Combination Treatment With and Without Protease Inhibitors for Women Who Begin Therapy for HIV Infection During Pregnancy

The optimal treatment strategy for women who initiate antiretroviral therapy during pregnancy is not known. Although PI-based antiretroviral regimens are prescribed with increasing frequency among pregnant women, the efficacy and safety of this approach is unknown. Pregnant women are at increased risk for glucose intolerance and insulin resistance; PIs are associated with glucose intolerance. Physiologic differences between pregnant women and nonpregnant adults may alter the pharmacokinetics of antiretroviral regimens. Fetal safety considerations and effects on perinatal HIV transmission must also be considered when selecting an antiretroviral regimen for pregnant women. This trial will compare PI-based and PI-sparing antiretroviral regimens for women initiating antiretroviral therapy in pregnancy. Women will be stratified on the basis of viral load (50,000 or less copies/ml or greater than 50,000 copies/ml) and gestational age at entry (20 or less weeks or greater than 20 weeks) and then randomized to one of two treatment groups. Group A will receive the PI nelfinavir (NFV) with zidovudine (ZDV) and lamivudine (d4T); Group B will receive nevirapine (NVP) with ZDV and d4T. Women will have clinic visits for physical and obstetrical examinations at 2, 4, 6, and 8 weeks after entry and then every 4 weeks until delivery. After delivery, infants in both groups may receive ZDV until they are 6 weeks old. Infants are evaluated for safety and to test the infant's blood for HIV-1 at birth and at Weeks 2, 8, 16, and 24. Women will continue on assigned antiretroviral therapy postpartum and will have 11 postpartum clinic visits over a period of 2 years. Blood samples from women will be evaluated for safety and for virologic, pharmacokinetic, and metabolic studies. The first 12 women randomized to Group A will undergo a 4-hour pharmacokinetic profile at 32 to 36 weeks gestation and at 8 weeks postpartum to determine the timing of the nelfinavir trough. The first 20 women randomized to Group B will undergo an 8-hour pharmacokinetic profile at either 16 to 24 weeks or 32 to 36 weeks gestation and then again at 8 weeks postpartum to characterize pharmacokinetics of nevirapine at steady state in pregnancy and in the postpartum period.