Prevalence and clinical correlates of YMDD variants during lamivudine therapy for patients with chronic hepatitis B

3-Fucosyllactose-mediated modulation of immune response against virus infection

Viral pathogens, particularly influenza and SARS-CoV-2, pose a significant global health challenge. Given the immunomodulatory properties of human milk oligosaccharides, in particular 2'-fucosyllactose and 3-fucosyllactose (3-FL), we investigated their dietary supplementation effects on antiviral responses in mouse models. This study revealed distinct immune modulations induced by 3-FL. RNA-sequencing data showed that 3-FL increased the expression of interferon receptors, such as Interferon Alpha and Beta Receptor (IFNAR) and Interferon Gamma Receptor (IFNGR), while simultaneously downregulating interferons and interferon-stimulated genes, an effect not observed with 2'-fucosyllactose supplementation. Such modulation enhanced antiviral responses in both cell culture and animal models while attenuating pre-emptive inflammatory responses. Nitric oxide concentrations in 3-FL-supplemented A549 cells and mouse lung tissues were elevated exclusively upon infection, reaching 5.8- and 1.9-fold increases over control groups, respectively. In addition, 3-FL promoted leukocyte infiltration into the site of infection upon viral challenge. 3-FL supplementation provided protective efficacy against lethal influenza challenge in mice. The demonstrated antiviral efficacy spanned multiple influenza strains and extended to SARS-CoV-2. In conclusion, 3-FL is a unique immunomodulator that helps protect the host from viral infection while suppressing inflammation prior to infection.

Efficacy and Safety of Antiviral Therapy for Immune-tolerant Hepatitis B Viral Infection in Children: A Systematic Review and Meta-analysis

BACKGROUND

Chronic hepatitis B virus (HBV) infection burden in children remains a pressing public health concern. Whether antiviral therapy should be administered to children with HBV in the immune-tolerant phase remains controversial. We performed a meta-analysis to evaluate antiviral therapy efficacy and safety in children with immune-tolerant hepatitis B (ITHB).

METHODS

A search was conducted in multiple databases (PubMed, Embase, Cochrane, Web of Science, CBM, CNKI and Wanfang Data) to identify clinical trials examining antiviral therapy efficacy and safety in children (1-18 years) with ITHB viral infection from inception to February 2023. Outcomes were calculated separately for controlled and single-arm studies.

RESULTS

Nine trials (442 patients), including 2 randomized controlled trials (RCTs), 3 non-RCTs and 4 single-arm studies, were included in this meta-analysis. In the RCTs, antiviral therapy group exhibited greater rates of HBsAg loss [risk ratio (RR) = 6.11, 95% confidence interval (CI): 1.67-22.31, P Z-test = 0.006], HBsAg serologic response (RR = 5.29, 95% CI: 1.47-19.07, P Z-test = 0.011) and HBeAg loss (RR = 3.00, 95% CI: 1.35-6.66, P Z-test = 0.007) compared with the control group at the end of follow-up. In single-arm studies, the pooled incidences of HBsAg loss, HBeAg loss and HBsAg seroconversion were 24% (95% CI: -0.1% to 48%), 24% (95% CI: -0.1% to 48%) and 24% (95% CI: -5% to 52%), respectively.

CONCLUSION

Current evidence suggests the effectiveness of antiviral therapy in children with HBV infection in the immune-tolerant stage, with few serious adverse events. Due to the limited quality and number of included studies, more high-quality studies are required to validate our findings.

Developments in pharmacotherapeutic agents for hepatitis B - how close are we to a functional cure?

INTRODUCTION

Hepatitis B virus (HBV) remains a public health concern given its global prevalence and potential complications including hepatocellular carcinoma (HCC). Current therapies, including nucleos(t)ide analogs (NA) and interferons (IFN), are effective in chronic treatment of HBV but rarely provide a functional cure due to inadequate host response and the presence of viral DNA. Therefore, novel therapies that enhance the innate immune response while suppressing DNA transcription may provide definitive treatment of HBV.

AREAS COVERED

In this review, the authors provide a brief overview of commonly used agents and their efficacy in treatment of HBV. Newer therapies with direct antiviral agents such as bepirovirsen (antisense oligonucleotide (ASO)) and entry inhibitors such as bulevirtide have shown efficacy in reducing viral load but demonstrate further reductions in conjunction with immune modulators such as therapeutic vaccines.

EXPERT OPINION

Combination therapy is far superior to monotherapy alone, necessitating the need for both immunomodulators and direct antiviral agents in chronic treatment of HBV. Therapies that target covalently closed circular (cccDNA) with immunomodulators like therapeutic vaccines have shown promising results and may ultimately achieve functional cure. However, therapies need to be evaluated in the context of the patient, considering both financial and socioeconomic factors.

Susceptibility of Drug Resistant Hepatitis B Virus Mutants to Besifovir

Currently, interferon alpha and nucleos(t)ide analogues (NAs) are clinically available to treat hepatitis B virus (HBV) infection. Several NAs, including lamivudine (LMV), adefovir (ADV), entecavir (ETV) and tenofovir (TDF or TAF) have been approved and administered to chronic hepatitis B (CHB) patients. NAs inhibit HBV DNA synthesis by targeting the reverse transcriptase (RT) domain of HBV polymerase. Several mutations in the RT domain which lead to drug resistance against NAs have been reported, even for TDF and TAF which are highly potent with very low resistance rate. Besifovir (BFV) is a new antiviral dGMP analogue able to be used as a new NA drug for the control of CHB infection. Drug resistance to BFV is not well known due to its shorter duration of clinical use. Recently, we reported that rtL180M (M) and rtM204V (V) mutations, already resistant to LMV, are associated with BFV resistance. However, the susceptibility to BFV of previously known HBV mutants resistant to various drugs has not been studied. To investigate this, we performed in vitro drug susceptibility assays using natural and artificial mutants that are associated with resistance to LMV, ADV, ETV or TDF. As a result, LMV-resistant mutants were not susceptible to BFV and ETV-resistant clones showed partial resistance against BFV as well. However, ADV-resistant mutants were highly sensitive to BFV. In case of tenofovir-resistant mutations, the HBV mutants harboring primary mutations to tenofovir resistance were susceptible to BFV. Therefore, our study revealed that BSV may serve as an alternative drug for patients with ADV-, ETV-, TDF- or TAF-resistance.

Pradefovir Treatment in Patients With Chronic Hepatitis B: Week 24 Results From a Multicenter, Double-Blind, Randomized, Noninferiority, Phase 2 Trial

BACKGROUND

Pradefovir is a liver-targeted prodrug of adefovir, a nucleoside/nucleotide analogue with antiviral activity against hepatitis B virus (HBV) DNA polymerase. This phase 2 study compared the efficacy and safety of oral pradefovir (30, 45, 60, or 75 mg) versus tenofovir disoproxil fumarate (TDF; 300 mg) and aimed to identify the most appropriate dose of pradefovir for the forthcoming phase 3 study.

METHODS

Treatment-naive and experienced (not on treatment >6 months) patients with chronic hepatitis B were eligible.

RESULTS

A total of 240 participants were randomized and treated in the study (48 per group). Approximately 80% were hepatitis B e antigen (HBeAg) positive, and 10% had liver cirrhosis. The reductions from baseline in HBV DNA levels achieved at week 24 were 5.40, 5.34, 5.33, and 5.40 log10 IU/mL, with pradefovir doses of 30-, 45-, 60-, and 75-mg, respectively, compared with 5.12 log10 IU/mL with TDF. However, HBeAg loss was attained by more participants who received 45-, 60-, or 75-mg pradefovir than by those receiving TDF (12%, 6%, and 9% vs 3%). The TDF group exhibited a more significant increase in serum creatinine than the pradefovir 30- and 45-mg groups, and serum phosphate levels were comparable among all groups. Most adverse events (AEs) were mild (grade 1). No treatment-related severe AEs were reported. Overall, AEs and laboratory abnormalities were comparable to those in the TDF group.

CONCLUSIONS

Pradefovir and TDF exhibited comparable reductions in HBV DNA levels. All treatments were safe and well tolerated.

CLINICAL TRIALS REGISTRATION

NCT00230503 and China Drug Trials CTR2018042.

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.

Variable Proportions of Phylogenetic Clustering and Low Levels of Antiviral Drug Resistance among the Major HBV Sub-Genotypes in the Middle East and North Africa

Hepatitis B virus (HBV) infection remains a major public health threat in the Middle East and North Africa (MENA). Phylogenetic analysis of HBV can be helpful to study the putative transmission links and patterns of inter-country spread of the virus. The objectives of the current study were to analyze the HBV genotype/sub-genotype (SGT) distribution, reverse transcriptase (RT), and surface (S) gene mutations and to investigate the domestic transmission of HBV in the MENA. All HBV molecular sequences collected in the MENA were retrieved from GenBank as of 30 April 2021. Determination of genotypes/SGT, RT, and S mutations were based on the Geno2pheno (hbv) 2.0 online tool. For the most prevalent HBV SGTs, maximum likelihood phylogenetic analysis was conducted to identify the putative phylogenetic clusters, with approximate Shimodaira-Hasegawa-like likelihood ratio test values ≥ 0.90, and genetic distance cut-off values ≤ 0.025 substitutions/site as implemented in Cluster Picker. The total number of HBV sequences used for genotype/SGT determination was 4352 that represented a total of 20 MENA countries, with a majority from Iran (n = 2103, 48.3%), Saudi Arabia (n = 503, 11.6%), Tunisia (n = 395, 9.1%), and Turkey (n = 267, 6.1%). Genotype D dominated infections in the MENA (86.6%), followed by genotype A (4.1%), with SGT D1 as the most common in 14 MENA countries and SGT D7 dominance in the Maghreb. The highest prevalence of antiviral drug resistance was observed against lamivudine (4.5%) and telbivudine (4.3%). The proportion of domestic phylogenetic clustering was the highest for SGT D7 (61.9%), followed by SGT D2 (28.2%) and genotype E (25.7%). The largest fraction of domestic clusters with evidence of inter-country spread within the MENA was seen in SGT D7 (81.3%). Small networks (containing 3-14 sequences) dominated among domestic phylogenetic clusters. Specific patterns of HBV genetic diversity were seen in the MENA with SGT D1 dominance in the Levant, Iran, and Turkey; SGT D7 dominance in the Maghreb; and extensive diversity in Saudi Arabia and Egypt. A low prevalence of lamivudine, telbivudine, and entecavir drug resistance was observed in the region, with almost an absence of resistance to tenofovir and adefovir. Variable proportions of phylogenetic clustering indicated prominent domestic transmission of SGT D7 (particularly in the Maghreb) and relatively high levels of virus mobility in SGT D1.

Dolutegravir/lamivudine as a first-line regimen in a test-and-treat setting for newly diagnosed people living with HIV

OBJECTIVES

Dolutegravir/lamivudine (DTG/3TC) is indicated for treatment-naive and experienced people with HIV; however, questions remain about its utility in a test-and-treat setting because of potential transmitted resistance and baseline hepatitis B virus (HBV) co-infection. We present feasibility and efficacy of DTG/3TC in newly diagnosed individuals in a test-and-treat setting.

DESIGN

The single-arm STAT study evaluated DTG/3TC in a US test-and-treat setting.

METHODS

Eligible adults initiated DTG/3TC 14 days or less after HIV-1 diagnosis without availability of baseline laboratory results. If baseline testing indicated DTG or 3TC resistance, HBV co-infection, or creatinine clearance less than 30 ml/min per 1.73 m2, participants remained on study with treatment modification. Efficacy endpoints included proportions of participants with HIV-1 RNA less than 50 copies/ml at Week 24, regardless of antiretroviral regimen, among all participants (intention-to-treat exposed) and those with available HIV-1 RNA data (observed).

RESULTS

Of 131 participants enrolled, 8% were female and 50% were non-white. Through Week 24, treatment was modified in eight participants [five with HBV co-infection, one with baseline M184V, one for adverse event (rash), one participant decision]. At Week 24, 78% (102/131) of all participants and 92% (102/111) of those with available data achieved HIV-1 RNA less than 50 copies/ml. Incidence of drug-related adverse events was low (7%); no drug-related serious adverse events occurred.

CONCLUSION

These data demonstrate the feasibility, efficacy, and safety of using DTG/3TC as a first-line regimen in a test-and-treat setting, with therapy adjustments for baseline resistance or HBV co-infection occurring safely via routine clinical care as needed [ClinicalTrials.gov, NCT03945981; see Supplemental Digital Content 1, video abstract (Video abstract summarizing the STAT study design and results), http://links.lww.com/QAD/C189].

Inflammation Pharmacological Reaction and YMDD Mutational Patterns in Lamivudine Therapeutics Hepatitis B Virus

Background/Aims: Emergence of tyrosine-methionine-aspartate-aspartate (YMDD) motif in reverse transcriptase is a serious problem in chronic hepatitis B(CHB) patients after Lamivudine (LAM) therapy. However, the relationship between inflammation pharmacological reaction and YMDD mutational patterns of CHB has not been well-characterized. The aim of this study was to investigate the inflammation pharmacological reaction and different YMDD mutants patterns of CHB patients. Methods: We investigated the inflammation pharmacological reaction and YMDD mutational patterns through biochemical, serological and virological detection among 83 CHB patients, including 25 YMDD mutants, 25 under detection, and 33 control patients without YMDD mutants. Results: Prevalence of YMDD mutation patterns is different. Among 25 YMDD mutants patients, YIDD was the dominant mutation (72%), followed YVDD (16%) and the hybrid YIDD + YVDD (12%). The time course during the YMDD mutations was also different. 52.4% patients developed the mutation less than 12 months after the LAM therapy. Serum hepatitis B virus (HBV) DNA level in patients with YMDD mutants were significantly higher than that in control and negative groups. Serum HbsAg and HbeAg in patients with YMDD mutants were also higher than those in control and negative groups, despite no significant difference was found forserum HbeAb. ALT and AST levels were also significantly higher in mutants group. Conclusions: Illuminating inflammation pharmacological reaction and YMDD mutational patterns of CHB during pathological process may have implications for future therapy in YMDD mutation patients. This may have impact on the choice of treatment strategies for lamivudine-resistant HBV.

Efficacy and cost-effectiveness of antiviral regimens for entecavir-resistant hepatitis B: A systematic review and network meta-analysis

BACKGROUND

Chronic hepatitis B (CHB) patients who had exposed to lamivudine (LAM) and telbivudine (LdT) had high risk of developing entecavir (ETV)-resistance after long-term treatment. We aimed to conduct a systematic review and a network meta-analysis on the efficacy and cost-effectiveness on antiviral regimens in CHB patients with ETV-resistance.

DATA SOURCES

We searched PubMed, EMBASE and Web of Science for studies on nucleos(t)ide analogues (NAs) treatment [including tenofovir disoproxil fumarate (TDF)-based rescue therapies, adefovir (ADV)-based rescue therapies and double-dose ETV therapy] in CHB patients with ETV-resistance. The network meta-analysis was conducted for 1-year complete virological response (CVR) and biological response (BR) rates using GeMTC and ADDIS. A cost-effective analysis was conducted to select an economic and effective treatment regimen based on the 1-year CVR rate.

RESULTS

A total of 6 studies were finally included in this analysis. The antiviral efficacy was estimated. On network meta-analysis, the 1-year CVR rate in ETV-TDF [odds ratio (OR)  = 22.30; 95 % confidence interval (CI): 2.78-241.93], LAM-TDF (OR  = 70.67; 95 % CI: 5.16-1307.45) and TDF (OR  = 16.90; 95 % CI: 2.28-186.30) groups were significantly higher than that in the ETV double-dose group; the 1-year CVR rate in the LAM-TDF group (OR  = 14.82; 95 % CI: 1.03-220.31) was significantly higher than that in the LAM/LdT-ADV group. The 1-year BR rate of ETV-TDF (OR = 28.68; 95 % CI: 1.70-1505.08) and TDF (OR = 21.79; 95 % CI: 1.43-1070.09) therapies were significantly higher than that of ETV double-dose therapy. TDF-based therapies had the highest possibility to achieve the CVR and BR at 1 year, in which LAM-TDF combined therapy was the most effective regimen. The ratio of cost/effectiveness for 1-year treatment was 8 526, 17 649, 20 651 Yuan in the TDF group, TDF-ETV group, and ETV-ADV group, respectively.

CONCLUSIONS

TDF-based combined therapies such as ETV-TDF and LAM-TDF therapies were the first-line treatment if financial condition is allowed.

Curcumin and Photobiomodulation in Chronic Viral Hepatitis and Hepatocellular Carcinoma

Immune modulation is a very modern medical field for targeting viral infections. In the race to develop the best immune modulator against viruses, curcumin, as a natural product, is inexpensive, without side effects, and can stimulate very well certain areas of the human immune system. As a bright yellow component of turmeric spice, curcumin has been the subject of thousands of scientific and clinical studies in recent decades to prove its powerful antioxidant properties and anticancer effects. Curcumin has been shown to influence inter- and intracellular signaling pathways, with direct effects on gene expression of the antioxidant proteins and those that regulate the immunity. Experimental studies have shown that curcumin modulates several enzyme systems, reduces nitrosative stress, increases the antioxidant capacity, and decreases the lipid peroxidation, protecting against fatty liver pathogenesis and fibrotic changes. Hepatitis B virus (HBV) affects millions of people worldwide, having sometimes a dramatic evolution to chronic aggressive infection, cirrhosis, and hepatocellular carcinoma. All up-to-date treatments are limited, there is still a gap in the scientific knowledge, and a sterilization cure may not yet be possible with the removal of both covalently closed circular DNA (cccDNA) and the embedded HBV DNA. With a maximum light absorption at 420 nm, the cytotoxicity of curcumin as photosensitizer could be expanded by the intravenous blue laser blood irradiation (IVBLBI) or photobiomodulation in patients with chronic hepatitis B infection, Hepatitis B e-antigen (HBeAg)-positive, noncirrhotic, but nonresponsive to classical therapy. Photobiomodulation increases DNA repair by the biosynthesis of complex molecules with antioxidant properties, the outset of repairing enzyme systems and new phospholipids for regenerating the cell membranes. UltraBioavailable Curcumin and blue laser photobiomodulation could suppress the virus and control better the disease by reducing inflammation/fibrosis and stopping the progression of chronic hepatitis, reversing fibrosis, and diminishing the progression of cirrhosis, and decreasing the incidence of hepatocellular carcinoma. Photodynamic therapy with blue light and curcumin opens new avenues for the effective prevention and cure of chronic liver infections and hepatocellular carcinoma. Blue laser light and UltraBioavailable Curcumin could be a new valuable alternative for medical applications in chronic B viral hepatitis and hepatocarcinoma, saving millions of lives.

The comparison of different antiviral therapies on the prognosis of hepatitis B virus-related hepatocellular carcinoma after curative treatments: A network meta-analysis

OBJECTIVE

The purpose of this study was to evaluate the efficacy of different nucleos(t)ide analogues in the prognosis of HBV-related hepatocellular carcinoma (HCC) patients after curative treatment by network meta-analysis.

METHODS

Literature retrieval was conducted in globally recognized databases, namely, PubMed, EMBASE, Cochrane Library databases, and Science Citation Index Expanded, to address relative studies investigating nucleot(s)ide analogues for HBV-related HCC patients after curative resection. Relative parametric data, including 1-, 3-, and 5-year overall survival rate and 1-, 3-, and 5-year recurrence-free survival rate were quantitatively pooled and estimated. The inconsistency factor, the cumulative ranking curve, and the publication bias were evaluated.

RESULTS

Fourteen observational studies of 2481 adults performed between 2000 and 2019 were eligible. In terms of overall survival, ADV (Adefovir dipivoxil) (Odds ratio (OR): 2.35, 95% confidence interval (CI): 1.17-4.73), Lamivudine (OR: 2.08, 95% CI: 1.78-5.58), and Entecavir (OR: 2.14, 95% CI: 1.59-2.88) were found to be more beneficial than control group while ADV has the highest probability of having the most efficacious treatment (SCURA values 66.3) for 5-year overall survival. In late recurrence-free survival, ADV (OR = 1.88, 95% CI: 1.77-4.60), Entecavir (OR = 1.96, 95% CI: 1.36-2.55), and Lamivudine (OR = 1.73, 95% CI: 1.06-2.82) all had better significant prognosis than patients without antiviral therapy postoperatively and patients with ADV as postoperative antiviral therapy has significantly recurrence-free survival benefit at 5-year follow-up compared to those undertaking Entecavir (OR = 1.96, 95% CI: 1.52-7.38) and Lamivudine (OR = 1.39, 95% CI: 1.09-3.01). Moreover, the application of ADV possessed the highest possibility of having the best clinical effects on 1- (surface under the cumulative ranking probabilities (SUCRA), 64.7), 3- (SUCRA, 64.7), and 5-year (SUCRA, 70.4) recurrence survival rate for HBV-related HCC patients.

CONCLUSIONS

Patients with postoperative nucleos(t)ide analogues antiviral therapy had better survival benefit than those without antiviral therapy for HBV-related HCC patients after curative treatment. Additionally, nucleotide analogues like ADV and Tenofovir disoproxil fumarate has better impact on early and late recurrence-free survival of patients after curative treatment than those undertaking nucleoside analogues.

Trends in chronic hepatitis B treatment-related research from 1973 to 2018: a bibliometric and visual analysis

OBJECTIVE

Chronic hepatitis B (CHB) is a worldwide disease and the most common cause of liver cancer. This study aimed to identify specific areas of research activity concerning CHB treatment between 1973 and 2018 and to aid in identifying new areas for future development.

METHODS

The literature was searched from the GoPubMed and Web of Science databases using terms related to CHB treatment, analyzed with bibliometric methods and visualized using VOSviewer.

RESULTS

A total of 9486 and 5883 papers were collected from PubMed and Web of science, respectively. The studies focused on two clusters of topics: antiviral therapy for CHB and progressive diseases, and drug resistance. Studies related to antiviral drugs concentrated on lamivudine (n = 788), entecavir (n = 390), and adefovir dipivoxil (n = 376). Studies addressing conditions developing from CHB highlighted hepatocellular carcinoma (n = 403) and cirrhosis (n = 223). China (n = 1978) contributed the most publications. The 10 most quantitatively prolific organizations were in France. All 20 of the most cited papers investigated antiviral treatments for CHB or CHB-associated cirrhosis.

CONCLUSIONS

Research on CHB treatment over the past 45 years has concentrated on antiviral therapy, CHB-associated progressive conditions, drug resistance and immunization. Although work on CHB treatment has made considerable progress, new approaches must be explored.

Establishment of stable cell lines in which the HBV genome replicates episomally for evaluation of antivirals

INTRODUCTION

Due to the increasing resistance to nucleot(s)ide analogs in patients with chronic hepatitis B, development of new antiviral drugs to eradicate hepatitis B virus is still urgently needed.

MATERIAL AND METHODS

To date, most studies on evaluating anti-HBV drugs have been performed using cell lines where the HBV genomic DNA is chromosomally integrated, e.g. Hep2.2.15 in HBV-infected livers of the viral episomal genome replicates in the nucleus and covalently closed circular DNA (cccDNA) serves as a transcriptional template. Another option involves the use of HBV-infected cells of HepaRG or NTCP-overexpressing cells. However, the development of the infection system is expensive and laborious, and its HBV expression level remained low.

RESULTS

Compared to HuH7 cells, the established stable cell lines based on episomal-type pEB-Multi vectors can been expressed HBV wild-type by qRT-PCR and immunoblotting (p < 0.05). These two vectors are also sensitive to Entecavir and against nucleoside analog Lamivudine in mutants cellines.

CONCLUSIONS

It is worth demonstrating how useful the established cell system is for evaluating antiviral agents and their mechanisms of action.

Hepatitis B Virus Infection: Overview

Hepatitis B virus (HBV) is a DNA virus, belonging to the Hepadnaviridae family. It is a partially double-stranded DNA virus with a small viral genome (3.2 kb). Chronic HBV infection remains a global public health problem. If left untreated, chronic HBV infection can progress to end-stage liver disease, such as liver cirrhosis and hepatocellular carcinoma (HCC). In recent years, tremendous advances in the field of HBV basic and clinical research have been achieved, ranging from the HBV biological characteristics, immunopathogenesis, and animal models to the development of new therapeutic strategies and new drugs against HBV. In this overview, we begin with a brief history of HBV discovery and treatment milestones. We then briefly summarize the HBV research advances, which will be detailed in the following chapters.

Tenofovir disoproxil fumarate monotherapy is superior to entecavir-adefovir combination therapy in patients with suboptimal response to lamivudine-adefovir therapy for nucleoside-resistant HBV: a 96-week prospective multicentre trial

BACKGROUND

A complete virological response is closely related to the long-term outcome of patients with chronic hepatitis B and prevention of emerging HBV mutations. We aimed to evaluate the efficacy of tenofovir disoproxil fumarate (TDF) monotherapy compared to entecavir-adefovir dipivoxil (ETV-ADV) combination therapy in patients with suboptimal responses to long-term lamivudine-adefovir dipivoxil (LAM-ADV) therapy for nucleoside analogue-resistant chronic hepatitis B.

METHODS

Patients (n=60) were randomized to TDF monotherapy or ETV-ADV combination therapy for 96 weeks. All patients had the rt204I/V mutation and serum HBV DNA was measured (>60 IU/ml) during LAM-ADV therapy. The primary end point was a complete virological response (HBV DNA <20 IU/ml) at week 96.

RESULTS

The median duration of prior LAM-ADV rescue therapy was 43 (7-108) months. A complete virological response was achieved in 86.6% and 53.3% of patients in the TDF and ETV-ADV groups, respectively, at week 96 (P=0.005). Reduction in serum HBV DNA was significantly greater in the TDF group than in ETV-ADV group (-3.2 ±1.2 versus -2.6 ±1.2; P=0.01). Hepatitis B e antigen loss (22.2% versus 16.6%; P=0.731) and biochemical responses (76.7% versus 73.3%; P=0.766) were not different between the TDF and ETV-ADV groups. No newly emerged mutations were detected. Both therapies demonstrated favourable safety profiles.

CONCLUSIONS

TDF therapy achieved a better complete virological response than ETV-ADV therapy in chronic hepatitis B patients with suboptimal response to long-term LAM-ADV rescue therapy. (KCT0000627).

Risk factors for resistance development against lamivudine during long-term treatment of chronic hepatitis B virus infections

BACKGROUND/AIM

The use of lamivudine for the treatment of chronic hepatitis B (CHB) is limited by high rates of lamivudine resistance. However, it is still in use in many regions. Factors associated with lamivudine resistance development have been studied in only a few European cohorts. The aim of our study was to assess the rate and risk factors for lamivudine resistance in a large real-life European cohort.

PATIENTS AND METHODS

We retrospectively analyzed patients with CHB treated in three German University centers over up to 12 years. Lamivudine resistance was defined as virologic breakthrough and presence of genotypic lamivudine resistance. The probability of resistance was estimated by Kaplan-Meier analysis and resistance predictors by Cox regression.

RESULTS

A total of 227 patients were included into the analysis (hepatitis B envelope antigen positive or negative). Rates of lamivudine resistance by years 1-7 were 7, 26, 35, 41, 46, 53, and 55%, respectively. Interestingly, two hepatitis B envelope antigen-negative patients developed resistance during the year 12 of treatment. Independent risk factors for resistance development were hepatitis B virus DNA levels of at least 10 copies/ml before and detectable hepatitis B virus DNA by month 6 of treatment.

CONCLUSION

Even after long-term response to lamivudine more than 10 years, resistance may still develop. Our findings further discourage the use of lamivudine for the treatment of CHB.

Long-term Efficacy of Tenofovir Disoproxil Fumarate Monotherapy for Multidrug-Resistant Chronic HBV infection

BACKGROUND & AIMS

There are no globally agreed upon treatment guidelines for patients with chronic hepatitis B virus (HBV) with multidrug resistance (MDR). We conducted a multicenter, prospective, real-world cohort study of effects of tenofovir disoproxyl fumarate (TDF) monotherapy and TDF-based combination therapy, as rescue therapy, in patients with multidrug-resistant chronic HBV infections.

METHODS

We recruited patients with chronic HBV infection with resistance to antivirals from 8 tertiary hospitals in Korea. Patients (n=423) received rescue therapy with TDF monotherapy (n=174) or TDF-based combination therapy (n=249). The median follow-up period was 180 weeks. A virologic response was defined as a serum HBV DNA level of <20 IU/mL.

RESULTS

Cumulative rates of virologic response did not differ significantly between the groups that received TDF monotherapy vs combination therapy at 48 weeks (71.7% vs 68.9%), 96 weeks (85.1% vs 84.2%), 144 weeks (92.1% vs 92.7%), 192 weeks (93.4% vs 95.7%), or 240 weeks (97.7% vs 97.2%). Serum levels of HBV DNA below 4.0 log₁₀ IU/mL (odds ratio, 2.478; 95% CI 1.959-3.135; P < .001) and the absence of mutations associated with resistance to adefovir (odds ratio, 1.570; 95% CI 1.279-1.926; P < .001) were associated with virologic response in patients with MDR. There was no significant difference of virologic response among patients of different ages, sex, patients with vs without cirrhosis, positivity for hepatitis B e antigen, or renal function (all P > .05).

CONCLUSION

In a multicenter, real-world cohort study, long-term use of TDF monotherapy showed non-inferior antiviral efficacy compared with that of TDF-based combination therapy in patients with MDR.

Current progress in the prevention of mother-to-child transmission of hepatitis B and resulting clinical and programmatic implications

There is currently no cure for hepatitis B chronic infections. Because new hepatitis B infections result mainly from perinatal transmission, preventing mother-to-child transmission is essential to reach by 2030 the goal of hepatitis B elimination set by the World Health Organization. The universal administration of hepatitis B vaccine to all infants, regardless of maternal status, starting with the birth dose, is the cornerstone of the strategy for elimination. Additional interventions, such as hepatitis B immune globulin administered to newborns and antiviral prophylaxis administered to hepatitis B infected pregnant women, may contribute to reaching the goal earlier. Hepatitis B immune globulin may remain out for reach of many pregnant women in low- and middle-income countries due to cost and logistic issues, but antivirals are cheap and do not require a cold chain for distribution. However, it has been observed that some viruses harbor mutations associated with escape from vaccine-elicited antibodies following immunization or administration of hepatitis B immune globulin. Also, resistance associated mutations have been described for several drugs used for treatment of hepatitis B infected patients as well as for the prevention of mother-to-child transmission. Whether these mutations have the potential to compromise the prevention of mother-to-child transmission or future treatment of the mother is a question of importance. We propose a review of important recent studies assessing tenofovir disoproxil fumarate for the prevention of mother-to-child transmission, and provides detailed information on the mutations possibly relevant in this setting.

Is Combination Antiviral Therapy Mandatory for Maintenance Therapy in Fully Suppressed Multidrug-Resistant Hepatitis B Patients?

Aim

The efficacy of tenofovir disoproxil fumarate (TDF) monotherapy as maintenance therapy in multidrug-resistant (MDR) hepatitis B virus (HBV) patients after complete virologic suppression (CVS) has not been well evaluated. We evaluated the efficacy of maintenance TDF monotherapy compared with conventional TDF plus entecavir combination therapy after CVS of MDR HBV.

Methods

In this single-center retrospective study, patients with MDR HBV who were previously treated with entecavir plus TDF combination therapy and achieved CVS were included. Patients were either maintained on entecavir plus TDF combination therapy or switched to TDF monotherapy after CVS. The primary endpoint was the virologic breakthrough, and secondary outcomes were liver cirrhosis (LC) or hepatocellular carcinoma (HCC) development. To overcome immortal time bias, time-varying Cox proportional hazard regression analysis was performed.

Results

A total of 201 patients were included, and 153 patients were maintained on entecavir plus TDF combination therapy (combination group); 48 patients were converted from combination therapy to TDF monotherapy (single group) after CVS. Five patients experienced a virologic breakthrough, one patient in the single group owing to poor transient compliance and four patients in the combination group (P = 0.51). One new case of LC developed in the single group; five cases of LC developed in the combination group (P = 0.35). No new HCC development occurred in the single group, while seven cases of HCC developments were noted in the combination group. However, these results were not statistically significant (P = 0.54).

Conclusions

For patients with suppressed HBV DNA, the efficacy of TDF monotherapy as maintenance therapy is comparable to that of entecavir plus TDF combination therapy.

Variable access to antiviral treatment of chronic hepatitis B in Canada: a descriptive study

BACKGROUND

Antiviral treatment for chronic hepatitis B is costly, which presents challenges for universal drug coverage for the estimated 480 000 people with the disease in Canada. We appraised criteria for reimbursement of chronic hepatitis B antivirals by public drug plans in Canada.

METHODS

In this descriptive study, we reviewed the reimbursement criteria for lamivudine, adefovir, tenofovir, entecavir, telbivudine, pegylated or standard interferon, and emtricitabine-tenofovir in the 10 provinces and the Yukon Territory as well as 3 federal programs: Correctional Services Canada, Veterans' Affairs and the Non-Insured Health Benefits Program. We extracted data from publicly available formularies. The primary outcomes extracted were prescriber details, reimbursement regulations and published list price.

RESULTS

All public drug insurance plans limit access to antiviral treatment in patients with chronic hepatitis B based on viral characteristics, fibrosis stage and/or specialist approval. Lamivudine use is restricted only in British Columbia and Ontario. Six plans (43%) cover entecavir or tenofovir with no restriction, and 8 plans (57%) cover these agents if patients have advanced fibrosis/cirrhosis. Nine plans (64%) provide coverage of interferon, although 4 of these programs reimburse only nonpegylated interferon, which is not currently recommended for chronic hepatitis B treatment.

INTERPRETATION

We found substantial variability among jurisdictions in reimbursement criteria for the treatment of chronic hepatitis B in Canada. The findings can inform health policy and support the development and adoption of a national chronic hepatitis B strategy to ensure equitable and timely access to treatment no matter where patients reside in Canada.

Management of Hepatitis B Virus Infection: 2018 Guidelines from the Canadian Association for the Study of Liver Disease and Association of Medical Microbiology and Infectious Disease Canada

Hepatitis B virus (HBV) infection is an important public health problem in Canada. In keeping with evolving evidence and understanding of HBV pathogenesis, the Canadian Association for the Study of Liver Disease periodically publishes HBV management guidelines. The goals of the 2018 guidelines are to (1) highlight the public health impact of HBV infection in Canada and the need to improve diagnosis and linkage to care, (2) recommend current best-practice guidelines for treatment of HBV, (3) summarize the key HBV laboratory diagnostic tests, and (4) review evidence on HBV management in special patient populations and include more detail on management of HBV in pediatric populations. An overview of novel HBV tests and therapies for HBV in development is provided to highlight the recent advances in HBV clinical research. The aim and scope of these guidelines are to serve as an up-to-date, comprehensive resource for Canadian health care providers in the management of HBV infection.

Interferon-based treatment is superior to nucleos(t)ide analog in reducing HBV-related hepatocellular carcinoma for chronic hepatitis B patients at high risk

BACKGROUND

The effect of nucleos(t)ide analogs (NAs) versus interferon (IFN) on the occurrence of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) is controversial. We assessed whether antiviral strategy affected HCC development in CHB patients at different HCC risks.

METHODS

1112 CHB patients with antiviral therapy were included in this retrospective study. Patients treated with NAs only were classified into NAs group (n = 682) while those received IFN treatment with or without NAs were defined as IFN group (n = 430). Propensity score matching (PSM) was applied to minimize baseline differences.

RESULTS

Totally, 31 patients developed HCC during follow-up (median 5.41 years). The cumulative HCC incidence at 10 years was significantly lower in the IFN group than NAs group (2.7% vs 8.0%, p < 0.001). Similar results were obtained in the PSM-cohort. Patients with IFN-based treatment were less likely to develop HCC than those with NAs (Hazard ratio = 0.15; 95% CI 0.04-0.66; p = 0.012). Subgroup analyses demonstrated that this superiority of IFN in reducing HCC development was obvious in patients at high- but not low-risk of HCC.

CONCLUSIONS

Reduction of HCC development was more significant in CHB patients at higher HCC risk with IFN-based therapy than NAs treatment.

Lamivudine plus tenofovir combination therapy versus lamivudine monotherapy for HBV/HIV coinfection: a meta-analysis

BACKGROUND

Currently, there is no consensus on the efficacy and safety of lamivudine (LAM) plus tenofovir disoproxil fumarate (TDF) combination therapy versus lamivudine monotherapy in HBV/HIV coinfected patients.

METHODS

A comprehensive literature search was performed in English and Chinese databases. Both relevant dichotomous and continuous variables were extracted, and the combined outcomes were expressed as a risk ratio (RR) or a standard mean difference (SMD).

RESULTS

Eleven eligible studies were included in our analysis. For HBV-relevant outcomes, the proportion of patients with undetectable HBV, the rates of serum alanine aminotransferase (ALT) normalization and hepatitis B e antigen (HBeAg) loss were higher in the combination therapy group than the monotherapy group (RR = 1.42, 95% CI: 1.14-1.76, P = 0.002; RR = 1.36, 95% CI: 1.17-1.58, P < 0.0001; RR = 2.74, 95% CI: 1.20-6.22, P = 0.02). In addition, the rate of HIV RNA-negative conversion was higher in the combination therapy group than the monotherapy group (RR = 1.26, 95% CI: 1.11-1.42, P = 0.0003).

CONCLUSION

LAM plus TDF combination therapy was more efficacious than LAM monotherapy in HBV/HIV coinfected patients. As time passes, this difference becomes more pronounced.

Immune-escape mutations and stop-codons in HBsAg develop in a large proportion of patients with chronic HBV infection exposed to anti-HBV drugs in Europe

Background

HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe.

Methods

This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence.

The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence.

Results

At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32–3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by analysing drug-naïve patients (29.5% vs 21.2%, P = 0.032). Strong correlation was observed between sP120T and rtM204I/V (P < 0.001), and their co-presence determined an increased HBV-DNA.

At least one NA-induced immune-escape mutation occurred in 28.6% of patients, and their selection correlated with genotype-A (OR[95%CI]:2.03[1.32–3.10],P = 0.001).

Finally, stop-codons are present in 8.4% of patients also at HBsAg-positions 172 and 182, described to enhance viral oncogenic-properties.

Conclusions

Immune-escape mutations and stop-codons develop in a large fraction of NA-exposed patients from Europe. This may represent a potential threat for horizontal and vertical HBV transmission also to vaccinated persons, and fuel drug-resistance emergence.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3161-2) contains supplementary material, which is available to authorized users.

Trends in hepatitis B virus resistance to nucleoside/nucleotide analogues in North China from 2009-2016: A retrospective study

Nucleos(t)ide analogues (NAs) are widely used in anti-hepatitis B virus (anti-HBV) therapy for effective inhibition of HBV replication. However, HBV resistance to NAs has emerged, resulting in virus reactivation and disease recurrence. Data on the current dynamics of HBV resistance are still rare in China. This study analysed 4491 plasma samples with HBV primary genotypic resistance mutations representative of the general HBV resistance situation in northern China from 2009-2016. We found that entecavir (ETV), representing 57.6% (12 713/22 060) of NA users in North China in 2016, has become the major NA for treating Chinese patients infected with HBV. Despite >50% of M204I/V±L180M among all HBV resistance cases annually and extensive exposure of patients to lamivudine (LAM), telbivudine (LdT) and adefovir dipivoxil (ADV), ETV resistance also showed a dramatically increased incidence, which rose to 17.1% in 2016. Moreover, A181T/V, ETV resistance mutations and multidrug resistance mutations were found more frequently in HBV genotype C compared with genotype B (21.2% vs. 8.5%, 12.4% vs. 7.9% and 5.9% vs. 3.0%, respectively), whereas M204I and N236T were more predominant in genotype B than genotype C (40.3% vs. 20.8% and 11.3% vs. 1.8%, respectively). In conclusion, we report the dynamic changes of HBV NA resistance mutation patterns and the current NA usage profile for anti-HBV treatment in North China over the past 8 years. These data provide valuable information on HBV NA resistance that is an important reference for clinicians to devise more effective treatment regimens for individual patients.

Efficacy and Safety of Entecavir 0. 5 mg in Treating Naive Chronic Hepatitis B Virus Patients in Egypt: Five Years of Real Life Experience

Background

The aim of the study was to evaluate the efficacy and safety of entecavir (ETV) among chronic hepatitis B (CHB) nucleos(t)ide-naive Egyptian patients.

Methods

Forty-eight CHB patients on ETV were included. Males comprised 83.3% (40 cases), while females comprised 16.7% (eight cases). Minimum age was 19 years, while maximum age was 64 years. Hepatitis B envelope antigen (HBeAg)-negative cases were 60.4%. HBeAg-positive cases were 39.6%. Factors including sex, positive HBeAg, baseline hepatitis B virus (HBV) DNA level, baseline alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were evaluated in terms of their predictive role in treatment response, which was defined as a serum HBV DNA decrease of < 10 IU/mL.

Results

Mean age of patients was 38.2 years; males were 83.3% and females were 16.7%. HBeAg-negative cases were 60.4%, while HBeAg-positive cases were 39.6%. Mean baseline DNA level was 44 × 10⁶ IU/mL. Ultrasound results showed 14 cases had hepatomegaly, 10 cases had bright liver, seven cases had coarse liver, and eight cases had cirrhosis. Of the cases, 45.8% showed a negative PCR after the first 6 months of therapy to reach 64.6% by the end of the first year. HBV DNA undetectability reached 91.3% and 100% after 4 and 5 years, respectively for those who completed the study period. ALT reduction started after 6 months of treatment and reached 53.37% after 5 years. Similarly AST showed the same pattern of decline and reached 54.37% after 5 years. Only two cases achieved HBeAg seroconversion. Three patients experienced virological breakthrough and the three cases shared similar characteristics of being less than 40 years, with baseline HBV DNA of ≥ 10⁵ IU/mL and positive HBeAg. None of the cases showed hepatitis B surface antigen (HBsAg) seroconversion.

Conclusion

ETV proved to have a potent antiviral efficacy and safety in nucleoside/tide-naive Egyptian patients. Rate of HBV DNA undetectability was higher in patients above 40 years of age and in patients who initially had a low viral load. ETV was well tolerated during the treatment period with a good overall safety profile.

Hypophosphatemia predicts a failure to recover from adefovir-related renal injury after dose reduction in lamivudine-resistant hepatitis B patients

AIM

In chronic hepatitis B patients receiving 10 mg adefovir, dose reduction is recommended when renal injury appears. However, recovery is not always achieved and markers that recommend switching to another antiviral agent are unknown. We investigated adefovir-related renal injury, recovery after dose reduction, and their predictors.

METHODS

The renal injury in 77 chronic hepatitis B patients receiving 10 mg adefovir and recovery after dose reduction to alternate day administration in those with adefovir-related renal injury were assessed. The predictors for >20% estimated glomerular filtration rate (eGFR) decline following treatment with 10 mg adefovir and for >20% eGFR recovery after dose reduction were investigated.

RESULTS

The adefovir dose was reduced in 26 patients (34%) at 59 ± 30 (mean ± standard deviation) months of 10 mg adefovir treatment because of decreases in eGFR (cumulative incidence 27%), serum phosphorus (9%), and uric acid (16%) levels, and increases in alkaline phosphatase (20%), bone type alkaline phosphatase (18%), urinary α1-microglobulin (18%), and urinary N-acetyl-β-D-glucosaminidase (18%) levels. The only significant predictor for >20% eGFR decline was age ≥50 years at the start of 10 mg adefovir treatment. The cumulative eGFR recovery rate was 42% at 42 ± 27 months after dose reduction, and ≥2.5 mg/dL serum phosphorus level at dose reduction was the only significant predictor for >20% eGFR recovery after dose reduction.

CONCLUSION

Patients aged ≥50 years are predisposed to adefovir-related renal injury and switching to another antiviral agent rather than adefovir dose reduction is recommended when hypophosphatemia is observed.

Efficacy and safety of entecavir versus lamivudine over 5 years of treatment: A randomized controlled trial in Korean patients with hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND/AIMS

Long-term data on antiviral therapy in Korean patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) are limited. This study evaluated the efficacy and safety of entecavir (ETV) and lamivudine (LAM) over 240 weeks.

METHODS

Treatment-naive patients with HBeAg-negative CHB were randomized to receive ETV 0.5 mg/day or LAM 100 mg/day during the 96 week double-blind phase, followed by open-label treatment through week 240. The primary endpoint was the proportion of patients with virologic response (VR; hepatitis B virus [HBV] DNA<300 copies/mL) at week 24. Secondary objectives included alanine aminotransferase (ALT) normalization and emergence of ETV resistance (week 96), VR and log reduction in HBV DNA levels (week 240), and safety evaluation.

RESULTS

In total, 120 patients (>16 years old) were included (ETV, n=56; LAM, n=64). Baseline characteristics were comparable between the two groups. A significantly higher proportion of ETV-treated patients achieved VR compared to LAM at week 24 (92.9% vs. 67.2%, P=0.0006), week 96 (94.6% vs. 48.4%, P<0.0001), and week 240 (95.0% vs. 47.6%, P<0.0001). At week 96, ALT normalization was observed in 87.5% and 51.6% of ETV and LAM patients, respectively (P<0.0001). Virologic breakthrough occurred in one patient (1.8%) receiving ETV and 26 patients (42.6%) receiving LAM (P<0.0001) up to week 96. Emergence of resistance to ETV was not detected. The incidence of serious adverse events was low and unrelated to the study medications.

CONCLUSIONS

Long-term ETV treatment was superior to LAM, with a significantly higher proportion of patients achieving VR. Both treatments were well tolerated.

Hepatitis B virus reactivation in breast cancer patients undergoing chemotherapy: A review and meta-analysis of prophylaxis management

Hepatitis B virus (HBV) reactivation during or after chemotherapy in patients with breast cancer has become a remarkable clinical problem. Prophylactic nucleos(t)ide analogues (NAs) are recommended for patients with breast cancer who are hepatitis B surface antigen (HBsAg) positive before chemotherapy. We performed an up-to-date meta-analysis to compare the efficacy of prophylactic lamivudine use with nonprophylaxis in HBsAg-positive breast cancer patients undergoing chemotherapy. PubMed, the Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched for relevant articles until June 2016. Eligible articles comparing the efficacy of prophylactic lamivudine use with nonprophylaxis in HBsAg-positive breast cancer patients undergoing chemotherapy were identified. Eight studies which had enrolled 709 HBsAg-positive breast cancer patients undergoing chemotherapy were analysed. Lamivudine prophylaxis significantly reduced the rates of chemotherapy-associated hepatitis B flares in chronic hepatitis B in breast cancer compared with patients with nonprophylaxis (odds ratio [OR]=0.15, 95% confidence interval [CI]: 0.07-0.35, P<.00001). Chemotherapy disruption rates attributed to HBV reactivation in the prophylaxis groups were significantly lower than the nonprophylaxis groups (OR=0.17, 95% CI: 0.07-0.43, P=.0002). Patients with lamivudine prophylaxis had a higher risk for tyrosine-methionine-aspartate-aspartate (YMDD) motif mutations than patients with nonprophylaxis (OR=6.33, 95% CI: 1.01-39.60, P=.05). Prophylactic antiviral therapy management is necessary for HBsAg-positive breast cancer patients undergoing chemotherapy, in spite of high correlation with lamivudine-resistant HBV variants with YMDD motif mutations.

The virological aspects of hepatitis B

Human hepatitis B virus (HBV) is a hepatotropic virus that is responsible for a significant burden of disease, causing liver disease and hepatocellular carcinoma. It is a small DNA virus with a replication strategy that is similar to that of a retrovirus. HBV is prone to mutagenesis and under the influence of diverse selection pressures, has evolved into a pool of quasispecies, genotypes and mutants, which confers a significant survival advantage. The genome is small, circular, and compact but has a complex replication strategy. The viral life cycle involves the formation of a covalently closed circular DNA (cccDNA), which is organized into a minichromosome that is the template for the synthesis of viral mRNA. HBV DNA (double-stranded linear form) can also integrate into the host genome, ensuring lifelong persistence of the virus. To date, despite great advances in therapeutics, once HBV is chronically established, it is incurable. This is by virtue of many aspects of its virological structure and viral life cycle. In this review, we aim to discuss important aspects of the virology of HBV with a focus on clinical implications.

Optimization and Synthesis of Pyridazinone Derivatives as Novel Inhibitors of Hepatitis B Virus by Inducing Genome-free Capsid Formation

The capsid of hepatitis B virus (HBV) plays a vital role in virus DNA replication. Targeting nucleocapsid function has been demonstrated as an effective approach for anti-HBV drug development. A high-throughput screening and mechanism study revealed the hit compound 4a as an HBV assembly effector (AEf), which could inhibit HBV replication by inducing the formation of HBV DNA-free capsids. The subsequent SAR study and drug-like optimization resulted in the discovery of the lead candidate 4r, with potent antiviral activity (IC₅₀ = 0.087 ± 0.002 μM), low cytotoxicity (CC₅₀ = 90.6 ± 2.06 μM), sensitivity to nucleoside analogue-resistant HBV mutants, and synergistic effect with nucleoside analogues in HepG2.2.15 cells.

[Efficacy of tenofovir-based rescue therapy for patients with drug-resistant chronic hepatitis B]

BACKGROUND/AIMS

Tenofovir disoproxil fumarate (TDF) plays a pivotal role in the management of drug-resistant chronic hepatitis B. However, it remains unclear whether TDF-nucleoside analogue combination therapy provides better outcomes than TDF monotherapy. This study aimed to compare the efficacy of TDF monotherapy with that of TDF-nucleoside analogue combination therapy in patients with drug-resistant chronic hepatitis B.

METHODS

This retrospective cohort study included 76 patients receiving TDF-based rescue therapy for more than 12 months. Suboptimal response was defined as serum HBV-DNA level of > 60 IU/mL during prior rescue therapy. Multi-drug resistance was defined as the presence of two or more drug resistance-related mutations confirmed by mutation detection assay. The relationship between baseline characteristics and virologic response (HBV DNA < 20 IU/mL) at 12 months were evaluated using logistic regression analysis.

RESULTS

Fifty-five patients (72.4%) were suboptimal responders to prior rescue therapy, and 26 (34.2%) had multi-drug resistance. Forty-two patients (55.3%) received combination therapy with nucleoside analogues. Virologic response at 12 months was not significantly different between the TDF monotherapy group and TDF-nucleoside analogue combination therapy group (p = 0.098). The serum HBV DNA level was reduced to -4.49 ± 1.67 log10 IU/mL in the TDF monotherapy group and to -3.97 ± 1.69 log10 IU/mL in the TDF-nucleoside analogue combination therapy group at 12 months (p = 0.18). In multivariate analysis, female sex (p = 0.032), low baseline HBV-DNA level (p = 0.013), and TDF monotherapy (p = 0.046) were predictive factors for virologic response at 12 months.

CONCLUSIONS

TDF monotherapy showed similar efficacy to that of TDF-nucleoside analogue combination therapy in patients with drug-resistant chronic hepatitis B.

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.

Efficacy of switching from adefovir to tenofovir in chronic hepatitis B patients who exhibit suboptimal responses to adefovir-based combination rescue therapy due to resistance to nucleoside analogues (SATIS study)

Background/Aims

It remains to be determined whether switching from adefovir (ADV) to tenofovir (TDF) provides better virological outcomes in patients exhibiting suboptimal responses to ADV plus nucleoside analogue (ADV+NA) therapy for NA-resistant chronic hepatitis B (CHB).

Methods

In this prospective trial, patients who showed partial responses (defined as serum hepatitis B virus [HBV] DNA >60 IU/mL) to ADV+NA therapy for NA resistance were randomly allocated to receive TDF plus NA (TDF+NA group, n=16) or to continue their current therapy (ADV+NA group, n=16). The primary end point was the proportion of patients with complete virological response (CVR, defined as serum HBV DNA <60 IU/mL) at 48 weeks.

Results

The median age was 52 years (16 men), and 28 were positive for hepatitis B e antigen (HBeAg). The baseline characteristics did not differ significantly between the two groups. The proportion with CVR was significantly higher in the TDF+NA group than in the ADV+NA group at 24 weeks (81.3% vs. 25.0%, P=0.001) and 48 weeks (87.5% vs. 37.5%, P=0.002). Furthermore, a decrease in the serum HBV DNA level of >2log₁₀ IU/mL was more likely in the TDF+NA group at both 24 and 48 weeks (68.8% vs. 56.3%, P=0.014 vs. 81.3% vs. 56.3%, P=0.001, respectively). During the follow-up, the rate of HBeAg seroconversion was higher in the TDF+NA group than the ADV+NA group (12.5% vs. 6.25%, P=0.640), as was that for the hepatitis B surface antigen (6.25% vs. 0%, P=0.080). No serious adverse events due to antiviral agents occurred.

Conclusion

In patients exhibiting suboptimal responses to ADV+NA therapy for NA-resistant CHB, switching from ADV to TDF might provide better virological outcomes.

The Effect of Prophylactic Lamivudine plus Adefovir Therapy Compared with Lamivudine Alone in Preventing Hepatitis B Reactivation in Lymphoma Patients with High Baseline HBV DNA during Chemotherapy

Prophylactic antiviral therapy is essential for lymphoma patients with high baseline HBV DNA who undergo cytotoxic chemotherapy. However, there are limited data on the optimal options. The present study was designed to compare the efficacy of prophylactic lamivudine (LAM) with lamivudine plus adefovir dipivoxil (LAM+ADV) in preventing hepatitis B virus (HBV) reactivation in lymphoma with, pre-chemotherapy HBV DNA load ≥2000 IU/ml. We retrospectively analyzed the medical records of 86 lymphoma patients with baseline HBV DNA load ≥2000 IU/ml during chemotherapy and received LAM or LAM+ADV as prophylaxis between January 1, 2008 and November 30, 2014 at Sun Yat-sen University Cancer Center, China. Sixty-five patients received LAM and 21 received LAM+ADV. The rate was significantly lower in the LAM+ADV group compared with the LAM group for HBV reactivation (23.8% vs 55.4%; p = 0.012), while no difference was observed between the two groups in patients for HBV-related hepatitis (21.3% vs 33.3%; p   =  0.349), and chemotherapy disruption (10.9% vs 19.0%; p = 0.337). In a multivariate analysis of factors associated with HBV reactivation in these patients, LAM+ADV treatment and HBeAg negative were the independent protective factors. Therefore, LAM+ADV should be considered for antiviral prophylaxis in lymphoma patients with pre-chemotherapy HBV DNA load ≥2000 IU/ml. Further study is warranted to confirm these findings.

Treatment for hepatitis B in patients with drug resistance

Persistent hepatitis B virus (HBV) infections affect about 240 million patients worldwide that are at risk of developing liver cirrhosis or hepatocellular carcinoma. HBV is a small, partially double stranded DNA virus with four overlapping genes and a unique life cycle, which involves the generation of an RNA template for replication via reverse transcription. Mutations occur frequently during chronic infection, and particular selection pressures select distinct mutants. Nucleoside and nucleotide analogues like lamivudine (LMV), entecavir (ETV), telbivudine (LdT), adefovir dipivoxil (ADV) and tenofovir (TDF) are used to achieve long-term suppression of viral replication. Importantly, these drugs have different barriers to resistance, explaining the higher incidence of treatment failure in the past due to drug resistant viral strains for the older compounds LMV, LdT and ADV. On a molecular level, drug resistant mutations usually affect the reverse transcriptase domain of the HBV polymerase protein. Secondary compensatory mutations restore the replication fitness of the mutant virus. From a clinical point of view, patients undergoing antiviral therapy require regular testing for HBV DNA (every 3-6 months). In case of insufficient viral suppression or viral breakthrough (>1 log increase in HBV DNA above nadir), strict adherence to therapy needs to be ensured. If drug resistance is suspected or even molecularly confirmed, rescue therapy strategies exist, usually switching to a noncross-resistant antiviral drug. LMV, LdT and ETV resistant HBV can be treated with TDF monotherapy, ADV resistance with ETV or TDF, and insufficient responses to TDF may require ETV either as mono- or combination therapy. Complex treatment histories with many antivirals may sometimes necessitate the combination of highly effective antivirals like ETV and TDF. Novel treatment targets such as core (capsid) inhibitors, siRNA targeting protein translation, entry inhibitors or immune modulators aim at improving the efficacy of antivirals in order to (functionally) cure hepatitis B.

Mutational analysis of reverse transcriptase and surface proteins of patients with partial virological response during mono and combination antiviral therapies in genotype D chronic hepatitis B

Introduction

The mutational pattern of chronic Hepatitis B virus (HBV) is unclear in patients who show incomplete response to antiviral therapy. The aims of this study were 1) to determine the benefit of combination therapy with adefovir dipivoxil (ADV) and Lamivudine (LAM) versus ADV or LAM alone in maintaining virological, biochemical and histological responses and 2) to investigate the patterns of mutations in the reverse transcriptase and surface proteins of HBV with LAM and/or ADF-resistant in partially-responded chronic hepatitis B (CHB) patients.

Methods

The study group consisted of 186 chronic HBV carriers who were admitted to the Tehran Hepatitis Network from 2010 to 2013. We retrospectively selected 86 patients who partially responded to different nucleoside analogue regimens. After 48 weeks of therapy, five groups of patients were defined including eight Lamivudine (LAM) Group (I), 30 Adefovir (ADV) Group (II), 16 ADV add on LAM Group (III), 32 ADV+LAM Group (IV), and 100 controls (no therapy). Reverse transcriptase (RT) and surface genes were amplified and sequenced for mutational analysis.

Results

All groups showed differences between mean values for age, gender, alanine transaminase (ALT), aspartate transaminase (AST), and HBV DNA levels groups showed significant differences than other groups (p < 0.05). The mutation frequencies for groups were I (1.7%), II (1.39%), III (2.28%), IV (2.0%), and V (0.38%). T54N, L80I/V, I91L/V, L180M, M204I/V, Q215P/S, and F221Y/S showed the highest number of mutations in all groups with different frequencies. Four new, unreported mutations were found.

Conclusion

Those patients who failed to respond in the first 48 weeks, whether they were receiving mono or combination therapy, should be tested genotypically, for the early modification of treatment.

Long-Term Efficacy of Tenofovir Disoproxil Fumarate Therapy in Nucleos(t)ide-Experienced Chronic Hepatitis B Patients

BACKGROUND AND OBJECTIVES

Tenofovir disoproxil fumarate (TDF) therapy is a therapeutic option for nucleos(t)ide analogue (NA)-experienced chronic hepatitis B (CHB) patients infected with hepatitis B virus (HBV). In this study, we evaluated the efficacy of TDF alone compared with the efficacy of TDF plus additional NA combinations in NA-experienced CHB patients.

METHODS

This retrospective cohort study included 108 patients with a serum HBV DNA level above 5.0 log10 IU/ml who were treated with TDF alone (monotherapy group) or TDF combined with additional NAs (combination therapy group) for 30 months.

RESULTS

At month 30, both therapies resulted in the suppression of HBV DNA levels: 66 of 66 patients (100 %) in the monotherapy group and 40 of 42 patients (95.23 %) in the combination therapy group achieved virologic suppression. Kaplan-Meier curves revealed median times for virologic suppression of 3.12 months in the monotherapy group and 5.23 months in the combination therapy group (p = 0.699). The probability of virologic suppression was comparable between treatment groups. At month 6, more patients achieved normal alanine aminotransferase (ALT) levels in the monotherapy group (p = 0.029). During the treatment period, no patients experienced severe renal dysfunction.

CONCLUSION

TDF monotherapy and TDF plus additional NAs have comparable antiviral efficacy in CHB patients after NA treatment failure.

Lamivudine-resistant rtL180M and rtM204I/V are persistently dominant during combination rescue therapy with entecavir and adefovir for hepatitis B

Adefovir (ADV) sequential monotherapy was included in the 2005 Asia-Pacific guidelines for the management of patients with lamivudine (LAM) resistance. However, following the development of ADV resistance, the proportion of resistant variants during combined rescue therapy with ADV and entecavir (ETV) were unknown. The present study characterized the dynamics of resistant variants in patients with chronic hepatitis B (CHB) and LAM-resistant variants during antiviral therapy consisting of ADV monotherapy followed by ADV-ETV combination therapy. A total of 3 patients were selected from a cohort of 55 patients with CHB due to developing ADV resistance. The patients had been previously treated with LAM (100 mg daily) for 21–24 months. At the initiation of sequential monotherapy with ADV, LAM-resistant variants (rtM204V/I and rtL180M) were detected in the three patients. These patients developed ADV resistance during 19–30 months of ADV sequential monotherapy, and then switched their antiviral regimen to ADV-ETV combination therapy. During ADV monotherapy and ADV-ETV combination therapy, the patients were monitored every 3 months for the first year of therapy, and then every 6 months thereafter. A total of 30 serum samples were collected from the patients throughout the monitoring period. In total, 10 mutants that were associated with commonly-used antiviral drugs were detected by pyrosequencing. During ADV sequential monotherapy, LAM-resistant variants were gradually decreased, whereas ADV-resistant rtA181V/T and rtN236T variants gradually increased in the viral population. During 30–41 months of ADV-ETV combination therapy, viral load reduction was 2.59–3.28 log₁₀ copies/ml; ADV-resistant variants rtA181T/V and rtN236T were undetectable following 11–24 months of combination therapy; and rtL180M and rtM204I/V remained dominant in the viral population. In conclusion, the results of the present study suggested that, in patients with LAM and ADV-resistant variants that developed during LAM-ADV sequential monotherapy, ETV-ADV combination therapy may partially inhibit the replication of HBV DNA; however, LAM-resistant rtL180M and rtM204I/V variants remained predominant following 30–41 months combination therapy.

A 96-week randomized trial of switching to entecavir in patients who achieved virological suppression on lamivudine therapy

BACKGROUND AND AIM

There are limited data assessing whether patients who achieved virological suppression on lamivudine but remain hepatitis B "e" antigen-positive should be switched to a more potent antiviral with a high genetic barrier to resistance or continue with lamivudine. We compared the safety and efficacy of switching with entecavir versus continuing lamivudine.

METHODS

This was a Phase IV, randomized, open-label, prospective study in a tertiary care setting. Seventy-three chronic hepatitis B patients who achieved virological suppression on lamivudine (serum hepatitis B virus DNA < 60 International Unit (IU)/mL) were enrolled. Entecavir or lamivudine were administered orally for up to 96 weeks. Virologic and serologic responses were measured throughout the study.

RESULTS

A significantly higher proportion of patients in the entecavir group achieved hepatitis B virus DNA < 60 IU/mL at Weeks 48 (100% [38/38] vs 62.8% [22/35]; P < 0.001) and 96 (97.4% [37/38] vs 57.1% [20/35]; P<0.001). A greater number of patients had virologic breakthrough (Week 96 cumulative incidence 42.9% vs 2.6%; P<0.001) and genotypic lamivudine resistance (28.6% [10/35] vs 0% [0/38]; P<0.001) in the lamivudine group. No serious adverse events or laboratory abnormalities were reported.

CONCLUSIONS

Even after achieving virological suppression on lamivudine therapy, the risk of emergent lamivudine resistance increases over time. Switching to entecavir resulted in a maintained virologic response and superior serologic responses versus continued lamivudine therapy. This study supports a rationale for switching to entecavir in chronic hepatitis B patients with virological suppression on lamivudine.

Overview of hepatitis B viral replication and genetic variability

Chronic infection with hepatitis B virus (HBV) greatly increases the risk for liver cirrhosis and hepatocellular carcinoma (HCC). HBV isolates worldwide can be divided into ten genotypes. Moreover, the immune clearance phase selects for mutations in different parts of the viral genome. The outcome of HBV infection is shaped by the complex interplay of the mode of transmission, host genetic factors, viral genotype and adaptive mutations, as well as environmental factors. Core promoter mutations and mutations abolishing hepatitis B e antigen (HBeAg) expression have been implicated in acute liver failure, while genotypes B, C, subgenotype A1, core promoter mutations, preS deletions, C-terminal truncation of envelope proteins, and spliced pregenomic RNA are associated with HCC development. Our efforts to treat and prevent HBV infection are hampered by the emergence of drug resistant mutants and vaccine escape mutants. This paper provides an overview of the HBV life cycle, followed by review of HBV genotypes and mutants in terms of their biological properties and clinical significance.

Pegylated interferon alfa for chronic hepatitis B: systematic review and meta-analysis

Conventional interferon alfa and nucleos(t)ide analogues, such as lamivudine, are frequently used for chronic hepatitis B (CHB) treatment, but are associated with adverse effects and viral resistance. Here we performed a systematic review and meta-analysis evaluating all studies of pegylated interferon alfa (PEG-IFNα) treatment in hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients with CHB. We searched electronic databases--PubMed, EMBASE, Cochrane Library and LILACS--for randomized controlled trials evaluating PEG-IFNα therapy between 1999 and September 2014. Virological response was the primary outcome. We identified 14 studies involving 2829 patients. Our analysis revealed that PEG-IFNα + lamivudine combination therapy produced better virological and biochemical responses than PEG-IFNα monotherapy in HBeAg-positive and HBeAg-negative patients at the end of treatment. PEG-IFNα + adefovir dipivoxil achieved better seroconversion rate than PEG-IFNα in HBeAg-positive patients at the end of treatment. The present findings demonstrated a beneficial response rate following PEG-IFNα combination therapy with nucelos(t)ides among HBeAg-positive and HBeAg-negative patients with CHB. Further trials are needed to investigate simultaneous and sequential therapy strategies.

Off-treatment efficacy of 3-year nucleos(t)ide analogues in chronic hepatitis B patients

Lamivudine, telbivudine, and entecavir are the first-line drugs covered by the Taiwan National Health Insurance as 3-year treatments for patients with chronic hepatitis B virus (HBV), but the optimal treatment duration of each remains unclear. We aimed to detect HBV treatment-cessation durability, and compare the predictors in patients with and without clinical relapse. In this retrospective cohort study, 210 patients with chronic HBV who tested hepatitis B e-antigen positive or hepatitis B e-antigen negative were treated for 3 years with a nucleos(t)ide analogue. Of these, 102 patients continued therapy after 3 years, while 88 patients stopped treatment and were followed for 1 year due to financial difficulties. Efficacy was assessed in terms of alanine aminotransferase (ALT) level normalization, HBV DNA clearance, virus breakthrough, clinical relapse, and liver decompensation. The durability predictors were evaluated by host factors, HBV DNA, and drug differences. Eighty patients (14 on lamivudine, 19 on telbivudine, and 47 on entecavir) were recruited. There was no difference in clinical-relapse rate among lamivudine, telbivudine, and entecavir (35.7% vs. 36.8% vs. 31.9%, respectively; p = 0.916), and liver decompensated hepatitis was absent. In baseline clinical characteristics, there were no differences between the clinical-relapse and nonrelapse groups in age, sex, cirrhosis, prior treatment, HBV DNA, pretreatment ALT, or hepatitis B e-antigen (HBeAg). The mean 3(rd) year serum ALT level differed significantly between clinical-relapse and nonrelapse patients (37.5 U/L vs. 27.7 U/L, respectively; p = 0.044). The 3-year nucleos(t)ide analogue off-treatment in patients with chronic HBV delivered according to the Taiwan National Health Insurance guidelines had an overall 33.8% 1-year clinical-relapse rate without any decompensated hepatitis flare-ups.

Genetic variation of hepatitis B virus and its significance for pathogenesis

Hepatitis B virus (HBV) has a worldwide distribution and is endemic in many populations. Due to its unique life cycle which requires an error-prone reverse transcriptase for replication, it constantly evolves, resulting in tremendous genetic variation in the form of genotypes, sub-genotypes, and mutations. In recent years, there has been considerable research on the relationship between HBV genetic variation and HBV-related pathogenesis, which has profound implications in the natural history of HBV infection, viral detection, immune prevention, drug treatment and prognosis. In this review, we attempted to provide a brief account of the influence of HBV genotype on the pathogenesis of HBV infection and summarize our current knowledge on the effects of HBV mutations in different regions on HBV-associated pathogenesis, with an emphasis on mutations in the preS/S proteins in immune evasion, occult HBV infection and hepatocellular carcinoma (HCC), mutations in polymerase in relation to drug resistance, mutations in HBV core and e antigen in immune evasion, chronicalization of infection and hepatitis B-related acute-on-chronic liver failure, and finally mutations in HBV x proteins in HCC.