Idenix Pharmaceuticals, Inc is conducting this research study to see if the investigational medication, LdT (Telbivudine), is safe and effective (that is, how well it works by decreasing the level of hepatitis B virus in your blood and improving the condition of your liver) in the treatment of decompensated hepatitis B infection. The results for patients taking LdT will be compared to results for patients taking lamivudine, which is a drug currently approved by the Food and Drug Adminstration (FDA) for the treatment of hepatitis B infection.

The primary objectives of this study are:

• To compare the antiviral and clinical efficacy of telbivudine (LdT) versus lamivudine in adults with decompensated chronic hepatitis B, over two years (104 weeks).
• To compare the safety and tolerability of telbivudine (LdT) versus lamivudine in patients with decompensated chronic hepatitis B, over two years (104 weeks).

The secondary objectives of this study are:

• To determine the comparative frequency of resistance-related virologic breakthrough during two years of treatment with LdT or lamivudine, and the clinical correlates of virologic breakthrough with regard to efficacy and safety.
• To characterize treatment-emergent HBV viral genotypes associated with virologic breakthrough, for the two study treatments.

Ages Eligible for Study:  16 Years   -   70 Years,  Genders Eligible for Study:  Both

Criteria

Inclusion Criteria

• Documented decompensated chronic hepatitis B defined by all of the following: 1. Clinical history compatible with decompensated chronic hepatitis B related cirrhosis; 2. Child-Turcotte-Pugh score > 7 points.
• Evidence of hepatic cirrhosis or portal hypertension.
• Detectable serum HBsAg at the Screening visit
• Elevated serum ALT level (1.2 – 10 x ULN) at the Screening visit
• Serum HBV DNA level ≥ 5 log10 copies/mL, as determined by the PCR assay at the central study laboratory at Screen.
• Patient is ambulatory.
• Patient is willing and able to comply with the study drug regimen and all other study requirements.
• The patient is willing and able to provide written informed consent to participate in the study.

Exclusion Criteria

• Patient is pregnant or breastfeeding. Women of childbearing potential must have a negative serum beta-human chorionic gonadotropin (b-HCG) at Screen.
• Patient is coinfected with hepatitis C virus (HCV), hepatitis D virus (HDV), or HIV.
• Patient previously received lamivudine, adefovir, or an investigational anti-HBV nucleoside or nucleotide analog at any time
• Patient has received interferon or other immunomodulatory treatment for HBV infection in the 12 months before Screening for this study.
• Patient has a medical condition that requires prolonged or frequent use of systemic acyclovir or famciclovir
• Patient is currently hospitalized for any reason.
• Patient is currently intubated or has an endotracheal tube for any reason, or requires chronic supplemental oxygen for any reason.
• Patient has grade 3 or 4 encephalopathy
• Patient has a history of variceal or gastrointestinal bleed within the past 6 months.
• Patient has a history of bacterial peritonitis in the past 6 months, or bacterial sepsis within the preceding 6 months.
• Patient has evidence of renal insufficiency defined as patient requires dialysis or has an estimated creatinine clearance, below 70 mL/min
• Patient has a history of hepatocellular carcinoma (HCC) or findings suggestive of possible HCC
• Patient has one or more additional known primary or secondary causes of liver disease, other than hepatitis B
• Patient has a history of clinically-evident pancreatitis.
• Patient is currently abusing alcohol or illicit drugs, or has a history of alcohol abuse or illicit substance abuse within the preceding two years.
• Patient has a medical condition that requires frequent or prolonged use of systemic corticosteroids
• Patient has been on warfarin or other anticoagulants within 30 days prior to Screening
• 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.
• Patient is enrolled or plans to enroll in another clinical trial of an investigational agent while participating in this study.
• Patient has any of the following laboratory values at Screening: * Hemoglobin < 9 g/dL for men or < 8 g/dL for women; * Total WBC < 1,500/ mm3; * Absolute neutrophil count (ANC) < 1,000/mm3; * Platelet count < 50,000/mm3; * Serum amylase or lipase >= 1.5 x ULN; * Serum albumin < 2.5 g/dL; * Total bilirubin >= 3 x ULN; * Serum creatinine > ULN AFP > 50 ng/mL (requires further work up)