Addition of Efavirenz or Nelfinavir to a Lamivudine/Zidovudine/Indinavir HIV Treatment Regimen

Prior ACTG studies have shown that the 3-drug combination regimen (IDV/ZDV/3TC) resulted in improved clinical outcomes and therefore may prolong the effects of therapy. The enhanced effects seen with combination therapies are likely related to a greater suppression of RNA replication and alterations in resistance patterns. Due to the progressive success of combination regimens, it is possible that more potent regimens will further enhance viral suppression and provide more durable treatment responses. In light of the additive suppression of HIV replication determined by pharmacological, immunological, and virological results, nelfinavir (NFV) as an addition to IDV/ZDV/3TC will be evaluated. Based on the potency of nonnucleoside reverse transcriptase inhibitors (NNRTIs) to suppress viral replication and the effectiveness of 3-drug regimens containing NNRTIs, efavirenz (EFV) will also be evaluated as an addition to IDV/ZDV/3TC. Patients with HIV infection, CD4 cell count less than or equal to 200 cells/mm3 or plasma HIV RNA greater than or equal to 100,000 copies/ml, and limited (no prior 3TC, NNRTI, or protease inhibitor) or no prior antiretroviral treatment are randomized to 1 of 3 arms. Patients are stratified by CD4 cell count (less than or equal to 50 cells/mm3 vs greater than 50 cells/mm3), HIV-1 RNA copy number (less than or equal to 40,000 copies/ml vs greater than 40,000 copies/ml), and prior antiretroviral therapy (no therapy vs any therapy), and then randomly assigned to 1 of 3 treatment arms: Arm 1: 3TC plus ZDV plus IDV. Arm 2: 3TC plus ZDV plus IDV plus EFV. Arm 3: 3TC plus ZDV plus IDV plus NFV. Patients are followed for at least 72 weeks \[AS PER AMENDMENT 2/16/99: 96 weeks\] beyond the enrollment of the last patient. Patients who experience virologic relapse will have the option of continuing randomized study medications, switching to Step 2 treatment, switching to another ACTG study, or seeking best available therapy for the remaining weeks of the study. Step 2 treatment consists of abacavir or 2 NNRTIs plus efavirenz plus amprenavir or another protease inhibitor. \[AS PER AMENDMENT 4/3/00: Optimally, Step 2 treatment regimens should contain 3 or 4 drugs to which the virus is susceptible. If this is not possible, a drug to which the virus is partially susceptible is acceptable, but a drug to which the virus is resistant should not be included.\]