Abstracts of the A.I.S.F. Annual Meeting 2010 / Digestive and Liver Disease 43S (2011), S65–S108 S85 T-26 Long-term FU of patients with CHC treated with telaprevir in combination with PEG-IFN alfa-2a and RBV: Interim analysis of the EXTEND study A. Alberti 1 , S. Zeuzem 2 , M.S. Sulkowski 3 , F. Zoulim 4 , K.E. Sherman 5 , L.J. Wei 6 , B. van Baelen 7 , J. Sullivan 8 , T.L. Kieffer 8 , S. De Meyer 7 , G. Picchio 9 , F. Tomaka 9 , C. Graham 8 , J.G. McHutchison 10 , EXTEND Study Team 1 University of Padova, Padova, Italy; 2 Johann Wolfgang Goethe University Medical Center, Frankfurt am Main, Germany; 3 Johns Hopkins University School of Medicine, Baltimore, MD, USA; 4 INSERM Unit 271, Lyon, France; 5 University of Cincinnati College of Medicine, Cincinnati, OH, USA; 6 Harvard School of Public Health, Boston, MA, USA; 7 Tibotec BVBA, Mechelen, Belgium; 8 Vertex Pharmaceuticals Incorporated, Cambridge, MA, USA; 9 Tibotec, Inc., Titusville, NJ, USA; 10 Duke University Medical Center, Durham, NC, USA Background: Telaprevir (TVR) is a potent, specific HCV protease inhibitor that in combination with PEG-IFN alfa-2a (P) and ribavirin (R) led to higher sustained viral response (SVR) rates than PR alone in both treatment-naïve and treatment-experienced genotype 1 HCV patients in Phase 2 clinical trials. EXTEND is a 3-year virology FU study on some of these patients. Here, we report an interim analysis of durability of virologic response in patients who had achieved SVR as well as changes in HCV variants in patients who had not achieved SVR. Methods: 867 patients who received at least one dose of TVR in PROVE1, 2, 3 or Study 107 and from whom baseline HCV sequences were available were eligible for enrollment; 202 entered the study. Patients who achieved SVR (n=123) were observed for a median time of 22 months (range: 5-35) post-SVR. Patients who did not achieve an SVR as defined in previous studies (n=79) were observed for a median time of 25 months (range: 7-36) after the end of the prior study. HCV RNA levels were assessed with the COBAS TaqMan ® HCV Test (version 2.0). Viral sequence was determined by nested RT-PCR followed by population sequencing of the NS3 protease (detecting variants present in >20% of viral population). Amino acid (AA) positions 36, 54, 155, and 156 that are associated with decreased susceptibility to TVR in genotype 1 HCV patients were analyzed. We report on patients who possessed identified variants with decreased susceptibility to TVR at time of treatment failure. Results: Ninety-nine percent (122/123) of patients maintained SVR during FU; one patient from PROVE2 experienced a late relapse 44 weeks after early discontinuation from study dosing, as previously presented. Variants were no longer detectable in 89% (50/56) of patients who had NS3 variants after failing to achieve an SVR. NS3 variants in each of the four AA positions associated with decreased susceptibility to TVR were no longer detectable in 88-100% of patients. In this cohort, there was no evidence to suggest that the time to undetectability of variants varied as a function of treatment arm, duration of TVR dosing, or non-response type (e.g., virologic breakthrough on treatment versus relapse). Conclusions: In this interim analysis, SVR after TVR-based therapy was durable, with 122 of 123 subjects maintaining HCV RNA undetectable during a median 21 months FU. Amongst patients who did not achieve SVR after TVR-based therapy variants associated with decreased sensitivity to TVR were no longer detectable in 89% of patients within the study period. T-27 The antifibrotic effect of sorafenib is due to decreased HSCs activation mediated by angiogenesis blockage S. De Minicis, L. Agostinelli, C. Rychlicki, S. Saccomanno, L. Trozzi, I. Pierantonelli, A. Benedetti, G. Svegliati-Baroni Department of Gastroenterology, Università Politecnica delle Marche, Ancona. Background: Liver cirrhosis represents the pathological response of the liver to all forms of chronic injuries and may lead to hepatocellular carcinoma. Recent evidence have shown that kinase inhibitors are able to interfere with liver cancer development and spreading by inhibiting angiogenesis. Angio- genesis is a key mechanism in both cancer and fibrosis development. Although sorafenib treatment has been shown to reduce liver fibrogenesis, the role of this molecule in interfering with the mechanisms of fibrogenesis are still under investigation. Aim: To investigate the role of sorafenib, a multikinase inhibitor, in a mouse model of liver fibrogenesis. Methods: Wild-type mice were treated by i.p. injection of CCl 4 (0.2 ml/Kg three times a week) for five weeks to induce fibrosis. Mice received orally either sorafenib (50 mg/kg) or vehicle starting 1 week later than fibrosis- induction. Results: Liver fibrosis induced by CCL 4 was reduced by sorafenib. Mor- phometry after Sirius red staining showed reduced collagen deposition in CCL 4 -treated mice exposed to sorafenib, in comparison to control mice treated with CCL 4 and vehicle (45% reduction; p<0.05). The increase in hy- droxyproline content and gene expression of collagenα1 (I), observed in CCL 4 treated-mice, were significantly blunted by sorafenib treatment (30% and 35% reduction respectively; p<0.05). Moreover, sorafenib treatment reduced, in vivo, angiogenetic gene expression markers such as Angiopoietin-1 and -2. Sorafenib reduced HSCs activation as shown by decreased αSMA-positive im- munoreactive parenchyma in CCL 4 -treated mice. In vitro, sorafenib blocked the activity of HSCs by inhibiting: (1) PDGF-induced proliferation, evaluated by western blot for PCNA and by RT-PCR for Ki67 gene expression (both 40% reduction); (2) PDGF-induced ERK- but not AKT-phosphorylation (45% reduction by Western blot); (3) TGFβ-induced collagen gene expression by RT-PCR (35% reduction). Conclusion: Sorafenib treatment reduces liver fibrosis, blocking the mecha- nisms of HSCs activation through the interaction with the angiogenetic process occurring in the damaged liver. T-28 A metabolic switch in rat liver: Correlation between temperature and hypoxia-inducible factor-1-alpha expression A. Ferrigno 1 , A. Bianchi 1,2,3 , P. Richelmi 1 , E. Gringeri 2 , D. Neri 2 , G. Ramadori 3 , U. Cillo 2 , M. Vairetti 1 1 Dept. Internal Medicine and Therapeutics, University of Pavia; 2 General Surgery, Univ. of Padua; 3 Dept. of Internal Medicine, University Medical Center, Göttingen, Germany Background and aim: Hypoxia inducible factor-1 alpha (HIF-1-alpha) is a conserved transcription factor that functions as a main regulator of gene expression in response to hypoxia. We previously supported the hypothesis that the hepatic oxygen consumption is directly affected by temperature and the adequate supply of oxygen may avoid the ischemic period during liver preservation [1]. In this study, we correlated the HIF-1-alpha expression with the temperature and the hepatic oxygen uptake using a model of isolated perfused rat liver. Materials and methods: Livers from male Wistar rats were perfused for 6 hours with an oxygenated Krebs-Henseleit buffer pH 7.4 at 37, 30, 20 and 10°C. Lactate dehydrogenase (LDH) release, bile production, oxygen up- take, ATP and lactate levels were evaluated. HIF-1-alpha mRNA and protein expression were analysed by RT-PCR and Elisa assay. Results: Livers perfused at 20 and 10°C showed a significant lower hepatic damage as compared with organs perfused at 30 and 37°C. In livers perfused at 10 and 20°C, low levels of lactate were observed while, at 30 and 37°C, high concentrations was found suggesting an increase in the anaerobic metabolism. Significant difference in oxygen uptake was found: a reduction was observed at 10 and 20°C as compared at 30 and 37°C. The oxygen supply in our experimental model at 10°C and 20°C is not far from the hepatic oxygen requirement at the same temperature. A marked decrease in mRNA and protein expression of HIF-1-alpha were observed at 10 and 20°C. ATP levels and bile flow were affected during perfusion at 30 and 37°C. Conclusions: Since oxygen consumption is strongly dependent on tempera- ture, it is likely that during liver perfusion at 10 and 20°C the oxygen supply are enough for the metabolism request as highlighted by minimum enzyme release and low HIF-1-alpha expression. Otherwise, at 30 and 37°C perfusion we observed a switch to anaerobic metabolism mediated by activation of HIF-