A Study to Evaluate the Efficacy and Safety Study of Povorcitinib in Participants With Prurigo Nodularis (STOP-PN2)

Primary Outcome Measures

1. Proportion of participants achieving Itch NRS4 and IGA-CPG-S-TS at Week 24
   Defined as proportion of participants achieving a ≥ 4-point improvement \[reduction\] in Itch NRS score from baseline (Itch NRS4) and an IGA CPG-S score of 0 or 1 with a ≥ 2-grade improvement from baseline (IGA-CPG-S-TS).

Secondary Outcome Measures

1. Proportion of participants achieving Itch NRS4 at Week 24
   Defined as percentage of participants that achieve a ≥ 4-point improvement (reduction) in Itch NRS score from baseline.
2. Proportion of participants achieving IGA-CPG-S-TS at Week 24
   Defined as percentage of participants that achieve IGA-CPG-S score of 0 or 1 with a ≥ 2 grade improvement from baseline.
3. Proportion of participants achieving Itch NRS4 at Week 4
   Defined as percentage of participants that achieve a ≥ 4-point improvement (reduction) in Itch NRS score from baseline.
4. Time to Itch NRS4
   Defined as time taken for the participant to achieve a ≥4 improvement in Itch NRS score from baseline.
5. Change from baseline in Itch NRS score at each postbaseline visit
   Itch will be measured using an NRS used to indicate the intensity of the worst itching over the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "no itching" and "10" represents "worst itching imaginable".
6. Percent change from baseline in NRS score at each postbaseline visit
   Itch will be measured using an NRS used to indicate the intensity of the worst itching over the past 24 hours using a 0 to 10 numeric rating scale, where "0" represents "no itching" and "10" represents "worst itching imaginable".
7. Proportion of participants achieving Itch NRS4 at each postbaseline visit
   Defined as percentage of participants that achieve a ≥ 4-point improvement in Itch NRS score from baseline.
8. Proportion of participants achieving IGA-CPG-S-TS at each postbaseline visit
   Defined as percentage of participants that achieve an IGA-CPG-S score of 0 or 1 with a ≥ 2 grade improvement from baseline.
9. Proportion of participants achieving Investigator's Global Assessment - Chronic Prurigo Activity (IGA-CPG-A) at each postbaseline visit
   Defined as percentage of participants that achieve an IGA-CPG-A score of 0 or 1 with a ≥ 2 grade improvement (reduction) from baseline.
10. Proportion of participants achieving ≥ 75% healed lesions in Prurigo Activity Score (PAS) at each postbaseline visit
    The modified PAS will be used in this study as defined by the protocol.
11. Proportion of participants achieving Itch NRS4 and IGA-CPG-S-TS at each postbaseline visit
    Defined as percentage of participants that achieve a ≥ 4-point improvement (reduction) in Itch NRS score and IGA-CPG-S score of 0 or 1 with a ≥ 2-grade improvement from baseline.
12. Change from baseline in Dermatology Life Quality Index (DLQI) score at each postbaseline visit.
    The DLQI is a simple, 10-question validated questionnaire to measure how much the skin problem has affected the participant over the previous 7 days.
13. Percent change from baseline in Dermatology Life Quality Index (DLQI) score at each postbaseline visit.
    The DLQI is a simple, 10-question validated questionnaire to measure how much the skin problem has affected the participant over the previous 7 days.
14. Proportion of participants with at least a 4-point decrease in DLQI score from baseline at each postbaseline visit for participants with DLQI score ≥ 4 at baseline
    Defined as percentage of participants with at least a 4-point decrease in DLQI score from baseline at each postbaseline visit for participants with DLQI score ≥ 4 at baseline.
15. Change from baseline in Skin Pain NRS score at each postbaseline visit
    Skin Pain NRS is an 11-point scale (0 to10) where 0 is "no pain" and 10 is the "worst pain imaginable".
16. Percent change from baseline in Skin Pain NRS score at each postbaseline visit
    Skin Pain NRS is an 11-point scale (0 to10) where 0 is "no pain" and 10 is the "worst pain imaginable".
17. Change from baseline in the Hospital Anxiety and Depression Scale (HADS) score at each postbasline visit
    HADS is a 14-item questionnaire that assesses the levels of anxiety and depression that a participant is currently experiencing. There are 7 questions each for measuring anxiety and for measuring depression, with 4 possible responses to each question (responses are scored as 0, 1, 2, or 3).
18. Percent change from baseline in the HADS score at each postbaseline visit
    HADS is a 14-item questionnaire that assesses the levels of anxiety and depression that a participant is currently experiencing. There are 7 questions each for measuring anxiety and for measuring depression, with 4 possible responses to each question (responses are scored as 0, 1, 2, or 3).
19. Change from baseline in EQ-5D-5L score at each postbaseline visit
    The EQ-5D-5L questionnaire is a standardized, validated instrument for use as a measure of health outcome.
20. Percent change from baseline in EQ-5D-5L score at each postbaseline visit
    The EQ-5D-5L questionnaire is a standardized, validated instrument for use as a measure of health outcome.
21. Change in Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F) score at each postbaseline visit
    The FACIT-F is a 13-item measure that assesses self-reported fatigue and its impact upon daily activities and function over the past 7 days.
22. Percent change in FACIT-F score at each postbaseline visit
    The FACIT-F is a 13-item measure that assesses self-reported fatigue and its impact upon daily activities and function over the past 7 days.
23. Proportion of participants with at least a ≥ 4-point increase in FACIT-F score at each postbaseline visit for participants with FACIT-F score ≤ 48 at baseline
    The FACIT-F is a 13-item measure that assesses self-reported fatigue and its impact upon daily activities and function over the past 7 days.
24. Number of Participants with Treatment Emergent Adverse Events (TEAE)
    Defined as any adverse event either reported for the first time or worsening of a pre-existing event after first dose of study drug.