Efficacy and safety of HSK21542 for pruritus management in hemodialysis patients: a multicenter, randomized, double-blind, placebo-controlled trial.

Background: Chronic kidney disease-associated pruritus (CKD-aP) is a common and distressing symptom in hemodialysis patients. This Phase II trial evaluated the efficacy and safety of HSK21542, a selective kappa-opioid receptor agonist, in managing CKD-aP. Methods: Adult patients on hemodialysis with moderate to severe pruritus, were randomized 1:1:1 to placebo, or HSK21542 (0.3 μg/kg or 0.6 μg/kg) administered thrice weekly post-dialysis for 12 weeks. The primary endpoint was the change from baseline in the weekly mean of the worst itching intensity Numerical Rating Scale (WI-NRS) score at week 12. Secondary endpoints included quality-of-life assessments, safety evaluations, and pharmacokinetic properties. Results: A total of 90 patients were enrolled. At week 12, mean changes in WI-NRS scores from baseline were -2.94 for the placebo group, -3.40 for the 0.3 μg/kg HSK21542 group, and -2.21 for the 0.6 μg/kg HSK21542 group. The percentages of patients who had a reduction of 3 points or above in their WI - NRS scores were 44.4% in the placebo group, 62.1% in the 0.3 μg/kg HSK21542 group, and 37.0% in the 0.6 μg/kg HSK21542 group. The 0.30 μg/kg HSK21542 group demonstrated more significant improvements in Skindex - 16 scores compared to the placebo. The 5-D Itch Scale scores also presented similar trends. Both the 0.3 μg/kg and 0.6 μg/kg doses of HSK21542 were well - tolerated, with no dose-dependent adverse effects. Conclusion: The 0.3 μg/kg dose of HSK21542 demonstrated superior efficacy and safety in reducing pruritus and improving quality of life in hemodialysis patients.