Gregory J. Dore

IL28B is associated with response to chronic hepatitis C interferon-alpha and ribavirin therapy

Hepatitis C virus (HCV) infects 3% of the worlds population. Treatment of chronic HCV consists of a combination of PEGylated interferon-α (PEG-IFN-α) and ribavirin (RBV). To identify genetic variants associated with HCV treatment response, we conducted a genome-wide association study of sustained virological response (SVR) to PEG-IFN-α/RBV combination therapy in 293 Australian individuals with genotype 1 chronic hepatitis C, with validation in an independent replication cohort consisting of 555 individuals. We report an association to SVR within the gene region encoding interleukin 28B (IL28B, also called IFNλ3; rs8099917 combined P = 9.25 × 10−9, OR = 1.98, 95% CI = 1.57–2.52). IL28B contributes to viral resistance and is known to be upregulated by interferons and by RNA virus infection. These data suggest that host genetics may be useful for the prediction of drug response, and they also support the investigation of the role of IL28B in the treatment of HCV and in other diseases treated with IFN-α.

Spontaneous viral clearance following acute hepatitis C infection: a systematic review of longitudinal studies

Summary.  A large number of studies have reported on spontaneous viral clearance rates in acute hepatitis C infection, however most have been small, and reported rates have varied quite widely. To improve the precision of the estimated rate of spontaneous viral clearance, a systematic review was conducted of longitudinal studies. Factors associated with viral clearance were also examined. Inclusion criteria for studies were: longitudinal assessment from time of acute hepatitis C; hepatitis C virus RNA analysis as determinant of viral clearance; untreated for acute hepatitis C. Information on study population, and factors that may influence viral clearance were extracted from each study. Viral clearance was defined among individuals with at least 6 months follow‐up following acute hepatitis C. The number of subjects with viral clearance was expressed as a proportion for each study and a weighted mean for proportion was calculated. A total of 31 studies were examined. Study populations included nine studies of post‐transfusion hepatitis, 19 of acute clinical hepatitis, and three of sero‐incident cases. In total, data was available for 675 subjects and the mean study population was 22 (range 4–67). The proportion with viral clearance ranged from 0.0 to 0.8, with a weighted mean of 0.26 (95% CI 0.22–0.29). Factors associated with viral clearance were female gender and acute clinical hepatitis C study population. Further studies are required to more clearly define predictors of clearance and guide therapeutic intervention strategies.

Estimation of stage-specific fibrosis progression rates in chronic hepatitis C virus infection: a meta-analysis and meta-regression.

Published estimates of liver fibrosis progression in individuals with chronic hepatitis C virus (HCV) infection are heterogeneous. We aimed to estimate stage‐specific fibrosis progression rates and their determinants in these individuals. A systematic review of published prognostic studies was undertaken. Study inclusion criteria were as follows: (1) presence of HCV infection determined by serological assays; (2) available information about age at assessment of liver disease or HCV acquisition; (3) duration of HCV infection; and (4) histological and/or clinical diagnosis of cirrhosis. Annual stage‐specific transition probabilities (F0→F1, … , F3→F4) were derived using the Markov maximum likelihood estimation method and a meta‐analysis was performed. The impact of potential covariates was evaluated using meta‐regression. A total of 111 studies of individuals with chronic HCV infection (n = 33,121) were included. Based on the random effects model, the estimated annual mean (95% confidence interval) stage‐specific transition probabilities were: F0→F1 0.117 (0.104–0.130); F1→F2 0.085 (0.075–0.096); F2→F3 0.120 (0.109–0.133); and F3→F4 0.116 (0.104–0.129). The estimated prevalence of cirrhosis at 20 years after the infection was 16% (14%–19%) for all studies, 18% (15%–21%) for cross‐sectional/retrospective studies, 7% (4%–14%) for retrospective‐prospective studies, 18% (16%–21%) for studies conducted in clinical settings, and 7% (4%–12%) for studies conducted in nonclinical settings. Duration of infection was the most consistent factor significantly associated with progression of fibrosis. Conclusion: Our large systematic review provides increased precision in estimating fibrosis progression in chronic HCV infection and supports nonlinear disease progression. Estimates of progression to cirrhosis from studies conducted in clinical settings were lower than previous estimates. (HEPATOLOGY 2008.)

EPIDEMIOLOGY AND NATURAL HISTORY OF HCV INFECTION

Worldwide, an estimated 130–170 million people have HCV infection. HCV prevalence is highest in Egypt at >10% of the general population and China has the most people with HCV (29.8 million). Differences in past HCV incidence and current HCV prevalence, together with the generally protracted nature of HCV disease progression, has led to considerable diversity in the burden of advanced liver disease in different countries. Countries with a high incidence of HCV or peak incidence in the recent past will have further escalations in HCV-related cirrhosis and hepatocellular carcinoma (HCC) over the next two decades. Acute HCV infection is difficult to detect because of the generally asymptomatic nature of the disease and the marginalization of at-risk populations. Around 25% of patients with acute HCV infection undergo spontaneous clearance, with increased rates among those with favourable IL28B genotypes, acute symptoms and in women. The remaining 75% of patients progress to chronic HCV infection and are subsequently at risk of progression to hepatic fibrosis, cirrhosis and HCC. Chronic hepatitis C generally progresses slowly in the initial two decades, but can be accelerated during this time as a result of advancing age and co-factors such as heavy alcohol intake and HIV co-infection.

Changes to AIDS dementia complex in the era of highly active antiretroviral therapy

OBJECTIVES To determine the protective efficacy of highly active antiretroviral therapy (HAART) against AIDS dementia complex (ADC) relative to other initial AIDS-defining illnesses (ADIs), Australian AIDS notification data over recent years were examined. METHODS All initial ADIs in Australia over the period 1992-1997 were included. Three initial ADI groups were established: ADC; other predominantly central nervous system (CNS) ADIs (toxoplasmosis and cryptococcosis); and non-CNS ADIs. For each ADI grouping, the proportion of total ADls, and median CD4 cell count in the pre-HAART era (1992-1995) were compared with the HAART era (1996 and 1997). RESULTS Initial ADls peaked in Australia in 1994 (n = 1049), with a gradual decline to 1996 (n = 722), and a marked decline in 1997 (n = 367). ADC constituted 4.4% of initial ADIs over the period 1992-1995, but increased after the introduction of HAART to 6.0% in 1996 and 6.5% in 1997 (P = 0.02). In contrast, the proportion of other CNS ADIs (1992-1995, 8.1%; 1996, 6.0%; 1997, 8.2%; P = 0.41) was stable over the period 1992-1997. The median CD4 cell count at ADC diagnosis increased from 70/mm3 in 1992-1995 to 120/mm3 in 1996 and 170/mm3 in 1997 (P = 0.04). Although the median CD4 cell count also increased significantly over this period for both other CNS ADIs (40-60/mm3; P = 0.02), and non-CNS ADIs (60-70/mm3; P = 0.02), the increase was small. CONCLUSION A proportional increase in ADC compared with other ADIs and a marked increase in the median CD4 cell count at ADC diagnosis have occurred since the introduction of HAART in Australia. These changes suggest that HAART has a lesser impact on ADC than on other ADIs, with the poor CNS penetration of many antiretroviral agents a possible explanation.

Simeprevir with pegylated interferon alfa 2a plus ribavirin in treatment-naive patients with chronic hepatitis C virus genotype 1 infection (QUEST-1): a phase 3, randomised, double-blind, placebo-controlled trial

BACKGROUND Although the addition of the HCV NS3/4A protease inhibitors boceprevir and telaprevir to pegylated interferon (peginterferon) alfa plus ribavirin has improved sustained virological response (SVR) in treatment-naive and treatment-experienced patients infected with hepatitis C virus (HCV) genotype 1, the regimens have a high pill burden and are associated with increased rates and severity of adverse events, such as anaemia and rash. The efficacy and safety of the combination of simeprevir, a one pill, once-daily, oral HCV NS3/4A protease inhibitor, plus peginterferon alfa 2a plus ribavirin were assessed in treatment-naive patients with HCV genotype 1 infection. METHODS In QUEST-1, a phase 3, randomised, double-blind multicentre trial undertaken in 13 countries (Australia, Europe, North America, Puerto Rico, and New Zealand), 394 patients (aged ≥18 years) with chronic HCV genotype 1 infection and no history of HCV treatment, stratified by HCV subtype and host IL28B genotype, were randomly assigned in a 2:1 ratio with a computer-generated allocation sequence to receive simeprevir (150 mg once daily, orally) plus peginterferon alfa 2a plus ribavirin for 12 weeks, followed by peginterferon alfa 2a plus ribavirin (simeprevir group), or placebo orally plus peginterferon alfa 2a plus ribavirin for 12 weeks, followed by peginterferon alfa 2a plus ribavirin (placebo group). Treatment duration was 24 weeks or 48 weeks in the simeprevir group according to criteria for response-guided therapy (ie, HCV RNA <25 IU/mL [undetectable or detectable] at week 4 and <25 IU/mL undetectable at week 12) and 48 weeks in the placebo group. Patients, study personnel, and the sponsor were masked to the treatment group assignment. The primary efficacy endpoint was sustained virological response 12 weeks after the planned end of treatment (SVR12) and was assessed with an intention-to-treat analysis. The results of the primary analysis (week 60) are presented for safety and SVR12. This trial is registered with ClinicalTrials.gov, number NCT01289782. FINDINGS Treatment with simeprevir, peginterferon alfa 2a, and ribavirin was superior to placebo, peginterferon alfa 2a, and ribavirin (SVR12 in 210 [80%] patients of 264 vs 65 [50%] of 130, respectively, adjusted difference 29·3% [95% CI 20·1-38·6; p<0·0001). Adverse events in the first 12 weeks of treatment led to discontinuation of simeprevir in two (<1%) patients and discontinuation of placebo in one patient (<1%); fatigue (106 [40%] vs 49 [38%] patients, respectively) and headache (81 [31%] vs 48 [37%], respectively) were the most common adverse events. The prevalences of anaemia (42 [16%] vs 14 [11%], respectively) and rash (72 [27%] vs 33 [25%]) were similar in the simeprevir and placebo groups. Addition of simeprevir did not increase severity of patient-reported fatigue and functioning limitations, but shortened their duration. INTERPRETATION Simeprevir once daily with peginterferon alfa 2a and ribavirin shortens therapy in treatment-naive patients with HCV genotype 1 infection without worsening the adverse event profiles associated with peginterferon alfa 2a plus ribavirin. FUNDING Janssen Infectious Diseases-Diagnostics.

Natural history of hepatitis C virus infection in HIV-infected individuals and the impact of HIV in the era of highly active antiretroviral therapy: a meta-analysis.

Objectives:To estimate stage-specific transition probabilities in individuals coinfected with HIV and hepatitis C virus (HCV), to examine the effect of covariates on these rates, and to investigate the effect of HIV on HCV-related cirrhosis in the era of highly active antiretroviral therapy (HAART). Design:Systematic review of natural history studies among HCV-infected individuals. Methods:Markov maximum likelihood estimation method was used to estimate stage-specific transition probabilities. A meta-analysis was performed to obtain pooled transition probabilities, and a meta-regression to investigate the impact of covariates on these rates. Risk of cirrhosis between individuals monoinfected with HCV and coinfected with HIV/HCV were compared by HAART status. Results:The estimated mean (95% confidence intervals) annual transition probabilities of 3567 individuals coinfected with HIV/HCV (n = 17 studies) were as follows: fibrosis stage (F) F0 → F1 0.122 (0.098–0.153); F1 → F2 0.115 (0.095–0.140); F2 → F3 0.124 (0.097–0.159); and F3 → F4 0.115 (0.098–0.135) units/year. The prevalence of cirrhosis after 20 and 30 years of HCV infection was 21% (16–28%) and 49% (40–59%), respectively. Longer duration of HCV infection was significantly associated with slower rate of fibrosis progression. The overall rate ratio of cirrhosis between individuals coinfected with HIV/HCV and monoinfected with HCV (n = 27 studies) was 2.1 (1.5–3.0), 2.5 (1.8–3.4) in the non-HAART group, and 1.7 (1.1–2.8) in the HAART group. Conclusion:The rate of fibrosis progression among individuals coinfected with HIV/HCV appears constant. Our results confirm that chronic hepatitis C outcomes are worse among coinfected individuals. Over the period studied, HAART did not appear to fully correct the adverse effect of HIV infection on HCV prognosis.

Hepatitis C virus treatment for prevention among people who inject drugs: Modeling treatment scale-up in the age of direct-acting antivirals.

Substantial reductions in hepatitis C virus (HCV) prevalence among people who inject drugs (PWID) cannot be achieved by harm reduction interventions such as needle exchange and opiate substitution therapy (OST) alone. Current HCV treatment is arduous and uptake is low, but new highly effective and tolerable interferon‐free direct‐acting antiviral (DAA) treatments could facilitate increased uptake. We projected the potential impact of DAA treatments on PWID HCV prevalence in three settings. A dynamic HCV transmission model was parameterized to three chronic HCV prevalence settings: Edinburgh, UK (25%); Melbourne, Australia (50%); and Vancouver, Canada (65%). Using realistic scenarios of future DAAs (90% sustained viral response, 12 weeks duration, available 2015), we projected the treatment rates required to reduce chronic HCV prevalence by half or three‐quarters within 15 years. Current HCV treatment rates may have a minimal impact on prevalence in Melbourne and Vancouver (<2% relative reductions) but could reduce prevalence by 26% in 15 years in Edinburgh. Prevalence could halve within 15 years with treatment scale‐up to 15, 40, or 76 per 1,000 PWID annually in Edinburgh, Melbourne, or Vancouver, respectively (2‐, 13‐, and 15‐fold increases, respectively). Scale‐up to 22, 54, or 98 per 1,000 PWID annually could reduce prevalence by three‐quarters within 15 years. Less impact occurs with delayed scale‐up, higher baseline prevalence, or shorter average injecting duration. Results are insensitive to risk heterogeneity or restricting treatment to PWID on OST. At existing HCV drug costs, halving chronic prevalence would require annual treatment budgets of US

HCV treatment for prevention among people who inject drugs: Modeling treatment scale-up in the age of direct-acting antivirals.

3.2 million in Edinburgh and approximately

Once-daily simeprevir (TMC435) with pegylated interferon and ribavirin in treatment-naïve genotype 1 hepatitis C: The randomized PILLAR study

50 million in Melbourne and Vancouver. Conclusion: Interferon‐free DAAs could enable increased HCV treatment uptake among PWID, which could have a major preventative impact. However, treatment costs may limit scale‐up, and should be addressed. (Hepatology 2013;58:1598–1609)