The selective kappa opioid receptor agonist difelikefalin significantly and rapidly reduces itch intensity among patients with chronic kidney disease (CKD)-associated pruritus undergoing haemodialysis, suggest the findings of the KALM-1 trial, which have been published in the New England Journal of Medicine.
The double-blind, placebo-controlled, phase 3 trial randomly assigned 378 patients undergoing haemodialysis with moderate-to-severe pruritus to either intravenous difelikefalin 0.5 μg/kg body weight or placebo three times per week for 12 weeks.
At the end of the treatment period, 82 of 158 patients (51.9%) receiving difelikefalin had a decrease of ≥3 points on the 24-hour Worst Itching Intensity Numerical Rating Scale (WI-NRS; range 0-10) compared to 51 of 165 (30.9%) receiving placebo. The imputed percentage of patients with a decrease of ≥3 points was 49.1 per cent vs 27.9 per cent, respectively (P
The imputed percentage of patients with a decrease of ≥4 points on the WI-NRS score at week 12 was significantly greater in the difelikefalin group than in the placebo group (37.1% vs 17.9%; P<.001>
Diarrhoea, dizziness and vomiting were more common in the difelikefalin group than in the placebo group.
The treatment effect was rapid (evident by week 1) and persisted throughout the 12-week study period.