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 log(10) copies/ml, respectively ITAD (97.5% confidence interval): 0.14 log(10) 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. (C) 2006 Lippincott Williams & Wilkins.