Results from a pilot study evaluating the safety and effectiveness of short course nucleoside analogue therapy in the prevention of mother to baby HIV transmission suggest that regimens involving ddI and d4T merit further investigation. Preliminary data from the BMS 094 trial were presented yesterday at the 13th International AIDS Conference in Durban.
HIV-positive pregnant South African women were randomised to one of four treatment arms at 34-36 weeks of pregnancy. Mothers received a short treatment course of either d4T alone, ddI alone, AZT alone, or d4T with ddI. Mothers and infants were followed for six weeks after delivery, and given formula feed to eliminate the transmission risk associated with breastfeeding. Infants received the same treatment as their mother, at standard paediatric doses for the first six weeks of life.
Data was available for 204 women, 54 of whom received ddI, 50 women being randomised to each of the other three arms. 210 infants were born to these women, and these were equally distributed across the four study arms. At entry, average maternal viral load was 4.5 log copies and average CD4 count was 399 cells.
Most women delivered vaginally. 12% of deliveries were by elective caesarean section, and 20% by emergency caesarean section, rates which were described as typical for this clinic.
At six weeks after delivery the rate of HIV infections was 3.6%, and was comparable across the treatment arms. When the infants who discontinued treatment because of death, or because they were HIV infected, were included in the analysis, this rate rose to 9.0%. The study was not powered to detect differences between the four regimens, only equivalence.
The cost of the regimens used in this study varies between sixty and one hundred US dollars per mother-infant pair.
Gray G et al. Preliminary efficacy, safety, tolerability and pharmacokinetics of short course regimens of nucleoside analogues for the prevention of mother-to-child transmission (MTCT) of HIV. 13th International AIDS Conference, abstract TuOrB355, Durban, 9-14 July 2000.