Mothers with high HBV DNA levels who received tenofovir disoproxil fumarate therapy late in pregnancy had reduced risk for perinatal mother-to-child transmission of hepatitis B virus infection vs. mothers who did not receive treatment, according to published findings in The New England Journal of Medicine.
Researchers also presented the study at The Liver Meeting 2015.
“We designed the current randomized, controlled trial to determine the efficacy and safety of [tenofovir disoproxil fumarate] therapy in mothers who have an HBV DNA level of more than 200,000 IU per milliliter. …[It] showed that 68% of the [tenofovir disoproxil fumarate]-treated mothers had the target HBV DNA level at delivery, which indicates that [tenofovir disoproxil fumarate] reduced maternal viremia,” Calvin Q. Pan, MD, FACP, FACG, of the division of gastroenterology and hepatology, New York University Langone Medical Center, New York University School of Medicine, and colleagues wrote.
In the study, Pan and colleagues randomly assigned 200 pregnant women positive for hepatitis B e antigen (HBeAg) to a dosage of tenofovir disoproxil fumarate (TDF, Gilead Sciences) from 30 to 32 weeks gestation until 4 weeks postpartum, or no treatment. The mothers were followed until 28 weeks postpartum and all infants received immunoprophylaxis after birth. Eighty-eight mothers and infants in the non-treated group and 92 mothers and infants in the TDF-treated group completed the study.
At delivery, 68% of mothers treated with TDF had reduced HBV DNA levels from baseline (n = 66) compared with non-treated mothers (n = 2; P < .001). At 28 weeks postpartum, mother-to-child transmission was lower in the TDF-treated group compared with the non-treated group in the intention-to-treat analysis (5% vs. 18%; P = .007) and per-protocol analysis (0% vs. 7%; P = .01).
In the intention-to-treat analysis, five mothers experienced treatment failure due to loss of follow-up (n = 2), withdrawing from the study (n = 1), a stillbirth at 36 weeks (n = 1) and a newborn death (n = 1). Eighteen infants in the non-treated group had immunoprophylaxis failure; six had HBV by 28 weeks and 12 were lost to follow-up.
The researchers note that the mother and infant safety profiles and birth defect rates in the TDF-treated group were similar to the non-treated group, but more mothers in the TDF-treated group had an increase in creatine kinase. No patient discontinued TDF treatment for lack of efficacy.
“Although we observed a similar rate of birth defects of 2% among infants with exposure to TDF, the current study was underpowered to evaluate potentially small differences in birth-defect rates. Furthermore, the postpartum cessation of TDF requires close monitoring,” the researchers wrote.
The researchers concluded: “TDF therapy should be strongly considered for mothers whose HBV DNA levels exceeded 200,000 IU/mL and started at gestation week 30 to 32.” – by Melinda Stevens
Disclosure: Please see the study for a list of all researchers’ relevant financial disclosures.