A Study of Entecavir in Pediatric Patients With Chronic Hepatitis B Virus (HBV)-Infection

Inclusion Criteria:

- 2-18 years of age

- Group A: Lamivudine naive (<1 week of Lamivudine) and not within 24 weeks of
screening; Group B: Lamivudine experienced (> 12 weeks of Lamivudine); Group C:
nucleoside/nucleotide experienced (> 12 weeks of nucleoside/tide therapy) added as a
country-specific protocol amendment (not all sites had Group C).

- HBV Deoxyribonucleic acid (DNA) ≥ 100000 copies/mL; ≥ 10000 copies for
nucleoside/nucleotide experienced (Group C)

- Detectable Hepatitis B surface antigen (HBsAg) for 24 weeks prior to screening

- Hepatitis B e antigen (HBeAg) positive

- Compensated liver and renal function

- Elevated alanine aminotransferase (ALT) at screening and during the 24 weeks prior to
screening (for Groups A and B)

Exclusion Criteria:

- Coinfection with Human immunodeficiency virus (HIV), Hepatitis C virus (HCV),
Hepatitis D Virus (HDV)

- Children who were breastfed while their mother received Lamivudine, or children whose
mothers received Lamivudine during pregnancy