Lamivudine therapy for chronic hepatitis B: is longer duration of treatment better?

The therapeutic response of antiviral therapy in HBsAg-positive renal transplant recipients and a long-term follow-up

BACKGROUND

Early prediction of lamivudine (LAM) response by individualized monitoring of serum HBV DNA like roadmap concept, and investigation of the outcome after LAM discontinuation in renal transplant recipients (RTRs) with chronic hepatitis B (CHB).

METHODS

We conducted a study on 19 RTRs with HBV infection receiving LAM treatment for 2 years from 2004 to 2007. HBV DNA level was assessed at baseline, 12, 24, 52, and 104 weeks after treatment. Risk factors of tyrosine-methionine-aspartate-aspartate (YMDD) mutation on treatment and relapse rate of HBV after LAM discontinuation were analyzed.

RESULTS

HBV DNA levels became undetectable in 32, 37, 63, and 53% of patients after 12, 24, 52, and 104 weeks of LAM treatment, respectively. Overall, three (16%) and five (33%) patients were detected with YMDD mutations at week 52 and 104, respectively. In the concept of roadmap, of the seven patients with inadequate virologic response (IAVR) at week 24, five had YMDD mutations. There was no significant association of YMDD mutations with age, gender, genotype, cirrhosis, HBeAg status, baseline HBV DNA, precore/core promoter mutations, and primary response, except IAVR at week 24 (P = 0.001). The relapse rate of HBV after LAM discontinuation was high (75%) during a median follow-up of 65 weeks.

CONCLUSIONS

The rate of LAM resistance in RTRs is similar to immunocompetent CHB patients in a 2-year therapy. By roadmap concept, RTRs with IAVR require a change in therapy to prevent viral resistance. Relapse after LAM withdrawal is frequent. Long-term antiviral therapy is crucial for immunosuppressed patients.

Chronic hepatitis B treatment: the cost-effectiveness of interferon compared to lamivudine

OBJECTIVE

To perform a cost-effectiveness evaluation from the perspective of the Brazilian National Health System of alternatives strategies (i.e., conventional interferon, pegylated interferon, and lamivudine) for the treatment of patients with chronic hepatitis B who present elevated aminotransferase levels and no evidence of cirrhosis at the beginning of treatment.

METHODS

A Markov model was developed for chronic hepatitis B (hepatitis B antigen e [HBeAg] positive and negative) with 40 years' time horizon. Costs and benefits were discounted at 5%. Annual rates of disease progression, costs due to complications, and the efficacy of medicines were obtained from the literature. One-way and probabilistic sensitivity analysis evaluated uncertainties.

RESULTS

For HBeAg positive patients, peginterferon (48 weeks) resulted in an increase of 0.21 discounted life-years gained compared to interferon (24 weeks). The incremental cost-effectiveness ratio (ICER) converted to US dollars using the 2009 purchasing power parity conversion factor was US$100,752.24 per life-year gained. For HBeAg negative patients, it was observed that interferon (48 weeks) compared with long-term lamivudine presented an increase of 0.45 discounted life-years gained and ICER of US$15,766.90 per life-year gained. In the sensitivity analysis, the ICER was more sensitive to variation in the probability of transition from chronic hepatitis B to compensated cirrhosis, discount rate, and medicine prices. Cost-effectiveness acceptability curve for HBeAg positive (pegylated interferon vs. conventional interferon) and negative (conventional interferon vs. lamivudine) showed that conventional interferon was cost-effective until three times the gross domestic product per capita.

CONCLUSIONS

For patients with chronic hepatitis B with elevated aminotransferase levels in the pretreatment and no cirrhosis who were HBeAg positive, pegylated interferon (48 weeks) provided more life-years gained when compared to conventional interferon (24 weeks), and the ICER surpasses the country's buying power, which makes conventional interferon the chosen alternative. For HBeAg negative patients, conventional interferon (48 weeks) compared to lamivudine provided more life-years gained at a favorable ICER.

Clinical outcomes of chronic hepatitis B patients with persistently detectable serum hepatitis B virus DNA during lamivudine therapy

BACKGROUND AND AIM

A small proportion of chronic hepatitis B patients have persistently detectable serum hepatitis B virus (HBV) DNA despite lamivudine therapy. The incidence and clinical outcomes of patients who persistently have detectable serum HBV-DNA during lamivudine therapy was investigated.

METHOD

We enrolled 221 chronic hepatitis B patients who underwent lamivudine therapy for more than 6 months. Among them, 180 were HBeAg positive. Serum HBV-DNA, HBeAg, anti-HBe and alanine aminotransferase (ALT) levels were serially monitored. The study groups were defined, using a hybridization assay, as patients with reductions in serum HBV-DNA below the detectable level (group I) or patients with persistently detectable serum HBV-DNA (group II) during the initial 6 months of lamivudine therapy.

RESULTS

The incidence of patients who had persistently detectable HBV-DNA was 7.7%. After the first year, the rates of viral breakthrough, HBeAg loss and serum ALT normalization of group I versus group II were 21% versus 63%, 38% versus 0%, and 71% versus 28%, respectively (P < 0.001). The log(10) reduction of serum HBV-DNA at 6 months was -4.58 log(10) for group I and -1.97 log(10) for group II (P < 0.001, bDNA assay). There were no pretreatment lamivudine-resistant mutants in group II.

CONCLUSION

Lamivudine had little effect on serum HBV-DNA suppression, viral breakthrough suppression and rate of HBeAg loss and ALT normalization in chronic hepatitis B patients with persistently detectable serum HBV-DNA during the initial 6 months of therapy. Early termination of lamivudine therapy is advocated for these patients.

Reactivation of hepatitis and lamivudine therapy in 11 HBsAg-positive renal allograft recipients: a single centre experience

BACKGROUND

In hepatitis B virus (HBV) surface antigen (HBsAg) (+) renal allograft recipients, the mortality associated with liver disease reaches 37-78%. An antiviral agent, lamivudine, has recently been reported to be safe and effective for preventing hepatic damage in these patients, although either resurgence of HBV-DNA levels after discontinuation or emerging resistant HBV mutants caused by long-term administration are still unsettled.

METHODS

Between July 1976 and December 2003, 555 renal transplantations were performed in our centre. Of these, 11 patients who were HBsAg (+) at the time of transplantation (2.0%) were selected for this study. We investigated the incidence of hepatitis reactivation for three yr after transplantation and their clinical courses, including the efficacy of lamivudine therapy in seven of the 11 patients.

RESULTS

Six episodes of hepatitis reactivation developed in five of the 11 patients (45.5%) within three yr after transplantation. Five episodes of six occurred within four months after transplantation. The patient who underwent the most severe reactivation needed intensive care including lamivudine administration and plasma exchange. Lamivudine caused no severe adverse effects and HBV-DNA levels dropped to under measurable levels within four months after lamivudine administration in all patients. Resistant HBV mutant emerged in only one patient, who had the longest lamivudine administration of 49 months.

CONCLUSIONS

For HBsAg (+) renal allograft recipients, careful monitoring of HBV-DNA levels and timely administration of lamivudine could prevent hepatic damage caused by reactivation of hepatitis.

Preemptive lamivudine therapy based on HBV DNA level in HBsAg-positive kidney allograft recipients

Hepatitis B surface antigen (HBsAg)-positive kidney transplant recipients have increased liver-related mortality. The impact of lamivudine treatment on patient survival, the optimal time to start treatment, and the feasibility of discontinuing treatment have not been determined. This study examined these issues with a novel management protocol. Serum hepatitis B virus (HBV) DNA levels were measured serially in HBsAg-positive kidney transplant recipients, and lamivudine was administered preemptively to patients with increasing HBV DNA levels with or without elevation of aminotransferase levels. Outcomes of patients who underwent transplantation before or after institution of this preemptive management strategy (in January 1996) were compared. Eleven de novo patients (91.7%) who underwent transplantation between 1996 and 2000 and 15 existing patients (39.5%) who underwent transplantation between 1983 and 1995 received preemptive lamivudine therapy for 32.6 +/- 13.3 months. The treatment criteria were met by de novo patients at 8.4 +/- 6.2 months (range, 1-18 months) after transplantation. Suppression of HBV DNA and normalization of aminotransferase levels were achieved in all treated patients, and 21.4% had hepatitis B e antigen (HBeAg) seroconversion. The survival of preemptively managed de novo transplant patients was similar to that of HBsAg-negative controls, whereas HBsAg-positive patients who underwent transplantation before January 1996 had inferior survival (relative risk of death, 9.7 [P <.001]; relative risk of liver-related mortality, 68.0 [P <.0001]). Eleven patients (40.7%) developed lamivudine resistance. Discontinuation of lamivudine was attempted in 12 low-risk patients after stabilization and was successful in 5 (41.7%). In conclusion, preemptive lamivudine therapy based on serial HBV DNA levels and clinical monitoring improved the survival of HBsAg-positive renal allograft recipients. Treatment can be discontinued safely in selected patients after stabilization to minimize the selection of drug-resistant HBV mutants.

Long-term evaluation of recombinant interferon alpha2b in the treatment of patients with hepatitis B e antigen-negative chronic hepatitis B in Taiwan

The effect of interferon (IFN) on hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) has not been fully investigated in Chinese patients. We enrolled 58 HBeAg-negative CHB Chinese patients with hepatitis B viremia in Taiwan to evaluate the response to IFN. 30 patients received recombinant IFN 5 million units 3 times weekly for 6-10 months, and 28 patients who refused IFN treatment served as controls. Rates of virological response and biochemical response were higher in the treated group at the end of treatment (57% vs 18%, P = 0.006, and 73% vs 29%, P = 0.002, respectively). Both effects were superior in the treated group at 6 months after IFN withdrawal (virological: 30% vs 7%, P = 0.06; biochemical: 47% vs 7%, P = 0.002). Improvement of liver histological activities with persistently biochemical response was found in 65% of the treated patients. After a mean of 32 months' follow-up, virological response was rarely maintained (17% vs 4%, P = 0.228) but biochemical response was better in the treated group (27% vs 4%, P = 0.039). None of the treated patients but five controls developed severe complications of CHB during the follow-up period. A larger total IFN dosage or a younger age (< or = 40 years) were associated with 'sustained' virological response. Younger age and higher baseline alanine transaminase values (> or = 120 Ul(-1)) were related to 'sustained' biochemical response.

Lamivudine and interferon-alpha combination treatment of childhood patients with chronic hepatitis B infection

BACKGROUND

The aim of our study was to compare the efficacy of combined interferon-alpha and lamivudine in children with chronic hepatitis B infection and two durations of treatment (6 and 12 months).

METHODS

Combination of interferon-alpha 2b (10 MU/m2 of body surface) and lamivudine 4 mg/kg (maximum, 100 mg) were given synchronously to 30 patients for 6 months (Group 1) and to 27 patients for 12 months (Group 2). Biochemical, virologic and serologic features were compared between two groups at the end of therapy and 6 months after therapy.

RESULTS

Hepatitis B e antigen clearances were 33 and 59% at the end of treatment and 37 and 56% 6 months after therapy in Groups 1 and 2, respectively (P > 0.05). Hepatitis B virus DNA clearances were 97 and 100% at the end of treatment and 97 and 96% 6 months after therapy in Groups 1 and 2, respectively (P > 0.05). In both groups normalization of alanine aminotransferase was maintained at the end of therapy and 6 months after therapy (P < 0.05). Sustained complete responses were obtained in 20 and 37% of patients at the end of therapy and 6 months after therapy, respectively (P = 0.07).

CONCLUSIONS

When the combination of large dosage interferon-alpha 2b and lamivudine therapy in children was compared at the end of therapy and 6 months after therapy, normalization of alanine aminotransferase and the clearances of hepatitis B e antigen and hepatitis B surface antigen in both groups were directly proportional to the duration of treatment. However, the higher complete response rate at 12 months of combination therapy was not statistically different from that at 6 months.

Drug discovery and development of antiviral agents for the treatment of chronic hepatitis B virus infection

A safe and effective vaccine for hepatitis B virus (HBV) has been available for nearly twenty years and currently campaigns to provide universal vaccination in developing countries are underway. Nevertheless, chronic HBV infection remains a leading cause of chronic hepatitis worldwide and there is a strong need for safe and effective antiviral therapies. Attempts to identify and develop antiviral agents to treat chronic HBV infection remains focused on nucleoside analogs such as 3TC (lamivudine), adefovir dipivoxil, (bis-POMPMEA), and others. However, advances in our understanding of the molecular biology of HBV and the development of new assays for HBV polymerase activity, such as the reconstitution of active HBV polymerase in vitro, should facilitate large screening efforts for non-nucleoside reverse transcriptase inhibitors. Recent advances have furthered our understanding of clinical resistance to lamivudine, have provided new approaches to treatment, and have offered new perspectives on the major challenges to the identification and development of antiviral agents for chronic HBV infection. Here, in an update to our previous review article that appeared in this series [59a], we focus on recent advances that have occurred in the areas of virus structure and replication, in vitro viral polymerase assays, cell culture systems, and animal models.

Treatment of viral hepatitis--2001

Chronic viral hepatitis may now be controlled and, in many cases, permanently eradicated. Rapid advances in the antiviral therapy of chronic hepatitis C infection have resulted in a greater than 50% sustained response rate, with genotypes 2 and 3 now considered 'curable diseases.' Current hepatitis B therapy leads to significant improvement in liver histology and overall survival. These advances, coupled with the fact that 8% of the world population is chronically infected with viral hepatitis, has sparked considerable interest in this condition on the part of the pharmaceutical industry. In 2001, the most effective therapy for chronic hepatitis C is the combination of pegylated interferon alpha and oral ribavirin. The treatment of hepatitis B consists of either interferon alpha or oral lamivudine, while newer nucleoside/nucleotide analogues, alone or in combination with existing therapy, are being explored.