Telbivudine Versus Lamivudine for Maintenance Therapy of Patients With Chronic Hepatitis B and Negative HBV Viral Load After 6 Month of Treatment With Telbivudine

Inclusion Criteria: * Male or female patients, \> 18 (having completed their 18th birthday). There is no upper limit of age * Documented HBeAg negative CHB * HBsAg positive \> 6 months * HBV DNA \> 2000 IU/mL * Patient is willing and able to comply with the study drug regimen and all other study requirements. * Written informed consent * Anti-viral HBV treatment naïve or previous treatment with interferon-alpha or pegylated interferon-alpha stopped at least 1 month prior to screening Exclusion Criteria: * Decompensated liver cirrhosis according to the judgment of the local investigator * Hepatocellular carcinoma * History of or laboratory signs of co-infection with HIV or HCV, HDV * Previous treatment with anti-viral drugs (previous treatment with interferon-α or pegylated interferon-α is not an exclusion criteria, but has to be stopped one month before screening) * History of hypersensitivity to any of the study drugs or to drugs with similar chemical structures or their excipients * Any medical condition that requires frequent or prolonged use of systemic corticosteroids (inhaled, topic or intra-articular corticosteroids are allowed) * Any medical condition requiring the chronic or prolonged use of potentially hepatotoxic drugs or nephrotoxic drugs. * Current abuse of alcohol or illicit drugs. * Use of other investigational drugs at the time of randomization, or within 30 days or 5 half-lives of enrollment, whichever is longer. * Any other concurrent medical or social condition which is, in the opinion of the investigator, likely to preclude compliance with the schedule of evaluations in the protocol, or likely to confound the efficacy or safety observations of the study. * Any of the following laboratory values during Screening: * Hemoglobin (HGB) \<11 g/dL for men or \<10 g/dL for women * Total WBC \<3000/mm3 * Absolute neutrophil count (ANC) \<1,500.mm3 * Platelet count \<50'000/mm3 * Serum amylase or lipase ≥ 1.5 x ULN * Serum albumin \<3 g/dL * Total bilirubin \> 51 μmol/L (\> 3.0 mg/dL) * Estimated calculated serum creatinine clearance \< 50 mL/min using the Cockcroft-Gault method using actual or ideal body weight whichever is less (Cockcroft and Gault 1976) * AFP (alpha-fetoprotein) \> 100 ng/mL * ALT \> 10x ULN * Women who are pregnant or breastfeeding. Women of childbearing potential must have a negative serum beta-human chorionic gonadotropin (β-HCG) during Screening.