title: Novel drug classes: entry inhibitors [enfuvirtide, chemokine (C-C motif) receptor 5 antagonists].
abstract: OBJECTIVE
  To provide an update on viral entry inhibitors focusing on recently published clinical trials, the routine clinical use of these medications, and future drug candidates.
  
  
  RESULTS
  Clinical trials and cohort studies support the efficacy of both enfuvirtide and maraviroc in the management of treatment-experienced patients. In clinical practice, tolerability issues, particularly injection site reactions, have limited the clinical use of enfuvirtide. Providers should be aware of the need for tropism determination and dosing requirements for maraviroc. The novel chemokine (C-C motif) receptor 5-blocking agent, vicriviroc, has shown promise and is currently in phase III clinical development.
  
  
  CONCLUSIONS
  The rapid pace of scientific discovery and pharmaceutical development has led to the release of several novel and well tolerated antiretroviral agents, with activity against resistant isolates. Entry inhibitors remain a critical therapeutic option for treatment-experienced patients. Providers need to be familiar with these agents, and future drug development should be encouraged.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: McKinnell
authors.forename: Michael S
authors.initials: MS
authors.lastname: Saag
mesh_terms: D065100:CCR5 Receptor Antagonists; D003510:Cyclohexanes / Q000494:pharmacology / Q000627:therapeutic use; D000077560:Enfuvirtide; D006678:HIV / Q000187:drug effects*; D015700:HIV Envelope Protein gp41 / Q000494:pharmacology / Q000627:therapeutic use; D023581:HIV Fusion Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D000077592:Maraviroc; D010446:Peptide Fragments / Q000494:pharmacology / Q000627:therapeutic use; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use; D011743:Pyrimidines / Q000494:pharmacology / Q000627:therapeutic use; D016879:Salvage Therapy; D014230:Triazoles / Q000494:pharmacology / Q000627:therapeutic use; D053586:Virus Internalization / Q000187:drug effects
chemical_list: D065100:CCR5 Receptor Antagonists; D003510:Cyclohexanes; D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010446:Peptide Fragments; D010879:Piperazines; D011743:Pyrimidines; D014230:Triazoles; D000077560:Enfuvirtide; D000077592:Maraviroc; C486781:vicriviroc