A randomized, double-blind study of triple nucleoside therapy of abacavir, lamivudine, and zidovudine versus lamivudine and zidovudine in previously treated human immunodeficiency virus type 1-infected children. The CNAA3006 Study Team

OBJECTIVES: Abacavir (ABC) is a potent inhibitor of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase. We compared the efficacy, safety, and tolerability of combination therapy with ABC, lamivudine (3TC), and zidovudine (ZDV) versus 3TC and ZDV in antiretroviral experienced HIV‐1‐infected children over 48 weeks. METHODS: Two hundred five HIV‐1‐infected children who had received previous antiretroviral therapy and had CD4(+) cell counts >/=100 cells/mm(3) were stratified by age and by previous treatment. Participants were randomly assigned to receive ABC (8 mg/kg twice daily [BID]) plus 3TC (4 mg/kg BID) and ZDV (180 mg/m(2) BID; ABC/3TC/ZDV group) or ABC placebo plus 3TC (4 mg/kg BID) and ZDV (180 mg/m(2); 3TC/ZDV group). Participants who met a protocol‐defined switch criteria (plasma HIV‐1 RNA >0.5 log(10) copies/mL above baseline at week 8 or >10 000 copies/mL after week 16) had the option to switch to open‐label ABC plus any antiretroviral combination or continue randomized therapy or withdraw from the study. RESULTS: The Kaplan‐Meier estimates (95% confidence interval) of the proportion of participants who maintained HIV‐1 RNA levels 10 000 copies/mL, a significantly higher proportion of participants in the ABC/3TC/ZDV group had HIV‐1 RNA