title: Nanofiltered C1 esterase inhibitor for treatment of laryngeal attacks in patients with hereditary angioedema.
abstract: BACKGROUND
  Laryngeal edema is a life-threatening manifestation of hereditary angioedema (HAE), an autosomal-dominant disorder caused by quantitative or functional C1 esterase inhibitor (C1 INH) deficiency. The preparation of nanofiltered C1 INH (C1 INH-nf) used in this study is indicated for routine prophylaxis against angioedema attacks in the United States and for treatment, preprocedure prevention, and routine prevention of HAE in Europe. The objective of this analysis was to evaluate the effectiveness and tolerability of C1 INH-nf when used for the treatment of laryngeal attacks.
  
  
  METHODS
  A post hoc analysis of an open-label treatment study evaluated the effectiveness of C1 INH-nf in the treatment of laryngeal attacks in patients with HAE. Outcomes included unequivocal or clinical relief rates and time from treatment to onset of relief. Data were compiled from this and three other studies for post hoc dosing and tolerability analyses. In all studies, C1 INH-nf at 1000 U was administered i.v., with a second 1000-U dose given after 60 minutes if indicated.
  
  
  RESULTS
  In the open-label treatment study, 60 (50/84) and 77% (65/84) of attacks achieved unequivocal relief within 1 and 4 hours, respectively, after treatment. Time to unequivocal relief was shorter with prompt treatment. When C1 INH-nf was administered within 4 hours of symptom onset, clinical relief was achieved in 94% (45/48) of attacks within 4 hours after treatment. Of 265 attacks from the four studies, 62% received two 1000-U doses of C1 INH-nf. No serious adverse events occurring within 7 days after treatment were attributed to study drug, and only one patient required intubation after receiving C1 INH-nf (14.5 hours after symptom onset).
  
  
  CONCLUSIONS
  This analysis supports that C1 INH-nf is an effective and well-tolerated therapy for laryngeal angioedema attacks.
authors.affiliation: 1Department of Clinical Immunology and Allergy, University of California-Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Riedl
authors.forename: William R
authors.initials: WR
authors.lastname: Lumry
authors.forename: H Henry
authors.initials: HH
authors.lastname: Li
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Craig
authors.forename: David
authors.initials: D
authors.lastname: Fitts
authors.forename: Ira
authors.initials: I
authors.lastname: Kalfus
authors.forename: Marc E
authors.initials: ME
authors.lastname: Uknis
mesh_terms: D054179:Angioedemas, Hereditary / Q000188:drug therapy*; D050718:Complement C1 Inhibitor Protein / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007819:Laryngeal Edema / Q000188:drug therapy*
chemical_list: D050718:Complement C1 Inhibitor Protein