After 48 weeks of treatment, darunavir/ritonavir and atazanavir/ritonavir had similar impacts on lipid and glucose values. People in both arms of this randomized trial generally perceived improved body changes through 48 weeks of therapy.

The protease inhibitor (PI) atazanavir has established a relatively good safety profile, with minimal impact on cholesterol and triglycerides. To compare potential side effects of ritonavir-boosted atazanavir and ritonavir-boosted darunavir, another PI, US researchers planned this open-label randomized exploratory study. They randomized antiretroviral-naive enrollees to receive one or the other PI combination, each with fixed-dose tenofovir/emtricitabine. The primary endpoint was change in triglycerides at treatment week 12.

Thirty-two of 34 people randomized to darunavir/ritonavir completed 12 weeks of treatment, as did 30 of 31 randomized to atazanavir/ritonavir. Twenty-nine of 34 (85%) in the darunavir group and 25 of 31 (81%) in the atazanavir group completed 48 weeks.

After 12 weeks of treatment, average total cholesterol rose more with darunavir than atazanavir (20.3 versus 4.6 mg/dL). At the same point, apolipoprotein A1 (a component of “good” HDL cholesterol) climbed an average of 10.7 mg/dL in the darunavir group while falling 0.7 mg/dL in the atazanavir group.

At treatment week 48 there were no clinically relevant differences between treatment groups in cholesterol, triglycerides, fasting glucose, or insulin sensitivity. Changes in adipose tissue (fat) were small and comparable in the darunavir and atazanavir groups. Study participants’ perceptions of body changes generally improved with either PI.

The authors conclude that “this first pilot comparison in HIV-1-infected subjects suggests that darunavir/ritonavir has a metabolic profile similar to atazanavir/ritonavir over 48 weeks of treatment.”

By Mark Mascolini

Source: Judith A. Aberg, Pablo Tebas, Edgar Turner Overton, Samir K. Gupta, Paul E. Sax, Alan Landay, Ron Falcon, Robert Ryan, Guy De La Rosa. Metabolic effects of darunavir/ritonavir versus atazanavir/ritonavir in treatment-naive, HIV type 1-infected subjects over 48 weeks. AIDS Research and Human Retroviruses. 2012; 28: 1184-1195.

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