A Study of Zidovudine/Lamivudine and Either Nevirapine or Nelfinavir for Reduction of Mother-to-child HIV Transmission During Breastfeeding

Background: Approximately 800,000 HIV-infected infants are born each year, two thirds of them in sub-Saharan Africa. The rate of HIV transmission from mother to infant is estimated at 13-48% in the absence of antiretroviral treatment. Interventions currently available to prevent mother to child transmission in resource-limited settings among breastfeeding populations child HIV transmission during the breastfeeding period. Because safe alternatives to breastfeeding are not currently a viable option for many HIV-infected women in sub-Saharan Africa, it is important to identify interventions to decrease transmission to the infant during this period. Objective: To demonstrate that a regimen using highly active antiretroviral therapy (HAART) to maximally suppress maternal viral load in the late antenatal period and during the first six months of lactation is safe, effective and can be implemented in resource poor settings in order to reduce the risk of HIV transmission to the infant. Study Design: The study will be an open label Phase II trial of Zidovudine/Lamivudine and depending on maternal CD4 count, either Nevirapine or Nelfinavir to assess the safety, tolerance and activity of maternal HAART to reduce the risk of transmission among breastfeeding HIV infected women in Kisumu Kenya. Justification: Transmission through breastfeeding accounts for 25-40% of all mother-to-child transmission of HIV. This trial will assess the safety and activity of a potent triple drug combination to lower maternal viral loadprenatally, intrapartum and during breast feeding. The regimen will be given to HIV infected women from 34 weeks gestation through 6 months of breastfeeding postpartum. Infants will receive a single dose of NVP. Women will be encouraged to breastfeed exclusively and wean abruptly at 6 months. Mother and infant will be followed for 24 months. Clinical and laboratory evaluations will be performed periodically to determine infection status of the infant and side effects of medications to mother and infant. The estimated sample size needed to address both transmission reduction of HAART in comparison to single dose NVP as well as related safety of the two HAART regimens is 520 mother-infant pairs. Comparison will be made with data from previous studies (HIVNET O12 in Uganda and the malaria vertical transmission study in Kisumu) and with data from current Prevention of Mother to Child Transmission (PMCT) programs in Kisumu. Expectations and significance: A HAART regimen of this nature may potentially show a dramatic decrease in transmission when compared to existing PMCT regimens. Given the continued decreasing costs of ARVs and the relatively low efficacy of existing PMCT regimens, such a regimen would be seriously considered for wide implementation in resource poor settings and elsewhere.