title: Recombinant FIXFc: a novel therapy for the royal disease?
abstract: BACKGROUND
  Hemophilia B, the deficiency or complete absence of coagulation factor IX (FIX), affects an estimated 80,000 people throughout the world. Some of these individuals are managed with prophylaxis, which involves the intravenous infusion of FIX concentrate two to three times weekly to prevent bleeding. Because FIX prophylaxis remains underutilized, patients with hemophilia B are at risk for bleeding that may be severe and potentially life- or limb-threatening, and they may experience arthropathy resulting from recurrent hemarthroses.
  
  
  METHODS
  This review focuses on recent advances in therapeutic protein fusion technology as they apply to FIX deficiency. The National Library of Medicine Medline database was searched for articles containing the term 'Fc fusion proteins'.
  
  
  CONCLUSIONS
  Genetically engineered recombinant FIX fused to the Fc portion of immunoglobulin significantly extends FIX half-life, thereby decreasing the frequency of prophylactic infusions. This in turn may increase the adoption of, and adherence to, prophylaxis, leading to better outcomes for hemophilia B patients.
authors.affiliation: Rush University Medical Center, Hemophilia and Thrombophilia Center, 1653 West Congress Parkway, Chicago, IL 60612-3833, USA. lvalentino@rush.edu
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Valentino
mesh_terms: D000818:Animals; D005164:Factor IX / Q000235:genetics / Q000627:therapeutic use*; D002836:Hemophilia B / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000627:therapeutic use*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000627:therapeutic use*; D011994:Recombinant Proteins / Q000235:genetics / Q000627:therapeutic use
chemical_list: D007141:Immunoglobulin Fc Fragments; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D005164:Factor IX