Utilization and Efficacy of Tenofovir DF in Adolescents With Chronic Hepatitis B Virus Infection

Study Overview
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Brief Summary
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The primary objective of this study is to characterize the long term (ie, 96 weeks of follow up) bone safety profile of open-label tenofovir disoproxil fumarate (tenofovir DF) treatment in CHB-infected adolescents. This includes prospectively evaluating and comparing the bone mineral density (BMD) change between CHB-infected adolescents 12 to < 18 years of age treated with tenofovir DF in European treatment centers who are assigned to one of two schedules for renal and bone laboratory monitoring and BMD measurement.

Official Title
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Pharmacoepidemiology Study to Define the Long-term Safety Profile of Tenofovir Disoproxil Fumarate (Tenofovir DF, Viread®) and Describe the Management of Tenofovir DF-associated Renal and Bone Toxicity in Chronic Hepatitis B (CHB)-Infected Adolescents Aged 12 to <18 Years in Europe

Conditions
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Hepatitis B

Intervention / Treatment
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* Drug: Tenofovir DF
* Radiation: DEXA Scan


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: 12 to <16 years of age Documented chronic hepatitis B virus (HBV) infection Weight ≥ 35 kg Able to swallow oral tablets Negative pregnancy test for females of childbearing potential Adequate kidney (renal) function Parent or legal guardian of potential study subjects able to provide written informed consent Key Exclusion Criteria: Previously received tenofovir DF Sexually-active males or females of reproductive potential who are not willing to use an effective method of contraception during the study Females who are pregnant or breastfeeding, or females who wish to become pregnant during the course of the study Known hypersensitivity to tenofovir DF, the metabolites or formulation excipients Any condition (including alcohol or substance abuse) or prior therapy that, in the opinion of the Investigator, would make the subject unsuitable for the study or unable to comply with treatment requirements Note: Other protocol defined Inclusion/Exclusion criteria may apply

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Tenofovir DF + increased bone/renal monitoring<br>Participants will receive tenofovir DF, plus laboratory bone biomarker testing and lumbar spine and whole-body DEXA scans every 24 weeks from baseline to Week 96 (5 scans), and monitoring of renal function at 4 and 12 weeks after baseline and every 12 weeks thereafter. With the exception of an enhanced monitoring protocol for bone and renal outcomes, participants will be managed according to local standards of care. | Drug: Tenofovir DF<br>* 300 mg tablet administered orally once daily for up to 96 weeks<br>* Other names: Viread®;Radiation: DEXA Scan<br>* Dual energy x-ray absorptiometry (DEXA) scans administered at protocol-specified time points<br>|
| Other: Tenofovir DF + prespecified bone monitoring<br>Participants will receive tenofovir DF, plus laboratory bone biomarker testing and lumbar spine and whole-body DEXA scans at baseline, Week 48, and Week 96. With the exception of pre-specified bone monitoring, participants will be managed according to local standards of care. | Drug: Tenofovir DF<br>* 300 mg tablet administered orally once daily for up to 96 weeks<br>* Other names: Viread®;Radiation: DEXA Scan<br>* Dual energy x-ray absorptiometry (DEXA) scans administered at protocol-specified time points<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants With Bone-Related Adverse Events and/or a ≥ 4% Reduction in Bone Mineral Density (BMD) From Baseline to Week 96 |  | Baseline to Week 96 |