The following members of the 067 Study Group participated in subject recruitment, enrollment, medical management, and data collection: William Powderly, MD, St. Louis, MO; Joseph Jemsek, MD, Huntersville, NC; Robert Eng, MD, East Orange, NJ; Dorece Norris, MD and Daniel Seekins, MD, Tampa, FL; Margaret Fischl, MD, Miami, FL; Chris Tsoukas, MD, Montreal, Canada; Livette Johnson, MD, New York, NY; Sharon Walmsley, MD, Toronto, Canada; Juan Sierra, MD, Mexico city, District Federal Mexico; Stefan Esser, MD and Essen, Germany; Prof Reinhold Schmidt, Hannover, Germany; Fernando Aiuti, MD, Rome, Italy; Alain Lafeuillade, MD, Toulon, France; Prof Jacques Reynes, Montpellier, France; Prof Daniel Vittecoq, Villejuif, France; Michele Bentata, MD, Bobigny, France; Prof Frederic Lucht, Saint Etienne, France; Miguel Jimenez Gorgolas, MD, Madrid, Spain; Juan Gonzalez Garcia, MD, Madrid, Spain; Juan Maria Gonzalez Lahoz, MD, Madrid, Spain; Pere Domingo, MD, Barcelona, Spain; Giuliano Stagni, MD, Perugia, Italy; Karam Mounzer, MD, Philadelphia, PA; Margaret Johnson, MD, London, United Kingdom; Gary L. Simon, MD,Washington, DC; Gracy McComsey, MD, Cleveland, OH; Mark Bloch, MD, Darlinghurst, Australia; Cheryl K. MacDonald, MD, Fort Worth, TX; Javier O. Morales Ramirez, MD, San Juan, Puerto Rico; Rohut Talwani, MD, Columbia, SC; Leonard Slater, MD, Oklahoma City, OK; Isidro G. Zavala Trujillo, MD, Zapopan, Jal, Mexico; Prof Jean-Michel Molina, Paris, France; Cecilia Shikuma, MD, Honolulu, HI; Prof Francisco Antunes, Lisbon, Portugal; Beatriz Grinsztejn, MD, Rio de Janeiro, Brazil; Jose Henrique Piloto, MD, Rio de Janeiro, Brazil; Flavio Telles, MD, Curitiba, Brazil; Jose Luiz Andrade, MD, Curitiba, Brazil; Waldo Belloso, MD, Buenos Aires, Argentina; Carlos Zala, MD, Buenos Aires, Argentina; Claudia Rodriguez, MD, Buenos Aires, Argentina; Sergio Lupo, MD, Santa Fe, Argentina; Elida Pallone, MD, Buenos Aires, Argentina; Angel Minguez, MD, Cordoba, Argentina; Arnaldo Casiro, MD, Buenos Aires, Argentina; Norma Luna, MD, Cordoba, Argentina; Jorge Corral, MD, Buenos Aires, Argentina; Abel Jasovich, MD, Buenos Aires, Argentina; Isabel Cassetti, MD, Buenos Aires, Argentina; Luis Noriega, MD, Santiago, Chile; Carlos Perez, MD, Santiago, Chile; MarceloWolff, MD, Santiago, Chile; Juan Echevarria, MD, Lima, Peru; Raul Salazar, MD, Lima, Peru; Andres Paredes, MD, Lima, Peru; and Frederico Rangel, MD, Recife, Brazil.Objective: The primary objective was to compare the change in fasting low-density lipoprotein (LDL) cholesterol from baseline to week 12 between patients receiving an atazanavir-containing regimen and those receiving comparator protease inhibitor (PI) regimens. Design: AI424-067 was a 48-week, open-label, randomized, prospective study of 246 patients on PI-based regimens with hyperlipidemia [fasting LDL cholesterol .130 mg/dL (.3.4 mmol/L)] and with HIV RNA ,50 copies per milliliter. Patients were randomized to switch to atazanavir (400 mg once daily) on day 1 (immediate switch) or maintain current PI regimen for the first 24 weeks, then switch to atazanavir (delayed switch). Methods: Plasma lipid levels were compared with baseline values at weeks 12, 24, and 48. Safety, viral load, and CD4 profiles were also evaluated. Results: At week 12, the mean percent changes in LDL cholesterol from baseline for the immediate-switch and delayed-switch groups were 215% and +1%, respectively (P , 0.0001). Favorable LDL cholesterol levels in the immediate-switch group were sustained through week 48. Both groups maintained comparable virologic control. Switching to atazanavir did not produce a significant change in safety or tolerability. Conclusions: A switch—either immediate or delayed—from a boosted or unboosted PI to unboosted atazanavir in patients with hyperlipidemia was associated with improvements in plasma lipid parameters without loss of virological suppression.2028-08-30