Study of Once-Daily Abacavir/Lamivudine Versus Tenofovir/Emtricitabine, Administered With Efavirenz in Antiretroviral-Naive, HIV-1 Infected Adult Subjects

Recently, the fixed-dose combinations (FDC) KIVEXA™ (abacavir/lamivudine) and TRUVADA
(tenofovir disoproxil fumarate/emtricitabine) have facilitated the usage of once-daily
regimens. However data from head-to-head randomized trials comparing these two FDCs as part
of an initial regimen are not available at present. The long-term toxicity profiles of these
regimens are of particular importance, as treatment of HIV is currently life-long and
therefore, minimizing long-term toxicity and maximizing adherence and duration of regimen
maintenance are critical therapy objectives.

The primary endpoint is estimated glomerular filtration rate (GFR), as measured by the
modified diet in renal disease (MDRD) equation, a validated estimate of renal function.