NCT04983979: ORTIZ

The ORTIZ Study: Optimising RASi Therapy With SZC

Terminated Phase 2 Results posted Last updated 8 June 2025

What this trial tests

Phase 2 trial testing Sodium Zirconium Cyclosilicate in CKD in 18 participants. Terminated before completion.

Timeline

17 June 2022

Primary endpoint
16 March 2023

16 May 2023

Quick facts

Lead sponsor	Barts & The London NHS Trust
Phase	Phase 2
Status	Terminated
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	quadruple
Primary purpose	treatment
Enrollment	18
Start date	17 June 2022
Primary completion	16 March 2023
Estimated completion	16 May 2023
Sites	1 location across United Kingdom

Drugs / interventions tested

• Sodium Zirconium Cyclosilicate — full drug profile →
• Placebo

Conditions studied

• CKD — all drugs for CKD →
• Diabetes Mellitus, Type 2 — all drugs for Diabetes Mellitus, Type 2 →
• Hyperkalemia — all drugs for Hyperkalemia →

Sponsor

Barts & The London NHS Trust — full company profile →

Who can join

18 and older, any sex, with CKD or Diabetes Mellitus, Type 2. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Proportion of Patients on Maximum Dose (300mg) Irbesartan Therapy at 12 Weeks Compared to Placebo Primary · Study end (week 12)

Difference in proportion of patients on maximum dose (300mg) Irbesartan therapy at the end of 12 weeks compared to placebo. Proportion is calculated per arm as number of individuals on maximum dose Irbesatan therapy divided by the number of individuals in the study arm. The difference in proportion is calculated as experimental arm - placebo comparator arm.

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	2
Placebo	3
Sodium Zirconium Cyclosilicate (SZC)	1
Placebo	0
Sodium Zirconium Cyclosilicate (SZC)	1
Placebo	2

Change in Potassium From Baseline at Each Time Point Secondary · At each study visit (weeks 1, 2, 4, 6, 8,12)

Difference in potassium from baseline at each study visit (weeks 1, 2, 4, 6, 8,12) calculated as a mean for each study visit.

Week 1

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	-0.58	± 0.53
Placebo	0.06	± 0.42

Week 2

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	-0.03	± 0.45
Placebo	0.24	± 0.54

Week 4

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	0.10	± 0.23
Placebo	0.08	± 0.36

Week 6

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	-0.10	± 0.54
Placebo	0.16	± 0.23

Week 8

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	0.05	± 0.52
Placebo	0.16	± 0.52

Week 12

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	-0.50	± 0.50
Placebo	0.16	± 0.48

Change in the BP at the End of the Study From Baseline Secondary · Study end (week 12)

Difference in systolic and diastolic BP from baseline to end of study follow-up (week 12) calculated as a mean for each study visit.

Systolic BP

Group	Value	95% CI
Sodium Zirconium Cyclocilicate	-3.75	± 26.80
Placebo	-28.90	± 28.20

Diastolic BP

Group	Value	95% CI
Sodium Zirconium Cyclocilicate	1.38	± 10.54
Placebo	-7.40	± 12.75

Proportion of Patients Who Have a Potassium of >6mmol/l, or >6.5mmol/l at Any Time During the Study Secondary · Cumulative across study follow-up, assessed at study end (week 12)

Difference in proportion of patients who have a potassium of \>6mmol/l,, or \>6.5mmol/l at any time during the study. Proportion is calculated per arm as number of individuals with a maximum potassium across study follow-up of \>6mmol/l or \>6.5mmol/l divided by the number of individuals in the study arm. The difference in proportion is calculated as experimental arm - placebo comparator arm.

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	1
Placebo	0

Proportion of Patients Who Have a Potassium of <3.5mmol/l • Secondary · Cumulative across study follow-up, assessed at study end (week 12)

Difference in proportion of patients who have a potassium of \<3.5mmol/l at any time during the study. Proportion is calculated per arm as number of individuals with a minimum potassium of \<3.5mmol/l across study follow-up divided by the number of individuals in the study arm. The difference in proportion is calculated as experimental arm - placebo comparator arm.

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	0
Placebo	0

Proportion of Patients Whose Glomerular Filtration Rate (GFR) Falls by >30% From the Previous Visit • Secondary · Cumulative. Calculated at each study visit. Assessed at study end (week 12).

Difference in proportion of patients with a sudden drop in GFR defined as \>30% decreased between study visits. Proportion is calculated per arm as number of individuals experiencing a sudden drop of GFR divided by the number of individuals in the study arm. The difference in proportion is calculated as experimental arm - placebo comparator arm.

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	1
Placebo	0

Change in GFR at the End of Study From Baseline Secondary · Study end (week 12)

Difference in GFR from baseline to end of study follow-up (week 12) calculated as a mean for each study visit.

eGFR at Baseline

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	41.00	± 18.49
Placebo	42.80	± 12.58

eGFR at 12 weeks

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	35.00	± 16.19
Placebo	40.80	± 7.79

Difference from baseline

Group	Value	95% CI
Sodium Zirconium Cyclosilicate (SZC)	-6.0	± 2.83
Placebo	-2.00	± 7.28

Frequency of Adverse Events Secondary · Study end (week 12)

A count of the number of adverse events reported in each study arm

Group	Value	95% CI
Sodium Zirconium Cyclocilicate	6
Placebo	6

Adverse events — posted to ClinicalTrials.gov

Time frame: 16 weeks. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Experimental: SZC

Serious: 0/4 (0%)

Deaths: 0/4

Placebo Comparator: Placebo

Serious: 1/5 (20%)

Deaths: 0/5

Serious adverse events (1 terms)

Reaction	System	Experimental: SZC	Placebo Comparator: Placebo
Broken left humerus	Surgical and medical procedures	—	—

Other adverse events (10 terms — click to expand)

Reaction	System	Experimental: SZC	Placebo Comparator: Placebo
Oedema	Blood and lymphatic system disorders	—	—
Stomach Cramps	Gastrointestinal disorders	—	—
Bradycardia	Cardiac disorders	—	—
Constipation	Gastrointestinal disorders	—	—
Hypoglycaemia	Blood and lymphatic system disorders	—	—
Itchiness	Skin and subcutaneous tissue disorders	—	—
Shortness of breath	Respiratory, thoracic and mediastinal disorders	—	—
Fluid overload	Endocrine disorders	—	—
Weight gain	General disorders	—	—
Worsening hypertension	Cardiac disorders	—	—

Most-reported serious reactions: Broken left humerus.

Data from ClinicalTrials.gov NCT04983979 adverse events section.

Sponsor's own description

The hypothesis is that 3 months' treatment with SZC versus placebo will enable RASi (Irbesartan) maximisation in a cohort of patients with diabetic kidney disease.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.