The severity of the itch was recorded by the participants twice daily in their eDiary, on a scale of 0 (none) to 3 (intense/severe). A weekly itch score (ISS7) was defined as the sum of the available daily itch severity scores in that week, divided by the number of days for which a daily itch severity score was available, multiplied by 7. The daily ISS was calculated as the average of the morning and evening scores. The possible range of the weekly score was therefore 0 (best score) to 21 (worst score) with higher scores indicating more severe itching. Least square (LS) mean and 95% confidence interval (CI) were calculated using analysis of covariance (ANCOVA) model. Multiple imputation performed both for the participants having missing ISS7 at week 12 and for participants using any disallowed concomitant medication.

The ITT analysis set included all randomized participants.

The severity of the itch was recorded by the participants twice daily in their eDiary, on a scale of 0 (none) to 3 (intense/severe). A weekly itch score (ISS7) was defined as the sum of the available daily itch severity scores in that week, divided by the number of days for which a daily itch severity score was available, multiplied by 7. The daily ISS was calculated as the average of the morning and evening scores. The possible range of the weekly score was therefore 0 (best score) to 21 (worst score) with higher scores indicating more severe itching. LS mean and 90% CI were calculated using ANCOVA model. Multiple imputation performed for the participants having missing ISS7 at week 12.

The ITT analysis set included all randomized participants.

The severity of the itch was recorded by the participants twice daily in their eDiary, on a scale of 0 (none) to 3 (intense/severe). A weekly itch score (ISS7) was defined as the sum of the available daily itch severity scores in that week, divided by the number of days for which a daily itch severity score was available, multiplied by 7. The daily ISS was calculated as the average of the morning and evening scores. The possible range of the weekly score was therefore 0 (best score) to 21 (worst score) with higher scores indicating more severe itching. The observed mean and standard deviation values are reported here with no imputation performed.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint. 'Number analyzed' = participants evaluable at specified timepoint.

The UAS was a composite eDiary-recorded score with numeric severity intensity ratings on a scale of 0 - 3 (0 = none to 3 = intense/severe) for (1) the number of wheals (hives); and (2) the intensity of the itch separately, measured twice daily (morning and evening). The daily UAS was the average of the morning and evening scores, which ranged from 0 (none) to 6 (severe). The UAS7 was the sum of the daily UAS scores over 7 days, which ranged from 0 (minimum) to 42 (highest urticaria severity). Higher scores indicated greater severity of urticaria symptoms.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The UAS was a composite eDiary-recorded score with numeric severity intensity ratings on a scale of 0 - 3 (0 = none to 3 = intense/severe) for (1) the number of wheals (hives); and (2) the intensity of the itch separately, measured twice daily (morning and evening). The daily UAS was the average of the morning and evening scores, which ranged from 0 (none) to 6 (severe). The UAS7 is the number of participants achieving the endpoint of less than or equal to 6. UAS7 was calculated as the sum of the daily UAS scores over 7 days, which ranged from 0 (minimum) to 42 (highest urticaria severity). Higher scores indicated greater severity of urticaria symptoms.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The UAS was a composite eDiary-recorded score with numeric severity intensity ratings on a scale of 0 - 3 (0 = none to 3 = intense/severe) for (1) the number of wheals (hives); and (2) the intensity of the itch separately, measured twice daily (morning and evening). The daily UAS was the average of the morning and evening scores, which ranged from 0 (none) to 6 (severe). The UAS7 was the sum of the daily UAS scores over 7 days, which ranged from 0 (minimum) to 42 (highest urticaria severity). Higher scores indicated greater severity of urticaria symptoms. Complete responders were participants with a UAS7 score = 0.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

Physician's (in-clinic) assessment of UAS score was performed using the in-clinic UAS. The physician, or the person designated, provided the sum of the score of the participant's urticaria lesions (number of wheals [hives]) and pruritus (itch) reflective of the participant's condition over the 12 hours prior to the visit using the rating scale of 0 - 6 (0 = none to 6 = intense/severe). Higher scores indicated greater severity of urticaria symptoms.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The wheals (hives) severity score, defined by number of wheals (hives), was recorded by the participant twice daily in their eDiary, on a scale of 0 (none) to 3 (> 12 hives/12 hours). A weekly number of wheals score was derived by adding up the average daily scores of the 7 days preceding the visit. The possible range of the weekly score was therefore 0 (no wheals) - 21 (highest hives activity).

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The weekly size of the largest wheals score was calculated from the eDiary data. A wheal score of 0 was assigned when <10 small wheals (diameter <3 centimeters [cm]) were present, presence of 10-50 small wheals or less than 10 large wheals (diameter >3 cm) was denoted by score of 1. A score of 2 was assigned when more than 50 small wheals or 10 to 50 large wheals were present. A score of 3 denoted wheals covering almost the entire body surface area. A weekly score was defined as the sum of the available daily size of the largest wheals scores in that week, divided by the number of days for which a daily score was available, multiplied by 7. The possible range of the weekly score was therefore 0 (best score) to 21 (worst score) with higher scores indicating more severity.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

Time to MID response was defined as time to a reduction from baseline in ISS7 of ≥5 points in ISS7 score by Week 12.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants achieving MID up to Week 12.

A responder was defined as a participant with a reduction from baseline in ISS7 of ≥5 points in ISS7 score.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

Percentage of angioedema-free days from Week 4 to Week 12 were calculated based on the diary data as the number of days in the diary between the dates of Week 4 and Week 12 visits with no angioedema episodes, divided by the total number of days with diary entries in this time span * 100%.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The DLQI consisted of 10 questions concerning participants' perception of the impact of skin diseases on different aspects of their health-related quality of life over the last week. The DLQI total score was calculated by adding the score of each question (scored as follows: Very much = 3; Yes [in question 7.a] = 3; A lot = 2; A little = 1; Not at all = 0; Not relevant = 0; No [in question 7.a] = 0; Question unanswered = 0), resulting in a maximum of 30 and a minimum of 0. The higher the score, the more the quality of life was impaired. A score higher than 10 indicated that the participant's life was being severely affected by their skin disease.

The ITT analysis set included all randomized participants. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The severity of the itch was recorded by the participants twice daily in their eDiary, on a scale of 0 (none) to 3 (intense/severe). A weekly itch score (ISS7) was defined as the sum of the available daily itch severity scores in that week, divided by the number of days for which a daily itch severity score was available, multiplied by 7. The daily ISS was calculated as the average of the morning and evening scores. The possible range of the weekly score was therefore 0 (best score) to 21 (worst score) with higher scores indicating more severe itching.

The transition intent-to-treat (TITT) analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint. 'Number analyzed' = participants evaluable at specified timepoint.

The UAS was a composite eDiary-recorded score with numeric severity intensity ratings on a scale of 0 - 3 (0 = none to 3 = intense/severe) for (1) the number of wheals (hives); and (2) the intensity of the itch separately, measured twice daily (morning and evening). The daily UAS was the average of the morning and evening scores, which can range from 0 (none) to 6 (severe). The UAS7 was the sum of the daily UAS scores over 7 days, which can range from 0 (minimum) to 42 (highest urticaria severity). Higher scores indicated greater severity of urticaria symptoms.

The TITT analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

Physician's (in-clinic) assessment of UAS score was performed using the in-clinic UAS. The physician, or the person designated, provided the sum of the score of the participant's urticaria lesions (number of wheals [hives]) and pruritus (itch) reflective of the participant's condition over the 12 hours prior to the visit using the rating scale of 0 - 6 (0 = none to 6 = intense/severe). Higher scores indicated greater severity of urticaria symptoms.

The TITT analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The wheals (hives) severity score, defined by number of wheals (hives), was recorded by the participant twice daily in their eDiary, on a scale of 0 (none) to 3 (> 12 hives/12 hours). A weekly number of wheals score was derived by adding up the average daily scores of the 7 days preceding the visit. The possible range of the weekly score was therefore 0 (no wheals) - 21 (highest hives activity).

The TITT analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint. 'Number analyzed' = participants evaluable at specified timepoint.

The weekly size of the largest wheals score was calculated from eDiary data. A wheal score of 0 was assigned when <10 small wheals (diameter <3 cm) were present, presence of 10-50 small wheals or less than 10 large wheals (diameter >3 cm) was denoted by score 1. A score of 2 was assigned when more than 50 small wheals or 10 to 50 large wheals were present. A score of 3 denoted wheals covering almost the entire body surface area. A weekly score was defined as sum of available daily size of the largest wheals scores in that week, divided by the number of days for which a daily score was available, multiplied by 7. The possible range of the weekly score was therefore 0 (best score) to 21 (worst score) with higher scores indicating more severity.

The TITT analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint. 'Number analyzed' = participants evaluable at specified timepoint.

Percentage of angioedema-free days from Week 12 to Week 24 was calculated based on the diary data as the number of days in the diary between the dates of Week 12 and Week 24 visits with no angioedema episodes, divided by the total number of days with diary entries in this time span * 100%.

The TITT analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint.

The DLQI consisted of 10 questions concerning participants' perception of the impact of skin diseases on different aspects of their health-related quality of life over the last week. The DLQI total score was calculated by adding the score of each question (scored as follows: Very much = 3; Yes [in question 7.a] = 3; A lot = 2; A little = 1; Not at all = 0; Not relevant = 0; No [in question 7.a] = 0; Question unanswered = 0), resulting in a maximum of 30 and a minimum of 0. The higher the score, the more the quality of life was impaired. A score higher than 10 indicated that the participant's life was being severely affected by their skin disease.

The TITT analysis set included all participants re-randomized in the transition period. 'Overall number of participants analyzed' = participants evaluable for this endpoint. 'Number analyzed' = participants evaluable at specified timepoint.

An adverse event (AE) was defined as any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. Serious AEs (SAEs) were defined as death, a life-threatening AE, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, a congenital anomaly or birth defect, or an important medical event that jeopardized participant and required medical intervention to prevent 1 of the outcomes listed in this definition. AEs were considered TEAEs if onset occurred or worsened on or after the first dose date. A summary of other non-serious AEs and all serious AEs, regardless of causality is located in Reported AE section.

The main treatment period safety analysis set included all randomized participants who received at least 1 dose of study drug during the main treatment period.

An AE was defined as any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. SAEs were defined as death, a life-threatening AE, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, a congenital anomaly or birth defect, or an important medical event that jeopardized participant and required medical intervention to prevent 1 of the outcomes listed in this definition. AEs were considered TEAEs if onset occurred or worsened on or after the first dose date. A summary of other non-serious AEs and all serious AEs, regardless of causality is located in Reported AE section.

The transition period safety analysis set included all randomized participants who received the study drug at Week 12.

Number of participants with positive ADA, positive ADA not treatment-related, and negative ADA are reported.

The main treatment period safety analysis set included all randomized participants who received at least 1 dose of study drug during the main treatment period. 'Overall number of participants analyzed' = participants with ADA status at any time during the main treatment period.

Number of participants with positive ADA, positive ADA not treatment-related, and negative ADA are reported.

The transition period safety analysis set included all randomized participants who received the study drug at Week 12. 'Overall number of participants analyzed' = participants with ADA status at any time during the transition period.