Continuing Sodium Zirconium Cyclosilicate (SZC) After Discharge Study

Inclusion Criteria:

• 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:

1. Diagnosed CKD (any stage) or

2. eGFR < 90 ml/min/1.73 m2 at, or within 3 months of, study screening, based onthe Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation (Leveyet 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), whereresult 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 isreceiving treatment for this episode of HK

• Male or female

• Capable and willing of giving signed informed consent as described in Appendix Awhich includes compliance with the requirements and restrictions listed in theinformed consent form (ICF) and in this protocol.

Exclusion Criteria:

• Hospitalisation for an acute cardiovascular event within 12 weeks prior to screening

• Unable to take oral SZC drug mix

• With a life expectancy of less than 6 months

• Any medical condition that, in the opinion of the investigator makes the participantnot suitable for inclusion

• QT interval corrected by the Fridericia method (QTcF) > 550 msec

• History of QT prolongation associated with other medications that requireddiscontinuation of that medication

• Congenital long QT syndrome

• Clinically significant arrythmias as judged by the investigator

• Ongoing treatment with SZC or patiromer before current ED visit/hospital admission (ongoing treatment with other K-binders before current ED visit/hospital admissionis 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 datefor a kidney transplant. Note: Emergency/unscheduled haemodialysis to treat HKduring 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.

• Known hypersensitivity to SZC or any of the excipients of the product

• Involvement in the planning and/or conduct of the study (applies to both AstraZenecastaff and/or staff at the study site)

• Judgment by the investigator that the participant should not participate in thestudy if the participant is unlikely to comply with study procedures, restrictions,and requirements

• Previous randomisation in the present study

• For women only: Women of child-bearing potential (WOCBP; ie, those who are notchemically or surgically sterilised or who are not post-menopausal) who are notwilling to use one of the methods of contraception described hereafter, or who arenot stable on the contraception method for the last one month, from the time ofsigning the informed consent throughout the study and 7 days after the last dose: (a) Combined (estrogen and progestogen containing) hormonal contraception associatedwith inhibition of ovulation: oral, intravaginal, transdermal (b) Progestogen-onlyhormonal 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 highlyeffective birth control method provided that partner is the sole sexual partner ofthe WOCBP participant and that the vasectomised partner has received medicalassessment of the surgical success (g) Sexual abstinence: it is considered a highlyeffective method only if defined as refraining from heterosexual intercourse duringthe entire period of risk associated with the study treatments. The reliability ofsexual abstinence needs to be evaluated in relation to the duration of the study andthe preferred and usual lifestyle of the participant.

• For WOCBP only: Women who have a positive pregnancy test at screening OR women whoare breastfeeding.