title: Randomized study of dual versus single ritonavir-enhanced protease inhibitors for protease inhibitor-experienced patients with HIV.
abstract: OBJECTIVE
  To compare activity and safety of a regimen containing lopinavir/ritonavir (LPV/r) + fosamprenavir (FPV) to regimens with LPV/r or FPV + r and to test the hypothesis that a ritonavir-enhanced dual protease inhibitor (PI) regimen has better antiviral activity.
  
  
  METHODS
  This study was a multicenter, open-label, randomized study. HIV-infected adults with prior PI failure were selectively randomized based on prior PI experience to either LPV/r, FPV + r, or LPV/r + FPV. All patients received tenofovir DF and 1 to 2 nucleoside reverse transcriptase inhibitors.
  
  
  RESULTS
  Baseline characteristics were similar across arms. Study enrollment and follow-up were stopped early (N = 56) because pharmacokinetic analyses showed significantly lower LPV and FPV exposures in the dual-PI arm. At Week 24, proportions achieving >1 log10 decline in HIV RNA or <50 copies/mL in the dual-PI versus single-PI arms combined were 75% vs. 61% in intent-to-treat (ITT, p = .17) and 100% vs. 64% in as-treated (AT) analyses (p = .02), respectively. Median CD4+ T cell/mm3 increases were 81 vs. 41 (ITT, p = .4) and 114 vs. 43 (AT, p = .08), respectively. Clinical events and toxicity rates were not different between arms.
  
  
  CONCLUSIONS
  The trial was unable to show a difference between dual versus single PIs in ITT analyses but favored dual PIs in AT analyses.
authors.affiliation: University of Washington School of Medicine and Harborview Medical Center, Seattle, Washington 98104, USA. acollier@u.washington.edu
authors.forename: Ann C
authors.initials: AC
authors.lastname: Collier
authors.forename: Camlin
authors.initials: C
authors.lastname: Tierney
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Downey
authors.forename: Susan H
authors.initials: SH
authors.lastname: Eshleman
authors.forename: Angela
authors.initials: A
authors.lastname: Kashuba
authors.forename: Karin
authors.initials: K
authors.lastname: Klingman
authors.forename: Emanuel N
authors.initials: EN
authors.lastname: Vergis
authors.forename: Gary E
authors.initials: GE
authors.lastname: Pakes
authors.forename: James F
authors.initials: JF
authors.lastname: Rooney
authors.forename: Alex
authors.initials: A
authors.lastname: Rinehart
authors.forename: John W
authors.initials: JW
authors.lastname: Mellors
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives; D000293:Adolescent; D000328:Adult; D002219:Carbamates / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D004359:Drug Therapy, Combination; D005260:Female; D005663:Furans; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects*; D006801:Humans; D061466:Lopinavir; D008297:Male; D008875:Middle Aged; D010755:Organophosphates / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D063065:Organophosphonates / Q000008:administration & dosage; D011744:Pyrimidinones / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D012367:RNA, Viral / Q000097:blood; D019438:Ritonavir / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D013449:Sulfonamides / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D000068698:Tenofovir; D019562:Viral Load
chemical_list: D002219:Carbamates; D005663:Furans; D017320:HIV Protease Inhibitors; D010755:Organophosphates; D063065:Organophosphonates; D011744:Pyrimidinones; D012367:RNA, Viral; D013449:Sulfonamides; D061466:Lopinavir; D000068698:Tenofovir; D000225:Adenine; D019438:Ritonavir; C426859:fosamprenavir