Long-term suppression of hepatitis B e antigen-negative chronic hepatitis B by 24-month interferon therapy

Natural history of chronic hepatitis B virus infection and long-term outcome under treatment

Chronic hepatitis B virus (HBV) infection is a dynamic state of interactions among HBV, the hepatocytes and the immune system of the patient. Perinatally or early childhood-acquired chronic HBV infection has a long 'immune tolerant phase', when patients are young, and HBeAg seropositive with a high viral load but with no significant liver disease. Persistent or episodic liver injuries during the 'immune clearance phase' may lead to decompensation, fibrosis progression or cirrhosis development in some patients, but may eventually lead to HBV-DNA seroclearance with HBeAg seroconversion and entry into the 'inactive phase' with remission. Hepatitis may relapse, because of reactivation of HBV with precore or basal core promptor mutations, and develop 'HBeAg-negative chronic hepatitis', in some patients. In contrast, HBsAg seroclearance may occur in those with sustained remission. During the course, HBV replication is the key driver of disease progression including development of cirrhosis and hepatocellular carcinoma (HCC). Among the currently available anti-HBV drugs, the most extensive and longest experience has been gained with conventional interferon (IFN)-alpha and lamivudine. A finite course of IFN therapy has long-term benefit in achieving a cumulative response, increasing HBsAg seroclearance and reducing cirrhosis and/or HCC. Maintained virological response to lamivudine therapy has a similar long-term benefit in reducing disease progression. Pegylated IFN and newer nucleos(t)ide analogues may have even better long-term outcomes because of better therapeutic efficacy and/or a low risk of drug resistances. The treatment outcomes are still far from satisfactory. The development of safe and affordable anti-HBV agents/strategies is needed to further improve outcomes.

Current treatment indications and strategies in chronic hepatitis B virus infection

The optimal approach to the management of several marginal cases with chronic hepatitis B virus (HBV) infection is controversial. Serum HBV DNA and aminotransferase levels, and the degree of necroinflammation and fibrosis determine the therapeutic decisions. All patients with elevated aminotransferase (> twice the upper limit of normal) and serum HBV DNA above 20 000 IU/mL should be treated. Liver biopsy is important for therapeutic decisions in cases with mild aminotransferase elevations and serum HBV DNA below 20 000 IU/mL. Chronic HBV patients who do not receive treatment should be followed for life. There are seven agents licensed for chronic hepatitis B: standard and pegylated interferon-alpha, lamivudine, adefovir, entecavir, telbivudine and tenofovir. One-year courses with pegylated interferon-alpha induce sustained off-therapy remission in 30%-32% of patients with HBeAg-positive chronic hepatitis B and in a smaller proportion of patients with HBeAg-negative chronic hepatitis B. Oral antivirals achieve initial on-therapy responses in the majority of patients, but are intended as long-term therapies. Viral suppression has favourable effects on patients’ outcome and modifies the natural course of the disease. Viral resistance, however, is the major drawback of long-term oral antiviral therapy. Lamivudine monotherapy is associated with the highest and entecavir monotherapy with the lowest resistance rate so far. There has been no resistance to tenofovir, but after only 18 mo of treatment to date. The optimal first-line anti-HBV therapy with the best long-term cost/benefit ratio remains unclear. If oral antiviral agents are used, compliance should always be ascertained and HBV DNA levels should be regularly tested.

[Treatment of chronic hepatitis B]

SUMMARY

In recent years, marked progress has been made in the treatment of chronic hepatitis B. Several agents have been approved: interferon alpha-(IFN), pegylated interferon alpha2a (PEG-IFN alpha2a), lamivudine, adefovir, entecavir, telbivudine and recently, tenofovir. Each drug has advantages and limitations. IFN and PEG-IFN alpha2a have the advantage of inducing a sustained virologic response after a defined, limited course of treatment. However, these drugs are only effective in a minority of patients and have frequent side effects. Analogues have the advantage of being administered orally, with good safety profiles and a potent antiviral effect. However, these drugs need to be administered indefinitely since withdrawal of therapy is generally associated with reactivation, and a sustained response is uncommon except in HBeAg positive patients who develop HBe seroconversion. In case of HBe seroconversion, therapy should usually be continued for at least another 24 weeks. The efficacy of lamivudine is limited by the emergence of lamivudine-resistant HBV. Adefovir is associated with a moderate incidence of resistance but its antiviral effect is not optimal. Entecavir has shown to be more effective with a favourable safety profile and a low incidence of resistance. Telbivudine is more potent and has a lower rate of resistance than lamivudine but the resistance rate is significantly higher than other approved drugs. Tenofovir has a potent antiviral effect with a good resistance profile. The future of chronic hepatitis B therapy appears to be different drug combinations. Normally the advantage of drug combinations versus monotherapy should be additive or synergistic antiviral effects and a decrease in viral resistance. Unfortunately, there are few data available and none of the evaluated analogue combinations have been shown to be better than monotherapy. The only combination which has shown a synergistic effect is of pegylated interferon alpha2a with lamivudine. Therefore, combinations of pegylated interferon with the most potent analogues need to be evaluated. The ultimate goal of therapy is HBsAg seroconversion which is more often observed with interferon. Indeed, quantification of serum HBsAg will be a useful tool to predict the treatment outcome. More potent drugs and new combinations as well as understanding the mechanisms of viral resistance should be evaluated to improve the efficacy of treatment.

Treatment of chronic hepatitis B: recommendations from an Italian workshop

The changing scenario of hepatitis B virus therapy has encouraged the organisation of a workshop, endorsed by three Italian scientific societies, aimed at defining the current recommendations for hepatitis B virus treatment. Liver histology and stage of disease remain fundamental for treatment decisions; interferon and nucleoside/nucleotide analogues-based therapy represent different strategies for different phases of the hepatitis B virus disease. The recommendations defined: new and lower cut-off of hepatitis B virus-DNA for eligibility to therapy according to disease stage, how to optimise the use of nucleoside/nucleotide analogues and to individualise the monitoring of response and what to do with treatment failures. Specific recommendations have also been given for cirrhosis patients, those immune suppressed and co-infected with HIV and other hepatitis viruses.

Hepatitis B: reflections on the current approach to antiviral therapy

This article summarizes the current state of antiviral therapy of hepatitis B with special attention given to areas that remain controversial or poorly defined. Strict adherence to liver association practice guidelines may result in missed opportunities to treat patients with significant underlying liver disease. In particular, recommended ALT thresholds may not appropriately reflect disease activity or degree of fibrosis. There is growing evidence that an alternative treatment paradigm for preventing late-stage disease complications may be indicated in highly viremic patients with early life exposure to hepatitis B. Pegylated interferon therapy is often a better choice for young to middle-aged patients with genotype A and B because of the higher rate of HBeAg seroconversion and a greater chance for HBsAg seroconversion in both HBeAg-positive and -negative patients as compared to nucleoside analogs. Nucleoside analog monotherapy is the current standard of care for many patients. However, long-term monotherapy results in resistance to a variable degree and sequential monotherapy may result in multi-drug resistant virus. Which patients would specifically benefit from early combination therapy also remains poorly defined. The rapidity and robustness of the suppression of HBV DNA while on a nucleoside analog should be monitored relatively early during treatment because it affects treatment outcome and the rate of resistance. While great progress has been made in treating hepatitis B, many important issues require further study.

Reviews for APASL guidelines: immunomodulator therapy of chronic hepatitis B

The primary aim of immunomodulator therapy is to help the natural human immune system to mount a defense against hepatitis B virus. IFN-alpha has been used for the treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B for over two decades and has been shown to be effective in suppressing HBV replication and in inducing serological response leading to long-term clinical benefits. IFN-alpha has been used in patients with well-compensated cirrhosis with comparable or better response to that in non-cirrhotic patients. IFN-alpha therapy in patients with cirrhosis has a similar side effect profile as in those without cirrhosis. However, IFN-alpha is contraindicated in patients with overt or decompensated cirrhosis. Pegylated IFN-alpha has been shown to be effective in treatment of chronic hepatitis B with sustained response rate in about one-third of the treated patients. Peg IFN-alpha treatment in non-responders to lamivudine or adefovir dipivoxil showed similar response rate to that seen in naïve patients. Thymosin alpha(1) is effective in treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B with a significantly increasing virological response over time after therapy.

Telbivudine versus lamivudine in patients with chronic hepatitis B

BACKGROUND

Reducing hepatitis B virus (HBV) replication to minimal levels is emerging as a key therapeutic goal for chronic hepatitis B.

METHODS

In this double-blind, phase 3 trial, 1370 patients with chronic hepatitis B were randomly assigned to receive 600 mg of telbivudine or 100 mg of lamivudine once daily. The primary efficacy end point was noninferiority of telbivudine to lamivudine for therapeutic response (i.e., a reduction in serum HBV DNA levels to fewer than 5 log10 copies per milliliter, along with loss of hepatitis B e antigen [HBeAg] or normalization of alanine aminotransferase levels). Secondary efficacy measures included histologic response, changes in serum HBV DNA levels, and HBeAg responses.

RESULTS

At week 52, a significantly higher proportion of HBeAg-positive patients receiving telbivudine than of those receiving lamivudine had a therapeutic response (75.3% vs. 67.0%, P=0.005) or a histologic response (64.7% vs. 56.3%, P=0.01); telbivudine also was not inferior to lamivudine for these end points in HBeAg-negative patients. In HBeAg-positive and HBeAg-negative patients, telbivudine was superior to lamivudine with respect to the mean reduction in the number of copies of HBV DNA from baseline, the proportion of patients with a reduction in HBV DNA to levels undetectable by polymerase-chain-reaction assay, and development of resistance to the drug. Elevated creatine kinase levels were more common in patients who received telbivudine, whereas elevated alanine aminotransferase and aspartate aminotransferase levels were more common in those who received lamivudine.

CONCLUSIONS

Among patients with HBeAg-positive chronic hepatitis B, the rates of therapeutic and histologic response at 1 year were significantly higher in patients treated with telbivudine than in patients treated with lamivudine. In both the HBeAg-negative and the HBeAg-positive groups, telbivudine demonstrated greater HBV DNA suppression with less resistance than did lamivudine. (ClinicalTrials.gov number, NCT00057265 [ClinicalTrials.gov].).

Therapeutic strategies in the management of patients with chronic hepatitis B virus infection

Currently available options for the treatment of chronic hepatitis B virus (HBV) infection include standard and pegylated interferon alfa and four oral antiviral agents (lamivudine, adefovir, entecavir, and telbivudine). These treatment strategies are either therapies of finite duration that aim to achieve sustained off-therapy responses, or long-term treatments that aim to maintain on-therapy remission. Pegylated interferon alfa may offer higher sustained off-therapy responses after 1 year, but most patients do not respond. Oral antivirals are the only candidates for long-term treatment of patients with chronic HBV infection. Viral suppression has favourable effects on patients' outcome and modifies the natural history of the disease. Viral resistance is the main drawback of long-term antiviral therapy. Lamivudine monotherapy is associated with higher resistance (year 1, 10-27%; year 2, 37-48%; year 4, 60-65%) than adefovir (year 1, 0%; year 2, 3%; year 5, 29%) or telbivudine (year 1, 3-4%; year 2, 9-22%). Entecavir resistance is rare in naive individuals (year 4, <1%), but increases over time in lamivudine-resistant patients (year 4, 43%). The best strategy for long-term therapy in chronic HBV infection has yet to be established.

A pilot study of 2 years of interferon treatment in patients with chronic delta hepatitis

High dose interferon treatment for 1 year is the only established treatment for chronic hepatitis D, but it is associated with a high relapse rate after treatment discontinuation. In this study, patients were treated with 10 MU interferon alpha 2b, thrice weekly for 2 years. Twenty-three patients were recruited and 15 completed the 2-year treatment and 6 months follow-up periods. Treatment response was assessed biochemically [normal alanine aminotransferase (ALT)], virologically (undetectable hepatitis D virus RNA) and histologically (at least 2 point decrease in the Knodell score) at the end of treatment (EOT) and at the end of follow-up. Out of 15 patients who finished the 2-year treatment period, seven patients (47%) had a biochemical response but only two (13%) had a normal ALT after follow-up. ALT decreased from the baseline value of 143.1 +/- 121.7 (mean +/- SD) to 39.7 +/- 20.6 (P < 0.01) at EOT. Virological response was observed in six patients at EOT and in two patients at follow-up. Two patients lost hepatitis B surface antigen. Of the 12 patients with paired liver biopsies, a histological improvement was observed in eight patients. Interferon treatment leads to a complete or partial response in a substantial number of patients but 2 years of treatment does not appear to increase sustained response rates over 1 year treatment.

Efficacy of antiviral therapy with lamivudine after initial treatment for hepatitis B virus-related hepatocellular carcinoma

AIM

The aim of this study was to determine whether antiviral therapy with lamivudine is beneficial in patients after initial treatment for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

METHODS

Forty-nine consecutive patients with HBV-related HCC completely treated by hepatic resection or radiofrequency ablation were retrospectively enrolled in this study. Comparison was made between 16 patients who received lamivudine therapy at a dose of 100 mg/day after treatment for HCC (lamivudine group) and 33 patients who did not (control group) in terms of changes in remnant liver function, HCC recurrence and survival.

RESULTS

Cumulative recurrence rates of HCC did not significantly differ between the two groups (P = 0.622). However, median Child-Pugh score at the time of HCC recurrence was significantly different; 5 (range 5-6) in the lamivudine group versus 7 (range 5-12) in the control group (P = 0.005). All patients in the lamivudine group were able to receive curative treatment for recurrent HCC. In contrast, 10 of 15 patients in the control group were unable to receive curative optimal therapy for recurrent HCC due to deterioration of remnant liver function. The cumulative survival rates of patients in the lamivudine group tended to be higher than those of patients in the control group (P = 0.063).

CONCLUSION

It is suggested that lamivudine therapy is beneficial for patients after initial treatment for HBV-related HCC because it contributes to improving remnant liver function, thus decreasing the risk of liver failure and increasing the chances of receiving available treatment modalities for recurrent HCC.

Lamivudine/pegylated interferon alfa-2b sequential combination therapy compared with lamivudine monotherapy in HBeAg-negative chronic hepatitis B

BACKGROUND AND AIM

Monotherapy has been proven insufficient in achieving sustained control of chronic hepatitis B. We aimed to assess the efficacy of combined sequential administration of lamivudine and pegylated interferon alfa-2b in patients with hepatitis Be antigen (HBeAg)-negative chronic hepatitis B.

METHODS

Eighteen patients were given sequential combination treatment starting with 3 months of lamivudine monotherapy followed by 9 months of pegylated interferon alfa-2b (after a 3-month period of concomitant administration of the two drugs) and 24 patients received lamivudine monotherapy.

RESULTS

At the end of treatment, 88.9% of the patients who received sequential combination treatment and 70.8% of those who received lamivudine monotherapy had hepatitis B virus (HBV) DNA levels below 400 copies/mL (P = not significant). At the end of treatment, 72.2% of the patients who received sequential combination treatment and 70.8% of those who received lamivudine monotherapy achieved alanine aminotransferase normalization (P = not significant). After 12 months of follow up, 33.3% of the patients who received sequential combination treatment and 16.7% of those who received lamivudine monotherapy had HBV-DNA levels below 400 copies/mL (P = 0.4). After 12 months of follow up, 72.2% of the patients who received sequential combination treatment and 25.0% of those who received lamivudine monotherapy had normal alanine aminotransferase levels (P < 0.01). Twenty-five percent of the patients in the lamivudine monotherapy group had virological breakthrough compared to none in the sequential combination treatment group (P = 0.06).

CONCLUSIONS

Sequential combination treatment is able to improve sustained biochemical response rates and prevent the emergence of lamivudine-resistant mutants in patients with HBeAg-negative chronic hepatitis B.

Sequential treatment with lamivudine and alpha-interferon in anti-HBe-positive chronic hepatitis B patients: a pilot study

BACKGROUND

In chronic hepatitis B, long-term use of alpha interferon is hampered by side effects, and long-term treatment with nucleos(t)ide analogues is burdened by drug-resistant mutants. We hypothesized that alternate rounds of lamivudine and alpha interferon might circumvent previous shortcomings.

AIM

To evaluate efficacy of sequential lamivudine or IFN-alpha2b monotherapies in preventing occurrence of tyrosine-methionine-aspartate-aspartate (YMDD) mutants and achieving virological and biochemical response.

METHODS

Fifteen patients with hepatitis B surface antigen, anti-HBe-positive chronic hepatitis received four consecutive rounds of monotherapy with lamivudine (100 mg/day), IFN-alpha2b (5MU/tiw), lamivudine, IFN-alpha2b. Serum HBV-DNA levels were evaluated during and off treatment, HBV polymerase and pre-core/core regions sequenced.

RESULTS

End-of-treatment response was achieved in 10 patients (67%). One patient did not respond, a second developed genotypic resistance at week 24. A rebound in viremia occurred in three patients at week 48. Six patients (40%) remained sustained responders. Triple promoter mutations at nucleotides 1762-1764-1896 prevailed in non-responders (60%) as compared to responders (20%). L180M/M204V mutations were identified during virological breakthrough.

CONCLUSION

Sequential approach of alternate rounds of lamivudine or interferon may help patients to tolerate a prolonged schedule of therapy and protect them from emergence of viral strains.

Future prospectives for the management of chronic hepatitis B

Chronic hepatitis B virus infection affects about 400 million people around the globe and causes approximately one million deaths a year. Since the discovery of interferon-α as a therapeutic option the treatment of hepatitis B has evolved fast and management has become increasingly complicated. The amount of viral replication reflected in the viral load (HBV-DNA) plays an important role in the development of cirrhosis and hepatocellular carcinoma. The current treatment modalities for chronic hepatitis B are immunomodulatory (interferons) and antiviral suppressants (nucleoside and nucleotide analogues) all with their own advantages and limitations. An overview of the treatment efficacy for both immunomodulatory as antiviral compounds is provided in order to provide the clinician insight into the factors influencing treatment outcome. With nucleoside or nucleotide analogues suppression of viral replication by 5-7 log₁₀ is feasible, but not all patients respond to therapy. Known factors influencing treatment outcome are viral load, ALT levels and compliance. Many other factors which might influence treatment are scarcely investigated. Identifying the factors associated with response might result in stopping rules, so treatment could be adapted in an early stage to provide adequate treatment and avoid the development of resistance. The efficacy of compounds for the treatment of mutant virus and the cross-resistance is largely unknown. However, genotypic and phenotypic testing as well as small clinical trials provided some data on efficacy in this population. Discontinuation of nucleoside or nucleotide analogues frequently results in viral relapse; however, some patients have a sustained response. Data on the risk factors for relapse are necessary in order to determine when treatment can be discontinued safely. In conclusion: chronic hepatitis B has become a treatable disease; however, much research is needed to tailor therapy to an individual patient, to predict the sustainability of response and determine the best treatment for those failing treatment.

Effects of lamivudine on outcome after liver resection for hepatocellular carcinoma in patients with active replication of hepatitis B virus

AIM

Patients with high serum hepatitis B virus (HBV) DNA concentrations are at high risk of tumor recurrence after liver resection for HBV-related hepatocellular carcinoma (HCC).

METHODS

Among 24 patients with high serum HBV DNA concentrations who underwent liver resection for HBV-related HCC, postoperative lamivudine therapy was chosen by 14 (lamivudine group). The other 10 patients were controls.

RESULTS

Clinicopathologic findings did not differ between the groups. Tumor-free survival rate after surgery was significantly higher in the lamivudine than the control group (P = 0.0086). By univariate analysis, multiple tumors were also a risk factor for a short tumor-free survival. By multivariate analysis, lack of lamivudine therapy and multiple tumors were independent risk factors for a short tumor-free survival. In four patients YMDD mutant viruses were detected after beginning lamivudine administration; in two of them, adefovir dipivoxil was administered because of sustained serum alanine aminotransferase elevations.

CONCLUSION

Lamivudine therapy improved tumor-free survival rate after curative resection of HBV-related HCC in patients with high serum concentrations of HBV DNA, although careful follow up proved necessary for the detection of YMDD mutant viruses.

Interferon therapy in HBeAg positive chronic hepatitis reduces progression to cirrhosis and hepatocellular carcinoma

BACKGROUND/AIMS

The long-term outcomes of interferon-alpha (IFN-alpha) therapy in hepatitis B e antigen (HBeAg) seropositive patients remain controversial. This study was conducted to address this issue.

METHODS

The long-term outcomes were compared in 233 IFN-treated patients and 233 well-matched untreated controls.

RESULTS

The cumulative incidence at the end of 15 years of follow-up (median 6.8 years, range 1.1-16.5 years) in the IFN-treated patients and controls was: HBeAg seroconversion 74.6% vs. 51.7% (P=0.031); hepatitis B surface antigen (HBsAg) seroclearance 3% vs. 0.4% (P=0.03); cirrhosis 17.8% vs. 33.7% (P=0.041); and hepatocellular carcinoma (HCC) 2.7% vs. 12.5% (P=0.011). Significant reduction of HCC was only observed in patients with pre-existing cirrhosis (P<0.01). Compared with untreated controls with persistent HBeAg, HBeAg seroconverters in untreated and IFN-treated group showed significantly lower incidence of cirrhosis and HCC (P=0.003-0.031), while non-seroconverters of IFN-treated group had marginally significant lower incidence of cirrhosis (P=0.065). Multivariate analysis showed that IFN therapy, HBeAg seroconversion and genotype B HBV infection are independent factors for better long-term outcomes.

CONCLUSIONS

IFN therapy reduces cirrhosis and HCC development.

Prediction of treatment-related HBsAg loss in HBeAG-negative chronic hepatitis B: a clue from serum HBsAg levels

BACKGROUND

Quantification of HBsAg in serum may be of clinical importance in predicting HBsAg seroconversion and complete response to treatment.

METHODS

Serum HBsAg was quantified by ADVIA Centaur in 63 patients with HBeAg-negative chronic hepatitis B (CHBe-). A total of 42 had received interferon-alpha2b (IFN-alpha2b) (median 12.1 months; 19 sustained responders including 12 HBsAg-seroconvertors; 23 non-sustained responders) and 21 were on lamivudine (LAM) (median 33.0 months). Measurements were done at baseline, during and at the end of treatment, and during and at the end of follow-up.

RESULTS

Baseline median [interquartile range (IQR)] HBsAg levels in all patients were 3286 (1602-7458) IU/ml, not different between IFN- and LAM-treated (P = 0.139). IFN significantly depressed HBsAg in all patients except IFN non-responders, but HBsAg decline persisted only in sustained responders. Low pretreatment HBsAg level was the only significant prognostic variable of HBsAg seroconversion by multivariate analysis. LAM treatment also suppressed HBsAg levels but at a significantly slower rate compared with IFN (P = 0.022). The median (IQR) estimated time to HBsAg undetectability (ETU-HBsAg), derived from best curve fitting, was 127 (87.6-263.5) months for LAM virological responders and 65.3 (36.3-95.0) months for IFN sustained responders (P = 0.002). In 12 HBsAg seroconvertors, ETU-HBsAg was similar to the real time of HBsAg loss (P = 0.525) and seroconversion (0.056).

CONCLUSIONS

In CHBe-, IFN induces a sharper decrease in serum HBsAg compared with LAM and low pretreatment levels are significantly associated with HBsAg serocon-version. Serial HBsAg measurements may be useful for prediction of HBsAg loss and our data suggest that to achieve this, 5.4 years of sustained response to IFN or 10.6 years of effective LAM therapy are probably needed.

The "return" of hepatitis B

There has been a significant advance in the treatment of chronic Hepatitis B virus (HBV) infection and the following drugs were approved for therapy: Conventional interferon (IFN), pegylated interferon alfa-2a (PEG IFN alpha2a), lamivudine, adefovir and entecavir. Compared to nucleoside analogues IFN induces higher rates of sustained remission and HBsAg loss. Conventional IFN in lower doses (1, 5-3 MIU) tiw for 4-6 mo has similar efficacy in comparison to "standard IFN therapy". Longer IFN treatment is a significant factor for long-term remission in HBeAg-negative CHB, but the higher actual IFN dose is not such a factor. PEG IFN is superior to conventional IFN. There is no significant difference between PEG IFN alpha2a at doses 90 mcg/wk and 180 mcg/wk in HBeAg-positive patients. These results provide a rational for further clinical trials with lower doses PEG IFN alpha2a given in prolonged course as maintenance or intermittent treatment. Serious new problems arose after the introduction of nucleoside/nucleotide analogues in clinical practice. The most important ones are drug-resistance and the high rates of relapse after treatment discontinuation. Therapy should only be recommended if the expected benefit exceeds significantly the abstain from treatment. The choice of therapy should take into account the patient's age, co-morbidity, severity of liver disease and the risk of drug-resistance. New antivirals significantly suppress HBV-replication, but have no effect on cccDNA in hepatocytes, and after the treatment discontinuation viral relapses occurs. At the present level of knowledge it is impossible "to eradicate the virus" The realistic treatment goal is to achieve durable response by clearance of HBeAg, sustained decrease of serum HBV DNA levels, normalization of ALT, improvement of liver histology and stopping of liver fibrogenesis. The competition between IFN based therapy and nucleoside or nucleotide analogues still remains. IFN can cure the liver disease while nucleotide analogues only suppress the viral replication during therapy and can reduce the liver fibrosis. Treatment should be prolonged for 24-mo or longer by using maintenance or intermittent treatment course with the lowest effective IFN and PEG IFN doses. Nucleoside/nucleotide analogues are a promising treatment option, but additional data for treatment duration and long-term post-treatment outcome are necessary.

Treatment of chronic hepatitis B

Treatment of chronic hepatitis B has improved substantially over the past five years. Pegylated interferon alpha2a and entecavir have been approved by the FDA and joined the armamentarium of therapies that includes inteferon alpha (IFN-alpha), lamivudine, and adefovir dipivoxil. Several key questions come to mind regarding treatment. Who should receive treatment? Which agent should they be given? How long should treatment last? Treatment is indicated for patients with a high pretreatment alanine aminotransferase level, detectable HBV DNA, and active inflammation on liver biopsy. When selecting an agent, the likelihood of achieving a sustained response should be weighed against long-term risks. IFN-alpha, lamivudine, and adefovir dipivoxil are equally efficacious; however, even though IFN-alpha and pegylated IFN-alpha have a durable response, both are associated with unpleasant side effects. Long-term lamivudine therapy has a high rate of drug resistance compared with adefovir dipivoxil, which has a low rate of drug resistance and a small risk of reversible nephrotoxicity. Entecavir reduces HBV load more effectively than the other therapies, but it is associated with increased drug resistance in patients with lamivudine-resistant HBV. The key to therapy seems to be some combination of therapies--both existing and those in development--that has yet to be determined.

[Treatment of viral hepatitis (I). Treatment of chronic hepatitis B]

In the past 25 years remarkable progress has been made in our understanding of the natural history of chronic HBV. The infection is now perceived as having three consecutive phases: immune tolerance, immune clearance, and inactive carrier status, with possible reactivation episodes. Accumulating evidence indicates that antiviral therapy can prevent progression of HBV-related liver disease, particularly among patients with sustained response. Five agents are now approved for therapy of chronic hepatitis B: interferon-alpha (standard and pegylated), lamivudine, adefovir and entecavir. All five drugs are effective in suppressing HBV DNA levels and improving serum alanineaminotransferase levels and hepatic histology, but it is still unclear who should be treated, with which agent (or combination of agents), for how long, and what endpoints measure the success or failure of treatment. Until a drug therapy results in lasting virological remission in most patients after a reasonably short period of treatment, individualized treatment decisions will remain key to maximizing efficacy, and chronic HBV infection will continue to be treated as a liver disease rather than as an infectious disease.

Management of chronic hepatitis B virus infection: a new era of disease control

When assessing patients with chronic hepatitis B virus (HBV) infection, consider the state of viral replication, the immune response and whether viral mutations could be present, as well as evidence for liver disease or extrahepatic manifestations. In wild-type infections, loss of hepatitis B e antigen (HBeAg), gain of anti-HBe and disappearance of HBV DNA from serum indicate immunosuppression of viral replication, or 'nonreplicative chronic HBV infection'. This 'healthy carrier' state must be distinguished from HBeAg-negative chronic hepatitis B (CHB) resulting from precore and core promoter mutations. HBeAg-negative CHB is common with genotypes D (Mediterranean region, south Asia) and C (north Asia) infections. Age, disease activity (alanine aminotransferase level) and severity (fibrosis stage, cirrhosis) influence treatment decisions. Following the marginal effectiveness of interferon and often temporary effectiveness of lamivudine due to drug resistance, treatment of CHB is entering a new era. Adefovir, entecavir, tenofovir, telbivudine and clevudine have equal or superior antiviral efficacy to lamivudine, whereas several agents are effective against lamivudine-resistant HBV. Pegylated-interferon (peginterferon) is superior to conventional interferon for obtaining sustained immunosuppression of HBV without drug resistance. Antiviral suppression of HBV replication for 2-5 years reverses hepatic fibrosis, prevents cirrhosis and, when cirrhosis is established, improves liver function, prevents hepatic decompensation and lowers the risk of liver cancer. Before embarking on immunosuppressive chemotherapy or organ transplantation in patients with chronic HBV infection, it is important to start antiviral therapy to prevent hepatitis flares. Antiviral therapy can be effective against membranous glomerulonephritis and polyarteritis nodosa caused by HBV. Further improvements in treatment of CHB are needed to prevent drug resistance and permanently suppress viral replication by eradicating viral templates or stimulating host immune responsiveness to HBV.

Treatment options in HBV

The available evidence on interferon-alpha (IFN) treatment for chronic hepatitis B is sufficient to conclude that in patients with HBeAg positive chronic hepatitis, standard IFN therapy significantly improves clearance of HBeAg (number needed to treat [NNT] = 4), loss of HBV-DNA (NNT = 4) and clearance of HBsAg (NNT = 18). HBeAg positive patients with normal or slightly raised ALT should be treated only if there is histological evidence of progressive disease. In patients with HBeAg negative chronic hepatitis, less than 20% of subjects who have achieved an end-of-treatment virological response after a course of standard IFN maintain a sustained virological response in the long-term. IFN treatment could help to delay or prevent disease decompensation and liver-related deaths but further large studies are needed. Lamivudine is effective at reducing, and sometimes clearing, HBV replication in heavily immunosuppressed patients and can be safely administered to patients with advanced liver disease. Lamivudine should be continued over an undefined extended period of time, with a switch from lamivudine to adefovir if there is an HBV-DNA breakthrough under therapy. Adefovir, excluding cost, is preferable to lamivudine as a first-choice because there is less chance of inducing resistance. The long-term benefit of lamivudine and adefovir and the role of combinations is under investigation.

Management of chronic hepatitis B virus infection: current perspectives for the nurse practitioner

PURPOSE

To address the clinical management of chronic hepatitis B virus (HBV) infection.

DATA SOURCES

Studies from the National Library of Medicine that examine the natural history, prevention, and antiviral therapy of chronic HBV infection, with emphasis on recent studies.

CONCLUSIONS

Chronic infection with HBV is a frequent cause of cirrhosis, liver cancer, and liver-related mortality worldwide. Strategies to prevent infection, screen for liver cancer in HBV carriers, and treat chronic hepatitis B are all important in managing this disorder.

IMPLICATIONS FOR PRACTICE

Much can be done to prevent and treat infection. Both classes of drugs to treat hepatitis B, nucleoside analogues and interferons, have advantages and disadvantages. Selection of therapy should be based on biochemical, histological, and virological parameters as well as consideration of several practical issues.

Personal view: the management of chronic hepatitis B infection

There are two new nucleoside analogues available for the management of chronic hepatitis B, adefovir and entecavir, and several more in development. In addition, pegylated interferon has become available. Large-scale population studies have re-emphasized the significance of viral load in predicting a poor outcome over the longer term. These new developments have prompted a reassessment of the indications and objectives of therapy for chronic hepatitis B. Hepatitis B virus deoxyribonucleic acid, rather than alanine aminotransferase should be the prime indication for therapy. Hepatitis B e antigen seroconversion can be achieved in 30-40% of treated patients whatever agent is used. However, it takes longer for nucleoside analogues to achieve the same seroconversion rates as interferon. In anti-HBe-positive disease long-term therapy is required for most patients because the relapse rate after withdrawal of therapy is very high, irrespective of the agent used. Viral resistance limits the use of lamivudine, and to a lesser extent adefovir. Resistance to entecavir has so far only been described in pre-existing lamivudine resistance. Although therapy with combinations of nucleoside analogues has not been investigated to any extent, this is the only way to reduce the emergence or resistance, and studies are urgently needed.

Therapy of hepatitis B -- viral suppression or eradication?

The practicing clinician is currently faced with a number of treatment options for chronic hepatitis B. Beginning in 1998 with the licensing of lamivudine and subsequently adefovir, the treatment paradigm shifted from 4 to 6 months of conventional alfa interferon to a year of nucleoside analog therapy. However, prolonged treatment with nucleoside analogs is often needed to optimize virological response. Recently, a 48-week regimen of pegylated interferon for hepatitis B e antigen (HBeAg)-positive and HBeAg-negative chronic hepatitis B has been shown to be effective, and long-term nucleoside analog therapy has been demonstrated to maintain viral suppression. These findings have added to the complexity of decision-making and have raised questions about whether a finite course of pegylated interferon or nucleoside analog therapy, with possible long-term maintenance, is better as first-line therapy. Each of these fundamentally different approaches has advantages and limitations, and both have a place in the therapeutic armamentarium against chronic hepatitis B. Long-term therapy with nucleoside analogs, however, raises a number of practical concerns that have not been fully addressed as of yet. I will present evidence in support of the recommendation that antiviral therapy should ideally be directed toward achieving the highest rate of viral clearance with the shortest interval of treatment.

Hepatitis B virus replication and liver disease progression: the impact of antiviral therapy

Chronic hepatitis B virus (HBV) infection is a serious health issue worldwide. The presence of HBV replication markers--hepatitis B e antigen (HBeAg) or HBV DNA--is associated with continuing hepatitis activity or intermittent hepatitis flares and subsequent disease progression, including hepatic decompensation and development of liver cirrhosis or hepatocellular carcinoma (HCC). Long-term (>10 years) prospective studies in patients >30 years of age have shown that HBeAg seropositivity is associated with increased risk of disease progression, and the risk of cirrhosis and HCC begins to increase at an HBV DNA level of 10(4) copies/ml. Therefore, elimination of HBV, or at least sustained or maintained suppression of HBV, is the key to reducing hepatitis and thereby halting or preventing disease progression. Therapy with interferon-alpha or a direct antiviral agent has been shown to reduce the risk of cirrhosis and prevent further disease worsening. In both the woodchuck hepatitis model and in HBV patients, maintained suppression of HBV replication by a direct antiviral agent may reduce the progression to HCC. However, the efficacy of current antiviral therapy is still far from satisfactory. The ability to achieve a high rate of sustained or maintained HBV suppression with a low risk of drug resistance would be the ultimate goal in the treatment of chronic HBV infection.

Established and emerging therapies for the treatment of viral hepatitis

Patients who are chronically infected with either hepatitis B or C viruses run the risk of developing cirrhosis and hepatocellular carcinoma in later life. Antiviral treatment offers the only means of interrupting this progression. To date, recombinant interferon alpha and the nucleos(t)ide analogues lamivudine and adefovir dipivoxil are the only licensed drugs for the treatment of chronic hepatitis B, whilst recombinant or pegylated interferons in combination with ribavirin are the ones used for chronic hepatitis C virus infections. The efficacy of these treatments, reasons for treatment failure, drug resistance and future options are discussed in the present review.

A partially overlapping treatment course with lamivudine and interferon in hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND

Treatment of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHBe-) with interferon or lamivudine alone is inefficient and reports of combination treatment with both drugs, equivocal so far.

AIM

To investigate the efficacy of a lamivudine-interferon combination therapy in 36 patients HBeAg-negative CHBe-.

METHODS

Lamivudine was administered from 1 to 12 months and interferon-alpha2b from 7 to 18 months. A historical control group of 36 CHBe- patients, matched for age and sex and treated with the same dosage of interferon-alpha2b was used. All patients were followed up for > or =12-month post-treatment.

RESULTS

The biochemical response rate at the end of treatment was 78% in lamivudine-interferon and 52.8% in interferon-control group (P = 0.026) and at 12-month post-treatment 38.9% and 22.2%, respectively (P = 0.125). Alanine aminotransferase normalization and serum HBV-DNA levels < or =30 000 cp/mL were observed in 50.0% of lamivudine-interferon-treated and 30.6% of interferon-treated patients at the end of treatment (P =0.093) and in 22.2% and 13.9% of patients, respectively, at 12-month post-treatment (P = 0.358). Moreover, alanine aminotransferase normalization and undetectable serum HBV-DNA (<400 cp/mL) was observed in 30.6% of lamivudine-interferon-treated and 8.3% of interferon-treated patients at the end of treatment (P = 0.017) and in 8.3% and 0% of patients, respectively, at 12-month post-treatment (P = 0.076).

CONCLUSIONS

In CHBe-, 12 months after ending a lamivudine-interferon partially overlapping 18-month combination course, 22% of patients still maintain normal alanine aminotransferase and HBV-DNA levels < or =30 000 cp/mL. However, a 12-month interferon monotherapy course may achieve similar responses.

Adefovir rapidly suppresses hepatitis B in HBeAg-negative patients developing genotypic resistance to lamivudine

Progression of hepatitis B in patients with lamivudine-resistant strains is slowed down by adefovir dipivoxil (ADV). Whether the time point of ADV administration (genotypic vs. phenotypic resistance) influences the outcome of therapy is unknown. We compared the outcome of ADV therapy in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B patients with genotypic and phenotypic resistance to lamivudine. Ten milligrams of ADV was administered daily for 2 years to 46 HBeAg-negative patients at the time of phenotypic resistance (group A, >6 log(10) copies/mL of hepatitis B virus [HBV] DNA and high alanine aminotransferase [ALT] levels) and 28 patients at the time of genotypic resistance (group B, 3-6 log(10) copies/mL of HBV-DNA and normal ALT). HBV DNA was assessed every 2 months using Versant 3.0 assay, and lamivudine resistance was confirmed via INNO-LiPA assay in all patients. By month 3, HBV DNA tested negative in all patients from group B compared with only 20 (46%) in group A (P < .0001). The 2-year rates of virological response were 100% in the former patients and 78% in the latter ones (P < .0001). ALT levels remained persistently normal in all group B patients, whereas in group A patients they normalized at rates of 50% at month 6 (P < .0001), 72% at month 12 (P < .01), and 93% at month 24. None of the patients developed ADV resistance or ADV-related side effects. In conclusion, to optimize antiviral treatment in HBeAg-negative patients selecting resistant strains to lamivudine, ADV should be added to lamivudine as soon as genotypic resistance is detected.

Outcome of hepatitis B e antigen-negative chronic hepatitis B on long-term nucleos(t)ide analog therapy starting with lamivudine

We determined the clinical outcome of hepatitis e antigen (HBeAg)-negative chronic hepatitis B patients treated with long-term nucleos(t)ide analog therapy starting with lamivudine. We evaluated 201 such patients treated for 3.8 +/- 1.4 years and 2 historical similar cohorts: 1 treated with interferon-alfa (n = 209) and 1 untreated (n = 195). Virological or biochemical remission rate at 48 months under lamivudine was 34% or 36%, respectively, whereas adefovir was administered in 79 patients with virological-biochemical breakthroughs or no response. Of the lamivudine-treated patients, 4 died, 1 underwent a transplantation, and another 8 developed major events, all having advanced fibrosis at baseline and all but 1 having experienced breakthroughs or no response. At 5 years, survival was 96%, and major event-free survival was 93%. The major event-free survival was significantly better in patients with than in those without virological remission under lamivudine. At the end of follow-up, both survival and major event-free survival were independently associated with type of and response to treatment, being significantly better in patients under long-term antiviral therapy or interferon sustained responders than in interferon non-sustained responders or untreated cases (5-year survival: 96% or 98% vs. 88% or 90%, respectively). In conclusion, in HBeAg-negative chronic hepatitis B, long-term nucleos(t)ide analog therapy starting with lamivudine significantly improves survival and reduces the risk of major complications, compared with interferon non-sustained responders or untreated patients. In such patients with advanced fibrosis, close follow-up for lamivudine resistance and prompt onset of additional antiviral therapy is required or the ab initio use of agent(s) with low resistance rates should be considered.

Immunomodulatory therapy for chronic hepatitis B virus infection

Hepatitis B virus (HBV) is one of the most prevalent viral pathogens of man with around 350 million chronically infected patients. It has been postulated that in persistently infected individuals the HBV-specific immune response is too weak to eliminate HBV from all infected hepatocytes, but sufficiently strong to continuously destroy HBV-infected hepatocytes and to induce chronic inflammatory liver disease. The primary aim in the treatment of chronic hepatitis B is to induce sustained disease remission and prevent serious complications like liver failure and/or hepatocellular carcinoma. The recent emergence of drug-resistant HBV mutants and post-treatment relapse as a consequence of nucleoside analogue monotherapy emphasizes that the principal goal should be to stimulate a successful immune response. In this paper we will focus on the immune response to HBV and we will review reported data on immunotherapeutic strategies like immunomodulatory drugs (cytokines and Thymic derivates) and vaccine therapies using currently available recombinant anti-HBV vaccines, lipopeptide-based T cell vaccine and newly developed genetic vaccines.

Intrahepatic hepatitis B virus covalently closed circular DNA can be a predictor of sustained response to therapy

BACKGROUND & AIMS

This study aimed to determine whether intrahepatic hepatitis B virus (HBV) covalently closed circular (ccc) DNA and total HBV DNA levels at the end of therapy would predict sustained response to therapy.

METHODS

Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients receiving either lamivudine monotherapy or combination of peginterferon and lamivudine had liver biopsy at the end of 1 year therapy and were followed for 52 more weeks after cessation of therapy. Serum HBV DNA, intrahepatic HBV ccc DNA, and total HBV DNA levels were determined.

RESULTS

Forty-seven patients, including 34 males and 13 females, were studied. Twenty-seven patients received combination therapy, and 20 patients received lamivudine monotherapy. Twenty-nine patients had end-of-treatment virologic response, and 15 patients had sustained response 52 weeks after therapy. At the end of treatment, log serum HBV DNA levels correlated well with log intrahepatic HBV cccDNA and log intrahepatic total HBV DNA levels. Log intrahepatic cccDNA and log intrahepatic total DNA levels were significantly lower among patients with sustained virologic response. The adjusted odds ratio for log cccDNA was 5.3 (95% CI: 1.5-18.2, P = .009) and, for log intrahepatic HBV DNA, was 4.4 (95% CI: 1.3-14.7, P = .015) to predict sustained virologic response. Using log cccDNA at -0.80 copies/genome equivalent as cutoff, the sensitivity, specificity, and positive and negative predictive values and accuracy of predicting sustained virologic response were 73%, 78%, 56%, 86%, and 77% respectively.

CONCLUSIONS

Intrahepatic HBV cccDNA and intrahepatic total HBV DNA levels at the end of therapy are superior to serum HBV DNA as surrogates of sustained virologic response.

HBV-DNA Suppression and Disease Course in HBV Cirrhosis Patients on Long-Term Lamivudine Therapy

In hepatitis B virus (HBV) cirrhosis patients on long-term lamivudine (LAM), the relationships between HBV suppression, development of viral resistance and disease outcome are unclear. We analysed the dynamic of serum HBV-DNA and its relationship with the clinical course of 59 patients (52 males, mean age 51.4 ±8.4 years, 12 HBeAg positive and 47 HBeAg negative, and 57 genotype D and two genotype A) with cirrhosis (45 in Child-Turcotte-Pugh class A) and high levels of serum HBV-DNA (median 14.7x107 genomes/ml) treated with LAM [median (range): 44 (15–78) months]. A total of 50 patients (84.7%) achieved a virological response (serum HBV-DNA negative by PCR) during the first 6 months of therapy, and nine (13.3%) achieved a reduction in viral load of >3 log10. Mutations in the YMDD motif of HBV polymerase were documented in 26 patients [median (range) 18: (7–42) months]. At the time of the emergence of mutants, 22 patients had HBV-DNA <105 genomes/ml and normal alanine aminotransferase (ALT) levels. The appearance of virological resistance was followed by an increase of HBV-DNA to ≥105 genomes/ml and of ALT values in 19 out of 26 patients [median (range): 8 (3–19) months]. Event-free survival was significantly longer ( P=0.001) in patients who maintained virological suppression than in those who did not have a complete virological response or suffered a breakthrough. Patients with advanced cirrhosis were more likely to develop liver failure after the emergence of YMDD mutants. The risk of development of hepatocellular carcinoma in patients with compensated cirrhosis and YMDD mutations was maintained, regardless of HBV-DNA serum levels.

Profound and maintained HBV-DNA suppression correlates with a better outcome. Early identification of LAM resistance mutations allows switching to other antivirals before liver decompensation or hepatocellular carcinoma development.

Clinical and molecular characterization of chronic hepatitis B in Albania: a country that is still highly endemic for HBV infection

Albania is a Mediterranean country, still with a high endemicity level of hepatitis B virus (HBV) infection. The chronic hepatitis B profile was characterized in this geographical area and used as a model to investigate the impact of endemicity level on the prevalence of the two major forms of chronic hepatitis B (HBeAg-positive and HBeAg-negative chronic hepatitis B). A cross-sectional study was conducted among 62 chronic hepatitis B patients consecutively admitted to the most important tertiary health care center for the diagnosis and treatment of liver disease in Albania. HBV-DNA was measured with an in-house PCR with a sensitivity of 10(4) copies/ml which uses primers encompassing the pre-core/core region. PCR products were subjected to sequencing and oligohybridization assay. Of the 62 patients, 75.8% had HBeAg-negative chronic hepatitis B. Genotype D was found in all 39 patients with detectable HBV viremia, for whom the heterogeneity of the region modulating HBeAg expression was assessed. Basic core promoter (BCP) mutations (1762/1764) were observed more often in anti-HBe-positive and older patients. In more than 90% of the HBeAg-negative chronic hepatitis B patients with detectable viremia, HBV that carries the G to A pre-core mutation at nucleotide 1896 was found. Patients with HBeAg-positive chronic hepatitis B were younger than HBeAg-negative chronic hepatitis B patients, and for symptomatic and asymptomatic liver-disease patients, the age of peak prevalence was at least 10 years lower for HBeAg-positive chronic hepatitis B patients. In conclusion, the virological and clinical pattern of chronic hepatitis B in Albania is similar to that observed in other Mediterranean countries; it seems to be independent of the HBV endemicity level.

Impact of interferon-alpha therapy on liver fibrosis progression in patients with HBeAg-negative chronic hepatitis B

The possible effect of interferon-alpha (IFNa) on liver fibrosis progression has not been adequately studied in chronic hepatitis B. We evaluated 147 patients with HBeAg-negative chronic hepatitis B who had > or =2 liver biopsies and had been treated with IFNa (n = 120) or had remained untreated (n = 27). The median interval between the two biopsies was 24 (12-160) months. All biopsies were scored blindly by a single liver histopathologist according to the classification of Ishak et al. (J Hepatol 1995; 22: 696-699). IFNa induced sustained biochemical response in 30, initial response and subsequent relapse in 57 and no response in 33 patients. Fibrosis improved in 17.5% of treated (sustained responders: 40%, relapsers: 9%, nonresponders: 12%) and 4% of untreated patients and worsened in 34% (sustained responders: 7%, relapsers: 40%, nonresponders: 48%) and 70% of cases, respectively (P = 0.002). The annual rate of fibrosis progression was worse in the untreated (0.427 +/- 0.119) than in treated patients (0.067 +/- 0.052, P = 0.001). However, the fibrosis progression rate in the untreated patients was not significantly different than the net fibrosis progression rate (after subtraction of IFNa duration) in nonresponders or relapsers. In multivariate analysis, worse fibrosis progression rate was associated with older age (P = 0.010), worse baseline grading score (P < 0.001), lower baseline fibrosis (P = 0.035) and the type of response to IFNa (P = 0.032). In conclusion, in HBeAg-negative chronic hepatitis B, IFNa significantly reduces the rate of fibrosis progression, but such an effect is mainly observed in patients with sustained biochemical responses. In relapsers and nonresponders, fibrosis benefit equals the treatment period. The strongest factor associated with fibrosis progression is the change in necroinflammatory activity.

Emerging treatments in chronic hepatitis B

Although the management of chronic hepatitis B has improved over the last decade, none of the available therapeutic agents, IFN-alpha, lamivudine and adefovir dipivoxil, can achieve sustained off-therapy responses in most cases. Therefore, several newer, mainly antiviral and immunomodulatory agents, are being evaluated. Pegylated IFN-alpha(2a) has been shown to be more effective than lamivudine or standard IFN-alpha monotherapy in achieving post-therapy biochemical and virological responses, and is expected to be licensed soon for the treatment of chronic hepatitis B. Newer antiviral agents, such as entecavir and telbivudine, appear to be quite effective initially, but their sustained off-therapy response rates remain unknown. The preliminary data of monotherapies with immunomodulatory agents, or of combination therapies, have been rather disappointing. Long-term maintenance treatment with antiviral agent(s) with good safety and tolerability profiles and low resistance rates appears to be the most realistic future therapeutic option for most chronic hepatitis B patients.

Advances in hepatitis B and C

PURPOSE OF REVIEW

Hepatitis B and C infections are prevalent around the world and a major health burden due to the associated complications of hepatic fibrosis, cirrhosis and hepatocellular carcinoma which occur in the context of chronic infection. Significant advances are being made in assessing and treating infected patients and recent studies are now targeting patients who have failed to respond to previous treatments or who have associated co-morbidities. The purpose of this article to review the recent literature on the subject of hepatitis B and C infections with particular focus on new treatment options, new approaches in patients who have previously failed therapy and in those who have co-morbidity.

RECENT FINDINGS

A large number of studies have been carried out investigating the roles of varying doses, targeting treatment in particular groups and new treatment options in patients infected with hepatitis B and C. Several key findings such as the value of prolonging treatment in patients with genotype 1 hepatitis C infection, the use of pegylated interferon in chronic hepatitis B infection and the emergence of new treatments such as adefovir for resistant hepatitis B infection, as well as treatment of patients co-infected with hepatitis C and human immunodeficiency virus, have dominated the recent literature. Patients in particular groups such as those who have had liver transplantation or who are immunosuppressed have also received added attention.

SUMMARY

Hepatitis B and C infections are the focus of much current attention with particular regard to new and emerging treatment options which are becoming increasingly focused on varying patient groups.

Chronic hepatitis B

Interferon alpha, lamivudine, and adefovir are the three drugs currently approved for the treatment of chronic hepatitis B virus (HBV). There are pros and cons associated with the use of each drug. Individualization of therapy, based upon factors such as patient comorbidities, response to prior therapies, and stage of disease, is recommended. Patients with abnormal liver enzymes, indices of active viral replication (HBV DNA positive hepatitis B early antigen positive) or evidence of necroinflammatory activity on liver biopsy, and compensated liver disease are potential candidates for treatment with interferon, lamivudine, or adefovir. Patients with abnormal liver enzymes, indices of active viral replication (HBV DNA positive HB(e)Ag positive), and decompensated liver disease are candidates for treatment with lamivudine or adefovir. Consideration of liver transplantation should occur concurrently. Interferon alpha treatment results in hepatitis B surface antigen loss and sustained suppression of HBV DNA replication in 30% to 40% of treated patients. Loss of HBsAg occurs in nearly 10% of patients and a higher than expected frequency of HBsAg loss occurs long-term. The main limitation of therapy is the side effects and the need for parenteral administration. Additionally, interferon therapy is not applicable to all patient groups. Lamivudine achieves HB(e)Ag seroconversion in 15% to 20% of patients treated for 12 months, but (HBsAg) loss is rare. Reduction in HBV DNA to undetectable levels (by hybridization assay) during treatment is nearly universal, and histologic improvement is seen in about 55% of patients. The main limitation of lamivudine therapy is the development of drug resistance, which occurs in 20% of patients after 12 months and increases with duration of therapy (55% at 3 years). Adefovir achieves HB(e)Ag seroconversion in 12% of patients treated for 12 months, but HBsAg loss is rare. An average 3.5 log reduction in HBV DNA levels is and histologic improvement occurs in 50% to 60% of patients. It is effective against both wild-type and lamivudine-resistant HBV. The risk of drug resistance is low and estimated to be approximately 2% to 3% after 2 years of treatment. Several new antiviral agents are currently under evaluation in clinical trials. In addition, there are two drugs (tenofovir and emtricitabine) that have been approved for HIV infection and that have anti-HBV activity. In the future, combination therapy for chronic HBV infection can be anticipated. Utilization of two or more anti-HBV drugs would be predicted to enhance efficacy and reduce the likelihood of emergence of drug resistance.

Current therapies for chronic hepatitis B virus infection

Patients who are chronically infected with the hepatitis B virus are at an increased risk of developing cirrhosis, hepatic decompensation and hepatocellular carcinoma. Therapeutic intervention offers the only means of interrupting this progression. Currently there are three licensed agents for the treatment of chronic hepatitis B virus infection. These are interferon-alpha, an immunomodulator, and two synthetic nucleos(t)ide analogs, namely lamivudine (Epivir, GlaxoSmithKline) and adefovir dipivoxil (Hepsera, Gilead Sciences). This review aims to summarize current experience with these drugs in the treatment and management of patients with chronic hepatitis B virus infection, their efficacy, and current problems of drug resistance. An outline of future treatment perspectives is also included.

The management of chronic viral hepatitis: A Canadian consensus conference 2004

Several government and nongovernment organizations held a consensus conference on the management of acute and chronic viral hepatitis to update previous management recommendations. The conference became necessary because of the introduction of new forms of therapy for both hepatitis B and hepatitis C. The conference issued recommendations on the investigation and management of chronic hepatitis B, including the use of lamivudine, adefovir and interferon. The treatment of hepatitis B in several special situations was also discussed. There were also recommendations on the investigation and treatment of chronic hepatitis C and hepatitis C-HIV coinfection. In addition, the document makes some recommendations about the provision of services by provincial governments to facilitate the delivery of care to patients with hepatitis virus infection. The present document is meant to be used by practitioners and other health care providers, including public health staff and others not directly involved in patient care.