Correction of serum potassium with sodium zirconium cyclosilicate in Japanese patients with hyperkalemia: a randomized, dose-response, phase 2/3 study

Single Dose of Sodium Zirconium Cyclosilicate Versus Sodium Polystyrene Sulfonate in Hospitalized Patients With Hyperkalemia

BACKGROUND

Sodium zirconium cyclosilicate (SZC) is an inorganic zirconium silicate compound that selectively exchanges potassium for hydrogen and sodium. "Once" doses of SZC (with option to redose) in patients with hyperkalemia in hospitalized settings have not been evaluated. We hypothesized that a once dose of SZC would be non-inferior to sodium polystyrene sulfonate (SPS) in reducing serum potassium.

OBJECTIVE

The objective of our study is to evaluate the effect of a "once" dose of SZC when compared with SPS in reducing serum potassium levels.

METHODS

This was a retrospective analysis of patients who received either a "once" dose of SZC or single or repeated doses of SPS for hyperkalemia. The primary endpoint was mean absolute reduction in the first serum potassium value at least 4 hours after administration. The secondary efficacy endpoints were the rate of additional potassium-lowering therapies and the rate of normokalemia within 48 hours. Safety endpoints were the incidence of electrolyte abnormalities, hypoglycemia, hypertension, hypotension, and colonic necrosis.

RESULTS

A total of 260 patients were included in the analysis. The mean initial serum potassium was similar between groups (5.6 ± 0.4). The absolute serum potassium reduction was -0.88 ± 0.64 mEq/L and -0.75 ± 0.65 mEq/L with SZC and SPS, respectively. The "once" regimen of SZC demonstrated non-inferiority compared with SPS (P < 0.0001). The proportion of patients achieving normokalemia within 48 hours and the proportion of patients receiving additional potassium-lowering therapies did not differ between groups.

CONCLUSION AND RELEVANCE

The "once" dose regimen (with redose option) of SZC was non-inferior to the "once" or repeated dosing regimen of SPS with regard to absolute potassium reduction. There were no significant differences in the rate of additional potassium-lowering therapies and the rate of normokalemia at 48 hours. The incidence of hypertension was less common among patients who received SZC.

Evaluation of safety, effectiveness and treatment patterns of sodium zirconium cyclosilicate in management of hyperkalaemia in China: a real-world study protocol

INTRODUCTION

Hyperkalaemia (HK) is a potentially life-threatening electrolyte imbalance associated with several adverse clinical outcomes. The efficacy and negative effects of currently existing treatment options have made HK management questionable. Sodium zirconium cyclosilicate (SZC), a novel highly selective potassium binder, is approved for the treatment of HK. The present study will be aimed to assess the safety, effectiveness and treatment patterns of SZC in Chinese patients with HK in a real-world clinical setting as it is required by China's drug review and approval process.

METHODS AND ANALYSIS

This is a multicentre, prospective cohort study which plans to enrol 1000 patients taking SZC or willing to take SZC from approximately 40 sites in China. Patients ≥18 years of age at the time of signing the written informed consent and with documented serum potassium levels ≥5.0 mmol/L within 1 year before study enrolment day will be included. Eligible patients will receive SZC treatment and will be followed up for 6 months from enrolment day. The primary objective will be to evaluate the safety of SZC for the management of HK in Chinese patients in terms of adverse events (AEs), serious AEs as well as discontinuation of SZC. The secondary objectives will include understanding the SZC dosage information in terms of its effectiveness and treatment patterns under real-world clinical practice and assessing effectiveness of SZC during the observational period.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Dalian Medical University (approval number: YJ-JG-YW-2020). All the participating sites have received the ethics approval. Results will be disseminated through national and international presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05271266.

Hyperkalemia: Prevalence, Predictors and Emerging Treatments

It is well established that an elevated potassium level (hyperkalemia) is associated with a risk of adverse events including morbidity, mortality and healthcare system cost. Hyperkalemia is commonly encountered in many chronic conditions including kidney disease, diabetes and heart failure. Furthermore, hyperkalemia may result from the use of renin-angiotensin-aldosterone system inhibitors (RAASi), which are disease-modifying treatments for these conditions. Therefore, balancing the benefits of optimizing treatment with RAASi while mitigating hyperkalemia is crucial to ensure patients are optimally treated. In this review, we will briefly discuss the definition, causes, epidemiology and consequences of hyperkalemia. The majority of the review will be focused on management of hyperkalemia in the acute and chronic setting, emphasizing contemporary approaches and evolving data on the relevance of dietary restriction and the use of novel potassium binders.

Effects and Safety of a Novel Oral Potassium-Lowering Drug-Sodium Zirconium Cyclosilicate for the Treatment of Hyperkalemia: a Systematic Review and Meta-Analysis

Background

Oral sodium zirconium cyclosilicate (SZC) is a novel potassium binder capable of achieving a rapid reduction of serum potassium (sK⁺) and maintaining a long-term normokalemia. We undertook a meta-analysis to summarize and evaluate the effects surrounding SZC in patients with hyperkalemia.

Method

We searched data sources from MEDLINE (from 1950 to Sep 2020), EMBASE (from 1970 to Sep 2020), and the Cochrane Library database (from 1950 to Sep 2020) for eligible studies. All randomized controlled trials (RCTs) regarding comparison of therapeutic effects of SZC in hyperkalemia participants were included.

Results

Seven studies, including 1697 patients with hyperkalemia, were analyzed. SZC significantly reduced mean sK⁺ (−0.42 mmol/L; 95% CI: −0.63 to −0.20 mmol/L, p = 0.0001) compared with placebo, with a significantly greater proportion of patients with normokalemia (RR 3.48, 95% CI 1.49 to 8.11, p = 0.004). Subgroup analyses showed that the longer durations of SZC treatment, the greater magnitudes of potassium reduction when compared with those of placebo (p between subgroups = 0.01) at correction phase. Besides, it also demonstrated sK⁺ tended to decrease more in patients who got longer treatment or larger dosage of SZC at maintenance phase; however, the difference did not reach statistical significance. Additionally, the drug was equally effective in studies with larger than 50% of patients with chronic kidney disease (CKD) or diabetes or patients using renin-angiotensin aldosterone system inhibitor (RAAS) inhibitors (all p < 0.05). The risk of edema (4.30, 1.17 to 15.84; p = 0.03) in SZC group was higher than those of placebo group. No statistically significant differences in the risks of other adverse events were observed between the two groups.

Conclusions

SZC effectively decreased the sK⁺ level in patients with hyperkalemia within 48 h and had benefits in the long-term control of serum potassium in patients who continued to receive SZC with a favorable safety profile from available data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10557-020-07134-2.