Study APV20002: Safety and Efficacy Results Through Week 684 for Pediatric Participants Living With HIV-1 Treated With Ritonavir-Boosted Fosamprenavir Oral Solution–Based Antiretroviral Therapy

APV20002 was a multicenter, international, open-label study that began in 2003 investigating the pharmacokinetics, efficacy, and safety of ritonavir-boosted fosamprenavir (FPV/r) oral solution (OS) in combination with nucleoside reverse transcriptase inhibitor-based antiretroviral therapy (ART) in participants living with HIV-1 aged 4 weeks to <2 years with a primary endpoint at Week 48 (48W). Participants in APV20002 could continue in the study post-48W until FPV OS was locally available in their countries. Children were required to discontinue after reaching >39 kg or if FPV OS had no clinical benefit. Fifty-nine participants were enrolled; 5/59 received a single FPV OS visit for pharmacokinetic determinations. Most (38/54; 70%) were antiretroviral experienced; 39/59 participants had >48 weeks on treatment, 4/39 of whom discontinued after 48 weeks due to an adverse event (AE). At 48W, 88% of participants had HIV-1 RNA <400 copies/mL by Observed analysis; the proportion with HIV-1 RNA <400 copies/mL remained high (84%-100%) through Week 684. The median CD4