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Efficacy and safety of switching from lopinavir/r to atazanavir/r in suppressed patients receiving a LPV/r-containing HAART: ATAZIP 96-week results

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Journal of the International AIDS Society200811 (Suppl 1) :P53

  • Published:


  • Treatment Failure
  • Virologic Failure
  • Lipid Parameter
  • Drug Discontinuation
  • Virological Suppression

Purpose of the study

To compare the efficacy and safety of switching from lopinavir/r (LPV/r) to atazanavir/r (ATV/r) in suppressed patients vs. continuing a LPV/r HAART at 2 years.


Randomized, open-label 96-week trial including patients with virological suppression (<200 copies/ml; >= 6 months) on a LPV/r-containing HAART. Patients were randomized 1:1 to either continue LPV/r or switch to ATV/r. Patients with >4 PI-associated mutations and/or failed to >2 PI-containing regimens were excluded. Primary end-point: proportion of patients with treatment failure (ITT switching = failure) at 48 weeks. Virologic failure: two consecutive viral load >200 copies/ml (OT).

Summary of results

248 patients were assigned to continue LPV/r (n = 127) or to switch to ATV/r (n = 121). Baseline characteristics were balanced, including age, sex, risk for HIV infection, liver enzymes, fasting lipid profile, time on prior ARV, previous exposure to PI-containing regimens, and median CD4 (around 450 cells/mm3). 30% had available evidence of harboring one or more PI-associated mutations (with 10% showing at least one major mutation, IAS definition). Treatment failure occurred in 30% (40/127) in the LPV/r arm and in 25% (33/121) in the ATV/r arm (difference -4.2%; 95% CI from -15.6% to 7.1%). Virological failure occurred in 9% (12/127) in the LPV/r arm and in 8% (11/121) in the ATV/r arm (difference -0.36%; 95% CI from -7.6 to 6.9%). Median CD4 changes from baseline were 100.5 and 40 cells/mm3 in the LPV/r and ATV/r arm, respectively. Adverse events leading to study drug discontinuation occurred in 6% in the LPV/r arm and 5% in the ATV/r arm. Fasting TG and total cholesterol decreased significantly in the ATV/r arm, -53 and -24 mg/dL, respectively. Changes in ALT/AST were similar in both arms and significant total bilirubin elevations were frequently seen in the ATV/r arm.


Switching to ATV/r in virologically suppressed patients who were receiving a LPV/r-containing HAART provided comparable and durable efficacy with improved lipid parameters.

Authors’ Affiliations

Hospital Clinic Universitari, Barcelona, Spain
Hospital de Bellvitge, Barcelona, Spain
Hospital de Sant Pau, Barcelona, Spain
Fundacio IrsiCaixa, Barcelona, Spain
Hospital Vall d'Hebrón, Barcelona, Spain
Hospital General Universitario de Elche, Elche, Spain
Hospital del Mar, Barcelona, Spain
Hospital Gregorio Marañón, Madrid, Spain
Hospital Principe de Asturias, Madrid, Spain
Hospital Clínico San Carlos, Madrid, Spain
Hospital Clínic Universitari, Barcelona, Spain


© Mallolas et al; licensee BioMed Central Ltd. 2008

This article is published under license to BioMed Central Ltd.