Three-year efficacy and safety of tenofovir disoproxil fumarate treatment for chronic hepatitis B

Evolution and diversity of the hepatitis B virus genome: Clinical implications

Hepatitis B virus (HBV) infection remains a significant global health burden. The genetic variation of HBV is complex. HBV can be divided into nine genotypes, which show significant differences in geographical distribution, clinical manifestations, transmission routes and treatment response. In recent years, substantial progress has been made through various research methods in understanding the development, pathogenesis, and antiviral treatment response of clinical disease associated with HBV genetic variants. This progress provides important theoretical support for a deeper understanding of the natural history of HBV infection, virus detection, drug treatment, vaccine development, mother-to-child transmission, and surveillance management. This review summarizes the mechanisms of HBV diversity, discusses methods used to detect viral diversity in current studies, and the impact of viral genome variation during infection on the development of clinical disease.

Synthesis of Chiral Acyclic Pyrimidine Nucleoside Analogues from DHAP-Dependent Aldolases

Dihydroxyacetone phosphate (DHAP)-dependent aldolases catalyze the aldol addition of DHAP to a variety of aldehydes and generate compounds with two stereocenters. This reaction is useful to synthesize chiral acyclic nucleosides, which constitute a well-known class of antiviral drugs currently used. In such compounds, the chirality of the aliphatic chain, which mimics the open pentose residue, is crucial for activity. In this work, three DHAP-dependent aldolases: fructose-1,6-biphosphate aldolase from rabbit muscle, rhanmulose-1-phosphate aldolase from Thermotoga maritima, and fuculose-1-phosphate aldolase from Escherichia coli, were used as biocatalysts. Aldehyde derivatives of thymine and cytosine were used as acceptor substrates, generating new acyclic nucleoside analogues containing two new stereocenters with conversion yields between 70% and 90%. Moreover, structural analyses by molecular docking were carried out to gain insights into the diasteromeric excess observed.

Renal dysfunction during treatment of chronic hepatitis B with tenofovir disoproxyl fumarate and associated risk factors

OBJECTIVES

To analyze the evolution of glomerular filtration rate (GFR) and the presence of renal tubular dysfunction during the treatment of chronic hepatitis B virus (HBV) infection with tenofovir disoproxil fumarate (TDF) and to determine the risk factors involved.

METHODS

Retrospective cohort observational study of adults with chronic hepatitis B. Exclusion: hepatitis C virus-HBV coinfection, diabetes, baseline GFR less than 60 ml/min. Measurements of serum and urinary creatinine and phosphate; urinary albumin, retinol-binding protein (RBP) and neutrophil gelatinase-associated lipocalin (NGAL) were performed. Univariate and multivariate analyses tracked factors associated with worsening GFR.

RESULTS

A total of 120 individuals were included: 35% NAÏVE (G1); 49.2% HBV using TDF (G2); 15.8% HBV-HIV using TDF (G3); 63.3% men; 60.8% white; 30% hypertensive. Average age was 50.5 years (SD ± 12.9 years). Reactive HBeAg predominated in G3 ( P  < 0.001) and cirrhosis in G2 ( P  < 0.036). NGAL was elevated in 5.3% of cases (G1 = 3.2%; G2 = 8.7%; G3 = 0%; P  = 0.582), RBP in 6.7% (G1, G3 = 0%; G2 = 13.6%; P  = 0.012), urinary phosphate/creatinine ratio in 16.2% (G1 = 15.2%; G2 = 14.5%; G3 = 23.5%; P  = 0.842) and urinary albumin/creatinine ratio in 12.9% (G1 = 12.2%; G2 = 10.7%; G3 = 21.1%; P  = 0.494). Worsening of renal function occurred in 22.5% of the population (G1 = 11.9%; G2 = 28.8%; G3 = 26.3%; P  = 0.122), independently associated only with systemic arterial hypertension [adjusted odds ratio (AOR) = 4.14; P  = 0.008], but not to TDF (AOR = 2.66; P  = 0.110) or male sex (AOR = 2.39; P  = 0.135). However, the concomitance of these variables generated a high estimated risk for this outcome (51%).

CONCLUSIONS

Renal tubular dysfunction was uncommon according to NGAL, RBP or urinary phosphate/creatinine ratio. TDF was not an independent factor for worsening renal function, significantly associated only with systemic arterial hypertension. However, in hypertensive men, the use of TDF should be monitored.

Islatravir: evaluation of clinical development for HIV and HBV

INTRODUCTION

Islatravir (ISL) is a nucleoside reverse transcriptase translocation inhibitor (NRTTI) that inhibits HIV RT through multiple mechanisms. Contrary to all approved NtRTIs, islatravir retains a 3'OH group. In vitro and clinical data show that ISL is an ultrapotent investigational drug with high tolerability.

AREAS COVERED

The historical development of islatravir and its mechanisms of HIV and HBV inhibition and resistance are covered. Additionally, the outcomes of Phase I and Phase II clinical trials are discussed.

EXPERT OPINION

Current first-line antiretroviral therapy, preexposure, and postexposure prophylactic interventions are highly effective in maintaining low or undetectable viral load. Despite these measures, an unusually high rate of new infections every year warrants developing novel antivirals that can suppress drug-resistant HIV and improve compliance. ISL, an NRTTI once deemed a long-acting drug, was placed on a clinical hold. The outcome of ongoing clinical trials with a reduced ISL dose will decide its future clinical application. Additionally, MK-8527, which inhibits HIV via same mechanism as that of ISL may supersede ISL. Data on ISL inhibition of HBV are scarce, and preclinical data show dramatically lower ISL efficacy against HBV than currently preferred nucleos(t)ide drugs, indicating that ISL may not be a potent anti-HBV drug.

Cost-effectiveness of treating all hepatitis B-positive individuals in the United States

Chronic hepatitis B virus (HBV) infection is a leading cause of liver disease and related mortality globally. However, most of the infected individuals in the United States remain undiagnosed and untreated. There is a need to understand more completely the economic and disease burden impact of removing treatment restrictions and increasing diagnosis and treatment. The PRoGReSs model, a dynamic HBV model that tracks the infected population by year, disease stage, and gender, was used to quantify the disease and economic burden of chronic HBV infection in the United States from 2020 to 2050 based on four scenarios: a status quo (base) scenario and three treat-all scenarios, in which screening, diagnosis, and treatment were maximized at different annual treatment price levels of $5382, $2000 and $750. Compared to the base scenario, the treat-all scenarios would avert 71,100 acute and 11,100 chronic incident cases of HBV, and 169,000 liver-related deaths from 2020 to 2050. At an annual treatment cost of $2000, treating all HBV infections would be highly cost-effective, and at $750 would be cost saving and would achieve a positive return on investment before 2050. Maximizing the diagnosed and treated HBV population in the United States would avert a significant number of cases of advanced liver disease and related mortality. Such interventions can also be cost-effective compared to the status quo strategy, and cost saving at a treatment price threshold of $750 annually, above the current lowest annual treatment cost of $362.

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.

Overview of the development of HBV small molecule inhibitors

Like tuberculosis and Acquired Immune Deficiency Syndrome (AIDS), hepatitis B is a globally recognized major public health threat. Although there are many small-molecule drugs for the treatment of hepatitis B, the approved drugs cannot eradicate the pathogenic culprit covalently closed circular DNA in patients, so the patients need long-term medication to control HBV amplification. Driven by a high unmet medical need, many pharmaceutical companies and research institutions have been engaged in the development of anti-HBV drugs to achieve a functional cure for chronic hepatitis B as soon as possible. This review summarizes the pathogenesis of hepatitis B virus and the research progress in the development of anti-HBV small molecule drugs, and introduces the cccDNA formation and transcription inhibitors and core inhibitors in detail, especially emphasizes the role of chinese herbal medicine in the treatment of chronic hepatitis B. Furthermore, this review proposes three potential strategies for cccDNA eradication in the future. We believe this review will provide meaningful guidance to achieve a functional cure for viral hepatitis B in the future.

Intranasal therapeutic vaccine containing HBsAg and HBcAg for patients with chronic hepatitis B; 18 months follow-up results of phase IIa clinical study

AIMS

HBsAg loss with anti-HBs acquisition is considered a functional cure and ideal treatment goal for patients with CHB. Our group have reported the efficacy of therapeutic vaccine with HBsAg and HBcAg (NASVAC) by intranasal and subcutaneous injection. In this study, we investigated the safety and efficacy of newly developed CVP-NASVAC, which contained NASVAC with mucoadhesive carboxyl vinyl polymer (CVP) in the dedicated device.

METHODS

A single dose, open-label, phase IIa clinical trial of CVP-NASVAC was conducted. Patients with CHB treated with nucleoside/nucleotide analogs (NAs) and HBV carriers not undergoing anti-HBV treatment were enrolled. CVP-NASVAC was injected through the nose for, in total, 10 times. Participants were followed-up for 18 months, and their HBsAg reduction and anti-HBs induction assessed as endpoints.

RESULTS

Among the patients with CHB treated with NAs (n = 27) and HBV carriers without NAs (n = 36), 74.1% and 75.0% exhibited reductions in their baseline HBsAg, and the mean reductions were -0.1454 log₁₀  IU/ml (p < 0.05) and -0.2677 log₁₀  IU/ml (p < 0.05), respectively. Anti-HBs antibody was detected in 40.7% and 58.3% of patients treated with and without NAs, respectively. Six of 71 (9.5%) patients were functionally cured after the CVP-NASVAC treatment.

CONCLUSIONS

Anti-HBs induction and HBsAg reduction was observed after CVP-NASVAC treatment in some patients with CHB. The CVP-NASVAC is a safe treatment, which might expect to achieve functional cure for patients with CHB.

Polyarthritis presented in a patient with untreated chronic hepatitis B infection

Hepatitis B virus (HBV) infection can cause arthritis, but it is rarely reported. In the current report, we present a case of chronic polyarthritis in a patient with untreated HBV infection. A 63-year-old woman suffering from polyarthritis in her fingers visited our institution. She had experienced exacerbations and remissions of polyarthritis for more than 20 years. She had been diagnosed with rheumatoid arthritis and had been treated with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and nonsteroidal anti-inflammatory drugs by her primary care doctor, but the csDMARDs were discontinued at the request of the patient 10 years before the first visit to our hospital. The blood test showed negative for rheumatoid factor and anticyclic citrullinated peptides antibody but positive for hepatitis B surface antigen. Hepatitis B surface antigen and HBV-Deoxyribo Nucleic Acid (DNA) were increased to 312.6 (IU/ml) and 4.6 (log copies/ml), respectively. Based on the results of abdominal computed tomography and echography, she was diagnosed with liver cirrhosis. Treatment for HBV infection was begun with oral tenofovir at 25 mg/day. The polyarthritis in her fingers gradually disappeared and has not relapsed for 6 months after the initiation of treatment for HBV infection. When polyarthritis is diagnosed, the possibility that chronic HBV infection can be one of the causes of polyarthritis should be considered.

Hepatitis B e antigen and e antibody in a multi-ethnic cohort of adult chronic hepatitis B virus patients followed at a single liver unit for a period of 20 years

Hepatitis B virus e antigen (HBeAg) loss and the appearance of antibodies to HBeAg (anti-HBe) are favourable events in the history of chronic hepatitis B virus (CHB) infection. Most CHB patients have the HBeAg/anti-HBe profiles +/- or -/+, and little is published on the derivation or fate of the +/+ and -/- profiles. We have used electronically accessible patient data to study the HBeAg and anti-HBe profiles of a multi-ethnic cohort of adult HBV patients seen at a single centre over a period of more than 20 years. 3594 HBsAg-positive patients were identified and patients with viral coinfection or acute HBV infection were excluded. Cross-sectional and longitudinal analyses of HBeAg/anti-HBe status were undertaken. Compared with White or Black patients, Chinese and Asian patients are more likely to be HBeAg positive during child-bearing years. Patients with +/+ profile are likely to undergo HBeAg loss and seroconversion during relatively short follow-up. Chinese patients have a relatively increased rate of seroconversion. For HBeAg-positive patients, the risk of seroconversion diminishes with advancing age. Despite HBeAg loss, seroconversion is seldom observed after age 60 years. The proportion of HBV patients with -/- increases with age, and most acquire this profile by HBeAg loss but without antecedent seroconversion. -/- patients can lose HBsAg and develop anti-HBs. It was not possible to demonstrate a favourable impact of antiviral treatment on the rate of HBeAg seroconversion.

Real-world study on HBsAg loss of combination therapy in HBeAg-negative chronic hepatitis B patients

Combination therapy with pegylated interferon (PEG-IFN) and nucleos(t)ide analogues (NAs) can enhance hepatitis B surface antigen (HBsAg) clearance. However, the specific treatment strategy and the patients who would benefit the most are unclear. Therefore, we assessed the HBsAg loss rate of add-on PEG-IFN and explored the factors associated with HBsAg loss in chronic hepatitis B (CHB) patients. This was a real-world cohort study of adults with CHB. Hepatitis B e antigen (HBeAg)-negative NAs-treated patients with baseline HBsAg ≤1500 IU/ml and HBV DNA < the lower limit of detection, or 100 IU/ml, received 48 weeks of add-on PEG-IFN. The primary outcome of the study was the rate of HBsAg loss at 48 weeks of combination treatment. Using multivariable logistic regression analysis, we determined factors associated with HBsAg loss. HBsAg loss in 2579 patients (mean age: 41.2 years; 80.9% male) was 36.7% (947 patients) at 48 weeks. HBsAg loss was highest in patients from south-central and southwestern China (40.0%). Factors independently associated with HBsAg loss included: increasing age (odds ratio = 0.961); being male (0.543); baseline HBsAg level (0.216); HBsAg decrease at 12 weeks (between 0.5 and 1.0 log₁₀ IU/ml [2.405] and >1.0 log₁₀ IU/ml [7.370]); alanine aminotransferase (ALT) increase at 12 weeks (1.365); haemoglobin (HGB) decrease at 12 weeks (1.558). There was no difference in the primary outcomes associated with the combination regimen. In conclusion, HBsAg loss by combination therapy was higher in patients from southern China than those from the north. An increased chance of HBsAg loss was associated with baseline characteristics and dynamic changes in clinical indicators.

Tenofovir disoproxil fumarate therapy to prevent hepatitis B virus vertical transmission-A review of maternal and infant outcomes

Hepatitis B virus (HBV) is a global health problem. Vertical transmission of HBV from HBV surface antigen (HBsAg)-positive mothers to their infants is the most common cause of HBV infection worldwide. The use of passive-active immunoprophylaxis is >90% effective in reducing the risk of vertical transmission, but immunoprophylaxis failure can occur in infants born to mothers with high viraemia. Thus, it is recommended that pregnant women with HBV-DNA level >200 000 IU/ml receive nucleos(t)ide analogue (NA) treatment [i.e. tenofovir disoproxil fumarate (TDF), lamivudine or telbivudine] during third trimester to prevent infant immunoprophylaxis failure. TDF is recommended as the first-line therapy based on available data on efficacy, safety and resistance profile. However, maternal immunological reconstitution following parturition can increase immune-mediated flares to viral antigens that is potentially exacerbated following TDF withdrawal. In this article, we review available data on the efficacy and safety of TDF administration to prevent HBV mother-to-child transmission. We also discuss changes in maternal viral markers [i.e. HBV-DNA, HBV e antigen and HBsAg] and alanine aminotransferase during follow-up post-partum in mothers received NA to prevent HBV vertical transmission.

A carrier-free metal-organic hybrid nanoassembly with combination anti-viral and hepato-protective activity for hepatitis B treatment

Hepatitis B represents a major global public health burden, which is caused by the hepatitis B virus (HBV) with a high infection rate. Although several anti-HBV drugs have been developed for clinical treatment of hepatitis B, the current therapeutic strategies still suffer from undeniable adverse effects, insufficient efficacy after systemic administration and chronic inflammation. Here, we develop a carrier-free metal-organic hybrid nanoassembly that is co-loaded with tenofovir (TFV), an anti-viral agent and phosphorylated glycyrrhetinic acid (GAP), an anti-inflammatory compound (TFV/GAP/NA) to enhance the anti-HBV effect and alleviate the inflammatory response for hepatitis B treatment. The nanoassembly is easily prepared through the ionic interactions between the anionic phosphonate/phosphate groups from TFV/GAP and the zirconium cation, which has a stable nanostructure and a high drug-loading capacity. The nanoassembly prolongs the circulation time with reduced drug leakage in the blood and elevates drug accumulation in the liver after intravascular administration. After internalization mediated by the GAP ligand-GA receptor interaction, TFV/GAP/NA disassembles by the phosphatase-triggered degradation of the phosphate ester bonds in GAP and releases TFV, GAP and GA within the HBV-positive hepatocytes. The released TFV interferes with the HBV polymerase to inhibit the viral DNA replication, while the released GAP and GA suppress the pro-inflammatory protein expression. In mouse models, treatment with TFV/GAP/NA inhibits HBV production and alleviates inflammation-mediated liver injury.

Costs and health impact of delayed implementation of a national hepatitis B treatment program in China

Background

Hepatitis B virus (HBV) infection is a leading public health problem in China. COVID-19 pandemic has interrupted the delivery of health care interventions worldwide, including HBV infection control.

Methods

In this study, we used a Markov model to quantify the costs and population health impact of HBV treatment in China for the following scenarios: 1) current practice with only 17% of treatment eligible HBV infected adults receiving antiviral treatment; 2) reaching the World Health Organization (WHO) treatment target of 80% by 2030 with a steady increase in treatment rate beginning in 2022; and 3) the effect of a 1-5-year delay in meeting the 2030 WHO treatment target. A one-way as well as a probabilistic sensitivity analysis were conducted.

Results

Without increasing antiviral treatment for treatment eligible HBV infected adults, the life-time health care costs for the estimated 89.2 million adults living with HBV in China is US$1305 billion and 10.8 million (12%) will die from HBV-related liver disease. Increasing treatment to achieve the WHO 80% target by 2030 would save US$472 billion and prevent 3.3 million HBV-related deaths. We estimated that a 1-year delay beyond 2030 in reaching the WHO 80% treatment target would likely lead to US$55 billion increase in future health care costs, and an additional 334 000 future deaths from HBV-related liver disease or cancer.

Conclusions

Reaching the WHO 2030 with minimal delays would have an immense health and economic benefit. Implementing a national treatment program for HBV in China should be a key priority for policymakers.

The impact of the COVID-19 pandemic on hepatitis B virus vaccination and transmission among men who have sex with men: a mathematical modelling study

Background

Methods

Results

Conclusions

Probability of HBsAg loss after nucleo(s)tide analogue withdrawal depends on HBV genotype and viral antigen levels

BACKGROUND & AIMS

Nucleo(s)tide analogue (NUC) withdrawal may result in HBsAg clearance in a subset of patients. However, predictors of HBsAg loss after NUC withdrawal remain ill-defined.

METHODS

We studied predictors of HBsAg loss in a global cohort of HBeAg-negative patients with undetectable HBV DNA who discontinued long-term NUC therapy. Patients requiring retreatment after treatment cessation were considered non-responders.

RESULTS

We enrolled 1,216 patients (991 with genotype data); 98 (8.1%) achieved HBsAg loss. The probability of HBsAg loss was higher in non-Asian patients (adjusted hazard ratio [aHR] 8.26, p <0.001), and in patients with lower HBsAg (aHR 0.243, p <0.001) and HBV core-related antigen (HBcrAg) (aHR 0.718, p = 0.001) levels. Combining HBsAg (<10, 10-100 or >100 IU/ml) and HBcrAg (<2log vs. ≥2 log) levels improved prediction of HBsAg loss, with extremely low rates observed in patients with HBsAg >100 IU/ml with detectable HBcrAg. HBsAg loss rates also varied with HBV genotype; the highest rates were observed for genotypes A and D, and none of the patients with HBV genotype E experienced HBsAg loss (p <0.001 for the overall comparison across genotypes; p <0.001 for genotypes A/D vs. genotypes B/C). HBV genotype C was independently associated with a higher probability of HBsAg loss when compared to genotype B among Asian patients (aHR 2.494; 95% CI 1.490-4.174, p = 0.001).

CONCLUSIONS

The probability of HBsAg loss after NUC cessation varies according to patient ethnicity, HBV genotype and end-of-treatment viral antigen levels. Patients with low HBsAg (<100 IU/ml) and/or undetectable HBcrAg levels, particularly if non-Asian or infected with HBV genotype C, appear to be the best candidates for treatment withdrawal.

LAY SUMMARY

A subset of patients may achieve clearance of hepatitis B surface antigen (HBsAg) - so-called functional cure - after withdrawal of nucleo(s)tide analogue therapy. In this multicentre study of 1,216 patients who discontinued antiviral therapy, we identified non-Asian ethnicity, HBV genotype C, and low hepatitis B surface antigen and hepatitis B core-related antigen levels as factors associated with an increased chance of HBsAg loss.

HBsAg Loss as a Treatment Endpoint for Chronic HBV Infection: HBV Cure

Despite the availability of effective vaccines and antiviral therapy over the past two to three decades, chronic hepatitis B virus (HBV) infection remains a major global health threat as a leading cause of cirrhosis and liver cancer. Functional HBV cure defined as hepatitis B surface antigen (HBsAg) loss and undetectable serum HBV DNA is associated with improved clinical outcomes in patients with chronic HBV infection. However, spontaneous loss of HBsAg is rare and occurs in only 1% of all HBsAg-positive individuals annually. Furthermore, the rate of functional cure with currently available antiviral therapy is even lower, <1% patients on treatment per year. Nonetheless, HBsAg loss has become the new target or therapeutic endpoint for antiviral treatment. Recently, there has been much excitement surrounding the development of novel antiviral agents such as small interfering RNA (siRNA), core assembly modulators (CAMs), nucleic acid polymers (NAPs) among others, which may be used in combination with nucleos(t)ide analogs and possibly immunomodulatory therapies to achieve functional cure in a significant proportion of patients with chronic hepatitis B. Novel assays with improved sensitivity for detection of very low levels of HBsAg and to determine the source of HBsAg production will also be required to measure efficacy of newer antiviral treatments for HBV cure. In this narrative review, we will define HBV cure, discuss various sources of HBsAg production, evaluate rates of HBsAg loss with current and future antiviral agents, review clinical factors associated with spontaneous HBsAg loss, and explore clinical implications of functional cure.

The impact of background liver disease on the long-term prognosis of very-early-stage HCC after ablation therapy

Background and aim

The long-term prognosis of hepatocellular carcinoma (HCC) treated at a very-early-stage (the Barcelona Clinical Liver Cancer (BCLC) classification stage 0) was unclear, especially in terms of background liver disease.

Methods

This single-center, retrospective study included 302 patients with BCLC stage 0 HCC treated with radiofrequency ablation (RFA) and followed for at least six months. We examined the impact of background liver disease on overall survival and recurrence.

Results

The median age was 72 (range; 36–91) years; the median tumor diameter was 15 (range; 8–20) mm. The etiologies of background liver disease were hepatitis B virus infection (HBV) in 24 cases, hepatitis C virus infection (HCV) in 195 cases, and non-viral (NBNC) in 83 cases. Among the patients with HCV, 63 had achieved sustained virological response (SVR) by antiviral therapy (HCV SVR) before developing HCC (n = 37) or after HCC treatment (n = 26), and 132 had active HCV infection (HCV non-SVR). The median overall survival was 85 (95% CI; 72–98) months, and the median recurrence-free survival was 26 (95% CI; 20–30) months. Active infection with hepatitis C virus negatively contributed to overall survival (HR 2.91, 95% CI 1.31–3.60, p = 0.003) and recurrence-free survival (HR 1.47, 95% CI 1.06–2.05, p = 0.011).

Conclusions

The prognosis of RFA treatment for very early-stage HCC was favorable. Achieving SVR in hepatitis C was important for further prognosis improvement.

Non-Inferior Efficacy of Tenofovir Disoproxil to Tenofovir Disoproxil Fumarate in Virologically Suppressed Chronic Hepatitis B Patients

PURPOSE

Tenofovir disoproxil (TD), modified from tenofovir disoproxil fumarate (TDF), was developed as a salt-free formulation, removing fumarate to improve the ease of oral intake by reducing the tablet's size. We evaluated the maintenance of antiviral effects and overall safety profile of TD 245 mg after switching from TDF 300 mg in patients with chronic hepatitis B (CHB).

PATIENTS AND METHODS

CHB patients with HBV-DNA <69 IU/mL after ≥24 weeks of TDF therapy were enrolled. The primary efficacy endpoint was the HBV-DNA suppression rate (HBV-DNA <69 IU/mL) at week 48; We evaluated the non-inferiority (10% margin) of TD to TDF in terms of efficacy. Safety was assessed based on adverse events (AEs), laboratory tests, bone mineral density, and renal function abnormalities.

RESULTS

Overall, 189 subjects were randomized in a 2:1 ratio, and 117 and 66 subjects in the TD and TDF groups, respectively, completed the study. In the per-protocol set, the HBV-DNA suppression rate at week 48 was 99.1% and 100% in the TD and TDF groups, respectively. The lower limit of the 97.5% one-sided confidence interval for the intergroup difference in HBV-DNA suppression rate was -2.8%, which was greater than the prespecified margin of non-inferiority. The changes in creatinine clearance from baseline to week 48 was significantly less in the TD group and in the TDF group; -0.8 ± 9.8 versus -2.4 ± 12.8 mL/min, respectively (P=0.017).

CONCLUSION

TD was non-inferior to TDF for maintaining viral suppression in CHB patients, showing the less decline of renal function.

Tenofovir versus lamivudine followed by tenofovir in severe exacerbation of hepatitis B: a randomized controlled study

Spontaneous severe acute exacerbation (SAE) is not uncommon in the natural history of chronic hepatitis B (CHB). Lamivudine (LAM) had the advantages of low price, quick onset, good efficacy and no drug resistance within 24 weeks. This study aimed to compare the short-term efficacy of tenofovir disoproxil fumarate (TDF) and LAM for 24 weeks followed by TDF in the treatment of CHB with severe acute exacerbation. Consecutive patients of CHB with SAE were randomized to receive either TDF (19 patients) or LAM for 24 weeks followed by TDF (18 patients). The primary endpoint was overall mortality or receipt of liver transplantation by week 24. This study was approved by the Institutional Review Board (IRB) of the Kaohsiung Veterans General Hospital (VGHKS12-CT5-10). The baseline characteristics were comparable between the two groups. By week 24, seven (37%) and five (28%) patients in the TDF and LAM/TDF groups died or received liver transplantation (P=0.487). Multivariate analysis showed that albumin level, prothrombin time (PT), and hepatic encephalopathy were independent factors associated with mortality or liver transplantation by week 24. Early reductions in HBV DNA of more than or equal to 2 log at 1 and 2 weeks were similar between the two groups. The biochemical and virological responses at 12, 24 and 48 weeks were also similar between the two groups. TDF and LAM for 24 weeks followed by TDF achieved a similar clinical outcome in CHB patients with SAE.

Potential Molecular Targets of Tenofovir Disoproxil Fumarate for Alleviating Chronic Liver Diseases via a Non-Antiviral Effect in a Normal Mouse Model

Accumulating evidence suggests that tenofovir disoproxil fumarate (TDF) can attenuate liver fibrosis directly, the mechanism of which, however, has not been fully elucidated, and there is a paucity of data concerning whether TDF can also mitigate other chronic liver diseases (CLDs). We aimed to identify the molecular targets and potential mechanism of TDF itself in ameliorating CLDs. RNA-sequencing was performed on mouse liver tissues treated with TDF or normal saline. Then the differentially expressed genes (DEGs) were screened, and enrichment analyses of the function and signaling pathways of DEGs were performed with Database for Annotation, Visualization, and Integrated Discovery (DAVID) and Metascape. Next, protein-protein interaction (PPI) networks were constructed and module analyses were utilized to identify significant genes. Subsequently, the DisGeNET platform was used to identify the potential target genes of TDF in mitigating these diseases. Finally, prediction of the transcription factors (TFs) and microRNAs (miRNAs) of the target genes was done to conjecture the underlying mechanism by which TDF relieved CLDs. As a result, a total of 854 DEGs were identified, and the DEGs were involved mainly in "immunity," "inflammation," and "metabolism" processes. In addition, 50 significant genes were obtained via PPI construction and module analyses. Furthermore, by means of DisGeNET, 19 genes (Adra2a, Cxcl1, Itgam, Cxcl2, Ccr1, Ccl5, Cxcl5, Fabp5, Sell, Lilr4b, Ccr2, Tlr2, Lilrb4a, Tnf, Itgb2, Lgals3, Cxcr4, Sucnr1, and Mme) were identified to be associated with nine CLDs. Finally, 34 miRNAs (especially mmu-miR-155-5p) and 12 TFs (especially Nfkb1) were predicted to be upstream of the nine target genes (Cxcl1, Cxcl2, Ccl5, Ccr2, Sell, Tlr2, Tnf, Cxcr4, and Mme) of TDF in ameliorating CLDs. In conclusion, our study suggests that TDF have the potential to ameliorate CLDs independently of its antiviral activity by affecting the expression of genes involved in hepatic immune, inflammatory, and metabolic processes via mmu-miR-155-5p-NF-κB signaling. These findings provided prima facie evidence for using TDF in CHB patients with concurrent CLDs.

Suboptimal Response to Tenofovir Alafenamide in Two Patients With HBeAg-Positive Hepatitis B: A Case Report

Tenofovir alafenamide (TAF) is one of the most potent first-line nucleot(s)ide analogs for treating chronic hepatitis B virus (HBV) infections. To date, no cases of TAF drug resistance and/or suboptimal response have been reported. To our knowledge, this is the first report of two adult male patients presenting a suboptimal response response to TAF monotherapy. Our study indicates long-term observations and extensive data are needed to further evaluate the efficacy and safety of TAF, and highlights the need for the development of robust novel direct-acting antivirals and immune therapies for HBV.

Tenofovir disoproxil fumarate in Chinese chronic hepatitis B patients: Results of a multicenter, double-blind, double-dummy, clinical trial at 96 weeks

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is a prodrug of a nucleotide analogue. As an antiviral drug, TDF has been proposed in the first-line treatment of chronic hepatitis B (CHB). Qingzhong, a brand name of TDF, commercialized by Jiangsu Chia-tai Tianqing Pharmaceutical Co Ltd., and Viread, another brand name of TDF, commercialized by GlaxoSmithKline, have both been approved by the State Food and Drug Administration, China.

AIM

To investigate the efficacy and safety of the two TDF agents in the treatment of Chinese CHB patients.

METHODS

This trial was registered at ClinicalTrials.gov with the identifier number of NCT02287857. A total of 330 Chinese CHB patients, among which 232 were hepatitis B e antigen (HBeAg)-positive, were included in this 5-year-long, multicenter, double-blinded, double-dummy, randomized-controlled, non-inferiority phase III trial. The participants were initially randomized into two groups: Group A (n = 161), in which the participants received 300 mg Qingzhong once a day for 48 wk; and Group B, in which the participants received 300 mg Viread once a day for 48 wk. Starting from week 49, all the participants in Groups A and B received 300 mg Qingzhong once a day until the 96^th week. In this study, the primary endpoint was the decrease in plasma level of hepatitis B virus (HBV) DNA at the 96^th week, while the secondary endpoints were suppression of HBV replication, alanine aminotransferase (ALT) normalization, HBeAg loss, and HBeAg seroconversion rates.

RESULTS

For the participants with HBeAg-positive CHB, the decrease in mean HBV DNA level relative to the baseline value was comparable between Groups A and B (5.77 vs 5.73 log₁₀ IU/mL, P > 0.05) at the 96^th week. In addition, similar percentages of HBeAg-positive participants in the two groups exhibited undetectable levels of HBV DNA, HBeAg loss, and HBeAg seroconversion (71.05% vs 77.97%, 31.00% vs 27.27%, and 20.22% vs 15.79%, respectively, in Group A vs Group B; P > 0.05). For the participants with HBeAg-negative CHB, the decrease in mean HBV DNA level relative to the baseline value was also comparable between Groups A and B (4.46 vs 4.70 log₁₀ IU/mL, P > 0.05) at the 96^th week. In addition, similar percentages of HBeAg-negative participants in the two groups exhibited undetectable levels of HBV DNA (87.23% vs 94.12% in Group A vs Group B, respectively; P > 0.05). Finally, similar percentages of CHB patients (HBeAg-positive or HBeAg-negative) in the two groups exhibited normalization of ALT (80.14% vs 84.57% in Group A vs Group B, respectively; P > 0.05), and similar incidences of adverse events were observed (106 vs 104 in Group A vs Group B, respectively; P > 0.05).

CONCLUSION

Both Qingzhong and Viread are effective and safe in the treatment of Chinese CHB patients according to the results of our clinical trial.

Changes in the Hepatitis B Surface Antigen Level According to the HBeAg Status and Drug Used in Long-term Nucleos(t)ide Analog-treated Chronic Hepatitis B Patients

Backgrounds/Aims

The HBsAg levels have been used to monitor the chronic hepatitis B (CHB) treatment response to antiviral therapy. On the other hand, it is unclear if the HBsAg quantification levels at each treatment point differ according to the HBeAg status and drug in CHB patients. This study compared the changes in HBsAg in CHB patients according to the HBeAg status and treatment drugs.

Methods

CHB patients with at least 1 year of follow-up treatment with one drug, either entecavir (ETV) or tenofovir (TDF), were enrolled in this study. The mean HBsAg levels were measured annually for up to 6 years. A linear mixed model was used to compare the HBsAg quantification levels during the follow-up period. An independent samples t-test was used to analyze the differences in the HBsAg quantification levels at each treatment time point.

Results

Ninety-seven patients were enrolled in this study; 59 among them were HBeAg-positive. Two patients in the TDF group achieved HBsAg seroconversion. The HBsAg level decreased during the follow-up in the ETV and TDF groups. The HBsAg level was lower in the TDF group than the ETV group during the follow-up. On the other hand, subgroup analysis showed that this trend was the same only in the HBeAg-negative patients, not in the HBeAg-positive patients. In the HBeAg-negative patients, HBsAg level in the TDF group was significantly lower than that in the ETV group at 36, 48, and 72 months. The change in HBsAg level from the baseline increased at a decreasing rate during the follow-up in both groups. Furthermore, the change in the HBsAg level in the TDF group was significantly larger than that of the ETV group at 36 months in the HBeAg-negative patients.

Conclusions

Although TDF might be more efficient than ETV in reducing the HBsAg level in HBeAg-negative patients in a few years, HBsAg seroconversion occurred very rarely. A further large-scale, long-term study will be needed to confirm the antiviral effects on the HBsAg level.

Cost-Effectiveness of One-Time Universal Screening for Chronic Hepatitis B Infection in Adults in the United States

BACKGROUND

An estimated 862,000 to 2.4 million people have chronic hepatitis B infection (CHB). Left undiagnosed and untreated CHB increases risk of death from liver cirrhosis or liver cancer. Hepatitis B screening is recommended for pregnant women and populations with increased CHB risk, but diagnosis rates remain low with only 33% of people with CHB aware of their infection.. This study aimed to assess the cost-effectiveness of universal adult screening for CHB.

METHODS

We used a Markov model to calculate the costs, population health impact and cost-effectiveness of one-time universal screening and CHB monitoring and treatment compared to current practice. Sensitivity analysis was performed on model parameters to identify thresholds for cost-savings or cost-effectiveness based on willinness-to-pay of $50,000/QALY . The analysis assumed testing would be performed during routine healthcare visits, and generic tenofovir or entecavir would be dispensed for treatment. Testing costs were based on Medicare reimbursement rates.

RESULTS

At an estimated 0.24% prevalence of undiagnosed CHB, universal HBsAg screening in adults 18-69 years old is cost-saving compared with current practice if antiviral treatment drug costs remain below $894 per year. Compared with current practice, universal screening would avert an additional 7.4 cases of compensated cirrhosis, 3.3 cases of decompensated cirrhosis, 5.5 cases of hepatocellular carcinoma, 1.9 liver transplants, and 10.3 HBV related deaths at a savings of $263,000 per 100,000 adults screened.

CONCLUSION

Universal HBsAg screening of adults in the US general population for CHB is cost-effective and likely cost-saving compared to current CHB screening recommendations.

Viral hepatitis: A brief introduction, review of management, advances and challenges

Viral hepatitis represents a major public health hazard and is associated with significant global mortality. Over the last decade, there have been significant developments in the prevention and treatment of viral hepatitis. These changes have led to a situation whereby global elimination has become a realistic goal, fully endorsed by the World Health Organization (WHO). By 2030, the WHO aims to reduce viral hepatitis mortality by 65% and reduce new infections by 90% by 2030. These are ambitious targets and will only be met through a sustained programme. This will require expertise from hepatologists and virologists and the fields of public health and primary care. In this article, we review the causes of viral hepatitis, its management through prevention and treatments, and the most pressing challenges and recent advances.

Ending risk-group HBV vaccination for MSM after the introduction of universal infant HBV vaccination: A mathematical modelling study

BACKGROUND

Risk-group HBV vaccination for men who have sex with men (MSM) was introduced in the Netherlands in 2002, followed by universal infant vaccination in 2011, that will enable termination of risk-group vaccination over time. The introduction of pre-exposure prophylaxis (PrEP) for HIV prevention might result in increased HBV testing and vaccination against HBV. The aim of this study was to investigate the impact of the transition from risk-group to universal HBV vaccination, accounting for improvements in HBV testing and treatment, as well as the introduction of PrEP.

METHODS

We developed a mathematical model for HBV transmission among MSM. Universal vaccination was modelled by assigning some MSM (5-15% in 2028 increasing to 80-90% in 2033 and thereafter) to be vaccinated when they become sexually active. We investigated different scenarios assuming 0.5% extra vaccination rate and 0.5% extra testing rate due to PrEP consultations; and 5% of HIV-negative MSM on PrEP, that will reduce the probability of HBV acquisition by 88%.

RESULTS

Universal vaccination resulted in a reduction of 24% (interquartile range; 22-25%) of the total number of HBV infections among MSM estimated to occur from 2020 to 2070. With universal vaccination, terminating risk-group vaccination in 2030 or 2040 resulted in 30% or 10% more HBV infections over 2020-2070, respectively, compared to continuation of risk-group vaccination until 2070. With PrEP and continued risk-group vaccination, the total number of HBV infections over 2020-2070 was reduced by 13%.

CONCLUSIONS

Universal HBV vaccination can lead to a major reduction in HBV incidence among MSM in the future. The reduction becomes smaller when ending risk-group HBV vaccination, but larger by PrEP use for HIV prevention. Efforts to keep high levels of HBV vaccination, testing, and treatment have to be continued in the coming decades in order to eliminate HBV as a health threat for MSM.

Comparison of tenofovir and entecavir in the development of acute kidney injury in cirrhotic chronic hepatitis B patients with refractory ascites

BACKGROUND AND AIM

Tenofovir disoproxil fumarate (TDF) and entecavir are effective antiviral medications that are recommended as first-line monotherapies for the treatment of chronic hepatitis B (CHB) infection, including decompensated liver cirrhosis with ascites. Acute kidney injury (AKI) commonly occurs in patients with cirrhosis and ascites. The aim of this study was to compare the development of AKI during TDF and entecavir treatment of CHB patients with cirrhotic refractory ascites.

METHODS

From January 2011 to April 2017, we identified patients who were diagnosed with cirrhosis with refractory ascites and received TDF or entecavir treatments at Kaohsiung Chang Gung Memorial Hospital. AKI was defined as an increase in serum creatinine of more than 0.3 mg/dL or 1.5-fold from baseline. All episodes of AKI were recorded and compared between those who received TDF and entecavir.

RESULTS

A total of 111 patients were enrolled in this retrospective study, of which 22 patients were treated with TDF and 89 were treated with entecavir. Patients with AKI episodes had a higher proportion of TDF treatment (P = 0.01), male (P = 0.023), hepatocellular carcinoma (P = 0.007), admission (P = 0.045), and mortality (P = 0.018). Logistic regression analysis illustrated that TDF treatment of patients with comorbidity was an independent risk factor for the development of AKI [odds ratio (OR), 3.756; 95% confidence interval (CI), 1.293-10.912; P = 0.015] and hepatorenal syndrome (OR, 7.651; 95% CI, 1.697-34.508; P = 0.008).

CONCLUSIONS

TDF treatment is a risk factor for AKI and HRS development in cirrhotic patients with refractory ascites in comparison with entecavir treatment, especially in patients with comorbidity.

The strategy and efficacy of prophylaxis against hepatitis B virus recurrence after liver transplantation for HBV-related diseases in the era of potent nucleos(t)ide analogues: A meta-analysis

OBJECTIVES

This meta-analysis aimed to evaluate the clinical outcome of liver transplant (LT) recipients under potent nucleoside or nucleotide analogue (NA)-based regimens and investigate different prophylactic schemes.

METHODS

We followed PRISMA statement to conduct this study. Two reviewers independently searched relevant literature via PubMed, Embase, Ovid MEDLINE, Web of Science and Insightmeme. Studies were included if they evaluated hepatitis B virus (HBV) recurrence under potent NA-based regimens in patients who received HBV-related LT. Primary and secondary outcomes were HBV recurrence, hepatocellular carcinoma (HCC) recurrence, all-cause and HBV recurrence-related mortality. Incidences with 95% confidence intervals were calculated and assessed by fixed and random effects models. Subgroup analyses were used to examine the impact of different treatment strategies.

RESULTS

Altogether 25 studies (N = 2327) were included, with a pooled HBV recurrence rate of 1.01% (95% CI 0.53%-1.59%). HBV viremia or hepatitis D virus superinfection did not influence HBV recurrence significantly (P = 0.23 and 0.71, respectively). The recurrence rate under an indefinite combination of potent NA and hepatitis B immunoglobulin (HBIG) was lower than that under potent NA monotherapy (P = 0.000) and similar to that under NA plus a finite course of HBIG (P = 0.48). The pooled HCC recurrence rate was 5.34% (95% CI 0.78%-12.48%). HBV recurrence-related mortality and all-cause mortality were 0% and 6.95% (95% CI 4.30%-10.08%), respectively.

CONCLUSIONS

Potent NA-based regimens provide satisfactory HBV antiviral prophylaxis and improve long-term outcomes for LT recipients. A finite combination of potent NA and HBIG is an alternative to life-long dual therapy.

Consensus Guidelines: Best Practices for Detection, Assessment and Management of Suspected Acute Drug-Induced Liver Injury During Clinical Trials in Adults with Chronic Viral Hepatitis and Adults with Cirrhosis Secondary to Hepatitis B, C and Nonalcoholic Steatohepatitis

With the widespread development of new drugs to treat chronic liver diseases (CLDs), including viral hepatitis and nonalcoholic steatohepatitis (NASH), more patients are entering trials with abnormal baseline liver tests and with advanced liver injury, including cirrhosis. The current regulatory guidelines addressing the monitoring, diagnosis, and management of suspected drug-induced liver injury (DILI) during clinical trials primarily address individuals entering with normal baseline liver tests. Using the same laboratory criteria cited as signals of potential DILI in studies involving patients with no underlying liver disease and normal baseline liver tests may result in premature and unnecessary cessation of a study drug in a clinical trial population whose abnormal and fluctuating liver tests are actually due to their underlying CLD. This position paper focuses on defining best practices for the detection, monitoring, diagnosis, and management of suspected acute DILI during clinical trials in patients with CLD, including hepatitis C virus (HCV) and hepatitis B virus (HBV), both with and without cirrhosis and NASH with cirrhosis. This is one of several position papers developed by the IQ DILI Initiative, comprising members from 16 pharmaceutical companies in collaboration with DILI experts from academia and regulatory agencies. It is based on an extensive literature review and discussions between industry members and experts from outside industry to achieve consensus regarding the recommendations. Key conclusions and recommendations include (1) the importance of establishing laboratory criteria that signal potential DILI events and that fit the disease indication being studied in the clinical trial based on knowledge of the natural history of test fluctuations in that disease; (2) establishing a pretreatment value that is based on more than one screening determination, and revising that baseline during the trial if a new nadir is achieved during treatment; (3) basing rules for increased monitoring and for stopping drug for potential DILI on multiples of baseline liver test values and/or a threshold value rather than multiples of the upper limit of normal (ULN) for that test; (4) making use of more sensitive tests of liver function, including direct bilirubin (DB) or combined parameters such as aspartate transaminase:alanine transaminase (AST:ALT) ratio or model for end-stage liver disease (MELD) to signal potential DILI, especially in studies of patients with cirrhosis; and (5) being aware of potential confounders related to complications of the disease being studied that may masquerade as DILI events.

Hepatitis B Virus Covalently Closed Circular DNA Predicts Postoperative Liver Cancer Metastasis Independent of Virological Suppression

New antiviral therapies against hepatitis B virus (HBV) focus on the elimination of covalently closed circular DNA (cccDNA). However, traditional cccDNA-specific quantitative PCR (qPCR) has a narrow effective range, hindering a reliable comparison between the levels of biopsy-derived cccDNAs. Collaterally, the prognostic role of cccDNA in HBV-related hepatocellular carcinoma (HCC) cannot be clearly defined. Here, we developed a peptide nucleic acid (PNA)-clamping qPCR method to provide a wider range of specific cccDNA quantification (up to 5 logs of effective range). Extrachromosomal DNA was extracted from para-neoplastic tissues for cccDNA quantification. In total, 350 HBV-related HCC patients were included for an outcome analysis. Without differential pre-dilution, cccDNA levels in para-neoplastic liver tissues were determined, ranging from < 2 × 10³ to 123.0 × 10⁶ copies/gram. The multivariate linear regression analysis showed that cccDNA was independently correlated with the HBV e antigen (p < 0.001) and serum HBV-DNA levels (p = 0.012). The Cox proportional hazard model analysis showed that cccDNA independently predicted overall survival (p = 0.003) and extrahepatic metastasis-free survival (p = 0.001). In virologically suppressed HCC patients, cccDNA still effectively predicted intrahepatic recurrence-free (p = 0.003) and extrahepatic metastasis-free (p = 0.009) survivals. In conclusion, cccDNA independently predicted postoperative extrahepatic metastasis-free survival.

Continuing besifovir dipivoxil maleate versus switching from tenofovir disoproxil fumarate for treatment of chronic hepatitis B: Results of 192-week phase 3 trial

Background/Aims

Besifovir dipivoxil maleate (BSV), an acyclic nucleotide phosphonate, shows potent antiviral activity against hepatitis B virus. Our previous 48-week trial revealed that BSV has comparable antiviral efficacy to tenofovir disoproxil fumarate (TDF) and better safety profiles in terms of improved renal and bone safety. This extension study evaluated the prolonged efficacy and safety of BSV in treatment-naive chronic hepatitis B patients.

Methods

Patients continued to participate in an open-label BSV study after an initial 48-week double-blind comparison of BSV and TDF treatment. The antiviral efficacy and drug safety was evaluated up to 192 weeks in two groups: patients continuing BSV treatment (BSV-BSV) and patients switching from TDF to BSV after 48 weeks (TDF-BSV).

Results

Among 197 patients receiving randomized treatments, 170 (86%) entered the open-label phase and 152 (77%) entered the 192-week extension study. Virological response rates over 192 weeks were 92.50% and 93.06% in the BSV-BSV and TDF-BSV groups, respectively (P=0.90). Hepatitis B envelop antigen seroconversion and alanine aminotransferase normalization rates were similar between the groups (P=0.75 and P=0.36, respectively). There were no drug-resistant mutations to BSV. Bone mineral density and renal function were well preserved in the BSV-BSV group, whereas these initially worsened then recovered after switching therapy in the TDF-BSV group.

Conclusions

BSV maintained potent antiviral efficacy after 192 weeks and showed no evidence of drug resistance. BSV was safe, well tolerated, and effective in patients who switched from TDF to BSV. Trial Registration Number: NCT01937806 (date: 10 Sep 2013).

Overview of Biologically Active Nucleoside Phosphonates

The use of the phosphonate motif featuring a carbon-phosphorous bond as bioisosteric replacement of the labile P–O bond is widely recognized as an attractive structural concept in different areas of medicinal chemistry, since it addresses the very fundamental principles of enzymatic stability and minimized metabolic activation. This review discusses the most influential successes in drug design with special emphasis on nucleoside phosphonates and their prodrugs as antiviral and cancer treatment agents. A description of structurally related analogs able to interfere with the transmission of other infectious diseases caused by pathogens like bacteria and parasites will then follow. Finally, molecules acting as agonists/antagonists of P2X and P2Y receptors along with nucleotidase inhibitors will also be covered. This review aims to guide readers through the fundamentals of nucleoside phosphonate therapeutics in order to inspire the future design of molecules to target infections that are refractory to currently available therapeutic options.

Epidemiology, Natural History, and Treatment of Hepatitis Delta Virus Infection in HIV/Hepatitis B Virus Coinfection

PURPOSE OF REVIEW

Limited data exist on the prevalence, determinants, and outcomes of hepatitis delta virus (HDV) infection among HIV/hepatitis B virus (HBV)-coinfected persons. This review provides current evidence on the epidemiology, natural history, and treatment of HDV infection in patients with HIV/HBV coinfection and highlights future research needs.

RECENT FINDINGS

Cross-sectional studies in Europe, Africa, South America, and Asia show that the prevalence of HDV among HIV/HBV-coinfected patients ranges from 1.2 to 25%. No studies have evaluated the prevalence of HDV infection among HIV/HBV-coinfected patients in the USA. HDV infection increases the risk of hepatic decompensation and hepatocellular carcinoma among HIV/HBV-coinfected patients. HDV treatment remains limited to pegylated interferon-alpha, which results in sustained virologic response in fewer than 25%. Data on the epidemiology, natural history, and treatment of HDV among HIV/HBV-coinfected persons remain limited. More research is needed to address these knowledge gaps in order to better manage HDV coinfection in HIV/HBV-coinfected patients.

Complex genetic encoding of the hepatitis B virus on-drug persistence

Tenofovir disoproxil fumarate (TDF) is one of the nucleotide analogs capable of inhibiting the reverse transcriptase (RT) activity of HIV and hepatitis B virus (HBV). There is no known HBV resistance to TDF. However, detectable variation in duration of HBV persistence in patients on TDF therapy suggests the existence of genetic mechanisms of on-drug persistence that reduce TDF efficacy for some HBV strains without affording actual resistance. Here, the whole genome of intra-host HBV variants (N = 1,288) was sequenced from patients with rapid (RR, N = 5) and slow response (SR, N = 5) to TDF. Association of HBV genomic and protein polymorphic sites to RR and SR was assessed using phylogenetic analysis and Bayesian network methods. We show that, in difference to resistance to nucleotide analogs, which is mainly associated with few specific mutations in RT, the HBV on-TDF persistence is defined by genetic variations across the entire HBV genome. Analysis of the inferred 3D-structures indicates no difference in affinity of TDF binding by RT encoded by intra-host HBV variants that rapidly decline or persist in presence of TDF. This finding suggests that effectiveness of TDF recognition and binding does not contribute significantly to on-drug persistence. Differences in patterns of genetic associations to TDF response between HBV genotypes B and C and lack of a single pattern of mutations among intra-host variants sensitive to TDF indicate a complex genetic encoding of the trait. We hypothesize that there are many genetic mechanisms of on-drug persistence, which are differentially available to HBV strains. These pervasive mechanisms are insufficient to prevent viral inhibition completely but may contribute significantly to robustness of actual resistance. On-drug persistence may reduce the overall effectiveness of therapy and should be considered for development of more potent drugs.

Validation of hepatocellular carcinoma risk scores in Japanese chronic hepatitis B cohort receiving nucleot(s)ide analog

BACKGROUND AND AIM

The prediction of hepatocellular carcinoma (HCC) development during nucleotide/nucleoside analog (NA) therapy is clinically important in patients with chronic hepatitis B. Although several useful models for HCC prediction have been previously reported, their usefulness in the Japanese population is unclear. Therefore, this study examines the applicability of these models in Japanese patients.

METHODS

Four hundred forty-three patients with no history of HCC who were treated with entecavir, tenofovir alafenamide, or tenofovir disoproxil fumarate were enrolled. PAGE-B, modified-PAGE-B, and REACH-B scores were calculated, and subsequent HCC development was investigated.

RESULTS

The mean follow-up duration was 5.1 years, and a total of 33 patients (7.4%) developed HCC during the follow-up period. Multivariate analysis revealed that old age (hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.01-1.09, P = 0.011), male gender (HR 2.62, 95% CI 1.06-6.49, P = 0.037), and low platelet count (HR 0.83, 95% CI 0.77-0.91, P < 0.001) were independent predictors of HCC development. These factors are the same as the factors identified in the PAGE-B model. Time-dependent area under the receiver operating characteristic (AUROC) curve revealed that the AUROCs for 3 and 7 years of PAGE-B (AUROC: 0.786 and 0.744 at 3 and 7 years, respectively) were continuously higher than those of REACH-B (0.658 and 0.543) and modified PAGE-B AUROC (0.772 and 0.731).

CONCLUSIONS

PAGE-B, which can easily identify high-risk cases, can be useful for predicting HCC development in Japanese patients treated with NA therapy.

Chronic hepatitis B exhibited higher rate of hepatocellular carcinoma occurrence than hepatitis C in cirrhotic patients after effective antiviral treatment

BACKGROUND/PURPOSE

Effective antiviral-therapy can reduce the risk of liver cirrhosis related hepatocellular carcinoma in patients with chronic hepatitis B and hepatitis C. Yet, the difference of hepatocellular carcinoma development in chronic hepatitis B and hepatitis C patients with cirrhosis after effective antiviral therapy treatment is unknown. In this study, We comprehensive explored the difference among them.

METHODS

1363 patients with cirrhosis and hepatitis B virus treated with nucleos(t)ide analogues (NUCs) with completely suppressed virus, and patients with cirrhosis and hepatitis C virus treated with pegylated interferon (peg-IFN)/ribavirin (RBV) combination therapy who achieved sustained virologic response were enrolled.

RESULTS

Total 261 developed hepatocellular carcinoma within a median follow-up of 4.25 years. Univariate analysis, patients developed hepatocellular carcinoma tended to be of older age, and had lower platelet counts, were chronic hepatitis B carriers, and had higher serum alfa-fetoprotein (AFP) (≥20 ng/mL), FIB-4 index and APRI scores. Subsequent multivariate analysis revealed older age, lower platelet counts, high AFP levels and chronic hepatitis B carriers were independent risk factors of hepatocellular carcinoma.

CONCLUSION

Our findings identify that chronic hepatitis B patients were with a higher risk of hepatocellular carcinoma compared to chronic hepatitis C patients after achieving virological response. Special attention should be paid to those patients.

Hepatitis B virus recurrence after liver transplantation: An old tale or a clear and present danger?

Hepatitis B virus (HBV) recurrence after liver transplantation (LT) has been described more than 50 years ago. Similarly, to other clinical conditions, in which impairment of host immune defense favors viral replication, early reports described in details recurrence and reactivation of HBV in liver transplant recipients. The evidence of a possible, severe, clinical evolution of HBV reappearance in a significant percentage of these patients, allowed to consider, for some years, HBV positivity a contraindication for LT. Moving from the old to the new millennium this picture has changed dramatically. Several studies contributed to establish efficient prophylactic protocols for HBV recurrence and with the advent of more potent anti-viral drugs an increased control of infection was achieved in transplanted patients as well as in the general immune-competent HBV population. Success obtained in the last decade led some authors to the conclusion that HBV is now to consider just as a “mere nuisance”. However, with regard to HBV and LT, outstanding issues are still on the table: (1) A standard HBV prophylaxis protocol after transplant has not yet been clearly defined; (2) The evidence of HBV resistant strains to the most potent antiviral agents is claiming for a new generation of drugs; and (3) The possibility of prophylaxis withdrawal in some patients has been demonstrated, but reliable methods for their selection are still lacking. The evolution of LT for HBV is examined in detail in this review together with the description of the strategies adopted to prevent HBV recurrence and their pros and cons.

Efficacy of oral antiviral drugs to prevent mother-to-child transmission of hepatitis B virus: a network meta-analysis

BACKGROUND

Hepatitis B is a serious global health problem. Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a major risk factor in the endemicity of HBV infection. Oral antiviral drugs are recommended to highly viremic mothers to decrease MTCT of HBV. The present network analysis compared the efficacy of available treatments to prevent the MTCT of HBV.

METHODS

The electronic databases of PubMed, Embase, Web of Science, Scopus, and Wanfang data were searched for eligible studies. Pair-wise meta-analysis and Bayesian network analysis were applied to compare the efficacy of antiviral drugs.

RESULTS

Seventy-five studies involving 12,740 pregnant females were eligible for analysis. On pair-wise analysis, lamivudine (OR 0.15, 95% CI 0.09-0.25, I-squared = 0%), telbivudine (OR 0.07, 95% CI 0.05-0.10, I-squared = 0%) and tenofovir (OR 0.07, 95% CI 0.04-0.13, I-squared = 0%) significantly decreased the MTCT rate. Results of multiple comparisons with ranking probability based on Bayesian analysis showed that tenofovir (SUCRA = 96.83%) appeared more effective than the two other drugs.

CONCLUSION

In addition to active and passive immunoprophylaxis, lamivudine, telbivudine and tenofovir in highly viremic mothers can further decrease MTCT of HBV. Based on direct and indirect evidence, tenofovir appears to be more effective than the two other drugs in the prevention of HBV MTCT.

An observational study on long-term renal outcome in patients with chronic hepatitis B treated with tenofovir disoproxil fumarate

In patients with chronic hepatitis B (CHB), long-term effects of tenofovir disoproxil fumarate (TDF) on renal function have been controversial. This study aimed to analyse the real-world long-term effects of TDF on renal function in Korean patients with CHB. We analysed a cohort of 640 treatment-naïve patients with CHB who were treated with TDF between May 2012 and December 2015 at Severance Hospital, Seoul, Republic of Korea. The mean age was 48.3 years old, and 59.5% were male. The proportions of hypertension and diabetes mellitus (DM) were 11.6% and 14.2%, respectively, and that of liver cirrhosis was 20.8%. During the 5-year follow-up, using a linear mixed model, serum creatinine increased from 0.77 ± 0.01 mg/dL to 0.85 ± 0.02 mg/dL (P < .001), and eGFR decreased from 102.6 ± 0.6 mL/min/1.73 m² to 93.4 ± 1.4 mL/min/1.73 m² (P < .001). In subgroup analysis, eGFR was statistically more decreased in patients with age > 60 than ≦60 years old (P = .027), and in patients with diuretic use than without diuretic use (P = .008). In multivariate analysis, the independent risk factors for eGFR decrease > 20% were baseline eGFR < 60mL/min/1.73 m² (P = .034) and the use of diuretics (P < .001). CHB patients on TDF experienced greater reduction in renal function with age > 60 and with diuretic use compared to those without these characteristics. Baseline eGFR < 60 mL/min/1.73 m² and use of diuretics were independent risk factors of eGFR decline of more than 20% on TDF therapy.

Will we need novel combinations to cure HBV infection?

Chronic hepatitis B is a numerically important cause of cirrhosis and hepatocellular carcinoma. Nucleoside analogue therapy may modify the risk. However, maintenance suppressive therapy is required, as a functional cure (generally defined as loss of HBsAg off treatment) is an uncommon outcome of antiviral treatment. Chronic hepatitis B is a numerically important cause of cirrhosis and hepatocellular carcinoma. Nucleoside analogue therapy may modify the risk. However, maintenance suppressive therapy is required, as a functional cure (generally defined as loss of HBsAg off treatment) is an uncommon outcome of antiviral treatment. Currently numerous investigational agents being developed to either interfere with specific steps in HBV replication or as host cellular targeting agents, that inhibit viral replication, and deplete or inactivate cccDNA, or as immune modulators. Synergistic mechanisms will be needed to incorporate a decrease in HBV transcription, impairment of transcription from HBV genomes, loss of cccDNA or altered epigenetic regulation of cccDNA transcription, and immune modulation or immunologically stimulated hepatocyte cell turnover. Nucleoside analogue suppressed patients are being included in many current trials. Trials are progressing to combination therapy as additive or synergistic effects are sought. These trials will provide important insights into the biology of HBV and perturbations of the immune response, required to effect HBsAg loss at different stages of the disease. The prospect of cures of hepatitis B would ensure that a wide range of patients could be deemed candidates for treatment with new compounds if these were highly effective, finite and safe. Withdrawal of therapy in short-term trials is challenging because short-term therapies may risk severe hepatitis flares, and hepatic decompensation. The limited clinical trial data to date suggest that combination therapy is inevitable.

Clinical efficacy and safety in telbivudine- or tenofovir-treated hepatitis B e antigen-positive pregnant women

BACKGROUND

Telbivudine (LdT) and tenofovir (TDF) are widely used in pregnant women to prevent vertical transmission; however, limited data are available on the differences in clinical efficacy and safety between the two drugs.

METHODS

A total of 307 hepatitis B e antigen (HBeAg)-positive pregnant women with complete follow-up data were enrolled, the patients with alanine aminotransferase (ALT) levels <1×ULN at baseline were enrolled to cohort 1 for treatment from 28 ±4 weeks gestation to delivery, while ALT levels >1×ULN at baseline were enrolled to cohort 2 for treatment from 28 ±4 weeks gestation and continued after delivery. The clinical efficacy and safety was compared in LdT- and TDF-treated patients. In addition, 32 patients in cohort 1 were analysed for nucleoside analogue (NA)-related resistance mutations at baseline and after delivery.

RESULTS

The results showed that HBV DNA levels were significantly lower at delivery than at baseline (P<0.001), but the decreases in HBV DNA, ALT, total bilirubin and total bile acid levels did not differ between the LdT- and TDF-treated patients at different time points (P>0.05) in the two cohorts. However, gastrointestinal adverse effects (vomiting) occurred more frequently in TDF-treated than LdT-treated patients (6.6% versus 0.0%; P=0.001). The results of NA-related resistance mutations analysis in cohort 1 revealed that short-term LdT or TDF treatment did not significantly change the NA-related resistance mutations (P>0.05).

CONCLUSIONS

This study revealed that the clinical efficacy in LdT- or TDF-treated HBeAg-positive Chinese pregnant women is similar, and gastrointestinal adverse effects occurred more frequently in TDF-treated patients.

Long-Term Effects of Tenofovir on Liver Histopathology in Patients with Chronic Viral Hepatitis B Infection

OBJECTIVE

The aim of this study to evaluate histopathological improvement and virological, serological and biochemical response rates in patients with chronic hepatitis B (CHB) who were treated with tenofovir disoproxil fumarate (TDF).

MATERIAL AND METHOD

A total of 91 nucleosid(t)e-naive CHB patients who received TDF were evaluated. Virological, serological and biochemical test results were assessed at baseline and every 12 weeks. Liver biopsy specimens were assessed according to the modified Ishak scoring.

RESULTS

The study was conducted on 52 patients. The mean age was 40±10 years and 40.4% were female. The mean follow-up period was 33±11 months. HBsAg seroclearance occurred in none of the patients. The serum level of HBV-DNA became undetectable in 94.2% of the patients. Mean histological activity index at baseline and on-treatment were 8.2±2.3 and 6.2±2.0 and the mean fibrosis scores were 2.65±1.3 and 2.33±1.1, respectively.

CONCLUSION

We determined that TDF therapy provided remarkably good HBV DNA suppression and biochemical response rates, but low seroconversion. Improvement of liver necroinflammation was detected, but no significant change observed in fibrosis.

HBcrAg, pg RNA and HBsAg dynamically supervise the seroconversion of HBsAg with anti-viral therapy: "Loss of HBsAg" maybe not a good end-point of anti-viral therapy

OBJECTIVE

We aimed to identify predictor of HBsAg seroconversion using serum quantitative pg-RNA, HBcrAg and HBsAg in CHB patients with anti-viral therapy.

METHOD

A total of 335 patients with anti-viral therapy between 2013 and 2017 were enrolled, only 23 achieved the seroconversion of HBsAg, other 138 patients without seroconversion of HBsAg were selected randomly in 312 patients. The samples date of 161 patients were analyzed at different time. We defined the decrease titer of pg-RNA, HBcrAg and HBsAg from baseline to 6 months and baseline to 12 months as Δpg-RNA, ΔHBcrAg and ΔHBsAg, then we used the Δpg-RNA, ΔHBcrAg and ΔHBsAg to predict HBsAg seroconversion.

RESULT

About 6.9% of patients achieved HBsAg seroconversion after a median of 3.61 years' treatment. Using ROC to predict seroconversion of HBsAg, ΔHBsAg of 0.64 log₁₀ IU/mL with AUC of 0.886 (0.802, 0.969; 95% CI) at 6 months and ΔHBsAg of 1.45 log₁₀ IU/mL with AUC of 0.939 (0.868, 1.000; 95% CI) at 12 months had the maximized Youden's index. The comparison of HBcrAg "conversion" rates using Kaplan-Meier method between 23 patients with HBsAg conversion and 138 patients with HBsAg no conversion indicated that the two groups had significant difference at the time of antiviral discontinuation (p = 0.0124).

CONCLUSION

According to our results, we can use ΔHBsAg to pick out the appropriate patients who have the potential to achieve seroconversion by sticking to antiviral therapy, that is very important to reach the target of functional cure or even clinical cure.

Tenofovir disoproxil fumarate reduces hepatocellular carcinoma, decompensation and death in chronic hepatitis B patients with cirrhosis

BACKGROUND

Lamivudine and entecavir reduce hepatic events and death in chronic hepatitis B (CHB) patients with cirrhosis, but the impact of tenofovir disoproxil fumarate (TDF) is less well studied.

AIM

To investigate the effectiveness of TDF therapy in CHB patients with cirrhosis.

METHODS

We studied TDF-treated and untreated CHB patients with cirrhosis from three tertiary centres. TDF cohort included consecutive patients who received TDF for ≥12 months while the untreated cohort were historical controls receiving routine clinical care prior to the availability of anti-viral therapy. The primary outcome was 5-year cumulative probability of hepatocellular carcinoma (HCC) with secondary outcomes being hepatic decompensation and death or liver transplantation (LT).

RESULTS

A total of 1088 (291 untreated and 797 TDF-treated) patients were included in the study. Five-year cumulative probabilities in untreated vs TDF-treated cohorts were 14.9% vs 9.8% for HCC (P = .07), 22.3% vs 5.9% for decompensation (P < .01) and 13.1% vs 1.1% for death or LT (P < .01) respectively. On multivariable Cox regression, TDF treatment was independently associated with reduced risks of HCC (adjusted hazard ratio [aHR] 0.46, P < .01), decompensating events (aHR 0.28, P = .01) and death or LT (aHR 0.06, P < .01). On sensitivity analyses, these risk reductions with TDF treatment were consistently demonstrated regardless of severity of liver disease and prior anti-viral treatment. TDF treatment led to sustained improvements in most validated prognostic scores for predicting HCC, decompensation and death.

CONCLUSIONS

Compared to untreated patients, TDF treatment reduces the risks of HCC, hepatic decompensation and death in CHB patients with cirrhosis at 5 years.