Twice-daily Trizivir versus Combivir-abacavir in antiretroviral-experienced adults with human immunodeficiency virus-1 infection: a formulation-switch trial.

Study Objective: To establish the clinical equivalence (noninferiority) of one tablet containing abacavir 300 mg-lamivudine 150 mg-zidovudine 300 mg (Trizivir) versus a tablet containing lamivudine 150 mg-zidovudine 300 mg (Combivir) given with one abacavir (ABC) 300-mg tablet, administered twice/day, in antiretroviral-experienced, human immunodeficiency virus (HIV)-1-infected patients.

Design: Randomized, open-label, parallel-group, multicenter, formulation-switch study.

Setting: Twenty seven outpatient treatment sites.