Clinical trial: effects of adefovir dipivoxil therapy in Asian and Caucasian patients with chronic hepatitis B

CHB patients with rtA181T-mutated HBV infection are associated with higher risk hepatocellular carcinoma due to increases in mutation rates of tumour suppressor genes

The HBV rtA181T mutation is associated with an increased risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). This study aimed to evaluate the mechanism by which rtA181T mutation increases the risk of HCC. We enrolled 470 CHB patients with rtA181T and rtA181V mutation in this study; 68 (22.15%) of the 307 patients with rtA181T mutation and 22 (13.5%) of the 163 patients with rtA181V mutation developed HCC (p < .05). The median follow-up periods were 8.148 and 8.055 years (p > .05). Serum HBV DNA and HBsAg levels in rtA181T-positive patients were similar to that in rtA181V-positive patients. However, the serum HBeAg levels in the rtA181T-positive patients were significantly higher than that in rtA181V-positive patients. In situ hybridization experiments showed that the HBV cccDNA and HBV RNA levels were significantly higher in the liver cancer tissues of patients with the rtA181T mutation compared to that in the tissues of patients with the rtA181V mutation. The percentage of anti-tumour hot-gene site mutations was significantly higher in the rtA181T-positive HCC liver tissue compared to that in the rtA181T-negative HCC liver tissue (7.65% and 4.3%, p < .05). This is the first study to use a large cohort and a follow-up of more than 5 years (average 8 years) to confirm that the rtA181T mutation increased the risk of HCC, and that it could be related to the increase in the mutation rate of hotspots of tumour suppressor genes (CTNNB1, TP53, NRAS and PIK3CA).

Factors affecting HBV DNA suppression in chronic hepatitis B patients treated with tenofovir disoproxil fumarate

Background: This study aims to determine the factors affecting HBV DNA suppression in chronic hepatitis B patients with tenofovir disoproxil fumarate (TDF). Methods: A case-control was carried out from October 2021 to August 2022 on 182 chronic hepatitis B patients who had TDF therapy regularly for 24 weeks at H. Adam Malik and USU Hospitals in Medan, Indonesia. The history of the samples was obtained, followed by physical examination, and blood collection. CTLA-4 polymorphism examination was carried out using real-time PCR, while the serum CTLA-4 levels were assessed with ELISA. Results: The CTLA-4 -1661G>A polymorphism, genotype GG+AG, increased 1.52 times risk of not achieving HBV DNA suppression to TDF compared to genotype AA (p=0.041). High CTLA-4 levels increased 2.28 times risk, high HBV DNA levels increased 2.09 times risk, low ALT levels increased 1.95 times risk of not achieving HBV DNA suppression (p= 0.009, 0.026, 0.036, respectively). There was no relationship between gender, age, ethnicity, obesity, baseline AST, HBeAg, genotype, liver fibrosis and HBV DNA suppression after 24 weeks of treatment (p>0.05). Conclusions: The levels of CTLA-4, HBV DNA, ALT, and CTLA-4 -1661G>A polymorphism have a potential relationship with the suppression of HBV DNA in chronic hepatitis B patients with TDF.

Efficacy and safety of Fuzheng Huayu tablet on persistent advanced liver fibrosis following 2 years entecavir treatment: A single arm clinical objective performance criteria trial

ETHNOPHARMACOLOGICAL RELEVANCE

Antiviral therapy can alleviate liver fibrosis in chronic hepatitis B, but it has a limited effect on advanced liver fibrosis/cirrhosis. Traditional Chinese medicine (TCM), particularly FuZheng HuaYu (FZHY) tablet, appears to have an antifibrotic effect, but its improving resolution of hepatitis b virus (HBV) -associated advanced fibrosis and experienced anti-viral treatment has not been investigated.

AIM OF THE STUDY

To observe the safety and efficacy of adjunctive FZHY on the HBV-associated cirrhosis patients who received 2 years of entecavir but still with advanced fibrosis.

METHODS

An open-label, multicentre, single arm trial. 251 patients were included and treated with TCM consisted of FZHY tablets 1.6 g and granules, three times a day in addition to entecavir 0.5 mg daily for an additional 48 weeks. Primary outcome was regression of fibrosis (the proportion of patients with a 1-point decrease in the Ishak liver fibrosis score from baseline to week 48).

RESULTS

Fibrosis regression occurred in 94 of 184 patients with paired liver biopsy (51.09%, 95% CI: 43.9～58.0). In 132 compensated cirrhosis patients (Ishak score ≥5), 56.06% (74/132, 95% CI: 47.5～64.2) showed fibrosis regression and reached the goal of 54% (15% more than entecavir mono-therapy). 10 patients occurred adverse reaction, most of them were mild, and all recovered or achieved remission.

CONCLUSIONS

The combination therapy of FZHY, TCM granules and ETV could regress the liver fibrosis in the patients with HBV cirrhosis, who experienced 2 years of ETV treatment, and it is safe and well tolerated.

Fanconi syndrome induced by adefovir dipivoxil: a case report and clinical review

More than 150 cases of Fanconi syndrome (FS) or hypophosphatemia osteomalacia induced by low-dose adefovir dipivoxil (ADV) have been reported since 2002, when ADV was introduced for the long-term treatment of hepatitis B virus (HBV) infection. Because the life expectancy of HBV-infected individuals has increased, the adverse effects of long-term treatment with antiviral therapies are increasingly observed, and nephrotoxicity is one of the most severe adverse effects of ADV. Therefore, the number of cases may be far higher than reported. Moreover, ADV-induced FS is often misdiagnosed or diagnosed long after it first develops. ADV-induced FS may seriously decrease patient quality of life and lead to bone fractures and even disability. Although progress has been made in the identification of biomarkers and treatments, few systematic clinical guidelines or clinical reviews for FS induced by ADV have been reported. In this study, we highlighted the recent progress toward understanding of FS induced by ADV, described a clinical case, and summarized the primary characteristics and laboratory findings of this disease.

Safety and therapeutic effects of anti-fibrotic Traditional Chinese Medicine Fuzheng Huayu on persistent advanced stage fibrosis following 2 years entecavir treatment: Study protocol for a single arm clinical objective performance criteria trial

BACKGROUND

Hepatitis B virus (HBV) infection is an important etiology for chronic hepatitis globally, and especially so in China. HBV infection can lead to the development of cirrhosis through the pathological process of liver fibrosis. The effective suppression of HBV replication with NAs or interferon-alpha can histologically regress the fibrotic pathological process, but there remain patients who have achieved anti-viral responses and normalization of serum liver tests, but not liver fibrosis regression. This subset of patients typically presents with advanced liver fibrosis at baseline. Therefore, it is reasonable to administer the anti-fibrotic agents, coupled with antivirals for patients with advanced liver fibrosis due to HBV, in order to improve the fibrotic regression of the patients. Fuzheng Huayu (FZHY) tablet is a botanical product with evidence demonstrating its efficacy against mild to moderate liver fibrosis. The current clinical trial evaluates the efficacy and safety of the combination therapy of traditional Chinese medicine (TCM) (FZHY and herbal granule) and entecavir for HBV compensated cirrhosis. We will enroll HBV patients who presented with a good viral response after 2 years of entecavir treatment but had advanced liver fibrosis (≥Ishak F5).

METHODS

This is a single-arm clinical trial, conducted in 20 centers in mainland China over a period of 60 weeks, including 48 weeks of treatment observation and 12 weeks of follow-up. The main inclusion criteria include HBsAg positive more than 6 months, 2 years administration of entecavir, HBV DNA less than 20 IU/ml, liver fibrotic stage ≥ F5, and Child-Pugh scoring <7 (Stage A). The sample size is estimated to be about 190, considering a 20% drop-out and 60% of patient's compliance for the second liver biopsy so a total of 350 participants will be enrolled. All eligible participants are divided into 3 subgroups according to the TCM clinic pattern. And all patients will take 1 Entecavir tablet (0.5 mg) per day, 4 FZHY tablets (1.6 g) three times a day, and specific TCM granule three times a day, which is decided by TCM clinical patterns (CPs) differentiation. The patients were treated for 48 weeks, and follow-up visits at 12, 24, 36, 48 weeks and 60 weeks. The patients will receive the second liver biopsy at the end of 48 weeks, with a 12 weeks follow-up after that.The primary endpoint is the proportion of subjects with a 1-point improvement of liver fibrosis stage using the Ishak score from baseline to week 48 in the study, according to consensus readings evaluated by a panel of hepato-pathologists. The secondary endpoints are the brightness-mode ultrasonic, fibrotic biomarkers. The adverse events (AEs) will be recorded for 60 weeks, and the safety of the combination therapy will be evaluated. Meanwhile, the efficacy in the 3 sub-groups will be stratified and analyzed.

DISCUSSION

The study has been designed to test the therapeutic effects and safety of the combination therapy of FZHY and herbal granule with entecavir on persistent advanced stage fibrosis/cirrhosis following 2 years entecavir treatment, and to explore an effective integrative therapy on HBV cirrhosis.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT02241616. Registered on September 16, 2014.

Bayesian Network Meta-Analysis for Assessing Adverse Effects of Anti-hepatitis B Drugs

BACKGROUND AND OBJECTIVE

Oral nucleoside/nucleotide analogues (NAs) have been advocated for chronic hepatitis B (CHB) treatment with good efficacy. However, less attention has been put on their adverse events. Therefore, a Bayesian network meta-analysis (NMA) was performed to evaluate the relative safety of five NAs (lamivudine, adefovir dipivoxil, entecavir, telbivudine, and tenofovir disoproxil fumarate) in CHB treatment among adults.

METHODS

Eligible randomized clinical trials (RCTs) and prospective cohort studies were systematically and thoroughly searched until May 1, 2019. Poisson-prior-based Bayesian NMA was performed to synthesize both direct and indirect evidence with reporting hazard ratios (HRs) and 95% credible intervals (CrIs) for serious adverse events (SAEs) and hepatic/renal impairments.

RESULTS

Thirty-three RCTs and 11 prospective cohort studies were identified. As to SAEs, no statistically significant difference was found of any comparison among five NAs. In terms of hepatotoxicity, lamivudine was safer than telbivudine (HR 0.45; 95% CrI 0.21, 0.85), and entecavir increased the risk by 102% (entecavir vs lamivudine: HR 2.02; 95% CrI 1.19, 3.27).

CONCLUSIONS

The findings from this large NMA could influence clinical practice, and the methodological framework of this study could provide evidence-based support to analyze sparse safety data in the field.

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Adefovir dipivoxil induced hypophosphatemic osteomalacia in chronic hepatitis B: a comparative study of Chinese and foreign case series

BACKGROUND

Adefovir dipivoxil (ADV)-induced renal tubular dysfunction and hypophosphatemic osteomalacia (HO) have been given great consideration in the past few years. However, no standard guidance is available due to a lack of powerful evidence from appropriate long-term prospective case-control studies and variations in the definition of renal adverse events. The aim of this study is to clarify clinical features of ADV-related HO in Chinese chronic hepatitis B patients with long-term ADV treatment in Chinese and non-Chinese comparative case series.

METHODS

Retrieval of case reports was based on Pubmed, CNKI, Wan Fang and VIP databases using the key words adefovir dipivoxil, hypophosphatemia, osteomalacia and Fanconi syndrome. We divided patients into Chinese (C group) and Foreign (F group) groups according to their nationality. Comparisons involving demographics, clinical manifestations, tests, treatment and prognosis were conducted between the two groups.

RESULTS

Of the patients screened, 120 Chinese patients were identified in the C group, and 32 non-Chinese patients were identified in the F group. The average age of the C group was younger than that of the F group (51.89 years ±10.96 years versus 56.47 years ±11.36 years, t = - 2.084, P = 0.039). No significant difference was found in gender (male to female, 3.29:1 versus 3:1, χ ²  = 0.039, P = 0.844). Although there was no significant difference in the duration of ADV therapy before ostalgia onset, the C group tended to develop adverse events earlier, by 2-3 years, while the F group developed adverse events at 4-5 years (Z = - 1.517, P = 0.129). Prognosis was good after adjustment of the ADV dose and supplemental administration of phosphate and calcitriol. Time to resolution of tubular dysfunction was commenced at the first month, and Chinese patients were more prone to recover in the first 3 months than non-Chinese patients (91.3% of patients in the C group versus 56.3% in the F group, Z = - 3.013, P = 0.003).

CONCLUSIONS

Sufficient attention is required for middle-aged males before and during exposure to long-term ADV therapy, regardless of nationality. The clinical picture, laboratory and radiograph alterations are important clues for those patients and are usually characterized by polyarthralgia, renal tubular dysfunction and mineralization defects. Implementation of an early renal tubular injury index is recommended for patients with higher risk, which would prevent further renal injury.

Prevalence of hepatitis B and clinical outcomes in inflammatory bowel disease patients in a viral-endemic region

Background

Little is known of the prevalence of hepatitis B virus (HBV) infection and its effect on choice of therapy and disease course in patients with inflammatory bowel disease (IBD). We assessed the prevalence of HBV in Hong Kong as well as determinants of altered transaminases, effects of HBV infection on therapeutic strategy and clinical course in IBD.

Methods

In this retrospective cohort, hepatitis B surface antigen (HBsAg), liver function tests, and IBD disease characteristics were recorded. Logistic regression was used to identify factors associated with altered transaminases.

Results

Four hundred six IBD patients were recruited. HBV infection was found in 5.7 % patients in Hong Kong. The use of steroids (OR, 2.52; p = 0.010) and a previous history of surgery (OR 2.33; p = 0.026) were associated with altered transaminases in IBD. There was no significant difference in disease control and use of IBD medication between HBsAg-positive and HBsAg-negative IBD patients.

Conclusion

The prevalence of HBV among patients with IBD in Hong Kong (5.7 %) is similar to that of general population (~7 %). There was no difference in disease control and use of IBD medication between subjects with or without HBV.

Intrahepatic IP-10 mRNA and plasma IP-10 levels as response marker for HBeAg-positive chronic hepatitis B patients treated with peginterferon and adefovir

INTRODUCTION

Interferon-y-inducible protein-10 (IP-10), also called CXCL10, is produced by different types of cells such as monocytes, neutrophils and hepatocytes. IP-10 functions as an inflammatory cytokine, which after binding to its receptor CXCR3, expressed on T-lymphocytes, leads to immune activation. We aimed to establish if IP-10 expression in liver tissue and in plasma of chronic hepatitis B (CHB) patients correlated with each other and further to investigate if IP-10 levels before and during therapy with peginterferon and adefovir could predict treatment outcome in CHB patients.

PATIENTS AND METHODS

A total of 86 CHB patients (41 HBeAg-positive and 45 HBeAg-negative) received combination therapy of peginterferon and adefovir for 48 weeks. Combined Response (CR) (HBeAg-negativity, HBV-DNA ≤ 2000 IU/mL, ALT normalization) and non-response (NR) were assessed at Week 72. Plasma IP-10 levels were measured at baseline and during treatment at Day 3 (D3) and Week 1 (W1). Pre-treatment liver biopsies from 40 of 86 patients were obtained and stored in liquid nitrogen for the analysis of intrahepatic IP-10 mRNA expression.

RESULTS

CR was achieved in 14/41 HBeAg-positive and 17/45 HBeAg-negative patients. Mean baseline plasma IP-10 levels were significantly higher in HBeAg-positive patients with CR than NR (3.20 vs 3.00 log pg/mL p = 0.03); but not in HBeAg-negative patients. Baseline IP-10 levels correlated with ALT-levels in HBeAg-positive and -negative patients (both p < 0.001), and with a decline of HBsAg-levels of ≥0.5 log IU/mL at Week 12 in HBeAg-positive patients (p = 0.001). Plasma IP-10 levels were associated with intrahepatic IP-10 mRNA expression, however, more strongly in HBeAg-positive (R = 0.79, p < 0.001) than in HBeAg-negative patients (R = 0.53, p = 0.011). IP-10 levels only correlated with HAI-scores in HBeAg-positive patients (R = 0.40 p = 0.025). Mean plasma IP-10 levels of both HBeAg-positive and -negative patients increased significantly at D3 compared to baseline (+0.30 log pg/mL p = 0.003), to then decline subsequently at W1 to a level still significantly higher than baseline (+0.14 log pg/mL p < 0.001). The increase of IP-10 was significantly higher in HBeAg-positive patients with NR than in those with CR (+0.35 versus +0.11 log pg/mL p = 0.003).

CONCLUSIONS

Baseline plasma IP-10 levels and IP-10 mRNA expression in the liver are correlated with each other, suggesting that plasma IP-10 reflects intrahepatic immune activation. Higher IP-10 levels at baseline seem to be associated with CR in HBeAg-positive patients treated with peginterferon and adefovir, but not in HBeAg-negative patients.

Nephrotoxicity caused by oral antiviral agents in patients with chronic hepatitis B treated in a hospital for tropical diseases in Thailand

BACKGROUND

There is increasing concern about the potential for nephrotoxicity in patients with chronic hepatitis B (CHB) treated long-term with nucleotide analogs.

METHODS

We examined renal dysfunction and its associated risk factors in patients with CHB treated with antiviral regimens containing either nucleosides or nucleotide analogs. We undertook a retrospective cohort study from 2006 to 2014 at the Hospital for Tropical Diseases, Bangkok, Thailand, and analyzed the data of 102 patients with a median follow-up time of 44.5 months (range 4-101 months).

RESULTS

Seventy-three patients were treated with an antiviral regime containing a nucleoside analog, and 29 with a regime containing a nucleotide analog. Abnormally elevated serum creatinine concentration was observed in 12 patients (11.8 %) after 8 years of treatment. Thirty one percent of patients treated with nucleotide analogs had elevated serum creatinine levels and three of these patients (10.3 %) developed nephrotoxicity. In contrast, serum creatinine concentrations were elevated in three of the 73 patients treated with a nucleoside analog (4.1 %), and none developed nephrotoxicity. The incidence of renal dysfunction by the nucleotide analog regimen was cumulative, with 11.1, 21.0, 26.5 and 47.6 % of patients affected after 2, 4, 6 and 8 years, respectively. Univariate and multivariate analysis indicated that a nucleotide analog-based regimen significantly predicted renal dysfunction (odds ratio 10.5, 95 % confidence intervals 2.6-42.4, P <0.001).

CONCLUSION

The long-term use of nucleotide analogs increased the risk of nephrotoxicity in patients with CHB. Thus, the regular assessment of renal function is recommended for all patients with CHB, particularly those treated with a nucleotide analog.

Predictors of kidney tubular dysfunction induced by adefovir treatment for chronic hepatitis B

AIM: To investigate the predictors of proximal kidney tubular dysfunction (PKTD) induced by adefovir dipivoxil (ADV) treatment for chronic hepatitis B.

METHODS: Seventy-nine patients (age at the evaluation of PKTD: 56.9 ± 10.7 years) with chronic hepatitis B undergoing long-term oral antiviral nucleos(t)ide analogue treatment were consecutively recruited. PKTD was defined by the presence of at least two of the following five abnormalities: phosphate diabetes, nondiabetic glucosuria, metabolic acidosis, β₂-microglobulinuria, or renal hypouricemia. The single-nucleotide polymorphisms (SNPs) in the SLC22A6 gene encoding human organic anion transporter 1 (hOAT1) and ABCC2 encoding multidrug resistance protein 2 (MRP2) were analyzed using the TaqMan Allelic Discrimination Demonstration Kit.

RESULTS: Nine (30.0%) of the 30 ADV-treated patients were diagnosed with PKTD, while no patients without ADV developed PKTD (P < 0.001). Three patients with ADV were diagnosed with symptomatic osteomalacia. Among the patients who took ADV, those with PKTD were of higher age at initiation, had significantly longer treatment duration, and had a significantly lower body mass index than those without PKTD. The incidence of PKTD dramatically increased after 96 mo from the start of ADV administration. In contrast, the SNPs were not correlated with PKTD. Logistic regression analysis extracted older age at initiation (OR = 5.0, 95%CI: 1.1-23.4; P = 0.040) and longer treatment duration (OR = 3.2, 95%CI: 1.2-8.6; P = 0.020) as significant factors associated with PKTD.

CONCLUSION: Our results suggest that the tubular function of the kidney of older patients undergoing long-term ADV treatment should be carefully evaluated.

Association between adefovir dipivoxil treatment and the risk of renal insufficiency in patients with chronic hepatitis B: A meta-analysis

Adefovir dipivoxil (ADV) is an effective antiviral drug against hepatitis B virus. The renal tolerance of ADV at the currently approved dose of 10 mg daily for the treatment of chronic hepatitis B (CHB) remains controversial. The present meta-analysis was therefore performed to evaluate the renal safety of ADV treatment in patients with CHB. Two independent investigators searched MEDLINE, Embase and China National Knowledge Infrastructure databases for eligible studies published in English or Chinese until June 1, 2014. The Peto odds ratios (Peto ORs) or the rates of each study were analyzed. Seven randomized controlled trials (RCTs), four cohort studies and six single-arm studies were identified. ADV treatment was not associated with a higher incidence of nephrotoxicity in RCTs [Peto OR, 1.781; 95% confidence interval (CI), 0.637-4.979; P=0.271] but appeared to increase nephrotoxicity significantly in cohort studies (Peto OR, 2.682; 95% CI, 1.470-4.894; P=0.001); the significant increase was further observed in CHB patients receiving long-term ADV treatment in cohort studies (Peto OR, 2.275; 95% CI, 1.127-4.593; P=0.022). The analysis based on single-arm studies showed that the rate of renal dysfunction in the ADV-treated patients was 10.6% (95% CI, 0.059-0.185); the subgroup analysis with the standard of createnine levels showed a lower rate (6.9%, 95% CI, 0.013-0.298) than those in the overall studies. In conclusion, although current evidence indicated a positive link between treatment with ADV in CHB patients and an increased risk of renal dysfunction, optimally designed studies are required for definitive conclusions.

Hepatitis B viral factors and treatment responses in chronic hepatitis B

Baseline and on-treatment hepatitis B viral factors are reported to affect treatment responses. A lower baseline hepatitis B virus (HBV) DNA level is a strong predictor of the response to antiviral therapy. HBV genotype A/B patients have better responses to interferon-based therapy than those with genotypes C/D. Regarding the association of HBV mutants with responses to antiviral therapy, current evidence is limited. On-treatment viral suppression is the most important predictor of response to nucleoside analogs. On-treatment hepatitis B surface antigen decline is significantly associated with response to pegylated interferon. In the future, individualized therapy should be based on treatment efficacy, adverse effects, baseline and on-treatment predictors of antiviral therapy.

Selection of chronic hepatitis B therapy with high barrier to resistance

Antiviral drug resistance is a crucial factor that frequently determines the success of long-term therapy for chronic hepatitis B. The development of resistance to nucleos(t)ide analogues has been associated with exacerbations in liver disease and increased risk of emergence of multidrug resistance. The selection of a potent nucleos(t)ide analogue with a high barrier to resistance as a first-line therapy, such as entecavir or tenofovir, provides the best chance of achieving long-term treatment goals and should be used wherever possible. The barrier to resistance of a given nucleos(t)ide analogue is influenced by genetic barrier, drug potency, patient adherence, pharmacological barrier, viral fitness, mechanism of action, and cross-resistance. In countries with limited health-care resources, the selection of a therapy with a high barrier to resistance is not always possible and alternative strategies for preventing resistance might be needed, although limited data are available to support these strategies.

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.

The management of chronic hepatitis B in Asian Americans

Hepatitis B virus (HBV) infection is common with major clinical consequences worldwide. In Asian Americans, the HBsAg carrier rate ranges from 7 to 16%; HBV is the most important cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). Patients are first diagnosed at different stages of clinical disease, which is categorized by biochemical and virologic tests. Patients at risk for liver complications should be identified and offered antiviral therapy. The two antiviral agents recommended for first-line treatment of chronic hepatitis B (CHB) are entecavir and tenofovir. The primary goal of therapy is sustained suppression of viral replication to achieve clinical remission, reverse fibrosis, and prevent and reduce progression to end-stage liver disease and HCC. Asian patients with chronic hepatitis, either HBeAg-positive or -negative, with HBV DNA levels >10(4) copies/mL (>2,000 IU/mL) and alanine aminotransferase (ALT) values above normal are candidates for antiviral therapy. HBeAg-negative patients with HBV DNA >10(4) copies/mL (>2,000 IU/mL) and normal ALT levels but who have either serum albumin ≤3.5 g/dL or platelet count ≤130,000 mm(3), basal core promoter mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive antiviral therapy. Considerations for treatment include pregnant women with high viremia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg-positive patients with risk factors, lifelong surveillance for HCC with alpha-fetoprotein testing and abdominal ultrasound examination at 6-month intervals is required. These recommendations are based on a review of relevant literature and the opinion of a panel of Asian American physicians with expertise in hepatitis B treatment.

Current Nucleos(t)ide Analogue Therapy for Chronic Hepatitis B

Although the prevalence of chronic hepatitis B has decreased considerably in recent years due to widespread use of the hepatitis B virus (HBV) vaccine, its prevalence still remains high in adults, and this can place a significant burden on health care in areas with endemic HBV. Since the introduction of nucleos(t)ide analogues (NUCs), there has been marked improvement in the care of patients with chronic hepatitis B, resulting in increased survival. However, the emergence of drug resistance in patients treated with NUCs is a major concern. The number of multi-drug resistant patients is increasing, and many patients may not respond to the currently available drugs. In this review, we describe the current status of NUC therapy for antiviral-naïve and -resistant patients.

Recent advances in the treatment of chronic hepatitis B

INTRODUCTION

At present, two strategies exist for the treatment of chronic hepatitis B (CHB): i) standard or pegylated interferon alpha (IFN) with mainly immune modulatory effects; and ii) nucleos(t)ide analogues (NA) with direct antiviral effects. The optimal treatment for an individual patient remains controversial.

AREAS COVERED

The treatment efficacy and prediction of response to antiviral agents for chronic hepatitis B are reviewed and discussed.

EXPERT OPINION

The rates of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) loss or seroconversion are continuously increasing in CHB patients after stopping a finite course of IFN, whereas long-term NA therapy is usually required to improve the adverse outcomes of CHB. Lower baseline HBV DNA level is a strong predictor for both sustained viral suppression and HBeAg seroconversion in patients receiving IFN-based as well as NAs therapy. In addition, HBeAg-positive patients with genotype A or B infection have better responses to IFN-based therapy than those with genotypes C or D infection. Furthermore, on-treatment predictors such as declines of serum HBV DNA, HBsAg and HBeAg levels may be helpful in making decisions of subsequent therapy. Regarding the association of host genetic factors with responses to antiviral therapy, current evidence is limited.

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

At present, there is no consensus treatment for patients who have poor response to Adevofir dipivoxil (ADV) monotherapy and no ADV-associated mutation. The purpose of this study was to evaluate the effect of a new therapeutic strategy combining Lamivudine (LAM) and ADV in patients with HBeAg-positive chronic hepatitis B (CHB) and poor response to ADV monotherapy. Thirty-one patients with chronic hepatitis B with HBV DNA > or = 10(4) copies/mL after 48 weeks of ADV monotherapy were included and received ADV plus LAM for 24 weeks. Compared with ADV monotherapy, ADV + LAM had an improved response rate at weeks 12 and 24 - compared with baseline, the median decrease in HBV-DNA level at week 12 and 24 were 1.27 and 2.03 log respectively. The virological response (VR) rate (HBV-DNA level <10(3) copies/mL) was 6.5% and 35.5% at weeks 12 and 24, respectively; the biochemical response (BR) rate (normalization of alanine aminotransferase levels) was 67.8% and 100%, respectively; the HBeAg loss rate was 6.9% and 34.5%, respectively; and the seroconversion rate (from HBeAg to HBeAb) was 3.5% and 6.9% respectively. No ADV-associated mutation was detected at baseline. After combination therapy for 24 weeks, no LAM-resistant or ADV-resistant mutations were detected. Only one patient had a mild adverse reaction. In conclusion, optimization of therapy combining LAM and ADV may be a good choice for patients with hepatitis B who have a poor response to ADV monotherapy.

Predictors of treatment response in chronic hepatitis B

The ultimate goal of treatment for chronic hepatitis B is to reduce liver-related complications and mortality. Sustained hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) clearance 6-12 months after stopping treatment are the short-term surrogate outcomes for interferon or peginterferon therapy. As most patients require long-term nucleos(t)ide analogue treatment, which also has the risk of drug resistance in the case of incomplete viral suppression, maintained hepatitis B virus (HBV) DNA suppression to an undetectable level is the appropriate surrogate outcome. Because no antiviral treatment is perfect, it is desirable for treatment response to be predicted and the treatment regimen modified accordingly. At baseline, high ALT and low HBV DNA levels can predict response to both (peg)interferon and nucleos(t)ide analogues. Genotype A HBV responds best to peginterferon but HBV genotype has no predictive value for nucleos(t)ide analogue treatment. HBV DNA is a good on-treatment predictor of response for nucleos(t)ide analogues but not for (peg)interferon. The data supporting the use of quantitative HBsAg and HBeAg to predict response to peginterferon is stronger than that for nucleos(t)ide analogues. In conclusion, predictors of response are useful to provide the most appropriate antiviral therapy to the most suitable patients, in order to achieve the best response and improve the clinical outcome of chronic hepatitis B patients.

Renal dysfunction in chronic hepatitis B patients treated with adefovir dipivoxil

Renal dysfunction has been reported in patients treated with adefovir dipivoxil (ADV); however, its incidence and clinical importance may be underappreciated given the lack of long-term follow-up and data outside of a clinical trial setting. Our goal was to examine the severity and incidence of renal dysfunction in a real-life setting for patients treated with ADV and whose baseline estimated glomerular filtration rate (eGFR) was >50 mL/minute. We performed a cohort study of 290 chronic hepatitis B patients: 145 patients treated with 10 mg ADV and 145 patients unexposed to ADV at two community clinics, who were matched for age (+/-10 years), sex, and baseline eGFR. The exposed and unexposed populations were well-matched with a similar mean age (46-47 years), proportion of male patients (76.5%), baseline serum creatinine (0.97-0.99 mg/dL), and baseline creatinine clearance (85.0-85.4 mL/minute). The incidence density for renal dysfunction defined by treatment termination and/or development of eGFR < or =50 mL/minute was five cases per 100 patient-years in the exposed group compared with 1.36 cases per 100 patient-years in the unexposed group (P = 0.02). The relative risk of exposed to unexposed was 3.68 (95% confidence interval 1.1-19.3). On Cox proportional hazard analysis also inclusive of sex, ADV was a significant predictor of significant renal dysfunction (hazard ratio [HR] 3.94, P = 0.03). There were also significant trends for age >50 years (HR 3.49, P = 0.087), mild renal impairment at baseline (HR 4.49, P = 0.073), and hypertension and/or diabetes mellitus (HR 2.36, P = 0.074).

CONCLUSION

ADV is an independent predictor for significant deterioration of renal function. Patients on ADV should be monitored, especially patients who are older, have baseline renal insufficiency, or have hypertension and/or diabetes mellitus.

Treatment predictors of a sustained virologic response in hepatitis B and C

Treatment predictors are important tools for the management of therapy in patients with chronic hepatitis B and C virus (HBV, HCV) infection. In chronic hepatitis B, several pretreatment parameters have been identified for prediction of virologic response to interferon alfa-based antiviral therapies or treatment with polymerase inhibitors. In interferon alfa and pegylated interferon alfa-treated patients, low baseline HBV DNA concentrations, HBV genotype A (B), and high baseline ALT levels are significantly associated with treatment response. In patients treated with nucleos(t)ide analogues, low baseline HBV DNA but not viral genotype is positively associated with virologic response. During treatment the best predictor of response is HBV DNA kinetics. Early viral suppression is associated with favourable virologic response and reduced risk for subsequent resistance mutations. For the current standard treatment with pegylated interferon alfa and ribavirin in patients with chronic hepatitis C, infection with HCV genotypes 2 and 3, baseline viral load below 400,000-800,000 IU/ml, Asian and Caucasian ethnicity, younger age, low GGT levels, absence of advanced fibrosis/cirrhosis, and absence of steatosis in the liver have been identified as independent pretreatment predictors of a sustained virologic response. After initiation of treatment, initial viral decline with undetectable HCV-RNA at week 4 of therapy (RVR) is the best predictor of sustained virologic response independent of HCV genotype.

Recent data on treatment of chronic hepatitis B with nucleos(t)ide analogues

Forty years ago in 1967, Professor Blumberg discovered the Australian Antigen, later known as the hepatitis B surface antigen, and was awarded the Nobel Prize. This discovery enables the diagnosis of hepatitis B virus (HBV) infection and defines its epidemiology. Viral hepatitis B infection affects global health situation, and chronic hepatitis B (CHB) is particularly serious in the Asia-Pacific region. HBV vaccines created the first breakthrough in HBV prevention. Through universal HBV vaccination program for the newborns, promoted since the mid-1980s, the main route that perpetuates chronic infection from mother to child is curbed. Most children and young adults now have immunity against HBV infection. The next breakthrough comes with therapy for CHB. This prevents progression to cirrhosis and hepatocellular carcinoma. Standard interferon therapy with modest efficacy has been largely replaced by therapy with nuclos(t)ide analogues or pegylated interferons alfa-2a and -2b. Lamivudine was approved by the FDA USA in 1998, followed by adefovir dipivoxil in 2002, entecavir in 2005, and telbivudine in 2006. Clevudine, tenofovir, and many promising candidates are in different stages of development and clinical trial. This paper critically reviews recent data published or presented since the APASL Consensus and Guideline Update of 2005. Clinical efficacy mostly in patients with raised serum alanine aminotransferase will be analyzed.