Recent data on treatment of chronic hepatitis B with nucleos(t)ide analogues

The long and stumble way to find potential active compounds from plants for defeating hepatitis B and C: review

Hepatitis is a liver illness caused by virus such as hepatitis A virus, hepatitis B virus and hepatitis C virus. Hepatitis B and C are considerably more usual and induce more cirrhosis and dead worldwide than hepatitis A. Although drugs that are currently often used in the medication of hepatitis B and C, the finding of recent drug from various resources including herbal has been intensively developed. Therefore, the purpose of this review is to consider the possibility of plant’s compounds as anti-HBV and anti-HCV. From the results of a review of several articles, several plant’s compound have shown effectiveness againts HBV and HCV by in silico, in vitro and in vivo studies. In conclusion, several plant’s active compounds are possibility to be developed as anti-hepatitis B and C.

Immune-Related lncRNAs with WGCNA Identified the Function of SNHG10 in HBV-Related Hepatocellular Carcinoma

Objective. The hepatitis B virus (HBV) infection led to hepatitis, which was one of common reasons for hepatocellular carcinoma (HCC). The immune microenvironment alteration played a crucial role in this process. The study aimed to identify immune-related long noncoding RNAs (lncRNAs) in HBV-related HCC and explore potential mechanisms. Methods. In total, 1,072 immune‐related genes (IRGs) were enriched in different co-expression modules with weighted gene co-expression network analysis (WGCNA) combining the corresponding clinical features in HBV-related HCC. The immune-related lncRNAs were selected from the crucial co-expression model based on the correlation analysis with IRGs. The immune-related lncRNAs were furtherly used to construct prognostic signature by the Cox proportional hazards regression and Lasso regression. Furthermore, the proliferation and migration ability of lncRNA SNHG10 were verified in vitro. Results. A total of nine co-expression modules were identified by WGCNA of which the “red” co-expression module was most correlated with various clinical characteristics. Additionally, the IRGs in this module were significantly enriched in multiple immune-related pathways. The twelve immune-related lncRNAs prognostic signature (HAND2-AS1, LINC00844, SNHG10, MALAT1, LINC00460, LBX2-AS1, MIR31HG, SEMA6A-AS1, LINC1278, LINC00514, CTBP-AS2, and LINC00205) was constructed. The risk score was an independent risk factor in HBV-related HCC and verified by principal components analysis (PCA), nomogram, and PCR between different cell lines. Moreover, the proportion of immune cells were significantly different between high-risk score group and low-risk score group. The malignant behavior of Hep3B was significantly different between si-lncRNA SNHG10 and control group. Conclusions. The immune-related lncRNAs prognostic signature provided some potential biomarkers and molecular mechanisms in HBV-related HCC.

Comprehensive analysis of hospital-based prospective cohort reveals the unique effectiveness and safety for nucleos(t)ide analogues in HBV patients

BACKGROUND

Nucleos(t)ide analogues (NAs) including lamivudine (LAM), telbivudine (LDT), adefovir dipivoxil(ADV), and entecavir (ETV) have been widely used as anti-HBV drugs. We aimed to study the effectiveness and safety of various NAs.

METHODS

Two thousand three hundred and eighty patients with chronic hepatitis B (CHB) were enrolled. The rate of virologic response, optimization therapy, and serologic responses were analyzed.

RESULTS

HBV DNA inhibitory capacity was shown to be LAM+ADV≈ETV>LDT>LAM>ADV. Virologic breakthrough rate and proportion of optimized treatment were LAM>ADV>LDT>LAM+ADV>ETV. However, virological response rate showed the opposite trend. The selection of anti-virals, HBeAg-negative, and lower HBV DNA levels after one year of anti-viral treatment, are favorable factors for the maintenance of virologic response.

CONCLUSIONS

This study's results were consistent with the major clinical guidelines to recommend ETV and TDF as the preferred treatment for CHB patients. LAM could be used for patients with lower HBV DNA load; ADV may be more applicable to non-cirrhotic patients with HBeAg-negative and lower HBV DNA load. LDT can be used to treat patients with HBeAg-positive, low HBV DNA load, and higher ALT levels due to higher HBeAg conversion rate in a baseline optimized population. The effectiveness of LAM+ADV is similar to and sometimes better than ETV treatment in a CHB population.

Hepatitis B virus therapy: What’s the future holding for us?

Hepatitis B is one of the leading causes of liver cancer worldwide and unfortunately the number of people affected with hepatitis B virus (HBV) infection is still on the rise. Although the HBV has been known to cause fatal illness since decades but the population effected by this lethal virus have still only a few options for its management. The major treatment strategies include interferons and nucleos(t)ide analogues. These agents have so far produced unsatisfactory results in terms of complete virus eradication. Interferons cannot be used for long term therapy because of their potential side effects. Prolong treatment with nucleos(t)ide analogues has also been reported to cause serious side effects besides the increasing resistance by the virus. The need for new innovative solutions for treatment of HBV has been realized by global research institutes and pharmaceutical industry. Present review focuses in detail on the new ideas that are being transformed into therapeutic tools for use as future therapies in HBV infection. Modern drug designing and screening methods have made the drug discovery process shorter and more reliable. HBV therapeutics will take a new turn in coming years owing to these intelligent drug designing and screening methods. Future therapy of HBV is aiming to include the use of vaccines (both prophylactic and therapeutic), immunomodulators such as antibodies, non-nucleoside antivirals such as RNAi and inhibitors of viral life cycle.

Combination therapy with pegylated interferon alpha-2b and adefovir dipivoxil in HBeAg-positive chronic hepatitis B versus interferon alone: a prospective, randomized study

Currently available monotherapies of oral nucleoside/nucleotide analogs or interferon are unable to achieve a sustained and effective response in most of patients with chronic hepatitis B (CHB). The objective of the present study was to compare the efficacy and safety of pegylated interferon (Peg-IFN) alpha-2b plus adefovir dipivoxil combination therapy versus Peg-IFN alpha-2b alone. Sixty-one HBeAg-positive chronic hepatitis B patients were randomized to receive Peg-IFN alpha-2b alone (1.5 μg/kg once weekly) or Peg-IFN alpha-2b plus adefovir (10 mg daily) for up to 52 weeks. Efficacy and safety analyses were performed on all participants who received at least one dose of study medication. The rate of HBeAg seroconversion and undetectable HBV-DNA were evaluated after 52 weeks of therapy. At the end of treatment, 11 of 30 (36.7%) patients receiving combination therapy achieved HBeAg seroconversion versus 8 of 31 (25.8%) in the monotherapy group (P=0.36). In contrast, the percentage of patients with undetectable serum HBV DNA was significantly higher in the combination group than in the monotherapy group (76.7% vs. 29.0%, P<0.001). Thyroid dysfunction was more frequent in the combination group than in the monotherapy group (P<0.05). In HBeAg-positive CHB, combination of Peg-IFN alpha-2b and adefovir for 52 weeks resulted, at the end of treatment, in a higher virological response but without significant impact on the rate of HBeAg seroconversion and possibly an adverse effect on thyroid function.

Role of lamivudine with transarterial chemoembolization in the survival of patients with hepatocellular carcinoma

BACKGROUND AND AIM

The purpose of the present study was to determine whether lamivudine in combination with transarterial chemoembolization (TACE) could reduce hepatitis B virus (HBV) activation and improve the survival of patients with hepatocellular carcinoma (HCC).

METHODS

From July 2008 to October 2011, a total of 181 consecutive HBV-related HCC patients undergoing TACE were randomized to two groups (92: lamivudine, 89: control). Follow up was every 3 months. Primary and secondary end-points were time to progression (TTP) and overall survival (OS), respectively, both of which were evaluated by the Kaplan Meier technique and summarized by the hazard ratio.

RESULTS

The level of HBV-DNA became undetectable in 42 (45.6%) patients in the lamivudine group, compared with 10 (11.2%) in the control group (P < 0.001). The median TTP was 8.2 months in lamivudine group and 4.3 months in control group (P = 0.005), and lamivudine therapy was an independent protective factor related to TTP (P = 0.006). Moreover, 1-, 2-, and 3-year survival rates were 83%, 69%, and 58% in lamivudine group and 60%, 48%, and 48% in control group, respectively (P = 0.002). With multivariate Cox regression model, lamivudine therapy (P = 0.002) and α-fetoprotein (AFP) level (P = 0.003) were two independent predictors for OS.

CONCLUSION

Lamivudine therapy could reduce HBV activation and improve survival of HCC patients treated with TACE. Lamivudine therapy and AFP level are two independent factors affecting OS.

Transient elastography-based risk estimation of hepatitis B virus-related occurrence of hepatocellular carcinoma: development and validation of a predictive model

Background

The purpose of this study was to develop and validate a novel transient elastography-based predictive model for occurrence of hepatocellular carcinoma (HCC).

Methods

A total of 1,250 patients with chronic hepatitis B and baseline liver stiffness values were recruited between May 2005 and December 2007. The predictive model for HCC occurrence was constructed based on a Cox proportional hazards model. We estimated baseline disease-free probabilities at 3 years. Discrimination and calibration were used to validate the model.

Results

HCC occurred in 56 patients during a median follow-up of 30.7 months. Multivariate analysis revealed that age, male gender, and liver stiffness values were independent predictors of HCC (all P<0.05), whereas hepatitis B virus DNA ≥20,000 IU/L showed borderline statistical significance (P=0.0659). We developed a predictive model for HCC using these four variables, which showed good discrimination capability, with an area under the receiver operating characteristic curve (AUROC) of 0.806 (95% confidence interval 0.738–0.874). We used the bootstrap method to assess discrimination. The AUROC remained largely unchanged between iterations, with an average value of 0.802 (95% confidence interval 0.791–0.812). The predicted risk of occurrence of HCC calibrated well with the observed risk, with a correlation coefficient of 0.905 (P<0.001).

Conclusion

This novel model accurately estimated the risk of HCC occurrence in patients with chronic hepatitis B.

Downregulation and altered function of natural killer cells in hepatitis B virus patients treated with entecavir

The aim of the present study was to investigate the natural killer (NK) cell phenotype and function in chronic hepatitis B virus (HBV) patients and to study the effects of entecavir therapy (10 mg/day, p.o.) on these responses. Peripheral blood NK cells were collected from 18 chronic HBV patients and 14 healthy controls. The effect of entecavir therapy on the phenotype and function of NK cells in chronic HBV patients was characterized by flow cytometry analysis. Concentrations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), HBV viral loads in both groups and potential associations between the frequency of peripheral NK cell subsets and clinical measures were determined. There was a significant reduction in the number of CD3(-)CD56(+) NK cells in chronic HBV patients compared with healthy controls. Furthermore, there were significant increases in the percentage of CD3(-)CD56(+)NKG2D(+) and CD3(-)CD56(+)NKP30(+) NK activating receptors in chronic HBV patients compared with healthy individuals, who exhibited downregulated expression following entecavir treatment. Spearman's correlation analysis revealed that there was a significant positive correlation between the percentage of NKG2D(+) and NKP30(+) NK cells and serum ALT levels. Characterization of NK cell degranulation indicated that the frequency of CD107a(+) NK cells in HBV patients (in response to K562 stimulation) was significantly greater than in healthy controls but decreased following entecavir treatment. Entecavir treatment of hepatitis B e antigen-positive chronic HBV-infected patients not only led to a reduction in HBV DNA loads and normalization of ALT and AST levels, but also resulted in the recovery of NK cell-mediated immunity.

Virologic responses to add-on adefovir dipivoxil treatment versus entecavir monotherapy in children with lamivudine-resistant chronic hepatitis B

PURPOSE

The aim of the study was to compare the virologic response to adefovir (ADV) add-on therapy with switching to entecavir (ETV) monotherapy in children and adolescents with chronic hepatitis B (CHB) who have developed lamivudine (LAM) resistance during LAM treatment.

METHODS

Twenty-seven consecutive patients with CHB who had developed LAM resistance during LAM treatment were included. Of these 27 patients, 8 patients were treated with the addition of ADV to ongoing LAM and 8 patients were treated by switching to ETV monotherapy and each of these 16 patients were compared with the 11 patients who were treated by switching to ADV alone, as a historical control. Therapeutic responses to treatment were evaluated at 12, 24, 36, and 48 weeks from the initiation of therapy by measuring the decrement of hepatitis B virus (HBV)-DNA titers.

RESULTS

The therapeutic period for HBV-DNA titer decrement (>2  log(10) IU/mL) was significantly shorter in both the LAM+ADV group and the ETV group than in the ADV group (P = 0.008); however, there was no significant difference between the LAM+ADV group and the ETV group. The rate of virologic response, defined as decrement in HBV-DNA titer to undetectable levels at 24 weeks, was significantly higher in both the LAM+ADV group and the ETV group than in the ADV group (P = 0.029).

CONCLUSIONS

Both the LAM+ADV combination therapy and ETV monotherapy exhibited significantly more effective virologic responses compared to the ADV monotherapy in children and adolescents with LAM-resistant CHB, although there was no significant difference between the LAM+ADV group and the ETV group.

[Entecavir therapy for patients with hepatitis B virus-related decompensated cirrhosis]

BACKGROUND/AIMS

Entecavie (ETV) has a potent antiviral effect and low rates of resistance in hepatitis B virus (HBV) and is the first-line monotherapy in patients with HBV-related decompensated cirrhosis. We evaluated the efficacy of 12 months treatment with ETV and tried to determine predictive factors of response.

METHODS

Forty-five consecutive decompensated cirrhotic patients who received ETV (0.5 mg/day) for more than six months were included. All patients were positive for HBV DNA, and the Child-Turcotte-Pugh (CTP) scores were over 8 point. Seventeen patients were HBeAg-positive. CTP score, model for end-stage liver disease (MELD) score, serum markers of liver function and HBV DNA were assessed every 3 months.

RESULTS

ETV treatment for 12 months resulted in improvement of CTP and MELD scores. Pre-treatment mean CTP and MELD score were decreased from 10.1 (±2.0) and 13.48 (±4.05) to 7.24 (±2.0) and 9.68 (±4.85) at 12 months, respectively. The 1-year cumulative rates of HBV DNA negativity and HBeAg loss were 88.9% and 52.9%, respectively, by intention-to-treat analysis. Thirty-two (71.1%) showed improvement in CTP score. Eleven patients did not show change, and 2 patients got worse. The AST/ALT, albumin, bilrubin, prothrombin time were significantly normalized within six months. The good responder group had high level of prothrombin time than the poor responder group (p=0.004).

CONCLUSIONS

Our result shows that entecavir can improve liver function in about 70% of patients with HBV related decompensated liver cirrhosis. INR may be a predictive factor of good response with entecavir in these patients.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2012 update

Large volume of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2008. These include further studies in asymptomatic subjects with chronic HBV infection and community-based cohorts, the role of HBV genotype/naturally occurring HBV mutations, the application of non-invasive assessment of hepatic fibrosis and quantitation of HBV surface antigen and new drug or new strategies towards more effective therapy. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings was discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Combination of hepatitis B viral antigens and DNA for prediction of relapse after discontinuation of nucleos(t)ide analogs in patients with chronic hepatitis B

AIM

  The factors associated with hepatitis recurrence after discontinuation of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B were analyzed to predict the risk of relapse more accurately.

METHODS

  A total of 126 patients who discontinued NA therapy were recruited retrospectively. The clinical conditions of a successful discontinuation were set as alanine aminotransferase (ALT) below 30 IU/L and serum hepatitis B virus (HBV) DNA below 4.0 log copies/mL.

RESULTS

  Relapse of hepatitis B were judged to occur when maximal serum ALT became higher than 79 IU/L or when maximal serum HBV DNA surpassed 5.7 log copies/mL following NA discontinuation since these values corresponded with mean values of ALT (30 IU/L) and HBV DNA (4.0 log copies/mL), respectively. At least 90% of patients with either detectable hepatitis B e antigen or serum HBV DNA higher than 3.0 log copies/mL at the time of NA discontinuation relapsed within one year. In the remaining patients, higher levels of both hepatitis B surface and core-related antigens at the time of discontinuation, as well as a shorter course of NA treatment, were significantly associated with relapse by multivariate analysis.

CONCLUSIONS

  It appears that negative results for hepatitis B e antigen and serum HBV DNA lower than 3.0 log copies/mL are essential for successful NA discontinuation, which may be attained by a longer treatment period. Levels of hepatitis B surface and core-related antigens are also significant factors independently associated with relapse of hepatitis.

The management of chronic hepatitis B in Asian Americans

Hepatitis B virus (HBV) infection is common with major clinical consequences worldwide. In Asian Americans, the HBsAg carrier rate ranges from 7 to 16%; HBV is the most important cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). Patients are first diagnosed at different stages of clinical disease, which is categorized by biochemical and virologic tests. Patients at risk for liver complications should be identified and offered antiviral therapy. The two antiviral agents recommended for first-line treatment of chronic hepatitis B (CHB) are entecavir and tenofovir. The primary goal of therapy is sustained suppression of viral replication to achieve clinical remission, reverse fibrosis, and prevent and reduce progression to end-stage liver disease and HCC. Asian patients with chronic hepatitis, either HBeAg-positive or -negative, with HBV DNA levels >10(4) copies/mL (>2,000 IU/mL) and alanine aminotransferase (ALT) values above normal are candidates for antiviral therapy. HBeAg-negative patients with HBV DNA >10(4) copies/mL (>2,000 IU/mL) and normal ALT levels but who have either serum albumin ≤3.5 g/dL or platelet count ≤130,000 mm(3), basal core promoter mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive antiviral therapy. Considerations for treatment include pregnant women with high viremia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg-positive patients with risk factors, lifelong surveillance for HCC with alpha-fetoprotein testing and abdominal ultrasound examination at 6-month intervals is required. These recommendations are based on a review of relevant literature and the opinion of a panel of Asian American physicians with expertise in hepatitis B treatment.

Tenofovir disoproxil fumarate in the treatment of chronic hepatitis B

Tenofovir is a nucleotide analog reverse transcriptase inhibitor approved recently by the US FDA for the treatment of chronic hepatitis B (CHB) in adult patients based on the results of two double-blind randomized trials demonstrating superiority of tenofovir compared with adefovir. Tenofovir is available orally as tenofovir disoproxil fumarate (ester pro-drug of tenofovir) and inhibits replication of both hepatitis B virus and HIV-1. Owing to its potent antiviral activity, favorable safety profile, and higher barrier to the development of resistance, tenofovir has replaced adefovir as a first-line oral monotherapy option in the treatment of CHB in the 2009 update of the American Association for the Study of Liver Diseases (AASLD) Practice Guidelines. Additionally, tenofovir monotherapy or in combination with nucleoside analogs are options for patients who have developed resistance to other CHB therapies including lamivudine and adefovir.

Review article: Hepatitis B and dialysis

The incidence of hepatitis B virus (HBV) infection in dialysis populations has declined over recent decades, largely because of improvements in infection control and widespread implementation of HBV vaccination. Regardless, outbreaks of infection continue to occur in dialysis units, and prevalence rates remain unacceptably high. For a variety of reasons, dialysis patients are at increased risk of acquiring HBV. They also demonstrate different disease manifestations compared with healthy individuals and are more likely to progress to chronic carriage. This paper will review the epidemiology, modes of transmission and diagnosis of HBV in this population. Prevention and treatment will be discussed, with a specific focus on strategies to improve vaccination response, new therapeutic options and selection of patients for therapy.

Risk assessment for the development of hepatocellular carcinoma: according to on-treatment viral response during long-term lamivudine therapy in hepatitis B virus-related liver disease

BACKGROUND & AIMS

To assess the risk for the development of hepatocellular carcinoma (HCC) according to the underlying liver status and on-treatment viral response during long-term lamivudine therapy in patients with hepatitis B virus-related liver disease.

PATIENTS AND METHODS

Between March 1997 and February 2005, a total of 872 patients were treated with lamivudine for more than one year. Between 1983 and 1998, a total of 699 patients were enrolled as historical controls.

RESULTS

For patients with compensated cirrhosis, HCC occurred in 4.9% (5/103) of cases with sustained viral suppression (persistently <141,500 copies/ml), 11.8% (20/170) in cases with viral breakthrough, and 19.4% (7/36) in cases with a suboptimal response (persistently 141,500 copies/ml): the mean follow-up was 5.1+/-2.7, 5.4+/-2.3, and 3.7+/-1.8 years, respectively. For the control group, HCC developed in 25.0% (37/148) of the cases during a mean follow-up of 6.1+/-4.3 years. Thus, the annual incidence of HCC was 0.95%, 2.18%, 5.26%, and 4.10% in patients with sustained viral suppression, viral breakthrough, suboptimal response, and the control group, respectively. The cumulative incidence of HCC in patients with sustained viral suppression was significantly lower than in patients with a suboptimal response and the controls (p=0.002 and p=0.005, respectively). In patients without cirrhosis and with decompensated cirrhosis, the preventive effects of lamivudine on the development of HCC were not observed (p=0.446 and p=0.123, respectively).

CONCLUSION

Lamivudine therapy reduced the incidence of HCC in patients with compensated cirrhosis when the viral suppression was sustained.

Avoiding and managing lamivudine resistance in chronic hepatitis B: current approaches and potential strategies including pegylated interferon

Since its approval for the treatment of chronic hepatitis B in 1998, lamivudine (LAM) has been used extensively throughout the world, because of its relatively low costs and favourable tolerability. However, clinical trials and cohort studies have demonstrated that a high rate of resistance to this drug develops and, as a result, it is no longer included as a first-line therapy in most current treatment guidelines. Nevertheless, because of its low cost, this drug continues to be used in many countries and the pool of patients who have developed resistance to LAM continues to increase. Thus, there is a clear need to develop coherent management strategies to treat such patients as well as limit the emergence of resistance in the first instance. The purpose of this review is to highlight the need to aim for long-term treatment success while limiting the emergence of drug resistance and its consequences for the future. In addition to add-on/switch strategies with other nucleos(t)ide analogs, currently available data suggest that interferon-based therapies, with their potential to induce a sustained response, are worthy of consideration not only for reducing de novo resistance but as an option for the management of those patients in whom drug resistance has already developed.

Virological response to antiviral therapy at week 12 indicates a great reduction of intrahepatic hepatitis B virus DNA and cccDNA in HBeAg-positive chronic hepatitis B patients

Early virological response is considered to be a predictor for the outcome of anti-hepatitis B virus (HBV) therapy. To analyze its correlation to intrahepatic HBV DNA and covalently closed circular DNA (ccc)DNA, 71 hepatitis B virus e antigen (HBeAg)-positive chronic hepatitis B patients were recruited: 34 patients were treated with lamivudine; 13 with interferon-alpha2b; and 24 with sequential therapy of lamivudine-interferon-alpha2b for 48 weeks. Intrahepatic HBV DNA and cccDNA load were measured at the baseline and at Week 48. Fifty-seven patients had virological response at Week 12. Median decreases of serum HBV DNA in patients with or without virological response at Week 12 were 4.0 log(10) (max. 6.2, min. 2.2) and 1.1 log(10) (max. 2.1, min. 0) (Z = -5.766, P = 0.0000), respectively. At Week 48 they were 4.1 log(10) (max. 7.4, min. 1.0) and 2.3 log(10) (max. 7.5, min. 0.3) (Z = -2.760, P = 0.006), respectively. For intrahepatic HBV DNA load they were 1.3 log(10) (max. 4.3, min. -1.2) and 0.6 log(10) (max. 3.5, min. -0.8), respectively, and for HBV cccDNA load they were 1.1 log(10) (max. 4.8, min. -0.5) and 0.5 log(10) (max. 3.0, min. -0.8) (Z = -2.097, P = 0.036), respectively at Week 48. Step-wise logistic regression analysis indicated that the baseline intrahepatic HBV DNA load effected virological response at Week 12 [odds ratio (OR) 0.405; 95% confidence interval (CI) 0.174-0.944; P = 0.036] and HBeAg seroconversion at Week 48 (OR 0.292; 95% CI 0.131-0.649; P = 0.003). In conclusion, virological response at Week 12 indicated a great reduction of intrahepatic DNA and cccDNA load in HBeAg-positive CHB patients. The baseline intrahepatic HBV DNA load affected virological response at Week 12 and HBeAg seroconversion at Week 48.

Tenofovir for the treatment of hepatitis B virus

Tenofovir disoproxil fumarate is a nucleotide analog reverse transcriptase inhibitor recently approved by the United States Food and Drug Administration (FDA) for the treatment of chronic hepatitis B virus (HBV) infection in adults. Tenofovir has been available in the United States for the treatment of human immunodeficiency virus (HIV) since 2001. It blocks HBV replication in liver cells and is available as a once-daily oral formulation. The efficacy of tenofovir for the treatment of chronic HBV has been demonstrated to be superior to adefovir in randomized controlled trials, which led to its FDA approval for use in chronic HBV. Because of its potent antiviral activity, favorable safety profile, and higher barrier to the development of resistance, tenofovir should replace adefovir as a first-line monotherapy option in the treatment of HBV in monoinfected patients. In the HIV-HBV-coinfected population, tenofovir is already a preferred agent in combination with other anti-HBV agents (lamivudine or emtricitabine), which are cotreatments for HIV as well. In addition, tenofovir monotherapy or in combination with nucleoside analogs are options for patients who have developed resistance to other therapies for chronic HBV, including lamivudine and adefovir.

Hepatitis B therapies and antiviral resistance detection and management

Hepatitis B virus (HBV) infection is an important health problem and a major cause of chronic hepatitis that can lead to cirrhosis and hepatocellular carcinoma. Durable viral suppression has been documented to lower the risk of hepatocellular carcinoma and disease progression. Treatment of chronic HBV infection remains a major clinical challenge because long-term use with approved oral antiviral agents is associated with drug resistance. Antiviral resistance can result in poor clinical outcomes; therefore first-line therapy with the most potent agent(s) is recommended to lower the risk. Early detection of resistance is paramount to possibly reduce the risk of liver-related morbidity and mortality. It is important that clinicians monitor for therapeutic efficacy and resistance, so as to optimize the management of chronic HBV.

Patterns of managing chronic hepatitis B treatment-related drug resistance: a survey of physicians in Mainland China, South Korea, Taiwan, and Thailand

PURPOSE

The emergence of antiviral resistance can negate the benefits of antiviral therapy in patients with chronic hepatitis B (CHB). This study aimed to assess how physicians in Asia manage suspected antiviral resistance.

METHODS

Randomly selected CHB-treating physicians in Mainland China, South Korea, Taiwan, and Thailand underwent a face-to-face interview. A standardized questionnaire was used to assess how physicians identify, monitor, and manage suspected resistance and its associated medical costs.

RESULTS

We interviewed 575 physicians from January to May 2008. Most physicians preferred a "prevention-of-antiviral resistance" strategy over a "rescue-once-resistance-develops" strategy. Physicians had encountered lamivudine resistance most frequently (96-100% of respondents), followed by the resistance to adefovir (18-58%) and entecavir (3-7%). While physicians in South Korea and Taiwan have access to resistance testing, physicians in Mainland China and Thailand have limited access to resistance testing but rely on HBV DNA and alanine aminotransferase (ALT) tests to identify resistance. Once resistance is suspected, 60% of the physicians in Mainland China, South Korea, and Thailand monitored these patients quarterly and the remaining 40% opted for monthly follow-up. In comparison, 70% of the Taiwanese physicians monitored these patients monthly. The average total direct medical costs, excluding antiviral costs, to manage a patient during the first year after suspected resistance is identified ranged from USD $319 to USD $709.

CONCLUSIONS

Limited access to HBV resistance tests causes physicians in Asia to manage suspected resistance by various HBV DNA assays and ALT tests. This raises concerns that resistance may not be detected early enough to be rescued efficiently.

Entecavir: a potent antiviral with minimal long-term resistance in nucleoside-naive chronic hepatitis B patients

Entecavir has demonstrated safety and efficacy in the treatment of chronic hepatitis B infection. It is the prototype for the cyclopentane class of nucleoside/nucleotide chronic hepatitis B antiviral agents. It has a high potency and, due to its structural formula and mechanism of action, entecavir is associated with emergence of minimal resistance in the long-term treatment of nucleoside-naive patients. Research suggests that long-term treatment may be required for chronic hepatitis B patients, especially those who acquire HBV early in life, to achieve maximum viral suppression and improve outcomes. Several recent studies have evaluated the long-term safety, efficacy and development of resistance in nucleoside-naive patients treated with entecavir. Results indicate that the long-term use of entecavir is well tolerated and associated with continuous clinical improvement -- with an increasing number of patients achieving undetectable levels of HBV DNA, HBeAg seroconversion and minimal resistance. These data underscore the position of entecavir for first-line therapy and highlight its role in the long-term treatment of chronic hepatits B.

Nucleos(t)ide analogues for hepatitis B virus: strategies for long-term success

Studies in the past decades have shown that active hepatitis B virus (HBV) replication is the key driver of liver injury and disease progression, and thus sustained viral suppression is of paramount importance in the management of chronic HBV infection. The nucleos(t)ide analogues lamivudine, adefovir, entecavir, telbivudine and tenofovir are potent inhibitors of HBV polymerase/reverse transcriptase activity and are highly effective in the suppression of HBV replication, but rarely eliminate the virus. Long-term therapy is usually required to achieve sustained hepatitis B e antigen seroconversion, HBV DNA suppression, ALT normalization and fibrosis reversal. Maintained long-term therapy has been demonstrated to significantly lower the rate of hepatic decompensation and development of cirrhosis or hepatocellular carcinoma. However, drug resistance is a serious risk on prolonged nucleos(t)ide analogue therapy, and this poses a critical challenge. Prevention and proper management of drug resistance are crucial to ensure long-term success.

Advances in the diagnosis and treatment of hepatitis B

PURPOSE OF REVIEW

Hepatitis B virus is responsible for much morbidity and mortality worldwide. Although the armament of drugs licensed for its treatment grows, it is increasingly apparent that the efficacy of these drugs is dependent upon much more that their pharmacology.

RECENT FINDINGS

A better understanding of the natural history of chronic hepatitis B infection together with recent advances in the molecular biology of antiviral resistance have given added dimensions to physicians' decision-making thought processes.

SUMMARY

The present review outlines the recent advances in diagnostic testing that enable a better understanding of an individual patient's phase of illness and also how such information can update treatment choices better. In the second part of this review, the licensed therapies and their relative merits are discussed, as is their role in managing resistance to antiviral therapy.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon alpha2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon alpha2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included.