The purpose of this study is to see if it is safe and effective to add a new protease inhibitor (PI), 141W94, to an anti-HIV regimen that includes 2 nucleoside reverse transcriptase inhibitors (NRTIs).

In this double-blind, placebo-controlled, pediatric study, 210 patients are randomized to receive 2 NRTIs plus either 141W94 or placebo. Enrollment of patients is sequential: patients 13 to 18 years of age are enrolled first, followed by children < 13 when the appropriate pediatric dose has been determined. Patients who are unable to swallow capsules will be accrued when a liquid formulation becomes available.

Inclusion Criteria

Your child may be eligible for this study if he/she:

• Is 6 months - 18 years of age.
• Is HIV-positive.
• Has a viral load (level of HIV in the body) greater than 10,000 copies/ml.
• Is able to take medications by mouth.
• Has consent of parent or legal guardian if under 18.
• Has a negative pregnancy test within 7 days of study entry.
• Agrees to practice abstinence or use effective methods of birth control for 1 month before and throughout the study.

Exclusion Criteria

Your child will not be eligible for this study if he/she:

• Has a serious illness, including any life-threatening infection or other chronic serious medical condition.
• Has an opportunistic (AIDS-related) infection or a serious bacterial infection.
• Is allergic to NRTIs.
• Is breast-feeding.
• Is unlikely to complete the study.
• Has received certain medications.
• Has received radiation therapy within the past 4 months, or will need to receive it during the study.