title: Boosted lopinavir- versus boosted atazanavir-containing regimens and immunologic, virologic, and clinical outcomes: a prospective study of HIV-infected individuals in high-income countries.
abstract: BACKGROUND
  Current clinical guidelines consider regimens consisting of either ritonavir-boosted atazanavir or ritonavir-boosted lopinavir and a nucleoside reverse transcriptase inhibitor (NRTI) backbone among their recommended and alternative first-line antiretroviral regimens. However, these guidelines are based on limited evidence from randomized clinical trials and clinical experience.
  
  
  METHODS
  We compared these regimens with respect to clinical, immunologic, and virologic outcomes using data from prospective studies of human immunodeficiency virus (HIV)-infected individuals in Europe and the United States in the HIV-CAUSAL Collaboration, 2004-2013. Antiretroviral therapy-naive and AIDS-free individuals were followed from the time they started a lopinavir or an atazanavir regimen. We estimated the 'intention-to-treat' effect for atazanavir vs lopinavir regimens on each of the outcomes.
  
  
  RESULTS
  A total of 6668 individuals started a lopinavir regimen (213 deaths, 457 AIDS-defining illnesses or deaths), and 4301 individuals started an atazanavir regimen (83 deaths, 157 AIDS-defining illnesses or deaths). The adjusted intention-to-treat hazard ratios for atazanavir vs lopinavir regimens were 0.70 (95% confidence interval [CI], .53-.91) for death, 0.67 (95% CI, .55-.82) for AIDS-defining illness or death, and 0.91 (95% CI, .84-.99) for virologic failure at 12 months. The mean 12-month increase in CD4 count was 8.15 (95% CI, -.13 to 16.43) cells/µL higher in the atazanavir group. Estimates differed by NRTI backbone.
  
  
  CONCLUSIONS
  Our estimates are consistent with a lower mortality, a lower incidence of AIDS-defining illness, a greater 12-month increase in CD4 cell count, and a smaller risk of virologic failure at 12 months for atazanavir compared with lopinavir regimens.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Cain
authors.forename: Andrew
authors.initials: A
authors.lastname: Phillips
authors.forename: Ashley
authors.initials: A
authors.lastname: Olson
authors.forename: Caroline
authors.initials: C
authors.lastname: Sabin
authors.forename: Sophie
authors.initials: S
authors.lastname: Jose
authors.forename: Amy
authors.initials: A
authors.lastname: Justice
authors.forename: Janet
authors.initials: J
authors.lastname: Tate
authors.forename: Roger
authors.initials: R
authors.lastname: Logan
authors.forename: James M
authors.initials: JM
authors.lastname: Robins
authors.forename: Jonathan A C
authors.initials: JA
authors.lastname: Sterne
authors.forename: Ard
authors.initials: A
authors.lastname: van Sighem
authors.forename: Peter
authors.initials: P
authors.lastname: Reiss
authors.forename: James
authors.initials: J
authors.lastname: Young
authors.forename: Jan
authors.initials: J
authors.lastname: Fehr
authors.forename: Giota
authors.initials: G
authors.lastname: Touloumi
authors.forename: Vasilis
authors.initials: V
authors.lastname: Paparizos
authors.forename: Anna
authors.initials: A
authors.lastname: Esteve
authors.forename: Jordi
authors.initials: J
authors.lastname: Casabona
authors.forename: Susana
authors.initials: S
authors.lastname: Monge
authors.forename: Santiago
authors.initials: S
authors.lastname: Moreno
authors.forename: Rémonie
authors.initials: R
authors.lastname: Seng
authors.forename: Laurence
authors.initials: L
authors.lastname: Meyer
authors.forename: Santiago
authors.initials: S
authors.lastname: Pérez-Hoyos
authors.forename: Roberto
authors.initials: R
authors.lastname: Muga
authors.forename: François
authors.initials: F
authors.lastname: Dabis
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Vandenhende
authors.forename: Sophie
authors.initials: S
authors.lastname: Abgrall
authors.forename: Dominique
authors.initials: D
authors.lastname: Costagliola
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Hernán
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods*; D000069446:Atazanavir Sulfate / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D003299:Cooperative Behavior; D019049:Developed Countries; D005060:Europe; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans; D061466:Lopinavir / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome; D014481:United States; D019562:Viral Load; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D061466:Lopinavir; D000069446:Atazanavir Sulfate
keywords: HIV; atazanavir; lopinavir; mortality; observational studies