Comparison of the Efficacy of Tenofovir Versus Tenofovir plus Entecavir in the Treatment of Chronic Hepatitis B in Patients With Poor Efficacy of Entecavir: A Systematic Review and Meta-analysis

The scientific basis of combination therapy for chronic hepatitis B functional cure

Functional cure of chronic hepatitis B (CHB) - or hepatitis B surface antigen (HBsAg) loss after 24 weeks off therapy - is now the goal of treatment, but is rarely achieved with current therapy. Understanding the hepatitis B virus (HBV) life cycle and immunological defects that lead to persistence can identify targets for novel therapy. Broadly, treatments fall into three categories: those that reduce viral replication, those that reduce antigen load and immunotherapies. Profound viral suppression alone does not achieve quantitative (q)HBsAg reduction or HBsAg loss. Combining nucleos(t)ide analogues and immunotherapy reduces qHBsAg levels and induces HBsAg loss in some patients, particularly those with low baseline qHBsAg levels. Even agents that are specifically designed to reduce viral antigen load might not be able to achieve sustained HBsAg loss when used alone. Thus, rationale exists for the use of combinations of all three therapy types. Monitoring during therapy is important not just to predict HBsAg loss but also to understand mechanisms of HBsAg loss using viral and immunological biomarkers, and in selected cases intrahepatic sampling. We consider various paths to functional cure of CHB and the need to individualize treatment of this heterogeneous infection until a therapeutic avenue for all patients with CHB is available.

Guidelines for Prevention and Treatment of Chronic Hepatitis B

To achieve the goal of the World Health Organization to eliminate viral hepatitis as a major public health threat by 2030, the Chinese Society of Infectious Diseases and the Chinese Society of Hepatology convened an expert panel in 2019 to update the guidelines for the prevention and treatment of chronic hepatitis B (CHB). The current guidelines cover recent advances in basic, clinical, and preventive studies of CHB infection and consider the actual situation in China. These guidelines are intended to provide support for the prevention, diagnosis, and treatment of CHB.

Efficacy of different nucleoside analog rescue therapies for entecavir-resistant chronic hepatitis B patients

BACKGROUND

Entecavir (ETV) is recommended as a first-line anti-HBV treatment. However, many chronic hepatitis B patients initiate anti-HBV treatment such as lamivudine and telbivudine with low genetic barriers in China, which leads to compensatory mutations and increases the rate of ETV resistance. The management of ETV resistance in China is an essential clinical issue.

METHODS

Patients from 2011 to 2017 with nucleos(t)ide analog resistance were screened and 72 patients with ETV resistance were included. These patients received different rescue therapies including an ETV and adefovir (ADV) combination therapy group (n = 25), a tenofovir (TDF) monotherapy group (n = 27), and an ETV and TDF combination therapy group (n = 20). Virologic, biochemical, and serologic responses were compared among the three groups.

RESULTS

The rate of ETV resistance among all HBV-resistant variants increased from 6.04% in 2011 to 15.02% in 2017. TDF monotherapy and TDF combination groups showed similar rates of negative HBV DNA at 48 weeks (74.07% vs 70.00%, P > 0.05), while the ETV and ADV group showed the worst virologic response (28.00%). Also, TDF monotherapy and TDF combination therapy showed similar decline of HBV DNA at weeks 12, 24, and 48. There was no significant difference in the rates of HBeAg clearance, ALT normalization, and abnormal renal function among the three groups.

CONCLUSIONS

TDF monotherapy showed a comparable virologic response to TDF and ETV combination therapy and a better virologic response than ETV and ADV combination therapy. Thus, TDF monotherapy is the preferred rescue therapy for ETV resistance.

Entecavir versus Tenofovir for the Prevention of Hepatocellular Carcinoma in Treatment-naïve Chronic Hepatitis B Patients in Korea

BACKGROUND

The occurrence of hepatocellular carcinoma (HCC) is a major concern during antiviral therapy for chronic hepatitis B. There are conflicting opinions regarding the effects of entecavir (ETV) and tenofovir disoproxil fumarate (TDF) on HCC prevention. We assessed these two antiviral medications for preventing HCC in treatment-naïve patients with chronic hepatitis B.

METHODS

We conducted a retrospective cohort study using nationwide claims data from the Korea Health Insurance Review and Assessment Service. We included 55,473 treatment-naïve adult cases where ETV or TDF treatment was started between 2013 and 2017 (cohort 1). The ETV and TDF groups were matched 1:2 based on age, sex, comorbidities, hospital type, and index date year. Patients were followed up until December 2018. The outcome was the development of HCC. Subgroup analyses were conducted according to sex, age, hospital type and the presence of cirrhosis. We also compared the outcomes of patients who had started antiviral therapy during the 2012-2014 period (cohort 2).

RESULTS

The matched participants (18,491 in the ETV and 36,982 in the TDF groups) were a part of the study for, on average, 41.2 months. The incidence of HCC did not differ significantly between the ETV (1.46 per 100 patient-years) and the TDF (1.36 per 100 patient-years) treatments (hazard ratio, 0.93; 95% confidence interval, 0.86-1.01; P = 0.081). By contrast, HCC incidence was significantly higher in the ETV group than tenofovir group of cohort 2.

CONCLUSION

In patients with chronic hepatitis B, the ETV treatment did not result in a higher rate of HCC than the TDF treatment.

2018 Korean Association for the Study of the Liver (KASL) Clinical Practice Guidelines of Chronic Hepatitis B: What's Different?

The clinical practice guideline for the management of chronic hepatitis B (CHB) was originally enacted in 2004 by the Korean Association for the Study of the Liver in order to provide medical practitioners with specific medical information regarding CHB to help them facilitate their understanding of the disease and treatment of the infected patients. Other than an update on the treatment of antiviral resistance in 2014, which is a partial revision, the guidelines for the treatment of chronic hepatitis B have been revised entirely three times in 2007, 2011, and 2015. Although several major international liver association have established and revised clinical practice guidelines, since the medical environment in each country is somewhat different depending on race, region, institution, and economic conditions, it is necessary to revise the Korean guidelines to that reflect our medical environment and own research results. In this review, major change and its background will be summarized about 2018 updated clinical practice guidelines for the management of CHB.

Protective effects of specific cannabinoid receptor 2 agonist GW405833 on concanavalin A-induced acute liver injury in mice

Cannabinoid receptor 2 (CB2R) is highly expressed in immune cells and plays an important role in regulating immune responses. In the current study, we investigated the effects of GW405833 (GW), a specific CB2R agonist, on acute liver injury induced by concanavalin A (Con A). In animal experiments, acute liver injury was induced in mice by injection of Con A (20 mg/kg, i.v.). The mice were treated with GW (20 mg/kg, i.p., 30 min after Con A injection) or GW plus the selective CB2R antagonist AM630 (2 mg/kg, i.p., 15 min after Con A injection). We found that Con A caused severe acute liver injury evidenced by significantly increased serum aminotransferase levels, massive hepatocyte apoptosis, and necrosis, as well as lymphocyte infiltration in liver tissues. Treatment with GW significantly ameliorated Con A-induced pathological injury in liver tissue, decreased serum aminotransferase levels, and decreased hepatocyte apoptosis. The therapeutic effects of GW were prevented by AM630. In cell experiments, we showed that CB2Rs were highly expressed in Jurkat T cells, but little expression in L02 liver cells. Treatment with GW (10-40 μg/mL) dose-dependently decreased the viability of Jurkat T cells and induced cell apoptosis, which was reversed by AM630. In the coculture of Jurkat T cells with L02 liver cells, GW dose-dependently protected L02 cells from apoptosis induced by Con A (5 μg/mL). The protective effect of GW was reversed by AM630 (1 μg/mL). Our results suggest that GW protects against Con A-induced acute liver injury in mice by inhibiting Jurkat T-cell proliferation through the CB2Rs.

A multicenter study of entecavir vs. tenofovir on prognosis of treatment-naïve chronic hepatitis B in South Korea

BACKGROUND & AIMS

It is currently unclear which antiviral agent, entecavir (ETV) or tenofovir disoproxil fumarate (TDF), is superior for improving prognosis in patients with chronic hepatitis B (CHB). Here, we assessed the ability of these 2 antivirals to prevent liver-disease progression in treatment-naïve patients with CHB.

METHODS

From 2012 to 2014, treatment-naïve patients with CHB who received ETV or TDF as a first-line antiviral agent were recruited from 4 academic teaching hospitals. Patients with decompensated cirrhosis or hepatocellular carcinoma (HCC) at enrollment were excluded. Cumulative probabilities of HCC and death or orthotopic liver transplant (OLT) were assessed.

RESULTS

In total, 2,897 patients (1,484 and 1,413 in the ETV and TDF groups, respectively) were recruited. The annual HCC incidence was not statistically different between the ETV and TDF groups (1.92 vs. 1.69 per 100 person-years [PY], respectively; adjusted hazard ratio [HR] 0.975 [p = 0.852] by multivariate analysis). Propensity score (PS)-matched and inverse probability of treatment weighting (ITPW) analyses yielded similar patterns of results (HR 1.021 [p = 0.884] and 0.998 [p = 0.988], respectively). The annual incidence of death or OLT was not statistically different between the ETV and TDF groups (0.52 vs. 0.53 per 100 PY, respectively; adjusted HR 1.202 [p = 0.451]). PS-matched and ITPW analyses yielded similar patterns of results (HR 1.248 [p = 0.385] and 1.239 [p = 0.360], respectively). These findings were consistently reproduced in patients with compensated cirrhosis (all p >0.05).

CONCLUSIONS

The overall prognosis in terms of HCC and death or OLT was not statistically different between the ETV and TDF groups. Further studies are needed to validate our results.

LAY SUMMARY

It is currently unclear which antiviral agent, entecavir or tenofovir disoproxil fumarate, is superior for improving prognosis in patients with chronic hepatitis B virus infection. In this analysis we found that there was no difference in terms of overall prognosis, including risk of hepatocellular carcinoma, death, or the need for a liver transplant, in patients receiving either antiviral.

Entecavir-based combination therapies for chronic hepatitis B: A meta-analysis

BACKGROUND

Currently, there is no consensus on the efficacy and safety of the entecavir (ETV) monotherapy versus the ETV-based combination therapy for chronic hepatitis B.

METHODS

A comprehensive literature search was performed on the comparison of ETV-based combination therapy and monotherapy for chronical hepatitis B (CHB) patients in the PubMed, Embase, Web of Science, the Cochrane Libraries, and the Chinese BioMedical Literature Database. Both dichotomous and continuous variables were extracted, and pooled outcomes were expressed as odds ratio (OR) or mean difference (MD).

RESULTS

We included randomized clinical trials (RCTs) and cohorts involving Group A: nucleos(t)ide-naive patients (four RCTs, n = 719 patients), Group B: nucleos(t)ide-resistant patients (four cohorts, n = 196 patients), and Group C: entecavir-treated patients with undetectable hepatitis B virus DNA (two RCTs and two cohorts, n = 297). Group A. ETV monotherapy was better for rates of undetectable HBV DNA, while the rates of the HBV DNA levels at the end of treatment, HBeAg Loss, ALT normalization were similar between the two groups [MD, -0.85 (95% CI, -0.173-0.03); OR, 0.92 (95% CI, 0.24-3.56); OR, 1.31 (95% CI, 0.17-9.82)]; Group B. ETV monotherapy was better for rates of undetectable HBV DNA, while the rates of the HBV DNA levels at the end of treatment, HBeAg Loss, ALT normalization were similar; Group C. The ETV-based combination therapy was better for the rate of HBV DNA relapse.

CONCLUSION

Based on the current data, ETV-based combination therapy seemed to be no better than ETV monotherapy. Further studies are needed to verify this conclusion.