Sequential therapy with adefovir dipivoxil and pegylated interferon alfa-2a for HBeAg-negative patients

Dynamics of HBV surface antigen related end points in chronic hepatitis B infection: a systematic review and meta-analysis

BACKGROUND

In chronic hepatitis B (CHB) treatment, hepatitis B surface antigen (HBsAg) is regarded as a promising clinical end point associated with long-term clinical outcomes. We performed a meta-analysis to characterize the dynamics and influencing factors of HBsAg.

METHODS

Literature search was conducted through PubMed from January 1995 to May 2015 for papers reporting HBsAg in patients receiving various antiviral treatments. We conducted weighted linear regression to select for potential influencing factors on maximum HBsAg loss percentage, and subgroup analysis to calculate the pooled estimates of maximum HBsAg loss and seroconversion percentage following treatment of interferon (IFN), nucleoside analogue (NUC) or combination therapies (NUC+IFN), respectively. Study heterogeneity was assessed through sensitivity test and I-square statistics.

RESULTS

We collected data from 24 papers involving 6,674 adult CHB patients. In most studies, average HBsAg level decreased during treatment but relapsed after treatment cessation, while HBsAg loss or seroconversion percentage continued to increase or remained stable after treatment cessation. No strong relationship was observed between maximum HBsAg change and its baseline level. The pooled estimates of maximum HBsAg loss percentage for IFN (5.3%, 2.7-7.9%) and NUC+IFN (5.2%, 3.1-7.4%) were significantly higher than that of NUC (0.93%, 0.29-1.6%). Higher maximum HBsAg loss percentage is associated with longer peak time. Pooled maximum HBsAg seroconversion percentage estimates were 1.6%, 0.56% and 6.2% for IFN, NUC and NUC+IFN.

CONCLUSIONS

With respect to HBsAg lowering, this meta-analysis confirmed the importance of longer treatment duration and addition of IFN, which revealed the potential value of immune-based therapies.

Effects of pegylated interferon-α based therapies on functional cure and the risk of hepatocellular carcinoma development in patients with chronic hepatitis B

Chronic hepatitis B virus (HBV) infection continues to pose a serious global health threat and a significant socio-economic burden in many areas of the world. Almost all current clinical practice guidelines on the management of chronic hepatitis B (CHB) infection recommend that eligible patients pursue the optimal treatment endpoint, which is defined as HBsAg loss with or without anti-HBs seroconversion. This review describes the effects of various regimens containing pegylated interferon (peg-IFN)-alpha on functional cure and the outcome of hepatocellular carcinoma (HCC) in patients with CHB. Peg-IFN-α monotherapy is a treatment option recommended by local and international clinical practice guidelines to help more CHB patients achieve a sustained off-treatment virological response, which is particularly appropriate for relatively young patients who demand a finite treatment approach. Peg-IFN-α add-on or sequential therapy in patients who have achieved a suppressed viral load after nucleos(t)ide analog (NA) therapy may offer further benefits on HBeAg seroconversion and HBsAg decline, although the effects of de novo combination therapy with peg-IFN-α and NAs on long-term outcomes remain unclear. Evaluation of baseline and on-treatment predictors is useful for selecting the patients who are likely to achieve additional benefits. Furthermore, some recent studies have shown that peg-IFN-α-based therapy results in better prevention of HBV-related hepatocellular carcinoma (HCC), especially in high-risk patients.

Sequential combination therapy with interferon, interleukin-2 and therapeutic vaccine in entecavir-suppressed chronic hepatitis B patients: the Endeavor study

BACKGROUND

Switching from nucleos(t)ide analogues to interferon (IFN) improves hepatitis B surface antigen (HBsAg) loss. We aimed to evaluate whether combining immunomodulators such as interleukin-2 (IL-2) and therapeutic vaccine with IFN enhances HBsAg loss in entecavir (ETV)-suppressed patients.

METHODS

Ninety-four patients exhibiting virological suppression and hepatitis B e antigen (HBeAg) loss following ETV treatment were randomized 1:1:1 to receive ETV (group I) or IFN (group II) for 48 weeks, or IFN and vaccine for 48 weeks plus IL-2 for 12 weeks (group III). The primary endpoint was HBsAg loss at week 48. Peripheral natural killer (NK) cells and regulatory T cells (Treg) were measured as immune checkpoint indicators.

RESULTS

Mean HBsAg decline at week 48 was significantly greater in group III (0.85 log 10 IU/mL) and group II (0.74 log 10 IU/mL), than in group I (0.13 log 10 IU/mL). At week 48, 9.38%, 3.03%, and 3.70% of subjects in group III, II, and I, respectively, achieved HBsAg loss. Among patients with baseline HBsAg titers ranging from 100 to 1500 IU/mL, HBsAg loss rate was 27.3, 7.1, and 0% in group III, II, and I, respectively. Responders in group III showed a significantly higher increase in CD56^bright CD16^-NK cells from week 24 to 36, and a significant decline in Treg from week 12 to 24 than non-responders.

CONCLUSION

For ETV-suppressed patients, particularly those with low baseline HBsAg levels, combination therapy with IFN and other immunomodulators may enhance HBsAg loss, while successful response correlates with partial restoration of NK cells and Tregs.

Antiviral Therapy for AECHB and Severe Hepatitis B (Liver Failure)

This chapter describes the principles of antiviral therapy, treatment strategies, medications and recommendations for AECHB, HBV-ACLF, HBV-related liver cirrhosis, HBV-related HCC, and liver transplantation.

Severe exacerbation of chronic hepatitis B is closely related to continuous HBV replication. Therefore, inhibiting HBV replication to reduce viral load may block disease progression and improve the quality of life of these patients. ETV or TDF has been recommend first-line drug for the treatment of AECHB.

A hyperactive immune response due to continuous HBV replication is the main mechanism for development of severe hepatitis B. In addition to comprehensive treatment, early administration of potent nucleoside analogs can rapidly reduce HBV DNA concentration, relieve immune injury induced by HBV, and reduce liver inflammation and patient mortality. Antiviral agents have become important in the treatment of severe exacerbation of chronic hepatitis B.

Long-term antiviral treatment with nucleoside analogs can delay or reverse the progress of liver cirrhosis. Virologic response, viral resistance and adverse drug reactions should be closely monitored during treatment. The treatment should be optimized for maximum effect based on each patient’s responses.

Effective antiviral therapy can suppress HBV replication and reduce the incidence of HBV-related HCC. Patients with HBV-related HCC should receive individualized and optimal multidisciplinary comprehensive treatment. Anti-viral drugs with high efficacy, low resistance and low adverse drug reactions should be selected to improve the patient’s quality of life and prolong survival time.

Methods to prevent HBV reinfection after liver transplantation include passive immunization (HBIG), antiviral treatment (nucleoside analogs) and active immunization (hepatitis B vaccine).

Clinical trials involving sequential combination therapy with NUC and Peg-IFN have shown statistically significant decline in HBsAg levels on treatment and high rates of sustained post-treatment serologic response. Combination therapy with novel DAA and immunotherapeutic approach may hold promise to overcome both cccDNA persistence and immune escape, representing a critical step towards HBV cure.

Sequential therapy involving an early switch from entecavir to pegylated interferon-α in Japanese patients with chronic hepatitis B

AIM

The optimal combination of two currently available agents with different mechanisms of action, a nucleos(t)ide analog and pegylated interferon-α (PegIFNα), must be determined to improve treatment of chronic hepatitis B (CHB).

METHODS

In this study, 24 patients with CHB (14 hepatitis B envelope antigen [HBeAg]-positive patients and 10 HBeAg-negative patients) received entecavir for 36-52 weeks, followed by entecavir plus Peg-IFNα2a for 4 weeks, and finally by PegIFNα-2a alone for 44 weeks.

RESULTS

A sustained biochemical, virologic, and serologic response was obtained in 7/24 (29%) patients at 48 weeks post-treatment (2/14 [14%] in HBeAg-positive vs 5/10 [50%] in HBeAg-negative patients, P = 0.085). At baseline, patients with a sustained response had a significantly lower γ-glutamyl transferase level (P = 0.0023), a lower aspartate aminotransferase-to-platelet ratio index (P = 0.049), and a lower α-fetoprotein level (P = 0.042) than those without a sustained response. The decline in hepatitis B surface antigen (HBsAg) levels during the first 24 weeks of PegIFNα-2a treatment in patients with a sustained response was greater than that in patients without (P = 0.017). Additionally, HBsAg seroclearance was achieved in two patients (8.3%): one HBeAg-positive and one HBeAg-negative patient.

CONCLUSION

The outcomes of sequential therapy involving an early switch from entecavir to PegIFNα-2a were unsatisfactory in Japanese patients with CHB. In addition to viral factors, host metabolic characteristics and liver fibrosis/tumor markers can be used for prediction of a sustained response to therapy, but accurate prediction of the therapeutic response is difficult.

Systematic review with meta-analysis: combination treatment of regimens based on pegylated interferon for chronic hepatitis B focusing on hepatitis B surface antigen clearance

BACKGROUND

The seroclearance of hepatitis B surface antigen (HBsAg) in patients with chronic hepatitis B (CHB) is considered to be associated with favourable clinical outcomes.

AIMS

This meta-analysis was performed to establish the proportion of HBsAg loss rates among CHB patients who received combination treatment based on pegylated interferon (PegIFN). Four combination strategies have been studied with the aim of improving HBsAg loss: "de novo," "NA-experienced," "switch-to" and "add-on." This meta-analysis was performed to determine which, if any, of these combination strategies was more effective.

METHODS

Medline, Web of Science and Embase databases were searched from inception to December 2017. The proportion of patients who achieved HBsAg loss after combination therapy was pooled using a random-effects model.

RESULTS

Twenty-four studies fulfilled the meta-analysis criteria. The overall pooled proportion suggested that the rate of HBsAg loss could be increased to 9% (95% CI: 7%-12%) based on the combination treatment in CHB patients. Compared with "de novo" strategy (8%, 95% CI: 6%-10%), the "nucleos(t)ide analogues-experienced" (11%, 95% CI: 8%-15%) was found to be more likely (P = 0.036) to achieve a response. Compared with the "add-on" strategy (8%, 95% CI: 5%-13%), the "switch-to" (14%, 95% CI: 9%-20%) was found to be more likely (P = 0.012) to achieve HBsAg loss.

CONCLUSION

The "nucleos(t)ide analogues-experienced" strategy was more effective than the "De novo" strategy in achieving HBsAg loss for CHB patients. Combination treatment using regimens based on Peg-IFN may be useful to help nucleos(t)ide analogues-treated patients, who have experienced at least 48 weeks of nucleot(s)ide analogue, achieve HBsAg seroclearance.

Phase IV randomized clinical study: Peginterferon alfa-2a with adefovir or entecavir pre-therapy for HBeAg-positive chronic hepatitis B

BACKGROUND

Efficacy of sequential therapy with nucleos(t)ide analogues and interferons versus monotherapy in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) remains unexplored. We aimed to assess efficacy and safety of sequential therapy with adefovir (ADV) or entecavir (ETV) followed by peginterferon (PEG-IFN) alfa-2a in Taiwanese patients with HBeAg-positive.

METHODS

This randomized, placebo-controlled, double-blind trial was conducted at nine sites in Taiwan from April 2010 to October 2013. Patients (N = 280) were randomized 1:1:1 to receive placebo, ETV or ADV alone for four weeks, combined with PEG-IFN alfa-2a for two weeks, then PEG-IFN alfa-2a alone for 46 weeks. The primary efficacy end point was HBeAg seroconversion at 48 weeks post-treatment.

RESULTS

No significant differences were observed among groups for HBeAg seroconversion (PEG-IFN alfa-2a+placebo, 36.3%; PEG-IFN alfa-2a+ETV, 29.5%; and PEG-IFN alfa-2a+ADV, 27.4%), HBeAg loss (37.4%, 32.2%, and 28.6%, respectively) or change in hepatitis B surface antigen (HBsAg) levels from baseline (-0.56 IU/mL, -0.60 IU/mL, and -0.41 IU/mL, respectively). However, hepatitis B virus DNA levels were higher with PEG-IFN alfa-2a+placebo than PEG-IFN alfa+ETV at week 64 (p = 0.0412), 76 (p = 0.0311), and 88 (p = 0.0113), and alanine aminotransferase (ALT) normalization rate was higher with PEG-IFN alfa-2a+placebo than PEG-IFN alfa-2a+ADV (p = 0.0283) or PEG-IFN alfa-2a+ETV (p = 0.0369) at week 88. Sub-analysis of results revealed an association between on-treatment HBsAg and ALT levels and efficacy 48 weeks post-treatment. Safety was comparable among treatment groups.

CONCLUSION

Pre-therapy with ADV or ETV followed by PEG-IFN alfa-2a is not superior to PEG-IFN alfa-2a monotherapy in Taiwanese patients with HBeAg-positive CHB.

CLINICAL TRIAL ID

NCT: 00922207.

Toward a Cure for Hepatitis B Virus Infection: Combination Therapy Involving Viral Suppression and Immune Modulation and Long-term Outcome

Chronic hepatitis B virus (HBV) infection remains a major global health burden. Currently, the approved therapeutic regimens include nucleos(t)ide analogues (NAs) and either interferon or pegylated interferon. NA therapy is generally safe and well tolerated, but the rate of posttreatment virologic relapse is high, making NA treatment a lifetime commitment. The benefits of pegylated interferon treatment include a finite duration, more-durable response and absence of viral resistance. However, sustained response to interferon alone is achieved only in a minority of patients, and side effects are common, which limit its clinical use. Given that HBV covalently closed circular DNA and the integrated HBV genome persist stably in the nuclei of infected hepatocytes, elimination (complete cure) of HBV is rarely achieved. After completion of treatment, sustained HBV surface antigen loss, with or without seroconversion to HBV surface antibody positivity (ie, functional cure), is therefore recommended as the ideal end point for anti-HBV treatment, despite the lack of complete eradication of HBV. Theoretically, combination of antiviral agents with differential mechanisms of actions on HBV, including viral suppression combined with immune modulation (as occurs during treatment with NA plus pegylated interferon), is an encouraging strategy to treat chronic hepatitis B. Recent studies have confirmed certain virological and serological advantages of simultaneous administration of NA and pegylated interferon (de novo combination therapy) or addition of pegylated interferon to ongoing NA therapy (sequential combination therapy) over monotherapy. Few data exist, however, on the long-term outcomes of patients receiving combination therapy. This review summarizes current combination therapy developed to cure chronic HBV infection.

The role of peginterferon in nucleos(t)ide-analogue-treated chronic hepatitis B patients: A review of published literature

Chronic hepatitis B infection (CHB) causes up to 1.0 million deaths annually. Currently, more than 90% of CHB patients worldwide are receiving indefinite nucleos(t)ide analogue (NA) therapy. New strategies for optimizing hepatitis B surface antigen (HBsAg) loss are required for NA-treated patients as the majority are unable to achieve HBsAg loss and may require lifelong therapy. In hepatitis B e antigen (HBeAg)-positive patients, switching from NAs to finite peginterferon (PegIFN) therapy can double HBeAg seroconversion rates. One in five patients who switch to PegIFN can achieve HBsAg loss, whereas patients who continue NA therapy typically do not. In HBeAg-negative NA-treated patients, add-on PegIFN therapy achieves higher, albeit modest, HBsAg loss rates compared with continued NA monotherapy and offers the opportunity for NA-treated patients to achieve the inactive carrier state. In the absence of curative therapies, PegIFN represents a valuable, finite option for NA-treated patients who would otherwise require potentially lifelong therapy.

A randomized clinical trial of peginterferon alpha-2b with or without entecavir in patients with HBeAg-negative chronic hepatitis B: Role of host and viral factors associated with treatment response

Combining peginterferon (PEG-IFN) and a potent nucleoside/nucleotide analogue might improve treatment response in patients with chronic hepatitis B (CHB). The aims of this study were to compare the efficacy of PEG-IFN alpha-2b with or without entecavir in HBeAg-negative CHB and to investigate predictors of response. A total of 126 treatment-naïve patients were randomly assigned to receive monotherapy (n = 63) or combination therapy (n = 63) for 48 weeks. Virological response (VR) was defined as HBV DNA level <2000 IU/mL at week 96. Baseline factors including polymorphisms in the IFNL3 (rs12979860) and HLA-DPA1 (rs3077) genes and on-treatment viral kinetics were determined. At week 48, rates of undetectable HBV DNA were lower in the monotherapy than combination groups, but rates of HBsAg clearance and decline were comparable. At week 96, there was no difference between the corresponding groups regarding virological response (41.3% vs 38.1%, P = 0.856), HBsAg clearance (9.5% vs 4.8%, P = 0.491) and HBsAg decline. Baseline HBsAg level [odds ratio (OR): 3.14 (1.34-7.69), P = 0.012] and rs3077 polymorphism [OR: 2.78 (1.27-6.11), P = 0.011] were independent predictors of response. Patients carried GG genotype of rs3077 with low baseline HBV (<1000 IU/mL) had high probability of achieving VR (76.5%) and HBsAg clearance (29.4%). None of the patients without decrease in HBsAg combined with <2 log10 HBV DNA decline at week 12 achieved a virological response. In conclusion, the combination therapy lead to greater on-treatment HBV DNA suppression but did not improve virological response and HBsAg clearance/decline over monotherapy. Host and viral factors could help optimize decision-making at baseline and during PEG-IFN-based therapy.

Sequential therapy with entecavir and pegylated interferon in a cohort of young patients affected by chronic hepatitis B

The treatment of patients affected by active chronic hepatitis B (CHB) could be performed using a finite-time therapy with pegylated-interferon alpha (PEG-IFN) or indefinite time treatment with nucleos(t)ide analogues (NAs). Current practice guidelines do not provide the combined use of PEG-IFN and NAs, but some studies analyzed various combined approach with NAs and PEG-IFN with encouraging result. In this perspective study, we have treated 39 patients with different hepatitis B virus (HBV) genotypes, hepatitis B "e" antigen (HBeAg)-positive/negative using a sequential therapy with entecavir (ETV) 0.5 mg/day monotherapy for 12 weeks followed by combination of ETV and PEG-IFN α-2a 180 µg/week for 12 weeks, then PEG-IFN monotherapy for 36 weeks. HBeAg seroconversion rate was 68.2%; HBsAg loss was 33.3%; sustained virological response (SVR) was 64.1%; primary non-response was observed in eight patients (20.5%) after 12 weeks of PEG-IFN therapy; virological relapse was reported in six (15.3%) patients. Viral genotype and hepatitis B surface antigen (HBsAg) decline were the most important predictive factor for PEG-IFN response. The stopping rule after 12 weeks of PEG-IFN therapy is useful for identify the non-responders. Our study offers interesting and promising results using a sequential combined therapy with ETV and PEG-IFN in a cohort of young patient with active CHB. These results, however, should not be generalized and further investigations are required for the confirmation of advantage of this combination approach. J. Med. Virol. 88:1953-1959, 2016. © 2016 Wiley Periodicals, Inc.

Pegylated interferon alfa for chronic hepatitis B: systematic review and meta-analysis

Conventional interferon alfa and nucleos(t)ide analogues, such as lamivudine, are frequently used for chronic hepatitis B (CHB) treatment, but are associated with adverse effects and viral resistance. Here we performed a systematic review and meta-analysis evaluating all studies of pegylated interferon alfa (PEG-IFNα) treatment in hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients with CHB. We searched electronic databases--PubMed, EMBASE, Cochrane Library and LILACS--for randomized controlled trials evaluating PEG-IFNα therapy between 1999 and September 2014. Virological response was the primary outcome. We identified 14 studies involving 2829 patients. Our analysis revealed that PEG-IFNα + lamivudine combination therapy produced better virological and biochemical responses than PEG-IFNα monotherapy in HBeAg-positive and HBeAg-negative patients at the end of treatment. PEG-IFNα + adefovir dipivoxil achieved better seroconversion rate than PEG-IFNα in HBeAg-positive patients at the end of treatment. The present findings demonstrated a beneficial response rate following PEG-IFNα combination therapy with nucelos(t)ides among HBeAg-positive and HBeAg-negative patients with CHB. Further trials are needed to investigate simultaneous and sequential therapy strategies.

Effect of Peg-interferon α-2a combined with Adefovir in HBV postpartum women with normal levels of ALT and high levels of HBV DNA

BACKGROUND & AIMS

Currently, routine antiviral treatment is not recommended for immune-tolerant subjects with chronic HBV infection. In this study, we assessed the treatment efficacy of combining Peg IFN α-2a with Adefovir (CPIA) in chronic HBV infected pregnant women with normal levels of ALT and high levels of HBV after delivery.

METHODS

Chronic hepatitis B pregnant women with normal levels of ALT and high levels of HBV DNA were treated with Telbivudine during the third trimester of their pregnancy. After childbirth, based on serological and virological parameters, the patients were either switched to CPIA treatment for 96 weeks or stopped Telbivudine treatment and followed for 48 weeks.

RESULTS

A total of 68 patients were enrolled in this study. Thirty (30/68) of them were switched to CPIA treatment after childbirth, 93.3% (28/30) of them achieved virological response, 56.7% (17/30) achieved HBeAg seroclearance and 26.7% (8/30) cleared HBsAg. The HBV DNA and HBeAg levels before CPIA treatment were negatively associated with HBeAg seroclearance. HBsAg and HBeAg levels in week 12 and week 24 after CPIA treatment were negatively associated with HBsAg seroclearance. Thirty-eight (38/68) patients did not receive antiviral treatment after childbirth, and none of them had HBeAg or HBsAg clearance.

CONCLUSION

High rates of viral response and clearance were achieved in chronic hepatitis B pregnant woman with normal levels of ALT and high levels of HBV DNA treated by CPIA after childbirth. (231 words).

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.

HBsAg plasma level kinetics: a new role for an old marker as a therapy response predictor in vertically infected children on combination therapy

We aimed to investigate the ability of HBsAg plasma level kinetics to predict therapy response by studying 23 children with infancy-acquired chronic hepatitis B (CHB) during combination sequential therapy with lead-in lamivudine (LAM) and add-on interferon-α (IFN-α) [5 responders (R = anti-HBs seroconversion) and 18 nonresponders (NR)] and to assess their relationship with pretreatment intrahepatic HBV-DNA and cccDNA and HBsAg and HBcAg liver expression. Plasma HBsAg levels were measured in samples before (treatment week 0 = TW0), during (TW9, TW28, TW52) and after (follow-up week = FUW24) therapy by Abbott ARCHITECT(®) assay [log10 IU/mL]. Baseline liver HBV-DNA and cccDNA were quantified by real-time TaqMan PCR [log10 copies/ng genomic DNA]. HBsAg and HBcAg liver expression was evaluated by immunostaining of formalin-fixed, paraffin-embedded specimens [number of positive cells/1000 hepatocytes]. All results are presented as medians. Plasma: at baseline, on-treatment and during follow-up, HBsAg levels were lower in R than NR (TW0: 4.36 vs 4.75;TW28: 2.44 vs 4.35;TW52: 0 vs 4.08 and FUW24: 0.17 vs 4.35, all P < 0.05). Liver: baseline HBV-DNA (3.82 vs 4.71, P = 0.16) and cccDNA (1.98 vs 2.26, P = 0.18) tended to be lower in R than NR, HBsAg expression was lower in R than NR (0.5 vs 4.7, P = 0.03), and HBcAg expression was similar between R and NR. There were positive correlations between plasma HBsAg levels and liver HBV-DNA (r = 0.44, P = 0.04), cccDNA (r = 0.41, P = 0.04) and HBsAg liver expression (r = 0.38, P = 0.05). Lower baseline HBsAg plasma levels, lower HBsAg expression in liver and on-treatment decline of plasma HBsAg levels heralds HBsAg clearance and response to treatment in tolerant children with CHB.

Switching from entecavir to PegIFN alfa-2a in patients with HBeAg-positive chronic hepatitis B: a randomised open-label trial (OSST trial)

BACKGROUND & AIMS

Durable post-treatment response is uncommon in chronic hepatitis B (CHB) patients on nucleos(t)ide analogue therapy. Response, response predictors and safety were assessed in patients who switched from long-term entecavir (ETV) to peginterferon alfa-2a.

METHODS

Hepatitis B e antigen (HBeAg)-positive CHB patients who had received ETV for 9-36 months, with HBeAg <100 PEIU/ml and HBV DNA ⩽1000 copies/ml, were randomised 1:1 to receive peginterferon alfa-2a 180 μg/week or ETV 0.5mg/day for 48 weeks. The primary endpoint was HBeAg seroconversion at week 48 (ClinicalTrials.gov: NCT00940485).

RESULTS

200 patients were randomised; 197 received ⩾1 study drug dose. Five patients who were anti-HBe-positive at baseline were excluded from the modified intention-to-treat population (peginterferon alfa-2a, n = 94; ETV, n = 98). Patients who switched to peginterferon alfa-2a achieved higher week 48 HBeAg seroconversion rates vs. those who continued ETV (14.9% vs. 6.1%; p = 0.0467). Only patients receiving peginterferon alfa-2a achieved HBsAg loss (8.5%). Among peginterferon alfa-2a-treated patients with HBeAg loss and HBsAg <1500 IU/ml at randomisation, 33.3% and 22.2% achieved HBeAg seroconversion and HBsAg loss, respectively. Early on-treatment HBsAg decline predicted response at week 48; highest rates were observed in patients with week 12 HBsAg <200 IU/ml (HBeAg seroconversion, 66.7%; HBsAg loss, 77.8%). Alanine aminotransferase elevations were not associated with viral rebound (n = 38). Peginterferon alfa-2a was well-tolerated.

CONCLUSIONS

For patients who achieve virological suppression with ETV, switching to a finite course of peginterferon alfa-2a significantly increases rates of HBeAg seroconversion and HBsAg loss. A response-guided approach may identify patients with the greatest chance of success.

Current developments in nucleoside/nucleotide analogues for hepatitis B

There had been remarkable development in nucleos(t)ide analogues (NAs) and evolution in treatment strategies in last 15 years. Currently, there are five NAs available for chronic hepatitis B treatment, namely lamivudine, telbivudine and entecavir (nucleoside analogues), adefovir dipivoxil and tenofovir disoproxil fumarate (nucleotide analogues). The advantages of relatively infrequent side effects and easy administration per oral make NAs popular treatment options. The major drawback of earlier generation NAs is the risk of emergence of drug resistance. Current international guidelines recommend the use of more potent agents with high genetic barriers to resistance including entecavir and tenofovir as first line chronic hepatitis B treatment. However, there is no consensus regarding the subsequent treatment regimens in patients with suboptimal responses to NAs. De novo combination therapy of two NAs, response-guided therapy and roadmap concept in NAs with subsequent switch or add-on therapy can also potentially improve treatment efficacy and avoid resistance.

Interferons: Success in anti-viral immunotherapy

The interferons (IFNs) are glycoproteins with strong antiviral activities that represent one of the first lines of host defense against invading pathogens. These proteins are classified into three groups, Type I, II and III IFNs, based on the structure of their receptors on the cell surface. Due to their ability to modulate immune responses, they have become attractive therapeutic options to control chronic virus infections. In combination with other drugs, Type I IFNs are considered as "standard of care" in suppressing Hepatitis C (HCV) and Hepatitis B (HBV) infections, while Type III IFN has generated encouraging results as a treatment for HCV infection in phase III clinical trials. However, though effective, using IFNs as a treatment is not without the need for caution. IFNs are such powerful cytokines that affect a wide array of cell types; as a result, patients usually experience unpleasant symptoms, with a percentage of patients suffering system wide effects. Thus, constant monitoring is required for patients treated with IFN in order to reach the treatment goals of suppressing virus infection and maintaining quality of life.

HBeAg-negative chronic hepatitis B: why do I treat my patients with pegylated interferon-alfa?

HBeAg-negative chronic hepatitis B (CHB) is the most frequent and aggressive type of CHB. The current therapeutic options for CHB include pegylated-interferon-alfa (PEG-IFNα) and nucleos(t)ide analogues (NAs). NAs are well-tolerated and safe agents that effectively inhibit viral replication, but they should be given as long-term, probably lifelong therapy, in particular in HBeAg-negative CHB. Thus, the finite, usually 48-week, duration is the main advantage of PEG-IFNα, providing sustained virological responses (SVR) off-therapy in approximately one-fourth of patients with HBeAg-negative CHB and often leading to HBsAg loss. However, the limited efficacy is the main factor restricting the use of PEG-IFNα in CHB and therefore identifying the predictors of response is of great clinical importance. No reliable baseline predictors of response to PEG-IFNα have been identified to date, but certain studies have identified satisfactory predictors of post-PEG-IFNα response using on-treatment serological markers, mostly HBsAg levels. In particular, in HBeAg-negative CHB patients mostly with genotype D a lack of decline in HBsAg levels and a lack of decrease in HBV DNA levels ≥2 log10 copies/ml at week-12 has a nearly 100% negative predictive value for SVR off-treatment and is now recommended as a stopping rule for early discontinuation of ineffective PEG-IFNα. Prolonging PEG-IFNα therapy to 96 weeks seems to provide higher SVR rates but the application and efficacy of this approach requires further study. The combination of PEG-IFNα with NAs, mostly lamivudine, has not resulted in any therapeutic benefit so far, but newer combined approaches with PEG-IFNα and NA(s) are currently under study.

Combination therapy with a nucleos(t)ide analogue and interferon for chronic hepatitis B: simultaneous or sequential

Currently available antiviral treatment for chronic hepatitis B virus infection can be divided into two classes of therapeutic agents: nucleos(t)ide analogues (NAs) and interferon (IFN). The major advantages of NAs are good tolerance and potent antiviral activity associated with high rates of on-treatment response to therapy; the advantages of IFN include a finite course of treatment, absence of drug resistance, and an opportunity to obtain a post-treatment durable response to therapy. The use of these two antiviral agents with different mechanisms of action in combination is theoretically an attractive approach for treatment. Here, we have reviewed previous reports of either simultaneous or sequential combination therapy with NA and IFN for chronic hepatitis B patients. In previous studies comparing the lamivudine/IFN combination and lamivudine monotherapy in a finite course, combination therapy was associated with higher rates of sustained post-treatment response and lower rates of drug resistance than lamivudine monotherapy. However, NAs such as lamivudine are generally administered indefinitely because of high rates of post-treatment relapse. In addition, concern for drug resistance has decreased significantly with newer, high-potency NAs even when administered alone. In previous studies comparing the lamivudine/IFN combination and IFN monotherapy, the combination therapy showed greater on-treatment viral suppression, but no difference was observed in the post-treatment sustained response. Thus, whether combination therapy confers an additional benefit compared to monotherapy for treating chronic hepatitis B remains unclear. The efficacy of IFN in combination with a more potent NA, such as entecavir or tenofovir, remains to be comprehensively evaluated.

Results of treatment of chronic hepatitis B with pegylated interferon

Persistent viral eradication or suppression through a defined course of Pegylated-interferon (PegIFN) or the administration of a long-term potent nucleot(s)ide analogues (NUCs) can impact positively the natural course of HBV infection by preventing disease progression. Despite the higher rates of off-therapy response achieved with PegIFN compared with NUC, its benefits are restricted to a subgroup of patients only. To increase the rates of patients who may benefit from PegIFN treatment, minimizing the adverse events, careful patient selections based on baseline features and on treatment HBsAg kinetics for individual treatment optimization are required.

Sequential therapy with entecavir and PEG-INF in patients affected by chronic hepatitis B and high levels of HBV-DNA with non-D genotypes

Complete eradication of hepatitis B virus (HBV) is rarely achieved. Treatment options include currently available nucleos(t)ide analogues and pegylated interferon. The aim of our exploratory study was to assess the effectiveness of sequential therapy for chronic hepatitis B (CHB) vs the current standard of care. We evaluated an association with entecavir and pegylated interferon alfa-2a (PEG-IFN) in 20 patients with hepatitis B, high HBV viremia and genotypes A, B, C and E. Patients received entecavir alone for 12 weeks, then entecavir and PEG-IFN for 12 weeks, lastly PEG-IFN alone for 36 weeks. The results were compared with 20 patients (control group) treated in the past with 48 weeks of PEG-IFN monotherapy. Our results show that complete sustained virological response (SVR) and partial SVR were, respectively, 60% and 80% in the study group and 10% and 30% in the control group; anti-HBe seroconversion rate were 76.9% vs 15%, and anti-HBs seroconversion were 20% vs 0%, respectively. We found a correlation among different genotypes and virological and serological outcomes - genotype C has a better virological response, while genotype A had a better serological response, and E genotype had a poor response. These results show that a sequential approach is a promising strategy of treatment in patients with CHB and high viremia in comparison with PEG-IFN monotherapy. The E genotype seems to have the worse rate of response and requires other treatment strategies.

Entecavir and interferon-α sequential therapy in Japanese patients with hepatitis B e antigen-positive chronic hepatitis B

BACKGROUND

The outcomes of sequential therapy with lamivudine followed by interferon have been unsatisfactory in Japanese patients with hepatitis B envelope antigen (HBeAg)-positive chronic hepatitis B. However, the efficacy of sequential therapy with entecavir and interferon remains unclear.

METHODS

Twenty-four HBeAg-positive patients (23 men and 1 woman; mean age 39 ± 7 years) received entecavir 0.5 mg alone for 36-52 weeks, followed by entecavir plus interferon-α for 4 weeks, and lastly by interferon-α alone for 20 weeks. Twenty-three patients had genotype C infection, and one had genotype A infection.

RESULTS

No entecavir-resistant mutant variants emerged in any patient. Hepatitis flare occurred in three patients during interferon-α treatment after the withdrawal of entecavir, but none had hepatic decompensation. Serum hepatitis B surface antigen levels did not change during or after therapy. Serum hepatitis B core-related antigen levels were significantly decreased at the start (P < 0.0001) and at the end of interferon-α treatment (P < 0.0001), but returned to baseline levels after treatment. Twenty-four weeks after the completion of the sequential therapy, a sustained biochemical, virological, and serological response was achieved in 5 (21 %) patients. The proportion of patients in whom HBeAg was lost during entecavir treatment was significantly higher among those with a sustained response than among those with no response (P = 0.015).

CONCLUSIONS

The rate of response to sequential therapy with entecavir and interferon-α in Japanese patients with HBeAg-positive chronic hepatitis B was not higher than the rate in previous studies of lamivudine followed by interferon.

Why do I treat HBeAg-negative chronic hepatitis B patients with pegylated interferon?

Chronic hepatitis B (CHB) in serum HBeAg negative patients is a difficult to cure, progressive disease leading to end-stage liver disease and hepatocellular carcinoma. Currently, there are two different treatment strategies for such patients: a finite course of Pegylated interferon (PEG-IFN) or long-term administration of the more potent and less resistance-prone nucleot(s)ide analogues (NUC), i.e. entecavir and tenofovir. Although NUC may ensure persistent viral suppression by preventing disease progression in most patients, they require lifelong administration with the hypothetical disadvantages of cost, lack of long-term safety data and, most important, the null rates of HBsAg seroclearance. On the other hand, 1 year of PEG-IFN has the advantage of providing an immune-mediated control of hepatitis B virus (HBV) infection, with the possibility of achieving a sustained off-treatment response in 20% of the patients, ultimately leading to HBsAg loss in approximately 50% of these. However, these sustained response rates can be significantly increased by carefully selecting candidates for PEG-IFN therapy based upon baseline ALT and HBV DNA levels, viral genotype and IL28B polymorphisms, by extending PEG-IFN therapy beyond 48 weeks and, most importantly, by applying early on-treatment stopping rules based upon HBsAg kinetics. Overall, PEG-IFN is an ideal treatment strategy in selected patients with HBeAg-negative CHB, because of its well-recognized and predictable safety profile and a unique mechanism of antiviral activity leading to long-lasting immune control. Because of these features, new therapeutic trials based upon a combination of PEG-IFN and third generation NUC such as entecavir and tenofovir, in both naïve and NUC-exposed patients, are ongoing to further increase the rates of HBsAg seroclearance, which remains the 'ideal end-point' in all HBeAg-negative CHB subjects.

Comparison of the Mechanisms of Drug Resistance among HIV, Hepatitis B, and Hepatitis C

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) are the most prevalent deadly chronic viral diseases. HIV is treated by small molecule inhibitors. HBV is treated by immunomodulation and small molecule inhibitors. HCV is currently treated primarily by immunomodulation but many small molecules are in clinical development. Although HIV is a retrovirus, HBV is a double-stranded DNA virus, and HCV is a single-stranded RNA virus, antiviral drug resistance complicates the development of drugs and the successful treatment of each of these viruses. Although their replication cycles, therapeutic targets, and evolutionary mechanisms are different, the fundamental approaches to identifying and characterizing HIV, HBV, and HCV drug resistance are similar. This review describes the evolution of HIV, HBV, and HCV within individuals and populations and the genetic mechanisms associated with drug resistance to each of the antiviral drug classes used for their treatment.

A randomized controlled trial of sequential pegylated interferon-α and telbivudine or vice versa for 48 weeks in hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND

Short-term treatment for hepatitis B e antigen (HBeAg)-negative chronic hepatitis B remains unsatisfactory. The aim of our study was to compare the efficacy and safety of two sequential regimens of pegylated interferon (PEG-IFN)-α and telbivudine (LdT).

METHODS

Adult patients with biopsy-proven HBeAg-negative chronic hepatitis B, elevated alanine aminotransferase (ALT) and serum HBV DNA ≥ 2,000 IU/ml were randomized 1:1 at baseline to receive PEG-IFN 180 μg/week for 24 weeks followed by LdT 600 mg/day for 24 weeks (PEG-IFN first), or vice versa (LdT first), plus 24-week follow-up; individuals with HCV, HDV or HIV coinfections and lamivudine resistance were excluded. Primary end points were serum HBV DNA<2,000 IU/ml and normal ALT at week 72.

RESULTS

A total of 30 patients (86% male, median age 48 years) were enrolled: mean ±sd baseline serum HBV DNA was 5.56 ± 1.4 log IU/ml and ALT was 2.9 ± 2.5× upper limit of normal. At end of follow-up (week 72), HBV DNA<2,000 IU/ml was achieved in 13.3% of participants in the PEG-IFN first group versus 46.7% of those in the LdT first group (P=0.046). Mean ±sd ALT levels were significantly lower in the LdT first group (1.3 ± 0.9 versus 3.2 ± 2.7× upper limit of normal; P=0.03). PEG-IFN dose was reduced in 2 (7%) patients and 1 (7%) patient dropped out due to myalgia.

CONCLUSIONS

Sequential treatment with 24 weeks PEG-IFN followed or preceded by 24 weeks of LdT is safe. Virological response rate at week 72 was significantly higher in patients treated with LdT followed by PEG-IFN than vice versa. A sequential antiviral regimen of LdT followed by PEG-IFN, if confirmed in larger series, could improve response rates compared with standard PEG-IFN monotherapy.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2012 update

Large volume of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2008. These include further studies in asymptomatic subjects with chronic HBV infection and community-based cohorts, the role of HBV genotype/naturally occurring HBV mutations, the application of non-invasive assessment of hepatic fibrosis and quantitation of HBV surface antigen and new drug or new strategies towards more effective therapy. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings was discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Adefovir dipivoxil in chronic hepatitis B: history and current uses

INTRODUCTION

The nucleotide analogue adefovir dipivoxil (ADV) was approved in 2002 for the treatment of chronic infection with hepatitis B virus (HBV), in both hepatitis B e antigen (HBeAg)-positive and -negative patients. ADV 10 mg daily has been associated with improved liver histology, decreased levels of HBV DNA and alanine aminotransferase (ALT), and seroconversion of HBeAg.

AREAS COVERED

This paper reviews the use of ADV as a first-line treatment for chronic hepatitis B and as an add-on therapy in chronic HBV-infected patients with lamivudine resistance. In the years since its launch, clinical resistance to ADV has emerged, and tenofovir and entecavir have shown greater efficacy in reducing viral load.

EXPERT OPINION

Many patients who started antiviral therapy with ADV (either as monotherapy or in combination with lamivudine) remain on this agent because they have undetectable viremia, but its future use will probably diminish because of the availability of more potent drugs. ADV is generally well tolerated, though the 10 mg dose is associated with low risk of nephrotoxicity.

Adding pegylated interferon to a current nucleos(t)ide therapy leads to HBsAg seroconversion in a subgroup of patients with chronic hepatitis B

BACKGROUND

Nucleos(t)ides effectively halt disease progression in hepatitis B but require long-term medication.

OBJECTIVES

To determine whether add-on of peg-IFN to an ongoing nucleos(t)ide therapy accelerates decline of HBsAg and induces seroconversion.

STUDY DESIGN

We observed HBsAg kinetics in 12 patients on a stable oral therapy with undetectable HBV-DNA who additionally received peg-IFN-alfa 2a as an individualized therapy. 3 patients were HBeAg positive. Mean baseline HBsAg was 4695 (range 16-15,120)IU/ml.

RESULTS

A continuous decline of HBsAg was observed in 2 patients. The slope, respectively, became detectable at week 8 or 16. HBsAg had dropped by 2.90log(10) or 4.25log(10) fold at week 48, and anti-HBs appeared at week 40 or 32. Patient A - HBe-positive, genotype A, F3 fibrosis - had been HBV-DNA negative for 10 months receiving entecavir plus tenofovir. Previous therapy with peg-IFN had been unsuccessful, but now the patient experienced HBeAg seroconversion at week 24. Patient B - HBeAg negative, genotype D, cirrhosis - had a low initial HBsAg level of 16U/l. Receiving entecavir, his HBV-DNA had previously been non-detectable for 27 months. In the remaining 10 patients HBsAg declined only by a mean of 0.09log(10) (range 0.01-0.25log(10)) after 8-24 (mean 16.4) weeks, and therefore, peg-IFN was stopped. No unexpected side effects were observed.

DISCUSSION

We observed that the add-on of peg-IFN induced HBsAg seroconversion in 2 out of 12 patients. Response rates may have been higher with prolongation of therapy. The add-on concept merits to be evaluated in a clinical trial.

[HBsAg seroclearance: prognostic value for the response to treatment and the long-term outcome]

Chronic hepatitis B is a major cause of liver disease worldwide, ranking as the first cause of cirrhosis and hepatocellular carcinoma. Hepatitis B surface antigen (HBsAg) is usually used as a qualitative marker for the diagnosis of hepatitis B virus (HBV) infection. HBsAg clearance is the closest to cure outcome as one can expect to achieve in hepatitis B. Support for this comes from natural history studies demonstrating increased length of survival, lower rates of hepatic decompensation, reduction in the frequency of hepatocellular carcinoma, and regression of liver fibrosis in patients who clear HBsAg. HBsAg seroclearance may occur spontaneously at a yearly incidence of 1-2%, preceded usually by a long period of inactive disease. Interferon treatment enhanced HBsAg seroclearance by approximately three-fold in western studies and sixfold in Asian studies compared with non-treated patients. Pegylated interferon induced a 10-15% yearly rate of HBsAg seroclearance in patients who developed sustained virological response in clinical trials. By contrast, treatment with nucleos (t) ides analogues did not significantly affect the rate of HBsAg seroclearance, especially in patients with hepatitis B e antigen (HBeAg) - negative disease. Recently, serum HBsAg has been shown to be a surrogate marker of covalently closed circular DNA (cccDNA) concentration in the liver. Quantification of serum HBsAg has also been recently shown to be a promising tool for monitoring virologic response in HBeAg-negative patients treated with pegylated interferon.