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Summary The majority of persons currently treated for chronic hepatitis B require long-term or lifelong therapy. New inhibitors of hepatitis B virus entry, replication, assembly, or secretion and immune modulatory therapies are in development. The introduction of these novel compounds for chronic hepatitis B necessitates a standardised appraisal of the efficacy and safety of these treatments and definitions of new or additional endpoints to inform clinical trials. To move the field forward and to expedite the pathway from discovery to regulatory approval, a workshop with key stakeholders was held in September 2016 to develop a consensus on treatment endpoints to guide the design of clinical trials aimed at hepatitis B cure. The consensus reached was that a complete sterilising cure, i.e ., viral eradication from the host, is unlikely to be feasible. Instead, a functional cure characterised by sustained loss of hepatitis B surface antigen with or without hepatitis B surface antibody seroconversion, which is associated with improved clinical outcomes, in a higher proportion of patients than is currently achieved with existing treatments is a feasible goal. Development of standardised assays for novel biomarkers toward better defining hepatitis B virus cure should occur in parallel with development of novel antiviral and immune modulatory therapies such that approval of new treatments can be linked to the approval of new diagnostic assays used to measure efficacy or to predict response. Combination of antiviral and immune modulatory therapies will likely be needed to achieve functional hepatitis B virus cure. Limited proof-of-concept monotherapy studies to evaluate safety and antiviral activity should be conducted prior to proceeding to combination therapies. The safety of any new curative therapies will be paramount given the excellent safety of currently approved nucleos(t)ide analogues. [ABSTRACT FROM AUTHOR]

Background & Aims: Suboptimal virologic response to nucleos(t)ide analogs may represent a significant risk factor for resistance development in patients with chronic hepatitis B virus infection; treatment options have not been well studied. We evaluated long-term efficacy and safety of tenofovir alone and in combination with emtricitabine in a prospective, placebo-controlled trial in patients who remained viremic on adefovir therapy. Methods: Hepatitis B e antigen-positive and -negative patients with hepatitis B virus DNA ⩾1000 copies/ml despite up to 96weeks of adefovir were randomized to double-blind tenofovir or emtricitabine/tenofovir for 168weeks. Patients with hepatitis B virus DNA ⩾400 copies/ml (⩾69IU/ml) at or after week 24 could switch to open-label emtricitabine/tenofovir. Results: Overall, 90/105 (86%) patients (46/53 tenofovir and 44/52 emtricitabine/tenofovir) completed the 168-week study period, including 74/105 (70%) patients (35/53 tenofovir and 39/52 emtricitabine/tenofovir) who completed the study on their initial randomized treatment. Long-term viral suppression (hepatitis B virus DNA <400 copies/ml) was maintained at week 168 in 84% and 82% of patients receiving either emtricitabine/tenofovir combination or tenofovir monotherapy, respectively (non-completer equal to failure analysis). Baseline viral load as well as the presence of lamivudine and/or adefovir resistance-associated mutations at baseline had no impact on long-term treatment response. No resistance to tenofovir was observed through 168weeks. Both treatments had a favorable safety profile. Conclusions: Tenofovir monotherapy is as effective as emtricitabine/tenofovir combination therapy in maintaining long-term viral suppression in patients with a suboptimal response to adefovir, and is well tolerated in this population. [Copyright &y& Elsevier]

Abstract: Because of the slow kinetics of viral clearance and the spontaneous genetic variability of hepatitis B virus (HBV), antiviral therapy of chronic hepatitis B remains a clinical challenge. Despite the recent development of lamivudine, adefovir dipivoxil and pegylated interferon alpha for the treatment of chronic HBV infection, there is still a major need for new antiviral compounds. Entecavir, a guanosine analog, has been recently approved in US for the therapy of chronic hepatitis B and its registration is expected soon in Europe. Extensive studies have been performed to characterize its antiviral activity in enzymatic and tissue culture models, as well as in animal models of HBV infection. In clinical trails, entecavir administration was associated with a significantly more potent viral suppression compared to lamivudine, and a significant advantage in terms of biochemical and histological improvement compared to lamivudine. Entecavir was tolerated as well as lamivudine in these phase III trials. No case of resistance was detected after two years of therapy in nucleoside naïve patients. Treatment of patients with lamivudine failure requires a higher dosage of entecavir and induces a significant decline in viraemia levels. However, 10% of these patients developed entecavir resistance after two years of therapy. The availability of entecavir as a new treatment option is providing clincians more choice to keep both viral replication and liver disease under control. This provides new hope for improved treatment concepts for chronic HBV infection. [Copyright &y& Elsevier]

Chronic hepatitis B virus (HBV) infection remains a major public health problem worldwide. Until recently, interferon (IFN)-α was the only approved drug for the treatment of chronic HBV infection. The recent registration of lamivudine, a dideoxycytidine analogue that inhibits both the HIV and HBV reverse transcriptases, has provided new perspectives for the treatment of chronic HBV infection. Lamivudine treatment for 12 months leads to a control of viral replication during therapy in the majority of the patients and to sustained anti-hepatitis B e (anti-HBe) seroconversion in 16 to 22% of the patients, associated with a biochemical and histological response. Further studies showed that extended lamivudine therapy increases the rate of anti-HBe seroconversion. However, long-term therapy is associated with the progressive emergence of drug resistant mutants. In most cases these mutants are not associated with a deterioration of the liver disease within the available follow-up. In the remaining patients and in particular settings such as liver transplantation, a severe exacerbation of the liver disease is observed and that requires add-on therapy. Lamivudine treatment of patients infected with a pre-core mutant also showed beneficial effect with the control of viral replication, and a biochemical and histological response in approximately 60% of the patients at 1 year. These patients face the same problem of drug resistant mutants, and the optimal duration of lamivudine treatment still needs to be determined in this clinical situation. Moreover, lamivudine therapy is the only therapeutic option in decompensated cirrhotic patients to allow liver transplantation, and in liver transplant patients with HBV recurrence following transplantation. Adverse effects of lamivudine therapy are comparable to those observed in placebo-treated patients. ALT flares have been observed mainly in relation to the re-occurrence of viral replication due to the rebound of viral replication after therapy withdrawal, or to the emergence of drug resistance mutants. Therefore, lamivudine provides a new treatment alternative for patients with chronic HBV infection. For each patient, its indication has to be weighed against the risk of developing viral resistance but also against the risk of natural history of the disease. [ABSTRACT FROM AUTHOR]

Summary Chronic hepatitis B virus (HBV) infection remains a global problem. Several HBV genotypes exist with different biology and geographical prevalence. Whilst the future aim of HBV treatment remains viral eradication, current treatment strategies aim to suppress the virus and prevent the progression of liver disease. Current strategies also involve identification of patients for treatment, namely those at risk of progressive liver disease. Identification of HBV genotype, HBV mutants and other predictive factors allow for tailoured treatments, and risk-surveillance pathways, such as hepatocellular cancer screening. In the future, these factors may enable stratification not only of treatment decisions, but also of patients at risk of higher relapse rates when current therapies are discontinued. Newer technologies, such as next-generation sequencing, to assess drug-resistant or immune escape variants and quasi-species heterogeneity in patients, may allow for more information-based treatment decisions between the clinician and the patient. This article serves to discuss how HBV genotypes and genetic variants impact not only upon the disease course and outcomes, but also current treatment strategies. Adopting a personalised genotypic approach may play a role in future strategies to combat the disease. Herein, we discuss new technologies that may allow more informed decision-making for response guided therapy in the battle against HBV. [ABSTRACT FROM AUTHOR]

Summary: Antiviral therapy of chronic hepatitis B remains a clinical challenge. The primary goal of therapy is to prevent liver disease progression. Because of the mechanism of viral persistence in infected hepatocytes, long-term antiviral therapy is needed in the majority of patients. Incomplete viral suppression and emergence of drug resistance is a major concern. The correct choice of a first-line potent therapy to achieve sustained long-term suppression of viral replication provides the best chance of preventing treatment failure and drug resistance. Clinical studies have demonstrated that drugs with a high barrier to resistance, such as entecavir and tenofovir, have significantly lower rates of resistance when compared with those with a low barrier to resistance such as lamivudine, adefovir, or telbivudine. Management of treatment failure requires a precise clinical and accurate virologic monitoring as well as an early treatment intervention with appropriate complementary drugs with respect to their cross-resistance profile. Long-term surveillance for treatment efficacy and possible emergence of drug resistance is necessary for those patients who have been sequentially treated with multiple antivirals. Finally, the identification of novel treatment targets remains a major research challenge to improve the efficacy of current antiviral therapy. [ABSTRACT FROM AUTHOR]

In HBV-infected patients, therapies with nucleoside analogues or IFNα remain ineffective in eradicating the infection. Our aim was to re-analyze the anti-HBV activity of a large panel of IFNs and cytokines in vitro using non-transformed cultured hepatocytes infected with HBV, to identify new immune-therapeutic options. HepaRG cells and primary human hepatocytes were infected with HBV and, when infection was established, treated with various concentrations of different IFNs or inflammatory cytokines. Viral parameters were evaluated by quantifying HBV nucleic acids by qPCR and Southern Blot, and secreted HBV antigens were evaluated using ELISA. The cytokines tested were type-I IFNs, IFNγ, type-III IFNs, TNFα, IL-6, IL-1β, IL-18 as well as nucleos(t)ide analogues tenofovir and ribavirin. Cytokines and drugs, with the exception of IL-18 and ribavirin, exhibited a suppressive effect on HBV replication at least as strong as, but often stronger than, IFNα. The cytokine presenting the highest effect on HBV DNA was IL-1β, which exerted its inhibition within picomolar range. Importantly, we noticed differential effects on other parameters (HBV RNA, HBeAg, HBsAg) between both IFNs and inflammatory cytokines, thus suggesting different mechanisms of action. The combination of IL-1β and already used therapies, i.e. IFNα or tenofovir, demonstrated a stronger or similar anti-HBV activity. IL-1β was found to have a very potent antiviral effect against HBV in vitro . HBV was previously shown to promptly inhibit IL-1β production in Kupffer cells. Strategies aiming at unlocking this inhibition and restoring local production of IL-1β may help to further inhibit HBV replication in vivo . [ABSTRACT FROM AUTHOR]

Background and Aims HBsAg loss is a desired, but rare, treatment-induced clinical endpoint in chronic hepatitis B (CHB). Few studies have evaluated viral factors contributing to HBsAg loss. Methods This study evaluated baseline interpatient sequence diversity across the HBV genome in tenofovir disoproxil fumarate-treated patients who lost HBsAg and compared it to that of control patients with high HBsAg levels throughout therapy. Twenty-one HBeAg+ patients (14 genotype (GT) A and 7 GT D) who achieved HBsAg loss and 27 controls (17 GT A and 10 GT D), were analyzed. Population sequencing was performed on baseline samples and pairwise genetic distances were calculated for 17 overlapping regions across the HBV genome as a measure of interpatient viral diversity. Results Overall, viral diversity was up to 10-fold higher across GT D patients compared to GT A patients throughout the HBV genome. Within the pol/RT and HBs genes, interpatient viral diversity was significantly lower among HBsAg loss patients for both GT A and D, with the difference driven largely by a reduction in diversity in the small S gene. Conversely, interpatient viral diversity was generally higher in HBsAg loss patients across the HBx gene regulatory elements and precore region. Conclusion In HBsAg loss patients, less interpatient viral diversity was observed within structural-coding regions while specific regions across the HBx and precore genes encoding nonstructural regulatory elements generally displayed higher interpatient viral diversity. These distinct patterns may reflect different responses to adaptive pressure for HBV genomic structural and nonstructural elements. [ABSTRACT FROM AUTHOR]

Background & Aims: Long-term viral suppression is a major goal to prevent disease progression in patients with HBV. Aim of this study was to investigate the efficacy and safety of entecavir plus tenofovir combination in 57 CHB partial responders or multidrug resistant patients. Methods: Investigator-initiated open-label cohort study. Quantitative HBV-DNA measurement and resistance testing (line-probe-assays and direct-sequencing) at baseline and every 3months. Results: Fifty seven patients (37 HBeAg+), median age 45years, previously treated with a median of three lines of antiviral therapy (range 1–6), 24/57 with advanced liver disease, were included. Median ALT at baseline was 1.0ULN (range 0.3–22) and HBV-DNA 1.5×104 IU/ml (range 500–1×1011 IU/ml). Median treatment duration of combination therapy was 21months. HBV-DNA level dropped 3 logs (median, range 0–8log; p <0.0001), 51/57 patients became HBV-DNA undetectable, median after 6months (95% CI, 4.6–7). The probability for HBV DNA suppression was not reduced in patients with adefovir or entecavir resistance or in patients with advanced liver disease. Viral suppression led to decline in ALT (median 0.7ULN; range 0.2–2.4; p =0.001). Five patients lost HBeAg (after 15, 18, 20, 21, and 27months, respectively), one patient showed HBs-seroconversion. Patients with advanced disease did not show clinical decompensation, two patients with cirrhosis and undetectable HBV DNA developed HCCs. No death, newly induced renal impairment or lactic acidosis were reported. Conclusions: Rescue therapy with entecavir and tenofovir in CHB patients harboring viral resistance patterns or showing only partial antiviral responses to preceding therapies was efficient, safe, and well tolerated in patients with and without advanced liver disease (249). [Copyright &y& Elsevier]

Background & Aims: Entecavir is a potent inhibitor of viral replication in nucleos(t)ide analogue (NA)-naïve chronic hepatitis B patients, but data on the efficacy in NA-experienced subjects are limited. Methods: In a multi-center cohort study we investigated 161 chronic hepatitis B patients (34% NA-experienced) treated with entecavir monotherapy. Results: During a median follow-up of 11 (3–23)months, 82 (79%) of 104 NA-naïve patients achieved virologic response (VR), defined as HBV DNA <80IU/ml, and none of the patients (0%) developed genotypic entecavir-resistance. VR was demonstrated in 31 (54%) of 57 NA-experienced patients during a median follow-up of 12 (3–31)months. Patients with lamivudine-resistant mutations at the start of entecavir monotherapy had a reduced probability of achieving VR compared to lamivudine-naïve patients (HR 0.14; 95% CI 0.04–0.58; p =0.007). Antiviral efficacy was not decreased by prior treatment with lamivudine when lamivudine-resistance had never developed (HR 0.81; 95% CI 0.43–1.52; p =0.52). Prior adefovir therapy without development of adefovir-resistance (HR 0.84; 95% CI 0.43–1.64; p =0.61) and presence of adefovir-resistance (HR 0.86; 95% CI 0.27–2.71; p =0.80) did not influence antiviral response to entecavir. Switching to a tenofovir-containing treatment regimen resulted in viral load decline in patients with entecavir-resistance associated mutations. Conclusions: Entecavir proved to be efficacious in NA-naïve patients. The antiviral efficacy of entecavir was not influenced by prior treatment with adefovir or presence of adefovir-resistance. Entecavir should not be used in patients with previous lamivudine-resistance, yet it may still be an option in lamivudine-experienced patients in case lamivudine-resistance never developed. [Copyright &y& Elsevier]