Time to response outcomes in hereditary angioedema

Abstract

In their recent article, Wasserman et al 1 Wasserman R.L. Levy R.J. Bewtra A.K. et al. Prospective study of C1 esterase inhibitor in the treatment of successive acute abdominal and facial hereditary angioedema attacks. Ann Allergy Asthma Immunol. 2011; 106: 62-68 Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar make an important contribution to the rapidly expanding field of therapeutic management of acute attacks of hereditary angioedema (HAE), providing data on time to onset of symptom relief and time to complete symptom resolution for abdominal and facial attacks treated with C1 esterase inhibitor (C1-INH). However, in comparing their study results with those of placebo-controlled trials of other products, the authors present a misleading comparison of C1-INH with ecallantide—misleading in that it is based on incomparable measures. Wasserman et al compare the median time to onset of relief for C1-INH (19.8 minutes) and for icatibant (48 minutes). 1 Wasserman R.L. Levy R.J. Bewtra A.K. et al. Prospective study of C1 esterase inhibitor in the treatment of successive acute abdominal and facial hereditary angioedema attacks. Ann Allergy Asthma Immunol. 2011; 106: 62-68 Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar However, the time cited for ecallantide (165 minutes) corresponds to the median time to significant improvement (defined as time to complete or near-complete symptom resolution), 2 Cicardi M. Levy R.J. McNeil D.L. et al. Ecallantide for the treatment of acute attacks in hereditary angioedema. N Engl J Med. 2010; 363: 523-531 Crossref PubMed Scopus (258) Google Scholar which would be more appropriately compared with the median time to complete resolution for C1-INH (11.0 hours). 1 Wasserman R.L. Levy R.J. Bewtra A.K. et al. Prospective study of C1 esterase inhibitor in the treatment of successive acute abdominal and facial hereditary angioedema attacks. Ann Allergy Asthma Immunol. 2011; 106: 62-68 Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar Prospective study of C1 esterase inhibitor in the treatment of successive acute abdominal and facial hereditary angioedema attacksAnnals of Allergy, Asthma & ImmunologyVol. 106Issue 1PreviewHereditary angioedema (HAE) is a rare disorder characterized by a quantitative or functional deficiency of C1 esterase inhibitor (C1-INH), resulting in periodic attacks of acute edema at various body locations. The symptoms of these painful attacks can be treated effectively with C1-INH concentrate. Full-Text PDF Author ResponseAnnals of Allergy, Asthma & ImmunologyVol. 106Issue 4PreviewWe agree that direct comparisons of different measures of response to different hereditary angioedema (HAE) treatments are complicated by the different end points used in the reported studies, patient variability, and the inherently subjective nature of the outcomes studied. Additionally, variations in response time by attack site may occur.1 The study populations in whom these treatments were tested were not identical, adding to the difficulty in comparison. These limitations are well understood and were noted in our report. Full-Text PDF