Robust antiviral responses in severe hepatitis flare persist after early retreatment cessation and lead toward hepatitis B surface antigen loss: A proof-of-concept study

Stopping Nucleos(t)ide Analogues in Chronic Hepatitis B Using HBsAg Thresholds: A Meta-Analysis and Meta-Regression

BACKGROUND AND AIMS

Recommendations for stopping nucleoside analogue (NA) therapy in hepatitis B e antigen-negative chronic hepatitis B (CHB) are unclear. End-of-treatment quantitative hepatitis B serum antigen (EOTqHBsAg) thresholds <100 IU/mL or <1000 IU/mL have been proposed as stopping criteria, which we assessed by meta-analysis and meta-regression.

METHODS

We searched PubMed, EMBASE, and conference abstracts for studies of hepatitis B e antigen-negative CHB NA discontinuation. Extracted studies were analyzed for risk of bias, pooled risk of hepatitis B serum antigen (HBsAg) loss, virological relapse (VR), and biochemical relapse (BR). Significant heterogeneity (I2) was addressed by subgroup analysis and random-effects meta-regression with known important covariates, including EOTqHBsAg thresholds, ethnicity, duration of therapy, and follow-up.

RESULTS

We found 24 articles (3732 subjects); 16 had low and 8 had moderate risk of bias. The pooled risks of HBsAg loss, VR, and BR for stopping therapy at EOTqHBsAg <100 IU/mL were 41.8%, 33.4%, and 17.3%, respectively, vs 4.6%, 72.1%, and 34.6%, respectively, for EOTqHBsAg ≥100 IU/mL. The pooled risks of HBsAg loss, VR, and BR for stopping therapy at EOTqHBsAg <1000 IU/mL were 22.0%, 52.7%, and 15.9%, respectively, vs 3.4%, 63.8%, and 26.4%, respectively, for EOTqHBsAg ≥1000 IU/mL. Multivariable analysis for HBsAg loss showed that ethnicity, follow-up duration, and EOTqHBsAg <100 IU/mL and ≥100 IU/mL explained 85% of the variance in heterogeneity; Asians with EOTqHBsAg <100 IU/mL had 28.2%, while non-Asians with EOTqHBsAg <1000 IU/mL had 38.4% HBsAg loss. Multivariable analysis showed EOTqHBsAg <100 IU/mL and ≥100 IU/mL and other covariates only explained 43% and 63% of the variance in heterogeneity for VR and BR, respectively, suggesting that other factors are also important for relapse.

CONCLUSIONS

While EOTqHBsAg thresholds, ethnicity, and follow-up duration strongly predict HBsAg loss, this is not true for VR and BR, hence stopping NA therapy should be considered cautiously.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hepatitis B flare: the good, the bad and the ugly

INTRODUCTION

Hepatitis B flare, defined as an event of abrupt ALT elevation to >5x ULN, is a frequent episode during the natural course or during/after antiviral therapy of chronic HBV infection, in both HBeAg-positive and HBeAg-negative patients with chronic hepatitis B or liver cirrhosis.

AREAS COVERED

The definition, pathogenesis, clinical presentation, and management of hepatitis B flares in the published literature were reviewed. Hepatitis B flares have been considered as a result of the robust immune response of the patient to an upsurging HBV/HBV-antigen(s). 'Host-dominating flares,' reflect effective immune response, may resolve with ALT normalization and decline of HBV/ antigen(s). Contradictorily, 'virus-dominating flares,' reflect ineffective immune response, are usually followed by persistent/intermittent hepatitis and may even develop hepatic decompensation/failure.

EXPERT OPINION

Not all hepatitis B flares require antiviral therapy, and close observation with combined HBsAg/ALT kinetics along the ascending ALT during hepatitis flare may differentiate hepatitis flares for an appropriate treatment/retreatment decision. More studies are needed to verify this proposal. Further immunologic studies using multiple samples during hepatitis B flare are important to clarify the precise underlying mechanisms as the basis for further improvement in the management of hepatitis flare.