Study of Therapeutic Vaccination With Intensified Schedule Plus Pegasys Dual Therapy on Chronic Hepatitis B Infection

Inclusion Criteria: 1. Age between 20 and 75 year-old 2. HBsAg-positive for \> 6 months apart (medical history can be alternative) 3. Currently being treated with entecavir 0.5 mg/day for more than 18 months 4. Undetectable HBV DNA in serum (\<20IU/mL) and HBeAg-negative or positive for \> 1year 5. HBsAg titer \< 3,000 IU/mL 6. ALT\<300 IU/L 7. Signed written informed consent after being instructed about the objective and procedure of the clinical study Exclusion Criteria: 1. Patients with decompensated liver cirrhosis, any one of the following ① Serum bilirubin \> 3 mg/dL ② Prothrombin time \> 6 seconds prolonged or INR \>2.3 ③ Serum albumin \< 2.8 g/dL ④ History of ascites, variceal hemorrhage, or hepatic encephalopathy ⑤ Child-Pugh score ≥7 (Child-Pugh class B or C) 2. Patients who have evidence of renal insufficiency defined as serum creatinine\>1.5 mg/dL 3. Patients with psychological problem including depression 4. Patients who have previous/current significant co-morbidities including congestive heart failure, chronic kidney disease, hematologic disease and malignancy including hepatocellular carcinoma(patients with malignancy cured 5 years before screening can be enrolled) 5. Patients with seropositivity for anti-HCV, anti-HDV or anti-HIV 6. Patients who have excessive alcohol consumption (\> 30 g/day) 7. Patients who have evidence of autoimmune hepatitis, hemochromatosis or Wilson's disease 8. Pregnant or breast feeding females or plan for pregnancy or no contraception 9. Patients with disease may deteriorate with interferon therapy(eg, autoimmune thyroiditis) 10. Patients who have an psoriasis 11. Patients who have history of antiviral-resistant HBV after previous treatment with oral antiviral agents 12. Previous diagnosis with immunodeficiency or concomitant treatment of immune suppressive agent or previous organ transplantation Recipients 13. Patients who have a history of hypersensitivity to study drug 14. Uncontrollable seizure, convulsion and/or central nervous system disorders 15. Patients with severe bone marrow disorder or with history of hypersensitivity to biologic agent such as vaccine. 16. Neutrophil count \< 1,500/mm3 or platelet count \< 75,000/mm3 or hemoglobin \< 10 g/dl 17. Patients with Pulmonary disease (in case of history of pulmonary disease with complete recovery, enrollment is on investigator's discretion) 18. Patients who have a fever ≥ 38 °C at the baseline 19. Patients who have a risk of febrile response or systemic reaction 20. Patients who the investigator deems inappropriate to participate in this study