Kerry Fisher

Publications of Kerry Fisher

• Virotherapy - cancer targeted pharmacology.

  Authors: Alison Tedcastle, Ryan Cawood, Ying Di, Kerry D Fisher, Len W Seymour

  Drug discovery today. 12/2011; 17(5-6):215-20.

  Building on their success in vaccination, many groups are now exploring the use of viruses as anticancer agents. In general, viral therapeutics provide the possibility to express anticancer proteinsBuilding on their success in vaccination, many groups are now exploring the use of viruses as anticancer agents. In general, viral therapeutics provide the possibility to express anticancer proteins directly at the tumour site, decreasing exposure to normal tissue during delivery and maximising therapeutic index. Some viruses are also 'oncolytic', either naturally or by design, and these agents function to kill cancer cells selectively before spreading to infect adjacent cells and repeat the process. This whole field of cancer 'virotherapy' is moving forward rapidly at the moment, with notable clinical successes demonstrated with a range of oncolytic agents developed as directly oncolytic and also as oncolytic cancer vaccines. Given the versatility of oncolytic viruses to express therapeutic proteins we anticipate this approach will provide the platform for useful application of a broad range of innovative biological therapies.

• Adenovirus vector vaccination induces expansion of memory CD4 T cells with a mucosal homing phenotype that are readily susceptible to HIV-1.

  Authors: Adel Benlahrech, Julian Harris, Andrea Meiser, Timos Papagatsias, Julia Hornig, Peter Hayes, Andre Lieber, Takis Athanasopoulos, Veronique Bachy, Eszter Csomor, Rod Daniels, Kerry Fisher, Frances Gotch, Len Seymour, Karen Logan, Romina Barbagallo, Linda Klavinskis, George Dickson, Steven Patterson

  Proceedings of the National Academy of Sciences of the United States of America. 11/2009;

  In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5 vaccine. We propose that this was due to activation and expansion of Ad5-specific mucosal-homing memory CD4 T cells. To test this hypothesis, Ad5 and Ad11 antibody titers were measured in 20 healthy volunteers. Dendritic cells (DCs) from these individuals were pulsed with replication defective Ad5 or Ad11 and co-cultured with autologous lymphocytes. Cytokine profiles, proliferative capacity, mucosal migration potential, and susceptibility to HIV infection of the adenovirus-stimulated memory CD4 T cells were measured. Stimulation of T cells from healthy Ad5-seropositive but Ad11-seronegative individuals with Ad5, or serologically distinct Ad11 vectors induced preferential expansion of adenovirus memory CD4 T cells expressing alpha(4)beta(7) integrins and CCR9, indicating a mucosal-homing phenotype. CD4 T-cell proliferation and IFN-gamma production in response to Ad stimulation correlated with Ad5 antibody titers. However, Ad5 serostatus did not correlate with total cytokine production upon challenge with Ad5 or Ad11. Expanded Ad5 and Ad11 memory CD4 T cells showed an increase in CCR5 expression and higher susceptibility to infection by R5 tropic HIV-1. This suggests that adenoviral-based vaccination against HIV-1 in individuals with preexisting immunity against Ad5 results in preferential expansion of HIV-susceptible activated CD4 T cells that home to mucosal tissues, increases the number of virus targets, and leads to a higher susceptibility to HIV acquisition.

• Cetuximab retargeting of adenovirus via the epidermal growth factor receptor for treatment of intraperitoneal ovarian cancer.

  Authors: Joanne Morrison, Simon S Briggs, Nicola K Green, Clemens Thoma, Kerry Fisher, Sean T Kehoe, Leonard William Seymour

  Human gene therapy. 01/2009;

  Aims: Gene and viro-therapy of ovarian cancer using type 5 adenovirus (Ad5) has demonstrated good activity in pre-clinical animal studies, particularly following intraperitoneal administration ofAims: Gene and viro-therapy of ovarian cancer using type 5 adenovirus (Ad5) has demonstrated good activity in pre-clinical animal studies, particularly following intraperitoneal administration of virus, however success in clinical trials has been limited by poor infectivity of ovarian cancer cells and inflammatory responses to Ad5. We previously demonstrated that covalent modification of Ad5 with reactive co-polymers based on poly hydroxypropylmethacrylamide (pHPMA) can shield the virus, offering protection from neutralizing antibodies and enabling retargeting to cancer up-regulated receptors using peptide ligands (basic Fibroblast Growth Factor, bFGF and murine Epidermal Growth Factor, EGF). These ligands may be less than ideal for clinical use, however, since they are potential mitogens. Accordingly in this study we investigated the use of an anti-EGF receptor (EGFR) antibody, cetuximab, to retarget adenovirus transduction of EGFR positive cells in vitro and in vivo. Results: Cetuximab retargeting altered the physico-chemical characteristics of Ad5, although it did not cause particle aggregation. While cetuximab stimulated internalization of EGFR, similarly to EGF, it inhibited EGFR phosphorylation. Adenovirus transduction was inhibited following polymer coating, but was rescued in EGFR-positive cells (and not in EGFR-negative cells) by cetuximab retargeting. Cetuximab retargeting of wild type adenovirus serotype 5 (Ad5WT) prolonged survival in an animal model of human ovarian cancer, similar to unmodified Ad5WT, but polymer-coating ameliorated stimulation of adhesion formation. Conclusions: Polymer-coating and covalent attachment of cetuximab successfully retargeted adenovirus to EGFR-positive cells, retained in vivo efficacy of an oncolytic adenovirus and ameliorated side effects caused by unmodified adenovirus.

• Cancer gene therapy with targeted adenoviruses.

  Authors: Houria Bachtarzi, Mark Stevenson, Kerry Fisher

  Expert opinion on drug delivery. 12/2008; 5(11):1231-40.

  Background: Clinical experience with adenovirus vectors has highlighted the need for improved delivery and targeting. Objective: This manuscript aims to provide an overview of the techniquesBackground: Clinical experience with adenovirus vectors has highlighted the need for improved delivery and targeting. Objective: This manuscript aims to provide an overview of the techniques currently under development for improving adenovirus delivery to malignant cells in vivo. Methods: Primary research articles reporting improvements in adenoviral gene delivery are described. Strategies include genetic modification of viral coat proteins, non-genetic modifications including polymer encapsulation approaches and pharmacological interventions. Results/conclusion: Reprogramming adenovirus tropism in vitro has been convincingly demonstrated using a range of genetic and physical strategies. These studies have provided new insights into our understanding of virology and the field is progressing. However, there are still some limitations that need special consideration before adenovirus-targeted cancer gene therapy emerges as a routine treatment in the clinical setting.

• Coating of adenovirus type 5 with polymers containing quaternary amines prevents binding to blood components.

  Authors: Vladimir Subr, Libor Kostka, Tom Selby-Milic, Kerry Fisher, Karel Ulbrich, Leonard W Seymour, Robert C Carlisle

  Journal of controlled release : official journal of the Controlled Release Society. 12/2008;

  Adenovirus type 5 (Ad5) gene therapy vectors require protection against antibodies, complement proteins and blood cells if they are to be delivered intravenously to treat metastatic disease. SuchAdenovirus type 5 (Ad5) gene therapy vectors require protection against antibodies, complement proteins and blood cells if they are to be delivered intravenously to treat metastatic disease. Such protection can be achieved by chemically modifying Ad5 with polymers based on hydrophilic HPMA. Here, such polymers were designed to include side chains bearing reactive carbonyl thiazolidine-2-thione groups (TTs) to covalently modify available amino groups of the lysine residues in the Ad5 capsid. Furthermore, the inclusion of side chains bearing positively charged quaternary ammonium groups (QAs) was designed to improve electrostatic interaction of the polymers with negatively charged Ad5 hexon protein. Finally, to enable triggered uncoating and reactivation of the Ad5, either the TTs or both the TTs and the QAs were linked to polymer backbone via reductively degradable disulfide bonds. SDS-PAGE demonstrated that these polymers covalently modified Ad5 capsid proteins in a reduction reversible manner. In infection studies, polymers containing QAs prevented binding of coagulation factor X to Ad5. Furthermore, the antibody and complement mediated binding of Ad5 to erythrocytes was reduced by such polymers (>95% without polymer, 25% following coating). These data indicate that coating Ad5 therapeutics with such polymers will improve blood circulation half-life and deposition at disease sites.

• Hyperthermia-induced targeting of thermosensitive gene carriers to tumors.

  Authors: Alenka Schwerdt, Arkadi Zintchenko, Massimo Concia, Nick Roesen, Kerry Fisher, Lars H Lindner, Rolf Issels, Ernst Wagner, Manfred Ogris

  Human gene therapy. 11/2008; 19(11):1283-92.

  Locoregional hyperthermia (HT) can be used for site-directed activation of macromolecular drug delivery systems. We have developed a gene delivery system based on thermosensitive block copolymersLocoregional hyperthermia (HT) can be used for site-directed activation of macromolecular drug delivery systems. We have developed a gene delivery system based on thermosensitive block copolymers (TSCs) with a phase transition temperature of 42 degrees C [Zintchenko, A., Ogris, M., and Wagner, E. (2006). Bioconjug. Chem. 17, 766-772], in which the statistical copolymer of vinylpyrrolidinone and N-isopropylacryamide is grafted on polyethylenimine (PEI). Here we applied polyplexes consisting of plasmid DNA and TSCs systemically in A/J mice bearing a syngeneic Neuro2A neuroblastoma tumor subcutaneously in each hind limb. One limb was selectively treated by HT at 42 degrees C, at the same time that polyplexes were injected via the tail vein. Hyperthermia led to increased accumulation of thermosensitive polymer and aggregation of thermosensitive polyplexes in HT-treated tumors, resulting in up to 10-fold increased DNA deposition compared with non-HT-treated tumor. The level of transgene expression induced by TSC polyplexes in HT-treated tumors was significantly higher and selective for tumor tissue. With nonthermosensitive PEI polyplexes HT did not influence transgene deposition or expression in tumor.

• Comparison of Molecular Strategies for Breast Cancer Virotherapy using Oncolytic Adenovirus.

  Authors: Leonard William Seymour, Miriam Bazan-Peregrino, Robert Carlisle, Ruben Hernandez-Alcoceba, Richard Iggo, Krisztian Homicsko, Gunnel Hallden, Vivien Mautner, Jerry Shen, Kerry Fisher

  Human gene therapy. 06/2008;

  Oncolytic viruses are regulated by the tumour phenotype to replicate and lyse cancer cells selectively. To identify optimal strategies for breast cancer we compared five adenoviruses with distinctOncolytic viruses are regulated by the tumour phenotype to replicate and lyse cancer cells selectively. To identify optimal strategies for breast cancer we compared five adenoviruses with distinct regulatory mechanisms: Ad-dl922-947 (targets G1-S checkpoint); Ad-Onyx-015 and Ad-Onyx-017 (target p53/mRNA export); Ad-vKH1 (targets Wnt pathway) and AdEHE2F (targets estrogen receptor/G1-S checkpoint/hypoxic signalling). The quantity of virus required to kill 50% of breast cancer cells after 6 days (EC50, PFU/cell) was measured. The most potent virus was Ad-dl922-947 (EC50 0.01-5.4 in SkBr3, MDA-231, MDA-468, MCF7, ZR75.1), followed by wild type (Ad-WT; EC50 0.3-5.5) and AdEHE2F (EC50 1.4-3.9). Ad-vKH1 (EC50 7.2-72.1), Ad-Onyx-017 (EC50 8.4-167) and Ad-Onyx-015 (EC50 17.7-377) showed less activity. Most viruses showed very limited cytotoxicity in normal human cells, including breast epithelium MCF10A (EC50 >722) and fibroblasts (EC50 >192) and only moderate cytotoxicity in normal microvascular endothelial cells (HMVEC, EC50 42.8-149), except Ad-dl922-947 which was active in HMVEC (EC50 1.6). After injection into MDA-231 xenografts, Ad-WT, AdEHE2F and Ad-dl922-947 showed replication, assessed by hexon staining and quantitative PCR measurement of viral DNA, and significantly inhibited tumour growth leading to extended survival. Following intravenous injection Ad-dl922-947 showed DNA replication (233% of the injected dose was measured in liver after 3 days) while AdEHE2F did not. Overall, AdEHE2F showed the best combination of low toxicity in normal cells and high activity in breast cancer in vitro and in vivo, suggesting that molecular targeting using estrogen reponse elements, hypoxia response elements and dysregulated G1-S checkpoint provides a good strategy for virotherapy of breast cancer.

• Virotherapy of ovarian cancer with polymer-cloaked adenovirus retargeted to the epidermal growth factor receptor.

  Authors: Joanne Morrison, Simon S Briggs, Nicola Green, Kerry Fisher, Vladimir Subr, Karel Ulbrich, Sean Kehoe, Leonard W Seymour

  Molecular therapy : the journal of the American Society of Gene Therapy. 03/2008; 16(2):244-51.

  Adenovirus gene therapy for intraperitoneal (IP) cancer is limited in clinical trials by inefficient tumor cell transduction and development of peritoneal adhesions. We have shown previously thatAdenovirus gene therapy for intraperitoneal (IP) cancer is limited in clinical trials by inefficient tumor cell transduction and development of peritoneal adhesions. We have shown previously that normal virus tropism can be ablated by physically shielding the virus surface with reactive hydrophilic polymers and that linkage of novel ligands enables virus "retargeting" through chosen receptors. To achieve tumor-selective infection, polymer-coated virus was retargeted using murine epidermal growth factor (mEGF). The resulting mEGF-polymer coated adenovirus lost its normal broad tropism and transduced cells selectively via the EGF receptor (EGFR). We assessed whether this approach could be used to target lytic "virotherapy" using wild-type adenovirus (Ad5WT) in a peritoneal xenograft model of human ovarian cancer. Oncolytic activity of Ad5WT was retained following polymer coating and mEGF-retargeting. Importantly, adhesion formation was markedly decreased compared with the unmodified virus, and no dose-limiting toxicities were observed following treatment with mEGF-retargeted polymer-coated virus. Restricting virus tropism by physical coating, coupled with tumor-selective retargeting promises to combine good anticancer efficacy with acceptable toxicity, enabling application of elevated virus doses leading to an improved therapeutic outcome.

• Directed evolution generates a novel oncolytic virus for the treatment of colon cancer.

  Authors: Irene Kuhn, Paul Harden, Maxine Bauzon, Cecile Chartier, Julie Nye, Steve Thorne, Tony Reid, Shaoheng Ni, Andre Lieber, Kerry Fisher, Len Seymour, Gabor M Rubanyi, Richard N Harkins, Terry W Hermiston

  PLoS ONE. 01/2008; 3(6):e2409.

  BACKGROUND: Viral-mediated oncolysis is a novel cancer therapeutic approach with the potential to be more effective and less toxic than current therapies due to the agents selective growth andBACKGROUND: Viral-mediated oncolysis is a novel cancer therapeutic approach with the potential to be more effective and less toxic than current therapies due to the agents selective growth and amplification in tumor cells. To date, these agents have been highly safe in patients but have generally fallen short of their expected therapeutic value as monotherapies. Consequently, new approaches to generating highly potent oncolytic viruses are needed. To address this need, we developed a new method that we term "Directed Evolution" for creating highly potent oncolytic viruses. METHODOLOGY/PRINCIPAL FINDINGS: Taking the "Directed Evolution" approach, viral diversity was increased by pooling an array of serotypes, then passaging the pools under conditions that invite recombination between serotypes. These highly diverse viral pools were then placed under stringent directed selection to generate and identify highly potent agents. ColoAd1, a complex Ad3/Ad11p chimeric virus, was the initial oncolytic virus derived by this novel methodology. ColoAd1, the first described non-Ad5-based oncolytic Ad, is 2-3 logs more potent and selective than the parent serotypes or the most clinically advanced oncolytic Ad, ONYX-015, in vitro. ColoAd1's efficacy was further tested in vivo in a colon cancer liver metastasis xenograft model following intravenous injection and its ex vivo selectivity was demonstrated on surgically-derived human colorectal tumor tissues. Lastly, we demonstrated the ability to arm ColoAd1 with an exogenous gene establishing the potential to impact the treatment of cancer on multiple levels from a single agent. CONCLUSIONS/SIGNIFICANCE: Using the "Directed Evolution" methodology, we have generated ColoAd1, a novel chimeric oncolytic virus. In vitro, this virus demonstrated a >2 log increase in both potency and selectivity when compared to ONYX-015 on colon cancer cells. These results were further supported by in vivo and ex vivo studies. Furthermore, these results have validated this methodology as a new general approach for deriving clinically-relevant, highly potent anti-cancer virotherapies.

• Striking out at disseminated metastases: the systemic delivery of oncolytic viruses.

  Authors: Kerry Fisher

  Current opinion in molecular therapeutics. 09/2006; 8(4):301-13.

  Oncolytic viruses are capable of selective replication in malignant cells and therefore offer levels of potency and specificity that are potentially far higher than conventional treatments forOncolytic viruses are capable of selective replication in malignant cells and therefore offer levels of potency and specificity that are potentially far higher than conventional treatments for cancer. New developments in vector design and administration regimes are gradually moving toward systemic applications, with the ultimate aim of treating common cancer indications that present with multiple disseminated metastases. Nevertheless, the delivery of therapeutic quantities of viruses via the blood stream to target cells in humans or stringent animal models remains a challenging task: the relatively large size of virus particles restricts their penetration into tissues, and defines their biodistribution and clearance kinetics. In addition, multiple interactions with blood cells and serum proteins can impact on vector bioavailability. Finally, the immunological response to virus administration can vary considerably from patient to patient and even more so between species, making it difficult to draw accurate clinical predictions from model systems. Unfortunately, the extensive experience gained from the application of low-molecular-weight therapeutic drugs provides little insight into the behavior of viral therapeutics administered into the blood stream. In this review, the fate of virus particles following intravenous delivery is described, followed by an assessment of the latest approaches to control and improve vector delivery.