Comparison of HBsAg changes between HBeAg-negative patients who discontinued or maintained entecavir therapy

Predictive models for functional cure in patients with CHB receiving PEG-IFN therapy based on HBsAg quantification through meta-analysis

BACKGROUND AND AIMS

The efficacy of achieving HBsAg clearance through pegylated interferon (PEG-IFNα) therapy in patients with chronic hepatitis B (CHB) remains uncertain, especially regarding the probability of achieving functional cure among patients with varying baseline HBsAg levels. We aimed to investigate the predictive value of HBsAg quantification for HBsAg seroclearance in CHB patients undergoing PEG-IFNα treatment.

METHODS

A systematic search was conducted in PubMed, Embase, and the Cochrane Library up to January 11, 2022. Subgroup analyses were performed for HBeAg-positive and HBeAg-negative patients, PEG-IFNα monotherapy and PEG-IFNα combination therapy, treatment-naive and treatment-experienced patients, and patients with or without liver cirrhosis.

RESULTS

This predictive model incorporated 102 studies. The overall HBsAg clearance rates at the end of treatment (EOT) and the end of follow-up (EOF) were 10.6% (95% CI 7.8-13.7%) and 11.1% (95% CI 8.4-14.1%), respectively. Baseline HBsAg quantification was the most significant factor. According to the model, it is projected that when baseline HBsAg levels are 100, 500, 1500, and 10,000 IU/ml, the HBsAg clearance rates at EOF could reach 53.9% (95% CI 40.4-66.8%), 32.1% (95% CI 24.8-38.7%), 14.2% (95% CI 9.8-18.8%), and 7.9% (95% CI 4.2-11.8%), respectively. Additionally, treatment-experienced patients with HBeAg-negative status, and without liver cirrhosis exhibited higher HBsAg clearance rates after PEG-IFNα treatment.

CONCLUSION

A successful predictive model has been established to predict the achievement of functional cure in CHB patients receiving PEG-IFNα therapy.

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.

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.

Higher end-of-treatment HBsAg levels is associated with later onset but not severe relapse in HBeAg-negative chronic hepatitis B patients stopping antivirals

BACKGROUND

Quantitative hepatitis B surface antigen (qHBsAg) level at end-of-treatment (EOT) predict clinical relapse (CR) after nucleos(t)ide analogues (Nuc) in chronic hepatitis B(CHB) patients. It is unclear if higher EOT qHBsAg leads to earlier onset or more severe off-Nuc CR.

AIM

This large cohort study investigates the association between EOT qHBsAg and CR onset/severity.

METHODS

This study enrolled HBeAg-negative CHB patients who had achieved undetectable HBV DNA for over 1 year after receiving Nuc therapy before discontinuation. The EOT qHBsAg level was categorised into three groups: <100, 100-999, ≥1000 IU/mL. The study assessed the predictability of qHBsAg levels for CR, and analysed and compared the incidence, time to onset and severity of CR among these three groups.

RESULTS

Patients with higher EOT qHBsAg showed a higher incidence of CR (≥1000, 100-999, <100 IU/mL: 73%, 65%, and 38%, p < 0.01) but a later onset of CR (median time to CR: 35, 33 and 27 weeks, p < 0.01). The predictabilities of EOT qHBsAg for CR were greater in patients aged <50-year-old or with genotype C than in those aged ≥50-year-old or with genotype B. There's no correlation between EOT qHBsAg level and ALT folds at CR (Pearson correlation coefficient: r = -0.03, p = 0.35). EOT qHBsAg was neither a predictor for severe hepatitis flare nor a predictor for hepatic decompensation.

CONCLUSIONS

Predictability using EOT qHBsAg levels for CR differed in subgroups of age and genotypes. Higher EOT qHBsAg levels correlate with higher incidence but later onset of CR. No correlation between EOT qHBsAg and relapse severity was observed.

COVID-19 Vaccination Alters NK Cell Dynamics and Transiently Reduces HBsAg Titers Among Patients With Chronic Hepatitis B

Coronavirus disease 2019 (COVID-19) vaccination may non-specifically alter the host immune system. This study aimed to evaluate the effect of COVID-19 vaccination on hepatitis B surface Ag (HBsAg) titer and host immunity in chronic hepatitis B (CHB) patients. Consecutive 2,797 CHB patients who had serial HBsAg measurements during antiviral treatment were included in this study. Changes in the HBsAg levels after COVID-19 vaccination were analyzed. The dynamics of NK cells following COVID-19 vaccination were also examined using serial blood samples collected prospectively from 25 healthy volunteers. Vaccinated CHB patients (n=2,329) had significantly lower HBsAg levels 1-30 days post-vaccination compared to baseline (median, -21.4 IU/ml from baseline), but the levels reverted to baseline by 91-180 days (median, -3.8 IU/ml). The velocity of the HBsAg decline was transiently accelerated within 30 days after vaccination (median velocity: -0.06, -0.39, and -0.04 log10 IU/ml/year in pre-vaccination period, days 1-30, and days 31-90, respectively). In contrast, unvaccinated patients (n=468) had no change in HBsAg levels. Flow cytometric analysis showed that the frequency of NK cells expressing NKG2A, an NK inhibitory receptor, significantly decreased within 7 days after the first dose of COVID-19 vaccine (median, -13.1% from baseline; p<0.001). The decrease in the frequency of NKG2A+ NK cells was observed in the CD56dimCD16+ NK cell population regardless of type of COVID-19 vaccine. COVID-19 vaccination leads to a rapid, transient decline in HBsAg titer and a decrease in the frequency of NKG2A+ NK cells.

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.

Utility of novel viral and immune markers in predicting HBV treatment endpoints: A systematic review of treatment discontinuation studies

Background & Aims

Antivirals represent the mainstay of chronic hepatitis B treatment given their efficacy and tolerability, but rates of functional cure remain low during long-term therapy. Treatment discontinuation has emerged as a strategy to maintain partial cure and achieve functional cure in select patient groups. We aimed to evaluate how data from treatment discontinuation studies exploring novel viral and/or immune markers could be applied to the functional cure program.

Methods

Treatment discontinuation studies evaluating novel viral and/or immune markers were identified by a systematic search of the PubMed database through to October 30, 2022. Data extraction focused on information regarding novel markers, including identified cut-off levels, timing of measurement, and associated effect on study outcomes of virological relapse, clinical relapse, and HBsAg seroclearance.

Results

From a search of 4,492 citations, 33 studies comprising a minimum of 2,986 unique patients met the inclusion criteria. Novel viral markers, HBcrAg and HBV RNA, were demonstrated across most studies to be helpful in predicting off-therapy partial cure, with emerging evidence to support a link with functional cure. From novel immune marker studies, we observed that treatment discontinuation has the potential to trigger immune restoration, which may be associated with a transient virological relapse. To this end, these studies support the combination of virus-directing agents with immunomodulator therapies to induce two key steps underlying functional cure: viral antigen load reduction and restoration of the host immune response.

Conclusions

Patients with a favourable profile of novel viral and immune markers stand to benefit from a trial of antiviral treatment discontinuation alongside novel virus-directing agents with the aim of achieving functional cure without excessive risk of severe clinical relapse.

Impact and implications

Select patients with chronic hepatitis B undergoing nucleoside analogue therapy may benefit from a trial of treatment discontinuation, aiming to maintain partial cure and/or achieve functional cure. We propose a profile of novel viral and immune markers to identify patients who are likely to achieve these goals without excessive risk of hepatic decompensation. Furthermore, treatment discontinuation may also be considered as a therapeutic strategy to trigger immune restoration, which may increase the chance of functional cure when used in conjunction with novel virus-directing agents.

What will it take to cure hepatitis B?

The current treatment of chronic HBV infection, pegylated interferon-α (pegIFNα) and nucleos(t)ide analog (NA), can suppress HBV replication, reverse liver inflammation and fibrosis and reduce the risks of cirrhosis, HCC, and HBV-related deaths, but relapse is common when the treatment is stopped before HBsAg loss. There have been major efforts to develop a cure for HBV, defined as sustained HBsAg loss after a finite course of therapy. This requires the suppression of HBV replication and viral protein production and the restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. Immune modulatory therapies to stimulate adaptive or innate immunity and/or to remove immune blockade are being tested. NAs are included in most and pegIFNα in some regimens. Despite the combination of 2 or more therapies, HBsAg loss remains rare in part because HbsAg can be derived not only from the covalently closed circular DNA but also from the integrated HBV DNA. Achievement of a functional HBV cure will require therapies to eliminate or silence covalently closed circular DNA and integrated HBV DNA. In addition, assays to differentiate the source of circulating HBsAg and to determine HBV immune recovery, as well as standardization and improvement of assays for HBV RNA and hepatitis B core-related antigen, surrogate markers for covalently closed circular DNA transcription, are needed to accurately assess response and to target treatments according to patient/disease characteristics. Platform trials will allow the comparison of multiple combinations and channel patients with different characteristics to the treatment that is most likely to succeed. Safety is paramount, given the excellent safety profile of NA therapy.

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 switch from tenofovir to entecavir prior to hepatitis B treatment cessation is associated with a reduced risk of off-therapy relapse: An observational study

BACKGROUND AND AIM

In HBeAg negative chronic hepatitis B (CHB) patients, clinical relapse (CR) occurs more frequently, much earlier and often more severely after stopping tenofovir (TDF) and other nucleos(t)ide analogues (Nucs) than after stopping entecavir (ETV). It is unknown whether off-Nuc hepatitis flare can be alleviated by switching from one Nuc to another.

METHODS

HBeAg-negative CHB patients who had stopped Nuc according to the APASL stopping rule and had been followed-up for > 48 weeks after Nuc cessation were recruited. Patients were classified as four groups: ETV monotherapy (mono-ETV), TDF monotherapy (mono-TDF), switched to ETV (switch-ETV), and switched to TDF (switch-TDF). Both switch groups had switched to the replacement Nuc > 12 weeks prior to end of therapy. Propensity score matching (PSM) was performed to minimize confounders among groups. Cox regression analysis was used to identify risks factors for off-Nuc CR and flares.

RESULTS

A total of 1309 patients (1022 mono-ETV, 219 mono-TDF, 40 switch-ETV and 28 switch-TDF) were enrolled. The median time to CR was 39, 13, 38 and 14 weeks in mono-ETV, mono-TDF, switch-ETV and switch-TDF respectively (P < 0.001). After PSM, the mono-ETV (adjusted HR: 0.39, P < 0.001) and switch-ETV patients (adjusted HR: 0.41, P = 0.003) had both significantly later occurrence and lower rates of CR and flare.

CONCLUSION

In summary, the incidence and timing of CR was determined by ETV or TDF in the last 3 months prior to end of treatment. Patients treated with non-ETV-Nuc switched to ETV > 12 weeks before end of the original Nuc therapy may reduce/defer CR.

Off-Therapy Response After Nucleos(t)ide Analogue Withdrawal in Patients With Chronic Hepatitis B: An International, Multicenter, Multiethnic Cohort (RETRACT-B Study)

BACKGROUND & AIMS

Functional cure, defined based on hepatitis B surface antigen (HBsAg) loss, is rare during nucleos(t)ide analogue (NA) therapy and guidelines on finite NA therapy have not been well established. We aim to analyze off-therapy outcomes after NA cessation in a large, international, multicenter, multiethnic cohort of patients with chronic hepatitis B (CHB).

METHODS

This cohort study included patients with virally suppressed CHB who were hepatitis B e antigen (HBeAg)-negative and stopped NA therapy. Primary outcome was HBsAg loss after NA cessation, and secondary outcomes included virologic, biochemical, and clinical relapse, alanine aminotransferase flare, retreatment, and liver-related events after NA cessation.

RESULTS

Among 1552 patients with CHB, cumulative probability of HBsAg loss was 3.2% at 12 months and 13.0% at 48 months of follow-up. HBsAg loss was higher among Whites (vs Asians: subdistribution hazard ratio, 6.8; 95% confidence interval, 2.7-16.8; P < .001) and among patients with HBsAg levels <100 IU/mL at end of therapy (vs ≥100 IU/mL: subdistribution hazard ratio, 22.5; 95% confidence interval, 13.1-38.7; P < .001). At 48 months of follow-up, Whites with HBsAg levels <1000 IU/mL and Asians with HBsAg levels <100 IU/mL at end of therapy had a high predicted probability of HBsAg loss (>30%). Incidence rate of hepatic decompensation and hepatocellular carcinoma was 0.48 per 1000 person-years and 0.29 per 1000 person-years, respectively. Death occurred in 7/19 decompensated patients and 2/14 patients with hepatocellular carcinoma.

CONCLUSIONS

The best candidates for NA withdrawal are virally suppressed, HBeAg- negative, noncirrhotic patients with CHB with low HBsAg levels, particularly Whites with <1000 IU/mL and Asians with <100 IU/mL. However, strict surveillance is recommended to prevent deterioration.

Should Treatment Indications for Chronic Hepatitis B Be Expanded?

BACKGROUND & AIM

Antiviral therapy has greatly improved the outcomes of patients with chronic hepatitis B virus (HBV) infection and active liver disease or advanced fibrosis/cirrhosis. However, current treatment does not eradicate HBV and long-term treatment is needed in most patients to maintain clinical benefit. Thus, professional society guidelines do not recommend treatment of all patients with chronic HBV infection. This review article will examine evidence for and against expansion of treatment to patients in whom treatment is not recommended based on current guidelines.

RESULTS

Available data support expanding treatment to immune tolerant patients and patients in the grey zones who have evidence of active/advanced liver disease based on liver biopsy or non-invasive tests and those who remain in the immune tolerant phase after age 40. Evidence supporting treatment expansion to confirmed inactive carriers and other immune tolerant patients is lacking.

CONCLUSIONS

HBV treatment indications can be more liberal when new therapies that can achieve HBsAg loss safely in a high percentage of patients after a finite course of treatment are available.

The Impact of Nucleos(t)ide Analogs Off-Therapy Among Chronic Hepatitis B Patients: A Systematic Review and Meta-Analysis

Background and Aim: Although most chronic hepatitis B (CHB) patients achieve effective virological suppression after receiving long-term nucleos(t)ide analogs (Nucs) therapy, the safety of off-therapy is controversial under the monitor.

Methods: We identified studies through searching PubMed, Embase, Cochrane Library, and Web of Science from January 1990 to February 2021. The eligible studies compare the long outcomes between discontinued and continued Nucs treatments groups among CHB patients. This study was conducted to investigate long-term outcomes, including biochemical, serological, and virological outcomes, as well as hepatocellular carcinoma (HCC) development rate between discontinued and maintained Nucs therapy groups among CHB patients.

Results: Five eligible studies covering 1,425 patients were selected for meta-analysis. Our result exhibits that patients with Nucs off-treatment have a higher risk of alanine aminotransferase (ALT) flares-up than those who continued Nucs therapy under the monitor (OR = 9.39, 95%CI = 3.87–22.78). Nucs off-therapy patients have a higher virological bound incidence (OR = 617.96, 95%CI = 112.48–3,395.14) and a higher HBV DNA level (OR = 9.39, 95%CI = 3.87–22.78) than those who continued Nucs therapy. There was no statistically significant difference in the risk of hyperbilirubinaemia, hepatic decompensation, and HCC development between both two groups. Patients in Nucs off-therapy group demonstrate a higher HBsAg loss rate than those in the continued group (OR = 7.10, 95%CI = 6.68–13.69).

Conclusions: Nucs off-therapy patients may exhibit a higher chance of achieving HBsAg loss than those who continue Nucs therapy. It requires close monitoring after Nucs off-therapy and timely restarting of Nucs therapy when ALT concentrations increase.

Hepatitis B surface antigen kinetics after discontinuation of and retreatment with oral antivirals in non-cirrhotic HBeAg-positive chronic hepatitis B

The outcome of nucleos(t)ide analogues (NAs) discontinuation and retreatment is still uncertain. We evaluated hepatitis B surface antigen (HBsAg) kinetics after NAs discontinuation and during retreatment due to off-treatment clinical relapse among non-cirrhotic HBeAg-positive CHB patients. Four groups were studied: 129 HBeAg-positive patients from a prospective cohort who stopped NAs therapy after achieving sustained response (Group A), 39 patients who received retreatment after off-treatment clinical relapse in the discontinuation group (Group B), 214 patients who maintained treatment after achieving sustained response (Group C) and 291 patients who firstly initiated antiviral treatment (Group D). During a 5-year follow-up, the cumulative incidence of HBsAg loss was significantly higher in Group A than Group C (22.3% vs. 1.6%, p < .001). The quantitative HBsAg (qHBsAg) level at enrolment and NAs discontinuation were independently associated with HBsAg loss. Additionally, patients in Group B showed significantly greater HBsAg loss than those in the Groups C and D, with 5-year cumulative incidences of 9.0%, 1.6% (p = .040) and 0.6% (p < .001), respectively. Moreover, patients in the Group B exhibited better virologic response (100% vs. 98.8%, p < .001) and HBeAg seroconversion (92.6% vs. 69.8%, p < .001) than those in Group D at year 5. Propensity score-matched analysis also showed the similar trend of HBsAg decline. NAs discontinuation with or without subsequent retreatment resulted in a more profound reduction of HBsAg in non-cirrhotic HBeAg-positive patients, suggesting that discontinuation may be a potential cure strategy for those with sustained virological suppression.

APASL guidance on stopping nucleos(t)ide analogues in chronic hepatitis B patients

Chronic hepatitis B virus (HBV) infection is currently incurable. Long-term treatment with potent and safe nucleos(t)ide analogs (NAs) can reduce hepatocellular carcinoma (HCC) and cirrhosis-related complications through profound viral suppression. However, indefinite therapy raises several crucial issues with pros and cons. Because seroclearance of hepatitis B surface (HBsAg) as functional cure is not easily achievable, a finite therapy including sequential 48-week pegylated interferon therapy may provide an opportunity to facilitate HBsAg seroclearance by the rejuvenation of exhausted immune cells. However, the cost of stopping NA is the high incidence of virological relapse and surge of alanine aminotransferase (ALT) levels, which may increase the risk of adverse outcomes (e.g., decompensation, fibrosis progression, HCC, or liver-related mortality). So far, the APASL criteria to stop NA treatment is undetectable HBV DNA levels with normalization of ALT; however, this criterion for cessation of treatment is associated with various incidence rates of virological/clinical relapse and more than 40% of NA-stoppers eventually receive retreatment. A very intensive follow-up strategy and identification of low-risk patients for virological/clinical relapse by different biomarkers are the keys to stop the NA treatment safely. Recent studies suggested that decreasing HBsAg level at the end-of-treatment to < 100-200 IU/mL seems to be a useful marker for deciding when to discontinue NAs therapy. In addition, several viral and host factors have been reviewed for their potential roles in predicting clinical relapse. Finally, the APASL guidance has proposed rules to stop NA and the subsequent follow-up strategy to achieve a better prognosis after stopping NA. In general, for both HBeAg-positive and HBeAg-negative patients who have stopped treatment, these measurements should be done every 1-3 months at the minimum until 12 months.

Current practice and contrasting views on discontinuation of nucleos(t)ide analog therapy in chronic hepatitis B

Introduction: Long-term, even indefinite treatment with nucleos(t)ide analogs (NAs) is the current first-line therapy for patients with chronic hepatitis B (CHB), regardless of its histological stage. Guidelines and recommendations on duration and endpoints of NA therapy in CHB are not identical and change over time.Areas covered: The authors review NA discontinuation approaches and views with an emphasis on HBeAg-negative patients based on published studies relevant to the topic, stressing on whether or not the optimal endpoint of HBsAg loss is practically achievable.Expert opinion: Discontinuation of NA therapy in HBeAg-negative noncirrhotic patients has to be considered after long-term effective treatment with controlled liver disease activity, undetectable viremia, and significant decline in serum HBsAg titers. Close post-treatment monitoring is required for early intervention in cases of severe clinical relapse. Immediate retreatment hampers the favorable outcome of HBsAg clearance (functional cure) and should be avoided in transient ALT flares. Predictors of such relapses are still under investigation and include viral and patient factors. For HBeAg-positive noncirrhotic patients, there is wide acceptance of the endpoint of HBeAg seroconversion, after a long consolidation period.