Publications by authors named "Catherine A Stedman"

This open-label, phase IIa study assessed the safety, pharmacokinetics, and efficacy of direct-acting antiviral agent (DAA) regimens in patients with chronic hepatitis C virus (HCV) infection. Multiple 6-12-week oral regimens of 400-800 mg once daily (QD) AL-335 + 50 mg QD/every other day odalasvir ± 75-150 mg QD simeprevir were evaluated in treatment-naïve, HCV genotype (GT)1/3-infected patients without cirrhosis. Safety/pharmacokinetic parameters, HCV-RNA, and sequencing data were assessed.

View Article and Find Full Text PDF

S282T in NS5B is the primary amino acid substitution associated with resistance to sofosbuvir (SOF) but has rarely been detected in patients treated with a SOF-based regimen. Here, the emergence and fitness of the S282T substitution in virologic failure patients administered SOF-based regimens across the SOF and ledipasvir (LDV)/SOF phase 2 and 3 programs was evaluated. Plasma samples collected at baseline and at virologic failure were amplified and deep sequenced (1% cutoff).

View Article and Find Full Text PDF

Background: Glecaprevir and pibrentasvir are direct-acting antiviral agents with pangenotypic activity and a high barrier to resistance. We evaluated the efficacy and safety of 8-week and 12-week courses of treatment with 300 mg of glecaprevir plus 120 mg of pibrentasvir in patients without cirrhosis who had hepatitis C virus (HCV) genotype 1 or 3 infection.

Methods: We conducted two phase 3, randomized, open-label, multicenter trials.

View Article and Find Full Text PDF

Background & Aims: Studies are needed to determine the optimal regimen for patients with chronic hepatitis C virus (HCV) genotype 2, 3, 4, or 6 infections whose prior course of antiviral therapy has failed, and the feasibility of shortening treatment duration. We performed a phase 2 study to determine the efficacy and safety of the combination of the nucleotide polymerase inhibitor sofosbuvir, the NS5A inhibitor velpatasvir, and the NS3/4A protease inhibitor GS-9857 in these patients.

Methods: We performed a multicenter, open-label trial at 32 sites in the United States and 2 sites in New Zealand from March 3, 2015 to April 27, 2015.

View Article and Find Full Text PDF

Background & Aims: We performed a phase 2 trial of the efficacy and safety of 4, 6, and 8 weeks of sofosbuvir, given in combination with the NS5A inhibitor velpatasvir and the NS3/4A protease inhibitor GS-9857, in patients with hepatitis C virus (HCV) infection.

Methods: We enrolled 161 treatment-naïve or previously treated patients infected with HCV genotypes 1 or 3 with or without compensated cirrhosis at 2 centers in New Zealand, from September 2014 through March 2015. All patients received sofosbuvir (400 mg) and velpatasvir (100 mg) plus GS-9857 (100 mg) once daily.

View Article and Find Full Text PDF
Article Synopsis
  • A study aimed at finding effective antiviral treatments for chronic hepatitis C patients with cirrhosis was conducted internationally.
  • Two cohorts were treated: treatment-naive patients received triple therapy for 24 weeks, while prior null responders received a more intensive quadruple therapy.
  • Results showed that the quadruple therapy was particularly successful, achieving a 65% sustained virological response in prior null responders, while the triple therapy had lower success rates and resistance issues were noted in certain infections.
View Article and Find Full Text PDF

Background: In phase 2 trials, treatment with the combination of the nucleotide polymerase inhibitor sofosbuvir and the NS5A inhibitor velpatasvir resulted in high rates of sustained virologic response in patients chronically infected with hepatitis C virus (HCV) genotype 2 or 3.

Methods: We conducted two randomized, phase 3, open-label studies involving patients who had received previous treatment for HCV genotype 2 or 3 and those who had not received such treatment, including patients with compensated cirrhosis. In one trial, patients with HCV genotype 2 were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir, in a once-daily, fixed-dose combination tablet (134 patients), or sofosbuvir plus weight-based ribavirin (132 patients) for 12 weeks.

View Article and Find Full Text PDF

Background: Effective treatment options are needed for patients with genotype 1 or 3 hepatitis C virus (HCV) infection in whom previous therapy has failed.

Objective: To assess the efficacy and safety of sofosbuvir plus velpatasvir, with and without ribavirin, in treatment-experienced patients.

Design: Randomized, phase 2, open-label study.

View Article and Find Full Text PDF

Background & Aims: We performed a phase 2 clinical trial to evaluate the efficacy and safety of ledipasvir and sofosbuvir, with or without ribavirin, in patients infected with hepatitis C virus (HCV) genotype 3 or 6.

Methods: We performed an open-label study of 126 patients with HCV genotype 3 or 6 infections at 2 centers in New Zealand from April 2013 through October 2014. Subjects were assigned 1 of 4 groups that received 12 weeks of treatment.

View Article and Find Full Text PDF
Article Synopsis
  • A study was conducted to explore effective hepatitis C treatment in patients also infected with HIV-1, using a specific drug combination over 12 weeks.
  • Out of 335 participants, 96% achieved a sustained virologic response, with similar success rates for different hepatitis C genotypes and regardless of prior treatment or liver condition.
  • Adverse effects were mostly mild, with no serious treatment discontinuations, indicating that the treatment was both effective and generally well-tolerated.
View Article and Find Full Text PDF

Background & Aims: We evaluated an all-oral regimen comprising the nucleotide polymerase inhibitor sofosbuvir (SOF) with the NS5A inhibitor ledipasvir (LDV) or the NS5B non-nucleoside inhibitor GS-9669 in patients with genotype 1 hepatitis C virus (HCV) infection.

Methods: A total of 113 patients were enrolled. Sofosbuvir (400 mg once daily) and LDV (90 mg once daily) plus ribavirin (RBV) were given for 12 weeks to treatment-naïve (TN) patients (n = 25) and those who did not respond to previous therapy (prior null responders, n = 9).

View Article and Find Full Text PDF

Purpose: The precise etiology of autoimmune hepatitis (AIH) remains unknown, although a number of genetic loci have been implicated in the susceptibility of type 1 AIH. The purpose of this study was to test for association of these loci with type 1 AIH in New Zealand Caucasians.

Methods: 77 AIH patients and 485 healthy controls were genotyped for the SNPs rs2187668 (HLA-DRB*03:01), rs660895 (HLA-DRB*04:01), rs3749971 (HLA-A1-B8-DR3), rs231775 (CLTLA4), rs1800629 (TNF), and rs1800682 (FAS) using predesigned TaqMan SNP genotyping assays.

View Article and Find Full Text PDF

Purpose: The etiology of autoimmune hepatitis (AIH) likely involves a complex interaction of genetic and environmental factors. We aim to investigate the associations between exposure to putative environmental factors and AIH and to quantify AIH risk in a first-degree relative.

Methods: We conducted a population-based case-control study.

View Article and Find Full Text PDF

Unlabelled: Autoimmune hepatitis (AIH) can lead to cirrhosis, hepatic failure, and death. We aimed to identify predictors of advanced liver fibrosis at presentation, predictors of incomplete response to initial immunosuppression, and predictors of poor liver-related outcomes in the population-based AIH cohort from Canterbury, New Zealand. Cases diagnosed after 1980 that fulfilled standard diagnostic criteria were included.

View Article and Find Full Text PDF

Background: The standard treatment for hepatitis C virus (HCV) infection is interferon, which is administered subcutaneously and can have troublesome side effects. We evaluated sofosbuvir, an oral nucleotide inhibitor of HCV polymerase, in interferon-sparing and interferon-free regimens for the treatment of HCV infection.

Methods: We provided open-label treatment to eight groups of patients.

View Article and Find Full Text PDF
Article Synopsis
  • Current interferon-based therapies for chronic hepatitis C have limitations in effectiveness and tolerance.
  • Telaprevir and boceprevir are the first direct-acting antivirals that work alongside pegylated interferon and ribavirin, with many more DAAs undergoing clinical testing.
  • Interferon-free treatment combinations have shown promise in achieving sustained virologic responses, with variations in drug effectiveness depending on the hepatitis C virus genotype.
View Article and Find Full Text PDF

Purpose: Epidemiological data on primary biliary cirrhosis (PBC) in the Southern Hemisphere is scarce. Our aim was to perform a population-based epidemiological study of PBC in Canterbury, New Zealand.

Methods: Multiple case-finding methods were employed.

View Article and Find Full Text PDF

Unlabelled: Population-based quantitative data on the mortality and cancer incidence of autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC) are scarce. Our aim was to systematically investigate the survival and risk of malignancy on population-based cohorts of AIH, PBC, and PSC in Canterbury, New Zealand. Multiple case-finding methods were employed, including searches of all public and private, adult and pediatric outpatient clinics, hospital notes, laboratory, radiology, and pathology reports.

View Article and Find Full Text PDF

Background & Aims: Little is known about the exact etiology of primary sclerosing cholangitis (PSC); epidemiologic data are scarce. We performed a population-based epidemiologic study of PSC in Canterbury, New Zealand.

Methods: By using multiple case-finding methods, we searched public and private adult and pediatric outpatient clinics, hospital discharge summaries, and radiology and pathology reports to identify all cases of PSC in the region.

View Article and Find Full Text PDF

Background And Aim: Allopurinol potentiates azathioprine and 6-mercaptopurine (6-MP) by increasing 6-thioguanine nucleotide (6-TGN) metabolite concentrations. The outcome might also be improved by adding allopurinol in individuals who preferentially produce 6-methylmercaptopurine nucleotides (6-MMPN), rather than 6-TGN. The aim of the present study was to investigate the effect of allopurinol on concentrations of 6-MMPN and 6-TGN in individuals with a high ratio of these metabolites (>20), which is indicative of a poor thiopurine response.

View Article and Find Full Text PDF

Background: Present interferon-based standard of care treatment for chronic hepatitis C virus (HCV) infection is limited by both efficacy and tolerability. We assessed the safety, tolerability, and antiviral activity of an all-oral combination treatment with two experimental anti-HCV drugs-RG7128, a nucleoside polymerase inhibitor; and danoprevir, an NS3/4A protease inhibitor-in patients with chronic HCV infection.

Methods: Patients from six centres in New Zealand and Australia who were chronically infected with HCV genotype 1 received up to 13 days oral combination treatment with RG7128 (500 mg or 1000 mg twice daily) and danoprevir (100 mg or 200 mg every 8 h or 600 mg or 900 mg twice daily) or placebo.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to investigate the epidemiology of autoimmune hepatitis (AIH) in Canterbury, New Zealand, due to limited existing data on its causes and prevalence.
  • Researchers identified 138 cases of AIH using both original and simplified criteria and found a point prevalence of 24.5 cases per 100,000 people by the end of 2008, with a notable female predominance.
  • The findings revealed that AIH predominantly affects individuals over 40, with peak occurrences in their 60s, challenging previous understandings of the disease's typical presentation.
View Article and Find Full Text PDF

The liver plays a key role in the metabolic conversion and elimination of endo- and xenobiotics. Hepatobiliary transport of many of these compounds is mediated by several ATP-binding cassette (ABC) transporters expressed at the canalicular membrane of the hepatocyte. Impaired function of these ABC transporters leads to impaired bile formation or cholestasis and mutations in these genes are associated with a variety of hereditary cholestatic syndromes.

View Article and Find Full Text PDF