title: Discontinuation of enfuvirtide in heavily pretreated HIV-infected individuals.
abstract: BACKGROUND
  Enfuvirtide was shown to be highly effective in treatment- experienced patients. Data on discontinuation of enfuvirtide and switch to new antiretroviral drugs are scarce. We aimed to evaluate the efficacy and the impact of discontinuing and/or switching enfuvirtide on virologic and clinical parameters in clinical practice.
  
  
  METHODS
  All HIV-infected individuals participating in the Swiss HIV Cohort Study who were treated with enfuvirtide for at least 4 weeks in combination with an optimized background antiretroviral regimen were included in this study.
  
  
  RESULTS
  A total of 151 patients were analyzed. The median baseline CD4 cell count was 108 cells/microL (interquartile range [IQR] 50-206) and HIV RNA was 4.7 log10 copies/mL (IQR 4.1-5.2). Virologic suppression, defined as a viral load below 50 copies/mL at 12 months, was achieved by 57.6% of patients. Overall, a median CD4 cell increase of 121 cells/microL (IQR 50-189) from baseline was noted. Up to 50% of patients discontinued enfuvirtide within the first year of treatment, mainly because of the patient's choice. After discontinuation of enfuvirtide, high rates of virologic failure and clinical progression were observed, notably when CD4 cell count at stopping enfuvirtide was below 100 cells/microL and no switch to new potent antiretroviral drugs such as darunavir, maraviroc, or raltegravir was performed.
  
  
  CONCLUSIONS
  Enfuvirtide provides high virologic and immunologic response in treatment-experienced patients in the setting of clinical practice. Enfuvirtide should not be discontinued but should be replaced by new potent antiretrovirals, particularly in case of severe immunosuppression.
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland.
authors.forename: Luigia
authors.initials: L
authors.lastname: Elzi
authors.forename: Gilbert
authors.initials: G
authors.lastname: Kaufmann
authors.forename: Rainer
authors.initials: R
authors.lastname: Weber
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Fux
authors.forename: Matthias
authors.initials: M
authors.lastname: Cavassini
authors.forename: Bernard
authors.initials: B
authors.lastname: Hirschel
authors.forename: Pietro
authors.initials: P
authors.lastname: Vernazza
authors.forename: Enos
authors.initials: E
authors.lastname: Bernasconi
authors.forename: Manuel
authors.initials: M
authors.lastname: Battegay
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015331:Cohort Studies; D000077560:Enfuvirtide; D005260:Female; D006678:HIV / Q000235:genetics / Q000254:growth & development*; D015700:HIV Envelope Protein gp41 / Q000008:administration & dosage*; D023581:HIV Fusion Inhibitors / Q000008:administration & dosage*; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000008:administration & dosage*; D012367:RNA, Viral / Q000097:blood
chemical_list: D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010446:Peptide Fragments; D012367:RNA, Viral; D000077560:Enfuvirtide