Entecavir Plus Adefovir in Lamivudine-Resistant Chronic Hepatitis B Patients Who Fail Lamivudine Plus Adefovir

Inclusion Criteria: 1. Male or female, 16 to 75 years of age 2. Compensated liver disease(Child-Pugh class A) 3. HBsAg positive at least 6 months or more 4. HBeAg positive or negative 5. Confirmation of Lamivudine-resistance HBV mutation anytime before the study 6. Patients with suboptimal response (HBV DNA \> 2000 IU/mL despite combination of Adefovir \[10 mg/day\] plus Lamivudine \[100 mg/day\] for 6 months or more). Serum HBV DNA should be determined by the PCR assay at the local laboratory at screening for this study 7. Patient is ambulatory. 8. Patient is willing and able to comply with the study drug regimen and all other study requirements. 9. The patient is willing and able to provide written informed consent to participate in the study. Exclusion Criteria: 1. Patient has a history of hepatocellular carcinoma (HCC) or findings suggestive of possible HCC, such as suspicious foci on imaging studies or elevated serum alpha fetoprotein (AFP) levels. In patients with such findings, HCC should be ruled-out prior to randomizing the patient for the present study. 2. Patient previously received oral antiviral agent other than Lamivudine or Adefovir 3. Patient has received interferon or other immunomodulatory treatment for HBV infection within 12 months before screening for this study. 4. Patient has concomitant other chronic viral infection (HCV or HIV) 5. Patient has evidence of renal insufficiency defined as serum creatinine \> 1.5 mg/dL 6. Patient has medical condition that requires use of systemic prednisolone or other immunosuppressive agent (including chemotherapeutic agent) 7. Patient is currently abusing alcohol or illicit drugs, or has a history of alcohol abuse or illicit substance abuse within the preceding two years. 8. Patient is pregnant or breastfeeding or willing to be pregnant 9. Patient has one or more additional known primary or secondary causes of liver disease, other than hepatitis B (e.g., alcoholism, autoimmune hepatitis, malignancy with hepatic involvement, hemochromatosis, alpha-1 antitrypsin deficiency, Wilson's Disease, other congenital or metabolic conditions affecting the liver, congestive heart failure or other severe cardiopulmonary disease, etc.). 10. A history of treated malignancy (other than hepatocellular carcinoma) is allowable if the patient's malignancy has been in complete remission, off chemotherapy and without additional surgical intervention, during the preceding three years. 11. Clinical signs of decompensated liver disease as indicated by any one of the following: * serum bilirubin \> 3 mg/dL * prothrombin time \> 6 seconds prolonged or INR \>1.6 * serum albumin \< 2.8 g/dL * History of ascites, variceal hemorrhage, or hepatic encephalopathy * Child-Pugh score ≥7