Compare Continuing Lamivudine Plus Adefovir or Adefovir Versus Switching to Entecavir Plus Adefovir in Patients With LAM-resistant Chronic Hepatitis B

Efficacy and Safety of Continuing Lamivudine Plus Adefovir or Adefovir Versus Switching to Entecavir Plus Adefovir in Patients With Chronic Hepatitis B Who Have Resistant Mutants to Lamivudine and Show Suboptimal Response to Combination of Lamivudine Plus Adefovir or Adefovir Monotherapy

The purpose of this study is to compare efficacy and safety of continuing Lamivudine plus Adefovir or Adefovir versus switching to Entecavir plus Adefovir in patients with LAM-resistant chronic hepatitis B who have suboptimal response to Lamivudine plus Adefovir or Adefovir

Inclusion Criteria:

• Chronic hepatitis B
• Age ≥ 20 year old
• Currently taking Lamivudine and Adefovir combination therapy or Adefovir monotherapy for chronic HBV infection for 24 weeks
• Proven Lamivudine resistant mutation
• HBV DNA levels at screening ≥ 15 IU/mL
• Females must be post-menopausal, unable to conceive, or test negative for pregnancy via urine test
• Patient is able to give written informed consent prior to study start and to comply with the study requirements

Exclusion Criteria:

• A history or current of decompensated cirrhosis or hepatocellular carcinoma
• Currently receiving antiviral, immunomodulatory, cytotoxic or corticosteroid therapy
• Co-infected with HCV or HIV
• A history of organ transplantation
• Pregnant or breast-feeding
• Current clinically relevant of abuse of alcohol or drugs.
• Significant immunocompromised, gastrointestinal, renal(serum creatinine ≥ 1.5 mg/dL), hematological, psychiatric, bronchopulmonary, biliary diseases excluding asymptomatic GB stone, neurological, cardiac, oncologic, allergic disease or medical illness that in the investigator's opinion might interfere with therapy
• malignancy in previous 5 years