Safety of a C1-inhibitor concentrate in pregnant women with hereditary angioedema.

BACKGROUND: Increased estrogen levels during pregnancy can exacerbate hereditary angioedema (HAE), yet disease and treatment ramifications remain poorly studied in pregnant women. OBJECTIVE: Data from the international Berinert Patient Registry were used to evaluate outcomes of pregnancies exposed to plasma-derived, pasteurized, nanofiltered C1-inhibitor concentrate (pnfC1-INH) during routine HAE management. METHODS: This observational registry, conducted between 2010 and 2014 at 30 U.S. and 7 European sites, gathered data on 318 subjects and 15,000 pnfC1-INH infusions. Whenever possible, the subjects who used pnfC1-INH during pregnancy were followed up to term to assess neonatal outcomes and to collect maternal adverse events (AE) that occurred up to 1 month after pnfC1-INH administration. RESULTS: The registry data base included 11 pregnancies in 10 subjects who used pnfC1-INH for HAE attack treatment and/or prophylaxis (>261 doses during pregnancy). Eight pregnancies concluded in the birth of a healthy baby. Of the remaining three pregnancies: one was voluntarily terminated at 9 weeks of gestation; a second ended as a first-trimester spontaneous abortion 1 week after the subject's most recent pnfC1-INH infusion and was considered unrelated to pnf-C1INH treatment; and the third occurred in a subject who exited the registry approximately 2 months before her due date, with no further follow up. As assessed for 30 days after each pnfC1-INH infusion, there were no AEs that were considered related to pnfC1-INH therapy. CONCLUSION: Administration of pnfC1-INH during pregnancy was generally safe and not associated with any treatment-related AEs. In all registry pregnancies followed up to term, the birth of a healthy baby was reported.

Efficacy and safety of an intravenous C1-inhibitor concentrate for long-term prophylaxis in hereditary angioedema.

BACKGROUND: The plasma-derived, pasteurized, nanofiltered C1-inhibitor concentrate (pnfC1-INH) is approved in the United States as an intravenous (IV) on-demand treatment for hereditary angioedema (HAE) attacks, and, in Europe, as on demand and short-term prophylaxis. OBJECTIVE: This analysis evaluated Berinert Patient Registry data regarding IV pnfC1-INH used as long-term prophylaxis (LTP). METHODS: The international registry (2010-2014) collected prospective and retrospective usage, dosing, and safety data on individuals who used pnfC1-INH for any reason. RESULTS: The registry included data on 47 subjects (80.9% female subjects; mean age, 44.8 years), which reflected 4082 infusions categorized as LTP and a total of 430.2 months of LTP administration. The median absolute dose of pnfC1-INH given for LTP was 1000 IU (range, 500-3000 IU), with a median time interval between infusion and a subsequent pnfC1-INH-treated attack of 72.0 hours (range, 0.0-166.4 hours). Fifteen subjects (31.9%) had no pnfC1-INH-treated HAE attacks within 7 days after pnfC1-INH infusion for LTP; 32 subjects (68.1%) experienced 246 attacks, with rates of 0.06 attacks per infusion and 0.57 attacks per month. A total of 81 adverse events were reported in 16 subjects (34.0%) (0.02 events per infusion; 0.19 events per month); only 3 adverse events were considered related to pnfC1-INH (noncardiac chest pain, postinfusion headache, deep vein thrombosis in a subject with an IV port). CONCLUSION: In this international registry, IV pnf-C1-INH given as LTP for HAE was safe and efficacious, with a low rate of attacks that required pnfC1-INH treatment, particularly within the first several days after LTP administration.

Critical role of kallikrein in hereditary angioedema pathogenesis: a clinical trial of ecallantide, a novel kallikrein inhibitor.

BACKGROUND: Hereditary angioedema (HAE) is a rare, autosomal-dominant disorder caused by C1 inhibitor gene mutation. Patients with HAE experience intermittent attacks of edema affecting the oropharynx, abdomen, gastrointestinal tract, and limbs. C1 inhibitor is the primary endogenous inhibitor of the kallikrein-kinin (contact) cascade. Unregulated kallikrein activation generates bradykinin, the likely mediator of the swelling and pain characterizing HAE attacks. Ecallantide, a novel, recombinant protein, potently inhibits kallikrein. This is the first placebo-controlled assessment in human beings of a therapeutic intervention to improve symptoms of HAE attacks under the hypothesis that the contact cascade is the putative pathway responsible for HAE pathology. OBJECTIVE: To determine the safety and efficacy of ecallantide in patients with HAE. METHODS: This double-blind, placebo-controlled, ascending-dose study assessed efficacy and tolerability of ecallantide (5, 10, 20, or 40 mg/m(2) intravenously) in individuals experiencing acute HAE attacks (N = 49). Twelve patients were assigned to each dose level: 10 to ecallantide and 2 to placebo, per cohort. RESULTS: Ecallantide treatment ameliorated the symptoms of HAE attacks: 72.5% (29/40) of patients treated with ecallantide versus 25.0% (2/8) of placebo patients reported significant improvement in symptoms within 4 hours (P = .0169). Ecallantide was well tolerated at all doses. CONCLUSION: Ecallantide, a potent, specific inhibitor of plasma kallikrein, significantly improved HAE symptoms over placebo. The trial provides strong support for the role of the kallikrein-kinin cascade and its end product, bradykinin, in the pathophysiology of HAE. Further clinical trials are underway. CLINICAL IMPLICATIONS: Ecallantide is a promising new therapy for HAE attacks.