title: Substitution of raltegravir for ritonavir-boosted protease inhibitors in HIV-infected patients: the SPIRAL study.
abstract: BACKGROUND
  Switching to raltegravir in selected patients treated with ritonavir-boosted protease inhibitors may result in similar efficacy and lower plasma lipids.
  
  
  METHODS
  SPIRAL is a 48-week multicentre, open-label trial in which HIV-infected adults with less than 50 copies/ml of plasma HIV RNA for at least the previous 6 months on ritonavir-boosted protease inhibitor-based therapy were randomized (1: 1) to switch from the ritonavir-boosted protease inhibitor to raltegravir or to continue on ritonavir-boosted protease inhibitor-based therapy. Primary endpoint was the proportion of patients free of treatment failure (noncompleter = failure) at 48 weeks. SPIRAL study was powered to show noninferior efficacy of raltegravir-based therapy with a margin of -12.5%.
  
  
  RESULTS
  Two hundred and seventy-three patients assigned to switch to raltegravir (n = 139) or to continue ritonavir-boosted protease inhibitor (n = 134) were included in the efficacy analysis. At 48 weeks, 89.2% (raltegravir-based therapy) and 86.6% (ritonavir-boosted protease inhibitor-based therapy) of the patients remained free of treatment failure [difference 2.6%; 95% confidence interval (CI) -5.2 to 10.6]. A total of 96.9% (raltegravir-based therapy) and 95.1% (ritonavir-boosted protease inhibitor-based therapy) of the patients remained free of virological failure (difference 1.8%; 95% CI -3.5 to 7.5). Switching to raltegravir was associated with significant decreases in plasma lipids and total-to-HDL cholesterol ratio relative to continuing ritonavir-boosted protease inhibitor. Severe adverse events and study drug discontinuations due to any adverse event occurred in 4 and 2% of the patients in each group.
  
  
  CONCLUSIONS
  In patients with sustained virological suppression on ritonavir-boosted protease inhibitor-based therapy, switching from ritonavir-boosted protease inhibitor to raltegravir demonstrated noninferior efficacy and resulted in a better lipid profile at 48 weeks than continuing ritonavir-boosted protease inhibitor.
authors.affiliation: Infectious Diseases Unit, Hospital Clínic-Institut d'Investigaciones Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain. esteban@fundsoriano.es
authors.forename: Esteban
authors.initials: E
authors.lastname: Martínez
authors.forename: María
authors.initials: M
authors.lastname: Larrousse
authors.forename: Josep M
authors.initials: JM
authors.lastname: Llibre
authors.forename: Felix
authors.initials: F
authors.lastname: Gutiérrez
authors.forename: Maria
authors.initials: M
authors.lastname: Saumoy
authors.forename: Antonio
authors.initials: A
authors.lastname: Antela
authors.forename: Hernando
authors.initials: H
authors.lastname: Knobel
authors.forename: Javier
authors.initials: J
authors.lastname: Murillas
authors.forename: Juan
authors.initials: J
authors.lastname: Berenguer
authors.forename: Judit
authors.initials: J
authors.lastname: Pich
authors.forename: Ignacio
authors.initials: I
authors.lastname: Pérez
authors.forename: José M
authors.initials: JM
authors.lastname: Gatell
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects / Q000379:methods; D018791:CD4 Lymphocyte Count; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D019428:HIV Integrase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D017320:HIV Protease Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011760:Pyrrolidinones / Q000009:adverse effects / Q000627:therapeutic use*; D012367:RNA, Viral / Q000097:blood; D000068898:Raltegravir Potassium; D019438:Ritonavir / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D019428:HIV Integrase Inhibitors; D017320:HIV Protease Inhibitors; D008055:Lipids; D011760:Pyrrolidinones; D012367:RNA, Viral; D000068898:Raltegravir Potassium; D019438:Ritonavir