No resistance to tenofovir disoproxil fumarate detected after up to 144 weeks of therapy in patients monoinfected with chronic hepatitis B virus

Association of tenofovir diphosphate and lamivudine triphosphate concentrations with HIV and hepatitis B virus viral suppression

OBJECTIVE

Concentrations of tenofovir diphosphate (TFV-DP) and lamivudine triphosphate (3TC-TP) in cells are correlates of medication adherence and antiviral activity. However, studies have yet to characterize the simultaneous relationship between TFV-DP and 3TC-TP concentrations with HIV and hepatitis B virus (HBV) suppression.

METHODS

Individuals with HIV/HBV coinfection on tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy (ART) were enrolled. Peripheral blood mononuclear cells (PBMCs) and dried blood spots (DBS) samples were collected and steady-state TFV-DP and 3TC-TP concentrations quantified using validated methods. The relationship between patient factors, TFV-DP, and 3TC-TP concentrations in PBMCs and DBS with HBV and HIV viral suppression were examined.

RESULTS

Of 138 participants on TDF-containing ART for a median duration (range) of 6 (0.75-15) years, the median age was 43 years and 64% were women. Overall, 128 (92.8%) and 129 (93.5%) had suppressed HIV and HBV viral loads, respectively. Of the 128 participants with suppressed HIV, 122 (95.3%) had suppressed HBV. Self-reported ART adherence, recent change to dolutegravir-based ART, TFV-DP, and 3TC-TP concentrations in PBMCs and DBS were associated with HIV RNA suppression, while HBe antigen positivity, HIV suppression, and TFV-DP concentrations in DBS were associated with HBV DNA suppression (including six persons with HBV nonsuppression and HIV suppression).

CONCLUSION

Long-term TDF/3TC-conatining ART was highly efficacious in individuals with HIV/HBV coinfection. Higher TFV-DP concentrations were predictive of suppression for both viruses. Persistent HBV viremia on TDF/3TC-containg ART requires additional research, but may represent poor adherence and the need for adherence interventions or novel antivirals.

Stopping nucleot(s)ide analogues in non-cirrhotic HBeAg-negative chronic hepatitis B patients: HBsAg loss at 96 weeks is associated with low baseline HBsAg levels

BACKGROUND AND AIMS

Current guidelines recommend long-term nucleot(s)ide analogue (NA) therapy for patients with HBeAg-negative chronic hepatitis B (CHB). However, disease remission has been described after stopping NA therapy, as well as HBsAg loss.

METHODS

We performed a prospective multi-centre cohort study of stopping NA therapy. Inclusion criteria were HBeAg-negative CHB, the absence of cirrhosis and HBVDNA<lower limit of quantification for ≥18 months. We assessed virological and biochemical outcomes including HBsAg loss, as well as NA restart rates, over 96 weeks.

RESULTS

In total, 110 patients [62% entecavir (ETV); 28% tenofovir (TDF), 10% other] were enrolled. Median age was 56 years, 57% were male, 85% were Asian, median baseline HBsAg level was 705 (214-2325) IU/ml. Virological reactivation occurred in 109/110 patients, median time to detection was 8 (4-12) weeks, and occurred earlier after stopping TDF versus ETV (median 4 vs. 12 weeks p < 0.001). At week 96, 77 (70%) remained off-treatment, 65 (59%) had ALT <2× ULN, 31 (28%) patients were in disease remission with HBVDNA <2000 IU/ml plus ALT <2× ULN and 7 (6%) patients had lost HBsAg. Baseline HBsAg ≤10 IU/ml was associated with HBsAg loss (6/9 vs. 1/101 p < 0.001). ALT >5× ULN occurred in 35 (32%); ALT flares were not associated with HBsAg loss. There were no unexpected safety issues.

CONCLUSION

Virological reactivation was very common after stopping NA therapy and occurred earlier after stopping TDF versus ETV. The majority of patients had ALT <2× ULN at week 96, but only one-third achieved disease remission and HBsAg loss was rare. Very low HBsAg levels at baseline were uncommon but predicted for HBsAg loss and disease remission.

Non-Inferior Efficacy of Tenofovir Disoproxil to Tenofovir Disoproxil Fumarate in Virologically Suppressed Chronic Hepatitis B Patients

PURPOSE

Tenofovir disoproxil (TD), modified from tenofovir disoproxil fumarate (TDF), was developed as a salt-free formulation, removing fumarate to improve the ease of oral intake by reducing the tablet's size. We evaluated the maintenance of antiviral effects and overall safety profile of TD 245 mg after switching from TDF 300 mg in patients with chronic hepatitis B (CHB).

PATIENTS AND METHODS

CHB patients with HBV-DNA <69 IU/mL after ≥24 weeks of TDF therapy were enrolled. The primary efficacy endpoint was the HBV-DNA suppression rate (HBV-DNA <69 IU/mL) at week 48; We evaluated the non-inferiority (10% margin) of TD to TDF in terms of efficacy. Safety was assessed based on adverse events (AEs), laboratory tests, bone mineral density, and renal function abnormalities.

RESULTS

Overall, 189 subjects were randomized in a 2:1 ratio, and 117 and 66 subjects in the TD and TDF groups, respectively, completed the study. In the per-protocol set, the HBV-DNA suppression rate at week 48 was 99.1% and 100% in the TD and TDF groups, respectively. The lower limit of the 97.5% one-sided confidence interval for the intergroup difference in HBV-DNA suppression rate was -2.8%, which was greater than the prespecified margin of non-inferiority. The changes in creatinine clearance from baseline to week 48 was significantly less in the TD group and in the TDF group; -0.8 ± 9.8 versus -2.4 ± 12.8 mL/min, respectively (P=0.017).

CONCLUSION

TD was non-inferior to TDF for maintaining viral suppression in CHB patients, showing the less decline of renal function.

Association between HBs Ag quantification and the risk of hepatocellular carcinoma in patients treated with tenofovir disoproxil fumarate or entecavir

This study evaluated the clinical implications of hepatitis B surface antigen quantification (qHBs Ag) in chronic hepatitis B (CHB) patients treated with entecavir (ETV) or tenofovir disoproxil fumarate (TDF) and identified the association between qHBs Ag and the risk of hepatocellular carcinoma (HCC) in these patients.Between January 2007 and December 2018, the qHBs Ag and clinical data of 183 CHB patients who initially received ETV (n = 45, 24.6%) or TDF (n = 138, 75.4%) were analyzed.The mean follow-up period of the 183 CHB patients was 45.3 months, of which 59 (32.2%) patients showed a reduction in qHBs Ag by >50% after 1 year of antiviral treatment (ETV or TDF). The HCC development (P = .179) or qHBs Ag reduction (P = .524) were similar in the ETV and TDF groups. Patients with a ≥50% decrease in qHBs Ag had a significantly lower incidence of HCC or decompensated cirrhosis complications (P = .005). Multivariate analysis showed that a >50% reduction of qHBs Ag (hazard ratio 0.085, P = .018) and the presence of cirrhosis (hazard ratio 3.32, P = .016) were independent factors predicting the development of HCC.Patients whose qHBs Ag value decreased >50% at 1 year after antiviral treatment for CHB showed a significant decrease in HCC or decompensated cirrhosis events. A reduction in qHBs Ag could be used as a predictive factor of HCC development or critical complications in CHB patients treated with TDF or ETV.

Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure

While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.

Epidemiology, Natural History, and Treatment of Hepatitis Delta Virus Infection in HIV/Hepatitis B Virus Coinfection

PURPOSE OF REVIEW

Limited data exist on the prevalence, determinants, and outcomes of hepatitis delta virus (HDV) infection among HIV/hepatitis B virus (HBV)-coinfected persons. This review provides current evidence on the epidemiology, natural history, and treatment of HDV infection in patients with HIV/HBV coinfection and highlights future research needs.

RECENT FINDINGS

Cross-sectional studies in Europe, Africa, South America, and Asia show that the prevalence of HDV among HIV/HBV-coinfected patients ranges from 1.2 to 25%. No studies have evaluated the prevalence of HDV infection among HIV/HBV-coinfected patients in the USA. HDV infection increases the risk of hepatic decompensation and hepatocellular carcinoma among HIV/HBV-coinfected patients. HDV treatment remains limited to pegylated interferon-alpha, which results in sustained virologic response in fewer than 25%. Data on the epidemiology, natural history, and treatment of HDV among HIV/HBV-coinfected persons remain limited. More research is needed to address these knowledge gaps in order to better manage HDV coinfection in HIV/HBV-coinfected patients.

Complex genetic encoding of the hepatitis B virus on-drug persistence

Tenofovir disoproxil fumarate (TDF) is one of the nucleotide analogs capable of inhibiting the reverse transcriptase (RT) activity of HIV and hepatitis B virus (HBV). There is no known HBV resistance to TDF. However, detectable variation in duration of HBV persistence in patients on TDF therapy suggests the existence of genetic mechanisms of on-drug persistence that reduce TDF efficacy for some HBV strains without affording actual resistance. Here, the whole genome of intra-host HBV variants (N = 1,288) was sequenced from patients with rapid (RR, N = 5) and slow response (SR, N = 5) to TDF. Association of HBV genomic and protein polymorphic sites to RR and SR was assessed using phylogenetic analysis and Bayesian network methods. We show that, in difference to resistance to nucleotide analogs, which is mainly associated with few specific mutations in RT, the HBV on-TDF persistence is defined by genetic variations across the entire HBV genome. Analysis of the inferred 3D-structures indicates no difference in affinity of TDF binding by RT encoded by intra-host HBV variants that rapidly decline or persist in presence of TDF. This finding suggests that effectiveness of TDF recognition and binding does not contribute significantly to on-drug persistence. Differences in patterns of genetic associations to TDF response between HBV genotypes B and C and lack of a single pattern of mutations among intra-host variants sensitive to TDF indicate a complex genetic encoding of the trait. We hypothesize that there are many genetic mechanisms of on-drug persistence, which are differentially available to HBV strains. These pervasive mechanisms are insufficient to prevent viral inhibition completely but may contribute significantly to robustness of actual resistance. On-drug persistence may reduce the overall effectiveness of therapy and should be considered for development of more potent drugs.

The Yin and the Yang of Treatment for Chronic Hepatitis B-When to Start, When to Stop Nucleos(t)ide Analogue Therapy

Over 257 million individuals worldwide are chronically infected with the Hepatitis B Virus (HBV). Nucleos(t)ide analogues (NAs) are the first-line treatment option for most patients. Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are both potent, safe antiviral agents, have a high barrier to resistance, and are now off patent. They effectively suppress HBV replication to reduce the risk of cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Treatment is continued long-term in most patients, as NA therapy rarely induces HBsAg loss or functional cure. Two diverging paradigms in the treatment of chronic hepatitis B have recently emerged. First, the public health focussed "treat-all" strategy, advocating for early and lifelong antiviral therapy to minimise the risk of HCC as well as the risk of HBV transmission. In LMICs, this strategy may be cost saving compared to monitoring off treatment. Second, the concept of "stopping" NA therapy in patients with HBeAg-negative disease after long-term viral suppression, a personalised treatment strategy aiming for long-term immune control and even HBsAg loss off treatment. In this manuscript, we will briefly review the current standard of care approach to the management of hepatitis B, before discussing emerging evidence to support both the "treat-all" strategy, as well as the "stop" strategy, and how they may both have a role in the management of patients with chronic hepatitis B.

Brief Report: Relationship Between ABCC4 SNPs and Hepatitis B Virus Suppression During Tenofovir-Containing Antiretroviral Therapy in Patients With HIV/HBV Coinfection

BACKGROUND

Incomplete hepatitis B virus (HBV) suppression during antiretroviral therapy (ART) in HIV and HBV coinfected patients is common, but underlying factors are not fully elucidated. We hypothesize that genetic factors that influence nucleoside analog pharmacokinetics will affect HBV treatment response.

METHODS

HIV/HBV coinfected patients on tenofovir disoproxil fumarate/lamivudine (TDF/3TC)-containing ART were enrolled. Selected ABCC4 single nucleotide polymorphisms (SNPs) with known effects on nucleoside pharmacokinetics were genotyped using TaqMan assays. Relationship between ABCC4 SNPs and unsuppressed HBV DNA (HBV DNA ≥20 IU/mL) were examined.

RESULTS

Of the 50 participants on TDF/3TC-containing ART for a median (range) of 1.5 (1-7.4) years, 20 (40%) had unsuppressed HBV DNA. Participants with unsuppressed compared with those with suppressed HBV DNA were more likely to have negative HBe antibody, lower body mass index, and lower CD4 count at enrollment. Carriers of ABCC4 rs11568695 (G3724A) variant allele were more likely than noncarriers to have unsuppressed HBV (61.1% vs. 29.0%, P = 0.038). Among 36 patients with suppressed HIV RNA (presumed good ART adherence), ABCC4 rs11568695 variant carriers were more likely than noncarriers to have unsuppressed HBV (58.8% vs. 20.0% P = 0.021). Logistic regression analysis that included genetic and nongenetic factors identified ABCC4 rs11568695 variant allele, body mass index, and male sex as predictors of unsuppressed HBV DNA.

CONCLUSIONS

We identified a novel association between ABCC4 rs11568695 SNP and poor HBV treatment response. If confirmed in further studies, ABCC4 genotyping could be used to identify individuals who may need intensified HBV therapy.

Long-Term Effects of Tenofovir on Liver Histopathology in Patients with Chronic Viral Hepatitis B Infection

OBJECTIVE

The aim of this study to evaluate histopathological improvement and virological, serological and biochemical response rates in patients with chronic hepatitis B (CHB) who were treated with tenofovir disoproxil fumarate (TDF).

MATERIAL AND METHOD

A total of 91 nucleosid(t)e-naive CHB patients who received TDF were evaluated. Virological, serological and biochemical test results were assessed at baseline and every 12 weeks. Liver biopsy specimens were assessed according to the modified Ishak scoring.

RESULTS

The study was conducted on 52 patients. The mean age was 40±10 years and 40.4% were female. The mean follow-up period was 33±11 months. HBsAg seroclearance occurred in none of the patients. The serum level of HBV-DNA became undetectable in 94.2% of the patients. Mean histological activity index at baseline and on-treatment were 8.2±2.3 and 6.2±2.0 and the mean fibrosis scores were 2.65±1.3 and 2.33±1.1, respectively.

CONCLUSION

We determined that TDF therapy provided remarkably good HBV DNA suppression and biochemical response rates, but low seroconversion. Improvement of liver necroinflammation was detected, but no significant change observed in fibrosis.

A randomized, double-blind, double-dummy, controlled, multicenter study of Qingzhong (tenofovir disoproxil fumarate) versus Viread for the treatment of chronic hepatitis B: First-stage results at week 48

BACKGROUND

Tenofovir disoproxil fumarate (TDF) has been widely recommended as a first-line antiviral agent to treat chronic hepatitis B (CHB). Qingzhong and Viread, formulations of TDF commercialized by Jiangsu Chia-tai Tianqing Pharmaceutical Co Ltd and GlaxoSmithKline, respectively, have both been approved by the State Food and Drug Administration, China. This study analyzed the efficacy and safety of these 2 TDF agents in Chinese patients with CHB.

METHODS

In this multicenter, randomized, double-blind, double-dummy, noninferiority phase 3 clinical trial (ClinicalTrials.gov identifier: NCT02287857), 330 Chinese patients with CHB [hepatitis B envelope antigen-positive (HBeAg) (+): 232] were randomly assigned to receive Qingzhong (group A: 161 patients) or Viread (group B: 169 patients) 300 mg once daily for 48 weeks. Subsequently, all patients were administered Qingzhong 300 mg once daily from week 49 to week 240. The primary end point was the degree of decline of plasma hepatitis B virus (HBV) DNA levels at week 48 and the secondary endpoints were viral suppression, normalization of alanine aminotransferase (ALT) levels, hepatitis B surface antigen (HBsAg)/HBeAg loss or seroconversion, and virological breakthrough.

RESULTS

Among patients with CHB who were HBeAg (+), the mean HBV DNA titer decreased similarly between the groups at week 48. The percentages of patients who achieved undetectable HBV DNA were similar between the groups (85.11% and 82.35% in groups A and B, respectively) and similar losses of HBeAg and HBeAg seroconversion rates were achieved. Moreover, for patients with CHB who were HBeAg (-), reductions in HBV DNA were similar. Among all patients with CHB, the rates of normalization of ALT and the loss of HBsAg were similar. The overall incidence of adverse events was comparable between the groups.

CONCLUSION

In conclusion, the 48-week administration of Qingzhong showed noninferior efficacy and safety profiles compared to Viread in Chinese patients with CHB.

Tenofovir and telbivudine combination therapy rapidly decreases viral loads in immune-tolerant chronic hepatitis B patients awaiting assisted reproduction: an open-label, randomized, controlled study

BACKGROUND

Immune-tolerant chronic hepatitis B (CHB) patients awaiting assisted reproduction (AR) are required to initiate antiviral therapy because of laboratory safety concerns. The antiviral therapy in this group has not been well assessed. We sought to explore the efficacy and safety of the combination therapy (COM) of tenofovir (TDF) and telbivudine (LdT).

PATIENTS AND METHODS

In this open-label, randomized, controlled study, we enrolled and randomized hepatitis B virus e-antigen (HBeAg)-positive CHB patients awaiting AR into the study COM group and the control (TDF) group. The COM group received combination therapy of TDF and LdT, and the TDF group received a single treatment of TDF. The patients were followed up for at least 48 weeks. The primary endpoint was the proportion of patients with undetectable HBV DNA level at week 12.

RESULTS

A total of 121 patients were recruited into the COM group (n=60) and the TDF group (n=61). The percentages of patients with undetectable HBV DNA levels were 90.0% (54/60) in the COM group and 67.2% (41/61) (P=0.002) in the TDF group at week 12; the percentages were 96.6% (58/60) in the COM group and 85.2% (52/61) in the TDF group at week 48 (P=0.028), respectively. HBeAg seroconversion occurred in 5/60 (8.3%) patients in the COM group and 2/61 (3.3%) patients in the TDF group at week 48 (P=0.233).

CONCLUSION

TDF and LdT combination therapy shows a rapid antivirological response in immune-tolerant CHB patients awaiting AR, which provide an alternative for this group at AR centers. However, the HBeAg seroconversion rate is unsatisfactory in the short term.

Frequency of Hepatitis B Virus Resistance Mutations in Women Using Tenofovir Gel as Pre-Exposure Prophylaxis

Intermittent use of a single antiretroviral agent in the presence of a replicating virus could potentially increase the development of antiviral resistance. The pericoital, before-and-after sex, dosing regimen used in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 tenofovir gel trial meant that women who were infected with hepatitis B virus (HBV) were exposed intermittently to tenofovir during their participation. The impact of this dosing regimen on HBV resistance was assessed by amplification of the HBV polymerase region from 37 stored plasma samples of women who were HBV surface antigen positive. All samples belonged to HBV genotype A. None of the known tenofovir resistance mutations (M240V/I, L180M, A194T, V214A, N238T) were identified in any individuals. While it is reassuring that no resistance mutations were found among women using topical tenofovir, the rapidly expanding access to oral tenofovir-containing HIV pre-exposure prophylaxis (PrEP), with higher systemic exposure to the drug, makes monitoring for potential HBV drug resistance important.

Treatment Outcome and Renal Safety of 3-Year Tenofovir Disoproxil Fumarate Therapy in Chronic Hepatitis B Patients with Preserved Glomerular Filtration Rate

Background/Aims

To investigate the treatment efficacy and renal safety of long-term tenofovir disoproxil fumarate (TDF) therapy in chronic hepatitis B (CHB) patients with preserved renal function.

Methods

The medical records of 919 CHB patients who were treated with TDF therapy were reviewed. All patients had preserved renal function with an estimated glomerular filtration rate (eGFR) of at least 60 mL/min/1.73 m².

Results

A total of 426 patients (184 treatment-naïve and 242 treatment-experienced) were included for analysis. A virologic response (VR) was defined as achieving an undetectable serum hepatitis B virus (HBV) DNA level, and the overall VR was 74.9%, 86.7%, and 89.4% at the 1, 2, and 3-year follow-ups, respectively. Achieving a VR was not influenced by previous treatment experience, TDF combination therapy, or antiviral resistance. In a multivariate analysis, being hepatitis B e antigen positive at baseline and having a serum HBV DNA level ≥2,000 IU/mL at 12 months were associated with lower VR rates during the long-term TDF therapy. The overall renal impairment was 2.9%, 1.8%, and 1.7% at the 1, 2, and 3-year follow-ups, respectively. With regard to renal safety, underlying diabetes mellitus (DM) and an initial eGFR of 60 to 89 mL/min/1.73 m² were significant independent predictors of renal impairment.

Conclusions

TDF therapy appears to be an effective treatment option for CHB patients with a preserved GFR. However, patients with underlying DM and initial mild renal dysfunction (eGFR, 60 to 89 mL/min/1.73 m²) have an increased risk of renal impairment.

Influence of hepatic steatosis on the outcomes of patients with chronic hepatitis B treated with entecavir and tenofovir

Background/Aims

The influence of hepatic steatosis (HS) on chronic hepatitis B (CHB) is unclear. We evaluated the influence of the degree of HS, assessed using the controlled attenuation parameter (CAP) of transient elastography (TE), on treatment outcomes in CHB patients initiated on antiviral therapy.

Methods

A total of 334 patients who were initiated on entecavir or tenofovir between 2007 and 2016 with available TE results were recruited.

Results

Of the total study population, 146 (43.7%) patients had HS (CAP > 238 dB/m). Three-hundred-three patients (90.7%) achieved complete virological response (CVR) (hepatitis B virus DNA<12 IU/L), and 25 patients (7.5%) developed hepatocellular carcinoma (HCC). Among hepatitis B e antigen (HBeAg)-positive patients (n=172, 51.5%), 37 (21.5%) experienced HBeAg loss. On univariate analysis, CAP value was not associated with the probability of HCC development (P=0.380). However, lower CAP value was independently associated with higher probability of HBeAg loss among HBeAg-positive patients (hazard ratio [HR]=0.991, P=0.026) and with CVR achievement in the entire study population (HR=0.996, P=0.004). The cumulative incidence of HBeAg loss among HBeAg-positive patients was significantly higher in patients without HS than in those with HS (log-rank, P=0.022).

Conclusions

CAP values were not correlated with HCC development in patients initiated on entecavir and tenofovir. However, CAP values were negatively correlated with the probability of HBeAg loss among HBeAg-positive patients and with CVR achievement.

Delayed viral suppression during antiviral therapy is associated with increased hepatocellular carcinoma rates in HBeAg-positive high viral load chronic hepatitis B

The treatment option in chronic hepatitis B (CHB) patients with persistent low-level viremia despite entecavir or tenofovir monotherapy is unclear. This study investigated the development of hepatocellular carcinoma (HCC) or cirrhosis in hepatitis B e antigen (HBeAg)-positive high viral load CHB patients, according to the time needed to achieve complete viral suppression. A total of 325 HBeAg-positive CHB patients with high viral load who were recently started on antiviral therapy with entecavir or tenofovir were included. The enrolled patients were divided into 2 groups with 4 separate criteria based on the time needed to achieve complete viral suppression: within 1, 2, 3 or 4 years of therapy initiation. The outcomes were development of HCC and cirrhosis. The cumulative incidence of HCC was significantly higher in patients failing complete viral suppression within 1 year (hazard ratio (HR), 4.54; 95% confidence interval (CI), 1.03-19.93; P = .045) or 2 years (HR, 3.38; 95% CI, 1.24-9.23; P = .018), than patients who achieved complete viral suppression within 1 or 2 years, respectively. Cumulative incidence of cirrhosis was also significantly higher in patients failing suppression within 1 year (HR, 1.95; 95% CI, 1.04-3.66; P = .037) or 2 years (HR, 2.44; 95% CI, 1.41-4.22; P = .001). When the time for achieving viral suppression exceeded 2 years, the cumulative incidence of HCC or cirrhosis was not different regardless of viral suppression. Complete hepatitis B virus suppression within 2 years of antiviral therapy initiation is associated with risk reduction in HCC or cirrhosis development.

Trends in hepatitis B virus resistance to nucleoside/nucleotide analogues in North China from 2009-2016: A retrospective study

Nucleos(t)ide analogues (NAs) are widely used in anti-hepatitis B virus (anti-HBV) therapy for effective inhibition of HBV replication. However, HBV resistance to NAs has emerged, resulting in virus reactivation and disease recurrence. Data on the current dynamics of HBV resistance are still rare in China. This study analysed 4491 plasma samples with HBV primary genotypic resistance mutations representative of the general HBV resistance situation in northern China from 2009-2016. We found that entecavir (ETV), representing 57.6% (12 713/22 060) of NA users in North China in 2016, has become the major NA for treating Chinese patients infected with HBV. Despite >50% of M204I/V±L180M among all HBV resistance cases annually and extensive exposure of patients to lamivudine (LAM), telbivudine (LdT) and adefovir dipivoxil (ADV), ETV resistance also showed a dramatically increased incidence, which rose to 17.1% in 2016. Moreover, A181T/V, ETV resistance mutations and multidrug resistance mutations were found more frequently in HBV genotype C compared with genotype B (21.2% vs. 8.5%, 12.4% vs. 7.9% and 5.9% vs. 3.0%, respectively), whereas M204I and N236T were more predominant in genotype B than genotype C (40.3% vs. 20.8% and 11.3% vs. 1.8%, respectively). In conclusion, we report the dynamic changes of HBV NA resistance mutation patterns and the current NA usage profile for anti-HBV treatment in North China over the past 8 years. These data provide valuable information on HBV NA resistance that is an important reference for clinicians to devise more effective treatment regimens for individual patients.

A long-term multicenter study: Entecavir versus Tenofovir in treatment of nucleos(t)ide analogue-naive chronic hepatitis B patients

BACKGROUND

Entecavir (ETV) and tenofovir disoproxil fumarat (TDF) are the two first-line therapies recommended in the treatment of chronic hepatitis B because of having potent antiviral effect and high genetic barriers against resistance. We aimed to compare efficacy of these drugs and to evaluate predictors of viral suppression.

METHODS

This multicenter retrospective study was conducted in nucleos(t)ide analogue-naive chronic hepatitis B (CHB) patients from different 6 centers.

RESULTS

Of the 252 patients, 166 received ETV and 86 TDF. The two groups were similar in terms of age, gender, baseline ALT levels and fibrosis scores. ETV had significantly higher baseline HBV DNA, histological activity index and lower hepatitis B early antigen (HBeAg) seropositivity. Treatment duration was longer in ETV group (P<0.001). In univariate analysis, undetectable HBV DNA and ALT normalization rates were detected significantly higher in ETV groups (P<0.001 and 0.049, respectively). There was no significant difference between groups in terms of HBeAg seroconversion, virological breakthrough, time to virological breakthrough and time to ALT normalization. Entecavir was more effective in reducing HBV DNA levels at the 3rd, 6th and 12th months of the treatment (P=0.06, 0.021 and 0.012, respectively). However, multivariate Cox regression analysis indicated that TDF therapy compared to ETV had an increased probability of achieving complete viral suppression (HR=1, 66; 95% CI 1.21-2.33; P=0.010). Hepatitis B surface antigen (HBsAg) seroconversion was occurred in only one patient in ETV group.

CONCLUSION

ETV leads to an early response on HBV DNA decline in the first year of the treatment. However, TDF is more successful than entecavir in achieving virological suppression.

Antiviral Efficacy of Tenofovir Monotherapy in Children with Nucleos(t)ide-naive Chronic Hepatitis B

BACKGROUND

The purpose was to compare the efficacy between tenofovir disoproxil fumarate (TDF) and lamivudine (LMV) in children with nucleos(t)ide-naive chronic hepatitis B (CHB) infection. Patients with CHB were treated with TDF in the immune-reactive phase and compared with a historical control group of patients treated with LMV before the TDF era.

METHODS

Hepatitis B virus (HBV) DNA titer decrements (> 3 log₁₀ IU/mL) were monitored after treatment initiation. The treatment duration for HBV DNA clearance (< 357 IU/mL) and complete response (HBeAg loss and HBV DNA clearance) were analyzed. The follow-up period was 96 weeks.

RESULTS

Sixteen patients were treated with TDF and compared with a historical control group of 24 patients treated with LMV. HBV DNA decrement (> 3 log₁₀ IU/mL) was achieved in 100% (16/16) of the TDF group but in only 62.5% (15/24) of the LMV group (P = 0.005) at 48 weeks. The HBV DNA clearance (< 357 IU/mL) in the TDF and LMV groups was, respectively, as follows: 62.5% (10/16) and 25.0% (6/24) at 12 weeks (P = 0.018), 81.3% (13/16) and 37.5% (9/24) at 24 weeks (P = 0.006), 93.8% (15/16) and 50.0% (12/24) at 48 weeks (P = 0.004), and 100% (16/16) and 54.2% (13/24) at 96 weeks (P = 0.001). Complete response occurred in 41.7% (5/12) of HBeAg-positive patients in the TDF group and 28.6% (6/21) of the LMV group at 96 weeks (P = 0.443).

CONCLUSION

TDF monotherapy for 96 weeks produced a significantly more effective virologic response than LMV monotherapy in children with nucleos(t)ide-naive CHB.

Switching from tenofovir and nucleoside analogue therapy to tenofovir monotherapy in virologically suppressed chronic hepatitis B patients with antiviral resistance

It is unclear whether chronic hepatitis B (CHB) patients with antiviral resistance, who achieve a complete virologic response (CVR) with tenofovir disoproxil fumarate (TDF) and nucleoside analogue (NUC) combination therapy, maintain CVR if switched to TDF monotherapy. We investigated the persistence of CVR after cessation of NUC in virologically suppressed antiviral resistant CHB patients using TDF+NUC combination therapy. This study recruited 76 antiviral-resistant CHB patients showing CVR on TDF+entecavir (ETV) (n = 52), TDF+lamivudine (LAM; n = 14), and TDF+telbivudine (LdT; n = 10) combination therapy, who were switched to TDF monotherapy as step-down therapy. At baseline, 47 patients were male and the median age was 53.0 years (range: 30-78 years); 72.3% cases were hepatitis B e antigen-positive (HBeAg+) and 23.7% were of liver cirrhosis. The median duration of TDF+NUC combination therapy was 20.8 months (range: 3-46 months). At a median follow-up of 24.7 months (range: 12-48 months) after switching to TDF monotherapy, all 76 patients maintained CVR, regardless of the duration of combination therapy and the type of prior NUC and antiviral resistance. Renal dysfunction was not observed during the treatment period. The step-down strategy of switching from TDF+NUC combination therapy to TDF monotherapy in virologically suppressed CHB patients with antiviral resistance should be considered.

Development of a digital droplet PCR assay to measure HBV DNA in patients receiving long-term TDF treatment

The COBAS TaqMan assay has a lower limit of quantification (LLOQ) of 169 HBV copies/mL and a lower limit of detection (LLOD) of 58 copies/mL. HBV DNA below the TaqMan LLOQ is classified as target not detected (TND) (<58 copies/mL) or target detected (TD) (between 58 and 169 copies/mL). Here we have developed a more sensitive digital droplet PCR (ddPCR) assay to evaluate the impact of long-term tenofovir disoproxil fumarate (TDF) treatment in patients that did or did not achieve HBsAg seroconversion. A ddPCR assay was developed to detect HBV DNA to 8 copies/mL. HBV DNA levels in plasma from patients with or without HBsAg seroconversion were assessed by ddPCR. For patients who did not achieve HBsAg seroconversion, the majority of TD samples (33/58, 57%) were HBV DNA positive by ddPCR while (10/37, 27%) of TND samples were positive. In contrast, for patients who achieved HBsAg seroconversion, HBV DNA was rarely detected by ddPCR after HBsAg seroconversion (1/28, 3.6%). ddPCR is a sensitive method to evaluate low-level viral replication in plasma samples. Frequent detection of HBV DNA by ddPCR among patients who did not achieve HBsAg seroconversion suggests new agents may be needed to suppress low levels of replicating HBV.

Week 4 viral load predicts long-term suppression of hepatitis B virus DNA during antiviral therapy: improving hepatitis B treatment in the real world

BACKGROUND

Entecavir and tenofovir potently suppress hepatitis B virus (HBV) replication so that serum HBV DNA levels <20 IU/mL can be achieved after 2 years. Despite this, inadequate suppression is reported in >20% of cases for unclear reasons.

AIM

We tested whether 4-week viral load (VL) assessment could improve 96-week treatment outcome.

METHODS

Data on all chronic hepatitis B patients treated with entecavir or tenofovir between 2005 and 2014 were entered prospectively. Full data capture included pre-treatment, weeks 4, 24, 48 and 96 HBV DNA titre, HBeAg, age, gender, antiviral agent and dose escalation. Compliance data were compiled from pharmacy records, doctors' letters and clinic bookings/attendance. Time to achieve complete viral suppression (HBV DNA < 20 IU/mL) was graphed using Kaplan-Meier curves. Factors affecting this were examined using a multivariate Cox Proportional Hazard model.

RESULTS

Among 156 patients treated, 72 received entecavir and 84 tenofovir. Pre-treatment HBV DNA titre, 4-week assessment and compliance impacted significantly on time to complete viral suppression. At 96 weeks, 90% of those assessed as compliant by 4-week HBV DNA had complete viral suppression versus 50% followed by 6-month VL estimation. Continuing care by the same physician was related to 4-week VL testing and optimal compliance.

CONCLUSIONS

Medium-term outcomes of HBV antiviral therapy are improved by early on-treatment VL testing, facilitating patient engagement and improved compliance. The observation that 90% complete viral suppression after 2 years monotherapy is achievable in a routine clinic setting questions the need for combination therapy in HBV cases with suboptimal response.

Efficacy and Safety of Tenofovir Disoproxil Treatment for Chronic Hepatitis B Patients with Genotypic Resistance to Other Nucleoside Analogues: A Prospective Study

Background:

Tenofovir disoproxil (TDF) is a promising salvage therapy for patients with chronic hepatitis B (CHB) who failed regimens of other nucleoside analogues (NAs). In this study, we aimed to investigate the clinical efficacy and safety of TDF monotherapy in Chinese CHB patients with genotypic resistance.

Methods:

A total of 33 CHB patients who had failed treatment with other NAs and had genotypic resistance were switched to TDF monotherapy for 48 weeks. Patients’ demographic data (age, sex, history of hepatitis B virus [HBV] therapy), laboratory testing results (hepatitis B e antigen [HBeAg] status, HBV DNA levels, alanine aminotransferase [ALT] levels, serum creatinine, urinary protein, genotypic assay), clinical symptoms, and liver color ultrasound examinations were collected for evaluation at day 0 (baseline) and the 12^th, 24^th, 36^th, and 48^th weeks after initiating treatment. Statistical analyses were carried out using rank sum test or rank correlation.

Results:

With regard to efficacy, the study found that all patients who switched to TDF monotherapy had undetectable HBV DNA levels after 48 weeks. In addition, patients with lower baseline HBV DNA levels realized earlier virological undetectability (r_s = 0.39, P = 0.030). ALT levels were normal in 30 of 33 patients (91%). HBeAg negative conversion occurred in 7 of 25 patients (28%), among whom HBeAg seroconversion (12%) and HBeAg seroclearance (16%) occurred. The time of complete virological response was significantly affected by the number of resistance loci (r_s = 0.36, P = 0.040). Concerning safety, the study found that no adverse events were observed during the 48 weeks.

Conclusion:

TDF monotherapy is an effective and safe salvage treatment for CHB patients who are resistant to other NAs.

Efficacy of long-term tenofovir-based rescue therapy in patients with chronic hepatitis B refractory to nucleoside/nucleotide analogs

BACKGROUND

Few studies have investigated the efficacy of long-term tenofovir disoproxil fumarate (TDF)-based rescue therapy in patients with chronic hepatitis B refractory to nucleoside/nucleotide analogs.

METHODS

We retrospectively analyzed 40 Japanese patients with chronic hepatitis B refractory to nucleoside/nucleotide analogs who received TDF-based rescue therapy [TDF monotherapy, TDF plus lamivudine (LAM) combination therapy, or TDF plus entecavir (ETV) combination therapy] followed up for a median of 45 months (range 14-99 months). Viral response, changes in hepatitis B surface antigen levels from the baseline, and viral breakthrough during therapy were analyzed.

RESULTS

The proportion of patients with undetectable serum hepatitis B virus (HBV) DNA levels (less than 2.1 log copies per milliliter) (viral response) during TDF-based rescue therapy was 68, 78, 85, 88, 83, 81, 88, and 100 % at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4 years respectively. There were no differences in the viral response rate between the TDF plus LAM group and the TDF plus ETV group. The mean reduction from the baseline in hepatitis B surface antigen levels in patients with LAM-resistant HBV was greater than the reductions in patients with adefovir dipivoxil (ADV)-resistant or ETV-resistant HBV at 2 and 3 years (P = 0.024, and P = 0.025 respectively). However, two patients with ADV- or ETV-resistant HBV at the baseline developed viral breakthrough during TDF-based rescue therapy.

CONCLUSIONS

Long-term therapy with a TDF-based rescue regimen demonstrated high viral suppression in patients in whom LAM plus ADV combination therapy, ETV plus ADV combination therapy, or ETV monotherapy had failed. However, patients with ADV- or ETV-resistant HBV at the baseline may develop viral breakthrough and resistance, and careful follow-up is advised.

Efficacy and safety of entecavir versus tenofovir treatment in chronic hepatitis B patients: A randomized controlled trial

AIM

Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are considered among the most potent antiviral agents for the treatment of chronic hepatitis B infection. We aimed to compare treatment efficacy and safety of ETV and TDF in nucleoside-naïve chronic hepatitis B patients.

METHODS

Inclusion criteria were compensated chronic hepatitis B patients who were either hepatitis B e antigen (HBeAg)-positive or HBeAg-negative. Exclusion criteria were co-infection with hepatitis C virus and/or HIV, concurrent malignancy, and decompensated cirrhosis. Virological, biochemical, and serological end-points at week 96 and 144 were compared. Of 400 patients, 200 patients received ETV and 200 received TDF.

RESULTS

There were no significant differences between the two groups in baseline characteristics including age (41.6 ± 11.5 vs. 41.2 ± 11.6, mean baseline hepatitis B virus DNA (5.91 ± 1.79 vs. 5.94 ± 1.68 log₁₀ IU/mL), mean baseline alanine aminotransferase (68.1 ± 64.1 vs. 76.8 ± 79.8 U/L), and cirrhosis (15.5% vs. 14.5%). At week 144 of treatment, 91 and 94% of the ETV and TDF groups, respectively, achieved undetectable hepatitis B virus DNA. In HBeAg-positive patients, HBeAg seroconversion could be achieved in 27.4% and 33.7% at week 144 for ETV and TDF groups, respectively. Quantitative hepatitis B surface antigen dropped significantly over 144 weeks of treatment period but only 1.0 to 1.5% experienced hepatitis B surface antigen loss. Safety profiles were consistent with previous reports of monotherapy.

CONCLUSION

Both ETV and TDF showed potent antiviral activity against hepatitis B. Either ETV or TDF can be recommended as a treatment of choice for patients with chronic hepatitis B. Both drugs were safe and well tolerated.

Tenofovir versus tenofovir plus entecavir for chronic hepatitis B with lamivudine resistance and entecavir resistance

We compared the viral suppressive efficacy of tenofovir disoproxil fumarate (TDF) mono-rescue therapy (TDF group) and TDF plus entecavir (ETV) combination-rescue therapy (TDF + ETV group) in chronic hepatitis B (CHB) patients with lamivudine resistance and entecavir resistance. One hundred and thirty-three CHB patients with lamivudine and entecavir resistance were investigated. Ninety-six patients were treated with TDF and 37 with TDF + ETV for at least 6 months. We compared the virologic response rate (HBV DNA level <20 IU/mL) between the two groups and identified the predictive factors of treatment outcome. There were no significant differences between the two groups in demographic characteristics. Up to 24 months [median: 18 (range 6-24) months], 85.4% and 89.2% of the TDF group and TDF + ETV group, respectively, achieved a virologic response (P=.068). Only the HBV DNA level at baseline was significantly associated with a virologic response in the multivariate analysis. In a subanalysis of patients with HBV DNA levels ≥4 log (IU/mL) at baseline, a higher proportion of patients in the TDF + ETV group than the TDF group achieved a virologic response (92.9% vs 68.3%; P<.001), while 90% of patients with HBV DNA (IU/mL) levels <4 log in all both TDF and TDF + ETV groups achieved a virologic response. TDF mono-rescue therapy is a reasonable option in patients with lamivudine resistance and entecavir resistance. However, the combination strategy should be considered in patients with high baseline HBV DNA levels.

No detectable resistance to tenofovir disoproxil fumarate in HBeAg+ and HBeAg- patients with chronic hepatitis B after 8 years of treatment

A major hurdle in the long-term treatment of chronic hepatitis B (CHB) patients is to maintain viral suppression in the absence of drug resistance. To date, no evidence of resistance to tenofovir disoproxil fumarate (TDF) has been observed. A cumulative evaluation of CHB patients who qualified for resistance surveillance over 8 years of TDF treatment was conducted. Patients in studies GS-US-174-0102 (HBeAg-) and GS-US-174-0103 (HBeAg+) were randomized 2:1 to receive TDF or adefovir dipivoxil (ADV) for 48 weeks followed by open-label TDF through year 8. Population sequencing of HBV pol/RT was attempted for all TDF-treated patients at baseline and, annually if viremic, at discontinuation, or with addition of emtricitabine. Overall, 88/641 (13.7%) patients qualified for sequence analysis at one or more time points. The percentage of patients qualifying for sequence analysis declined over time, from 9 to 11% in years 1-2 to <4% over years 3-8. Forty-one episodes of virologic breakthrough (VB) occurred throughout the study, with most (n=29, 70%) associated with nonadherence to study medication. Fifty-nine per cent of VB patients with an opportunity to resuppress HBV achieved HBV DNA resuppression. A minority of patients who qualified for sequencing had polymorphic (41/165, 24.8%) or conserved (17/165, 10.3%) site changes in pol/RT, with six patients developing lamivudine and/or ADV resistance-associated mutations. No accumulation of conserved site changes was detected. The long-term treatment of CHB with TDF monotherapy maintains effective suppression of HBV DNA through 8 years, with no evidence of TDF resistance or accumulation of conserved site changes.

Diabetes mellitus and metformin in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Diabetes mellitus, a risk factor for cancer, is also globally endemic. The clinical link between these two diseases has been the subject of investigation for a century, and diabetes mellitus has been established as a risk factor for HCC. Accordingly, metformin, a first-line oral anti-diabetic, was first proposed as a candidate anti-cancer agent in 2005 in a cohort study in Scotland. Several subsequent large cohort studies and randomized controlled trials have not demonstrated significant efficacy for metformin in suppressing HCC incidence and mortality in diabetic patients; however, two recent randomized controlled trials have reported positive data for the tumor-preventive potential of metformin in non-diabetic subjects. The search for biological links between cancer and diabetes has revealed intracellular pathways that are shared by cancer and diabetes. The signal transduction mechanisms by which metformin suppresses carcinogenesis in cell lines or xenograft tissues and improves chemoresistance in cancer stem cells have also been elucidated. This review addresses the clinical and biological links between HCC and diabetes mellitus and the anti-cancer activity of metformin in clinical studies and basic experiments.

Three-year efficacy and safety of tenofovir in nucleos(t)ide analog-naïve and nucleos(t)ide analog-experienced chronic hepatitis B patients

BACKGROUND AND AIMS

This study compared the efficacy and safety of tenofovir disoproxil fumarate (TDF) up to 3 years of innucleos(t)ide analog (NA)-naïve and NA-experienced chronic hepatitis B (CHB) patients.

METHODS

Tenofovir disoproxil fumarate-treated NA-naïve and NA-experienced CHB patients were retrospectively analyzed.

RESULTS

After 3 years of TDF therapy, 97.7%, 71%, and 45.5% NA-naïve patients achieved a virological response, alanine aminotransferase normalization, and hepatitis B e antigen seroconversion, respectively. Compared with NA-naïve patients, NA-experienced patients without drug resistance and infected with lamivudine/telbivudine-resistant mutants showed similar results. In contrast, patients previously infected with adefovir-resistant mutants and with a suboptimal entecavir response showed significantly lower rates of virological response and hepatitis B e antigen loss/seroconverion than NA-naïve patients. Mean estimated glomerular filtration rate markedly reduced within 12 months of TDF therapy; however, it did not decrease significantly during 12-36 months of treatment. Diabetes mellitus was an independent predictor of a ≥ 0.5 mg/dL increase above baseline in serum creatinine level, and age, hypertension, diabetes mellitus, and baseline creatinine level were independent factors for > 20% decline in estimated glomerular filtration rate from baseline. Liver stiffness measurements improved significantly, but bone mineral density did not change significantly during treatment. Hepatocellular carcinoma incidence was low at 36 months. Age of > 60 years, cirrhosis, a low baseline platelet count and a high α-fetoprotein level at 12 months were significant predictors of hepatocellular carcinoma development.

CONCLUSIONS

Tenofovir disoproxil fumarate is effective and safe for NA-naïve and NA-experienced CHB patients and should be used cautiously in patients with comorbidities because of a renal dysfunction risk.

Effects of long-term tenofovir-based combination antiretroviral therapy in HIV-hepatitis B virus coinfection on persistent hepatitis B virus viremia and the role of hepatitis B virus quasispecies diversity

OBJECTIVE

Hepatitis B virus (HBV) can persist in some HIV-HBV coinfected individuals on tenofovir disoproxil fumarate (TDF)-containing combination antiretroviral therapy (cART) but HBV resistance to TDF has not been reported and the source of persistent HBV DNA on TDF is poorly understood. The aims of this study were to assess long-term HBV suppression in HIV-HBV coinfected individuals receiving TDF and investigate quasispecies variation using ultradeep pyrosequencing (UDPS).

METHODS

Ninety-two HIV-HBV coinfected participants on, or about to commence, TDF-containing cART were enrolled [Australia (n = 40), Thailand (n = 52)] and followed for 2 years with study visits every 6 months. HBV reverse transcriptase sequencing was performed on samples with HBV DNA more than 400 IU/ml by population-based methods and UDPS. Quasispecies diversity was assessed using Shannon entropy.

RESULTS

Over 24 months, viremia was detected at least once in 17% (n = 16) of the cohort. Novel mutations were not identified in on TDF samples tested by population-based sequencing (n = 19). Using UDPS, the median Shannon entropy value in samples prior to TDF in patients aviremic on TDF was not statistically different from those who were viremic on TDF (n = 50; 8.4 and 9.1, respectively, P = 0.9). Longitudinal Shannon entropy analysis of on TDF samples from five participants showed three individuals with significant changes in viral diversity over time.

CONCLUSION

Persistent viremia on TDF-containing cART is common but TDF-resistance was not detected. In some individuals, changes in viral diversity over time were observed on TDF which could potentially be active viral replication. Further follow-up will be needed to determine the clinical significance of detectable HBV DNA on TDF-containing cART.

Long-Term Efficacy of Tenofovir Disoproxil Fumarate Therapy in Nucleos(t)ide-Experienced Chronic Hepatitis B Patients

BACKGROUND AND OBJECTIVES

Tenofovir disoproxil fumarate (TDF) therapy is a therapeutic option for nucleos(t)ide analogue (NA)-experienced chronic hepatitis B (CHB) patients infected with hepatitis B virus (HBV). In this study, we evaluated the efficacy of TDF alone compared with the efficacy of TDF plus additional NA combinations in NA-experienced CHB patients.

METHODS

This retrospective cohort study included 108 patients with a serum HBV DNA level above 5.0 log10 IU/ml who were treated with TDF alone (monotherapy group) or TDF combined with additional NAs (combination therapy group) for 30 months.

RESULTS

At month 30, both therapies resulted in the suppression of HBV DNA levels: 66 of 66 patients (100 %) in the monotherapy group and 40 of 42 patients (95.23 %) in the combination therapy group achieved virologic suppression. Kaplan-Meier curves revealed median times for virologic suppression of 3.12 months in the monotherapy group and 5.23 months in the combination therapy group (p = 0.699). The probability of virologic suppression was comparable between treatment groups. At month 6, more patients achieved normal alanine aminotransferase (ALT) levels in the monotherapy group (p = 0.029). During the treatment period, no patients experienced severe renal dysfunction.

CONCLUSION

TDF monotherapy and TDF plus additional NAs have comparable antiviral efficacy in CHB patients after NA treatment failure.

The frequency and skewed T-cell receptor beta-chain variable patterns of peripheral CD4(+)CD25(+) regulatory T-cells are associated with hepatitis B e antigen seroconversion of chronic hepatitis B patients during antiviral treatment

The frequency and T-cell receptor beta-chain variable (TCRBV) patterns of peripheral CD4(+)CD25(+) regulatory T-cells (Tregs) are ambiguously altered in chronic hepatitis B (CHB) patients following tenofovir disoproxil fumarate (TDF) treatment. Moreover, the clinical significance of these parameters in relation to hepatitis B e antigen (HBeAg) seroconversion (SC) is largely unknown. In this study, the circulation of Tregs in HBeAg-positive CHB patients was determined by flow cytometry, and the molecular profiles of frequent TCRBV patterns of Tregs were analyzed using a gene melting spectral pattern. The parameters, such as Treg frequency, the number of skewed TCRBV patterns, hepatitis B virus (HBV) DNA levels, and alanine aminotransferase (ALT) levels, were analyzed by comparing their associations in seroconverting and non-seroconverting patients following TDF treatment. The Treg frequency was significantly correlated with the ALT level in seroconverting but not in non-seroconverting patients. Similarly, skewed TCRBV patterns were remarkably associated with HBV DNA levels in the SC group. Six TCRBV families (BV3, BV11, BV12, BV14, BV20, and BV24) were more prevalent than other TCRBV members in seroconverting patients pretreated with TDF, while BV12, BV15, and BV22 were predominant in non-seroconverting patients during TDF treatment. Taken together, the preferential TCRBV patterns may be associated with immune responses related to SC. The dynamic frequency and skewed TCRBV patterns of peripheral Tregs could contribute to predicting SC in CHB patients. Moreover, the conserved TCRBV complementarity-determining region (CDR3) motif may be targeted to develop personalized immunotherapy for CHB patients.

Treatment Outcomes With First-line Therapies With Entecavir and Tenofovir in Treatment-Naive Chronic Hepatitis B Patients in a Routine Clinical Practice

BACKGROUND

Given their high efficacy, entecavir (ETV) and tenofovir (TDF), are the recommended first-line therapies for chronic hepatitis B, but it is not clear whether the efficacy reported from pivotal trials is similar to the outcomes seen in routine practice.

GOALS

Our goal was to examine the treatment outcomes of antiviral therapy in such setting.

PATIENTS AND METHODS

We conducted a retrospective study of 557 consecutive treatment-naive patients who started either ETV (n=443) or TDF (n=114) at 3 US liver clinics between January 2005 and 2012. Primary study endpoint was complete viral suppression (CVS) rate (hepatitis B virus DNA<40 IU/mL).

RESULTS

The majority of patients in both ETV and TDF groups were Asians, hepatitis B e antigen (HBeAg) negative, male, and with similar pretreatment alanine aminotransferase and hepatitis B virus DNA levels. Similar proportions of patients in the ETV and TDF groups achieved CVS at 24 months: 87.7% versus 87.0%, respectively. Cumulative rates of virological breakthrough in the ETV and TDF groups were 1.0% versus 4.8% (P=0.26) and 3.7% versus 9.8% (P=0.04) at month 12 and 24, respectively; and all were associated with medication nonadherence. Cumulative rate of medication nonadherence was lower in the ETV than TDF group: 4.6% versus 7.8% at month 12 and 8.9% versus 16.9% at month 24, respectively.

CONCLUSIONS

Patients treated with either ETV or TDF achieve a similar rate of CVS at 24 months. The primary contributor to suboptimal response was medication nonadherence. Attention to medication adherence is needed in a routine clinical setting.

Efficacy of Tenofovir-Based Combination Therapy versus Tenofovir Monotherapy in Chronic Hepatitis B Patients Presenting with Suboptimal Responses to Pretreatment: A Meta-Analysis

Background/Aims. It remains unclear whether tenofovir disoproxil fumarate- (TDF-) based combination therapy produces better outcomes than TDF monotherapy in chronic hepatitis B (CHB) patients. The aim of this study was to compare the efficacy of the two regimens by performing a meta-analysis. Methods. A comprehensive literature search was performed on the comparison of TDF-based combination therapy and monotherapy for CHB patients in the PubMed, Embase, Web of Science, and the Cochrane Libraries. Both dichotomous and continuous variables were extracted and pooled outcomes were expressed as risk ratio (RR) or standard mean difference (SMD). Results. Nine eligible studies (1089 subjects in total) were included in our analysis. The proportion of patients with undetectable HBV DNA at 24, 48, and 96 weeks were similar between the two comparable groups (62.5% versus 70.9%, P = 0.086; 78.1% versus 83.7%, P = 0.118; 86.4% versus 87.9%, P = 0.626, resp.). HBV DNA reduction, rates of ALT normalization, hepatitis B e antigen (HBeAg) loss, and HBeAg seroconversion were also similar between the two groups. Conclusions. On the current data, TDF-based combination therapy seemed to be no better than those achieved by monotherapy. Further studies are needed to verify this comparison.

Evaluation of antiviral resistant hepatitis B virus subpopulations in patients with chronic hepatitis B by using terminal restriction fragment length polymorphism

Antiviral therapies with nucleotide analogues (NA) is crucial in the treatment of chronic hepatitis B as it substantially protects patients from the complications of the disease . However in most of the available NA therapies, resistance emerges in the patients' HBV populations. Therefore, detection of antiviral resistance as early as possible by means of genotypically monitoring the patients' HBV pool during NA therapy is critical to manage treatment regime. In this research study we have investigated the sensitivity and specificity of the terminal restriction fragment length polymorphism (T-RFLP) method in detecting HBV subpopulations carrying antiviral resistance mutations. For this aim, differentiation of mutant strains from wild type strains was demonstrated by PCR-RFLP method. With using recombinant plasmids containing mutant and wild type HBV genomes, we constructed artificial HBV genome populations in order to determine the sensitivity of PCR-T-RFLP method in detecting antiviral resistant minor HBV populations. Finally by comparing with the DNA sequencing method, we demonstrated the specificity of T-RFLP method in genotyping HBV populations. As a result we showed that T-RFLP is able to detect HBV subpopulations representing as low as 1 % of the whole viral population. Additionally T-RFLP showed 100 % concordance with the DNA sequencing method in genotyping HBV populations. As a conclusion, considering the other genotyping methods used in evaluating HBV populations, T-RFLP showed high sensitivity and specificity profiles in detecting antiviral resistant HBV subpopulations. Therefore T-RFLP method can be easily employed in genotypic evaluation of patients' HBV populations during the course of antiviral treatment.

Effect of tenofovir disoproxil fumarate on drug-resistant HBV clones

BACKGROUND & AIMS

Tenofovir disoproxil fumarate (TDF) has been approved for chronic hepatitis B treatment, and favorable susceptibility of hepatitis B virus (HBV) has been indicated. However, differences in TDF susceptibility among HBV genotypes and drug-resistant strains are unclear. In this study, TDF susceptibilities between genotypes A and C were evaluated in vitro and in vivo using several drug-resistant HBV clones.

METHODS

HBV expression plasmids were constructed from sera of HBV carriers, and drug-resistant substitutions were introduced by site-directed mutagenesis. TDF susceptibility was evaluated by changes of core-associated HBV replication intermediates in vitro or by change of serum HBV DNA in human hepatocyte chimeric mice carrying each HBV clone in vivo.

RESULTS

TDF susceptibilities of lamivudine-resistant clones (rtL180M/M204V) and lamivudine plus entecavir-resistant clones (rtL180M/S202G/M204V) were similar to wild type clones in vitro. However, lamivudine plus adefovir-resistant clones (rtA181T/N236T) acquired tolerance to TDF, and the rtN236T mutation was considered to be a causal substitution for TDF resistance. Furthermore, genotypic differences in TDF susceptibility were also observed between genotypes A and C in vitro, and the differences could be confirmed in vivo (p = 0.023).

CONCLUSIONS

The present study indicates that TDF susceptibility varies among HBV genotypes and drug-resistant HBV clones.

Real life adherence of chronic hepatitis B patients to entecavir treatment

BACKGROUND

Real-life prospective data on adherence to nucleos(t)ide analogues in chronic hepatitis B patients are scarce.

AIMS

We investigated adherence to entecavir in relation to virological response.

METHODS

In this prospective study, we provided 100 consecutive chronic hepatitis B patients with a medication dispenser that monitored entecavir intake during 16 weeks therapy. Hepatitis B virus (HBV) DNA was measured at baseline and after 16 weeks. Beliefs about medicines were evaluated using a questionnaire.

RESULTS

Adherence over 16 weeks averaged 85 ± 17%, with 70% of patients exhibiting good (i.e. ≥ 80%) adherence. Patients with poor (i.e. <80%) adherence were significantly younger (p=0.01), with more often indifferent attitudes towards entecavir (p=0.03) Viral breakthrough did not occur during the study. Adherence in patients with HBV DNA after 16 weeks > 20 IU/mL (n=18) and ≤ 20 IU/mL (n=81) averaged 83% and 91% respectively (p=0.19). In multivariate analysis, adherence was not a significant predictor of HBV DNA negativity (adjusted OR 1.02; p=0.34), after adjustment for duration of entecavir treatment (p<0.001) and HBe-status (p=0.001).

CONCLUSIONS

70% of chronic hepatitis B patients exhibited good adherence to entecavir, with younger age and an indifferent attitude being risk factors for poor adherence. Poor adherence was not an independent predictor of virological response.

Comparable efficacy with entecavir monotherapy and tenofovir-entecavir combination in chronic hepatitis B patients

OBJECTIVES

The long-term goal for chronic hepatitis B patients is to maintain viral suppression in order to reduce disease progression risk. Because patients with previous treatment failure may have multiple viral resistance mutations, finding effective therapy is challenging. Because recent studies have shown that the combination of entecavir and tenofovir is effective in achieving virological response in many patients with prior treatment failure and multiple drug resistance mutations, we compared outcomes with this combination versus monotherapy.

METHODS

With a retrospective chart review we compared results in 35 patients with previous treatment failure treated with the entecavir-tenofovir combination to results in patients treated with entecavir monotherapy.

RESULTS

Although combination therapy resulted in significantly faster achievement of DNA negativity compared to entecavir monotherapy, the modest ten-week advantage is unlikely to be important for most patients since entecavir resistance develops extremely slowly. Significantly more patients on combination therapy experienced viral breakthroughs, most of which were attributed to non-adherence due to difficulties with the combination regimen.

CONCLUSIONS

Our findings of reasonably comparable efficacy over time in the combination and monotherapy arms combined with the increased costs and compliance issues related to combination therapy weigh in favor of entecavir monotherapy in patients with previous treatment failure. However, because our study was a retrospective analysis of a small patient population, it will be important to confirm these findings with a randomised, controlled trial that compares these treatment approaches in treatment-experienced patients.

Similar efficacy and safety of tenofovir in Asians and non-Asians with chronic hepatitis B

AIM: To compare the efficacy and safety of tenofovir disoproxil fumarate (TDF) in Asian and non-Asian chronic hepatitis B (CHB) patients.

METHODS: The efficacy and safety of the initial 48 wk of treatment with TDF was compared in a post-hoc analysis of combined data from 217 Asians and 299 non-Asians included in Studies 102 and 103 and a post-approval, open-label trial (Study 123). Patient groups were compared according to baseline hepatitis B e antigen (HBeAg) status and viral load. The main outcome measures included the proportion of patients who achieved a hepatitis B virus (HBV) DNA level < 400 copies/mL at Week 48 of treatment. Secondary measures included: HBV DNA and alanine aminotransaminase (ALT) levels over time; proportion of patients with normal ALT levels; proportion of patients with HBeAg loss/seroconversion and proportion of patients with hepatitis B surface antigen loss/seroconversion; changes in liver histology. Safety and tolerability were evaluated by the occurrence of adverse events (AEs), serious AEs, laboratory abnormalities, discontinuation of the study drug due to AEs, or death. The primary efficacy and safety analysis set included all patients who were randomly assigned to treatment and received at least one dose of study drug.

RESULTS: At week 48, similar proportions of Asians and non-Asians reached HBV DNA < 400 copies/mL (96% of Asian and 97% of non-Asian patients with HBeAg-negative CHB and 83% of Asian and 79% of non-Asian patients with HBeAg-positive CHB had HBV DNA) and normal ALT (78% of Asian and 81% of non-Asian patients with HBeAg-negative CHB and 71% of Asian and 74% of non-Asian patients with HBeAg-positive CHB had normal ALT). On-treatment HBV DNA decline rates were similar between Asians and non-Asians regardless of baseline HBeAg status and viral load. HBV DNA decline during the first four weeks was 2.9 log₁₀ copies/mL in HBeAg-negative Asians and non-Asians, and in HBeAg-positive non-Asians, and 3.1 log10 copies/mL in HBeAg-positive Asians. HBeAg loss and seroconversion was achieved in 14% of Asians vs 26% and 24%, respectively, in non-Asians. Liver histology improved in 77.2% of Asians and 71.5% of non-Asians. No resistance to TDF developed. No renal safety signals were observed.

CONCLUSION: TDF demonstrated similar viral suppression, normalization of ALT, improvements in liver fibrosis, and no detectable resistance in Asian and non-Asian patients regardless of baseline HBeAg status.

Short Term Virologic Efficacies of Telbivudine versus Entecavir against Hepatitis B-Related Hepatocellular Carcinoma

Telbivudine has been reported to be more effective than lamivudine. However, because of the resistance rate to telbivudine (TLV), the current guidelines recommend entecavir (ETV) or tenofovir (TNV) as the first-line therapy for chronic hepatitis B. We investigated the short term virologic efficacy of TLV in comparison with ETV as the first-line agent of HBV suppression in HBV-related advanced HCC patients. A total of 86 consecutive patients with HBV-related HCC for whom antiviral treatment was initiated in Incheon St. Mary's Hospital between 2010 and 2013 were analyzed. Virologic responses were investigated on the 4th, 12th, and 24th weeks of the antiviral therapies. In patients with advanced TNM stage cancer (stage 3 or 4) and poor liver function (Child-Pugh class B or C), the virologic response rates at weeks 12 and 24 were 25% (1/4) and 42.8% (3/7) in the TLV group and 33.3% (1/3) and 33.3% (1/3) in the ETV group, respectively (P = 0.424, P = 0.800). The short term efficacy of TLV was similar to that of ETV. Since TLV is highly cost-effective, it should be considered as a first-line antiviral agent in patients with advanced HCC, poor liver function, and short life expectancies.

Tenofovir disoproxil fumarate is superior to lamivudine plus adefovir in lamivudine-resistant chronic hepatitis B patients

AIM: To assess the efficacy of tenofovir disoproxil fumarate (TDF) in lamivudine (LAM)-resistant patients with a suboptimal response to LAM plus adefovir (ADV).

METHODS: We retrospectively analyzed the efficacy of switching to tenofovir disoproxil fumarate in suboptimal responders to lamivudine plus adefovir. Charts were reviewed for LAM-resistant chronic hepatitis B (CHB) patients who visited the Zhejiang Province People’s Hospital and The First Affiliated Hospital, College of Medicine, Zhejiang University, from June 2009 to May 2013. Patients whose serum hepatitis B virus (HBV) DNA remained detectable despite at least 6 mo of LAM plus ADV combination therapy were included. Patients with a suboptimal response to LAM plus ADV were randomized to switch to TDF monotherapy (300 mg/d orally; TDF group) or to continuation with LAM (100 mg/d orally) plus ADV (10 mg/d orally; LAM plus ADV group) and were followed for 48 wk. Serum HBV DNA was determined at baseline and weeks 4, 12, 24, 36, and 48. HBV serological markers and biochemistry were assessed at baseline and weeks 12, 24, and 48. Resistance surveillance and side effects were monitored during therapy.

RESULTS: Fifty-nine patient were randomized to switch to TDF (n = 28) or continuation with LAM plus ADV (n = 31). No significant differences were found between the groups at baseline. Prior to TDF therapy, all patients had been exposed to LAM plus ADV for a median of 11 mo (range: 6-24 mo). No difference was seen in baseline serum HBV DNA between the two groups [5.13 ± 1.08 log₁₀ copies/mL (TDF) vs 5.04 ± 31.16 log₁₀ copies/mL (LAM + ADV), P = 0.639]. There was no significant difference in the rates of achieving complete virological response (CVR) at week 4 between the TDF and LAM + ADV groups (17.86% vs 6.45%, P = 0.24). The rate of achieving CVR in the TDF and LAM plus ADV groups was 75% vs 16.13% at week 12, 82.14% vs 22.58% at week 24, 89.29% vs 25.81% at week 36, and 96.43% vs 29.03% at week 48, respectively (P < 0.001). The rate of alanine aminotransferase normalization was significantly higher in the TDF than in the LAM plus ADV group at week 12 (75% vs 17.86%, P < 0.001), but not at week 24 (78.57% vs 54.84%, P = 0.097) or 48 (89.26% vs 67.74%, P = 0.062). Patients were hepatitis B e antigen (HBeAg) positive at baseline. There was no significant difference in HBeAg negativity between the TDF and LAM plus ADV groups at week 48 (4% vs 0%, P = 0.481). There were no drug-related adverse effects at week 48 in either group.

CONCLUSION: Switching to TDF monotherapy was superior to continuous add-on therapy in patients with LAM-resistant CHB with a suboptimal response to LAM plus ADV.

Hepatitis B virus infection in children

For two decades, hepatitis B vaccine has been integrated into national routine childhood vaccination programs in almost all countries. The prevalence of HBsAg has decreased in children worldwide. However, there are children who miss the benefit of hepatitis B vaccine in some regions and countries. Long-term follow-up studies have revealed the clinical outcomes of chronic hepatitis B virus infection in children. A small percentage of chronically infected children develop liver cirrhosis and hepatocellular carcinoma. However, it is controversial who should be treated and when antiviral treatment should be initiated in children. Compared with adult studies, the data are insufficient to evaluate the pathogenesis of hepatitis B infection and the efficacy of antiviral treatment in childhood. New antiviral drugs have been approved for children and adults. Also, oral antiviral drugs are administered to pregnant women to reduce the hepatitis B virus mother-to-child transmission rate.

Incidence of natural resistance mutations in naïve chronic hepatitis B patients: a systematic review and meta-analysis

BACKGROUND AND AIM

Studies focused on the naturally occurring resistance mutation rate in treatment-naïve chronic hepatitis B (CHB) patients have set off a furious dispute. We conduct this meta-analysis to appraise the pooled incidence of spontaneous hepatitis B virus resistance mutations worldwide and its distribution.

METHODS

We searched PubMed, EMBASE, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure until December 31, 2013. Cross-sectional or case-control studies reporting incidence of natural resistance mutations in untreated CHB patients were included. Pooled incidence was performed in fixed- or random-effects models, and heterogeneity among studies was assessed.

RESULTS

A total of 106 studies were included involving 12,212 naive CHB patients. The summarized incidence of natural mutations worldwide was 5.73% (95% confidence interval [CI]: 4.85-6.61%), primary mutation rate 5.39% (95%CI: 4.54-6.24%), and secondary mutation rate 2.94% (95%CI: 1.59-4.29%). The pooled incidence reached up to 8.00% (95%CI: 6.63-9.38%) in China, higher than that in other countries (1.88% [95%CI: 1.06-2.69%]). Mutation rtM204V/I had the highest incidence of 4.89% (95%CI: 4.13-5.65%), and other primary mutations seldom spontaneously occurred. In subgroup analysis, genotype C hepatitis B virus infection, male, and hepatitis B antigen (HBeAg) negative patients had a slightly higher natural mutation rate.

CONCLUSION

The resistance mutations occurred frequently in untreated CHB patients, especially in China. The lamivudine resistance had the highest natural prevalence rate, while other nucleos(t)ide analogues showed rarely spontaneous resistance. Detecting the spontaneous resistance mutations will benefit the clinical management of CHB patients.

Tenofovir disoproxil fumarate vs adefovir dipivoxil in Chinese patients with chronic hepatitis B after 48 weeks: a randomized controlled trial

Tenofovir disoproxil fumarate (TDF) has demonstrated long-term efficacy and a high barrier to resistance in multiple chronic hepatitis B (CHB) populations outside of China. This study aimed to evaluate the efficacy and safety of TDF compared with adefovir dipivoxil (ADV) in Chinese patients with CHB during 48 weeks of treatment (ClinicalTrial.gov number, NCT01300234). A Phase 3, multicentred, randomized, double-blind, controlled trial compared the efficacy and safety of TDF with ADV in Chinese patients with CHB. The primary endpoint was the proportion of patients with HBV DNA <400 copies/mL in each treatment group at Week 48, using an unpooled Z-test for superiority. Secondary endpoints included viral suppression, serologic response, histological improvement, normalization of alanine aminotransferase (ALT) levels and the emergence of resistance mutations. A total of 509 patients, 202 hepatitis B e antigen (HBeAg)-positive and 307 HBeAg-negative, with HBV DNA ≥10(5) copies/mL received either TDF 300 mg od or ADV 10 mg od. At Week 48, TDF demonstrated superior viral suppression compared with ADV in both HBeAg-positive (76.7% vs 18.2%, P < 0.0001) and HBeAg-negative (96.8% vs 71.2%, P < 0.0001) patients. The majority of patients in both treatment arms achieved ALT normalization (>85%). No resistance to TDF was observed. The frequency of adverse events was comparable between treatment arms (TDF 3.9% vs ADV 4.8%). In this double-blind, randomized, clinical trial, TDF demonstrated superiority over ADV with respect to viral suppression in Chinese patients with CHB at 48 weeks of treatment and without the development of resistance.

Recent advances in prevention of hepatitis B recurrence after liver transplantation

Liver transplantation is the only effective treatment for hepatitis B virus (HBV)-related end-stage liver disease. However, without antiviral prophylaxis, the recurrence rate of hepatitis B is as high as 80%-100%, which leads to a 50% mortality rate in the first 2 years after liver transplantation. Combination therapy of hepatitis B immunoglobulin (HBIG) and lamivudine demonstrated a higher efficacy of prophylaxis and further reduced the rate of recurrence to < 10%. The strategy of HBIG combined with lamivudine has been the standard treatment in many centers. However, the high rate of lamivudine resistance and the many disadvantages of HBIG have compelled surgeons to reconsider the long-term efficacy of this strategy for the prevention of HBV reinfection. Recently, new nucleos(t)ide analogues, such as entecavir and tenofovir, have been approved as first-line monotherapies for the treatment of chronic hepatitis B infection. These antiviral medicines have replaced lamivudine as the first choice in the prevention of HBV recurrence after liver transplantation. Various therapies that are composed of entecavir, tenofovir, and lamivudine plus adefovir, with or without HBIG have been adopted in several liver transplant centers. This article reviews the recent advances in prophylaxis for the recurrence of hepatitis B after liver transplantation.