Adding pegylated interferon to entecavir for hepatitis B e antigen-positive chronic hepatitis B: A multicenter randomized trial (ARES study)

From chronic immune thrombocytopenia to severe aplastic anemia: recent insights into the evolution of eltrombopag

Thrombopoietin (TPO) is the most potent cytokine stimulating thrombopoiesis. Therapy with exogenous TPO is limited by the formation of antibodies cross-reacting with endogenous TPO. Mimetics of TPO are compounds with no antigenic similarity to TPO. Eltrombopag is an orally-active nonpeptide small molecule that binds to the transmembrane portion of the TPO receptor MPL. Initial trials of eltrombopag have centered on immune thrombocytopenia (ITP), which is due to both increased destruction and decreased production of platelets. Eltrombopag at 25-75 mg/day has been shown to be highly effective in raising the platelet count in ITP with suboptimal response to immunosuppression and splenectomy. These successful results led to the exploration of eltrombopag in other thrombocytopenic disorders. In hepatitis C viral infection, eltrombopag raises the platelet count sufficiently enough to allow treatment with ribavirin and pegylated interferon. Because MPL is expressed on hematopoietic cells, eltrombopag use in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) might enhance leukemic proliferation. Clinical trials of eltrombopag in MDS and AML, however, have shown amelioration of thrombocytopenia without promoting disease progression. In severe aplastic anemia (SAA) not responding to immunosuppression with anti-thymocyte globulin (ATG) and cyclosporine, eltrombopag as a single agent at 150-300 mg/day results in an overall response rate of 40-70%. At high doses, adverse effects including pigmentation, gastrointestinal upset and hepatic derangement have become evident. Current studies have examined the first-line use of eltrombopag in combination with ATG in SAA. In a recent study, eltrombopag used at 150 mg/day with horse ATG resulted in an overall response rate of 90% in newly diagnosed SAA patients, with a complete response rate of about 50%. Clonal karyotypic aberrations are, however, found in 10-20% of SAA patients treated with eltrombopag. The safety and efficacy of eltrombopag in SAA require further evaluation, particularly when it is used with less intensive immunosuppression.

Phase IIb trial of in vivo electroporation mediated dual-plasmid hepatitis B virus DNA vaccine in chronic hepatitis B patients under lamivudine therapy

AIM

To assess the efficacy and safety of in vivo electroporation (EP)-mediated dual-plasmid hepatitis B virus (HBV) DNA vaccine vs placebo for sequential combination therapy with lamivudine (LAM) in patients with chronic hepatitis B.

METHODS

Two hundred and twenty-five patients were randomized to receive either LAM + vaccine (vaccine group, n = 109) or LAM + placebo (control group, n = 116). LAM treatment lasted 72 wk. Patients received the DNA vaccine or placebo by intramuscular injection mediated by EP at weeks 12 (start of treatment with vaccine or placebo, SOT), 16, 24, and 36 (end of treatment with vaccine or placebo, EOT).

RESULTS

In the modified intent-to-treat population, more patients had a decrease in HBV DNA > 2 log₁₀ IU/mL in the vaccine group at week 12 after EOT compared with the control group. A trend toward a difference in the number of patients with undetectable HBV DNA at week 28 after EOT was obtained. Adverse events were similar. In the dynamic per-protocol set, which excluded adefovir (ADV) add-on cases at each time point instantly after ADV administration due to LAM antiviral failure, more patients had a decrease in HBV DNA > 2 log₁₀ IU/mL in the vaccine group at week 12 and 28 after EOT compared with the control group. More patients with undetectable HBV DNA at week 28 after EOT in the vaccine group were also observed. Among patients with a viral load < 1000 copies/mL at week 12, more patients achieved HBeAg seroconversion in the vaccine group than among controls at week 36 after EOT, as well as less virological breakthrough and YMDD mutations.

CONCLUSION

The primary endpoint was not achieved using the HBV DNA vaccine. The HBV DNA vaccine could only be beneficial in subjects that have achieved initial virological response under LAM chemotherapy.

Recent advances in treatment of chronic hepatitis B with entecavir

Entecavir (ETV) is a potent hepatitis B virus inhibitor with a high barrier to resistance, and it has been recommended as one of the first-line drugs for treating chronic hepatitis B (CHB) by guidelines from several international and national societies. This paper reviews the recent advances in the treatment of CHB with ETV, in terms of treatment adherence, efficacy in the treatment of various kinds of patients with CHB, management of patients with partial virological response, viral resistance or treatment failure to ETV, treatment cessation, sequential or combination therapy with ETV and pegylated interferon, as well as the surveillance of hepatocellular carcinoma.

HBsAg clearance in chronic hepatitis B patients with add-on pegylated interferon alfa-2a to ongoing tenofovir treatment: A randomized controlled study

BACKGROUND/AIMS

The ideal end point of treatment for chronic hepatitis B virus (HBV) infection is sustained off-therapy hepatitis B surface antigen (HBsAg) loss with or even without seroconversion to anti-HBs. We investigated the role of adding PEGylated interferon (PEG IFN) to ongoing tenofovir treatment in chronic HBV patients for achieving HBsAg clearance.

PATIENTS AND METHODS

In this randomized controlled trial, chronic HBV patients who have been receiving tenofovir for >6 months with HBV viral load <2000 IU/ml were randomized into two groups. One group (add-on therapy) was given subcutaneous PEG IFN 180 mcg weekly for 12 months in addition to tenofovir. Patients in the other group received only tenofovir 300 mg orally on a daily basis. Patients in both groups were followed up for a total of two years, and patients in both groups were given tenofovir 300 mg daily indefinitely until they developed HBsAg clearance.

RESULTS

Twenty-three patients were allocated to the PEG IFN and tenofovir (add-on therapy) group, and another 25 patients were recruited to the tenofovir monotherapy group. Before randomization, patients had received tenofovir for 1135 mean days (range203 to 1542 days). One patient (4.3%) in add-on therapy lost HBsAg and seroconverted. Within two years, mean HBsAg decreased significantly with add-on therapy (from 4753 IU/ml to 2402; P= 0.03); and it decreased from 5957 IU/ml to 4198; P= 0.09 in tenofovir monotherapy group. More patients in the add-on group developed serious side effects, with treatment discontinuation, and dose reductions (P = 0.3).

CONCLUSION

PEG IFN and tenofovir add-on therapy was successful in achieving HBsAg clearance and seroconversion in 4.3% of the patients. Add-on therapy patients had a significant decrease in HBsAg levels in two years; and no significant decrease in HBsAg levels with the tenofovir monotherapy. With no significant HBsAg clearance, the utility of this combination regimen is questionable.

Intensification with pegylated interferon during treatment with tenofovir in HIV-hepatitis B virus co-infected patients

In hepatitis B "e" antigen (HBeAg) positive patients with hepatitis B virus (HBV) mono-infection, intensification of nucleos(t)ide analogue treatment with pegylated interferon (PegIFN) could help induce higher HBeAg seroclearance rates. Our aim was to determine the long-term effect of adding PegIFN to tenofovir (TDF)-containing antiretroviral therapy on seroclearance in HBeAg-positive patients co-infected with the human immunodeficiency virus (HIV) and HBV. In this prospective matched cohort study, 46 patients with 1-year PegIFN intensification during TDF-containing antiretroviral therapy (TDF+PegIFN) were matched 1:1 to controls undergoing TDF without PegIFN (TDF) using a time-dependent propensity score based on age, CD4+ count and liver cirrhosis status. Kinetics of HBeAg quantification (qHBeAg) and hepatitis B surface antigen quantification (qHBsAg) were estimated using mixed-effect linear regression and time to HBeAg seroclearance or HBsAg seroclearance was modelled using proportional hazards regression. At baseline, previous TDF exposure was a median 39.8 months (IQR=21.4-59.4) and median qHBeAg and qHBsAg levels were 6.9 PEIU/mL and 3.72 log₁₀ IU/mL, respectively (P>.5 between groups). Median follow-up was 33.4 months (IQR=19.0-36.3). During intensification, faster average declines of qHBeAg (-0.066 vs -0.027 PEIU/mL/month, P=.001) and qHBsAg (-0.049 vs -0.026 log₁₀ IU/mL/month, P=.09) were observed in patients undergoing TDF+PegIFN vs TDF, respectively. After intensification, qHBeAg and qHBsAg decline was no different between groups (P=.7 and P=.9, respectively). Overall, no differences were observed in HBeAg seroclearance (TDF+PegIFN=13.2 vs TDF=12.6/100 person·years, P=.5) or HBsAg seroclearance rates (TDF+PegIFN=1.8 vs TDF=1.3/100 person·years, P=.7). In conclusion, PegIFN intensification in HBeAg-positive co-infected patients did not lead to increased rates of HBeAg or HBsAg clearance, despite faster declines of antigen levels while on PegIFN.

Potential strategies for "cure" of hepatitis B

Hepatitis B is a worldwide health problem and the main cause of liver cirrhosis, liver failure, and liver cancer. The steady state of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in HBV infected hepatocytes and virus specific immune tolerance contribute to the chronic persistent infection and hard-to-cure of hepatitis B. The presently available therapeutics for hepatitis B can control viral replication, but rarely eliminate HBV surface antigen (HBsAg) or HBV cccDNA. The "cure" of hepatitis B, which is characterized by the HBsAg loss or HBsAg seroconversion, and cccDNA clearance, has been the goal of researchers for years. In recent years, with the robust progress in understanding the HBV pathogenesis and the rapid development of gene editing technology, the "cure" of hepatitis B becomes prospective. This paper aims to summarize the potential strategies for the "cure" of hepatitis B.

Interferon Treatment for Hepatitis B

Chronic hepatitis B virus (HBV) infection has a significant public health impact. There are currently 7 approved therapies for chronic HBV, including standard and pegylated interferon (IFN)-α, and 5 nucleos(t)ide analogs (NUCs). IFN offers benefits over NUCs, including a finite duration of therapy and a higher rate of clearance of hepatitis Be antigen and surface antigen. These benefits need to be weighed against the potential adverse effects of IFN therapy. Some patients should not receive IFN because of advanced liver disease or comorbidities. This article reviews the mechanisms of action, efficacy, and clinical use of IFN therapy for HBV infection.

Baseline HBsAg and HBcrAg titres allow peginterferon-based 'precision medicine' in HBeAg-negative chronic hepatitis B patients

Quantitative hepatitis B core-related antigen (qHBcrAg) has been proposed as an additional marker to quantitative HBsAg (qHBsAg), for management of chronic hepatitis B. Evaluate baseline combination of qHBsAg and qHBcrAg for identification of patients that could benefit from pegylated interferon-alpha-2a (PegIFN)-based therapy. Sixty-two HBeAg-negative patients treated with PegIFN or PegIFN plus tenofovir disoproxil fumarate (PegIFN+TDF). HBsAg and HBcrAg titres were evaluated at baseline. Thirty patients received PegIFN and 32 PegIFN+TDF. SR was 10 of 30 and 17 of 32 in PegIFN and PegIFN+TDF patients, respectively. Cut-offs determined by maximized Youden's index for identifying patients likely to respond to therapy were as follows: 3.141 log₁₀ IU/mL and 3.450 log₁₀ U/mL for HBsAg and HBcrAg, respectively. At the end of 3 years post-treatment follow-up, HBsAg loss was observed in 7 of 30 and 6 of 32 in PegIFN and PegIFN+TDF patients, respectively. The AUC was estimated to be 0.716 (95% CI [0.578, 0.855]) for HBsAg and 0.668 (95% CI [0.524, 0.811]) for HBcrAg (P=.5541). PPVs for AUCs(95%CI) were 0.762(0.590-0.947), 0.714(0.533-1.000) and 0.800(0.611-1.000), and NPVs for AUCs(95%CI) were 0.756(0.660-0.899), 0.718(0.630-0.857) and 0.765(0.675-0.889) for qHBsAg, qHBcrAg and the combination of both markers, respectively. Baseline qHBsAg 3.141 log₁₀ IU/mL and qHBcrAg 3.450 log₁₀ U/mL thresholds used separately or in combination allow prediction of response, prior to PegIFN-based therapy, with a PPV of 80.3% and NPV of 76.5%. Baseline qHBsAg is predictive of HBsAg loss. Both markers could be used, separately or in combination, for PegIFN-based 'precision therapy'. Our results emphasize that the combination of PegIFN alpha-2a plus TDF with 53% of SR might be an alternative to finite therapy.

Aiming for cure in HBV and HDV infection

Chronic hepatitis B virus (HBV) infection continues to be a major health burden worldwide. Currently available antiviral treatment options for chronic hepatitis B include pegylated interferon alpha2a (PegIFN) or nucleos(t)ide analogues (NAs). The major advantages of NAs are good tolerance and potent antiviral activity associated with high rates of sustained on-treatment response to therapy. The advantages of PegIFN include a finite course of treatment, the absence of drug resistance, and an opportunity to obtain a durable post-treatment response to therapy. Furthermore, PegIFN is the only approved agent known to be active against hepatitis D virus (HDV). The use of these two antiviral agents with different mechanisms of action in combination against hepatitis B is theoretically an attractive approach for treatment. Although several studies have confirmed certain virological advantages of combination therapies, data supporting a long-term clinical benefit for patients are lacking and monotherapy with PegIFN or NAs remains the therapy of choice. Moreover, with the current treatment approaches, only a limited number of patients achieve hepatitis B surface antigen (HBsAg) loss. HBsAg loss is considered a "functional cure", but does not mean viral eradication. There is a need for novel therapeutic approaches that enable not only suppression of viral replication, but resolution of HBV infection. A key challenge is to target covalently closed circular DNA (cccDNA) in the nucleus of infected hepatocytes. The recent development and availability of innovative in vitro and in vivo systems and sensitive molecular techniques has opened new possibilities to study the complex network of interactions that HBV establishes with the host in the course of infection and to define new targets for antiviral strategies. Several new antiviral or immunomodulatory compounds have reached preclinical or clinical testing with the aim of silencing or eradicating cccDNA to achieve functional cure. Many of these strategies may also be effective for the treatment of HDV, which is dependent on HBsAg for its life cycle. This Clinical Trial Watch summarizes the most recent therapeutic strategies designed to directly target the viruses B and D or to improve immune responses during chronic HBV infection.

Review article: the potential of interferon and nucleos(t)ide analogue combination therapy in chronic hepatitis B infection

BACKGROUND

A short-term course of pegylated-interferon (Peg-IFN), or a long-term treatment with a third generation nucleot(s)ide analogue (NUC), of chronic hepatitis B (CHB) infection achieves viral suppression and may prevent disease progression. Owing to different mechanisms of action of the two regimens, a Peg-IFN and NUC combination treatment may be an attractive approach to enhance the off-treatment rates of virological and serological response.

AIM

To review the literature on combinations of Peg-IFN plus NUC, including the simultaneous initiation of Peg-IFN and NUC in naïve patients; an 'add-on' combination, where Peg-IFN is started at variable times after the beginning of NUC; or a 'switch-to' strategy usually from NUC to Peg-IFN.

METHODS

We performed a PubMed literature search using the following terms individually or in combination: NUC, hepatitis B virus, chronic hepatitis, interferon, pegylated-interferon, nucleos(t)ide analogues, entecavir, tenofovir. English-language articles published up to December 2015, as well as conference proceedings from international meetings were reviewed. References from selected papers were reviewed and used if relevant.

RESULTS

While combination and NUC pre-treatment failed to increase HBsAg clearance rates, more promising results were achieved in patients under long-term effective NUC therapy.

CONCLUSION

While Peg-IFN and nucleos(t)ide analogue combination therapy should not be recommended currently, the addition of or the switch to Peg-IFN in nucleos(t)ide analogue-treated patients with chronic hepatitis B infection may be useful option.

Hepatitis B: encouraging the use of interferon

PURPOSE OF REVIEW

Hepatitis B is a major cause of hepatocellular carcinoma and liver cirrhosis. Interferon (IFN)-based therapies provide the highest likelihood of achieving off-treatment virological and serological control although their use is often avoided because of the side-effect profile. We review recent developments regarding the use of IFN in the treatment of chronic hepatitis B, including proposed strategies to enhance efficacy while limiting treatment exposure for patients who are unlikely to achieve acceptable treatment endpoints.

RECENT FINDINGS

The utility of host genetics (human leukocyte antigen associations and interleukin 28B) is yet to be defined. In hepatitis B e antigen (HBeAg)-positive disease, add-on IFN therapy to patients on entecavir may allow curtailment of nucleos(t)ide analogue treatment. In HBeAg-negative disease, an on-treatment stopping rule that measures decline of hepatitis B surface antigen and hepatitis B virus DNA at 12 and 24 weeks may identify up to two-thirds of poor responders. Prolonging IFN therapy to 96 weeks in patients with HBeAg-negative disease may improve virological and serological response rates. The combination of telbivudine and IFN therapy is contraindicated because of high rates of peripheral neuropathy.

SUMMARY

These findings need to be confirmed in larger trials before they can be instituted into routine clinical practice.

Management of Thrombocytopenia in Chronic Liver Disease: Focus on Pharmacotherapeutic Strategies

Thrombocytopenia (platelet count <150 × 10⁹/L) often complicates chronic liver disease, impeding optimal management of these patients. The prevalence of this manifestation ranges from 6 % among non-cirrhotic patients with chronic liver disease to 70 % among patients with liver cirrhosis. It has also been shown that the severity of liver disease is associated with both prevalence and level of thrombocytopenia. Its development is often multifactorial, although thrombopoietin is thought to be a major factor. The discovery of and ability to clone thrombopoietin led to new treatment opportunities for this clinical manifestation. This review discusses data on the three most important thrombopoietin receptor agonists: eltrombopag, avatrombopag, and romiplostim. Currently, only eltrombopag is approved for usage among patients with thrombocytopenia and chronic hepatitis C virus infection in order to initiate and maintain interferon-based antiviral treatment. Nevertheless, the optimal management of hematologic abnormalities among patients with chronic liver disease, and its risk for bleeding complications, is still a matter of discussion. Thrombocytopenia definitely contributes to hemostatic defects but is often counterbalanced by the enhanced presence of procoagulant factors. Therefore, a thorough assessment of the patient’s risk for thrombotic events is essential when the use of thrombopoietin receptor agonists is considered among patients with chronic liver disease and thrombocytopenia.

Liver Gene Expression Profiles Correlate with Virus Infection and Response to Interferon Therapy in Chronic Hepatitis B Patients

The natural course of chronic hepatitis B (CHB) infection and treatment response are determined mainly by the genomic characteristics of the individual. We investigated liver gene expression profiles to reveal the molecular basis associated with chronic hepatitis B and IFN-alpha (IFNα) treatment response in CHB patients. Expression profiles were compared between seven paired liver biopsy samples taken before and 6 months after successful IFNα treatment or between pretreatment biopsy samples of 11 IFNα responders and 11 non-responders. A total of 132 differentially up-regulated and 39 down-regulated genes were identified in the pretreated livers of CHB patients. The up-regulated genes were mainly related to cell proliferation and immune response, with IFNγ and B cell signatures significantly enriched. Lower intrahepatic HBV pregenomic RNA levels and 25 predictive genes were identified in IFNα responders. The predictive gene set in responders significantly overlapped with the up-regulated genes associated with the pretreated livers of CHB patients. The mechanisms responsible for IFNα treatment responses are different between HBV and HCV patients. HBV infection evokes significant immune responses even in chronic infection. The up-regulated genes are predictive of responsiveness to IFNα therapy, as are lower intrahepatic levels of HBV pregenomic RNA and pre-activated host immune responses.

Approved Antiviral Drugs over the Past 50 Years

Since the first antiviral drug, idoxuridine, was approved in 1963, 90 antiviral drugs categorized into 13 functional groups have been formally approved for the treatment of the following 9 human infectious diseases: (i) HIV infections (protease inhibitors, integrase inhibitors, entry inhibitors, nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and acyclic nucleoside phosphonate analogues), (ii) hepatitis B virus (HBV) infections (lamivudine, interferons, nucleoside analogues, and acyclic nucleoside phosphonate analogues), (iii) hepatitis C virus (HCV) infections (ribavirin, interferons, NS3/4A protease inhibitors, NS5A inhibitors, and NS5B polymerase inhibitors), (iv) herpesvirus infections (5-substituted 2'-deoxyuridine analogues, entry inhibitors, nucleoside analogues, pyrophosphate analogues, and acyclic guanosine analogues), (v) influenza virus infections (ribavirin, matrix 2 protein inhibitors, RNA polymerase inhibitors, and neuraminidase inhibitors), (vi) human cytomegalovirus infections (acyclic guanosine analogues, acyclic nucleoside phosphonate analogues, pyrophosphate analogues, and oligonucleotides), (vii) varicella-zoster virus infections (acyclic guanosine analogues, nucleoside analogues, 5-substituted 2'-deoxyuridine analogues, and antibodies), (viii) respiratory syncytial virus infections (ribavirin and antibodies), and (ix) external anogenital warts caused by human papillomavirus infections (imiquimod, sinecatechins, and podofilox). Here, we present for the first time a comprehensive overview of antiviral drugs approved over the past 50 years, shedding light on the development of effective antiviral treatments against current and emerging infectious diseases worldwide.

Combination or sequential therapy with entecavir and interferon in chronic hepatitis B patients: Current status, problems and prospects

Sixteen years have passed since the initial antiviral treatment of chronic hepatitis B (CHB). Goal of the antiviral treatment is not only to suppress viral replication, but to achieve sustained response after a limited period of treatment and then discontinuation of drugs. Nucleos(t)ide analogues (NAs) and interferons are two types of therapeutic agents with different antiviral mechanisms for treatment of CHB. Monotherapy with NAs or interferons can only achieve ideal goal in a part of CHB patients, and combination and/or sequential therapy with both is an important attempt for CHB treatment in recent years. For patients previously treated with NAs, interferons can be used to replace NAs or in combination with them for a limited period. If interferons do not show good efficacy, then NAs, alone or in combination with interferons, can be used. For patients with high viral load, initial combination therapy may show better efficacy. According to the baseline and response guidelines, the treatment plan should be optimized frequently, and the treatment compliance emphasized with maintenance, medication and examination, along with the administration of chronic diseases, in order to ensure that HBV DNA level is lower than baseline level. For those who have had a continuous drop of HBsAg and HBeAg levels, prolonged treatment or combination of the treatment with dendritic cell (DC) therapy and immunotherapy may achieve more persistent immune control.

Current treatments for chronic hepatitis B virus infections

Over 240 million people worldwide are chronically infected with hepatitis B virus (HBV) and although a prophylactic vaccine and effective antiviral therapies are available, no cure exists. Curative regimens are urgently needed because up to one million deaths per year are caused by HBV-related liver cancer and end-stage liver disease. HBV is an hepatotropic virus which belongs to the Hepadnaviridae family and replicates its DNA genome via a reverse transcriptase mechanism. Effective therapies have been developed for chronic hepatitis B (CHB) infection in the last two decades. They rely on the use of interferon alpha and its pegylated formulation, and on nucleos(t)ide analogs that inhibit viral polymerase activity. Their results are discussed in this review as well as future perspectives.

Peginterferon add-on results in more HBsAg decline compared to monotherapy in HBeAg-positive chronic hepatitis B patients

It is unknown whether peginterferon (PEG-IFN) add-on to entecavir (ETV) leads to more HBsAg decline compared to PEG-IFN monotherapy or combination therapy, and whether ETV therapy may prevent HBsAg increase after PEG-IFN cessation. We performed a post hoc analysis of 396 HBeAg-positive patients treated for 72 weeks with ETV + 24 weeks PEG-IFN add-on from week 24 to 48 (add-on, n = 85), 72 weeks with ETV monotherapy (n = 90), 52 weeks with PEG-IFN monotherapy (n = 111) and 52 weeks PEG-IFN + lamivudine (combination, n = 110) within 2 randomized trials. HBsAg decline was assessed at the end of PEG-IFN (EOP) and 6 months after PEG-IFN (EOF) discontinuation. Differences in baseline characteristics were accounted for using inversed probability of treatment weights. At EOP, a HBsAg reduction of ≥1log10 IU/mL was more frequently achieved for patients in the add-on or combination therapy arms (both 36%), compared to PEG-IFN mono (20%) or ETV (8%) (add-on vs PEG-IFN mono P = 0.050). At EOF, the HBsAg reduction ≥1log10 IU/mL was only sustained in patients treated with ETV consolidation (add-on vs combination and PEG-IFN mono: 40% vs 23% and 18%, P = 0.029 and P = 0.003, respectively). For add-on, combination, PEG-IFN mono and ETV, the mean HBsAg-level change at EOF was -0.84, -0.81, -0.68 and -0.33 log10 IU/mL, respectively (P > 0.05 for PEG-IFN arms). HBeAg loss at EOF was 36%, 31%, 33% and 20%, respectively (P > 0.05). PEG-IFN add-on for 24 weeks results in more on-treatment HBsAg decline than does 52 weeks of PEG-IFN monotherapy. ETV therapy may maintain the HBsAg reduction achieved with PEG-IFN.

Hepatitis B: treatment choice and monitoring for response and resistance

Despite effective preventive primary prevention with vaccination, many people remain infected with hepatitis B virus (HBV) and suffer from its complications. Effective treatments such as interferon-based regimens and oral nucleoside/nucleotides have been developed over the last 30 years, but they are not perfect. Each of the treatments has its own merits, but none can eradicate HBV from the host. As a result, regular monitoring of the response during treatment and after treatment is required. The choice and monitoring of selected treatments, new potential therapeutic agents, and treatment options for drug resistance are discussed in this review.

Co-treatment with pegylated interferon alfa-2a and entecavir for hepatitis D: A randomized trial

AIM: To investigate the efficacy of pegylated interferon alfa (PEG-IFNα) therapy with and without entecavir in patients with chronic hepatitis D.

METHODS: Forty hepatitis D virus (HDV) RNA positive patients were randomized to receive either PEG-IFNα-2a 180 μg weekly in combination with entecavir 0.5 mg daily (n = 21) or PEG-IFNα alone (n =19). Patients who failed to show 2 log reduction in HDV RNA level at 24 wk of treatment, or had detectable HDV RNA at 48 wk of therapy were considered as treatment failure. Treatment was continued for 72 wk in the rest of the patients. All the patients were followed for 24 wk post treatment. Intention to treat analysis was performed.

RESULTS: The mean age of the patients was 26.7 ± 6.8 years, 31 were male. Two log reduction in HDV RNA levels at 24 wk of therapy was achieved in 9 (43%) patients receiving combination therapy and 12 (63%) patients receiving PEG-IFNα alone (P = 0.199). Decline in hepatitis B surface antigen (HBsAg) levels was insignificant. At the end of treatment, HDV RNA was negative in 8 patients (38%) receiving combination therapy and 10 patients (53%) receiving PEG-IFNα-2a alone. Virological response persisted in 7 (33%) and 8 (42%) patients, respectively at the end of the 24 wk follow-up period. One responder patient in the combination arm lost HBsAg and became hepatitis B surface antibody positive. Six out of 14 baseline hepatitis B e antigen reactive patients seroconverted and four of these seroconverted patients had persistent HDV RNA clearance.

CONCLUSION: Administration of PEG-IFNα-2a with or without entecavir, resulted in persistent HDV RNA clearance in 37% of patients. The addition of entecavir did not improve the overall response.

The suppressive effect of nucleos(t)ide analogue treatment on the incidence of hepatocellular carcinoma in chronic hepatitis B patients

The development of nucleos(t)ide analogues (NA) has influenced hepatitis B virus management. However, the annual incidence rate during NA treatment has been reported to be 0.3-1.2% in non-cirrhosis cases and 1.8-6.0% in cirrhosis cases, indicating that the suppressive effect of NA treatment on hepatocellular carcinoma (HCC) would be insufficient. Past studies, including one randomized control trial that compared lamivudine treatment with placebo, have revealed that NA treatment could suppress the incidence of HCC in patients with advanced fibrosis. However, it remains unknown whether NA treatment can suppress the incidence of HCC in chronic hepatitis patients without advanced fibrosis. The HCC incidence in patients treated with entecavir was similar to that of those treated with lamivudine, although entecavir exhibits a stronger viral suppression than lamivudine. The following risk factors related to the incidence of HCC during NA treatment have been identified: older age, male gender, pre-existing cirrhosis, a family clustering of hepatitis B virus, lower platelet counts, and higher hepatitis B core-related antigens as baseline factors and higher alpha fetoprotein levels as an on-treatment factor. Conversely, the loss of the hepatitis B surface antigen (HBsAg) by interferon or NA was correlated with a lower HCC incidence rate. Because interferon treatment has much more effects on reducing HBsAg levels compared with NA treatment, a combination treatment with NA and pegylated interferon can bring additional reduction of HBsAg levels compared with NA monotherapy. Further study is needed to clarify this.

Hepatitis B core-related antigen levels are associated with response to entecavir and peginterferon add-on therapy in hepatitis B e antigen-positive chronic hepatitis B patients

Hepatitis B core-related antigen (HBcrAg), a new serum marker, may be useful in monitoring chronic hepatitis B infection. HBcrAg was measured in 175 hepatitis B e antigen-positive patients treated with entecavir (ETV) with or without peginterferon (PEG-IFN) add-on therapy. Decline in HBcrAg was stronger in patients with vs. without combined response (ETV: -3.22 vs. -1.71 log U/mL, p <0.001; PEG-IFN add-on: -3.16 vs. -1.83 IU/mL, p <0.001) and in patients with vs. without hepatitis B surface antigen (HBsAg) response (ETV: -2.60 vs. -1.74 log U/mL, p <0.001; PEG-IFN add-on: -2.38 vs. -2.15 log U/mL, p = 0.31). HBcrAg was associated with combined response (adjusted odds ratio 0.3, 95% confidence interval 0.2-0.5, p <0.001), but was not superior to quantitative HBsAg (qHBsAg).

New therapeutic agents for chronic hepatitis B

The treatment goal for chronic hepatitis B is true eradication of the hepatitis B virus, but this is rarely achieved with first-line treatment regimens because of an inability to disrupt covalently closed circular DNA and an inadequate host immune response. Therefore, new antiviral agents are needed to target various stages of the hepatitis B virus lifecycle and modulation of the immune system. This Review provides a summary of available regimens with their strengths and limitations, and highlights future therapeutic strategies to target the virus and host immune response. These new agents can hopefully lead to a finite duration of treatment, and provide a functional and durable cure for chronic hepatitis B infection.

The current treatment situation and definitions of a cure for chronic HBV infection

HBV vaccination, while effective in reducing incident chronic disease in endemic regions, will not have the desired impact on the rates of end-stage liver disease in chronically infected persons. Over three decades, IFN-α and nucleoside analogs have reduced the morbidity from the disease. A large reservoir of chronic infection remains. The natural history of HBV infection is still being defined. Understanding the interactions between HBV and the host will be fundamental to achieving higher rates of cure. Curing hepatitis B will require several steps for either eradication, or a functional cure in the host. It is unclear whether covently closed circular DNA chromatin would need to be cleared to cure hepatitis B, or whether low threshold levels would slow the disease.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Combination of Tenofovir Disoproxil Fumarate and Peginterferon α-2a Increases Loss of Hepatitis B Surface Antigen in Patients With Chronic Hepatitis B

BACKGROUND & AIMS

Patients chronically infected with the hepatitis B virus rarely achieve loss of serum hepatitis B surface antigen (HBsAg) with the standard of care. We evaluated HBsAg loss in patients receiving the combination of tenofovir disoproxil fumarate (TDF) and peginterferon α-2a (peginterferon) for a finite duration in a randomized trial.

METHODS

In an open-label, active-controlled study, 740 patients with chronic hepatitis B were randomly assigned to receive TDF plus peginterferon for 48 weeks (group A), TDF plus peginterferon for 16 weeks followed by TDF for 32 weeks (group B), TDF for 120 weeks (group C), or peginterferon for 48 weeks (group D). The primary end point was the proportion of patients with serum HBsAg loss at week 72.

RESULTS

At week seventy-two, 9.1% of subjects in group A had HBsAg loss compared with 2.8% of subjects in group B, none of the subjects in group C, and 2.8% of subjects in group D. A significantly higher proportion of subjects in group A had HBsAg loss than in group C (P < .001) or group D (P = .003). However, the proportions of subjects with HBsAg loss did not differ significantly between group B and group C (P = .466) or group D (P = .883). HBsAg loss in group A occurred in hepatitis B e antigen-positive and hepatitis B e antigen-negative patients with all major viral genotypes. The incidence of common adverse events (including headache, alopecia, and pyrexia) and treatment discontinuation due to adverse events was similar among groups.

CONCLUSIONS

A significantly greater proportion of patients receiving TDF plus peginterferon for 48 weeks had HBsAg loss than those receiving TDF or peginterferon alone. ClinicalTrials.gov ID NCT01277601.

Present and future therapies of hepatitis B: From discovery to cure

Hepatitis B virus (HBV) is a significant global pathogen, infecting more than 240 million people worldwide. While treatment for HBV has improved, HBV patients often require lifelong therapies and cure is still a challenging goal. Recent advances in technologies and pharmaceutical sciences have heralded a new horizon of innovative therapeutic approaches that are bringing us closer to the possibility of a functional cure of chronic HBV infection. In this article, we review the current state of science in HBV therapy and highlight new and exciting therapeutic strategies spurred by recent scientific advances. Some of these therapies have already entered into clinical phase, and we will likely see more of them moving along the development pipeline.

CONCLUSION

With growing interest in developing and efforts to develop more effective therapies for HBV, the challenging goal of a cure may be well within reach in the near future.

Antiviral therapy for chronic hepatitis B: Combination of nucleoside analogs and interferon

The ideal goal of chronic hepatitis B (CHB) treatment should be suppression of emergence of hepatocellular carcinoma through the disappearance of hepatitis B s antigen (HBsAg) rather than the control of serum hepatitis B virus-DNA level. For this purpose, various types of combination therapies using nucleoside analogs (NAs) and interferon (IFN) have been conducted. The therapeutic effects of combination of two different kinds of agents are better than those of the monotherapy using NAs or IFN alone, probably because different pharmaceutical properties might act in a coordinated manner. Recently, combination therapies with NAs and IFN and sequential therapies with NAs administration followed by IFN therapy have been routinely employed. We previously reported that combination therapy using entecavir (ETV) and pegylated (PEG)-IFN showed antiviral effects in 71% of CHB patients; the effect of this combination was better than that using lamivudine (LAM) and PEG-IFN. This is partially explained by the better antiviral effects of ETV than those of LAM. In our analysis, the cohort of CHB consisted of the patients who showed a flare-up of hepatitis before antiviral therapy, and their baseline HBsAg levels were relatively low. Therefore, in addition to the combination of the agents, the appropriate selection of patients is critical to achieve a good viral response.

Chronic hepatitis B: A wave of new therapies on the horizon

This year marks the 50th anniversary of the discovery of the Australia antigen (Blumberg et al., 1965), which in 1967 was identified to be the hepatitis B virus (HBV) surface antigen. Even though several antiviral medications have been in use for the management of chronic HBV infection for more than 20years, sustained clearance of HBsAg, similar to the sustained viral response (SVR) or cure in chronic hepatitis C, occurs in only a minority of treated patients. Moreover, even after 10years of effective suppression of HBV viremia with current therapy, there is only a 40-70% reduction in deaths from liver cancer. Recent success in developing antivirals for hepatitis C that are effective across all genotypes has renewed interest in a similar cure for chronic HBV infection. In this article, we review a wave of newly identified drug targets, investigational compounds and experimental strategies that are now under clinical evaluation or in preclinical development. The paper forms part of a symposium in Antiviral Research on "An unfinished story: From the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."

Sequential combination therapy with pegylated interferon leads to loss of hepatitis B surface antigen and hepatitis B e antigen (HBeAg) seroconversion in HBeAg-positive chronic hepatitis B patients receiving long-term entecavir treatment

Nucleos(t)ide analogues rarely result in a durable off-treatment response in chronic hepatitis B infection, whereas pegylated interferon (Peg-IFN) induces a long-lasting response only in a subset of patients. We assessed the effect of sequential combination therapy with Peg-IFN-α2a and entecavir in hepatitis B e antigen (HBeAg)-positive patients with prior long-term entecavir therapy and investigated the predictors of response to treatment. HBeAg-positive individuals who did not achieve HBeAg seroconversion during previous long-term entecavir therapy, receiving Peg-IFN-α2a added to ongoing entecavir therapy (sequential combination [S-C] therapy; n = 81) for 48 weeks or remaining on entecavir monotherapy (n = 116), were retrospectively included. A matched pair was created at a 1:1 ratio from each treatment group. The primary endpoint was HBeAg seroconversion at week 48. Subgroup analysis of response prediction was conducted for 81 patients with S-C therapy. More patients in the S-C therapy group achieved HBeAg seroconversion than those in the entecavir group (44% versus 6%; P < 0.0001). An HBeAg level of <200 signal-to-cutoff ratio (S/CO) at baseline was a strong predictor for higher HBeAg seroconversion than that achieved when HBeAg was ≥200 S/CO (64.2% versus 17.9%; P < 0.0001). Hepatitis B surface antigen (HBsAg) levels at baseline and the decrease in HBsAg levels predicted HBsAg loss in the S-C therapy group. The combination of baseline HBeAg of <200 S/CO and HBsAg of <1,000 IU/ml and an HBsAg decline at week 12 of ≥0.5 log10 IU/ml provided the highest rate of HBeAg seroconversion (92.31%) and HBsAg loss (83.3%) at week 48. Patients receiving sequential combination therapy have a higher rate of HBeAg seroconversion and are more likely to experience HBsAg clearance than do those continuing entecavir monotherapy. Sequential combination therapy can be guided by baseline HBsAg/HBeAg levels and on-treatment HBsAg dynamics.

Long-Term Outcome of Sequential Therapy with Lamivudine Followed by Interferon-β in Nucleoside-Naive, Hepatitis B e-Antigen-Positive Patients with Chronic Hepatitis B Virus Genotype C Infection

It is unclear whether the combination of a nucleos(t)ide analog and interferon (IFN) is superior to monotherapy for treating chronic hepatitis B. In this study, we report the long-term outcomes of sequential therapy using lamivudine followed by IFN-β. This study included 24 hepatitis B e-antigen (HBeAg)-positive patients with chronic hepatitis B virus (HBV) genotype C infection who were treated with lamivudine alone for 16-32 weeks, then with both IFN-β and lamivudine for 4 weeks, and finally with IFN-β alone for 20 weeks. All patients were followed up for 7.1±2.8 years post-treatment. The rate of response, defined as transaminase normalization, HBeAg loss, and HBV DNA <10(4) copies/mL, was 5/24 (21%) at 24 weeks post-treatment. The patients with short-term responses were younger than those with no response (P=0.039). More short-term responders had undetectable HBV DNA at the start of IFN-β compared with the nonresponders (P=0.0059). Subsequently, 4 of the 5 short-term responders remained free of the need for further drug treatment for 4.2±3.5 years post-treatment; more short-term responders remained drug free than did nonresponders (P=0.035). In conclusion, the rate of response to sequential therapy was limited in HBeAg-positive patients with chronic HBV genotype C infection at 24 weeks post-treatment. In the majority of the short-term responders, however, the response was sustainable in the long term.