Continuing Sodium Zirconium Cyclosilicate (SZC) After Discharge Study

Prior treatment

• Hospitalisation for an acute cardiovascular event within 12 weeks prior to screening
• Unable to take oral SZC drug mix
• Ongoing treatment with SZC or patiromer before current ED visit/hospital admission (ongoing treatment with other K-binders before current ED visit/hospital admission is allowed).
  • Note: Initiation of any SZC or patiromer during the current ED visit/hospitalisation preceding enrolment is allowed.
• Chronic haemodialysis or peritoneal dialysis or the recipient of or scheduled date for a kidney transplant. Note: Emergency/unscheduled haemodialysis to treat HK during the current ED visit/hospitalisation preceding enrolment is allowed.
• Participation in another clinical study with an investigational medicinal product (IMP) administered during the month before screening.
• Previous randomisation in the present study
• For women only: Women of child-bearing potential (WOCBP; ie, those who are not chemically or surgically sterilised or who are not post-menopausal) who are not willing to use one of the methods of contraception described hereafter, or who are not stable on the contraception method for the last one month, from the time of signing the informed consent throughout the study and 7 days after the last dose: (a) Combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation: oral, intravaginal, transdermal (b) Progestogen-only hormonal contraception associated with inhibition of ovulation: oral, injectable, implantable (c) Intrauterine device (d) Intrauterine hormone-releasing system (e) Bilateral tubal occlusion (f) Vasectomised partner (vasectomised partner is a highly effective birth control method provided that partner is the sole sexual partner of the WOCBP participant and that the vasectomised partner has received medical assessment of the surgical success (g) Sexual abstinence: it is considered a highly effective method only if defined as refraining from heterosexual intercourse during the entire period of risk associated with the study treatments. The reliability of sexual abstinence needs to be evaluated in relation to the duration of the study and the preferred and usual lifestyle of the participant.

Other illness

• Any medical condition that, in the opinion of the investigator makes the participant not suitable for inclusion
• Known hypersensitivity to SZC or any of the excipients of the product

Lab values

• QT interval corrected by the Fridericia method (QTcF) \> 550 msec
• History of QT prolongation associated with other medications that required discontinuation of that medication
• Congenital long QT syndrome

Other

• With a life expectancy of less than 6 months
• Clinically significant arrythmias as judged by the investigator
• Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site)
• Judgment by the investigator that the participant should not participate in the study if the participant is unlikely to comply with study procedures, restrictions, and requirements
• For WOCBP only: Women who have a positive pregnancy test at screening OR women who are breastfeeding.

• Must be 18 years of age or older, at the time of signing the informed consent
• Admitted to hospital (inpatient care; directly or from ED)
• With:
  • Diagnosed CKD (any stage) or
  • eGFR \< 90 ml/min/1.73 m2 at, or within 3 months of, study screening, based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation (Levey et al, 2009).
  • Note: Race/ethnicity should not be included in CKD-EPI equation calculation.
• Local laboratory K+ measurement within 24 hours of baseline visit (visit 2), where result is either:
• Hyperkalaemic as defined by site's local practice and K+ ≤ 6.5 mmol/L.
• Or, normokalaemic: K+ between ≥ 3.5 and ≤ 5.0 mmol/L, where patient started and is receiving treatment for this episode of HK
• Male or female
• Capable and willing of giving signed informed consent as described in Appendix A which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.