Study Of An Investigational Regimen Including FDA Approved HIV Drugs In HIV-Infected Pediatric Subjects

Inclusion Criteria: * Male or female 4 weeks to \<2 years of age. Cohort 1 (6 months - \<2 years): Subjects must be \<2 years of age at the Week 2 visit therefore the maximum age at screening is 22 months. Cohort 2 (4 weeks - \<6 months): Subjects must be \<6 months of age at the Week 2 visit, therefore the maximum age at screening is 4 months for entry into this cohort. * Parent or legal guardian is willing and able to provide written informed consent for the subject to participate in the trial. * Screening plasma HIV-1 RNA level \>=400copies/mL. * Subjects who, in the investigator's opinion, and following viral resistance testing if conducted, are able to construct an active Nucleoside Reverse Transcriptase Inhibitor (NRTI) backbone regimen consisting of 2 NRTIs. * Subjects must meet one of the following criteria: Therapy-naïve or PI-naïve subjects (defined as having received less than one week of any PI). PI-experienced subjects defined as having prior experience with no more than three PIs. Prior RTV-boosted PI therapy will be considered as only one PI as long as the RTV dose was lower than that recommended for use of RTV as an antiretroviral agent. Exclusion Criteria: * Prior history of having received APV. * Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) therapy within 14 days prior to study drug administration (single or multiple dose) or anticipated need for concurrent NNRTI therapy during the study period. * PI therapy within 5 days prior to study drug…