title: The LOPSAQ study: 48 week analysis of a boosted double protease inhibitor regimen containing lopinavir/ritonavir plus saquinavir without additional antiretroviral therapy.
abstract: OBJECTIVE
  To evaluate the virological, immunological and clinical responses to the boosted double protease inhibitor (PI) regimen combination of lopinavir/ritonavir and saquinavir ('LOPSAQ') without reverse transcriptase inhibitors (RTI) in HIV-positive patients who have few viable RTI treatment options.
  
  
  METHODS
  Cohort study of 128 heavily pre-treated patients who were experiencing therapy failure on their current regimen due to RTI resistance and/or systemic toxicities. Patients with PI-resistance mutations or RTI toxicity underwent a structured treatment interruption (STI) (n=76) until virus reverted to wild-type or until resolution of toxicity symptoms. Baseline was defined as the time point when lopinavir/ritonavir plus saquinavir therapy was initiated. Virological response was defined as viral load<400 copies/mL at week 48.
  
  
  RESULTS
  A total of 78 (61%) patients experienced a virological response to therapy (ITT). Median viral load at baseline was 5.06 log10 copies/mL; at week 48 median was 2.16 log10 copies. Median CD4 at week 48 was 280 cells/mm3 compared with 172 cells at baseline. At week 48, 78/128 patients were still on therapy. In univariable analyses, significant predictors of virological response included higher CD4 count (P<0.001), lower viral load (P=0.002), less PI-experience (P=0.006) at baseline and fewer PI-resistance mutations (P=0.043) at end of prior failing regimen; in the multivariable analysis only higher CD4 count at baseline (P=0.009) and fewer number of drugs previously taken (P=0.003) could be specified as independent predictors for response.
  
  
  CONCLUSIONS
  The combination of lopinavir/ritonavir and saquinavir without RTIs is a potential option as salvage therapy for patients experiencing therapy failure due to RTI resistance or toxicity. This regimen may not be suitable for patients with very low baseline CD4 cell counts, very broad antiretroviral therapy experience or extensive PI-resistance mutations.
authors.affiliation: Medical HIV Treatment & Research Unit, Hospital of the Johann Wolfgang Goethe University, Frankfurt, Germany.
authors.forename: Schlomo
authors.initials: S
authors.lastname: Staszewski
authors.forename: Errol
authors.initials: E
authors.lastname: Babacan
authors.forename: Christoph
authors.initials: C
authors.lastname: Stephan
authors.forename: Annette
authors.initials: A
authors.lastname: Haberl
authors.forename: Amina
authors.initials: A
authors.lastname: Carlebach
authors.forename: Peter
authors.initials: P
authors.lastname: Gute
authors.forename: Stephan
authors.initials: S
authors.lastname: Klauke
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Hermschulte
authors.forename: Martin
authors.initials: M
authors.lastname: Stuermer
authors.forename: Brenda
authors.initials: B
authors.lastname: Dauer
mesh_terms: D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015331:Cohort Studies; D004347:Drug Interactions; D005260:Female; D006678:HIV / Q000235:genetics / Q000254:growth & development*; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D017320:HIV Protease Inhibitors / Q000008:administration & dosage*; D006801:Humans; D061466:Lopinavir; D008297:Male; D008875:Middle Aged; D011744:Pyrimidinones / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D019438:Ritonavir / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D016879:Salvage Therapy; D019258:Saquinavir / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D019562:Viral Load
chemical_list: D017320:HIV Protease Inhibitors; D011744:Pyrimidinones; D061466:Lopinavir; D019258:Saquinavir; D019438:Ritonavir