Efficacy and safety of atazanavir-based highly active antiretroviral therapy in patients with virologic suppression switched from a stable, boosted or unboosted protease inhibitor treatment regimen: the SWAN Study (AI424-097) 48-week results.

BACKGROUND: Atazanavir is a once-daily protease inhibitor (PI) for the treatment of human immunodeficiency virus (HIV) infection that has previously been studied in cohorts of treatment-naive and treatment-experienced patients. Limited data are available on the usefulness of switching from a PI-based regimen to a regimen based on a different PI, such as atazanavir, in HIV-infected patients experiencing virologic suppression but seeking regimen simplification. METHODS: The Switch to Another Protease Inhibitor (SWAN) study was a 48-week, open-label trial involving HIV-positive patients with virologic suppression who were receiving stable PI-based regimens (with or without ritonavir). Patients were randomized 2 : 1 to switch to atazanavir (400 mg per day)--or, if they were receiving tenofovir, to atazanavir-ritonavir (300/100 mg per day)--or to continue to receive their existing PI. The proportion of patients who experienced virologic rebound (defined as an HIV RNA load >or=50 copies/mL) was compared through study week 48. RESULTS: Patients either received an atazanavir-containing regimen (278 patients) or continued to receive a comparator PI-containing regimen (141 patients). The proportion of patients who experienced virologic rebound was significantly lower among those who switched to an atazanavir-containing regimen (19 [7%] of 278) than it was among those who continued to receive a comparator PI regimen (22 [16%] of 141; P=.004). Patients who switched to atazanavir therapy experienced significantly fewer total cholesterol, fasting triglyceride, and non-high density lipoprotein cholesterol elevations than did patients in the comparator PI group (P<.001); patients receiving atazanavir had comparable rates of adverse event-related discontinuation and serious adverse events. CONCLUSIONS: In patients with virologic suppression who were receiving other PIs, switching to a once-per-day regimen containing atazanavir provided better maintenance of virologic suppression (as demonstrated by significantly lower rates of virologic rebound and treatment failure than those observed with continued unmodified therapy), a comparable safety profile, and improved lipid parameters, compared with those for patients who continued their prior PI-based regimen through 48 weeks.

96-week comparison of once-daily atazanavir/ritonavir and twice-daily lopinavir/ritonavir in patients with multiple virologic failures.

BACKGROUND: In BMS Study 045, once-daily (QD) atazanavir/ritonavir (ATV/RTV) demonstrated comparable efficacy and safety to twice-daily (BID) lopinavir/ritonavir (LPV/RTV) over 48 weeks in treatment-experienced patients. Results of extended follow-up to 96 weeks are presented. METHODS: BMS Study 045 was an open-label, randomized, multi-national trial of HIV-infected patients with virologic failure on two or more prior HAART regimens designed to evaluate the efficacy and safety of ATV/RTV (300/100 mg) QD and LPV/RTV (400/100 mg) BID, each with tenofovir (300 mg) QD and one nucleoside reverse transcriptase inhibitor. The primary efficacy measure was the time-averaged difference (TAD) in reduction in HIV RNA from baseline. Secondary objectives included evaluation of safety and plasma lipid levels through week 96. RESULTS: Over 96 weeks, the ATV/RTV regimen demonstrated similar virologic efficacy to the LPV/RTV regimen. Mean reductions from baseline in HIV RNA were -2.29 and -2.08 log10 copies/ml, respectively [TAD (97.5% confidence interval): 0.14 log10 copies/ml (-0.13, 0.41)]. The LPV/RTV regimen resulted in significant increases in total cholesterol (+9%) and fasting triglycerides (+30%) in comparison with the ATV/RTV regimen, which demonstrated decreases in these parameters [-7 and -2%, respectively, (P < 0.0001)]. Grade 2-4 diarrhoea occurred less frequently in ATV/RTV patients (3%) in comparison with LPV/RTV patients (13%) (P < 0.01). Grade 3-4 elevations in bilirubin were more common in ATV/RTV patients (53%) than LPV/RTV patients (< 1%) (P < 0.0001), with no resulting discontinuations. CONCLUSIONS: Regimens containing once-daily ATV/RTV demonstrated comparable efficacy and safety, with significant reductions in total cholesterol and fasting triglycerides and improved gastrointestinal-tolerability in comparison with twice-daily regimens containing LPV/RTV over 96 weeks in treatment-experienced patients.

Atazanavir--a once-daily HIV protease inhibitor that does not cause dyslipidemia in newly treated patients: results from two randomized clinical trials.

Protease inhibitor (PI) treatment can result in dyslipidemia in a significant proportion of patients. Atazanavir (ATV) is a once-daily PI that has not been associated with clinically relevant increases in total cholesterol (TC), fasting low-density lipoprotein cholesterol (LDL-C), or fasting triglyceride (TG) concentrations. The objectives of this paper were to evaluate lipid profiles in untreated patients, and investigate the frequency and severity of dyslipidemia in the same individuals after treatment with ATV or nelfinavir (NFV) for 48 weeks. Two multinational, randomized, active-controlled, blinded trials compared the safety and efficacy of ATV and NFV in combination with two nucleoside reverse transcriptase inhibitors (NRTIs) in antiretroviral (ARV)-naive patients. Serum lipid concentrations were analyzed in patients who had available measurements both at baseline and at week 48. Patients who had missing data at either time point were not included. Lipid levels remained within baseline ranges at week 48 with ATV treatment, whereas clinically relevant elevations in TC, fasting LDL-C, and fasting TG concentrations occurred with NFV treatment. Mean changes from pre-treatment baseline in fasting LDL-C ranged from -6 percent to +6 percent in the ATV-treatment groups, and from +27 percent to +31 percent in the NFV-treatment groups. After 48 weeks, there was a substantive increase in the proportion of NFV-treated patients who would be recommended for lipid-lowering treatment by National Cholesterol Education Program (NCEP) guidelines, whereas a lesser proportion of ATV-treated patients would be recommended for lipid-lowering treatment. Atazanavir does not lead to dyslipidemia in ARV-naive patients, and may limit the need for lipid-lowering strategies to reduce the risk of cardiovascular disease.