Anrikefon (HSK21542) is a novel, selective, peripherally restricted kappa opioid receptor agonist. To assess its efficacy and safety for patients with chronic kidney disease (CKD)-associated pruritus, Bi-Cheng Liu, PhD, and colleagues conducted a multicenter, double-blind, randomized, controlled phase 3 trial (NCT05135390).
The researchers screened 652 patients from 50 centers in China from June 2022 to June 2024. Of that initial group, 545 patients were randomly assigned 1:1 to receive anrikefon (n=275) or placebo (n=270) three times weekly for 12 weeks. This was followed by an optional open-label extension phase with anrikefon treatment for 40 weeks.
The study’s primary end point was the percentage of participants to achieve at least a four-point reduction from baseline to week 12 in weekly mean 24-hour worst itching intensity numerical rating scale (WI-NRS) score. The secondary outcomes were the percentage of patients achieving at least a three-point reduction in weekly mean WI-NRS score from baseline to week 12, and changes in itch-related quality of life from baseline (using Skindex-10 and 5-D itch scales).