Discontinuation of oral antivirals in chronic hepatitis B: A systematic review

A Simulation-Based Assessment of Levetiracetam Concentrations Following Fixed and Weight-Based Loading Doses: A Meta-Regression and Pharmacokinetic Modeling Analysis

Current recommendations for refractory status epilepticus (SE) unresponsive to benzodiazepines suggest a loading dose of levetiracetam (LEV) of 60 mg/kg to a maximum of 4500 mg. LEV therapeutic drug monitoring can help guide therapy and is garnering increasing attention. The objective of this study is to simulate the probability of target attainment (PTA) of fixed dose and weight-based loading doses of LEV with respect to established therapeutic target concentrations. Meta-regression of the current literature was performed to evaluate the relationship between intravenous LEV loading dose and seizure cessation in refractory SE patients. A previously published pharmacokinetic model was used to simulate the PTA capacity of competing single intravenous dosing schemes (fixed vs weight-based dosing) to achieve maximum (Cpeak) and 12-h (C12h) plasma concentrations that exceed 12 mg/L. The meta-regression indicated that dosage was not a statistically significant modulator of seizure control at dosages between 20 and 60 mg/kg. Stochastic simulations showed all dosing schemes achieved plasma Cpeak >12 mg/L, but C12h levels were <12 mg/L in subjects over 60 kg with a fixed dose ≤2000 mg or in subjects <60 kg with a weight-based dose <30 mg/kg. Dosages of 40 and 60 mg/kg provided ≥90% PTAs across all weights. Using a weight-based loading dose of 40 mg/kg, up to a suggested maximum of 4500 mg, improves the likelihood of achieving a sustained therapeutic drug concentration after the initial LEV dose, whereas fixed <3000 mg may not achieve the desired concentration before maintenance dosing.

Limited Sustained Remission After Nucleos(t)ide Analog Withdrawal: Results From a Large, Global, Multiethnic Cohort of Patients With Chronic Hepatitis B (RETRACT-B Study)

INTRODUCTION

Complete viral suppression with nucleos(t)ide analogs (NAs) has led to a profound reduction in hepatocellular carcinoma and mortality among patients with chronic hepatitis B. Finite therapy yields higher rates of functional cure; however, initial hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) elevations are almost certain after treatment interruption. We aimed to analyze off-treatment outcomes beyond 12 months after NA cessation.

METHODS

Patients with well-suppressed chronic hepatitis B who were hepatitis B e antigen-negative at NA cessation and remained off treatment without hepatitis B surface antigen (HBsAg) loss at 12 months were included (n = 945). HBV DNA and ALT fluctuations were allowed within the first 12 months. We used Kaplan-Meier methods to analyze outcomes beyond 12 months. Sustained remission was defined as HBV DNA <2,000 IU/mL and ALT <2× upper limit of normal (ULN) and an ALT flare as ALT ≥5× ULN.

RESULTS

Cumulative probability of sustained remission was 29.7%, virological relapse was 65.2% with a mean peak HBV DNA of 5.0 ± 1.5 log 10 IU/mL, an ALT flare was 15.6% with a median peak ALT × ULN of 8.3 (5.7-11.3), HBsAg loss was 9.9% and retreatment was 34.9% at 48 months after NA cessation. A single occurrence of virological relapse or an ALT flare within the first 12 months off-treatment were associated with significantly lower rates of sustained remission beyond 12 months.

DISCUSSION

Despite allowing for HBV DNA and ALT fluctuations within the first 12 months off-treatment, most patients without HBsAg loss did not maintain a sustained response thereafter. The best candidates for NA withdrawal are patients with low HBsAg levels at NA cessation, and those without profound or recurrent virological and biochemical relapses in the first off-treatment year.

Evaluation of chronic hepatitis B patients who voluntarily discontinued oral antiviral therapy: is there an answer to the controversial topic?

OBJECTIVE

The uncertain treatment duration for nucleos(t)ide analogues (NA) used in the treatment of chronic hepatitis B (CHB) is an important problem for both patients and physicians. The aim of this study was to evaluate the determinants of virologic relapse (VR) and the optimum time of treatment discontinuation in the follow-up of CHB patients who voluntarily discontinued treatment after virological suppression was achieved under NA use.

METHODS

Data from 138 patients from 11 centers were included in this registry-based study. Factors associated with VR were investigated using multivariate Cox regression analysis.

RESULTS

Ninety-nine (71.7%) of the patients were HBeAg (Hepatitis B e antigen) negative. During the 24-month follow-up period after treatment discontinuation, VR occurred in 58.7% (n = 81) of all patients and 57.6% (n = 57) of HBeAg-negative patients. The duration of NA treatment was significantly shorter (cutoff 60 months) in HBeAg-negative patients who later developed VR. In addition, the duration of virologic remission achieved under NA treatment was significantly shorter (cutoff 52 months) in those who later developed VR. In the Cox multivariate regression model of HBeAg-negative patients, having less than 60 months of NA treatment (HR = 2.568; CI:1.280-5.148; P  = 0.008) and the levels of alanine aminotransferase being equal to or higher than twice the upper level of normal at the beginning of treatment (HR = 3.753; CI:1.551-9.081; P  = 0.003) were found to be statistically significant and independently associated with VR.

CONCLUSION

The findings of this study may provide clinical guidance in terms of determining the most appropriate discontinuation time for NA.

Quantitative Measurement of Serum HBcrAg Can Be Used to Assess the Feasibility of Safe Discontinuation of Antiviral Therapy for Chronic Hepatitis B

Hepatitis B virus (HBV) infection is a serious global health problem, and chronic HBV infection significantly increases the risk of liver fibrosis, cirrhosis, and even hepatocellular carcinoma in patients. Current first-line therapeutics such as nucleos(t)ide analogues and interferons are unable to completely clear cccDNA, so the vast majority of patients need to take long-term or even lifelong medication. However, long-term virological and biochemical responses can be achieved in some patients after drug withdrawal. Successfully screening these patients with drug withdrawal advantages is difficult. Hepatitis-B-core-related antigen (HBcrAg) is a new HBV serological marker that which can reflect the level and transcription activity of cccDNA in hepatocytes. Therefore, HBcrAg has potential value in guiding patients in drug withdrawal. This review summarizes previous reports on HBcrAg and evaluates the application value of HBcrAg in safe drug discontinuation.

Elimination of the hepatitis B virus: A goal, a challenge

The hepatitis B elimination is a goal proposed by the WHO to be achieved by 2030 through the adoption of synergistic measures for the prevention and chronic HBV infection treatment. Complete cure is characterized by the HBV elimination from the body and is the goal of the chronic hepatitis B treatment, which once achieved, will enable the hepatitis B elimination. This, today, has been a scientific challenge. The difficulty in achieving a complete cure is due to the indefinite maintenance of a covalently closed episomal circular DNA (cccDNA) reservoir and the maintenance and persistence of an insufficient and dysfunctional immune response in chronically infected patients. Among the measures adopted to eliminate hepatitis B, two have the potential to directly interfere with the virus cycle, but with limited effect on HBV control. These are conventional vaccines-blocking transmission and antiviral therapy-inhibiting replication. Vaccines, despite their effectiveness in protecting against horizontal transmission and preventing mother-to-child vertical transmission, have no effect on chronic infection or potential to eliminate the virus. Treatment with antivirals suppresses viral replication, but has no curative effect, as it has no action against cccDNA. Therapeutic vaccines comprise an additional approach in the chronic infection treatment, however, they have only a modest effect on the immune system, enhancing it temporarily. This manuscript aims to address (1) the cccDNA persistence in the hepatocyte nucleus and the immune response dysfunction in chronically infected individuals as two primary factors that have hampered the treatment and HBV elimination from the human body; (2) the limitations of antiviral therapy and therapeutic vaccines, as strategies to control hepatitis B; and (3) the possibly promising therapeutic approaches for the complete cure and elimination of hepatitis B.

Routine evaluation of HBV-specific T cell reactivity in chronic hepatitis B using a broad-spectrum T-cell epitope peptide library and ELISpot assay

BACKGROUND

The clinical routine test of HBV-specific T cell reactivity is still limited due to the high polymorphisms of human leukocyte antigens (HLA) in patient cohort and the lack of universal detection kit, thus the clinical implication remains disputed.

METHODS

A broad-spectrum peptide library, which consists of 103 functionally validated CD8+ T-cell epitopes spanning overall HBsAg, HBeAg, HBx and HBpol proteins and fits to the HLA polymorphisms of Chinese and Northeast Asian populations, was grouped into eight peptide pools and was used to establish an ELISpot assay for enumerating the reactive HBV-specific T cells in PBMCs. Totally 294 HBV-infected patients including 203 ones with chronic hepatitis B (CHB), 13 ones in acute resolved stage (R), 52 ones with liver cirrhosis (LC) and 26 ones with hepatocellular carcinoma (HCC) were detected, and 33 CHB patients were longitudinally monitored for 3 times with an interval of 3-5 months.

RESULTS

The numbers of reactive HBV-specific T cells were significantly correlated with ALT level, HBsAg level, and disease stage (R, CHB, LC and HCC), and R patients displayed the strongest HBV-specific T cell reactivity while CHB patients showed the weakest one. For 203 CHB patients, the numbers of reactive HBV-specific T cells presented a significantly declined trend when the serum viral DNA load, HBsAg, HBeAg or ALT level gradually increased, but only a very low negative correlation coefficient was defined (r = - 0.21, - 0.21, - 0.27, - 0.079, respectively). Different Nucleotide Analogs (NUCs) did not bring difference on HBV-specific T cell reactivity in the same duration of treatment. NUCs/pegIFN-α combination led to much more reactive HBV-specific T cells than NUCs monotherapy. The dynamic numbers of reactive HBV-specific T cells were obviously increasing in most CHB patients undergoing routine treatment, and the longitudinal trend possess a high predictive power for the hepatitis progression 6 or 12 months later.

CONCLUSION

The presented method could be developed into an efficient reference method for the clinical evaluation of cellular immunity. The CHB patients presenting low reactivity of HBV-specific T cells have a worse prognosis for hepatitis progression and should be treated using pegIFN-α to improve host T-cell immunity.

Sustained response and HBsAg loss after nucleo(s)tide analogue discontinuation in chronic hepatitis B patients: the prospective SNAP study

BACKGROUND & AIM(S)

Current guidelines suggest that nucleos(t)ide analogues (NA) can be discontinued before HBsAg loss in a selected group of chronic hepatitis B (CHB) patients. We aimed to study the safety and off-treatment response after NA cessation.

METHODS

This is a prospective, multicentre, cohort study in which eligible patients discontinued NA therapy. Adult patients, with a CHB mono-infection, HBeAg-negative, without a (history of) liver cirrhosis, who had achieved long-term viral suppression were eligible. Follow-up visits were planned at week 2-4-8-12-24-36-48-72-96. Re-treatment criteria included severe hepatitis (ALT >10x ULN), signs of imminent liver failure (bilirubin >1.5x ULN or INR >1.5), or at the physician's own discretion.

RESULTS

In total, 33 patients were enrolled. Patients were predominantly Caucasian (45.5%) and had genotype A/B/C/D/unknown in 3/4/6/10/10 (9.1/12.1/18.2/30.3/30.3%). At week 48, 15 patients (45.5%) achieved a sustained response (HBV DNA <2,000 IU/mL). At week 96, 13 patients (39.4%) achieved a sustained response, 4 (12.1%) achieved HBsAg loss, and 12 (36.4%) were re-treated. Severe hepatitis was the main reason for re-treatment (n=7, 21.2%). One patient with severe hepatitis developed jaundice, without signs of hepatic decompensation. Re-treatment was successful in all patients.

CONCLUSION

NA therapy can be ceased in a highly selected group of CHB patients if close follow-up can be guaranteed. Treatment cessation may increase the chance of HBsAg loss in selected patients, which is counterbalanced by a significant risk of severe hepatitis.

IL-15 boosts activated HBV core-specific CD8+ progenitor cells via metabolic rebalancing in persistent HBV infection

A rebalance between energy supply and demand in HBV-specific-CD8+ activated progenitor (AP) cells could restore the functionality of proliferative progeny (PP) in e-antigen(Ag)-negative chronic hepatitis B (CHBe(-)). We observed that quiescent progenitor (QP [TCF1+/FSClow]) HBVcore-specific-CD8+ cells displayed a memory-like phenotype. Following Ag-encounter, the generated AP [TCF1+/FSChigh] subset maintained the PD1+/CD127+ phenotype and gave rise to proliferative progeny (PP [ TCF1-/FSChigh]). In AP cells, IL-15 compared to IL2 decreased the initial mTORC1 boost, but maintained its activation longer linked to a catabolic profile that correlated with enhanced PP effector abilities. In nucleos(t)ide analogue (NUC)-treated CHBe(-), AP subset showed an anabolic phenotype associated with a dysfunctional PP pool. In CHBe(-) cases with low probability of HBVcore-specific-CD8+ cell on-NUC-treatment restoration, according to a clinical predictive model, IL-15/anti-PD-L1 treatment re-established their reactivity. Therefore, IL-15 could improve AP pool energy balance by decreasing intensity but extending T cell activation and by inducing a more catabolic metabolism.

Changes and gaps of global and regional disease burden of hepatitis B infection in children younger than 5 years old between 2015 and 2019: A real-world data review

Hepatitis B virus (HBV) infection has been declared an ongoing health threat, especially infections among children. We compared and updated the disease burden of HBV infection and the effectiveness of vaccination among children younger than 5 years to offer indications for hepatitis B prevention across the world. The country-level data on the prevalence of hepatitis B surface antigen (HBsAg), the coverages of hepatitis B vaccine birth-dose (HepB-BD), three-dose series (HepB3), income level, population density/size, and human development index were collected from open access databases including WHO, UNICEF, and World Bank. Comparison of the prevalence of HBsAg under 5 years old between 2015 and 2019 based on vaccination coverages was conducted by the gamma generalized linear mixed model. Globally, more than 6.3 million HBV infections were estimated in children under 5 years in 2019, compared to 10.1 million in 2015 within the 179 countries involved. The pooled average prevalence of HBsAg among children younger than 5 years decreased from 1.4% (95% confidence interval [CI]: 1.1-1.8) to 0.9% (95% CI: 0.7-1.2). The rate difference or rate ratio was -0.5% (95% CI: -0.6% to -0.3%) or 0.51(95% CI: 0.44-0.58), respectively. Countries from the African region or with lower income/population density/human development indexes bore the most significant disease burden of hepatitis B. Higher coverages of hepatitis B vaccine birth-dose or primary series correlated with significant HBsAg prevalence decreases and much-decreased ratio, independently. Hepatitis B prevention among children under 5 years has significantly been achieved while remaining the most life-threatening disease burden, unequally distributed worldwide. The hepatitis B vaccination should be prioritized for all newborns, especially in those resource-constrained countries or regions.

Higher HBeAg-reversion virological relapse and lower sustained remission after treatment cessation in tenofovir-treated HBeAg-positive patients

A complete investigation of the clinical outcomes after treatment cessation in HBeAg-positive patients with HBeAg loss is limited. We retrospectively recruited 242 HBeAg-positive patients with HBeAg loss after a median duration of 37.2 months with tenofovir (TDF, n = 77) or entecavir (ETV, n = 165) treatment. There were 77 (31.8%) patients with sustained virological remission (SVR), 85 (35.1%) with HBeAg-reversion virological relapse, 80 (33.1%) with HBeAg-negative virological relapse after treatment cessation, and 23 (9.5%) with HBsAg loss. Clinical data at baseline, on-treatment and during off-treatment follow-up were analyzed. The 3-year cumulative incidences of overall, HBeAg-reversion and HBeAg-negative virological relapse were 70.2%, 54%, and 53.5%, respectively. The common factors associated with HBeAg-reversion and HBeAg-negative virological relapse were tenofovir treatment (hazard ratio [HR] = 5.411, p < 0.001; HR = 2.066, p = 0.006, respectively) and HBsAg at end of treatment (EOT) (HR = 1.461, p = 0.001; HR = 1.303, p = 0.019, respectively). The 5-year cumulative incidence of HBsAg loss in SVR patients was 13.7% and EOT HBsAg was the only associated factor (HR = 0.524, p = 0.024). Compared to that of ETV-treated patients, TDF-treated patients had a significantly higher 3-year cumulative incidence of virological relapse (87.3% vs. 62.8%, p < 0.001), earlier HBeAg-reversion virological relapse (2.9 vs. 7.8 months, p < 0.001), a higher rate of HBeAg-reversion virological relapse (53.2% vs. 26.7%) and a lower SVR rate (15.6% vs. 39.4%) (p < 0.001). In summary, the clinical outcomes after treatment cessation in HBeAg-positive patients with HBeAg loss were composed of HBeAg-reversion virological relapse, HBeAg-negative virological relapse and SVR. TDF was significantly associated with off-treatment virological relapse. EOT HBsAg plays an important role in HBsAg loss among SVR patients and posttreatment virological relapse.

Safety considerations for withdrawal of nucleos(t)ide analogues in patients with chronic hepatitis B: First, do no harm

Nucleos(t)ide analogues (NA) are widely used to treat hepatitis B virus (HBV) infection, but they cannot eradicate the virus and treatment duration can be lifelong if the endpoint is set at seroclearance of the hepatitis B surface antigen (HBsAg). As an alternative strategy, finite NA therapy without the prerequisite of HBsAg seroclearance has been proposed to allow treatment cessation in patients with sustained undetectable HBV viremia for two to three years. However, reactivation of viral replication almost always follows NA withdrawal. Whereas HBV reactivation might facilitate HBsAg seroclearance in some, it could lead to serious acute flare-ups in a certain proportion of patients. Occurrence and consequences of NA withdrawal flares are complicated with various factors involving the virus, host, and treatment. Accurate risk prediction for severe flares following NA cessation is essential to ensure patient safety. The risks of life-threatening flares in patients who discontinued NA according to the stopping rules of current guidelines or local reimbursement policies have recently been quantitatively estimated in large-scale studies, which also provided empirical evidence to help identify vulnerable patients at risk of devastating outcomes. Moreover, risk predictors were further explored and validated to hopefully aid in patient selection and management. In this narrative review with a focus on patient safety, we summarize and discuss current literature on the incidence of severe flares following NA cessation, risk stratification for candidate selection, rules of posttreatment monitoring, and indications for treatment resumption. We also share our thoughts on the limitations of existing knowledge and suggestions for future research.

Incidence of Hepatic Decompensation After Nucleos(t)ide Analog Withdrawal: Results From a Large, International, Multiethnic Cohort of Patients With Chronic Hepatitis B (RETRACT-B Study)

INTRODUCTION

Despite improvements in the management of chronic hepatitis B (CHB), risk of cirrhosis and hepatocellular carcinoma remains. While hepatitis B surface antigen loss is the optimal end point, safe discontinuation of nucleos(t)ide analog (NA) therapy is controversial because of the possibility of severe or fatal reactivation flares.

METHODS

This is a multicenter cohort study of virally suppressed, end-of-therapy (EOT) hepatitis B e antigen (HBeAg)-negative CHB patients who stopped NA therapy (n = 1,557). Survival analysis techniques were used to analyze off-therapy rates of hepatic decompensation and differences by patient characteristics. We also examined a subgroup of noncirrhotic patients with consolidation therapy of ≥12 months before cessation (n = 1,289). Hepatic decompensation was considered related to therapy cessation if diagnosed off therapy or within 6 months of starting retreatment.

RESULTS

Among the total cohort (11.8% diagnosed with cirrhosis, 84.2% start-of-therapy HBeAg-negative), 20 developed hepatic decompensation after NA cessation; 10 events were among the subgroup. The cumulative incidence of hepatic decompensation at 60 months off therapy among the total cohort and subgroup was 1.8% and 1.1%, respectively. The hepatic decompensation rate was higher among patients with cirrhosis (hazard ratio [HR] 5.08, P < 0.001) and start-of-therapy HBeAg-positive patients (HR 5.23, P < 0.001). This association between start-of-therapy HBeAg status and hepatic decompensation remained significant even among the subgroup (HR 10.5, P < 0.001).

DISCUSSION

Patients with cirrhosis and start-of-therapy HBeAg-positive patients should be carefully assessed before stopping NAs to prevent hepatic decompensation. Frequent monitoring of viral and host kinetics after cessation is crucial to determine patient outcome.

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.

Current Therapy of Chronic Viral Hepatitis B, C and D

The majority of chronic viral hepatitis cases are induced via infection with the hepatitis B virus (HBV), hepatitis C virus (HCV), or hepatitis D virus (HDV). These patients are at increased risk for progressive liver disease leading to cirrhosis as well as hepatocellular carcinoma (HCC). HBV infection is well controlled by the currently available nucleosides as well as nucleotides, and the development of cirrhosis can be prevented. Additionally, it has been shown that HBV-induced liver fibrosis can regress during successful antiviral treatment; however, a "functional cure", i.e., loss of HBsAg, is a rare event when these drugs are used. Therefore, novel therapeutic strategies are aiming at the selective suppression of HBsAg levels in combination with immunostimulation. The development of directly acting antivirals (DAAs) has revolutionized HCV therapy, as almost all patients can be cured via this treatment. Additionally, DAA therapy has few, if any, side effects, and is generally well tolerated by patients. HDV remains the most challenging type of chronic viral hepatitis. Although novel therapeutic options have recently been approved, response rates are still less favorable compared to HBV and HCV. This review discusses current and future options for the treatment of chronic HBV, HCV, and HDV infection.

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.

Chronic hepatitis B - A scoping review on the guidelines for stopping nucleos(t)ide analogue therapy

INTRODUCTION

Nucleos(t)ide analogues (NAs) are effective in suppressing the replication of the hepatitis B virus. However, NAs cannot effectively induce hepatitis B surface antigen (HBsAg) seroclearance, which represents the optimal treatment endpoint in chronic hepatitis B (CHB). Hence, most CHB patients are advised for indefinite NA therapy, but recent data has supported the concept of finite NA therapy before HBsAg seroclearance.

AREAS COVERED

This article covered the latest evidence on stopping NAs in CHB, with focused analysis on international guidelines. Articles were retrieved by a literature search on PubMed with the keywords "chronic hepatitis B", "antiviral therapy", "nucleos(t)ide analogue", "cessation", "stopping" and "finite". Studies up till 1 December 2022 were included.

EXPERT OPINION

Finite NA therapy in CHB has potential in enhancing HBsAg seroclearance, however it also carries rare but potentially severe risks. NA cessation before HBsAg seroclearance is only suitable for a highly-selected group of patients, whereas the majority of CHB patients should be treated indefinitely or until HBsAg seroclearance. Current guidelines have provided recommendations on stopping NAs, but further research is required to optimize the monitoring and retreatment protocol after stopping NAs.

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.

A novel anti-HBV agent, E-CFCP, restores Hepatitis B virus (HBV)-induced senescence-associated cellular marker perturbation in human hepatocytes

Cellular senescence is a cellular state with a broad spectrum of age-related physiological conditions that can be affected by various infectious diseases and treatments. Therapy of hepatitis B virus (HBV) infection with nucleos(t)ide analogs [NA(s)] is well established and benefits many HBV-infected patients, but requires long-term, perhaps lifelong, medication. In addition to the effects of HBV infection, the effects of NA administration on hepatocellular senescence are still unclear. This study investigated how HBV infection and NA treatment influence cellular senescence in human hepatocytes and humanized-liver chimeric mice chronically infected with live HBV. HBV infection upregulates or downregulates multiple cellular markers including senescence-associated β-galactosidase (SA-β-Gal) activity and cell cycle regulatory proteins (e.g., p21^CIP1) expression level in hepatocellular nuclei and humanized-mice liver. A novel highly potent anti-HBV NA, E-CFCP, per se did not have significant disturbance on markers evaluated. Besides, E-CFCP treatment restored HBV-infected cells to their physiological phenotypes that are comparable to the HBV-uninfected cells. The results reported here demonstrate that, regardless of the mechanism(s), chronic HBV infection perturbates multiple senescence-associated markers in human hepatocytes and humanized-mice liver, but E-CFCP can restore this phenomenon.

Emerging Therapies for Chronic Hepatitis B and the Potential for a Functional Cure

Worldwide, an estimated 296 million people are living with chronic hepatitis B virus (HBV) infection, with a significant risk of morbidity and mortality. Current therapy with pegylated interferon (Peg-IFN) and indefinite or finite therapy with nucleoside/nucleotide analogues (Nucs) are effective in HBV suppression, hepatitis resolution, and prevention of disease progression. However, few achieve hepatitis B surface antigen (HBsAg) loss (functional cure), and relapse often occurs after the end of therapy (EOT) because these agents have no direct effect on durable template: covalently closed circular DNA (cccDNA) and integrated HBV DNA. Hepatitis B surface antigen loss rate increases slightly by adding or switching to Peg-IFN in Nuc-treated patients and this loss rate greatly increases up to 39% in 5 years with finite Nuc therapy with currently available Nuc(s). For this, great effort has been made to develop novel direct-acting antivirals (DAAs) and immunomodulators. Among the DAAs, entry inhibitors and capsid assembly modulators have little effect on reducing HBsAg levels; small interfering RNA, antisense oligonucleotides, and nucleic acid polymers in combination with Peg-IFN and Nuc may reduce HBsAg levels significantly, even a rate of HBsAg loss sustained for > 24 weeks after EOT up to 40%. Novel immunomodulators, including T-cell receptor agonists, check-point inhibitors, therapeutic vaccines, and monoclonal antibodies may restore HBV-specific T-cell response but not sustained HBsAg loss. The safety issues and the durability of HBsAg loss warrant further investigation. Combining agents of different classes has the potential to enhance HBsAg loss. Compounds directly targeting cccDNA would be more effective but are still in the early stage of development. More effort is required to achieve this goal.

A Semi-mechanistic Model to Characterize the Long-Term Dynamics of Hepatitis B Virus Markers During Treatment With Lamivudine and Pegylated Interferon

Antiviral treatments against hepatitis B virus (HBV) suppress viral replication but do not eradicate the virus, and need therefore to be taken lifelong to avoid relapse. Mathematical models can be useful to support the development of curative anti-HBV agents; however, they mostly focus on short-term HBV DNA data and neglect the complex host-pathogen interaction. This work aimed to characterize the effect of treatment with lamivudine and/or pegylated interferon (Peg-IFN) in 1,300 patients (hepatitis B envelope antigen (HBeAg)-positive and HBeAg-negative) treated for 1 year. A mathematical model was developed incorporating two populations of infected cells, namely I 1 , with a high transcriptional activity, that progressively evolve into I 2 , at a rate δ tr , representing cells with integrated HBV DNA that have a lower transcriptional activity. Parameters of the model were estimated in patients treated with lamivudine or Peg-IFN alone (N = 894), and the model was then validated in patients treated with lamivudine plus Peg-IFN (N = 436) to predict the virological response after a year of combination treatment. Lamivudine had a larger effect in blocking viral production than Peg-IFN (99.4-99.9% vs. 91.8-95.1%); however, Peg-IFN had a significant immunomodulatory effect, leading to an enhancement of the loss rates of I 1 (×1.7 in HBeAg-positive patients), I 2 (> ×7 irrespective of HBeAg status), and δ tr (×4.6 and ×2.0 in HBeAg-positive and HBeAg-negative patients, respectively). Using this model, we were able to describe the synergy of the different effects occurring during treatment with combination and predicted an effect of 99.99% on blocking viral production. This framework can therefore support the optimization of combination therapy with new anti-HBV agents.

Hepatitis B Therapeutic Vaccine: A Patent Review

Viral hepatitis has long been underrated as a danger to global health. The UN only recently called for worldwide action to tackle viral hepatitis and lessen the disease burden in its "2030 Agenda for Sustainable Development". Hepatitis B virus (HBV), which causes liver cirrhosis and malignancy, is a main cause of death globally. This review analyses innovative HBV therapeutic vaccine candidates for which a patent was filed between January 2010 and March 2022 and presents future improvement techniques for vaccine efficacy. Although there is a preventative vaccine for HBV infection, over 3% of people worldwide have the disease on a long-term basis and can no longer benefit from it. Most people will have chronic HBV infection for the rest of their lives once it has been diagnosed. Moreover, only a small percentage of treated patients experience a functional cure with persistent hepatitis B surface antigen reduction. A significant proportion of deaths are caused by liver cirrhosis and hepatocellular cancer, which are both caused by chronic hepatitis B infection. Hence, there is an urgent need for novel medications due to the inadequacies of the current therapies.

Action Mechanisms and Scientific Rationale of Using Nasal Vaccine (HeberNasvac) for the Treatment of Chronic Hepatitis B

Nasvac (HeberNasvac^®) is a novel therapeutic vaccine for chronic hepatitis B (CHB). This product is a formulation of the core (HBcAg) and surface (HBsAg) antigens of the hepatitis B virus (HBV), administered by nasal and subcutaneous routes, in a distinctive schedule of immunizations. In the present review article, we discuss the action mechanisms of HeberNasvac, considering the immunological properties of the product and their antigens. Specifically, we discuss the capacity of HBcAg to activate different pathways of innate immunity and the signal transduction after a multi-TLR agonist effect, and we review the results of recent clinical trials and in vitro studies. Aimed at understanding the clinical results of Nasvac and other therapeutic vaccines under development, we discuss the rationale of administering a therapeutic vaccine through the nasal route and also the current alternatives to combine therapeutic vaccines and antivirals (NUCs). We also disclose potential applications of this product in novel fields of immunotherapy.

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.

Sustained viral response and relapse after discontinuation of oral antiviral drugs in HBeAg-positive patients with chronic hepatitis B infection

Objective

To investigate the sustained virological response and relapse in chronic hepatitis B (CHB) patients with hepatitis B e antigen (HBeAg) positive after stopping oral antiviral drugs, and to monitor the disease progression and the incidence of adverse events such as liver cirrhosis and hepatocellular carcinoma.

Methods

This is a prospective observational study. Patients who continued nucleos(t)ide analogue (NA) treatment after achieving HBeAg seroconversion for more than 3 years were enrolled. After signing the informed consent form, patients stopped NA treatment and received follow-up. During the follow-up, the antiviral treatment information of the patients was collected, and the follow-up observation was carried out every 3 months since the enrollment. We monitored the virological indexes, liver and kidney function, serology and liver imaging during follow-up. The purpose of this study was to explore the sustained virological response rate, HBV DNA recurrence rate, clinical relapse rate and the related factors after drug withdrawal.

Results

A total of 82 patients were enrolled, including 42 males (51.22%) and 40 females (48.78%), with a median age of 34.00 (31.00, 37.25) years. All enrolled patients were followed up for 1 year. At the end of the follow-up, 36.59% (30/82) of patients had sustained virological response, 63.41% (52/82) of patients had HBV DNA reactivation, 17.07% (14/82) of patients had clinical relapse, and 10.98% (9/82) of patients had HBeAg reversion. During the follow-up, there were no adverse events such as liver cirrhosis and hepatocellular carcinoma. The median level of hepatitis B surface antigen (HBsAg) in patients with sustained virological response was lower than that in patients with HBV DNA reactivation (2.92 vs.3.18 log₁₀IU/ml, Z=-1.492/P=0.136), and the median level of baseline HBsAg in patients with HBV DNA reactivation was lower than that in patients with clinical relapse (3.01 vs.3.45 log₁₀IU/mL, Z=-1.795/P=0.073), but the difference was not significant. There was no significant statistical difference between patients with sustained virological response and HBV DNA reactivation of the median total treatment time [69.50 (56.25, 86.00) vs.62.50 (44.00, 88.50) months, Z=-0.689/P=0.491], and the consolidation treatment time [41.50 (36.75, 54.75) vs.40.50 (36.00, 53.75) months, Z=-0.419/P=0.675].

Conclusion

The sustained virological response rate of HBeAg positive CHB patients after stopping oral antiviral treatment is lower, and it is more common in patients with lower HBsAg levels. Patients still need to be closely monitored after stopping NA therapy.

Ivermectin Inhibits HBV Entry into the Nucleus by Suppressing KPNA2

Hepatitis B virus (HBV) specifically infects human hepatocytes and increases the risks of cirrhosis and liver cancer. Currently, nucleic acid analogs are the main therapeutics for chronic hepatitis caused by HBV infection. Although nucleic acid analogs can eliminate HBV DNA by inhibiting HBV reverse transcriptase, they cannot lead to negative conversion of covalently closed circular DNA (cccDNA) and hepatitis B surface antigen (HBsAg). In this study, we revealed that the antifilarial drug ivermectin suppresses HBV production by a different mechanism from the nucleic acid analog entecavir or Na⁺ taurocholate co-transporting polypeptide-mediated entry inhibitor cyclosporin A. Ivermectin reduced the levels of several HBV markers, including HBsAg, in HBV-infected human hepatocellular carcinoma cells (HepG2-hNTCP-C4 cells) and humanized mouse hepatocytes (PXB hepatocytes). In addition, ivermectin significantly decreased the expression of HBV core protein and the nuclear transporter karyopherin α2 (KPNA2) in the nuclei of HepG2-hNTCP-C4 cells. Furthermore, depletion of KPNA1-6 suppressed the production of cccDNA. These results suggest that KPNA1-6 is involved in the nuclear import of HBV and that ivermectin suppresses the nuclear import of HBV by inhibiting KPNA2. This study demonstrates the potential of ivermectin as a novel treatment for hepatitis B.

Health inequalities in the management of chronic hepatitis B virus infection in patients from sub-Saharan Africa in high-income countries

Chronic hepatitis B virus disproportionately affects migrant communities in high-income countries, reflecting increased migration from sub-Saharan Africa. Chronic hepatitis B virus is endemic in sub-Saharan Africa, yet the natural history of chronic infection experienced by patients remains incompletely understood, with evidence of variability across genotypes and regions within sub-Saharan Africa. Clinical guidelines recommending treatment thresholds are not specific to sub-Saharan African patients and are based on natural history studies from Western Pacific Asian countries. Access to standard of care treatment is available for sub-Saharan African people with chronic hepatitis B virus infection in high-income countries; however, the evidence base for these treatments was not established in this cohort and areas of uncertainty remain, particularly regarding HCC surveillance and treatment discontinuation. Participation in phase III clinical trials for chronic hepatitis B therapies is almost non-existent amongst sub-Saharan African patients, even when residing in high-income countries that participate in multicentre trials. Engagement with sub-Saharan African patients with chronic hepatitis B in high-income countries is challenging because of the stigma associated with the diagnosis, absence of routine screening systems and the complexities involved in navigating the healthcare system. Nonetheless, improved engagement is critical if we are to achieve global hepatitis B virus elimination.

Perspectives on current controversial issues in the management of chronic HBV infection

Clinical and basic research in the past decades has achieved consensus in the understanding of chronic hepatitis B virus (HBV) infection and the management of chronic hepatitis B and HBV-cirrhosis. However, debatable challenges to the existing consensus in the concept and/or definitions have emerged. These include (1). alanine aminotransferase upper limit of normal: traditional laboratory-defined vs fixed; (2). nomenclature for phases of chronic HBV infection: classical vs EASL proposal; (3). indication of antiviral therapy: to treat patients vs to treat HBV; (4). finite vs indefinite long-term antiviral therapy: A. finite therapy in HBV-cirrhosis; B. retreatment decision: biochemical markers vs HBsAg/ALT kinetics. The pros and cons of these controversial issues were reviewed, assessed, and discussed in depth based on relevant lines of scientific evidence, intended to clarify or solve these controversial issues.

Significance of serum HBV RNA in non-cirrhotic HBeAg-negative chronic hepatitis B patients who discontinue effective antiviral therapy

HBV RNA is considered as a promising predictor in patients who discontinue nucleos(t)ide analogues (NAs). We determined HBV RNA levels in non-cirrhotic HBeAg-negative patients who discontinued NAs and assessed their predictability for 12-month outcomes. Fifty-seven patients of DARING-B study were included. HBV RNA levels were determined in stored monthly serum samples drawn at 0-3 months after end of therapy (EOT). Other markers previously determined in the same cohort including hepatitis B core-related antigen (HBcrAg) were also assessed. HBV RNA at EOT was detectable in 7% of patients, who developed virological/clinical relapse and required retreatment at month 2; in patients with undetectable EOT HBV RNA, 12-month cumulative rates of virological relapse, clinical relapse and retreatment were 68%, 28% and 21%, respectively (p ≤ 0.008). HBV RNA at month-1 after EOT was detectable in 19% of patients being associated with higher probability only of virological relapse (p = 0.001). HBV RNA levels correlated significantly to HBV DNA, HBcrAg, ALT and interferon-induced protein-10, but not HBsAg levels. Combined EOT HBV RNA and HBcrAg detection and/or HBsAg >1000 IU/ml was associated only with higher probability of retreatment having higher sensitivity and lower specificity than HBV RNA alone. In conclusion, serum HBV RNA is detectable in a minority of non-cirrhotic HBeAg-negative patients under effective long-term NAs therapy offering low sensitivity but 100% specificity for early retreatment due to severe clinical relapses after NA discontinuation. The combinations of EOT HBV RNA with HBcrAg and/or high HBsAg levels increase sensitivity but decrease specificity for prediction of retreatment after NAs withdrawal.

Real-world tertiary referral centre experience stopping nucleos(t)ide analogue therapy in patients with chronic hepatitis B

BACKGROUND: Identifying strategies for stopping nucleos(t)ide analogues (NUC) in patients with chronic hepatitis B (CHB) is a major goal in CHB management. Our study describes our tertiary-centre experience stopping nucleos(t)ide analogues (NUC) in CHB. METHODS: We conducted a retrospective cohort study of all individuals with CHB seen at the Calgary Liver Unit between January 2009 and May 2020 who stopped NUC. We collected baseline demographics and HBV lab parameters before and after stopping NUC with results stratified by off-treatment durability. Clinical flare was defined as alanine aminotransferase (ALT) over twice the upper limit of normal and virological flare as HBV DNA >2000 IU/mL. RESULTS: Forty-seven (3.5%) of the 1337 individuals with CHB stopped NUC therapy. During follow-up, six patients (12.8%) restarted NUCs because of a flare. All flares occurred within six months of discontinuation. Median time to restart treatment was 90 days (Q1 65, Q3 133). Upon restarting, all showed suppression of HBV DNA and ALT normalization. Factors associated with restarting NUC therapy included hepatitis B e antigen (HBeAg) positive status at first appointment and longer NUC consolidation therapy. Age, sex, ethnicity, liver stiffness measurement, choice of NUC, and quantitative hepatitis B surface antigen (qHBsAg) level at stopping were not associated with sustained response off-treatment. Six patients had functional cure with HBsAg loss. CONCLUSIONS: Stopping long-term NUC is feasible in HBeAg negative CHB. Hepatic flares can occur despite low levels of qHBsAg. Finite NUC therapy can be considered in eligible patients who are adherent to close monitoring and follow-up, particularly in the first six months after stopping NUC therapy.

Dynamic Changes in Liver Stiffness in Patients with Chronic Hepatitis B Undergoing Antiviral Therapy

This is a retrospective single-center study that included 87 subjects. All subjects had chronic hepatitis B or HBV cirrhosis and underwent nucleos(t)ide analogs (NUC) treatment for more than one year. The study aimed to evaluate the dynamic changes in liver stiffness (LS) measured by transient elastography (TE) during a median interval of 64 months. Patients were assessed prior to starting therapy and followed up annually. Liver stiffness measurements (LSM) were performed annually, and ten valid LSMs were obtained in each session. Reliable LSMs were defined as the median value of 10 measurements with Interquartile range/median (IQR/M) ≤ 30%. A significant decrease in liver stiffness values (p < 0.001) was observed during follow-up. In patients with liver cirrhosis, the LSMs decreased significantly after only one year, 24.6 ± 4.3 kPa vs. 13.5 ± 4.2 kPa (p = 0.007), whereas the decrease in non-cirrhotic patients was not significant, 7.31 ± 3.62 vs. 6.80 ± 2.41 (p = 0.27). Liver stiffness decrease was more significant in patients with initially higher transaminases. Undetectable viral load was achieved in 73.5% of patients in year one, 82.7% in year two, and 90.8% in year three of treatment. In conclusion, our study reveals a decrease in liver stiffness by TE in patients with chronic hepatitis B when undergoing anti-HBV therapy in the first two years. It can be used as a method for follow-up in patients undergoing NUC therapy.

Incidence and Predictors of Relapse After Stopping Antiviral Therapy in Pediatric Chronic Hepatitis B

BACKGROUND

There are no definite end-points for stopping therapy in pediatric chronic hepatitis B (CHB). The study objective was to evaluate the incidence of relapse after stopping antiviral therapy and to identify its predictors.

METHODS

All hepatitis B surface antigen (HBsAg) positive children presenting to our hospital, who had been on antivirals for at least 2 years with undetectable hepatitis B virus-deoxyribonucleic acid (HBV-DNA) and normal alanine aminotransferase (ALT) on 3 consecutive occasions over last 12 months were included. Antivirals were stopped if liver biopsy showed histological activity index <5 and fibrosis (Ishak) <3. Virological relapse was defined as the elevation of HBV-DNA (>2000 IU/mL) and biochemical relapse as a rise in ALT levels to >2 times the upper limit of normal. Those having biochemical relapse were started on pegylated interferon alpha-2b-based sequential therapy.

RESULTS

Of the 114 children with CHB screened, 31 HBsAg-positive children fulfilled inclusion criteria and antivirals were stopped in them. Virological and biochemical relapse was seen in 12 (38.7%) and 5 (16.1%) children within 12 months of stopping antiviral treatment. On Cox regression, hepatitis B e antigen (HBeAg) positive status at the time of stopping antiviral therapy (HR: 6.208, 95% CI: 1.630-23.638) and longer time taken for HBV-DNA to become undetectable while on antivirals (HR: 1.027, 95% CI: 1.000-1.055) were the independent predictors of relapse.

CONCLUSION

Discontinuation of antiviral treatment in children with CHB resulted in relapse in one-third of the patients. Relapse was frequent in those who were HBeAg-positive at the time of stopping therapy and in those who required longer therapy for HBV-DNA to become undetectable.

Current challenges in the functional cure of HBe-Antigen-negative chronic hepatitis B

This editorial discusses current challenges in treatment stop in e-antigen-negative chronic hepatitis B, with attention to immunologic and virologic markers associated with functional cure, new therapeutic options for those cases unsuitable for treatment discontinuation, and safety after treatment withdrawal.

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.

Risks and benefits of oral HIV pre-exposure prophylaxis for people with chronic hepatitis B

Individuals with chronic hepatitis B virus (HBV) infection who are at substantial risk of HIV acquisition benefit from pre-exposure prophylaxis (PrEP) with tenofovir-based antiviral therapy. Considering that tenofovir potently inhibits HBV, providing PrEP to individuals with HBV effectively results in treatment of their HBV infection. However, some clinicians might be hesitant to initiate PrEP in people with chronic HBV due to unknown risks of HBV reactivation, hepatitis, and acute liver failure during periods of antiviral cessation. Unfortunately, these knowledge gaps affect scale up of PrEP among people with chronic HBV. Emerging data regarding the risks and benefits of antiviral cessation in people with chronic HBV suggest that PrEP can be safely initiated despite the risks of non-adherence or discontinuation. People with chronic HBV who stop PrEP should be closely monitored for HBV reactivation and hepatitis flares after antiviral cessation.

Surrogate Markers for Hepatitis B Virus Covalently Closed Circular DNA

Chronic infection with the hepatitis B virus (HBV) is one of the most common causes of liver disease worldwide. Chronic HBV infection is currently incurable because of the persistence of the viral template for the viral transcripts, covalently closed circular deoxyribonucleic acid (cccDNA). Detecting changes in cccDNA transcriptional activity is key to understanding fundamental virology, determining the efficacy of new therapies, and deciding the optimal clinical management of HBV patients. In this review, we summarize surrogate circulating biomarkers that have been used to infer cccDNA levels and activity in people with chronic hepatitis B. Moreover, we outline the current shortcomings of the current biomarkers and highlight the clinical importance in improving them and expanding their use.

Differential Relapse Patterns After Discontinuation of Entecavir vs Tenofovir Disoproxil Fumarate in Chronic Hepatitis B

BACKGROUND AND AIMS

Whether entecavir (ETV) and tenofovir disoproxil fumarate (TDF) differentially affect relapse and outcomes following treatment discontinuation across different patient subpopulations remains unclear. We aimed to compare rates of off-therapy hepatitis B surface antigen (HBsAg) loss, virological and clinical relapse, and retreatment between chronic hepatitis B (CHB) patients who discontinued TDF or ETV therapy.

METHODS

This study included 1402 virally suppressed CHB patients who stopped either ETV (n = 981) or TDF (n = 421) therapy between 2001 and 2020 from 13 participating centers across North America, Europe, and Asia. All patients were hepatitis B e antigen-negative at treatment discontinuation. Inverse probability of treatment weighting was used to balance the treatment groups. Outcomes were analyzed using survival methods.

RESULTS

During a median off-treatment follow-up of 18 months, HBsAg loss occurred in 96 (6.8%) patients overall. Compared with ETV, TDF was associated with a higher rate of HBsAg loss (P = .03); however, the association was no longer significant after statistical adjustment (P = .61). Virological relapse occurred earlier among TDF-treated patients (P < .01); nonetheless, rates became comparable after the first year off therapy (P = .49). TDF was significantly associated with a higher clinical relapse rate than ETV throughout follow-up (P < .01). The development of a virological or clinical relapse did not affect the rate of HBsAg loss. Retreatment rates were not significantly different between the treatment groups.

CONCLUSIONS

TDF and ETV have differential relapse patterns but are associated with similar rates of HBsAg loss and retreatment following discontinuation. Finite therapy can be considered for CHB patients on either TDF or ETV therapy.

Drug Discovery Study Aimed at a Functional Cure for HBV

Hepatitis B virus (HBV) causes acute and, most importantly, chronic hepatitis B worldwide. Antiviral treatments have been developed to reduce viral loads but few patients with chronic hepatitis B (CHB) achieve a functional cure. The development of new therapeutic agents is desirable. Recently, many novel agents have been developed, including drugs targeting HBV-DNA and HBV-RNA. This review provides an overview of the developmental status of these drugs, especially direct acting antiviral agents (DAAs). Serological biomarkers of HBV infection are essential for predicting the clinical course of CHB. It is also important to determine the amount and activity of covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes. Hepatitis B core-associated antigen (HBcrAg) is a new HBV marker that has an important role in reflecting cccDNA in CHB, because it is associated with hepatic cccDNA, as well as serum HBV DNA. The highly sensitive HBcrAg (iTACT-HBcrAg) assay could be a very sensitive HBV activation marker and an alternative to HBV DNA testing for monitoring reactivation. Many of the drugs currently in clinical trials have shown efficacy in reducing hepatitis B surface antigen (HBsAg) levels. Combination therapies with DAAs and boost immune response are also under development; finding the best combinations will be important for therapeutic development.

Low positivity rates for HBeAg and HBV DNA in rheumatoid arthritis patients: a case-control study

Background

The rates of hepatitis B virus (HBV) infection in rheumatoid arthritis (RA) patients are controversial when considering the reported outcomes. It was speculated that HBV infection status was altered after RA, and variations inn HBV infection rates became apparent.

Methods

To compare the positive proportions of hepatitis B e antigen (HBeAg) and HBV DNA, a retrospective case–control study was performed between 27 chronic hepatitis B (CHB) patients with RA and 108 age- and gender-matched CHB patients. In addition, the positivity rates of hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) were surveyed among the 892 RA patients.

Results

Compared to CHB patients, CHB patients with RA exhibited lower rates of HBeAg positivity (11.1% vs. 35.2%, P = 0.003), HBV DNA positivity (37.0% vs. 63.9%, P = 0.007) and ALT elevation (11.1% vs. 35.2%, P = 0.024). In the 892 RA patients, the prevalence of HBsAg (3.0%) was lower than that reported in the Chinese national data (7.2%), whereas the anti-HBc positivity rate of 44.6% was higher than that of 34.1%.

Conclusion

HBV infection status was altered after suffering from RA. Compared to the matched CHB patients, low positive proportions of HBeAg and HBV DNA were observed for CHB patients with RA.

Model to predict on-treatment restoration of functional HBV-specific CD8+ cell response foresees off-treatment HBV control in eAg-negative chronic hepatitis B

BACKGROUND

Hepatitis B virus (HBV)-specific CD8⁺ cell response restoration during nucleos(t)ide analogue (NUC) treatment could lead to off-treatment HBV control in e-antigen-negative chronic hepatitis B (CHBe(-)).

AIM

To predict this response with variables involved in T-cell exhaustion for use as a treatment stopping tool.

METHODS

In NUC-treated CHBe(-) patients, we considered a functional response in cases with HBV-specific CD8⁺ cells against core and polymerase HBV epitopes able to proliferate and secrete type I cytokines after antigen encounter. We performed a logistic regression model (LRM) to predict the likelihood of developing this response, based on patient age (subrogate of infection length), HBsAg level, NUC therapy starting point and duration (antigenic pressure). We discontinued treatment and assessed HBV DNA dynamics, HBsAg decline and loss during off-treatment follow-up according to LRM likelihood.

RESULTS

We developed an LRM that predicted the presence of a proliferative type I cytokine-secreting CD8⁺ cell response, which correlated positively with treatment duration and negatively with treatment initiation after the age of 40 years and with age adjusted by HBsAg level. We observed a positive correlation between LRM probability and intensity of proliferation, number of epitopes with the functional proliferating response and type I cytokine secretion level. Off-treatment, HBsAg loss, HBsAg decline >50% and HBV control were more frequent in the group with >90% LRM probability.

CONCLUSIONS

Short-term low-level antigen exposure and early long-term NUC treatment influence the restoration of a functional HBV-specific CD8⁺ cell response. Based on these predictors, a high likelihood of detecting this response at treatment withdrawal is associated with off-treatment HBV control and HBsAg decline and loss.

Screening and Identification of HBV Epitopes Restricted by Multiple Prevalent HLA-A Allotypes

Although host T cell immune responses to hepatitis B virus (HBV) have been demonstrated to have important influences on the outcome of HBV infection, the development of T cell epitope-based vaccine and T cell therapy and the clinical evaluation of specific T cell function are currently hampered markedly by the lack of validated HBV T cell epitopes covering broad patients. This study aimed to screen T cell epitopes spanning overall HBsAg, HBeAg, HBx and HBpol proteins and presenting by thirteen prevalent human leukocyte antigen (HLA)-A allotypes which gather a total gene frequency of around 95% in China and Northeast Asia populations. 187 epitopes were in silico predicted. Of which, 62 epitopes were then functionally validated as real-world HBV T cell epitopes by ex vivo IFN-γ ELISPOT assay and in vitro co-cultures using peripheral blood mononuclear cells (PBMCs) from HBV infected patients. Furthermore, the HLA-A cross-restrictions of each epitope were identified by peptide competitive binding assay using transfected HMy2.CIR cell lines, and by HLA-A/peptide docking as well as molecular dynamic simulation. Finally, a peptide library containing 105 validated epitopes which cross-binding by 13 prevalent HLA-A allotypes were used in ELISPOT assay to enumerate HBV-specific T cells for 116 patients with HBV infection. The spot forming units (SFUs) was significantly correlated with serum HBsAg level as confirmed by multivariate linear regression analysis. This study functionally validated 62 T cell epitopes from HBV main proteins and elucidated their HLA-A restrictions and provided an alternative ELISPOT assay using validated epitope peptides rather than conventional overlapping peptides for the clinical evaluation of HBV-specific T cell responses.

Prediction of Sustained Response After Nucleo(s)tide Analogue Cessation Using HBsAg and HBcrAg Levels: A Multicenter Study (CREATE)

BACKGROUND & AIMS

Predictors of successful nucleo(s)tide analogue (NA) therapy withdrawal remain elusive. We studied the relationship between end-of-treatment levels of hepatitis B core-related antigen (HBcrAg) and hepatitis B surface antigen (HBsAg) and outcome after therapy cessation.

METHODS

Patients who discontinued NA therapy in centers in Asia and Europe were enrolled. HBcrAg and HBsAg were measured at treatment cessation, and associations with off-treatment outcomes were explored. The SCALE-B (Surface antigen, Core-related antigen, Age, ALT, and tenofovir for HBV) score was calculated as previously reported. End points included sustained virologic response (VR; hepatitis B virus DNA level <2000 IU/mL), HBsAg loss, and alanine aminotransferase (ALT) flares (>3× upper limit of normal). Re-treated patients were considered nonresponders.

RESULTS

We analyzed 572 patients, 457 (80%) were Asian and 95 (17%) were hepatitis B e antigen positive at the start of NA therapy. The median treatment duration was 295 weeks. VR was observed in 267 (47%), HBsAg loss was observed in 24 (4.2%), and ALT flare was observed in 92 (16%). VR (67% vs 42%) and HBsAg loss (15% vs 1.5%) was observed more frequently in non-Asian patients when compared to Asian patients (P < .001). Lower HBcrAg levels were associated with higher rates of VR (odds ratio [OR], 0.701; P < .001) and HBsAg loss (OR, 0.476; P < .001), and lower rates of ALT flares (OR, 1.288; P = .005). Similar results were observed with HBsAg (VR: OR, 0.812; P = .011; HBsAg loss: OR, 0.380; P < .001; and ALT flare: OR, 1.833; P < .001). Lower SCALE-B scores were associated with higher rates of VR, HBsAg loss, and lower rates of ALT flares in both Asian and non-Asian patients (P < .001).

CONCLUSIONS

In this multicenter study, off-treatment outcomes after NA cessation varied with ethnicity. Lower levels of HBcrAg and HBsAg were associated with favorable outcomes. A risk score comprising both factors can be used for risk stratification.