Potassium Correction for RAAS Optimization in Chronic Kidney Disease (PROMISE)

Potassium Correction for Renin-angiotensin-aldosterone System Optimization in Chronic Kidney Disease

The goal of this placebo-controlled, double-blinded cross-over trial is to test whether patiromer, compared with placebo, better enables up-titration of RAAS-blocker treatment in patients with chronic kidney disease stage 3b/4.

The main questions it aims to answer are:

• Does patiromer allow uptitration of irbesartan, resulting in a significant reduction in albuminuria and blood pressure?
• Does patiromer allow uptitration of irbesartan, resulting in a significant reduction in blood pressure?

The trial contains the following interventions:

• Participants will be switched from their ACEi/ARB to a standardised dose of irbesartan (150 mg/d).
• During two 12-week study periods, participants will receive either patiromer 8.4 g/d or placebo. The order of study periods is randomized.
• At the start of each study period irbesartan will be up-titrated to 300 mg/d.
• After 1 and 6 weeks, at both periods, plasma potassium will be measured and the irbesartan dose will be reduced to 150 mg/d in case plasma potassium exceeds 5.0 mmol/L.
• At 12 weeks from the start of the study period, the endpoints will be assessed.
• Between the two study periods, there is a 6-week washout. Irbesartan dose during the wash-out period will be 150mg/d. After washout, participants will switch from the patiromer arm to the placebo arm or vice versa.

Study Overview

• Status: Recruiting
• Conditions: Hypertension; Chronic Kidney Diseases; Hyperkalemia
• Intervention / Treatment: Drug: Patiromer 8400 MG [Veltassa]; Drug: Placebo

Detailed Description

The PROMISE trial is a randomized, double-blind, placebo controlled cross-over trial where individuals are participating for 36 weeks. The trial consists of a 6-week run-in period, followed by two 12-week study periods, separated by a 6-week washout period.

First, during a run-in period, each participant will be converted from their ACEi/ARB dose to irbesartan 150 mg once daily. Individuals who already used irbesartan 150mg once daily before trial participation will remain on this dose during the run-in period. After six weeks, blood and 24-hour urine samples will be collected (baseline visit) and participants will be randomized to patiromer or placebo (start of study period A). The participant, research team, and treating physician will be blinded to treatment allocation (patiromer or placebo), while irbesartan will remain open-label.

At one week after start of study period A and B, participants will perform a home blood pressure measurement and visit a local lab to verify the plasma potassium level (safety visit), in combination with a scheduled phone consultation. The following actions may be taken: 1) If plasma potassium is >5.0 mmol/L or eGFR is >25% lower than baseline, the dose of irbesartan will be reduced to 150 mg/d and remain so during the remainder of the study period; 2) If systolic blood pressure is <110 mmHg, the participant has symptoms of hypotension, and plasma potassium is <5.0 mmol/L, antihypertensive co-medication may be adjusted, if applicable. If there is no antihypertensive co-medication that can be adjusted, the irbesartan dose will be reduced to 150 mg/d during the remainder of the study period.

At six weeks after start of the study period, there will be an in-hospital study visit. Blood samples will be collected, and office blood pressure will be measured. Any of the same two actions as described above may be taken in case of hyperkalaemia, severe acute kidney function decline or hypotension, respectively.

At the end of each 12-week study period, blood and 24-hour urine samples will be collected, and home (as well as office) blood pressure will be measured to establish the study endpoints. In addition, the study medication (patiromer/placebo) will be stopped and irbesartan dose will be reduced (or maintained) at 150 mg once daily. After a 6-week washout period, the second baseline will take place (measurements identical to the first baseline), which marks the start of study period B. During study period B, participants who had been randomized to patiromer in period A will now receive placebo and vice versa. The measurements during study period B will be identical to period A. At 12 weeks after the start of study period B, the protocol is completed and patients will return to their original medication.

The investigators chose a cross-over study design to be able to use participants as their own control; this will enhance statistical power and reduce the number of required participants. Based on previous studies, it is known that 6 weeks are sufficient to reach stable albuminuria and blood pressure after an ARB dose change. Therefore, even if halfway the 12-week study period a dose reduction is made, there is enough time for albuminuria and blood pressure to stabilize before the end of the study period (i.e., when the primary endpoint is established). A 6-week washout period is inserted to avoid carry-over effects.

• Study Type: Interventional
• Enrollment (Estimated): 44
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Martin de Borst, prof. dr.; Phone Number: +31503616161; Email: m.h.de.borst@umcg.nl
• Study Contact Backup: Name: Caspar van Lieshout, MD; Phone Number: +31503616161; Email: c.j.van.lieshout@umcg.nl

Study Locations

• Netherlands
  • Groningen, Netherlands
    • Recruiting
    • University Medical Center Groningen
    • Contact: Martin de Borst, prof. dr.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years;
• CKD stage 3b-4 (eGFR 15-44 mL/min/1.73 m2)
• Albumin-creatinine ratio >3 mg/mmol, or proteinuria >0.05g/24u, or protein-creatinine ratio > 5mg/mmol
• Systolic blood pressure >130 mmHg or use of one or more antihypertensive drugs;
• Serum K+ 4.0-5.0 mmol/L;
• On sub-maximal dose ACEi/ARB

Exclusion Criteria:

• prior ACEi/ARB dose reduction due to a drop in eGFR by >25% in the last year;
• history of severe hyperkalaemia (>6.0 mmol/L) in the last year;
• pregnancy or breastfeeding
• life expectancy <12 months
• the use of lithium, potassium-sparing diuretics, potassium supplements, trimethoprim or NSAIDS
• kidney transplant recipients, or diagnosis of autosomal dominant polycystic kidney disease or other non-glomerular kidney disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Patiromer; All participants will receive patiromer 8.4g/d (powder for oral suspension) during one of the two 12-week study periods. Following a 6-week washout, participants will switch from the patiromer arm to the placebo arm or vice versa (cross-over design).	Drug: Patiromer 8400 MG [Veltassa]; Patiromer is a cation-exchanging polymer intended for oral intake that is not resorbed from the gastro-intestinal tract. Patiromer has been approved by the European Medicines Agency (EMA) and is available for clinical use in The Netherlands for the indication of hyperkalemia in adults. It contains calcium-sorbitol complex as a counter-ion. Patiromer increases the faecal excretion of potassium in the gastro-intestinal lumen by exchange with part of the calcium. This results in a lower concentration of free potassium in the gastro-intestinal lumen, reducing in turn plasma potassium concentration. After initiation of patiromer, a clinically significant reduction in plasma potassium can be observed at around 7 hours, the effect persists for approximately 24 hours. Patiromer is excreted by the fecal route, 24-48 hrs after ingestion. Since patiromer is not absorbed or metabolized by the body, other drugs are not expected to influence the efficacy of patiromer.
Placebo Comparator: Placebo; All participants will receive placebo 8.4g/d (powder for oral suspension) during one of the two 12-week study periods. Following a 6-week washout, participants will switch from the patiromer arm to the placebo arm or vice versa (cross-over design).	Drug: Placebo; Placebo is a powder with a similar appearance, smell, and taste as patiromer, but without and clinically detectable effects. It is intended for oral intake.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Albumin-creatinine ratio (ACR)	The primary study endpoint is the difference in ACR in 24-hour urine at the end of each study visit, compared to the ACR at the start of the study period. This is a continuous variable that will be presented quantitatively. In case of non-normal distribution, this parameter will be log-transformed. The primary hypothesis test will be the difference between placebo and treatment groups after 2 periods.	At the end of both 12-week study periods (patiromer and placebo)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	Systolic and diastolic blood pressure, assessed by a 24-hour ambulatory blood pressure measurement at the end of each study period (continuous data)	At the end of both 12-week study periods (patiromer and placebo)
Plasma potassium	Plasma potassium level at the end of each study period (continuous data)	At the end of both 12-week study periods (patiromer and placebo)
Kidney function	Kidney function, as reflected by the estimated glomerular filtration rate (eGFR) using the combined cystatin C-creatinine-based CKD-EPI formula, at the end of each study period (continuous data)	At the end of both 12-week study periods (patiromer and placebo)
Irbesartan dose	Irbesartan dose at the end of each study period (continuous data)	At the end of both 12-week study periods (patiromer and placebo)
Adverse events	Numbers of AE/SAE during each study period (count data)	At the end of both 12-week study periods (patiromer and placebo)

Collaborators and Investigators

• Sponsor: University Medical Center Groningen
• Collaborators: Isala; Health Holland; Dutch Kidney Foundation; Vifor Pharma, Inc.; Amsterdam University Medical Center; Frisius Medisch Centrum
• Investigators: Principal Investigator: Liffert Vogt, prof. dr., Amsterdam University Medical Centre; Principal Investigator: Femke Waanders, dr., Isala Zwolle; Study Chair: Martin de Borst, prof. dr., University Medical Center Groningen; Principal Investigator: Aaltje Adema, dr., Frisius Medisch Centrum

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: February 5, 2024
• First Submitted That Met QC Criteria: February 5, 2024
• First Posted (Actual): February 13, 2024

Study Record Updates

• Last Update Posted (Actual): December 19, 2025
• Last Update Submitted That Met QC Criteria: December 12, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Chronic Disease; Disease Attributes; Metabolic Diseases; Renal Insufficiency; Water-Electrolyte Imbalance; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Hypertension; Renal Insufficiency, Chronic; Hyperkalemia; patiromer
• Other Study ID Numbers: 17237 (Other Identifier: City of Hope Medical Center)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Participants will be asked for permission to use collected personal information and biological samples for further research. Study data will be stored for 25 years in accordance with national guidelines.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No