly disease.

High response rates for T-VEC in early metastatic melanoma (stage IIIB/C-IVM1a).

Talimogene laherparepvec (T-VEC) is a modified herpes simplex virus, type 1 (HSV-1), which can be administered intralesionally in patients with stage IIIB/C-IVM1a unresectable melanoma (EMA label). The phase 3 OPTiM registration study showed an overall response rate (ORR) of 26%. Since December 2016, 48 eligible patients started treatment at the Netherlands Cancer Institute. We included 26 patients in this study with a follow up time ≥6 months, reporting Overall Response Rate (ORR), Disease Control Rate (DCR), Adverse Events (AE), prior treatment for melanoma and baseline characteristics, documented in a prospectively maintained database. In house developed treatment protocol consists of clinical evaluation, periodic PET-CT and histological biopsies for response evaluation. Median follow-up was 12.5 months. Of 26 patients, 16 (61.5%) had a Complete Response (CR) as their best response. Seven (26.9%) patients had a Partial Response (PR) as their best response, 1 (3.8%) patient Stable Disease (SD) and 2 (7.7%) patients Progressive Disease (PD). Best ORR was 88.5%. DCR was 92.3%. Grade 1-2 AEs occurred in all patients. Mostly, these consisted of fatigue, influenza-like symptoms and injection site erythema. All patients underwent prior treatment. Prior treatment did not influence response or toxicity of T-VEC. Best ORR for T-VEC monotherapy at our institute was 88.5% with 61.5% achieving a CR. This prospective study for T-VEC in early metastatic (stage IIIB/C-IVM1a) melanoma demonstrated superior results to the phase 3 OPTiM study and confirms the role of oncolytic immunotherapy for melanoma.

Oncolytic virus therapy in Japan: progress in clinical trials and future perspectives.

Oncolytic virus therapy is a promising new option for cancer. It utilizes genetically engineered or naturally occurring viruses that selectively replicate in and kill cancer cells without harming normal cells. T-VEC (talimogene laherparepvec), a second-generation oncolytic herpes simplex virus type 1, was approved by the US Food and Drug Administration for the treatment of inoperable melanoma in 2015 and subsequently approved in Europe in 2016. Other oncolytic viruses using different parental viruses have also been tested in Phase III clinical trials and are ready for drug approval: Pexa-Vec (pexastimogene devacirepvec), an oncolytic vaccinia virus, CG0070, an oncolytic adenovirus, and REOLYSIN (pelareorep), an oncolytic reovirus. In Japan, as of May 2018, several oncolytic viruses have been developed, and some have already proceeded to clinical trials. In this review, we summarize clinical trials assessing oncolytic virus therapy that were conducted or are currently ongoing in Japan, specifically, T-VEC, the abovementioned oncolytic herpes simplex virus type 1, G47Δ, a third-generation oncolytic herpes simplex virus type 1, HF10, a naturally attenuated oncolytic herpes simplex virus type 1, Telomelysin, an oncolytic adenovirus, Surv.m-CRA, another oncolytic adenovirus, and Sendai virus particle. In the near future, oncolytic virus therapy may become an important and major treatment option for cancer in Japan.

The Role of Oncolytic Viruses in the Treatment of Melanoma.

PURPOSE OF REVIEW: Oncolytic virotherapy is a new approach to the treatment of cancer and its success in the treatment of melanoma represents a breakthrough in cancer therapeutics. This paper provides a review of the current literature on the use of oncolytic viruses (OVs) in the treatment of melanoma. RECENT FINDINGS: Talimogene laherparepvec (T-VEC) is the first OV approved for the treatment of melanoma and presents new challenges as it enters the clinical setting. Several other OVs are at various stages of clinical and pre-clinical development for the treatment of melanoma. Reports from phase Ib-III clinical trials combining T-VEC with checkpoint blockade are encouraging and demonstrate potential added benefit of combination immunotherapy. OVs have recently emerged as a standard treatment option for patients with advanced melanoma. Several OVs and therapeutic combinations are in development. Immunooncolytic virotherapy combined with immune checkpoint inhibitors is promising for the treatment of advanced melanoma.

Oncolytic Virotherapy: A Contest between Apples and Oranges.

Viruses can be engineered or adapted for selective propagation in neoplastic tissues and further modified for therapeutic transgene expression to enhance their antitumor potency and druggability. Oncolytic viruses (OVs) can be administered locally or intravenously and spread to a variable degree at sites of tumor growth. OV-infected tumor cells die in situ, releasing viral and tumor antigens that are phagocytosed by macrophages, transported to regional lymph nodes, and presented to antigen-reactive T cells, which proliferate before dispersing to kill uninfected tumor cells at distant sites. Several OVs are showing clinical promise, and one of them, talimogene laherparepvec (T-VEC), was recently granted marketing approval for intratumoral therapy of nonresectable metastatic melanoma. T-VEC also appears to substantially enhance clinical responsiveness to checkpoint inhibitor antibody therapy. Here, we examine the T-VEC paradigm and review some of the approaches currently being pursued to develop the next generation of OVs for both local and systemic administration, as well as for use in combination with other immunomodulatory agents.

Oncolytic Virotherapy by HSV.

Oncolytic virotherapy is a kind of antitumor therapy using viruses with natural or engineered tumor-selective replication to intentionally infect and kill tumor cells. An early clinical trial has been performed in the 1950s using wild-type and non-engineered in vitro-passaged virus strains and vaccine strains (first generation oncolytic viruses). Because of the advances in biotechnology and virology, the field of virotherapy has rapidly evolved over the past two decades and innovative recombinant selectivity-enhanced viruses (second generation oncolytic viruses). Nowadays, therapeutic transgene-delivering "armed" oncolytic viruses (third generation oncolytic viruses) have been engineered using many kinds of viruses. In this chapter, the history, mechanisms, rationality, and advantages of oncolytic virotherapy by herpes simplex virus (HSV) are mentioned. Past and ongoing clinical trials by oncolytic HSVs (G207, HSV1716, NV1020, HF10, Talimogene laherparepvec (T-VEC, OncoVEXGM-CSF)) are also summarized. Finally, the way of enhancement of oncolytic virotherapy by gene modification or combination therapy with radiation, chemotherapy, or immune checkpoint inhibitors are discussed.

Talimogene Laherparepvec: An Oncolytic Virus Therapy for Melanoma.

OBJECTIVE: To review the efficacy and safety of talimogene laherparepvec (T-VEC) as well as its pharmacology, pharmacokinetics, drug-drug interactions, handling procedures, cost considerations, and place in therapy. DATA SOURCES: Searches of PubMed (1966 to February 2017) and Cochrane Library (1999 to February 2017) were conducted using the terms talimogene laherparepvec, T-VEC, OncoVEX, immunotherapy, melanoma, and oncolytic virus. Additional information was determined from bibliographies, manufacturer product labeling and website, meeting abstracts, Food and Drug Administration website, and clinicaltrials.gov. STUDY SELECTION AND DATA EXTRACTION: A total of 79 English-language publications were identified. Articles that assessed T-VEC's pharmacokinetics, pharmacodynamics, mechanism, dosing, safety, and efficacy were included as well as narrative reviews that provided practical information. DATA SYNTHESIS: Clinical trials have confirmed the safety and efficacy of T-VEC as monotherapy for the treatment of advanced melanoma, with an overall response rate (ORR) of 26%. Relative to granulocyte-macrophage colony-stimulating factor, T-VEC significantly increased durable response rate (DRR; 16.3% vs 2.1%, P < 0.001); however, median overall survival was not improved (23.3 vs 18.9 months, P = 0.051). Phase 1b trials have combined T-VEC and immunotherapies with promising results. T-VEC's adverse effects are generally considered mild to moderate in severity. CONCLUSION: T-VEC is the first approved oncolytic virus for local treatment of unresectable cutaneous, subcutaneous, and nodal lesions in melanoma recurrent after initial surgery. T-VEC improves ORR and DRR as a single agent, shows promise in combination therapy, and is well tolerated. Ongoing trials will determine if T-VEC has a role in early treatment or in combination therapy for melanoma or other malignancies.

The application of self-assembled nanostructures in peptide-based subunit vaccine development.

Peptide based-vaccines are becoming one of the most widely investigated prophylactic and therapeutic health care interventions against a variety of diseases, including cancer. However, the lack of a safe and highly efficient adjuvant (immune stimulant) is regarded as the biggest obstacle to vaccine development. The incorporation of a peptide antigen in a nanostructure-based delivery system was recently shown to overcome this obstacle. Nanostructures are often formed from antigens conjugated to molecules such as polymers, lipids, and peptide, with the help of self-assembly phenomenon. This review describes the application of self-assembly process for the production of peptide-based vaccine candidates and the ability of these nanostructures to stimulate humoral and cellular immune responses.

[Malignant melanoma : Current status]. / Malignes Melanom : Aktueller Stand.

CLINICAL ISSUE: The incidence of malignant melanoma is continuously increasing. The prognosis of metastatic disease is still limited. STANDARD TREATMENT: Until a few years ago palliative chemotherapy with a limited response rate was the standard treatment for metastatic melanoma. TREATMENT INNOVATIONS: Immunotherapy and targeted therapy provide new treatment options. Immune checkpoint inhibitors have significantly improved the prognosis. DIAGNOSTIC WORK-UP: Regional lymph node sonography, computed tomography (CT) of the neck, chest and abdomen and brain magnetic resonance imaging (MRI) are routinely used. As an alternative to CT scans 18 F fluorodeoxyglucose positron emission tomography (FDG-PET) may be used. PERFORMANCE AND ACHIEVEMENTS: Immunotherapy provides the chance of long-term disease control in metastatic melanoma. Ipilimumab may provide long-term tumor control in approximately 20% of patients. Median overall survival of approximately 2 years is achieved during therapy with anti-programmed cell death (PD) 1 antibodies. For combined therapy of ipilimumab and nivolumab a response rate of almost 60% is achieved and 2­year survival is also approximately 60%. The range of immune-mediated side effects demands particular consideration. For response evaluation immune-related response criteria were defined. Furthermore, immunotherapeutic approaches, such as talimogene laherparepvec (T-VEC), which is a modified herpes virus can be used for intralesional injection. PRACTICAL RECOMMENDATIONS: An individual definition of the appropriate therapy for each patient is of particular importance. In the context of modern therapy regimens close patient monitoring is crucial.

Local intralesional talimogene laherparepvec therapy with complete local response in oral palatine mucosal melanoma: a case report.

BACKGROUND: Mucosal melanoma, an aggressive type of malignancy different from the cutaneous melanomas commonly seen in the head and neck region, represents < 1% of all malignant melanomas. The pathogenesis of mucosal melanoma is unknown. Targetable mutations commonly seen in cutaneous melanoma, such as in the BRAF and NRAS genes, have a lower incidence in mucosal melanoma. Mucosal melanoma carries a distinct mutational pattern from cutaneous melanoma. Surgery with negative margins is the first-line treatment for mucosal melanoma, and systemic therapy is not well defined. Talimogene laherparepvec, an oncolytic viral immunotherapy, is United States Food and Drug Administration approved for the treatment of advanced malignant cutaneous melanoma, with local therapeutic benefits. Mucosal melanoma was initially excluded from talimogene laherparepvec's initial phase III clinical trial. CASE PRESENTATION: We present the case of a white female patient in her 40s with past medical history of systemic lupus erythematous, scleroderma, and estrogen-receptor-positive invasive ductal breast carcinoma. Following a bilateral mastectomy, the patient was found to have BRAF-negative mucosal melanoma of her hard palate with a soft palate skip lesion. Owing to the presence of a skip mucosal lesion as well as the anticipated defect and need for free-flap reconstructive surgery, nonsurgical management was considered. The patient was referred to medical oncology, where-based on the patient's complicated medical history and the risk of immunotherapy possibly worsening her prior autoimmune diseases-local talimogene laherparepvec injections were chosen as the primary therapy for her mucosal lesions. Though talimogene laherparepvec is approved for the treatment of cutaneous melanoma, there are limited data available on the use of talimogene laherparepvec in mucosal melanomas. CONCLUSION: The patient had a complete local tumor response at both the primary lesion as well as the skip lesion with the local injections. She had no side effects and maintained a high quality of life during treatment.

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.

Corrigendum: Myelomodulatory treatments augment the therapeutic benefit of oncolytic viroimmunotherapy in murine models of malignant peripheral nerve sheath tumors.

[This corrects the article DOI: 10.3389/fimmu.2024.1384623.].

Where Are We Now with Oncolytic Viruses in Melanoma and Nonmelanoma Skin Malignancies?

Skin cancer prognosis has greatly improved recently due to the introduction of immune checkpoint inhibitors (ICIs). However, many patients with advanced skin cancer still experience immunotherapy resistance and disease progression during ICI treatment, thus calling for novel therapeutics which address this treatment gap. Talimogene laherparepvec (T-VEC) has gained popularity in recent years as a viable treatment option for patients with skin cancer. In preclinical studies, T-VEC demonstrated both a direct anti-tumor effect in injected lesions as well as a systemic immune-mediated effect in non-injected lesions, which could pose additional benefits when combined with ICI therapy. Following promising results from the OPTiM trial, the Food and Drug Administration (FDA) approved the usage of T-VEC as a single agent in advanced melanoma. However, the MASTERKEY-265 trial demonstrated that adding T-VEC to pembrolizumab did not offer additional clinical benefit in patients with melanoma. Nevertheless, the promising efficacy of T-VEC and its approval by the FDA helped oncolytic viruses (OVs) gain wide attention in cancer therapy, and extensive research has been undertaken to evaluate the usage of OVs in other tumors such as sarcomas and breast cancers. Here, we provide a review of clinical results from 2022 to 2024 that investigate the efficacy and safety of OVs as a monotherapy or in combination with other therapies in skin malignancies. Furthermore, we delineate the current limitations in OV utilization and outline future directions to enhance clinical outcomes for patients with skin malignancies receiving OV-based therapies.