Long-term monitoring shows hepatitis B virus resistance to entecavir in nucleoside-naïve patients is rare through 5 years of therapy

Umbilical Cord-Derived Mesenchymal Stem Cell Transplantation in Hepatitis B Virus Related Acute-on-Chronic Liver Failure Treated with Plasma Exchange and Entecavir: a 24-Month Prospective Study

BACKGROUND & AIM

Search for an effective therapy for patients with hepatitis B virus related acute-on-chronic liver failure (HBV-ACLF) remains an important issue. This study investigated the efficacy of umbilical cord-derived mesenchymal stem cell (UC-MSC) transplantation in patients with HBV-ACLF.

METHODS

45 consecutive entecavir-treated HBV-ACLF patients were prospectively studied. Among these patients, 11 received both plasma exchange (PE) and a single transplantation of UC-MSCs (group A), while 34 received only PE (group B). The primary endpoint was survival at 24 months.

RESULTS

Compared with group B, levels of albumin, alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, prothrombin time (PT), international normalized ratio (INR) and model for end-stage liver disease score in group A improved significantly at 4 weeks after transplantation (p < 0.05). Levels of albumin, PT and INR in group A were also markedly improved at 24 months (p < 0.05). Group A had significantly higher cumulative survival rate at 24 months (54.5 % v.s. 26.5 %, p = 0.015 by log rank test). Between the two groups, levels of creatinine, White blood cell, hemoglobin and platelet were similar. HBeAg loss and hepatocellular carcinoma incidence were similar at 24 months. Group assignment (relative risk: 2.926, 95%confidence interval: 1.043-8.203, p = 0.041) was an independent predictor for survival at 24 months. Success rate of UC-MSC transplantation was 100 % in group A. No severe adverse event was observed in any patient.

CONCLUSION

UC-MSC transplantation is safe and effective for HBV-ACLF patients treated with PE and entecavir. It further improves the hepatic function and survival.

Comparison of 208-week sequential therapy with telbivudine and entecavir in HBeAg-positive chronic hepatitis B patients with suboptimal responses to 24 weeks of Peg-IFNα-2a therapy: An open-labelled, randomized, controlled, "real-life" trial

The purpose of the study was to compare the efficacy and safety of 208-week sequential therapy with telbivudine and entecavir in HBeAg-positive chronic hepatitis B (CHB) patients with suboptimal responses to 24 weeks of Peg-IFNα-2a therapy. This was an open-label, randomized, controlled, "real-life" trial. HBeAg-positive CHB patients with serum HBV DNA ≥5.0 lg IU/mL and a < 1 lg IU/mL decline of HBsAg level from baseline who underwent at least 24 weeks of Peg-IFNα-2a therapy were included. Enrolled patients were randomized to receive either telbivudine (600 mg/d, n = 95) or entecavir (0.5 mg/d, n = 95) for 208 consecutive weeks. Six patients were lost to follow-up (4 patients in the telbivudine group and 2 in the entecavir group). Treatment was combined with adefovir when week 24 HBV DNA levels declined to <2 lg IU/mL versus baseline, when viral breakthrough occurred during treatment,or when HBV DNA remained detectable at 52 weeks (HBV DNA ≥500 IU/mL). Responses and safety were assessed after 208 weeks of treatment. There were no significant differences among the baseline characteristics, including age, gender, and ALT, HBV DNA, HBsAg or HBeAg levels. After 208 weeks of treatment, there was no significant difference in the rates of undetectable HBV DNA (HBV DNA<500 IU/mL) between the telbivudine group and the entecavir group (84/91,92.31% vs 88/93,94.62%, respectively, P = .525). More patients in the telbivudine group than the entecavir group achieved HBeAg clearance (74.73% vs 46.24%, respectively, P < .001) and HBeAg seroconversion (64.84% vs 38.71%, respectively, P < .001). Univariate analysis (Enter, a = 0.05) of both groups showed that telbivudine, male gender and baseline HBeAg levels were significantly correlated with HBeAg seroconversion after 208 weeks of sequential therapy. Cox regression analysis (Enter, a = 0.05) of the telbivudine group showed that the HBeAg seroconversion rate at 208 weeks was significantly correlated with gender (male) (P = .006, HR=4.406), baseline HBeAg level (P = .005, HR=0.433) and 24 w-HBeAg level reduction of more than 0.5 lg IU/ml from baseline (P = .027, HR=0.487). All patients tolerated sequential telbivudine treatment; only slightly elevated creatine kinase levels were observed. Stratification analysis found that patients with baseline HBeAg levels less than 3 lg COI who switched to telbivudine may have had significantly improved HBeAg seroconversion rates. In conclusion, telbivudine promotes HBeAg seroconversion that merits investigation in HBeAg-positive CHB patients with suboptimal responses to 24 weeks of Peg-IFNα-2a therapy. We would suggest that patients with baseline HBeAg levels under 3 lg COI switch to telbivudine to achieve higher HBeAg seroconversion rates and use the early reductions in HBeAg levels (24 weeks) to guide treatment.

Entecavir maleate versus entecavir in Chinese chronic hepatitis B predominantly genotype B or C: Results at week 144

Reports on the efficacy and safety of long-term entecavir treatment in chronic hepatitis B (CHB) predominantly genotype B or C are insufficient. This study presents the efficacy and safety of entecavir maleate in Chinese CHB patients. Patients were randomly assigned to receive 48-week treatment with either 0.5 mg/day entecavir (group A) or 0.5 mg/day entecavir maleate (group B), and then all patients received treatment with 0.5 mg/day entecavir maleate from week 49. Two hundred and seventy-five patients with CHB (HBeAg-positive: 218) were analysed, predominantly (98.5%) with genotype B or C. Baseline characteristics were balanced. For the HBeAg-positive CHB patients, the mean HBV DNA level decreased similarly (A: by 6.36 log10 IU/mL vs B: by 6.31 log10 IU/mL) between groups at week 144. The percentages of patients who achieved undetectable HBV DNA were similar (A: 70.59% vs B: 66.67%) between groups. Similar HBeAg loss rates (A: 43.53% vs B: 40.23%; P>.05) and HBeAg seroconversion rates (A: 21.52% vs B: 21.18%) were achieved. For the HBeAg-negative CHB patients, similar reductions in HBV DNA levels from baseline (A: by 6.13 log10 IU/mL vs B: by 5.65 log10 IU/mL) and percentages of patients who achieved undetectable HBV DNA (A: 100% vs B: 100%) were achieved. The overall incidence of adverse events was comparable between groups. In conclusions, 48-week administration of entecavir maleate and entecavir showed similar efficacy and safety in Chinese patients with CHB. Long-term entecavir maleate treatment was effective and safe in CHB patients.

Development of a digital droplet PCR assay to measure HBV DNA in patients receiving long-term TDF treatment

The COBAS TaqMan assay has a lower limit of quantification (LLOQ) of 169 HBV copies/mL and a lower limit of detection (LLOD) of 58 copies/mL. HBV DNA below the TaqMan LLOQ is classified as target not detected (TND) (<58 copies/mL) or target detected (TD) (between 58 and 169 copies/mL). Here we have developed a more sensitive digital droplet PCR (ddPCR) assay to evaluate the impact of long-term tenofovir disoproxil fumarate (TDF) treatment in patients that did or did not achieve HBsAg seroconversion. A ddPCR assay was developed to detect HBV DNA to 8 copies/mL. HBV DNA levels in plasma from patients with or without HBsAg seroconversion were assessed by ddPCR. For patients who did not achieve HBsAg seroconversion, the majority of TD samples (33/58, 57%) were HBV DNA positive by ddPCR while (10/37, 27%) of TND samples were positive. In contrast, for patients who achieved HBsAg seroconversion, HBV DNA was rarely detected by ddPCR after HBsAg seroconversion (1/28, 3.6%). ddPCR is a sensitive method to evaluate low-level viral replication in plasma samples. Frequent detection of HBV DNA by ddPCR among patients who did not achieve HBsAg seroconversion suggests new agents may be needed to suppress low levels of replicating HBV.

Hepatitis B in renal transplant patients

Hepatitis B virus (HBV) poses a significant challenge for both dialysis patients and kidney transplant recipients despite its decreasing rates, especially in developed countries. The best preventive method is vaccination. Patients with chronic renal disease should ideally be vaccinated prior to dialysis, otherwise, reinforced vaccination practices and close antibody titer monitoring should be applied while on dialysis. HBV infected dialysis patients who are renal transplant candidates must be thoroughly examined by HBV-DNA, and liver enzyme testing and by liver biopsy. When needed, one must consider treating patients with tenofovir or entecavir rather than lamivudine. Depending on the cirrhosis stage, dialysis patients are eligible transplant recipients for either a combined kidney-liver procedure in the case of decompensated cirrhosis or a lone kidney transplantation since even compensated cirrhosis after sustained viral responders is no longer considered an absolute contraindication. Nucleoside analogues have led to improved transplantation outcomes with both long-term patient and graft survival rates nearing those of HBsAg(-) recipients. Moreover, in the cases of immunized HBsAg(-) potential recipients with concurrent prophylaxis, we are enabled today to safely use renal grafts from both HBsAg(+) and HBsAg(-)/anti-HBc(+) donors. In so doing, we avoid unnecessary organ discarding. Universal prophylaxis with entecavir is recommended in HBV kidney recipients and should start perioperatively. One of the most important issues in HBV(+) kidney transplantation is the duration of antiviral prophylaxis. In the absence of robust data, it seems that prophylactic treatment may be discontinued in selected stable, low-risk recipients during maintenance immunosuppression and should be reintroduced when the immune status is altered. All immunosuppressive agents in kidney transplantation can be used in HBV(+) recipients. Immunosuppression is intimately associated with increased viral replication; thus it is important to minimize the total immunosuppression burden long term.

Compartmental HBV evolution and replication in liver and extrahepatic sites after nucleos/tide analogue therapy in chronic hepatitis B carriers

BACKGROUND

Hepatitis B virus (HBV) variants are associated with nucleos/tide analogue (NA) response and liver disease but it is unknown whether NA influences extrahepatic HBV persistence.

OBJECTIVES

To investigate HBV replication and genetic evolution in hepatic and extrahepatic sites of chronic hepatitis B (CHB) before and after NA therapy.

STUDY DESIGN

A total of 13 paired plasma, peripheral blood mononuclear cells (PBMC), were collected from chronic HBV carriers at baseline and after a median 53 weeks NA therapy as well as liver biopsy (N=7 baseline, N=5 follow-up). HBV covalently closed circular DNA (cccDNA) and messenger (m) RNA in liver and PBMC were analyzed. HBV polymerase (P)/surface (S), basal core promoter (BCP)/pre-core (PC)/C gene clonal sequencing was done in plasma, peripheral blood mononuclear cells (PBMC), and liver.

RESULTS

Compare to baseline, at ∼53 weeks follow-up, there was no significant change in HBV cccDNA levels in liver (0.2-0.08 copies/hepatocyte, p>0.05) or in PBMC 0.003-0.02 copies/PBMC, p>0.05), and HBV mRNA remained detectable in both sites. At baseline, BCP variants were higher in PBMC vs. liver and plasma. After therapy, drug resistant (DR) and immune escape (IE) variants increased in liver but IE and PC variants were more frequent in PBMC. HBV P/S diversity was significantly higher in PBMC compared to plasma.

CONCLUSION

Continuous HBV replication occurs in liver and PBMC and shows compartmentalized evolution under selective pressure of potent NA therapy.

Week 4 viral load predicts long-term suppression of hepatitis B virus DNA during antiviral therapy: improving hepatitis B treatment in the real world

BACKGROUND

Entecavir and tenofovir potently suppress hepatitis B virus (HBV) replication so that serum HBV DNA levels <20 IU/mL can be achieved after 2 years. Despite this, inadequate suppression is reported in >20% of cases for unclear reasons.

AIM

We tested whether 4-week viral load (VL) assessment could improve 96-week treatment outcome.

METHODS

Data on all chronic hepatitis B patients treated with entecavir or tenofovir between 2005 and 2014 were entered prospectively. Full data capture included pre-treatment, weeks 4, 24, 48 and 96 HBV DNA titre, HBeAg, age, gender, antiviral agent and dose escalation. Compliance data were compiled from pharmacy records, doctors' letters and clinic bookings/attendance. Time to achieve complete viral suppression (HBV DNA < 20 IU/mL) was graphed using Kaplan-Meier curves. Factors affecting this were examined using a multivariate Cox Proportional Hazard model.

RESULTS

Among 156 patients treated, 72 received entecavir and 84 tenofovir. Pre-treatment HBV DNA titre, 4-week assessment and compliance impacted significantly on time to complete viral suppression. At 96 weeks, 90% of those assessed as compliant by 4-week HBV DNA had complete viral suppression versus 50% followed by 6-month VL estimation. Continuing care by the same physician was related to 4-week VL testing and optimal compliance.

CONCLUSIONS

Medium-term outcomes of HBV antiviral therapy are improved by early on-treatment VL testing, facilitating patient engagement and improved compliance. The observation that 90% complete viral suppression after 2 years monotherapy is achievable in a routine clinic setting questions the need for combination therapy in HBV cases with suboptimal response.

Comparison of the Efficacy of Tenofovir Versus Tenofovir plus Entecavir in the Treatment of Chronic Hepatitis B in Patients With Poor Efficacy of Entecavir: A Systematic Review and Meta-analysis

PURPOSE

This study aimed to compare the efficacy between tenofovir disoproxil fumarate (TDF) and TDF plus entecavir (ETV) combination therapy in patients with chronic hepatitis B (CHB) with a poor response to ETV.

METHODS

We searched the China National Knowledge Infrastructure (CNKI), PubMed, EMBASE, and SCOPE libraries for articles using the keywords chronic hepatitis B virus or CHB or HBV, entecavir or ETV, and tenofovir or TDF.

FINDINGS

Five studies (from CNKI and PubMed) with a total of 408 patients met the inclusion criteria: 212 patients in the TDF group and 196 patients in the TDF plus ETV group. The rates of viral suppression between the 2 groups were comparable at weeks 24 and 48 of treatment (P = 0.546 vs P = 0.818). In addition, the subanalysis revealed that no significant differences were observed in the rates of viral suppression between the 2 groups at week 24 (subgroup 1 [partial response to ETV]: P = 0.822; subgroup 2 [resistance to ETV]: P = 0.294) and week 48 (subgroup 1: P = 0.797; subgroup 2: P = 0.545). No significant differences were found in alanine aminotransferase normalization, hepatitis B e antigen loss, hepatitis B e antigen seroconversion, virologic breakthrough, and tolerability between the 2 groups at weeks 24 and 48. Therefore, the results suggest that TDF monotherapy should be chosen for patients with CHB with a poor response to ETV for reasons of economy and convenience.

IMPLICATIONS

We conclude that TDF monotherapy is comparable to TDF-ETV combination therapy for patients with a poor response to ETV; thus, TDF monotherapy may be a better choice for these patients. However, because of the limited citations in this meta-analysis, complete and systematic evidence is needed to evaluate the differences in efficacy and tolerability between TDF and TDF-ETV. Larger and longer randomized clinical trials and further studies should be conducted to verify the results.

Economic Analysis and Budget Impact of Tenofovir and Entecavir in the First-Line Treatment of Hepatitis B Virus in Italy

BACKGROUND

Chronic hepatitis B is a common, progressive disease, particularly when viral replication is detected. Oral antivirals can suppress viral replication and prevent or delay the development of cirrhosis and liver-related complications. The treatments of chronic hepatitis B cannot totally cure the disease but can prevent its progression to hepatocellular carcinoma, decreasing the levels of both morbidity and mortality. To date, there are several therapies indicated by the international guidelines as first-line treatments for the management of hepatitis B; two of the most effective are those based on either tenofovir or entecavir.

OBJECTIVE

The aim of this study is to evaluate the cost-effectiveness of tenofovir and entecavir in the treatment of naïve patients with chronic hepatitis B. The two treatments are compared with the "no treatment" and to one another.

METHODS

The cost-effectiveness analysis was conducted using a Markov model; patients entered one of the following health states: chronic hepatitis, cirrhosis (compensated or decompensated), hepatocellular carcinoma, liver transplantation or death. The analysis was carried out from the perspective of the Italian National Health Service by considering a life-time horizon with cycles lasting 1 year and with costs and QALYs (quality-adjusted life years) discounted at a rate of 3.5%. The results of the model were analysed in terms of incremental cost-effectiveness ratio (ICER).

RESULTS

ICERs for tenofovir and entecavir emerging from the comparison versus "no treatment" were equal to €10,274.73 and €16,300.44 per QALY gained, respectively, on the life-time horizon. Tenofovir was dominant in the direct comparison with entecavir, indicating more QALYs and a lower consumption of resources. The Monte Carlo simulation demonstrated that in 97% (tenofovir) and in 85% (entecavir) of the scenarios performed, the cost per QALY fell below the threshold of €30,000/QALY. The budget impact analysis showed savings for tenofovir amounting to 33% compared to entecavir in the first year on treatment and to 31% in following years.

CONCLUSIONS

Entecavir and tenofovir are recommended for the treatment of patients with chronic Hepatitis B in the Italian Health System. In particular, tenofovir appeared to be the more cost-effective drug for the management of chronic hepatitis B virus (HBV) infections. These results could help decision makers and clinicians to address their decision when choosing a first-line treatment for the management of people affected by chronic HBV.

Predictive Value of Antiviral Effects in the Development of Hepatocellular Carcinoma in the General Korean Population with Chronic Hepatitis B

Background/Aims

The benefit of oral antiviral therapy in preventing hepatocellular carcinoma (HCC) in the general population is not well understood. We used a novel prediction method to estimate the risk of HCC in the Korean population based on various treatment guidelines.

Methods

The 5-year risk of HCC following antiviral therapy was calculated using an HCC risk prediction model. A virtual cohort that represented Koreans (>40 years old) with chronic hepatitis B virus (HBV) infection was established using the fifth National Health and Nutrition Examination Survey. The antiviral indications tested were the Korean National Health Insurance (NHI) and European Association for the Study of the Liver (EASL) guidelines as well as a new extended indication (serum HBV DNA >2,000 IU/mL regardless of serum aminotransferase level).

Results

A total of 993,872 subjects were infected with HBV in the general Korean population. Over a 5-year period, 2,725 HCC cases were predicted per 100,000 persons (0.55%/yr). When the cohort was treated based on the Korean NHI, the EASL, and the newly extended indications, HCC risks decreased to 2,531 (-7.1%), 2,089 (-23.3%), and 1,122 (-58.8%) cases per 100,000 persons, respectively (p<0.0001).

Conclusions

Simulated risk prediction suggests that extending of oral antiviral indication may reduce the HCC risk in the general population.

Comparative evaluation of long-term monotherapies & combination therapies in patients with chronic hepatitis B: A pilot study

Background & objectives:

Reduction of viraemia in patients with chronic hepatitis B virus (HBV) infection using nucleoside/nucleotide analogues reduces fatal liver disease-related events, but development of resistance in virus presents serious clinical challenge. Therefore, comparative evaluation of prolonged antiviral monotherapy and combination therapies was prospectively studied to assess their influence on viral suppression, rapidity of response, development of drug resistance and surfacing mutants in chronic liver disease (CLD) patients.

Methods:

A total of 158 (62eAg-ve) chronic hepatitis B patients were prospectively studied for 24 months. Final analysis was performed on patients treated with lamivudine (LAM, n = 28), adefovirdipivoxil (ADV, n = 24), tenofovir disoproxil fumarate (TDF, n = 26), entecavir (ETV, n = 25), LAM + ADV (n = 28) and LAM + TDF (n = 27). Quantitative hepatitis B virus DNA was detected using real-time polymerase chain reaction. Multiple comparisons among drugs and genotypic mutations were analyzed.

Results:

Progressive biochemical and virological response were noted with all the regimens at 24 months except LAM and ADV which were associated with viral breakthrough (VBT) in 46.4 and 25 per cent, respectively. Mutations: rtM204V (39.3%), M204V+L180M (10.7%) while rtA181V (8.1%) and rtN236T (8.3%) were observed with LAM and ADV regimen, respectively. LAM + ADV combination therapy revealed VBT in seven per cent of the cases without mutations whereas TDF, ETV and LAM + TDF therapies neither showed VBT nor mutations.

Interpretation & conclusions:

LAM was the least potent drug among all therapeutic options followed by ADV. TDF and ETV were genetically stable antivirals with a strong efficacy. Among newer combination therapies, LAM + TDF revealed more efficacy in virological remission and acted as a profound genetic barrier on long term. Hence, newer generation molecules (TDF, ETV) and effective combination therapy should be a certain choice.

Current antiviral drugs and their analysis in biological materials - Part II: Antivirals against hepatitis and HIV viruses

This review is a Part II of the series aiming to provide comprehensive overview of currently used antiviral drugs and to show modern approaches to their analysis. While in the Part I antivirals against herpes viruses and antivirals against respiratory viruses were addressed, this part concerns antivirals against hepatitis viruses (B and C) and human immunodeficiency virus (HIV). Many novel antivirals against hepatitis C virus (HCV) and HIV have been introduced into the clinical practice over the last decade. The recent broadening portfolio of these groups of antivirals is reflected in increasing number of developed analytical methods required to meet the needs of clinical terrain. Part II summarizes the mechanisms of action of antivirals against hepatitis B virus (HBV), HCV, and HIV, their use in clinical practice, and analytical methods for individual classes. It also provides expert opinion on state of art in the field of bioanalysis of these drugs. Analytical methods reflect novelty of these chemical structures and use by far the most current approaches, such as simple and high-throughput sample preparation and fast separation, often by means of UHPLC-MS/MS. Proper method validation based on requirements of bioanalytical guidelines is an inherent part of the developed methods.

Genotyping of HBV and tracking of resistance mutations in treatment-naïve patients with chronic hepatitis B

BACKGROUND AND AIMS

Resistance mutation analogs to nucleos(t)ides have been described in treatment-naïve patients with chronic hepatitis B (CHB), with clinical implications. The aim of this study was to investigate primary resistance mutations and genotypes circulating in patients naïve to chronic hepatitis B, in the Northern and Northeastern regions of Brazil.

METHODS

We conducted a study of resistance mutations and genotypic characterization of hepatitis B virus (HBV) in 189 treatment-naïve patients chronically infected with HBV.

RESULTS

Drug resistance-associated mutations located in the RT domain of the P gene (rtHBV) were found in 6% of the treatment-naïve patients from the Northeastern Region. The mutations were rtA194T, rtL180M + rtM204V, rtS202I, rtM204I, and rtA181S. No patient in the Northern Region had the resistance mutation. In the gene S region, the frequency of vaccine escape mutations was 2.4% in the Northeastern Region and 8.6% in the Northern Region.

CONCLUSION

This information before the start of treatment may contribute to clinical decision making, reducing treatment failure and the risk of progression to cirrhosis and hepatocellular carcinoma for CHB.

Chronic Hepatitis B, C, and D

Chronic hepatitis B, C, and D virus infections contribute significantly to the morbidity and mortality of immunocompromised individuals. To contextualize discussion of these infections in immunocompromised patients, this paper provides an overview of aspects of infection in normal hosts. It then describes differences in disease, diagnostic testing, and therapeutic management observed in immunocompromised patients.

Efficacy and Safety of Lamivudine Versus Entecavir for Treating Chronic Hepatitis B Virus-related Acute Exacerbation and Acute-on-Chronic Liver Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Oral nucleos(t)ide analogs are recommended for patients with chronic hepatitis B virus (HBV)-related acute exacerbation (AE) and acute-on-chronic liver failure (ACLF). The efficacy and safety of administering entecavir (ETV) and lamivudine (LAM) to such patients remain unclear.

METHODS

A comprehensive literature search was performed to select studies published before December 2015 on therapy involving ETV or LAM for chronic HBV-related AE with or without ACLF. The main outcomes were short-term (within 4 mo) and long-term (beyond 4 mo) mortality. The secondary outcomes were virological and biochemical responses, ACLF recurrence, and safety.

RESULTS

Three prospective and 8 retrospective cohort studies involving 1491 patients were selected. An overall analysis revealed comparable short-term and long-term mortality rates among all patients who received ETV or LAM [short term: risk ratio (RR)=0.99; 95% confidence interval (CI), 0.78-1.27; long term: RR=0.82; 95% CI, 0.45-1.52]. However, in patients with ACLF, ETV yielded a more favorable long-term outcome than did LAM (RR=0.60; 95% CI, 0.45-0.80). Furthermore, ETV resulted in more efficient virological and biochemical responses than did LAM regarding the HBV DNA undetectable rate (RR=1.34; 95% CI, 1.09-1.63), HBV DNA reduction rate (weighted mean difference=-0.41; 95% CI, -0.69 to -0.13), and serum alanine aminotransferase normalization rate (RR=1.13; 95% CI, 1.05-1.21).

CONCLUSIONS

ETV and LAM treatments exerted similar effects on the mortality rate of patients with chronic HBV-related AE with or without ACLF. However, ETV yielded a more favorable long-term outcome than did LAM in patients with ACLF; ETV was associated with greater clinical improvements. Additional larger, long-term randomized controlled trials are required to confirm these conclusions.

Long-term real-world entecavir therapy in treatment-naïve hepatitis B patients: base-line hepatitis B virus DNA and hepatitis B surface antigen levels predict virologic response

BACKGROUND/AIMS

Entecavir is a potent nucleoside analogue with high efficacy and barrier for resistance. We aimed to investigate the long-term efficacy and viral resistance rate of entecavir and explore the factors associated with virologic response, including quantitative hepatitis B surface antigen (qHBsAg) levels.

METHODS

One thousand and nine treatment-naïve chronic hepatitis B (CHB) patients were evaluated for cumulative rates of virologic response, biochemical response, and entecavir mutations. The role of baseline qHBsAg for virologic response was assessed in 271 patients with qHBsAg prior to entecavir treatment.

RESULTS

The median duration of entecavir treatment was 26.5 months. The cumulative rate of virologic response at years 1, 3, and 5 were 79.0%, 95.6%, and 99.4%, respectively. The cumulative rate of entecavir resistance was 1.0% and 2.1% in years 3 and 5. Multivariate analysis identified baseline hepatitis B e antigen (HBeAg) negative status (p < 0.001) and lower hepatitis B virus (HBV) DNA (p < 0.001) as predictors of virologic response. Lower qHBsAg was an independent predictor of virologic response in patients with baseline qHBsAg. There were no serious adverse events during treatment.

CONCLUSIONS

Long-term entecavir treatment of nucleos(t)ide-naïve CHB patients was associated with an excellent virologic response and a low rate of entecavir-resistant mutations at 5 years. Baseline HBV DNA load, qHBsAg levels, and HBeAg status were predictors of virologic response during entecavir treatment.

Efficacy of tenofovir-based rescue therapy for chronic hepatitis B patients with resistance to lamivudine and entecavir

BACKGROUND/AIMS

Tenofovir disoproxil fumarate (TDF) monotherapy for 48 weeks provided a virological response comparable to that of TDF and entecavir (ETV) combination therapy in patients infected with ETV-resistant hepatitis B virus (HBV). Little long-term data in routine clinical practice are available regarding the optimal treatment of patients with ETV-resistant HBV.

METHODS

We investigated the long-term antiviral efficacy of combination therapy of TDF+lamivudine (LAM) or TDF+ETV compared to that of TDF monotherapy in 73 patients with resistance to both LAM and ETV.

RESULTS

Patients were treated with TDF monotherapy (n=12), TDF+LAM (n=19), or TDF+ETV (n=42) for more than 6 months. The median duration of TDF-based rescue therapy was 37 months. Virologic response (VR) was found in 63 patients (86.3%). The rates of VR among the three groups (TDF monotherapy, TDF+LAM, and TDF+ETV) were not statistically different (log-rank P=0.200) at 12 months (59.3%, 78.9%, and 51.8%, respectively) or at 24 months (88.4%, 94.7%, and 84.2%). In addition, treatment efficacy of TDF-based combination or TDF monotherapy was not statistically different with ETV-resistant strains or exposure to other antiviral agents. In multivariate analysis, only lower baseline HBV DNA level was an independent predictor for VR (hazard ratio, 0.723; 95% confidence interval, 0.627-0.834; P<0.001).

CONCLUSIONS

TDF monotherapy was as effective as combination therapy of TDF+LAM or TDF+ETV in maintaining long-term viral suppression in chronic hepatitis B patients with resistance to both LAM and ETV. HBV DNA level at the start of TDF rescue therapy was the only independent predictor of subsequent VR.

Recommendations for screening, monitoring, prevention, prophylaxis and therapy of hepatitis B virus reactivation in patients with haematologic malignancies and patients who underwent haematologic stem cell transplantation-a position paper

SCOPE

Hepatitis B virus (HBV) infection reactivation is associated with high morbidity and mortality in patients with haematologic malignancy and/or haematopoietic stem cell transplantation (HSCT). However, information on this issue is limited. The scope of this position paper is to provide recommendations on HBV screening, monitoring, prophylaxis, treatment and vaccination in the patients described above.

METHODS

These recommendations were developed from one meeting of experts attended by different Italian scientific societies as well as from a systematic literature review (of articles published through December 31, 2016) on HBV infection in haematologic patients and in patients who underwent haematopoietic stem cell transplantation published in the same issue of the journal. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess each recommendation's quality.

QUESTIONS ADDRESSED

These recommendations provide the answers to the following questions: (a) HBV screening and monitoring: Who should be screened before chemotherapy? Which screening tests should be used? Should HBV-DNA detection be used to monitor HBV reactivation before starting antivirals? What is the best timeline to monitor HBV reactivation? (b) Prophylaxis in HBsAg-positive patients: Which antiviral drugs should be used to treat HBsAg-positive patients? How long should antiviral prophylaxis be provided to HBsAg-positive patients? (c) Prophylaxis in patients with resolved HBV infection: Which patients with resolved HBV infection should receive antiviral prophylaxis? Which antiviral drug should be used? How long should antiviral prophylaxis be provided? (d) HBV infection management strategy in autologous (auto-HSCT) and allogeneic HSCT (allo-HSCT): Which HSCT recipients should receive antiviral prophylaxis? Which antiviral drug should be used? How long should antiviral prophylaxis be provided? (e) Choice of antiviral drugs in the treatment of HBV reactivation: Should third-generation anti-HBV drugs be preferred to first- or second-generation antiviral drugs in the treatment of HBV reactivation with or without hepatitis flare in haematologic patients? (f) Immunization against HBV in patients with haematologic malignancies and/or patients who underwent HSCT: Should these patients be vaccinated? Which HBV vaccination schedule should be adopted?

RECOMMENDATIONS

Haematologic patients should be screened for hepatitis B surface antigen (HBsAg) plus anti-hepatitis B core protein (HBc), and HBV DNA before chemotherapy. HBV DNA levels should be monitored monthly in all HBV-positive patients who do not receive prophylaxis. HBsAg-positive haematologic patients and those undergoing HSCT should receive third-generation antiviral therapy as prophylaxis. Anti-HBc-positive lymphoma patients and those receiving HSCT should receive antiviral prophylaxis. All HBV-negative haematologic patients should be vaccinated for HBV. The acquisition of data from well-designed studies is desirable in the near future.

Naturally occurring mutations in the reverse transcriptase region of hepatitis B virus polymerase from treatment-naïve Korean patients infected with genotype C2

AIM

To report naturally occurring mutations in the reverse transcriptase region (RT) of hepatitis B virus (HBV) polymerase from treatment naïve Korean chronic patients infected with genotype C2.

METHODS

Here, full-length HBV reverse transcriptase RT sequences were amplified and sequenced from 131 treatment naïve Korean patients chronically infected with hepatitis B genotype C2. The patients had two distinct clinical statuses: 59 patients with chronic hepatitis (CH) and 72 patients with hepatocellular carcinoma (HCC). The deduced amino acids (AAs) at 42 previously reported potential nucleos(t)ide analog resistance (NAr) mutation positions in the RT region were analyzed.

RESULTS

Potential NAr mutations involving 24 positions were found in 79 of the 131 patients (60.3%). Notably, AA substitutions at 2 positions (rt184 and rt204) involved in primary drug resistance and at 2 positions (rt80 and rt180) that functioned as secondary/compensatory mutations were detected in 10 patients (1 CH patient and 9 HCC patients) and 7 patients (1 CH and 6 HCC patients), respectively. The overall mutation frequencies in the HCC patients (3.17%, 96/3024 mutations) were significantly higher than the frequencies in the CH patients (2.09%, 52/2478 mutations) (P = 0.003). In addition, a total of 3 NAr positions, rt80, rt139 and rt204 were found to be significantly related to HCC from treatment naïve Korean patients.

CONCLUSION

Our data showed that naturally occurring NAr mutations in South Korea might contribute to liver disease progression (particularly HCC generation) in chronic patients with genotype C2 infections.

A different inhibitor is required for overcoming entecavir resistance: a comparison of four rescue therapies in a retrospective study

AIMS

Little clinical data are available regarding re-establishing the effective inhibition of entecavir (ETV)-resistant mutants. In this retrospective study, we aimed to compare the efficacies of four treatment regimens as rescue therapy for those chronic hepatitis B (CHB) patients with ETV resistance.

METHODS

A total of 65 patients with ETV resistance were assigned either with tenofovir disoproxil fumarate (TDF) monotherapy (n = 21), ETV (0.5 mg) plus adefovir (ADV) combination therapy (n = 19), ETV (1.0 mg) monotherapy (n = 11) or ETV (0.5 mg) plus TDF combination therapy (n = 14). The efficacy and safety of four treatment regimens were compared.

RESULTS

There were no significant differences among the four study groups in baseline characteristics, including HBV DNA levels (χ²  = 0.749, P = 0.862) and hepatitis B e antigen-positivity (χ²  = 0.099, P = 0.992). The median reduction in serum HBV DNA level from baseline at week 48 was -2.37 ± 1.07 log₁₀ IU ml^-1 , -2.16 ± 0.81 log₁₀ IU ml^-1 , -1.17 ± 1.23 log₁₀ IU ml^-1 and -2.49 ± 1.10 log₁₀ IU ml^-1 , respectively (F = 4.078, P = 0.011). The TDF group and ETV (0.5 mg) + TDF group have the highest undetectable HBV DNA rate (76.19% vs. 78.57%) compared to the ETV (0.5 mg) + ADV group and the ETV (1.0 mg) group (63.16% vs. 18.18%, respectively). Two patients in the ETV (1.0 mg) group experienced virological breakthrough at week 48 and was attributed to poor drug adherence.

CONCLUSIONS

TDF monotherapy appeared to deliver the highest undetectable HBV DNA rate in patients with ETV resistance, and ADV plus ETV combination therapy could be another choice for patients with financial restraint.

Current treatment guidelines of chronic hepatitis B: The role of nucleos(t)ide analogues and peginterferon

Chronic hepatitis B is prevalent worldwide and is a major contributor to death from cirrhosis and hepatocellular carcinoma. Thus, the goals of therapy are to prevent the development of cirrhosis, hepatocellular carcinoma and liver-related death. Safe and effective therapy is available but complete cure is not yet possible. The decision to treat is complex and must be individualized. Each of the three major liver societies, the American Association for the Study of Liver Diseases (AASLD), the European Association for the Study of the Liver (EASL) and the Asian Pacific Association for the Study of the Liver (APASL) have developed treatment guidelines to provide healthcare professionals guidance on management of chronic HBV infection. This review will cover the specific, evidence-based or expert opinion guideline recommendations on who should be treated, what to treat with, how to monitor, when to stop therapy and management of treatment failure.

Potential Efficacy of Pegylated Interferon-α and a Nucleos(t)ide Analogue as Combination Therapy for HBeAg-Positive Chronic Hepatitis B

Background/Aims

Despite the potent suppression of the hepatitis B virus with modern antiviral agents, only a minority of HBeAg-positive patients achieve hepatitis B e antigen seroconversion. We aimed to explore the potential efficacy of combination therapy consisting of pegylated interferon (p-IFN) and an oral antiviral agent in patients with HBeAg-positive chronic hepatitis B.

Methods

The treatment protocol consisted of p-IFN-α-2a at 180 μg/wk for 48 weeks, with either entecavir or tenofovir added 8 weeks after the initiation of p-IFN and continued for at least 6 months after HBe seroconversion was achieved.

Results

To date, 10 patients have been treated under the protocol (eight adults, mean age 36±8 years; two adolescents, aged 12 and 16 years). All eight adult patients experienced loss of HBeAg at a mean of 72.3±66.9 weeks, including six patients who also developed anti-HBe and one patient who had HBs seroconversion. Although both adolescents remain on therapy, one adolescent had HBs seroconversion without HBe seroconversion. A total of nine of our 10 patients experienced a favorable serological transition.

Conclusions

The combination of p-IFN and a modern oral antiviral agent may be more effective than monotherapy with either class of agent in the treatment of HBeAg-positive chronic hepatitis B patients.

Immune Tolerant Chronic Hepatitis B: The Unrecognized Risks

Chronic infection with hepatitis B virus (HBV) progresses through multiple phases, including immune tolerant, immune active, immune control, and, in a subset of patients who achieve immune control, reactivation. The first, the immune tolerant phase, is considered to be prolonged in duration but essentially benign in nature, lacking long-term consequences, and thus not recommended for antiviral therapy. This review challenges the notion that the immune tolerant phase is truly benign and considers the possibility that events during this phase may contribute significantly to cirrhosis, hepatocellular carcinoma (HCC), and the premature death of 25% of HBV carriers worldwide. Thus, earlier treatment than recommended by current guidelines should be considered. Low therapeutic coverage exacerbated by restrictive treatment guidelines may facilitate disease progression in many patients but also increase the risk of neonatal and horizontal transmission from untreated mothers to their children. While a prophylactic vaccine exists, there are many areas worldwide where the treatment of adults and the delivery of an effective vaccination course to newborns present difficult challenges.

Hepatitis B Virus Immunopathology, Model Systems, and Current Therapies

Most people develop acute hepatitis B virus (HBV)-related hepatitis that is controlled by both humoral and cellular immune responses following acute infection. However, a number of individuals in HBV-endemic areas fail to resolve the infection and consequently become chronic carriers. While a vaccine is available and new antiviral drugs are being developed, elimination of persistently infected cells is still a major issue. Standard treatment in HBV infection includes IFN-α, nucleoside, or nucleotide analogs, which has direct antiviral activity and immune modulatory capacities. However, immunological control of the virus is often not durable. A robust T-cell response is associated with control of HBV infection and liver damage; however, HBV-specific T cells are deleted, dysfunctional, or become exhausted in chronic hepatitis patients. As a result, efforts to restore virus-specific T-cell immunity in chronic HBV patients using antiviral therapy, immunomodulatory cytokines, or therapeutic vaccination have had little success. Adoptive cell transfer of T cells with specificity for HBV antigen⁺ cells represents an approach aiming to ultimately eliminate residual hepatocytes carrying HBV covalently closed circular DNA (cccDNA). Here, we discuss recent findings describing HBV immunopathology, model systems, and current therapies.

Cost-Effectiveness Comparison Between the Response-Guided Therapies and Monotherapies of Nucleos(t)ide Analogues for Chronic Hepatitis B Patients in China

BACKGROUND AND OBJECTIVE

Nucleos(t)ide analogue (NA) monotherapies are typically used as the primary treatment for chronic hepatitis B (CHB) patients, including lamivudine (LAM), telbivudine (TBV), adefovir (ADV), entecavir (ETV) and tenofovir (TDF). For high-resistance NAs (LAM, TBV, ADV), they can generate excellent clinical outcomes by using response-guided therapy; however, their pharmacoeconomic profiles remain unclear in China. We aimed to evaluate the cost effectiveness between response-guided therapies and monotherapies of NAs for Chinese hepatitis B e-antigen (HBeAg)-positive and -negative CHB patients.

METHODS

We constructed a Markov model to simulate CHB progression associated with 12 treatment strategies using effectiveness and cost data from the published literature. We measured the lifetime costs, quality adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). One-way sensitivity (especially to extend the range of the TDF price) and probabilistic sensitivity analyses were used to explore the uncertainties of the model.

RESULTS

For both HBeAg-positive and -negative patients, no treatment strategy generated the lowest lifetime costs (US$31,185-US$31,338) and QALYs (7.54-7.58). ETV and TDF monotherapies were not dominated by other treatments, whereas, the ICER of ETV monotherapy was the lowest (US$6112/QALY-US$8533/QALY). For each high-resistance NA, compared with its monotherapy, the ICERs of its response-guided therapies were below the willingness-to-pay threshold of US$22,833/QALY. Additionally, TDF monotherapy was the preferred treatment when its price dropped to US$1820/year or lower.

CONCLUSION

Among 12 treatment strategies evaluated, ETV monotherapy is the most cost-effective treatment for treatment-naive CHB patients in China. The response-guided therapies of high-resistance NAs are more cost-effective than their monotherapies.

Relationship between pre-existing resistance mutations and HBV genotype in patients with HBV related liver cirrhosis

AIM

To investigate the relationship between hepatitis B virus (HBV)-related drug resistance mutations and HBV genotype in patients with HBV-related liver cirrhosis (LC).

METHODS

Serum samples were collected from 112 patients with HBV-related LC who did not receive prior anti-viral treatment. HBV reverse transcriptase regions were amplified by PCR, and PCR products were directly sequenced.

RESULTS

Among 112 HBV-related LC patients, 13 (11.61%, 13/112) had lamivudine resistance associated mutations, 15 (13.39%, 15/112) had adefovir resistance associated mutations, and 1 had mutations associated with both lamivudine and adefovir resistance. All of these resistance mutations occurred in patients infected with HBV genotype C, and there was no mutation in patients infected with HBV genotype B.

CONCLUSION

Adefovir/lamivudine resistance associated mutations exist in patients with HBV-related LC, and the mutations are related to HBV genotype. Compared with patients infected with HBV genotype B, those infected with HBV genotype C are prone to resistance mutations.

On-treatment HBV DNA dynamics predict virological breakthrough in entecavir-treated HBeAg-positive chronic hepatitis B

BACKGROUND & AIMS

Virological breakthrough (VBT) could be a manifestation of chronic hepatitis B (CHB) in patients treated with long-term nucleot(s)ide analogues. We aimed to determine the association of on-treatment serum hepatitis B virus (HBV) DNA with VBT in HBeAg-positive CHB patients receiving entecavir (ETV) treatment.

METHODS

A retrospective cohort study, including 162 consecutive patients (95 men and 67 women; mean age, 43.1±13.4 years) with HBeAg-positive CHB treated with ETV for at least 48 weeks between August 2008 and May 2015, was conducted. Univariate and multivariate cox regression analysis were used to identify associations with VBT and clinical factors, including HBV DNA and HBeAg serum status.

RESULTS

Among the 162 ETV-treated HBeAg-positive CHB patients, eighteen patients (11.1%) experienced VBT (VBT group), whereas the other 144 patients were without VBT (non-VBT group). The cumulative rate of HBV DNA < 100 IU/mL in the VBT group and the non-VBT group at week 48 were 44.44% and 70.14%, and at week 96 were 58.33% and 92.56%, respectively (p = 0.015). The cumulative rate of HBeAg seroclearance in the VBT group and non-VBT group at week 48 and week 96 were statistically significant (p = 0.014). Multivariate analysis disclosed that failure to achieve HBeAg seroclearance were the factors significantly associated with VBT.

CONCLUSIONS

Our results demonstrated that on-treatment HBV DNA could probably predict VBT in ETV-treated HBeAg-positive chronic hepatitis B patients. Failure to achieve HBeAg seroclearance was associated with VBT in ETV-treated HBeAg-positive CHB patients. HBV DNA >100IU/mL at 48 weeks is potentially a predictor for VBT.

Management of Antiviral Resistance in Chronic Hepatitis B

The primary goal of therapy for chronic hepatitis B (CHB) is to prevent liver disease progression. Hepatitis B surface antigen (HBsAg) seroclearance or seroconversion is regarded as an optimal endpoint to discontinue treatment. However, HBsAg seroclearance occurs very rarely with nucleos(t)ide analog (NUC) treatment, and long-term, almost indefinite, NUC treatment is required for the majority of patients. In patients with drug-resistant hepatitis B virus (HBV), a combination of tenofovir disoproxil fumarate (TDF) and entecavir (ETV), which is currently regarded as the strongest combination therapy against HBV, would be potentially safe to prevent the emergence of additional HBV resistance mutations. However, long-term tolerance data are lacking, and cost may be an issue for combination therapies. Several recent, well-designed, randomized controlled trials have shown that TDF monotherapy provides similar antiviral efficacy compared with the combination of TDF and ETV. Furthermore, no additional HBV resistance mutations emerged during TDF monotherapy for up to 96 weeks. Considering a comparable antiviral efficacy, extremely low risk of TDF-resistance, lower cost, and better safety potential, TDF monotherapy would be a reasonable choice for the treatment of drug-resistant patients with CHB.

Resistance mutations of hepatitis B virus in entecavir-refractory patients

The emergence of resistance mutations in the reverse transcriptase gene of hepatitis B virus (HBV) is associated with treatment failure. Entecavir (ETV) is one of the most potent anti‐HBV reagents; it has a very low resistance rate and is used as the first‐line treatment for chronic hepatitis B. In this study, we isolated HBVs in 4 ETV‐refractory patients (2 with viral breakthrough, 1 with partial virological response, and 1 with flare‐up) and assessed ETV resistance using replication‐competent 1.38‐fold HBV genome‐length molecular clones. The full genome sequences of infected HBVs in ETV‐refractory patients were determined. The HBV molecular clones were generated with the patient‐derived sequences. After transfection of these molecular clones into HepG2 cells, viral replications and ETV susceptibilities were evaluated by measuring the amount of intracellular core‐particle‐associated HBV DNA using Southern blotting and real‐time polymerase chain reaction. Among these cases, ETV‐resistant variants were detected in 2 patients with viral breakthrough and responsible amino acid mutations in reverse transcriptase were successfully identified in these variants. No ETV‐resistant mutation was detected in the other cases. The identified ETV‐resistant mutations did not confer resistance to tenofovir disoproxil fumarate. Conclusion: The HBV replication model with patient‐derived sequences is useful for assessing replication efficiency, susceptibility to anti‐HBV reagents, and responsible resistance mutations and can aid in choosing the appropriate treatment strategy for treatment‐failure cases of chronic hepatitis B. (Hepatology Communications 2017;1:110‐121)

Comparison of the long-term efficacy between entecavir and tenofovir in treatment- naïve chronic hepatitis B patients

BACKGROUND

There have been limited studies directly comparing the long-term efficacy between entecavir (ETV) and tenofovir disoproxil fumarate (TDF). This study was aimed to compare the long-term efficacy between them in treatment-naïve chronic hepatitis B (CHB).

METHODS

Out of 345 CHB patients who received first line therapy with ETV (n = 200) or TDF (n = 145) in a cohort, 210 patients were analyzed using propensity score matching, at a ratio of 1:1.

RESULTS

Two groups showed no difference in baseline characteristics. During the follow-up of 12 months, HBV DNA levels were similarly suppressed in both groups (ETV vs. TDF; -5.01 vs. -5.242 log10IU/mL, P = 0.559). At month 12, both groups showed no difference in terms of the serologic, biochemical and virologic (VR) response. In multivariate analysis, the initial virologic response at 3 months (IVR-3) was independent factor for VR at 1 year. During the long-term follow-up, HBV DNA levels were more strongly suppressed by TDF than ETV in hepatitis B e antigen (HBeAg) positive patients (P = 0.035), especially with high viral load (P = 0.012), although there was no significant difference in overall VR between two groups. The type of antivirals was not an independent factor for long-term VR.

CONCLUSIONS

Although either ETV or TDF, overall, may show a comparable long-term antiviral efficacy in treatment-naïve CHB, TDF might be better regimen than ETV in the subgroup of HBeAg-positive CHB, especially with a higher HBV DNA levels.

Efficacy and safety of entecavir versus tenofovir treatment in chronic hepatitis B patients: A randomized controlled trial

AIM

Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are considered among the most potent antiviral agents for the treatment of chronic hepatitis B infection. We aimed to compare treatment efficacy and safety of ETV and TDF in nucleoside-naïve chronic hepatitis B patients.

METHODS

Inclusion criteria were compensated chronic hepatitis B patients who were either hepatitis B e antigen (HBeAg)-positive or HBeAg-negative. Exclusion criteria were co-infection with hepatitis C virus and/or HIV, concurrent malignancy, and decompensated cirrhosis. Virological, biochemical, and serological end-points at week 96 and 144 were compared. Of 400 patients, 200 patients received ETV and 200 received TDF.

RESULTS

There were no significant differences between the two groups in baseline characteristics including age (41.6 ± 11.5 vs. 41.2 ± 11.6, mean baseline hepatitis B virus DNA (5.91 ± 1.79 vs. 5.94 ± 1.68 log₁₀ IU/mL), mean baseline alanine aminotransferase (68.1 ± 64.1 vs. 76.8 ± 79.8 U/L), and cirrhosis (15.5% vs. 14.5%). At week 144 of treatment, 91 and 94% of the ETV and TDF groups, respectively, achieved undetectable hepatitis B virus DNA. In HBeAg-positive patients, HBeAg seroconversion could be achieved in 27.4% and 33.7% at week 144 for ETV and TDF groups, respectively. Quantitative hepatitis B surface antigen dropped significantly over 144 weeks of treatment period but only 1.0 to 1.5% experienced hepatitis B surface antigen loss. Safety profiles were consistent with previous reports of monotherapy.

CONCLUSION

Both ETV and TDF showed potent antiviral activity against hepatitis B. Either ETV or TDF can be recommended as a treatment of choice for patients with chronic hepatitis B. Both drugs were safe and well tolerated.

Antiviral therapies for managing viral hepatitis in lymphoma patients

INTRODUCTION

In patients with lymphoma the detection of positive hepatitis B or C viruses (HBV and HCV) serology involves crucial therapeutic consequences. In HBV-infected patients the serological profile of active (HBsAg-positive) or resolved (HBsAg-negative/anti-HBcAb-positive) infection is associated to differential risk of viral reactivation during rituximab-based therapy and require appropriate strategies of monitoring and of antiviral prophylaxis. In HCV-associated NHL patients consolidated data demonstrated that interferon (IFN)-based antiviral therapy (AT) is able to induce lymphoma regression strictly related to viral eradication, while preliminary data of the new direct-acting antivirals (DAAs) are very promising. Areas covered: This review summarizes current evidences about HBV reactivation risk in patients undergoing rituximab-based treatments and appropriate options of antiviral prophylaxis with lamivudine, entecavir or tenofovir, as well as pre-emptive strategy in HBsAg-negative/HBcAb-positive patients. Moreover previous experiences with IFN-based AT as well as recent studies with DAAs in HCV-associated indolent lymphomas or diffuse large B-cell lymphoma (DLBCL) are reviewed. Expert opinion: Entecavir or tenofovir prophylaxis is recommended for HBsAg-positive patients, while universal prophilaxis with lamivudine may be preferred in HBsAg-negative/anti-HBc-positive patients. In asymptomatic patients with HCV-associated indolent lymphoma DAA-based AT should be used as first-line option, while in DLBCL its deliver after immunochemotherapy-induced complete remission is suggested.

Tenofovir versus tenofovir plus entecavir for chronic hepatitis B with lamivudine resistance and entecavir resistance

We compared the viral suppressive efficacy of tenofovir disoproxil fumarate (TDF) mono-rescue therapy (TDF group) and TDF plus entecavir (ETV) combination-rescue therapy (TDF + ETV group) in chronic hepatitis B (CHB) patients with lamivudine resistance and entecavir resistance. One hundred and thirty-three CHB patients with lamivudine and entecavir resistance were investigated. Ninety-six patients were treated with TDF and 37 with TDF + ETV for at least 6 months. We compared the virologic response rate (HBV DNA level <20 IU/mL) between the two groups and identified the predictive factors of treatment outcome. There were no significant differences between the two groups in demographic characteristics. Up to 24 months [median: 18 (range 6-24) months], 85.4% and 89.2% of the TDF group and TDF + ETV group, respectively, achieved a virologic response (P=.068). Only the HBV DNA level at baseline was significantly associated with a virologic response in the multivariate analysis. In a subanalysis of patients with HBV DNA levels ≥4 log (IU/mL) at baseline, a higher proportion of patients in the TDF + ETV group than the TDF group achieved a virologic response (92.9% vs 68.3%; P<.001), while 90% of patients with HBV DNA (IU/mL) levels <4 log in all both TDF and TDF + ETV groups achieved a virologic response. TDF mono-rescue therapy is a reasonable option in patients with lamivudine resistance and entecavir resistance. However, the combination strategy should be considered in patients with high baseline HBV DNA levels.

Pediatric hepatitis B treatment

Although the introduction of hepatitis B vaccine has been contributing to the reduction in the prevalence of hepatitis B virus (HBV) carriers worldwide, the treatment of children with chronic HBV infection is a challenge to be addressed. HBeAg seroconversion, which induces low replication of HBV, is widely accepted as the first goal of antiviral treatment in children with chronic hepatitis B. However, spontaneous HBeAg seroconversion is highly expected in children with chronic HBV infection. Therefore, the identification of children who need antiviral treatment to induce HBeAg seroconversion is essential in the management of chronic HBV infection. Guidelines and experts' opinion show how to identify children who should be treated and how to treat them. If decompensated cirrhosis is absent, interferon-alpha is the first-line antiviral treatment. Nucleos(t)ide analogues (NAs), such as lamivudine, adefovir, entecavir and tenofovir, are also available for the treatment of children, although the approval age differs among them. If decompensated cirrhosis is present, NAs are the first-line antivirals. When the emergence of drug-resistant HBV variants is taken into consideration, entecavir (approved for age 2 years or older) and tenofovir (age 12 years or older), which have high genetic barriers, will play a central role in the treatment of HBV infection. However, the optimal duration of NA treatment and adverse events of long-term NA treatment remain unclear in children. In resource-constrained countries and regions, the financial burden of visiting hospitals, receiving routine blood examination and purchasing antiviral drugs is heavy. Moreover, there is no clear evidence that the induction of HBeAg seroconversion by antiviral treatment prevents the progression of liver disease to cirrhosis and hepatocellular carcinoma in children with chronic HBV infection. It is thus imperative to clarify the clinical impact of antiviral treatment in children with HBV infection.

Use of telbivudine in kidney transplant recipients with chronic hepatitis B virus infection: A preliminary experience

Telbivudine is a relatively novel oral nucleoside analogue with favourable efficacy and tolerability in treatment-naïve chronic hepatitis B virus (HBV) infection, but its data in kidney transplant recipients (KTRs) was lacking. The efficacy and tolerability of telbivudine in four treatment-naïve HBsAg-positive KTRs were reviewed (treatment duration 54 (36-72) months) HBV DNA declined from 2.6 × 10(5) (7.8 × 10(3) -1.5 × 10(7) ) copies/mL at baseline to 170 (0.0-3.2 × 10(4) ) copies/mL at 12 months, and became undetectable at 24 and 36 months (P = 0.060, 0.118 and 0.005 compared with baseline). Alanine aminotransferase levels dropped from 46.5 (30-48) IU/mL at baseline to 28 (13-45) IU/mL, 34.5 (15-71) IU/mL and 26 (12-41) IU/mL at 12, 24 and 36 months, respectively (P = 0.109, 0.715 and 0.068 compared with baseline). Serum creatinine level and estimated glomerular filtration rate (eGFR) remained stable after 36 months of treatment (P all > 0.05 compared with baseline). No virological breakthrough, cirrhosis or hepatocellular carcinoma occurred. Our pilot data suggests that telbivudine has favourable efficacy and renal safety profiles in HBsAg-positive KTRs.

Entecavir for patients with lamivudine‐resistant chronic hepatitis B virus infection

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To evaluate the benefits and harms of entecavir versus no intervention, placebo, and non‐entecavir interventions in adults with lamivudine‐resistant, chronic hepatitis B virus infection.

Hepatitis B virus long-term impact of antiviral therapy nucleot(s)ide analogues (NUCs)

The goal of antiviral therapy is to improve the quality of life and survival of patients with chronic hepatitis B (CHB) by halting the progression to cirrhosis, end-stage liver disease or hepatocellular carcinoma (HCC), thus preventing anticipated liver-related death. Oral administration of potent and less resistance-prone nucleot(s)ide analogues (NUCs), such as entecavir (ETV) and tenofovir disoproxil fumarate (TDF) has become the most popular treatment strategy worldwide because of their excellent efficacy and safety profile as well as easy management confirmed in both registration trials and in clinical practice studies. Long-term administration of ETV or TDF suppresses HBV replication in >95% of patients, resulting in biochemical remission, histological improvement including the regression of cirrhosis and prevention or reversal of clinical decompensation but not the development of HCC, particularly in patients with cirrhosis. Moreover, NUCs can be administered to all patients including those with severe liver disease, the elderly and in those who do not respond, are unwilling to take or have contraindications to interferon. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs therapy with the associated costs, unknown long-term safety and the low rates of hepatitis B surface antigen (HBsAg) seroclearance, which is still the best stopping rule for NUCs-treated patients with cirrhosis.

No detectable resistance to tenofovir disoproxil fumarate in HBeAg+ and HBeAg- patients with chronic hepatitis B after 8 years of treatment

A major hurdle in the long-term treatment of chronic hepatitis B (CHB) patients is to maintain viral suppression in the absence of drug resistance. To date, no evidence of resistance to tenofovir disoproxil fumarate (TDF) has been observed. A cumulative evaluation of CHB patients who qualified for resistance surveillance over 8 years of TDF treatment was conducted. Patients in studies GS-US-174-0102 (HBeAg-) and GS-US-174-0103 (HBeAg+) were randomized 2:1 to receive TDF or adefovir dipivoxil (ADV) for 48 weeks followed by open-label TDF through year 8. Population sequencing of HBV pol/RT was attempted for all TDF-treated patients at baseline and, annually if viremic, at discontinuation, or with addition of emtricitabine. Overall, 88/641 (13.7%) patients qualified for sequence analysis at one or more time points. The percentage of patients qualifying for sequence analysis declined over time, from 9 to 11% in years 1-2 to <4% over years 3-8. Forty-one episodes of virologic breakthrough (VB) occurred throughout the study, with most (n=29, 70%) associated with nonadherence to study medication. Fifty-nine per cent of VB patients with an opportunity to resuppress HBV achieved HBV DNA resuppression. A minority of patients who qualified for sequencing had polymorphic (41/165, 24.8%) or conserved (17/165, 10.3%) site changes in pol/RT, with six patients developing lamivudine and/or ADV resistance-associated mutations. No accumulation of conserved site changes was detected. The long-term treatment of CHB with TDF monotherapy maintains effective suppression of HBV DNA through 8 years, with no evidence of TDF resistance or accumulation of conserved site changes.

Tenofovir disoproxil fumarate (TDF) vs. emtricitabine (FTC)/TDF in lamivudine resistant hepatitis B: A 5-year randomised study

BACKGROUND & AIMS

Long-term treatment with tenofovir disoproxil fumarate (TDF) alone, or in combination with emtricitabine (FTC) is associated with sustained viral suppression in patients with lamivudine resistant (LAM-R) chronic hepatitis B (CHB).

METHODS

LAM-R CHB patients were randomised 1:1 to receive TDF 300mg or FTC 200mg and TDF 300mg once daily in a prospective, double blind, study. The proportion of patients with plasma hepatitis B virus (HBV) DNA<69IU/ml (<400copies/ml) at week 96 (primary efficacy endpoint) was reported previously. Here we present week 240 follow-up data.

RESULTS

Overall, 280 patients were randomised to receive TDF (n=141) or FTC/TDF (n=139), and 85.4% completed 240weeks of treatment. At week 240, 83.0% of patients in the TDF arm, and 82.7% of patients in the FTC/TDF treatment arm had HBV DNA<69IU/ml (p=0.96). Rates of normal alanine aminotransferase (ALT) and normalised ALT were similar between groups (p=0.41 and p=0.97 respectively). Hepatitis B e antigen loss and seroconversion at week 240 were similar between groups, (p=0.41 and p=0.67 respectively). Overall, six patients achieved hepatitis B surface antigen (HBsAg) loss and one patient (FTC/TDF arm) had HBsAg seroconversion by week 240. No TDF resistance was observed up to week 240. Treatment was generally well tolerated, and renal events were mild and infrequent (∼8.6%). The mean change in bone mineral density at week 240 was -0.98% and -2.54% at the spine and hip, respectively.

CONCLUSIONS

TDF monotherapy was effective and well tolerated in LAM-R CHB patients for up to 240weeks.

LAY SUMMARY

The goal of oral antiviral treatment for chronic hepatitis B (CHB) is to achieve and maintain undetectable HBV DNA levels. Treatment options with enhanced potency, and low risk of resistance development for patients infected with lamivudine resistant (LAM-R) HBV are required. Tenofovir disoproxil fumarate (TDF) monotherapy was effective and well tolerated without TDF resistance development in CHB patients with LAM-R, for up to 240weeks. Clinical trial number: NCT00737568.

Tenofovir alafenamide demonstrates broad cross-genotype activity against wild-type HBV clinical isolates and maintains susceptibility to drug-resistant HBV isolates in vitro

Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir (TFV). This study evaluated the antiviral activity of TAF against wild-type genotype A-H HBV clinical isolates as well as adefovir-resistant, lamivudine-resistant, and entecavir-resistant HBV isolates. Full length HBV genomes or the polymerase/reverse transcriptase (pol/RT) region from treatment-naïve patients infected with HBV genotypes A-H were amplified and cloned into an expression vector under the control of a CMV promoter. In addition, 11 drug resistant HBV constructs were created by site-directed mutagenesis of a full length genotype D construct. Activity of TAF was measured by transfection of each construct into HepG2 cells and assessment of HBV DNA levels following treatment across a range of TAF concentrations. TAF activity in vitro was similar against wild-type genotype A-H HBV clinical isolates. All lamivudine- and entecavir-resistant isolates and 4/5 adefovir-resistant isolates were found to be sensitive to inhibition by TAF in vitro as compared to the wild-type isolate. The adefovir-resistant isolate rtA181V + rtN236T exhibited low-level reduced susceptibility to TAF. TAF is similarly active in vitro against wild-type genotype A-H HBV clinical isolates. The TAF sensitivity results for all drug-resistant isolates are consistent with what has been observed with the parent drug TFV. The in vitro cell-based HBV phenotyping assay results support the use of TAF in treatment of HBV infected subjects with diverse HBV genotypes, in both treatment-naive and treatment-experienced HBV infected patients.

Analysis of the prevalence of drug-resistant hepatitis B virus in patients with antiviral therapy failure in a Chinese tertiary referral liver centre (2010-2014)

OBJECTIVES

To study the prevalence of drug-resistant HBV in patients with therapy failure in a Chinese tertiary referral liver centre.

METHODS

1223 HBV-infected patients who underwent genotypic resistance testing between 2010-2014 were studied.

RESULTS

3TC genotypic resistance was the most common (46.5%), followed by LdT resistant (46.2%), ETV intermediate (37.9%), ADV resistant (11.4%), TDF intermediate (11.4%) and ETV resistant (1.7%). The 3TC resistance rate increased from 39.8% in 2010 to 56.6% in 2013, before decreasing to 49.5% in 2014, evidence of a lagging effect of l-nucleoside consumption. M204I, N236T and L180M+M204V+V173L/S202G were the most common substitutions for l-nucleoside (3TC and LdT), ADV and ETV genotypic resistant phenotypes, respectively. 3TC-exposed patients showed a high multiple genetic resistance rate (3TC-resistant+LdT-resistant+ETV intermediate; 58.8%). Resistance rates to 3TC, LdT and ETV in HCC patients were significantly higher than in cirrhosis and CHB patients. Resistance rates to different drugs showed no statistical difference between genotype B and C patients, whilst some amino acid substitution showed genotype bias, e.g. N236T incidence in genotype B was significantly higher than in genotype C (43.2% vs. 5.9%; P<0.0001), and genotype C isolates had a significantly higher A181V/T incidence than genotype B (54.9% vs. 19.3%; P<0.0001).

CONCLUSIONS

3TC genotypic resistance was most common in this centre, whilst ETV had the lowest resistance rate. HBV genotypes had no impact on antiviral drug resistance, except for some drug resistance substitutions bias. Optional initial therapy and subsequent rescue treatment should be based on knowledge of nucleos(t)ide analogue resistance.

Recapitulation of treatment response patterns in a novel humanized mouse model for chronic hepatitis B virus infection

There are ~350 million chronic carriers of hepatitis B (HBV). While a prophylactic vaccine and drug regimens to suppress viremia are available, chronic HBV infection is rarely cured. HBV's limited host tropism leads to a scarcity of susceptible small animal models and is a hurdle to developing curative therapies. Mice that support engraftment with human hepatoctyes have traditionally been generated through crosses of murine liver injury models to immunodeficient backgrounds. Here, we describe the disruption of fumarylacetoacetate hydrolase directly in the NOD Rag1^-/- IL2RγNULL (NRG) background using zinc finger nucleases. The resultant human liver chimeric mice sustain persistent HBV viremia for >90 days. When treated with standard of care therapy, HBV DNA levels decrease below detection but rebound when drug suppression is released, mimicking treatment response observed in patients. Our study highlights the utility of directed gene targeting approaches in zygotes to create new humanized mouse models for human diseases.

An evaluation of entecavir for the treatment of chronic hepatitis B infection in adults

Entecavir is a nucleoside analogue of 2'-deoxyguanosine whose intracellular triphosphate form inhibits replication of the hepatitis B virus. Entecavir is recommended as a first-line monotherapy option for nucleos(t)ide-naïve patients with HBeAg-positive or -negative chronic hepatitis B infection. Entecavir has a three-step mechanism of action: It maintains viral suppression with a greater than 90% chance of undetectable hepatitis B virus DNA during continuous therapy, improves liver histology, and reduces the risk of liver failure or hepatocellular carcinoma development. The safety profile of long-term entecavir therapy is favorable; however, its optimal treatment duration is unknown. Entecavir monotherapy is not a rescue option for patients with lamivudine/adefovir resistance or baseline lamivudine-resistant mutants; rather, combination treatment is recommended for patients with lamivudine/adefovir resistance.