WI-NRS score: Participants were asked daily to assign a numerical score to the intensity of their most severe (worst) pruritus in the past 24 hours using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus. Daily scores were averaged for a weekly score. A negative change from Baseline indicates improvement.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method.

WI-NRS score: Participants were asked daily to assign a numerical score to the intensity of their most severe (worst) pruritus in the past 24 hours using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus. Daily scores were averaged for a weekly score. A negative change from Baseline indicates improvement.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

WI-NRS score: Participants were asked daily to assign a numerical score to the intensity of their most severe (worst) pruritus in the past 24 hours using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus. Daily scores were averaged for a weekly score. A negative change from Baseline indicates improvement.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked to place a line perpendicular to the VAS line at the point that represents the intensity of their average pruritus experienced over the previous 3 days using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked to place a line perpendicular to the VAS line at the point that represents the intensity of their average pruritus experienced over the previous 3 days using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

This tool evaluates pruritus in 5 domains: duration, degree, direction, disability and distribution. Duration, degree and direction each consist of 1 item. The disability domain contains 4 items and the distribution domain includes 16 items. The first 4 domains are measured on a 5-point Likert scale. The scores from each domain are added together to obtain a total 5-D score ranging from 5 (no pruritus) and 25 (most severe pruritus).

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

This tool evaluates pruritus in 5 domains: duration, degree, direction, disability and distribution. Duration, degree and direction each consist of 1 item. The disability domain contains 4 items and the distribution domain includes 16 items. The first 4 domains are measured on a 5-point Likert scale. The scores from each domain are added together to obtain a total 5-D score ranging from 5 (no pruritus) and 25 (most severe pruritus).

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

WI-NRS score: Participants were asked daily to assign a numerical score to the intensity of their most severe (worst) pruritus in the past 24 hours using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus. Daily scores were averaged for a weekly score. A negative change from Baseline indicates improvement.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked daily to self-assess the intensity of their pruritus on a Weekly Average Itch Severity Score, which is a Component of Urticaria Activity Score 7 (UAS7). The score for pruritis was graded from 0 (none) to 3 (intense), which was averaged over 7 consecutive days. The greater the severity of the disease the higher the score. Per protocol, the UAS7 tool was completed only by participants in the CIU Cohort.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked daily to self-assess the intensity of their pruritus on a Weekly Average Itch Severity Score, which is a Component of Urticaria Activity Score 7 (UAS7). The score for pruritis was graded from 0 (none) to 3 (intense), which was averaged over 7 consecutive days. The greater the severity of the disease the higher the score. Per protocol, the UAS7 tool was completed only by participants in the CIU Cohort

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked to place a line perpendicular to the VAS line at the point that represents the intensity of their average sleeplessness experienced over the previous 3 nights using a scale from 0 to 10, with 0 indicating no sleeplessness and 10 indicating the worst imaginable sleeplessness at every visit.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked to place a line perpendicular to the VAS line at the point that represents the intensity of their average sleeplessness experienced over the previous 3 nights using a scale from 0 to 10, with 0 indicating no sleeplessness and 10 indicating the worst imaginable sleeplessness at every visit.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked daily to assign a numerical score to the intensity of their difficulty falling asleep last night due to itch using a scale from 0 to 10, with 0 indicating not difficult at all and 10 indicating extremely difficult.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked daily to assign a numerical score to the intensity of their difficulty falling asleep last night due to itch using a scale from 0 to 10, with 0 indicating not difficult at all and 10 indicating extremely difficult.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked daily to assign a numerical score to the quality of their sleep in the previous night using a scale from 0 to 10, with 0 indicating best possible sleep and 10 indicating worst possible sleep.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

Participants were asked daily to assign a numerical score to the quality of their sleep in the previous night using a scale from 0 to 10, with 0 indicating best possible sleep and 10 indicating worst possible sleep.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

The DLQI is a 10-question questionnaire that considers symptoms and feelings, daily activities, leisure, school, personal relationships, and treatment. Each question, except question 7, is answered on a scale of 0 to 3 (0 for not at all, 1 for a little, 2 for a lot, and 3 for very much), taking into account the previous week. For question 7: participants were asked "Over the last week, has your skin prevented you from working or studying?" If answered yes, score=3; If no, a second question will be asked: "Over the last week how much has your skin been a problem at work or studying?" If further answered a lot, score=2; if a little, score=1; if not at all or not relevant, score=0. The DLQI total score is defined as the sum of all 10-question scores with minimum of 0 meaning no effect on quality of life and 30 meaning extremely large effect.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

The DLQI is a 10-question questionnaire that considers symptoms and feelings, daily activities, leisure, school, personal relationships, and treatment. Each question, except question 7, is answered on a scale of 0 to 3 (0 for not at all, 1 for a little, 2 for a lot, and 3 for very much), taking into account the previous week. For question 7: participants were asked "Over the last week, has your skin prevented you from working or studying?" If answered yes, score=3; If no, a second question will be asked: "Over the last week how much has your skin been a problem at work or studying?" If further answered a lot, score=2; if a little, score=1; if not at all or not relevant, score=0. The DLQI total score is defined as the sum of all 10-question scores with minimum of 0 meaning no effect on quality of life and 30 meaning extremely large effect.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

ItchyQoL focuses on impact of pruritus on daily activities and on the level of psychological stress. It contains 22 items. The frequency items are scored using a 5-point Likert scale ranging from "never" to "all the time". The bother items are scored from 1 (not bothered) to 5 (severely bothered). The recall period in ItchyQoL is the past week. The ItchyQoL total score is defined as the sum of all 22-items scores. Total scores can be classified as little (0-30), mild (31-50), moderate (51-80), and severe (81-110).

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

ItchyQoL focuses on impact of pruritus on daily activities and on the level of psychological stress. It contains 22 items. The frequency items are scored using a 5-point Likert scale ranging from "never" to "all the time". The bother items are scored from 1 (not bothered) to 5 (severely bothered). The recall period in ItchyQoL is the past week. The ItchyQoL total score is defined as the sum of all 22-items scores. Total scores can be classified as little (0-30), mild (31-50), moderate (51-80), and severe (81-110).

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method. Once a participant started treatment period (through Week 8), missing data in treatment period were imputed. Once a participant started the follow up (FU) period, missing data in FU period were imputed.

WI-NRS score: Participants were asked daily to assign a numerical score to the intensity of their most severe (worst) pruritus in the past 24 hours using a scale from 0 to 10, with 0 indicating no pruritus and 10 indicating the worst imaginable pruritus. Daily scores were averaged for a weekly score. A negative change from Baseline indicates improvement.

Modified intent to treat (mITT) set: all randomized participants who received at least 1 dose of KPL-716 or placebo and had at least 1 post-baseline efficacy assessment in the double-blind treatment period. Missing data were imputed using the last observation carried forward (LOCF) method.