Abstract: TH-PO1113

Acute Efficacy of Sodium Zirconium Cyclosilicate for Hyperkalemia in Outpatients with Potassium ≥6.0 mEq/L: Post-Hoc Subgroup Analysis of a Phase 3 Trial

Session Information

Category: Fluid, Electrolytes, and Acid-Base

  • 704 Fluid, Electrolyte, Acid-Base Disorders


  • Packham, David K., University of Melbourne, Melbourne, New South Wales, Australia
  • Roger, Simon D., Renal Research, Gosford, New South Wales, Australia
  • Pergola, Pablo E., Renal Associates PA, San Antonio, Texas, United States
  • Lerma, Edgar V., UIC/ Advocate Christ, Oak Lawn, Illinois, United States
  • Adler, Scott H., AstraZeneca, Gaithersburg, Maryland, United States
  • Singh, Bhupinder, ZS Pharma Inc., member of the AstraZeneca Group, San Mateo, California, United States
  • Lavin, Philip T., Boston Biostatistics Research Foundation, Framingham, Massachusetts, United States
  • Fishbane, Steven, Hofstra Northwell Health School of Medicine, Great Neck, New York, United States
  • Kosiborod, Mikhail, Saint Luke's Mid America Heart Institute, Kansas City, Missouri, United States

Treatment for patients (pts) with potassium (K) ≥6.0 mEq/L is often hospital-based. Sodium zirconium cyclosilicate (ZS) is an investigational, oral, highly selective K-binder shown to restore normokalemia in hyperkalemic pts. We report subgroup results for outpatients with K ≥6.0 mEq/L during acute treatment in a 12 mo Phase 3 study.


We performed a post-hoc analysis of an international, multicenter, open-label, single-arm trial that enrolled 751 pts (≥18y) with point-of-care (iSTAT) K ≥5.1mEq/L. Immediate treatment decisions were based on iSTAT K data, and confirmed by central laboratory serum K. During acute phase, pts received 10g ZS TID (24–72h) until K 3.5–5.0 was achieved by iSTAT K. Post-hoc endpoints were: final K, change in K from baseline, achievement of K 3.5–5.0 and adverse events (AE) during acute phase. Proportions were calculated using last observation carried forward.


At baseline, 126 (17%) of pts had serum K ≥6.0mEq/L. 99% completed the acute phase. Most pts (71%) had CKD and 74% used RAASi with no discontinuations observed. Median acute phase treatment duration was 1 day; median ZS dose was 30g. Mean (95% CI) baseline serum K was 6.2 (6.2, 6.3), final K was 4.6 (4.5, 4.7), with mean K change of -1.6 (-1.7, -1.5). The majority of pts achieved normokalemia; no patients had K >6.0 at 24h (Figure). Serum K values were higher than i-STAT K values. AEs were observed in 11 of 126 pts including 3 gastrointestinal disorders, 3 infections, 2 musculoskeletal disorders, 1 peripheral edema. No AEs were serious. There was 1 report of hypokalemia (3.0–<3.5 mEq/L) in the acute phase.


Oral outpatient treatment with ZS rapidly normalized K in pts with baseline K ≥6.0mEq/L with few adverse events and may be a viable therapy for this high-risk pt population.


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