TY - JOUR A1 - Weibel, Stephanie A1 - Basse-Luesebrink, Thomas Christian A1 - Hess, Michael A1 - Hofmann, Elisabeth A1 - Seubert, Carolin A1 - Langbein-Laugwitz, Johanna A1 - Gentschev, Ivaylo A1 - Sturm, Volker Jörg Friedrich A1 - Ye, Yuxiang A1 - Kampf, Thomas A1 - Jakob, Peter Michael A1 - Szalay, Aladar A. T1 - Imaging of Intratumoral Inflammation during Oncolytic Virotherapy of Tumors by \(^{19}\)F-Magnetic Resonance Imaging (MRI) JF - PLoS ONE N2 - Background Oncolytic virotherapy of tumors is an up-coming, promising therapeutic modality of cancer therapy. Unfortunately, non-invasive techniques to evaluate the inflammatory host response to treatment are rare. Here, we evaluate \(^{19}\)F magnetic resonance imaging (MRI) which enables the non-invasive visualization of inflammatory processes in pathological conditions by the use of perfluorocarbon nanoemulsions (PFC) for monitoring of oncolytic virotherapy. Methodology/Principal Findings The Vaccinia virus strain GLV-1h68 was used as an oncolytic agent for the treatment of different tumor models. Systemic application of PFC emulsions followed by \(^1H\)/\(^{19}\)F MRI of mock-infected and GLV-1h68-infected tumor-bearing mice revealed a significant accumulation of the \(^{19}\)F signal in the tumor rim of virus-treated mice. Histological examination of tumors confirmed a similar spatial distribution of the \(^{19}\)F signal hot spots and \(CD68^+\)-macrophages. Thereby, the \(CD68^+\)-macrophages encapsulate the GFP-positive viral infection foci. In multiple tumor models, we specifically visualized early inflammatory cell recruitment in Vaccinia virus colonized tumors. Furthermore, we documented that the \(^{19}\)F signal correlated with the extent of viral spreading within tumors. Conclusions/Significance These results suggest \(^{19}\)F MRI as a non-invasive methodology to document the tumor-associated host immune response as well as the extent of intratumoral viral replication. Thus, \(^{19}\)F MRI represents a new platform to non-invasively investigate the role of the host immune response for therapeutic outcome of oncolytic virotherapy and individual patient response. KW - inflammation KW - fluorescence microscopy KW - oncolytic viruses KW - fluorescence imaging KW - macrophages KW - magnetic resonance imaging KW - histology KW - in vivo imaging Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130311 VL - 8 IS - 3 ER - TY - JOUR A1 - Ehrig, Klaas A1 - Kilinc, Mehmet O. A1 - Chen, Nanhai G. A1 - Stritzker, Jochen A1 - Buckel, Lisa A1 - Zhang, Qian A1 - Szalay, Aladar A. T1 - Growth inhibition of different human colorectal cancer xenografts after a single intravenous injection of oncolytic vaccinia virus GLV-1h68 JF - Journal of Translational Medicine N2 - Background: Despite availability of efficient treatment regimens for early stage colorectal cancer, treatment regimens for late stage colorectal cancer are generally not effective and thus need improvement. Oncolytic virotherapy using replication-competent vaccinia virus (VACV) strains is a promising new strategy for therapy of a variety of human cancers. Methods: Oncolytic efficacy of replication-competent vaccinia virus GLV-1h68 was analyzed in both, cell cultures and subcutaneous xenograft tumor models. Results: In this study we demonstrated for the first time that the replication-competent recombinant VACV GLV-1h68 efficiently infected, replicated in, and subsequently lysed various human colorectal cancer lines (Colo 205, HCT-15, HCT-116, HT-29, and SW-620) derived from patients at all four stages of disease. Additionally, in tumor xenograft models in athymic nude mice, a single injection of intravenously administered GLV-1h68 significantly inhibited tumor growth of two different human colorectal cell line tumors (Duke’s type A-stage HCT-116 and Duke’s type C-stage SW-620), significantly improving survival compared to untreated mice. Expression of the viral marker gene ruc-gfp allowed for real-time analysis of the virus infection in cell cultures and in mice. GLV-1h68 treatment was well-tolerated in all animals and viral replication was confined to the tumor. GLV-1h68 treatment elicited a significant up-regulation of murine immune-related antigens like IFN-γ, IP-10, MCP-1, MCP-3, MCP-5, RANTES and TNF-γ and a greater infiltration of macrophages and NK cells in tumors as compared to untreated controls. Conclusion: The anti-tumor activity observed against colorectal cancer cells in these studies was a result of direct viral oncolysis by GLV-1h68 and inflammation-mediated innate immune responses. The therapeutic effects occurred in tumors regardless of the stage of disease from which the cells were derived. Thus, the recombinant vaccinia virus GLV-1h68 has the potential to treat colorectal cancers independently of the stage of progression. KW - oncolytic virotherapy KW - colorectal KW - vaccinia virus KW - cancer KW - metastasis Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129619 VL - 11 IS - 79 ER - TY - JOUR A1 - Duggal, Rohit A1 - Geissinger, Ulrike A1 - Zhang, Qian A1 - Aguilar, Jason A1 - Chen, Nanhai G. A1 - Binda, Elena A1 - Vescovi, Angelo L. A1 - Szalay, Aladar A. T1 - Vaccinia virus expressing bone morphogenetic protein-4 in novel glioblastoma orthotopic models facilitates enhanced tumor regression and long-term survival JF - Journal of Translational Medicine N2 - No abstract availableBackground: Glioblastoma multiforme (GBM) is one of the most aggressive forms of cancer with a high rate of recurrence. We propose a novel oncolytic vaccinia virus (VACV)-based therapy using expression of the bone morphogenetic protein (BMP)-4 for treating GBM and preventing recurrence. Methods: We have utilized clinically relevant, orthotopic xenograft models of GBM based on tumor-biopsy derived, primary cancer stem cell (CSC) lines. One of the cell lines, after being transduced with a cDNA encoding firefly luciferase, could be used for real time tumor imaging. A VACV that expresses BMP-4 was constructed and utilized for infecting several primary glioma cultures besides conventional serum-grown glioma cell lines. This virus was also delivered intracranially upon implantation of the GBM CSCs in mice to determine effects on tumor growth. Results: We found that the VACV that overexpresses BMP-4 demonstrated heightened replication and cytotoxic activity in GBM CSC cultures with a broad spectrum of activity across several different patient-biopsy cultures. Intracranial inoculation of mice with this virus resulted in a tumor size equal to or below that at the time of injection. This resulted in survival of 100% of the treated mice up to 84 days post inoculation, significantly superior to that of a VACV lacking BMP-4 expression. When mice with a higher tumor burden were injected with the VACV lacking BMP-4, 80% of the mice showed tumor recurrence. In contrast, no recurrence was seen when mice were injected with the VACV expressing BMP-4, possibly due to induction of differentiation in the CSC population and subsequently serving as a better host for VACV infection and oncolysis. This lack of recurrence resulted in superior survival in the BMP-4 VACV treated group. Conclusions: Based on these findings we propose a novel VACV therapy for treating GBM, which would allow tumor specific production of drugs in the future in combination with BMPs which would simultaneously control tumor maintenance and facilitate CSC differentiation, respectively, thereby causing sustained tumor regression without recurrence. KW - cancer stem cells (CSCs) and differentiation KW - glioblastoma multiforme (GBM) KW - vaccinia virus (VACV) KW - bone morphogenetic protein (BMP) Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129626 VL - 11 IS - 155 ER - TY - JOUR A1 - Wang, Huiqiang A1 - Chen, Nanhai G. A1 - Minev, Boris R. A1 - Szalay, Aladar A. T1 - Oncolytic vaccinia virus GLV-1h68 strain shows enhanced replication in human breast cancer stem-like cells in comparison to breast cancer cells JF - Journal of Translational Medicine N2 - Background: Recent data suggest that cancer stem cells (CSCs) play an important role in cancer, as these cells possess enhanced tumor-forming capabilities and are responsible for relapses after apparently curative therapies have been undertaken. Hence, novel cancer therapies will be needed to test for both tumor regression and CSC targeting. The use of oncolytic vaccinia virus (VACV) represents an attractive anti-tumor approach and is currently under evaluation in clinical trials. The purpose of this study was to demonstrate whether VACV does kill CSCs that are resistant to irradiation and chemotherapy. Methods: Cancer stem-like cells were identified and separated from the human breast cancer cell line GI-101A by virtue of increased aldehyde dehydrogenase 1 (ALDH1) activity as assessed by the ALDEFLUOR assay and cancer stem cell-like features such as chemo-resistance, irradiation-resistance and tumor-initiating were confirmed in cell culture and in animal models. VACV treatments were applied to both ALDEFLUOR-positive cells in cell culture and in xenograft tumors derived from these cells. Moreover, we identified and isolated CD44\(^+\)CD24\(^+\)ESA\(^+\) cells from GI-101A upon an epithelial-mesenchymal transition (EMT). These cells were similarly characterized both in cell culture and in animal models. Results: We demonstrated for the first time that the oncolytic VACV GLV-1h68 strain replicated more efficiently in cells with higher ALDH1 activity that possessed stem cell-like features than in cells with lower ALDH1 activity. GLV-1h68 selectively colonized and eventually eradicated xenograft tumors originating from cells with higher ALDH1 activity. Furthermore, GLV-1h68 also showed preferential replication in CD44\(^+\)CD24\(^+\)ESA\(^+\) cells derived from GI-101A upon an EMT induction as well as in xenograft tumors originating from these cells that were more tumorigenic than CD44\(^+\)CD24\(^-\)ESA\(^+\) cells. Conclusions: Taken together, our findings indicate that GLV-1h68 efficiently replicates and kills cancer stem-like cells. Thus, GLV-1h68 may become a promising agent for eradicating both primary and metastatic tumors, especially tumors harboring cancer stem-like cells that are resistant to chemo and/or radiotherapy and may be responsible for recurrence of tumors. KW - tumors KW - therapy KW - metastasis KW - identification KW - lines KW - gene expression KW - in-vitro propagation KW - acute myeloid leukemia KW - epithelial-mesenchymal transition KW - subpopulation Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130019 VL - 10 IS - 167 ER - TY - JOUR A1 - Patil, Sandeep S. A1 - Gentschev, Ivaylo A1 - Adelfinger, Marion A1 - Donat, Ulrike A1 - Hess, Michael A1 - Weibel, Stephanie A1 - Nolte, Ingo A1 - Frentzen, Alexa A1 - Szalay, Aladar A. T1 - Virotherapy of Canine Tumors with Oncolytic Vaccinia Virus GLV-1h109 Expressing an Anti-VEGF Single-Chain Antibody JF - PLoS One N2 - Virotherapy using oncolytic vaccinia virus (VACV) strains is one promising new strategy for cancer therapy. We have previously reported that oncolytic vaccinia virus strains expressing an anti-VEGF (Vascular Endothelial Growth Factor) single-chain antibody (scAb) GLAF-1 exhibited significant therapeutic efficacy for treatment of human tumor xenografts. Here, we describe the use of oncolytic vaccinia virus GLV-1h109 encoding GLAF-1 for canine cancer therapy. In this study we analyzed the virus-mediated delivery and production of scAb GLAF-1 and the oncolytic and immunological effects of the GLV-1h109 vaccinia virus strain against canine soft tissue sarcoma and canine prostate carcinoma in xenograft models. Cell culture data demonstrated that the GLV-1h109 virus efficiently infect, replicate in and destroy both tested canine cancer cell lines. In addition, successful expression of GLAF-1 was demonstrated in virus-infected canine cancer cells and the antibody specifically recognized canine VEGF. In two different xenograft models, the systemic administration of the GLV-1h109 virus was found to be safe and led to anti-tumor and immunological effects resulting in the significant reduction of tumor growth in comparison to untreated control mice. Furthermore, tumor-specific virus infection led to a continued production of functional scAb GLAF-1, resulting in inhibition of angiogenesis. Overall, the GLV-1h109-mediated cancer therapy and production of immunotherapeutic anti-VEGF scAb may open the way for combination therapy concept i.e. vaccinia virus mediated oncolysis and intratumoral production of therapeutic drugs in canine cancer patients. KW - angiogenesis KW - microenvironment KW - model KW - cancer KW - therapy KW - pet dogs KW - nude-mice KW - breast-tumors KW - microvascular density KW - endothelial growth-factor Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130039 VL - 7 IS - 10 ER - TY - JOUR A1 - Haddad, Dana A1 - Chen, Chun-Hao A1 - Carlin, Sean A1 - Silberhumer, Gerd A1 - Chen, Nanhai G. A1 - Zhang, Qian A1 - Longo, Valerie A1 - Carpenter, Susanne G. A1 - Mittra, Arjun A1 - Carson, Joshua A1 - Au, Joyce A1 - Gonen, Mithat A1 - Zanzonico, Pat B. A1 - Szalay, Aladar A. A1 - Fong, Yuman T1 - Imaging Characteristics, Tissue Distribution, and Spread of a Novel Oncolytic Vaccinia Virus Carrying the Human Sodium Iodide Symporter JF - PLoS One N2 - Introduction: Oncolytic viruses show promise for treating cancer. However, to assess therapy and potential toxicity, a noninvasive imaging modality is needed. This study aims to determine the in vivo biodistribution, and imaging and timing characteristics of a vaccinia virus, GLV-1h153, encoding the human sodium iodide symporter (hNIS. Methods: GLV-1h153 was modified from GLV-1h68 to encode the hNIS gene. Timing of cellular uptake of radioiodide \(^{131}\)I in human pancreatic carcinoma cells PANC-1 was assessed using radiouptake assays. Viral biodistribution was determined in nude mice bearing PANC-1 xenografts, and infection in tumors confirmed histologically and optically via Green Fluorescent Protein (GFP) and bioluminescence. Timing characteristics of enhanced radiouptake in xenografts were assessed via \(^{124}\)I-positron emission tomography (PET). Detection of systemic administration of virus was investigated with both \(^{124}\)I-PET and 99m-technecium gamma-scintigraphy. Results: GLV-1h153 successfully facilitated time-dependent intracellular uptake of \(^{131}\)I in PANC-1 cells with a maximum uptake at 24 hours postinfection (P < 0.05). In vivo, biodistribution profiles revealed persistence of virus in tumors 5 weeks postinjection at 10\(^9\) plaque-forming unit (PFU)/gm tissue, with the virus mainly cleared from all other major organs. Tumor infection by GLV-1h153 was confirmed via optical imaging and histology. GLV-1h153 facilitated imaging virus replication in tumors via PET even at 8 hours post radiotracer injection, with a mean % ID/gm of 3.82 \(\pm\) 60.46 (P < 0.05) 2 days after intratumoral administration of virus, confirmed via tissue radiouptake assays. One week post systemic administration, GLV1h153-infected tumors were detected via \(^{124}\)I-PET and 99m-technecium-scintigraphy. Conclusion: GLV-1h153 is a promising oncolytic agent against pancreatic cancer with a promising biosafety profile. GLV-1h153 facilitated time-dependent hNIS-specific radiouptake in pancreatic cancer cells, facilitating detection by PET with both intratumoral and systemic administration. Therefore, GLV-1h153 is a promising candidate for the noninvasive imaging of virotherapy and warrants further study into longterm monitoring of virotherapy and potential radiocombination therapies with this treatment and imaging modality. KW - nude mice KW - pancreatic cancer KW - engineered measles-virus KW - positron-emission-tomography KW - malignant pleural mesothelioma KW - reporter gene KW - replicating adenovirus KW - NA/I symporter KW - breast cancer KW - viral therapy Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130041 VL - 7 IS - 8 ER - TY - JOUR A1 - Hofmann, Elisabeth A1 - Weibel, Stephanie A1 - Szalay, Aladar A. T1 - Combination treatment with oncolytic Vaccinia virus and cyclophosphamide results in synergistic antitumor effects in human lung adenocarcinoma bearing mice N2 - Background The capacity of the recombinant Vaccinia virus GLV-1h68 as a single agent to efficiently treat different human or canine cancers has been shown in several preclinical studies. Currently, its human safety and efficacy are investigated in phase I/II clinical trials. In this study we set out to evaluate the oncolytic activity of GLV-1h68 in the human lung adenocarcinoma cell line PC14PE6-RFP in cell cultures and analyzed the antitumor potency of a combined treatment strategy consisting of GLV-1h68 and cyclophosphamide (CPA) in a mouse model of PC14PE6-RFP lung adenocarcinoma. Methods PC14PE6-RFP cells were treated in cell culture with GLV-1h68. Viral replication and cell survival were determined by plaque assays and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively. Subcutaneously implanted PC14PE6-RFP xenografts were treated by systemic injection of GLV-1h68, CPA or a combination of both. Tumor growth and viral biodistribution were monitored and immune-related antigen profiling of tumor lysates was performed. Results GLV-1h68 efficiently infected, replicated in and lysed human PC14PE6-RFP cells in cell cultures. PC14PE6-RFP tumors were efficiently colonized by GLV-1h68 leading to much delayed tumor growth in PC14PE6-RFP tumor-bearing nude mice. Combination treatment with GLV-1h68 and CPA significantly improved the antitumor efficacy of GLV-1h68 and led to an increased viral distribution within the tumors. Pro-inflammatory cytokines and chemokines were distinctly elevated in tumors of GLV-1h68-treated mice. Factors expressed by endothelial cells or present in the blood were decreased after combination treatment. A complete loss in the hemorrhagic phenotype of the PC14PE6-RFP tumors and a decrease in the number of blood vessels after combination treatment could be observed. Conclusions CPA and GLV-1h68 have synergistic antitumor effects on PC14PE6-RFP xenografts. We strongly suppose that in the PC14PE6-RFP model the enhanced tumor growth inhibition achieved by combining GLV-1h68 with CPA is due to an effect on the vasculature rather than an immunosuppressive action of CPA. These results provide evidence to support further preclinical studies of combining GLV-1h68 and CPA in other highly angiogenic tumor models. Moreover, data presented here demonstrate that CPA can be combined successfully with GLV-1h68 based oncolytic virus therapy and therefore might be promising as combination therapy in human clinical trials. KW - Vaccinia virus KW - Chemotherapy KW - Combination therapy KW - Cyclophosphamide KW - Lung cancer Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110168 ER - TY - JOUR A1 - Schäfer, Simon A1 - Weibel, Stephanie A1 - Donat, Ulrike A1 - Zhang, Qian A1 - Aguilar, Richard J. A1 - Chen, Nanhai G. A1 - Szalay, Aladar A. T1 - Vaccinia virus-mediated intra-tumoral expression of matrix metalloproteinase 9 enhances oncolysis of PC-3 xenograft tumors N2 - Background: Oncolytic viruses, including vaccinia virus (VACV), are a promising alternative to classical mono-cancer treatment methods such as surgery, chemo- or radiotherapy. However, combined therapeutic modalities may be more effective than mono-therapies. In this study, we enhanced the effectiveness of oncolytic virotherapy by matrix metalloproteinase (MMP-9)-mediated degradation of proteins of the tumoral extracellular matrix (ECM), leading to increased viral distribution within the tumors. Methods: For this study, the oncolytic vaccinia virus GLV-1h255, containing the mmp-9 gene, was constructed and used to treat PC-3 tumor-bearing mice, achieving an intra-tumoral over-expression of MMP-9. The intra-tumoral MMP-9 content was quantified by immunohistochemistry in tumor sections. Therapeutic efficacy of GLV-1h255 was evaluated by monitoring tumor growth kinetics and intra-tumoral virus titers. Microenvironmental changes mediated by the intra-tumoral MMP-9 over-expression were investigated by microscopic quantification of the collagen IV content, the blood vessel density (BVD) and the analysis of lymph node metastasis formation. Results: GLV-1h255-treatment of PC-3 tumors led to a significant over-expression of intra-tumoral MMP-9, accompanied by a marked decrease in collagen IV content in infected tumor areas, when compared to GLV-1h68-infected tumor areas. This led to considerably elevated virus titers in GLV-1h255 infected tumors, and to enhanced tumor regression. The analysis of the BVD, as well as the lumbar and renal lymph node volumes, revealed lower BVD and significantly smaller lymph nodes in both GLV-1h68- and GLV-1h255- injected mice compared to those injected with PBS, indicating that MMP-9 over-expression does not alter the metastasis-reducing effect of oncolytic VACV. Conclusions: Taken together, these results indicate that a GLV-1h255-mediated intra-tumoral over-expression of MMP-9 leads to a degradation of collagen IV, facilitating intra-tumoral viral dissemination, and resulting in accelerated tumor regression. We propose that approaches which enhance the oncolytic effect by increasing the intra-tumoral viral load, may be an effective way to improve therapeutic outcome. KW - Biochemie Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78220 ER - TY - JOUR A1 - Draganov, Dobrin D. A1 - Santidrian, Antonio F. A1 - Minev, Ivelina A1 - Duong, Nguyen A1 - Kilinc, Mehmet Okyay A1 - Petrov, Ivan A1 - Vyalkova, Anna A1 - Lander, Elliot A1 - Berman, Mark A1 - Minev, Boris A1 - Szalay, Aladar A. T1 - Delivery of oncolytic vaccinia virus by matched allogeneic stem cells overcomes critical innate and adaptive immune barriers JF - Journal of Translational Medicine N2 - Background Previous studies have identified IFNγ as an important early barrier to oncolytic viruses including vaccinia. The existing innate and adaptive immune barriers restricting oncolytic virotherapy, however, can be overcome using autologous or allogeneic mesenchymal stem cells as carrier cells with unique immunosuppressive properties. Methods To test the ability of mesenchymal stem cells to overcome innate and adaptive immune barriers and to successfully deliver oncolytic vaccinia virus to tumor cells, we performed flow cytometry and virus plaque assay analysis of ex vivo co-cultures of stem cells infected with vaccinia virus in the presence of peripheral blood mononuclear cells from healthy donors. Comparative analysis was performed to establish statistically significant correlations and to evaluate the effect of stem cells on the activity of key immune cell populations. Results Here, we demonstrate that adipose-derived stem cells (ADSCs) have the potential to eradicate resistant tumor cells through a combination of potent virus amplification and sensitization of the tumor cells to virus infection. Moreover, the ADSCs demonstrate ability to function as a virus-amplifying Trojan horse in the presence of both autologous and allogeneic human PBMCs, which can be linked to the intrinsic immunosuppressive properties of stem cells and their unique potential to overcome innate and adaptive immune barriers. The clinical application of ready-to-use ex vivo expanded allogeneic stem cell lines, however, appears significantly restricted by patient-specific allogeneic differences associated with the induction of potent anti-stem cell cytotoxic and IFNγ responses. These allogeneic responses originate from both innate (NK)- and adaptive (T)- immune cells and might compromise therapeutic efficacy through direct elimination of the stem cells or the induction of an anti-viral state, which can block the potential of the Trojan horse to amplify and deliver vaccinia virus to the tumor. Conclusions Overall, our findings and data indicate the feasibility to establish simple and informative assays that capture critically important patient-specific differences in the immune responses to the virus and stem cells, which allows for proper patient-stem cell matching and enables the effective use of off-the-shelf allogeneic cell-based delivery platforms, thus providing a more practical and commercially viable alternative to the autologous stem cell approach. KW - vaccinia KW - cancer KW - stem Cells KW - oncolysis KW - oncolytic virus KW - virotherapy KW - immunity KW - immunotherapy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226312 SN - 100 VL - 17 ER - TY - JOUR A1 - Minev, Boris R. A1 - Lander, Elliot A1 - Feller, John F. A1 - Berman, Mark A1 - Greenwood, Bernadette M. A1 - Minev, Ivelina A1 - Santidrian, Antonio F. A1 - Nguyen, Duong A1 - Draganov, Dobrin A1 - Killinc, Mehmet O. A1 - Vyalkova, Anna A1 - Kesari, Santosh A1 - McClay, Edward A1 - Carabulea, Gabriel A1 - Marincola, Francesco M. A1 - Butterfield, Lisa H. A1 - Szalay, Aladar A. T1 - First-in-human study of TK-positive oncolytic vaccinia virus delivered by adipose stromal vascular fraction cells JF - Journal of Translational Medicine N2 - Background ACAM2000, a thymidine kinase (TK)-positive strain of vaccinia virus, is the current smallpox vaccine in the US. Preclinical testing demonstrated potent oncolytic activity of ACAM2000 against several tumor types. This Phase I clinical trial of ACAM2000 delivered by autologous adipose stromal vascular fraction (SVF) cells was conducted to determine the safety and feasibility of such a treatment in patients with advanced solid tumors or acute myeloid leukemia (AML). Methods Twenty-four patients with solid tumors and two patients with AML participated in this open-label, non-randomized dose-escalation trial. All patients were treated with SVF derived from autologous fat and incubated for 15 min to 1 h with ACAM2000 before application. Six patients received systemic intravenous application only, one patient received intra-tumoral application only, 15 patients received combination intravenous with intra-tumoral deployment, 3 patients received intravenous and intra-peritoneal injection and 1 patient received intravenous, intra-tumoral and intra-peritoneal injections. Safety at each dose level of ACAM2000 (1.4 × 106 plaque-forming units (PFU) to 1.8 × 107 PFU) was evaluated. Blood samples for PK assessments, flow cytometry and cytokine analysis were collected at baseline and 1 min, 1 h, 1 day, 1 week, 1 month, 3 months and 6 months following treatment. Results No serious toxicities (> grade 2) were reported. Seven patients reported an adverse event (AE) in this study: self-limiting skin rashes, lasting 7 to 18 days—an expected adverse reaction to ACAM2000. No AEs leading to study discontinuation were reported. Viral DNA was detected in all patients’ blood samples immediately following treatment. Interestingly, in 8 patients viral DNA disappeared 1 day and re-appeared 1 week post treatment, suggesting active viral replication at tumor sites, and correlating with longer survival of these patients. No major increase in cytokine levels or correlation between cytokine levels and skin rashes was noted. We were able to assess some initial efficacy signals, especially when the ACAM2000/SVF treatment was combined with checkpoint inhibition. Conclusions Treatment with ACAM2000/SVF in patients with advanced solid tumors or AML is safe and well tolerated, and several patients had signals of an anticancer effect. These promising initial clinical results merit further investigation of therapeutic utility. Trial registration Retrospectively registered (ISRCTN#10201650) on October 22, 2018. KW - clinical trial KW - oncolytic vaccinia virus KW - stromal vascular fraction KW - immunotherapy of cancer Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224105 VL - 17 ER -