Effect on Metabolic Values after Switching from Lopinavir/ritonavir (Kaletra) to Atazanavir (Reyataz)

Protease inhibitor (PI)-based HAART regimens are recognized as both effective and durable, and are often recommended as first-line therapy for treatment-naive people with HIV. However, there are concerns about major long-term toxicities associated with PIs, primarily metabolic complications. These include hyperlipidemia (elevated blood fat levels), hyperglycemia (elevated triglycerides), and body shape changes.

Among the PIs, atazanavir (Reyataz) appears to have the most favorable metabolic profile. In the current study, presented at the 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention in Sydney, Australia (July 22-25, 2007), Spanish researchers at Hospital Carlos III in Madrid assessed the potential benefit of replacing lopinavir/ritonavir (Kaletra) with an atazanavir-based regimen in HIV patients whose virus was fully suppressed.

In the Simplification LOpinavir to ATazanavir Trial (SLOAT), patients receiving lopinavir/ritonavir for more than 6 months and with undetectable HIV RNA either continued therapy with lopinavir/ritonavir or replaced it with atazanavir. After 12 months of follow up, measures of total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides (TG), and glucose were compared for both groups of patients.

Results

• A total of 186 patients on lopinavir/ritonavir with HIV RNA < 50 copies/ml for longer then 6 months were identified.

• Overall, 100 switched to atazanavir (51 to atazanavir/ritonavir 300/100 mg once daily and 49 to atazanavir 400 mg once daily) and 86 stayed on lopinavir/ritonavir.

• All patients received the PI along with 2 NRTIs.

• At baseline, median total cholesterol and TG levels were significantly higher in the atazanavir group.

• There were no significant differences between the two groups in median age, route of infection, or hepatitis B or C serostatus.

• Significant reductions in median total cholesterol (-19 mg/dl) and TG (-80 mg/dl) (P < 0.001) levels were observed 12 months after switching to atazanavir, while it remained stable in the lopinavir/ritonavir arm.

• Greater reductions in total cholesterol and TG levels in patients on atazanavir were seen with and without ritonavir.

Conclusion

Based on these findings, the study authors concluded that the switch from lopinavir/ritonavir to atazanavir/ritonavir "provides an overall significant reduction in total cholesterol and TG levels." However, they noted "no significant benefit" on glucose, HDL cholesterol, or LDL cholesterol.

Hospital Carlos III, Infectious Diseases, Madrid, Spain.

08/24/07

Reference
G Ramírez-Olivencia, A Ruiz-Sancho, L Martín-Carbonero, and others. Metabolic results in the Simplification LOpinavir to ATazanavir Trial (SLOAT). 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention. July 22-25, 2007. Sydney, Australia. Abstract (poster) TUPEB071.