Toxicology studies were performed in rats and rhesus macaques to establish a safe starting dose for intratumoral injection of an oncolytic vesicular stomatitis virus expressing human interferon-b (VSV-hIFNb) in patients with hepatocellular carcinoma (HCC). No adverse events were observed after administration of 7.59Â10 9 TCID 50 (50% tissue culture infective dose) of VSV-hIFNb into the left lateral hepatic lobe of Harlan Sprague Dawley rats. Plasma alanine aminotransferase and alkaline phosphatase levels increased and platelet counts decreased in the virus-treated animals on days 1 and 2 but returned to pretreatment levels by day 4. VSV-hIFNb was also injected into normal livers or an intrahepatic McA-RH7777 HCC xenograft established in Buffalo rats. Buffalo rats were more sensitive to neurotoxic effects of VSV; the no observable adverse event level (NOAEL) of VSV-hIFNb in Buffalo rats was 10 7 TCID 50 . Higher doses were associated with fatal neurotoxicity and infectious virus was recovered from tumor and brain. Compared with VSV-hIFNb, toxicity of VSV-rIFNb (recombinant VSV expressing rat IFN-b) was greatly diminished in Buffalo rats (NOAEL, >10 10 TCID 50 ). Two groups of two adult male rhesus macaques received 10 9 or 10 10 TCID 50 of VSV-hIFNb injected directly into the left hepatic lobe under computed tomographic guidance. No neurological signs were observed at any time point. No abnormalities (hematology, clinical chemistry, body weights, behavior) were seen and all macaques developed neutralizing anti-VSV antibodies. Plasma interleukin-6, tumor necrosis factor-a, and hIFN-b remained below detection levels by ELISA. On the basis of these studies, we will be proposing a cautious approach to dose escalation in a phase I clinical trial among patients with HCC.

Helicobacterfelis inoculated per os into germfree mice and their conventional non-germfree counterparts caused a persistent chronic gastritis of-1 year in duration. Mononuclear leukocytes were the predominant inflammatory cell throughout the study, although polymorphonuclear cell infiltrates were detected as well. Immunohistochemical analyses of gastric mucosa from H. felis-infected mice revealed the presence of mucosal B220+ cells coalescing into lymphoid follicles surrounded by aggregates of Thy-1.2+ T cells; CD4+, CD5+, and of T cells predominated in organized gastric mucosal and submucosal lymphoid tissue, and CD11b+ cells occurred frequently in the mucosa. Follicular B cells comprised immunoglobulin M' (IgM+) and IgA+ cells. Numerous IgA-producing B cells were present in the gastric glands, the lamina propria, and gastric epithelium. Infected animals developed anti-H. felis serum IgM antibody responses up to 8 weeks postinfection and significant levels of IgG anti-H. felis antibody in serum, which remained elevated throughout the 50-week course of the study.

The sodium-iodide symporter (NIS) is primarily a thyroid protein, providing for the accumulation of iodide for biosynthesis of thyroid hormones. Native NIS expression has made possible the use of radioactive iodide to image and treat thyroid disease successfully. The current study, using adult male beagle dogs, was carried out in preparation for a Phase I clinical trial of adenovirus-mediated NIS gene (approved symbol SLC5A5) therapy for prostate cancer. Direct intraprostatic injection of virus (Ad5/CMV/NS) was followed by iv injection of 3 mCi 123I and serial image acquisition. The dogs were then given a therapeutic dose of 131I (116 mCi/m2) and observed for 7 days. SPECT/CT fusion imaging revealed clear images of the NIS-transduced prostates. Dosimetry calculations revealed an average absorbed dose to the prostate of 23 +/- 42 cGy/mCi 131I, with acceptably low radiation doses to other organs. This study demonstrated the successful introduction of localized NIS expression in the prostate gland of dogs, with no vector-related toxicity observed. None of the animals experienced any surgical complications, and serum chemistry panels showed no significant change following therapy. The results presented provide further evidence of the safety and efficacy of NIS as a therapeutic gene and support translation of this work into the clinical setting.

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