A Study of Pegasys (Peginterferon Alfa-2a) Added to Nucleos(t)Ide Analogue Treatment in Participants With HBeAg-Negative Chronic Hepatitis B Genotype D Showing Stable Hepatitis B Virus (HBV) Deoxyribonucleic Acid (DNA) Suppression

Inclusion Criteria: * Adult participants, 18 - 65 years of age * Chronic hepatitis B * Negative for HBeAg * On monotherapy with any nucleos(t)ide analogue (NA) but telbivudine at enrolment, and HBV DNA persistently below 20 IU/ml for at least 12 months * HBsAg \>100 IU/ml at the beginning of the Lead-in phase, confirmed before addition of Pegasys * Showing a steady HBsAg kinetic (HBsAg decrease \<0.5 log10 IU/ml from Week -12 to start of the Add-on phase) * Negative pregnancy test for women of childbearing potential * Women of childbearing potential and fertile males with female partners of childbearing potential must be using reliable contraception during and for 3 months after the Add-on phase Exclusion Criteria: * Coinfection with Hepatitis A virus (HAV), Hepatitis C virus (HCV), Hepatitis D virus (HDV), Human Immunodeficiency virus (HIV) * Evidence of decompensated liver disease (Child-Pugh \>/=6) * History or other evidence of a medical condition associated with chronic liver disease (e.g. hemochromatosis, autoimmune hepatitis, alcoholic liver disease, toxin exposure) * Known hypersensitivity to peginterferon alfa-2a * Pregnant of breastfeeding women * Evidence of alcohol and/or drug abuse * History of severe psychiatric disease, especially depression * History of immunologically mediated disease * History or evidence of bleeding from esophageal varices or other conditions consistent with decompensated liver disease * History or evidence of severe pulmonary disease associated with functional limitations * History of severe cardiac disease * History of severe seizure disorder or current anticonvulsant use * Evidence of an active or suspected cancer or a history of malignancy (other than basocellular carcinoma or in situ cervical carcinoma) within 5 years prior to study entry * History of having received any systemic anti-neoplastic (including radiation) or immunomodulatory (including systemic corticosteroids) treatment \</= 6 months prior to the first dose or the expectation that such a treatment will be needed at any time during the study * History or other evidence of severe retinopathy