Telbivudine effectively blocks transmission of hepatitis B virus (HBV) infection from mothers to their infants when administered during early and middle pregnancy, according to a study published in BMC Gastroenterology.
In areas where HBV infection is widespread, transmission of HBV most commonly occurs via mothers passing on the virus to their infants during pregnancy or in the perinatal period. Immunoprophylaxis at birth, in the form of the HBV vaccine and hepatitis B immunoglobulin, aims to prevent mother-to-infant transmission but is ineffective in up to 10% of immunized infants.
Since high maternal viral load is a known risk factor for HBV transmission, one strategy to prevent mother-to-infant transmission of HBV is to treat mothers with antiviral agents during pregnancy. Telbivudine, a nucleoside analogue for chronic HBV, has a pregnancy category B rating and has been shown to be safe and effective for preventing mother-to-infant transmission when given during the second and third trimesters. However, data are lacking on whether telbivudine during early pregnancy is safe and effective for blocking HBV transmission.
Researchers evaluated the safety and efficacy of telbivudine in early and middle pregnancy for preventing mother-to-child HBV transmission in China, where HBV infection affects approximately 7.2% of the population.
Participants had elevated alanine aminotransferase (ALT) levels and viral loads of HBV DNA ≥1.0 × 107 copies/mL. A total of 62 and 61 women received telbivudine beginning at 12 and 20 to 28 weeks of gestation, respectively, and 65 women did not receive an antiviral agent. Telbivudine was discontinued 12 weeks after delivery.
While baseline viral loads and alanine aminotransferase (ALT) levels were similar in all groups, both groups treated with telbivudine had significantly lower viral loads and ALT levels than the untreated group before delivery and at 12 weeks postpartum (P <.001) for all comparisons).
At 28 weeks postpartum, HBV infection was found in 0% of infants born to mothers treated with telbivudine during early (12 weeks) and middle (20 to 28 weeks) pregnancy, compared with 18.4% of infants born to mothers receiving no antiviral treatment.
Rates of adverse events related to pregnancy were similar in all groups. Virologic resistance was not detected in participants treated with telbivudine.
“To our knowledge, our present study is the first report concerning early treatment of pregnant women with telbivudine,” the researchers wrote.
“There was no difference in the efficacy of telbivudine between groups A [early pregnancy] and B [middle pregnancy]. This indicates that telbivudine treatment begun during middle pregnancy can be as effective as that started during early pregnancy. Because of the relatively small sample size in this study, our findings need to be verified in large cohorts,” they wrote.
Sun W, Zhao S, Ma L, et al. Telbivudine treatment started in early and middle pregnancy completely blocks HBV vertical transmission. BMC Gastroenterol. 2017;17(1):51. doi:10.1186/s12876-017-0608-7