Add-on adefovir is superior to a switch to entecavir as rescue therapy for Lamivudine-resistant chronic hepatitis B

Antiviral Therapy in Lamivudine-Resistant Chronic Hepatitis B Patients: A Systematic Review and Network Meta-Analysis

The relative efficacy of different strategies for chronic hepatitis B (CHB) patients with lamivudine resistance (LAM-R) has not yet been systematically studied. Clinical trials were searched in PUBMED, MEDLINE, EMBASE, and CNKI databases up to February 15, 2016. Nine trials including 764 patients met the entry criteria. In direct meta-analysis, TDF showed a stronger antiviral effect than any one of ETV, LAM/ADV, and ADV against LAM-R hepatitis B virus. LAM/ADV therapy was superior to ADV in suppressing viral replication. ETV achieved similar rate of HBV DNA undetectable compared to ADV or LAM/ADV. In network meta-analysis, TDF had higher rates of HBV DNA undetectable compared to ETV (OR, 24.69; 95% CrI: 5.36–113.66), ADV (OR, 37.28; 95% CrI: 9.73–142.92), or LAM/ADV (OR, 21.05; 95% CrI: 5.70–77.80). However, among ETV, ADV, and LAM/ADV, no drug was clearly superior to others in HBV DNA undetectable rate. Moreover, no significant difference in the rate of ALT normalization or HBeAg loss was observed compared the four rescue strategies with each other. TDF appears to be a more effective rescue therapy than LAM/ADV, ETV, or ADV. LAM plus ADV therapy was a better treatment option than ETV or ADV alone for patients with LAM-R.

Hepatitis B surface antigen levels at 6 months after treatment can predict the efficacy of lamivudine-adefovir combination therapy in patients with lamivudine-resistant chronic hepatitis B

Background/Aims

Quantitation of hepatitis B surface antigen (HBsAg) is an increasingly popular method to determine the treatment response in chronic hepatitis B (CHB) patients. The clinical value of HBsAg level measurement during rescue therapy for lamivudine (LMV)-resistant CHB patients have not been evaluated to date. Therefore, this study investigated the correlation between HBsAg level and treatment response in LMV-resistant CHB patients treated with adefovir (ADV) add-on therapy.

Methods

LMV-resistant CHB patients treated with LMV-ADV combination therapy for over 2 years were included. HBsAg levels were measured at 6 month intervals until 1 year, and annually thereafter. Treatment response was assessed by determining the virological response (VR, undetectable HBV DNA levels) during treatment.

Results

Fifty patients were included, of which 40 showed a VR. HBsAg levels were not different significantly at baseline (4.0 vs. 3.6 Log10 IU/mL, P=0.072). However, the HBsAg level decreased after 6 months of treatment in patients with a VR and became different significantly between the groups thereafter (3.9 vs. 3.3 at 6 months, P=0.002; 3.8 vs. 3.2 at 1 year, P=0.004; 3.9 vs. 3.2 at 2 years, P=0.008; 3.7 vs. 3.1 at 3 years, P =0.020).

Conclusions

The HBsAg level at 6 months after treatment can help predict treatment response.

Long-term outcomes of two rescue therapies in lamivudine-refractory patients with chronic hepatitis B: combined lamivudine and adefovir, and 1-mg entecavir

BACKGROUND/AIMS

Adefovir (ADV) and lamivudine (LAM) combination therapy (ADV+LAM) has been a useful option for patients with LAM-resistant (LAM-r) chronic hepatitis B (CHB). However, the long-term outcomes of LAM+ADV and 1-mg entecavir (ETV) rescue therapies have still been limited. The aim of this study was to determine the long-term outcomes of these two rescue therapies.

METHODS

Sixty patients with LAM-r CHB underwent rescue therapy with LAM+ADV (n=36) or 1-mg ETV (n=24). We determined the duration of rescue therapy, timing and type of mutation, undetectable serum hepatitis B virus (HBV) DNA by PCR (lower limitation of detection, < 140 copies/mL), biochemical response (alanine aminotransferase < 40 IU/mL), and the incidence of hepatitis B virus e antigen (HBeAg) seroconversion and virologic breakthrough.

RESULTS

Baseline characteristics did not differ between the two therapy groups. The duration of rescue therapy was 56 months (range, 14-100 months) in the ADV+LAM group and 42 months (range, 12-73 months) in the ETV group (P=0.036). The cumulative rates of HBV DNA undetectability and HBeAg seroconversion up to 6 years were 88.6% and 43.0%, respectively, in the ADV+LAM group, and 45.8% and 31.8% in the ETV group. The rate of virologic breakthrough and resistance was 14.4% in the ADV+LAM group and 71.9% in the ETV group (P=0.001).

CONCLUSIONS

Combination of LAM and ADV therapy for up to 6 years achieved modest rates of virological suppression and resistance. ETV is not an optimal therapy because the risk of viral breakthrough to ETV increases over time.

The feasibility of discontinuing lamivudine in lamivudine-resistant chronic hepatitis B patients on lamivudine and adefovir combination therapy

OBJECTIVES

This study investigated the antiviral efficacy of adefovir (ADV) rescue therapy and the feasibility of lamivudine (LAM) discontinuation in LAM-resistant chronic hepatitis B (CH-B) patients who had attained a virological response (VR) with LAM + ADV combination therapy.

METHODS

The VR and virological breakthrough (VBT) were analyzed in 106 consecutively enrolled LAM-resistant CH-B patients who received ADV rescue therapy during a mean follow-up period of 55.2 months. Seventy-four patients achieved VR, and were divided into the LAM-discontinuation group (n = 39) and the LAM-continuation group (n = 35). The VR and VBT between the 2 groups were compared.

RESULTS

For all 106 LAM-resistant CH-B patients, the overall cumulative probabilities of VR at 1, 2, 3 and 5 years of ADV rescue therapy were 40.6, 55.7, 64.6 and 81.3%, respectively. The cumulative probabilities of VBT at 1, 2, 3 and 5 years were 0, 2.9, 8.8 and 13.9%, respectively. Whether they discontinued or continued LAM after achieving VR on LAM + ADV therapy, VR and VBT were not significantly different during a mean follow-up period of 40.4 months.

CONCLUSIONS

There was a good long-term VR with ADV rescue therapy for LAM-resistant CH-B patients. Moreover, discontinuing LAM was found to be feasible for patients who attained VR during ADV + LAM therapy.

Entecavir plus adefovir combination therapy versus lamivudine add-on adefovir for lamivudine-resistant chronic hepatitis B: A meta-analysis

To determine whether adefovir (ADV) in combination with entecavir (ETV) is more effective than with lamivudine (LAM) in patients with lamivudine-resistant chronic HBV infection, electronic databases were searched through May 10th, 2013 to obtain relevant trials which met the inclusion criteria. Meta-analysis was performed on randomized controlled trials (RCTs) and non-randomized studies. Four trials containing a total of 323 patients were included. Serum HBV DNA reductions after 3 and 6 months of treatment in the ETV + ADV group were greater than that of LAM + ADV group (mean difference (MD) = 0.90, 95% confidence interval (CI): 0.74-1.07, P < 0.00001; MD = 0.81, 95% CI: 0.57-1.06, P < 0.00001). The rate of 6 months HBV DNA undetectability with ETV and ADV was higher than that of LAM and ADV (relative risk (RR) = 1.63, 95% CI: 1.14-2.34, P < 0.007). There were higher rates of serum ALT normalization than those in LAM + ADV group after 6 months of treatment (RR = 1.40, 95% CI: 1.11-1.77, P < 0.005). The ETV + ADV group had lower viral breakthrough and genotypic mutation rates than LAM + ADV group after 12 months of treatment (RR = 0.24, 95% CI: 0.10-0.58, P = 0.002). The combination of ETV plus ADV is a more effective rescue therapy than LAM add-on ADV in patients with LAM-resistant HBV.

Entecavir 1mg versus combined lamivudine/adefovir dipivoxil in chronic HBV Egyptian patients resistant to LAM monotherapy, non-randomised controlled study

BACKGROUND AND STUDY AIMS

The development of antiviral-resistant mutations with long-term treatment remains a major concern in the treatment of chronic hepatitis B virus (HBV) infection. The study aimed to compare the therapeutic efficacy of entecavir 1mg versus combined lamivudine/adefovir dipivoxil (Lam/Adv) in chronic HBV patients resistant to lamivudine monotherapy.

PATIENTS AND METHODS

This study included two groups of lamivudine-resistant patients who received lamivudine 100mg for 1-3 years. Group 1 was composed of 25 cases (52% HBeAg+ve) who received combined Lam/Adv, and group 2 was composed of 13 patients (30.8% HBeAg+ve) who received entecavir 1mg. Pre-enrolment assessment included biochemical, serological and quantitative HBV-DNA testing as well as HBeAg and hepatitis B envelope antibody (HBeAb) assessment. Evaluation was done at 3, 6, 12, 24 and 36 months of treatment by the same parameters. Hepatitis B surface antigen and antibody (HbsAg and HBsAb) were assessed after each year of treatment.

RESULTS

At the end of 36 months of treatment, 16 cases (69%) in group 1 completed the study period, versus 13 (100%) in group 2. Two cases in group 1 underwent HBeAg seroconversion, accompanied by HBV-DNA undetectability, at 6 and 12months, respectively; no cases were seroconverted in group 2. Both treatments achieved improvement in alanine aminotransferase (ALT), bilirubin and alpha-foetoprotein equally at the end of the study. HBV-DNA undetectability was better achieved in group 2 when compared to group 1. HBeAg seroconversion was only achieved in two cases in group 1, whereas no cases lost HBeAg in group 2. None of our cases achieved HbsAg seroconversion or loss at the end of the study period.

CONCLUSION

The entecavir 1-mg monotherapy group achieved better HBV-DNA undetectability starting at 3 months of treatment when compared to the Lam/Adv group; however, both lines of treatment showed almost similar results over the rest of the study period. HBeAg seroconversion was only achieved in two cases in the combined Lam/Adv group, whereas no cases lost HBeAg in the other group.

Comparison of the efficacy of Lamivudine plus adefovir versus entecavir in the treatment of Lamivudine-resistant chronic hepatitis B: a systematic review and meta-analysis

BACKGROUND

Hepatitis B virus infection remains 1 of the major health threats worldwide. Currently, lamivudine plus adefovir combination therapy or entecavir monotherapy is usually used for the treatment of patients with lamivudine-resistant chronic hepatitis B (CHB). However, there are few systematic comparisons between the efficacy of lamivudine plus adefovir and the efficacy of entecavir in the treatment of these patients.

OBJECTIVE

The goal of this systematic study and meta-analysis was to assess the efficacy of lamivudine plus adefovir compared with entecavir for the treatment of patients with lamivudine-resistant CHB.

METHODS

A comprehensive literature search of PUBMED, Web of Science, WANFANG database, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Review, were screened to obtain citations from January 1990 to January 2012 in this study. Data analysis was done by using the Review Manager Software 5.1.

RESULTS

Eight studies were suitable for analysis. A total of 696 patients with lamivudine-resistant CHB were studied and grouped according to treatment: 341 patients in the entecavir group and 355 patients in the lamivudine plus adefovir group. The results found that the rates of undetectable hepatitis B virus DNA levels, alanine aminotransferase normalization, hepatitis B e antigen loss, and hepatitis B e antigen seroconversion were not significantly different between the lamivudine plus adefovir group and the entecavir group. Moreover, the rate of adverse reactions was also not significantly different between the 2 groups. However, virologic breakthrough for the patients with lamivudine resistance was higher in the entecavir group than in the lamivudine plus adefovir group.

CONCLUSIONS

For these CHB patients with lamivudine resistance, lamivudine plus adefovir was a better treatment option than entecavir alone.

Two rescue therapies in lamivudine-resistant patients with chronic hepatitis B in the central China: adefovir monotherapy and adefovir plus lamivudine

The emergence of mutations that confer drug resistance in patients with chronic hepatitis B (CHB) is increasing in China. We aimed to compare the cumulative efficacy and resistance of adefovir (ADV) monotherapy and ADV add-on lamivudine (LAM) (ADV+LAM) therapy in LAM-resistant patients. One-hundred adult CHB patients with LAM-resistance mutations were identified. Of these 100, 52 patients were treated with ADV monotherapy and 48 were treated with ADV+LAM combination therapy for at least 24 months. After 2-year treatment, the cumulative rates of serum alanine aminotransferase normalization were, respectively, 73.1 and 83.3 % in the ADV monotherapy and ADV+LAM therapy groups (P = 0.216). Additionally, 36 patients receiving ADV plus LAM had hepatitis B e antigen loss/seroconversion, as compared with 30 in patients (P = 0.068). More patients who received LAM plus ADV than those who received ADV alone had HBV DNA levels below 1,000 international unit/milliliters (83.3 vs. 50 %, P < 0.001). Viral breakthrough and genotypic mutations were detected in 19 (36.5 %) and 9 (18.8 %) patients in the ADV monotherapy and ADV+LAM therapy groups, respectively (P = 0.048). ADV+LAM combination therapy demonstrated faster and significantly greater suppression of HBV DNA compared with ADV therapy alone for patients with LAM-resistance mutations. ADV+LAM was superior to ADV monotherapy in achieving the initial viral breakthrough and genotypic mutations. ADV+LAM combination therapy was rational for most of LAM-resistant Chinese patients with chronic hepatitis B.

Efficacy of adefovir-based combination therapy for patients with Lamivudine- and entecavir-resistant chronic hepatitis B virus infection

Treatment strategies for entecavir (ETV)-resistant chronic hepatitis B (CHB) patients are not yet well established. The aim of this study was to evaluate overall antiviral efficacy and to compare the efficacy of combination therapy with adefovir (ADV) plus nucleoside analogues (lamivudine [LAM], telbivudine [LdT], or ETV) in patients infected with LAM- and ETV-resistant hepatitis B virus (HBV) variants. Virologic, biochemical, and serologic responses during combination therapy with ADV plus nucleoside analogues were assessed. Propensity score analysis was used to select a matched group of patients for the comparison of rescue therapy regimens. A total of 67 consecutive patients were analyzed. Complete virologic suppression was achieved in 27 patients. The overall cumulative incidence of complete virologic suppression at month 24 was 47.4%: 44.3% in the LAM or LdT plus ADV group and 51.4% in the group given ETV and ADV. There was no significant difference between these two groups (P = 0.234). The cumulative incidences of complete virologic suppression were still comparable between the two groups selected and matched using the propensity score model (P = 0.419). Virologic breakthrough was observed in 9 patients, and rtA181V substitution was newly detected in one patient. Hepatitis B e antigen (HBeAg) negativity and lower baseline HBV DNA level were associated with complete virologic suppression in univariate analysis. In multivariate analysis, lower baseline HBV DNA level remained an independent predictor. In conclusion, combination therapy with ADV plus nucleoside analogues fails to show sufficient antiviral efficacy in CHB patients with resistance to both LAM and ETV. Further study is warranted to evaluate the efficacy of a more potent tenofovir-based regimen in such patients.

Efficacy of adefovir-based combination therapy for patients with Lamivudine- and entecavir-resistant chronic hepatitis B virus infection

Treatment strategies for entecavir (ETV)-resistant chronic hepatitis B (CHB) patients are not yet well established. The aim of this study was to evaluate overall antiviral efficacy and to compare the efficacy of combination therapy with adefovir (ADV) plus nucleoside analogues (lamivudine [LAM], telbivudine [LdT], or ETV) in patients infected with LAM- and ETV-resistant hepatitis B virus (HBV) variants. Virologic, biochemical, and serologic responses during combination therapy with ADV plus nucleoside analogues were assessed. Propensity score analysis was used to select a matched group of patients for the comparison of rescue therapy regimens. A total of 67 consecutive patients were analyzed. Complete virologic suppression was achieved in 27 patients. The overall cumulative incidence of complete virologic suppression at month 24 was 47.4%: 44.3% in the LAM or LdT plus ADV group and 51.4% in the group given ETV and ADV. There was no significant difference between these two groups (P = 0.234). The cumulative incidences of complete virologic suppression were still comparable between the two groups selected and matched using the propensity score model (P = 0.419). Virologic breakthrough was observed in 9 patients, and rtA181V substitution was newly detected in one patient. Hepatitis B e antigen (HBeAg) negativity and lower baseline HBV DNA level were associated with complete virologic suppression in univariate analysis. In multivariate analysis, lower baseline HBV DNA level remained an independent predictor. In conclusion, combination therapy with ADV plus nucleoside analogues fails to show sufficient antiviral efficacy in CHB patients with resistance to both LAM and ETV. Further study is warranted to evaluate the efficacy of a more potent tenofovir-based regimen in such patients.

Lamivudine plus adefovir combination therapy for lamivudine resistance in hepatitis-B-related hepatocellular carcinoma patients

Background/Aims

Lamivudine (LAM) plus adefovir (ADV) combination therapy has been accepted as one of the best treatments for LAM-resistant chronic hepatitis B (CHB). The aim of this study was to determine the efficacy of this combination therapy in hepatocellular carcinoma (HCC) patients.

Methods

The medical records of CHB patients who developed LAM resistance and were treated with LAM plus ADV combination therapy for more than 6 months were reviewed. Their virological response (VR; undetectable HBV DNA) and biochemical response (BR; alanine aminotransferase normalization) were evaluated, and the findings of HCC and non-HCC patients were compared.

Results

The data from 104 patients (19 with HCC and 85 without HCC) were analyzed. The VR rates did not differ significantly between the HCC and non-HCC groups: 33.3% vs. 55.6% at 12 months (P=0.119), 58.3% vs. 67.2% at 24 months (P=0.742), 50% vs. 69.8% at 36 months (P=0.280), and 66.7% vs. 71.0% at 48 months (P=1.000). The BR rates also did not differ significantly between the groups: 55.6% vs. 84.0% at 12 months (P=0.021), 58.3% vs. 83.8% at 24 months (P=0.057), 70.0% vs. 77.8% at 36 months (P=0.687), and 66.7% vs. 80.6% at 48 months (P=0.591).

Conclusions

The efficacy of LAM plus ADV combination therapy is comparable in HCC and non-HCC patients.

Adding adefovir vs. switching to entecavir for lamivudine-resistant chronic hepatitis B (ACE study): a 2-year follow-up randomized controlled trial

BACKGROUND

Management of lamivudine-resistant chronic hepatitis B (CHB) remains challenging, as inappropriate choice of treatment may cause multidrug resistance. Until now, randomized trials directly comparing adding adefovir and switching to entecavir monotherapy have not been reported.

AIMS

This multicentre prospective randomized study was designed to compare the efficacy of these two strategies.

METHODS

Two hundred and nineteen lamivudine-resistant CHB patients were randomized to either adefovir-lamivudine combination group or entecavir monotherapy group (n = 110 vs. 109), and followed up for 24 months.

RESULTS

One hundred and eighty patients completed this study. At month 24, virological response rate [hepatitis B virus (HBV) DNA <60 IU/ml] was higher in the adefovir-lamivudine combination group compared with entecavir group (56.7% vs. 40%, P = 0.025), although biochemical and serological response rates were not significantly different. Genotypic resistance (9.2% vs. 24.6%, P = 0.005) and combined viral breakthrough (2.0% vs. 17.6%, P < 0.001) were more frequent in the entecavir group. However, by subgroup analysis, virological response rates were not significantly different between the two therapies in HBeAg-positive patients (44.9% vs. 35.7%, P = 0.268) or in patients with high baseline HBV DNA (≥7 log IU/ml) (40.7% vs. 31.3%, P = 0.320) at month 24.

CONCLUSION

This study showed that adefovir-lamivudine combination provides significantly higher antiviral efficacy and the lower resistance rate compared with the entecavir monotherapy in the management of lamivudine-resistant CHB. However, it had limited efficacy in HBeAg-positive patients or in patients with high baseline HBV DNA.

Treatment of lamivudine-resistant chronic hepatitis B infection: a multicenter retrospective study

OBJECTIVES

To compare the efficacy of rescue therapies in lamivudine (LAM)-resistant chronic hepatitis B (CHB) infections including: (1) adefovir dipivoxil (ADV) monotherapy, (2) ADV plus LAM combination therapy and (3) entecavir (ETV) 1.0 mg monotherapy.

MATERIALS AND METHODS

The authors designed a multicenter-retrospective study. Eight institutions participated in the study from Korea.

RESULTS

A total of 343 LAM-resistant CHB patients were enrolled. The proportion of patients with undetectable serum hepatitis B virus (HBV) DNA levels at month 24 after the initiation of rescue therapy was higher in the ADV plus LAM combination therapy group (39/64, 60.9%) than in the ADV monotherapy (50/126, 39.7%) and ETV 1.0 mg monotherapy (19/48, 39.6%) groups (p = 0.014). Mean serum HBV DNA levels at 24 months were 2.07 ± 1.21 log(10) IU/ml in the ADV plus LAM combination therapy group, 2.74 ± 1.74 log(10) IU/ml in the ADV monotherapy group and 3.08 ± 1.97 log(10) IU/ml in the ETV 1.0 mg monotherapy group (p = 0.014). In multivariate analysis, a finding of undetectable serum HBV DNA level at 6 months and ADV plus LAM combination therapy (vs. ADV) was an independent factor for predicting undetectable serum HBV DNA at month 24 (odds ratio, 1.003; 95% confidence interval, 1.000-1.006; p = 0.026).

CONCLUSIONS

ADV plus LAM combination therapy is more effective in reducing viral load than switching to ADV or ETV 1.0 mg in patients with LAM-resistant CHB.

Efficacy of 3 years of adefovir monotherapy in chronic hepatitis B patients with lamivudine resistance

AIM

To study the effect of rescue monotherapy with adefovir (ADV) in patients with chronic hepatitis B (CHB) who developed drug resistance to lamivudine (LAM).

METHODS

A total of 76 treated CHB patients with resistance to LAM were enrolled in the present study. The patients' baseline characteristics, such as age, gender, blood tests and hepatitis B virus (HBV) DNA were collected; therapy duration and the response of each patient were also recorded. ADV monotherapy was set as the observation group A. Twenty-four patients with LAM resistance, who were set as group B, accepted combined therapy with LAM + ADV. Patients were followed up at 0, 12, 24, 52, 104 and 156 wk. Hepatitis B surface antigen status, hepatitis B e antigen (HBeAg)/anti-HBe status, HBV DNA level and biochemical indexes were monitored. Sequencer of HBV polymerase gene was performed on the ABI 3730 automated sequencer. If no desired effects had been achieved during the course of treatment, patients' choices were also taken into account. The control group was tested at the same time.

RESULTS

In the two groups, 27 cases developed viral breakthrough after LAM treatment response. The remaining 49 cases underwent biochemical rebound accompanied by rtM204I/V or rtL180M mutation. In group A, 52 cases finished 156 wk of ADV monotherapy; of whom, 36 cases were HBeAg positive and 16 HBeAg negative. In patients whose baseline HBV DNAs were 10(3)-10(5) copies/mL, 88.8% of patients' HBV DNAs were lower than the lower test limit (10(3) copies/mL) after 12 to 156 wk of ADV treatment. In patients whose baseline HBV DNAs were ≥ 10(6) copies/mL, 41.1%-47.0% of patients' HBV DNAs were lower than the lower test limit after the same course of ADV therapy (χ(2) were 4.35-5.4, 41.1%-47.0% vs 88.8% group 10(3)-10(5) copies/mL, P < 0.01). In group A, seroconversion of HBeAg developed in 8 of 36 cases (22.2%). In group B, 24 cases finished 156 wk of LAM + ADV; of whom, 17 cases were HBeAg positive and 7 HBeAg negative. In patients whose baseline HBV DNAs were 10(3)-10(5) copies /mL, 81.8% of patients' HBV DNAs were lower than the lower test limit (10(3) copies/mL) after 12 to 156 wk of treatment. In the patients whose baseline HBV DNAs were ≥ 10(6) copies/mL, 46.1%-53.8% of patients' HBV DNAs were lower than the lower test limit after the same course of LAM + ADV therapy (χ(2) were 4.1-5.0, 46.1%-53.8% vs 81.8% group 10(3)-10(5) copies/mL, P < 0.05-0.01). In group B, 4 of 17 cases (23.5%) developed seroconversion of HBeAg. Treatment outcomes in groups A and B were comparable.

CONCLUSION

In both group A and B, the ratios of virological response have similar efficacy in patients with lower baseline HBV DNAs.

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.

Cost-effectiveness analysis of antiviral treatments for HBeAg-positive chronic hepatitis B in Canada

OBJECTIVE

To conduct a cost-effectiveness analysis of currently available nucleos(t)ide antiviral treatments (lamivudine, telbivudine, entecavir, and tenofovir) for chronic hepatitis B in Canada.

METHODS

Markov modeling was used to project the lifetime health benefits and costs associated with the antiviral treatments. The hypothetical patient population was hepatitis B e antigen-positive chronic hepatitis B-infected patients aged 34 years. Quality-adjusted life-years were used as a measure of effectiveness. Long-term cumulative incidence of liver complications was also projected. Treatment effectiveness data were derived from the literature; meta-analysis was conducted when there was a large variance in reported effectiveness data. Costs were obtained from a cost analysis of treating chronic hepatitis B-related complications in Canada. Stochastic parameter uncertainty was examined in probabilistic sensitivity analysis by using second-order Monte Carlo simulation. Alternative modeling assumptions were assessed in scenario analysis. One-way sensitivity analysis was used to explore each parameter's impact on the uncertainty of the results.

RESULTS

In the base-case analysis, telbivudine was dominated by entecavir and tenofovir. Tenofovir strictly dominated lamivudine, telbivudine, and entecavir. Over the 72-year period of the model, the expected life expectancy (undiscounted) of lamivudine, telbivudine, entecavir, and tenofovir was 35.71, 36.94, 37.65, and 37.99 years, respectively. Tenofovir had the highest expected quality-adjusted life-years at 11.86 (discounted) in all comparisons. Scenario and sensitivity analyses proved the robustness of the base-case results. The projected 10-year cumulative incidence of cirrhosis and hepatocellular carcinoma was 11.40% and 3.05%, respectively, for tenofovir, which is significantly lower than that for lamivudine.

CONCLUSION

Tenofovir generated the best results compared with all other therapies under evaluation.

Viral response at 6 months is associated with treatment outcome of adefovir add-on therapy for lamivudine-resistance

BACKGROUND AND AIM

  Adefovir add-on therapy is recommended for patients infected with lamivudine-resistant hepatitis B virus (HBV). We aimed to describe the long-term treatment outcome and predictors for good response of adefovir add-on therapy.

METHODS

A total of 559 chronic hepatitis B (CHB) patients who had been treated for at least 12 months with adefovir add-on therapy due to resistance to lamivudine were retrospectively included. Complete virologic response (CVR) was defined as serum HBV DNA <9IU/mL. Viral responses at 6months were classified as PCR negativity, partial virologic response (PVR, HBV DNA <2000 IU/mL), or inadequate virologic response (IVR, HBV DNA≥2000IU/mL).

RESULTS

The median duration of follow-up was 31.5 months (range, 12-56). The cumulative probabilities of CVR during adefovir add-on therapy were 58%, 70%, 78%, and 80% at 12, 24, 36, and 43 months, respectively. The cumulative rates of resistance to adefovir were 0.4%, 0.8%, and 3.1% at 12, 24, and 36 months, respectively. The only baseline factor associated with CVR (hazard ratio 0.83, 95% confidence interval 0.62-0.91, P≤0.001) and resistance to adefovir (hazard ratio 1.925, 95% confidence interval 1.13-3.30, P=0.017) was serum HBV DNA level. Comparison of the cumulative rates of CVR and resistance to adefovir according to viral response at 6months showed significant differences among the three groups (P<0.0001 and P= 0.0005, respectively).

CONCLUSIONS

Pre-treatment HBV DNA level and viral response at 6months is associated with treatment outcome for adefovir-add on therapy in lamivudine resistance.

Comparison of rescue strategies in lamivudine-resistant patients with chronic hepatitis B

Lamivudine (LAM) resistance now poses a major problem in the management of patients with chronic hepatitis B virus (HBV) infection. We retrospectively collected clinical data on chronic HBV-infected patients who had developed LAM resistance under de novo LAM monotherapy and subsequently took nucleos(t)ide analogs as rescue strategy in our hospital. From initiation of rescue therapies to January 2012, incidence of antiviral drug resistance was 23.67%, 18%, 6.94% and 0% (P=0.007) in the group of switching to adefovir dipivoxil (ADV) monotherapy, switching to entecavir (ETV) monotherapy, adding on ADV and switching to combination of ADV and ETV. At month 12, the median levels of serum HBV DNA were respectively 9300IU/mL, 4648IU/mL, 2054IU/mL and 100IU/mL (P<0.001), and the cumulative rates of serum ALT normalization were respectively 75%, 84%, 93% and 100% (P=0.003). Additionally, the strategy of switching to ADV monotherapy induced more single rtA181T mutations. In conclusion, switching to ADV monotherapy has been widely used in real-world clinical practice in China, however, due to the high incidence of drug resistance, switching to neither ADV nor ETV monotherapy is optimal when LAM resistance occurs; combination of ADV and ETV is most effective, whereas the strategy of adding on ADV is rational for most of LAM-resistant Chinese patients with chronic hepatitis B.

Clinical prediction of failure of Lamivudine prophylaxis for hepatitis B virus-infected patients undergoing cytotoxic chemotherapy for malignancy

Although lamivudine (LAM) prophylaxis is recommended for patients infected with hepatitis B virus (HBV) undergoing chemotherapy for malignant disease, HBV reactivation sometimes occurs during or after LAM administration. The aim of this study was to determine predictors of LAM prophylactic failure in patients with malignancies. Patients with malignancies were routinely screened for serum hepatitis B surface antigen (HBsAg) from June 2002 to August 2008. All consecutive, HBsAg-positive patients received LAM prophylaxis during and after completion of chemotherapy. We assessed risk factors for virologic breakthrough and withdrawal hepatitis. Death without HBV reactivation was regarded as a competing risk event, which was adjusted by Fine and Gray's model. A total of 110 patients were included in this study. They received LAM prophylaxis for a median of 9.2 months. Virologic breakthrough occurred in 15 patients at a median of 10.9 months from the initiation of LAM prophylaxis. Withdrawal hepatitis occurred in 15 patients at a median of 2.4 months after cessation of LAM prophylaxis. Multivariable analysis showed that high baseline HBV DNA titer (≥2,000 IU/ml) (hazard ratio [HR], 9.94; P = 0.0063) and the use of rituximab (HR, 3.19; P = 0.027) were significant predictors of virologic breakthrough and that high baseline HBV DNA titer (HR, 5.90; P = 0.007), liver cirrhosis (HR, 10.4; P = 0.002), and distant metastasis (HR, 5.14; P = 0.008) were independent risk factors for withdrawal hepatitis. Patients with high viremia, liver cirrhosis, rituximab treatment, and distant metastasis are at high risk of prophylactic failure and need antiviral agents with a greater barrier to resistance.

Antiviral efficacy of combination therapy with entecavir and adefovir for entecavir/lamivudine-resistant hepatitis B virus with or without adefovir resistance

There is little clinical information on the management of hepatitis B virus (HBV) that is resistant to multiple drugs including entecavir (ETV). The present retrospective cohort study assessed the antiviral efficacy of ETV/adefovir dipivoxil (ADV) combination therapy for ETV-resistant HBV with prior lamivudine (LAM) resistance, and either with or without previous ADV resistance. The cumulative probability of achieving a virological response (undetectable serum HBV DNA) was compared by Kaplan-Meier analysis and the Breslow method. Seventeen patients with ETV-resistant HBV who were treated with ETV/ADV combination therapy for at least 6 months at a tertiary care center, were included; seven had dual resistance to ETV and LAM [ADV-r(-) group] and 10 had triple resistance to ETV, LAM, and ADV [ADV-r(+) group]. The median follow-up period was 9 months (range, 6-23). A virological response was noted in seven patients after a median of 3 months (range, 3-12) of treatment; five in the ADV-r(-) group and two in the ADV-r(+) group. The cumulative probability of a virological response was significantly higher in the ADV-r(-) group than in the ADV-r(+) group (6 months cumulative probability, 57.1% vs. 11.1%). In conclusion, ETV/ADV combination therapy led to virological responses in five of seven patients with resistance to ETV and LAM, but a significantly poorer response in patients with prior ADV resistance than in those without prior ADV resistance. Therefore, ETV/ADV combination therapy could be a useful therapeutic option for ETV- and LAM-resistant HBV without prior ADV resistance.

Adefovir dipivoxil in chronic hepatitis B: history and current uses

INTRODUCTION

The nucleotide analogue adefovir dipivoxil (ADV) was approved in 2002 for the treatment of chronic infection with hepatitis B virus (HBV), in both hepatitis B e antigen (HBeAg)-positive and -negative patients. ADV 10 mg daily has been associated with improved liver histology, decreased levels of HBV DNA and alanine aminotransferase (ALT), and seroconversion of HBeAg.

AREAS COVERED

This paper reviews the use of ADV as a first-line treatment for chronic hepatitis B and as an add-on therapy in chronic HBV-infected patients with lamivudine resistance. In the years since its launch, clinical resistance to ADV has emerged, and tenofovir and entecavir have shown greater efficacy in reducing viral load.

EXPERT OPINION

Many patients who started antiviral therapy with ADV (either as monotherapy or in combination with lamivudine) remain on this agent because they have undetectable viremia, but its future use will probably diminish because of the availability of more potent drugs. ADV is generally well tolerated, though the 10 mg dose is associated with low risk of nephrotoxicity.

Lamivudine plus adefovir combination therapy versus entecavir monotherapy for lamivudine-resistant chronic hepatitis B: a systematic review and meta-analysis

Background

Chronic hepatitis B virus (HBV) infection represents a serious global health problem and resistance to lamivudine (LAM) has become a serious clinical challenge. Previous rescue therapy for the treatment of chronic LAM-resistant hepatitis B infected patients included switching to entecavir (ETV) and adding adefovir (ADV) or tenofovir (TFV). At present, switching to ETV is not recommended for rescue therapy for LAM-resistant chronic hepatitis B (CHB). The aim of this report was to determine whether add-on ADV was a superior rescue strategy in the treatment of CHB patients with LAM resistance.

Methods

We searched Medline/PubMed, EMBASE, Web of Knowledge, and the Cochrane Library. Relative risks (RRs) of virologic response, virologic breakthrough, normalization of serum alanine aminotransferase (ALT) levels and HBeAg seroconversion rates were studied. Factors predicting virologic response, standardized mean differences (SMD) in HBV DNA levels and safety were reviewed.

Results

Six eligible trials (451 patients in total) were included in the analysis. The rate of virologic breakthrough in the ETV group was higher than that in the LAM plus ADV group. There were no statistical differences in virologic response, ALT normalization and HBeAg seroconversion in either group 48 weeks post treatment. LAM plus ADV combination therapy produced faster and greater HBV DNA reduction rates 24 weeks post therapy compared to ETV monotherapy. HBV DNA baseline levels and the initial virologic response (IVR) were predictive of the virologic response. Additionally, combination therapy or monotherapy were both well tolerated.

Conclusions

LAM plus ADV combination therapy was more effective and produced longer-lasting effects than switching to ETV monotherapy in treating CHB patients with LAM resistance. However, considering the practical benefits and limitations of ADV, individualized therapy will be needed in patients with prior history of LAM resistant infections.