Resolution of recurrent hepatitis B in two liver transplant recipients treated with famciclovir

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.

Adefovir dipivoxil: review of a novel acyclic nucleoside analogue

Adefovir dipivoxil (ADF) is a novel acyclic nucleoside analogue that has recently been approved for the treatment of chronic hepatitis B virus (HBV). Adefovir was initially assessed at higher doses for the treatment of human immunodeficiency virus (HIV) infection. However, in these studies, nephrotoxicity proved a dose-limiting side effect. Large randomised controlled studies have recently shown that ADF results in histological, virological and biochemical improvement in both hepatitis B e antigen (HBeAg)-positive and HBeAg-negative chronic HBV. While the rate of HBeAg seroconversion at 1 year (12%) was lower than both lamivudine and interferon, this increases with prolonged treatment. The clinical improvements occurred without serious side effects or the development of resistance at the dose of 10 mg daily, in treatment trials of up to 2 years, although resistance has now been observed. In addition, the drug is efficacious in HBV/HIV co-infection and hepatitis B-infected liver transplant recipients, particularly in those who have developed lamivudine resistance. ADF can be added as a treatment option to existing treatment options (interferon-alpha and lamivudine) and assumes a role in the ongoing management of chronic HBV. The optimal use of ADF as either a monotherapy or as part of combination therapy requires further assessment.

Nucleoside analogues and other antivirals for treatment of hepatitis B in the peritransplant period

Chronic HBV infection is a common cause of advanced liver disease that is associated with substantial mortality. Furthermore, chronic hepatitis B was historically a controversial indication for liver transplantation because of a low post-transplant survival, with graft infection being the major contributor to adverse outcomes. The initial use of hepatitis B immune globulin as prophylaxis, followed later by combined therapy with lamivudine, markedly reduced viral recurrence and improved the survival of patients transplanted for acute or chronic hepatitis B with liver failure. Lamivudine alone can also be used for long-term prophylaxis against de novo HBV infection that can be transmitted by organs from donors positive for anti-HBc or anti-HBs. When used in patients with decompensated chronic hepatitis B with cirrhosis, lamivudine has been shown to improve clinical manifestations, prolong pretransplant survival, and defer, or even obviate, the need for transplantation. Despite prophylaxis, viral mutations with breakthrough reinfection may occur and lead to liver failure. The recently approved adefovir dipivoxil, which is active against lamivudine-resistant mutation, and other nucleoside analogs that are in various phases of development, offer hope as rescue therapy for viral recurrence. Other therapeutic alternatives in the future may include gene therapy and immune interventions.

Seroconversion after the addition of famciclovir therapy in a child with hepatitis B virus infection after liver transplantation who developed lamivudine resistance

There is very little information about hepatitis B virus (HBV) infection in children after liver transplantation. This is the first report of the addition of famciclovir in a child who developed lamivudine resistance.A 5-year-old boy who was serum HBsAg-negative and was not vaccinated against HBV underwent living-related liver transplantation for fulminant hepatitis A. The donor was his mother, who was serum HBcAb-positive. No immunoprophylaxis was administered. HBV infection developed after 18 months and was treated with 3 mg/kg daily of lamivudine. Serum alanine aminotransferase normalized and HBV DNA load decreased significantly. Sixteen months later, lamivudine resistance developed; a mutation (M552I) was confirmed by sequencing through the YMDD locus of the HBV polymerase gene. The addition of 750 mg daily of famciclovir led to seroconversion and the disappearance of serum HBV DNA. Lamivudine in combination with famciclovir might be a therapeutic option for HBV reinfection after liver transplantation, also in children. Suppression of viral replication to undetectable values is possible even in the lamivudine-resistant mutant.

Famciclovir treatment of hepatitis B infection following liver transplantation: a long-term, multi-centre study

Famciclovir is a novel guanosine nucleoside analogue with activity against herpes viruses and hepatitis B virus (HBV). Several preliminary reports have described efficacy of famciclovir in patients with recurrent hepatitis B after orthotopic liver transplantation (OLT). This report describes the largest study to date of long-term famciclovir treatment in patients with de novo or recurrent hepatitis B post-OLT. One hundred thirty patients with detectable serum HBV DNA after OLT received oral famciclovir 500 mg tid on a compassionate-use basis. Safety analyses included all treated patients; efficacy was assessed in all patients and a subgroup of 73 patients with complete baseline HBV DNA and alanine aminotransferase (ALT) data who had received > or =6 months of treatment. Efficacy parameters included serum levels of HBV DNA, ALT, and anti-HBe or anti-HBs seroconversion rates. Of the 70 patients treated for > or =6 months who could be evaluated for response/non-response to famciclovir, 52 (74%) were responders, defined as patients who experienced a 70% decrease or more in HBV DNA levels from baseline, or who became HBV DNA-negative, for at least two consecutive visits. In famciclovir responders, HBV DNA levels decreased by a median of 91% after 12 weeks of treatment, 95% after 6 months and >99% after 18 months of treatment. Marked differentiation between responders and non-responders could be made soon after the onset of treatment. Among anti-HBe positive patients with evidence of HBV replication, 12/13 were responders. Patients with high baseline ALT levels experienced more rapid suppression of HBV DNA during therapy with famciclovir. Famciclovir therapy was safe and well tolerated; serious adverse events were reported infrequently. Famciclovir treatment may be beneficial in patients with hepatitis B infection post-OLT.

Hepatitis B

The hepatitis B virus is a hepatotropic virus that can produce a variety of clinical syndromes in patients ranging in age from infants to elderly adults. Worldwide, it is among the leading causes of fulminant hepatic failure, cirrhosis, and hepatocellular carcinoma. Recent advances have led to effective antiviral treatments using interferon and nucleoside analogues. Highly effective vaccinations also are used widely and ultimately may lead to eradication of this life-threatening virus.

Famciclovir treatment of chronic hepatitis B in heart transplant recipients: a prospective trial

Hepatitis B may take a rapid and aggressive course in patients under immunosuppression. Nucleoside analogues have been shown to suppress viral replication effectively. To investigate the effect of famciclovir in immunosuppressed patients, 21 heart transplant recipients with chronic hepatitis B infection were included in a prospective study.

PATIENTS AND METHODS

Patients have been treated with Famciclovir for a median of 14 months. Hepatitis B virus replication and biochemical parameters were regularly tested and liver biopsies were taken before treatment and after a median time of 7 months. HBV-polymerase was sequenced in all patients before therapy and in those patients who experienced virological breakthrough.

RESULTS

Nineteen patients were treated for at least 6 months. Hepatitis B virus-DNA levels declined in all patients and became negative in 8 patients. Mean hepatitis B virus-DNA levels decreased from 199+/-269 to 34+/-53 pg/ml after 24 weeks (P=0.003). During treatment HBeAg became negative in five patients. Mean alanine aminotransferase decreased from 42+/-26 to 24+/-10 U/L (P=0.006). Histological analysis revealed improved inflammatory activity according to the Ishak-score in 11/16 (69%) patients. Total inflammatory activity scores decreased from 8 to 6 (median, NS), but interface hepatitis score (P=0.02) and lobular inflammation score (P=0.006) improved significantly. Median fibrosis scores fell from 5 to 3 (P=0.002). Three patients developed virological breakthrough on famciclovir after 7, 8, and 26 months of treatment showing HBV-polymerase amino acid changes L528 M, S567A, and I581K, respectively.

CONCLUSIONS

Famciclovir improves not only biochemical and virological features but also hepatic inflammation and liver fibrosis in patients with chronic hepatitis B under heavy immunosuppression. Virological breakthrough may develop and requires close monitoring.