12-Week Safety and Efficacy Study of BCX4161 as an Oral Prophylaxis Against HAE Attacks

An angioedema attack was defined as swelling at any location reported by participant, which had no swelling earlier. Total number of confirmed attacks during the treatment period standardized to a weekly attack-rate to adjust for the total duration of treatment. The attack rate was derived for each participant by treatment period. The weekly attack rate was equal to the total number of confirmed attacks during a treatment period divided by the duration of the treatment (in days) times 7 days.

The number of attack free days was the sum of the days during the treatment period for which participants reported no attacks.

The number of participants who reported no attacks during the 12-week treatment period.

Angioedema Activity Score (AAS) consists of 5 questions (period in which swelling occurred, physical discomfort, daily activity restriction, cosmetic disfigurement, and overall severity) to be answered for each day during which a subject experiences an HAE attack. A score between 0 (no symptoms) and 3 (Severe symptoms) was assigned to the responses for each question and the total daily score will be derived as the sum of the 5 question scores for each day during which the subject experiences a confirmed attack. Daily AAS ranged from 0 to 15 with higher scores indicating the greater disease severity. For participants who completed the study, the 84-day AAS was obtained by sum of AAS score during the treatment period and ranged from 0 (best) to 1,260 (worst).For participants who discontinued the study prematurely the 84-day AAS was obtained using the formula: Sum of AAS score of each day on treatment ∗ 84/Number of days on treatment.

Angioedema Quality of Life questionnaire (AE-QoL) consisted of 4 domains (i.e., functioning, fatigue/mood, fear/shame, and nutrition) and a total score based on a total of 17 possible responses. The results of all the responses are summed up and transformed to a scale ranging from 0 (best) to 100 (worst).

An adverse event (AE) is any untoward medical occurrence in a clinical study participant. No causal relationship with study drug or with the clinical study itself is implied. An AE could be an unfavorable and unintended sign, symptom (including an abnormal laboratory finding), syndrome, or illness that developed or worsened during the clinical study. A serious adverse event (SAE) is any untoward medical occurrence resulting in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results in a congenital anomaly/birth defect, or other medically important event. Any graded abnormality that occurred following the initiation of study drug and up to 30 days after the last dose of study drug, and represented at least a 1-grade increase from the baseline assessment, was defined as treatment emergent.

The EuroQoL five-dimensional, 5-level (EQ-5D-5L) was used to assess overall wellbeing and comprised the following five domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each domain has 5 response levels: no problems, slight problems, moderate problems, severe problems, and extreme problems. It included the EQ Visual Analogue scale (EQ VAS) to rate overall health on a scale of 0 (worst health) to 100 (best health).