Heart FailurePhase 4SAFE-KNCT07523867
Spironolactone Alternate Dosing vs Finerenone in Elevated Potassium - K Safety Study
A Phase 4 study testing Finerenone and Spironolactone (drug) in people with Heart Failure and Diabetic Kidney Disease, run by Hospital de Messejana Dr. Carlos Alberto Studart Gomes.
Trial summary
This study evaluates the safety of finerenone compared with alternate-day spironolactone in patients with heart failure and diabetic kidney disease at increased risk of hyperkalemia. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Heart Failure, Diabetic Kidney Disease, Hyperkalemia
- What is being tested?
- Finerenone and Spironolactone (drug)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- Apr 2026to Nov 2026
- Phase
- Phase 4
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- Diagnosis of heart failure, regardless of left ventricular ejection fraction
- Diagnosis of type 2 diabetes mellitus
- Diabetic kidney disease, defined by the presence of albuminuria (urinary albumin-to-creatinine ratio ≥ 30 mg/g)
- Estimated glomerular filtration rate (eGFR) ≥ 25 mL/min/1.73 m²
- Serum potassium between 5.0 and 5.5 mEq/L at screening
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- Receiving or eligible to receive standard of care therapy for heart failure
- Ability to provide written informed consent
- Ability to comply with study procedures and follow-up visits
Who cannot join
- Serum potassium > 5.5 mEq/L at screening
- Acute kidney injury at the time of enrollment
- Symptomatic hypotension or systolic blood pressure < 90 mmHg
- Clinically significant arrhythmias requiring immediate intervention
- Known hypersensitivity or contraindication to finerenone or spironolactone
- Use of potassium-sparing diuretics other than the study drugs
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- Pregnancy or breastfeeding
- Participation in another interventional clinical trial
- Any condition that, in the opinion of the investigator, would make participation unsafe or interfere with study procedures
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Safety of Finerenone Versus Alternate-Day Spironolactone in Patients With Heart Failure and Diabetic Kidney Disease at High Risk for Hyperkalemia: The SAFE-K Randomized Trial
This study evaluates the safety of finerenone compared with alternate-day spironolactone in patients with heart failure and diabetic kidney disease at increased risk of hyperkalemia.
Patients with chronic kidney disease and heart failure often benefit from mineralocorticoid receptor antagonists, but their use is frequently limited by elevated potassium levels. Finerenone has been associated with a lower risk of hyperkalemia in clinical trials, but direct comparisons with spironolactone in high-risk patients are limited.
Read more
In this randomized study, eligible participants will be assigned to receive either finerenone once daily or spironolactone on alternate days, in addition to standard therapy. Patients will be closely monitored during hospitalization and followed for 4 weeks.
The primary outcome is clinically relevant hyperkalemia, defined by elevated potassium levels or the need to adjust or discontinue treatment due to hyperkalemia. Secondary outcomes include changes in potassium levels, kidney function, and clinical events.
This study aims to provide practical evidence to guide the safe use of mineralocorticoid receptor antagonists in patients at high risk for hyperkalemia.
Read the detailed description
This is a prospective, randomized, open-label, blinded endpoint (PROBE), single-center study designed to compare the safety of finerenone versus alternate-day spironolactone in patients with heart failure and diabetic kidney disease at increased risk of hyperkalemia.
Mineralocorticoid receptor antagonists (MRAs) are a cornerstone therapy in patients with heart failure and have demonstrated benefits in patients with diabetic kidney disease. However, their use is often limited by hyperkalemia, particularly in patients with impaired renal function and elevated baseline potassium levels. Finerenone, a non-steroidal MRA, has shown a more favorable safety profile compared to steroidal MRAs in previous trials, but direct head-to-head comparisons in high-risk populations are lacking.
Eligible participants will be adults with heart failure and diabetic kidney disease with elevated baseline potassium levels. After providing informed consent, participants will be randomized in a 1:1 ratio to receive either finerenone once daily or spironolactone administered on alternate days, in addition to standard of care therapy.
Participants will undergo intensive monitoring during hospitalization, including daily assessment of serum potassium and renal function for up to 7 days or until discharge. After hospital discharge, participants will be followed in the outpatient setting for a total of 4 weeks, with scheduled visits and laboratory monitoring.
The primary endpoint is the incidence of clinically relevant hyperkalemia within 4 weeks, defined as serum potassium ≥ 5.5 mEq/L, treatment interruption or dose adjustment due to hyperkalemia, or the need for potassium-lowering therapy.
Secondary endpoints include change in serum potassium levels, time to first hyperkalemia event, incidence of severe hyperkalemia (≥ 6.0 mEq/L), treatment discontinuation, changes in renal function, and exploratory clinical outcomes such as heart failure hospitalization, arrhythmias, and all-cause mortality.
This study aims to provide pragmatic, clinically applicable evidence to inform the use of MRAs in a high-risk cardiorenal population.
- Conditions
- Heart Failure, Diabetic Kidney Disease, Hyperkalemia
- Being tested
- Finerenone, Spironolactone (drug)
- Keywords
- Finerenone, Spironolactone, Heart Failure Treatment, Chronic Kidney Disease, Hyperkalemia, Mineralocorticoid Receptor Antagonist, Cardiorenal Syndrome
- Medical subject headings
- Heart Failure, Diabetic Nephropathies, Hyperkalemia, Renal Insufficiency, Chronic, Cardio-Renal Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FinerenoneDrug
Finerenone 10 mg administered orally once daily. Treatment is given in addition to standard of care therapy for heart failure and diabetic kidney disease. Dose interruption or discontinuation may occur according to protocol-defined safety criteria, particularly in the setting of hyperkalemia.
Spironolactone (drug)Drug
Spironolactone 25 mg administered orally on alternate days. Treatment is given in addition to standard of care therapy for heart failure and diabetic kidney disease. Dose interruption or discontinuation may occur according to protocol-defined safety criteria, particularly in the setting of hyperkalemia.
| Study group | Role | What they receive |
|---|---|---|
| Finerenone | Experimental | Participants assigned to this arm will receive finerenone 10 mg orally once daily, in addition to standard of care therapy for heart failure and diabetic kidney disease. Receives: Drug: Finerenone |
| Alternate-Day Spironolactone | Active comparator | Participants assigned to this arm will receive spironolactone 25 mg orally on alternate days, in addition to standard of care therapy for heart failure and diabetic kidney disease. Receives: Drug: Spironolactone (drug) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Clinically Relevant Hyperkalemia
Clinically relevant hyperkalemia is defined as the occurrence of any of the following: serum potassium ≥ 5.5 mEq/L, temporary or permanent discontinuation or dose adjustment of the study drug due to hyperkalemia, or need for potassium-lowering therapy.
Measured: Up to 4 weeks after randomization
Secondary outcomes (4)
Change in Serum Potassium
Mean change in serum potassium from baseline to 4 weeks.
Measured: Baseline to 4 weeks
Time to First Hyperkalemia Event
Time from randomization to first occurrence of serum potassium ≥ 5.5 mEq/L.
Measured: Up to 4 weeks
Temporary or Permanent Discontinuation of Study Drug
Incidence of temporary or permanent interruption of study drug due to hyperkalemia.
Measured: Up to 4 weeks
Change in Albuminuria and in Renal Function
Change in urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) from baseline to 4 weeks.
Measured: Up to 4 weeks.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Apr 2026
- Study startApr 2026 (estimated)
- Primary completionOct 2026 (estimated)
- Study completionNov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Heart FailureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomized in a 1:1 ratio to receive either finerenone once daily or spironolactone administered on alternate days, in addition to standard of care therapy. Participants will be followed for 4 weeks with intensive monitoring of serum potassium and renal function.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospital de Messejana Dr. Carlos Alberto Studart Gomes
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Jefferson L. Vieira, Hospital de Messejana Dr. Carlos Alberto Studart Gomes
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07523867
- Sponsor's protocol ID
- HM-IC-SAFEK
- Acronym
- SAFE-K
- Status last verified
- May 2026
- First submitted
- 5 Apr 2026
- Last updated
- 13 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided