Study to Compare Tenofovir Alafenamide (TAF) Versus Tenofovir Disoproxil Fumarate (TDF) in Participants With Chronic Hepatitis B Infection Who Are Positive for Hepatitis B e Antigen
Condition: HBeAg-positive Chronic Hepatitis B
MeSH terms: Hepatitis A; Hepatitis B; Hepatitis B, Chronic; Hepatitis; Hepatitis, Chronic
Intervention: TAF; TDF; TAF Placebo; TDF Placebo
Intervention description: 25 mg tablet administered orally once daily; 300 mg tablet administered orally once daily; Tablet administered orally once daily; Tablet administered orally once daily
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 875.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Hepatitis; Tenofovir; Viread

Summary:

      The primary objective of this study is to compare the efficacy, safety, and tolerability of
      tenofovir alafenamide (TAF) versus tenofovir disoproxil fumarate (TDF) in treatment-naive and
      treatment-experienced adults with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B
      virus (HBV) infection.
    

Eligibility criteria:

        Key Inclusion Criteria:

          -  Ability to understand and sign a written informed consent form, which must be obtained
             prior to initiation of study procedures.

          -  Adult males and non-pregnant, non-lactating females.

          -  Documented evidence of chronic HBV infection.

          -  HBeAg-positive, chronic hepatitis B with all of the following:

               -  HBeAg-positive at screening.

               -  Screening HBV DNA ≥ 2 x 10^4 IU/mL

               -  Screening serum alanine aminotransferase (ALT) level > 60 U/L (males) or > 38 U/L
                  (females) and ≤ 10 x the upper limit of the normal range (ULN).

          -  Treatment-naive participants (defined as < 12 weeks of oral antiviral treatment with
             any nucleoside or nucleotide analogue) OR treatment-experienced participants (defined
             as participants meeting all entry criteria [including HBV DNA and serum ALT criteria]
             and with ≥ 12 weeks of previous treatment with any nucleoside or nucleotide analogue).

          -  Previous treatment with interferon (pegylated or non-pegylated) must have ended at
             least 6 months prior to the baseline visit.

          -  Adequate renal function.

          -  Normal electrocardiogram (ECG).

        Key Exclusion Criteria:

          -  Females who are breastfeeding.

          -  Males and females of reproductive potential who are unwilling to use an "effective",
             protocol specified method(s) of contraception during the study.

          -  Co-infection with hepatitis C virus, human immunodeficiency virus (HIV), or hepatitis
             D virus.

          -  Evidence of hepatocellular carcinoma .

          -  Any history of, or current evidence of, clinical hepatic decompensation.

          -  Abnormal hematological and biochemical parameters, including aspartate
             aminotransferase (AST) > 10 x ULN.

          -  Received solid organ or bone marrow transplant.

          -  History of malignancy within the past 5 years, with the exception of specific cancers
             that are cured by surgical resection; individuals under evaluation for possible
             malignancy are not eligible.

          -  Currently receiving therapy with immunomodulators (eg, corticosteroids),
             investigational agents, nephrotoxic agents, or agents capable of modifying renal
             excretion.

          -  Individuals receiving ongoing therapy with drugs not to be used with tenofovir
             alafenamide or tenofovir disoproxil fumarate or individuals with a known
             hypersensitivity to study drugs, metabolites, or formulation excipients.

          -  Current alcohol or substance abuse judged by the investigator to potentially interfere
             with participant compliance.

          -  Any other clinical condition or prior therapy that, in the opinion of the
             Investigator, would make the participant unsuitable for the study or unable to comply
             with dosing requirements.

        Note: Other protocol defined Inclusion/Exclusion criteria may apply.