A Study of 141W94 Used Alone or in Combination With Zidovudine Plus 3TC in HIV-Infected Patients

To determine the proportion of patients whose plasma HIV-1 RNA level remains below a detectable level (less than 500/ml) after 24 weeks of study therapy with either 141W94 monotherapy or 141W94 plus zidovudine (ZDV) and lamivudine (3TC). To determine the safety and tolerability of 141W94 monotherapy and the combination of 141W94 plus 3TC in patients with HIV infection. Although dramatic inhibition of HIV-1 replication is achieved with ritonavir or indinavir monotherapy, in both cases maximum suppression required combination treatment together with nucleoside analog RT inhibitors. This study tests the hypothesis that monotherapy with 141W94 doses that result in Cmin levels far in excess of the IC90 corrected for plasma protein binding for HIV-1 can achieve the same virologic and immunologic effects in terms of magnitude and durability, as has been observed with combinations of other protease inhibitors plus nucleoside analogs. Although dramatic inhibition of HIV-1 replication is achieved with ritonavir or indinavir monotherapy, in both cases maximum suppression required combination treatment together with nucleoside analog RT inhibitors. This study tests the hypothesis that monotherapy with 141W94 doses that result in Cmin levels far in excess of the IC90 corrected for plasma protein binding for HIV-1 can achieve the same virologic and immunologic effects in terms of magnitude and durability, as has been observed with combinations of other protease inhibitors plus nucleoside analogs. In this randomized, double-blind study, patients' HIV RNA is screened 30 days prior to entry. Patients satisfying enrollment criteria must have been on a stable antiretroviral regimen for 30 days prior to study screening and remain on the same regimen until entry. Patients are stratified based on the screening HIV-1 RNA copy number obtained within 30 days of entry: 5,000 - 50,000 copies/ml versus greater than 50,000 copies/ml. In addition, patients are stratified based on previous antiretroviral use: naive versus experienced. Patients are randomized to one of 2 treatment arms: Arm A - 141W94, plus Zidovudine (ZDV) and Lamivudine (3TC) or Arm B - 141W94, plus ZDV placebo and 3TC placebo. \[AS PER AMENDMENT 8/25/97: Patients assigned to the monotherapy arm are advised to discontinue their study medication immediately and initiate antiretroviral therapy with indinavir, nevirapine, stavudine and 3TC, as outlined in ACTG 347 roll-over protocol, ACTG 373. Patients in the three-drug arm continue on study therapy.\] \[AS PER AMENDMENT 12/19/97: Patients receive study treatment for 56 weeks and are followed through week 68.\]