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Abstract: TH-PO1155

Hexasodium Fytate (SNF472) for Treatment of Calciphylaxis

Session Information

  • Late-Breaking Posters
    November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

  • 502 Bone and Mineral Metabolism: Clinical


  • Sinha, Smeeta, Northern Care Alliance NHS Foundation Trust Salford Care Organisation, Salford, United Kingdom
  • Nigwekar, Sagar U., Massachusetts General Hospital, Boston, Massachusetts, United States
  • Gould, Lisa, South Shore Health, South Weymouth, Massachusetts, United States
  • Serena, Thomas E, SerenaGroup Research Foundation, Cambridge, Massachusetts, United States
  • Moe, Sharon M., Indiana University School of Medicine, Indianapolis, Indiana, United States
  • Aronoff, George R., DaVita Inc, Denver, Colorado, United States
  • Chatoth, Dinesh K., Fresenius Medical Care Holdings Inc, Waltham, Massachusetts, United States
  • Hymes, Jeffrey L., Fresenius Medical Care Holdings Inc, Waltham, Massachusetts, United States
  • Carroll, Kevin, KJC Statistics Ireland Limited, Dublin, Ireland
  • Alperovich Lehrer, Gabriela, CSL Vifor, Barcelona, Spain
  • Keller, Laurence H, CSL Vifor, Wilmington, North Carolina, United States
  • Perelló, Joan, CSL Vifor, Palma de Mallorca, Spain
  • Gold, Alex, CSL Vifor, Wilmington, North Carolina, United States
  • Chertow, Glenn, Stanford University School of Medicine, Stanford, California, United States

Calciphylaxis (or calcific uremic arteriolopathy, CUA) is a rare serious condition with no approved therapies characterized by severely painful ischemic skin lesions due to calcification in arterioles. CALCIPHYX was a phase 3, randomized, double-blind, placebo-controlled trial of hexasodium fytate, or SNF472, a selective inhibitor of vascular calcification, in patients on maintenance hemodialysis with calciphylaxis.


Adults with ≥1 ulcerated calciphylaxis lesion and Pain VAS score of ≥50/100 received SNF472 7 mg/kg or placebo IV during hemodialysis 3 times weekly for 12 weeks. Alternate primary efficacy outcomes were BWAT-CUA (an 8-item modification of the Bates-Jensen Wound Assessment Tool to assess relevant features of calciphylaxis) and Pain Visual Analog Scale (VAS). Safety outcomes included CUA wound-related complications.


A total of 148 patients were screened, 71 were enrolled, and treatment was completed by 34 (91.9%) and 26 (76.5%) subjects in the SNF472 and placebo groups, respectively. At baseline, mean (SD) BWAT-CUA score was 19.8 (5.21), Pain VAS was 69.1 (27.9), and 69.0% of patients were treated with sodium thiosulfate. At Week 12, mean (SD) absolute change from baseline in BWAT-CUA was -5.3 (5.2) in the SNF472 group and -6.0 (6.2) in the placebo group, corresponding to a LS mean (SE) difference of 0.27 (1.33) (95% CI: -2.46, 3.00; p=0.88). Mean (SD) change from baseline in Pain VAS was -19.5 (26.9) in the SNF472 group and -32.2 (38.5) in the placebo group, corresponding to a LS mean (SE) difference of 11.49 (7.93) (95% CI: -4.80, 27.78; p=0.15). SNF472 was safe and well tolerated. Adverse events (AEs) leading to death were less frequent in patients randomized to SNF472: 1 (2.6%) vs. 6 (18.2%) in patients randomized to placebo. CUA wound-related AEs (11 [29.9%] vs. 16 [48.5%]) and wound-related infections (1 [2.6%] vs. 7 [21.2%]) were also less frequent in patients randomized to SNF472.


CALCIPHYX did not meet either alternate primary efficacy outcome. BWAT-CUA and Pain VAS improved similarly in both groups. There were numerically fewer AEs leading to death and CUA-wound related events and infections in patients treated with SNF472 compared to placebo. Detailed primary and post-hoc analyses will be presented.


  • Commercial Support – CSL Vifor