Study of SP16 to Prevent Acute Kidney Injury in Patients with Chronic Kidney Disease Undergoing Heart Surgery with Heart-Lung Machine

1 1

What is this study about?

This clinical trial is studying people who have Chronic Kidney Disease along with heart valve problems or other Cardiovascular Disease who need planned heart surgery. The study will test a treatment called SP16, which is an anti-inflammatory medication given as an injection under the skin. Some participants will receive SP16 while others will receive placebo. The purpose of the study is to evaluate the safety of SP16 and to see if it can prevent a serious complication called Acute Kidney Injury that can occur after heart surgery in people with existing kidney disease. During the surgery, a heart-lung-machine, also called cardiopulmonary bypass, will be used to temporarily take over the work of the heart and lungs.

The study will involve people with chronic kidney disease who are scheduled for heart surgery such as coronary artery bypass grafting (a procedure to improve blood flow to the heart), aortic valve surgery (repair or replacement of the valve between the heart and the main artery), mitral valve surgery (repair or replacement of the valve between the upper and lower chambers on the left side of the heart), or a combination of these procedures. Participants will receive the study medication or placebo before their surgery. After the surgery, they will be carefully monitored in the hospital to check their kidney function by measuring substances in their blood and urine. The medical team will watch for any side effects or complications, particularly during the first 72 hours after surgery.

The observation period will continue for about 90 days after the surgery. During this time, participants will have follow-up visits where doctors will check their kidney function, heart function using ultrasound imaging of the heart called echocardiography, and measure specific markers in the blood such as NT-proBNP, which indicates how well the heart is working. The study will track whether participants develop kidney injury after surgery, how severe it becomes, how long it takes for kidney function to return to normal, and whether any participants need dialysis, which is a treatment that filters the blood when the kidneys cannot do so properly. The medical team will also monitor oxygen levels in the blood and record any adverse events or serious health problems that occur throughout the study period.

1 Baseline assessment before surgery

Before the scheduled heart surgery, a baseline assessment will be performed. This is referred to as Visit 1 and includes an evaluation of heart function using echocardiography, which is an ultrasound examination of the heart.

Blood tests will be taken to measure baseline levels of certain markers, including NT-proBNP, which is a substance in the blood that indicates how well the heart is functioning.

Additional measurements will be taken on the day of surgery, referred to as Day 0 or Visit 2, which serve as the starting point for comparison during the trial.

2 Treatment administration on the day of surgery

On the day of the scheduled heart surgery, the study medication will be administered. The medication is called SP16 or a placebo, which is an inactive substance that looks identical to the real medication.

The medication will be given as a subcutaneous injection, which means it will be injected under the skin.

The heart surgery will be performed using a heart-lung machine, also known as cardiopulmonary bypass or CPB. This machine temporarily takes over the function of the heart and lungs during the operation.

3 Monitoring during the first 72 hours after surgery

During the first 72 hours following the surgery, close monitoring will be conducted to assess safety and detect any adverse events, which are unwanted or harmful reactions that may occur.

Blood tests will be performed regularly to check kidney function by measuring serum creatinine, a waste product that healthy kidneys normally filter from the blood.

The medical team will watch for signs of acute kidney injury, which is a sudden decrease in kidney function that can occur after heart surgery. This condition is assessed using the KDIGO criteria, a standardized system for classifying kidney injury severity.

4 Daily assessments during the first week after surgery

On Day 1 after surgery, heart function will be assessed using point of care echocardiography. Blood will be drawn to measure NT-proBNP levels and central venous oxygen saturation, which indicates how much oxygen is in the blood returning to the heart.

On Day 5 after surgery, another heart function assessment will be performed, and central venous oxygen saturation will be measured again.

On Day 7 after surgery, final measurements will be taken during the hospital stay, including NT-proBNP levels and central venous oxygen saturation.

Throughout the first seven days, kidney function will be monitored daily to determine if acute kidney injury has developed and to assess its severity stage.

5 Hospital discharge and recovery monitoring

If acute kidney injury occurs after surgery, monitoring will continue to track how many days it takes for kidney function to return to baseline levels, or until discharge from the hospital, whichever occurs first.

If kidney function deteriorates significantly, renal replacement therapy may be necessary. This is a treatment that performs the work of the kidneys when they are not functioning properly, commonly known as dialysis.

All adverse events and serious adverse events will continue to be recorded throughout the hospital stay and observation period.

6 Follow-up visit at 90 days after surgery

Approximately 90 days after the heart surgery, a follow-up visit will be scheduled. This visit may occur within 7 days before or after the 90-day mark.

During this visit, heart function will be assessed again using echocardiography and compared to the measurements taken before surgery.

Blood tests will be performed to measure NT-proBNP levels and kidney function markers.

The assessment will determine whether there has been sustained impairment of kidney function, defined as a 25% or greater increase in serum creatinine compared to baseline levels.

Information will be collected about whether dialysis was required at any time during the 90-day observation period.

This visit marks the end of the observation period for the trial.

Who Can Join the Study?

You must be 18 years of age or older.
You can be male or female.
You must be scheduled for one of the following heart surgeries: CABG (coronary artery bypass graft, a surgery to improve blood flow to the heart), aortic valve surgery (surgery to replace or repair the valve between the heart and main artery, with or without repair of the aortic root which is the beginning of the main artery), mitral valve surgery (surgery on the valve between two chambers of the heart), or a combination of aortic or mitral valve surgery with CABG.
Your surgery is expected to use a CPB (cardiopulmonary bypass, a machine that temporarily takes over the function of the heart and lungs during surgery).
You must be able to provide written informed consent, which means you agree in writing to participate in the study after understanding what it involves.
You must understand the study procedures and be willing to follow all requirements during the clinical trial.
You must have CKD Stage 2 to 3b (chronic kidney disease, a condition where the kidneys do not work as well as they should). This means your eGFR (estimated glomerular filtration rate, a measurement of how well your kidneys are filtering waste from your blood) must be between 30 and 90 ml/min/1.73 m², and this kidney condition must have been known for at least 3 months before joining the study.
Your BMI (body mass index, a measure of body fat based on your height and weight) must be between 19 and 40 kg/m².
If you are a woman who can become pregnant or a man who can father a child, you must use contraceptive measures (birth control methods to prevent pregnancy).

Who Cannot Join the Study?

No exclusion criteria have been provided in the available study information

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

No sites found in this category

Other Sites

Site Name	City	Country	Status
Universitaetsklinikum Erlangen AöR	Erlangen	Germany

Trial status

Country	Status	Recruitment Start
Germany	Not yet recruiting	02.03.2026

Trial locations

Investigated drugs:

SP16

SP16 is an experimental medication being tested in this clinical trial. It is being studied to see if it can help prevent acute kidney injury in people with chronic kidney disease who are having planned heart surgery that uses a heart-lung machine. The trial will look at whether SP16 is safe to use and whether it can protect the kidneys during and after this type of surgery.

A placebo is also being used in this trial. A placebo looks like the real medication but contains no active medicine. It is used to compare against SP16 to help researchers understand if SP16 actually works.

Investigated diseases:

Chronic Kidney Disease – Chronic Kidney Disease is a long-term condition where the kidneys gradually lose their ability to filter waste and excess fluids from the blood. The disease progresses through five stages, with stage 1 being the mildest and stage 5 being the most severe, also known as kidney failure. In the early stages, people may not notice any symptoms, but as the disease advances, waste products build up in the body. Common signs include fatigue, swelling in the legs and ankles, changes in urination frequency, and difficulty concentrating. The progression can occur over months to years, depending on the underlying cause and how well the condition is managed. Risk factors include diabetes, high blood pressure, heart disease, and a family history of kidney problems.

Valvular Heart Disease – Valvular Heart Disease occurs when one or more of the heart valves do not work properly, affecting blood flow through the heart. The heart has four valves that keep blood flowing in the correct direction, and problems arise when these valves become narrowed, leaky, or do not close properly. This condition can be present from birth or develop over time due to aging, infections, or other heart conditions. Symptoms may include shortness of breath, chest pain, fatigue, dizziness, and irregular heartbeat, though some people may not experience symptoms for years. The disease can progress slowly or rapidly depending on which valve is affected and the severity of the damage. As the condition worsens, the heart must work harder to pump blood, which can lead to complications affecting overall heart function.

Cardiovascular Disease – Cardiovascular Disease is a general term for conditions affecting the heart and blood vessels throughout the body. It includes problems such as coronary artery disease, heart rhythm disorders, and blood vessel diseases. The condition often develops when blood vessels become narrowed or blocked due to buildup of fatty deposits called plaque on the vessel walls. This process, called atherosclerosis, can reduce blood flow to the heart and other organs. Symptoms vary depending on the specific type but may include chest pain, shortness of breath, numbness in the limbs, and fatigue. The disease typically develops gradually over many years, with risk factors including high blood pressure, high cholesterol, smoking, diabetes, and lack of physical activity.

Trial ID:

2025-522491-89-00

Protocol code:

UKER-SP16-AKI-01

Trial Phase:

Therapeutic exploratory (Phase II)

Other Trials to Consider

#1 Clinical Trials Search in Europe

Study of SP16 to Prevent Acute Kidney Injury in Patients with Chronic Kidney Disease Undergoing Heart Surgery with Heart-Lung Machine

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?