Hyaluronidase expression within tumors increases virotherapy efficacy and T cell accumulation

Oncolytic viruses (OVs) preferentially infect and selectively replicate in cancer cells. OVs have been tested in clinical trials as monotherapy or in combination with chemotherapy, radiotherapy, and immunotherapy. However, the dense extracellular matrix hampers the intratumoral spreading and efficacy of OVs. Previously we described VCN-01, an oncolytic adenovirus expressing a soluble version of human sperm hyaluronidase (hyal) PH20, which exhibited enhanced intratumoral distribution and antitumor activity in different models. Here, we present two oncolytic adenoviruses designed to increase the secretion of PH20 compared to VCN-01. ICO15K-40SAPH20, encoding PH20 under an Ad40 splice acceptor, and ICO15K-E1aPH20 expressing PH20 fused to the E1A gene by P2A peptide. We demonstrate that increased hyal activity improves antitumor efficacy in both a sensitive immunodeficient model and an immunocompetent model. Moreover, we show that hyal activity impacts T cell accumulation in tumors, highlighting the value of a hyaluronidase-expressing virus for combinations with other immunotherapies in cancers involving dense stroma

Phase I, multicenter, open-label study of intravenous VCN-01 oncolytic adenovirus with or without nab-paclitaxel plus gemcitabine in patients with advanced solid tumors

Gastrointestinal neoplasms; Oncolytic virotherapy; Tumor microenvironmentNeoplasias gastrointestinales; Viroterapia oncolítica; Microambiente tumoralNeoplàsies gastrointestinals; Viroteràpia oncolítica; Microambient tumoralBackground VCN-01 is an oncolytic adenovirus (Ad5 based) designed to replicate in cancer cells with dysfunctional RB1 pathway, express hyaluronidase to enhance virus intratumoral spread and facilitate chemotherapy and immune cells extravasation into the tumor. This phase I clinical trial was aimed to find the maximum tolerated dose/recommended phase II dose (RP2D) and dose-limiting toxicity (DLT) of the intravenous delivery of the replication-competent VCN-01 adenovirus in patients with advanced cancer. Methods Part I: patients with advanced refractory solid tumors received one single dose of VCN-01. Parts II and III: patients with pancreatic adenocarcinoma received VCN-01 (only in cycle 1) and nab-paclitaxel plus gemcitabine (VCN-concurrent on day 1 in Part II, and 7 days before chemotherapy in Part III). Patients were required to have anti-Ad5 neutralizing antibody (NAbs) titers lower than 1/350 dilution. Pharmacokinetic and pharmacodynamic analyses were performed. Results 26% of the patients initially screened were excluded based on high NAbs levels. Sixteen and 12 patients were enrolled in Part I and II, respectively: RP2D were 1×1013 viral particles (vp)/patient (Part I), and 3.3×1012 vp/patient (Part II). Fourteen patients were included in Part III: there were no DLTs and the RP2D was 1×1013 vp/patient. Observed DLTs were grade 4 aspartate aminotransferase increase in one patient (Part I, 1×1013 vp), grade 4 febrile neutropenia in one patient and grade 5 thrombocytopenia plus enterocolitis in another patient (Part II, 1×1013 vp). In patients with pancreatic adenocarcinoma overall response rate were 50% (Part II) and 50% (Part III). VCN-01 viral genomes were detected in tumor tissue in five out of six biopsies (day 8). A second viral plasmatic peak and increased hyaluronidase serum levels suggested replication after intravenous injection in all patients. Increased levels of immune biomarkers (interferon-γ, soluble lymphocyte activation gene-3, interleukin (IL)-6, IL-10) were found after VCN-01 administration. Conclusions Treatment with VCN-01 is feasible and has an acceptable safety. Encouraging biological and clinical activity was observed when administered in combination with nab-paclitaxel plus gemcitabine to patients with pancreatic adenocarcinoma.MB-P, EB, and MC were funded by CDTI (PANCATHER project IDI-20130759). The clinical study was supported by VCN Biosciences

Arming Oncolytic Adenoviruses: Effect of Insertion Site and Splice Acceptor on Transgene Expression and Viral Fitness

Oncolytic adenoviruses (OAds) present limited efficacy in clinics. The insertion of therapeutic transgenes into OAds genomes, known as "arming OAds", has been the main strategy to improve their therapeutic potential. Different approaches were published in the decade of the 2000s, but with few comparisons. Most armed OAds have complete or partial E3 deletions, leading to a shorter half-life in vivo. We generated E3+ OAds using two insertion sites, After-fiber and After-E4, and two different splice acceptors linked to the major late promoter, either the Ad5 protein IIIa acceptor (IIIaSA) or the Ad40 long fiber acceptor (40SA). The highest transgene levels were obtained with the After-fiber location and 40SA. However, the set of codons of the transgene affected viral fitness, highlighting the relevance of transgene codon usage when arming OAds using the major late promoter

Active Adenoviral Vascular Penetration by Targeted Formation of Heterocellular Endothelial–epithelial Syncytia

The endothelium imposes a structural barrier to the extravasation of systemically delivered oncolytic adenovirus (Ad). Here, we introduced a transendothelial route of delivery in order to increase tumor accumulation of virus particles (vp) beyond that resulting from convection-dependent extravasation alone. This was achieved by engineering an Ad encoding a syncytium-forming protein, gibbon ape leukemia virus (GALV) fusogenic membrane glycoprotein (FMG). The expression of GALV was regulated by a hybrid viral enhancer-human promoter construct comprising the human cytomegalovirus (CMV) immediate-early enhancer and the minimal human endothelial receptor tyrosine kinase promoter (“eTie1”). Endothelial cell-selectivity of the resulting Ad-eTie1-GALV vector was demonstrated by measuring GALV mRNA transcript levels. Furthermore, Ad-eTie1-GALV selectively induced fusion between infected endothelial cells and uninfected epithelial cells in vitro and in vivo, allowing transendothelial virus penetration. Heterofusion of infected endothelium to human embryonic kidney 293 (HEK 293) cells, in mixed in vitro cultures or in murine xenograft models, permitted fusion-dependent transactivation of the replication-deficient Ad-eTie1-GALV, due to enabled access to viral E1 proteins derived from the HEK 293 cytoplasm. These data provide evidence to support our proposed use of GALV to promote Ad penetration through tumor-associated vasculature, an approach that may substantially improve the efficiency of systemic delivery of oncolytic viruses to disseminated tumors

Use of Tissue-Specific MicroRNA to Control Pathology of Wild-Type Adenovirus without Attenuation of Its Ability to Kill Cancer Cells

Replicating viruses have broad applications in biomedicine, notably in cancer virotherapy and in the design of attenuated vaccines; however, uncontrolled virus replication in vulnerable tissues can give pathology and often restricts the use of potent strains. Increased knowledge of tissue-selective microRNA expression now affords the possibility of engineering replicating viruses that are attenuated at the RNA level in sites of potential pathology, but retain wild-type replication activity at sites not expressing the relevant microRNA. To assess the usefulness of this approach for the DNA virus adenovirus, we have engineered a hepatocyte-safe wild-type adenovirus 5 (Ad5), which normally mediates significant toxicity and is potentially lethal in mice. To do this, we have included binding sites for hepatocyte-selective microRNA mir-122 within the 39 UTR of the E1A transcription cassette. Imaging versions of these viruses, produced by fusing E1A with luciferase, showed that inclusion of mir-122 binding sites caused up to 80-fold decreased hepatic expression of E1A following intravenous delivery to mice. Animals administered a ten-times lethal dose of wild-type Ad5 (5610 10 viral particles/mouse) showed substantial hepatic genome replication and extensive liver pathology, while inclusion of 4 microRNA binding sites decreased replication 50-fold and virtually abrogated liver toxicity. This modified wild-type virus retained full activity within cancer cells and provided a potent, liver-safe oncolytic virus. In addition to providing many potent new viruses for cancer virotherapy, microRNA control of virus replication should provide a new strategy for designing safe attenuated vaccines applied across a broad range of viral disease

Phase I, multicenter, open-label study of intravenous VCN-01 oncolytic adenovirus with or without nab-paclitaxel plus gemcitabine in patients with advanced solid tumors

Background VCN-01 is an oncolytic adenovirus (Ad5 based) designed to replicate in cancer cells with dysfunctional RB1 pathway, express hyaluronidase to enhance virus intratumoral spread and facilitate chemotherapy and immune cells extravasation into the tumor. This phase I clinical trial was aimed to find the maximum tolerated dose/recommended phase II dose (RP2D) and dose-limiting toxicity (DLT) of the intravenous delivery of the replication-competent VCN-01 adenovirus in patients with advanced cancer. Methods Part I: patients with advanced refractory solid tumors received one single dose of VCN-01. Parts II and III: patients with pancreatic adenocarcinoma received VCN-01 (only in cycle 1) and nab-paclitaxel plus gemcitabine (VCN-concurrent on day 1 in Part II, and 7days before chemotherapy in Part III). Patients were required to have anti-Ad5 neutralizing antibody (NAbs) titers lower than 1/350 dilution. Pharmacokinetic and pharmacodynamic analyses were performed. Results 26% of the patients initially screened were excluded based on high NAbs levels. Sixteen and 12 patients were enrolled in Part I and II, respectively: RP2D were 1 x10(13) viral particles (vp)/patient (Part I), and 3.3x10(12) vp/patient (Part II). Fourteen patients were included in Part Ill: there were no DLTs and the RP2D was 1 x10(13) vp/patient. Observed DLTs were grade 4 aspartate aminotransferase increase in one patient (Part I, 1x10(13) vp), grade 4 febrile neutropenia in one patient and grade 5 thrombocytopenia plus enterocolitis in another patient (Part II, 1 x10(13) vp). In patients with pancreatic adenocarcinoma overall response rate were 50% (Part II) and 50% (Part III). VCN-01 viral genomes were detected in tumor tissue in five out of six biopsies (day 8). A second viral plasmatic peak and increased hyaluronidase serum levels suggested replication after intravenous injection in all patients. Increased levels of immune biomarkers (interferon- r,soluble lymphocyte activation ne-3, interleukin (IL)-6, IL-10) were found after VCN-01 administration. Conclusions Treatment with VCN-01 is feasible and has an acceptable safety. Encouraging biological and clinical activity was observed when administered in combination with nab-paditaxel plus gemcitabine to patients with pancreatic adenocarcinoma

Combining Regulatory Angiogenic Gene Therapy and Virotherapy for the Treatment of Breast Cancer

This thesis describes the design of a virotherapy strategy capable of destroying both breast cancer vasculature and tumour cells, using an oncolytic adenovirus expressing angiogenesis-regulating proteins. Five oncolytic adenoviruses were compared to identify the best virotherapy agent for breast cancer, including measurement of cytotoxicity in vitro, and replication, intra-tumoural spread and anticancer efficacy in vivo. The viruses tested were Ad-dI922-947 (targets G1-8 checkpoint defects); Ad-Onyx-015 and Ad-Onyx-017 (target p53/mRNA nuclear export defects); Ad-vKH1 (targets Wnt pathway defects) and AdEHE2F (targets estrogen receptor/G1-8 checkpoint/hypoxia signalling defects). AdEHE2F demonstrated optimal oncolytic activity and selectivity against breast cancer, accordingly this virus was engineered to express potent regulatory angiogenic proteins, namely soluble Flt1 and soluble Delta like-4 (0114). sFlt1 is the soluble extra-cellular domain of VEGFR1 and binds to and sequesters VEGFA, thereby preventing VEGFR2 stimulation which is crucial to trigger angiogenesis. sOll4 is the soluble extracellular domain of 0114 and has been previously shown to block 01l4/Notch signalling. 01l4/Notch signalling increases a chaotic and non-functional angiogenesis which ultimately delays tumour growth. Importantly, VEGF and 0114 are the only angiogenesis genes reported to be haploinsufficient in vascular development and both have been shown to have a good anti-tumour effect. sFlt1 and sOll4 genes were substituted for the viral genes E3 6.7K1gp19K of AdEHE2F, thereby using endogenous adenoviral machinery to drive production. The activities of AdEHE2F viruses expressing either sFlt1 or sOll4 were compared in vitro and in vivo. sFlt1 (expressed from AdEHE2F) inhibited endothelial cell proliferation and sprouting whereas sOll4 increased proliferation and branching in vitro. In vivo AdEHE2F expressing sFlt1 or sOll4 both showed superior anticancer activity compared to parental AdEHE2F, indicating at least additive efficacy between virotherapy and regulatory angiogenic approaches.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Combining regulatory angiogenic gene therapy and virotherapy for the treatment of breast cancer

This thesis describes the design of a virotherapy strategy capable of destroying both breast cancer vasculature and tumour cells, using an oncolytic adenovirus expressing angiogenesis-regulating proteins. Five oncolytic adenoviruses were compared to identify the best virotherapy agent for breast cancer, including measurement of cytotoxicity in vitro, and replication, intra-tumoural spread and anticancer efficacy in vivo. The viruses tested were Ad-dl922-947 (targets G1-S checkpoint defects); Ad-Onyx-015 and Ad-Onyx-017 (target p53/mRNA nuclear export defects); Ad-vKH1 (targets Wnt pathway defects) and AdEHE2F (targets estrogen receptor/G1-S checkpoint/hypoxia signalling defects). AdEHE2F demonstrated optimal oncolytic activity and selectivity against breast cancer, accordingly this virus was engineered to express potent regulatory angiogenic proteins, namely soluble Flt1 and soluble Delta like-4 (Dll4). sFlt1 is the soluble extra-cellular domain of VEGFR1 and binds to and sequesters VEGF-A, thereby preventing VEGFR2 stimulation which is crucial to trigger angiogenesis. sDll4 is the soluble extracellular domain of Dll4 and has been previously shown to block Dll4/Notch signalling. Dll4/Notch signalling increases a chaotic and non-functional angiogenesis which ultimately delays tumour growth. Importantly, VEGF and Dll4 are the only angiogenesis genes reported to be haploinsufficient in vascular development and both have been shown to have a good anti-tumour effect. sFlt1 and sDll4 genes were substituted for the viral genes E3 6.7K/gp19K of AdEHE2F, thereby using endogenous adenoviral machinery to drive production. The activities of AdEHE2F viruses expressing either sFlt1 or sDll4 were compared in vitro and in vivo. sFlt1 (expressed from AdEHE2F) inhibited endothelial cell proliferation and sprouting whereas sDll4 increased proliferation and branching in vitro. In vivo AdEHE2F expressing sFlt1 or sDll4 both showed superior anticancer activity compared to parental AdEHE2F, indicating at least additive efficacy between virotherapy and regulatory angiogenic approaches.This thesis is not currently available in OR

Inhibition of Delta-like-4-mediated signaling impairs reparative angiogenesis after ischemia

Rationale: Notch signaling regulates vascular development. However, the implication of the Notch ligand Delta-like 4 (Dll4) in postischemic angiogenesis remains unclear.<p></p> Objective: We investigated the role of Dll4/Notch signaling in reparative angiogenesis using a mouse model of ischemia.<p></p> Methods and Results: We found Dll4 weakly expressed in microvascular endothelial cells of normoperfused muscles. Conversely, Dll4 is upregulated following ischemia and localized at the forefront of sprouting capillaries. We analyzed the effect of inhibiting endogenous Dll4 by intramuscular injection of an adenovirus encoding the soluble form of Dll4 extracellular domain (Ad-sDll4). Dll4 inhibition caused the formation of a disorganized, low-perfused capillary network in ischemic muscles. This structural abnormality was associated to delayed blood flow recovery and muscle hypoxia and degeneration. Analysis of microvasculature at early stages of repair revealed that Dll4 inhibition enhances capillary sprouting in a chaotic fashion and causes excessive leukocyte infiltration of ischemic muscles. Furthermore, Dll4 inhibition potentiated the elevation of the leukocyte chemoattractant CXCL1 (chemokine [C-X-C motif] ligand 1) following ischemia, without altering peripheral blood levels of stromal cell–derived factor-1 and monocyte chemoattractant protein-1. In cultured human monocytes, Dll4 induces the transcription of Notch target gene Hes-1 and inhibits the basal and tumor necrosis factor-α–stimulated production of interleukin-8, the human functional homolog of murine CXCL1. The inhibitory effect of Dll4 on interleukin-8 was abolished by DAPT, a Notch inhibitor, or by coculturing activated human monocytes with Ad-sDll4–infected endothelial cells.<p></p> Conclusions: Dll4/Notch interaction is essential for proper reparative angiogenesis. Moreover, Dll4/Notch signaling regulates sprouting angiogenesis and coordinates the interaction between inflammation and angiogenesis under ischemic conditions.<p></p