Combination of Lamivudine and adefovir therapy in HBeAg-positive chronic hepatitis B patients with poor response to adefovir monotherapy

When can we stop nucleoside analogues in patients with chronic hepatitis B?

Treatment with nucleoside analogue (NAs) is now the most common treatment for chronic hepatitis B (CHB) and is recommended by all guidelines. Stopping NAs is a controversial issue in these patients, unless the clinical endpoints of HBeAg seroconversion or HBsAg seroclearance are achieved. While HBeAg seroconversion can occur in a significant number of patients, HBsAg seroclearance rates are low. HBsAg seroclearance is increasingly accepted as the ideal end of treatment, representing a functional cure. Treatment withdrawal leads to relapse in 50% of patients who achieve HBeAg seroconversion and complete at least 12 months of consolidation therapy. In HBeAg negative CHB, the Asian Pacific Association for the Study of the Liver (APASL) stopping rules show that although clinical relapse occurs in approximately 43% and virological relapse occurs in 70%, very few patients experience flare or decompensation. NAs treatment for >2 years was associated with a lower rate of relapse. Recently, stopping NA therapy was shown to be associated with HBsAg in 20%-39% of HBeAg negative patients and more frequently in those with low quantitative HBsAg (qHBsAg). However, the most optimal level is unclear. Quantitative HBsAg is becoming a useful tool to predict a sustained response or relapse before stopping therapy. In conclusion, stopping NA therapy is generally safe and can be an option in specific situations such as HBeAg seroconversion. However, it is associated with disease relapse. Thus, patient selection based on qHBsAg may help identify patients who are more likely to achieve HBsAg seroclearance or a sustained response.

The efficacy of zinc finger antiviral protein against hepatitis B virus transcription and replication in tansgenic mouse model

Aim

The zinc finger antiviral protein (ZAP) is a mammalian host restriction factor, and it could inhibit HBV RNA synthesis in vitro experiments. However, the role of ZAP against HBV in vivo environment is unclear. This study aimed to investigate whether ZAP could act against HBV transcription and replication in ZAP tansgenic mouse model.

Methods

HBV-replication-competent plasmid pHBV4.1 was transferred to ZAP transgenic ICR mouse via the tail vein using a hydrodynamic in vivo transfection procedure, and ICR mouse were used as controls. HBV RNA and HBV DNA replication intermediates in the liver were respectively analyzed by Northern blotting and Southern blotting. The expression of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in the liver tissue was detected by immunohistochemical staining.

Results

As compared to ICR control mouse, the levels of 3.5 kb mRNA in ZAP transgenic mouse were decreased by 8.4%; while the level of HBV DNA replication intermediates was decreased by 82%. In addition, the expression of HBsAg and HBcAg in ZAP transgenic mouse liver were both significantly less than that of ICR control mouse.

Conclusions

Our findings suggest that ZAP could inhibit HBV replication in vivo in mice, which offers a new target for anti-HBV drug development.

Management of chronic hepatitis B infection: current treatment guidelines, challenges, and new developments

Chronic hepatitis B (CHB) virus infection is a global public health problem, affecting more than 400 million people worldwide. The clinical spectrum is wide, ranging from a subclinical inactive carrier state, to progressive chronic hepatitis, cirrhosis, decompensation, and hepatocellular carcinoma. However, complications of hepatitis B virus (HBV)-related chronic liver disease may be reduced by viral suppression. Current international guidelines recommend first-line treatment of CHB infection with pegylated interferon, entecavir, or tenofovir, but the optimal treatment for an individual patient is controversial. The indications for treatment are contentious, and increasing evidence suggests that HBV genotyping, as well as serial on-treatment measurements of hepatitis B surface antigen and HBV DNA kinetics should be used to predict antiviral treatment response. The likelihood of achieving a sustained virological response is also increased by extending treatment duration, and using combination therapy. Hence the paradigm for treatment of CHB is constantly evolving. This article summarizes the different indications for treatment, and systematically reviews the evidence for the efficacy of various antiviral agents. It further discusses the shortcomings of current guidelines, use of rescue therapy in drug-resistant strains of HBV, and highlights the promising clinical trials for emerging therapies in the pipeline. This concise overview presents an updated practical approach to guide the clinical management of CHB.

Optimization therapy for the treatment of chronic hepatitis B

Chronic hepatitis B (CHB) is currently medically managed with either interferon-alpha or one of the five nucleos(t)ide analogs. However, there are still a large number of CHB patients whose response to the above therapies remains less than satisfactory, and their incomplete or non-response to antiviral therapies has plagued clinicians worldwide. In recent years, a newly proposed optimization therapy has provided us with a new approach to solve this problem. The key points in this optimization therapy are to initiate antiviral therapy with an appropriate agent at the correct time point, and to adjust treatments in patients with poor early responses by adding a second agent or switching to another more potent agent. In this review, we summarize recent developments in optimization therapy for the treatment of CHB, and provide an outlook for future research in this field.

Prolonged Combination Therapy is More Effective than Monotherapy in Management of Chronic Hepatitis B Patients With Sustained Virological Response: An Experience From a 'Real-World' Clinical Setting

BACKGROUND

Little is known about the duration of combination therapy for patients with chronic hepatitis B (CHB) and suboptimal response to nucleos(t)ide analogues(NAs) monotherapy.

OBJECTIVES

This study aimed to assess whether monotherapy could be used for treatment of CHB patients, who poorly responded to Adefovir Dipivoxil (ADV) but obtained good responses after at least 12-month lamivudine (LAM) or telbivudine (LdT) add-on therapy.

PATIENTS AND METHODS

Forty-five patients were enrolled, and the baseline time-point was determined according to enrollment data. Twenty-six patients chose to continue combination therapy (LAM+ADV or LdT+ADV, Group A) and 19 patients switched to single-drug maintenance therapy (LAM or LdT or ADV, Group B).

RESULTS

There were no significant differences between two groups in baseline characteristics (P > 0.05). At 12th month, sustained virological response rate was greater in group A compared to group B (96.2% vs. 47.4%, P < 0.001), and the rates of NAs-associated resistance were 0% in group A and 15.8% in group B. Alanine aminotransferase normalization rate was also significantly higher in group A compared with group B (92.3% vs. 36.8%, P < 0.001). Among hepatitis positive patients with Be antigen (HBeAg)-, 40% (4/10) in group A and 9.1% (1/11) in group B achieved HBeAg seroconversion at the 12th month. Of patients in group B with positive-HBeAg before the previous combination therapy and detectable HBV DNA at 6 months of previous combination therapy were associated with high risks of viral relapse after switching to single-drug maintenance therapy.

CONCLUSIONS

Prematurely switching to single-drug maintenance therapy would be resulted in viral relapse, and prolonged combination therapy was effective to maintain sustained responses for patients with initial suboptimal response to ADV.

Efficacy of switching to telbivudine plus adefovir in suboptimal responders to lamivudine plus adefovir

AIM: To examine the efficacy of telbivudine (LdT) + adefovir (ADV) vs continuation of lamivudine (LAM) + ADV in patients with LAM-resistant chronic hepatitis B (CHB) who show a suboptimal response to LAM + ADV.

METHODS: This was a randomized, active-control, open-label, single-center, parallel trial. All eligible patients were enrolled in this study in Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea, between March 2010 and March 2011. Hepatitis Be antigen (HBeAg)-positive CHB patients whose serum hepatitis B virus (HBV) DNA remained detectable despite at least 6 mo of LAM + ADV therapy were included. Enrolled patients were randomized to either switching to LdT (600 mg/d orally) plus ADV (10 mg/d orally) (LdT + ADV group) or to continuation with LAM (100 mg/d orally) plus ADV (10 mg/d orally) (LAM + ADV group), and were followed for 48 wk. One hundred and six patients completed the 48-wk treatment period. Serum HBV DNA, HBeAg status, liver biochemistry and safety were monitored at baseline and week 12, 24, 36 and 48.

RESULTS: The duration of prior LAM + ADV treatment was 18.3 (LdT + ADV) and 14.9 mo (LAM + ADV), respectively (P = 0.131). No difference was seen in baseline serum HBV DNA between the two groups [3.66 (LdT + ADV) vs 3.76 (LAM + ADV) log₁₀ IU/mL, P = 0.729]. At week 48, although there was no significant difference in the mean reduction of serum HBV DNA from baseline between LdT + ADV group and LAM + ADV group (-0.81 vs -0.47 log₁₀ IU/mL, P = 0.167), more patients in the LdT + ADV group had undetectable HBV DNA levels compared to those in the LAM + ADV group (30.2% vs 11.5%, P = 0.019). Three patients with LdT + ADV treatment and 2 patients with LAM + ADV treatment achieved HBeAg loss. The patients in both groups tolerated the treatment well without serious adverse events. The proportion of patients with estimated glomerular filtration rate ≥ 90 mL/min per 1.73 m² in the LdT + ADV group increased from 49.1% (26/53) at baseline to 58.5% (31/53) at week 48, while that in the LAM + ADV group decreased from 37.7% (20/53) at baseline to 30.2% (16/53) at week 48.

CONCLUSION: The switch to LdT + ADV in suboptimal responders to LAM + ADV showed a significantly higher rate of virologic response at week 48. These results suggest that LdT + ADV could be a therapeutic option for patients who are unable to use enofovir disoproxil fumarate for any reason.

Efficacy of telbivudine treatment for hepatitis B e antigen-positive chronic hepatitis B patients with poor response to adefovir dipivoxil

Telbivudine (LdT) has demonstrated potent antiviral activity in nucleos(t)ide analogue (NA)-naïve chronic hepatitis B patients (CHB), but data on its efficacy in NA-experienced patients are limited. The aim of this study was to investigate the effect of LdT in hepatitis B e antigen-positive CHB patients with poor response to initial adefovir dipivoxil (ADV). Forty-two CHB patients with HBV DNA > 4 log10  copies/mL after 12 months of ADV monotherapy were enroled in the study and thereafter treated with LdT 600 mg daily for 18 months. Telbivudine led to a rapid decrease in viral load, and viral replication was persistently suppressed with a reduction of 2.26 log10  copies/mL 18 months after LdT treatment. The rates corresponding to virological and biochemical response at the end of observation were 97.6% (41/42) and 65.8% (25/38), respectively. HBeAg loss was found in 30.8% (12/39) of patients, while HBeAg/anti-HBe seroconversion was found in 17.9% (7/39). Only one patient was detected to have LdT-associated mutation, and no severe adverse events were reported. Optimization therapy with LdT monotherapy may be a good choice for CHB patients with poor response to ADV, and switching to LdT may be the most cost-effective rescue therapeutic strategy for patients with poor response to initial ADV monotherapy.

Resolution of adefovir-related nephrotoxicity by adefovir dose-reduction in patients with chronic hepatitis B

BACKGROUND

Chronic hepatitis B patients (CHB) treated with adefovir were followed up to evaluate nephrotoxicity and its outcome.

AIM

To assess the incidence of renal dysfunction during adefovir therapy in Asian patients and factors associated with it, and evaluate strategies to improve adefovir-related renal dysfunction and their impact on viral suppression.

METHODS

Chronic hepatitis B clinic patients from a tertiary hospital on adefovir treatment, with their clinical and laboratory parameters were extracted from the hospital electronic clinical database in an observational study design. Patients were excluded if they had liver/renal transplant, baseline renal impairment or were on dialysis. Adefovir-related renal dysfunction was defined as adefovir-related abnormal serum creatinine (ARASC) > 125 μmol/L (males), >90 μmol/L (females); adefovir-related abnormal GFR <60 mL/min; and adefovir-related increased serum creatinine >0.5 mg/dL, without other known causes of nephrotoxicity.

RESULTS

A total of 271/383 adefovir-treated patients were suitable for analysis and 33(12%) patients developed abnormal serum creatinine. Cumulative increase in proportion of patients with ARASC was 33.8% and GFR ≤60 mL/min was 38.3% by 6 years, while serum creatinine increase ≥0.5 mg/dL was 21.48% by 5 years. Using multivariate analysis, the only independent baseline predictor of ARASC was GFR ≤76.1 mL/min. Patients who had ARASC had similar levels of viral suppression to those who did not have ARASC. Those who had ARASC either continued adefovir (24%), switched therapy (24%) or had adefovir dose reduction (52%). ARASC resolved and GFR normalised in almost all patients after either switching therapy or reducing adefovir dose, with no difference between the two strategies (P = 0.737). Those with adefovir dose reduction had no significant increase in HBV DNA (P = 0.170).

CONCLUSIONS

Adefovir-related renal dysfunction occurred in a significant number of adefovir-treated patients, but reduction of the dose led to renal improvement without compromising treatment efficacy.

Lamivudine plus adefovir or telbivudine plus adefovir for chronic hepatitis B patients with suboptimal response to adefovir

BACKGROUND

There is no standard management of chronic hepatitis B (CHB) patients with suboptimal response to nucleoside/nucleotide analogues (NAs). This study aimed to evaluate two different NA combination therapies in patients with suboptimal response to adefovir (ADV).

METHODS

In this study, 72 CHB patients with suboptimal response to ADV were assessed, with 37 patients receiving lamivudine plus ADV (group A) and 35 patients receiving telbivudine plus ADV (group B).

RESULTS

Baseline characteristics between two groups were similar. At month 12, rates of biochemical response (BR) and virological response (VR) were similar between groups A and B (17/19 versus 18/20 for BR, [P=0.269] and 30/37 versus 31/35 for VR [P=0.377]), and cumulative rates of serological response were greater in group B than in group A (10/26 versus 2/28 in hepatitis B e antigen [HBeAg] loss [P=0.006] and 7/26 versus 1/28 in HBeAg/hepatitis B e antibody seroconversion [P=0.022]). After 12-month treatment, 8.1% (3/37) of patients in group A and 5.7% (2/35) of patients in group B had VR; among patients in group A, two had rtM204V/I and rtL180M and one had rtN236T, whereas the two patients in group B had rtM204I+rtL180M.

CONCLUSIONS

Both combination therapies led to a significant decrease in HBV DNA. HBeAg serological outcomes were higher with telbivudine plus ADV combination therapy.

Factors predicting the efficacy of adefovir dipivoxil on treatment-naïve chronic hepatitis B patients at 48 weeks

Background/Aims

To reveal possible factors predicting the effect of adefovir dipivoxil (ADV) treatment on chronic hepatitis B (CHB) and optimize the utilization of ADV.

Methods

In total, 168 treatment-naïve CHB patients were enrolled, including 117 hepatitis B e antigen (HBeAg)-positive patients and 51 HBeAg-negative patients who met the inclusion criteria. All patients were treated with ADV 10 mg per day for 48 weeks. Multiple logistic regression analyses were used to investigate baseline factors, and responses at weeks 12 and 24 were analyzed as predictive values.

Results

Multiple regression analyses showed that baseline HBeAg status and HBV DNA levels significantly affected the virological response (VR) (p<0.05), baseline ALT levels were an independent predictor of serological response (SR) (p<0.05) and the body mass index (BMI) may affect the biochemical response (BR) (p<0.05). There was a statistically significant difference in the VR and SR between patients with a primary nonresponse (PNR) at week 12 and those with a VR at week 12 (p<0.01). Additionally, the VR was significantly different between patients with HBV DNA lower than 10³ copies/mL at week 24 and those with greater than 10³ copies/mL (p<0.01).

Conclusions

Patients with negative HBeAg, lower HBV DNA levels and higher ALT values at baseline are more suitable for ADV treatment, whereas patients with lower BMIs may be more amenable to ALT normalization. Adjustments for treatment strategy should be considered if PNR at week 12 or HBV DNA ≥10³ copies/mL at week 24 is observed.