title: Lopinavir/ritonavir monotherapy as maintenance treatment in HIV-infected individuals with virological suppression: results from a pilot study in Brazil.
abstract: OBJECTIVE
  The aim of the study was to evaluate the possibility of using lopinavir/ritonavir (LPV/RTV) alone as maintenance therapy in HIV-infected individuals with virological suppression.
  
  
  METHODS
  This was a single-armed single-centre pilot trial.
  
  
  METHODS
  Asymptomatic HIV-infected patients on highly active antiretroviral therapy (HAART) including LPV/RTV, and with plasma HIV RNA <40 copies/mL for at least 6 months, were enrolled in the study, during which they continued with LPV/RTV alone. The intention was to recruit 25 patients to be followed for 2 years. Viral failure was defined as two consecutive HIV RNA measurements >40 copies/mL. Nadir and baseline CD4 cell counts, highest ever HIV RNA load, time with undetectable viraemia before monotherapy, number of previous antiretroviral (ARV) regimens, and gene polymorphism at CYP3A4 and CYP3A5 were evaluated.
  
  
  RESULTS
  All patients (27) completed the study. Their median age was 43 years, and 66% were men. Ten patients (37%) failed to maintain virological suppression (the median time to HIV rebound was 10.5 months, with a range of 4-23 months). One patient developed full resistance to LPV and another developed neurocognitive impairment while on LPV/RTV which improved after HAART reintroduction. There were no differences between failures and nonfailures according to the analysed parameters. Patients with viral failure were successfully resuppressed.
  
  
  CONCLUSIONS
  LPV/RTV maintenance therapy was associated with 37% failure, a higher than expected failure rate. In order to ensure that unnecessary risks are not being taken in patients on LPV/RTV, this finding should be further evaluated in large randomized trials for longer periods of follow-up.
authors.affiliation: Hospital de Clinicas-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. esprinz@hcpa.ufrgs.br
authors.forename: E
authors.initials: E
authors.lastname: Sprinz
authors.forename: M B
authors.initials: MB
authors.lastname: Bay
authors.forename: R K
authors.initials: RK
authors.lastname: Lazzaretti
authors.forename: M W
authors.initials: MW
authors.lastname: Jeffman
authors.forename: V S
authors.initials: VS
authors.lastname: Mattevi
mesh_terms: D000328:Adult; D000368:Aged; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods; D001938:Brazil; D018791:CD4 Lymphocyte Count / Q000379:methods; D051544:Cytochrome P-450 CYP3A; D004334:Drug Administration Schedule; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D061466:Lopinavir; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011110:Polymorphism, Genetic / Q000187:drug effects; D011744:Pyrimidinones / Q000008:administration & dosage*; D012367:RNA, Viral; D019438:Ritonavir / Q000008:administration & dosage*; D019562:Viral Load; D014766:Viremia / Q000188:drug therapy
chemical_list: D011744:Pyrimidinones; D012367:RNA, Viral; D061466:Lopinavir; C510164:CYP3A5 protein, human; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D019438:Ritonavir