Maternal and nenonatal tenofovir and emtricitabine to prevent vertical transmission of HIV-1: tolerance and resistance.

Objective: Viral resistance occurs with a high frequency after single-dose nevirapine. We aimed to evaluate the tolerance and resistance profiles of a combination of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) given to HIV-1-infected delivering women and their newborns.
Design: An open-label phase I/II trial in Cambodia, Côte d'Ivoire and South Africa.
Methods: HIV-1-infected pregnant women received zidovudine from the enrollment until the beginning of labor, when single-dose nevirapine and two tablets of TDF/FTC were given. One daily tablet of TDF/FTC was then administered for 7 days postpartum. All infants received single-dose nevirapine with single-dose TDF (13 mg/kg) and single-dose FTC (2 mg/kg) and 1 week of zidovudine. Mothers and infants were followed for 2 months. Serious adverse events, kinetic of maternal plasma HIV-1 RNA, pediatric HIV infection and genotypic resistance and viral subtype were assessed.
Results: Thirty-six HIV-1-infected pregnant women were enrolled: median age 28 years (interquartile range: 26-31 years), median CD4 cell count 462 cells/μl (interquartile range: 376-632) and median HIV-1 RNA 3.7 log10 copies/ml (interquartile range: 2.95-4.11). Two infants had clinical serious adverse events, including one who died (neonatal sepsis). One transient grade 3 neutropenia and two grade 3/4 hyperbilirubinemia were also reported in neonates. One HIV pediatric in-utero infection was diagnosed (2.8%; 95% confidence interval 0-15.4%). Genotypic viral resistance to nevirapine was detected in one mother out of 34 (2.9%) at one month postpartum, but was also detectable at enrollment.
Conclusion: The combination of TDF/FTC to delivering women and their neonates appears well tolerated and to minimize the occurrence of nevirapine viral resistance.