Highly active antiretroviral therapy (HAART) regimens including the protease inhibitor atazanavir (Reyataz), appear to be safe and effective during pregnancy, according to a small US study presented as a poster to the Third International AIDS Society Conference on HIV Pathogenesis and Treatment in Rio de Janeiro, Brazil.
In resource-rich countries, HAART regimens used in pregnancy often contain a protease inhibitor, with most data concerning the use of older drugs which are not ritonavir “boosted.” The improvement in the prognosis of HIV-positive individuals thanks to HAART means that more women are considering pregnancy and data are needed on the safety and efficacy of newer protease inhibitors before and during pregnancy.
In a study supported by the pharmaceutical company Bristol Myers Squibb, investigators from Springfield, Massachusetts, conducted a retrospective, observational study involving all women exposed to atazanavir during pregnancy up to February 2005.
Data were gathered on maternal CD4 cell count and viral load and side-effects commonly associated with atazanavir, particularly bilirubin levels and jaundice. In addition, the investigators gathered information on the HIV infection status of infants, their birth weight, height and whether or not they had hyperbilirubinaemia.
A total of nine women were included in the investigators’ analysis. All but one of the women had delivered their infants, the remaining woman being still pregnant with twins. In total, six women were treated with “boosted” atazanavir. Of the women not on HAART at the beginning of pregnancy, the mean viral load was just under 32,000 copies/ml. By the time of delivery, all the women had a viral load below 100 copies/ml and five had a viral load below 50 copies/ml. Mean CD4 cell count increased from a baseline of 366 cells/mm3 to 450 cells/mm3.
Total maternal bilirubin at the time of delivery ranged from 0.3 – 3.5mg/dl. No liver, kidney or pancreatic abnormalities were seen in the mothers and treatment was generally well tolerated.
At the time of birth, three infants had mild hyperbilirubinaemia, the highest level being 10.2mg/dl. Two of these infants required brief phototherapy. Mean birth weight was 2205 grams and mean birth height was 52cm. All eight infants born so far are HIV-negative.
“Atazanavir-based regimens in this cohort of pregnant women were very well tolerated”, write the investigators, who note that the infants will be followed for a year post delivery to confirm their HIV-negative status. “Until prospective data are available, this series will help inform the field”, conclude the investigators.
Morris A et al. Atazanavir use in pregnancy. Third International AIDS Society Conference on HIV Pathogenesis and Therapy, Rio, poster presentation xxx, 2005.