INDICATIONS AND USAGE
EPIVIR-HBV is indicated for the treatment of chronic hepatitis B associated with evidence of hepatitis B viral replication and active liver inflammation. This indication is based on 1-year histologic and serologic responses in adult patients with compensated chronic hepatitis B, and more limited information from a study in pediatric patients ages 2 to 17 years (see Description of Clinical Studies below).
Description of Clinical Studies
Adults
The safety and efficacy of EPIVIR-HBV were evaluated in 4 controlled studies in 967 patients with compensated chronic hepatitis B. All patients were 16 years of age or older and had chronic hepatitis B virus infection (serum HBsAg positive for at least 6 months) accompanied by evidence of HBV replication (serum HBeAg positive and positive for serum HBV DNA, as measured by a research solution-hybridization assay) and persistently elevated ALT levels and/or chronic inflammation on liver biopsy compatible with a diagnosis of chronic viral hepatitis. Three of these studies provided comparisons of EPIVIR-HBV 100 mg once daily versus placebo, and results of these comparisons are summarized below.
- Study 1 was a randomized, double-blind study of EPIVIR-HBV 100 mg once daily versus placebo for 52 weeks followed by a 16-week no-treatment period in treatment-naive US patients.
- Study 2 was a randomized, double-blind, 3-arm study that compared EPIVIR-HBV 25 mg once daily versus EPIVIR-HBV 100 mg once daily versus placebo for 52 weeks in Asian patients.
- Study 3 was a randomized, partially-blind, 3-arm study conducted primarily in North America and Europe in patients who had ongoing evidence of active chronic hepatitis B despite previous treatment with interferon alfa. The study compared EPIVIR-HBV 100 mg once daily for 52 weeks, followed by either EPIVIR-HBV 100 mg or matching placebo once daily for 16 weeks (Arm 1), versus placebo once daily for 68 weeks (Arm 2). (A third arm using a combination of interferon and lamivudine is not presented here because there was not sufficient information to evaluate this regimen.)
Principal endpoint comparisons for the histologic and serologic outcomes in lamivudine (100 mg daily) and placebo recipients in placebo-controlled studies are shown in the following tables.
Table 3. Histologic Response at Week 52 Among Adult Patients Receiving EPIVIR-HBV 100 mg Once Daily or Placebo |
Study 1
|
Study 2
|
Study 3
|
Assessment
|
EPIVIR-HBV (n = 62)
|
Placebo (n = 63)
|
EPIVIR-HBV (n = 131)
|
Placebo (n = 68)
|
EPIVIR-HBV (n = 110)
|
Placebo (n = 54)
|
Improvement*
|
55%
|
25%
|
56%
|
26%
|
56%
|
26%
|
No Improvement
|
27%
|
59%
|
36%
|
62%
|
25%
|
54%
|
Missing Data
|
18%
|
16%
|
8%
|
12%
|
19%
|
20%
|
* Improvement was defined as a ≥2-point decrease in the Knodell Histologic Activity Index (HAI)1 at Week 52 compared with pretreatment HAI. Patients with missing data at baseline were excluded.
Table 4. HBeAg Seroconversion* at Week 52 Among Adult Patients Receiving EPIVIR-HBV 100 mg Once Daily or Placebo
Seroconversion
|
Study 1
|
Study 2
|
Study 3
|
EPIVIR-HBV (n = 63)
|
Placebo (n = 69)
|
EPIVIR-HBV (n = 140)
|
Placebo (n = 70)
|
EPIVIR-HBV (n = 108)
|
Placebo (n = 53)
|
Responder
|
17%
|
6%
|
16%
|
4%
|
15%
|
13%
|
Nonresponder
|
67%
|
78%
|
80%
|
91%
|
69%
|
68%
|
Missing Data
|
16%
|
16%
|
4%
|
4%
|
17%
|
19%
|
* Three-component seroconversion was defined as Week 52 values showing loss of HBeAg, gain of HBeAb, and reduction of HBV DNA to below the solution-hybridization assay limit. Subjects with negative baseline HBeAg or HBV DNA assay were excluded from the analysis.
Normalization of serum ALT levels was more frequent with lamivudine treatment compared with placebo in Studies 1-3.
The majority of lamivudine-treated patients showed a decrease of HBV DNA to below the assay limit early in the course of therapy. However, reappearance of assay-detectable HBV DNA during lamivudine treatment was observed in approximately one third of patients after this initial response.
Pediatrics
The safety and efficacy of EPIVIR-HBV were evaluated in a double-blind clinical trial in 286 patients ranging from 2 to 17 years of age, who were randomized (2:1) to receive 52 weeks of lamivudine (3 mg/kg once daily to a maximum of 100 mg once daily) or placebo. All patients had compensated chronic hepatitis B accompanied by evidence of hepatitis B virus replication (positive serum HBeAg and positive for serum HBV DNA by a research branched-chain DNA assay) and persistently elevated serum ALT levels. The combination of loss of HBeAg and reduction of HBV DNA to below the assay limit of the research assay, evaluated at Week 52, was observed in 23% of lamivudine subjects and 13% of placebo subjects. Normalization of serum ALT was achieved and maintained to Week 52 more frequently in patients treated with EPIVIR-HBV compared with placebo (55% versus 13%). As in the adult controlled trials, most lamivudine-treated subjects had decreases in HBV DNA below the assay limit early in treatment, but about one third of subjects with this initial response had reappearance of assay-detectable HBV DNA during treatment. Adolescents (ages 13 to 17 years) showed less evidence of treatment effect than younger children.
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