The time to beginning of relief of symptoms has been assessed by using a patient-reported visual analogue scale ("VAS") ranging from 0 mm (no symptoms at all) to 100 mm (extremely disabling). Time to beginning of relief of symptoms at the location that showed first "VAS" score decrease of at least 20 mm from baseline score (t= 0 min) to the next assessment time-point). Assessment time-points were taken on pre-scheduled time-points after drug administration: baseline (0 minutes), 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 8 hours, 12 hours, 16 hours, 24 hours, 48 hours. Time to beginning of relief has been calculated as median time, by using the exact time-points on which each assessment was performed.

Average number of HAE attacks normalized to a 28 day period

Prior to the treatment period, patients enrolled in the study, were asked about the amount of "HAE" attacks in the past 2 years, (calculated to attacks/week), this number is defined as "Historical". During the treatment period, patients received a dose of 50 IU/kg of "rhC1INH" administered by slow "IV" injection over 4 to 5 minutes, once a week during an eight week period. The amount of attacks during this period is defined as "Prophylaxis" (calculated to attacks/week).