By: Katie Williams, Ivanhoe Health Correspondent (Ivanhoe Newswire) – It was previously unclear whether adding antiretroviral drugs to the standard zidovudine prophylaxis treatment in infants born to mothers with human immunodeficiency virus (HIV) was effective and safe. Now, a new study sheds light on the most effective and least toxic treatment.
48 hours after the infants’ birth, researchers assigned formula-fed infants born to women with a peripartum diagnosis of HIV type 1 (HIV-1) infection to one of three regimens: zidovudine for 6 weeks (zidovudine-alone group), zidovudine for 6 weeks plus three doses of nevirapine during the first 8 days of life (two-drug group), or zidovudine for 6 weeks plus nelfinavir and lamivudine for 2 weeks (three drug group). The primary outcome for infants unaffected by HIV at birth was HIV-1 infection at 3 months of age.
1,684 infants were enrolled in the Americas and South Africa for the study; 566 were in the zidovudine-alone group, 562 in the two-drug group, and 556 in the three-drug group. The general rate of in utero transmission of HIV-1 based on the Kaplan-Meier estimates was 5.7% (93 infants) with no noteworthy differences among the groups. Intrapartum transmission occurred in 24 infants in the group solely taking zidovudine compared to 11 infants in the two-drug group and 12 in the three drug group. The general transmission rate was 8.5% (140 infants), with an increased rate in the zidovudine-alone group. The variables associated with transmission were zidovudine monotherapy, a higher maternal viral load, and maternal use of illegal substances. The three-drug group also had an increased rate of neutropenia, or abnormally low number of white blood cells.
Dr. James Kublin, Executive Director of The HIV Vaccine Trials Network at the Fred Hutchinson Cancer Research Center, Seattle, Washington, told Ivanhoe, "This study has demonstrated that with the addition of with one additional drug added on to zidovudine, we’re able to cut in half the number of infants who become HIV infected as a result of their mother’s infection. The importance of that was that even within the small study that was conducted to demonstrate these results, approximately 2 dozen infants were saved from having to live a life with HIV. "
Researchers conclude from this study that a two- or three-drug ART regimen is superior to taking zidovudine alone in preventing intrapartum HIV transmission. Additionally, the two-drug regimen is less toxic than the three-drug regimen. However, there is a better way to prevent prenatal HIV transmission.
"The ultimate strategy to prevent perinatal transmission for HIV is in the HIV vaccine. Even with the rigorous regimen following intrapartum exposure to HIV, we are nonetheless seeing two percent of these children still getting infected. The biggest challenge for these advances is the deployment of them within the regional centers where these women and infants are cared for."
Putting this study’s findings into effect globally proves itself as a challenge in many ways. Dr. Kublin cites some of these problems as additional costs, staff training, and other competing public health interventions.
Source: New England Journal of Medicine