Tenofovir in Early Pregnancy to Prevent Mother-to-child Transmission of Hepatitis B Virus
Condition: Hepatitis B
MeSH terms: Hepatitis A; Hepatitis B; Hepatitis
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) remains the major mode of
      transmission in most high and intermediate HBV endemic areas, despite existing WHO
      immunoprophylaxis recommendations. This immunoprophylaxis regimen, if given optimally, can
      prevent 75-80% of HBV MTCT, but optimal implementation is difficult because it requires
      administering monovalent HBV vaccine and hepatitis B immunoglobulin (HBIg) within 24 hours of
      birth. Due to the barriers of giving HBIg, the World Health Organization (WHO) states,
      "…owing to concerns related to supply, safety and cost, the use of HBIg is not feasible in
      most settings." Clearly, global control of HBV transmission will require improved MTCT
      prevention. Therefore, the investigators hypothesize that treating HBV early in pregnancy
      will lead to undetectable HBV DNA levels at delivery and prevention of MTCT of HBV without
      HBIg; a concept that has already been proven with HIV. Tenofovir disoproxil fumarate (TDF),
      an approved anti-HBV drug, is promising to prevent MTCT of HBV due to its high potency
      against hepatitis B and its safety record in pregnant women. A randomized, controlled
      clinical trial (RCT) will be necessary to determine if TDF given to HBV-infected pregnant
      women early in pregnancy plus vaccine to the newborn can decrease MTCT of HBV without HBIg.
      However, before embarking on a RCT, several critical knowledge gaps need to be addressed
      including the ideal timing for TDF initiation. The purpose of this proposal is to address
      these knowledge gaps.
    

Detailed description: 
      The investigators hypothesize that anti-HBV therapy given in the late first or early second
      trimester achieves undetectable HBV DNA at delivery in >=95% of pregnant women with chronic
      hepatitis B. The one-arm, open-label, interventional study aims: 1, To estimate the time to
      complete HBV DNA suppression (<100 IU/ml) in 170 HBV DNA positive women who start TDF in the
      late first or early second trimester; and to estimate the proportion of women with HBV DNA
      <100 IU/ml at delivery. 2, To address potential barriers to and the efficacy of implementing
      TDF in early pregnancy to prevent mother-to-child transmission of hepatitis B. The
      investigators will measure potential barriers to acceptability and effectiveness of this
      intervention: adherence, potential hepatitis B flares in mothers (safety), and the proportion
      of hepatitis B infections in the offspring at 1 year of age (efficacy).
    

Intervention name(s): Tenofovir Disoproxil Fumarate
Intervention type(s): Drug
Intervention description(s): 300 mg daily
Other intervention name(s): Viread
Intervention MeSH terms: Tenofovir
Intervention model: Single Group Assignment
Intervention model description: Single group study.
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: mother to child transmission; hepatitis B; tenofovir