Amprenavir in combination with lamivudine and zidovudine versus lamivudineand zidovudine alone in HIV-1-infected antiretroviral-naive adults

Objectives: To compare the antiviral activity and safety of a new protease inhibitor, amprenavir (141W94) in combination with lamivudine and zidovudin e, versus lamivudine and zidovudine alone in HIV-1 infected, antiretroviral -naive subjects. Design: Subjects (n-232) with a CD4 T cell count of greater than or equal t o 200 cells/mm(3), plasma HIV-1 RNA levels of greater than or equal to 1000 0 copies/ml, and less than or equal to4 weeks of prior nucleoside antiretro viral therapy, were stratified according to baseline plasma HIV-1 RNA level (10000-30000; 30000-100000; or >100000 copies/ml), Subjects received doubl e-blind treatment with either 1200 mg amprenavir twice daily in combination with lamivudine (150 mg twice daily) and zidovudine (300 mg twice daily) ( amprenavir/lamivudine/zidovudine) or matched placebo, lamivudine and zidovu dine for 10 weeks. Thereafter, subjects with confirmed plasma HIV-1 RNA lev els of greater than or equal to 400 copies/ml could add open-label amprenav ir or switch to other antiretrovirals and continue treatment for up to a mi nimum of 48 weeks. The primary endpoint of the study was defined as the pro portion of subjects with plasma HIV-1 RNA of <400 copies/ml at 48 weeks. Re sults: At 48 weeks, a significantly greater proportion of amprenavir/lamivu dine/zidovudine subjects had plasma HIV-1 RNA levels <400 copies/ml than la mivudine/zidovudine subjects in the overall population: 41 versus 3% (inten t-to-treat missing equals failure analysis) (P<0.001); 93 versus 42% (as-tr eated analysis) (P<0.001); and within each of the three randomization strat a (P<0.001), Subjects on amprenavir/lamivudine/zidovudine experienced longe r time to event (permanent discontinuation of randomized therapy or viral r ebound) than those on lamivudine/zidovudine (median of 33 versus 13 weeks; P<0.001). A significantly greater incidence of drug-related nausea, vomitin g, rash and oral/perioral paresthesia was observed with amprenavir/lamivudi ne/zidovudine than with lamivudine/zidovudine. Conclusions: Amprenavir in combination with lamivudine and zidovudine, has potent and durable antiviral activity in antiretroviral-naive subjects over 48 weeks. Amprenavir was safe and generally well tolerated.