To determine the steady-state pharmacokinetics of 141W94 in combination with saquinavir, indinavir and nelfinavir after multiple oral dosing. To determine the steady-state pharmacokinetics of saquinavir, indinavir, and nelfinavir in combination with 141W94 after multiple oral dosing. To assess the safety and tolerability of multiple doses of 141W94 when combined with saquinavir, indinavir and nelfinavir.

Patients will be randomized to receive open label 141W94 in combination with saquinavir, indinavir and nelfinavir. The randomized phase will be preceded by a single dose pharmacokinetic interaction study of 141W94 and indinavir in 12 patients. Data from this single dose investigation will be used to determine the dose of indinavir to be used in the randomized phase.

Inclusion Criteria

Concurrent Medication:

Allowed provided used with caution:

Medications that may interact at CYP3A4 (either a substrate, inhibitor or inducer of the enzyme) should be used with caution.

Patients must have:

• Documented HIV infection.

• CD4+ cell count >= 200 cells/mm3.

  1. Anticipated need for treatment with cytotoxic chemotherapeutic agents within the study time period.

• Treatment with immunomodulating agents.

• Medications that should not be administered with 141W94:

Terfenadine. Astemizole. Cisapride. Triazolam. Midazolam. Ergotamine/Dihydroergotamine-containing regimens. Antiretroviral drugs. Vitamin E supplements. Other experimental agents.

Anticipated need for radiation therapy within the study time period.

1. Prior protease inhibitors.

• Antiretroviral therapy within 2 weeks prior to entry.
• Treatment with cytotoxic chemotherapeutic agents within 4 weeks prior to entry.

Radiation therapy within 4 weeks prior to entry. Current alcohol or illicit drug use that, in the opinion of the investigator, may interfere with the patient's ability to comply with the dosing and protocol evaluations.