title: C1 esterase inhibitor concentrate in 1085 Hereditary Angioedema attacks--final results of the I.M.P.A.C.T.2 study.
abstract: BACKGROUND
  The placebo-controlled study International Multicentre Prospective Angioedema C1-INH Trial 1 (I.M.P.A.C.T.1) demonstrated that 20 U/kg C1 esterase inhibitor (C1-INH) concentrate (Berinert®; CSL Behring, Marburg, Germany) is effective in treating acute abdominal and facial Hereditary Angioedema (HAE) attacks.
  
  
  METHODS
  I.M.P.A.C.T.2 was an open-label extension study of I.M.P.A.C.T.1 to evaluate the safety and efficacy of long-term treatment with 20 U/kg C1-INH for successive HAE attacks at any body location. Efficacy outcomes included patient-reported time to onset of symptom relief (primary) and time to complete resolution of all symptoms (secondary), analysed on a per-patient and per-attack basis. Safety assessments included adverse events, vital signs, viral safety and anti-C1-INH antibodies.
  
  
  RESULTS
  During a median study duration of 24 months, 1085 attacks were treated in 57 patients (10-53 years of age). In the per-patient analysis, the median time to onset of symptom relief was 0.46 h and was similar for all types of attacks (0.39-0.48 h); the median time to complete resolution of symptoms was 15.5 h (shortest for laryngeal attacks: 5.8 h; 12.8-26.6 h for abdominal, peripheral and facial attacks). Demographic factors, type of HAE, intensity of attacks, time to treatment, use of androgens and presence of anti-C1-INH antibodies had no clinically relevant effect on the efficacy outcomes. There were no treatment-related safety concerns. No inhibitory anti-C1-INH antibodies were detected in any patient.
  
  
  CONCLUSIONS
  A single dose of 20 U/kg C1-INH concentrate is safe and provides reliable efficacy in the long-term treatment of successive HAE attacks at any body location.
authors: Penn State University College of Medicine, Hershey, PA 17033, USA. tcraig@hmc.psu.edu
authors: T J
authors: TJ
authors: Craig
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authors: Bewtra
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authors: Bahna
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authors: Machnig
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authors: Keinecke
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authors: Wasserman
mesh_terms: D000293:Adolescent; D000328:Adult; D054179:Angioedemas, Hereditary / Q000188:drug therapy*; D000906:Antibodies / Q000276:immunology; D002648:Child; D050718:Complement C1 Inhibitor Protein / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000906:Antibodies; D050718:Complement C1 Inhibitor Protein