U.S. Akarca

Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B: a randomised trial

BACKGROUND Treatment of HBeAg-positive patients with chronic hepatitis B is not effective in most. A combination of immunomodulatory pegylated interferon alfa-2b and antiviral lamivudine might improve the rate of sustained response. METHODS 307 HBeAg-positive patients with chronic hepatitis B were assigned combination therapy (100 microg/week pegylated interferon alfa-2b and 100 mg/day lamivudine) or monotherapy (100 microg/week pegylated interferon alfa-2b and placebo) for 52 weeks. During weeks 32-52 the pegylated interferon dose was 50 microg/week in both treatment groups. The analyses were based on the modified intention-to-treat population after exclusion of 24 patients from one centre withdrawn for misconduct, ten who lost HBeAg before the study start, and seven who received no study medication. All included patients were followed up for 26 weeks after treatment. FINDINGS 49 (36%) of 136 patients assigned monotherapy and 46 (35%) of 130 assigned combination therapy had lost HBeAg at the end of follow-up (p=0.91). More of the combination-therapy than of the monotherapy group had cleared HBeAg at the end of treatment (57 [44%] vs 40 [29%]; p=0.01) but relapsed during follow-up. Patterns were similar when response was assessed by suppression of serum hepatitis B virus (HBV) DNA or change in concentrations of alanine aminotransferase. Response rates (HBeAg loss) varied by HBV genotype (p=0.01): A, 42 (47%) patients; B, ten (44%); C, 11 (28%); and D, 26 (25%). INTERPRETATION Treatment with pegylated interferon alfa-2b is effective for HBeAg-positive chronic hepatitis B. Combination with lamivudine in the regimen used is not superior to monotherapy. HBV genotype is an important predictor of response to treatment.

Sustained HBeAg and HBsAg Loss After Long-term Follow-up of HBeAg-Positive Patients Treated With Peginterferon α-2b

BACKGROUND & AIMS The aim of this study was to evaluate the long-term sustainability of response in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B treated with pegylated interferon (PEG-IFN) alpha-2b alone or in combination with lamivudine. METHODS All 266 patients enrolled in the HBV99-01 study were offered participation in a long-term follow-up (LTFU) study. Patients were treated with PEG-IFN alpha-2b (100 mug/wk) alone or in combination with lamivudine (100 mg/day) for 52 weeks. Initial response was defined as HBeAg negativity at 26 weeks posttreatment. For the LTFU study, patients had one additional visit after the initial study (mean interval, 3.0 +/- 0.8 years). RESULTS Of 266 patients enrolled in the initial study, 172 (65%) participated in the LTFU study. At LTFU, HBeAg and hepatitis B surface antigen (HBsAg) negativity were observed in 37% and 11% of 172 patients, respectively. Sixty-four patients were classified as initial responders and 108 as nonresponders. Among the initial responders, sustained HBeAg negativity and HBsAg loss were observed in 81% and 30%, respectively. Significantly higher rates of HBeAg negativity were observed in genotype A-infected initial responders compared with those with genotype non-A (96% vs 76%; P = .06) as well as HBsAg loss (58% vs 11%; P < .001). CONCLUSIONS HBeAg loss after treatment with PEG-IFN alpha-2b alone or in combination with lamivudine is sustained in the majority of patients and is associated with a high likelihood of HBsAg loss, particularly in genotype A-infected patients. Therefore, PEG-IFN alpha-2b remains an important treatment option in this era of nucleos(t)ide analogue therapy.

Novel hybridization indicator methylene blue for the electrochemical detection of short DNA sequences related to the hepatitis B virus

Abstract A novel assay for the voltammetric detection of DNA sequences related to the hepatitis B virus (HBV), using MB as the hybridization indicator was performed. The voltammetric signals of MB have been investigated at bare CPE, double stranded DNA (dsDNA)-modified CPE and single stranded DNA (ssDNA)-modified CPE by means of differential pulse voltammetry and cyclic voltammetry and the increased peak currents were observed, in respect to the order of electrodes. The extent of hybridization between the 21-mer oligonucleotides of complementary sequences was determined by the enhancement of the voltammetric signal of MB. The response of the hybridization of the probe with the single-base mismatch oligonucleotide at CPE was detected by MB. In this case, the unbound guanine bases increased the voltammetric signal obtained with the hybrid-modified CPE. Control experiments with the noncomplementary oligonucleotides were performed to assess whether the DNA biosensor responds selectively, via hybridization, to the target. Numerous factors, affecting the probe immobilization, target hybridization and indicator binding reactions are optimized to maximize the sensitivity and reduce the assay time. The new indicator MB holds great promise for rapid screening of HBV infection.

Tenofovir disoproxil fumarate (TDF), emtricitabine/TDF, and entecavir in patients with decompensated chronic hepatitis B liver disease

Data are limited on the safety and effectiveness of oral antivirals other than lamivudine and adefovir dipivoxil for treatment of chronic hepatitis B (CHB) in patients with decompensated liver disease. This Phase 2, double‐blind study randomized 112 patients with CHB and decompensated liver disease to receive either tenofovir disoproxil fumarate (TDF; n = 45), emtricitabine (FTC)/TDF (fixed‐dose combination; n = 45), or entecavir (ETV; n = 22). The primary endpoint was safety; more specifically, tolerability failure (adverse events resulting in permanent treatment discontinuation) and confirmed serum creatinine increase ≥0.5 mg/dL from baseline or confirmed serum phosphorus <2 mg/dL. Patients with insufficient viral suppression (e.g., confirmed HBV DNA ≥400 copies/mL at week 8 or 24) could begin open‐label FTC/TDF but were considered failures in this interim week 48 analysis for efficacy endpoints. Tolerability failure was infrequent across arms: 6.7% TDF, 4.4% FTC/TDF, and 9.1% ETV (P = 0.622) as were confirmed renal parameters meeting threshold 8.9%, 6.7%, and 4.5% (P = 1.000), respectively. Six patients died (none considered related to study drug) and six received liver transplants (none had HBV recurrence). The adverse event and laboratory profiles were consistent with advanced liver disease and complications, with no unexpected safety signals. At week 48, HBV DNA was <400 copies/mL (69 IU/mL) in 70.5% (TDF), 87.8% (FTC/TDF), and 72.7% (ETV) of patients. Proportions with normal alanine aminotransferase were: 57% (TDF), 76% (FTC/TDF), and 55% (ETV). Hepatitis B e antigen (HBeAg) loss/seroconversion occurred in 21%/21% (TDF), 27%/13% (FTC/TDF), and 0%/0% (ETV). Child‐Turcotte‐Pugh and Modification for End‐stage Liver Disease scores improved in all groups. Conclusion: All treatments were well tolerated in patients with decompensated liver disease due to CHB with improvement in virologic, biochemical, and clinical parameters. (HEPATOLOGY 2011.)

Early on‐treatment prediction of response to peginterferon alfa‐2a for HBeAg‐negative chronic hepatitis B using HBsAg and HBV DNA levels

Peginterferon alfa‐2a results in a sustained response (SR) in a minority of patients with hepatitis B e antigen (HBeAg)–negative chronic hepatitis B (CHB). This study investigated the role of early on‐treatment serum hepatitis B surface antigen (HBsAg) levels in the prediction of SR in HBeAg‐negative patients receiving peginterferon alfa‐2a. HBsAg (Architect from Abbott) was quantified at the baseline and during treatment (weeks 4, 8, 12, 24, 36, and 48) and follow‐up (weeks 60 and 72) in the sera from 107 patients who participated in an international multicenter trial (peginterferon alfa‐2a, n = 53, versus peginterferon alfa‐2a and ribavirin, n = 54). Overall, 24 patients (22%) achieved SR [serum hepatitis B virus (HBV) DNA level < 10,000 copies/mL and normal alanine aminotransferase levels at week 72]. Baseline characteristics were comparable between sustained responders and nonresponders. From week 8 onward, serum HBsAg levels markedly decreased in sustained responders, whereas only a modest decline was observed in nonresponders. However, HBsAg declines alone were of limited value in the prediction of SR [area under the receiver operating characteristic curve (AUC) at weeks 4, 8, and 12 = 0.59, 0.56, and 0.69, respectively]. Combining the declines in HBsAg and HBV DNA allowed the best prediction of SR (AUC at week 12 = 0.74). None of the 20 patients (20% of the study population) in whom a decrease in serum HBsAg levels was absent and whose HBV DNA levels declined less than 2 log copies/mL exhibited an SR (negative predictive value = 100%). Conclusion: At week 12 of peginterferon alfa‐2a treatment for HBeAg‐negative CHB, a solid stopping rule was established with a combination of declines in serum HBV DNA and HBsAg levels from the baseline. Quantitative serum HBsAg in combination with HBV DNA enables on‐treatment adjustments of peginterferon therapy for HBeAg‐negative CHB. (HEPATOLOGY 2010)

Historical epidemiology of hepatitis C virus (HCV) in selected countries

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6 358 000 cases in 2008 and Brazil with 2 106 000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV‐infected populations are critical for addressing HCV‐related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

Electrochemical DNA biosensor for the detection of TT and Hepatitis B virus from PCR amplified real samples by using methylene blue.

DNA biosensors based on nucleic acid hybridization processes are rapidly being developed towards the goal of rapid and inexpensive diagnosis of genetic and infectious diseases. Electrochemical transducers are often being used for detecting the DNA hybridization event, due to their high sensitivity, small dimensions, low cost, and compatibility with microfabrication technology. In this study, an electrochemical biosensor for the voltammetric detection of DNA sequences related to the Hepatitis B virus (HBV) and TT virus (TTV) from polymerase chain reaction (PCR) amplified real samples is described for the first time. The biosensor relies on the immobilization of the 21- or 24-mer single stranded oligonucleotides (probe) related to the HBV and TTV sequences and hybridization of these oligonucleotides with their complementary sequences (target) at carbon paste electrode (CPE). The extent of hybridization between the probe and target sequences was determined by using square wave voltammetry (SWV) with moving average baseline correction and methylene blue (MB) as the hybridization indicator. As a result of the interaction between MB and the bound guanine bases of hybrid at CPE surface, the MB signal decreased, when it was compared with the MB signal, which was observed with probe modified CPE. The difference between the MB signals, obtained from the hybrid modified and the probe modified CPE is used to detect the DNA sequences of the infectious diseases from PCR amplified real samples. Numerous factors affecting the target hybridization and indicator binding reactions are optimized to maximize the sensitivity.

Strategies to manage hepatitis C virus (HCV) disease burden

The number of hepatitis C virus (HCV) infections is projected to decline while those with advanced liver disease will increase. A modeling approach was used to forecast two treatment scenarios: (i) the impact of increased treatment efficacy while keeping the number of treated patients constant and (ii) increasing efficacy and treatment rate. This analysis suggests that successful diagnosis and treatment of a small proportion of patients can contribute significantly to the reduction of disease burden in the countries studied. The largest reduction in HCV‐related morbidity and mortality occurs when increased treatment is combined with higher efficacy therapies, generally in combination with increased diagnosis. With a treatment rate of approximately 10%, this analysis suggests it is possible to achieve elimination of HCV (defined as a >90% decline in total infections by 2030). However, for most countries presented, this will require a 3–5 fold increase in diagnosis and/or treatment. Thus, building the public health and clinical provider capacity for improved diagnosis and treatment will be critical.

Efficacy of Entecavir With or Without Tenofovir Disoproxil Fumarate for Nucleos(t)ide-Naïve Patients With Chronic Hepatitis B

BACKGROUND & AIMS Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent antiviral agents that might have additive or synergistic antiviral activity in treatment of patients with chronic hepatitis B (CHB). We compared the efficacy and safety of ETV monotherapy with those of a combination of ETV and TDF. METHODS We performed a randomized, open-label, multicenter, superiority study of 379 nucleos(t)ide-naïve patients with hepatitis B e antigen (HBeAg)-positive (n = 264) or HBeAg-negative (n = 115) CHB. Subjects were given ETV 0.5 mg (n = 182) or a combination of ETV 0.5 mg and TDF 300 mg (n = 197) for 100 weeks. RESULTS At week 96, comparable proportions of patients in each study arm achieved the primary end point of a level of hepatitis B virus (HBV) DNA <50 IU/mL (83.2% vs 76.4%; P = .088). Among HBeAg-positive patients, a greater proportion given combination therapy achieved levels of HBV DNA <50 IU/mL than those given ETV alone (80.4% vs 69.8%; P = .046). However, this difference was observed only in patients with baseline levels of HBV DNA ≥ 10(8) IU/mL (79% vs 62%) and not in those with baseline levels of HBV DNA <10(8) IU/mL (83% in both arms). Rates of HBeAg loss and HBeAg seroconversion were comparable between groups, whereas the rate of alanine aminotransferase normalization was greater in the ETV monotherapy group. No HBV variants associated with ETV or TDF resistance were detected. Safety profiles were consistent with previous reports of ETV or TDF monotherapy. CONCLUSIONS The antiviral efficacy of ETV monotherapy is comparable to that of ETV plus TDF in a mixed population of nucleos(t)ide-naïve patients with CHB (70% HBeAg positive). The combination therapy could provide an incremental benefit to HBeAg-positive patients with baseline levels of HBV DNA ≥ 10(8) IU/mL.

DNA Electrochemical Biosensor for the Detection of Short DNA Sequences Related to the Hepatitis B Virus

Nucleic acid hybridization forms the basis for the diagnosis of genetic and infectious diseases. Electrochemical biosensors, coupling the inherent specificity of DNA recognition reactions with the high sensitivity of physical transducers, thus hold great promise for sequence-specific detection. An electrochemical biosensor for the voltammetric detection of DNA sequences related to the hepatitis B virus (HBV) is described. Synthetic single-stranded oligonucleotides (“probe”) have been immobilized onto carbon paste electrodes with the adsorption at a controlled potential. The probes were hybridized with different concentrations of complementary (‘target’) sequences. The formed hybrids on the electrode surface were evaluated by differential pulse voltammetry using cobalt phenanthroline, [Co(phen)33+] as the indicator of hybridization reaction.