The purpose of this study is to see if 3 anti-HIV drug combinations are safe and effective in patients who have failed previous anti-HIV treatments using nelfinavir (NFV).

Patients receive 1 of 3 salvage regimens. Treatments A and B include delavirdine, 1 of 2 doses of indinavir, and 2 nucleoside reverse transcriptase inhibitors (NRTIs) to which the patient has not been exposed. Treatment C includes ritonavir, indinavir, and 2 NRTIs to which the patient has not been exposed. When virologic failure is first observed, the patient must return in 2 weeks for confirmation of failure and start the salvage regimen within 1 month of the first assay in which failure was observed. Patients who have less than 400 copies/ml HIV RNA after 16 weeks of therapy are considered responders and continue on the study. Those who have more than 400 copies/ml after 16 weeks of therapy are considered nonresponders and should be discontinued from the study. In addition, patients who respond and subsequently rebound with a viral load 0.5 log above the nadir and greater than 400 copies/ml on 2 consecutive assays at least 2 weeks apart are considered treatment failures and should be discontinued from the study. Patients have regular physical exams, as well as virologic, immunologic, and pharmacokinetic assessments.

• Drug: Indinavir sulfate
• Drug: Ritonavir
• Drug: Delavirdine mesylate

Inclusion Criteria

Patients may be eligible for this study if they:

• Are HIV-positive.
• Had a viral load of less than 400 copies/ml, followed by an increase in viral load while taking an anti-HIV drug combination including NFV (treatment failure).
• Can start the study treatment within 1 month of treatment failure.
• Have a viral load of less than 30,000 copies/ml when they enter the study.
• Have not taken nonnucleoside reverse transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs) other than NFV.