A Phase IIIb Study to Compare Entecavir Plus Tenofovir vs. Adefovir Added to Continuing Lamivudine Therapy in Adult Patients With Lamivudine-Resistant Hepatitis B Infection

A Comparative Study of the Antiviral Efficacy and Safety of Entecavir Plus Tenofovir Versus Adefovir Added to Continuing Lamivudine in Adults With Lamivudine- Resistant Chronic Hepatitis B Virus Infection

The purpose of this clinical research study is to find out whether a combination of entecavir (ETV) plus tenofovir (TNF) works better against Hepatitis B virus than adefovir (ADV) added to continuing lamivudine (LVD) therapy in patients whose Hepatitis B virus (HBV) is resistant against lamivudine. The safety of this treatment will also be studied.

Inclusion Criteria:

• Chronic HBV infection
• History of lamivudine (LVD) treatment, and lamivudine resistance (LVDr), receiving LVD at screening visit
• Compensated liver function
• HBV DNA ≥ 172,000 IU/mL
• Hepatitis B e-antigen (HBeAg)-positive or HBeAg-negative

Exclusion Criteria:

• Evidence of decompensated cirrhosis
• Coinfection with human immunodeficiency virus (HIV), hepatitis C virus (HCV), or hepatitis D virus (HDV)
• Recent history of pancreatitis
• Serum alpha fetoprotein > 100 ng/mL
• Except lamivudine, any prior therapy with nucleoside or nucleotide analogue antiviral agents with activity against hepatitis B