Current and future antiviral drug therapies of hepatitis B chronic infection

Targeting chronic liver diseases: Molecular markers, drug delivery strategies and future perspectives

Chronic liver inflammation, a pervasive global health issue, results in millions of annual deaths due to its progression from fibrosis to the more severe forms of cirrhosis and hepatocellular carcinoma (HCC). This insidious condition stems from diverse factors such as obesity, genetic conditions, alcohol abuse, viral infections, autoimmune diseases, and toxic accumulation, manifesting as chronic liver diseases (CLDs) such as metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), alcoholic liver disease (ALD), viral hepatitis, drug-induced liver injury, and autoimmune hepatitis. Late detection of CLDs necessitates effective treatments to inhibit and potentially reverse disease progression. However, current therapies exhibit limitations in consistency and safety. A potential breakthrough lies in nanoparticle-based drug delivery strategies, offering targeted delivery to specific liver cell types, such as hepatocytes, Kupffer cells, and hepatic stellate cells. This review explores molecular targets for CLD treatment, ongoing clinical trials, recent advances in nanoparticle-based drug delivery, and the future outlook of this research field. Early intervention is crucial for chronic liver disease. Having a comprehensive understanding of current treatments, molecular biomarkers and novel nanoparticle-based drug delivery strategies can have enormous impact in guiding future strategies for the prevention and treatment of CLDs.

Varicella-zoster virus-related neurological complications: From infection to immunomodulatory therapies

The Varicella-zoster virus (VZV), classified as a neurotropic member of the Herpesviridae family, exhibits a characteristic pathogenicity, predominantly inducing varicella, commonly known as chickenpox, during the initial infectious phase, and triggering the reactivation of herpes zoster, more commonly recognized as shingles, following its emergence from a latent state. The pathogenesis of VZV-associated neuroinflammation involves a complex interplay between viral replication within sensory ganglia and immune-mediated responses that contribute to tissue damage and dysfunction. Upon primary infection, VZV gains access to sensory ganglia, establishing latent infection within neurons. During reactivation, the virus can spread along sensory nerves, triggering a cascade of inflammatory mediators, chemokines, and immune cell infiltration in the affected neural tissues. The role of both adaptive and innate immune reactions, including the contributions of T and B cells, macrophages, and dendritic cells, in orchestrating the immune-mediated damage in the central nervous system is elucidated. Furthermore, the aberrant activation of the natural defence mechanism, characterised by the dysregulated production of immunomodulatory proteins and chemokines, has been implicated in the pathogenesis of VZV-induced neurological disorders, such as encephalitis, myelitis, and vasculopathy. The intricate balance between protective and detrimental immune responses in the context of VZV infection emphasises the necessity for an exhaustive comprehension of the immunopathogenic mechanisms propelling neuroinflammatory processes. Despite the availability of vaccines and antiviral therapies, VZV-related neurological complications remain a significant concern, particularly in immunocompromised individuals and the elderly. Elucidating these mechanisms might facilitate the emergence of innovative immunomodulatory strategies and targeted therapies aimed at mitigating VZV-induced neuroinflammatory damage and improving clinical outcomes. This comprehensive understanding enhances our grasp of viral pathogenesis and holds promise for pioneering therapeutic strategies designed to mitigate the neurological ramifications of VZV infections.

Recent progress on the application of compound formulas of traditional Chinese medicine in clinical trials and basic research in vivo for chronic liver disease

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic liver diseases mainly include chronic viral liver disease, metabolic liver disease, cholestatic liver disease (CLD), autoimmune liver disease, and liver fibrosis or cirrhosis. Notably, the compound formulas of traditional Chinese medicine (TCM) is effective for chronic liver diseases in clinical trials and basic research in vivo, which provide evidence of chronic liver disease treatment with integrated TCM and traditional Western medicine.

AIM OF THE REVIEW

This paper aims to provide a comprehensive review of the compound formulas of TCM for treating different chronic liver diseases to elucidate the composition, main curative effects, and mechanisms of these formulas and research methods.

MATERIALS AND METHODS

Different keywords related to chronic liver diseases and keywords related to the compound formulas of TCM were used to search the literature. PubMed, Scopus, Web of Science, and CNKI were searched to screen out original articles about the compound formulas of TCM related to the treatment of chronic liver diseases, mainly including clinical trials and basic in vivo research related to Chinese patent drugs, classic prescriptions, proven prescriptions, and hospital preparations. We excluded review articles, meta-analysis articles, in vitro experiments, articles about TCM monomers, articles about single-medicine extracts, and articles with incomplete or uncertain description of prescription composition. Plant names were checked with MPNS (http://mpns.kew.org).

RESULTS

In this review, the clinical efficacy and mechanism of compound formulas of TCM were summarized for the treatment of chronic viral hepatitis, nonalcoholic fatty liver disease, CLD, and liver fibrosis or cirrhosis developed from these diseases and other chronic liver diseases. For each clinical trial and basic research in vivo, this review provides a detailed record of the specific composition of the compound formulas of TCM, type of clinical research, modeling method of animal experiments, grouping methods, medication administration, main efficacy, and mechanisms.

CONCLUSION

The general development process of chronic liver disease can be summarized as chronic hepatitis, liver fibrosis or cirrhosis, and hepatocellular carcinoma. The compound formulas of TCM have some applications in these stages of chronic liver diseases. Owing to the continuous progress of medical technology, the benefits of the compound formulas of TCM in the treatment of chronic liver diseases are constantly changing and developing.

The role of Traditional Chinese medicine in anti-HBV: background, progress, and challenges

Chronic hepatitis B (CHB) remains a major world's most serious public health issues. Despite the remarkable effect of nucleos(t)ide analogues (NAs) in inhibiting hepatitis B virus (HBV) deoxyribonucleic acid (DNA) as the first-line drug, there are several limitations still, such as poor antigen inhibition, drug resistance, low-level viremia, restricting patients' functional cure. Due to the constraints of NAs, traditional medicines, such as traditional Chinese medicine (TCM), have become more prevalently used and researched in the clinical treatment of CHB as complementary alternative therapies. As a consequence, the review focuses on the background based on HBV's life cycle as well as the NAs' limitations, progress based on direct and indirect pathway of targeting HBV of TCM, and challenges of TCM. We found TCMs play an increasingly important role in anti-HBV. In a direct antiviral way, they regulate HBV infection, replication, assembly, and other aspects of the HBV life cycle. As for indirect way, TCMs can exert anti-HBV effects through targeting the host, including immune regulation, apoptosis, autophagy, oxidative stress, etc. Especially, TCMs have the advantages of strong antigenic inhibition compared to NAs. Specifically, we can combine the benefits of TCMs in strong HBV antigen inhibition with the benefits of NAs in targeted antiviral effects, in order to find a suitable combination of "TCM + NAs" to contribute to Chinese knowledge of the realisation of the "global elimination of HBV by 2030" goal of the World Health Organization.

Tenofovir disoproxil fumarate versus tenofovir alafenamide on risk of osteoporotic fracture in patients with chronic hepatitis B: A nationwide claims study in South Korea

BACKGROUND

As tenofovir disoproxil fumarate (TDF) requires long-term use, a reduction in bone density should be considered a possibility when treating patients with chronic hepatitis B (CHB) with aging and systemic diseases. Patients treated with tenofovir alafenamide (TAF) have improved bone mineral density loss compared to patients treated with TDF. Although improvements in bone density caused by TAF have been reported, studies on the actual reduction of fractures are insufficient.

AIM

To evaluate the impact of TAF on the risk of osteoporotic fractures in comparison with that of TDF.

METHODS

Using the national claims data of the Health Insurance Review and Assessment Service, we conducted a retrospective cohort study of 32,582 patients with CHB who had been initially treated with TDF or TAF between November 2017 and December 2020. The numbers of patients treated with TDF and TAF were 20,877 and 11,705, respectively. The annual fracture rate per 100 patients in each group was calculated, and the Cox proportional hazard ratio (HR) was analysed after applying inverse probability treatment weights (IPTW) for both groups.

RESULTS

Among 32,582 patients, the average age was 47.8 ± 11.2 years, 64.5% were men, and the follow-up period was 24.4 ± 11.6 months. The incidence of osteoporotic fractures was 0.78 and 0.49 per 100 person-years in the TDF and TAF groups, respectively. After application of IPTW, the HR was 0.68 (95% confidence interval 0.55-0.85, p = 0.001).

CONCLUSION

TAF-treated patients with CHB had a significantly lower risk of osteoporotic fracture than TDF-treated patients.

Hepatitis B Virus Epsilon (ε) RNA Element: Dynamic Regulator of Viral Replication and Attractive Therapeutic Target

Hepatitis B virus (HBV) chronically infects millions of people worldwide, which underscores the importance of discovering and designing novel anti-HBV therapeutics to complement current treatment strategies. An underexploited but attractive therapeutic target is ε, a cis-acting regulatory stem-loop RNA situated within the HBV pregenomic RNA (pgRNA). The binding of ε to the viral polymerase protein (P) is pivotal, as it triggers the packaging of pgRNA and P, as well as the reverse transcription of the viral genome. Consequently, small molecules capable of disrupting this interaction hold the potential to inhibit the early stages of HBV replication. The rational design of such ligands necessitates high-resolution structural information for the ε-P complex or its individual components. While these data are currently unavailable for P, our recent structural elucidation of ε through solution nuclear magnetic resonance spectroscopy marks a significant advancement in this area. In this review, we provide a brief overview of HBV replication and some of the therapeutic strategies to combat chronic HBV infection. These descriptions are intended to contextualize our recent experimental efforts to characterize ε and identify ε-targeting ligands, with the ultimate goal of developing novel anti-HBV therapeutics.

Synthetic gRNA/Cas9 ribonucleoprotein targeting HBV DNA inhibits viral replication

The presence of hepatitis B virus (HBV) covalently closed circular (ccc) DNA (cccDNA), which serves as a template for viral replication and integration of HBV DNA into the host cell genome, sustains liver pathogenesis and constitutes an intractable barrier to the eradication of chronic HBV infection. The current antiviral therapy for HBV infection, using nucleos(t)ide analogues (NAs), can suppress HBV replication but cannot eliminate integrated HBV DNA and episomal cccDNA. Clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 is a powerful genetic tool that can edit integrated HBV DNA and minichromosomal cccDNA for gene therapy, but its expression and delivery require a viral vector, which poses safety concerns for therapeutic applications in humans. In the present study, we used synthetic guide RNA (gRNA)/Cas9-ribonucleoprotein (RNP) as a nonviral formulation to develop a novel CRISPR/Cas9-mediated gene therapy for eradicating HBV infection. We designed a series of gRNAs targeting multiple specific HBV genes and tested their antiviral efficacy and cytotoxicity in different HBV cellular models. Transfection of stably HBV-infected human hepatoma cell line HepG2.2.15 with HBV-specific gRNA/Cas9 RNPs resulted in a substantial reduction in HBV transcripts. Specifically, gRNA5 and/or gRNA9 RNPs significantly reduced HBV cccDNA, total HBV DNA, pregenomic RNA, and HBV antigen (HBsAg, HBeAg) levels. T7 endonuclease 1 (T7E1) cleavage assay and DNA sequencing confirmed specific HBV gene cleavage and mutations at or around the gRNA target sites. Notably, this gene-editing system did not alter cellular viability or proliferation in the treated cells. Because of their rapid DNA cleavage capability, low off-target effects, low risk of insertional mutagenesis, and readiness for use in clinical application, these results suggest that synthetic gRNA/Cas9 RNP-based gene-editing can be utilized as a promising therapeutic drug for eradicating chronic HBV infection.

Burgeoning therapeutic strategies to curb the contemporary surging viral infections

Significant efforts and initiatives were already made in the health care systems, however in the last few years; our world is facing emergences of viral infections which potentially leading to considerable challenges in terms of higher morbidity, mortality, increased and considerable financial loads on the affected populations. Over ten major epidemics or pandemics have been recorded in the twenty-first century, the ongoing coronavirus pandemic being one of them. Viruses being distinct obligate pathogens largely dependent on living beings are considered as one of the prominent causes of death globally. Although effective vaccines and antivirals have led to the eradication of imperative viral pathogens, the emergences of new viral infections as well as novel drug-resistant strains have necessitated the implementation of ingenious and efficient therapeutic approaches to treat viral outbreaks in the future. Nature being a constant source of tremendous therapeutical resources has inspired us to develop multi-target antiviral drugs, overcoming the challenges and limitations faced by pharmaceutical industry. Recent breakthroughs in the understanding of the cellular and molecular mechanisms of viral reproduction have laid the groundwork for potential treatment approaches including antiviral gene therapy relying on the application of precisely engineered nucleic acids for disabling pathogen replication. The development of RNA interference and advancements in genome manipulating tools have proven to be especially significant in this regard. In this review, we discussed mode of actions and pathophysiological events associated with the viral infections; followed by distributions, and advancement made towards the detection strategies for timely diagnosis. In the later section, current approaches to cope up the viral pathogens and their key limitations have also been elaborated. Lastly, we also explored some novel and potential targets to treat such infections, where attentions were made on next generation gene editing technologies.

Chronic hepatitis B: New potential therapeutic drugs target

Chronic hepatitis B (CHB) infection remains the most causative agent of liver-related morbidity and mortality worldwide. It impacts nearly 300 million people. The current treatment for chronic infection with the hepatitis B virus (HBV) is complex and lacks a durable treatment response, especially hepatitis B surface antigen (HBsAg) loss, necessitating indefinite treatment in most CHB patients due to the persistence of HBV covalently closed circular DNA (cccDNA). New drugs that target distinct steps of the HBV life cycle have been investigated, which comprise inhibiting the entry of HBV into hepatocytes, disrupting or silencing HBV cccDNA, modulating nucleocapsid assembly, interfering HBV transcription, and inhibiting HBsAg release. The achievement of a functional cure or sustained HBsAg loss in CHB patients represents the following approach towards HBV eradication. This review will explore the up-to-date advances in the development of new direct-acting anti-HBV drugs. Hopefully, with the combination of the current antiviral drugs and the newly developed direct-acting antiviral drugs targeting the different steps of the HBV life cycle, the ultimate eradication of CHB infection will soon be achieved.

Tenofovir alafenamide treatment may not worsen the lipid profile of chronic hepatitis B patients: a propensity score-matched analysis

Background/Aims

Tenofovir alafenamide (TAF) has shown less favorable effect on lipids compared to tenofovir disoproxil fumarate (TDF) in clinical trials. However, data regarding these outcomes in patients with chronic hepatitis B (CHB) are scarce. Therefore, this study aimed to evaluate the effect of TAF on the lipid in patients with CHB.

Methods

A total of 237 TAF-treated CHB patients compared with TDF, inactive CHB, and non-hepatitis B virus (HBV)-infected control groups using propensity score matching (PSM).

Results

Following PSM, each analysis was conducted on cohorts via the matching of 70:140 (TAF:TDF), 89:89 (TAF:inactive CHB), 140:560 (TAF:non-HBV infected control), and 368:1,472 (TDF:non-HBV-infected control). A significant decrease in the total cholesterol (TC) level was noted at 48 weeks in the TDF group compared to the TAF group (176.3±32.9 vs. 156.7±27.7, P<0.001) and the non-HBV-infected control group (175.0±29.5 vs. 156.2±28.3, P<0.001). However, no significant change in TC was observed in the TAF group and inactive CHB or non-HBV-infected control groups at 48 weeks. For the subgroup analyses of TAF vs. non-HBV-infected control subjects and inactive CHB patients whose detailed lipid profile information were available, no between-group differences in TC, low-density lipoprotein (LDL)-cholesterol, highdensity lipoprotein (HDL)-cholesterol, TC/HDL ratio, and LDL/HDL ratio were observed at 48 weeks.

Conclusions

TDF seems to have a lipid-lowering effect compared to the non-HBV-infected control and TAF-treated groups. However, in real practice, TAF might not worsen the lipid profiles of subjects compared to non-HBV-infected controls and patients with inactive CHB.

Present and future management of viral hepatitis

Viral hepatitis can result in important morbidity and mortality, with its impact on health conditioned by the specific type of hepatitis, the geographical region of presentation and the development and access to new drugs, among other factors. Most acute presentation forms are self-limiting and may even go unnoticed, with just a small percentage of cases leading to acute liver failure that may necessitate transplantation or even cause the death of the patient. However, when they become chronic, as in the case of hepatitis B virus and C virus, unless they are diagnosed and treated adequately they may have severe consequences, like cirrhosis or hepatocarcinoma. Understanding of the mechanisms of transmission, the pathogenesis, the presence of vaccinations and the development over recent years of new highly-efficient, potent drugs have meant that we are now faced with a new scenario in the management of viral hepatitis, particularly hepatitis B virus and hepatitis C virus. The spectacular advances in hepatitis C virus treatment have led the World Health Organization to propose the objective of its eradication by 2030. The key aspect to achieving this goal is to ensure that these treatments reach all the more vulnerable population groups, in whom the different types of viral hepatitis have a high prevalence and constitute a niche that may perpetuate infection and hinder its eradication. Accordingly, micro-elimination programs assume special relevance at the present time.

Low-level viremia in nucleoside analog-treated chronic hepatitis B patients

ABSTRACT

Low-level viremia (LLV) was defined as persistent or intermittent episodes of detectable hepatitis B virus (HBV) DNA (<2000 IU/mL, detection limit of 10 IU/mL) after 48 weeks of antiviral treatment. Effective antiviral therapies for chronic hepatitis B (CHB) patients, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), have been shown to inhibit the replication of HBV DNA and prevent liver-related complications. However, even with long-term antiviral therapy, there are still a number of patients with persistent or intermittent LLV. At present, the research on LLV to address whether adversely affect the clinical outcome is limited, and the follow-up treatment for these patients is open to question. At the same time, the mechanism of LLV is not clear. In this review, we summarize the incidence of LLV, the association between LLV and long-term outcomes, possible mechanisms, and management strategies in these patient populations.

Targeting Multiple Signal Transduction Pathways of SARS-CoV-2: Approaches to COVID-19 Therapeutic Candidates

Due to the complicated pathogenic pathways of coronavirus disease 2019 (COVID-19), related medicinal therapies have remained a clinical challenge. COVID-19 highlights the urgent need to develop mechanistic pathogenic pathways and effective agents for preventing/treating future epidemics. As a result, the destructive pathways of COVID-19 are in the line with clinical symptoms induced by severe acute coronary syndrome (SARS), including lung failure and pneumonia. Accordingly, revealing the exact signaling pathways, including inflammation, oxidative stress, apoptosis, and autophagy, as well as relative representative mediators such as tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), Bax/caspases, and Beclin/LC3, respectively, will pave the road for combating COVID-19. Prevailing host factors and multiple steps of SARS-CoV-2 attachment/entry, replication, and assembly/release would be hopeful strategies against COVID-19. This is a comprehensive review of the destructive signaling pathways and host-pathogen interaction of SARS-CoV-2, as well as related therapeutic targets and treatment strategies, including potential natural products-based candidates.

Role of STAT1 in the resistance of HBV to IFN-α

The objective of the present study was to explore the mechanism of hepatitis B virus (HBV) resistance to interferon (IFN), and the role of signal transducer and activator of transcription 1 (STAT1). HepG2.2.15 cells were stimulated with a long-term (6-24 weeks) low-dose interferon (IFN)α-2b (10-70 IU/ml), so as to construct and screen a HepG2.2.15 cell model resistant to IFNα-2b. The changes of STAT1 and other proteins in the JAK-STAT signaling pathway, before and after drug resistance, were compared. The phosphorylation of STAT1 in HepG2.2.15 cells resistant to IFNα-2b was significantly decreased, and the expression level of 2',5'-oligoadenylate synthetase 1 was downregulated. Decreased phosphorylation of STAT1 in the JAK-STAT signaling pathway a contributor to the development of resistance to IFN-α in HBV.

The association of the heterogeneity of HBV reverse transcriptase quasispecies with antiviral efficacy after treatment with nucleos(t)ide analogues for 10 years

To assess the heterogeneity of HBV reverse transcriptase (RT) quasispecies during 10 years of antiviral therapy and their association with antiviral efficacy. Nineteen patients with chronic hepatitis B (CHB) infection receiving nucleos(t)ide analogues (NAs) were enrolled. Based on the antiviral efficacy after 1 year of treatment, 5 patients were grouped into an early virologic response (EVR) group, while 8 patients were grouped into a late virologic response (LVR) group. Furthermore, 6 CHB patients that had undergone antiviral treatment for 10 years were grouped into a virologic breakthrough (VBT) group. The HBV RT from each patient were amplified, cloned, and sequenced. The complexity of the RT gene in the EVR group was significantly higher than that in the LVR (P = 0.0393) and VBT groups (P = 0.0141). Phylogenetic tree analysis showed that the average branch length of the EVR and LVR groups were significantly greater than that of VBT group (P < 0.001). The complexity (at the nucleotide level) of the RT quasispecies was negatively correlated with the corresponding HBV DNA load (P = 0.0163) at one year post-antiviral treatment. Moreover, both the LVR and VBT groups accumulated more deleterious mutations than the EVR group. After 1 year of NAs treatment, the increased HBV quasispecies complexity and evolutionary topologies, coupled with less deleterious mutations, are likely associated with a favorable efficacy during long-term antiviral treatment.

Efficacy of 104-week Telbivudine-based optimization strategy in patients with HBeAg-negative chronic hepatitis B virus infections

Background

Evaluate the safety and efficacy of 104-week regimen of Telbivudine(LdT)-based optimization strategy for Chinese patients who have chronic hepatits B(CHB) with HBeAg-negative.

Methods

This multi-center, open-label, prospective study enrolled 108 HBeAg-negative CHB patients who received LdT (600 mg/day) for 24 weeks, Adefovir (ADV) was added if HBV DNA remained detectable at week 24, otherwise LdT was maintained to use until 104 weeks. HBV DNA, alanine amino transferase (ALT), hepatitis B surface antigen(HBsAg), creatinine kinase(CK), and estimated glomerular filtration rate (eGFR) were measured, safety was assessed.

Results

Eighty-eight patients (81%) had HBV-DNA undetectable at 24 weeks and maintained to receive LdT monotherapy until 104 weeks, whereas the other 20 patients had HBV-DNA detectable and ADV was used in combination. For all patients, 72% of patients reached ALT normalization at 24 weeks, which increased to 80% at 52 weeks and 104 weeks, respectively.. 81% of total patients had undetectable HBV-DNA at 24 weeks, 92% at 52 weeks, and 94% at 104 weeks. The HBsAg titre declined steadily from baseline to 104 weeks (3.62 vs. 2.98 log10 IU/mL, p < 0.05), and the eGFR increased steadily from baseline to 104 weeks (92.9 vs. 104.4 mL/min/1.73 m², p < 0.05). Although 79 patients (73%) had at least one time of elevated CK, most of these patients had CK elevated in Grade 1/2.

Conclusions

LdT was well tolerated and effective, and 94% of patients achieved virological suppression after 104 weeks.

Trial registration

This study was registered in clinicaltrials.gov on January 31, 2012 and the ID No. was NCT01521975.

Development of an in vivo delivery system for CRISPR/Cas9-mediated targeting of hepatitis B virus cccDNA

Chronic hepatitis B virus (HBV) infection constitutes a global health issue with limited current therapeutic efficacy owing to the persistence of viral episomal DNA (cccDNA). The CRISPR/Cas9 system, a newly developed, powerful tool for genome editing and potential gene therapy, requires efficient delivery of CRISPR components for successful therapeutic application. Here, we investigated the effects of lentiviral- or adeno-associated virus 2 (AAV2) vector-mediated delivery of 3 guide (g)RNAs/Cas9 selected from 16 gRNAs. These significantly suppressed HBV replication in cells, with WJ11/Cas9 exhibiting highest efficacy and chosen for in vivo study. AAV2/WJ11-Cas9 also significantly inhibited HBV replication and significantly reduced cccDNA in the tested cells. Moreover, AAV2/WJ11-Cas9 enhanced entecavir effects when used in combination, indicative of different modes of action. Notably, in humanized chimeric mice, AAV2/WJ11-Cas9 significantly suppressed HBcAg, HBsAg, and HBV DNA along with cccDNA in the liver tissues without significant cytotoxicity; accordingly, next generation sequencing data showed no significant genomic mutations. To our knowledge, this represents the first evaluation of the CRISPR/Cas9 system using an HBV natural infection mode. Therefore, WJ11/Cas9 delivered by comparatively safer AAV2 vectors may provide a new therapeutic strategy for eliminating HBV infection and serve as an effective platform for curing chronic HBV infection.

Tooth loss associated with the use of tenofovir disoproxil fumarate

WHAT IS KNOWN AND OBJECTIVE

The frequent tenofovir disoproxil fumarate (TDF)-related adverse drug reactions (ADRs) are nephrotoxicity and bone toxicity; however, tooth-related ADRs of TDF have not been reported. We describe the case of a 41-year-old Han Chinese man with chronic hepatitis B with TDF-associated tooth loss.

CASE SUMMARY

He presented with halitosis, gingival swelling and tooth loss after TDF use. After excluding the possibility of other drug-related ADRs, TDF was considered a possible cause and switched with tenofovir alafenamide fumarate (TAF). After 6 months, the oral symptoms disappeared, with no additional tooth loss.

WHAT IS NEW AND CONCLUSION

This is the first report of such ADRs. The ADR score was 7, indicating tooth loss as a potential TDF-related ADR.

Advanced Therapeutics, Vaccinations, and Precision Medicine in the Treatment and Management of Chronic Hepatitis B Viral Infections; Where Are We and Where Are We Going?

The management of chronic hepatitis B virus (CHB) infection is an area of massive unmet clinical need worldwide. In spite of the development of powerful nucleoside/nucleotide analogue (NUC) drugs, and the widespread use of immune stimulators such as interferon-alpha (IFNα) or PEGylated interferon-alpha (PEG-IFNα), substantial improvements in CHB standards of care are still required. We believe that the future for CHB treatment now rests with advanced therapeutics, vaccination, and precision medicine, if all are to bring under control this most resilient of virus infections. In spite of a plethora of active drug treatments, anti-viral vaccinations and diagnostic techniques, the management of CHB infection remains unresolved. The reason for this is the very complexity of the virus replication cycle itself, giving rise to multiple potential targets for therapeutic intervention some of which remain very intractable indeed. Our review is focused on discussing the potential impact that advanced therapeutics, vaccinations and precision medicine could have on the future management of CHB infection. We demonstrate that advanced therapeutic approaches for the treatment of CHB, in the form of gene and immune therapies, together with modern vaccination strategies, are now emerging rapidly to tackle the limitations of current therapeutic approaches to CHB treatment in clinic. In addition, precision medicine approaches are now gathering pace too, starting with personalized medicine. On the basis of this, we argue that the time has now come to accelerate the design and creation of precision therapeutic approaches (PTAs) for CHB treatment that are based on advanced diagnostic tools and nanomedicine, and which could maximize CHB disease detection, treatment, and monitoring in ways that could genuinely eliminate CHB infection altogether.

Perception of and Attitude towards Hepatitis B Infection among Saudi Pregnant Females Attending Antenatal Care Unit in Al-Ahsa City, Kingdom of Saudi Arabia

Objective This study aimed to assess the knowledge and attitudes of pregnant females in Al-Ahsa city, Kingdom of Saudi Arabia (KSA) toward hepatitis B virus infection. Methods A cross-sectional study was done at the Maternity and Children's Hospital, Al-Ahsa. A total of 422 of every third pregnant women were recruited from 6/12/2019 to 20/12/2019. Self-administered questionnaire was provided that contained three aspects: sociodemographic, perception and source of information about hepatitis B, and attitude toward hepatitis B infection. Analysis was performed using SPSS version 21 (IBM Corp., Armonk, NY). Results A total of 422 pregnant women participated in this study with a response rate of 93.7%. Among them, 44.79% had a university degree or higher education level, about 82% had information about hepatitis B virus (HBV) during their pregnancy, 0.9% knew a person with HBV, 48.1% knew that hepatitis B is caused by virus, 72% knew that hepatitis B has vaccine, 41.9% knew that hepatitis B spreads via mother, 79.6% were willing to do hepatitis B test during pregnancy, 80.1% were willing to allow for kids' vaccination against HBV, and 83.4% were willing to allow their kids for hepatitis B testing. There was a significant relationship between the level of education and the knowledge score. And there was a significant relationship between the level of education and attitudes score. Conclusion There is insufficient knowledge among pregnant women regarding hepatitis B infection, while pregnant women showed remarkably positive attitudes regarding therapy and immunization. So, we highly recommend for awareness campaigns about viral hepatitis regarding means of transmission, and possible treatment options.

Present and Future Therapies for Chronic Hepatitis B

Chronic hepatitis B (CHB) remains the leading cause of liver-related morbidity and mortality across the world. If left untreated, approximately one-third of these patients will progress to severe end-stage liver diseases including liver failure, cirrhosis, and hepatocellular carcinoma (HCC). High level of serum HBV DNA is strongly associated with the development of liver failure, cirrhosis, and HCC. Therefore, antiviral therapy is crucial for the clinical management of CHB. Current antiviral drugs including nucleoside/nucleotide analogues (NAs) and interferon-α (IFN-α) can suppress HBV replication and reduce the progression of liver disease, thus improving the long-term outcomes of CHB patients. This chapter will discuss the standard and optimization antiviral therapies in treatment-naïve and treatment-experienced patients, as well as in the special populations. The up-to-date advances in the development of new anti-HBV agents will be also discussed. With the combination of the current antiviral drugs and the newly developed antiviral agents targeting the different steps of the viral life cycle or the newly developed agents modulating the host immune responses, the ultimate eradication of HBV will be achieved in the future.

The Signaling Pathways, and Therapeutic Targets of Antiviral Agents: Focusing on the Antiviral Approaches and Clinical Perspectives of Anthocyanins in the Management of Viral Diseases

As the leading cause of death worldwide, viruses significantly affect global health. Despite the rapid progress in human healthcare, there are few viricidal and antiviral therapies that are efficient enough. The rapid emergence of resistance, and high costs, as well as the related side effects of synthetic antiviral drugs, raise the need to identify novel, effective, and safe alternatives against viral diseases. Nature has been of the most exceptional help and source of inspiration for developing novel multi-target antiviral compounds, affecting several steps of the viral life cycle and host proteins. For that matter and due to safety and efficacy limitations, as well as high resistance rate of conventional therapies, hundreds of natural molecules are preferred over the synthetic drugs. Besides, natural antiviral agents have shown acceptable antiviral value in both preclinical and clinical trials.This is the first review regarding molecular and cellular pathways of the virus life cycle, treatment strategies, and therapeutic targets of several viral diseases with a particular focus on anthocyanins as promising natural compounds for significant antiviral enhancements. Clinical applications and the need to develop nano-formulation of anthocyanins in drug delivery systems are also considered.

Plasma miR-146a predicts serological conversion of hepatitis B e-antigen (HBeAg) in chronic hepatitis B patients treated with nucleotide analogs

Background

To investigate the association of plasma miR-146a with serological conversion of hepatitis B e-antigen (HBeAg) in patients with chronic hepatitis B (CHB) treated with nucleotide analogs (NAs).

Methods

This was a retrospective study of 115 HBeAg-positive patients with CHB treated at Xiangya Hospital, Central South University, Changsha, China, between September 2009 and March 2014. Patients were grouped according to whether they had achieved seroconversion of HBeAg by 104 weeks of NAs treatment. We assessed plasma miR-146a using miScript polymerase chain reaction (PCR). Serum alanine transaminase (ALT), hepatitis B virus (HBV) deoxyribonucleic acid (DNA) load, hepatitis B surface antigen (HBsAg) titer, HBeAg titer, and plasma miR-146a were measured at 0, 24, 48, and 104 weeks of treatment. Finally, we also determined ΔmiR-146a_24w and ΔmiR-146a_48w.

Results

ΔmiR-146a_48w was independently associated with seroconversion of HBeAg at 104 weeks [odds ratio (OR) =1.302; 95% confidence interval (CI), 1.159-1.962; P=0.029]. We obtained an area under the receiver operating characteristic (ROC) curve (AUC) of ΔmiR-146_48w of 0.757 for seroconversion of HBeAg (P=0.013). At the optimal cutoff value equivalent to a Youden index of 67.9%, the specificity and sensitivity of ΔmiR-146_48w were 63.7% and 88.3%, respectively. Positive (PPV) and negative (NPV) predictive values were 70.87% and 84.48%, respectively.

Conclusions

ΔmiR-146a_48w was independently associated with seroconversion of HBeAg in CHB patients treated with NAs.

Orthologous CRISPR/Cas9 systems for specific and efficient degradation of covalently closed circular DNA of hepatitis B virus

Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is the major cause of viral persistence and chronic hepatitis B. CRISPR/Cas9 nucleases can specifically target HBV cccDNA for decay, but off-target effects of nucleases in the human genome limit their clinical utility. CRISPR/Cas9 systems from four different species were co-expressed in cell lines with guide RNAs targeting conserved regions of the HBV genome. CRISPR/Cas9 systems from Streptococcus pyogenes (Sp) and Streptococcus thermophilus (St) targeting conserved regions of the HBV genome blocked HBV replication and, most importantly, resulted in degradation of over 90% of HBV cccDNA by 6 days post-transfection. Degradation of HBV cccDNA was impaired by inhibition of non-homologous end-joining pathway and resulted in an erroneous repair of HBV cccDNA. HBV cccDNA methylation also affected antiviral activity of CRISPR/Cas9. Single-nucleotide HBV genetic variants did not impact anti-HBV activity of St CRISPR/Cas9, suggesting its utility in targeting many HBV variants. However, two or more mismatches impaired or blocked CRISPR/Cas9 activity, indicating that host DNA will not likely be targeted. Deep sequencing revealed that Sp CRISPR/Cas9 induced off-target mutagenesis, whereas St CRISPR/Cas9 had no effect on the host genome. St CRISPR/Cas9 system represents the safest system with high anti-HBV activity.

Effect of WSP, a Chinese Herbal Formula, on Th17/Treg Ratio and HBeAg Seroconversion in Telbivudine-Treated HBeAg-Positive Chronic Hepatitis B Patients with High Baseline ALT Levels (20-30 Times the ULN)

Chronic hepatitis B (CHB) is a global health problem. Clinically, many patients have baseline alanine aminotransferase (ALT) levels above 20 times the upper limit of normal (ULN), but there are few reports about these patients. The prospective randomized placebo-controlled clinical study was designed to investigate the effect of WSP, a Chinese herbal formula, on telbivudine- (LDT-) treated HBeAg-positive CHB patients with high baseline ALT levels (20–30 times the ULN) and kidney-yang deficiency syndrome. Eligible patients were randomized to receive LDT 600 mg/day in combination with WSP (treatment group) or placebo granules (control group) 16.28 g/day for 52 weeks. The results showed that HBeAg seroconversion (SC) rate (44.1%) in the treatment group (n=34) was significantly superior to that (20.6%) in the control group (n=34) at 52 weeks (P < 0.05). Meanwhile, WSP could promote HBV DNA negative conversion (85.3% versus 61.8%, P < 0.05) and ALT normalization (94.1% versus 76.5%, P < 0.05) compared with the placebo. There were no drug-related serious adverse events. During the treatment, the peripheral blood Th17/Treg ratio first increased and then decreased in the treatment group and reached the peak at 12 weeks (P < 0.05). At 12, 24, 36, and 52 weeks, Th17/Treg ratio in the treatment group was better than those in the control group (all P < 0.05). In addition, the patients (n=22) with HBeAg SC had higher Th17/Treg ratio than the patients (n=46) without SC at 12 weeks (0.68±0.26 versus 0.43±0.18, P < 0.001). In conclusion, WSP could safely enhance HBeAg SC and promote HBV DNA negative conversion and ALT normalization in LDT-treated HBeAg-positive CHB patients with high baseline ALT levels (20–30 times the ULN) and kidney-yang deficiency syndrome. Th17/Treg ratio was not only related to the mechanisms of WSP but also a good predictor of 52-week HBeAg SC.

Preparation and Characterization of PLGA Nanoparticles Containing Plasmid DNA Encoding Human IFN-lambda-1/IL-29

During the 15 years since the discovery of type III human interferons [IFN-λ1(IL-29), IFN-λ2(IL-28A), and IFN-λ3(IL-28B)], numerous biological properties such as anticancer, antiviral, and immunomodulatory activities of this new IFN family have been investigated. Several studies have shown that the encapsulation of pcDNA with PLGA nanoparticles (NPs) protects them against DNase enzyme action and increases the efficiency of gene delivery to the cells. The purpose of this study was to encapsulate pcDNA encoding IFN-λ1 (pIFN-λ1) with a simple and cost-effective method using PLGA NPs. The pIFN-λ1-loaded PLGA NPs were produced by a double-emulsion-solvent evaporation method and characterized in terms of size, size distribution, and zeta potential by DLS and morphologically by SEM and TEM. The bioactivity of NPs was also examined by fluorescent microscopy. The results showed that IFN-λ1 expressed by HEK293T cells could protect HepC-2 cells from the cytopathic effects of EMCV. The NPs were spherical in shape with a mean diameter of 380 ± 3 nm, a zeta potential of -3.3 ± 7.6 mV, an encapsulation efficiency of 75 ± 5%, and a loading capacity of 0.83 ± 0.06. The NPs were also bioactive and easily engulfed by RAW264.7 cells. The pIFN-λ1 could be sustainably released from NPs. Due to the facility and affordability of encapsulation of pIFN-λ1 in the PLGA NPs proposed in this study and the advantages of encapsulation by PLGA, it appeared rational to use pIFN-λ1-loaded NPs instead of naked pIFN-λ1 to determine other unexplained activities of this new cytokine or to use it as an alternative or adjunct to current IFN-α therapy.

Antiviral effects of hepatitis B virus S gene-specific anti-gene locked nucleic acid in transgenic mice

AIM

To assess the antiviral effects of hepatitis B virus (HBV) S gene-specific anti-gene locked nucleic acid (LNA) in transgenic mice.

METHODS

Thirty HBV transgenic mice were acclimatized to laboratory conditions and positive for serum HBV surface antigen (HBsAg) and HBV DNA, were randomly divided into 5 groups (n = 7), including negative control (blank control, unrelated sequence control), positive control (lamivudine, anti-sense-LNA), and anti-gene-LNA experimental group. LNA was injected into transgenic mice by tail vein while lamivudine was administered by gavage. Serum HBV DNA and HBsAg levels were determined by fluorescence-based PCR and enzyme-linked immune sorbent assay, respectively. HBV S gene expression amounts were assessed by reverse transcription polymerase chain reaction. Positive rates of HBsAg in liver cells were evaluated immunohistochemistry.

RESULTS

Average rate reductions of HBsAg after treatment on the 3^rd, 5^th, and 7^th days were 32.34%, 45.96%, and 59.15%, respectively. The inhibitory effect of anti-gene-LNA on serum HBsAg peaked on day 7, with statistically significant differences compared with pre-treatment (0.96 ± 0.18 vs 2.35 ± 0.33, P < 0.05) and control values (P < 0.05 for all). Average reduction rates of HBV DNA on the 3^rd, 5^th, and 7^th days were 38.55%, 50.95%, and 62.26%, respectively. This inhibitory effect peaked on the 7^th day after treatment with anti-gene-LNA, with statistically significant differences compared with pre-treatment (4.17 ± 1.29 vs 11.05 ± 1.25, P < 0.05) and control values (P < 0.05 for all). The mRNA levels of the HBV S gene (P < 0.05 for all) and rates of HBsAg positive liver cells (P < 0.05 for all) were significantly reduced compared with the control groups. Liver and kidney function, and histology showed no abnormalities.

CONCLUSION

Anti-gene-LNA targeting the S gene of HBV displays strong inhibitory effects on HBV in transgenic mice, providing theoretical and experimental bases for gene therapy in HBV.

Anti-HBV effect of interferon-thymosin α1 recombinant proteins in transgenic Dunaliella salina in vitro and in vivo

The aim of the present study was to investigate the anti-hepatitis B virus (HBV) effect of interferon (IFN)-thymosin α1 (TA1) in a transgenic Dunaliella salina (TDS) system in vitro and in vivo. The toxicity of TDS in the HepG2.2.15 cell line was assessed using an MTT assay. The effect of TDS on the secretion of HBV early antigen (HBeAg) and HBV surface antigen (HBsAg) in culture supernatants was measured using ELISA. In addition, HBV-DNA was analyzed using quantitative polymerase chain reaction. Drug treatment experiments were performed in vivo on ducks congenitally infected with duck HBV (DHBV). The drug was administered once daily for 21 continuous days. Blood was drawn from all ducks prior to treatment, following treatment for 7, 14 and 21 days, and following drug withdrawal for 5 days. Serum DHBV-DNA was determined using quantitative PCR. In addition, the histology of duck liver tissues was assessed using hematoxylin and eosin, and orcein staining. The results demonstrated that TDS suppressed cell viability and HBsAg and HBeAg secretion in HepG2.2.15 cells. Furthermore, the treatment index values for HBsAg and HBeAg following TDS treatment were 2.96 and 3.07 respectively, which were greater than those of the IFN-α treated group. In addition, the DHBV-infected duck model experiments indicated that serum DHBV-DNA levels were significantly decreased in the group of TDS (20 g/kg) following treatment for 7, 14 and 21 days compared with the control group. Following withdrawal of the drug for 5 days, the levels of DHBV-DNA did not relapse in the medium and high dose groups of TDS (10 and 20 g/kg, respectively). Histological analysis of duck liver also demonstrated that TDS and IFN-α treatment alleviated inflammation and HBsAg signals in duck livers. In conclusion, TDS markedly suppresses HBV replication in vitro and in vivo and its anti-HBV effect is greater than that of IFN-α.

Polymeric therapeutic delivery systems for the treatment of infectious diseases

Infectious diseases caused by germs, parasites, fungi, virus and bacteria are one of the leading causes of death worldwide. Polymeric therapeutics are nanomedicines that offer several advantages making them useful for the treatment of infectious diseases such as targeted drug release mechanism, ability to maintain the drug concentration within a therapeutic window for a desired duration, biocompatibility with low immunogenicity and reduced drug toxicity resulting in enhanced therapeutic efficacy of the incorporated drug. Although polymeric therapeutics have been evaluated for the treatment of infectious diseases in vitro and in vivo with improved therapeutic efficacy, most treatments for infectious disease have not been evaluated using polymeric therapeutics. This review will focus on the applications of polymeric therapeutics for the treatment of infectious diseases (preclinical studies and clinical trials), with particular focus on parasitic and viral infections.

Protective Effects of Moringa oleifera on HBV Genotypes C and H Transiently Transfected Huh7 Cells

Chronic hepatitis B infection treatment implicates a long-lasting treatment. M. oleifera extracts contain compounds with antiviral, antioxidant, and antifibrotic properties. In this study, the effect of M. oleifera was evaluated in Huh7 cells expressing either HBV genotypes C or H for the antiviral, antifibrotic, anti-inflammatory, and antioxidative responses. Huh7 cells were treated with an aqueous extract of M. oleifera (leaves) at doses of 0, 30, 45, or 60 μg/mL. The replicative virus and TGF-β1, CTGF, CAT, IFN-β1, and pgRNA expressions were measured by real time. HBsAg and IL-6 titers were determined by ELISA. CTGF, TGF-β1, IFN-β1, and pgRNA expressions decreased with M. oleifera treatment irrespective of the HBV genotype. HBsAg secretion in the supernatant of transfected Huh7 cells with both HBV genotypes was decreased regardless of the dose of M. oleifera. Similar effect was observed in proinflammatory cytokine IL-6, which had a tendency to decrease at 24 hours of treatment. Transfection with both HBV genotypes strongly decreased CAT expression, which is retrieved with M. oleifera treatment. M. oleifera treatment reduced fibrosis markers, IL-6, and HBsAg secretion in HBV genotypes C and H. However, at the level of replication, only HBV-DNA genotype C was slightly reduced with this treatment.

Toward cure chronic hepatitis B infection and hepatocellular carcinoma prevention: Lessons learned from nucleos(t)ide analogues therapy

Nucleos(t)ide analogues (NAs) could successfully suppress hepatitis B virus (HBV) replication in patients with chronic hepatitis B (CHB). However, due to probable development of drug resistance or low/delayed response, these treatments may not be satisfactory. In addition to the HBV DNA polymerase inhibiting activity, these drugs could lead to changes in cytokines profiles. It is important to monitor these changes so that they could be used as target of treatment. Evaluating the previously reported immune responses due to NAs treatments, it was concluded that interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), and IL-12 increase after the treatment. This will be followed by the improved capacity of immune cells for eliminating HBV. In contrast, regulatory responses including IL-10 and transforming growth factor-beta (TGF-β) significantly decreased as the result of NAs therapy. Unexpectedly, T helper (Th) 17-associated cytokines also decreased significantly. These results could be used to employ the new strategies to suppress viral replication, minimize HBV DNA levels, inducing hepatitis B e antigen (HBeAg) seroconversion or even hepatitis B surface antigen (HBsAg) seroclearance. In order to accomplish these goals, extended treatment with high dose of both IL-12 and IFN in combination with high barrier to resistance NA might significantly improve the HBsAg seroclearance rate. Considering the danger of emerging aberrant immune responses, determining the optimum dosage as well as close monitoring of patients during the treatment is strongly advised. In order to make HBV immunotherapy practical, further studies are needed to confirm these results.

Systematic review with meta-analysis: the efficacy and safety of tenofovir to prevent mother-to-child transmission of hepatitis B virus

BACKGROUND

Preventing mother to child transmission of chronic hepatitis B infection in the setting of a high maternal viral load is challenging. The idea has emerged from antepartum tenofovir treatment with combination immunoprophylaxis.

AIMS

To demonstrate the efficacy and safety of tenofovir to prevent mother to child transmission of hepatitis B virus.

METHODS

PubMed, EMBASE, and Cochrane databases were searched through August 16, 2016. Comparative trials of second or third trimester tenofovir administration vs. controls for patients with chronic hepatitis B infection and non-comparative case series assessing mother to child transmission rates and evaluating maternal and foetal safety outcomes were included.

RESULTS

Ten studies (one randomised controlled trial, four non-randomised controlled trials and five case series) that enrolled 733 women were included. The pooled results from comparative trials (599 pregnancies) showed that tenofovir significantly reduced the risk of infant hepatitis B surface antigen seropositivity by 77% (odds ratio=0.23, 95% confidence intervals=0.10-0.52, P=.0004) without heterogeneity (I² =0%). In the case series analysis (134 pregnancies), only two cases (1.5%) of mother to child transmission with extremely high maternal viral load and non-compliance to treatment were identified. Maternal and foetal safety parameters including congenital malformation and foetal death were re-assuring.

CONCLUSIONS

For pregnant women with high hepatitis B virus DNA levels, tenofovir administration in the second or third trimester can prevent mother to child transmission when combined with hepatitis B immunoglobulin and the hepatitis B vaccine. Tenofovir is safe and tolerable for both the mother and foetus.

Identification of anti-HBV activities in Paeonia suffruticosa Andr. using GRP78 as a drug target on Herbochip®

Background

Herbochip^® technology is a high throughput drug screening platform in a reverse screening manner, in which potential chemical leads in herbal extracts are immobilized and drug target proteins can be used as probes for screening process [BMC Complementary and Alternative Medicine (2015) 15:146]. While herbal medicines represent an ideal reservoir for drug screenings, here a molecular chaperone GRP78 is demonstrated to serve as a potential target for antiviral drug discovery.

Methods

We cloned and expressed a truncated but fully functional form of human GRP78 (hGRP78^1-508) and used it as a probe for anti-HBV drug screening on herbochips. In vitro cytotoxicity and in vitro anti-HBV activity of the herbal extracts were evaluated by MTT and ELISA assays, respectively. Finally, anti-HBV activity was confirmed by in vivo assay using DHBV DNA levels in DHBV-infected ducklings as a model.

Results

Primary screenings using GRP78 on 40 herbochips revealed 11 positives. Four of the positives, namely Dioscorea bulbifera, Lasiosphaera fenzlii, Paeonia suffruticosa and Polygonum cuspidatum were subjected to subsequent assays. None of the above extracts was cytotoxic to AML12 cells, but P. cuspidatum extract (PCE) was found to be cytotoxic to HepG2 2.2.15 cells. Both PCE and P. suffruticosa extract (PSE) suppressed secretion of HBsAg and HBeAg in HepG2 2.2.15 cells. The anti-HBV activity of PSE was further confirmed in vivo.

Conclusion

We have demonstrated that GRP78 is a valid probe for anti-HBV drug screening on herbochips. We have also shown that PSE, while being non-cytotoxic, possesses in vitro and in vivo anti-HBV activities. Taken together, our data suggest that PSE may be a potential anti-HBV agent for therapeutic use.

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-017-0132-2) contains supplementary material, which is available to authorized users.

Telbivudine therapy for chronic hepatitis B: A journey to identify super-responders and to optimize treatment using the roadmap model

Hepatitis B virus (HBV) infection is one of the most serious health problems worldwide with a high risk for cirrhosis and liver cancer. Several antiviral agents have been approved for the treatment of chronic hepatitis B, leading to a rapid reduction in HBV DNA and normalization of serum alanine aminotransferase levels. Telbivudine, a potent inhibitor of HBV replication, has been shown to be well tolerated. Because of the emergence of drug resistance, optimization strategies for telbivudine therapy have been shown to improve patient responses. Optimal baseline characteristics in so-called super-responders have been used to predict the virological response. Baseline HBV DNA levels < 9 log₁₀ copies/mL (2 × 10⁸  IU/mL) or alanine aminotransferase levels of more than or equal to twofold the upper limit of normal in HBeAg-positive patients and HBV DNA < 7 log₁₀ copies/mL (2 × 10⁶  IU/mL) in HBeAg-negative patients were strong predictors for virological response. In addition, the roadmap model, based on early virological response at week 24 of therapy, is considered as a powerful tool to identify patients at risk of treatment failure (HBV DNA ≥ 300 copies/mL, i.e. 60 IU/mL) and to reduce the risk of antiviral resistance. When considering pre-treatment characteristics and on-treatment responses, telbivudine may provide physicians with a wide choice of options to effectively treat patients with chronic hepatitis B, especially those with or at risk of renal impairment, or women of childbearing age.

Targeting Inflammation in Cancer Prevention and Therapy

Inflammation is associated with the development and malignant progression of most cancers. As most of the cell types involved in cancer-associated inflammation are genetically stable and thus are not subjected to rapid emergence of drug resistance, the targeting of inflammation represents an attractive strategy both for cancer prevention and for cancer therapy. Tumor-extrinsic inflammation is caused by many factors, including bacterial and viral infections, autoimmune diseases, obesity, tobacco smoking, asbestos exposure, and excessive alcohol consumption, all of which increase cancer risk and stimulate malignant progression. In contrast, cancer-intrinsic or cancer-elicited inflammation can be triggered by cancer-initiating mutations and can contribute to malignant progression through the recruitment and activation of inflammatory cells. Both extrinsic and intrinsic inflammation can result in immunosuppression, thereby providing a preferred background for tumor development. In clinical trials, lifestyle modifications including healthy diet, exercise, alcohol, and smoking cessation have proven effective in ameliorating inflammation and reducing the risk of cancer-related deaths. In addition, consumption of certain anti-inflammatory drugs, including aspirin, can significantly reduce cancer risk, suggesting that common nonsteroidal anti-inflammatory drugs (NSAID) and more specific COX2 inhibitors can be used in cancer prevention. In addition to being examined for their preventative potential, both NSAIDs and more potent anti-inflammatory antibody-based drugs need to be tested for their ability to augment the efficacy of more conventional therapeutic approaches on the basis of tumor resection, radiation, and cytotoxic chemicals. Cancer Prev Res; 9(12); 895-905. ©2016 AACR.

X region mutations of hepatitis B virus related to clinical severity

Chronic hepatitis B virus (HBV) infection remains a major health problem, with more than 240 million people chronically infected worldwide and potentially 650000 deaths per year due to advanced liver diseases including liver cirrhosis and hepatocellular carcinoma (HCC). HBV-X protein (HBx) contributes to the biology and pathogenesis of HBV via stimulating virus replication or altering host gene expression related to HCC. The HBV X region contains only 465 bp encoding the 16.5 kDa HBx protein, which also contains several critical cis-elements such as enhancer II, the core promoter and the microRNA-binding region. Thus, mutations in this region may affect not only the HBx open reading frame but also the overlapped cis-elements. Recently, several types of HBx mutations significantly associated with clinical severity have been described, although the functional mechanism in most of these cases remains unsolved. This review article will mainly focus on the HBx mutations proven to be significantly related to clinical severity via epidemiological studies.

Status and development of anti-HBV drugs based on "HBF drug watch"

Hepatitis B virus (HBV) infection is a major public health threat globally. Present therapies can only suppress viral replication instead of viral elimination. With the application of direct anti-viral agents (DAAs) to hepatitis C virus (HCV) infection, many pharmaceutical industries pay their attention to investigating anti-HBV drugs. As a result, the update of anti-HBV drugs at the website http://www.hepb.org/professionals/hbf_drug_watch.htm speeds up. In this review, we summarize all the drugs available in the market and those in clinical trials based on this website.

Efficacy of telbivudine with conditional tenofovir intensification in patients with chronic hepatitis B: results from the 2-year roadmap strategy

Background:

A 2-year roadmap study was conducted to evaluate the efficacy and safety of tenofovir intensification at Week 24 in patients with chronic hepatitis B (CHB) receiving telbivudine.

Scope:

A prospective multicenter study was conducted in treatment-naive patients with hepatitis B e antigen (HBeAg)-positive CHB. All patients received telbivudine (600 mg/day) until Week 24. Thereafter, patients with detectable hepatitis B virus (HBV) DNA (≥300 copies/mL) were administered tenofovir (300 mg/day) plus telbivudine, and patients with undetectable HBV DNA continued telbivudine monotherapy until Week 104. The primary endpoint was the proportion of patients with undetectable HBV DNA (<300 copies/mL) at Weeks 52 and 104.

Findings:

A total of 105 patients were enrolled in the trial, of which 100 were eligible for efficacy analysis. Undetectable HBV DNA levels were observed at Week 24 in 55 patients who continued on with telbivudine monotherapy. The remaining 45 patients with detectable HBV DNA received tenofovir add-on therapy. With monotherapy, 100% (55/55) and 94.5% (52/55) of patients achieved HBV DNA <300 copies/mL at Weeks 52 and 104, respectively; the corresponding values for patients with add-on therapy were 84.4% (38/45) and 93.3% (42/45). Overall, undetectable HBV DNA (<300 copies/mL) was found in 93% (93/100) and 94% (94/100) of patients at Weeks 52 and 104, respectively. HBeAg seroconversion rate was 44.4% (44/99) at Week 104 for the overall patient population. One patient in the monotherapy group and six in the intensification group demonstrated HBsAg clearance at Week 104. HBsAg seroconversion was observed in four patients at Week 104, all belonged to the tenofovir intensification group. Eight patients sustained HBsAg loss during a posttreatment follow-up period of 16 weeks. Alanine aminotransferase (ALT) normalization was constant in the telbivudine monotherapy group, whereas a progressive improvement was observed in the tenofovir intensification group. Two patients in the monotherapy and none in the intensification group experienced viral breakthrough by Week 104. There were no reports of myopathy in either group. The mean changes in estimated glomerular filtration rate (eGFR), estimated using the Modification of Diet in Renal Disease (MDRD) formula, from baseline to Week 104 were +6.145 mL/min/1.73 m² (p=0.0230) and +7.954 mL/min/1.73 m² (p=0.0154) in the telbivudine monotherapy and tenofovir intensification groups, respectively. The incidence of serious AEs was four in the telbivudine monotherapy and two in the tenofovir intensification group. The main limitation of this study was limited sample size, which made the power of the observation low, and the absence of a comparative subgroup to assess the progression of patients with detectable HBV DNA without treatment intensification.

Conclusions:

Data from this 2-year roadmap study confirmed that telbivudine with add-on tenofovir was effective and well tolerated in patients with CHB. Telbivudine was associated with an improvement in eGFR from baseline in both the groups.

Effect of Telbivudine Versus Other Nucleos(t)ide Analogs on HBeAg Seroconversion and Other Outcomes in Patients with Chronic Hepatitis B: A Network Meta-Analysis

INTRODUCTION

A comprehensive and up-to-date network meta-analysis (NMA) helps to determine the comparative efficacies of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B (CHB). The aim of this NMA was to assess the efficacy of telbivudine versus adefovir, entecavir, lamivudine, and tenofovir in nucleos(t)ide-naïve hepatitis B e antigen (HBeAg)-positive patients with CHB.

METHODS

A systematic review was conducted to search Medline, Medline-In Process, EMBASE, and the Cochrane Central Register of Controlled Trials databases for publications of randomized controlled trials (RCTs). NMA was performed to compare the efficacy outcomes of telbivudine versus other approved NAs at 1- and 2-year time points.

RESULTS

A total of 75 RCTs were included in the systematic review. At the 1-year time point, telbivudine was associated with significantly higher rates of: (1) HBeAg seroconversion than adefovir [odds ratio (OR) 1.99 (95% credible interval (CrI): 1.05, 3.45)], entecavir [OR 2.00 (95% CrI: 1.44, 2.82)] and lamivudine [OR 1.49 (95% CrI: 1.10, 2.03)]; (2) HBeAg loss than entecavir [OR 1.85 (95% CrI: 1.28, 2.76)] and lamivudine [OR 1.62 (95% CrI: 1.20, 2.24)]; (3) alanine aminotransferase (ALT) normalization than lamivudine [OR 1.50 (95% CrI: 1.05, 2.21)]; and (4) hepatitis B virus (HBV) DNA suppression than adefovir [OR 2.77 (95% CrI: 1.28, 5.45)] and lamivudine [OR 2.97 (95% CrI: 1.99, 4.53)]. At the 2-year time point, the relative efficacy outcomes were not statistically significant.

CONCLUSION

At 1 year, telbivudine was superior to adefovir, entecavir and lamivudine in HBeAg seroconversion, and to entecavir and lamivudine in HBeAg loss. Telbivudine was also superior to lamivudine in ALT normalization and to adefovir and lamivudine in suppressing HBV DNA levels.

FUNDING

Novartis Pharma AG.

IFN-lambda therapy: current status and future perspectives

Interferon-lambda (IFN-λ), the most recently described type III IFN, plays a crucial part by acting on specific cell types, controlling viral infections and establishing robust innate immunity against cancer. In contrast to IFN-α or IFN-γ, IFN-λ has a restricted cell response pattern, which could make this new IFN a better choice for disease targeting and reducing adverse events. Although IFN-λ is considered to have pivotal roles in cancer, viral infections and autoimmune diseases, clinical trials have only been conducted for treatment of chronic hepatitis C virus infection. In this review, we discuss the current and the potential clinical applications of IFN-λ in the context of current IFN therapy.

CRISPR/Cas9-based tools for targeted genome editing and replication control of HBV

Hepatitis B virus (HBV) infection remains a major global health problem because current therapies rarely eliminate HBV infections to achieve a complete cure. A different treatment paradigm to effectively clear HBV infection and eradicate latent viral reservoirs is urgently required. In recent years, the development of a new RNA-guided gene-editing tool, the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9) system, has greatly facilitated site-specific mutagenesis and represents a very promising potential therapeutic tool for diseases, including for eradication of invasive pathogens such as HBV. Here, we review recent advances in the use of CRISPR/Cas9, which is designed to target HBV specific DNA sequences to inhibit HBV replication and to induce viral genome mutation, in cell lines or animal models. Advantages, limitations and possible solutions, and proposed directions for future research are discussed to highlight the opportunities and challenges of CRISPR/Cas9 as a new, potentially curative therapy for chronic hepatitis B infection.