This study evaluates the efficacy and safety of switching to Tenofovir Disoproxil from Tenofovir Disoproxil Fumarate in Chronic Hepatitis B Patients who pretreated with Tenofovir Disoproxil Fumarate.

In Open-Label, phase 3 studies, we randomly assigned patients with hepatitis B e antigen (HBeAg)-negative or HBeAg-positive chronic HBV infection to receive Tenofovir Disoproxil or Tenofovir Disoproxil Fumarate (ratio, 2:1) once daily for 48 weeks

Tenofovir Disoproxil and Tenofovir Disoproxil Fumarate is a nucleotide analogue and a potent inhibitor of human immunodeficiency virus type 1 reverse transcriptase and hepatitis B virus (HBV) polymerase.

The primary efficacy end point at week 48 of this study was defined as the combination of an HBV DNA level of less than 400 copies per milliliter and histologic improvement .

Inclusion Criteria:

• Chronic hepatitis B virus (HBV) infection, defined as positive serum hepatitis B s-antigen (HBsAg) for at least 6 months.
• HBeAg negative and HBeAb positive at screening

Exclusion Criteria:

• Pregnant women, women who are breast feeding, or women who believe they may wish to become pregnant during the course of the study
• Males and females of reproductive potential who are unwilling to use an effective method of contraception during the study.
• Decompensated liver disease defined as conjugated bilirubin > 1.5 x ULN, prothrombin time (PT) > 1.5 x ULN, platelets < 75,000/mL, serum albumin < 3.0 g/dL, or prior history of clinical hepatic decompensation (eg, ascites, jaundice, encephalopathy, variceal hemorrhage)
• Significant renal, cardiovascular, pulmonary, or neurological disease
• currently receiving therapy with immunomodulators (eg, corticosteroids, etc.), investigational agents, nephrotoxic agents, or agents susceptible of modifying renal excretion