A randomized controlled trial of nanofiltered C1 inhibitor concentrate (C1INH-nf; CiINRYZE®, Lev Pharmaceuticals) for the acute treatment of HAE was recently completed. To obtain additional information about the efficacy and safety of C1INH-nf for HAE, an open-label extension study was initiated. Results of treatment for laryngeal attacks are reported here.
71 subjects with HAE were enrolled in the randomized placebo-controlled trial while 88 HAE subjects were screened and enrolled in an acute treatment open-label extension protocol. Subjects were eligible to receive open-label injections of C1INH-nf (1,000 units i.v.) for acute attacks of angioedema occurring at any location. Subjects could receive a second open-label injection of 1,000 units C1INH-nf 60 minutes after the first injection if they had not begun to improve. 24 subjects have been followed for greater than one year.
447 attacks were treated in 82 subjects (32.9% male) who had at least one attack. Number of attacks ranged from 1–57 with a mean of 5.45 ± 8.28 and a median of 3. Subjects received 1 injection for 287 attacks and 2 injections for 160 attacks. 50 laryngeal attacks in 28 subjects were treated with C1 inhibitor and the median time to improvement was 50 minutes. This was irrespective of whether subjects received open-label C1INH-nf < 4 times, ≥ 4 times, or ≥ 10 times. Of note 5 subjects in this study required narcotic rescue for persistent GI or GU pain associated with their HAE attacks. None of the subjects treated for laryngeal attacks in this study required hospitalization or intubation. There were no serious adverse events secondary to C1 INH-nf administration. In the randomized controlled trial, 15 subjects were treated for 18 laryngeal attacks and similarly did not require intubation or hospitalization.
C1INH-nf is effective and safe for the acute treatment of laryngeal HAE attacks.
These results are consistent with clinical experience in Europe and support use of C1INH-nf as the optimal treatment of acute laryngeal HAE attacks.
Ira Kalfus, Grant monies (from industry related sources) Bruce Zuraw has received grant support from Lev/Viropharma and Pharming.; Employee Glenn Tillotson is a full-time employee of ViroPharma Incorporated, he holds no stock of the company.Bruce Zuraw is a fulltime employee of University of California, in Department of Medicine in San Diego. He receives consultancy fees from Dyax, CSL Behring, Jerini and ViroPharma. He has received grant support from Lev/Viropharma and Pharming.; Consultant fee, speaker bureau, advisory committee, etc. Bruce Zuraw receives consultancy fees from Dyax, CSL Behring, Jerini and ViroPharma.Ira Kalfus is a part -time consultant to ViroPharma Incorporated, he holds stock in ViroPharma.; No Product/Research Disclosure Information