title: Monotherapy with boosted PIs as an ART simplification strategy in clinical practice.
abstract: BACKGROUND
  Data on the efficacy of simplifying therapy using darunavir/ritonavir and lopinavir/ritonavir monotherapy in clinical practice remain limited.
  
  
  METHODS
  A retrospective single-centre study including patients initiating darunavir/ritonavir or lopinavir/ritonavir monotherapy with a plasma HIV-1 viral load (pVL) <50 copies/mL and at least one subsequent follow-up visit. The primary endpoint was the percentage of patients remaining free of virological failure (VF; defined as a confirmed pVL >50 copies/mL or as any change in the regimen after a single determination with a pVL >50 copies/mL) during the follow-up. We also evaluated the percentage of patients remaining free of treatment failure (TF; defined as VF or the early discontinuation of monotherapy for any reason) and compared the effectiveness of the two regimens. Effectiveness was evaluated using cumulative survival analysis (at Weeks 48 and 96). Factors associated with VF and TF were analysed using Cox regression.
  
  
  RESULTS
  A total of 522 patients were included (309 receiving lopinavir/ritonavir and 213 receiving darunavir/ritonavir). The median follow-up was 64.3 (30.5-143.0) weeks. The percentage of patients free of VF and TF was 94% (95% CI 91%-96%) and 79% (95% CI 75%-82%) at 48 weeks, respectively, and 86% (95% CI 81%-89%) and 62% (95% CI 57%-67%) at 96 weeks, respectively. The risk of VF was similar for the two regimens (HR=1.0, 95% CI 0.6-1.8; P=0.962). Lopinavir/ritonavir monotherapy was associated with a 1.5-fold greater risk of TF (95% CI 1.1-2.1; P=0.012) and a 2.3-fold greater risk of discontinuation of therapy due to adverse events (95% CI 1.3-3.9; P=0.003).
  
  
  CONCLUSIONS
  The virological efficacy of darunavir/ritonavir and lopinavir/ritonavir monotherapy is high in clinical practice. Treatment discontinuation due to safety issues is more frequent with lopinavir/ritonavir.
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain Universitat Autònoma de Barcelona, Barcelona, Spain jrsantos@flsida.org.
authors.forename: José R
authors.initials: JR
authors.lastname: Santos
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Llibre
authors.affiliation: Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Berrio-Galan
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Bravo
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Miranda
authors.affiliation: IrsiCaixa Foundation, Barcelona, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Pérez-Alvarez
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain Universitat Politécnica de Catalunya, Barcelona, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Pérez-Alvarez
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain IrsiCaixa Foundation, Barcelona, Spain Universitat de Vic - Universitat Central de Catalunya, Vic, Spain.
authors.forename: Roger
authors.initials: R
authors.lastname: Paredes
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain Universitat Autònoma de Barcelona, Barcelona, Spain IrsiCaixa Foundation, Barcelona, Spain Universitat de Vic - Universitat Central de Catalunya, Vic, Spain.
authors.forename: Bonaventura
authors.initials: B
authors.lastname: Clotet
authors.affiliation: Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Moltó
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects / Q000379:methods*; D000069454:Darunavir; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1 / Q000302:isolation & purification; D006801:Humans; D061466:Lopinavir / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D012189:Retrospective Studies; D019438:Ritonavir / Q000009:adverse effects / Q000627:therapeutic use; D013449:Sulfonamides / Q000009:adverse effects / Q000627:therapeutic use; D016019:Survival Analysis; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D044966:Anti-Retroviral Agents; D013449:Sulfonamides; D061466:Lopinavir; D019438:Ritonavir; D000069454:Darunavir
keywords: NRTI-sparing regimens; darunavir/ritonavir; lopinavir/ritonavir monotherapy; routine clinical setting