BMS reports on atazanavir efficacy and safety in treatment experienced patients

Graham McKerrow, HIV i-Base

Two registrational studies were presented to the conference by Bristol-Myers Squibb (BMS) researchers looking at the safety and efficacy of once-a-day doses of the protease inhibitor (PI) atazanavir (ATV, Reyataz) in patients who had experienced virological failure with prior regimens.

L Nieto-Cisneros and colleagues presented the 24-week results of the multinational BMS043 study comparing the efficacy, lipid profile and safety of non-boosted ATV versus lopinavir/ritonavir (LPV/RTV) in combination with two NRTIs in patients who have experienced virological failure with prior PI-containing regimens. [1]

The researchers report significant virological responses for both regimens with a greater decrease in RNA for LPV/RTV versus ATV (mean changes from baseline (SE), HIV RNA (log10 c/ml) –2.11 (0.09) versus –1.67 (0.08) and for CD4 (cells/mm3) +121 (14) versus +94 (13). A post-hoc analysis showed decrease in viral load was comparable between regimens in patients without nucleoside mutations at baseline. Mean lipid changes from baseline (LDL cholesterol, total cholesterol, HDL cholesterol and triglycerides) were lower for ATV (–6%, –2%, +12%, –2%) versus LPV/RTV (+5%, +17%, +18%, +55%). Incidence of side effects was comparable between regimens.

The researchers conclude: “Significant reductions in HIV RNA and robust increases in CD4 cell counts were observed in this PI-failing, ARV-experienced population. While non-boosted ATV demonstrated less antiviral efficacy than the boosted LPV/RTV regimen, ATV had a more favourable lipid profile. ATV may be an option for some ARV-experienced patients, eg, where lipid management is a priority.”

R Badaro and colleagues are conducting and ongoing study of ATV/RTV, ATV/saquinavir (SQV) and LPV/RTV in combination with tenofovir (TFV) and another NRTI, in patients who have experienced virologic failure to multiple HAART regimens. The 16-week results of this multinational three-arm study of 350 patients report similar efficacy between ATV/RTV and LPV/RTV, with ATV/SQV having lower efficacy versus LPV/RTV. Mean total cholesterol and triglyceride changes from baseline were favourable for both ATV regimens compared to LPV/RTV. Adverse events were comparable among all regimens.

The researchers conclude: “In this highly ARV-experienced population, the efficacy of ATV/RTV QD is similar to LPV/RTV BID through 16 weeks. ATV, when boosted with RTV or combined with SQV, is safe, well-tolerated and with a more favourable lipid profile than LPV/RTV.”

References

1. Nieto-Cisneros L, Zala C, Fessel WJ et al. Antiviral efficacy, metabolic changes and safety of atazanavir (ATV) versus lopinavir/ritonavir (LPV/RTV) in combination with two NRTIs in patients who have experienced virological failure with prior PI-containing regimen(s): 24-week results from BMS AI424-043. Abstract 117.

2. Badaro R, DeJesus E, Lazzarin A, et al. Efficacy and safety of atazanavir (ATV) with ritonavir (RTV) or saquinavir (SQV) versus lopinavir/ritonavir (LPV/RTV) in combination with tenofovir (TFV) and one NRTI in patients who have experienced virologic failure to multiple HAART regimens: 16-week results from BMS AI424-045. Abstract 118.

	HIV Treatment Bulletin Vol 4 No7 August / September 2003