AST-120 (Kremezin®) for the Renal Protection and Attenuation of Decline in Acute Kidney Disease

Study Procedures：

• Total Number of Subjects The total number of subjects planned for enrollment is 100.

The study will include two groups:

• Experimental Group: 50 patients receiving AST-120 (6g/day) in combination with standard post-AKD care.
• Control Group: 50 patients receiving only standard post-AKD care. The sample size is determined based on the statistical power needed to detect a significant difference in the primary endpoint (percentage changes in IS levels), with consideration for potential dropout rates. The evaluable number is estimated to be close to 90, allowing for a 10% dropout rate, making the enrolled number 100.

• Interventions, Procedures, and Tests for Each Group

Subjects will undergo the following interventions, procedures, and tests according to the schedule:

• Baseline (Day 0):

• Demographic data collection.
• Blood tests for serum creatinine, eGFR, IS, p-CS, and urinary albumin-to-creatinine ratio (UACR).
• Randomization into experimental or control groups.
• Treatment Period (Day 1-14):

• Experimental Group: Receive AST-120 (6g/day, divided into three doses per day).
• Control Group: Standard post-AKD care only.
• Both groups will undergo regular clinical assessments and adverse event monitoring.
• Day 14:

• Blood tests for IS, p-CS, serum creatinine, eGFR, and UACR.
• Follow-up (Day 90 and Day 180):
• Assess eGFR, serum creatinine, UACR.
• Monitor for major adverse kidney events (MAKE) and major adverse cardiovascular events (MACE).

• Trial Procedure Timeline

The trial procedure follows this timeline:

• Day 0: Baseline measurements and randomization.
• Day 1-14: Treatment phase (AST-120 administration or standard care).
• Day 14: Blood tests and assessment of treatment efficacy.
• Day 90 and Day 180: Follow-up visits for MAKE and MACE assessments, and blood tests for kidney function.

• Specimen Collection and Processing

• Specimen: Blood samples will be collected on Day 0 (baseline), Day 14 (end of treatment), Day 90, and Day 180 (follow-up).
• Transport and Storage: Specimens will be transported to the laboratory within the hospital for immediate processing. They will be stored in a temperature-controlled facility if needed.
• Processing: Blood samples will undergo centrifugation for serum separation. Serum will be used for measuring IS, p-CS, serum creatinine, and other biomarkers.
• Analysis: The following tests will be performed:

• IS and p-CS levels.
• Serum creatinine and eGFR.
• UACR.

• Clinical Data Collection and Questionnaires

Clinical data collected will include:

• Demographic data (age, sex, medical history).
• Lab results for IS, p-CS, creatinine, eGFR, UACR. No specific questionnaires will be used for this study.

Inclusion/Exclusion Criteria： Inclusion criteria

• Age between 18 and 80 years.
• Diagnosis of acute kidney disease (AKD) during hospitalization, with AKD stage 2 or 3 according to the KDIGO-AKD criteria, defined by an increase in serum creatinine to 2 times or more from baseline within 7 to 90 days.
• Post-discharge estimated glomerular filtration rate (eGFR) between 30 and 60 ml/min/1.73m², calculated using the MDRD equation.
• Hospitalization duration not exceeding 1 month.

Exclusion criteria

• Patients with cancer or hematological malignancies.
• Patients with AKD etiologies that cannot be managed in an outpatient setting (e.g., diabetic foot, obstructive uropathy with sepsis, cirrhosis).

• Patients presenting any of the following conditions, considered as excessively vulnerable populations or other conditions:

• Bedridden.
• Requiring nasogastric tube feeding.
• Long-term use of oxygen therapy.
• Use of urinary catheters.

Patients unsuitable for AST-120 treatment, including:

• Patients with severe constipation (defined as requiring the daily use of more than one laxative).
• Patients with abnormal liver function (defined as ALT levels greater than 5 times the upper limit or total bilirubin > 2mg/dL).
• Patients with a history of peptic ulcers within the last month.
• Pregnant women.
• Patients allergic to the study drug.