A Phase 4 interventional study of Sodium zirconium cyclosilicate in Hyperkalemia, Diet Modification and Chronic Kidney Disease, sponsored by Leiden University Medical Center. Recruiting at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-03-06.
Sponsored by Leiden University Medical Center · Phase 4, Interventional, and Treatment
Rationale: Several studies have shown that higher urinary potassium excretion (as proxy for potassium intake) is associated with better kidney outcomes, lower blood pressure and improved survival. These associations are also observed in patients with (advanced) CKD. However, application in daily practice in patients with CKD, is impaired by the risk of hyperkalemia, due to metabolic acidosis and impaired renal potassium excretion in these patients. As a consequence, patients with CKD are advised to restrict their intake of fruit and vegetables, as these healthy food components are important sources of dietary potassium. This is particularly undesirable for patients with CKD in view of the very high risk of cardiovascular disease.
Concomitant use of sodium zirconium cyclosilicate (SZC) could allow a more liberal intake of fruit and vegetables for patients with CKD, as SZC effectively treats hyperkalemia and counteracts metabolic acidosis [1]. With this strategy, the beneficial effects of potassium in fruits and vegetables on (vascular) health could also become accessible to patients with CKD.
Objective: To demonstrate that a potassium-rich diet, including the use of SZC as potential rescue treatment (in case of hyperkalemia), does not result in an unacceptable rise in plasma potassium (i.e. max rise of 0.5 mmol/L and no hyperkalemia). Study Design: Investigator initiated, single center, cross-over randomized clinical trial with non-inferiority design (14 weeks, 2 groups: regular diets vs. diet with potassium rich fruits and vegetables with sodium zirconium cyclosilicate if necessary) Study population: Outpatients ( age ≥ 18 years ) with chronic kidney disease stage IIIb/IV and use of inhibitor of the renin-angiotensin system (RASi).
Intervention: Addition of fruit- and vegetables that contain 40 mmol of potassium on top of regular diet. Addition of SZC after 1 week in case hyperkaliemia develops (serum potassium > 5,5 mmol/L). Weekly measurement of plasma potassium and dose adjustment of SZC if needed
133 studies on the registry are indexed under Hyperkalemia; 25 are open to participants now.
This study's planned enrollment of 16 is below the median of 87 across 102 interventional studies indexed under Hyperkalemia.
Browse Hyperkalemia studies →Leiden University Medical Center is the lead sponsor of 334 studies on the registry; 110 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with chronic kidney disease stage 3b to 4 will be treated for 6 weeks with a potassium enriched diet (adding +40mmol/day in the form of fruits/vegetables/nuts)
Drug: Sodium zirconium cyclosilicate
Patients with chronic kidney disease stage 3b to 4 will followed for 6 weeks, during their regular diet
In the case of hyperkalemia patients will be treated with Sodium zirconium cyclosilicate to allow the continuation of potassium enriched diet. In case hyperkalemia arises in the control group, patients will be treated with Sodium zirconium cyclosilicate as well.
Also known as: Lokelma
The difference of serum potassium at baseline and after six weeks of treatment with potassium enriched diet (non-inferiority design) compared to the control group. With an intention to treat analysis.
Time frame: 6 weeks
Ambulatory blood pressure (average systolic and diastolic blood pressure over 24 hours)
Time frame: 6 weeks
24 hours albuminuria
Time frame: 6 weeks
urinary potassium (mmol/l)
Time frame: 6 weeks
Plasma bicarbonate
Time frame: 6 weeks
Quality of life, using SF36 questionnaire
36-Item Short Form Survey. Scoring can range from 0 to 100. Higher scores indicate better health status
Time frame: 6 weeks
Effect on stool (assessed with Bristol Stool Chart)
Scoring can range form 1 to 7. Where score of 1 indicates obstipation, score of 4 indicates normal defecation and 7 indicates watery defecation.
Time frame: 6 weeks
Difference in serum potassium one week after start of study (SCZ free period)
Time frame: 6 weeks
Per protocol analysis of difference in serum potassium after six week (end of study)
Time frame: 6 weeks
Incidence of severe hyperkalemia (serum potassium above 6.5 mmol/l or above 6.0 with ECG features of hyperkalemia)
Time frame: 6 weeks
Incidence of hyperkalemia (serum potassium above 5.5 mmol/l)
Time frame: 6 weeks
Necessity for treatment of hyperkalemia
Time frame: 6 weeks
urinary sodium (mmol/l)
Time frame: 6 weeks
Plan to share: Undecided
No publications or documents are linked to this record.
Started Apr 2024 (actual). Primary completion is estimated for May 2025, 12 months after the start.
Of 16 phase 4 interventional studies under Hyperkalemia, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 44. This study's planned 12 months is below that.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Sodium zirconium cyclosilicate
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