Fosamprenavir/r vs atazanvir/r in treatment-naive patients

Simon Collins, HIV i-Base

Keith Pappa presented 48 week results from a GSK study in 106 treatment-naive patients randomised to either fosamprenavir/r (1400mg/100mg QD) or atazanavir/r (300mg/100mg QD), both with tenofovir plus FTC backbone.

While the study was not powered for a difference between these two arms, the atazanavir group showed greater suppression to both <400 copies/mL (87 vs 79%) and for the primary endpoint of suppression to <50 copies/mL (83% vs 75%).

Lipid increases from baseline included: total cholesterol +11 vs + 27 mg/dL; triglycerides +34 vs +6 mg/dL; LDL +4 vs +4 mg/dL; and HDL +5 vs +11 mg/dL in the fosamprenavir/r and atazanavir/r arms respectively.


Whatever the power of the study, (p-values for the statistical virological difference between the two arms was p=0.3), these results do not appear to show any benefit of using fosamprenavir over atazanavir.


Smith K, Weinberg W, DeJesus E et al. Once-daily ritonavir (100mg) boosting of fosamprenavir (FPV/r) or atazanavir (ATZ/r) withtenofovir(TDF)/emtricitabine(FTC) in antiretroviral-naive HIV-infected patients: 48-week safety/efficacy results from COL103952 (ALERT). 4thIAS 2007. Abstract WEPEB023.

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