Publications (10)96.4 Total impact
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Article: Single- and multiple-ascending-dose studies of the NS3 protease inhibitor asunaprevir in subjects with or without chronic hepatitis C.
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ABSTRACT: Hepatitis C virus (HCV) protease inhibitors combined with pegylated alfa interferon-ribavirin have demonstrated improved efficacy compared with pegylated alfa interferon-ribavirin alone for the treatment of chronic hepatitis C. Asunaprevir (BMS-650032), a novel HCV NS3 protease inhibitor in clinical development, was evaluated for safety, antiviral activity, and resistance in four double-blind, placebo-controlled, sequential-panel, single- and multiple-ascending-dose (SAD and MAD) studies in healthy subjects or subjects with chronic HCV genotype 1 infection. In SAD studies, subjects (healthy or with chronic HCV infection) were randomized to receive asunaprevir in dose groups of 10 to 1,200 mg or a placebo. In MAD studies, healthy subjects were randomized to receive asunaprevir in dose groups of 10 to 600 mg twice daily or a placebo for 14 days; subjects with HCV infection received asunaprevir in dose groups of 200 to 600 mg twice daily, or a placebo, for 3 days. Across all four studies, headache and diarrhea were the most frequent adverse events in asunaprevir recipients. Asunaprevir at doses of 200 to 600 mg resulted in rapid HCV RNA decreases from the baseline; maximal mean changes in HCV RNA over time were 2.7 and 3.5 log(10) IU/ml in the SAD and MAD studies, respectively. No enrichment of signature asunaprevir-resistant viral variants was detected. In conclusion, the novel NS3 protease inhibitor asunaprevir, when administered at single or multiple doses of 200 to 600 mg twice daily, is generally well tolerated, achieving rapid and substantial decreases in HCV RNA levels in subjects chronically infected with genotype 1 HCV.Antimicrobial Agents and Chemotherapy 01/2012; 56(4):1838-44. · 4.84 Impact Factor -
Article: Multiple ascending dose study of BMS-790052, a nonstructural protein 5A replication complex inhibitor, in patients infected with hepatitis C virus genotype 1.
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ABSTRACT: The antiviral activity, resistance profile, pharmacokinetics (PK), safety, and tolerability of BMS-790052, a nonstructural protein 5A (NS5A) replication complex inhibitor, were evaluated in a double-blind, placebo-controlled, sequential panel, multiple ascending dose study. Thirty patients with chronic hepatitis C virus (HCV) genotype 1 infection were randomized to receive a 14-day course of BMS-790052 (1, 10, 30, 60, or 100 mg once daily or 30 mg twice daily) or placebo in a ratio of 4:1. The mean maximum decline from baseline in HCV RNA ranged from 2.8 to 4.1 log(10) IU/mL; the placebo group showed no evidence of antiviral activity. Most patients experienced viral rebound on or before day 7 of treatment with BMS-790052 monotherapy; viral rebound was associated with viral variants that had been previously implicated in resistance development in the in vitro replicon system. The PK profile was supportive of once-daily dosing with median peak plasma concentrations at 1-2 hours postdose and mean terminal half-life of 12-15 hours. Steady state was achieved following 3-4 days of daily dosing. BMS-790052 was well tolerated in all dose groups, with adverse events occurring with a similar frequency in BMS-790052- and placebo-treated groups. There were no clinically relevant changes in vital signs, laboratory, or electrocardiogram parameters. Conclusion: BMS-7590052 is the first NS5A replication complex inhibitor with multiple dose proof-of-concept in clinic. At doses of 1-100 mg daily, BMS-790052 was well tolerated, had a PK profile supportive of once-daily dosing, and produced a rapid and substantial decrease in HCV-RNA levels in patients chronically infected with HCV genotype 1.Hepatology 08/2011; 54(6):1956-65. · 11.66 Impact Factor -
Article: Phase 1b study of pegylated interferon lambda 1 with or without ribavirin in patients with chronic genotype 1 hepatitis C virus infection.
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ABSTRACT: Interferon lambda 1 (IFN-lambda1) is a type III IFN that produces intracellular responses similar to those of IFN-alpha but in fewer cell types because of differences in the receptor distribution pattern, and this could potentially result in an improved safety profile. This was an open-label three-part study of patients with chronic hepatitis C virus (HCV) genotype 1 infection. Part 1 evaluated single-agent pegylated interferon lambda (PEG-IFN-lambda) at 1.5 or 3.0 microg/kg administered every 2 weeks or weekly for 4 weeks in patients who had relapsed after previous IFN-alpha-based treatment. Part 2 evaluated weekly doses of PEG-IFN-lambda ranging from 0.5 to 2.25 microg/kg in combination with ribavirin (RBV) for 4 weeks in treatment-relapse patients. Part 3 evaluated weekly PEG-IFN-lambda at 1.5 microg/kg in combination with RBV for 4 weeks in treatment-naive patients. Fifty-six patients were enrolled: 24 patients in part 1, 25 patients in part 2, and 7 patients in part 3. Antiviral activity was observed at all PEG-IFN-lambda dose levels (from 0.5 to 3.0 microg/kg). Two of seven treatment-naive patients (29%) achieved rapid virological response. Treatment was well tolerated with minimal flu-like symptoms and no significant hematologic changes other than RBV-associated decreases in hemoglobin. The most common adverse events were fatigue (29%), nausea (12%), and myalgia (11%). Six patients experienced increases in aminotransferases that met protocol-defined criteria for dose-limiting toxicity (DLT) or temporarily holding therapy with PEG-IFN-lambda. Most DLT occurred in patients with high PEG-IFN-lambda exposure. CONCLUSION: Weekly PEG-IFN-lambda with or without daily RBV for 4 weeks is well tolerated with minimal adverse events and hematologic effects and is associated with clear antiviral activity across a broad range of doses in patients with chronic HCV.Hepatology 09/2010; 52(3):822-32. · 11.66 Impact Factor -
Article: Morpholino oligonucleotide-triggered beta-catenin knockdown compromises normal liver regeneration.
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ABSTRACT: Wnt/beta-catenin activation is seen during early liver regeneration (LR) observed as stabilization and translocation to the nucleus followed by an overall decrease. However, beta-catenin continues to be in hepatocyte nucleus and membrane, secondary to its increased gene expression at 6-72 h. In the present study, we examined the effect of ablating beta-catenin transcription on LR. Twelve male fisher rats were subjected to two-third partial hepatectomy followed by administration of beta-catenin antisense phospho-morpholino oligonucleotide (AS) in six or mismatch control (CON) injection in the remaining 6 via superior mesenteric vein. Three animals from each group were sacrificed at 24 h and 7 days for liver assessment. AS group exhibited a significant decrease in total beta-catenin at 24 h. A significant decrease in liver/body weight ratio was also observed in the AS group at 24 h and 7 days that was due to decreased proliferation. Among the targets of this pathway c-myc and uPAR levels showed significant decrease while cyclin-D1 remained unaffected. We demonstrate the importance of beta-catenin in early liver regeneration especially in hepatocyte proliferation. Also, c-myc and uPAR might be crucial downstream effectors of beta-catenin during liver regeneration.Journal of Hepatology 08/2005; 43(1):132-41. · 9.26 Impact Factor -
Article: Peginterferon alfa-2a for hepatitis C after liver transplantation: two randomized, controlled trials.
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ABSTRACT: There is currently no effective treatment for recurrent hepatitis C after orthotopic liver transplantation (OLT). We therefore performed two randomized, controlled trials--a prophylaxis trial and a treatment trial--to evaluate the safety and efficacy of peginterferon alfa-2a in patients who had undergone OLT. The prophylaxis trial enrolled 54 patients within 3 weeks after OLT, and the treatment trial enrolled 67 patients 6 to 60 months after OLT. In each trial, patients were randomized to treatment with once weekly injections of 180 microg peginterferon alfa-2a or no antiviral treatment for 48 weeks and were followed up for 24 weeks thereafter. Peginterferon alfa-2a treated patients had significantly lower hepatitis C virus RNA levels and more favorable changes in hepatic histological features compared with untreated controls. However, only 2 treated patients in the prophylaxis trial (8%) and 3 in the treatment trial (12%) achieved a sustained virological response. In the prophylaxis trial, 8 patients (31%) in the peginterferon alfa-2a group and 9 (32%) in the untreated group were withdrawn prematurely; whereas in the treatment trial, 10 patients (30%) in the peginterferon alfa-2a group and 6 (19%) in the untreated group were withdrawn prematurely. The incidence of acute rejection was similar in the treated and untreated groups in both the prophylaxis (12% vs. 21%; P = .5) and treatment (12% vs. 0%; P = .1) trials. In conclusion, peginterferon alfa-2a treatment for 48 weeks is safe and tolerable and offers some efficacy in the post-OLT setting. Randomized controlled studies are needed to establish the efficacy of pegylated interferon and ribavirin in patients who have undergone OLT.Hepatology 03/2005; 41(2):289-98. · 11.66 Impact Factor -
Article: Parathyroid-hormone-related protein as a regulator of pRb and the cell cycle in arterial smooth muscle.
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ABSTRACT: Parathyroid hormone-related protein (PTHrP), a normal product of arterial vascular smooth muscle (VSM), contains a nuclear localization signal (NLS) and at least 2 translational initiation sites, one that generates a conventional signal peptide and one that disrupts the signal peptide. These unusual features allow PTHrP either to be secreted in a paracrine/autocrine fashion, and thereby to inhibit arterial smooth muscle proliferation, or to be retained within the cytosol and to translocate into the nucleus, thereby serving as an intracrine stimulator of smooth muscle proliferation. Here, we demonstrate 2 important findings. First, PTHrP dramatically increases the percentage of VSM cells in the S and in G2/M phases of the cell cycle. These effects require critical serine and threonine residues at positions Ser119, Ser130, Thr132, and Ser138 in the carboxy-terminus of PTHrP and are associated with the phosphorylation of the key cell cycle checkpoint regulator retinoblastoma protein, pRb. Second, because PTHrP devoid of the NLS serves as an inhibitor of VSM proliferation, we hypothesized that local delivery of NLS-deleted PTHrP to the arterial wall at the time of angioplasty might prevent neointimal hyperplasia. As hypothesized, using a rat carotid angioplasty model, adenoviral delivery of NLS-deleted PTHrP completely abolished the development of the neointima after angioplasty. PTHrP interacts with key cell cycle regulatory pathways within the arterial wall. Moreover, NLS-deleted PTHrP delivered to the arterial wall at the time of angioplasty seems to have promise as an agent that could reduce or eliminate the neointimal response to angioplasty.Circulation 08/2004; 110(2):177-85. · 14.74 Impact Factor -
Article: Hepatocyte growth factor gene therapy for pancreatic islets in diabetes: reducing the minimal islet transplant mass required in a glucocorticoid-free rat model of allogeneic portal vein islet transplantation.
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ABSTRACT: Islet transplantation for diabetes is limited by the availability of human islet donors. Hepatocyte growth factor (HGF) is a potent beta-cell mitogen and survival factor and improves islet transplant outcomes in a murine model. However, the murine model employs renal subcapsular transplant and immunodeficient mice, features not representative of human islet transplantation protocols. Therefore, we have developed a more rigorous, marginal-mass rat islet transplant model that more closely resembles human islet transplantation protocols: islet donors are allogeneic Lewis islets; recipients are normal Sprague Dawley rats; islets are delivered intraportally; and immunosuppression is accomplished using the same immunosuppressants employed by the Edmonton group. We demonstrate that 1) surprisingly, the Edmonton immunosuppression regimen induces marked insulin resistance and beta-cell toxicity in rats, 2) adenovirus does not adversely affect islet transplant outcomes, 3) the Edmonton immunosuppressants may delay or block rejection of adenovirally transduced islets, and more importantly, 4) pretransplant islet adenoviral gene therapy with HGF markedly improves islet transplant outcomes, 5) this enhanced function persists for months, and 6) HGF enhances islet function and survival even in the setting of immunosuppressant-induced insulin resistance and beta-cell toxicity. This approach may enhance islet transplantation outcomes in humans.Endocrinology 03/2004; 145(2):467-74. · 4.46 Impact Factor -
Article: The processing and utilization of hepatocyte growth factor/scatter factor following partial hepatectomy in the rat
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ABSTRACT: Hepatocyte growth factor/scatter factor (HGF/SF) is a pluripotent growth factor capable of acting as a motogen, a morphogen, and a mitogen. Originally, HGF/SF was found as a blood-borne mitogen for hepatocytes and has since been determined to be very important in liver repair. Previous studies have established that HGF/SF must be proteolytically cleaved to elicit its effects. After liver injury by toxins such as carbon tetrachloride or after surgical resection, partial hepatectomy (PHX), HGF/SF concentrations increase in the blood. The aims of this study were to examine (1) which form of HGF/SF is present in the normal liver, (2) which form is present in the regenerating liver after PHX, and (3) if the HGF/SF used after PHX is derived from existing liver reservoirs. Both single-chain HGF/SF and active two-chain HGF/SF are present in normal liver, with the former being the dominant form. After PHX, the liver can be described as having two phases with regard to the use of endogenous HGF/SF. The first phase from 0 to 3 hours is the consumptive phase and is characterized by a decrease in both single-chain HGF/SF and active two-chain HGF/SF. The second phase is the productive phase. It is characterized by a pronounced reappearance of both single-chain HGF/SF as well as two-chain HGF/SF. The activation index shows a 5-fold increase over sham operations during the productive phase. The use of radiolabeled HGF/SF showed that during the first 3 hours, HGF/SF is used in part from hepatic stores. Furthermore, during the first 3 hours after PHX, only active two-chain HGF/SF is seen in the plasma.Hepatology 12/2003; 34(4):688 - 693. · 11.66 Impact Factor -
Article: Adenovirus-mediated hepatocyte growth factor expression in mouse islets improves pancreatic islet transplant performance and reduces beta cell death.
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ABSTRACT: Hepatocyte growth factor (HGF) increases beta cell proliferation and function in rat insulin promoter (RIP)-targeted transgenic mice. RIP-HGF mouse islets also function superiorly to normal islets in a transplant setting. Here, we aimed to determine whether viral gene transfer of the HGF gene into mouse islets ex vivo could enhance the performance of normal islets in a streptozotocin-diabetic severe combined immunodeficient mouse marginal islet mass model in which 300 uninfected or adenovirus (Adv) LacZ-transduced islet equivalents were insufficient to correct hyperglycemia. In dramatic contrast, 300 AdvHGF-transduced islet equivalents promptly (day 1) and significantly (p < 0.01) decreased random non-fasting blood glucose levels, from 351 +/- 20 mg/dl to an average of 191 +/- 7 mg/dl over 8 weeks. At day 1 post-transplant, beta cell death was significantly (p < 0.05) decreased, and the total insulin content was significantly (p < 0.05) increased in AdvHGF-transduced islets containing grafts. This anti-beta cell death action of HGF was independently confirmed in RIP-HGF mice and in INS-1 cells, both treated with streptozotocin. Activation of the phosphatidylinositol 3-kinase/Akt intracellular-signaling pathway appeared to be involved in this beta cell protective effect of HGF in vitro. In summary, adenoviral delivery of HGF to murine islets ex vivo improves islet transplant survival and blood glucose control in a subcapsular renal graft model in immuno-incompetent diabetic mice.Journal of Biological Chemistry 01/2003; 278(1):343-51. · 4.77 Impact Factor -
Article: Hepatocytes undergo phenotypic transformation to biliary epithelium in organoid cultures.
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ABSTRACT: Organoid cultures of hepatocytes in the presence of hepatocyte growth factor (HGF) and epidermal growth factor (EGF) display characteristic histologic organization. Biliary epithelium covers the surface of the tissue exposed to the culture medium. Hepatocytes, stellate cells and endothelial cells compose the underlying structures. In order to investigate the origin of the biliary epithelial cells in the organoid cultures, we utilized the retrorsine/DPPIV system of hepatocyte transplantation to create hybrid livers in which clones of DPPIV hepatocytes colonize variable portions of the lobules. We demonstrate that, as others have shown, biliary epithelium in this in vivo system remains that of the recipient (DPPIV negative) rat. Hepatocytes are the only cells positive for the DPPIV marker enzyme in the hybrid livers. Organoid cultures were prepared from the hybrid livers. Overall, 46.82% of the hepatocytes placed into culture were positive for DPPIV at time zero (after isolation). At 21 days in culture, 47.54% of the biliary epithelium on the surface of the organoid cultures was positive for DPPIV. Since the only DPPIV cells inoculated in the cultures were hepatocytes, this finding demonstrates that, in the conditions of the organoid cultures, hepatocytes do undergo phenotypic transition to biliary epithelial cells.Hepatology 09/2002; 36(2):278-83. · 11.66 Impact Factor
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- Hepatology (3)
- Hepatology (2)
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- Journal of Biological Chemistry (1)
- Journal of Hepatology (1)
Institutions
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2005
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Indiana University-Purdue University Indianapolis
Indianapolis, IN, USA
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2003–2004
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University of Pittsburgh
- Division of Pediatric Endocrinology
Pittsburgh, PA, USA
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