Long-term efficacy of interferon alpha-2b and lamivudine in combination compared to lamivudine monotherapy in patients with chronic hepatitis B. An Italian multicenter, randomized trial

Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B: a randomised trial

BACKGROUND

Treatment of HBeAg-positive patients with chronic hepatitis B is not effective in most. A combination of immunomodulatory pegylated interferon alfa-2b and antiviral lamivudine might improve the rate of sustained response.

METHODS

307 HBeAg-positive patients with chronic hepatitis B were assigned combination therapy (100 microg/week pegylated interferon alfa-2b and 100 mg/day lamivudine) or monotherapy (100 microg/week pegylated interferon alfa-2b and placebo) for 52 weeks. During weeks 32-52 the pegylated interferon dose was 50 microg/week in both treatment groups. The analyses were based on the modified intention-to-treat population after exclusion of 24 patients from one centre withdrawn for misconduct, ten who lost HBeAg before the study start, and seven who received no study medication. All included patients were followed up for 26 weeks after treatment.

FINDINGS

49 (36%) of 136 patients assigned monotherapy and 46 (35%) of 130 assigned combination therapy had lost HBeAg at the end of follow-up (p=0.91). More of the combination-therapy than of the monotherapy group had cleared HBeAg at the end of treatment (57 [44%] vs 40 [29%]; p=0.01) but relapsed during follow-up. Patterns were similar when response was assessed by suppression of serum hepatitis B virus (HBV) DNA or change in concentrations of alanine aminotransferase. Response rates (HBeAg loss) varied by HBV genotype (p=0.01): A, 42 (47%) patients; B, ten (44%); C, 11 (28%); and D, 26 (25%).

INTERPRETATION

Treatment with pegylated interferon alfa-2b is effective for HBeAg-positive chronic hepatitis B. Combination with lamivudine in the regimen used is not superior to monotherapy. HBV genotype is an important predictor of response to treatment.

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.

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.

Peginterferon alfa-2a alone, lamivudine alone, and the two in combination in patients with HBeAg-negative chronic hepatitis B

BACKGROUND

Available treatments for hepatitis B e antigen (HBeAg)-negative chronic hepatitis B are associated with poor sustained responses. As a result, nucleoside and nucleotide analogues are typically continued indefinitely, a strategy associated with the risk of resistance and unknown long-term safety implications.

METHODS

We compared the efficacy and safety of peginterferon alfa-2a (180 microg once weekly) plus placebo, peginterferon alfa-2a plus lamivudine (100 mg daily), and lamivudine alone in 177, 179, and 181 patients with HBeAg-negative chronic hepatitis B, respectively. Patients were treated for 48 weeks and followed for an additional 24 weeks.

RESULTS

After 24 weeks of follow-up, the percentage of patients with normalization of alanine aminotransferase levels or hepatitis B virus (HBV) DNA levels below 20,000 copies per milliliter was significantly higher with peginterferon alfa-2a monotherapy (59 percent and 43 percent, respectively) and peginterferon alfa-2a plus lamivudine (60 percent and 44 percent) than with lamivudine monotherapy (44 percent, P=0.004 and P=0.003, respectively; and 29 percent, P=0.007 and P=0.003, respectively). Rates of sustained suppression of HBV DNA to below 400 copies per milliliter were 19 percent with peginterferon alfa-2a monotherapy, 20 percent with combination therapy, and 7 percent with lamivudine alone (P<0.001 for both comparisons with lamivudine alone). Loss of hepatitis B surface antigen occurred in 12 patients in the peginterferon groups, as compared with 0 patients in the group given lamivudine alone. Adverse events, including pyrexia, fatigue, myalgia, and headache, were less frequent with lamivudine monotherapy than with peginterferon alfa-2a monotherapy or combination therapy.

CONCLUSIONS

Patients with HBeAg-negative chronic hepatitis B had significantly higher rates of response, sustained for 24 weeks after the cessation of therapy, with peginterferon alfa-2a than with lamivudine. The addition of lamivudine to peginterferon alfa-2a did not improve post-therapy response rates.

Antiviral therapy for treatment-naïve hepatitis B virus patients

Hepatitis B virus infection is a major public health problem worldwide,responsible for considerable morbidity and mortality from chronic liver disease. It is estimated that there are 350 million hepatitis B virus carriers globally. The prevalence of chronic hepatitis B infection varies greatly in different regions of the world. In the United States, approximately 1.5 million people are infected and 50,000 to 100,000 new cases are reported annually despite the availability of effective vaccines. This article reviews various antiviral therapies for treatment naïve hepatitis B virus patients.

Management of Hepatitis B Patients with Antiviral Resistance

Drug resistance is an expected consequence of antiviral therapy for chronic hepatitis B because of the high rate of hepatitis B virus (HBV) replication, the lack of proofreading during reverse transcription of the pregenomic RNA and the low efficacy of available therapies in eliminating covalently closed circular HBV DNA. Mutations involving the YMDD motif of the catalytic domain of HBV reverse transcriptase have been reported in patients who have received lamivudine, emtricitabine and telbivudine. Drug-resistant mutations affecting other regions of HBV polymerase have also been reported, but at much lower rates in patients who have received adefovir dipivoxil or entecavir. Antiviral resistance is initially manifested as virological breakthrough infection. In most patients, this is followed by biochemical breakthrough and, in some patients, hepatitis flares and hepatic decompensation. Monitoring drug resistance may improve the management of patients with antiviral-resistant HBV and can guide the selection of salvage therapy. The optimal management of patients with antiviral-resistant HBV continues to evolve. The ideal approach is to prevent antiviral resistance through judicious use of antiviral therapy and the use of more potent antiviral agents, possibly in combination.

Effect of Long-Term Lamivudine in Chronic Hepatitis B Virus-Infected Children

Objective

To evaluate, retrospectively, biochemical, serological and histological responses in chronic hepatitis B (CHB)-infected children who received combination therapy and continued with prolonged treatment with lamivudine (3TC).

Patients and methods

CHB infection was defined as the presence of hepatitis B surface antigen (HBsAg), hepatitis Be antigen (HBeAg) and hepatitis B virus (HBV) DNA in serum screened at 3-month intervals for at least 1 year, serum alanine aminotransferase (ALT) levels >1.5 times the normal limit and CHB with histological activity index (HAI) >5 by liver biopsy. A total of 99 children with CHB infection were treated with IFN-α (three times a week, 5 MU/m2) and 3TC (4 mg/kg/d) orally for 6 months. End of therapy response (CR) was defined as ALT normalization, HBV-DNA clearance and e seroconversion. Partial responders (PR) were defined as patients who had ALT normalization and HBV-DNA clearance, but who had not had e seroconversion. Forty-five children with PR at the end of the sixth month continued to receive 3TC alone thereafter. Breakthrough infection was determined as re-emergence of HBV DNA in serum after its clearance. The response rate, side effects and the breakthrough infection rate were examined on prolonged 3TC treatment. Liver biopsy was held in 29 patients at median 32 (14–66) months of 3TC; pre- and post-treatment liver histology was compared.

Results

Pre- and post-treatment evaluation was carried out in 45 children [mean age: 11 ±4.2 years, 31 males (69%), 14 females (31%)] with PR at the end of the sixth month of combination therapy. The initial mean ALT values and HAI scores were 75.6 ±60 IU/l and 8 ±3.3, respectively. 3TC was continued for median 33 (14–66) months and CR was achieved in 15.6% (7/45) and 5.6% (2/36) at the end of first and second year, and 0% (none) at the end of third and fourth year, respectively. Breakthrough incidence was detected in six (13.3%) cases at 12 months and increased to 69.4% ( n=25) and 82.4% ( n=14) at the end of the second and third years, respectively. Patients with breakthrough continued to receive 3TC. Seroconversion and CR of the mutant virus was achieved in one patient (2.9%) at month 46 of treatment with 3TC. Liver biopsy was held in 29 cases at median 32 (14–66) months of 3TC. Pre- and post-treatment mean HAI scores were 8 ±3.3 and 3.9 ±2.1, respectively ( P=0.000). Mean necrosing scores were not different at the beginning and end of therapy ( P=1.0). Inflammation, bridging and fibrosis scores decreased to 0.8 ±0.6, 1.3 ±1.2 and 0.6 ±0.8, respectively ( P=0.000, P=0.002, P=0.000).

Conclusion

The long-term 3TC usage in children with PR does not induce complete response and is associated with high breakthrough incidence. However, histological improvement is achieved and/or sustained even in children with HBV DNA breakthrough.

Short-term corticosteroids then lamivudine and plasma exchanges to treat hepatitis B virus-related polyarteritis nodosa

OBJECTIVE

To assess the efficacy and safety of lamivudine, an antiviral agent that strongly inhibits hepatitis B virus (HBV) DNA replication, combined with plasma exchanges after short-term corticosteroids for HBV-related polyartertitis nodosa (PAN).

METHODS

Ten patients (8 men, 2 women, mean +/- SD age 50.4 +/- 14.4 years) with previously untreated HBV-related PAN were included in a multicenter, prospective, observational trial. Oral prednisone (1 mg/kg/day) was given for 1 week, then tapered and withdrawn within 1 week. Then, lamivudine (100 mg/day or less in the case of renal insufficiency) was started for a maximum of 6 months. Plasma exchanges were performed simultaneously and scheduled as follows: 3/week for 3 weeks, 2/week for 2 weeks, then 1/week until hepatitis B e antigen (HBeAg) to anti-HBe antibody (HBeAb) seroconversion was obtained or until 2-3 months of clinical recovery was sustained. The primary trial endpoint was clinical recovery from HBV-PAN at 6 months. The secondary endpoint was loss of detectable serum HBeAg and HBV DNA, and HBeAg to HBeAb seroconversion at 9 months.

RESULTS

One death, attributed to catheter-related septicemia, was recorded. At 6 months, all 9 survivors had achieved clinical recovery and by 9 months, 6 of 9 (66%) had seroconverted.

CONCLUSION

The strategy of short-term steroids followed by lamivudine and plasma exchanges effectively led to recovery from HBV-PAN. Because of its oral administration and good safety profile, lamivudine should henceforth be considered the antiviral agent of choice to treat HBV-related PAN.

Treatment of hepatitis B with interferon and combination therapy

Pegylated interferon alpha-a (40 kDa) has recently been shown to be superior to conventional interferon. Furthermore, in a pilot study, pegylated interferon alpha-2b together with lamivudine was superior to lamivudine monotherapy. Therefore, the pegylated interferons alone or in combination with antiviral agents are likely to be the treatment of the future. Selecting patients for treatment and knowing when to treat them is as important as knowing which medicine to treat them with.

Interferon–Lamivudine Combination is No Better than Lamivudine Alone in Anti-Hbe-Positive Chronic Hepatitis B

Background and aims

Results of studies using lamivudine and interferon combination in the treatment of chronic hepatitis B are not consistent or conclusive. This study aimed to evaluate the efficacy of interferon plus lamivudine use versus single lamivudine in anti-HBe-positive chronic hepatitis B.

Methods

Eighty patients were treated with either lamivudine or lamivudine plus simultaneously started interferon. Patients were assigned in groups according to random allocation rule. Lamivudine was given 150 mg/day for 96 weeks in each group; interferon was administered 10 MU three times a week for 24 weeks in the combination therapy group.

Results

Alanine aminotransferase (ALT) normalization was achieved earlier in patients treated with lamivudine alone. At the end of treatment, there was no difference between the groups with respect to HBV DNA negativity, ALT normalization and breakthrough rate. Histological improvement was remarkable in each group, but fibrosis score and necro-inflammatory activity were much lower in lamivudine-treated patients.

Conclusions

Addition of interferon to the lamivudine regimen does not increase the effectiveness of the treatment. Considering the side effects of interferon treatment, this combination seems not to be convenient for anti-HBe-positive chronic hepatitis B.

Sequential combination therapy of HBe antigen-negative/virus-DNA-positive chronic hepatitis B with famciclovir or lamivudine and interferon-alpha-2a

BACKGROUND/AIMS

Hepatitis B e antigen-negative/hepatitis B virus (HBV) DNA-positive chronic hepatitis B (CHBe-) exhibits a high relapse rate on monotherapy with lamivudine or interferon-alpha (IFN-alpha). We investigated, whether sequential therapy with famciclovir or lamivudine followed by combination with IFN-alpha-2a improves durable virologic response in CHBe- characterized by mutation analysis of the HBV precore genome region.

METHODS

Fourteen patients were treated with famciclovir (n=3) or lamivudine for 4 weeks to reduce the viral load, and subsequently with the combination of the nucleoside analogue and IFN-alpha-2a until 16 weeks beyond the loss of serum HBV-DNA.

RESULTS

Median duration of therapy was 29.0 weeks (range 20.6-48.3 weeks). Serum HBV-DNA was undetectable and alanine aminotransferase had normalized in all patients at the end of treatment. Seven (50%) patients maintained a sustained response 12 months after end of treatment. Only two of them had been infected by HBV with the G1896A mutation. Most patients (5/7) with the G1896A mutation relapsed within 4 months after therapy.

CONCLUSION

Sequential combination therapy can induce sustained virologic response in a subgroup of CHBe-, but most with the G1896A precore mutant HBV relapse. Trials of CHBe- should be based on characterization of HBV mutants.

Molecular therapies for viral hepatitis

Current treatment modalities available for hepatitis B virus (HBV) or hepatitis C virus (HCV) infections are not efficient. The enormous disease burden caused by these two infections makes the development of novel therapies critical. For HCV, the development of an effective vaccine is urgent in view of the escalating number of infected individuals. Molecular therapies for HBV and HCV infection can be directed at reducing viral load by interfering with the life cycle of the viruses or at generating immune response against viral epitopes. The antiviral approaches consist of the delivery or expression of antisense RNAs, ribozymes or dominant negative proteins. Viral biology can be interrupted by attacking various potential targets within the two viruses. DNA-based vaccination strategies are being explored for both prevention and treatment of these diseases. Both non-viral and recombinant viral vectors are being developed for safe, effective and long-term gene transfer to the liver. Although no "ideal" vector is available at this time, the ingenuity of numerous investigators is leading to the improvement of the vector systems, promising successful application of gene therapy to the prevention and treatment of viral hepatitis in the foreseeable future.

Comparison of Antiviral Effect of Lamivudine with Interferon-α2A versus -α2B in Children with Chronic Hepatitis B Infection

Aim

To compare additive efficacy of combination therapy including interferon (IFN)-α2a+lamivudine (3TC) to IFN-α2b+3TC in children with chronic hepatitis B virus (HBV) infection.

Material and methods

Chronic hepatitis B infection was determined by presence of HBsAg, HBeAg and HBV DNA in serum screened at 3 months intervals for at least 1 year, serum alanine transaminase (ALT) levels more than 1.5-times the upper normal limit and chronic hepatitis with histological activity index (HAI) more than 6 by liver biopsy. Sixty-three children with chronic hepatitis B infection were treated randomly with thrice-weekly subcutaneous injections of 5 MU/m2 recombinant IFN-α2a ( n=29) or recombinant IFN-α2b ( n=34) with the same dose, intervals for 6 months. Patients also received 3TC (4 mg/kg/day, max 100 mg/day) orally daily combined with IFN and continued for 12 months. End of therapy response was defined as ALT normalization, HBV DNA clearance and HBe/anti-HBe seroconversion. Breakthrough infection was determined as re-emergence of HBV DNA in serum after its clearance. Response rate, incidence of side effects and breakthrough infection were compared between IFN-α2a+3TC- and IFN-α2b+3TC-treated patients.

Results

Response rate was 44.8% ( n=13) with IFN-α2a+3TC and 47.1% ( n=16) with IFN-α2b+3TC ( P=1.0). No significant difference was found in respect to the DNA clearance ( P=0.32), anti-HBe ( P=1.0), anti-HBs ( P=0.09) seroconversion and response rates ( P=1.0) between the groups. Breakthrough infection was detected in 1 (3.4%) case on IFN-α2a and none of the cases on IFN-α2b ( P=0.46). All of the patients experienced flu-like symptoms, malaise and fatigue; however, side effect interfering with therapy was not encountered.

Conclusion

No significant difference was found in response rates achieved by combination therapies based on IFN-α2a and IFN-α2b. Clinical efficacy of 3TC and two different IFN subtypes was found similar.

Review article: current management of chronic hepatitis B

Chronic hepatitis B can be diagnosed in patients with increased aminotransferases, hepatitis B virus viraemia and necroinflammation with fibrosis on liver biopsy. Although, ideally, all patients with chronic hepatitis B should be treated, therapeutic intervention is currently recommended for cases with a relatively satisfactory likelihood of response and/or advanced disease. A realistic therapeutic approach aims to sustain hepatitis B e antigen (HBeAg) loss and hepatitis B e antibody (anti-HBe) seroconversion in HBeAg-positive chronic hepatitis B and to sustain biochemical and virological remission in HBeAg-negative chronic hepatitis B. Currently, three drugs are licensed for chronic hepatitis B: interferon-alpha, lamivudine and adefovir dipivoxil. In patients with HBeAg-positive chronic hepatitis B, all of these drugs achieve HBeAg loss (24-33%) and anti-HBe seroconversion (12-30%) rates significantly superior to those observed in untreated placebo controls. In patients with HBeAg-negative chronic hepatitis B, the sustained off-therapy response rate is 20-25% after a > or =12-month course of interferon-alpha and minimal (<10%), if any, after a 12-month course of lamivudine or adefovir. Long-term lamivudine induces an initial response in 70-90% of patients, but only 30-40% of patients remain in remission after the third year due to progressively increasing viral resistance. Long-term adefovir achieves a response in approximately 70% of patients at 12 months, which is maintained at 24 months with rare (<2%) drug resistance. Adefovir is also effective against lamivudine-resistant strains. Many other anti-viral agents, immunomodulatory approaches and combination therapies are currently being evaluated in chronic hepatitis B.

Comparison of 12-month courses of interferon-alpha-2b-lamivudine combination therapy and interferon-alpha-2b monotherapy among patients with untreated chronic hepatitis B

We compared the use of prolonged synchronous combination therapy with interferon (IFN)-alpha-2b and lamivudine with the use of IFN-alpha-2b monotherapy in patients with untreated hepatitis B e antigen (HBeAg)-positive chronic hepatitis B virus (HBV) infection. Thirty-three patients received therapy with lamivudine (100 mg daily) and IFN-alpha-2b (10 million U 3 times per week) for 12 months; 16 patients received IFN-alpha-2b alone (10 million U 3 times per week for 12 months). The primary end point was sustained suppression of HBV DNA and HBeAg seroconversion, which was observed in 15 (45%) of 33 patients treated with combination therapy and in 3 (19%) of 16 patients treated with monotherapy (P=.133). Both therapeutic regimens were well tolerated. Combination therapy increased the rate of sustained suppression of HBeAg and resulted in significant improvement in Knodell histologic activity index scores, compared with monotherapy. However, there was no significant difference in rates of sustained suppression between the 2 groups at the end of follow-up.

Serum HBV DNA as a marker of efficacy during therapy for chronic HBV infection: analysis and review of the literature

Currently, compounds under evaluation for treatment of chronic hepatitis B virus (HBV) infection are evaluated with liver histology as the primary end point for efficacy. However, because of practical limitations in serial liver biopsies, there is a need for alternate markers to assess efficacy over shorter periods of time. Considering the direct correlation between viral replication and disease progression during human immunodeficiency virus and hepatitis C virus infection, we explored whether such a correlation exists for HBV infection. We reviewed the literature and conducted an analysis to investigate the relationship between absolute or treatment-induced changes in HBV DNA levels and other accepted markers of disease activity. A total of 26 prospective studies met our selection criteria, including 33 evaluable treatment arms. The study treatments consisted of nucleosides and/or interferon regimens and control arms. We found statistically significant and consistent correlations between viral load level or change and histologic grading and biochemical and serologic response. Our analysis suggests that a treatment-induced reduction in HBV DNA level can be used for assessing efficacy of treatment regimens. Further, we observed that quantitative HBV DNA has a broader dynamic range than histology, allowing demonstration of differences between 2 active treatments of unequal potency. The analysis showed stronger results in studies using nucleoside regimens and in hepatitis B e antigen (HBeAg)-positive patients. In conclusion, the goal of anti-HBV therapy should be profound and durable viral suppression, as defined by very sensitive assays. Additional prospective studies are needed to precisely determine the desirable level of viremia to attain.

Lamivudine: in children and adolescents with chronic hepatitis B virus infection

Lamivudine, the negative enantiomer of 2'-deoxy-3'-thiacytidine, is a dideoxynucleoside analog that prevents hepatitis B virus (HBV) DNA synthesis by competitively inhibiting the viral reverse transcriptase and DNA polymerase stages of HBV replication and by terminating proviral DNA chain extension. A dose-ranging study established that once daily oral lamivudine 3 mg/kg up to a maximum of 100 mg/day has the optimum efficacy and tolerability profile for achieving a maximal reduction in serum HBV DNA levels in children aged 2 to 12 years and adolescents aged 13 to 17 years with chronic HBV infection and active viral replication (chronic hepatitis B). Significantly more children and adolescents with chronic hepatitis B receiving lamivudine demonstrated a virologic response (undetectable serum hepatitis Be antigen and undetectable HBV DNA level) [23 vs 13%; p = 0.04] and/or biochemical response (55 vs 12%; p < 0.001) compared with placebo in a large, randomized, double-blind, 52-week phase III study. Despite the emergence of YMDD-variant HBV in 19% of lamivudine-treated children and adolescents, serum alanine aminotransferase and HBV DNA levels remained below baseline in these patients. Oral lamivudine is generally well tolerated by children and adolescents with chronic hepatitis B, with a similar tolerability profile to placebo at the recommended once daily dosage of 3 mg/kg up to a maximum of 100 mg/day.

Continued Lamivudine Therapy in Patients with Chronic Hepatitis B

From September 1995 through April 2002, 286 patients with chronic hepatitis B were started on lamivudine at the Toranomon Hospital in Tokyo, Japan, and most of them continued with it. At present, 16 patients received lamivudine for 5 years, 7 of whom for 7 years or longer. YMDD mutants increased gradually and developed in 69% of them during the 7 years on lamivudine. Biochemical and virological responses were achieved in 9 of the 16 patients (56%) at 5 years, and in 4 of the 7 patients (57%) at 7 years. Histological assessments were performed at 3 years in the 16 patients and further at 4 and 7 years in the 7 patients. Necroinflammatory changes improved remarkably with a decrease in the total histological activity score from 11.3 +/- 3.0 to 4.1 +/- 1.7 (p < 0.0001) at 3 years in the 16 patients. Histological improvements continued in 4 of the 7 patients (57%) at 7 years on lamivudine, while the pathology was unchanged in 2 patients (29%) and aggravated in the remaining 1 patient (14%). Severe acute exacerbation of hepatitis developed in 1 patient, who received additional interferon-alpha therapy to cope with it. Based on my experience, the continuation of lamivudine in patients with chronic hepatitis B benefits approximately two thirds of them with persistent virological and biochemical responses accompanied by histological improvements. Breakthrough hepatitis induced by YMDD mutants along the way in a small number of patients needs to be diagnosed promptly by regular monitoring for transaminases and, if it develops, it can be treated with interferon or other antiviral agents.

In vivo immunization following virus suppression: a novel approach for inducing immune control in chronic hepatitis B

summary. Antiviral treatment of patients with active chronic hepatitis B may lead to significant reduction in morbidity and mortality. However, after stopping nucleoside therapy, relapse rates are high in those without acquired specific immunity. We have treated two chronic hepatitis B patients with in vivo immunization. In vivo immunization aims to optimize conditions for an effective immune response: following rapid and profound virus suppression by interferon-lamivudine combination therapy, lamivudine is withdrawn intermittently for 4 weeks during continued interferon therapy. In both patients with profound virus suppression a rapid rebound in viral replication was observed after lamivudine withdrawal; despite continued interferon. These periods of renewed viral replication were followed by rises in hepatitis activity. After re-introduction of lamivudine HBV DNA became undetectable by PCR followed by normalization of serum ALT. These observations are a stimulus to further explore the concept of in vivo immunization as a novel therapeutic approach for chronic hepatitis B.

Long-term prognosis by lamivudine monotherapy for severe acute exacerbation in chronic hepatitis B infection: emergence of YMDD motif mutant and risk of breakthrough hepatitis -- an open-cohort study

BACKGROUND/AIMS

Comparison of long-term prognosis in patients with chronic hepatitis B treated with lamivudine, with or without severe acute exacerbation (SAE).

METHODS

In chronic hepatitis B HBeAg-positive patients on lamivudine monotherapy, 21 patients with SAE were retrospectively compared with 63 patients without SAE. Both groups were matched for age and sex. We investigated the efficacy and problems associated with monotherapy with respect to SAE.

RESULTS

In SAE and non-SAE, HBeAg seroconversion rates were 21.1 vs. 27.6%, 20.0 vs. 50.0%, and 14.3 vs. 66.7% at 1, 2, and 3 years, respectively. YMDD mutant emerged later in SAE than in non-SAE, but the emergence rates in SAE almost exceeded those of non-SAE from 2 years (rates of about 35%). DNA breakthrough (hepatitis B virus DNA becoming detectable after a period of negativity, accompanied by emergence of YMDD mutant) and breakthrough hepatitis (alanine aminotransferase becoming abnormal after a period of normalization, accompanied by DNA breakthrough) also appeared later in SAE than in non-SAE, but the rates in SAE exceeded those of non-SAE at 3 years.

CONCLUSIONS

Our results suggest that Japanese genotype C-dominant hepatitis B patients with SAE seem to be at greater risk of re-exacerbation after temporary relief of the initial SAE by long-term lamivudine monotherapy, compared with those without SAE.

Combination and newer therapies for chronic hepatitis B

Worldwide the need for effective therapy for chronic hepatitis B is similar to that for chronic hepatitis C. Current licensed treatment for chronic hepatitis B (interferon (IFN)-alpha, lamivudine) does not significantly alter the natural history of the disease because the frequency of sustained response is too low; however, a sustained response to antiviral therapy improves survival. Conversion of active chronic hepatitis B to the inactive hepatitis B carrier state (persistently HBeAg-negative, HBV-DNA < 10(5) copies/mL and alanine aminotransferase (ALT) normal) is the major therapeutic goal. If present 6-12 months after stopping treatment, a sustained response is assumed. Clinical benefit is also likely if HBV-DNA levels < 10(5) copies/mL and ALT normality are being maintained long-term by antiviral therapy. New drugs are adefovir, entecavir, and pegylated IFN. The two nucleoside analogs are active against lamivudine-resistant hepatitis B and are as yet not associated with resistance. Peg-IFN has higher efficacy than standard IFN; its tolerance is similar. Combination therapy appears most effective: IFN-lamivudine combination for induction of a sustained response, and lamivudine-adefovir for long-term antiviral therapy. Uncertainty exists whether the additional effect outweighs the burden of adverse effects and cost. Chronic hepatitis B affects a rather heterogeneous patient population. Differentiation based on HBeAg status is fading with emergence of categorization based on disease stage and immune competence.

Therapy of chronic hepatitis B: current challenges and opportunities

Better understanding of hepatitis B virus (HBV) replication, natural history and the immunopathogenesis of chronic hepatitis B, together with the introduction of effective agents with different mechanisms of action are the basis for better therapeutic strategies against chronic hepatitis B. Among currently available drugs, interferon-alpha and thymosin-alpha1 have only modest efficacy (approximately 40% vs 9-20% in controls). In the past decade, lamivudine has dominated in the treatment of chronic HBV infection because it is easy to use, safe, and is effective in terms of hepatitis B e antigen and/or HBV-DNA loss, ALT normalization, and improvement in histology. The response rate increases with increasing pretherapy alanine aminotransferase (ALT) levels, suggesting that patients with stronger endogenous immune response against HBV have a better response to direct antiviral agents. Lamivudine is also beneficial in decompensated cirrhotics with HBV replication. Hepatitic flares may occur after stopping lamivudine therapy in nonresponders and also in responders. Therefore, prolonged therapy is usually required. However, tyrosine-methionine-aspartate-aspartate (YMDD) mutations conferring resistance to lamivudine start to emerge after 6-9 months of therapy, and hepatitis flare, even decompensation, may develop after viral breakthrough. Thus the benefits of long-term lamivudine therapy must be balanced against the concern about YMDD mutations and the durability of treatment response. Adefovir dipivoxil, entecavir, emtricitabine, clevudine and other nucleoside/ nucleotide analogues have shown encouraging results and some agents appear effective in patients with YMDD mutants. Further development of new drugs and new strategies may help to improve treatment in the new century.

Drug treatment of pediatric chronic hepatitis B

Children with chronic hepatitis B are at risk of developing long-term complications such as cirrhosis and hepatocarcinoma. It is estimated that half to two-thirds of affected children will clear the hepatitis B e antigen (HBeAg) naturally before reaching adulthood. As in adults, treatments in children accelerate the virological response (DNA negativity and HBeAg loss, with anti-HBe seroconversion), which is associated with normalization of transaminase levels. Treatments also favor subsequent loss of hepatitis B surface antigen (HbsAg), the ultimate goal for minimizing long-term consequences. Interferon-alpha was the first approved treatment for pediatric chronic hepatitis B, and was shown to promote DNA negativity and HBeAg loss in 26% of treated patients (6 MU/m(2) body surface area for 6 months) at 1 year and 33% at 18 months (versus 11% in controls). 10% of treated patients also lost HBsAg. Adverse effects mainly included fever, flu-like symptoms and growth impairment during the treatment phase. Nucleotide analogs have now emerged as promising alternatives for the treatment of chronic hepatitis B. Lamivudine dose-ranging studies showed a higher clearance in children, and the optimal dosage was established to be 3 mg/kg once daily in children up to 12 years of age. Efficacy trials showed complete virological response (HBeAg loss and DNA negativity) in 23% of all treated patients after 1 year, and in 34% of patients with initial transaminase levels >2 x the upper limit of normal. Lamivudine resistance due to mutant/variant viruses is observed in 19% of children after 1 year, a figure that may increase by an average of 20% per year. Other nucleotide analogs, such as adefovir, will soon be tested in children, and have shown promising results in adults without so far demonstrating viral resistance. Finally, therapeutic vaccines aiming to induce a cellular immune response towards hepatitis B antigens are being tested in adults, but no clinical benefit has so far been established.

Combination therapy for children with chronic hepatitis B virus infection

BACKGROUND AND AIM

To compare the therapeutic efficacy of two different interferon (INF)-alpha and lamivudine (LAM) combination therapy regimens in childhood chronic hepatitis B (CHB) infections.

METHODS

Thirty-two children with CHB infection were prospectively evaluated in two random groups. In the first group, patients received INF-alpha 10 MU/m2 and LAM 4 mg/kg (max 100 mg) simultaneously for 6 months, and then LAM alone was continued for 6 months. In the second group, LAM was started alone for the first 2 months, then INF-alpha added to LAM for 6 months, after which INF-alpha was stopped, and LAM alone was continued for 4 months. The same doses of LAM and INF-alpha were used in both groups.

RESULTS

In the first group, the mean values of alanine aminotransferase (ALT) were 125 +/- 100 IU/L and 28 +/- 8 IU/L at the beginning of the treatment and at the end of the 12 months, respectively (P < 0.05). At the end of 6 months of the follow-up period, the mean ALT value was 36 +/- 37 IU/L. In group 2, mean ALT values were 111 +/- 63 IU/L, 35 +/- 2 IU/L and 34 +/- 2 IU/L initially, at the end of 12 months and at the end of 6 months of follow up, respectively (P < 0.05). At the end of therapy, the ratios of hepatitis B early antigen (HBeAg) clearance and antibody to HBeAg (anti-HBe) seroconversion were 65% and 47% in group 1 and 60% and 40% in group 2, respectively (P > 0.05). After 6 months from completion of therapy, rates of seroconversion to anti-HBe were found to be 64% and 47% in group 1, and 53% and 46% in group 2, respectively (P > 0.05). Hepatitis B virus (HBV) DNA was detectable by polymerase chain reaction in only one patient in group 1 at the end of therapy and 6 months after termination of therapy. Clearance of HBV DNA in group 2 was observed in all but one patient at the end of the therapy. However, two patients relapsed within 6 months of cessation of therapy. Complete response occurred in 47% and 40% of patients at the end of the therapy in group 1 and 2, respectively (P > 0.05). These ratios were changed to 47% and 46%, respectively, 6 months after discontinuation of drugs (P > 0.05).

CONCLUSIONS

Comparison of our two different combination regimens disclosed similar results in the normalization of ALT, clearance of HBeAg and HBV DNA and seroconversion to anti-HBe. However, the most beneficial combination of LAM and INF-alpha treatment modalities needs to be further investigated.

A preliminary benefit-risk assessment of lamivudine for the treatment of chronic hepatitis B virus infection

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

Hepatitis B treatment: rational combination chemotherapy based on viral kinetic and animal model studies

Hepatitis B virus (HBV) causes a generally non-cytopathic infection in the liver. Even though HBV is a DNA virus, it replicates via reverse transcription which is coordinated within the viral nucleocapsid by the virus-specific polymerase. The major transcriptional template is the viral mimichromosome from which the viral DNA exists as a covalently closed circular (ccc) molcule. The virus infects hepatocytes but can also be found in non-hepatocyte reservoirs such as bile-duct epithelium, mesangial cells of the kidney, pancreatic islet cells and lymphoid cells. When patients infected with HBV are treated with either interferon alpha or lamivudine, responses are variable and unpredictable. Sophisticated mathematical models analysing the dynamics of viral clearance during antiviral therapy have recently been applied to chronic hepatitis B. Typically complex profiles, rather than the usual biphasic responses seen with other diseases have been observed, indicating that antiviral efficacy requires substantila improvement. This may be achieved with combination chemotherapy. However, chronic hepatitis B is a complex and heterogeneous disease entity, and the challenge for the future is to define measurable end-points of treatment and address key virological issues such as the role of cccDNA and extra-hepatocyte replication in treatment failure. Clearly, new therapies and effective combination therapy protocols are urgently required in order to improve the present poor response rates in patients undergoing treatment.