Durability of serologic response after lamivudine treatment of chronic hepatitis B

Evaluation of HBsAg Seroclearance in Patients with Hepatitis B

Objective

Hepatitis B surface antigen (HBsAg) seroclearance/seroconversion is regarded as an indicator of the ultimate immune control of hepatitis B virus (HBV) infections. HBsAg loss is the most important endpoint, as it shows deep suppression of HBV replication and viral protein expression. This study was aimed to retrospectively evaluate the HBsAg seroclearance/seroconversion status in patients with acute or chronic hepatitis B (CHB) diagnosis.

Materials and methods

Patients diagnosed with acute or CHB at the Harran University Faculty of Medicine Department of Gastroenterology between January 2012 and December 2020 were included in this study. This study was designed as a retrospective historical cohort. Experimental analysis of the data was done with the help of the SPSS version 22.0 package program.

Results

Of 1,053 patients with positive HBsAg, 854 patients with sufficient data in their files were included in this study. There were 494 (57.8%) males and 360 (42.2%) females; the mean age was 42.71 ± 14.31 (range 18-88). The mean duration of illness was 86.13 ± 72.92 months. In the 9-year follow-up of 854 patients, 65 (7.9%) of the last HBsAg test were negative and seroclearance had developed. The last anti-HBs test was positive in 49 (75.4%) of 65 patients who developed seroclearance, and it was found that seroconversion had developed. Twenty-seven of 30 (90%) of the patients who developed seroclearance had liver transplantation. Sixteen of 19 (84.2%) of them had acute hepatitis B, 14 of 477 (2.9%) were hepatitis carriers, 5 of 201 (2.5%) had e-negative CHB, 2 of 36 (5.6%) had cirrhosis, and 1 of 43 (2.3%) of them were delta hepatitis who developed seroclearance disease; none of the 38 e-positive CHB patients developed seroclearance.

Conclusion

In the 9-year follow-up of patients who were positive for HBsAg at their first admission, approximately one-tenth (7.9%) developed seroclearance, and two-thirds also developed seroconversion. After liver transplantation and acute hepatitis B, almost all patients developed seroclearance, whereas, in approximately 3% of carriers (e-negative CHB and cirrhotic patients) seroclearance developed.

How to cite this article

Taşkın MC, Uyanikoglu A, Cindoglu C. Evaluation of HBsAg Seroclearance in Patients with Hepatitis B. Euroasian J Hepato-Gastroenterol 2022;12(2):65-68.

Telbivudine Plus Adefovir Versus Lamivudine Plus Adefovir for Lamivudine-Resistant Chronic Hepatitis B: TeSLA Randomized Trial

Background: In countries with unavailable tenofovir, a combination of lamivudine (LMV) and adefovir (ADV) is recommended for the treatment of LMV-resistant chronic hepatitis B (CHB). Considering that telbivudine (L-dT) was demonstrated to be superior to LMV in previous studies, L-dT and ADV combination therapy is expected to show better antiviral efficacy than the combination of LMV and ADV in patients with LMV-resistant CHB. Methods: This was a prospective randomized multicenter study. The primary endpoint was Hepatitis B Virus (HBV) DNA reduction after 52 weeks of treatment. The secondary endpoints were HBV DNA undetectability, hepatitis B e antigen seroconversion, the incidence of virological and biochemical breakthroughs, and safety during the study period. Results: A total of 43 LMV-resistant CHB patients were enrolled. Twenty-one were treated with LMV + ADV and 22 with L-dT + ADV. After 52 weeks of antiviral treatment, the HBV DNA reduction showed no significant intergroup difference (-4.54 ± 1.23 log IU/mL in the LMV + ADV group, -4.24 ± 1.46 log IU/mL in the L-dT + ADV group, P = 0.475). There were no significant intergroup differences in HBV DNA undetectability rates, mean HBV DNA level, or hepatitis B e antigen seroconversion rate at 13, 26, 39, and 52 weeks of treatment. In terms of safety, the mean creatine phosphokinase level was significantly higher in the L-dT + ADV group. Conclusions: In the treatment of LMV-resistant CHB, the combination of L-dT and ADV did not show any clinical benefit compared to the combination of LMV and ADV.

Perspectives on stopping nucleos(t)ide analogues therapy in patients with chronic hepatitis B

Long-term treatment with nucleos(t)ide analogs (NAs) is the current first line therapy for patients with chronic hepatitis B (CHB), recommended by most of the current guidelines. NAs prevent disease progression, liver failure, decrease the risk of hepatocellular carcinoma (HCC), and have favorable safety profiles. However, low rates of on-therapy functional cure (hepatitis B surface antigen [HBsAg] loss), which is regarded as the optimal end point, prevent many patients from stopping NA therapy with the need for a lifelong treatment. The higher likelihood of HBsAg loss associated with stopping as compared to continuing NAs has got a lot of attention recently. Recommendations regarding endpoints allowing for safely stopping NA therapy differ between international guidelines. Whereas in HBeAg-positive patients, HBeAg seroconversion with at least one year of consolidation therapy is an acceptable endpoint of treatment, the recommendations for HBeAg-negative ones differ. Some guidelines propose ≥3 years of HBV DNA undetectability to stop NA while others regard HBsAg loss as the only acceptable endpoint. Stopping NA can lead to substantial rates of virologic relapses and consequent ALT flares in some cases. Moreover, no reliable predictor(s) of post-NA relapses have been identified so far. Quantitative HBsAg is becoming an increasingly promising marker to predict safe NA cessation. On the other hand, investigating the role of the immune system in mediating sustained virologic responses after NA withdrawal is needed to suggest immunological biomarkers to safely stop NA. In this article, we will review relevant literature regarding NA stopping strategy and discuss promising viral and immunological biomarkers to predict antiviral responses and thus to help identify patients who are more likely to achieve HBsAg seroclearance.

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Switching to peginterferon for chronic hepatitis B patients with hepatitis B e antigen seroconversion on entecavir - A prospective study

Nucleos(t)ide analogues (NA) are effective in suppressing hepatitis B virus (HBV) replication, but most patients require long-term treatment. This study aimed to investigate switching to peginterferon as a strategy to stop NA. Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients who developed HBeAg seroconversion during NA treatment were studied. All patients received open-label peginterferon alfa-2a 180 μg/wk for 48 weeks, and NA was stopped at week 4 of peginterferon treatment. The primary endpoint was sustained response, which was defined as negative HBeAg, positive anti-HBe and HBV DNA <2000 IU/mL at week 72. Other secondary endpoints including HBsAg loss at week 72 were also studied. Forty-one patients treated with entecavir for 56 ± 23 months were recruited. Sustained response was achieved in 30 patients (73%, 95% confidence interval 58%-84%). At week 72, 31 (76%) patients had HBeAg seroconversion, 56 (23%) patients had undetectable HBV DNA, 31 (76%) patients had normal ALT, and 6 patients (15%) had HBsAg loss. Baseline HBsAg level was the best predictor for both sustained response and HBsAg loss; the best HBsAg cut-off for sustained response was <1500 IU/mL and that for HBsAg loss was <500 IU/mL by receiver operating characteristic curve analysis. Twenty-two of 25 (88%) patients with baseline HBsAg <1500 IU/mL had sustained response. Five of 10 (50%) patients with baseline HBsAg <500 IU/mL developed HBsAg loss. Switching to peginterferon can be considered as a treatment option in NA-treated patients with HBeAg seroconversion, particularly among those with lower HBsAg levels.

Hepatitis B Surface Antigen Loss with Tenofovir Disoproxil Fumarate Plus Peginterferon Alfa-2a: Week 120 Analysis

BACKGROUND AND AIMS

Hepatitis B surface antigen (HBsAg) loss is the ideal clinical endpoint but is achieved rarely during oral antiviral treatment. A current unmet need in CHB management is achievement of HBsAg loss with a finite course of oral antiviral therapy, thereby allowing discontinuation of treatment. Significantly higher rates of HBsAg loss at 72 weeks post-treatment have been demonstrated when tenofovir disoproxil fumarate (TDF) was combined with pegylated interferon (PEG-IFN) for 48 weeks compared with either monotherapy. This analysis provides follow-up data at week 120.

METHODS

In an open-label, active-controlled study, 740 patients with chronic hepatitis B were randomly assigned to receive TDF plus PEG-IFN for 48 weeks (group A), TDF plus PEG-IFN for 16 weeks followed by TDF for 32 weeks (group B), TDF for 120 weeks (group C), or PEG-IFN for 48 weeks (group D). Efficacy and safety at week 120 were assessed.

RESULTS

Rates of HBsAg loss at week 120 were significantly higher in group A (10.4%) than in group B (3.5%), group C (0%), and group D (3.5%). Rates of HBsAg loss and HBsAg seroconversion in group A were significantly higher than rates in group C (P < 0.001 for both) or group D (HBsAg loss: P = 0.002; HBsAg seroconversion: P < 0.001).

CONCLUSIONS

The results of this analysis confirm the results from earlier time points which demonstrate the increased rate of HBsAg loss in patients treated with a finite course of PEG-IFN plus TDF compared with the rates in patients receiving either monotherapy.

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.

When can we stop nucleoside analogues in patients with chronic hepatitis B?

Treatment with nucleoside analogue (NAs) is now the most common treatment for chronic hepatitis B (CHB) and is recommended by all guidelines. Stopping NAs is a controversial issue in these patients, unless the clinical endpoints of HBeAg seroconversion or HBsAg seroclearance are achieved. While HBeAg seroconversion can occur in a significant number of patients, HBsAg seroclearance rates are low. HBsAg seroclearance is increasingly accepted as the ideal end of treatment, representing a functional cure. Treatment withdrawal leads to relapse in 50% of patients who achieve HBeAg seroconversion and complete at least 12 months of consolidation therapy. In HBeAg negative CHB, the Asian Pacific Association for the Study of the Liver (APASL) stopping rules show that although clinical relapse occurs in approximately 43% and virological relapse occurs in 70%, very few patients experience flare or decompensation. NAs treatment for >2 years was associated with a lower rate of relapse. Recently, stopping NA therapy was shown to be associated with HBsAg in 20%-39% of HBeAg negative patients and more frequently in those with low quantitative HBsAg (qHBsAg). However, the most optimal level is unclear. Quantitative HBsAg is becoming a useful tool to predict a sustained response or relapse before stopping therapy. In conclusion, stopping NA therapy is generally safe and can be an option in specific situations such as HBeAg seroconversion. However, it is associated with disease relapse. Thus, patient selection based on qHBsAg may help identify patients who are more likely to achieve HBsAg seroclearance or a sustained response.

Antiviral response is not sustained after cessation of lamivudine treatment in chronic hepatitis B patients: A 10-year follow-up study

Although the ideal end point for antiviral treatment in patients with chronic hepatitis B (CHB) is loss of HBsAg, the typical clinical end points are HBeAg seroconversion in HBeAg-positive patients and long-term DNA suppression in HBeAg-negative patients. We evaluated the long-term antiviral response after cessation of lamivudine treatment in CHB patients. A total of 157 patients who had discontinued lamivudine between 1997 and 2014 were enrolled (97 HBeAg-positive and 60 HBeAg-negative CHB patients). The long-term durability of the antiviral response (viralogical relapse; HBV DNA ≥10⁴  copies/ml) and the clinical course of these patients were analyzed retrospectively. In HBeAg-positive patients, the mean follow-up period after discontinuation was 72.3 months. The cumulative probabilities of virological relapse at 1, 12, 24, 48, 60, 96, and 120 months were 10.3%, 40.2%, 55.6%, 62.8%, 65.9%, 67.0%, and 67.0%, respectively. In HBeAg-negative patients, the cumulative probabilities of a virological relapse at 1, 12, 24, 48, 60, 96, and 120 months were 25.0%, 35.0%, 41.7%, 43.3%, 43.3%, 46.7%, and 48.3%, respectively. Younger age (HR 1.732, 95%CI: 1.058-2.835, P = 0.02) was predictive of non-virological relapse in HBeAg-positive patients. And achievement of undetectable HBV DNA level within 3 months of treatment discontinuation was associated with decreased rate of virological relapse (HR 0.159, 95%CI: 0.069-0.367 P < 0.01) in HBeAg-negative patients. Despite meeting the requirements for treatment discontinuation, approximately half of the CHB patients treated with lamivudine relapsed. Thus, the antiviral response is not reliably sustained after lamivudine treatment cessation. J. Med. Virol. 89:849-856, 2017. © 2016 Wiley Periodicals, Inc.

Clinical outcomes and predictors for relapse after cessation of oral antiviral treatment in chronic hepatitis B patients

BACKGROUND

Little is known about stopping rules of nucelos(t)ide analog (NA) treatment for chronic hepatitis B (CHB).

METHODS

A total of 113 consecutive patients with CHB (45 HBeAg-positive and 68 HBeAg-negative CHB patients), who met the cessation criteria of NA treatment as per the Asian-Pacific Association for the Study of the Liver (APASL) guideline, were enrolled in this prospective cohort study. The primary endpoint was to evaluate virological relapse (VR) rate within 1 year, which was defined as reappearance of hepatitis B virus (HBV)-DNA > 2000 IU/mL after cessation of NA treatment. In this cohort, entecavir was used in 81 (71.7 %) and lamivudine in 32 (28.3 %) patients.

RESULTS

Within 1 year after NA treatment, VR occurred in 26 (57.8 %) HBeAg-positive patients and in 37 (54.4 %) HBeAg-negative patients. In univariate and subsequent multivariate analysis, age > 40 years [odds ratio (OR) 10.959; 95 % confidence interval (CI) 2.211-54.320; P = 0.003) and a pre-treatment HBV DNA level >2000,000 IU/mL (OR 9.285; 95 % CI 1.545-55.795; P = 0.036) were identified as independent risk factors for VR in HBeAg-positive patients, and age > 40 years (OR 6.690; 95 % CI 1.314-34.057; P = 0.022) and an end-of-treatment HBcrAg level >3.7 log IU/mL (OR 3.751; 95 % CI 1.187-11.856; P = 0.024) were identified in HBeAg-negative patients. During follow up, neither hepatic decompensation nor hepatocellular carcinoma (HCC) occurred, and HBV DNA suppression was achieved in all patients who received antiviral re-treatment.

CONCLUSION

Our data suggested that the APASL stopping rule could be applied if a candidate was properly selected using individual risk factors. However, regular monitoring should be performed after cessation of NA treatment and long-term outcomes need to be evaluated further.

Durability of the virological response after lamivudine discontinuation in lamivudine-resistant patients with a complete virological response after lamivudine and adefovir combination therapy

We investigated the durability of virological response after lamivudine (LAM) discontinuation in LAM-resistant chronic hepatitis B (CHB) patients with complete virological response after LAM-adefovir (ADV) combination therapy. We enrolled 58 patients switched to ADV monotherapy with undetectable viral loads (<12 IU/ml) and normal alanine aminotransferase levels after ADV add-on combination treatment for at least 6 months in LAM-resistant CHB patients. Virologic relapse was defined as HBV DNA detection at more than 20 IU/ml by quantitative polymerase chain reaction determined on two consecutive measurements. During median 40.9 months of follow-up (range 11.5-79.0 months), seven (12.1%) patients experienced virological relapse. The cumulative rate of virological relapse at 3 and 5 years was 5.5% and 22.4%, respectively. Two patients had elevated alanine aminotransferase during virological relapse. These seven patients with virological relapse had undetectable HBV DNA after switching to tenofovir therapy. In our study, switching to ADV monotherapy resulted in sustained HBV DNA suppression in 87.9% of the patients during median 40.9 months follow-up. This adapting step-down strategy, switching from combination therapy to monotherapy in virologically suppressed CHB patients with stable liver disease, may reduce the cost burden and the risk of potentially harmful effects of combination therapy. J. Med. Virol. 89:85-90, 2017. © 2016 Wiley Periodicals, Inc.

Association between clinical features and YMDD mutations in patients with chronic hepatitis B following lamivudine therapy

The aim of the present study was to investigate the correlation between feature and genotype with regard to the tyrosine-methionine-aspartate-aspartate (YMDD) mutation in chronic hepatitis B patients after lamivudine (LAM) therapy. A total of 30 patients with chronic hepatitis B were recruited, who underwent one year of LAM therapy. The patients' alanine aminotransferase (ALT) level and hepatitis B envelope antigen (HBeAg) seroconversion were evaluated, hepatitis B virus (HBV) DNA was genotyped using a new genotyping method and YMDD mutations were analyzed prior to treatment and at 6 and 12 months after LAM treatment. Furthermore, the secondary protein structure of the HBV DNA polymerase gene (P gene) was analyzed. Following treatment, the results suggested that LAM therapy improved ALT normalization. There was no correlation between clinical effects and ALT level before treatment. After 12 months treatment, the rate of HBeAg loss increased and the rate of HBeAg seroconversion decreased linearly with the rise of baseline ALT level. While ALT normalization and HBeAg seroconversion were highest in patients with HBV genotype B, HBeAg loss and HBVDNA loss were highest in those with genotype C. The effect was predominant in genotype D. No YMDD mutations were identified prior to 6 months of LAM therapy. The rate of YMDD mutations after 12 months LAM therapy was 12.12%. Two patients with rtM204V + rtL180M belonged to genotype C and another patient with rtL180M alone belonged to genotype D. The turn of secondary protein structure of P gene changed to β sheet when a rtM204V mutation occurred, and no change of secondary protein structure was associated with the rtL180M mutation. Thus, the present results indicate that one year of LAM therapy is able to improve ALT normalization. Long-term LAM therapy may induce YMDD mutation and drug resistance.

Off-treatment durability of antiviral response to nucleoside analogues in patients with chronic hepatitis B

BACKGROUND

Off-treatment durability of nucleoside analogue (NA) therapy in patients with chronic hepatitis B has not been well investigated. In this study we monitored antiviral effect of NA therapy and evaluated off-treatment durability after NA cessation in patients with chronic hepatitis B.

PATIENTS AND METHODS

A total of 94 consecutive patients (39 HBeAg-negative and 55 HBeAg-positive patients) who received NA therapy were followed up for approximately 9 years. We discontinued NA according to the following criteria; undetectable serum HBV-DNA by polymerase chain reaction (PCR) on three separate occasions at least 6 months apart in HBeAg-negative patients (APASL stopping recommendation), and seroconversion from HBeAg-positive to HBeAb-positive and undetectable serum HBV-DNA by PCR for at least 12 months in HBeAg-positive patients.

RESULTS

The cumulative rate of relapse after NA cessation was 48 % and 40 % in HBeAg-negative and -positive patients, respectively. Higher baseline serum alanine aminotransferase level was the only significant predictor for maintaining remission. No patients experienced decompensation after relapse. HBsAg loss occurred at an annual rate of 1.4 % and 0.4 % in HBeAg-negative and -positive patients, respectively. Hepatocellular carcinoma developed at an annual rate of 0.6 % in both HBeAg-negative and -positive patients.

CONCLUSIONS

Almost half of the patients did not relapse after cessation of NA therapy in both HBeAg-negative and -positive patients. Therefore, NA therapy could be discontinued with close monitoring if the APASL stopping recommendation is satisfied even in HBeAg-negative patients.

Durability of Hepatitis B e Antigen Seroconversion in Chronic Hepatitis B Patients Treated with Entecavir or Tenofovir

INTRODUCTION

Loss of HBeAg and development of anti-HBe (seroconversion) is seen as a milestone and endpoint in the treatment of HBeAg-positive patients with chronic hepatitis B (CHB). Among patients treated with nucleos(t)ide analogs (NA), recurrent viremia is common after discontinuation of therapy. Entecavir (ETV) and tenofovir (TDF) are highly potent NA. The durability of virological response and HBeAg seroconversion in patients treated with these agents is not well studied.

METHODS

We retrospectively studied the outcomes of 54 HBeAg-positive CHB patients who were treated with either ETV (n = 30) or TDF (23) or both (n = 1) that achieved virological response and underwent seroconversion and consolidation therapy before cessation of treatment.

RESULTS

Only 4 (7%) patients had sustained virological, serological, and biochemical remission. Thirteen patients (24%) continued to have HBV DNA levels below 2000 IU/mL and normal alanine aminotransferase activity (ALT). Thirty-seven patients (69%) developed HBV DNA >2000 IU/mL, with 20 having elevated ALT. Among these 37 patients, 23 (62%) remained HBeAg negative/anti-HBe positive, 12 (32%) became HBeAg positive, and 2 (5%) were HBeAg and anti-HBe negative. Duration of consolidation therapy did not correlate with low versus high level of virological relapse.

CONCLUSIONS

Durability of HBeAg seroconversion associated with ETV or TDF was not superior to that reported in patients treated with less potent NA. Our results, aggregated with others, suggest HBeAg seroconversion should not be considered as a treatment endpoint for most HBeAg-positive patients treated with NA. Future updates of treatment guidelines should reconsider HBeAg seroconversion as an endpoint to therapy.

Inhibition of hepatitis B virus cccDNA by siRNA in transgenic mice

The elimination of viral covalently closed circular DNA (cccDNA) from the nucleus of infected hepatocytes is an obstacle to achieving sustained viral clearance during antiviral therapy of chronic hepatitis B virus (HBV) infection. The aim of our study was to determine whether treatment with siRNA is able to suppress viral cccDNA amplification using a HBV-transgenic mice model. The experimental results revealed that siRNAs can serve as efficient alternative anti-HBV agents, because they showed better inhibitory effect on viral replication and antigen expression in transgenic mice. More importantly, the siRNA markedly inhibited HBV cccDNA amplification.

Harnessing the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated Cas9 system to disrupt the hepatitis B virus

The current therapies to treat hepatitis B virus (HBV) infection are limited. Recently, clustered regularly interspaced short palindromic repeat (CRISPR) systems, originally identified in bacteria and archaea, have been found to consist of an RNA-based adaptive immune system that degrades complimentary sequences of invading plasmids and viruses. Here, we studied the effects of the CRISPR/CRISPR-associated Cas9 system that was targeted to the surface antigen (HBsAg)-encoding region of HBV, both in a cell culture system and in vivo. The HBsAg levels in the media of the cells and in the sera of mice were analyzed by a quantitative enzyme-linked immunosorbent assay. The HBV DNA levels were assessed by quantitative PCR and HBsAg expression in mouse livers was assessed by an immunohistochemical assay. The amount of HBsAg secreted in the cell culture and mouse serum was reduced by CRISPR/Cas9 treatment. Immunohistochemistry analyses showed almost no HBsAg-positive cells in the liver tissue of CRISPR/Cas9-S1+X3-treated mice. The CRISPR/Cas9 system efficiently produced mutations in HBV DNA. Thus, CRISPR/Cas9 inhibits HBV replication and expression in vitro and in vivo and may constitute a new therapeutic strategy for HBV infection.

Current developments in nucleoside/nucleotide analogues for hepatitis B

There had been remarkable development in nucleos(t)ide analogues (NAs) and evolution in treatment strategies in last 15 years. Currently, there are five NAs available for chronic hepatitis B treatment, namely lamivudine, telbivudine and entecavir (nucleoside analogues), adefovir dipivoxil and tenofovir disoproxil fumarate (nucleotide analogues). The advantages of relatively infrequent side effects and easy administration per oral make NAs popular treatment options. The major drawback of earlier generation NAs is the risk of emergence of drug resistance. Current international guidelines recommend the use of more potent agents with high genetic barriers to resistance including entecavir and tenofovir as first line chronic hepatitis B treatment. However, there is no consensus regarding the subsequent treatment regimens in patients with suboptimal responses to NAs. De novo combination therapy of two NAs, response-guided therapy and roadmap concept in NAs with subsequent switch or add-on therapy can also potentially improve treatment efficacy and avoid resistance.

When to stop nucleos(t)ide analogues treatment for chronic hepatitis B? Durability of antiviral response

Introduction of nucleos(t)ide analogues (NAs) for oral antiviral therapy has dramatically improved the clinical outcome in patients with chronic hepatitis B (CHB). Although current international guidelines for the management of CHB provide information regarding when to begin the antiviral therapy with NAs, there is no clear consensus on when to stop the treatment, especially for those who respond to the therapy. Hepatitis B surface antigen loss has been regarded as an ideal endpoint of oral antiviral therapy with NAs, however since this is rarely achieved, practical endpoints have been suggested by the international guidelines. Despite the stopping rules recommended by the international guidelines, whether oral antiviral therapy with NAs can be safely discontinued is of major concern. While attention has been drawn to whether antiviral treatment with NAs can be a finite therapy, there is lack of sufficient data on off-treatment durability of highly potent NAs. Based on the available evidences, current guidelines for stopping NA therapy seems to be inadequate in terms of off-treatment durability, with relapse rates of more than 40% for both hepatitis Be antigen (HBeAg)-positive and HBeAg-negative patients. Therefore, further studies are required to accumulate data on off-treatment durability of highly potent NAs, and future studies are warranted to identify adequate predictive markers that could provide supplementary information to guide the timing of stopping NA therapy.

Hepatitis B and C in African Americans: current status and continued challenges

Viral hepatitis remains a public health concern in the United States, resulting in excess morbidity and mortality for the individual and representing a burden to societies as evidenced by billions of dollars in health care expenditures. As with many chronic diseases, race and ethnicity influence various aspects of disease pathogenesis, including mechanisms of persistence, disease progression, disease sequelae, and response to therapy. For hepatitis B and C infections, African Americans disproportionately bear a large burden of disease in the United States. The role and importance of African American race, however, have been less well-characterized in the literature among the population of viral hepatitis-infected individuals. The differences in epidemiology, manifestations of liver disease, response to therapy, and differential trends in liver transplantation in African Americans compared with other racial and ethnic groups deserve special attention. This review will address the current status of hepatitis B and C infection in African Americans in the United States and identify some of the remaining challenges in diagnosis, characterization of natural history, and treatment. For the purposes of this review, the terms African American and black will be used interchangeably throughout the text.

A cost-utility analysis of drug treatments in patients with HBeAg-positive chronic hepatitis B in Thailand

BACKGROUND

Only lamivudine has been included for patients with chronic hepatitis B (CHB) in the National List of Essential Drugs (NLED), a pharmaceutical reimbursement list in Thailand. There have also been no economic evaluation studies of CHB drug treatments conducted in Thailand yet. In order to fill this gap in policy research, the objective of this study was to compare the cost-utility of each drug therapy (Figure 1) with palliative care in patients with HBeAg-positive CHB.

METHODS

A cost-utility analysis using an economic evaluation model was performed to compare each drug treatment for HBeAg-positive CHB patients. A Markov model was used to estimate the relevant costs and health outcomes during a lifetime horizon based on a societal perspective. Direct medical costs, direct non-medical costs, and indirect costs were included, and health outcomes were denoted in life years (LYs) and quality-adjusted life years (QALYs). The results were presented as an incremental cost effectiveness ratio (ICER) in Thai baht (THB) per LY or QALY gained. One-way sensitivity and probabilistic sensitivity analyses were applied to investigate the effects of model parameter uncertainties.

RESULTS

The ICER values of providing generic lamivudine with the addition of tenofovir when drug resistance occurred, generic lamivudine with the addition of tenofovir based on the road map guideline, and tenofovir monotherapy were -14,000 (USD -467), -8,000 (USD -267) , and -5,000 (USD -167) THB per QALY gained, respectively. However, when taking into account all parameter uncertainties in the model, providing generic lamivudine with the addition of tenofovir when drug resistance occurred (78% and 75%) and tenofovir monotherapy (18% and 24%) would yield higher probabilities of being cost-effective at the societal willingness to pay thresholds of 100,000 (USD 3,333) and 300,000 (USD 10,000) THB per QALY gained in Thailand, respectively.

CONCLUSIONS

Based on the policy recommendations from this study, the Thai government decided to include tenofovir into the NLED in addition to generic lamivudine which is already on the list. Moreover, the results have shown that the preferred treatment regimen involves using generic lamivudine as the first-line drug with tenofovir added if drug resistance occurs in HBeAg-positive CHB patients.

Prior exposure to lamivudine increases entecavir resistance risk in chronic hepatitis B Patients without detectable lamivudine resistance

The efficacy of entecavir (ETV) treatment in chronic hepatitis B (CHB) patients who were exposed to lamivudine (LAM) but had no detectable LAM resistance (LAM-R) is not well evaluated. In this study, we aimed to evaluate whether the probability of developing genotypic resistance to ETV in LAM-exposed patients with or without LAM-R is comparable to that in antiviral-naive patients. This retrospective cohort study included 500 consecutive patients with CHB who started ETV monotherapy at a single tertiary hospital in Korea. The patients were divided into three groups: nucleos(t)ide analogue (NA)-naive patients (group 1, n=142), patients who were previously exposed to LAM and had no currently or previously detected LAM-R (group 2, n=233), and patients with LAM-R when starting ETV (group 3, n=125). The overall median ETV treatment duration was 48.7 months. The probabilities of virologic breakthrough were significantly increased not only in group 3 (hazard ratio [HR]=14.4, P<0.001) but also in group 2 (HR=5.0, P<0.001) compared to group 1. Genotypic ETV resistance (ETV-R) developed more frequently in group 2 (HR=13.0, P=0.013) as well as group 3 (HR=43.9, P<0.001) than in group 1: the probabilities of developing ETV-R in groups 1, 2, and 3 were <1.0%, 8.0%, and 28.2%, respectively, at month 48. The results of this study indicate that ETV-R occurred more frequently in LAM-exposed patients, even though they had no detectable LAM-R, than in NA-naive patients. Therefore, LAM-exposed CHB patients, regardless of the presence or absence of LAM-R, should be monitored more cautiously for the development of ETV-R during ETV monotherapy.

Loss of HBsAg and antiviral treatment: from basics to clinical significance

Accurate prediction of the sustained virological response (SVR) to antiviral therapy against chronic hepatitis B (CHB) is still a crucial problem needing profound investigation. In recent years, quantification of hepatitis B surface antigen (HBsAg), a reliable predictor of SVR and an ideal endpoint of treatment, has attracted increasing attention. Serum HBsAg titer may reflect the level of intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in most patients, and vary with natural phases of chronic HBV infection, genotypes and variants, antiviral therapy, and other related factors. Serum HBsAg <200 IU/mL or yearly reduction ≥0.5 log10IU/mL may be the optimum cut-off values for prediction of the chance of spontaneous seroclearance of HBsAg. Serum HBsAg <1,000 IU/mL with HBV DNA <2,000 IU/mL may identify most of the inactive HBV carriers from active HBeAg(-) hepatitis. Interferon-based therapy can lead to more significant HBsAg decline than therapy based on nucleoside and/or nucleotide analogues. Different patterns or kinetics of HBsAg decline during therapy are related to different probabilities of SVR. A low HBsAg level, <3,000 IU/mL at baseline, or HBsAg level, <1,500 IU/mL at week 12, or a rapid on-treatment HBsAg decline of ≥0.5 log10IU/mL at week 12, may predict higher probability of SVR. However these cut-off values must be further validated for larger cohort of patients across genotypes worldwide. Incorporation of serum HBsAg level, HBeAg status, HBV DNA load, HBV genotypes, and other related factors might help establish new concept of more practical "response-guided treatment (RGT)" rules for antiviral therapy.

Should lamivudine monotherapy be stopped or continued in patients infected with hepatitis B with favorable responses after more than 5 years of treatment?

Regarding the limited evidence for determining the optimal duration of antiviral treatment for hepatitis B, the long-term outcome of patients with favorable responses to over 5 years of lamivudine monotherapy was investigated. Two hundred seventy-one patients who had received lamivudine for at least 5 years were enrolled. Ultimately, 72 patients without YMDD mutations and showing hepatitis B virus (HBV) DNA levels <2.5 pg/ml after 5 years of treatment were analyzed. Mean treatment duration with lamivudine was 9.1 ± 2.6 years. During the treatment, HBeAg and HBsAg loss/seroconversion rates were 95 and 6.9%, respectively. Decompensation and hepatocellular carcinoma (HCC) developed in 2.8 and 6.9% of patients, respectively. Old age and cirrhosis were risk factors for HCC development. Finally, 11.1% of patients developed YMDD mutations after 8.3 ± 2.4 years of treatment. There was no hepatic decompensation among the patients who developed delayed YMDD mutations. Sixteen patients who achieved a complete response stopped lamivudine and four patients showed relapses 10.3 ± 8.5 months after stopping lamivudine. Relapsed patients had more cirrhotic livers and higher rates of HBeAg positivity at 5 years than patients who maintained complete response. The present study suggests that patients who do not develop YMDD mutations over 5 years of treatment with lamivudine may continue lamivudine monotherapy until the loss of HBsAg. However, even for the patients showing favorable response over 5 years of treatment, those in older ages, with cirrhosis or who show poor HBeAg responses should be on careful monitoring to detect the development of viral mutations, relapse and even HCC.

Quasispecies and pre-existing drug-resistant mutations of hepatitis B virus in patients with chronic hepatitis B

Background/Aims

To investigate pre-existing hepatitis B virus (HBV) quasispecies and the genotypic evolution of several variants.

Methods

From six patients with lamivudine (LAM) failure, serum samples at pretreatment, 6 months of LAM therapy, and virologic breakthrough were obtained. One hundred clones with HBV inserts in each patient were sequenced at each time point. Pretreatment serum samples were also analyzed from six patients who achieved good responses to LAM therapy.

Results

Among the six patients with LAM failure, the analysis of 100 clones from patient 1 revealed the substitutions L180M in 1% of clones and V173L in 2% of clones. Patient 2 had substitutions of L80V, W153Q, and L180M. In patient 3, mutations conferring resistance to adefovir at V84I (5%), I169L (1%), and N236H (7%) and entecavir at S202G (2%) were detected. Patient 4 had mutations at T128N (1%), I169L (1%), V173L (2%), A181V (1%), and Q215H (1%). In patient 5, M204V/I was detected in 1% and 2% of clones, respectively. L80I and V173L were also identified in patient 6. In the six patients who responded to LAM, the degree of overall quasispecies was less than those with LAM failure.

Conclusions

Various HBV quasispecies associated with drug resistance existed before treatment, and the quasispecies dynamically changed through LAM therapy.

Telbivudine treatment is associated with high hepatitis B e antigen seroconversion and immune modulatory effects in chronic hepatitis B patients

Chronic hepatitis B (CHB) is characterized by an impaired immune response to hepatitis B virus. Among the nucleos(t)ides used in CHB treatment, telbivudine is associated with the highest rates of hepatitis B e antigen (HBeAg) seroconversion rates, which are similar to those observed with pegylated interferon (PegIFN). Besides direct antiviral effect, modulation of the immune system may be an additional benefit for telbivudine-treated patients. Indeed, there is much clinical data indicating an IFN-like behaviour for telbivudine in contrast to other oral nucleos(t)ides, such as high HBeAg seroconversion, similar hepatitis B surface antigen (HBsAg) decline and biphasic viral kinetics. Clinical studies, animal models and in vitro studies suggest that both the innate and adaptive immune system responses contribute to high HBeAg seroconversion during telbivudine treatment through modulation of the function and/or expression of CD4+/CD8+ T cells, Th1/Th2, Treg, PD-1/PD-L1, Th17, IL-21 and TFH. The results described in this review suggest that the antiviral effect of telbivudine may be attributable not only to direct suppression of hepatitis B virus, but also to immunoregulatory effects. Hypothetically, telbivudine shares some common signal pathways with IFN.

Precore and basal core promoter mutations in Asian American patients with hepatitis B e antigen-positive chronic hepatitis B

BACKGROUND

Prior studies have shown that precore mutations abolish and basal core promoter (BCP) mutations down-regulate hepatitis B e antigen (HBeAg) production. Thus, the presence of precore and BCP mutations in HBeAg-positive patients indicates an infection with a mixed viral population of wild-type and precore and/or BCP mutant hepatitis B virus (HBV). To date, there has been limited study of the prevalence and clinical significance of precore and BCP mutations in patients with HBeAg-positive chronic hepatitis B.

AIM

To determine the prevalence, predictors and clinical characteristics of mixed wild-type and precore/BCP HBV infection, through a cross-sectional study, in a US cohort of patients with chronic hepatitis B.

METHODS

We conducted a retrospective study of 828 chronic hepatitis B patients with HBV genotype and mutation panel testing seen at three US gastroenterology and liver clinics from June 2005 to September 2009.

RESULTS

A majority of our patients (92.3%) were either Vietnamese or Chinese American. In the HBeAg-positive cohort, 17% of patients had precore mutations only, 28% had BCP mutations only and 5% had both BCP and precore mutations. On multivariate analyses, HBV genotype C, increasing age, lower HBV DNA level and an ALT quotient >2 were independent predictors for the presence of precore and/or BCP mutations.

CONCLUSIONS

The current distinction and management recommendations for HBeAg-positive vs. HBeAg-negative patients with chronic hepatitis B should be reassessed. Additional biomarkers and treatment endpoints should be studied for their usefulness in predicting continued viral suppression after treatment discontinuation.

Assessing long-term treatment efficacy in chronic hepatitis B and C: between evidence and common sense

Chronic infection with the hepatitis B and C virus represents a major health problem worldwide, as it is estimated that roughly 400 and 200 million people respectively, are infected by each virus. By definition, any antiviral therapy that claims to be effective should have as its ultimate efficacy end point an improvement in patients' survival, or at least a reduction in the development rates of liver-related complications. However, this is extremely complicated to prove as the natural course of both viral diseases is extremely slow, requiring decades to evolve in cirrhosis and even more years to lead to liver complications. For this reason, clinicians and health authorities have relied on so called surrogate end points to assess the efficacy of any therapeutic intervention for viral hepatitis. Obviously, this allows for standardization in study designs that ultimately translates into an accelerated time frame for therapeutic drugs as well as healthcare innovations to enter the viral hepatitis clinical practice. However, it also calls for demonstration that surrogate end points in the treatment of patients with chronic hepatitis B or C are good and reliable markers of long-term efficacy.

Durability of viral response after off-treatment in HBeAg positive chronic hepatitis B

AIM: To evaluate the durability in hepatitis B e antigen (HBeAg) positive chronic hepatitis B patients who discontinued antiviral treatment.

METHODS: A total of 48 HBeAg positive chronic hepatitis B patients who were administered nucleoside analogues and maintained virological response for ≥ 6 mo [hepatitis B virus (HBV) DNA < 300 copies/mL and HBeAg seroconversion] before cessation of treatment were enrolled between February 2007 and January 2010. The criteria for the cessation of the antiviral treatment were defined as follows: (1) achievement of virological response; and (2) duration of consolidation therapy (≥ 6 mo). After treatment cessation, the patients were followed up at 3-6 mo intervals. The primary endpoint was serologic and virologic recurrence rates after withdrawal of antiviral treatment. Serologic recurrence was defined as reappearance of HBeAg positivity after HBeAg seroconversion. Virologic recurrence was defined as an increase in HBV-DNA level > 10⁴ copies/mL after HBeAg seroconversion with previously undetectable HBV-DNA level.

RESULTS: During the median follow-up period of 18.2 mo (range: 5.1-47.5 mo) after cessation of antiviral treatment, the cumulative serological recurrence rate was 15 % at 12 mo. The median duration between the cessation of antiviral treatment and serologic recurrence was 7.2 mo (range: 1.2-10.9 mo). Of the 48 patients with HBeAg positive chronic hepatitis, 20 (41.6%) showed virological recurrence. The cumulative virologic recurrence rates at 12 mo after discontinuing the antiviral agent were 41%. The median duration between off-treatment and virologic recurrence was 7.6 mo (range: 4.3-27.1 mo). The mean age of the virological recurrence group was older than that of the non-recurrence group (46.7 ± 12.1 years vs 38.8 ± 12.7 years, respectively; P = 0.022). Age (> 40 years) and the duration of consolidation treatment (≥ 15 mo) were significant predictive factors for offtreatment durability in the multivariate analysis [P = 0.049, relative risk (RR) 0.31, 95% CI (0.096-0.998) and P = 0.005, RR 11.29, 95% CI (2.054-65.12), respectively]. Patients with age (≤ 40 years) who received consolidation treatment (≥ 15 mo) significantly showed durability in HBeAg positive chronic hepatitis B patients (P = 0.014). These results suggest that additional treatment for more than 15 mo after HBeAg seroconversion in patients who are ≤ 40 years old may be beneficial in providing a sustained virological response.

CONCLUSION: Our data suggest that HBeAg seroconversion is an imperfect end point in antiviral treatment. Long-term consolidation treatment (≥ 15 mo) in younger patients is important for producing better prognosis in HBeAg positive chronic hepatitis B.

High frequency of recurrent viremia after hepatitis B e antigen seroconversion and consolidation therapy

BACKGROUND

The primary treatment endpoint for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B is HBeAg seroconversion; however, data on the durability of response are inconsistent.

GOALS

Our goal was to investigate the rate of recurrent viremia after HBeAg seroconversion and subsequent discontinuation of therapy.

METHODS

We retrospectively studied 88 consecutive Asian American patients who achieved HBeAg seroconversion [loss of HBeAg and development of antibody to HBeAg (anti-HBe)] among 458 HBeAg-positive patients who received oral antiviral therapy at 3 US clinics between March 1998 and November 2010. Recurrent viremia was defined as reappearance of detectable serum hepatitis B virus DNA (>100 IU/mL) on 2 consecutive laboratory tests from previously undetectable levels.

RESULTS

Antiviral medications used at the time of HBeAg seroconversion included: lamivudine (23%), adefovir (34%), entecavir (36%), tenofovir (4%), and combination therapy (3%). Antiviral therapy was continued after HBeAg seroconversion in 49 patients (group I) and discontinued in the other 39 patients after consolidation therapy [median=12 months (range, 1 to 55 mo)] (group II). No patients in group I experienced recurrent viremia, whereas 90% in group II did. Elevated alanine aminotransferase also occurred in 38% of group II patients [median peak alanine aminotransferase 249 IU/mL (range, 93 to 1070 IU/mL)].

CONCLUSIONS

Despite consolidation therapy, almost all patients who discontinued therapy after achieving HBeAg seroconversion and complete viral suppression experienced recurrent viremia, and close to half also experienced biochemical flares. HBeAg seroconversion does not seem to be a durable treatment endpoint for many patients, and they should be monitored carefully for virologic relapse and biochemical flares if antiviral therapy is withdrawn.

Cost-effectiveness analysis of antiviral treatments for HBeAg-positive chronic hepatitis B in Canada

OBJECTIVE

To conduct a cost-effectiveness analysis of currently available nucleos(t)ide antiviral treatments (lamivudine, telbivudine, entecavir, and tenofovir) for chronic hepatitis B in Canada.

METHODS

Markov modeling was used to project the lifetime health benefits and costs associated with the antiviral treatments. The hypothetical patient population was hepatitis B e antigen-positive chronic hepatitis B-infected patients aged 34 years. Quality-adjusted life-years were used as a measure of effectiveness. Long-term cumulative incidence of liver complications was also projected. Treatment effectiveness data were derived from the literature; meta-analysis was conducted when there was a large variance in reported effectiveness data. Costs were obtained from a cost analysis of treating chronic hepatitis B-related complications in Canada. Stochastic parameter uncertainty was examined in probabilistic sensitivity analysis by using second-order Monte Carlo simulation. Alternative modeling assumptions were assessed in scenario analysis. One-way sensitivity analysis was used to explore each parameter's impact on the uncertainty of the results.

RESULTS

In the base-case analysis, telbivudine was dominated by entecavir and tenofovir. Tenofovir strictly dominated lamivudine, telbivudine, and entecavir. Over the 72-year period of the model, the expected life expectancy (undiscounted) of lamivudine, telbivudine, entecavir, and tenofovir was 35.71, 36.94, 37.65, and 37.99 years, respectively. Tenofovir had the highest expected quality-adjusted life-years at 11.86 (discounted) in all comparisons. Scenario and sensitivity analyses proved the robustness of the base-case results. The projected 10-year cumulative incidence of cirrhosis and hepatocellular carcinoma was 11.40% and 3.05%, respectively, for tenofovir, which is significantly lower than that for lamivudine.

CONCLUSION

Tenofovir generated the best results compared with all other therapies under evaluation.

Virologic response is not durable after adefovir discontinuation in lamivudine-resistant chronic hepatitis B patients

Background/Aims

We investigated the durability of the biochemical and virologic responses after adefovir (ADV) discontinuation in lamivudine-resistant (LMV-R) chronic hepatitis B (CHB) patients, and the outcomes of ADV discontinuation compared to that of ADV maintenance.

Methods

The indication for ADV treatment cessation was an undetectable level of hepatitis B virus (HBV) DNA documented on two occasions at least 6 months apart. All patients received additional ADV for at least 12 months after the confirmation of undetectable HBV DNA (Cobas TaqMan PCR assay, <70 copies/mL). Of 36 patients who had a sufficient ADV therapeutic effect, 19 discontinued ADV treatment, while the others maintained it. A virologic rebound was arbitrarily defined as the redetection of HBV DNA at a level higher than 10⁵ copies/mL.

Results

In the ADV discontinuation group, ADV treatment and additional therapy were administered for medians of 33 months (range, 12-47 months) and 18 months, respectively. The patients were followed for a median of 12 months (range, 3-30 months) after ADV cessation. During that period, 18 of 19 patients (95%) experienced viral relapse. Viral rebound was observed in six patients (32%). However, 12 of 18 patients (67%) exhibited serum HBV DNA levels of less than 10⁵ copies/mL. Biochemical relapses were observed in four of the six patients with viral rebound. In the ADV maintenance group, patients were treated for a median of 53 months (range, 31-85 months), and 9 patients (53%) experienced viral breakthrough.

Conclusions

During short-term follow-up after ADV discontinuation, most patients (95%) exhibited viral relapse, whereas and viral breakthrough occurred in about half of patients (53%) maintained on ADV therapy. Therefore, the durability of virologic response after ADV discontinuation in LMV-R patients was unsatisfactory. In addition, and viral breakthrough was not infrequent in the ADV continuation group.

Current Nucleos(t)ide Analogue Therapy for Chronic Hepatitis B

Although the prevalence of chronic hepatitis B has decreased considerably in recent years due to widespread use of the hepatitis B virus (HBV) vaccine, its prevalence still remains high in adults, and this can place a significant burden on health care in areas with endemic HBV. Since the introduction of nucleos(t)ide analogues (NUCs), there has been marked improvement in the care of patients with chronic hepatitis B, resulting in increased survival. However, the emergence of drug resistance in patients treated with NUCs is a major concern. The number of multi-drug resistant patients is increasing, and many patients may not respond to the currently available drugs. In this review, we describe the current status of NUC therapy for antiviral-naïve and -resistant patients.

Lamivudine plus adefovir is a good option for chronic hepatitis B patients with viral relapse after cessation of lamivudine treatment

Aim

Currently, there is no consensus on the retreatment recommendation of chronic hepatitis B (CHB) patients with viral rebound after cessation of treatment. In the search of reasonable treatment, we compared the efficacy and safety of adefovir (ADV) plus lamivudine (LAM) and LAM alone for the retreatment of patients with viral relapse but without genotypic resistance after cessation of LAM.

Methods

This is a prospective controlled study, and a total of 53 hepatitis B e antigen (HBeAg)-positive patients with viral rebound but without resistance were received either LAM plus ADV or LAM alone treatment.

Results

After 1-year treatment, more patients who received LAM plus ADV than those who received LAM alone had ALT normalization (84% versus 53.6%, P = 0.018) or HBV DNA levels below 1000 copies/mL (80% versus 42.9%, P < 0.006). Seven patients receiving LAM plus ADV had HBeAg seroconversion, as compared with 0 in patients receiving ALM alone (28% versus 0%, P = 0.003). During 1-year retreatment, five patients receiving LAM alone had virological breakthrough and all of them had LAM resistance strains (rtM204V/I), while no LAM- or ADV- associated resistance strains were detected in patients receiving LAM plus ADV. All patients receiving LAM plus ADV were well tolerated, and no serious side effects were noted.

Conclusions

Patients treated with LAM plus ADV exhibited significantly greater virological, biochemical and serological responses compared with LAM alone. These data suggested that combination of LAM plus ADV would be a good option for the retreatment of CHB patients with viral relapse after cessation of LAM.

Significant changes in liver stiffness measurements in patients with chronic hepatitis B: 3-year follow-up study

For patients with chronic hepatitis B (CHB) infection, changes in liver stiffness measurement (LSM) over time are not known. We examined changes longitudinally in a cohort of patients. Four hundred and twenty-six patients with CHB underwent transient elastography. Patients were followed regularly, and repeat elastography was performed at 3 years. Hepatitis serology, viral load and routine liver biochemistry were monitored. Of the 426 patients, 38 (9%) were hepatitis B e-antigen (HBeAg)-positive, 293 (69%) were HBeAg-negative and 95 (22%) were patients with prior hepatitis B surface antigen (HBsAg) seroclearance. A total of 110 patients received oral antiviral therapy. There was a significant decline of LSMs at the follow-up measurement compared to baseline (6.1 vs 7.8 kPa respectively, P = 0.002) in treated patients who had elevated alanine aminotransferase (ALT) at baseline and subsequent normalization after 3 years (normal ALT limit being 30 U/L for males and 19 U/L for females). In nontreated patients, only the patients with persistently normal ALT at both time points had significantly lower LSMs at the follow-up measurement compared to baseline: 4.9 vs 5.3 kPa, respectively, in patients who remained positive for HBsAg (P = 0.005) and 5.1 vs. 5.4 kPa, respectively, in patients who had HBsAg seroclearance (P = 0.026). In patients who remained positive for HBsAg, independent factors associated with a significant decline in LSM of ≥1 kPa included antiviral therapy (P = 0.011) and the ALT levels at the follow-up time point (P = 0.024). Thus, in patients with CHB, a significant decline in LSM after 3 years was observed in treated patients with ALT normalization and in untreated patients who had persistently normal ALT. Antiviral therapy and follow-up ALT levels were independent significant factors associated with a decline in LSM.

Update of chronic hepatitis B

PURPOSE OF REVIEW

We review here new developments in chronic hepatitis B (CHB) treatment, based on review of published articles between December 2009 and November 2010.

RECENT FINDINGS

It is estimated that two-thirds of US CHB patients have not been identified, evaluated and appropriately treated, largely due to lack of knowledge and awareness of CHB among medical professionals and at-risk populations. Seven medications have been approved to treat CHB in adults, but only four medications have been approved to treat CHB in children.Hepatitis B e antigen (HBeAg) seroconversion is still an important treatment endpoint in HBeAg-positive patients. Durability of nucleoside analogue treatment-related HBeAg seroconversion is still questionable. Hepatitis B surface antigen (HBsAg) seroclearance has been achieved in some patients with antiviral therapy. HBsAg quantitation and kinetics is now being studied to determine its role in the natural history of CHB and whether these measures may predict future response to current antiviral therapy.

SUMMARY

Great advances have been made in understanding the HBeAg seroconversion durability. The clinical significance of serum HBsAg kinetics has been recognized in naive CHB patients and patients with antiviral therapy. More education programs are needed to improve the public awareness of the importance of CHB to the health of whole population.

Efficacy and safety of prolonged 3-year telbivudine treatment in patients with chronic hepatitis B

BACKGROUND

In the GLOBE trial, telbivudine demonstrated superior efficacy to lamivudine at 2 years in patients with chronic hepatitis B (CHB).

AIMS

To investigate the long-term efficacy and safety of telbivudine in the telbivudine-treated cohort from the GLOBE trial.

METHODS

Virological and biochemical responses were assessed in 213 HBeAg-positive and 186 HBeAg-negative CHB patients who continued telbivudine treatment for 3 years.

RESULTS

Undetectable hepatitis B virus DNA and HBeAg seroconversions were achieved by 77 and 37% of HBeAg-positive patients respectively. Cumulative HBeAg seroconversion rate was 46%. HBeAg seroconversion was sustained at 52 weeks off therapy in 84% of the patients enrolled in the off-treatment follow-up arm of the study. Undetectable viraemia and normal alanine aminotransferase (ALT) levels at 3 years were achieved by 85 and 83% of HBeAg-negative patients respectively. Genotypic resistance rates for the study population who continued therapy during the third year were 11.3 in HBeAg-positive and 6.5% in HBeAg-negative patients. Patients with undetectable viraemia at treatment week 24 had optimal outcomes at 3 years. In the HBeAg-positive population, cumulative HBeAg seroconversion occurred in 58%. Resistance rates for HBeAg-positive and HBeAg-negative patients were 3.6 and 6.2% respectively. The telbivudine safety profile during prolonged therapy was similar to that in the GLOBE trial.

CONCLUSIONS

Three years of telbivudine treatment yielded high rates of viral suppression and ALT normalization with a favourable safety profile. High rates of HBeAg seroconversion were achieved with prolonged telbivudine therapy and were sustained in the majority of patients over 52 weeks off therapy.

Review article: chronic hepatitis B - anti-viral or immunomodulatory therapy?

BACKGROUND

First-line treatment options for chronic hepatitis B (CHB) consist of nucleos(t)ide analogues with a high barrier to resistance (entecavir and tenofovir) or the immunomodulatory agent peginterferon (PEG-IFN). The optimal choice for individual patients remains controversial.

AIM

To review treatment options for CHB, with a focus on deciding between prolonged nucleos(t)ide analogue therapy or a finite course of PEG-IFN.

METHODS

A comprehensive literature search was undertaken.

RESULTS

Long-lasting, treatment-maintained suppression of hepatitis B virus (HBV) DNA without resistance is achievable in most patients by entecavir or tenofovir. A sustained off-treatment response is, however, unlikely and long-term therapy must be anticipated. PEG-IFN offers a higher rate of sustained response in a subgroup of patients, but is frequently complicated by side effects. Pre-treatment predictors of response, including HBV genotype, alanine aminotransferase and HBV DNA levels, aid in selecting patients for PEG-IFN therapy. Furthermore, on-treatment markers such as quantitative hepatitis B surface antigen may be applied to identify nonresponders early during the PEG-IFN treatment course, thereby preventing unnecessary treatment.

CONCLUSIONS

Both nucleos(t)ide analogues and PEG-IFN can be prescribed as first-line treatment options for CHB. However, PEG-IFN should only be considered for patients with a high chance of response based on pre-treatment and on-treatment factors.

Treatment of HBeAg-negative chronic hepatitis B patients with nucleos(t)ide analogues

Current agents used in the treatment of chronic hepatitis B (CHB) can be classified into interferons-α (IFN-α: standard or pegylated) and nucleos(t)ide analogues (NUCs). NUCs are now used in most CHB patients for several reasons. They can be given to all CHB patients, even those with contraindications to IFN-α. NUCs are more convenient to use (one oral tablet daily) than IFN-α (subcutaneous injections) and are well tolerated with a good safety profile, while IFN-α has frequent and potentially severe side effects and worsens the patient's quality of life. All NUCs are potent anti-hepatitis B virus agents (all but adefovir are more potent than IFN-α) with entecavir(ETV) and tenofovir offering the highest potency and most importantly minimal to negligible risk of resistance during long-term monotherapy [corrected]. Prolongation of entecavir or tenofovir monotherapy maintains and slightly increases the initially high virological remission rates (67-76% of HBeAg-positive and 90-93% of HBeAg-negative patients) and this is expected to result in improved long-term outcomes. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs and the finite duration (48 weeks) the main advantage of IFN-α. However, only a minority of IFN-α-treated patients achieve durable sustained off-treatment responses (HBeAg-positive: 30-35%, HBeAg-negative: 20-25%), while NUCs may be safely discontinued in HBeAg-positive patients with stable HBeAg seroconversion. Because there will always be concerns for safety and family planning issues with long-term therapy, NUCs should be used judiciously and should not be prescribed in young CHB patients with mild liver disease.

Chronic hepatitis B: peginterferon or nucleos(t)ide analogues?

Pegylated interferon-α (PEG-IFN) is still an important treatment option for both HBeAg-positive and HBeAg-negative chronic hepatitis B (CHB) patients even with the availability of potent nucleos(t)ide analogues (NUCs) with a low risk of resistance. The major advantages of PEG-IFN-based treatment include the limited duration of treatment and the good probability of achieving a sustained off-treatment response. Responders to PEG-IFN have an increased probability of HBsAg loss and survival. However, the limited number of patients who achieve a response and the high costs and side-effects associated with PEG-IFN limit its clinical use. The potent NUCs entecavir and tenofovir are therefore often used as a first-line treatment option. Unfortunately, the off-treatment durability of response to NUCs is generally low, requiring long-term continuous therapy. Recent progress making it possible to select patients with a high probability of achieving a response to PEG-IFN, and to adapt therapy early on in probable non-responders, should help further optimize the utilization of PEG-IFN in CHB.

Long-term therapy with tenofovir is effective for patients co-infected with human immunodeficiency virus and hepatitis B virus

BACKGROUND & AIMS

We investigated the long-term efficacy and renal safety of tenofovir disoproxil fumarate (TDF), administered to patients co-infected with human immunodeficiency virus and hepatitis B virus (HBV) as part of an antiretroviral therapy.

METHODS

We performed a multicenter, prospective cohort study of 102 patients co-infected with human immunodeficiency virus and HBV who were treated with TDF.

RESULTS

At baseline, 80% of patients had a detectable viral load (HBV DNA >20 IU/mL). Among patients positive for hepatitis B e antigen (HBeAg) (n = 67), 92% had a virologic response (HBV DNA <20 IU/mL) after 5 years of treatment. There was no difference between patients with or without lamivudine resistance at baseline (P = .39). Loss rates of HBeAg and hepatitis B s antigen (HBsAg) were 46% and 12%, respectively. Among HBeAg-negative patients (n = 15), 100% had a virologic response after 4 years of treatment and 2 (13%) lost HBsAg. Twenty subjects (20%, all HBeAg-negative) had undetectable HBV DNA at baseline; during a median follow-up period of 52 months (interquartile range, 41-63 mo), 19 (95%) maintained a virologic response and 2 (10%) lost HBsAg. Overall, one patient acquired a combination of resistance mutations for anti-HBV drugs and experienced a virologic breakthrough. Three (3%) patients discontinued TDF because of increased serum creatinine levels. The estimated decrease in renal function after 5 years of TDF therapy was 9.8 mL/min/1.73 m(2), which was most pronounced shortly after TDF therapy was initiated.

CONCLUSIONS

TDF, administered as part of antiretroviral therapy, is a potent anti-HBV agent with a good resistance profile throughout 5 years of therapy. Only small nonprogressive decreases in renal function were observed.

The Role of Interferon in Hepatitis B Therapy

Despite the introduction of new nucleos(t)ide analogues in recent years, peginterferon is still recommended as a potential first-line treatment option by current practice guidelines for the management of chronic hepatitis B. Peginterferon offers the advantage of higher sustained off-treatment response rates compared to nucleos(t)ide analogues because of its immunomodulatory effects. Sustained transition to the inactive hepatitis B surface antigen (HBsAg) carrier state can be achieved in about 30% of hepatitis B e antigen (HBeAg)-positive patients and 20% of HBeAg-negative patients. Recent studies have focused on identification of pretreatment and on-treatment factors that allow the selection of patients who are likely to achieve a sustained response to peginterferon therapy in order to avoid the side-effects and costs associated with unnecessary treatment. Future studies need to address whether specific virologic benchmarks can guide individualized decisions concerning therapy continuation and whether peginterferon combined with new potent nucleos(t)ide analogues improves treatment outcomes.

Endpoints of hepatitis B treatment

The goal of hepatitis B treatment is to prevent the development of cirrhosis, liver failure, and hepatocellular carcinoma. Ideally, clinical studies should demonstrate that hepatitis B therapies can prevent liver-related complications; however, these clinical endpoints evolve over years or decades. Therefore, clinical trials have relied on intermediate endpoints to evaluate the efficacy of treatment and to determine when treatment can be stopped. Intermediate endpoints that have been used include biochemical, histological, virological, and serological endpoints. This review will discuss the validity of these intermediate endpoints as surrogates of clinical endpoints, and the rates at which these intermediate endpoints can be achieved with currently available therapies.

Hepatitis B virus DNA and hepatitis B surface antigen levels in chronic hepatitis B

Despite universal vaccination, chronic hepatitis B (CHB) continues to be a major health burden worldwide, with an estimated 350-400 million people infected with the virus. Over the past decade, rapid progress has been made with regards to antiviral therapy for CHB, from conventional interferon to pegylated interferon, and with the earliest oral agent lamivudine to the current, more potent drugs such as entecavir and tenofovir. There have also been new developments in the diagnostic and monitoring tools for CHB. Qualitative hepatitis B surface antigen (HBsAg) testing has been used to diagnose patients infected with CHB. More recently, quantitative HBsAg titers have been used to predict treatment outcome when measured at baseline or early into treatment. The progress on the use of hepatitis B virus (HBV) DNA levels has been more rapid. Serum HBV DNA levels have been shown to be important in the natural history of CHB infection, with higher levels being significantly associated with the development of cirrhosis and hepatocellular carcinoma. For patients receiving antiviral therapy, the baseline and early on-treatment HBV DNA levels are important in determining treatment outcomes. Monitoring of HBV DNA levels during therapy will allow for early detection of drug resistance. The end-of-treatment and post-treatment HBV DNA levels have been demonstrated to be important indicators of treatment success and relapse, respectively. With newer and more powerful antiviral agents, and with the development of quantitative assays that are highly sensitive, further studies are needed to optimize the use of these tools and agents in the modern management of CHB.