A Safety Study to Evaluate 12 Weeks of Treatment with Clevudine in Patients Infected with Hepatitis B Virus.

Inclusion Criteria: HBV DNA positive with DNA levels at screening greater than or equal to 3,000,000 copies/mL. Documented to be HBsAg positive for > 6 months OR HBsAg positive and IgM anti-HBc negative and anti-HBs negative. Patients may be HBeAg positive, and anti-HBe negative OR HBeAg negative (pre-core mutant) and anti-HBe positive. HBeAg positive and anti-HBe negative OR HBeAg negative (pre-core mutant) and anti-HBe positive with positive HBsAg for the previous 6 months AST and ALT levels which are less than or equal to 10 times the upper limit of normal. Bilirubin levels less than or equal to 1.5 x ULN or bilirubin levels > 1.5 x ULN with diagnosis of Gilbert's disease and conjugated bilirubin within normal limits. Exclusion Criteria: Currently receiving antiviral, immunomodulatory or corticosteroid therapy Previous treatment with lamivudine, lobucavir, adefovir, famciclovir, or any other investigational nucleoside for HBV infection Previous treatment with interferon must have ended at least 6 months prior to screening visit History of ascites, variceal hemorrhage or hepatic encephalopathy Co-infection with HCV or HIV Evidence of cirrhosis or hepatocellular carcinoma (alpha fetoprotein)