Lamivudine/interferon combination therapy in anti-HBe positive chronic hepatitis B patients: a controlled pilot study

Histological response to combination therapy with nucleos(t)ide analogs and peginterferon alpha in treatment-naïve chronic hepatitis B patients

Although nucleos(t)ide analog (NA) monotherapy is effective in hepatitis B virus suppression and fibrosis regression, serological response rates are not satisfactory. Studies assessing the benefits of combination therapy with NAs and peginterferon alpha (PegIFNα) in patients with chronic hepatitis B (CHB) have produced conflicting results and mainly focused on serological outcomes. Histological changes in response to combination therapy have not been evaluated in real-world practice. This study aimed to evaluate the histological changes in response to NA-PegIFNα combination therapy in CHB patients and to comprehensively compare the efficacy of NA-PegIFNα combination therapy and NA monotherapy. We conducted a retrospective analysis of data from 40 CHB patients who underwent either NA-PegIFNα combination therapy or NA monotherapy. Changes in histology at 48 weeks after treatment initiation were evaluated. Serological characteristics were also analysed and compared between the NA-PegIFNα combination therapy and NA monotherapy groups and between histological responders and nonresponders. Compared to baseline biopsies, both fibrosis staging and necroinflammatory grading scores were significantly lower in the second biopsies examined post-treatment in both groups. Nearly all patients experienced a reduction in inflammation (87.5% in both groups), but there was a subgroup of patients who exhibited either no significant improvement or fibrosis progression (33.3% and 31.2% in the NA monotherapy and NA-PegIFNα combination therapy groups, respectively). Nearly, all patients achieved ALT normalization and sustained virological response (SVR) after 48 weeks of antiviral treatment. Approximately one-third of individuals (36.8% and 30% in the two groups, respectively) achieved HBeAg loss at 48 weeks after treatment initiation. Although there were no significant differences in overall rates of histological, biochemical, virological and serological responses between the two groups, an earlier virological response and a higher cumulative SVR rate over time were observed during long-term follow-up in patients treated with NA-PegIFNα combination therapy (P = 0.0129). Trends of more rapid HBeAg loss and a higher cumulative HBeAg loss rate throughout long-term follow-up were also observed but were not statistically significant. The ALT normalization rates at 24 and 48 weeks after treatment initiation were associated with the histological response. Significant regression of fibrosis and resolution of necroinflammation were induced with either NA-PegIFNα combination therapy or NA monotherapy. Significant biochemical, virological and serological responses were observed in both groups, and the response rates at 48 weeks were similar in the two groups. Over time during long-term follow-up, the virological and serological responses were faster and superior following the combination regimen.

Combination Therapy for Chronic Hepatitis B: Current Updates and Perspectives

Nucleos(t)ide analogues (NUCs) and interferon have been used for several decades to treat chronic hepatitis B; however, the therapeutic response remains unsatisfactory. Although NUC therapy exhibits potent on-treatment viral suppression, frequent off-therapy virological relapses suggest an indefinite treatment course. Interferon modulates the innate and adaptive antiviral immune responses and thus increases the chance of viral eradication. Interferon therapy has the advantage of a finite duration, absence of drug resistance, and durable posttreatment responses. Therefore, the combination of NUCs and interferon can theoretically facilitate a synergistic therapeutic effect. This paper summarizes the current strategies of various combination therapies into three categories: the simultaneous “dual” strategy, sequential combination “add-on” strategy, and “switch” strategy. Generally, dual therapy exhibits greater on-treatment and off-therapy viral suppression and lower drug resistance compared with NUC monotherapy. Compared with interferon monotherapy, dual therapy has greater on-treatment viral suppression but shows no difference in off-therapy sustained virological responses. Specific add-on or switch strategies provide promising on-treatment efficacy in select patients. Pretreatment or on-treatment quantitative hepatitis B surface antigen and e antigen are predictive for the treatment efficacy of combination therapy. The optimal schedule of combination regimens and individualized therapy remain to be comprehensively evaluated.

Combination therapy of interferon and nucleotide/nucleoside analogues for chronic hepatitis B

Chronic hepatitis B is one of the leading causes of cirrhosis and hepatocellular carcinoma globally. At present, seven drugs, including two interferons and five oral nucleos(t)ide analogues (NAs), have been approved for the treatment of chronic hepatitis B. Interferon works by immunomodulation, but is successful in less than a third of treated patients and is a relatively weak antiviral. NAs directly suppress the hepatitis B virus but have limited durability. Based on current data, combination of NA and interferon results in greater viral suppression but does not translate to off-treatment sustained response. Concomitant or sequential treatment also does not make a difference. Combining telbivudine and interferon also runs the risk of severe peripheral neuropathy. On the other hand, interferon switch or additional therapy in patients well controlled with NAs appears to improve the durability of off-treatment response. This article reviews current data on interferon and NA combination and discusses potential future developments.

Adefovir dipivoxil in the treatment of chronic hepatitis B virus infection

Adefovir dipivoxil (Hepsera, Gilead Sciences) is a prodrug of adefovir, with potent antiviral activity against hepatitis B virus. Adefovir dipivoxil therapy, 10 mg daily for 48 weeks, is effective in hepatitis B e antigen-positive and -negative chronic hepatitis B. In hepatitis B e antigen-negative chronic hepatitis B, adefovir dipivoxil was recently found to maintain its efficacy even after 3 years of therapy. Adefovir dipivoxil is effective in patients with compensated or decompensated chronic viral B liver disease, and in pre- and post-transplant hepatitis B virus patients who develop resistance to lamivudine (Epivir, GlaxoSmithKline). It is well-tolerated and safe even after the third year of long-term therapy, and is associated with low rates of viral resistance. All these characteristics make adefovir dipivoxil an important drug for the treatment of hepatitis B virus infection and an excellent candidate for long-term maintenance therapy in chronic viral B liver disease.

Recent advances in the treatment of chronic hepatitis B

INTRODUCTION

At present, two strategies exist for the treatment of chronic hepatitis B (CHB): i) standard or pegylated interferon alpha (IFN) with mainly immune modulatory effects; and ii) nucleos(t)ide analogues (NA) with direct antiviral effects. The optimal treatment for an individual patient remains controversial.

AREAS COVERED

The treatment efficacy and prediction of response to antiviral agents for chronic hepatitis B are reviewed and discussed.

EXPERT OPINION

The rates of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) loss or seroconversion are continuously increasing in CHB patients after stopping a finite course of IFN, whereas long-term NA therapy is usually required to improve the adverse outcomes of CHB. Lower baseline HBV DNA level is a strong predictor for both sustained viral suppression and HBeAg seroconversion in patients receiving IFN-based as well as NAs therapy. In addition, HBeAg-positive patients with genotype A or B infection have better responses to IFN-based therapy than those with genotypes C or D infection. Furthermore, on-treatment predictors such as declines of serum HBV DNA, HBsAg and HBeAg levels may be helpful in making decisions of subsequent therapy. Regarding the association of host genetic factors with responses to antiviral therapy, current evidence is limited.

Immunomodulators as adjuvants for vaccines and antimicrobial therapy

A highly effective strategy for combating infectious diseases is to enhance host defenses using immunomodulators, either preventatively, through vaccination, or therapeutically. The effectiveness of many vaccines currently in use is due in part to adjuvants, molecules that have little immunogenicity by themselves but which help enhance and appropriately skew the immune response to an antigen. The development of new vaccines necessitates the development of new types of adjuvants to ensure an appropriate immune response. Herein, we review commonly used vaccine adjuvants and discuss promising adjuvant candidates. We also discuss various other immunomodulators (namely cytokines, Toll-like receptor agonists, and host defense peptides) that are, or have potential to be, useful for antimicrobial therapies that exert their effects by boosting host immune responses rather than targeting pathogens directly.

Effect of nucleoside analog-interferon sequential therapy on patients with acute exacerbation of chronic hepatitis B

AIM

Nucleoside analog (NA)-interferon (IFN) sequential therapy may enable the long-term control of chronic hepatitis B (CHB) and the withdrawal of the nucleoside analog. We evaluated the efficacy of NA-IFN sequential therapy for acute exacerbation of CHB.

METHODS

A total of 12 patients with acute exacerbation of CHB, nine of whom were positive for hepatitis B e antigen (HBeAg), were enrolled in this study. All the patients were treated with lamivudine 100 mg/day alone for 20 weeks, then with both IFN-alpha 6 megaunits three times per week and lamivudine for 4 weeks, and lastly, with IFN-alpha alone for 20 weeks. Patients whose serum alanine aminotransferase (ALT) level was normalized, whose serum hepatitis B virus (HBV) DNA level decreased to less than 5 log copies/mL, and HBeAg level was absent 24 weeks after the end of treatment were defined as having sustained virological response (SVR). The other patients were defined as having no response (NR).

RESULTS

Four out of nine (44.4%) HBeAg-positive and all three HBeAg-negative patients achieved SVR. The levels of serum alanine aminotransferase (ALT), HBV DNA and HBV core-related antigen were similar between SVR and NR patients at baseline. Three of four patients (75.0%) whose serum HBeAg became negative at the end of treatment achieved SVR, while one of five (20.0%) whose serum HBeAg remained positive achieved SVR.

CONCLUSION

NA-IFN sequential therapy for patients with acute exacerbation of CHB enables the withdrawal of treatment and is particularly effective for patients whose serum HBeAg has become undetectable by the end of the IFN treatment.

A randomized controlled trial of pegylated interferon-alpha2a plus adefovir dipivoxil for hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND

Pegylated interferon (PEG-IFN)-alpha monotherapy is the current standard of care for short-term antiviral treatment of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). We aimed to assess the safety and efficacy of PEG-IFN-alpha plus adefovir dipivoxil (ADV) versus PEG-IFN-alpha monotherapy for compensated HBeAg-negative CHB.

METHODS

A multicentre randomized controlled trial was performed in eight outpatient hepatology/infectious disease clinics in central Italy. A total of 60 patients (67% male and median age 48 years) with biopsy-proven HBeAg-negative compensated CHB (mean alanine aminotranferase [ALT] levels 3.3 +/-3x the upper normal limit and serum hepatitis B virus [HBV] DNA 5.8 +/-0.9 log(10) IU/ml) were randomized at baseline to receive PEG-IFN-alpha2a 180 microg/week plus ADV 10 mg/day or PEG-IFN-alpha2a monotherapy for 48 weeks. Post-treatment follow-up was for 24 additional weeks. The primary end point was sustained HBV DNA suppression defined as serum HBV DNA<2,000 IU/ml after 24 weeks of post-treatment follow-up. The secondary end point was ALT normalization at the end of follow-up.

RESULTS

At week 48, HBV DNA was undetectable in 20/30 (67%) in the combination group versus 11/30 (37%) patients in the monotherapy group (P=0.02). ALT normalization was achieved in 17/30 (57%) versus 10/30 (30%) patients, respectively (P=0.03). At week 72, sustained virological response was achieved in 7/30 (23.3%) in the combination group versus 6/30 (20%) patients in the monotherapy group (P=0.75); 5 (16%) patients in each group dropped out because of adverse events or non-compliance.

CONCLUSIONS

In HBeAg-negative CHB, combination PEG-IFN-alpha2a plus ADV for 48 weeks is safe and resulted in greater on-treatment efficacy than PEG-IFN-alpha2a monotherapy. No difference in sustained virological and biochemical response rates were observed between the two treatment regimens.

Combination treatment in HBeAg-negative chronic hepatitis B

Chronic hepatitis B (CHB) represents an important public health problem. HBeAg-negative CHB is frequently associated with advanced liver disease and its prevalence is increasing. Monotherapy with either interferon (conventional or pegylated) or nucleoside/nucleotide analogues has its limitations. It has been suggested that a combination of these agents might increase antiviral efficacy. However, existing data do not support this hypothesis, even though combination treatment appears to reduce the risk for emergence of lamivudine resistance. Nevertheless, most existing combination studies are small, and it is possible that they have not been designed to detect significant differences between combination treatment and monotherapies. Another limitation of these studies is that, in most of them, lamivudine treatment was discontinued after 1 year, a strategy that is not followed in clinical practice. It was thought to be interesting to evaluate the combination of a short course of interferon (particularly pegylated) with the long-term administration of nucleotide or nucleoside analogues. The efficacy of combining pegylated interferon with the newer nucleotide or nucleoside analogues or of nucleotide with nucleoside analogues could also be evaluated. However, findings show that until more data are available, combination therapy cannot be recommended as first-line treatment in patients with CHB. On the other hand, add-on therapy with adefovir or tenofovir is the treatment of choice in patients who develop resistance to lamivudine. In patients with cirrhosis, a combination of lamivudine/adefovir may also be used as initial treatment; another option would be to add tenofovir in patients with an insufficient response to entecavir.

Response to antiviral treatment in patients infected with hepatitis B virus genotypes E-H

No data on antiviral response of HBV genotypes E-H are available so far although these HBV genotypes contribute significantly to the global HBV burden. Of 49 patients with HBV genotypes E-H, 23 received interferon (IFN)-alpha, 12 nucleos(t)ide analogues and 14 patients were untreated. HBV genotype was determined by direct sequencing of the HBV S gene. Sustained virological response in IFN-treated patients was defined as normalization of ALT and decrease of HBV-DNA <4,000 IU/ml 6 months after treatment. Virological response with nucleos(t)ide analogues was assumed in patients with a HBV-DNA <200 IU/ml after 48 weeks of treatment. HBV genotype E was found in 61.2% (n = 30), HBV genotype F in 8.2% (n = 4), HBV genotype H in 10.2% (n = 5) of patients. Among patients with HBV genotype G (20.4%; n = 10) there were four HBV genotype G/A and three HBV genotype G/C co-infections. Patients had Caucasian (43%), African (55%), or Asian (2%) background. End of treatment response was 70% (16/23) and sustained virological response was 35% (8/23) for patients treated with IFN-alpha. Sustained virological response was 36% for HBV genotype E (n = 5/14), 50% for HBV genotype F or H (n = 2/4), and 20% for HBV genotype G (n = 1/5). Virus suppression at week 48 was achieved in 67% of patients treated with nucleos(t)ide analogues. According to the present preliminary data HBV genotypes E, F, and H appear to be sensitive to IFN-alpha. Lower rates of response to IFN-alpha in patients with HBV genotype G might be related to the frequent occurrence of double infection.

Prevention and management of drug resistance for antihepatitis B treatment

Emergence of drug resistance in antiviral therapy for chronic hepatitis B negates treatment benefits. There is a lower chance for emergence of resistance for drugs with rapid and potent viral suppression and a high genetic barrier for resistant mutations. Measurement of viral load at 24 weeks' treatment to aid decision making is mandatory for patients receiving drugs that are associated with a higher resistance rate. Combination treatment with drugs that belong to different groups is associated with a lower chance of resistance. To ensure better control of viral replication in patients with drug resistance, the addition of another drug without an overlapping resistance profile should be given as early as possible, preferably at the time when genotypic resistance emerges. With such strategies, most patients can be maintained in clinical remission. However, because of the mechanism of viral persistence, research efforts should continue to anticipate and prevent the emergence of multidrug-resistant strains.

Interferons and their use in persistent viral infections

In 2007, the world celebrated the 50th anniversary of the discovery of interferon (IFN) by Isaacs and Lindenmann. Subsequently, the IFN-alpha gene was cloned, fully sequenced and IFN-alpha was produced in recombinant form. Recombinant IFN-alpha is now used as the basis for treatment of chronic hepatitis C virus infection and can also be used to treat certain forms of chronic hepatitis B virus infections. IFNs have also been used in other viral infections, although with less success. The antiviral mechanisms of IFNs are reviewed in this chapter as well as the utility of IFNs in the treatment of persistent viral infections.

Adding interferon to lamivudine enhances the early virologic response and reversion of the precore mutation in difficult-to-treat HBV infection

BACKGROUND

The virologic impact of adding interferon to antiviral nucleoside therapy was studied in Japanese patients having perinatally transmitted hepatitis B virus (HBV) genotype C.

METHODS

Sixty-four patients including 41 positive for hepatitis B e antigen (HBeAg) were assigned to receive either (1) a combination of interferon-alpha (6 million units daily for 2 weeks, then three times weekly) plus lamivudine (100 mg daily) for 24 weeks followed by lamivudine alone for 28 weeks (n = 30) or (2) 52-week lamivudine monotherapy (n = 34).

RESULTS

The combination treatment enhanced the early virologic response, and HBV clearance was more frequent at week 8 for patients with baseline HBV DNA < or = 7 log copies/ml (90% vs. 33%, P = 0.013) and at week 24 for patients with baseline HBV DNA > 7 log copies/ml (75% vs. 40%, P = 0.080). In the combination arm, YMDD mutants emerged less often at week 52 (8% vs. 30%, P = 0.047). However, reversion of the precore mutation was more prominent with combination treatment than with monotherapy (McNemar test, P = 0.014 and P = 0.103, respectively). HBeAg seroconversion (P = 0.429) and sustained off-treatment HBV suppression to < or =5 log copies/ml (log-rank test, P = 0.195) were not improved.

CONCLUSIONS

Simultaneous commencement of treatment with interferon and a nucleoside analog may be worthy as a treatment option to augment the early virologic response and prevent drug resistance in difficult-to-treat patients. Combination treatment was also shown to enhance reversion of the precore mutation. Further studies are warranted to clarify the therapeutic implications of this phenomenon.

Pharmacology, clinical efficacy and safety of lamivudine in hepatitis B virus infection

Lamivudine was the first nucleoside analog for the treatment of chronic hepatitis B (CHB). It is well-tolerated and induces a decrease in serum HBV DNA levels associated with normalization of serum alanine aminotransferase levels. However, a sustained response with hepatitis B 'e' antigen to anti-hepatitis B e seroconversion is obtained in a smaller proportion of patients and hepatitis B surface antigen loss is exceptional. The response is maintained during therapy, and needs to be continued indefinitely in the majority of patients since withdrawal of treatment is generally followed by a rapid reappearance of the virus. However, mutations can be induced in long-term 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.

Systematic review: combination therapies for treatment-naïve chronic hepatitis B

BACKGROUND

There is a renewed interest in use of combination therapies in treatment-naïve chronic hepatitis B (CHB) because of limitations of monotherapies.

AIM

To discuss the current status of combination therapies in treatment-naïve CHB.

METHODS

PubMed search was done using 'combination', 'sequential' and 'chronic hepatitis B' as the search terms.

RESULTS

The two most popular combination therapies include 'combination of nucleos(t)ide analogues' and 'combination of interferons and nucleos(t)ide analogues'. Combination therapies using two nucleos(t)ide analogues do not lead to higher long-term efficacy. However, addition of a nucleos(t)ide analogue with a good resistance profile to a nucleos(t)ide analogue with a lower genetic barrier to resistance decreases the risk of emergent resistance to the latter. Greater sustained virological, biochemical and seroconversion rates are observed with addition of lamivudine to conventional interferon, but pegylated-interferon monotherapy is equally effective as combination with lamivudine. Again, resistance to lamivudine is lower with its combination with interferons.

CONCLUSIONS

The answer to the question whether hepatitis B can be treated better with combination or monotherapy remains largely unknown. Additional trials are warranted of combination therapies of peginterferon and potent nucleos(t)ide analogues or therapies with the combined use of nucleos(t)ide analogues or immunomodulators.

Combination therapy of thymosin alpha-1 and lamivudine for HBeAg positive chronic hepatitis B: A prospective randomized, comparative pilot study

BACKGROUND AND AIM

Monotherapy of lamivudine, interferon-alpha (IFN-alpha), and thymosin alpha-1 (Talpha1) is unlikely to be sufficient for the eradication of a chronic hepatitis B virus (HBV) infection. The aim of our study is to elucidate whether the combination of Talpha1 and lamivudine is superior to lamivudine monotherapy in hepatitis B e antigen (HBeAg) positive naïve patients with chronic hepatitis B.

METHODS

Sixty-seven patients were assigned to two different groups in a randomized manner. The combination group (n = 34) received Talpha1 (1.6 mg subcutaneously, twice a week) and lamivudine (100 mg orally, daily) for 24 weeks, followed by continuous lamivudine therapy. The monotherapy group (n = 33) received lamivudine monotherapy continuously.

RESULTS

The incidence of HBeAg seroconversion at 24 weeks was 26.5% (9/34) in the combination group and 6.1% (2/33) in the monotherapy group (P = 0.024). However, there was no statistically significant difference between 26.5% (9/34) in the combination group and 12.1% (4/33) in the monotherapy group at 52 weeks (P = 0.138). The emergence of viral breakthrough gradually increased to 35.3% (12/34) in the combination group, and to 21.2% (7/33) in the monotherapy group at 52 weeks (P = 0.201).

CONCLUSIONS

The combination treatment of Talpha1 and lamivudine did not have an obvious benefit of virological and biochemical response as compared to the lamivudine monotherapy during the combination period. In addition, after the cessation of Talpha1 treatment, the combination therapy did not prevent the occurrence of viral and biochemical breakthroughs.

The role of the woodchuck model in the treatment of hepatitis B virus infection

Experimental studies of animals with chronic hepadnavirus infection could provide valuable insight into optimal therapeutic strategies for individuals with chronic HBV infection. In this review, we focus on the contributions of the woodchuck model to our understanding of HBV biology and on its role in the development of antiviral drug. Furthermore, we consider the implications of studies focusing on the natural history of WHV infection for the management of HBV and the capacity of treatment to prevent complications of chronic hepatitis B infection.

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.

Cross-study analysis of the relative efficacies of oral antiviral therapies for chronic hepatitis B infection in nucleoside-naive patients

BACKGROUND AND OBJECTIVE

Lamivudine and adefovir were approved for treatment of chronic hepatitis B virus (HBV) infection based on placebo-controlled trials, and entecavir was recently approved on the basis of its superiority over lamivudine in phase II/III trials; however, to date, these three therapies have not been compared head to head.

METHODS

To evaluate the relative efficacy of these therapies, we applied a predefined protocol of established statistical techniques to compare data from phase III entecavir trials with published clinical trial results with lamivudine, adefovir and placebo in nucleoside-naive hepatitis B e antigen (HBeAg)-positive and -negative populations.

RESULTS

A comprehensive literature search identified 612 publications/data sources, of which 28 satisfied predefined inclusion criteria. Independent reviewers extracted week 48-52 histological, virological, biochemical and serological endpoints from these sources, which were analysed with a fixed-effects model. For each of the three histological endpoints in HBeAg-positive patients (Histological Improvement, Ranked Assessment of Necroinflammation [RA-N] and Ranked Assessment of Fibrosis [RA-F]), entecavir was superior to adefovir. Entecavir was superior to lamivudine for Histological Improvement and comparable to lamivudine for RA-N and RA-F. With respect to reducing HBV DNA levels, entecavir (-6.98 log(10) copies/mL) was more effective than lamivudine (-5.46 log(10) copies/mL, p < 0.0001) and adefovir (-3.60 log(10) copies/mL, p < 0.0001), and lamivudine was more effective than adefovir (p < 0.0001). The parallel goals of HBV DNA reduction below the limit of quantitation (LOQ) [by polymerase chain reaction] and ALT normalisation were achieved more often with entecavir (69% and 67% of patients, respectively) than with lamivudine (38% and 59%, respectively; p < 0.0001 and p < 0.05, respectively) or adefovir (21% and 48%, respectively; both p < 0.0001), and more often with lamivudine than with adefovir (p < 0.0001 and p < 0.05, respectively). HBeAg seroconversion rates were higher with entecavir (21% of patients) and lamivudine (18%) than with adefovir (12%, p < 0.01 and p < 0.05, respectively). For each of the three histological endpoints in the HBeAg-negative population, entecavir was comparable to adefovir. Entecavir was superior to lamivudine for Histological Improvement, and comparable to lamivudine for RA-N and RA-F, and all three antivirals were superior to placebo. Entecavir proved superior to lamivudine and adefovir in lowering HBV DNA levels (-5.20 vs -4.66 vs -3.91 log(10) copies/mL, respectively; p < 0.0005 and p < 0.0001, respectively) and in suppressing HBV DNA below the LOQ (91% vs 73% vs 51% of patients, respectively; both p < 0.0001); in the latter respect, lamivudine was in turn superior to adefovir (p < 0.0001). Entecavir was also superior to lamivudine in normalising ALT (76% vs 69% patients, respectively; p < 0.05).

CONCLUSIONS

Over a 12-month treatment period, this analysis predicts that the antiviral efficacy of entecavir would be superior to that of lamivudine, which in turn would be superior to that of adefovir, in nucleoside-naive patients with chronic HBV infection.

Pegylated interferon Alfa-2b monotherapy and pegylated interferon Alfa-2b plus lamivudine combination therapy for patients with hepatitis B virus E antigen-negative chronic hepatitis B

Forty-eight hepatitis B virus (HBV) E antigen-negative chronic hepatitis B patients received pegylated interferon alfa-2b either alone or with lamivudine for 48 weeks and were followed for an additional 24 weeks. At the end of follow-up, virological response rates (HBV DNA levels of <400 copies/ml) were similar in the monotherapy (24%) and combination therapy (26%) groups.

[Sequential combination therapy with prednisone, lamivudine and interferon alfa-2b for HBeAg-positive chronic hepatitis B]

INTRODUCTION

Despite the development of potent, new antiviral drugs, the percentage of HBeAg seroconversion is approximately 35%. Immunosuppression before antiviral administration has recently been investigated with contradictory results. We evaluated the safety and efficacy of lamivudine and interferon alfa-2b with prior immunosuppression with prednisone in patients with HBeAg-positive chronic hepatitis B (CHB).

METHODS

A randomized controlled study was conducted in a sample of 44 patients with HBeAg-positive CHB and persistently elevated alanine transferase (ALT) levels. The patients were distributed into two groups: 22 patients received prednisone 40 mg daily for 4 weeks, followed by 2 weeks without treatment, and lamivudine 150 mg daily for 4 weeks; lamivudine plus interferon alfa 2b (10 MIU every other day) was then administered for 24 weeks followed by continuous lamivudine 150 mg daily to complete 58 weeks. A further 22 patients received the same treatment regimen and duration, but without prednisone.

RESULTS

Virologic response defined as HBeAg seroconversion plus a decrease of serum HBV DNA < 105 copies/ml 24 weeks after concluding the treatment was observed in 68% of the patients receiving previous immunosuppression compared with 54% of the control group (p = 0.26). Forty-five percent of patients with prednisone priming showed histologic improvement compared with 23% of the control group (p = 0.10). A significant proportion of patient with previous immunosuppression showed improvement in necroinflammatory activity (45% vs 23%) and fibrosis (50 vs 23%) compared with the control group.

CONCLUSIONS

Virologic response was clinically, but not statistically, superior in the group with prednisone priming. Histologic improvement was notable in the group with previous immunosuppression.

Combination therapy for chronic hepatitis B: simultaneous or sequential?

Various regimens of combination or sequential therapy using nucleoside/nucleotide analogues (NAs) and interferon-alfa (IFN-alpha) have been tried for the treatment of chronic hepatitis B. To date, combination therapy of two NAs and of IFN-alpha and NAs fails to achieve extra viral suppression. Sequential therapy with lamivudine followed by IFN-alpha seems to have better sustained virologic response. However, the long-term beneficial effect of using this approach remains to be defined.

Treatment alternatives for hepatitis B cirrhosis: a cost-effectiveness analysis

BACKGROUND

Hepatitis B virus (HBV) patients with cirrhosis are at risk for developing costly, morbid, or mortal events, and therefore need highly effective therapies. Lamivudine is effective but is limited by viral resistance. In contrast, adefovir and entecavir have lower viral resistance, but are more expensive. The most cost-effective approach is uncertain.

METHODS

We evaluated the cost-effectiveness of six strategies in HBV cirrhosis: (1) No HBV treatment ("do nothing"), (2) lamivudine monotherapy, (3) adefovir monotherapy, (4) lamivudine with crossover to adefovir on resistance ("adefovir salvage"), (5) entecavir monotherapy, or (6) lamivudine with crossover to entecavir on resistance ("entecavir salvage"). The primary outcome was the incremental cost per quality-adjusted life-year (QALY) gained.

RESULTS

The "do nothing" strategy was least effective yet least expensive. Compared with "do nothing," using adefovir cost an incremental US dollars 19,731. Entecavir was more effective yet more expensive than adefovir, and cost an incremental US dollars 25,626 per QALY gained versus adefovir. Selecting between entecavir versus adefovir was highly dependent on the third-party payer's "willingess-to-pay" (e.g., 45% and 60% of patients fall within budget if willing-to-pay US dollars 10K and US dollars 50K per QALY gained for entecavir, respectively). Both lamivudine monotherapy and the "salvage" strategies were not cost-effective. However, between the two salvage strategies, "adefovir salvage" was more effective and less expensive than "entecavir salvage."

CONCLUSION

Both entecavir and adefovir are cost-effective in patients with HBV cirrhosis. Choosing between adefovir and entecavir is highly dependent on available budgets. In patients with HBV cirrhosis with previous lamivudine resistance, "adefovir salvage" appears more effective and less expensive than "entecavir salvage."

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.

Interferon/long-term lamivudine combination therapy in anti-HBe positive chronic hepatitis B patients

BACKGROUND

Monotherapy with a single antiviral agent is insufficient in controlling hepatitis B virus infection in the majority of patients with anti-HBe positive chronic hepatitis B. Interferon/long-term lamivudine combination therapy was evaluated to determine if this strategy would improve treatment efficacy and reduce the emergence of lamivudine resistance.

METHODS

In total, 36 consecutive anti-HBe positive patients were treated with interferon (3 MU subcutaneously three times weekly) and lamivudine (100 mg orally once a day) for 12 months. After completion of the combined treatment, all patients continued to receive lamivudine monotherapy indefinitely.

RESULTS

Overall, 35 patients (97%) showed virological response at 12 months. Four patients (11%) cleared HBsAg and developed anti-HBs. During the follow-up time, after the discontinuation of interferon, of 30 +/- 12 months (range: 7-57 months), 13 patients (36%) exhibited breakthrough infection. The cumulative rates of breakthrough infection at the end of 1, 2, 3 and 4 years of treatment were 0%, 14%, 32%, and 59%, respectively.

CONCLUSIONS

Combination therapy appears to be effective and may also delay the selection of lamivudine-resistant variants. However, controlled trials are definitely warranted to clarify the potential benefits of combination antiviral treatment over monotherapy.

Interferon-α plus lamivudine vs lamivudine reduces breakthroughs, but does not affect sustained response in HBeAg negative chronic hepatitis B

AIM: To investigate the efficacy of combination treatment of IFN-α and lamivudine compared to lamivudine monotherapy, after 24 mo of administration in HBeAg-negative hepatitis B patients.

METHODS: Fifty consecutive patients were randomly assigned to receive IFN-α-2b (5 MU thrice per week, n = 24) plus lamivudine (100 mg daily) or lamivudine only (n = 26) for 24 mo. Patients were followed up for further 6 mo. The primary outcome was the proportion with sustained virological response (undetectable serum HBV DNA concentrations) and or sustained biochemical response (transaminase levels within normal range) at 30 mo (6 mo after the end of therapy). Secondary end-points were timed from initial virological (biochemical) response to VBR (BBR, respectively) and the emergence of YMDD mutants across the two arms.

RESULTS: Five of twenty-four (21%) patients in the combination arm vs 3/26 (12%) in the lamivudine arm had sustained response (i.e., normal serum transaminase levels and undetectable HBV DNA by PCR assay) 6 mo after treatment discontinuation. A reduction in the emergence of YMDD mutants and in the development of virological breakthroughs was observed in patients receiving combination treatment (10% vs 46%, P = 0.01 and 14% vs 46%, P = 0.03, respectively). Time from initial virologic response to virologic breakthrough (VBR) was greater among initial responders receiving combination treatment compared to those receiving lamivudine (22.9 mo vs 15.9 mo, respectively; P = 0.005).

CONCLUSION: Our results demonstrate that IFN-α plus lamivudine combination therapy does not increase the sustained response, compared to lamivudine. However, combination therapy reduces the likelihood of VBR due to YMDD mutants and prolongs the time period until the breakthrough development.

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Peginterferon Alfa-2a, lamivudine, and the combination for HBeAg-positive chronic hepatitis B

BACKGROUND

Current treatments for chronic hepatitis B are suboptimal. In the search for improved therapies, we compared the efficacy and safety of pegylated interferon alfa plus lamivudine, pegylated interferon alfa without lamivudine, and lamivudine alone for the treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B.

METHODS

A total of 814 patients with HBeAg-positive chronic hepatitis B received either peginterferon alfa-2a (180 microg once weekly) plus oral placebo, peginterferon alfa-2a plus lamivudine (100 mg daily), or lamivudine alone. The majority of patients in the study were Asian (87 percent). Most patients were infected with hepatitis B virus (HBV) genotype B or C. Patients were treated for 48 weeks and followed for an additional 24 weeks.

RESULTS

After 24 weeks of follow-up, significantly more patients who received peginterferon alfa-2a monotherapy or peginterferon alfa-2a plus lamivudine than those who received lamivudine monotherapy had HBeAg seroconversion (32 percent vs. 19 percent [P<0.001] and 27 percent vs. 19 percent [P=0.02], respectively) or HBV DNA levels below 100,000 copies per milliliter (32 percent vs. 22 percent [P=0.01] and 34 percent vs. 22 percent [P=0.003], respectively). Sixteen patients receiving peginterferon alfa-2a (alone or in combination) had hepatitis B surface antigen (HBsAg) seroconversion, as compared with 0 in the group receiving lamivudine alone (P=0.001). The most common adverse events were those known to occur with therapies based on interferon alfa. Serious adverse events occurred in 4 percent, 6 percent, and 2 percent of patients receiving peginterferon alfa-2a monotherapy, combination therapy, and lamivudine monotherapy, respectively. Two patients receiving lamivudine monotherapy had irreversible liver failure after the cessation of treatment--one underwent liver transplantation, and the other died.

CONCLUSIONS

In patients with HBeAg-positive chronic hepatitis B, peginterferon alfa-2a offers superior efficacy over lamivudine, on the basis of HBeAg seroconversion, HBV DNA suppression, and HBsAg seroconversion.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2005 update

BACKGROUND/AIMS

A large amount of new data on the treatment of chronic hepatitis B has become available such that the 2003 consensus statement requires revision and update.

METHODS

New data were presented, discussed and debated in an expert pre-meeting to draft a revision. The revised contents were finalized after discussion in a general meeting of APASL.

RESULTS

Conceptual background, including the efficacy and safety profile of currently available and emerging drugs, was reviewed. Nineteen recommendations were formed and unresolved issues and areas for further study were suggested.

CONCLUSION

The current therapy of chronic hepatitis B is modestly effective but not satisfactory. The development of new drugs and new strategies is required to further improve the outcomes of treatment.

Lamivudine vs lamivudine and interferon combination treatment of HBeAg(-) chronic hepatitis B

To determine whether combination treatment of HBeAg(-) chronic hepatitis B is beneficial we studied 78 patients with HBeAg(-), HBV DNA-positive chronic hepatitis B who were randomized to lamivudine, 100 mg, qd, for 12 months or lamivudine-interferon (9 MU, t.i.w.) in combination. In the combination arm, 2 months of lamivudine treatment preceded 10 months of combination treatment. Biochemical, virologic and histologic responses were assessed at the end of treatment, after six and a median 27 months of drug-free follow-up (short- and long-term follow-up, respectively). Virologic response was defined as undetectable HBV DNA with a hybridization assay and biochemical response as normal alanine aminotransferase (ALT). Change in HBV DNA was also assessed by real-time polymerase chain reaction (PCR). Presence of YMDD mutants at the end of treatment was investigated with a line probe assay. Both treatment regimes led to a median 2 log decline in HBV DNA levels. Virologic end of treatment responses were 90 and 92% with mono- and combination treatment, respectively. Corresponding virologic responses at short- and long-term follow-up were 59 and 54%, and 27 and 25%, respectively. Patients having a baseline HBV DNA value > or =200 pg/mL were more likely to relapse within 6 months off therapy than those patients with a baseline HBV DNA level <200 pg/mL (P = 0.041). YMDD mutants were observed in 53% of patients receiving lamivudine compared with 24% of patients receiving the combination regime (P = 0.017). In conclusion, efficacy of combination treatment is similar to lamivudine monotherapy. However, combination treatment decreases the development of YMDD mutant strains compared with lamivudine monotherapy.

Relationship between serum b2-microglobulin levels and virological breakthrough in HBeAg-negative chronic hepatitis B patients, under long-term treatment schedules including lamivudine

AIM: Predictive value of serum b2-microglobulin (b2m) levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).

METHODS: Serum b2m levels were calculated during treatment in 25 CHB patients under long-term LAM monotherapy (group A) and 12 patients under initial interferon plus LAM treatment followed by LAM monotherapy (group B), using the MEIA technology. We used Cox proportional hazard models in order to investigate the association between serum b2m levels and VB.

RESULTS: Seven of 25 patients (28%), 9/25 (36%) and 14/25 (56%) from group A and 0/12, 2/12 (16.6%) and 3/12 (25%) from group B exhibited VB at months 12, 24 and 36 of treatment, respectively. All patients, from both groups, who did not show VB exhibited b2m elevation in mo 3. The duration of b2m elevation was significantly longer in the virological responder’s subgroup from group A than the non-responder’s one (7.3±2.6 vs 3.8±3.4 mo, P = 0.02). In comparison to group A patients whose b2m levels were increased at 3 mo, patients whose b2m levels were decreased had 4.6 times higher risk of experiencing VB (RR = 4.6, P = 0.024). When baseline variables were simultaneously included in the same Cox model, decreased b2m status was still associated with increased risk of VB (RR = 12.2, P = 0.03).

CONCLUSION: In HBeAg-negative CHB patients under either long-term LAM monotherapy or initial combination treatment, serum b2m levels at 3 mo of treatment, compared to baseline ones, might be a predictor of risk for VB.

Three-phase sequential combined treatment with lamivudine and interferon in young patients with chronic hepatitis B

Alpha-interferon (IFN) or lamivudine monotherapy are ineffective in treating chronic HBeAg positive patients with high viral load and low alanine aminotransferase (ALT) levels. We investigated whether priming lamivudine treatment might enhance the antiviral and immunostimulant action of lamivudine/IFN combination in young tolerant patients. Eleven chronic HBeAg positive patients received: 100 mg/day lamivudine for 3 months followed by IFN 5 MU/m2/tiw with lamivudine 100 mg/day for 6 months and then lamivudine alone 100 mg/day for 9 months. Quantitative hepatitis B virus (HBV)-DNA was evaluated during treatment and core-promoter, precore and polymerase HBV mutants were detected by direct sequencing at the end of therapy. Serum HBV-DNA levels dropped during lamivudine monotherapy and in combination with IFN. After IFN withdrawal, viraemia transiently increased to high levels in five of 11 (45%) patients who showed rt M204V/I lamivudine mutant resistant. Two patients cleared HBeAg without anti-HBe seroconversion. One patient presented core-promoter (A1762T/G1764A) and precore stop codon mutations. Hence, three-phase sequential combined lamivudine/IFN treatment reduced HBV-DNA serum level, but did not lead to HBeAg and HBV-DNA clearance in these highly viraemic, normal ALT patients. Lamivudine/IFN combination did not prevent the emergence of YMDD lamivudine resistance. New schedules of antiviral treatments must be evaluated in this population at risk of disease progression.

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.

Extended lamivudine treatment in patients with HBeAg-negative chronic hepatitis B

BACKGROUND/AIMS

The histological and clinical outcome of lamivudine 100mg/day was assessed in 76 HBeAg-negative chronic hepatitis B patients previously randomised to a double-blind comparison study of lamivudine and placebo.

METHODS

Paired liver biopsies were available before 1 year of randomised lamivudine treatment and after 2 years of further open-label treatment for 48 patients. Serum samples were analysed for hepatitis B markers and ALT levels (n=74).

RESULTS

The histological activity index improved, remained unchanged and worsened in 64, 32 and 5%, respectively, for patients without YMDD-variant HBV compared to 15, 54 and 31% with the variant. None of the 42/48 patients without cirrhosis at baseline progressed to cirrhosis. Of 24/48 patients without bridging fibrosis at pre-treatment, 83% (20/24) did not progress to bridging fibrosis. Median HBV DNA remained below the lower limit of detection and ALT < or =1 times the ULN for patients without the variant whereas levels gradually increased to 11.3Meq/ml (bDNA assay) and 2 times the upper limit of normal by month 24 for patients with variant.

CONCLUSIONS

The clinical benefit of lamivudine is greatest for patients without YMDD variants over 2 years of extended treatment. Additional therapies should be considered for patients with YMDD variants.

Anti-infective activity of immunomodulators

The availability of a vast array of recombinant and synthetic IMMUNOMODULATORS is a significant milestone toward the development of effective therapies for infectious diseases. This is evinced by licensing of several recombinant human CYTOKINES, including COLONY-STIMULATING FACTORS, INTERLEUKINS, INTERFERONS and erythropoietin, for clinical use in patients. Diverse combinations with INTERFERONS and other CYTOKINES for the treatment of various infections have been proposed. Others, including various CHEMOKINES, synthetic CpG oligodeoxynucleotides and glucans, are extensively being investigated in clinical and preclinical studies. Considerable advances have been made on compounds exhibiting CYTOKINE inhibitory properties useful for new treatments of infectious and inflammatory diseases. Many of the major developments and current trends are highlighted in this review. Novel strategies based on the engineering of CYTOKINES and inhibitors are poised to revolutionize therapeutic options contingent upon scientific evidence rather than dictates of discursive empiricism in the coming decades.

Review article: Nucleoside analogues for the treatment of chronic hepatitis B

Current accepted treatment for chronic hepatitis B uses either the immunomodulator interferon alpha or nucleoside analogues lamivudine or adefovir. Interferon has side effects which mean it is often poorly tolerated. Long-term use of lamivudine is associated with increasing viral resistance for each year it is taken and the rebound viraemia that can occur when the drug is stopped is also of concern to many. Adefovir appears to have less of the resistance issues of lamivudine but is still a relatively new drug and at present its use is principally limited to patients with lamivudine-resistant disease. A number of other nucleoside analogues are currently being developed with some now at the stage of early clinical trials. A proportion share the significant resistance problems of lamivudine but many appear to have more potent anti-viral effect than the drugs currently available. If some of these newer anti-viral agents are approved for use in chronic hepatitis B, the potential for prolonged suppression of hepatitis B virus replication with resultant stabilization or improvement in liver disease may be achieved.

Combination of alpha-interferon with lamivudine reduces viral breakthrough during long-term therapy

BACKGROUND AND AIM

Viral breakthrough is frequently encountered during long-term lamivudine therapy, mostly associated with YMDD mutants. In this study, we investigated the effects of alpha-interferon (IFN-alpha) combined with lamivudine on the occurrence of viral breakthrough during long-term lamivudine therapy.

METHODS

Eighty-three patients with biopsy-proven chronic hepatitis B were randomly allocated to a combination of lamivudine and IFN-alpha (LAM/IFN; n = 41) or lamivudine only (LAM; n = 42), and then followed up for >12 months. We calculated the cumulative rate of undetectable serum HBV-DNA and hepatitis B e antigen (HBeAg) loss, as well as the cumulative occurrence rate of viral breakthrough. We also evaluated the relationship between YMDD mutants and the occurrence of viral breakthrough.

RESULTS

There was no difference in cumulative rates of undetectable serum HBV-DNA (100%vs 100% at 24 months, P = 0.13) and cumulative rates of serum HBeAg loss between the LAM/IFN group and the LAM group (49%, 61% and 67%vs 31%, 39% and 42%, respectively, at 12, 24 and 36 months; P = 0.07). The cumulative occurrence rate of viral breakthrough, however, was significantly lower in the LAM/IFN group compared with the LAM group (5%, 20% and 30%vs 10%, 55% and 58%, respectively, at 12, 24 and 36 months; P = 0.006). From the patients with viral breakthrough, YMDD mutants were detected in 82% (18 of 22) of the LAM group in contrast with 56% (five of nine) of the LAM/IFN group in their sera.

CONCLUSION

IFN-alpha combined with lamivudine may reduce viral breakthrough during long-term lamivudine therapy, probably by suppressing the appearance of YMDD mutants.

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.

Treatments for hepatitis B

New optimism surrounds treatments for chronic hepatitis B (CHB). Interferon- alpha , lamivudine, and adefovir dipivoxil are currently approved by the United States Food and Drug Administration for the treatment of CHB. All 3 treatments possess unique characteristics with respect to their side effect profiles, potencies, and treatment niches within the spectrum of CHB. New agents, which are in various stages of clinical development, represent potential improvements within existing, as well as novel, classes of antiviral therapy, and they offer significant promise of a cure for the many patients with chronic and progressive hepatitis B. However, there remain many challenges in understanding the implications of drug resistance, the role of combination therapy, and how to define the response to therapy within subsets of patients with hepatitis B.