TAF prophylaxis prevents mother-to-child transmission of HBV

Treatment with tenofovir alafenamide (TAF) is generally safe and effective for the prevention of hepatitis B virus (HBV) mother-to-child transmission (MTCT), reports a study, noting that the expected 8-week prenatal duration is feasible.

Pregnant women with HBV DNA of 5.3–9.0 log10 IU/mL treated with TAF from the first day of 33 gestational weeks to delivery (expected 8 week) or to 4 weeks postpartum (expected 12 week) were randomized and followed until 6 months postpartum. All infants received standard immunoprophylaxis (hepatitis B immunoglobulin and vaccine).

The safety of both mothers and infants was the primary endpoint, while the HBV-MTCT rate of infants at age 7 months was secondary.

A total of 119 and 120 intention-to-treat (ITT) pregnant women were enrolled, of which 115 and 116 were followed until delivery, and 110 and 112 per-protocol mother-infant dyads in two groups completed the study.

TAF was well tolerated, with no treatment discontinuation due to adverse events (0 percent, 95 percent confidence interval [CI], 0‒1.6). None of the infants had congenital defects or malformations at delivery (0 percent, 95 percent CI, 0‒1.6). The physical development of infants was normal at birth (n=231) and at 7 months (n=222).

In addition, the majority of women (97 percent, 95 percent CI, 93.9‒98.5) achieved HBV DNA <5.3 log10 IU/mL at delivery.

Among infants in the ITT and per-protocol analysis groups, the HBV-MTCT rates were 7.1 percent (95 percent CI, 4.5‒11.1) and 0 percent (95 percent CI, 0‒1.7), respectively, at the age of 7 months.

Furthermore, 15.1 percent (95 percent CI, 9.8‒22.7) and 18.3 percent (95 percent CI, 12.4‒26.2) of women in the two groups had mildly elevated alanine aminotransferase levels at 3 and 6 months postpartum, respectively (p=0.507). Notably, none of them experienced alanine aminotransferase flare (0 percent vs 0 percent).