The purpose of this study is to see if it is safe and effective to add DMP 266 to an anti-HIV treatment program of indinavir and nucleoside reverse transcriptase inhibitors (NRTIs).

In this double-blind, placebo-controlled study, 300 patients are randomized to 1 or 2 reverse transcriptase inhibitors of their choice plus blinded therapy on Arm A or B as follows:

Arm A: DMP 266 placebo plus indinavir. Arm B: DMP 266 plus indinavir. After 16 weeks, patients may switch the NRTI portion of their regimen if they meet a treatment failure criterion. After the completion of the 24-week period, patients have the option to continue on open-label DMP 266 and indinavir.

Inclusion Criteria

Patients must have:

• CD4+ cell count of at least 50 cells/mm3.
• HIV RNA level of at least 10,000 copies/ml by reverse transcriptase polymerase chain reaction (RT-PCR, Amplicor test kit) at screening.
• Signed, informed consent from parent or legal guardian for patients less than 18 years of age.

Exclusion Criteria

Prior Medication:

Excluded:

• DMP 266.
• Other nonnucleoside reverse transcriptase inhibitors.

Required:

One or two NRTIs (except ZDV and d4T in combination) for a minimum of 8 weeks, within 12 weeks prior to screening.