A Study of Invirase (Saquinavir)/Ritonavir in HIV-Infected Infants and Children.

• AUC0-12h and Ctrough for saquinavir [ Time Frame: Day 14 (or Day 28 for patients switching from an NNRTI-containing regimen) ] [ Designated as safety issue: No ]
• AEs and laboratory parameters [ Time Frame: Week 24 and Week 48 ] [ Designated as safety issue: No ]

• AUC0-12h and Ctrough for ritonavir [ Time Frame: Day 14 (or Day 28 for patients switching from an NNRTI-containing regimen) ] [ Designated as safety issue: No ]
• Change from baseline in HIV-RNA, CD4 and CD8. [ Time Frame: Week 24 and Week 48 ] [ Designated as safety issue: No ]

This single arm study will assess the pharmacokinetics, safety and activity of saquinavir (Invirase hard gel capsules, film coated tablets or opened capsules) boosted by combination with ritonavir, in HIV-1 infected infants and children between the ages of 4 months and 6 years. Patients will commence treatment with saquinavir 50mg/kg bid plus ritonavir 2.5mg/kg or 3.0mg/kg (dependent on body weight), and a background antiretroviral regimen. If drug exposures are found to be dissimilar to those previously seen in older children and adults, or are associated with toxicities, subsequent dose adjustments will be made. The anticipated time on study treatment is 3-12 months, and the target sample size is <100 individuals.

• Drug: saquinavir [Invirase]
  50mg/kg po bid (starting dose) for 48 weeks
• Drug: ritonavir
  2.5-3.0mg/kg po bid (starting dose) for 48 weeks

Inclusion Criteria:

• infants and children, 4 months to <6 years;
• confirmed HIV-1 infection;
• patients for whom saquinavir/ritonavir together with >=2 background ARVs is considered appropriate.

Exclusion Criteria:

• body weight >4kg/8.8 pounds;
• use of any concomitant medications that may interfere with the pharmacokinetics of saquinavir or ritonavir;
• malabsorption, severe chronic diarrhea or vomiting within 28 days of the study.