Tenofovir versus Placebo to Prevent Perinatal Transmission of Hepatitis B.

BACKGROUND: Pregnant women with an elevated viral load of hepatitis B virus (HBV) have a risk of transmitting infection to their infants, despite the infants' receiving hepatitis B immune globulin. METHODS: In this multicenter, double-blind clinical trial performed in Thailand, we randomly assigned hepatitis B e antigen (HBeAg)-positive pregnant women with an alanine aminotransferase level of 60 IU or less per liter to receive tenofovir disoproxil fumarate (TDF) or placebo from 28 weeks of gestation to 2 months post partum. Infants received hepatitis B immune globulin at birth and hepatitis B vaccine at birth and at 1, 2, 4, and 6 months. The primary end point was a hepatitis B surface antigen (HBsAg)-positive status in the infant, confirmed by the HBV DNA level at 6 months of age. We calculated that a sample of 328 women would provide the trial with 90% power to detect a difference of at least 9 percentage points in the transmission rate (expected rate, 3% in the TDF group vs. 12% in the placebo group). RESULTS: From January 2013 to August 2015, we enrolled 331 women; 168 women were randomly assigned to the TDF group and 163 to the placebo group. At enrollment, the median gestational age was 28.3 weeks, and the median HBV DNA level was 8.0 log10 IU per milliliter. Among 322 deliveries (97% of the participants), there were 319 singleton births, two twin pairs, and one stillborn infant. The median time from birth to administration of hepatitis B immune globulin was 1.3 hours, and the median time from birth to administration of hepatitis B vaccine was 1.2 hours. In the primary analysis, none of the 147 infants (0%; 95% confidence interval [CI], 0 to 2) in the TDF group were infected, as compared with 3 of 147 (2%; 95% CI, 0 to 6) in the placebo group (P=0.12). The rate of adverse events did not differ significantly between groups. The incidence of a maternal alanine aminotransferase level of more than 300 IU per liter after discontinuation of the trial regimen was 6% in the TDF group and 3% in the placebo group (P=0.29). CONCLUSIONS: In a setting in which the rate of mother-to-child HBV transmission was low with the administration of hepatitis B immune globulin and hepatitis B vaccine in infants born to HBeAg-positive mothers, the additional maternal use of TDF did not result in a significantly lower rate of transmission. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT01745822 .).

Pharmacokinetics and virologic response of zidovudine/lopinavir/ritonavir initiated during the third trimester of pregnancy.

OBJECTIVE: To evaluate the pharmacokinetics and HIV viral load response following initiation during the third trimester of pregnancy of zidovudine plus standard-dose lopinavir boosted with ritonavir (LPV/r), twice daily, until delivery for the prevention of mother-to-child transmission of HIV. DESIGN: Prospective study nested within a multicenter, three-arm, randomized, phase III prevention of mother-to-child transmission of HIV trial in Thailand (PHPT-5, ClinicalTrials.gov Identifier: NCT00409591). METHODS: Women randomized to receive 300 mg zidovudine and 400/100 mg LPV/r twice daily from 28 weeks' gestation, or as soon as possible thereafter, until delivery had intensive steady-state 12-h blood sampling performed. LPV/r pharmacokinetic parameters were calculated using noncompartmental analysis. Rules were defined a priori for a LPV/r dose escalation based on the proportion of women with an LPV area under the concentration-time curve (AUC) below 52 microg h/ml (10th percentile for LPV AUC in nonpregnant adults). HIV-1 RNA response was assessed during the third trimester. RESULTS: Thirty-eight women were evaluable; at entry, median (range) gestational age was 29 (28-36) weeks, weight 59.5 (45.0-91.6) kg, CD4 cells count 442 (260-1327) cells/microl and HIV-1 RNA viral load 7818 (<40-402 015) copies/ml. Geometric mean (90% confidence interval) LPV AUC, Cmax and Cmin were 64.6 (59.7-69.8) microg h/ml, 8.1 (7.5-8.7) microg/ml and 2.7 (2.4-3.0) microg/ml, respectively. Thirty-one of 38 (81%) women had an LPV AUC above the AUC target. All women had a HIV-1 viral load less than 400 copies/ml at the time of delivery. CONCLUSION: A short course of zidovudine plus standard-dose LPV/r initiated during the third trimester of pregnancy achieved adequate LPV exposure and virologic response.