METHODS: We analyzed the outcome of HAE attacks treated with rhC1-INH and their occurrence after dosing during erythema marginatum (EM), or before medical procedures. The patients were treated at home with 2100 U rhC1-INH per occasion. They recorded the study indices, any side effects, symptom severity, and patient satisfaction.
RESULTS: 421 HAE attacks occurred in 7 patients. RhC1-INH was administered 90.0 (0.0-2910.0) [median (min-max)] minutes after the onset of the attacks with a severity (upon injecting) of 62.0 (10.0-99.0) on VAS. The symptoms improved within 60.0 (0.0-1320.0) minutes; complete resolution took 820.0 (60.0-4320.0) minutes. Time from the onset of the attack to dosing with rhC1-INH correlated with time to the nadir of worsening (R=0.1929, p<0.0001), to the beginning of improvement (R=0.2370 p<0.0001), and to the complete resolution of symptoms (R=0.3322, p<0.0001). A second and a third injection of rhC1-INH was necessary in 12 and 1 attacks, respectively. RhC1-INH was administered as prevention before medical procedures in eight, and during EM in eleven cases. None of these was followed by a HAE attack. Recurrence of the attack, or drug-related systemic adverse events did not occur. Mean VAS score of patient satisfaction was 93.9.
CONCLUSIONS: Acute treatment with rhC1-INH was an effective and well-tolerated; it prevented the development of HAE attacks when administered during EM, or before medical procedures. Early intervention resulted in better outcomes.