Tenofovir to Prevent Hepatitis B Transmission in Mothers with High Viral Load

Anna Gawrys, Mercer University College of Pharmacy

Center for Disease Control (CDC) states that 40% of infants whose mothers are infected with hepatitis B virus (HBV) will develop a chronic HBV infection. Screening pregnant patients for HBV is recommended, and the infants of women who test positive should receive hepatitis B immune globulin (HBIG) and a hepatitis B vaccine within 12 hours of birth. [1]

For perinatal HBV exposure, CDC guidelines recommend post exposure prophylaxis with hepatitis B vaccine and a HBIG dose administered 12- 24 hours after birth, followed by completion of a three-dose vaccine series. Hepatitis B vaccines is stated to be safe when administered to infants, children, adolescents, and adults.  [2]

Tenofovir disoproxil fumarate (TDF) is an antiviral drug indicated for the treatment of chronic hepatitis B in adults. Tenofovir is pregnancy category B. The recommended dose for the treatment of chronic hepatitis B is 300 mg taken once daily. [3]

Title: Tenofovir to Prevent Hepatitis B Transmission in Mothers with High Viral Load [4]
Design Multicenter, open-label, randomized, parallel-group, placebo controlled cohort study; N= 197
Objective To assess the use of tenofovir disoproxil fumarate (TDF) during pregnancy for the prevention of mother-to-child transmission of hepatitis B virus (HBV)
Study Groups Tenofovir disoproxil fumarate (TDF) (n= 97); placebo (n= 100)
Methods Pregnant women 20 to 35 years of age who were positive for hepatitis B e antigen (HBeG) and who had an HBV deoxyribonucleic acid (DNA) level higher than 200,000 IU per milliliter were randomly assigned, in 1:1 ratio, to receive usual care without antiviral therapy or to receive TDF (from 30 to 32 weeks of gestation until postpartum week 4. All the infants received immunoprophylaxis.
Duration March 2012 through June 2013
Primary Outcome Measure The rates of mother-to-child transmission of hepatitis B virus
Baseline Characteristics   TDF Placebo
Maternal characteristics at baseline
No. of women, n 97 100
Age, yr 27.4 ±.0 26.8 ± 3.0
HBV DNA – log10IU/mL 8.2 ± 0.5 8.0 ± 0.7
Infant characteristics at birth
No. of infants, n 95 88
Gestational age, wk 39.2 ± 1.0 38.9 ± 1.3
Weight, kg 3.6 ± 2.7 3.4 ± 0.5
Positive for hepatitis B e antigen, n (%) 73 (77) 85 (97)
Detectable HBV DNA, n (%) 3 (3) 15 (17)
Results The rates of mother-to-child transmission of hepatitis B virus
  TDF Placebo p-value
Intention-To-Treat Analysis, n (%) 5 (5) 18 (18) p= 0.007
Per-Protocol Analysis, n (%) 0 6 (7) p= 0.01
Adverse Events Common Adverse Events: N/A
Serious Adverse Events: still birth (1%)
Percentage that Discontinued due to Adverse Events: 1%
Study Author Conclusions In a cohort of HBeAg-positive mothers with an HBV DNA level of more than 200,000 IU per milliliter during the third trimester, the rate of mother-to-child transmission was lower among those who received TDF therapy than among those who received usual care without antiviral therapy.

This study shows that the transmission of the virus from mother to child may be prevented if the mother is placed on tenofovir therapy during pregnancy. A limitation of the study is its small number of participants, which indicates that more research is necessary. While this trial may impact clinical prescribing practices for HBV positive mothers, more clinical data is needed before an update to the guidelines is warranted. Although there were no adverse events reported, one stillbirth occurred in a patient with a past medical history of fetal death.  Overall, this therapy appears to be a safe and effective option to prevent HBV in newborns.

References

  1. Center for Disease and Control and Prevention. http://www.cdc.gov/hepatitis/hbv/perinatalxmtn.htm  Accessed June 23, 2016
  2. Center for Disease Control and Prevention. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5416a1.htm?s_cid=rr5416a1_e Accessed June 23, 2016
  3. Vireadâ (tenofovirdisoproxil fumarate) [package insert].  Foster City, CA:  Gilead Sciences, Inc.; 2016
  4. Pan CQ, Duan Z, Dai E, et al. Tenofovir to Prevent Hepatitis B Transmission in Mothers with High Viral Load. N Engl J Med. 2016;374(24):2324-34.

 

 

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