Atif Zaman, MD, MPH reviewing Pan CQ et al. N Engl J Med 2016 Jun 16.

Third-trimester maternal therapy with this antiviral agent was effective and safe.

Studies have indicated that oral antiviral agents against hepatitis B (HBV) are generally safe and effective for preventing mother-to-child transmission, especially in the setting of high baseline maternal viral loads; however, these studies were small and of low quality. Now, researchers have conducted a manufacturer-sponsored, open-label trial at several academic centers in China. A total of 200 HBV-infected pregnant women (age range, 20–35) positive for hepatitis B e antigen (HBeAg) and with baseline HBV DNA >200,000 IU/mL were randomized to usual care (control) or tenofovir disoproxil fumarate (TDF; 300 mg daily from 30 to 32 weeks' gestation until postpartum week 4). All infants received immunoprophylaxis shortly after birth. The primary outcomes were rates of mother-to-child transmission (defined as the proportion of infants with hepatitis B surface antigen (HBsAg) positivity or HBV DNA levels >20 IU/mL) and birth defects assessed at postpartum week 28.

At delivery, 68% of mothers in the TDF group and 2% of those in the control group had HBV DNA levels <200,000 IU/mL (P<0.001). At postpartum week 28, mother-to-child transmission was significantly lower in the TDF group than the control group based on intention-to-treat analysis (5% vs. 18%; P=0.007); in per-protocol analysis performed because 12 control participants withdrew consent before delivery, these rates were 0% versus 7% (P=0.01). Maternal and neonatal safety profiles were similar between groups. Rates of birth defects were 2% and 1% in the TDF and control groups, respectively (P=1.00).

CITATION(S):

Pan CQ et al. Tenofovir to prevent hepatitis B transmission in mothers with high viral load. N Engl J Med 2016 Jun 16; 374:2324.

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