A Phase II Study of the Prolongation of Virologic Success (ACTG 372A) and Options for Virologic Failure (ACTG B/C/D) in HIV-Infected Subjects Receiving Indinavir in Combination With Nucleoside Analogs: A Rollover Study for ACTG 320

Group A:

To compare the time to confirmed virologic failure (2 consecutive plasma HIV-RNA concentrations of 500 copies/ml or more) between the treatment arms: abacavir (ABC) or placebo in combination with zidovudine (ZDV), lamivudine (3TC), and indinavir (IDV). To evaluate the safety and tolerability of these treatment arms. [AS PER AMENDMENT 06/16/99: To compare the time to confirmed treatment failure, permanent discontinuation of treatment, or death between the treatment arms.] [AS PER AMENDMENT 12/27/01: Groups B, C, and D completed follow-up on March 4, 1999. Therefore, only information pertinent to Group A is applicable.]

Group B:

To compare the proportion of patients who achieve plasma HIV-1 RNA concentrations below 500 copies/ml, as assessed by the standard Roche Amplicor assay at Week 16, or to compare the absolute changes in plasma HIV-1 RNA concentrations at Week 16 across the treatment arms: ABC or approved nucleoside analogs and nelfinavir (NFV) or placebo in combination with efavirenz (EFV) and adefovir dipivoxil. To compare the safety and tolerability of these treatment arms.

Group C:

To monitor plasma HIV-1 RNA trajectory over time and determine the time to a confirmed plasma HIV-1 RNA concentration above 2,000 copies/ml on 2 consecutive determinations for patients treated with ZDV or stavudine (d4T) plus 3TC and IDV.

Group D:

To evaluate plasma HIV-1 RNA responses at Weeks 16 and 48. To evaluate the safety and tolerability of the treatment arms: ABC, EFV, adefovir dipivoxil, and NFV.

This study explores new treatment options for ACTG 320 enrollees (and, if needed, a limited number of non-ACTG 320 volunteers) who have been receiving ZDV (or d4T) plus 3TC and IDV and are currently exhibiting a range of virologic responses. By dividing the study into the corresponding, nonsequential cohorts (Groups A, B, C, D), different approaches to evaluating virologic success, i.e., undetectable plasma HIV-1 RNA levels, and virologic failure, i.e., plasma HIV-1 RNA levels of 500 copies/ml or more [AS PER AMENDMENT 12/27/01: 200 copies/ml or more], are explored while maintaining long-term follow-up of ACTG 320 patients. [AS PER AMENDMENT 12/27/01: Groups B, C, and D completed follow-up on March 4, 1999. Therefore, only information pertinent to Group A is applicable. This study will examine the question of whether intensification of therapy can prolong the virologic benefit in individuals whose plasma HIV-1 RNA concentrations have been below the limits of assay detection on ZDV (or d4T) plus 3TC plus IDV.]