Safety, tolerability, efficacy and pharmacodynamics of the selective JAK1 inhibitor GSK2586184 in patients with systemic lupus erythematosus.

We aimed to evaluate the pharmacodynamics, efficacy, safety and tolerability of the JAK1 inhibitor GSK2586184 in adults with systemic lupus erythematosus (SLE). In this adaptive, randomized, double-blind, placebo-controlled study, patients received oral GSK2586184 50-400 mg, or placebo twice daily for 12 weeks. Primary endpoints included interferon-mediated messenger RNA transcription over time, changes in Safety of Estrogen in Lupus National Assessment-SLE Disease Activity Index score, and number/severity of adverse events. A pre-specified interim analysis was performed when ≥ 5 patients per group completed 2 weeks of treatment. In total, 84-92% of patients were high baseline expressors of the interferon transcriptional biomarkers evaluated. At interim analysis, GSK2586184 showed no significant effect on mean interferon transcriptional biomarker expression (all panels). The study was declared futile and recruitment was halted at 50 patients. Shortly thereafter, significant safety data were identified, including elevated liver enzymes in six patients (one confirmed and one suspected case of Drug Reaction with Eosinophilia and Systemic Symptoms), leading to immediate dosing cessation. Safety of Estrogen in Lupus National Assessment-SLE Disease Activity Index scores were not analysed due to the small number of patients completing the study. The study futility and safety data described for GSK2586184 do not support further evaluation in patients with SLE. Study identifiers: GSK Study JAK115919; ClinicalTrials.gov identifier: NCT01777256.

Quantitative analysis of HBV cccDNA from clinical specimens: correlation with clinical and virological response during antiviral therapy.

Attempts to investigate changes in various forms of intrahepatic hepatitis B virus (HBV) DNA during antiviral therapy have been hampered by limitations in technologies and scarcity of adequate tissue for analysis. We used a sensitive, specific assay to detect and quantitate covalently closed circular DNA (cccDNA) from total intrahepatic HBV DNA in clinical liver specimens. Total HBV DNA and cccDNA from 21 needle-biopsy specimens were quantified, with levels ranging from 0.1 to 9.8 copies/cell and 0.3 to 491.0 copies/cell, respectively. Then, we performed the same determinations on baseline and week-52 liver needle-biopsy specimens from eight patients enrolled in a clinical trial and evaluated the association between intrahepatic HBV DNA levels and serological and virological endpoints. In most patients, levels of intrahepatic HBV DNA, including cccDNA, decreased over the 52-week study, regardless of therapy or serological outcome. Higher ratios of cccDNA to total HBV DNA were detected at week 52 than at baseline indicating a shift in predominance of nonreplicating virus in posttreatment specimens. In patients who achieved treatment-related or spontaneous hepatitis B e antigen (HBeAg) responses, including those harbouring tyrosine-methionine-aspartate-aspartate-mutant HBV, levels of intrahepatic and serum HBV DNA suppression were greater than those in patients without HBeAg responses. In conclusion, this pilot study of intrahepatic HBV replicative forms in patients with chronic hepatitis B indicated that total intrahepatic and, specifically, cccDNA levels are not static but change as a reflection of serological and virological events.

T-helper cell response to woodchuck hepatitis virus antigens after therapeutic vaccination of chronically-infected animals treated with lamivudine.

BACKGROUND/AIMS: Immunotherapy of patients chronically-infected with hepatitis B virus (HBV) may have the risk of fulminant hepatitis. This risk might be diminished if immunotherapy was carried out under conditions of low viremia. METHODS: Five woodchucks chronically-infected with woodchuck hepatitis virus (WHV), a virus closely related to HBV, were treated with lamivudine for 23 weeks. At week 10, when viremia had decreased by 3-5 logs, three woodchucks were vaccinated with woodchuck hepatitis virus surface antigen (WHsAg) plus the T-helper determinant FISEAIIHVLHSR. RESULTS: It was found that the administration of lamivudine only, had no effect on the T-helper response against WHV antigens. By contrast, vaccination induced T-helper responses against WHV antigens, shifting the cytokine profile from Th2 to Th0/Th1, but was without effect on viremia, WHsAg levels, or anti-WHs antibodies. Analysis of liver biopsies showed that lamivudine administration may have reduced hepatic inflammation. By contrast, vaccination clearly enhanced hepatic inflammation. After lamivudine withdrawal, viremia returned to high levels. CONCLUSIONS: These results suggest that therapeutic vaccination of chronically-infected woodchucks under conditions of low viremia shifts the cytokine profile against viral antigens towards Th0/Th1. This shift may prevent the efficient induction of anti-WHs antibodies.

Extended lamivudine treatment in patients with chronic hepatitis B enhances hepatitis B e antigen seroconversion rates: results after 3 years of therapy.

A study in Chinese patients with chronic hepatitis B showed that treatment with lamivudine for 1 year significantly improves liver histology and enhances hepatitis B e antigen (HBeAg) seroconversion compared with placebo. Fifty-eight patients from this 1-year study have received long-term treatment with lamivudine 100 mg; the outcome of 3 years of lamivudine is reported here. Before treatment, all patients had detectable HBeAg. HBeAg seroconversion (HBeAg-negative, anti-HBe-positive), hepatitis B virus (HBV)-DNA suppression, alanine transaminase (ALT) normalization, emergence of YMDD variant HBV, liver histology, and long-term safety were assessed. After 3 years of continuous treatment with lamivudine 100 mg daily, 40% (23 of 58) of patients achieved HBeAg seroconversion. In patients with baseline serum ALT >2 x upper limit of normal (ULN), the rate of HBeAg seroconversion was 65% (17 of 26). Median serum HBV-DNA concentrations were below the level of detection, and median ALT concentrations were within the normal range throughout 3 years of treatment. YMDD variant HBV emerged in 33 of 58 (57%) patients during the 3 years, of whom 9 (27%) achieved HBeAg seroconversion (6 after emergence of YMDD variant HBV). ALT levels and histologic scores after emergence of YMDD variant HBV did not show major deterioration. Lamivudine was well tolerated during 3 years of therapy. In conclusion, these data in Chinese patients with chronic hepatitis B show enhanced seroconversion rates with extended lamivudine treatment. Up to two thirds of patients with moderately elevated pretreatment ALT achieved HBeAg seroconversion after 3 years of therapy.

A multicenter United States-Canadian trial to assess lamivudine monotherapy before and after liver transplantation for chronic hepatitis B.

Seventy-seven liver transplant candidates were enrolled in a multicenter study in which patients were treated with lamivudine (100 mg daily) without the adjunctive use of hepatitis B immune globulin. Treatment was begun while patients awaited liver transplantation and continued after transplantation. All were hepatitis B surface antigen (HBsAg) positive, and 61% had detectable hepatitis B e antigen (HBeAg) and HBV DNA when treatment was begun. Forty-seven underwent liver transplantation and 30 did not. Median study participation was 38 months (range, 2.7-48.5) in the transplanted patients and 26 months (range, 0.1-37) in the nontransplanted group. Twenty-five of 42 (60%) transplanted patients with 12 or more weeks of posttransplantation follow-up were HBsAg negative at the last study visit. At treatment week 156, 13 of 22 (59%) remained HBsAg negative, and all 9 reinfected patients were HBV-DNA positive before treatment. In the nontransplanted patients, HBeAg was initially detectable in 20 of 27 (74%) but this decreased to 3 of 17 (18%) after 104 weeks of treatment, and significant improvement in biochemical parameters was observed. HBV-DNA polymerase mutants were detected in 15 (21%) and 6 (20%) of the transplanted and nontransplanted patients, respectively. When compared with historical cohorts, lamivudine-treated patients appeared to have improved survival, and transplanted patients had a decrease in the rate of recurrent HBV infection. Lamivudine therapy was partially effective in preventing recurrent HBV infection when given before and after transplantation. Thus, future trials using a combination of HBIg and lamivudine are needed to assess the optimal prophylactic therapy.

Combination therapy with lamivudine and adenovirus causes transient suppression of chronic woodchuck hepatitis virus infections.

Treatment of hepatitis B virus carriers with the nucleoside analog lamivudine suppresses virus replication. However, rather than completely eliminating the virus, long-term treatment often ends in the outgrowth of drug-resistant variants. Using woodchucks chronically infected with woodchuck hepatitis virus (WHV), we investigated the consequences of combining lamivudine treatment with immunotherapy mediated by an adenovirus superinfection. Eight infected woodchucks were treated with lamivudine and four were infected with approximately 10(13) particles of an adenovirus type 5 vector expressing beta-galactosidase. Serum samples and liver biopsies collected following the combination therapy revealed a 10- to 20-fold reduction in DNA replication intermediates in three of four woodchucks at 2 weeks after adenovirus infection. At the same time, covalently closed circular DNA (cccDNA) and viral mRNA levels both declined about two- to threefold in those woodchucks, while mRNA levels for gamma interferon and tumor necrosis factor alpha as well as for the T-cell markers CD4 and CD8 were elevated about twofold. Recovery from adenovirus infection was marked by elevation of sorbitol dehydrogenase, a marker for hepatocyte necrosis, as well as an 8- to 10-fold increase in expression of proliferating cell nuclear antigen, a marker for DNA synthesis, indicating significant hepatocyte turnover. The fact that replicative DNA levels declined more than cccDNA and mRNA levels following adenovirus infection suggests that the former decline either was cytokine induced or reflects instability of replicative DNA in regenerating hepatocytes. Virus titers in all four woodchucks were only transiently suppressed, suggesting that the effect of combination therapy is transient and, at least under the conditions used, does not cure chronic WHV infections.

Long-term therapy of chronic hepatitis B with lamivudine.

Lamivudine therapy induces improvements in chronic hepatitis B in a high proportion of patients, but prolonged therapy is limited by the development of viral resistance. We analyzed clinical responses and virologic resistance in 27 patients treated continuously with lamivudine for 2 to 4 years. Serum transaminases, hepatitis B virus (HBV) DNA by both branched DNA (bDNA) signal amplification and quantitative polymerase chain reaction were monitored at 4- to 8-week intervals. Virologic resistance to lamivudine was confirmed by the presence of mutations in the YMDD motif of the polymerase gene by restriction fragment-length polymorphism analysis. Serum HBV-DNA levels decreased rapidly in all treated patients, falling by 4 to 5 logs within 1 year. Transaminase levels also decreased and were normal in 70% of patients at 1 year, at which point liver histology had improved in 81% of patients. Viral resistance began to emerge after 8 months of therapy, eventually developing in 14 patients, including 76% of hepatitis B e antigen (HBeAg)-positive patients but only 10% of HBeAg-negative patients. Lamivudine withdrawal led to reappearance of wild-type HBV species, but retreatment led to more rapid reappearance of the mutant virus. Clinical, serum biochemical, and histologic improvements were maintained in the 13 patients who did not develop resistance. Thus, long-term therapy with lamivudine resulted in maintained improvements in virologic, biochemical, and histologic features of disease in most patients with HBeAg-negative chronic hepatitis B and in the subgroup of HBeAg-positive patients with high serum transaminase levels. A high rate of resistance limited efficacy, particularly in patients who remained HBeAg positive on therapy.

Lamivudine treatment for decompensated cirrhosis resulting from chronic hepatitis B.

The prognosis of decompensated cirrhosis resulting from chronic hepatitis B is poor, and the benefits of treatment with interferon are outweighed by serious side effects and by the risk of fatal exacerbation of disease activity. Lamivudine rapidly reduces hepatitis B virus (HBV)-DNA in serum to undetectable levels. We have treated 35 patients with chronic hepatitis B and decompensated cirrhosis with lamivudine 100 mg or 150 mg orally once daily. Pretreatment, all were positive for HBV-DNA in serum. Ten had Child-Pugh class B and 25 had Child-Pugh class C liver disease. Seven patients underwent liver transplantation within 6 months of treatment initiation, 5 patients died within 6 months, and 23 patients were treated for at least 6 months (mean = 19 months). In a majority of these 23 cases, there was a slow but marked improvement in liver function, which was most apparent after 9 months of treatment, with a decrease in serum bilirubin from 67 +/- 13 to 30 +/- 4 micromol/L (P <.05, baseline vs. 9 months), an increase in serum albumin from 27 +/- 1 to 34 +/- 1g/L (P <.05), and a decrease in Child-Pugh score from 10.3 +/- 0.4 to 7.5 +/- 0.5 (P <.05). Three patients developed resistance to lamivudine because of a mutation in the YMDD motif, but liver function did not deteriorate. We conclude that inhibition of viral replication with lamivudine results in a significant improvement of liver function in patients with decompensated HBV cirrhosis, but the long-term benefits remain uncertain.

Quantitation of hepatitis B viremia and emergence of YMDD variants in patients with chronic hepatitis B treated with lamivudine.

Hepatitis B viremia and emergence of hepatitis B virus (HBV) YMDD variants with reduced susceptibility to lamivudine were analyzed in patient sera from a phase II study of extended lamivudine therapy. Within 12 weeks, all patients exhibited a marked virologic response to lamivudine: >99% reduction (median 5 log decrease) in serum HBV DNA levels. Virus remained at >104 genomes/mL in 11 patients and decreased to <104 genomes/mL in the remaining 12 patients. In 10 patients, detectable YMDD variants emerged during the course of treatment. Six patients, including 3 with YMDD variants, experienced hepatitis B e antigen seroconversion while on lamivudine therapy or soon after its discontinuation. No patients with HBV DNA levels >104 genomes/mL seroconverted. Thus, patients who respond to lamivudine therapy with dramatic reductions in viral DNA level (to <104 genomes/mL) appear more likely to seroconvert than patients who do not achieve this level of HBV clearance.

Lamivudine as initial treatment for chronic hepatitis B in the United States.

BACKGROUND AND METHODS: Although the nucleoside analogue lamivudine has shown promise in patients with chronic hepatitis B, long-term data on patients from the United States are lacking. We randomly assigned previously untreated patients with chronic hepatitis B to receive either 100 mg of oral lamivudine or placebo daily for 52 weeks. We then followed them for an additional 16 weeks to evaluate post-treatment safety and the durability of responses. The primary end point with respect to efficacy was a reduction of at least 2 points in the score on the Histologic Activity Index. On this scale, scores can range from 0 (normal) to 22 (most severe abnormalities). RESULTS: Of the 143 randomized patients, 137 were included in the efficacy analysis: 66 in the lamivudine group and 71 in the placebo group. The other six patients were excluded at the base-line visit because of the absence of a documented history of hepatitis B surface antigen for at least six months. After 52 weeks of treatment, lamivudine recipients were more likely than placebo recipients to have a histologic response (52 percent vs. 23 percent, P<0.001), loss of hepatitis B e antigen (HBeAg) in serum (32 percent vs. 11 percent, P=0.003), sustained suppression of serum hepatitis B virus (HBV) DNA to undetectable levels (44 percent vs. 16 percent, P<0.001), and sustained normalization of serum alanine aminotransferase levels (41 percent vs. 7 percent, P<0.001), and they were less likely to have increased hepatic fibrosis (5 percent vs. 20 percent, P=0.01). Lamivudine recipients were also more likely to undergo HBeAg seroconversion, defined as the loss of HBeAg, undetectable levels of serum HBV DNA, and the appearance of antibodies against HBeAg (17 percent vs. 6 percent, P=0.04). HBeAg responses persisted in most patients for 16 weeks after the discontinuation of treatment. Lamivudine was well tolerated. Self-limited post-treatment elevations in serum alanine aminotransferase were more common in lamivudine recipients: 25 percent had serum alanine aminotransferase levels that were at least three times base-line levels, as compared with 8 percent of placebo recipients (P=0.01). The clinical condition of all patients remained stable during the study. CONCLUSIONS: In U.S. patients with previously untreated chronic hepatitis B, one year of lamivudine therapy had favorable effects on histologic, virologic, and biochemical features of the disease and was well tolerated. HBeAg responses were generally sustained after treatment.

Two sensitive PCR-based methods for detection of hepatitis B virus variants associated with reduced susceptibility to lamivudine.

Two novel assays, a restriction fragment length polymorphism (RFLP) assay and an assay based on the 5'-nuclease activity of Taq DNA polymerase, were developed for screening viral variants in lamivudine-treated patients' sera containing <1,000 copies of the hepatitis B virus (HBV) genome per ml. Both assays were designed to detect single-nucleotide changes within the HBV DNA polymerase gene that are associated with lamivudine resistance in vitro and have been used to screen a number of patients' sera for variant virus. Results obtained with these assays and standard sequencing technology were compared with regard to throughput, ability to detect individual virus species present at low concentrations, and ability to detect, distinguish, and quantitate wild-type (wt) and HBV tyrosine methionine(552) aspartate aspartate motif variants in mixed viral populations. Unlike DNA sequencing, both assays are amenable to high-throughput screening and were shown to be able to quantitatively detect variant virus in the presence of a background of wt virus. As with DNA sequencing, both new assays incorporate a PCR amplification step and are able to detect the relatively low amounts of virus found in lamivudine-treated patients' sera. However, these assays are far less labor intensive than the DNA-sequencing techniques presently in use. Overall, the RFLP assay was more sensitive than DNA sequencing in detecting and determining the ratios of wt to variant virus. Furthermore, the RFLP assay and 5'-nuclease assay were equally sensitive in the detection of mixed viral species, but the RFLP assay was superior to the 5'-nuclease assay in the quantitation of mixed viral species. These assays should prove useful for further understanding of virological response to therapy and disease progression.

Extended lamivudine retreatment for chronic hepatitis B: maintenance of viral suppression after discontinuation of therapy.

In patients with chronic hepatitis B, brief lamivudine therapy suppresses hepatitis B virus (HBV) DNA but results infrequently in sustained losses of virus replication posttreatment. We evaluated treatment response and its posttreatment durability during up to 18 months of lamivudine therapy (100 mg/d) in 24 patients who had hepatitis B e antigen (HBeAg) despite 1 to 3 months of prior therapy. Therapy was to be stopped after HBeAg loss or seroconversion (acquisition of antibody to HBeAg); posttreatment monitoring continued for 6 months. During therapy, which was well tolerated, HBV DNA became undetectable in all evaluable patients, accompanied by reduced alanine transaminase (ALT) activity. The cumulative 18-month confirmed loss of HBeAg during therapy was 9 of 24 (38%) and seroconversion was 5 of 24 (21%). Therapy was discontinued after HBeAg loss/seroconversion in 7 patients, and HBeAg status was maintained in all. Four of the patients with HBeAg responses lost HBsAg at least once. In 10 (43%) of 23 patients tested, we identified HBV polymerase YMDD mutations, 3 with detectable HBV DNA (2 with ALT elevations) and 7 without virological/biochemical breakthrough. In conclusion, up to 18 months of lamivudine therapy was well tolerated, suppressed HBV replication consistently, and tripled the frequency of HBeAg losses observed during brief-duration therapy; HBeAg loss/seroconversion remained durable posttreatment. The emergence of YMDD-variant HBV was relatively common but occurred typically without reappearance of detectable HBV DNA or ALT elevation. Our observations suggest that lamivudine can be stopped after confirmed HBeAg loss or seroconversion.

Chronic active hepatitis B exacerbations in human immunodeficiency virus-infected patients following development of resistance to or withdrawal of lamivudine.

Lamivudine is a nucleoside analog with activity against human immunodeficiency virus (HIV) and hepatitis B virus (HBV). Patients coinfected with HIV and HBV may have hepatitis flares when lamivudine therapy is discontinued or when resistance of HBV to lamivudine emerges. This retrospective, descriptive study conducted in three tertiary care medical centers describes patients coinfected with HIV type 1 and HBV who presented with a spectrum of clinical and subclinical hepatitic responses to lamivudine withdrawal or resistance. One patient had fulminant hepatic failure and a second patient had subclinical hepatitis when lamivudine therapy was discontinued and a more efficacious antiretroviral regimen was substituted. Three patients had flares of hepatitis after 13 to 18 months of lamivudine therapy. Lamivudine withdrawal or emergence of lamivudine-resistant mutants in patients coinfected with HIV and HBV may result in severe hepatitis. Clinicians caring for patients with coinfection with HIV and HBV should be aware of the possibility that a hepatitis B flare may occur in previously asymptomatic carrier patients.

Emergence of drug-resistant populations of woodchuck hepatitis virus in woodchucks treated with the antiviral nucleoside lamivudine.

Lamivudine [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] reduces woodchuck hepatitis virus (WHV) titers in the sera of chronically infected woodchucks by inhibiting viral DNA synthesis. However, after 6 to 12 months, WHV titers begin to increase toward pretreatment levels. Three WHV variants with mutations in the active site of the DNA polymerase gene are present at this time (W. S. Mason et al., Virology 245:18-32, 1998). We have asked if these mutant viruses were responsible for the lamivudine resistance and if their emergence caused an immediate rise in virus titers. Cell cultures studies implied that the mutants were resistant to lamivudine. Emergence of mutant WHV was not always associated, however, with an immediate rise in virus titers in the serum. One of the three types of mutant viruses became prominent in serum up to 7 months before titers in serum actually began to increase, at a time when wild-type virus was still predominant in the liver. The two other mutants did not show this behavior but were detected in serum and liver later, just at the time that virus titers began to rise. A factor linking all three mutants was that a similar duration of drug administration preceded the rise in titers, irrespective of which mutant ultimately prevailed. A simple explanation for these results is that the increase in virus titers following emergence of drug-resistant mutants can occur only as the preexisting wild-type virus is cleared from the hepatocyte population, allowing spread of the mutants. Thus, prolonged suppression of virus titers in the serum may sometimes be a measure of the stability of hepatocyte infection rather than of a successful therapeutic outcome.

Mutational pattern of hepatitis B virus on sequential therapy with famciclovir and lamivudine in patients with hepatitis B virus reinfection occurring under HBIg immunoglobulin after liver transplantation.

Famciclovir (FCV) and lamivudine (LAM) reduce viral replication in patients with recurrent hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT). Eighteen of 20 patients with insufficient response to FCV were treated with 100 mg LAM daily after OLT. These patients had shown nonresponse (n = 5), partial response (n = 7), or breakthrough (n = 6) during FCV therapy. Despite passive immunoprophylaxis with hepatitis B immunoglobulin after liver transplantation, HBV reinfection had occurred in 14 of 15 transplanted patients. HBV-DNA levels and the regions A to E of the HBV-DNA polymerase gene were analyzed before and after treatment failure to either therapy. Within 4 weeks on LAM, all but 1 patient showed a 95% average reduction of the HBV-DNA level. As with FCV, we did not observe any severe side-effects attributable to LAM. However, 7 patients developed a breakthrough within 12, 29 (n = 2), 32, 37, 54, and 145 weeks under treatment with LAM associated with the methionine-to-valine signature mutation (M552V) in the YMDD motif in all. With FCV, no unique, but a dominant, resistance pattern with the L528M mutation was identified for patients with breakthrough under FCV. In contrast, nonresponders or patients with partial response to FCV did not exhibit such mutations. Our results indicate that the L528M mutation is a risk factor for LAM breakthrough, because breakthrough during LAM occurred earlier in patients with this mutation (50 +/- 10 weeks vs. 120 +/- 21 weeks). Because breakthrough on either treatment is frequent for this specific group of patients, the use of combination therapy should be explored.

Efficacy of lamivudine in patients with hepatitis B e antigen-negative/hepatitis B virus DNA-positive (precore mutant) chronic hepatitis B. Lamivudine Precore Mutant Study Group.

This placebo controlled, double-blind study evaluated the efficacy and safety of lamivudine in patients with hepatitis B e antigen (HBeAg)-negative/hepatitis B virus (HBV) DNA-positive chronic hepatitis B. Patients were randomized to receive 100 mg lamivudine orally once daily for 52 weeks (n = 60) or placebo for 26 weeks (n = 65). Patients who were HBV DNA positive at week 24 were withdrawn at week 26. The primary efficacy endpoint was loss of serum HBV DNA plus normalization of alanine transaminase (ALT) at week 24. A significantly higher proportion of patients receiving lamivudine (63%) had a complete response at week 24 compared with patients receiving placebo (6%) (P <.001). Secondary efficacy parameters included histological response from baseline to week 52 in the lamivudine-treated patients. At week 52, 60% of lamivudine-treated patients with liver biopsy specimens available showed histological improvement (>/=2-point reduction in Knodell necro-inflammatory score), 29% showed no change, and 12% worsened. In a ranked assessment of pretreatment and post-treatment biopsy pairs 11% improved, 86% showed no change, and 2% worsened in fibrosis. At week 52, 27% of patients receiving lamivudine had YMDD (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase) variant HBV. The incidence of adverse events and laboratory abnormalities was similar in both groups. In conclusion, lamivudine treatment results in a significant virological and biochemical improvement compared with placebo, induces an improvement or no change in histology in most patients, and is well tolerated. The response to lamivudine therapy in HBeAg-negative patients is similar to the response reported in previous studies of patients with HBeAg-positive chronic hepatitis B.

Lamivudine therapy of WHV-infected woodchucks.

Hepatitis B viruses establish a chronic, productive, and noncytopathic infection of hepatocytes. Viral products are produced by transcription from multiple copies (5-50) of covalently closed circular (ccc) viral DNA. This cccDNA does not replicate, but can be replaced by DNA precursors that are synthesized in the cytoplasm. The present study was carried out to determine if long-term treatment with an inhibitor of viral DNA synthesis would lead to loss of virus products, including cccDNA, from the liver of woodchucks chronically infected with woodchuck hepatitis virus. Viral DNA synthesis was inhibited with the nucleoside analog, lamivudine (2'-deoxy-3'-thiacytidine). Lamivudine treatment produced a slow but progressive decline in viral titers in serum, to about 0.3% or less of the initial level. However, even after maintenance of drug therapy for 3-12 months, > 95% of the hepatocytes in most animals were still infected. Significant declines in the percentage of infected hepatocytes and of intrahepatic cccDNA levels were observed in only three woodchucks, two in the group receiving lamivudine and one in the placebo control group. Moreover, virus titers eventually rose in woodchucks receiving lamivudine, suggesting that drug-resistant viruses began to spread through the liver starting at least as early as 9-12 months of treatment. Three types of mutation that may be associated with drug resistance were found at this time, in a region upstream of the YMDD motif in the active site of the viral reverse transcriptase. The YMDD motif itself remained unchanged. Not unexpectedly, the lamivudine therapy did not have a impact on development of liver cancer.

Efficacy of lamivudine re-treatment in a patient with hepatitis B virus (HBV) recurrence after liver transplantation and HBV-DNA breakthrough during the first treatment.

BACKGROUND: Transplantation for terminal hepatitis B virus (HBV) disease is aggravated by a high rate of reinfection and disease recurrence. Lamivudine, a new nucleoside analog, is a potent inhibitor of HBV synthesis, but its use may lead to the emergence of HBV-DNA polymerase mutants resistant to the drug. METHODS AND RESULTS: We describe the case of a patient who developed an HBV recurrence after liver transplantation and was treated with lamivudine. An HBV-DNA breakthrough occurred 7 months after the start of therapy, and the drug was stopped after 9 months. The molecular state of HBV-DNA was analyzed, and a mutation in the YMDD (tyrosine, methionine, aspartate, aspartate) locus of HBV-DNA polymerase was identified. Nine months after the suspension of lamivudine the patient experienced a new hepatic attack accompanied by high HBV-DNA levels. Lamivudine was given again. Serum HBV-DNA levels normalized after 45 days of re-treatment, but lamivudine-resistant mutants were again the prevalent viral population after 3 months. CONCLUSIONS: The case described suggests that retherapy with lamivudine after a first emergence of YMDD mutants is temporarily effective in recontrolling HBV synthesis but ultimately induces the accelerated reemergence of a prevalently mutant population of HBV. This emphasizes the need for combined antiviral therapy.

Identification and characterization of mutations in hepatitis B virus resistant to lamivudine. Lamivudine Clinical Investigation Group.

Cirrhosis and hepatocellular carcinoma occur as long-term complications of chronic hepatitis B virus (HBV) infection. Antiviral therapy is potentially a successful approach for the treatment of patients with HBV infection, which includes the nucleoside analog, lamivudine [(-)2'-deoxy-3'-thiacytidine, 3TC]. Although resistance to lamivudine therapy has been reported in several HBV-infected patients, the pattern of resistance-associated mutations in HBV has not been fully characterized. We report a DNA sequence database that includes a 500-base pair region of the HBV polymerase gene from 20 patients with clinical manifestations of lamivudine resistance. Analysis of the database reveals two patterns of amino acid substitutions in the tyrosine, methionine, aspartate, aspartate (YMDD) nucleotide-binding locus of the HBV polymerase. HBV DNA from the sera of patients in Group I exhibits a substitution of valine for methionine at residue 552, accompanied by a substitution of methionine for leucine at residue 528. Patients in Group II had only an isoleucine-for-methionine substitution at position 552. Reconstruction of these mutations in an HBV replication-competent plasmid was performed in a transient transfection cell assay to determine the function/relevance of these mutations to lamivudine resistance. Both Group I and Group II mutations resulted in a substantial decrease in sensitivity to lamivudine treatment (> 10,000-fold shift in IC50 over wild-type [wt] IC50), strongly indicating that these mutations were involved in resistance to lamivudine. A hypothetical model of the HBV reverse transcriptase has been generated for further study of the role of these mutations in lamivudine resistance.