Serum hepatitis B virus RNA level is associated with biochemical relapse in patients with chronic hepatitis B infection who discontinue nucleos(t)ide analogue treatment

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

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

PegIFN alpha-2a reduces relapse in HBeAg-negative patients after nucleo(s)tide analogue cessation: A randomized-controlled trial

BACKGROUND & AIMS

Nucleo(s)tide analogue (NUC) cessation can lead to hepatitis B surface antigen (HBsAg) clearance but also a high rate of virological relapse. However, the effect of pegylated interferon alpha-2a (PegIFN-α-2a) on virological relapse after NUC cessation is unknown. Therefore, this study aimed to evaluate the effect of switching from NUC to PegIFN-α-2a treatment for 48 weeks on virological relapse up to week 96.

METHODS

In this multicenter randomized-controlled clinical trial, 180 non-cirrhotic patients with HBeAg-negative chronic hepatitis B on continuous NUC therapy for ≥2.5 years, with HBV DNA levels <60 IU/ml, were randomized to discontinue NUC therapy (n = 90) or receive 48 weeks of PegIFN-α-2a treatment (n = 90). Patients were followed up for up to 96 weeks. The primary endpoint was the virological relapse rate up to week 96.

RESULTS

Intention-to-treat analysis revealed patients in the interferon monotherapy group had significantly lower cumulative virological relapse rates than the NUC cessation group until week 96 (20.8% vs. 53.6%, p <0.0001). Consistently, a significantly lower proportion of patients in the interferon monotherapy group had virological relapse than those in the NUC cessation group at 48 weeks off treatment (17.8% vs. 36.7%, p = 0.007). The virological relapse rate positively correlated with HBsAg levels in the NUC cessation group. The interferon monotherapy group had a lower cumulative clinical relapse rate (7.8% vs. 20.9%, p = 0.008) and a higher HBsAg loss rate (21.5% vs. 9.0%, p = 0.03) than the NUC cessation group.

CONCLUSIONS

Switching from NUC to PegIFN-α-2a treatment for 48 weeks significantly reduces virological relapse rates and leads to higher HBsAg loss rates than NUC treatment cessation alone in patients with HBeAg-negative chronic hepatitis B.

IMPACT AND IMPLICATIONS

Nucleo(s)tide analogue (NUC) cessation can lead to HBsAg clearance but also a high rate of virological relapse, but an optimized scheme to reduce the virological relapse rate after NUC withdrawal is yet to be reported. This randomized-controlled trial investigated the effect of switching from NUC to PegIFN-α-2a treatment for 48 weeks on virological relapse up to week 96 in patients with HBeAg-negative chronic hepatitis B. The interferon monotherapy group had a significantly lower cumulative virological relapse rate (20.8% vs. 53.6%, p <0.0001) and higher HBsAg loss rate (21.5% vs. 9.0%, p = 0.03) than the NUC cessation group up to week 96. This provides an optimized strategy for NUC cessation in HBeAg-negative patients.

TRIAL REGISTRATION NUMBER

NCT02594293.

Biogenesis of serum HBV RNA and clinical phenomena of serum HBV RNA in chronic hepatitis B patients before and after receiving nucleos(t)ide analogues therapy

There are estimated 300 million people afflicted with chronic hepatitis B (CHB) worldwide. The risk of liver cirrhosis and hepatocellular carcinoma (HCC) increases considerably with chronic hepatitis B infection. While current therapeutics are effective in controlling hepatitis B virus (HBV) infection and disease progression, a cure for HBV infection remains unattainable due to an intranuclear replicative intermediate known as covalently closed circular DNA (cccDNA). It has recently been shown that serum HBV RNA is a non-invasive biomarker that reflects cccDNA transcriptional activity. This review provides a comprehensive overview and the latest updates on the molecular characteristics and clinical significance of serum HBV RNA, such as species of serum HBV RNA, forms of serum HBV RNA carriers and predictive value for relapses in CHB patients after nucleos(t)ide analogues (NAs) discontinuation and development of liver fibrosis and HCC. Furthermore, we summarize standardized assays for testing serum HBV RNA, the dynamic changes of serum HBV RNA levels in treatment-naïve CHB patients and those under NAs therapy, as well as the host and viral influencing factors of serum HBV RNA levels. Finally, we discuss the future perspectives in studies of serum HBV RNA.

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.

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.

Advances in determining new treatments for hepatitis B infection by utilizing existing and novel biomarkers

INTRODUCTION

Chronic hepatitis B (CHB) infection is a major global health threat and accounts for significant liver-related morbidity and mortality. An improved understanding of how hepatitis B virus (HBV) interacts with the host immune system allows the discovery of novel biomarkers and new treatment options. Viral biomarkers including hepatitis B surface antigen (HBsAg) and newer ones like HBV RNA and hepatitis B core-related antigen appear to be useful to select patients who are likely to benefit from cessation of long-term antiviral therapy. These markers can also help to confirm target engagement for novel compounds, and efficacy in HBsAg reduction and seroclearance is deemed essential as this is how the current treatment endpoint of functional cure is defined.

AREAS COVERED

In this review, the authors discuss the current standard of care and the gaps between such standard and the ideal goals for treatment in CHB. The authors highlight novel viral and immunological biomarkers that are potentially useful to evaluate treatment response. Novel treatment approaches in relation to these novel biomarkers are also evaluated.

EXPERT OPINION

Novel serum viral biomarkers and immunological markers are indispensable in the HBV functional cure program. These will likely become part of standard monitoring soon.

Effects of Entecavir on Serum Hepatitis B Virus-DNA, Interferon-γ, and Pregenomic RNA in Patients with Chronic Hepatitis B Virus Infection

Background: Entecavir (ETV) has been widely used in the clinical treatment of the Hepatitis B Virus (HBV). However, whether ETV is helpful in the recovery of T cell immune function remains unclear. Objectives: We aimed to assess the effects of ETV on serum HBV-DNA, interferon-γ (IFN-γ), and pregenomic RNA (pgRNA) in patients with infection. Methods: The clinical data of 300 HBV patients admitted from January 2017 to January 2019 were retrospectively analyzed, of whom 193 cases administered with ETV were assigned to an observation group, and the remaining 107 untreated cases (who refused treatment) were assigned to a blank control group. Their liver function [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], serum HBV markers [hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg)], IFN-γ, HBV-DNA, HBV pgRNA, negative conversion rates of HBeAg and HBV-DNA, and adverse reactions were compared. Results: The levels of HBsAg, IFN-γ, HBV-DNA, and HBV pgRNA were lower in the observation group than in the blank control group 12, 24, and 48 weeks after treatment (P < 0.05). The HBeAg and HBV-DNA negative conversion rates of the observation group were higher than those of the blank control group 12, 24, and 48 weeks after treatment (P < 0.05). Conclusions: Antiviral therapy with ETV can inhibit the replication of HBV-DNA, increase the HBV-DNA negative conversion rate, enhance immune function, and reduce the expression of HBV pgRNA in HBV patients.

Circulating HBV RNA: From biology to clinical applications

Chronic HBV infection can hardly be cured due to the persistence of an intrahepatic pool of viral covalently closed circular DNA (cccDNA) transcription template, which is refractory to current antivirals. The direct analyses of cccDNA quantity and transcriptional activity require an invasive biopsy. Recently, circulating HBV RNA has been identified as a promising noninvasive surrogate marker of cccDNA and can be used for monitoring disease progression and predicting prognosis of patients with chronic HBV infection. To better understand this surrogate biomarker of cccDNA, we reviewed the current knowledge about the molecular characteristics and potential clinical applications of circulating HBV RNA. Specifically, we summarized the reported species and existing forms of circulating HBV RNA and discussed their biogenesis and the capacity of de novo infection by RNA virions. Moreover, we described the potential applications of circulating HBV RNA in different clinical scenarios, such as classifying the phases of chronic HBV infection, analyzing sustained on-treatment and off-treatment outcomes of treated patients, as well as predicting HCC development. Perspectives on future research of circulating HBV RNA were also proposed in this review.

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.

Serum Pregenomic RNA Combined With Hepatitis B Core-Related Antigen Helps Predict the Risk of Virological Relapse After Discontinuation of Nucleos(t)ide Analogs in Patients With Chronic Hepatitis B

Background and Aim

Cessation of nucleos(t)ide analogs (NAs) therapy in patients with chronic hepatitis B (CHB) is uncommon. Although criteria for discontinuation appear in some guidelines, the indicators for assessing discontinuation of NAs are limited, whether NAs can be safely ceased remains a difficult clinical issue. Our study aimed to investigate the role of serum pregenomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) at the end of treatment (EOT) in guiding the safe discontinuation of NAs in CHB patients.

Methods

This is a retrospective study, clinical data of all CHB patients who discontinued NAs treatment at West China Hospital between June 2020 and January 2021 were collected, including EOT pgRNA, HBcrAg, hepatitis B surface antigen (HBsAg), etc. All patients should meet the Asian-Pacific guideline for discontinuation. Observing virological relapse (VR) rates during 1 year of NAs discontinuation and analyzing the relationship between EOT pgRNA, HBcrAg, and VR.

Results

A total of 64 patients were enrolled in this study and 33 (51.5%) patients experienced VR in 1 year. EOT pgRNA positivity (OR = 14.59, p = 0.026) and EOT higher HBcrAg levels (OR = 14.14, p = 0.001) were independent risk factors for VR. The area under the receiver-operating characteristic (AUROC) value of EOT HBcrAg for VR was 0.817 (p < 0.001), optimal cut-off value was 3.3 log10 U/mL. Patients with EOT pgRNA positivity and EOT HBcrAg >3.3 log10 U/mL were more likely to experience VR after discontinuation of NAs (88.9 vs. 45.5%, p = 0.027).

Conclusion

According to current guidelines, a higher VR rate occurs after cessation of NAs. EOT pgRNA positivity and higher HBcrAg level carries a higher risk of VR. Combining these novel markers can better help us assess whether patients can safely cease NAs treatment.