A Study to Evaluate the Efficacy and Safety of INCB054707 in Participants With Prurigo Nodularis

Each evening, the participants assessed their worst level of itch during the past 24 hours on a scale of 0 (no itch) to 10 (worst itch imaginable). The Baseline Itch NRS score was determined by averaging the 7 daily Itch NRS scores before Day 1 (i.e., Day -7 to Day -1). If ≥4 of the 7 days of the daily Itch NRS scores were missing prior to Day 1, then the Baseline Itch NRS score was set to missing. The by-visit Itch NRS score for postbaseline visits was determined by averaging the 7 daily Itch NRS scores before the visit day. If 4 or more daily Itch NRS scores out of the 7 days before the visit day were missing, the Itch NRS score at the visit was set to missing.

Time frame: Baseline; Week 16

Population: Intent-to-Treat (ITT) Population: all randomized participants. Treatment groups for this population were defined according to the treatment assignment at randomization. Missing post-Baseline values and rescue therapy recipients for all subsequent visits after the initiation date of rescue therapy were imputed as nonresponders. The 95% confidence interval was based on the Clopper-Pearson exact method.

A TEAE is any AE either reported for the first time or the worsening of a pre-existing event after the first dose of study drug up to 30 days after the last dose of study drug. The severity of AEs was assessed using Common Terminology Criteria for Adverse Events version 5.0 Grades 1 through 5. The investigator made an assessment of intensity for each AE and serious adverse event (SAE) reported during the study and assigned it to 1 of the following categories. Grade 1: mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; treatment not indicated. Grade 2: moderate; minimal, local, or noninvasive treatment indicated; limiting age-appropriate activities of daily living. Grade 3: severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living. Grade 4: life-threatening consequences; urgent treatment indicated. Grade 5: fatal.

Time frame: up to 215 days

Population: Extension Evaluable Population

An AE is any untoward medical occurrence associated with the use of a drug in humans, whether or not it is considered drug related. An AE can therefore be any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drug. A TEAE is any AE either reported for the first time or the worsening of a pre-existing event after the first dose of study drug up to 30 days after the last dose of study drug.

Time frame: up to 215 days

Population: Extension Evaluable Population: all participants who received at least 1 dose of povorcitinib during the Extension Period

A TEAE is any AE either reported for the first time or the worsening of a pre-existing event after the first dose of study drug up to 30 days after the last dose of study drug. The severity of AEs was assessed using Common Terminology Criteria for Adverse Events version 5.0 Grades 1 through 5. The investigator made an assessment of intensity for each AE and serious adverse event (SAE) reported during the study and assigned it to 1 of the following categories. Grade 1: mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; treatment not indicated. Grade 2: moderate; minimal, local, or noninvasive treatment indicated; limiting age-appropriate activities of daily living. Grade 3: severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living. Grade 4: life-threatening consequences; urgent treatment indicated. Grade 5: fatal.

Time frame: up to 152 days

Population: Safety Population

An adverse event (AE) is any untoward medical occurrence associated with the use of a drug in humans, whether or not it is considered drug related. An AE can therefore be any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drug. A TEAE is any AE either reported for the first time or the worsening of a pre-existing event after the first dose of study drug up to 30 days after the last dose of study drug.

Time frame: up to 152 days

Population: Safety Population: all participants who received at least 1 dose of study drug. Treatment groups for this population were determined according to the actual treatment the participant received on Day 1.

The IGA for chronic prurigo considers the number of pruriginous lesions, which includes papules, nodules, plaques, umbilicated ulcers, and ulcers, and uses them as an overall severity rating on a scale of 0 to 4. 0: clear; no pruriginous lesions (0 lesions). 1: almost clear; rare palpable pruriginous lesions (approximately 1-5 lesions). 2: mild; few palpable pruriginous lesions (approximately 6-19 lesions). 3: moderate: many palpable pruriginous lesions (approximately 20-100 lesions). 4: severe; abundant palpable pruriginous lesions (over 100 lesions). The IGA-TS is defined as an IGA score of 0 or 1 with a ≥2-grade improvement from Baseline.

Time frame: Baseline; Week 16

Population: ITT Population. Missing post-Baseline values were imputed as non-responders. The 95% confidence interval was based on the Clopper-Pearson exact method.

Each evening, the participants assessed their worst level of itch during the past 24 hours on a scale of 0 (no itch) to 10 (worst itch imaginable). The Baseline Itch NRS score was determined by averaging the 7 daily Itch NRS scores before Day 1 (i.e., Day -7 to Day -1). If ≥4 of the 7 days of the daily Itch NRS scores were missing prior to Day 1, then the Baseline Itch NRS score was set to missing. The by-visit Itch NRS score for postbaseline visits was determined by averaging the 7 daily Itch NRS scores before the visit day. If 4 or more daily Itch NRS scores out of the 7 days before the visit day were missing, the Itch NRS score at the visit was set to missing.

Time frame: up to 122 days

Population: ITT Population. The time to a ≥4-point improvement from Baseline in itch NRS score was estimated using the Kaplan-Meier method. The confidence interval for the median time to a ≥4-point improvement from Baseline was calculated using the method of Brookmeyer and Crowley. Only participants with available data were analyzed.