A Study of the Safety and Efficacy of Pegylated Inferferon Alfa-2b (PEG-Intron™) Versus Pegylated Interferon Alfa-2a (PEGASYS™) in Participants With Chronic Hepatitis B (P08450)

Inclusion Criteria:

• Must be able to adhere to dose and visit schedules

• ≥ 40 kg

• Hepatitis B surface antigen (HBsAg) positive for at least 6 months

• Anti-HBs negative

• Female participants of childbearing potential must agree to use an acceptable method of contraception from at least 2 weeks prior to Day 1 and continue until at least 1month after last dose of study drug Inclusion Criteria for HBeAg(+) participants:

• HBeAg(+)

• Anti-HBe(-) Inclusion Criteria for HBeAg(-) participants:

• HBeAg(-)

• Anti-HBe(+)

Exclusion Criteria:

• Co-infection with the human immunodeficiency virus (HIV) or hepatitis C or hepatitis Dvirus

• Prior treatment with interferon for hepatitis B

• Use of nucleoside/nucleotide analogues within 6 months of the screening visit or atany time during the study

• Use of any investigational drug within 30 days of the screening visit

• Prior treatment with herbal remedies with known hepatotoxicity. All herbal remediesused for hepatitis B treatment must be discontinued before Day 1

• Evidence of decompensated liver disease including, but not limited to, a history orpresence of clinical ascites, bleeding varices, or hepatic encephalopathy

• Diabetic and/or hypertensive with clinically significant ocular examination findings

• History of stroke or transient ischemic attack

• Immunologically mediated disease (e.g., inflammatory bowel disease [Crohn's disease,ulcerative colitis], celiac disease, rheumatoid arthritis, idiopathic thrombocytopenicpurpura, systemic lupus erythematosus, autoimmune hemolytic anemia, scleroderma,sarcoidosis, severe psoriasis requiring oral or injected treatment, or symptomaticthyroid disorder)

• Chronic pulmonary disease (e.g., chronic obstructive pulmonary disease, interstitiallung disease, pulmonary fibrosis, sarcoidosis)

• Current or history of any clinically significant cardiac abnormalities/dysfunction

• Any medical condition requiring, or likely to require, chronic systemic administrationof corticosteroids during the course of the trial

• Myelodysplastic syndromes

• Organ transplants (including hematopoietic stem cell transplants) other than corneaand hair

• Pregnant or nursing, or intending to become pregnant during the trial period