Validation of a Scoring Algorithm for the Clinician-Reported Outcome ”Prurigo Activity and Severity (PAS)’’ Tool: Results Based on Clinical Studies of Dupilumab in Adults with Prurigo Nodularis

Speaker(s)

Zeidler C1, Stander S1, Rhoten S2, Wratten S3, Zhang D4, Msihid J5, Brookes E6, O’Malley J7, Bansal A8, Wiggins S6, Zahn J8, Thomas RB8, Bahloul D5
1Center for Chronic Pruritus, University Hospital Münster, Munster, Germany, 2IQVIA, San Francisco, CA, USA, 3IQVIA, Manchester, UK, 4IQVIA, Falls Church, VA, USA, 5Sanofi, Chilly-Mazarin, France, 6Sanofi, Reading, UK, 7Sanofi, Cambridge, MA, USA, 8Regeneron, Tarrytown, NY, USA

Presentation Documents

OBJECTIVES: Prurigo nodularis (PN), a pruritic skin disease, is characterized by multiple localized/generalized pruriginous lesions. The prurigo activity and severity (PAS) tool, a clinician-reported outcome (ClinRO) measure, is a clinically relevant indicator of activity and severity of PN. A 5-item PAS version (adapted from 7-item PAS) has been used in two phase-3 PN dupilumab trials. This study validated the psychometric properties of a PAS score (range: 0 to 11) derived as the sum of the items assessing the estimated number of pruriginous lesions, percentage of pruriginous lesions with excoriations/crusts, and percentage of healed pruriginous lesions and estimated the within-patient improvement threshold of PAS score in PN patients participating in the dupilumab clinical trials.

METHODS: Psychometric properties of PAS score were assessed using ClinRO and patient-reported outcome data pooled from the phase-3 trials (N=311; NCT04183335, NCT04202679) of dupilumab in adult patients with PN uncontrolled on topical therapies. Within-patient meaningful improvement thresholds were established using target anchors (patient global impression of severity [PGIS], PGI change [PGIC], investigator’s global assessment for PN activity [IGA PN-A] and stage [IGA PN-S]).

RESULTS: PAS score had good internal consistency (α > 0.70) and excellent test-retest reliability (intraclass correlation coefficient ≥ 0.8). Mostly moderate-to-strong correlations (absolute r = 0.32-0.87) with conceptually related-measures, and weaker-to-moderate correlations (absolute r <0.5) with less-related measures, supported the construct validity. PAS score differentiated well between groups known to be different at baseline, Week 12, and Week 24 (p<0.0001). Significant differences in mean PAS score changes over time were observed for groups defined using the target anchors (p<0.0001). Using anchor-based approach, an absolute change of 3 points (range: 2.0–4.0) represents a within-patient meaningful improvement threshold for PAS score.

CONCLUSIONS: The PAS score is a fit-for-purpose tool for assessing disease activity and severity in adults with PN uncontrolled on topical therapies.

Code

CO32

Topic

Clinical Outcomes, Patient-Centered Research, Study Approaches

Topic Subcategory

Clinical Outcomes Assessment, Clinical Trials, Clinician Reported Outcomes, Instrument Development, Validation, & Translation

Disease

No Additional Disease & Conditions/Specialized Treatment Areas, Sensory System Disorders (Ear, Eye, Dental, Skin)