HPTN 046

Phase III Trial to Determine the Efficacy and Safety of an Extended Regimen of Nevirapine in Infants Born to HIV Infected Women to Prevent Vertical HIV Transmission During Breastfeeding

Study Summary

What was HPTN 046?

A Phase III, randomized, placebo-controlled trial designed to determine the efficacy and safety of an extended daily regimen of nevirapine (NVP) in infants born to HIV-infected women to prevent vertical HIV transmission during breastfeeding.

Who participated in the study?

HIV-1 infected women and their breastfeeding infants.

What happened during the study?

HPTN 046 compared nevirapine (NVP) given to breastfeeding infants born to HIV infected mothers through 6 weeks of age to an extended regimen given through 6 months of age or cessation of breastfeeding, whichever was earliest.


The study found that the overall risk of HIV transmission through breast milk at age 6 months was lower with extended daily infant NVP, 1.1%, compared to 2.4% in infants in the placebo arm who had only 6 weeks of NVP (p=0.048). The study also demonstrated that extended infant NVP is most important for infants of mothers with high CD4+ cell counts (> 350 cells/mm3) who are not receiving antiretroviral therapy for their own health; among these infants, breast milk transmission was much lower with 6 months of NVP, 0.7%, compared to 2.8% of infants in the placebo arm who received only 6 weeks of NVP (p=0.014).

Why was this study important?

Other studies had shown that giving daily infant NVP for 6 weeks, 14 weeks or 6 months to breastfeeding infants reduces HIV transmission through breast milk compared to single dose NVP, but no other study had directly compared 6 weeks of NVP to 6 months of NVP to determine if the longer regimen is better for prevention of HIV transmission through breast milk.