A Study of Switching From Entecavir to Tenofovir Disoproxil Fumarate in Subjects With Chronic Hepatitis B

Exclusion Criteria

• •QTc \> 450 millisecond (msec) or \> 480 msec for subjects with bundle branch block
• •Received any interferon or Hepatitis B vaccine therapy within 24 weeks prior to initiation of the study treatment.
• •Received overdose of nonsteroidal anti-inflammatory drugs (NSAIDs) (excluding temporary or topical use) within 7 days prior to initiation of the study treatment.
• •Received any of the following drugs within 8 weeks prior to initiation of the study treatment (excluding topical products such as ointment and/or cream etc).
• •* Drugs causing renal impairment (examples: aminoglycosides, amphotericin B, vancomycin, foscarnet, cisplatin, pentamidine, tacrolimus, cyclosporine, some contrast mediums \[ionic high-osmolar contrast media, ionic low-osmolar contrast media\]
• •* Competitors of renal excretion (except temporary use, example: probenecid)
• •* Immunosuppressants (examples: azathioprine, cycolphosphamide) or chemotherapeutics (example: etoposide)
• •* Glucocorticoid preparation
• •Received TDF, Adefovir pivoxil (ADV) or Tenofovir Alafenamide Fumarate (TAF) within 2 years prior to initiation of the study treatment
• •Participation in another clinical study within 6 months prior to screening, or planned participation in another clinical study simultaneously with this study.
• •Co-infection with human immunodeficiency virus (HIV) or hepatitis C virus (HCV)
• •Subjects with serious complication other than compensated CHB (cancer, significant renal, cardiovascular, pulmonary, or neurological disease, uncontrollable diabetes, etc.)
• •Received or have a plan for solid organ or bone marrow transplantation
• •Has proximal tubulopathy.
• •Subjects with decompensated CHB who meet the following: direct bilirubin \> 1.5 times upper limit of normal (ULN), Prothrombin Time (PT) \< 60%, platelets \< 75,000/mm3 and serum albumin \< 3.0 g/dL
• •Autoimmune hepatitis (Antinuclear titer \> 1:160), excluding CHB
• •Subjects with or suspected of having hepatocellular carcinoma (HCC) (including both primary and metastatic) from diagnostic imaging at screening, or with serum alpha-fetoprotein (AFP) \> 50 nanogram (ng)/mL at screening
• •History of HCC (except subjects who underwent resection or received curative treatment by radiofrequency, and with AFP \<=10 ng/mL at screening)
• •Woman who is pregnant, possibly pregnant, lactating or planning a pregnancy during the study period.
• •Psychiatry disorder or cognitive disorder that may affect the subject's ability to give informed consent or to follow specified study procedures.
• •Subjects with a history of alcohol or drug abuse
• •Subjects whom the investigator (or sub-investigator) considers ineligible for the study.
• •Subjects with hypersensitivity to study treatments or their components, nucleoside and/or nucleotide analogues. Subjects with drug allergy that, in the investigator's (sub-investigator's) \[or medical monitor's\] opinion, labeled contraindication for participation in the study, or other allergy.