A randomized trial of simplified maintenance therapy with abacavir, lamivudine, and zidovudine in human immunodeficiency virus infection

This randomized study evaluated the efficacy and tolerability of continued treatment with protease inhibitor plus nucleoside-analogue combination regimens (n = 79) or a change to the simplified regimen of abacavir-lamivudine-zidovudine (n = 84) in patients with suppressed human immunodeficiency virus type 1 (HIV-1) RNA for greater than or equal to 6 months who did not have the reverse transcriptase 215 mutation. After a median follow-up of 84 weeks, virologic failure was 6% in the continuation and 15% in the simplified group (P = .081). Previous zidovudine monotherapy or dual therapy and archived reverse transcriptase resistance mutations in HIV-1 DNA at baseline were significant predictors of failure. Study treatment was discontinued because of adverse events in 20% of the continuation and 7% of the simplified group (P = .021). Simplification to abacavir-lamivudine-zidovudine significantly decreased nonfasting cholesterol and triglyceride levels; however, this switch strategy carries a risk of virologic failure when treatment history or resistance testing suggest the presence of archived resistance mutations to the simplified regimen.