Background: Hereditary angioedema (HAE) may occur at or spread to multiple anatomic locations during an acute attack. Recombinant human C1 esterase inhibitor (rhC1-INH) is approved for treating acute HAE attacks.
Objective: To examine the time to the beginning of symptom relief with rhC1-INH by attack location.
Methods: Data for patients ≥12 years of age with an acute HAE attack who received rhC1-INH 50 IU/kg or placebo were pooled from two double-blind clinical trials with open-label extensions. The time to the beginning of symptom relief was defined as the first time point that the visual analog scale severity score at an attack location decreased by ≥20 mm versus baseline, with persistence. Data were reported as median time values (95% confidence interval [CI]).
Results: For abdominal attacks, the median time to the beginning of symptom relief was 60.0 minutes (95% CI, 47.0-62.0 minutes; n = 194 attacks) with rhC1-INH versus 240.0 minutes (95% CI, 45.0-720.0 minutes; n = 15 attacks) with placebo. The median time to the beginning of symptom relief for peripheral attacks was 105.0 minutes (95% CI, 90.0-120.0 minutes; n = 169 attacks) with rhC1-INH versus 303.0 minutes (95% CI, 180.0-720.0 minutes; n = 17 attacks) with placebo. For oro-facial-pharyngeal-laryngeal attacks or urogenital attacks, the median time to the beginning of symptom relief with rhC1-INH was 64.5 minutes (95% CI, 60.0-120.0 minutes; n = 36 attacks) and 119.0 minutes (95% CI, 40.0-270.0 minutes; n = 13 attacks), respectively, versus 306.0 minutes (95% CI, 30.0-495.0 minutes; n = 6 attacks) and 320.0 minutes (n = 1 attack) with placebo.
Conclusion: In shortening the median time to the beginning of symptom relief of acute HAE attacks, rhC1-INH 50 IU/kg was efficacious, regardless of attack location.