LAM-resistant Chronic Hepatitis B Research Articles

Entecavir/peginterferon alfa-2a combination in the treatment of two genotypes of chronic hepatitis B patients with lamivudine resistance

Purpose: To investigate the efficacy of entecavir plus peginterferon alfa-2a in the treatment of chronic hepatitis B (CHB) patients with different hepatitis B virus (HBV) genotypes resistant to lamivudine (LAM). 
 Methods: 119 LAM-resistant CHB patients treated in Baoshan People's Hospital from May 2018 to May 2020 were selected. All patients received entecavir and peginterferon alfa-2a for 24 months and were scheduled for regular outpatient review and telephone follow-up. Polymerase chain reaction (PCR) was conducted to determine the HBV genotype and HBV-DNA clearance. Alanine aminotransferase (ALT) normalization rate, HBV-DNA clearance rates, and hepatitis B e-antigen (HBeAg) seroconversion rate were determined in CHB patients with different genotypes. Quality of life for all patients was assessed using SF-36 Scale. 
 Results: Five out of 119 patients were lost during follow-up, with a follow-up rate of 95.80 %. Two HBV genotypes were identified, of which 42 (36.8 %) were type B and 72 (63.2 %) type C. At the 6th and 12th month of follow-up, the HBV-DNA clearance rate, ALT normalization rate, and HBeAg seroconversion rate were significantly higher in CHB patients with genotype B than in patients with genotype C (p < 0.05). There were no significant differences between the three rates in the two groups at 18th and 24th month of follow-up (p > 0.05). The quality of life (QOL) of the patients differed between the two groups (p < 0.05). 
 Conclusion: Entecavir plus peginterferon alfa-2a are effective in treating LAM-resistant CHB patients with different genotypes. Genotype B CHB patients are more suitable for this combination protocol.

Efficacy of entecavir-based rescue therapy in lamivudine-resistant chronic hepatitis B patients in China: a retrospective study.

Limited studies have investigated the antiviral efficacy of entecavir (ETV)-based rescue therapy in lamivudine (LAM)-resistant chronic hepatitis B (CHB) patients. We retrospectively analyzed the efficacy of entecavir (ETV) monotherapy versus ETV-tenofovir disoproxil fumarate (TDF) combination therapy in 220 LAM-resistant CHB patients. Among 220 patients, 114 patients were treated with ETV monotherapy and 106 were treated with ETV-TDF combination therapy for at least 24 months. There were no significant differences between the two groups in baseline characteristics. During the follow-up of 24 months, virologic response (VR) occurred in 146 (66.4%) patients (58 patients belonged to the ETV monotherapy group and 88 patients belonged to the ETV-TDF combination group). The VR rates were different between the ETV and ETV-TDF groups (32.5% vs. 57.5% at 6 months, 50.0% vs. 77.4% at 12 months; and 50.9% vs. 83.0% at 24 months, P<0.001). In addition, both groups showed no difference in terms of the biochemical and HBeAg response. The rates of viral breakthrough at 6, 12 and 24 months were significantly different between ETV and ETV-TDF groups (2.63%, 4.39% and 9.65% vs. 0.00%, 0.94% and 1.89% at 6, 12 and 24 months, respectively). The ETV-TDF group was superior to the ETV group in achieving a virologic response. Moreover, the ETV-TDF was lower than the ETV group in achieving the initial viral breakthrough and genotypic mutations. Therefore, ETV-TDF combination therapy might be a better regimen than ETV monotherapy in the subgroup of LAM-resistant Chinese patients with CHB.

Evaluating the efficacy of switching from lamivudine plus adefovir to tenofovir disoproxil fumarate monotherapy in lamivudine-resistant stable hepatitis B patients.

BackgroundThe efficacy of switching to tenofovir disoproxil fumarate (TDF) monotherapy from lamivudine (LAM) plus adefovir dipivoxil (ADV) combination therapy (stable switching) in patients with LAM-resistant chronic hepatitis B (CHB) and undetectable hepatitis B virus (HBV) DNA is not clear.MethodsIn this non-inferiority trial, patients with LAM-resistant CHB and undetectable serum HBV DNA (<20 IU/mL) for >6 months after initiating LAM+ADV combination therapy were randomized (1:2) either to continue the combination therapy (LAM+ADV group, n = 58) or switched to TDF monotherapy (TDF group, n = 111). They were followed-up with serum biochemistry tests and HBV DNA measurement at 12-week intervals for 96 weeks. The primary endpoint of this study was the proportion of patients with viral reactivation at week 96.ResultsPatients with CHB enrolled in this study (n = 169) included 74 patients with compensated liver cirrhosis. In total, 9 patients (4 in the LAM+ADV group and 5 in the TDF group) dropped-out from the study. After a mean follow-up period of 96 weeks, the proportion of HBV reactivation observed was 6.8% (4/58) in the LAM+ADV group and 4.5% (5/111) in the TDF group by using intention-to-treat analysis (difference, -2.3%; 95% CI, -9.84–5.24%). None of the subjects in either group experienced viral reactivation based on per protocol analysis. No serious adverse reactions were observed. In the subgroup analysis for estimated glomerular filtration rate (eGFR) before and after treatment, decreased eGFR was observed only in the TDF group with cirrhosis (85.22 vs. 79.83 mL/min/1.73 m2, p = 0.000)ConclusionsStable switching to TDF monotherapy yielded non-inferior results at 96 weeks compared to the results obtained with LAM+ADV combination therapy in patients with LAM-resistant CHB and undetectable HBV DNA. However, TDF monotherapy in patients with cirrhosis requires close attention with respect to renal function.Trial registrationClinicalTrials.gov NCT01732367

Durability of the virological response after lamivudine discontinuation in lamivudine-resistant patients with a complete virological response after lamivudine and adefovir combination therapy.

We investigated the durability of virological response after lamivudine (LAM) discontinuation in LAM-resistant chronic hepatitis B (CHB) patients with complete virological response after LAM-adefovir (ADV) combination therapy. We enrolled 58 patients switched to ADV monotherapy with undetectable viral loads (<12 IU/ml) and normal alanine aminotransferase levels after ADV add-on combination treatment for at least 6 months in LAM-resistant CHB patients. Virologic relapse was defined as HBV DNA detection at more than 20 IU/ml by quantitative polymerase chain reaction determined on two consecutive measurements. During median 40.9 months of follow-up (range 11.5-79.0 months), seven (12.1%) patients experienced virological relapse. The cumulative rate of virological relapse at 3 and 5 years was 5.5% and 22.4%, respectively. Two patients had elevated alanine aminotransferase during virological relapse. These seven patients with virological relapse had undetectable HBV DNA after switching to tenofovir therapy. In our study, switching to ADV monotherapy resulted in sustained HBV DNA suppression in 87.9% of the patients during median 40.9 months follow-up. This adapting step-down strategy, switching from combination therapy to monotherapy in virologically suppressed CHB patients with stable liver disease, may reduce the cost burden and the risk of potentially harmful effects of combination therapy. J. Med. Virol. 89:85-90, 2017. © 2016 Wiley Periodicals, Inc.

Efficacy of Tenofovir-based Rescue Therapy in Lamivudine-resistant Chronic Hepatitis B Patients With Failure of Lamivudine and Adefovir Combination

PurposeIn chronic hepatitis B patients, lamivudine (LAM) and adefovir (ADV) combination therapy is commonly used as a rescue therapy for LAM resistance, but it often results in incomplete viral suppression. We investigated the antiviral efficacy of tenofovir (TDF)/LAM combination therapy versus TDF monotherapy in LAM-resistant chronic hepatitis B (CHB) patients who failed to respond to LAM plus ADV rescue therapy. MethodsAmong 108 patients with LAM-resistant CHB who had a partial virologic response (VR) to LAM and ADV combination therapy, Eighty one patients were finally included in this study. FindingsResistance to ADV (ADV-R) was present in 32 patients (39.5%), and the remaining 49 patients (60.5%) had a partial virologic response to LAM/ADV combination (ADV-P). The study subjects were treated with TDF alone (n=15) or TDF/LAM combination (n=66). VR was achieved in 61 patients (75.3%). The rates of VR at 6 and 12 months were not significantly different between TDF monotherapy and TDF/LAM combination therapy groups (46.7 vs. 68.2% at 6 months, and 66.7 vs. 75.9% at 12 months, log-rank P=0.357). Treatment efficacy of TDF alone or TDF/LAM combination was not statistically different according to pre-existing ADV or LAM resistant strains. In multivariate analysis, absolute HBV DNA levels at the start of TDF rescue treatment (P<0.001; OR, 0.556; 95% CI, 0.422-0.731) were the only significantly associated with VR. ImplicationsTDF monotherapy was as effective as TDF/LAM combination therapy in maintaining viral suppression in patients with LAM-resistant patients who failed to respond to LAM/ADV combination therapy.

Entecavir plus adefovir versus adefovir plus lamivudine in hepatitis B virus e antigen-positive, lamivudine-resistant chronic hepatitis B

Background and Aim In areas of the world where tenofovir disoproxil fumarate is not marketed, adefovir (ADV) + lamivudine (LAM) is recommended and widely used for LAM-resistant chronic hepatitis B (CHB). This study hypothesizes that entecavir (ETV) + ADV, where both components are active against LAM-resistant hepatitis B virus (HBV), will provide greater antiviral potency than ADV + LAM where only ADV is active. Methods Open-label, randomized trial in hepatitis B virus e antigen-positive LAM-experienced CHB patients with LAM resistance treated with ETV 1 mg + ADV 10 mg (n = 138), ADV + LAM 100 mg (n = 137), or ETV (n = 140). Results At week 48, there was no significant difference in the primary endpoint of HBV-DNA < 50 IU/mL between the treatment groups (25.4% [ETV + ADV] vs 19.7% [ADV + LAM], P = 0.2619; vs 16.4% [ETV], P = 0.1336). However, at week 96, rates of HBV-DNA < 50 IU/mL were significantly greater with ETV + ADV than with ADV + LAM (43.5% vs 28.5%; P = 0.0095). Rates of virologic breakthrough and resistance to ETV or ADV were low through week 96 with both combinations. The delayed benefit of ETV + ADV is likely related to the high baseline viremia in this cohort relating to continued LAM exposure after treatment failure. All three therapies had favorable safety profiles. Conclusions In patients with LAM-resistant HBV, ETV + ADV demonstrated greater antiviral efficacy than ADV + LAM and comparable safety over 2 years, and may therefore be a preferable treatment option for LAM-resistant CHB, especially in regions where alternative rescue therapies are not available. In highly viremic patients, the benefit of ETV + ADV became apparent after a longer treatment duration.

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.

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

Background/AimsAdefovir (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.MethodsSixty 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.ResultsBaseline 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).ConclusionsCombination 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.

Partial Virological Response to Adefovir Add-On Lamivudine Rescue Therapy in Patients with Lamivudine-Resistant Chronic Hepatitis B

Background/Aims: In patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB) receiving adefovir (ADV) add-on LAM therapy, insufficient viral suppression or the appearance of additional ADV resistance has remained unresolved. This study determined the partial virological response (PVR) criteria to predict a virological response (VR) at week 96 in these patients. Methods: 96 patients with LAM-resistant CHB (ADV add-on LAM therapy >2 years) were analyzed. For predicting VR at week 96, the area under the receiver operating characteristic curve values at different time points were compared to establish the optimal time point, and the maximal Youden index was calculated to determine the optimal cut-off hepatitis B virus (HBV) DNA level. Results: 50 (52.1%) patients achieved VR at 2 years after ADV add-on LAM therapy. The optimal PVR criteria were determined to be HBV DNA 500 IU/ml at week 48. 44 (45.8%) patients who met optimal PVR criteria showed a significantly higher risk for detectable HBV DNA levels at week 96 than those with a favorable VR (HBV DNA <500 IU/ml) at week 48. Conclusions: This study suggested optimal PVR criteria in patients with LAM-resistant CHB receiving ADV add-on LAM therapy. Modification of the antiviral agent regimen should be considered if the serum HBV DNA level exceeds 500 IU/ml at week 48.

Virologic Responses to Add‐on Adefovir Dipivoxil Treatment Versus Entecavir Monotherapy in Children With Lamivudine‐resistant Chronic Hepatitis B

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. 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. 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). 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.

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 log10 IU/ml in the ADV plus LAM combination therapy group, 2.74 ± 1.74 log10 IU/ml in the ADV monotherapy group and 3.08 ± 1.97 log10 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.

Cost-effectiveness analysis of different rescue therapies in patients with lamivudine-resistant chronic hepatitis B in China

BackgroundSeveral rescue therapies have been used in patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB); however, the economic outcome of these therapies is unclear. The object of the current analysis was to evaluate the lifetime cost-effectiveness of rescue therapies among patients with LAM-resistant CHB.MethodsA Markov model was developed to simulate the clinical course of patients with LAM-resistant CHB. From the perspective of Chinese health care, a lifetime cost-utility analysis was performedfor 4 rescue strategies: adefovir (ADV), entecavir (ETV) or tenofovir (TDF) monotherapy and combination therapy using LAM and ADV. A hypothetical cohort of 45-year-old patients with genotypic or clinical LAM-resistant CHB entered the model, and the beginning health state was LAM-resistant CHB without other complications. The transition probabilities, efficacy and resistance data for each rescue therapy as well as the costs and utility data were estimated from the literature. The discount rate (3%) utilized for costs and benefits. Sensitivity analyses were used to explore the impact of uncertainty on the results.ResultsIn LAM-resistant HBeAg-positive and HBeAg-negative CHB cohorts, TDF monotherapy and combination therapy were on the efficiency frontier for both positive and negative populations. Compared with no treatment, the use of combination therapy cost an additional $6,531.7 to gain 1 additional quality-adjusted life year (QALY) for HBeAg-positive patients and $4,571.7 to gain 1 additional QALY for HBeAg-negative patients. TDF monotherapy for HBeAg-positive patients, shows greater increase in QALYs but higher incremental cost-effectiveness ratio (ICER) in comparison with combination therapy. In probabilistic sensitivity analyses, combination therapy was the preferred option for health care systems with limited health resources, such as Chinese health care system.ConclusionIn Chinese patients with LAM-resistant CHB, combination therapy is a more cost-effective option than the competing rescue therapies.

RtL180M mutation of hepatitis B virus is closely associated with frequent virological resistance to adefovir dipivoxil therapy

We intended to investigate the effects of pre-existing mutations at reverse transcriptase region of hepatitis B virus (HBV) on the occurrence of virological breakthrough (VB) to adefovir dipivoxil (ADV) in patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB). Ninety-seven patients with LAM-resistant CHB were treated with ADV at a dose of 10 mg daily, and were followed for a median period of 13 months. Just before the initiation of ADV therapy, the whole length of reverse transcriptase region of serum HBV-DNA was sequenced using direct sequencing. All patients had genotype C HBV and mutations in the YMDD motif, specifically, YIDD (65%), YVDD (28%), or both (7%). The rtL180M and rtL80V/I mutations were identified in 68% and 69%, respectively. The cumulative probability of VB was 19% and 27% at 1 and 2 years, respectively. There was no difference in the occurrence of VB with regard to types of YMDD mutation or rtL80V/I. However, interestingly, patients carrying rtL180M experienced VB during ADV monotherapy more frequently than those not carrying rtL180M (2-year cumulative probability of VB: 37% vs 3% at 2 years, P < 0.01). On multivariate Cox proportional hazards analysis, rtL180M (hazard ratio [HR]: 8.62, 95% confidence interval: 1.08-69.09, P = 0.042) and decrease in HBV-DNA for 1 year of treatment (HR: 0.69, 95% CI: 0.51-0.95, P = 0.024) are independently associated with VB. The rtL180M mutation of HBV, as well as a small decrease in HBV-DNA after 1 year of treatment might be closely associated with frequent occurrence of virological resistance to ADV in patients with LAM-resistant CHB.

The mutation patterns of HBV P gene and genotyping in patients with lanivudine-resistant chronic hepatitis B

To analyze the mutation patters of HBV P gene and genotyping of heptitis B virus in patients with chronic hepatitis B (CHB) after the emergence of drug-resistance during lamivudine (LAM) therapy. LAM-resistant mutations and genotype of HBV were dectected in patients with LAM-resistant CHB in our hospital from Sep. 2008 to June. 2010. 107 patients had 8 mutation patterns. YMDD mutations happened in 100%, only YMDD mutation were 43 patients, while others were YMDD combined with rtL180M mutations; the HBV genotype among 107chronic hepatitis was mainly B (25.2%) and C (73.8%) and only 1 patient was happend B and C mixed infection. Genetype C was mainly YMDD combined with rtL180M mutations pattern, the rate is 60.7% (48/79); while genetype B was mainly rtM204 mutation pattern, the rate is 66.7% (18/27); there were significant difference between the genetype B and C in mutation pattern (chi2 = 8.4, 7.2, respectively, P < 0. 01). YMDD mutation is the major mutation pattern of HBV P gene after emergence of LAM-resistance. Genotypes of hepatitis B virus can determine the related mulation patterns of HBV P gene.

Initial Virological Response and Viral Mutation with Adefovir Dipivoxil Added to Ongoing Lamivudine Therapy in Lamivudine-Resistant Chronic Hepatitis B

Although adefovir dipivoxil (ADV) has been used for antiviral treatment of lamivudine (LAM)-resistant chronic hepatitis B (CHB) patients, the long-term efficacy of this treatment is not well understood. Initial virological response (IVR) has been reported to be an important factor in relation to the development of ADV-resistance. We therefore examined the factors associated with IVR and ADV mutation in these patients. Forty-nine LAM-resistant CHB patients with ADV add-on LAM therapy, 47% of whom were hepatitis B e-antigen (HBeAg)-positive with median treatment duration of 23 months, were enrolled in this study. Patients were classified into IVR and non-IVR groups on the basis of viral suppression status. Mutational analysis of the HBV polymerase/reverse transcriptase (rt) domain was performed by PCR-direct sequencing. Serum HBV DNA was undetectable (<2.6 log10 copies/mL) in 67, 82, and 84% of patients at 24, 48, and 96 weeks, respectively, after ADV add-on LAM therapy. IVR was achieved in 82% of patients, and ALT normalized at week 24 in 90% of IVR and 78% of non-IVR patients. The lower pretreatment HBV DNA level and virus-containing mutations other than double mutation of rtL180M + rtM204V were significantly associated with IVR (P=0.002 and P=0.014, respectively). ADV-resistant mutations in the RT motif, reported previously, were not detected. IVR is useful for predicting the antiviral efficacy of ADV and LAM combination therapy in LAM-resistant CHB.

Rescue therapy for lamivudine‐resistant chronic hepatitis B: Comparison between entecavir 1.0 mg monotherapy, adefovir monotherapy and adefovir add‐on lamivudine combination therapy

There have been no reports comparing the therapeutic results of adefovir (ADV) and entecavir (ETV) rescue therapy for patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB). We aimed to compare the cumulative efficacy and resistance of ETV 1.0 mg monotherapy, ADV monotherapy and ADV add-on LAM combination therapy in LAM-refractory patients. One hundred and four patients were included in the following three treatment groups; group 1 (n = 24), LAM was switched to ETV (1.0 mg once a day); group 2 (n = 44), LAM was switched to ADV (10 mg once a day); and group 3 (n = 36), ADV was added to LAM (10 mg once a day). After 6 months of rescue treatment, alanine aminotransferase normalization was observed in 75.0%, 65.9% and 74.3% of patients receiving ETV monotherapy, ADV monotherapy and ADV add-on therapy, respectively. A significantly higher log(10)HBV-DNA drop at 6 months occurred in the ADV add-on group compared with the ETV group. The rate of HBV-DNA polymerase chain reaction undetectability (<300 copies/mL) 6 months after initiation of ETV monotherapy, ADV monotherapy and ADV add-on therapy was 33.3%, 27.3% and 68.6%, respectively (P = 0.003). The cumulative HBeAg seroconversion rate was significantly higher in ADV add-on/ADV monotherapy groups compared with the ETV monotherapy group (P = 0.022). Viral breakthrough and genotypic resistance were detected in six (25.0%) and six (13.6%) patients in the ETV and ADV monotherapy groups, whereas no cases of genotypic resistance were detected in ADV add-on group 24 months after initiation of antiviral treatment (P < 0.01). Adefovir add-on treatment in patients with LAM-resistant CHB suppresses HBV replication more effectively than ETV or ADV monotherapy. Additionally, no genotypic resistance was detected in the ADV add-on group.

Overlap/Switch to Adefovir Monotherapy for Lamivudine-resistant Patients Who Responded to Combination Therapy: A Pilot Controlled Study

The aim of this study was to investigate the outcome of overlap/switch to adefovir dipivoxil (ADV) monotherapy for chronic hepatitis B (CHB) patients with lamivudine (LAM)-resistant HBV, who responded to LAM plus ADV combination therapy. In 29 of 35 LAM-resistant CHB patients, serum HBV-DNA levels decreased to <3.7 log genome equivalent (LGE)/mL at 12 months after LAM plus ADV combination therapy, defined as complete virological response (CVR). The 29 CVR patients were randomly allocated to continuation of combination therapy or switch to ADV monotherapy within 12 months. The cumulative rates of sustained CVR were compared between the two groups. The follow-up duration after randomization was 19.3-36.7 months (median, 28.2 months) for the combination group and 21.0-36.4 months (29.0 months) for the overlap/switch group. The cumulative rate of sustained CVR during the follow-up period was 100% in all patients of both groups. The total medical expenses during follow-up after randomization were median US$20,949 for the combination group and US$16,107 for the overlap/switch group (p=0.012). Overlap/switch to ADV monotherapy sufficiently repressed the replication of LAM-resistant mutants without the development of ADV-resistant mutants. The rate of sustained CVR was not influenced by treatment regimen (continuation of combination therapy or switching to ADV monotherapy), the duration of the overlap period, or patient and virological characteristics. In LAM-resistant CHB patients who achieved CVR to LAM plus ADV combination therapy, CVR was maintained after overlap/switch to ADV monotherapy, suggesting that it could be a useful regimen for such patients.

Meta-analysis: Adefovir dipivoxil in combination with lamivudine in patients with lamivudine-resistant hepatitis B virus

BackgroundCurrently, there are no conclusive results on the efficacy of adefovir dipivoxil (ADV) plus lamivudine (LAM) in LAM-resistant patients with chronic hepatitis B (CHB). The aim of study was to evaluate the efficacy of rescue therapy with ADV plus LAM compared to ADV monotherapy in LAM-resistant CHB patients.ResultsWe searched PUBMED, EMBASE, Web of Science, CNKI (National Knowledge Infrastructure), VIP database, the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews. Six eligible trials (442 patients in total) were included and evaluated for methodologic quality and heterogeneity. Greater virological response and lower emergence rate of ADV-associated mutants was observed in ADV plus LAM compared to ADV monotherapy (both P < 0.05). On the contrary, the rate of ALT normalization, HBeAg clearance and seroconversion were all similar between ADV plus LAM and ADV (all P > 0.05). Additionally, adding-on or switch-to ADV was both well tolerated.ConclusionThe combination of ADV with LAM was superior in inhibiting HBV replication and preventing drug resistance as compared to ADV alone for LAM-resistant CHB patients.

Factors contributing to antiviral effect of adefovir dipivoxil therapy added to ongoing lamivudine treatment in patients with lamivudine-resistant chronic hepatitis B

The antiviral effect of adefovir dipivoxil (ADV) added to ongoing lamivudine (LAM) treatment for LAM-resistant chronic hepatitis B (CHB) differs among patients. We investigated clinical factors affecting the response to ADV therapy in LAM-resistant CHB. The subjects were 75 LAM-resistant CHB patients treated with ADV in addition to LAM. Virological response (VR) was defined as HBV DNA clearance (<2.6 logcopies/ml) at 12 months after the start of ADV therapy. Clinical factors contributing to VR were examined by univariate and multivariate analyses. Lower HBV DNA at baseline and negative hepatitis B e antigen (HBeAg) were significant factors affecting VR in univariate analysis. In multivariate analysis, lower HBV DNA at baseline (P = 0.005), negative HBeAg (P = 0.009), and higher ALT (P = 0.036) were significant independent factors contributing to VR. In HBeAg-positive patients, HBV DNA clearance was more frequently observed during ADV therapy in patients with baseline HBV DNA < or = 7.0 logcopies/ml than in those with baseline HBV DNA >7.0 logcopies/ml. By contrast, the link of lower HBV DNA at baseline to better therapeutic response was not evident in HBeAg-negative patients. In ADV therapy added to ongoing LAM treatment for LAM-resistant CHB, lower baseline HBV DNA and negative HBeAg contributed to a better antiviral effect. Addition of ADV should be done promptly before marked increase in HBV DNA, especially in CHB patients showing LAM resistance positive for HBeAg.

Viral genotype and baseline load predict the response to adefovir treatment in lamivudine-resistant chronic hepatitis B patients

To determine the factors associated with virological response (VR), HBeAg loss or the emergence of adefovir (ADV)-related mutations in ADV-treated chronic hepatitis B (CHB) patients with lamivudine (LAM) resistance. Fifty-four LAM-resistant CHB patients (46% HBeAg-positive) were treated with ADV monotherapy (n=28) or ADV plus LAM (n=26) for a mean of 30.4 months. Thirty-eight patients (70.4%) achieved VR defined as HBV-DNA levels <10(4)copies/ml within the first 12 months of treatment. Six (24%) of 25 HBeAg-positive patients exhibited HBeAg loss and 20% seroconverted to anti-HBe. Eight patients (14.8%) developed ADV-related mutations. In the multivariate analysis, female gender (HR=0.20, 95% CI: 0.05-0.76, p=0.018), HBeAg-negative (HR=0.37, 95% CI: 0.14-0.96, p=0.040) and low baseline HBV-DNA levels (HR=0.65, 95% CI: 0.45-0.95, p=0.027) were independent predictors of VR, whereas low HBV-DNA levels (HR=0.36, 95% CI: 0.11-1.20, p=0.095) and HBV-genotype D (HR=0.06, 95% CI: 0.004-0.84, p=0.037) independently predicted HBeAg loss. ADV therapy suppresses viral replication in more than 70% of LAM-R patients. Factors associated with virologic response are female gender, HBeAg-negative status and low baseline serum HBV-DNA levels. Genotype D HBV infection and low baseline HBV-DNA levels independently predict HBeAg loss.