Efficacy of recombinant human C1 esterase inhibitor across anatomic locations in acute hereditary angioedema attacks

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.

To examine the time to the beginning of symptom relief with rhC1-INH by attack location.

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]).

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.

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.