Ten-year efficacy and safety of tenofovir disoproxil fumarate treatment for chronic hepatitis B virus infection

VIR-2218 (elebsiran) plus pegylated interferon-alfa-2a in participants with chronic hepatitis B virus infection: a phase 2 study

BACKGROUND

Chronic hepatitis B virus (HBV) remains a global concern, with current treatments achieving low rates of HBsAg seroclearance. VIR-2218 (elebsiran), a small interfering RNA agent against HBV transcripts, reduces HBsAg concentrations. We aimed to evaluate the safety and antiviral activity of VIR-2218 with and without pegylated interferon-alpha-2a treatment in participants with chronic HBV.

METHODS

This open-label, phase 2 study was conducted at 23 sites in six countries (New Zealand, Australia, Hong Kong, Thailand, South Korea, and Malaysia). Adults (aged 18-65 years) with chronic HBV infection without cirrhosis and with HBsAg more than 50 IU/mL and HBV DNA less than 90 IU/mL who were on continued nucleoside or nucleotide reverse transcriptase inhibitor (NRTI) therapy for 2 months or longer were eligible. Participants were enrolled into one of six cohorts to receive VIR-2218 200 mg subcutaneously every 4 weeks, with or without 180 μg subcutaneous pegylated interferon-alfa-2a once per week. Cohort 1 received six doses of VIR-2218 (total 20 weeks); cohort 2 received six doses of VIR-2218 starting at day 1, plus 12 doses of pegylated interferon-alfa-2a starting at week 12 (total 24 weeks); cohort 3 received six doses of VIR-2218 and 24 doses of pegylated interferon-alfa-2a (total 24 weeks); cohort 4 received six doses of VIR-2218 and up to 48 doses of pegylated interferon-alfa-2a (total 48 weeks); cohort 5 received up to 13 doses of VIR-2218 and up to 44 doses of pegylated interferon-alfa-2a (total 48 weeks); and cohort 6 received three doses of VIR-2218 and 12 doses of pegylated interferon-alfa-2a (total 12 weeks). The primary endpoints were the incidence of adverse events and clinical assessments (including results of laboratory tests). Secondary endpoints were the mean maximum reduction of serum HBsAg at any timepoint; the proportion of participants with serum HBsAg seroclearance at any timepoint and for more than 6 months after the end of treatment; and the proportion of participants with anti-HBs seroconversion at any timepoint. For patients who were HBeAg-positive, we also assessed the proportion with HBeAg seroclearance or anti-HBe seroconversion at any timepoint. This study is registered with ClinicalTrials.gov, NCT03672188, and is ongoing.

FINDINGS

Between July 2, 2020, and Nov 2, 2021, 124 individuals were screened for eligibility, 84 of whom were enrolled (15 in cohort 1, 15 in cohort 2, 18 in cohort 3, 18 in cohort 4, 13 in cohort 5, and five in cohort 6). Participants were predominantly HBeAg-negative, Asian, and male (66 [79%] participants were male and 18 [21%] were female). Most treatment emergent adverse events were grades 1-2. Three (20%) participants in cohort 1, four (27%) in cohort 2, eight (44%) in cohort 3, seven (39%) in cohort 4, six (46%) in cohort 5, and two (40%) in cohort 6 reported treatment-emergent adverse events related to VIR-2218. 12 (80%) participants in cohort 2, 12 (67%) in cohort 3, 14 (78%) in cohort 4, 13 (100%) in cohort 5, and three (60%) in cohort 6 reported treatment-emergent adverse events related to pegylated interferon-alfa-2a. Two (13%) participants in cohort 1 had elevations in alanine aminotransferase, compared with 13 (87%) participants in cohort 2, 15 (83%) in cohort 3, 17 (94%) in cohort 4, 11 (85%) in cohort 5, and three (60%) in cohort 6. The mean maximum change from baseline at any timepoint in HBsAg concentration was -2·0 log10 IU/mL (95% CI -2·1 to -1·8) in cohort 1, -2·2 log10 IU/mL (-2·5 to -1·8) in cohort 2, -2·5 log10 IU/mL (-2·8 to -2·1) in cohort 3, -2·4 log10 IU/mL (-3·1 to -1·8) in cohort 4, -3·0 log10 IU/mL (-3·7 to -2·3) in cohort 5, and -1·7 log10 IU/mL (-2·1 to -1·4) in cohort 6. 11 participants (one in cohort 2, one in cohort 3, five in cohort 4, and four in cohort 5) receiving VIR-2218 plus pegylated interferon-alfa-2a had HBsAg seroclearance at any timepoint. Of these, ten (91%; one in cohort 2, five in cohort 4, and four in cohort 5) had anti-HBs seropositivity. Six participants (one in cohort 2, three in cohort 4, and two in cohort 5) had sustained HBsAg seroclearance through to 24 weeks after the end of treatment. No participants receiving VIR-2218 monotherapy (cohort 1) or VIR-2218 plus pegylated interferon-alfa-2a 12-week regimen (cohort 6) had HBsAg seroclearance. 12 (42%) of 26 participants (one of four in cohort 1, two of six in cohort 2, four of seven in cohort 3, four of six in cohort 4, and one of three in cohort 5) who were HBeAg positive at baseline had HBeAg seroclearance or anti-HBe seroconversion.

INTERPRETATION

The results of this phase 2 study support further development of VIR-2218 as a potential therapy for patients with chronic HBV infection. Additional clinical trials of VIR-2218 with and without pegylated interferon-alfa-2a in combination with an HBsAg-targeting monoclonal antibody are ongoing.

FUNDING

Vir Biotechnology.

Limited Value of HBV-RNA for Relapse Prediction After Nucleos(t)ide Analogue Withdrawal in HBeAg-negative Hepatitis B Patients

International guidelines suggest cessation of nucleos(t)ide analogues (NA) independent of HBsAg loss in HBeAg-negative patients after 2-3 years of viral suppression. Detectable HBV-RNA levels at the time of NA cessation were linked to a better prediction of relapse after NA withdrawal in small cohorts of HBeAg-negative patients. This study proves the impact of HBV-RNA levels in the prediction of relapse in a large cohort of HBeAg-negative patients, mainly infected with genotype B or C. Serum levels of HBV-RNA, HBsAg, anti-HBc and HBcrAg were determined before NA withdrawal in 154 HBeAg-negative patients, participating either in a therapeutic vaccination trial (NCT02249988) or in an observational register trial (NCT03643172). Importantly, vaccination showed no impact on relapse. Endpoints of the study were virological relapse (HBV-DNA > 2000 IU/mL) or biochemical relapse (attendant ALT levels ≥ 2 × ULN) 24 weeks after NA cessation. Virological relapse occurred in 54.5% of patients (N = 84/154), including eight patients (10%) developing an ALT flare. Baseline HBV-RNA level did not differ significantly between relapsers and off-treatment responders (p = 0.92). No significant difference occurred in proportions of detectable HBV-RNA levels between off-treatment responders (N = 27/70; 38.6%) and relapsers (N = 31/84; 36.9%) (p = 0.99). Combining predefined HBsAg cut-offs (100 IU/mL, p = 0.0013), anti-HBc cut-offs (325 IU/mL, p = 0.0117) or HBcrAg cut-offs (2 log U/mL, p = 0.66) with undetectable HBV-RNA (HBsAg, p = 0.0057; anti-HBc, p = 0.085; HBcrAg, p = 0.60) did not improve relapse prediction. The value of HBV-RNA levels at timepoint of NA cessation for the prediction of relapse is limited in HBeAg-negative patients. Trial Registration: ABX 203-002: NCT02249988; Terminator 2: NCT03643172.

From tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF): perspectives in pediatric patients

INTRODUCTION

Hepatitis B virus (HBV) affects hundreds of millions globally, with many cases stemming from perinatal transmission. Chronic hepatitis B (CHB) in children can progress to cirrhosis and hepatocellular carcinoma (HCC) in adulthood. Treatment options include interferons and nucleos(t)ide reverse transcriptase inhibitors (N[t]RTIs) such as tenofovir alafenamide (TAF).

AREAS COVERED

This review covers the epidemiology of pediatric CHB and current treatments, with a focus on tenofovir-based therapies, particularly tenofovir disoproxil fumarate (TDF) and TAF. TDF has been used for years, but its risks of bone mineral density loss and renal impairment have raised concerns. TAF, with lower systemic exposure, appears to mitigate these risks. Ongoing trials are evaluating TAF's safety in younger children. There are knowledge gaps in long-term safety and the potential for combination therapies.

EXPERT OPINION

TAF offers a safer alternative to TDF for children with CHB, showing high antiviral efficacy and fewer side effects. However, more data is needed on its use in younger children and long-term safety. The future of CHB treatment in pediatrics may include combination therapies and personalized approaches, potentially improving outcomes and minimizing risks over a lifetime of treatment. As research progresses, TAF is likely to become a cornerstone in pediatric CHB management.

A systematic review and meta-analysis of the risk of hepatitis B virus (HBV) resistance in people treated with entecavir or tenofovir

BACKGROUND

As nucleos/tide analogue (NA) therapy (e.g. entecavir and tenofovir) for chronic Hepatitis B virus (HBV) infection becomes more widely indicated and available, understanding drug resistance is essential. A systematic review to quantify resistance to these agents has not previously been undertaken.

METHODS

We performed a systematic review and random-effects meta-analysis to estimate the risk of HBV resistance to entecavir and tenofovir. We searched nine databases up to 29-Aug-23. We included studies of HBV infection featuring >10 individuals, written in English, reporting treatment ≥48 weeks, with assessment of HBV resistance based on viral sequence data. Data were analysed according to prior exposure history to NA, and choice of NA agent. Analyses were performed in R.

FINDINGS

62 studies involving a total of 12,358 participants were included. For entecavir, in treatment-naive individuals (22 studies; 4326 individuals), resistance increased over time to 0.9 % at ≥5 years (95 %CI 0.1-2.3 %), and resistance was increased in NA-experienced individuals (18 studies; 1112 individuals), to 20.1 % (95 %CI 1.6-50.1 %) at ≥5 years. For tenofovir, pooled resistance risk was 0.0 % at all time points, whether previously NA naive (11 studies; 3778 individuals) or experienced (19 studies; 2059 individuals). There was a lack of consistent definitions, poor global representation and insufficient metadata to support subgroup analysis.

INTERPRETATION

We have generated the first pooled estimates of HBV entecavir and tenofovir resistance over time. HBV resistance to entecavir in treatment-experienced groups in particular may represent a clinical and public health challenge. To date, tenofovir appears to have an excellent resistance profile, but due to data gaps, we caution that existing studies under-estimate the true real-world risk of resistance. Robust prospective data collection is crucial to reduce health inequities and reduce blind-spots in surveillance as treatment is rolled out more widely.

Eight-year efficacy and safety of tenofovir alafenamide for treatment of chronic hepatitis B virus infection: Final results from two randomised phase 3 trials

BACKGROUND

In two phase 3 studies, tenofovir alafenamide (TAF) showed non-inferior efficacy versus tenofovir disoproxil fumarate (TDF), with more favourable renal and bone safety in patients with chronic hepatitis B (CHB).

AIMS

Here, we report the studies' final 8-year results.

METHODS

CHB patients (hepatitis B e antigen [HBeAg]-negative and HBeAg-positive) were randomised (2:1) to double-blind TAF 25 mg/day or TDF 300 mg/day for up to 3 years, followed by open-label (OL) TAF through year 8. Virological, biochemical, serological and fibrosis responses, and safety, including bone and renal parameters, were evaluated. Resistance to TAF was assessed annually by deep sequencing of polymerase/reverse transcriptase and by phenotyping.

RESULTS

Among 1298 patients randomised to double-blind TAF (n = 866) or double-blind TDF (n = 432), 775 in the TAF group and 382 in the TDF group received OL TAF, including 180 and 202 who switched from TDF to TAF at year 2 (TDF2y → TAF6y) or year 3 (TDF3y → TAF5y), respectively. At year 8, among patients in the TAF8y, TDF2y → TAF6y and TDF3y → TAF5y groups, 69%, 66% and 73% (missing-equals-failure analysis) and 95%, 94% and 97% (missing-equals-excluded) of patients, respectively, achieved HBV DNA <29 IU/mL. Estimated glomerular filtration rate (Cockcroft-Gault method; eGFRCG) and hip/spine bone mineral density (BMD) remained stable in patients receiving double-blind/OL TAF, with only small declines at year 8. Decreases in eGFRCG and hip/spine BMD observed during double-blind TDF improved after switching to OL TAF. No patients developed resistance to TAF.

CONCLUSION

Long-term TAF treatment exhibited favourable safety and tolerability with high rates of viral suppression and no development of resistance.

CLINICALTRIALS

gov numbers NCT01940341 and NCT01940471.

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.

Perspective on Emerging Therapies to Achieve Functional Cure of Chronic Hepatitis B

Purpose of Review

Advancements in our understanding of the hepatitis B viral (HBV) life cycle have paved the way for novel approaches to treat HBV infection. This review summarizes the various strategies being pursued to achieve a functional cure, defined as loss of hepatitis B surface antigen (HBsAg) and absence of viral replication 6 months off-therapy.

Recent Findings

Direct acting antiviral, host targeting antiviral, and immunological approaches are in various stages of development as treatment for chronic HBV infection.

Summary

Novel treatments are being developed in pursuit of a cure for HBV. Current evidence suggests a single therapeutic agent alone may be insufficient, necessitating the need for combination therapy targeting HBV and the host immune response. Ongoing research focused on identifying the best therapeutic combination holds promise in achieving functional cure for HBV.

Targeted delivery strategies: The interactions and applications of nanoparticles in liver diseases

In recent years, nanoparticles have been broadly utilized in various drugs delivery formulations. Nanodelivery systems have shown promise in solving problems associated with the distribution of hydrophobic drugs and have promoted the accumulation of nanomedicines in the circulation or in organs. However, the injection dose of nanoparticles (NPs) is much greater than that needed by diseased tissues or organs. In other words, most of the NPs are localized off-target and do not reach the desired tissue or organs. With the rapid development of biodegradable and biosafety nanomaterials, the nanovectors represent assurance of safety. However, the off-target effects also induce concerns about the application of NPs, especially in the delivery of gene editing tools. Therefore, a complete understanding of the biological responses to NPs in the body will clearly guide the design of targeted delivery of NPs. The different properties of various nanodelivery systems may induce diverse interactions between carriers and organs. In this review, we describe the relationship between the liver, the most influenced organ of systemic administration of NPs, and targeted delivery nanoplatforms. Various transport vehicles have adopted multiple delivery strategies for the targeted delivery to the cells in the homeostasis liver and in diseased liver. Additionally, nanodelivery systems provide a novel strategy for treating incurable diseases. The appearance of a targeted delivery has profoundly improved the application of NPs to liver diseases.

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.

The Use of Tenofovir Disoproxil Fumarate in the Management of eAg-Negative Chronic Hepatitis B Infection

Background/Objectives: Currently, there are insufficient data to recommend the treatment of patients with hepatitis B e antigen (HBeAg)-negative chronic infection who have normal ALT and low HBV DNA, since the prognosis is generally regarded as favorable. The aim of this pilot study was to determine whether the use of tenofovir disoproxil fumarate (TDF) 300 mg/day for 3 years was able to achieve functional cure (HBsAg loss) and HBsAg seroconversion in HBeAb-positive individuals. Methods: Fifty patients not on antiviral therapy (40% men, mean age 48.9 ± 10.9 years, 84% Asians) with minimal fibrosis were enrolled. Results: TDF reduced HBV DNA significantly to undetectable levels after 6 months. Overall, 48.3% of inactive carriers (baseline HBV DNA < 2000 IU/mL) remained HBV DNA negative 6 months after treatment withdrawal, which was significantly higher than the 5.6% in those who were not inactive carriers (baseline HBV DNA ≥ 2000 IU/mL) (p = 0.003). The HBsAg levels did not drop throughout the study period with no difference between inactive carriers versus those who were not. Five inactive carriers achieved functional cure, but none of these were amongst those who were not inactive carriers. No renal dysfunction or ALT flare on treatment withdrawal was observed. Conclusions: TDF could potentially be used to induce functional cure in patients who are inactive carriers with normal ALT, low HBV DNA and without advanced fibrosis.

An Overview of the Unfolded Protein Response (UPR) and Autophagy Pathways in Human Viral Oncogenesis

Autophagy and Unfolded Protein Response (UPR) can be regarded as the safe keepers of cells exposed to intense stress. Autophagy maintains cellular homeostasis, ensuring the removal of foreign particles and misfolded macromolecules from the cytoplasm and facilitating the return of the building blocks into the system. On the other hand, UPR serves as a shock response to prolonged stress, especially Endoplasmic Reticulum Stress (ERS), which also includes the accumulation of misfolded proteins in the ER. Since one of the many effects of viral infection on the host cell machinery is the hijacking of the host translational system, which leaves in its wake a plethora of misfolded proteins in the ER, it is perhaps not surprising that UPR and autophagy are common occurrences in infected cells, tissues, and patient samples. In this book chapter, we try to emphasize how UPR, and autophagy are significant in infections caused by six major oncolytic viruses-Epstein-Barr (EBV), Human Papilloma Virus (HPV), Human Immunodeficiency Virus (HIV), Human Herpesvirus-8 (HHV-8), Human T-cell Lymphotropic Virus (HTLV-1), and Hepatitis B Virus (HBV). Here, we document how whole-virus infection or overexpression of individual viral proteins in vitro and in vivo models can regulate the different branches of UPR and the various stages of macro autophagy. As is true with other viral infections, the relationship is complicated because the same virus (or the viral protein) exerts different effects on UPR and Autophagy. The nature of this response is determined by the cell types, or in some cases, the presence of diverse extracellular stimuli. The vice versa is equally valid, i.e., UPR and autophagy exhibit both anti-tumor and pro-tumor properties based on the cell type and other factors like concentrations of different metabolites. Thus, we have tried to coherently summarize the existing knowledge, the crux of which can hopefully be harnessed to design vaccines and therapies targeted at viral carcinogenesis.

Persistent hiccups due to aripiprazole: a case report and review of the literature

Introduction: Aripiprazole, a commonly prescribed antipsychotic, has been rarely associated with the onset of hiccups. This study aims to elucidate the prevalence, risk factors, and management of aripiprazole-induced hiccups. Methods: We report a case of aripiprazole-induced hiccups in a 32-year-old male diagnosed with Somatic Symptom Disorder per DSM-5 criteria.A comprehensive literature review was conducted, identifying 29 case reports of aripiprazole-induced hiccups. Patient demographics, dosage, onset and duration of hiccups, and management strategies were analyzed. Results: Aripiprazole-induced hiccups predominantly affected adolescents and middle-aged male patients (86.7%). The majority of hiccups developed within 1-2 days post-prescription (90.9%) and resolved within 1-4 days after discontinuation of aripiprazole. Discontinuation of aripiprazole was the most effective management strategy (51.7%). Co-administration with benzodiazepines was identified as a significant risk factor. Discussion: The findings suggest that clinicians should be vigilant for the onset of hiccups during the early stages of aripiprazole treatment, especially in male patients and those co-administered with benzodiazepines. Conclusion: Clinicians should be vigilant for hiccups during early aripiprazole treatment. Considering personality and psychological factors is crucial in managing hiccups in psychiatric patients.

A novel nomogram for predicting HBeAg seroclearance in HBeAg-positive chronic hepatitis B patients treated with nucleos(t)ide analogues

INTRODUCTION AND OBJECTIVES

Seroclearance of hepatitis B e antigen (HBeAg) is an important treatment goal for patients with chronic hepatitis B (CHB). This study developed a nomogram for predicting HBeAg seroclearance in CHB patients treated with nucleos(t)ide analogues (NAs).

PATIENTS AND METHODS

Five hundred and sixty-nine CHB patients treated with NAs from two institutions between July 2016 to November 2021 were retrospectively included. One institution served as the training set (n = 374) and the other as the external validation set (n = 195). A predictive nomogram was established based on cox regression analysis.

RESULTS

The overall HBeAg seroclearance rates were 27.3 and 21.5 % after the median follow-up of 100.2 weeks and 65.1 weeks in the training set and validation set, respectively. In the training set, baseline aspartate aminotransferase, gamma-glutamyl transpeptidase, HBeAg, and hepatitis B core antibody levels were independently associated with HBeAg seroclearance and were used to establish the HBEAg SeroClearance (ESC)-nomogram. The calibration curve revealed that the ESC-nomogram had a good agreement with actual observation. The ESC-nomogram showed relatively high accuracy for predicting 48 weeks, 96 weeks, and 144 weeks of HBeAg seroclearance in the training set (AUCs: 0.782, 0.734 and 0.671) and validation set (AUCs: 0.699, 0.718 and 0.689). The patients with high ESC-nomogram scores (≥ 79.51) had significantly higher cumulative incidence of HBeAg seroclearance and seroconversion than patients with low scores (< 79.51) in both sets (P < 0.01).

CONCLUSIONS

The novel ESC-nomogram showed good performance for predicting antiviral efficacy in HBeAg-positive CHB patients with NAs treatment.

Gene-Editing and RNA Interference in Treating Hepatitis B: A Review

The hepatitis B virus (HBV) continues to cause substantial health and economic burdens, and its target of elimination may not be reached in 2030 without further efforts in diagnostics, non-pharmaceutical prevention measures, vaccination, and treatment. Current therapeutic options in chronic HBV, based on interferons and/or nucleos(t)ide analogs, suppress the virus replication but do not eliminate the pathogen and suffer from several constraints. This paper reviews the progress on biotechnological approaches in functional and definitive HBV treatments, including gene-editing tools, i.e., zinc-finger proteins, transcription activator-like effector nucleases, and CRISPR/Cas9, as well as therapeutics based on RNA interference. The advantages and challenges of these approaches are also discussed. Although the safety and efficacy of gene-editing tools in HBV therapies are yet to be demonstrated, they show promise for the revitalization of a much-needed advance in the field and offer viral eradication. Particular hopes are related to CRISPR/Cas9; however, therapeutics employing this system are yet to enter the clinical testing phases. In contrast, a number of candidates based on RNA interference, intending to confer a functional cure, have already been introduced to human studies. However, larger and longer trials are required to assess their efficacy and safety. Considering that prevention is always superior to treatment, it is essential to pursue global efforts in HBV vaccination.

Hepatitis B Virus and microRNAs: A Bioinformatics Approach

In recent decades, microRNAs (miRNAs) have emerged as key regulators of gene expression, and the identification of viral miRNAs (v-miRNAs) within some viruses, including hepatitis B virus (HBV), has attracted significant attention. HBV infections often progress to chronic states (CHB) and may induce fibrosis/cirrhosis and hepatocellular carcinoma (HCC). The presence of HBV can dysregulate host miRNA expression, influencing several biological pathways, such as apoptosis, innate and immune response, viral replication, and pathogenesis. Consequently, miRNAs are considered a promising biomarker for diagnostic, prognostic, and treatment response. The dynamics of miRNAs during HBV infection are multifaceted, influenced by host variability and miRNA interactions. Given the ability of miRNAs to target multiple messenger RNA (mRNA), understanding the viral-host (human) interplay is complex but essential to develop novel clinical applications. Therefore, bioinformatics can help to analyze, identify, and interpret a vast amount of miRNA data. This review explores the bioinformatics tools available for viral and host miRNA research. Moreover, we introduce a brief overview focusing on the role of miRNAs during HBV infection. In this way, this review aims to help the selection of the most appropriate bioinformatics tools based on requirements and research goals.

Tenofovir-Induced Fanconi Syndrome Presenting with Life-Threatening Hypokalemia: Review of the Literature and Recommendations for Early Detection

Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor that has been widely used for the treatment of patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. Despite the excellent safety records of this regimen, a few cases of acute renal failure and Fanconi syndrome have been reported among HIV patients exposed to TDF. However, in the HBV monoinfection scenario, only five cases of TDF-associated Fanconi syndrome have been reported thus far, two of them providing a confirmatory kidney biopsy. Here, we describe the case of a 68-year-old woman with chronic hepatitis B (CHB) who developed TDF-induced Fanconi syndrome that reverted after TDF withdrawal from tenofovir alafenamide. Though the overall risk of TDF-associated severe renal toxicity in HBV patients appears to be negligible, both glomerular and tubular functions should be monitored in patients exposed to TDF.

Five-year results of a treatment program for chronic hepatitis B in Ethiopia

BACKGROUND

In sub-Saharan Africa, less than 1% of treatment-eligible chronic hepatitis B (CHB) patients receive antiviral therapy. Experiences from local CHB programs are needed to inform treatment guidelines and policies on the continent. Here, we present 5-year results from one of the first large-scale CHB treatment programs in sub-Saharan Africa.

METHODS

Adults with CHB were enrolled in a pilot treatment program in Addis Ababa, Ethiopia, in 2015. Liver enzymes, viral markers, and transient elastography were assessed at baseline and thereafter at 6-month intervals. Tenofovir disoproxil fumarate was initiated based on the European Association for the Study of the Liver (EASL) criteria, with some modifications. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

In total, 1303 patients were included in the program, of whom 291 (22.3%) started antiviral therapy within the initial 5 years of follow-up. Among patients on treatment, estimated 5-year hepatocellular carcinoma-free survival was 99.0% in patients without cirrhosis at baseline, compared to 88.8% in patients with compensated cirrhosis, and 54.2% in patients with decompensated cirrhosis (p < 0.001). The risk of death was significantly higher in patients with decompensated cirrhosis at baseline (adjusted hazard ratio 44.6, 95% confidence interval 6.1-328.1) and in patients older than 40 years (adjusted hazard ratio 3.7, 95% confidence interval 1.6-8.5). Liver stiffness declined significantly after treatment initiation; the median change from baseline after 1, 3, and 5 years of treatment was - 4.0 kPa, - 5.2 kPa, and - 5.6 kPa, respectively.

CONCLUSIONS

This pilot program demonstrates the long-term benefits of CHB therapy in a resource-limited setting. The high mortality in patients with cirrhosis underscores the need for earlier detection of CHB and timely initiation of antiviral treatment in sub-Saharan Africa.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov (NCT02344498) on January 26, 2015.

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.

Awareness of HBV Functional Cure and Attitude Toward Related Clinical Trials Among Patients with Chronic Hepatitis B in China

Purpose

HBV functional cure is an optimal treatment goal for chronic hepatitis B (CHB) at present and numerous new drugs aiming for HBV functional cure are in development. We carried out an internet-based survey to understand the treatment status, unmet needs, awareness of HBV functional cure and attitude toward related clinical trials among CHB patients in China.

Patients and Methods

An internet-based anonymous survey was conducted on CHB patients who reside in mainland China. Determinants of awareness and attitude were identified by logistic regression models.

Results

Of the 1220 CHB patients who completed the survey questionnaire, 11.1% (135/1220) were aware of HBV functional cure and 50.2% (612/1220) answered "definitely will" to participate in related clinical trials. Participants who knew their HBsAg level (HBsAg<1500 IU/mL: OR=3.03, 95% CI: 1.87-4.92; HBsAg≥1500 IU/mL: OR=2.57, 95% CI: 1.35-4.88), who expected to achieve HBsAg loss with treatment (OR=1.63, 95% CI: 1.07-2.50) and who were dissatisfied with current treatment due to the failure of achieving HBsAg loss (OR=1.67, 95% CI: 1.10-2.53) had better awareness of HBV functional cure. Participants who had HBsAg level less than 1500 IU/mL (OR=1.45, 95% CI: 1.05-1.99), treatment with pegylated interferon alpha with or without nucleos(t)ide (OR=1.68, 95% CI: 1.11-2.53) and better awareness of HBV functional cure (OR=1.62, 95% CI: 1.01-2.61) were more likely to say "definitely will" to participate in related clinical trials.

Conclusion

Chinese CHB patients reported a low awareness of HBV functional cure. Although CHB patients in China reported a low rate of HBV functional cure awareness, they had a high acceptance of related clinical trials.

IP10 and Anti-HBc can Predict Virological Relapse and HBsAg Loss in Chronic Hepatitis B Patients after Nucleos(t)ide Analog Discontinuation

INTRODUCTION

To assess predictive ability of serum interferon-inducible protein 10 (IP10) and hepatitis B core antibody (anti-HBc) levels for virological relapse (VR) and hepatitis B surface antigen (HBsAg) loss after nucleos(t)ide analog (NA) discontinuation.

METHODS

In this multicenter prospective study, overall 139 patients were followed up for 24 months after NA discontinuation.

RESULTS

End of treatment (EOT) IP10 and anti-HBc were 29.2 (5.1-66.4) pg/mL and 193.6 (136.9-221.4) IU/mL. EOT IP10 and anti-HBc were independent predictors for VR and HBsAg loss in Cox regression analysis. Cumulative rates of VR in patients with EOT IP10 > 26.99 pg/mL was 31.9% (vs. 70.1%, hazard ratio [HR] 2.998, p < 0.001). Cumulative incidences of VR in patients with EOT anti-HBc ≤141.35 IU/mL was 49.1% (vs. 60.6%, HR 2.99, p < 0.001). Cumulative probabilities of VR was 16.7% in patients with EOT IP10 > 26.99 pg/mL plus anti-HBc ≤141.35 IU/mL (vs. 73.6%, HR 6.464, p < 0.001). Cumulative probabilities of HBsAg loss in patients with EOT IP10 > 93.5 pg/mL was 46.2% (vs. 4.7%, HR 10.94, p < 0.001). Cumulative probabilities of HBsAg loss in patients with EOT anti-HBc ≤78.42 IU/mL were 47.1% (vs. 5%, HR 12.27, p < 0.001). Patients with EOT IP10 > 93.5 pg/mL plus anti-HBc ≤78.42 IU/mL had the highest 24-month cumulative HBsAg loss rate (53.8% vs. 4%, HR 16.83, p < 0.001).

CONCLUSION

High EOT IP10 and low EOT anti-HBc levels were related to both lower risk of VR and higher probability of HBsAg loss.

Baseline serum HBV RNA is associated with the risk of hepatitis flare after stopping nucleoside analog therapy in HBeAg-negative participants

BACKGROUND AND AIMS

HBV RNA in peripheral blood reflects HBV cccDNA transcriptional activity and may predict clinical outcomes. The prospective Melbourne HBV-STOP trial studied nucleot(s)ide analog discontinuation in HBeAg-negative non-cirrhotic participants with long-term virological suppression. Ninety-six weeks after stopping treatment, the proportion of participants with virological relapse (HBV DNA > 2000 IU/mL), biochemical relapse (ALT > 2 × ULN and HBV DNA > 2000 IU/mL), or hepatitis flare (ALT > 5 × ULN and HBV DNA > 2000 IU/mL) was 89%, 58%, and 38%, respectively. We evaluated the ability of serum HBV RNA levels to predict these outcomes.

APPROACH RESULTS

HBV RNA levels were measured using the Roche cobas 6800/8800 HBV RNA Investigational Assay. Sixty-five participants had baseline and longitudinal off-treatment specimens available for RNA testing. HBV RNA was detectable at baseline in 25% of participants and was associated with a higher risk of biochemical relapse (81% vs. 51%, p value 0.04) and hepatitis flare (63% vs. 31%, p value 0.04). Participants who had undetectable serum HBV RNA as well as HBsAg ≤ 100 IU/mL at baseline were less likely to experience virological relapse (4 of 9, 44%) than participants with detectable HBV RNA and HBsAg level > 100 IU/mL (15/15, 100%; p value 0.0009). Off-treatment levels of HBV RNA were correlated with HBV DNA and were associated with the risk of hepatitis flare.

CONCLUSIONS

Serum HBV RNA may be a useful biomarker for guiding clinical decision-making before stopping nucleot(s)ide analog therapy. Baseline HBV RNA and HBsAg levels are associated with the risk of clinical relapse, hepatitis flare, and disease remission off-treatment.

Past, present, and future of long-term treatment for hepatitis B virus

The estimated world prevalence of hepatitis B virus (HBV) infection is 316 million. HBV infection was identified in 1963 and nowadays is a major cause of cirrhosis and hepatocellular carcinoma (HCC) despite universal vaccination programs, and effective antiviral therapy. Long-term administration of nucleos(t)ide analogues (NA) has been the treatment of choice for chronic hepatitis B during the last decades. The NA has shown a good safety profile and high efficacy in controlling viral replication, improving histology, and decreasing the HCC incidence, decompensation, and mortality. However, the low probability of HBV surface antigen seroclearance made necessary an indefinite treatment. The knowledge, in recent years, about the different phases of the viral cycle, and the new insights into the role of the immune system have yielded an increase in new therapeutic approaches. Consequently, several clinical trials evaluating combinations of new drugs with different mechanisms of action are ongoing with promising results. This integrative literature review aims to assess the knowledge and major advances from the past of hepatitis B, the present of NA treatment and withdrawal, and the future perspectives with combined molecules to achieve a functional cure.

Lower end of treatment HBsAg and HBcrAg were associated with HBsAg loss after nucleos(t)ide analog cessation

BACKGROUND

Since hepatitis B surface antigen (HBsAg) loss is rarely achieved with nucleos(t)ide analog (NA) treatment, most patients require life-long NA treatment. Previous studies have shown that some patients remain virologically responsive even after NA cessation. However, there is still controversy surrounding whether NA discontinuation increases the HBsAg loss rate. Therefore, this study aimed to assess the cumulative rate of HBsAg loss and identify the predictors of HBsAg loss after NA discontinuation.

METHODS

This multicenter prospective study included HBV e antigen (HBeAg)-positive patients without cirrhosis from 12 hospitals in China who met the inclusion criteria. The enrolled patients stopped NA and were followed up with clinical and laboratory assessments every 3 months for 24 months after NA cessation or until clinical relapse (CR) occurred.

RESULTS

Overall, 158 patients were classified into two groups. Group A included patients with HBsAg positivity at NA cessation (n = 139), and Group B included patients with HBsAg negativity at NA cessation (n = 19). In Group A, the 12-month and 24-month cumulative rates of HBsAg loss were4.3%and 9.4%, respectively. End of treatment (EOT) HBsAg (hazard ratio (HR) = 0.152, P < 0.001) and EOT hepatitis B core-related antigen (HBcrAg) (HR = 0.257, P = 0.001) were associated with HBsAg loss. The areas under the receiver operating characteristic curves for EOT HBsAg and HBcrAg levels were 0.952 (P < 0.001) and 0.765 (P < 0.001), respectively. Patients with EOT HBsAg ≤ 135 IU/mL (59.2% vs. 1.3%, P < 0.001) or HBcrAg ≤ 3.6 logU/mL (17% vs. 5.4%, P = 0.027) had a higher 24-month cumulative HBsAg loss rate. In Group B, none of the patients experienced virological relapse after NA cessation. Only 1 (5.3%) patient had HBsAg reversion.

CONCLUSIONS

EOT HBsAg ≤ 135 IU/mL or HBcrAg ≤ 3.6 logU/mL can be used to identify patients with a higher likelihood of HBsAg loss after NA cessation. Patients with HBsAg negativity after NA cessation have favorable clinical outcomes, and HBsAg loss was durable in most cases.

Effectiveness and safety of tenofovir amibufenamide and its comparison with tenofovir alafenamide in patients with chronic hepatitis B: results from a retrospective real-world study

Background/aim: Tenofovir amibufenamide (TMF) has shown potent antiviral efficacy in randomized clinical studies. This study aimed to reveal the effectiveness and safety of tenofovir amibufenamide in the real world and compared tenofovir amibufenamide to tenofovir alafenamide (TAF) in patients with chronic hepatitis B (CHB). Methods: In this retrospective study, tenofovir amibufenamide-treated chronic hepatitis B patients were divided into treatment-naive (TN) and treatment-experienced (TE) groups. Furthermore, tenofovir alafenamide-treated patients were enrolled using the propensity score matching method (PSM). We assessed the virological response (VR, HBV DNA < 100 IU/mL) rate, renal function, and blood lipid changes during 24 weeks of treatment. Results: Virologic response rates at week 24 were 93% (50/54) in the treatment-naive group and 95% (61/64) in the treatment-experienced group. The ratios of alanine transaminase (ALT) normalization were 89% (25/28) in the treatment-naive group and 71% (10/14) in the treatment-experienced group (p = 0.306). Additionally, serum creatinine decreased in both the treatment-naive and treatment-experienced groups, (-4.44 ± 13.55 μmol/L vs. -4.14 ± 9.33 μmol/L, p = 0.886), estimated glomerular filtration rate (eGFR) increased (7.01 ± 12.49 ml/min/1.73 m² vs. 5.50 ± 8.16 ml/min/1.73 m², p = 0.430), and low-density lipoprotein cholesterol (LDL-C) levels increased (0.09 ± 0.71 mmol/L vs. 0.27 ± 0.68 mmol/L, p = 0.152), whereas total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) levels decreased continuously from 3.26 ± 1.05 to 2.49 ± 0.72 in the treatment-naive group and from 3.31 ± 0.99 to 2.88 ± 0.77 in the treatment-experienced group. Using propensity score matching, we further compared virologic response rates between the tenofovir amibufenamide and tenofovir alafenamide cohorts. Virologic response rates in treatment-naive patients were higher in the tenofovir amibufenamide cohort [92% (35/38) vs. 74% (28/38), p = 0.033]. Virologic response rates in treatment-experienced patients showed no statistical difference between the tenofovir amibufenamide and tenofovir alafenamide cohorts. Conclusion: Tenofovir amibufenamide had profound antiviral effectiveness and no adverse effects on renal function or blood lipids. Additionally, tenofovir amibufenamide was more efficient than tenofovir alafenamide in inhibiting viral replication, which needs to be demonstrated in future studies.

Current and novel modalities for management of chronic hepatitis B infection

Over 296 million people are estimated to have chronic hepatitis B viral infection (CHB), and it poses unique challenges for elimination. CHB is the result of hepatitis B virus (HBV)-specific immune tolerance and the presence of covalently closed circular DNA as mini chromosome inside the nucleus and the integrated HBV. Serum hepatitis B core-related antigen is the best surrogate marker for intrahepatic covalently closed circular DNA. Functional HBV “cure” is the durable loss of hepatitis B surface antigen (HBsAg), with or without HBsAg seroconversion and undetectable serum HBV DNA after completing a course of treatment. The currently approved therapies are nucleos(t)ide analogues, interferon-alpha, and pegylated-interferon. With these therapies, functional cure can be achieved in < 10% of CHB patients. Any variation to HBV or the host immune system that disrupts the interaction between them can lead to reactivation of HBV. Novel therapies may allow efficient control of CHB. They include direct acting antivirals and immunomodulators. Reduction of the viral antigen load is a crucial factor for success of immune-based therapies. Immunomodulatory therapy may lead to modulation of the host immune system. It may enhance/restore innate immunity against HBV (as toll-like-receptors and cytosolic retinoic acid inducible gene I agonist). Others may induce adaptive immunity as checkpoint inhibitors, therapeutic HBV vaccines including protein (HBsAg/preS and hepatitis B core antigen), monoclonal or bispecific antibodies and genetically engineered T cells to generate chimeric antigen receptor-T or T-cell receptor-T cells and HBV-specific T cells to restore T cell function to efficiently clear HBV. Combined therapy may successfully overcome immune tolerance and lead to HBV control and cure. Immunotherapeutic approaches carry the risk of overshooting immune responses causing uncontrolled liver damage. The safety of any new curative therapies should be measured in relation to the excellent safety of currently approved nucleos(t)ide analogues. Development of novel antiviral and immune modulatory therapies should be associated with new diagnostic assays used to evaluate the effectiveness or to predict response.

A multicenter randomized-controlled trial of nucleos(t)ide analogue cessation in HBeAg-negative chronic hepatitis B

BACKGROUND & AIMS

Nucleos(t)ide analogues (NUCs) are the standard and mostly lifelong treatment for chronic HBeAg-negative hepatitis B, as functional cure (loss of HBsAg) is rarely achieved. Discontinuation of NUC treatment may lead to functional cure; however, to date, the evidence for this has been based on small or non-randomized clinical trials. The STOP-NUC trial was designed with the aim of increasing the HBsAg loss rate using a NUC treatment interruption approach.

METHODS

In this multicenter, randomized-controlled trial, 166 HBeAg-negative patients with chronic hepatitis B on continuous long-term NUC treatment, with HBV DNA <172 IU/ml (1,000 copies/ml) for ≥4 years, were randomized to either stop (Arm A) or continue NUC treatment (Arm B) for a 96-week observation period. In total, 158 patients were available for final analysis, 79 per arm. The primary endpoint was sustained HBsAg loss up to week 96.

RESULTS

Our study met its primary objective by demonstrating HBsAg loss in eight patients (10.1%, 95% CI 4.8%-19.5%) in Arm A and in no patient in Arm B (p = 0.006). Among patients with baseline HBsAg levels <1,000 IU/ml, seven (28%) achieved HBsAg loss. In Arm A, re-therapy was initiated in 11 (13.9%) patients, whereas 32 (40.5%) patients achieved sustained remission. A decrease of HBsAg >1 log IU/ml was observed in 16 patients (20.3%) in Arm A and in one patient (1.3%) in Arm B. No serious adverse events related to treatment cessation occurred.

CONCLUSIONS

Cessation of NUC treatment was associated with a significantly higher rate of HBsAg loss than continued NUC treatment, which was largely restricted to patients with end of treatment HBsAg levels <1,000 IU/ml.

IMPACT AND IMPLICATIONS

As HBeAg-negative patients with chronic hepatitis B on nucleos(t)ide analogues (NUCs) rarely achieve functional cure, treatment is almost always lifelong. The STOP-NUC trial was conducted to investigate whether discontinuing long-term NUC treatment can increase the cure rate. We found that some patients achieved functional cure after stopping NUCs, which was especially pronounced in patients with HBsAg levels <1,000 at the end of NUC treatment, and that many did not need to resume therapy. The results of the Stop-NUC trial provide evidence for the concept of stopping NUC treatment as a therapeutic option that can induce functional cure.

Hepatitis B

Hepatitis B virus (HBV) infection is a major public health problem, with an estimated 296 million people chronically infected and 820 000 deaths worldwide in 2019. Diagnosis of HBV infection requires serological testing for HBsAg and for acute infection additional testing for IgM hepatitis B core antibody (IgM anti-HBc, for the window period when neither HBsAg nor anti-HBs is detected). Assessment of HBV replication status to guide treatment decisions involves testing for HBV DNA, whereas assessment of liver disease activity and staging is mainly based on aminotransferases, platelet count, and elastography. Universal infant immunisation, including birth dose vaccination is the most effective means to prevent chronic HBV infection. Two vaccines with improved immunogenicity have recently been approved for adults in the USA and EU, with availability expected to expand. Current therapies, pegylated interferon, and nucleos(t)ide analogues can prevent development of cirrhosis and hepatocellular carcinoma, but do not eradicate the virus and rarely clear HBsAg. Treatment is recommended for patients with cirrhosis or with high HBV DNA levels and active or advanced liver disease. New antiviral and immunomodulatory therapies aiming to achieve functional cure (ie, clearance of HBsAg) are in clinical development. Improved vaccination coverage, increased screening, diagnosis and linkage to care, development of curative therapies, and removal of stigma are important in achieving WHO's goal of eliminating HBV infection by 2030.

Predicting the loss of hepatitis B surface antigen following haematopoietic stem cell transplantation in patients with chronic HBV infection

Clearance of hepatitis B surface antigen (HBsAg) is an ideal therapeutic goal for patients with chronic hepatitis B virus (HBV) infection. Haematopoietic stem cell transplantation (HSCT) is the most effective therapy for a variety of haematological diseases. For patients with chronic HBV infection who received allo-HSCT, recipient hepatitis B serological status might change after allo-HSCT; however, data on the loss of HBsAg following allo-HSCT are relatively rare. We first reviewed patients with chronic HBV infection who received allo-HSCT in our centre from 2010 to 2020, and 125 patients were included in our study. A total of 62 patients (49.6%) with chronic HBV infection achieved HBsAg loss after allo-HSCT. Positivity for HBeAb and HBsAb in donors as well as no cytomegalovirus (CMV) infection were identified as independent risk factors for HBsAg loss after allo-HSCT. A predictive model including positivity for HBeAb and HBsAb in donors and no CMV infection was subsequently developed and performed well with effective discrimination and calibration. In addition, patients could benefit when this model is used in the clinic, as revealed via decision-curve analysis (DCA). However, multicentre prospective studies are required for validation.

Meta-analysis of the occurrence of hepatocellular carcinoma after the treatment of entecavir and tenofovir for chronic hepatitis B

BACKGROUND

Tenofovir and Entecavir are recommended as the first-line medicine of treatment for chronic hepatitis B. The occurrence of hepatocellular carcinoma after the treatment of chronic hepatitis B is a major problem. For the time being it is still unclear whether there remains a difference in risk correlation of hepatocellular carcinoma after the treatment of Tenofovir and Entecavir for chronic hepatitis B. Since previous studies have raised different ideas, this article aims to come to a conclusion targeting such a topic through analyzing the latest data.

METHODS

We searched some databases, such as PubMed, Web of Science, and Cochrane Library, for related studies on patients with chronic hepatitis B receiving the treatment of Tenofovir and Entecavir and then developing hepatocellular carcinoma. The search time was set to begin from the establishment time of the above-mentioned databases to May 2022. Two researchers were designated to screen the literature independently according to the inclusion and exclusion criteria set in this study; they then evaluated the quality of the literature included and extracted the data. Revman 5.3 software was used for meta-analysis.

RESULTS

After screening the literature, a total of 20 pieces of cohort study literature conformed to the inclusion criteria. Among which were 62,860 cases of patients receiving Entecavir, and 27,544 cases of patients receiving Tenofovir; there were 3669 cases with the occurrence of hepatocellular carcinoma in the Entecavir group and 1089 cases with the occurrence of hepatocellular carcinoma in Tenofovir group. The result of Meta analysis of these 20 pieces of literature shows that compared with the Tenofovir group, the Entecavir group has a lower occurrence rate of hepatocellular carcinoma, and the difference is statistically significant. The results are expressed as odd ratio (OR) and 95% confident interval (95%CI), (OR = 1.66, 95%CI: 1.35-2.05, P < .05). The result of Meta analysis of 10 studies related to Korea shows that the occurrence rate of hepatocellular carcinoma in the Tenofovir group is lower than that of the Entecavir group, and the difference is statistically significant (OR = 1.59, 95%CI: 1.29-1.95, P < .05). The result of meta-analysis of 5 studies related to China shows that the occurrence rate of hepatocellular carcinoma of Tenofovir group is lower than that of Entecavir group, and the difference is statistically significant (OR = 2.35, 95%CI: 1.15-4.81, P < .05).

CONCLUSION

The occurrence rate of hepatocellular carcinoma after the treatment of tenofovir for chronic hepatitis B is lower than that of the treatment of entecavir.

Systematic review and individual-patient-data meta-analysis of non-invasive fibrosis markers for chronic hepatitis B in Africa

In sub-Saharan Africa, simple biomarkers of liver fibrosis are needed to scale-up hepatitis B treatment. We conducted an individual participant data meta-analysis of 3,548 chronic hepatitis B patients living in eight sub-Saharan African countries to assess the World Health Organization-recommended aspartate aminotransferase-to-platelet ratio index and two other fibrosis biomarkers using a Bayesian bivariate model. Transient elastography was used as a reference test with liver stiffness measurement thresholds at 7.9 and 12.2kPa indicating significant fibrosis and cirrhosis, respectively. At the World Health Organization-recommended cirrhosis threshold (>2.0), aspartate aminotransferase-to-platelet ratio index had sensitivity (95% credible interval) of only 16.5% (12.5-20.5). We identified an optimised aspartate aminotransferase-to-platelet ratio index rule-in threshold (>0.65) for liver stiffness measurement >12.2kPa with sensitivity and specificity of 56.2% (50.5-62.2) and 90.0% (89.0-91.0), and an optimised rule-out threshold (<0.36) with sensitivity and specificity of 80.6% (76.1-85.1) and 64.3% (62.8-65.8). Here we show that the World Health Organization-recommended aspartate aminotransferase-to-platelet ratio index threshold is inappropriately high in sub-Saharan Africa; improved rule-in and rule-out thresholds can optimise treatment recommendations in this setting.

Current Best Practice in Hepatitis B Management and Understanding Long-term Prospects for Cure

The hepatitis B virus (HBV) is a major cause of cirrhosis and hepatocellular carcinoma worldwide. Despite an effective vaccine, the prevalence of chronic infection remains high. Current therapy is effective at achieving on-treatment, but not off-treatment, viral suppression. Loss of hepatitis B surface antigen, the best surrogate marker of off-treatment viral suppression, is associated with improved clinical outcomes. Unfortunately, this end point is rarely achieved with current therapy because of their lack of effect on covalently closed circular DNA, the template of viral transcription and genome replication. Major advancements in our understanding of HBV virology along with better understanding of immunopathogenesis have led to the development of a multitude of novel therapeutic approaches with the prospect of achieving functional cure (hepatitis B surface antigen loss) and perhaps complete cure (clearance of covalently closed circular DNA and integrated HBV DNA). This review will cover current best practice for managing chronic HBV infection and emerging novel therapies for HBV infection and their prospect for cure.

LINK-B: study protocol of a retrospective and prospective project for identification and linkage to care of people living with hepatitis B in a large health area of Barcelona

INTRODUCTION

An estimated 290 million people are living with hepatitis B virus (HBV) worldwide; in Spain, the prevalence of hepatitis B virus surface antigen (HBsAg) is 0.4%. In our setting, many HBsAg-positive individuals are not linked to care, which implies a barrier to receiving treatment and controlling the infection. The main objective of this project is to evaluate the performance of a programme designed to achieve appropriate linkage to specialist care of HBsAg-positive individuals, newly tested or previously tested and lost to follow-up.

METHODS AND ANALYSIS

This is a retrospective and prospective study in which all HBsAg-positive cases recorded in the microbiology database will be identified. The retrospective phase will include cases detected between 2018 and 2020, and the prospective phase will run from January 2021 to June 2022. The project will be carried out in a tertiary university hospital covering the northern health area of Barcelona with a catchment population of 450 000 inhabitants and 16 affiliated primary care centres. The central laboratory detects approximately 1200 HBsAg-positive individuals every year; therefore, we expect to identify around 4000 patients over the duration of the project. The medical records of HBsAg-positive individuals will be consulted to identify and retrieve those who have not been appropriately linked to care. Candidates will be contacted to offer specialist disease assessment and follow-up. A website will be created to provide HBV-related information to primary care physicians, and a mobile phone application will be available to patients to improve the linkage circuits and ensure follow-up continuity.

ETHICS AND DISSEMINATION

The Vall d'Hebrón Hospital Ethics Committee (PR(AG)201/2021) and the Spanish Agency of Medicines and Medical Devices approved this study. The findings will be disseminated through peer-reviewed publications and conference presentations. This programme could increase the number of HBsAg-positive individuals properly linked to care and achieve better HBV monitoring, which will have a positive impact on WHO's viral hepatitis elimination goals.

Low anti-HBc levels are associated with lower risk of virological relapse after nucleos(t)ide analogue cessation in HBe antigen-negative patients

BACKGROUND AND AIMS

Low anti-HBc serum levels at the time of therapy cessation were linked to a higher relapse risk in predominantly HBeAg-positive cohorts. We investigated the association of anti-HBc levels with relapse in HBeAg-negative patients.

METHODS

Serum levels of anti-HBc, HBsAg and HBcrAg were determined in 136 HBeAg-negative patients, participating in a vaccination trial (ABX-203, NCT02249988), before treatment cessation or vaccination. Importantly, vaccination showed no impact on relapse. The correlation between the biomarkers and their predictive value for relapse (HBV DNA >2000 IU/ml ± ALT >2xULN) was investigated.

RESULTS

After therapy cessation 50% (N = 68) of patients relapsed. Median anti-HBc prior to treatment stop was significantly higher among relapsers compared to off-treatment responders (520 IU/ml vs. 330 IU/mL, p = .0098). The optimal anti-HBc cut-off to predict relapse was 325 IU/ml according to the Youden-Index. About 35% of patients with anti-HBc level < 325 IU/ml versus 60% of those with values ≥325 IU/mL relapsed (p = .0103; sensitivity 50%, specificity 75%). Combining the optimal cut-offs of HBsAg (>3008 IU/mL) or HBcrAg (≥1790 U/ml) with anti-HBc increased the proportion of patients with relapse to 80% (p < .0001) and 74% (p = .0006), respectively.

CONCLUSION

In contrast to predominantly HBeAg-positive cohorts, in our cohort of HBeAg-negative patients lower anti-HBc levels are associated with a significantly lower relapse risk after nucleos(t)ide analogue cessation. The vast majority of included patients were either genotype B or C and the applicability to other genotypes has to be further evaluated. However, anti-HBc level as an indicator of the host response might be prospectively further explored for prediction models.

Advances in Immunotherapy for Hepatitis B

Hepatitis B virus (HBV) is a hepatotropic virus with the potential to cause chronic infection, and it is one of the common causes of liver disease worldwide. Chronic HBV infection leads to liver cirrhosis and, ultimately, hepatocellular carcinoma (HCC). The persistence of covalently closed circular DNA (cccDNA) and the impaired immune response in patients with chronic hepatitis B (CHB) has been studied over the past few decades. Despite advances in the etiology of HBV and the development of potent virus-suppressing regimens, a cure for HBV has not been found. Both the innate and adaptive branches of immunity contribute to viral eradication. However, immune exhaustion and evasion have been demonstrated during CHB infection, although our understanding of the mechanism is still evolving. Recently, the successful use of an antiviral drug for hepatitis C has greatly encouraged the search for a cure for hepatitis B, which likely requires an approach focused on improving the antiviral immune response. In this review, we discuss our current knowledge of the immunopathogenic mechanisms and immunobiology of HBV infection. In addition, we touch upon why the existing therapeutic approaches may not achieve the goal of a functional cure. We also propose how combinations of new drugs, and especially novel immunotherapies, contribute to HBV clearance.

On-therapy HBsAg kinetics can predict HBsAg loss after nucleos(t)ide analogues interruption in HBeAg-negative patients. The cup is half full and half empty

BACKGROUND

Nucleos(t)ide analogues withdrawal may improve HBsAg loss rates. However, conditions to select patients are not well established.

AIMS

to evaluate the impact of HBsAg kinetics before treatment interruption on post-treatment response.

METHODS

Longitudinal, ambispective study in non-cirrhotic chronic hepatitis B HBeAg-negative patients, analysing on-treatment and post-treatment HBsAg kinetics. On-treatment HBsAg kinetics diagnostic accuracy (AUROC) to identify HBsAg loss was evaluated.

RESULTS

52 HBeAg-negative patients stopped treatment after 8.2 years, and 6 (11.5%) achieved HBsAg loss one year after withdrawal. Multivariate analysis showed that on-treatment HBsAg kinetics was related to HBsAg loss (OR=0.10; 95%CI=0.016-0.632; p = 0.014) with a high diagnostic accuracy (AUROC=0.935). A significant HBsAg decline ≥1 log10 IU/mL showed a positive and negative predictive value of 50% and of 97.6%, respectively. After treatment interruption, HBsAg decline speed (log10 IU/mL/year) accelerated in patients treated >6 years (from -0.06 to -0.20, p<0.05) and remained stable in treated <6 years (from -0.12 to -0.12 p=ns).

CONCLUSIONS

On-treatment HBsAg kinetics can predict post-treatment HBsAg loss rate. Half of patients with a significant HBsAg decline can eliminate HBsAg the first year after withdrawal. Post-treatment HBsAg decline is faster not only in patients who lost the HBsAg but also in those who remain HBsAg-positive.

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.

Safety and Effectiveness of Tenofovir Alafenamide in Usual Clinical Practice Confirms Results of Clinical Trials: TARGET-HBV

BACKGROUND

Nucleos(t)ide analogues, with a proven record of safety and efficacy, have been the therapy of choice for over a decade for the treatment of chronic hepatitis B. The approval of tenofovir alafenamide (TAF) in 2016 provided an additional treatment option.

AIMS

The aim of this study was to evaluate the characteristics and clinical outcomes of patients treated with TAF in usual clinical practice.

METHODS

Retrospective data from electronic health records was obtained from those enrolled in TARGET-HBV, a longitudinal observational cohort study of patients with chronic hepatitis B managed according to local practice standards at community and academic medical centers throughout the U.S.

RESULTS

Of 500 patients enrolled, most were male (66%) and of Asian race (66%) with median age of 55 years. Cirrhosis was evident in 15%. Most patients (82%) had switched to TAF after treatment with other antivirals. The perceived safety profile of TAF was cited as the primary reason for changing therapy (32%). TAF was well tolerated and only 4 patients discontinued therapy due to adverse event during a median duration of TAF dosing of 74 weeks. Among those with paired laboratory data 12-18 months after switching to TAF, biochemical response and HBV DNA suppression was maintained. Most patients had normal renal function which was essentially unchanged throughout follow-up.

CONCLUSIONS

TAF is frequently utilized in routine clinical practice due to the perception of its improved safety profile. The current study supports the growing body of evidence regarding the safety and effectiveness of TAF. Trial Registration ClinicalTrials.gov identifier: NCT03692897, https://clinicaltrials.gov/ct2/show/NCT03692897 .

How to achieve functional cure of HBV: Stopping NUCs, adding interferon or new drug development?

Functional cure of hepatitis B is defined as sustained undetectable circulating HBsAg and HBV DNA after a finite course of treatment. Barriers to HBV cure include the reservoirs for HBV replication and antigen production (covalently closed circular DNA [cccDNA] and integrated HBV DNA), the high viral burden (HBV DNA and HBsAg) and the impaired host innate and adaptive immune responses against HBV. Current HBV therapeutics, 1 year of pegylated-interferon-α (PEG-IFNα) and long-term nucleos(t)ide analogues (NUCs), rarely achieve HBV cure. Stopping NUC therapy may lead to functional cure in some Caucasian patients but rarely in Asian patients. Switching from a NUC to IFN after HBV DNA suppression increases the chance of HBsAg clearance mainly in those with low HBsAg levels. Novel antiviral strategies that inhibit viral entry, translation and secretion of HBsAg, modulate capsid assembly, or target cccDNA transcription/degradation have shown promise in clinical trials. Novel immunomodulatory approaches including checkpoint inhibitors, metabolic modulation of T cells, therapeutic vaccines, adoptive transfer of genetically engineered T cells, and stimulation of innate and B-cell immune responses are being explored. These novel approaches may be further combined with NUCs or PEG-IFNα in personalised strategies, according to virologic and disease characteristics, to maximise the chance of HBV cure. The development of curative HBV therapies should be coupled with the development of standardised and validated virologic and immunologic assays to confirm target engagement and to assess response. In addition to efficacy, curative therapies must be safe and affordable to meet the goal of global elimination of hepatitis B.

Management and Treatment of Patients with Chronic Hepatitis B: Towards Personalized Medicine

The currently available antiviral treatments (Peg-Interferon-α and Nucleos(t)ide Analogues, NA) for chronic hepatitis B (CHB) achieve a functional cure (serum HBsAg and HDV-DNA clearance) of HBV infection in a limited number of patients. Nevertheless, the continuous pharmacological suppression of viral replication by NA halts liver disease progression lowering the risk of HCC development and improving the survival. In the near future, to fully exploit the potential of old and new drugs for HBV treatment a personalized approach to the patients will be required according to an accurate definition of their virologic, immunologic and clinical profile.

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.

Natural antibody IgG levels are associated with HBeAg-positivity and seroconversion in chronic hepatitis B patients treated with entecavir

B1 cell-derived natural antibodies are non-specific polyreactive antibodies and can activate the complement pathway leading to lysis of enveloped virus particles before activation of the adaptive immune response. We investigated the relationship between natural antibody levels and treatment outcomes of 126 treatment-naïve chronic hepatitis B (CHB) patients, who underwent entecavir (ETV) treatment. Serum IgG1-3 and complement C3 levels were significantly higher in HBeAg-positive patients. In pre-treatment, IgG1 (odd ratios [OR] 2.3, p < 0.0001), IgG2 (OR 9.8, p < 0.0001), IgG3 (OR 7.4, p < 0.0001), and C3 (OR 7.2, p < 0.0001) were associated with HBeAg-positive patients. At baseline, IgG2 (OR 10.2, p = 0.025), IgG4, (OR 3.4, p = 0.026), and complement C1q (OR 5.0, p = 0.0068) were associated with seroconverters. Post-treatment levels of IgG1-4 and C3/C1q were also associated with HBeAg-positive patients and seroconverters. High levels of IgG2-4 and C1q were observed in seroconverters but not in virological responders. Thus, high pretreatment and post-treatment levels of natural antibody IgG1-4, complement C3, and/or C1q were significantly associated with HBeAg-positivity and HBeAg seroconverters in CHB patients with ETV treatment. These results suggest that the presence of preexisting host immunity against chronic hepatitis B is closely related to outcome of ETV treatment.

Finite nucleos(t)ide analogue therapy in hepatitis B e antigen-negative chronic hepatitis B: From an "option" to an "active recommendation"

Nucleos(t)ide analogue (Nuc) including entecavir, tenofovir disoproxil fumarate, and tenofovir alafenamide may suppress hepatitis B virus (HBV) DNA profoundly but have no direct action on covalently closed circular DNA, which is a very stable template for HBV production. Therefore, decades of long-term Nuc therapy are required to maintain HBV suppression and to achieve hepatitis B surface antigen (HBsAg) loss in hepatitis B e antigen (HBeAg)-negative patients. However, there are concerns including financial burden, adherence, and willingness for indefinite long-term Nuc therapy. Patients lost to follow-up and hence not monitored may risk severe relapse that may deteriorate to hepatic decompensation or even hepatic failure. Cessation of Nuc therapy in HBeAg-negative patients was initially considered in early 2000s. Earlier findings in Asian patients that finite Nuc therapy over 2-3 years is feasible and safe have founded Asian-Pacific Association for the Study of Liver stopping rule since 2008. Subsequent studies have confirmed the feasibility and safety of the strategy of finite Nuc therapy, which has finally been accepted as "an option" by American and European liver associations since 2016. More recent large studies since 2018 have further confirmed the pivotal finding of greatly increased HBsAg loss rate (~5-year 39%) after stopping Nuc therapy. With the high HBsAg loss rate as the main justification, the paradigm shift from indefinite long-term therapy to finite Nuc therapy in HBeAg-negative patients has been changing from an "option" to an "active recommendation" aiming to achieve HBsAg loss. More studies are needed to fine-tuning the strategy, including research for the optimal duration of consolidation therapy, timing to stop, and to start retreatment.

Evaluation of Tenofovir Disoproxil Fumarate Treatment in Patients with Chronic Hepatitis B

Objective

The main purpose of chronic hepatitis B (CHB) treatment is to improve the patients' life quality and prevent the disease from progressing to cirrhosis or hepatocellular carcinoma. Continuous suppression of hepatitis B virus (HBV) DNA with nucleoside or nucleotide analogues is the most critical way to achieve this goal. This study aimed to evaluate the CHB patients retrospectively followed up with tenofovir disoproxil fumarate (TDF) treatment.

Materials and Methods

The study was planned as retrospective research by Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Infectious Diseases and Clinical Microbiology between January 2001 and December 2020. We evaluated all treatment-naive and treatment-experienced patients who received TDF (245 mg/day) treatment with the diagnosis of CHB. The data were obtained by reviewing the file information registered in the hospital automation system. HBsAg, Anti-HBs, HBeAg, Anti-HBe, HBV DNA, aspartate aminotransferase (AST), alanine aminotransferase (ALT) values of the patients were evaluated at 1st, 3rd, 6th, 12th months, and 6-month follow-ups throughout the treatment. Virological (HBV-DNA of < 50 IU/ml), biochemical (decrease below 40 IU/Ml in patients with pre-treatment value of ALT >40 IU/ml) and serological (Anti-HBe seroconversion in HBeAg positives and HBsAg negative and anti-HBs seroconversion in all patients) responses were examined. Adverse effects were also assessed during the treatment.

Results

Data from 131 patients who received TDF treatment were evaluated. Virological responses were determined as 78.6%, 81.3%, 94.2%, and 100% in the patients at 24th week, 48th week, 4th year, and 8th year, respectively. While there was no Anti-HBs seroconversion in any patients in four years of the treatment, it was observed at a rate of 10.5% in the eighth year. We did not determine any significant adverse effects requiring discontinuation of the treatment in the long-term follow-up of 131 patients under TDF treatment.

Conclusion

As a result of our study, TDF was an effective and well-tolerated choice for CHB treatment.

Safety of current antiviral drugs for chronic hepatitis B

INTRODUCTION

Oral nucleos(t)ide analogues (NUCs) are recommended as first-line therapy for chronic hepatitis B due to higher HBV-DNA suppression rates and safety profile. Long-term treatment with NUCs is often necessary to achieve durable viral suppression.

AREAS COVERED

This review provides an overview of the long-term safety data that have become available since entecavir (ETV) and tenofovir disoproxil fumarate (TDF) were first approved, and recent data on tenofovir alafenamide (TAF) in patients with CHB.

EXPERT OPINION

NUCs generally show remarkable safety in patients taking them for long periods. Nevertheless, renal and bone toxicity may occur in a minority of patients on TDF therapy. These effects have been overcome by the recent release of TAF. Moreover, the currently available data do not allow firm conclusions on superiority of TDF on ETV about HCC risk reduction. Observational studies involving more homogeneous cohorts are therefore needed; furthermore long-term studies assessing impact of TAF on this important topic are warranted.

Cost-savings and potential cost-savings through the distribution of generic antiretroviral drugs within the statutory health insurance market of Germany between January 2017 and June 2019

Abstract

Background

Recent patent losses for antiretroviral drugs (ARV) have led to the debate of cost-saving through the replacement of patented drugs with generic drugs. The split of recommended single-tablet regimens (STR) into their single substance partners is one of the considerations mentioned in said debate. Particularly, generic tenofovir disoproxil/emtricitabine (TDF/FTC) is expected to hold untapped cost-saving potential, which may curb increasing overall expenditures for combined antiretroviral therapy (cART) within the statutory health insurance (SHI) of Germany.

Methods

Data of ARV reimbursed by the SHI were used to describe the trends of defined daily doses (DDD) as well as the revenue within the German ARV market. They were also used to determine the cost-savings of moving to generic drugs. The time period observed was between January 2017 and June 2019. The potential cost-savings were determined with following assumption in mind: the maximum possible use of generic ARV, including 1) the split of STR and replacing all substance partners with generic ones, and 2) replacing patented tenofovir alafenamide/emtricitabine (TAF/FTC) with generic TDF/FTC.

Results

Throughout the observation period, the DDD of generic ARV increased nearly five-fold while their revenue increased more than four-fold. Total cost-saving showed a sharp increase over the same period, with generic TDF/FTC accounting for a share of around 70%. The largest potential cost-saving could have been achieved through replacing patented TAF/FTC with generic TDF/FTC, peaking at nearly 10% of total revenue, but showing decreasing trends in general.

Conclusion

The progressive distribution of generic ARV ensured increasing cost-savings_, but consequently curbed the potential cost-savings. Unique price reductions of generic TDF/FTC have played a pivotal role for these effects. In any case, substituting with generic ARV should not fail to adhere to the treatment guidelines and continue to consider the medical requirements for the treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07390-4.

Comparison of Tenofovir Alafenamide and Entecavir Therapy in Patients with Chronic Hepatitis B Initially Treated with Tenofovir Disoproxil: A Retrospective Observational Survey

Background: In chronic hepatitis B patients with or exposed to the risk of osteoporosis or renal dysfunction, switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide fumarate (TAF) or entecavir (ETV) may be the right choice. Objectives: This study aimed to present real-life data in terms of the efficacy and safety of a TAF/ETV treatment change while receiving TDF. Methods: This retrospective study was conducted on 344 adult patients from 10 centers. The data of patients who had changed to ETV (n = 107) and TAF (n = 237) while receiving TDF were analyzed. The data collected at 0 and 6 months of treatment were analyzed. The virological response was assessed based on undetected hepatitis B virus (HBV) DNA. Serum alanine aminotransferase (ALT) values were used to evaluate the biochemical response. For renal function, serum creatinine and phosphorus, as well as estimated glomerular filtration rate (eGFR), were recorded. Moreover, lumbar spine and hip T-scores along with the serum lipid profile were evaluated. Results: The mean age of patients was 41.14 ± 13.46 years, and 224 (65.1%) of the participants were male. The treatment arms were not significantly different in terms of demographic characteristics, comorbid diseases, infection duration, family history of HBV infection, blood platelet count, serum biomarkers, such as ALT, phosphorus, creatinine, total bilirubin, albumin, lipid profile, and HBV DNA levels at the beginning. No statistically significant difference was found between the proportion of undetectable HBV DNA of the two treatment groups after 6 months (P = 0.221). The ALT normalization in the ETV and TAF groups at the sixth month compared to the baseline levels was not significantly different (P = 0.853, P = 0.330, respectively). There was no statistically significant difference between the two treatment arms regarding changes in eGFR, creatinine, phosphorus, hip, and spine T-scores from baseline to 6 months (P = 0.296, P = 0.78, P = 0.141, P = 0.832, P = 0.947, respectively). In those who switched to TAF or ETV, low-density lipoproteins cholesterol were observed to be significantly higher after 6 months compared to baseline values (P = 0.002, P = 0.049, respectively). The TC increased significantly in the TAF group (P = 0.035). Conclusions: Our study showed that switching to ETV and TAF sustained the viral suppression and biochemical response achieved by TDF therapy. The treatment switch to TAF of ETV can control renal dysfunction and reduce bone mineral density caused by TDF.

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.

Tenofovir disoproxil fumarate directly ameliorates liver fibrosis by inducing hepatic stellate cell apoptosis via downregulation of PI3K/Akt/mTOR signaling pathway

Background

Antifibrotic agent for the treatment of liver fibrosis has not been developed so far. Long term treatment of chronic hepatitis B patients with antiviral drugs tenofovir disoproxil fumarate (TDF) and entecavir (ETV) results in the regression of liver fibrosis, but the underlying mechanism has not been clarified. Therefore, we aimed to investigate the direct impact of TDF and ETV on liver fibrosis.

Methods

Activated hepatic stellate cell (HSC) cell lines were used to evaluate the effects of TDF and ETV. After treatment with each antiviral agent, cell viability, morphology, apoptotic features, autophagy and antifibrosis signalling pathways were examined. Then, collagen deposition, fibrosis markers and activated HSCs were measured in liver tissues of the liver fibrosis model mice.

Results

After TDF treatment, the viabilities of LX2 and HSC-T6 cells were decreased, and the cells exhibited apoptotic features, but ETV did not induce these effects. Cleavage of PARP and Caspase-3 and the inhibition of the antiapoptotic gene Bcl-xl indicated activated HSC apoptosis following TDF treatment. TDF simultaneously increased autophagy, which also regulated apoptosis through crosstalk. TDF inactivated the PI3K/Akt/mTOR signalling pathway, which was associated with the activation of both apoptosis and autophagy. In the liver fibrosis mouse model, the fibrotic area and activated HSC markers were decreased by TDF but not ETV treatment. Additionally, apoptotic cells were concentrated in the periportal fibrotic area after TDF treatment, which indicated the specific antifibrotic effect of TDF.

Conclusions

TDF directly ameliorates liver fibrosis by downregulating the PI3K/Akt/mTOR signalling pathway, which results in the apoptosis of activated HSCs. The antifibrotic effects of TDF indicate that it may be a therapeutic agent for the treatment of liver fibrosis.