A Phase 3b, Randomized, Double-Blind, Double-Dummy Study Evaluating the Antiviral Efficacy, Safety, and Tolerability of Tenofovir Disoproxil Fumarate (DF) Monotherapy Versus Emtricitabine Plus Tenofovir DF Fixed-Dose Combination Therapy in Subjects With Chronic Hepatitis B Who Are Resistant to Lamivudine

Fecha de inicio: 1 de septiembre de 2008

Inclusion Criteria * Chronic HBV infection, defined as positive serum HBsAg for at least 6 months * 18 through 75 years of age, inclusive * HBV DNA ≥ 10\^3 IU/mL * Receiving treatment with lamivudine with confirmation of HBV reverse transcriptase mutation(s) known to confer resistance to lamivudine (rtM204I/V with or without rtL180M) by central laboratory assessment prior to randomization; adefovir dipivoxil treatment of ≤ 48 weeks at the time of screening (inclusive of combination adefovir dipivoxil + lamivudine at entry) was allowed * Willing and able to provide written informed consent * Negative serum pregnancy test (for females of childbearing potential only) * Calculated creatinine clearance ≥ 50 mL/min * Hemoglobin ≥ 10 g/dL * Neutrophils ≥ 1000 /mm\^3 * No prior oral HBV therapy with approved nucleotide and/or nucleoside therapy or other investigational agents for HBV infection other than lamivudine or adefovir dipivoxil Exclusion Criteria * Pregnant women, women who are breast feeding or who believe they may wish to become pregnant during the course of the study * Males and females of reproductive potential who are not willing to use an effective method of contraception during the study * Alanine aminotransferase (ALT) ≥ 10 × the upper limit of the normal range (ULN) * Decompensated liver disease * Interferon or pegylated interferon therapy within 6 months of the screening visit * Alpha fetoprotein \> 50 ng/mL * Evidence of hepatocellular carcinoma * Coinfection with hepatitis C virus, HIV, or hepatitis D virus * Significant renal, cardiovascular, pulmonary, or neurological disease * Received solid organ or bone marrow transplantation * Receiving therapy with immunomodulators (eg, corticosteroids, etc.), investigational agents, nephrotoxic agents, or agents susceptible of modifying renal excretion * Proximal tubulopathy * Known hypersensitivity to the study drugs, the metabolites or formulation excipients