Phase IV, Double-Blind, Placebo-Controlled, Randomized-Withdrawal Trial Evaluating Sodium Zirconium Cyclosilicate (SZC) for the Management of Hyperkalaemia in Patients With Symptomatic Heart Failure With Reduced Ejection Fraction and Receiving Spironolactone (REALIZE-K)

  • End date
    May 31, 2024
  • participants needed
  • sponsor
Updated on 27 October 2022


The main objective of this study is to evaluate the efficacy of SZC as compared with placebo in keeping potassium levels within the normal range (3.5-5.0 mEq/L) while on spironolactone ≥25 mg daily without assistance of rescue therapy for hyperkalaemia (HK).


REALIZE-K is a Phase 4, multinational, multicenter, double-blind, placebo-controlled, randomized-withdrawal, parallel-group study that includes the following 3 phases: screening, 4-6 week open-label run-in phase where sodium zirconium cyclosilicate (SZC) and spironolactone will be optimized, followed by an 8-month double-blind, placebo-controlled, randomized withdrawal treatment phase.

Patients meeting the following criteria will enter the 4-6 week open-label run-in phase: symptomatic heart failure with reduced ejection fraction (HFrEF); receiving an angiotensin-converting enzyme inhibitor (ACEi), angiotensin II receptor blocker (ARB), or angiotensin receptor-Neprilysin inhibitor (ARNi); receiving no spironolactone or eplerenone, or receiving low-dose spironolactone (<25 mg daily); receiving a beta-blocker unless contraindicated; AND with hyperkalemia (sK+ 5.1-5.9 mEq/L) and an eGFR >/= 30 mL/min/1.73m2, OR normokalemic (sK+ 3.5-5.0 mEq/L) and 'at risk' of developing hyperkalemia (ie, history of hyperkalemia within the past 24 months and eGFR >/= 30 mL/min/1.73m2, or sK+ >/= 4.5 mEq/L and eGFR 30-60 mL/min/1.73m2 and/or age >75 years).

Patients who are normokalemic on SZC and receiving spironolactone >/= 25 mg daily at the end of the open-label run-in phase will enter the 8-month double-blind, placebo-controlled, randomized withdrawal treatment phase. Eligible patients will be randomized 1:1, stratified by run-in phase sK+ cohort.

Condition Hyperkalaemia, Heart Failure With Reduced Ejection Fraction
Treatment Placebo, Spironolactone, Sodium Zirconium Cyclosilicate
Clinical Study IdentifierNCT04676646
Last Modified on27 October 2022


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