Antiviral Responses to NNRTI-Based vs. PI-Based ARV Therapy in HIV Infected Infants Who Have or Have Not Received Single Dose NVP for Prevention of Mother-to-Child Transmission of HIV

Single dose nevirapine (SD NVP) has greatly reduced the rate of mother-to-child transmission (MTCT) of HIV. Non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens are recommended for use by the World Health Organization (WHO) in resource-limited settings. However, research suggests that mothers and infants exposed to SD NVP experience higher virologic failure rates when treated with NNRTI-based regimens than their unexposed counterparts. Data show that the use of SD NVP is associated with NNRTI resistance in HIV infected women and infants. The purpose of this trial was to compare and evaluate virologic responses to an NNRTI-based regimen versus a protease-inhibitor (PI)-based regimen in HIV infected infants who had or had not been exposed to SD NVP intrapartum and after birth. \>\> \>\> Participants were enrolled into one of two Cohorts with proposed enrollment into each Cohort of 288 participants. Cohort I participants must have received SD NVP for prevention of MTCT. Cohort II participants and their mothers must not have previously received NVP or any other NNRTIs. Participants in both Cohorts were randomly assigned to receive either an NNRTI (Coh I:NVP and Coh II: NVP) or PI (Coh I: LPV/r and Coh II: LPV/r) -based regimen. The NNRTI-based regimen included NVP, zidovudine (ZDV) and lamivudine (3TC). The PI-based regimen included lopinavir/ritonavir (LPV/r), ZDV and 3TC. If participants experienced adverse reactions to ZDV, stavudine (d4T) could be substituted. Randomization was stratified by age (6-\<12 months vs. \>=12 months, with the 2-\<6 month stratum added in protocol version 4.0 when the lower age limit was decreased from 6 months to 2 months). \>\> \>\> Study visits were scheduled at entry, weeks 2, 4, 8, 12, 16, 24 and then every 24 weeks. A physical exam, blood collection, and assessments of HIV-related symptoms occurred at all visits. \>\> \>\> Based on a Data Safety and Monitoring Committee (DSMB) review of study data on April 20 2009, enrollment to Cohort I was closed and interim results released. Data from this and another similar study (AIDS Clinical Trials Group (ACTG) A5208) conducted in mothers, showed that the PI-based regimen was more effective than the NNRTI-based regimen in infants who had received SD NVP for prevention of MTCT. Cohort II was allowed to remain open for enrollment and the lower age limit for enrollment reduced from 6 months to 2 months. \>\> \>\> In June 2010, follow-up for all subjects was extended from the original 24 weeks beyond enrollment of the last subject to 48 weeks. On October 27 2010, the DSMB conducted a final review of Cohort II data, and recommended results be unblinded and released. As found in Cohort I, the PI-based regimen was more effective than the NNRTI-based regimen in infants who had not been previously exposed to SD NVP for PMTCT. Primary and secondary outcome results for Cohort I include all follow-up until April 20, 2009 and for Cohort II, all follow-up until October 27, 2010. \>\> \>\> Version 5.0 of the protocol (March 21, 2011) extended follow-up on all subjects for an additional 5 years to December 2016. The purpose of the extension was to collect long term safety and virologic efficacy data in this study population and to pilot administration of a series of neuropsychological tests. During the extension, participants did not receive any medications through the study, but instead through their local clinics. Clinic visits took place every 3 months. Adverse event summaries use all follow-up in both Cohorts until December, 2016. \>\> \>\>