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Home > Treatment > HIV Meds Quarterly > Summer 2009 > Atazanavir
Regimen Simplification: Atazanavir vs Atazanavir/Ritonavir

The ARIES study evaluated induction-maintenance strategy in which ARV-naive patients were treated with atazanavir/ritonavir (ATV/r) + abacavir/lamivudine for 36 weeks. Patients whose HIV RNA was <50 copies/mL (n = 419) at that time were randomized to discontinue ritonavir (with dosage adjustment of ATV to 400 mg once daily) or to continue the ritonavir booster. The two groups were well matched for baseline HIV RNA and CD4 levels.

At 48 weeks into the maintenance phase, HIV RNA remained <50 copies/mL in 86% of ATV recipients vs 81% of ATV/r recipients; this difference was not statistically significant. With patients whose baseline HIV RNA was >100,000 copies/mL, the findings were similar: HIV RNA remained suppressed in 87% of ATV recipients and 82% of ATV/r recipients. Mean CD4 count increases were 240 cells/µL and 259 cells/µL, respectively. Modest decreases in total cholesterol, LDL, and triglyceride levels were seen in the ATV treatment arm, whereas small increases in these values were seen in the ATV/r arm. Of the patients who experienced virologic failure (1 on the ATV arm and 7 on the ATV/r arm), none accrued primary protease mutations.

Clinical Bottom Line

In patients with virologic suppression on an initial regimen of ATV/r + abacavir/lamivudine, simplification to unboosted ATV + these NRTIs is likely to maintain regimen efficacy.


Squires K, Young B, DeJesus E, et al. Similar efficacy and tolerability of atazanavir (ATV) compared to ATV/ritonavir (RTV, r), each in combination with abacavir/lamivudine (ABC/3TC), after initial suppression with ABC/3TC + ATV/r in HIV-1 infected patients: 84 week results of the ARIES trial. In: Program and abstracts of the 5th IAS Conference on HIV Pathogenesis, Treatment, and Prevention; July 19-22, 2009; Cape Town, South Africa. Abstract WELBB103.