ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

Please note that you are viewing an archived section from 2022 and some content may be unavailable. To unlock all content for 2022, please visit the archives.

Abstract: SA-PO401

Correlation of Serum Phosphate With Pruritus Severity and Response to Difelikefalin

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis

Authors

  • Block, Geoffrey A., Denver Nephrology, Denver, Colorado, United States
  • Evenepoel, Pieter, University Hospitals Leuven, Leuven, Belgium
  • Fishbane, Steven, Northwell Health, Great Neck, New York, New York, United States
  • Budden, Jeffrey J., Vifor Pharma Ltd, Glattbrugg, Zurich, Switzerland
  • Morin, Isabelle, Vifor Pharma Ltd, Glattbrugg, Zurich, Switzerland
  • Menzaghi, Frederique, Cara Therapeutics Inc, Stamford, Connecticut, United States
  • Wen, Warren, Cara Therapeutics Inc, Stamford, Connecticut, United States
  • Lerma, Edgar V., University of Illinois at Chicago College of Medicine, Chicago, Illinois, United States
Background

Chronic kidney disease-associated pruritus (CKD-aP) is often reported by hemodialysis (HD) patients, thought to result from inadequate serum phosphate (sP) control, but recent studies refute this. Difelikefalin (DFK) is a selective kappa opioid receptor agonist approved in the United States and Europe for treatment of moderate-to-severe pruritus in adults undergoing HD. DFK significantly reduced itch in the Phase 3 KALM-1 and -2 trials. This analysis determined the correlation of sP to pruritus severity and response to DFK.

Methods

The KALM trials enrolled HD patients with moderate-to-severe CKD-aP (mean weekly worst itch numerical rating scale (WI-NRS) >4 [KALM-1] or ≥5 [KALM-2]). Patients were randomized 1:1 to intravenous DFK 0.5 µg/kg or placebo (PBO) 3 times/week (Wk) for 12 wks. Correlation between sP and WI-NRS at baseline and Wk 12 was assessed, as well as response to DFK in patients with and without hyperphosphatemia (sP ≤5.5 vs >5.5 mg/dL) at baseline.

Results

In pooled data (DFK and PBO), patients with baseline sP ≤5.5 mg/dL (N=438) had similar baseline characteristics to patients with sP >5.5 mg/dL (N=407). Baseline WI-NRS (7.1±1.4 vs 7.2±1.5) and anti-itch medication use (37.9% vs 38.1%) were similar. No correlation was observed between WI-NRS and sP values at baseline (p=0.54) [Figure] or Wk 12 (p=0.27). Clinically relevant improvement in WI-NRS following DFK treatment was similar in sP subgroups ≤5.5 vs >5.5 mg/dL (39.3% vs 40.2% for ≥4-point improvement; 51.1% vs 57.6% for ≥3-point improvement) and a significantly higher proportion of patients in the DFK group vs placebo reported a ≥4-point improvement in both sP subgroups (p≤0.017).

Conclusion

sP did not correlate with pruritus severity or response to DFK in patients with CKD-aP.

Funding

  • Commercial Support –