Safety and efficacy of entecavir for the treatment of chronic hepatitis B

Entecavir competitively inhibits deoxyguanosine and deoxyadenosine phosphorylation in isolated mitochondria and the perfused rat heart

Deoxyguanosine kinase (dGK) is reported responsible for the phosphorylation of deoxyadenosine (dA) and deoxyguanosine (dG) in the mitochondrial purine salvage pathway. Antiviral nucleoside analogs known as nucleoside reverse transcriptase inhibitors (NRTIs) must be phosphorylated by host enzymes for the analog to become active. We address the possibility that NRTI purine analogs may be competitive inhibitors of dGK. From a group of such analogs, we demonstrate that entecavir (ETV) competitively inhibited the phosphorylation of dG and dA in rat mitochondria. Mitochondria from the brain, heart, kidney, and liver showed a marked preference for phosphorylation of dG over dA (10-30-fold) and ETV over dA (2.5-4-fold). We found that ETV inhibited the phosphorylation of dG with an IC50 of 15.3 ± 2.2 μM and that ETV and dG were both potent inhibitors of dA phosphorylation with IC50s of 0.034 ± 0.007 and 0.028 ± 0.006 μM, respectively. In addition, the phosphorylation of dG and ETV followed Michaelis-Menten kinetics and each competitively inhibited the phosphorylation of the other. We observed that the kinetics of dA phosphorylation were strikingly different from those of dG phosphorylation, with an exponentially lower affinity for dGK and no effect of dA on dG or ETV phosphorylation. Finally, in an isolated heart perfusion model, we demonstrated that dG, dA, and ETV were phosphorylated and dG phosphorylation was inhibited by ETV. Taken together, these data demonstrate that dGK is inhibited by ETV and that the primary role of dGK is in the phosphorylation of dG rather than dA.

Clinical Results of Tenofovir Disoproxil Fumarate in a Hemodialysis Patient with Chronic Hepatitis B

A male hepatitis B virus (HBV) carrier in his 40s under hemodialysis treatment exhibited chronic hepatitis (alanine aminotransferase: 41 IU/L, HBV-DNA: >9.1 log copies/mL). Following discontinuation of the initial treatment with pegylated interferon-α-2a at 24 weeks due to adverse effects, the administration of tenofovir disoproxil fumarate (TDF) (300 mg/week) led to a rapid improvement in hepatitis markers: HBV DNA became undetectable at month 34, and seroconversion of hepatitis B envelope antigen was confirmed at 45 months. No side effects were recorded during TDF treatment. TDF is a newly approved nucleoside analogue that may cause severe side effects via proximal tubular injury in patients with renal dysfunction. However, few reports have described its use in hemodialysis patients, whose anuric state may render them less susceptible to side effects including kidney injury. Hepatitis improved remarkably without any adverse drug reactions in the present case. TDF may therefore be considered for chronic hepatitis B patients receiving hemodialysis.

Revisiting HBV resistance to entecavir with a phenotypic approach

Treatment adaptation after hepatitis B virus (HBV) treatment failure relies on genotypic resistance testing. However, the results of such tests are not always consistent with treatment response. These discrepancies may be due to differences in resistance levels between isolates with the same genotypic resistance testing profiles. We explored this hypothesis by investigating six cases of entecavir treatment failure with an integrative strategy combining genotypic and phenotypic resistance testing, medical record review and therapeutic drug monitoring. Among isolates with genotypic reduced susceptibility to entecavir, one displayed a higher level of resistance to entecavir (mean fold change in entecavir IC₅₀ of 1 508 ± 531 vs. 318 ± 53, p = 0.008). This isolate harbored a substitution (rt250L) at a position reported to be associated with resistance (rt250V). Reversion to wild-type amino acid at this position partially restored susceptibility to entecavir, confirming that the rt250L mutation was responsible for the high level of resistance to entecavir. This is the first description of entecavir treatment failure associated with selection of the rt250L mutation without other entecavir resistance mutations. One isolate with genotypic resistance to entecavir, harboring the rt173L mutation, displayed a lower level of resistance than the other, harboring the rt202G mutation (mean fold change of 323 ± 124 vs. 6 036 ± 2 100, p = 0.20). These results suggest that isolates harboring the rt250L mutations should be considered resistant to entecavir, whereas isolates harboring the rt173L mutations should be considered to display reduced susceptibility to entecavir. An integrative approach to antiviral drug resistance in HBV would provide a more accurate assessment of entecavir treatment failures and help to improve the accuracy of genotypic testing algorithms.

Antiviral drug utilization and annual expenditures for patients with chronic HBV infection in Guangzhou, China, in 2008-2015

BACKGROUND

The aims of this study were to describe antiviral drug (AD) utilization and costs in patients with chronic HBV infection.

METHODS

We conducted a retrospective study of patients in the hospital and calculated annual proportions of AD utilization and costs among patients. A two-part model was used to estimate adjusted odds ratio (OR) for antiviral therapy and cost ratios for antiviral costs associated with demographics.

RESULTS

Of a total of 14,920 records, 143,658 records were involved in the analysis. The annual proportions of AD utilization were 56.99% (45.65%) for inpatients (outpatients) during 2008-2015 and increased annually. Entecavir (ETV), in particular, increased from 11.08% to 70.26% (11.05% to 49.35%) for inpatients (outpatients). The patients with medical insurance were more likely to use AD than patients without insurance, and the adjusted OR was 1.11 (95% CI: 1.03, 1.19) for inpatients and 1.66 (1.59, 1.73) for outpatients. With the disease progressing, the proportion of antiviral costs in total direct medical costs decreased from 13.91% to 4.07% (71.29% to 49.29%) for inpatients (outpatients).

CONCLUSIONS

The use of AD for chronic HBV infection was less than expected based on established guidelines, and only half of patients received antiviral treatment. However, the AD utilization, especially ETV, increased annually. Reimbursement policy was the most important factor affecting antiviral treatment. Antiviral therapy was an important part of the direct medical costs, especially in the early stage of disease.

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.

Concomitant food intake does not affect the efficacy of entecavir in chronic hepatitis B patients with virological response: a randomized, multicenter, noninferiority trial

Background

Little clinical data are available about the effect of food on the antiviral efficacy of entecavir for chronic hepatitis B virus (HBV) infection. The present study evaluated whether entecavir administration in the fed state had comparable efficacy to the fasted condition for maintenance of viral suppression in HBV-infected patients with virological response on entecavir therapy.

Methods

In this multicenter, randomized, open-label, noninferiority study, patients who were currently receiving entecavir and showed a serum HBV DNA level of <20 IU/mL were randomized to take entecavir either under the fasted or fed condition for 48 weeks.

Results

We randomly assigned 50 patients to the fasted group and 46 patients to the fed group. The full analysis set consisted of 49 patients in the fasted group and 44 patients in the fed group. At week 48, the proportion of patients with HBV DNA <20 IU/mL was not significantly different between the fasted and fed groups (98% vs 100%, P=1.00). The mean log₁₀ HBV DNA changes from baseline were similar between the two groups (−0.004 vs −0.012 log₁₀ IU/mL, P=0.43). There were no significant differences in the proportions of patients with normal alanine aminotransferase (87.8% vs 95.5%, P=0.27) and hepatitis B e-antigen seroconversion (0% vs 6.7%, P=0.47) between the two groups. None of the patients showed viral breakthrough. In pharmacokinetic analysis, the maximum concentration and the area under the concentration– time curve to the last quantifiable concentration decreased by 26.4% and 9.3%, respectively, in the fed group compared with the fasted group. However, the differences between two groups were not statistically significant (P=0.28 and 0.83, respectively).

Conclusion

In patients with virological response under entecavir therapy, concomitant food intake did not affect the antiviral efficacy. For patients with adherence problem, taking entecavir with food may be considered to improve compliance.

Hepatitis B infection among HIV infected individuals in Gabon: Occult hepatitis B enhances HBV DNA prevalence

In Gabon, a central African country, human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are endemic. In a recent study, conducted in a semi-urban area (Franceville, Gabon), HBV infection was found to be more prevalent among HIV infected individuals. This study aims to investigate the prevalence and genetic diversity of hepatitis B virus infection among HIV infected individuals, predominantly under antiretroviral therapy, living in fully urbanized area: Libreville, capital of Gabon. Serological and molecular tests were performed to detect HBV infection among patients living with HIV/AIDS (PLHA). We used Monolisa HBsAg ULTRA, Anti-HBc Plus and Anti-HBs Plus EIA kits for serological analyses. HBV DNA viral load (HBV DNA VL) was determined by real time PCR and molecular characterization of HBV strains was performed by sequencing and phylogenetic analysis of partial HBV surface and core genes. At all, 70.2% of patients were under antiretroviral therapy. The prevalence of HBsAg was 8.8% (43/487). Detectable HBV DNA was found in 69.7% (30/43) of HBsAg positive patients and in 17.5% (24/137) HBsAg negative patients. HBV DNA VL was significantly higher among patient with CD4 cell counts less than 200 cells/mm³ than those with CD4 cell counts greater than 500 cells/mm³ (p = 0.008). We confirmed the presence of HBV sub-genotypes QS-A3 (40%), and A4 (20%) and HBV-E genotype (40%). The percentage of resistance to Lamivudine was high (40%) and varied according to the M204V/I motif. Occult hepatitis B infection (OBI) was found in patients with isolated HBcAb and among patients who had completed their HBsAg seroconversion. We detected HBV DNA for one patient without any HBV serological marker. This study provides a new landmark for the comprehension of HBV infection in PLHA in urban areas. OBI enhances HBV DNA prevalence and should be investigated in all HBsAg negative individuals.

A five years study of antiviral effect of entecavir in Chinese chronic hepatitis B patients

Entecavir (ETV) is a potent viral replication inhibitor for chronic hepatitis B (CHB) patients. To investigate the efficacy of ETV in Chinese nucleos(t)ide(NA)-experienced CHB patients. Among 89 CHB patients with ETV monotherapy for ≥6 months, 33/89 (37%) or 56/89 (73%) were NA-naïve or NA-experienced. During a median follow-up of 5.75 years, all NA-naïve CHB patients achieved VR without genotypic ETV-resistance. However, VR was observed in 50/56 (~90%) of NA-experienced CHB patients during a median follow-up of 4.75 years. Antiviral efficacy was not reduced in patients with previous lamivudine (LAM) with/without LAM-resistance (HR 0.465; 95% CI 0.196–1.100; p > 0.05) (HR 0.472; 95% CI 0.205–1.091; p > 0.05). Patients with a primary treatment failure to adefovir (ADV) had a reduced probability of achieving VR compared to NA-naïve (HR 0.496; 95% CI 0.287–0.857; p < 0.01). Previous ADV-experienced patients with a partial VR (HR 1.253; 95% CI 0.429–3.665; p > 0.05) did not influence antiviral response to ETV. The antiviral efficacy of ETV is not influenced by previous treatment LAM with/without LAM-resistance. ETV may still be an option in ADV-experienced patients with a partial VR, but not advised in patients with a primary treatment failure to ADV.

An evaluation of entecavir treatment among nucleos(t)ide-naïve Moroccan patients with chronic hepatitis B

OBJECTIVE

To analyse the efficacy and safety of entecavir (ETV) treatment in nucleos(t)ide (NUC)-naïve Moroccan patients with chronic hepatitis B.

METHODS

We retrospectively analysed 41 NUT-naïve Moroccan patients with chronic hepatitis B who received ETV 0,5 mg/day monotherapy for at least 3 months, of whom 3 were HBV envelope antigen (HbeAg) positive and 38 were HBeAg negative. The primary end point was the proportion of patients achieving virological response. Secondary end points included biochemical response (alanine transaminase (ALT) normalisation), serological response (HbeAg and HBV surface antigen (HBsAg) loss or seroconversion) and safety.

RESULTS

The median follow-up duration was 74 weeks (48-144 weeks) and mean age was 43.8 years. Of 41 patients, 6 were primary non-responders and 2 achieved partial virological response at week 48, whereas 35 achieved undetectable hepatitis B virus (HBV) DNA at month 12. Viral suppression was maintained in 97.6% of patients after 3 years of ETV treatment. One patient experienced a virological breakthrough at month 12 of treatment. ALT normalisation occurred in 100% of the patients after 1 year of treatment. Only three patients in our study were HbeAg positive, of whom one has experienced seroconversion at month 12 of treatment. However, HBsAg loss or seroconversion was not achieved during the period of the study. No serious adverse event was reported.

CONCLUSIONS

These preliminary results showed that ETV is a safe and potent inhibitor of HBV in NUC-naïve Moroccan patients, but we need to observe more patients for a longer period of time, in order to assess the long-term effectiveness, safety, resistance profile and predictive factors for virological and serological response of ETV.

Clinical course of partial virological responders under prolonged entecavir monotherapy in patients with chronic hepatitis B

Studies about long-term entecavir (ETV) therapy for partial virological response (PVR) are lacking. This study aimed to assess the clinical course of PVR patients receiving ETV therapy and analyze the efficacy of tenofovir (TDF). We retrospectively evaluated 130 patients who showed a PVR to ETV. Among these patients, 102 were nucleot(s)ide analogue (NUC)-naïve and 28 were lamivudine (LAM)-experienced. The cumulative rates of VR were 54.1%, 70.8%, and 83.7% for the NUC-naïve group and 37.0%, 42.8%, and 42.8% for the LAM-experienced group after 24, 36, and 48 months of ETV therapy, respectively (P  = 0.008). Low HBV DNA level at 12 months (P < 0.001) and absence of a LAM treatment history (P  = 0.031) were significant associated factors for VR. In VR prediction at 36 months of ETV therapy in NUC-naïve patients, HBV DNA level <95 IU/ml at 12 months showed a 92.9% sensitivity and a 78.3% specificity (AUROC, 0.909; P < 0.001). ETV resistance did not develop in NUC-naïve patients with HBV DNA levels <95 IU/ml at 12 months. The cumulative probability of VR in patients who switched to or additionally received TDF was 91.3% at 15 months. Prolonged ETV therapy induced a VR without the risk of ETV resistance in NUC-naïve patients with HBV DNA levels <95 IU/ml at 12 months. All patients with LAM-experienced or NUC-naïve with HBV DNA levels ≥95 IU/ml at 12 months should be switched to TDF rescue therapy.

Impact of a new reimbursement program on hepatitis B antiviral medication cost and utilization in Beijing, China

Background

Hepatitis B virus (HBV) infection is a significant clinical and financial burden for chronic hepatitis B (CHB) patients. In Beijing, China, partial reimbursement on antiviral agents was first implemented for the treatment of CHB patients in July 1, 2011.

Aims

In this study, we describe the medical cost and utilization rates of antiviral therapy for CHB patients to explore the impact of the new partial reimbursement policy on the medical care cost, the composition, and antivirals utilization.

Methods

Clinical and claims data of a retrospective cohort of 92,776 outpatients and 2,774 inpatients with non-cirrhotic CHB were retrieved and analyzed from You'an Hospital, Beijing between February 14, 2008 and December 31, 2012. The propensity score matching was used to adjust factors associated with the annual total cost, including age, gender, medical insurance type and treatment indicator.

Results

Compared to patients who paid out-of-pocket, medical cost, especially antiviral costs increased greater among patients with medical insurance after July 1, 2011, the start date of reimbursement policy. Outpatients with medical insurance had 16% more antiviral utilization; usage increased 3% among those who paid out-of-pocket after the new partial reimbursement policy was implemented.

Conclusions

Direct medical costs and antiviral utilization rates of CHB patients with medical insurance were higher than those from paid out-of-pocket payments, even after adjusting for inflation and other factors. Thus, a new partial reimbursement program may positively optimize the cost and standardization of antiviral treatment.

Purpura with ulcerative skin lesions and mixed cryoglobulinemia in a quiescent hepatitis B virus carrier

Mixed cryoglobulinemia is occasionally seen in patients with hepatitis B virus (HBV) infection. This report presents the case of a quiescent HBV carrier who had type II mixed cryoglobulinemia, protracted purpura, ulcerative skin lesions and advanced chronic kidney disease. The cutaneous manifestations of the patient improved along with a decrease in the serum cryoglobulin and HBV-deoxyribonucleic acid levels following the initiation of oral entecavir in combination with plasmapheresis. However, the patient ultimately required prednisolone due to the limited benefits of these treatments. We also discuss various concerns regarding steroid treatment in patients with mixed cryoglobulinemia complicated by HBV infection.

Effects of entecavir and lamivudine for hepatitis B decompensated cirrhosis: Meta-analysis

AIM: To compare the effects of entecavir (ETV) and lamivudine (LAM) for the treatment of hepatitis B decompensated cirrhosis using a meta-analysis.

METHODS: We conducted a literature search for all eligible studies published prior to May 30, 2013 using PUBMED, MEDLINE, EMBASE, the China National Knowledge Infrastructure (CNKI), the VIP database, the Wanfang database and the Cochrane Controlled Trial Register. Randomized controlled trials (RCTs) comparing ETV with LAM for the treatment of hepatitis B decompensated cirrhosis were included. The data were analyzed with Review Manager Software 5.0.2. We used RR as an effect measure, and reported its 95%CI. The meta-analysis was performed using either a fixed-effect or random-effect model, based on the absence or presence of significant heterogeneity. Two reviewers assessed the risk of bias and extracted data independently and in duplicate. The analysis was executed using the main outcome parameters including hepatitis B virus (HBV) DNA undetectability, HBV DNA level, hepatitis B e antigen (HBeAg) seroconversion, alanine aminotransferase (ALT) level, albumin level, total bilirubin (TBIL) level, prothrombin time activity (PTA) level, Child-Turcotte-Pugh (CTP) score, mortality, drug-resistance, and adverse reactions. Meta-analysis of the included trials and subgroup analyses were conducted to examine the association between pre-specified characteristics and the therapeutic effects of the two agents.

RESULTS: Thirteen eligible trials (873 patients in total) were included and evaluated for methodological quality and heterogeneity. Of these studies, all had baseline comparability, 12 of them reported baseline values of the two treatment groups in detail. Following various treatment durations (12, 24, 36, 48 and > 48 wk), both ETV and LAM significantly reduced HBV DNA level, however, reductions were greater in the ETV group (MD = -0.66, 95%CI: -0.83-0.50, P < 0.00001), (MD = -0.93, 95%CI: -1.36-0.51, P < 0.0001), (MD = -1.4, 95%CI: -1.78-1.01, P < 0.00001), (MD = -1.18, 95%CI: -1.90-0.46, P = 0.001), (MD = -0.14, 95%CI: -0.17-0.11, P < 0.00001, respectively). At 12, 24 and 48 wk of treatment, ETV had a significant effect on the rate of HBV DNA undetectability (RR = 1.55, 95%CI: 1.22-1.99, P = 0.0004), (RR = 1.25, 95%CI: 1.13-1.38, P < 0.0001), (RR = 1.2, 95%CI: 1.10-1.32, P < 0.0001, respectively). Although HBeAg seroconversion in the ETV group was more pronounced than that in the LAM group at 24 wk (27.90% vs 26.19%) and 48 wk (31.52% vs 25.00%) of treatment, there was no statistically significant difference between them (RR = 1.49, 95%CI: 0.98-2.28, P = 0.07), (RR = 1.27, 95%CI: 0.98-1.65, P = 0.07, respectively). Following various treatment durations, both the ETV group and the LAM group showed significantly improved liver function (ALT, AIB, TBIL, PTA and CTP levels) and reduced mortality (ETV 6.37%, LAM 7.89%). The effects in the ETV group (0.33%) were statistically lower than those in the LAM group (14.33%) regarding the rate of drug-resistance (RR = 0.1, 95%CI: 0.04-0.24, P≤ 0.00001). In addition, no severe adverse reactions were observed in the two treatment groups.

CONCLUSION: ETV and LAM significantly improved liver function and reduced mortality. Both drugs produced similar serological responses, and were safe and well tolerated. However, ETV resulted in a better virological response and lower drug-resistance, but is more expensive.

Downregulation and altered function of natural killer cells in hepatitis B virus patients treated with entecavir

The aim of the present study was to investigate the natural killer (NK) cell phenotype and function in chronic hepatitis B virus (HBV) patients and to study the effects of entecavir therapy (10 mg/day, p.o.) on these responses. Peripheral blood NK cells were collected from 18 chronic HBV patients and 14 healthy controls. The effect of entecavir therapy on the phenotype and function of NK cells in chronic HBV patients was characterized by flow cytometry analysis. Concentrations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), HBV viral loads in both groups and potential associations between the frequency of peripheral NK cell subsets and clinical measures were determined. There was a significant reduction in the number of CD3(-)CD56(+) NK cells in chronic HBV patients compared with healthy controls. Furthermore, there were significant increases in the percentage of CD3(-)CD56(+)NKG2D(+) and CD3(-)CD56(+)NKP30(+) NK activating receptors in chronic HBV patients compared with healthy individuals, who exhibited downregulated expression following entecavir treatment. Spearman's correlation analysis revealed that there was a significant positive correlation between the percentage of NKG2D(+) and NKP30(+) NK cells and serum ALT levels. Characterization of NK cell degranulation indicated that the frequency of CD107a(+) NK cells in HBV patients (in response to K562 stimulation) was significantly greater than in healthy controls but decreased following entecavir treatment. Entecavir treatment of hepatitis B e antigen-positive chronic HBV-infected patients not only led to a reduction in HBV DNA loads and normalization of ALT and AST levels, but also resulted in the recovery of NK cell-mediated immunity.

Continuous long-term entecavir therapy in naïve chronic hepatitis B patients showing partial virologic response

Background/Aims

We investigated the efficacy of continuous long-term entecavir 0.5 mg treatment in naïve chronic hepatitis B patients showing a partial virologic response (PVR).

Methods

A total of 227 patients were included. PVR was defined as a more than 1 log₁₀ IU/mL decline in detectable serum hepatitis B virus (HBV) DNA by polymerase chain reaction (PCR; ≥20 IU/mL) at week 48. A complete virologic response (CVR) was defined as undetectable serum HBV DNA by PCR (<20 IU/mL) at week 48.

Results

At week 48, the rate of the PVR was 64/227 (28.2%). Among patients with PVR, the cumulative rates of virologic response (serum HBV DNA <20 IU/mL) at weeks 96 and 144 were 45.2% and 73.8%, respectively. The cumulative rates of genotypic resistance were not significantly different between patients with a PVR and patients with a CVR (p=0.057). However, the cumulative rates of virologic breakthrough were higher in patients with PVR than in patients with CVR (4% vs 0% and 11.2% vs 0% at weeks 96 and 144, respectively; p<0.001).

Conclusions

Long-term continuous entecavir 0.5 mg treatment in patients with a PVR resulted in an additional virologic response without a significant increase in genotypic resistance. However, the rate of virologic breakthrough was higher in the partial responders.

Efficacy and Safety of Telbivudine Compared to Entecavir Among HBeAg+ Chronic Hepatitis B Patients: a Meta-Analysis Study

BACKGROUND

Hepatitis B virus (HBV) infection is a serious global health problem that is associated with huge social and economic costs. Early antiviral drugs, such as interferon-α2b, peginterferon-α2a, lamivudine, and adefovir, all have their limitations (such as low responses or safety concerns) in clinical application. Telbivudine and entecavir are two of the latest nucleotide drugs and both have been shown to have potent viral suppression. However, in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB), inconsistent results have been generated for efficacy between telbivudine and entecavir. Therefore, evidence-based medical data are required to compare the efficacies, in terms of virological and biochemical responses, and safety between telbivudine and entecavir.

OBJECTIVES

We aimed to compare the early antiviral efficacy and safety of telbivudine and entecavir in the treatment of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB).

PATIENTS AND METHODS

A search for relevant randomized controlled trials (RCTs) on HBeAg-positive CHB patients treated with telbivudine and entecavir for 24 or 52 weeks, published before December 2011, was performed. Primary efficacy endpoint was the cumulative rate of undetectable HBV DNA, and secondary efficacy endpoints included rates of alanine aminotransferase (ALT) normalization, HBeAg disappearance, HBeAg seroconversion and adverse events. Meta-analysis was performed using the Review Manager v5.1.4 software package. We assessed the pooled risk ratios (RRs) and 95% confidence intervals (CIs) using the fixed-or random-effects model.

RESULTS

Six randomized controlled trials (RCTs) involving 555 patients were included. Telbivudine was associated with significantly higher rates of HBeAg disappearance (RR = 1.46, 95% CI: 1.11 - 1.91) and HBeAg seroconversion (RR = 1.76, 95%CI: 1.25-2.48) than entecavir, but had higher adverse events (RR = 2.11, 95%CI: 1.23 - 3.60), compared with entecavir. There was no difference between telbivudine and entecavir in the rate of cumulative undetectable HBV DNA (RR = 0.99, 95% CI: 0.90 - 1.10) and ALT normalization (RR = 0.93, 95% CI: 0.85 - 1.00).

CONCLUSIONS

Telbivudine is associated with significantly higher rates of HBeAg disappearance and HBeAg seroconversion than entecavir, whereas entecavir is superior to telbivudine in safety. Both drugs have similar efficacy on rates of cumulative undetectable HBV DNA and ALT normalization.

Efficacy of entecavir treatment for up to 5 years in nucleos(t)ide-naïve chronic hepatitis B patients in real life

OBJECTIVE

To analyze the efficacy and safety of entecavir (ETV) treatment for up to 5 years in nucleos(t)ide-naïve chronic hepatitis B patients in real life.

METHODS

We retrospectively analyzed 230 nucleos(t)ide naïve chronic hepatitis B patients who received ETV 0.5 mg/day monotherapy for at least 3 months, of whom 113 were HBeAg positive and 117 were HBeAg negative. The primary endpoints was cumulative probability of achieving a virological response (undetectable serum HBV DNA, <100IU/mL). Secondary endpoints were rates of ALT normalization (ALT < upper limit of normal), HBeAg seroconversion, resistance, and safety.

RESULTS

The median follow-up duration was 27.5 months (3-73 months) and mean age was 42 years. With 230, 214, 180, 142, 88, 42 and 11 patients followed-up for at least 3 months,6 months, 1, 2, 3, 4 and 5 years, respectively. In all, Incremental increases were observed in the rates of undetectable HBV DNA. 67.0%, 85.0%, 89.4%, 94.4%, 95.5%, 97.6%, 100% had undetectable HBV DNA at month 3, month 6, 1 year, 2 years, 3 years, 4 years and 5 years. Proportions of patients achieving normal ALT were 73.9%, 85.5%, 82.8%, 89.4%, 80.7%, 85.7%, 100%, respectively. The rate of HBeAg seroconversion reached 21.4% and 15.4% at year2, 3, respectively. One patient achieved HBsAg seroclearance after 1 year, and achieved anti-HBs seroconversion at year 3. Of 180 patients, HBV DNA was detectable (partial virological response, PVR) in 19 patients at year 1 of follow-up, twelve of 14 (85.7%) patients with PVR need more than 1 year of continuous ETV therapy to achieved VR. At baseline, no ETV-resistance was detected in 25 ETV-naïve patients. One patient developed ETV-resistance mutations due to noncompliance. No serious adverse event was reported.

CONCLUSION

Long-term ETV treatment of nucleos(t)ide-naïve was effective and safe in real life. Adjustment of ETV monotherapy in nucleos(t)ide-naïve patients with a partial virological response at 1 year may be unnecessary.

Virologic responses to add-on adefovir dipivoxil treatment versus entecavir monotherapy in children with lamivudine-resistant chronic hepatitis B

PURPOSE

The aim of the study was to compare the virologic response to adefovir (ADV) add-on therapy with switching to entecavir (ETV) monotherapy in children and adolescents with chronic hepatitis B (CHB) who have developed lamivudine (LAM) resistance during LAM treatment.

METHODS

Twenty-seven consecutive patients with CHB who had developed LAM resistance during LAM treatment were included. Of these 27 patients, 8 patients were treated with the addition of ADV to ongoing LAM and 8 patients were treated by switching to ETV monotherapy and each of these 16 patients were compared with the 11 patients who were treated by switching to ADV alone, as a historical control. Therapeutic responses to treatment were evaluated at 12, 24, 36, and 48 weeks from the initiation of therapy by measuring the decrement of hepatitis B virus (HBV)-DNA titers.

RESULTS

The therapeutic period for HBV-DNA titer decrement (>2  log(10) IU/mL) was significantly shorter in both the LAM+ADV group and the ETV group than in the ADV group (P = 0.008); however, there was no significant difference between the LAM+ADV group and the ETV group. The rate of virologic response, defined as decrement in HBV-DNA titer to undetectable levels at 24 weeks, was significantly higher in both the LAM+ADV group and the ETV group than in the ADV group (P = 0.029).

CONCLUSIONS

Both the LAM+ADV combination therapy and ETV monotherapy exhibited significantly more effective virologic responses compared to the ADV monotherapy in children and adolescents with LAM-resistant CHB, although there was no significant difference between the LAM+ADV group and the ETV group.

Long-term continuous entecavir therapy in nucleos(t)ide-naïve chronic hepatitis B patients

BACKGROUND & AIMS

We determined the antiviral potency and viral resistance rate after 4 years of continuous entecavir treatment in patients with chronic hepatitis B (CHB) infection.

METHODS

The cumulative rates of undetectable hepatitis B virus DNA (HBV DNA;<2.6 log(10) copies/ml), hepatitis B e antigen (HBeAg) seronegativity, seroconversion, alanine aminotransferase (ALT) normalization, and entecavir signature mutations were calculated in 474 nucleos(t)ide-naïve CHB patients (HBeAg-positive: 47%) on continuous entecavir treatment for 4 years.

RESULTS

Median age was 47 years and follow-up period was 2.4 years, with 403, 281, 165, and 73 patients followed-up for at least 1, 2, 3, and 4 years, respectively. Incremental increases were observed in the rates of undetectable HBV DNA, HBeAg seroclearance and seroconversion, and ALT normalization, reaching 96%, 42%, 38% and 93%, respectively, by the fourth year. In all, 100% and 93% of patients negative and positive for HBeAg, respectively, had undetectable HBV DNA at year 4. Of 165 patients, HBV DNA was detectable in nine patients after 3 years. Multivariate analysis identified HBV DNA level (≤7.6 log(10) copies/ml, OR=15.8; 95% CI=43.1-79.9, P=0.001) as an independent predictor of undetectable HBV DNA at year 3. Five patients experienced virological breakthrough including two (0.4%) who developed entecavir-resistance mutations.

CONCLUSIONS

Continuous treatment of nucleos(t)ide-naïve CHB patients with entecavir over 4 years was associated with 96% chance of undetectable HBV DNA and only 0.4% chance of emerging entecavir-resistant mutations.