#5500 THE IMPACT OF CHRONIC KIDNEY DISEASE-ASSOCIATED PRURITUS RELIEF ON SKINDEX-10 DISEASE AND SOCIAL FUNCTIONING DOMAINS

Abstract

Abstract Background and Aims Chronic kidney disease-associated pruritus (CKD-aP) is a serious condition that greatly impacts patients’ quality of life (QoL). Moderate-severe pruritus affects up to 47% of patients undergoing haemodialysis (HD) [1]. The aim of this analysis was to assess the impact of itch relief on the disease and social functioning domains of the Skindex-10 questionnaire in a post hoc analysis of the difelikefalin (DFK) Phase 3 studies in patients with CKD-aP undergoing HD. Method Patients with moderate-to-severe CKD-aP (mean Worst Itch Numerical Rating Scale [WI-NRS] score ≥4 [KALM-1] or ≥5 [Study 3105 and KALM-2]) undergoing HD were enrolled and randomised 1:1 to receive intravenous DFK 0.5 µg/kg or placebo (KALM-1 and -2) or open-label DFK (Study 3105) 3 times/week for 12 weeks. Data from all patients who completed the studies were included in the present analysis irrespective of study drug exposure; data were pooled for patients receiving DFK and placebo from the KALM studies. The 12-week change from baseline in the Skindex-10 questionnaire subdomains were assessed for disease (Q1–3) and social functioning (Q7–10). Change from baseline in the mood/emotional distress domain has previously been reported (Q4–6) [2]. Results Skindex-10 scores were available for 914 patients (KALM studies: n = 720; Study 3105: n = 194). At Week 12, patients with a clinically relevant (WI-NRS ≥3-point) change (decrease) in itch (KALM: n = 305; 3105: n = 143) reported a relative mean (± standard error) corresponding improvement of 59.7%±2.0 (KALM) and 65.9%±2.6 (3105) from baseline in the disease domain of Skindex-10, compared with 18.4%±2.3 and 30.7%±4.4 of patients with <3-point WI-NRS improvement (KALM: n = 415 [Figure A]; 3105: n = 51 [Figure B]). In addition, a much greater improvement in QoL was reported for the social functioning domain for patients with ≥3-point WI-NRS improvement, compared with patients with <3-point improvement (66.2%±3.5 vs 11%±7.6 in the KALM studies; 75.5%±4.0 vs 49.4%±8.5 in Study 3105). Overall, the patients with ≥3-point WI-NRS change reported relative mean improvement from baseline ranging from 64%±2.3 to 70.2%±2.6 across the total Skindex-10 scale compared with 15.1%±4.8 to 35.4%±5.5 of patients with <3-point improvement at Week 12 across all studies. Conclusion In this post hoc analysis, patients with CKD-aP undergoing HD who reported a clinically meaningful reduction in itch intensity also achieved a substantially greater improvement in both the disease and social functioning domains of Skindex-10, as well as overall itch-related QoL.