ARIES 144 week results: durable virologic suppression in HIV-infected patients simplified to unboosted atazanavir/abacavir/lamivudine.

BACKGROUND

The open-label study ARIES (ClinicalTrials.gov NCT00440947) utilized a ritonavir (/r)-boosted protease inhibitor treatment simplification strategy. Antiretroviral-naïve subjects received abacavir/lamivudine (ABC/3TC) + atazanavir/ ritonavir (ATV/r) from baseline through randomization at week 36, then maintained or discontinued ritonavir for an additional 108 weeks. Non-inferiority of the unboosted regimen was demonstrated at week 84. In this optional extension phase, virologic suppression and adverse events were assessed through week 144.

METHODS

Patients were randomized at week 36 if they had confirmed HIV RNA <50 copies/mL by week 30 and no previous virologic failure (VF; defined as failure to achieve HIV RNA <400 copies/mL or confirmed rebound after achieving HIV RNA ≥400 copies/mL). Three hundred sixty-nine subjects who completed 84 weeks in ARIES participated in the extension phase and maintained their randomized regimen for an additional 60 weeks post randomization.

RESULTS

At week 144, 146/189 (77%) versus 132/180 (73%) subjects in the unboosted ATV and ATV/r groups, respectively, maintained HIV RNA <50 copies/mL. Post randomization (weeks 36-144), treatment-related grade 2-4 adverse events were more common in the ATV/r-treated (23%) compared to the ATV-treated (13%) group; the most frequently reported was increased serum bilirubin (6% of ATV-treated subjects vs 14 % of ATV/r-treated subjects). During the extension phase, 3% (11/369) of subjects met protocol-defined VF (5 ATV-treated and 6 ATV/ r-treated subjects); one ATV/r-treated subject had treatment-emergent major viral resistance-associated mutations. The median change in fasting triglycerides from baseline to week 144 was significantly different (P=.001) in the ATV-treated (-8.5 mg/dL) compared to the ATV/r-treated (28.5 mg/dL) groups.

CONCLUSIONS

These long-term study results demonstrate that ATV in combination with ABC/3TC is a potent, well-tolerated regimen in patients who have achieved initial suppression on a ritonavir-boosted regimen.