A Study of Pegylated Interferon Alfa-2A in Combination With Lamivudine or Entecavir Compared With Untreated Control Group in Children With Hepatitis B Envelope Antigen (HBeAg)-Positive Chronic Hepatitis B (CHB) in the Immune-Tolerant Phase

Inclusion Criteria:

• Positive for HBsAg and HBeAg for more than 6 months prior to baseline

• Detectable HBV-DNA (>20,000 IU/mL) as measured by polymerization chain reaction (PCR)or hybridization on at least 2 occasions at least one month apart with the latestdetermination obtained less than or equal to (</=) 42 days prior to baseline

• Compensated liver disease (Child-Pugh Class A clinical classification)

• Either Liver biopsy performed within 2 years prior to baseline showing no or minimalfibrosis (Liver Biopsy Scores and stable normal ALT levels (less than or equal toupper limit of normal [ULN]) during the 6 months leading up to baseline (including twoseparate occasions at least 1 month apart over the 6 months prior to baseline).Screening ALT levels must be normal (</= ULN) OR Stable normal ALT levels (</= ULN),during the 1 year leading up to baseline (including three separate occasions at least 1 month apart over the 1 year prior to baseline) and no signs of hepatocellularcarcinoma (HCC), advanced fibrosis/cirrhosis, or splenomegaly on liver abdominalultrasound at screening. Screening ALT levels must be normal (</= ULN)

Exclusion Criteria:

• Participants who have received investigational drugs or licensed treatments with antiHBV activity (Exception: Participants who have had a limited [</= 7-day] course ofacyclovir for herpetic lesions more than 1 month before the study baseline visit arenot excluded)

• Participants who have participated in any other clinical trial or who have receivedany investigational drug within 6 months prior to baseline

• Known hypersensitivity to interferon (IFN), pegylated interferon-alfa-2a or lamivudineor entecavir

• Positive test results at screening for hepatitis A virus Immunoglobulin M (IgM)antibody (Ab), anti-hepatitis C virus (HCV) Ab, anti- hepatitis D (HDV) Ab oranti-human immunodeficiency virus (HIV) Ab

• Decompensated liver disease (e.g., Child-Pugh Class B or C clinical classification orclinical evidence such as ascites or varices)

• Advanced fibrosis or cirrhosis

• Suspicion of HCC on liver abdominal ultrasound (all patients to have liver abdominalultrasound within 6 months prior to baseline)

• History or other evidence of a medical condition associated with chronic liver diseaseother than CHB including metabolic liver diseases such as hemochromatosis, Wilson'sdisease or alpha-1 anti-trypsin deficiency

• Active substance abuse within 6 months prior to screening

• Sexually active females of childbearing potential and sexually active males who arenot willing to utilize reliable contraception during treatment and for 90 daysfollowing the end of treatment

• Females who are pregnant or who are breastfeeding (females of childbearing potentialwho have a positive urine or serum pregnancy test result within 24 hours of baselineare excluded)