Modern approaches to treating cancer with oncolytic viruses Текст научной статьи по специальности «Клиническая медицина»

MIR ournal

Microbiology Independent Research Journal

DOI: 10.18527/2500-2236-2022-9-1-91-112 REVIEW

Modern approaches to treating cancer with oncolytic viruses

Irina V. Vorobjeva1 , Oleg P. Zhirnov12

1 The N. F. Gamaleya National Research Center for Epidemiology and Microbiology, D. I. Ivanovsky Institute of Virology, 18 Gamaleya St., Moscow, 123098 Russia

2 The Russian-German Academy of Medical and Biotechnological Sciences, 7 Nobel st., Skolkovo Innovation Center, Moscow, 121205 Russia

ABSTRACT

According to the World Health Organization, cancer is the second leading cause of death in the world. This serves as a powerful incentive to search for new effective cancer treatments. The development of new oncolytic viruses that are capable of destroying cancer cells selectively is one of the modern approaches to cancer treatment. The advantage of this method - selective lysis of tumor cells with the help of viruses - leads to an increase in the antitumor immune response of the body, which, in turn, promotes the destruction of the primary tumor and its metastases. Significant progress in the development of this method has been achieved in the last decade. In this review, we analyze the literature data on the oncolytic viruses that have demonstrated a positive therapeutic effect against malignant neoplasms in various localizations. We discuss the main mechanisms of the oncolytic activity of viruses and assess their advantages over other methods of cancer therapy as well as the prospects for their use in clinical practice.

Keywords: oncolytic viruses, oncolytic virotherapy, antitumor therapy, malignant neoplasms, cancer Received: October 5, 2021 Accepted: September 5, 2022 Published: December 30, 2022

For correspondence: Irina Vorobjeva, PhD, N. F. Gamaleya National Research Center for Epidemiology and Microbiology, D. I. Ivanovsky Research Institute of Virology, 18 Gamaleya St., Moscow, 123098 Russia; e-mail: vorobjeva@inbox.ru Citation: Vorobjeva IV, Zhirnov OP. Modern approaches to treating cancer with oncolytic viruses. MIR J 2022; 9(1), 91-112. doi: 10.18527/2500-2236-2022-9-1-91-112.

Copyright: © 2022 Vorobjeva et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License (CC BYNC-SA), which permits unrestricted use, distribution, and reproduction in any medium, as long as the material is not used for commercial purposes, provided that the original author and source are cited. Conflict of interest: Authors have no commercial or financial interests.

msm

INTRODUCTION

Cancer is the second leading cause of death worldwide. According to the World Health Organization (WHO), 9.9 million deaths from cancer were registered worldwide in 2020 [1]. In the same year, 556,036 cases of oncological diseases were detected in Russia as reported by the State Cancer Registry. According to the statistics, the most common localizations in the overall cancer incidence in Russia are the mammary gland (11.8%), skin (10.9%), trachea, bronchi, lung (9.8%), colon (7.2%), prostate gland (7.9%), stomach (5.8%), rectum, rectosigmoid junction (5.1%), lymphatic and hematopoietic systems (5%), uterine body (4.3%), kidney (3.8%), pancreas (3.4%), cervix (2.8%), urinary bladder (2.8%), and ovary (2.4%) [2].

Until recently, the main methods of cancer treatment have been chemotherapy and radiation therapy, which have serious side effects. Cancer drug therapy is less painful and can be the preferred treatment in many cases. However, many tumors are resistant to the standard treatments, which leads to relapses of disease over time. One of the new approaches for cancer treatment is oncolytic virotherapy, which is actively developing in the last decade. The most difficult problem in oncolytic virotherapy is the choice of a virus that can infect a tumor, destroy it, and induce an immune response to tumor cells. Antitumor efficacy in animal experiments has been shown for many viral families, which has led to the

initiation of clinical trials for the treatment of various forms of cancer.

Oncolytic virotherapy has a long history. Back in 1904, George Dock described a clinical case with a sharp decrease in the number of leukocytes in a patient with leukemia after an influenza infection [3]. In the same year, the Italian physician Nicola De Pace described the disappearance of a malignant tumor of the cervix in a patient after immunization with a live rabies vaccine due to a dog bite. Immunization of several similarly diagnosed patients with attenuated rabies vaccine led to a decrease in the tumor size, but later the disease recurred with a lethal outcome in all patients [4]. In 1940, Pack conducted the first clinical trial using a rabies vaccine to treat melanoma which caused partial remission [5]. In the 1960s, a study by Lindenmann and Klein showed that immunization of mice with a homogenate of tumor cells infected with the influenza virus led to a humoral immune response against the antigens associated with tumor cells [6, 7].

Wild-type viral strains that are non-pathogenic or low pathogenic for humans can serve as oncolytic viruses without genetic modifications (for example, reovirus) [8]. In addition, genetically modified viruses with a decreased pathogenicity and increased therapeutic effect are designed [9, 10]. The development of recombinant DNA technologies has created new possibilities to obtain a wide range of chimeric (recombinant) viruses with modifications aimed at destroying cancer cells. The first of such studies was published in 1991 and described a genetically modified herpes simplex virus type 1 (HSV1, dl-sptk) with a reduced neurovirulence due to the removal of the j34.5 gene that encodes thymidine kinase (HSV-TK) [11]. The modification of the viral genome reduced the reproduction of the virus in normal cells while retaining normal reproduction in tumor cells containing an increased concentration of TK [12]. The dependence of the TK-defective virus on the level of this enzyme in the cell allowed for using the modified virus for the treatment of glioma in mice, subsequently leading to tumor regression.

To date, nine viral families with oncolytic potential have been described, namely: Rhabdoviridae, Poxviridae, Herpesviridae, Reoviridae, Adenoviridae, Paramyxoviridae, Picornaviridae, Togaviridae, and Parvoviridae. The representatives of these families have shown a positive therapeutic effect in the treatment of malignant neoplasms of various origins and localizations. Several oncolytics have been developed and approved for use in clinical practice, including a genetically modified enterovirus ECHO-7 (Latvia) named RIGVIR® which has oncolytic and immu-nomodulatory properties and is adapted to melanoma [13]. In 2003, the China Food and Drug Administration (CFDA) approved a new medication Gendicine® based on

the adenoviral (Ad) vector with E1-deletion for the treatment of head and neck cancer. However, the replication-deficient oncolytic virus had low transfection efficiency for cancer cells. Nevertheless, Gendicine® is a commercially available medication that is used in clinical practice. The investigation of this drug for the treatment of lung cancer, liver cancer, gynecological malignancies, and soft tissue sarcomas is still ongoing [14]. The onco-lytic based on a genetically modified adenovirus H101, named Oncorine®, was approved in China in 2005 for the treatment of malignant head and neck tumors originating from squamous epithelial cells [15]. The FDA and the European Medicines Agency (EMA) have approved the HSV1-based anticancer oncolytic Talimogene la-herparepvec (T-VEC®) for the treatment of inoperable dermal, subcutaneous, and nodular lesions in patients with melanoma recurrence after surgical removal of the primary tumor [16, 17]. This virus is modified for selective growth in tumor cells and expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) that has immunostimulatory activity.

Thus, oncolytic viruses are promising antitumor agents that can be used both for independent therapy of malignant neoplasms and for treatment in combination with surgical methods, chemotherapy, radiation therapy, or immunotherapy.

Main mechanisms of action of the oncolytic viruses

According to the current classification, eight main hallmarks distinguish tumor cells from healthy ones, which include: maintenance of proliferative signaling, evasion of growth suppressors, resistance to cell death, enabling replicative immortality, induction of angiogenesis, activation of invasion and metastasis, reprogramming of energy metabolism and evasion of immune destruction [18, 19]. The possibility to direct viruses to various cellular targets determines the strategy for choosing a virus for the treatment of human cancer.

The effectiveness of oncolysis depends primarily on the ability of viruses to infect and destroy cancer cells selectively. Some wild-type viruses such as vesicular stomatitis virus (VSV), HSV, Newcastle disease virus (NDV), and reovirus predominantly infect tumor cells, reproduce using the cell's replication machinery [20-23], and cause cancer cell death by apoptosis, necrosis, or autophagy [24-27]. Other viruses, such as adenovirus, require modification of the viral genome to limit replication in normal cells. This mechanism is called targeting. Thus, the p53 protein - a transcription factor that blocks the cell cycle and induces apoptosis - is not functional in most tumor cells due to direct mutations in the p53 or in proteins that

control its activity or stability like p14ARF and Mdm2 [28, 29]. The early adenovirus gene E1B encodes the E1B 55K protein, which binds to p53 and protects the infected cell from premature death. Therefore, the adenovirus with the non-functional E1B 55K protein replicates in tumor cells, whereas in normal cells its replication is abortive [30-33]. Other DNA viruses, such as SV40 or human papilloma virus 16 (HPV16), are also able to deactivate the p53 protein [29].

Another example is the influenza A virus with the deletion in the gene encoding the nonstructural NS1 protein (delNS1) that promotes virus resistance to the host interferon (IFN) system. This modified virus is able to kill cancer cells carrying a defective P53 gene via an alternative p53-independent pathway [34, 35]. The ability of mammalian cells to secrete type I IFNs is an important innate immunity mechanism against viral infections. Tumor cells may have defects in the genes that are involved in the synthesis of IFNs, resulting in a decreased expression of these genes [36-40]. The absence of a functioning IFN system in cancer cells makes them more sensitive to infection with cytolytic viruses [35-38]. Thus, the delNS1 influenza virus has an increased cytolytic potential in cancer cells [39] and reduced reproductive activity in healthy cells with an active IFN system [40, 41]. Such influenza viruses can serve as directed killers of cancer cells. Similarly, the representative of another viral family HSV1 fights the host's IFN system with the ICP0 protein (expressed by the j34.5 gene). Deletion of this gene in the HSV1 genome enables active replication of the virus in cancer cells selectively, but not in healthy cells with an active IFN system [42].

The therapeutic effect of viruses is determined not only by the lysis of cancer cells but also by stimulation of antitumor immunity and elimination of immune suppression through pro-inflammatory activation of the tumor immune microenvironment (TIME) [43-49]. Cancer cells can escape the immune system by means of mutations in tumor antigens. By infecting tumor cells, oncolytic viruses trigger an inflammatory response that promotes the recognition of virus-infected cancer cells by host immune cells. This results in the induction of cytokines that activate the immune system, leading to the recruitment and activation of dendritic cells (DCs), stimulation of specific T lymphocytes, and activation of an effective antitumor response. During apoptosis and/or necrosis, damage-associated molecular patterns (DAMPs) are released [50]. They are recognized by the antigen-presenting T cells in the tumor microenvironment, which eventually leads to tumor death.

In order to enhance the cytolytic immune effect, oncolytic viruses are engineered to express additional

immunostimulatory factors. This phenomenon is known as arming. Cytokines, chemokines, costimulatory proteins, bispecific T cell activators (BiTE), or immune checkpoint blockers are used as transgenes. For example, the oncolytic virus JX-594 of the Poxviridae family is the modified smallpox vaccinia virus (VV) strain Wyeth, in which the gene encoding TK has been removed to reduce the virulence and limit the reproduction in normal cells, while the gene expressing the immunostimulatory GM-CSF protein and the lacZ reporter gene has been inserted in order to activate antigen-presenting cells [51-53]. Another example is adenovirus LOAd703 (serotype 5/35), an oncolytic virus for the treatment of patients with pancreatic cancer, that expresses the human CD40L (TMZ-CD40L) and 41BB (4-1BBL) ligands activating the CD40 and 4-1BB pathways [54]. This genetic combination enhances the Th1 immunity by increasing the production of cytokines and co-stimulatory molecules. Adenoviruses can generate cytotoxic proteins while replicating. For instance, the adenovirus death protein (ADP) synthesized in the late stage of infection causes cell lysis. During lysis, new virions that infect other tumor cells are released [55, 56]. The modified human adenovirus C serotype 5 (Ad5), which contains both ADP and a chimeric suicide gene or sodium-iodide symporter (NIS, a human reporter gene), was shown to selectively suppress the growth of prostate tumor cells [57-59]. Ad5 adenoviruses are widely used to create new oncolytic viruses. However, the disadvantage of Ad5 is its wide distribution in the human population and, as a result, the formation of immune resistance in up to 90% of the population [60, 61]. The pre-existing immunity to adenovirus may limit the infection of cancer cells with the corresponding oncolytic virus, as well as increase the viral toxicity to liver cells and the blood coagulation system [62, 64, 65]. It is necessary to increase the specificity of the oncolytic virus to the cancer cells to overcome the immune resistance to oncolytic virotherapy. For this purpose, special elements regulating the specific replication of the virus in the cancer cell are included in the viral genome, which reduces the overall viral toxicity and promotes a stronger immune response to the tumor [62, 64, 65]. Another approach to overcome the immune barrier is to use new, less common oncolytic adenoviruses of other serotypes for the genome construction, e.g., Ad26 or Ad24 [61, 63]. The possibility of using type B adenoviruses (Ad11p), to which the majority of the population is not immune, is also being studied [66].

In order to overcome the immune barrier, it is also possible to sequentially apply several oncolytic viruses that do not have cross-immunity. The sequential viro-therapy has an advantage due to the ability of cytolytic

viruses of various families to trigger different mechanisms of programmed death (apoptosis, pyroptosis, autophagic cell death, necroptosis, etc.) and inflammation of cancer cells [27]. This approach allows for creating a platform for a polyvalent effect focused on a deeper damage and eradication of the tumor and its metastases, affecting chemotherapy-resistant stem cancer cells as well. The diagram that illustrates the principle of sequential virotherapy using oncolytic viruses of various families is presented in Fig. 1.

Sequential virotherapy allows: (1) to avoid the immune reaction of the macroorganism that neutralizes the oncolytic virus; (2) to modify the virus and at the same time adjust the therapy, depending on the type and location of the tumor (or its metastases); (3) to selectively induce the death of cancer cells through the apoptotic and/ or necrotic pathway, depending on the properties of the oncolytic virus, and thereby affect the level of the inflammatory response in the tumor; (4) to develop specifically optimized sets of viruses for the treatment of tumors of various origins to achieve their complete eradication in the future. As a result, the complete eradication of both the primary tumor cells and their stem clones becomes possible.

In addition to the modifications of viruses known as targeting and arming, another modification of oncolytic viruses - shielding - is used to increase the virus spread. For example, if a patient is immune to an oncolytic virus, biodegradable synthetic polymers can be used to deliver the virus in order to prevent its neutralization. Currently, several polymers, e.g., a cationic polymer associated with polyethylene glycol (PEG), poly-(N-(2-hydroxypropyl) methacrylamide) (pHPMA) [67, 68], and a DNA aptamer, are being studied for this purpose [69].

The blood circulation in the tumor, which supports the growth and metastasis of cancer cells, can be damaged by oncolytic viruses. The formation of new blood vessels (angiogenesis) is controlled by chemical signals, such as vascular endothelial growth factor (VEGF) that binds to receptors on the surface of normal endothelial cells. This triggers signaling pathways in endothelial cells, which promote the formation and growth of new blood vessels. Angiogenesis inhibitors interact with VEGF, preventing its activation and formation of new blood vessels. Virus-induced suppression of angiogenesis in malignant tumors has been shown for adenovirus [70, 71], herpesvirus [72], VV [73], vesicular stomatitis virus (VSV) [74, 75], and measles virus [76, 77]. To increase the efficiency of virus penetration into the tumor vasculature, the viruses can be targeted to vascular endothelial cells. An example is the non-replicating adenovirus vector Ad5 with an E1 deletion modified with a mouse promoter (PPE-1-3X), Fas transgene, and tumor necrosis factor receptor 1 (TNFR1). This vector, named VB-111, showed an antitumor effect in clinical trials by infecting the angiogenic vasculature [70]. The antitumor effect has also been shown for the adenovirus FGF2-Ad-TK expressing HSV-TK, which targets fibroblast growth factor 2 (FGF2) [71]. In HSV1 oncolytic vectors, the j34.5 gene is deleted to reduce the neurovirulence, leading to efficient selective virus replication only in dividing cells [72]. Antiangiogenic HSV1 oncolytic vectors express angiogenesis inhibitors or target pro-angiogenic factors [78]. The modified VV (JX-594), which selectively targets the tumor vasculature by activation of the ras/MAPK signaling pathway, has been shown to cause the collapse of tumor vessels when administered intravenously [73]. The JX-594 virus, which expresses the hGM-CSF transgenes and p-galactosidase, replicates in

Fig. 1. The principle of sequential virotherapy based on consecutive exposure of cancer tumor to set of oncolytic viruses

the endothelial cells of the tumor vessels in mice when injected intravenously, causing tumor necrosis. Effective suppression of the tumor growth was also observed when the mutant VSV (VSVDelta51) was used in combination with the vascular disruptor agent ZD6126 [75].

One of the problems in treating cancer is its recurrence due to the presence of tumor cells that are resistant to the traditional treatment methods [79]. Regarding their properties, these cells have a lot in common with normal stem cells; therefore, they are called cancer stem cells (CSC) [80]. These cells can self-renew, they are plu-ripotent and can remain dormant without dividing for a long time [81]. CSC cells have been isolated from solid tumors in lungs, liver, head and neck, and pancreas as well as from melanoma and sarcoma [82]. However, CSC cells may be susceptible to infection with oncolytic viruses. For example, it was shown that the Zika virus of the Flaviviridae family infected glioblastoma stem cells

[83]. Additionally, the adenovirus expressing the protein responsible for autophagy - Beclin-1 - was shown to induce autophagy in both CSCs and normal cancer cells

[84].

A promising development in oncotherapy is the use of oncolytic viruses in combination with immunother-apy, which is carried out using monoclonal antibodies (mAb) that inhibit checkpoints serving as key regulators of the immune system. The first immunomodulator that showed a positive effect in the treatment of melanoma was the mAb ipilimumab - an inhibitor of cytotoxic T lymphocyte associated protein 4 (CTLA-4) that suppresses early activation and proliferation of T cells [85]. Pembrolizumab/nivolumab has been shown to suppress T-cells by inhibiting programmed cell death protein 1 (PD1) [86, 87]. The combination of HSV1-derived T-VEC with ipilimumab or pembrolizumab allowed for changing the antitumor immunity and enhancing the antitumor effect of T-VEC in the treatment of patients with brain melanoma metastases when traditional chemotherapeu-tic agents were ineffective [88, 89].

Thus, several advantages of the treatment of malignant neoplasms with oncolytic viruses in comparison to the existing types of therapy can be emphasized:

• Unlike chemotherapy and radiation therapy, onco-lytic viruses can selectively destroy tumor cells, including CSC, without targeting healthy cells due to local administration, higher selective targeting, and possible genetic modifications.

• If combined with oncolytic viruses, the effect of chemotherapy drugs can be enhanced [90, 91].

• It is possible to use attenuated viruses that can penetrate the blood-brain barrier for the targeted destruction of distant metastases.

• Oncolytic viruses can be adapted to the type of tumor and targeted by genetic modification, which opens up ample opportunity to create targeted anticancer treatment against tumors of various types and localizations.

• A directed change of the gene expression in cancer cells can be accomplished through the treatment of tumors with oncolytic viruses, which can eventually lead to tumor regression after the infection. For this purpose, genetic elements, or entire cellular genes, such as the pro-apoptotic p53 protein gene, the apoptin protein gene, cytokines encoding genes, and the tumor necrosis factor gene, or genes encoding other factors that affect proliferation and/or cause programmed death of cancer cells, are artificially integrated into the viral genome [92-97].

• Sequential application of a set of oncolytic viruses of different types - the sequential virotherapy -achieves a polyvalent effect enabling a deeper damage and eradication of the tumor and its metastases, as well as affecting the chemotherapy-resistant stem cancer cells.

Families of cytolytic viruses with oncolytic potential

The most studied viruses with oncolytic activity are adenoviruses and herpesviruses. Adenoviruses are known to have oncolytic activity against a large group of malignant tumors of diverse origin and different localization. To date, adenoviruses make up the largest group of viruses with oncolytic potential. They have also demonstrated a positive therapeutic effect on the largest number of malignant neoplasms of different nosologies. The oncolytic viruses from different viral families, their target tumors, and conducted clinical trials are presented in Table 1.

The largest number of developed oncolytic viruses are based on Ad5. The viral oncolytics ONYX-015, On-corine (H101), and DNX2401 are in different phases (Ph) of clinical trials involving patients with head and neck squamous cell carcinoma, glioma, and pancreatic ad-enocarcinoma. The successful results of intratumoral administration of Oncorine (H101) in a Ph3 clinical trial allowed this oncolytic to be licensed in China [105]. Its subsequent use in a clinical trial against malignant pleural effusion resulted in complete recovery in 38% of the patients [151]. The oncolytics ORCA-010 and GC0070 showed promising clinical results. The main disadvantage of these oncolytic viruses, which can reduce their effectiveness, is the high level of vector-specific neutralizing antibodies in patients. This issue could be resolved by using chimpanzee adenovirus vectors or viruses of other types, as well as by the antigen shielding.

Table 1. Malignant neoplasms as targets for oncolytic viruses

JS Viral oncolytic Tumor specificity Refe-

tu Strain Design rences

0NYX-015 Type 2/5, deletion of 827 bp in E1B gene, disrupting E1B 55K protein expression Recurrent squamous cell carcinoma of the head and neck (Ph2)! Adenocarcinoma of the pancreas (Phi) Metastatic solid tumors (Phi) Breast cancer Colorectal adenocarcinoma Hepatocellular carcinoma Melanoma Prostate cancer (Ph2) [98] [99] [100] [101] [102] [103] [104] [58]

Oncorine (H101) E1B deletion, E3 partial deletion Squamous cell carcinoma of the head and neck (Ph3) [105]

<u DNX-2401 Deletion of 24 bp in E1A, insertion of RGD-4C motif into the fiber protein Glioma (Phi) Glioblastoma (Phi) [106]

> o c VCN-01 Insertion of RGDK motif, human hyaluronidase PH 20 Pancreatic ductal adenocarcinoma Melanoma [107]

ONCOS-102 Deletion of 24 bp in E1A, insertion of RGD, GM-CSF, replacement of Ad5 knob domain by Ad3 knob domain Solid tumors (Phi) Mesothelioma Ovarian cancer [108] [109] [110]

ICOVIR-7, Deletion of 24 bp in E1A, insertion of RGD-4C, modification of the E2F promoter Solid tumors [111]

ICOVIR-5 Deletion of 24 bp in E1A, insertion of RGB, modification of the E2F promoter Melanoma (Phi) [112]

CG0070 Modification of E2F promoter, insertion of GM-CSF Bladder cancer (Phi, Ph2) [113]

Talimogene laherparepvec (T-VEC) ICP34.5, ICP47 deletion, GM-CSF insertion Melanoma, including melanoma with a mutation in the BRAF gene (licensed by FDA, EMA) Neuroendocrine tumors Breast cancer (Phi) Squamous cell carcinoma of the head and neck [114, 115] [116] [117] [118]

<u C HF-10 Lack of UL43, UL49.5, UL55, UL56, and LAT expression, overexpression of UL53, UL54 Squamous cell carcinoma of the head and neck (Phi, Ph2) Pancreas cancer (Phi) [119] [120] [183]

CU &■ G207 ICP34.5 deletion, replacement of ICP6 by LacZ Glioma (Phi) [121]

SEPREHVIR (HSV1716) ICP34.5 deletion Solid tumors (Phi) Neuroblastoma [122] [123]

M032 IL12 expression Glioma (Phi) [156]

G47A ICP34.5, ICP47 deletion, replacement of ICP6 by LacZ Prostate cancer [124]

<U C ';S 1 s ■ MV-CEA CEA insertion Ovarian cancer (Phi) Breast cancer Colorectal cancer Prostate cancer Hepatocellular carcinoma Mesothelioma Myeloma Glioma [125] [126] [126] [127] [128] [129] [130] [131]

MV-NIS NIS insertion Glioma [130] [131]

NDV V4UPM, MTH-68/H NDV thermostable vaccine strain for poultry Glioma [132] [160]

'Ph - clinical trial phase

JS Viral oncolytic Tumor specificity Refe-

tu Strain Design rences

<u C PVS-RIPO Live attenuated type 1 (Sabin) poliovirus vaccine strain, insertion of internal ribosomal entry site (IRES) of HRV2 Glioma [133]

E o u S¡ SVV-001 Seneca Valley Virus, isolate 001 Glioma Neuroendocrine tumors (retinoblastoma) Small cell lung carcinoma [134] [135]

<u Pexastimogene devacirepvec (Pexa Vec/ JX-594) J2R gene replaced by hGM-CSFand lacZ Colorectal cancer (Ph1) Hepatocellular adenocarcinoma (Ph1) Neuroblastoma (Ph1) Solid tumors (Ph1) [136] [137] [138] [139]

•is 1 GL-ONC1 Insertion of three cassettes (Renilla luciferase-Aequorea green fluorescent protein, p-galactosidase, and p-glucuronidase), deletion of A56R, F14.5 L, and J2R genes. Squamous cell carcinoma of the head and neck (Ph1) Peritoneal carcinomatosis (Ph1) [140] [141]

Reoviridae Pelareorep (Reolysin) Natural reovirus Pancreatic ductal adenocarcinoma (Ph2) Breast cancer (Ph2) Colorectal adenocarcinoma Squamous non-small cell lung cancer Melanoma (Ph2) [142] [143] [144] [145] [146]

Parvo-viridae H-1 PV H-1 protoparvovirus (H-1PV) Pancreatic ductal adenocarcinoma with peritoneal carcinomatosis [147]

<u ri MG1MA3 MAGE-A3 insertion Glioblastoma (Ph2) [148] [161]

vi dov -a « -s R VSV-IFNß Insertion of IFNp, NIS genes Myeloma Acute myeloid leukemia Squamous non-small cell lung cancer Endometrial cancer [148] [148] [149] [150]

The large size of the HSV1 genome (about 150x103 bp) opens considerable opportunities for genetic modification of the virus. Removal of the genes that are not essential for replication allows for the insertion of transgenes that provide oncolytic properties. The first oncolytic candidate - the T-VEC virus (Talimogene laherparepvec, commercial name Imlygic) - was officially approved by the FDA and EMA for the treatment of patients with inoperable melanoma. The T-VEC oncolytic was created on the basis of HSV1 virus with the deletion of the genes encoding the infected cell proteins (ICP) ICP34.5 and ICP47 and the insertion of two copies of the human protein hGM-CSF gene which increases the presentation of the tumor antigen by dendritic cells [152, 153]. As a result, cancer but not healthy cells are infected by the virus [114]. There are ongoing clinical trials (Phi) on the use of T-VEC alone or in combination with ipilimumab/pem-brolizumab for the treatment of patients with squamous cell carcinoma. Another viral oncolytic of the Herpesviri-dae family is the spontaneous HF-10 mutant, whose genome lacks the UL43, UL49.5, UL55, UL56, and LATgenes, which ensures active reproduction of the virus in cancer

cells [119, 120, 154]. Due to the enhanced induction of CD4+, CD8+, and NK cells, HF-10 effectively suppresses tumor growth, as it was demonstrated against melanoma, pancreatic adenocarcinoma, squamous cell carcinoma of the head and neck, and breast cancer on intratumoral and peritoneal administration [155]. The second generation of oncolytic viruses derived from HSV1 includes the M032 virus expressing interleukin 12 (IL12), which is being tested (Ph1) for the treatment of glioma [156]. G47A is the third-generation oncolytic virus with a deleted ICP47, unlike the G207 virus [124]. Currently, research is underway to create genetic variants of the herpes virus, and a wide range of targeted viral vectors has already been created. Thus, more than 20 viral strains, which are currently at different stages of clinical research, have been developed only for the treatment of glioblastoma tumors [157]. New candidates, such as ONCR-177, contain the genes expressing IL12, CCL4, and FLT3LC proteins and include anti-CTLA-4 and PD1 blocking sequences to increase NK and T cells activation and DC availability as well as to prevent depletion of T cells. Candidate C134, which contains the human cytomegalovirus IRS1 gene

in addition to the ICP34.5, was created to increase the activity of the oncolytic virus against glioma [i58]. The genome of another virus, RPi, was modified by adding the genes that encode GM-CSF, and gibbon ape leukemia virus fusogenic membrane protein GALV-GP/R. Further modification (virus RP2) was made to express anti-CT-LA-4 to enhance antitumor activity against squamous cell carcinoma [i59].

The vaccine strains of paramyxoviruses, picornavi-ruses, poxviruses, and adenoviruses are promising for the development of new oncolytic viruses. The viruses of these families (both vaccine strains and their wild-type precursors) are capable of replicating in malignant cells of neurogenic origins, which makes them promising candidates for the development of new oncolytic viruses for the treatment of brain tumors and cerebral metastases [i60, i6i]. It was shown that various genetically modified viruses based on the vaccine strains are active against a broad range of malignant neoplasms (Table i). A viral oncolytic from the Paramyxoviridae family (MV-CEA) has passed the clinical trials (Phi) involving patients with ovarian cancer.

An oncolytic from the Poxviridae family JX-594 (known as Pexa Vec) has successfully passed the clinical trials (Phi) involving patients with refractory metastatic colorectal cancer, hepatocellular adenocarcinoma, neu-roblastoma, and solid tumors. However, the clinical trials (Ph3) in patients with advanced hepatocellular carcinoma showed no clinical efficacy of this oncolytic and were discontinued. The clinical trials (Phi) of the viral onco-lytic of the Poxviridae family GL-ONCi in patients with head and neck squamous cell carcinoma and peritoneal carcinomatosis are ongoing.

Reoviruses infect tumor cells with the activated pro-oncogenic Ras-dependent signaling pathway, which provides selective inhibition of protein kinase R (PKR) phosphorylation, thus promoting virus reproduction [i62]. The oncolytic Reolysin® (later named Pelareorep), which showed activity against many malignant tumors, was developed based on the reovirus type 3. An important property of the reovirus is its ability to cross the blood-brain barrier and penetrate cells of both the primary tumor and metastases in the brain [i63, i64]. Reolysin® is in clinical trials (Ph2) in patients with pancreatic ductal adenocar-cinoma, breast cancer, and melanoma.

Influenza A viruses - vaccine strains or avian influenza viruses - are good candidates for the treatment of malignant tumors. In a pilot experiment, a positive therapeutic effect was shown for the virus with an altered gene encoding the NSi protein in a model of intradermal melanoma implants in mice, as well as against non-small-cell lung cancer in experiments in transgenic

immunocompetent mice [4i, i65]. By the i2th day after infection, the amount of tumor mass in the lungs of mice decreased by 70% compared with the uninfected animals [i65]. The defect in the viral NSi protein led to disruption of the cellular IFN response and promoted the activation of tumor cell apoptosis, which implied the increased pro-inflammatory and antitumor effect of the virus with the modified NS1 gene [27, 39].

VSV of the Rhabdoviridae family was shown to infect cells with a defective IFN signaling pathway, including cancer cells, subsequently causing their lysis by apopto-sis. The oncolytic viruses based on VSV were shown to be active against non-small-cell lung cancer, endometrial cancer, and leukemia (T-cell leukemia, acute myeloid leukemia) in experimental models [i48-i50]. The tumor specificity of viruses from the rhabdovirus and parvovirus families is shown in Table i.

Clinical trials of oncolytic viruses against various nosological forms of cancer

Most clinical studies of oncolytic viruses have been carried out against melanoma and malignant neoplasms of the gastrointestinal tract. As a rule, clinical trials are conducted in groups of patients with stage III and IV cancer as well as in patients with metastases and relapses of the disease. Melanoma (stages III and IV), glioma, and adenocarcinoma of the pancreas have a poor prognosis and lead to a high mortality rate in patients. Glioma and pancreatic adenocarcinoma are often diagnosed in the late stages of the disease when the standard methods of therapy are ineffective. Maximal progress in the use of viral oncolytics has been achieved against these nosolog-ical forms of cancer. This may explain the large number of conducted clinical trials [i66].

Melanoma treatment

Melanoma (melanocarcinoma, melanosarcoma) is a malignant tumor that develops from melanin-producing cells - melanocytes and melanoblasts. These tumors are localized mainly on the skin, less often on the retina and mucous membranes; they are often recurrent and quickly metastasize to distant organs through the lymphogenous and hematogenous pathways. Melanoma is characterized by a wide variety of histological structures and clinical manifestations. Surgical excision of melanoma can cure the tumor in the early stages of the disease but is ineffective for the treatment of metastatic melanoma. Melanoma responds poorly to radiation and chemotherapy. The dacarbazine treatment regimens used in clinical practice give an objective response rate (ORR - the proportion of the patients who have an objective response

(total response: complete + partial + stabilization)) only in 15% of cases and prolong remission by five years. For example, in metastatic melanoma without mutations in the BRAF gene, immune checkpoint inhibitors (ipilim-umab, pembrolizumab, and nivolumab) are used as the first-line therapy. The treatment with nivolumab and ipi-limumab results in an ORR of 18% [167]. The estimated five-year survival rate for patients with early melanoma is 98%, after the spread of melanoma to the lymph nodes -68%, and after metastasis to distant organs - 30%. The melanoma mortality rate is 15-20%. According to the American Cancer Society, the life expectancy of patients with stage III and IV metastatic melanoma is about four months without treatment, and 6-8 months after standard treatment (surgery, chemotherapy) [168].

The oncolytic Imlygic® (T-VEC) successfully passed three phases of clinical trials in patients with melanoma and was approved by the FDA and EMA for clinical use in 2015 [16]. Clinical trials were performed in a group of patients with stage III and IV metastatic melanoma (according to the Classification of Malignant Tumors, TNM and American Joint Committee on Cancer, AJCC; Table 2). The virus was injected into the tumor or subcutane-ously. Nine HSV seronegative patients with metastatic melanoma were involved in the Ph1 trial. A stable positive effect was observed in two cases [169]. The clinical trial (Ph2) was performed in a group of 50 patients with inoperable melanoma (stages iiic-iv). The observed ORR was 26% including eight patients with a complete response and five with a partial response. The overall survival rate (OSR), defined as the percentage of patients alive during a selected period after diagnosis, reached 58% in one year and 52% in two years [170]. The clinical trial (Ph3) was conducted in a group of 436 patients with melanoma (Illb-IV). The durable response rate (DRR) reached 16.3%. The median overall survival (mOS) - the length of time from the start of treatment or from the moment of diagnosis, that half of the group of the diagnosed patients remain alive - was 23.3 months [115]. Additionally, treatment with T-VEC was studied in combination with anti-CTLA-4 (ipilimumab) and anti-PD1 (pembrolizumab) monoclonal antibodies in patients with a progressive stage Illb and IV melanoma. In clinical trial (Ph1) in a group of eight patients using the combination of T-VEC therapy with ipilimumab, the ORR reached 50% and the OSR - 67% in 1.5 years [170]. The Ph2 trial included 198 patients and resulted in the ORR of 39% (the ORR of ipilimumab monotherapy is only 18%) [167]. The combination therapy in 21 patients using oncolytic T-VEC with pembrolizumab (Ph1) showed the ORR of 48% [171]. Thus, Imlygic® proved to be an effective oncolytic for the treatment of advanced melanoma, while its use

in combination with immunotherapy increased the total treatment efficiency.

Two phases of the clinical trials with the attenuated viral oncolytic HF-10 were completed in patients with melanoma. In a Ph2 study, 46 patients with stage IIIb-IV melanoma were treated with HF-10 and ipilimumab combination. The ORR reached 41%, and the mOS was 21.8 months (the ORR with ipilimumab monotherapy is only 18%) [172, 173]. Thus, HF-10 is a promising viral oncolytic for the treatment of melanoma, especially in combination with immunotherapy.

Two phases of the clinical trials with a reovirus-based oncolytic Pelareorep (Reolysin) were completed in patients with melanoma using intravenous administration. In the Ph2 clinical trial involving 21 patients, Reolysin monotherapy proved to be ineffective, since the onco-lytic induced the production of neutralizing anti-reo-virus antibodies (NARA) that may have limited the efficiency of viral replication and the oncolytic effect [174, 175]. The clinical study Ph2 (14 patients with advanced melanoma) with Reolysin/Carboplatin (Paclitaxel) combination therapy showed the ORR of 21%, while the mOS reached 5.2 months (Reolysin+Carboplatin) and 10.9 months (Reolysin+Paclitaxel). With Carboplatin or Pacli-taxel monotherapy in the other clinical trials, the mOS reached three and nine months respectively [176, 177]. Therefore, as it follows from the presented data, the use of reoviruses for the treatment of melanoma requires additional investigations.

The clinical trials with a recombinant Vaccinia-GM-CSF virus have been conducted in patients with metastatic melanoma. The virus replicated well in cancer cells, causing inflammatory lymphocytic infiltration and tumor necrosis

[178]. In the Ph1 trial (12 patients), the intratumoral administration of the oncolytic resulted in the 21% ORR and led to an increase in the T cell immune response to the melanoma-specific antigens (gp100 and MART-1) [178]. More studies are needed for the development of efficient VV-based oncolytics for the treatment of advanced melanoma.

Glioma treatment

Glioma is a brain tumor. The main treatment for gliomas is surgery combined with radiation and chemotherapy. There are a few clinical trials involving patients with gliomas due to the development of complications after surgical operations (changes in mental status, speech impairment, cerebral edema). The 10-year survival rate for a low-grade glioma is 47% and the mOS is 11.6 years

[179]. Due to the aggressive course of the disease, the mOS of patients with a grade III glioma is three years, and with a grade IV glioma - from 6 to 15 months [180].

The HSV-derived G207 oncolytic passed a Phi clinical trial (27 patients with glioblastoma), showing the mOS of 6.6 months (Table 3). With a combination of radiotherapy and G207 treatment, the mOS reached 7.5 months [181]. However, this effect is comparable to the results of the standard treatment regimens for glioma without the use of oncolytic viruses.

In a Phi trial (25 patients with recurrent malignant glioma), the Ad-based oncolytic DNX-2401 demonstrated the mOS of 36 months. At the same time, the tumor size decreased by 95% in three patients [106]. That exceeds the results of the standard treatment, although additional studies are required for a wider DNX-2401 application. Additionally, an oncolytic based on NDV (strain HUJ) showed the mOS of 7 months in a Ph1 study in 11 patients with recurrent glioblastoma, which corresponds to the results of the standard treatment [132].

Thus, the treatment of gliomas with viral oncolytics showed promising results and requires further confirmation in Ph2 and Ph3 studies.

Treatment of ductal adenocarcinoma of the pancreas

Ductal adenocarcinoma of the pancreas is a malignant neoplasm that is difficult to treat. The mortality from this type of cancer in Russia is 3.4% [2]. The main methods of treatment are surgical resection, radiation, and chemotherapy. The prognosis is poor since the disease is usually diagnosed at a late stage. Immunosuppressive factors such as T , M2 (tumor-associated macrophages), ILi0, and

transforming growth factor p (TGFp), accumulate in the tumor microenvironment, thus limiting the effectiveness of chemotherapy and immunotherapy for pancreatic cancer. The five-year survival rate of patients with this disease is 6% [i]. The clinical trials of ipilimumab and gemcitabine in patients with pancreatic ductal adenocarcinoma showed the ORR of i0.8% with the mOS of i0 months [i82].

Oncolytic viruses (herpesviruses and reoviruses) have shown an antitumor effect against pancreatic cancer (Table 4) [i20, i83]. According to the Ph2 trial in 34 patients with pancreatic ductal adenocarcinoma, the treatment with the viral oncolytic Reolysin leads to the mOS of i0.2 months [i42]. These results do not differ from the results of monoclonal antibody therapy. Reolysin may be considered a promising candidate for cancer treatment, although more studies are needed including clinical trials with a larger number of patients. Currently, there are ongoing Phi clinical trials of the oncolytic viruses ONYX0i5, T-VEC, and H-i0 in patients with pancreatic adenocarcinoma.

Thus, a number of viral oncolytics based on the herpes virus or adenovirus have successfully passed clinical trials and showed a positive therapeutic effect against inoperable melanoma and squamous cell carcinoma of the head and neck in the absence of pronounced side effects and general toxicity. One oncolytic virus can have a positive therapeutic effect on several histological forms of a tumor, and a stronger therapeutic effect can be achieved by combining viral oncolytics with immuno-therapy.

Table 2. Clinical trials of oncolytic viruses in melanoma patients

Oncolytic virus Clinical trial data

Phase of clinical trials, Ph Number of patients Tumor type, stage Administration route ORR (%), mOS (months)

T-VEC Ph1 9 Metastatic melanoma i.t. 2 patients with a stable positive effect

Ph2 50 Melanoma IIIc, IV i.t. 26%, i2 months

Ph3 436 Melanoma IIIb, IIIc, IV 295 patients, i.t. 141 patients, s.c. 26.4%, 23.3 months

HF10 (Canerpaturev-C-REV) Ph1 28 Metastatic melanoma i.t. 66.7%, 34.6 months

Ph2 (+ipilimumab) 46 Metastatic melanoma i.t. 4i%, 2i.8 months

Coxsackievirus A21 (CAVATAK) Ph2 57 Melanoma IIIc, IV i.t. 28%, 6 months

Pelareorep (Reolysin) Ph2 Ph2 (+carboplatin/ paclitaxel) 21 14 Metastatic melanoma i.v. 2i%, 5.2 /i0.9 months

Vaccinia GM-CSF (Pexa-VEC) Ph1 12 Melanoma IV i.t. 2i%

i.t. - intratumoral injection, i.v. - intravenous injection, s.c. - subcutaneous injection

Table 3. Clinical trials of oncolytic viruses in glioma patients

Oncolytic virus Clinical trial data

Phase of clinical trials, Ph Number of patients Tumor type, stage Administration route mOS (months)

HSV 1716 (Seprehvir) Phi 9 Malignant glioma i.t. 24 months

Ph2 No data Recurrent glioma in children i.t. No data

G207 Phia 21 Glioblastoma i.t. 6.6 months

Phib 6 Glioblastoma i.t. 6.6 months

ONYX015 Phi 24 Malignant glioma i.t. 6.2 months

DNX-2401 Phi 25 Recurrent malignant glioma i.t. 5 patients 36 months

Reolysin Phi 12 Recurrent malignant glioma, III, IV stages i.t. 1 patient 5 months 1 patient 54months

NDV Phi 11 Recurrent glioblastoma i.v. 7 months

i.t. - intratumoral injection, i.v. - intravenous injection

Table 4. Clinical trials of oncolytic viruses in pancreatic cancer patients

Oncolytic virus Clinical trials data

Phase of clinical trials, Ph Number of patients Tumor type, stage Administration route mOS (months)

ONYX0i5 Phi 23 Inoperable adenocarcinoma CT controlled injection No data

Ph2 (+gemcitabine therapy) 21 Progressive and metastatic adenocarcinoma i.v., endoscopic probe, gemcitabine therapy 6 patients, partial tumor regression

Hi0 Phi 8 Pancreatic adenocarcinoma i.t., through the catheter in the course of surgery 3 patients, partial tumor regression, 6 months

T-VEC Phi 17 Pancreatic adenocarcinoma No data No data

Reolysin Ph2 34 Pancreatic adenocarcinoma i.v. 10.2 months

i.t. - intratumoral injection, i.v. - intravenous injection

REFERENCES

1. Sung H, Siegel RL, Laversanne M, Soerjomataram I,

Jemal A, Bray F, Global Cancer Statistic 2020: GLOB-OCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021; 71(3), 209-49. doi: 10.3322/caac.21660.

2. Malignant neoplasms in Russia in 2020 (morbidity

and mortality). P. Hertsen Moscow Oncology Research Institute - the filial branch of the National Medical Research Radiological Centre (NMRRC), Ministry of Health of the Russian Federation, 2021. Kaprin AD, Starinsky VV, Shakhzadova AO (eds.) (In Russian).

3. Dock G. The Influence of Complicating Diseases upon

Leukaemia. Am J Med Sci 1904, 127, 563-92.

4. Altinoz MA, Guloksuz S, Elmaci I. Rabies virus vac-

cine as an immune adjuvant against cancers and glioblastoma: new studies may resurrect a neglected potential. Clin Transl Oncol 2017; 19(7), 785-92. doi: 10.1007/s12094-017-1613-6.

5. Pack GT. Note on the experimental use of ra-

bies vaccine for melanomatosis. AMA Arch Derm Syphilol 1950; 62(5), 694-5. doi: 10.1001/arch-derm.1950.01530180083015.

6. Lindenmann J, Klein PA. Immunity to Transplant-

able Tumors Following Viral Oncolysis.Ii. Antigenic Similarities between Three Unspecific Mouse Tumors. J Immunol 1965; 94, 461-6. PubMed PMID: 14279800.

7. Lindenmann J, Klein PA. Viral oncolysis: increased

immunogenicity of host cell antigen associated with influenza virus. J Exp Med 1967; 126(1), 93108. doi: 10.1084/jem.126.1.93.

8. Coffey MC, Strong JE, Forsyth PA, Lee PW. Reovi-

rus therapy of tumors with activated Ras pathway. Science 1998; 282(5392), 1332-4. doi: 10.1126/sci-ence.282.5392.1332.

9. Bell J, McFadden G. Viruses for tumor therapy. Cell

Host Microbe 2014; 15(3), 260-5. doi: 10.1016/j. chom.2014.01.002.

10. Bai Y, Hui P, Du X, Su X. Updates to the antitumor

mechanism of oncolytic virus. Thorac Cancer 2019; 10(5), 1031-5. doi: 10.1111/1759-7714.13043.

11. Martuza RL, Malick A, Markert JM, Ruffner KL, Coen DM.

Experimental therapy of human glioma by means of a genetically engineered virus mutant. Science 1991; 252(5007), 854-6. doi: 10.1126/science.1851332.

12. Hengstschlager M, Pfeilstocker M, Wawra E. Thy-

midine kinase expression. A marker for malignant cells. Adv Exp Med Biol 1998; 431, 455-60. PubMed PMID: 9598110.

13. DoninaS, Strele I, Proboka G, Auzins J, Alberts P, Jons-

son B et al. Adapted ECHO-7 virus Rigvir immunotherapy (oncolytic virotherapy) prolongs survival in melanoma patients after surgical excision of the tumour in a retrospective study. Melanoma Res 2015; 25(5), 421-6. doi: 10.1097/CMR.0000000000000180.

14. Yu Xia, Xiugin Li, Wei Sun. Applications of Recom-

binant Adenovirus p53 Gene Therapy for Cancers in the Clinic in China. Curr Gene Ther 2020; 20(2), 127-41. doi: 10.2174/1566523220999200731003206.

15. Frew SE, Sammut SM, Shore AF, Ramjist JK, Al-Bad-

er S, Rezaie R et al. Chinese health biotech and the billion-patient market. Nat Biotechnol 2008; 26(1), 37-53. doi: 10.1038/nbt0108-37.

16. Raman SS, Hecht JR, Chan E. Talimogene laher-

parepvec: review of its mechanism of action and clinical efficacy and safety. Immunotherapy 2019; 11(8), 705-23. doi: 10.2217/imt-2019-0033.

17. Greig SL. Talimogene Laherparepvec: First Global

Approval. Drugs 2016; 76(1), 147-54. doi: 10.1007/ s40265-015-0522-7.

18. Hanahan D, Weinberg RA. The hallmarks of can-

cer. Cell 2000; 100(1), 57-70. doi: 10.1016/s0092-8674(00)81683-9.

19. Hanahan D, Weinberg RA. Hallmarks of cancer: the

next generation. Cell 2011; 144(5), 646-74. doi: 10.1016/j.cell.2011.02.013.

20. Norman KL, Lee PW. Reovirus as a novel oncolyt-

ic agent. J Clin Invest 2000; 105(8), 1035-8. doi: 10.1172/JCI9871.

21. Stojdl DF, Lichty B, Knowles S, Marius R, Atkins H,

Sonenberg N et al. Exploiting tumor-specific defects in the interferon pathway with a previously unknown oncolytic virus. Nat Med 2000; 6(7), 82i-5. doi: i0.i038/77558.

22. Sinkovics JG, Horvath JC. Newcastle disease vi-

rus (NDV): brief history of its oncolytic strains. J Clin Virol 2000; i6(i), i-i5. doi: i0.i0i6/si386-6532(99)00072-4.

23. Farassati F, Yang AD, Lee PW. Oncogenes in Ras sig-

nalling pathway dictate host-cell permissiveness to herpes simplex virus i. Nat Cell Biol 200i; 3(8), 74550. doi: i0.i038/3508706i.

24. Mullen JT, Tanabe KK. Viral oncolysis. Oncologist 2002;

7(2), i06-i9. doi: i0.i634/theoncologist.7-2-i06.

25. Russell SJ, Peng KW, Bell JC. Oncolytic virotherapy.

Nat Biotechnol 20i2; 30(7), 658-70. doi: i0.i038/ nbt.2287.

26. Ye T, Jiang K, Wei L, Barr MP, Xu O, Zhang G et al. On-

colytic Newcastle disease virus induces autophagy-dependent immunogenic cell death in lung cancer cells. Am J Cancer Res 20i8; 8(8), i5i4-27. PubMed PMID: 302i0920.

27. Zhirnov OP. Biochemical Variations in Cytolytic Ac-

tivity of Ortho- and Paramyxoviruses in Human Lung Tumor Cell Culture. Biochemistry (Mosc) 20i7; 82(9), i048-54. doi: i0.ii34/S00062979i7090085.

28. Rivlin N, Brosh R, Oren M, Rotter V. Mutations in the

p53 Tumor Suppressor Gene: Important Milestones at the Various Steps of Tumorigenesis. Genes Cancer 20ii; 2(4), 466-74. doi: i0.ii77/i94760i9ii408889.

29. Ries S, Korn WM. ONYX-0i5: mechanisms of action

and clinical potential of a replication-selective adenovirus. Br J Cancer 2002; 86(i), 5-ii. doi: i0.i038/ sj.bjc.6600006.

30. Heise C, Sampson-Johannes A, Williams A, McCor-

mick F, Von Hoff DD, Kirn DH. ONYX-0i5, an EiB gene-attenuated adenovirus, causes tumor-specific cytolysis and antitumoral efficacy that can be augmented by standard chemotherapeutic agents. Nat Med i997; 3(6), 639-45. doi: i0.i038/nm0697-639.

31. Vaillancourt MT, Atencio I, Ouijano E, Howe JA, Ram-

achandra M. Inefficient killing of quiescent human epithelial cells by replicating adenoviruses: potential implications for their use as oncolytic agents. Cancer Gene Ther 2005; i2(8), 69i-8. doi: i0.i038/ sj.cgt.7700840.

32. Vdovichenko GV, Petrishchenko VA, Sergeev AA,

Kim II, Fatiukhina OE, Shishkina LN et al. [Preclinical studies of the anticancer adenovirus canceroly-sin preparation]. Vopr Virusol 2006; 5i(6), 39-42. PubMed PMID: i72i4082 (In Russian).

33. Razumov IA, Sviatchenko VA, Protopopova EV, Koch-

neva GV, Kiselev NN, Gubanova NV et al. [Oncolytic properties of some orthopoxviruses, adenoviruses and parvoviruses in human glioma cells]. Vestn Ross Akad Med Nauk 2013; 12, 4-8. PubMed PMID: 24741936 (In Russian).

34. Zhirnov OP, Klenk HD. Control of apoptosis in influ-

enza virus-infected cells by up-regulation of Akt and p53 signaling. Apoptosis 2007; 12(8), 1419-32. doi: 10.1007/s10495-007-0071-y.

35. Matveeva OV, Chumakov PM. Defects in interferon

pathways as potential biomarkers of sensitivity to oncolytic viruses. Rev Med Virol 2018; 28(6), e2008. doi: 10.1002/rmv.2008.

36. de Oueiroz N, Xia T, Konno H, Barber GN. Ovarian

Cancer Cells Commonly Exhibit Defective STING Signaling Which Affects Sensitivity to Viral Oncolysis. Mol Cancer Res 2019; 17(4), 974-86. doi: 10.1158/1541-7786.MCR-18-0504.

37. Ebrahimi S, Ghorbani E, Khazaei M, Avan A, Ry-

zhikov M, Azadmanesh K et al. Interferon-Mediated Tumor Resistance to Oncolytic Virotherapy. J Cell Biochem 2017; 118(8), 1994-9. doi: 10.1002/ jcb.25917.

38. Liikanen I, Monsurro V, Ahtiainen L, Raki M, Hak-

karainen T, Diaconu I et al. Induction of interferon pathways mediates in vivo resistance to oncolytic adenovirus. Mol Ther 2011; 19(10), 1858-66. doi: 10.1038/mt.2011.144.

39. Zhirnov OP, Konakova TE, Wolff T, Klenk HD. NS1

protein of influenza A virus down-regulates apop-tosis. J Virol 2002; 76(4), 1617-25. doi: 10.1128/ jvi.76.4.1617-1625.2002.

40. Garcia-Sastre A, Egorov A, Matassov D, Brandt S,

Levy DE, Durbin JE et al. Influenza A virus lacking the NS1 gene replicates in interferon-deficient systems. Virology 1998; 252(2), 324-30. PubMed PMID: 9878611.

41. Muster T, Rajtarova J, Sachet M, Unger H, Fleis-

chhacker R, Romirer I et al. Interferon resistance promotes oncolysis by influenza virus NS1-dele-tion mutants. Int J Cancer 2004; 110(1), 15-21. doi: 10.1002/ijc.20078.

42. Hummel JL, Safroneeva E, Mossman KL. The role of

ICP0-Null HSV-1 and interferon signaling defects in the effective treatment of breast adenocarcino-ma. Mol Ther 2005; 12(6), 1101-10. doi: 10.1016/j. ymthe.2005.07.533.

43. Breitbach CJ, Lichty BD, Bell JC. Oncolytic Viruses:

Therapeutics With an Identity Crisis. EBioMedicine 2016; 9, 31-6. doi: 10.1016/j.ebiom.2016.06.046.

44. Jain RK, Stylianopoulos T. Delivering nanomedicine

to solid tumors. Nat Rev Clin Oncol 20i0; 7(ii), 653-64. doi: i0.i038/nrclinonc.20i0.i39.

45. Pipiya T, Sauthoff H, Huang YQ, Chang B, Cheng J,

Heitner S et al. Hypoxia reduces adenoviral replication in cancer cells by downregulation of viral protein expression. Gene Ther 2005; i2(ii), 9ii-7. doi: i0.i038/sj.gt.3302459.

46. Chaurasiya S, Hew P, Crosley P, Sharon D, Potts K,

Agopsowicz K et al. Breast cancer gene therapy using an adenovirus encoding human IL-2 under control of mammaglobin promoter/enhancer sequences. Cancer Gene Ther 20i6; 23(6), i78-87. doi: i0.i038/cgt.20i6.i8.

47. Parker JN, Gillespie GY, Love CE, Randall S, Whit-

ley RJ, Markert JM. Engineered herpes simplex virus expressing IL-i2 in the treatment of experimental murine brain tumors. Proc Natl Acad Sci U S A 2000; 97(5), 2208-i3. doi: i0.i073/pnas.040557897.

48. Heiber JF, Barber GN. Vesicular stomatitis virus ex-

pressing tumor suppressor p53 is a highly attenuated, potent oncolytic agent. J Virol 20ii; 85(20), i0440-50. doi: i0.ii28/JVI.05408-ii.

49. Bai FL, Yu YH, Tian H, Ren GP, Wang H, Zhou B et al.

Genetically engineered Newcastle disease virus expressing interleukin-2 and TNF-related apoptosis-inducing ligand for cancer therapy. Cancer Biol Ther 20i4; i5(9), i226-38. doi: i0.4i6i/cbt.29686.

50. Guo ZS, Liu Z, Kowalsky S, Feist M, Kalinski P, Lu B

et al. Oncolytic Immunotherapy: Conceptual Evolution, Current Strategies, and Future Perspectives. Front Immunol 20i7; 8, 555. doi: i0.3389/ fimmu.20i7.00555.

51. Parato KA, Breitbach CJ, Le Boeuf F, Wang J, Stor-

beck C, Ilkow C et al. The oncolytic poxvirus JX-594 selectively replicates in and destroys cancer cells driven by genetic pathways commonly activated in cancers. Mol Ther 20i2; 20(4), 749-58. doi: i0.i038/ mt.20ii.276.

52. Dranoff G, Jaffee E, Lazenby A, Golumbek P, Lev-

itsky H, Brose K et al. Vaccination with irradiated tumor cells engineered to secrete murine granulo-cyte-macrophage colony-stimulating factor stimulates potent, specific, and long-lasting anti-tumor immunity. Proc Natl Acad Sci U S A i993; 90(8), 3539-43. doi: i0.i073/pnas.90.8.3539.

53. Kim JH, Oh JY, Park BH, Lee DE, Kim JS, Park HE et al.

Systemic armed oncolytic and immunologic therapy for cancer with JX-594, a targeted poxvirus expressing GM-CSF. Mol Ther 2006; i4(3), 36i-70. doi: i0.i0i6/j.ymthe.2006.05.008.

54. Eriksson E, Milenova I, Wenthe J, Stahle M, Leja-Jar-

blad J, Ullenhag G et al. Shaping the Tumor Stroma and Sparking Immune Activation by CD40 and 4-1BB Signaling Induced by an Armed Oncolytic Virus. Clin Cancer Res 2017; 23(19), 5846-57. doi: 10.1158/1078-0432.CCR-17-0285.

55. Tollefson AE, Scaria A, Hermiston TW, Ryerse JS,

Wold LJ, Wold WS. The adenovirus death protein (E3-11.6K) is required at very late stages of infection for efficient cell lysis and release of adenovirus from infected cells. J Virol 1996; 70(4), 2296-306. doi: 10.1128/JVI.70.4.2296-2306.1996.

56. Murali VK, Ornelles DA, Gooding LR, Wilms HT,

Huang W, Tollefson AE et al. Adenovirus death protein (ADP) is required for lytic infection of human lymphocytes. J Virol 2014; 88(2), 903-12. doi: 10.1128/JVI.01675-13.

57. Oneal MJ, Trujillo MA, Davydova J, McDonough S, Ya-

mamoto M, Morris JC, 3rd. Characterization of infec-tivity-enhanced conditionally replicating adenovec-tors for prostate cancer radiovirotherapy. Hum Gene Ther 2012; 23(9), 951-9. doi: 10.1089/hum.2012.047.

58. Freytag SO, Stricker H, Lu M, Elshaikh M, Aref I, Prad-

han D et al. Prospective randomized phase 2 trial of intensity modulated radiation therapy with or without oncolytic adenovirus-mediated cytotoxic gene therapy in intermediate-risk prostate cancer. Int J Radiat Oncol Biol Phys 2014; 89(2), 268-76. doi: 10.1016/j.ijrobp.2014.02.034.

59. Barton KN, Stricker H, Elshaikh MA, Pegg J, Cheng J,

Zhang Y et al. Feasibility of adenovirus-mediated hNIS gene transfer and 131I radioiodine therapy as a definitive treatment for localized prostate cancer. Mol Ther 2011; 19(7), 1353-9. doi: 10.1038/ mt.2011.89.

60. Hendrickx R, Stichling N, Koelen J, Kuryk L, Lip-

iec A, Greber UF. Innate immunity to adenovirus. Hum Gene Ther 2014; 25(4), 265-84. doi: 10.1089/ hum.2014.001.

61. Uusi-Kerttula H, Hulin-Curtis S, Davies J, Parker AL.

Oncolytic Adenovirus: Strategies and Insights for Vector Design and Immuno-Oncolytic Applications. Viruses 2015, 7, 6009-42. doi: 10.3390/v7112923.

62. Varnavski A, Calcedo R, Bove M et al. Evaluation of

toxicity from high-dose systemic administration of recombinant adenovirus vector in vector-naïve and pre-immunized mice. Gene Ther 2005; 12, 427-36. doi: 10.1038/sj.gt.3302347.

63. Cheng T, Song Y, Zhang Y, Zhang C, Yin J, Chi Y,

Zhou D. A novel oncolytic adenovirus based on simian adenovirus serotype 24. Oncotarget 2017; 8, 26871-85. doi: 10.18632/oncotarget.15845.

64. Gürlevik E, Woller N, Strüver N, Schache P, Kloos A,

Manns MP et al. Selectivity of Oncolytic Viral Replication Prevents Antiviral Immune Response and Toxicity, but Does Not Improve Antitumoral Immunity. Molecular Therapy 2010, 18(11), 1972-82. doi: 10.1038/mt.2010.163.

65. Lu SC, Hansen MJ, Hemsath JR, Parrett BJ, Zell BN,

Barry MA. Modulating Oncolytic Adenovirus Im-munotherapy by Driving Two Axes of the Immune System by Expressing 4-1BBL and CD40L. Hum Gene Ther 2022; 33(5-6), 250-61. doi: 10.1089/ hum.2021.197.

66. Wu H, Mei YF. An oncolytic adenovirus 11p vector ex-

pressing adenovirus death protein in the E1 region showed significant apoptosis and tumour-killing ability in metastatic prostate cells. Oncotarget 2019; 10(20), 1957-74. doi: 10.18632/oncotarget.26754.

67. Kim J, Li Y, Kim SW, Lee DS, Yun CO. Therapeutic ef-

ficacy of a systemically delivered oncolytic adenovirus - biodegradable polymer complex. Biomaterials 2013; 34(19), 4622-31. doi: 10.1016/j.biomateri-als.2013.03.004.

68. Hofherr SE, Mok H, Gushiken FC, Lopez JA, Barry MA.

Polyethylene glycol modification of adenovirus reduces platelet activation, endothelial cell activation, and thrombocytopenia. Hum Gene Ther 2007; 18(9), 837-48. doi: 10.1089/hum.2007.0051.

69. Muharemagic D, Zamay A, Ghobadloo SM, Evgin L,

Savitskaya A, Bell JC et al. Aptamer-facilitated Protection of Oncolytic Virus from Neutralizing Antibodies. Mol Ther Nucleic Acids 2014; 3, e167. doi: 10.1038/mtna.2014.19.

70. Brenner AJ, Cohen YC, Breitbart E, Bangio L, Saranto-

poulos J, Giles FJ et al. Phase I dose-escalation study of VB-111, an antiangiogenic virotherapy, in patients with advanced solid tumors. Clin Cancer Res 2013; 19(14), 3996-4007. doi: 10.1158/1078-0432. CCR-12-2079.

71. Saito K, Khan K, Sosnowski B, Li D, O'Malley BW,

Jr. Cytotoxicity and antiangiogenesis by fibro-blast growth factor 2-targeted Ad-TK cancer gene therapy. Laryngoscope 2009; 119(4), 665-74. doi: 10.1002/lary.20127.

72. Mineta T, Rabkin SD, Yazaki T, Hunter WD, Martu-

za RL. Attenuated multi-mutated herpes simplex virus-1 for the treatment of malignant gliomas. Nat Med 1995; 1(9), 938-43. doi: 10.1038/nm0995-938.

73. Breitbach CJ, Arulanandam R, De Silva N, Thorne SH,

Patt R, Daneshmand M et al. Oncolytic vaccinia virus disrupts tumor-associated vasculature in humans. Cancer Res 2013; 73(4), 1265-75. doi: 10.1158/0008-5472.CAN-12-2687.

74. Breitbach CJ, De Silva NS, Falls TJ, Aladl U, Evgin L,

Paterson J et al. Targeting tumor vasculature with an oncolytic virus. Mol Ther 20ii; i9(5), 886-94. doi: i0.i038/mt.20ii.26.

75. Alajez NM, Mocanu JD, Krushel T, Bell JC, Liu FF.

Enhanced vesicular stomatitis virus (VSVDelta5i) targeting of head and neck cancer in combination with radiation therapy or ZD6i26 vascular disrupting agent. Cancer Cell Int 20i2; i2(i), 27. doi: i0.ii86/i475-2867-i2-27.

76. Msaouel P, Iankov ID, Dispenzieri A, Galanis E. At-

tenuated oncolytic measles virus strains as cancer therapeutics. Curr Pharm Biotechnol 20i2; i3(9), i732-4i. doi: i0.2i74/i38920ii2800958896.

77. Li H, Peng KW, Dingli D, Kratzke RA, Russell SJ. On-

colytic measles viruses encoding interferon beta and the thyroidal sodium iodide symporter gene for mesothelioma virotherapy. Cancer Gene Ther 20i0; i7(8), 550-8. doi: i0.i038/cgt.20i0.i0.

78. Kurozumi K, Hardcastle J, Thakur R, Shroll J, No-

wicki M, Otsuki A et al. Oncolytic HSV-i infection of tumors induces angiogenesis and upregulates CYR6i. Mol Ther 2008; i6(8), i382-9i. doi: i0.i038/ mt.2008.ii2.

79. Kruger GM, Morrison SJ. Brain repair by endoge-

nous progenitors. Cell 2002; ii0(4), 399-402. doi: i0.i0i6/s0092-8674(02)00899-i.

80. Diehn M, Cho RW, Lobo NA, Kalisky T, Dorie MJ,

Kulp AN et al. Association of reactive oxygen species levels and radioresistance in cancer stem cells. Nature 2009; 458(7239), 780-3. doi: i0.i038/na-ture07733.

81. Trumpp A, Wiestler OD. Mechanisms of Disease: can-

cer stem cells-targeting the evil twin. Nat Clin Pract Oncol 2008; 5(6), 337-47. doi: i0.i038/ncponciii0.

82. Ebben JD, Treisman DM, Zorniak M, Kutty RG,

Clark PA, Kuo JS. The cancer stem cell paradigm: a new understanding of tumor development and treatment. Expert Opin Ther Targets 20i0; i4(6), 62i-32. doi: i0.i5i7/i47i2598.20i0.485i86.

83. Zhu Z, Gorman MJ, McKenzie LD, Chai JN, Hubert CG,

Prager BC et al. Zika virus has oncolytic activity against glioblastoma stem cells. J Exp Med 20i7; 2i4(i0), 2843-57. doi: i0.i084/jem.20i7i093.

84. Tong Y, You L, Liu H, Li L, Meng H, Qian Q et al. Po-

tent antitumor activity of oncolytic adenovirus expressing Beclin-i via induction of autophagic cell death in leukemia. Oncotarget 20i3; 4(6), 860-74. doi: i0.i8632/oncotarget.i0i8.

85. Robert C, Thomas L, Bondarenko I, O'Day S, Weber J,

Garbe C et al. Ipilimumab plus dacarbazine for previously untreated metastatic melanoma. N Engl

J Med 20ii; 364(26), 25i7-26. doi: i0.i056/NEJ-Moaii0462i.

86. Robert C, Long GV, Brady B, Dutriaux C, Maio M,

Mortier L et al. Nivolumab in previously untreated melanoma without BRAF mutation. N Engl J Med 20i5; 372(4), 320-30. doi: i0.i056/NEJMoai4i2082.

87. Ribas A, Puzanov I, Dummer R, Schadendorf D, Ha-

mid O, Robert C et al. Pembrolizumab versus investigator-choice chemotherapy for ipilimumab-re-fractory melanoma (KEYNOTE-002): a randomised, controlled, phase 2 trial. Lancet Oncol 20i5; i6(8), 908-i8. doi: i0.i0i6/Si470-2045(i5)00083-2.

88. Puzanov I, Milhem MM, Minor D, Hamid O, Li A,

Chen L et al. Talimogene Laherparepvec in Combination With Ipilimumab in Previously Untreated, Unresectable Stage IIIB-IV Melanoma. J Clin Oncol 20i6; 34(22), 26i9-26. doi: i0.i200/Jœ.20i6.67.i529.

89. Afzal MZ, Shirai K. Response to the Rechallenge With

Talimogene Laherparepvec (T-VEC) After Ipilim-umab/Nivolumab Treatment in Patient With Cutaneous Malignant Melanoma Who Initially Had a Progression on T-VEC With Pembrolizumab. J Immunother 20i9; 42(4), i36-4i. doi: i0.i097/ CJI.0000000000000265.

90. Gomez-Gutierrez JG, Nitz J, Sharma R, Wechman SL,

Riedinger E, Martinez-Jaramillo E et al. Combined therapy of oncolytic adenovirus and temozolomide enhances lung cancer virotherapy in vitro and in vivo. Virology 20i6; 487, 249-59. doi: i0.i0i6/j.vi-rol.20i5.i0.0i9.

91. Lee JC, Shin DW, Park H, Kim J, Youn Y, Kim JH et

al. Tolerability and safety of EUS-injected adeno-virus-mediated double-suicide gene therapy with chemotherapy in locally advanced pancreatic cancer: a phase i trial. Gastrointest Endosc 2020; 92(5), i044-52.ei. doi: i0.i0i6/j.gie.2020.02.0i2.

92. Balogh A, Bator J, Marko L, Nemeth M, Pap M, Se-

talo G, Jr., et al. Gene expression profiling in PCi2 cells infected with an oncolytic Newcastle disease virus strain. Virus Res 20i4; i85, i0-22. doi: i0.i0i6/j.virusres.20i4.03.003.

93. Lu SC, Hansen MJ, Hemsath JR, Parrett BJ, Zell BN,

Barry MA. Modulating Oncolytic Adenovirus Im-munotherapy by Driving Two Axes of the Immune System by Expressing 4-iBBL and CD40L. Hum Gene Ther 2022; 33(5-6), 250-6i. doi: i0.i089/ hum.202i.i97.

94. Chen W, Wu Y, Liu W, Wang G, Wang X, Yang Y et

al. Enhanced antitumor efficacy of a novel fiber chimeric oncolytic adenovirus expressing p53 on hepatocellular carcinoma. Cancer Lett 20ii; 307(i), 93-i03. doi: i0.i0i6/j.canlet.20ii.03.02i.

95. Porter CE, Rosewell Shaw A, Jung Y, Yip T, Castro PD,

Sandulache VC et al. Oncolytic Adenovirus Armed with BiTE, Cytokine, and Checkpoint Inhibitor Enables CAR T Cells to Control the Growth of Heterogeneous Tumors. Mol Ther 2020; 28(5), 1251-62. doi: 10.1016/j.ymthe.2020.02.016.

96. Li Y, Xiao F, Zhang A, Zhang D, Nie W, Xu T et al. On-

colytic adenovirus targeting TGF-p enhances antitumor responses of mesothelin-targeted chimeric antigen receptor T cell therapy against breast cancer. Cell Immunol 2020; 348, 104041. doi: 10.1016/j. cellimm.2020.104041.

97. Kochneva GV, Sivolobova GF, Yudina KV, Babkin IV,

Chumakov PM, Netesov SV. Oncolytic poxviruses. Molecular Genetics, Microbiology and Virology 2012; 27(1), 8-16. doi: 10.3103/S0891416812010041 (In Russian).

98. Nemunaitis J, Khuri F, Ganly I, Arseneau J, Posner M,

Vokes E et al. Phase II trial of intratumoral administration of 0NYX-015, a replication-selective adenovirus, in patients with refractory head and neck cancer. J Clin Oncol 2001; 19(2), 289-98. doi: 10.1200/ JCO.2001.19.2.289.

99. Mulvihill S, Warren R, Venook A, Adler A, Randlev B,

Heise C et al. Safety and feasibility of injection with an E1B-55 kDa gene-deleted, replication-selective adenovirus (ONYX-015) into primary carcinomas of the pancreas: a phase I trial. Gene Ther 2001; 8(4), 308-15. doi: 10.1038/sj.gt.3301398.

100. Nemunaitis J, Senzer N, Sarmiento S, Zhang YA, Ar-zaga R, Sands B et al. A phase I trial of intravenous infusion of ONYX-015 and enbrel in solid tumor patients. Cancer Gene Ther 2007; 14(11), 885-93. doi: 10.1038/sj.cgt.7701080.

101. Bazan-Peregrino M, Carlisle RC, Hernandez-Alcoce-ba R, Iggo R, Homicsko K, Fisher KD et al. Comparison of molecular strategies for breast cancer viro-therapy using oncolytic adenovirus. Hum Gene Ther 2008; 19(9), 873-86. doi: 10.1089/hum.2008.047.

102. Zhang ZL, Zou WG, Luo CX, Li BH, Wang JH, Sun LY et al. An armed oncolytic adenovirus system, ZD55-gene, demonstrating potent antitumoral efficacy. Cell Res 2003; 13(6), 481-9. doi: 10.1038/ sj.cr.7290191.

103. He LF, Gu JF, Tang WH, Fan JK, Wei N, Zou WG et al. Significant antitumor activity of oncolytic adenovi-rus expressing human interferon-beta for hepatocellular carcinoma. J Gene Med 2008; 10(9), 983-92. doi: 10.1002/jgm.1231.

104. Hu HJ, Liang X, Li HL, Du CM, Hao JL, Wang HY et al. The armed oncolytic adenovirus ZD55-IL-24 eradicates melanoma by turning the tumor cells from the

self-state into the nonself-state besides direct killing. Cell Death Dis 2020; 11(11), 1022. doi: 10.1038/ s41419-020-03223-0.

105. Xia ZJ, Chang JH, Zhang L, Jiang WO, Guan ZZ, Liu JW et al. [Phase III randomized clinical trial of intratumoral injection of E1B gene-deleted adeno-virus (H101) combined with cisplatin-based chemotherapy in treating squamous cell cancer of head and neck or esophagus]. Ai Zheng (Chinese Journal of Cancer) 2004; 23(12), 1666-70. PubMed PMID: 15601557 (In Chinese).

106. Lang FF, Conrad C, Gomez-Manzano C, Yung WKA, Sawaya R, Weinberg JS et al. Phase I Study of DNX-2401 (Delta-24-RGD) Oncolytic Adenovirus: Replication and Immunotherapeutic Effects in Recurrent Malignant Glioma. J Clin Oncol 2018; 36(14), 141927. doi: 10.1200/Jœ.2017.75.8219.

107. Rodriguez-Garcia A, Gimenez-Alejandre M, Rojas JJ, Moreno R, Bazan-Peregrino M, Cascallo M et al. Safety and efficacy of VCN-01, an oncolytic adenovirus combining fiber HSG-binding domain replacement with RGD and hyaluronidase expression. Clin Cancer Res 2015; 21(6), 1406-18. doi: 10.1158/1078-0432.CCR-14-2213.

108. Ranki T, Pesonen S, Hemminki A, Partanen K, Kaire-mo K, Alanko T et al. Phase I study with ONCOS-102 for the treatment of solid tumors - an evaluation of clinical response and exploratory analyses of immune markers. J Immunother Cancer 2016; 4, 17. doi: 10.1186/s40425-016-0121-5.

109. Kuryk L, Moller AW, Garofalo M, Cerullo V, Pesonen S, Alemany R et al. Antitumor-specific T-cell responses induced by oncolytic adenovirus ON-COS-102 (AdV5/3-D24-GM-CSF) in peritoneal mesothelioma mouse model. J Med Virol 2018; 90(10), 1669-73. doi: 10.1002/jmv.25229.

110. Kuryk L, Moller AW. Chimeric oncolytic Ad5/3 virus replicates and lyses ovarian cancer cells through desmoglein-2 cell entry receptor. J Med Virol 2020; 92(8), 1309-15. doi: 10.1002/jmv.25677.

111. Nokisalmi P, Pesonen S, Escutenaire S, Sarkioja M, Raki M, Cerullo V et al. Oncolytic adenovirus ICO-VIR-7 in patients with advanced and refractory solid tumors. Clin Cancer Res 2010; 16(11), 3035-43. doi: 10.1158/1078-0432.CCR-09-3167.

112. Garcia M, Moreno R, Gil-Martin M, Cascallo M, de Olza MO, Cuadra C et al. A Phase 1 Trial of Oncolytic Adenovirus ICOVIR-5 Administered Intravenously to Cutaneous and Uveal Melanoma Patients. Hum Gene Ther 2019; 30(3), 352-64. doi: 10.1089/hum.2018.107.

113. Packiam VT, Lamm DL, Barocas DA, Trainer A, Fand B, Davis RL, 3rd, et al. An open label, single-arm,

phase II multicenter study of the safety and efficacy of CG0070 oncolytic vector regimen in patients with BCG-unresponsive non-muscle-invasive bladder cancer: Interim results. Urol Oncol 2018; 36(10), 440-7. doi: 10.1016/j.urolonc.2017.07.005.

114. Conry RM, Westbrook B, McKee S, Norwood TG. Talimogene laherparepvec: First in class oncolytic virotherapy. Hum Vaccin Immunother 2018; 14(4), 839-46. doi: 10.1080/21645515.2017.1412896.

115. Andtbacka RH, Kaufman HL, Collichio F, Amatru-da T, Senzer N, Chesney J et al. Talimogene Laherparepvec Improves Durable Response Rate in Patients With Advanced Melanoma. J Clin Oncol 2015; 33(25), 2780-8. doi: 10.1200/JC0.2014.58.3377.

116. Kloker LD, Berchtold S, Smirnow I, Schaller M, Fehrenbacher B, Krieg A et al. The Oncolytic Herpes Simplex Virus Talimogene Laherparepvec Shows Promising Efficacy in Neuroendocrine Cancer Cell Lines. Neuroendocrinology 2019; 109(4), 346-61. doi: 10.1159/000500159.

117. Soliman H, Hogue D, Han H, Mooney B, Costa R, Lee MC et al. A Phase I Trial of Talimogene Laherparepvec in Combination with Neoadjuvant Chemotherapy for the Treatment of Nonmetastatic Triple-Negative Breast Cancer. Clin Cancer Res 2021; 27(4), 1012-8. doi: 10.1158/1078-0432.CCR-20-3105.

118. Harrington KJ, Kong A, Mach N, Chesney JA, Fernandez BC, Rischin D et al. Talimogene Laher-parepvec and Pembrolizumab in Recurrent or Meta-static Squamous Cell Carcinoma of the Head and Neck (MASTERKEY-232): A Multicenter, Phase 1b Study. Clin Cancer Res 2020; 26(19), 5153-61. doi: 10.1158/1078-0432.CCR-20-1170.

119. Fujimoto Y, Mizuno T, Sugiura S, Goshima F, Kohno S, Nakashima T et al. Intratumoral injection of herpes simplex virus HF10 in recurrent head and neck squamous cell carcinoma. Acta Otolaryngol 2006; 126(10), 1115-7. doi: 10.1080/00016480600702100.

120. Nakao A, Kasuya H, Sahin TT, Nomura N, Kan-zaki A, Misawa M et al. A phase I dose-escalation clinical trial of intraoperative direct intratumoral injection of HF10 oncolytic virus in non-resectable patients with advanced pancreatic cancer. Cancer Gene Ther 2011; 18(3), 167-75. doi: 10.1038/ cgt.2010.65.

121. Markert JM, Razdan SN, Kuo HC, Cantor A, Knoll A, Karrasch M et al. A phase 1 trial of oncolytic HSV-1, G207, given in combination with radiation for recurrent GBM demonstrates safety and radiographic responses. Mol Ther 2014; 22(5), 1048-55. doi: 10.1038/mt.2014.22.

122. Streby KA, Currier MA, Triplet M, Ott K, Dish-man DJ, Vaughan MR et al. First-in-Human Intravenous Seprehvir in Young Cancer Patients: A Phase 1 Clinical Trial. Mol Ther 2019; 27(11), 1930-8. doi: 10.1016/j.ymthe.2019.08.020.

123. Wang PY, Swain HM, KunklerAL, Chen CY, Hut-zen BJ, Arnold MA et al. Neuroblastomas vary widely in their sensitivities to herpes simplex virotherapy unrelated to virus receptors and susceptibility. Gene Ther 2016; 23(2), 135-43. doi: 10.1038/gt.2015.105.

124. Fukuhara H, Martuza RL, Rabkin SD, Ito Y, Todo T. Oncolytic herpes simplex virus vector g47delta in combination with androgen ablation for the treatment of human prostate adenocarcinoma. Clin Cancer Res 2005; 11(21), 7886-90. doi: 10.1158/1078-0432.CCR-05-1090.

125. Galanis E, Hartmann LC, Cliby WA, Long HJ, Peeth-ambaram PP, Barrette BA et al. Phase I trial of intra-peritoneal administration of an oncolytic measles virus strain engineered to express carcinoembryon-ic antigen for recurrent ovarian cancer. Cancer Res 2010; 70(3), 875-82. doi: 10.1158/0008-5472.CAN-09-2762.

126. Delpeut S, Sisson G, Black KM, Richardson CD. Measles Virus Enters Breast and Colon Cancer Cell Lines through a PVRL4-Mediated Macropinocytosis Pathway. J Virol 2017; 91(10), e02191-16. doi: 10.1128/ JVI.02191-16.

127. Msaouel P, Iankov ID, Allen C, Morris JC, von Messling V, Cattaneo R et al. Engineered measles virus as a novel oncolytic therapy against prostate cancer. Prostate 2009; 69(1), 82-91. doi: 10.1002/ pros.20857.

128. Blechacz B, Splinter PL, Greiner S, Myers R, Peng KW, Federspiel MJ et al. Engineered measles virus as a novel oncolytic viral therapy system for hepatocel-lular carcinoma. Hepatology 2006; 44(6), 1465-77. doi: 10.1002/hep.21437.

129. Delaunay T, Achard C, Boisgerault N, Grard M, Pe-tithomme T, Chatelain C et al. Frequent Homozygous Deletions of Type I Interferon Genes in Pleural Mesothelioma Confer Sensitivity to Oncolytic Measles Virus. J Thorac Oncol 2020; 15(5), 827-42. doi: 10.1016/j.jtho.2019.12.128.

130. Packiriswamy N, Upreti D, Zhou Y, Khan R, Miller A, Diaz RM et al. Oncolytic measles virus therapy enhances tumor antigen-specific T-cell responses in patients with multiple myeloma. Leukemia 2020; 34(12), 3310-22. doi: 10.1038/s41375-020-0828-7.

131. Allen C, Opyrchal M, Aderca I, Schroeder MA, Sarkaria JN, Domingo E et al. Oncolytic measles virus strains have significant antitumor activity

against glioma stem cells. Gene Ther 2013; 20(4), 444-9. doi: 10.1038/gt.2012.62.

132. Zulkifli MM, Ibrahim R, Ali AM, Aini I, Jaafar H, Hilda SS et al. Newcastle diseases virus strain V4UPM displayed oncolytic ability against experimental human malignant glioma. Neurol Res 2009; 31(1), 3-10. doi: 10.1179/174313208X325218.

133. Sosnovtseva AO, Lipatova AV, Grinenko NF, Baklau-shev VP, Chumakov PM, Chekhonin VP. Sensitivity of C6 Glioma Cells Carrying the Human Poliovirus Receptor to Oncolytic Polioviruses. Bull Exp Biol Med 2016; 161(6), 821-5. doi: 10.1007/s10517-016-3520-1.

134. Liu Z, Zhao X, Mao H, Baxter PA, Huang Y, Yu L et al. Intravenous injection of oncolytic picornavirus SVV-001 prolongs animal survival in a panel of primary tumor-based orthotopic xenograft mouse models of pediatric glioma. Neuro Oncol 2013; 15(9), 1173-85. doi: 10.1093/neuonc/not065.

135. Reddy PS, Burroughs KD, Hales LM, Ganesh S, Jones BH, Idamakanti N et al. Seneca Valley virus, a systemically deliverable oncolytic picornavirus, and the treatment of neuroendocrine cancers. J Natl Cancer Inst 2007; 99(21), 1623-33. doi: 10.1093/ jnci/djm198.

136. Park SH, Breitbach CJ, Lee J, Park JO, Lim HY, Kang WK et al. Phase 1b Trial of Biweekly Intravenous Pexa-Vec (JX-594), an Oncolytic and Immu-notherapeutic Vaccinia Virus in Colorectal Cancer. Mol Ther 2015; 23(9), 1532-40. doi: 10.1038/ mt.2015.109.

137. Park BH, Hwang T, Liu TC, Sze DY, Kim JS, Kwon HC et al. Use of a targeted oncolytic poxvirus, JX-594, in patients with refractory primary or metastatic liver cancer: a phase I trial. Lancet Oncol 2008; 9(6), 53342. doi: 10.1016/S1470-2045(08)70107-4.

138. Cripe TP, Ngo MC, Geller JI, Louis CU, Currier MA, Racadio JM et al. Phase 1 study of intratumoral Pexa-Vec (JX-594), an oncolytic and immunotherapeu-tic vaccinia virus, in pediatric cancer patients. Mol Ther 2015; 23(3), 602-8. doi: 10.1038/mt.2014.243.

139. Kim MK, Breitbach CJ, Moon A, Heo J, Lee YK, Cho M et al. Oncolytic and immunotherapeutic vaccinia induces antibody-mediated complement-dependent cancer cell lysis in humans. Sci Transl Med 2013; 5(185), 185ra63. doi: 10.1126/scitrans-lmed.3005361.

140. Mell LK, Brumund KT, Daniels GA, Advani SJ, Zak-eri K, Wright ME et al. Phase I Trial of Intravenous Oncolytic Vaccinia Virus (GL-ONC1) with Cisplatin and Radiotherapy in Patients with Locoregionally Advanced Head and Neck Carcinoma. Clin Cancer

Res 2017; 23(19), 5696-702. doi: 10.1158/1078-0432.CCR-16-3232.

141. Lauer UM, Schell M, Beil J, Berchtold S, Koppen-hofer U, Glatzle J et al. Phase I Study of Oncolytic Vaccinia Virus GL-ONC1 in Patients with Peritoneal Carcinomatosis. Clin Cancer Res 2018; 24(18), 4388-98. doi: 10.1158/1078-0432.CCR-18-0244.

142. Noonan AM, Farren MR, Geyer SM, Huang Y, Tahi-ri S, Ahn D et al. Randomized Phase 2 Trial of the Oncolytic Virus Pelareorep (Reolysin) in Upfront Treatment of Metastatic Pancreatic Adenocarci-noma. Mol Ther 2016; 24(6), 1150-8. doi: 10.1038/ mt.2016.66.

143. Bernstein V, Ellard SL, Dent SF, Tu D, Mates M, Dh-esy-Thind SK et al. A randomized phase II study of weekly paclitaxel with or without pelareorep in patients with metastatic breast cancer: final analysis of Canadian Cancer Trials Group IND.213. Breast Cancer Res Treat 2018; 167(2), 485-93. doi: 10.1007/ s10549-017-4538-4.

144. Jonker DJ, Tang PA, Kennecke H, Welch SA, Cripps MC, Asmis T et al. A Randomized Phase II Study of FOLFOX6/Bevacizumab With or Without Pelareorep in Patients With Metastatic Colorectal Cancer: IND.210, a Canadian Cancer Trials Group Trial. Clin Colorectal Cancer 2018; 17(3), 231-9, e7. doi: 10.1016/j.clcc.2018.03.001.

145. Bradbury PA, Morris DG, Nicholas G, Tu D, Tehfe M, Goffin JR et al. Canadian Cancer Trials Group (CCTG) IND211: A randomized trial of pelareorep (Reoly-sin) in patients with previously treated advanced or metastatic non-small cell lung cancer receiving standard salvage therapy. Lung Cancer 2018; 120, 142-8. doi: 10.1016/j.lungcan.2018.03.005.

146. Mahalingam D, Fountzilas C, Moseley J, Noronha N, Tran H, Chakrabarty R et al. A phase II study of REOLYSIN((R)) (pelareorep) in combination with carboplatin and paclitaxel for patients with advanced malignant melanoma. Cancer Chemother Pharmacol 2017; 79(4), 697-703. doi: 10.1007/ s00280-017-3260-6.

147. Grekova SP, Aprahamian M, Daeffler L, Leuchs B, Angelova A, Giese T et al. Interferon gamma improves the vaccination potential of oncolytic par-vovirus H-1PV for the treatment of peritoneal carcinomatosis in pancreatic cancer. Cancer Biol Ther 2011; 12(10), 888-95. doi: 10.4161/cbt.12.10.17678.

148. Naik S, Nace R, Barber GN, Russell SJ. Potent systemic therapy of multiple myeloma utilizing onco-lytic vesicular stomatitis virus coding for interferon-beta. Cancer Gene Ther 2012; 19(7), 443-50. doi: 10.1038/cgt.2012.14.

149. Patel MR, Jacobson BA, Ji Y, Drees J, Tang S, Xiong K et al. Vesicular stomatitis virus expressing interferon-beta is oncolytic and promotes antitumor immune responses in a syngeneic murine model of non-small cell lung cancer. Oncotarget 20i5; 6(32), 33i65-77. doi: i0.i8632/oncotarget.5320.

150. Liu YP, Steele MB, Suksanpaisan L, Federspiel MJ, Russell SJ, Peng KW et al. Oncolytic measles and vesicular stomatitis virotherapy for endometrial cancer. Gynecol Oncol 20i4; i32(i), i94-202. doi: i0.i0i6/j.ygyno.20i3.ii.0i0.

151. Liang M. Oncorine, the World First Oncolytic Virus Medicine and its Update in China. Curr Cancer Drug Targets 20i8; i8(2), i7i-6. doi: i0.2i74/i5680096i 8666171129221503.

152. Kaufman HL, Ruby CE, Hughes T, Slingluff CL, Jr. Current status of granulocyte-macrophage colony-stimulating factor in the immunotherapy of melanoma. J Immunother Cancer 20i4; 2, ii. doi: i0.ii86/205i-i426-2-ii.

153. Smith KD, Mezhir JJ, Bickenbach K, Veerapong J, Charron J, Posner MC et al. Activated MEK suppresses activation of PKR and enables efficient replication and in vivo oncolysis by Deltagam-ma(i)34.5 mutants of herpes simplex virus i. J Virol 2006; 80(3), iii0-20. doi: i0.ii28/JVI.80.3.iii0-1120.2006.

154. Sahin TT, Kasuya H, Nomura N, Shikano T, Yama-mura K, Gewen T et al. Impact of novel oncolytic virus HFi0 on cellular components of the tumor microenviroment in patients with recurrent breast cancer. Cancer Gene Ther 20i2; i9(4), 229-37. doi: i0.i038/cgt.20ii.80.

155. Watanabe D, Goshima F, Mori I, Tamada Y, Matsu-moto Y, Nishiyama Y. Oncolytic virotherapy for malignant melanoma with herpes simplex virus type i mutant HFi0. J Dermatol Sci 2008; 50(3), i85-96. doi: i0.i0i6/j.jdermsci.2007.i2.00i.

156. Patel DM, Foreman PM, Nabors LB, Riley KO, Gil-lespie GY, Markert JM. Design of a Phase I Clinical Trial to Evaluate M032, a Genetically Engineered HSV-i Expressing IL-i2, in Patients with Recurrent/Progressive Glioblastoma Multiforme, Ana-plastic Astrocytoma, or Gliosarcoma. Hum Gene Ther Clin Dev 20i6; 27(2), 69-78. doi: i0.i089/ humc.20i6.03i.

157. Liu BL, Robinson M, Han ZQ, Branston RH, English C, Reay P et al. ICP34.5 deleted herpes simplex virus with enhanced oncolytic, immune stimulating, and anti-tumour properties. Gene Ther 2003; i0(4), 292-303. doi: i0.i038/sj.gt.330i885.

158. Shah AC, Parker JN, Gillespie GY, Lakeman FD, Me-leth S, Markert JM et al. Enhanced antiglioma activity of chimeric HCMV/HSV-i oncolytic viruses. Gene Ther 2007; i4(i3), i045-54. doi: i0.i038/ sj.gt.3302942.

159. Thomas S, Kuncheria L, Roulstone V, Kyula JN, Mansfield D, Bommareddy PK et al. Development of a new fusion-enhanced oncolytic immunotherapy platform based on herpes simplex virus type i. J Immunother Cancer 20i9; 7(i), 2i4. doi: i0.ii86/ s40425-0i9-0682-i.

160. Freeman AI, Zakay-Rones Z, Gomori JM, Linetsky E, Rasooly L, Greenbaum E et al. Phase I/II trial of intravenous NDV-HUJ oncolytic virus in recurrent glioblastoma multiforme. Mol Ther 2006; i3(i), 22i-8. doi: i0.i0i6/j.ymthe.2005.08.0i6.

161. Geletneky K, Hajda J, Angelova AL, Leuchs B, Capper D, Bartsch AJ et al. Oncolytic H-i Parvovirus Shows Safety and Signs of Immunogenic Activity in a First Phase I/IIa Glioblastoma Trial. Mol Ther 20i7; 25(i2), 2620-34. doi: i0.i0i6/j.ymthe.20i7.08.0i6.

162. Strong JE, Coffey MC, Tang D, Sabinin P, Lee PW. The molecular basis of viral oncolysis: usurpation of the Ras signaling pathway by reovirus. EMBO J i998; i7(i2), 335i-62. doi: i0.i093/emboj/i7.i2.335i.

163. Maitra R, Ghalib MH, Goel S. Reovirus: a targeted therapeutic - progress and potential. Mol Cancer Res 20i2; i0(i2), i5i4-25. doi: i0.ii58/i54i-7786. MCR-i2-0i57.

164. Samson A, Scott KJ, Taggart D, West EJ, Wilson E, Nuovo GJ et al. Intravenous delivery of oncolytic reovirus to brain tumor patients immunologically primes for subsequent checkpoint blockade. Sci Transl Med 20i8; i0(422). doi: i0.ii26/scitrans-lmed.aam7577.

165. Masemann D, Köther K, Kuhlencord M, Varga G, Roth J, Lichty BD et al. Oncolytic influenza virus infection restores immunocompetence of lung tumor-associated alveolar macrophages. Oncoimmunology 20i8; 7(5), ei423i7i. doi: i0.i080/2i62402X.20i7.i423i7i.

166. Macedo N, Miller DM, Haq R, Kaufman HL. Clinical landscape of oncolytic virus research in 2020. J Im-munother Cancer 2020; 8(2), e00i486. doi: i0.ii36/ jitc-2020-00i486.

167. Chesney J, Puzanov I, Collichio F, Singh P, Mil-hem MM, Glaspy J et al. Randomized, Open-Label Phase II Study Evaluating the Efficacy and Safety of Talimogene Laherparepvec in Combination With Ipilimumab Versus Ipilimumab Alone in Patients With Advanced, Unresectable Melanoma.

J Clin Oncol 2018; 36(17), 1658-67. doi: 10.1200/ JCO.2017.73.7379.

168. American Cancer Society Survival rates for melanoma skin cancer (2011-2017) by stage. Available at https://www.cancer.org/cancer/melanoma-skin-cancer/detection-diagnosis-staging/survival-rates-for-melanoma-skin-cancer-by-stage.html. Accessed on 1 October 2022.

169. Hu JC, Coffin RS, Davis CJ, Graham NJ, Groves N, Guest PJ et al. A phase I study of OncoVEXGM-CSF, a second-generation oncolytic herpes simplex virus expressing granulocyte macrophage colony-stimulating factor. Clin Cancer Res 2006; 12(22), 6737-47. doi: 10.1158/1078-0432.CCR-06-0759.

170. Senzer NN, Kaufman HL, Amatruda T, Nemunaitis M, Reid T, Daniels G et al. Phase II clinical trial of a granulocyte-macrophage colony-stimulating factor-encoding, second-generation oncolytic her-pesvirus in patients with unresectable metastatic melanoma. J Clin Oncol 2009; 27(34), 5763-71. doi: 10.1200/Jœ.2009.24.3675.

171 Long GV, Atkinson V, Cebon JS, Jameson MB, Fitzharris BM, McNeil CM et al. Standard-dose pembro-lizumab in combination with reduced-dose ipi-limumab for patients with advanced melanoma (KEYNOTE-029): an open-label, phase 1b trial. Lancet Oncol 2017; 18(9), 1202-10. doi: 10.1016/S1470-2045(17)30428-X.

172. Zawit M, Swami U, Awada H, Arnouk J, Milhem M, Zakharia Y. Current status of intralesional agents in treatment of malignant melanoma. Ann Transl Med 2021; 9(12), 1038. doi: 10.21037/atm-21-491.

173. Andtbacka RHI, Ross MI, Agarwala SS, Taylor MH, Vetto JT, Neves RI. Efficacy and genetic analysis for a phase II multicenter trial of HF10, a replication-competent HSV-1 oncolytic immunotherapy, and ipilimumab combination treatment in patients with stage IIIb-IV unresectable or metastatic melanoma. J Clin Oncol 2018; 36, 15_Suppl, 9541. doi: 10.1200/Jœ.2018.36.15_suppl.9541.

174. Vidal L, Pandha HS, Yap TA, White CL, Twigger K, Vile RG et al. A phase I study of intravenous oncolytic reovirus type 3 Dearing in patients with advanced cancer. Clin Cancer Res 2008; 14(21), 712737. doi: 10.1158/1078-0432.CCR-08-0524.

175. Rao RD, Holtan SG, Ingle JN, Croghan GA, Kott-schade LA, Creagan ET et al. Combination of paclitaxel and carboplatin as second-line therapy for patients with metastatic melanoma. Cancer 2006; 106(2), 375-82. doi: 10.1002/cncr.21611.

176. Hodi FS, Soiffer RJ, Clark J, Finkelstein DM, Halus-ka FG. Phase II study of paclitaxel and carboplatin for malignant melanoma. Am J Clin Oncol 2002; 25(3), 283-6. doi: 10.1097/00000421-200206000-00016.

177. Galanis E, Markovic SN, Suman VJ, Nuovo GJ, Vile RG, Kottke TJ et al. Phase II trial of intravenous administration of Reolysin((R)) (Reovirus Sero-type-3-dearing Strain) in patients with metastatic melanoma. Mol Ther 2012; 20(10), 1998-2003. doi: 10.1038/mt.2012.146.

178. Kaufman HL, Deraffele G, Mitcham J, Moroziewicz D, Cohen SM, Hurst-Wicker KS et al. Targeting the local tumor microenvironment with vaccinia virus expressing B7.1 for the treatment of melanoma. J Clin Invest 2005; 115(7), 1903-12. doi: 10.1172/JCI24624.

179. Ohgaki H, Kleihues P. Population-based studies on incidence, survival rates, and genetic alterations in astrocytic and oligodendroglial gliomas. J Neuro-pathol Exp Neurol 2005; 64(6), 479-89. doi: 10.1093/ jnen/64.6.479.

180. Bleeker FE, Molenaar RJ, Leenstra S. Recent advances in the molecular understanding of glioblastoma. J Neurooncol 2012; 108(1), 11-27. doi: 10.1007/ s11060-011-0793-0.

181. Markert JM, Liechty PG, Wang W, Gaston S, Braz E, Karrasch M et al. Phase Ib trial of mutant herpes simplex virus G207 inoculated pre-and post-tumor resection for recurrent GBM. Mol Ther 2009; 17(1), 199-207. doi: 10.1038/mt.2008.228.

182. de Jesus VHF, Camandaroba MPG, Calsavara VF, Riechelmann RP. Systematic review and meta-analysis of gemcitabine-based chemotherapy after FOLFIRINOX in advanced pancreatic cancer. Ther Adv Med Oncol 2020; 12, 1758835920905408. doi: 10.1177/1758835920905408.

183. Hidalgo M, Cascinu S, Kleeff J, Labianca R, Lohr JM, Neoptolemos J et al. Addressing the challenges of pancreatic cancer: future directions for improving outcomes. Pancreatology 2015; 15(1), 8-18. doi: 10.1016/j.pan.2014.10.001.