Evaluation of Tenofovir Disoproxil Fumarate in Adolescents With Chronic Hepatitis B Infection

Inclusion Criteria

- Male or female, 12 through 17 years of age, inclusive (consent of parent/legal
guardian required)

- Documented chronic HBV infection

- HBeAg positive or HBeAg negative

- Weight > 35 kg

- Able to swallow oral tablets

- HBV DNA > 100,000 copies/mL (polymerase chain reaction [PCR] method)

- ALT > 2 × upper limit of normal (ULN) at screening, OR any history of ALT > 2 × ULN
over the past 24 months

- Willing and able to provide written informed consent/assent (child and parent/legal
guardian)

- Negative serum pregnancy test (for postmenarchal females only)

- Estimated glomerular filtration rate (creatinine clearance [using the Schwartz
formula]) > 80 mL/min/1.73m^2

- Adequate hematologic function (absolute neutrophil count ≥ 1,500/mm^3; hemoglobin ≥
10.0 g/dL)

- No prior TDF therapy (participants may have received prior interferon or oral
anti-HBV nucleoside/nucleotide therapy; participants must have discontinued
interferon therapy ≥ 6 months prior to screening; participants experienced on
anti-HBV nucleoside/nucleotide therapy must have discontinued therapy ≥ 16 weeks
prior to screening to avoid flare if randomized to the placebo arm)

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

- Decompensated liver disease

- Receipt of interferon (pegylated or not) therapy within 6 months of the Screening
Visit

- Receipt of anti-HBV nucleoside/nucleotide therapy within 16 weeks of the Screening
Visit

- Alpha fetoprotein > 50 ng/mL

- Evidence of hepatocellular carcinoma (HCC)

- Coinfection with HIV, HCV, or HDV

- History of significant renal disease (eg, nephrotic syndrome, renal dysgenesis,
polycystic kidney disease, congenital nephrosis, acute tubular necrosis, other renal
disease)

- History of significant bone disease (eg, osteomalacia, chronic osteomyelitis,
osteogenesis imperfecta, osteochondroses, multiple bone fractures)

- Significant cardiovascular, pulmonary, or neurological disease

- Evidence of a gastrointestinal malabsorption syndrome that may interfere with
absorption of orally administered medications

- History of solid organ or bone marrow transplantation

- Ongoing therapy with nephrotoxic agents, competitors of renal excretion, systemic
chemotherapeutic agents, systemic corticosteroids, interleukin-2 (IL-2), or other
immunomodulating or investigational agents

- Known hypersensitivity to the study drugs, the metabolites or formulation excipients

- Any other condition (including alcohol or substance abuse) or prior therapy that, in
the opinion of the Investigator, would make the participants unsuitable for the study
or unable to comply with dosing requirements