Finerenone for the Treatment of Type 2 Diabetes-Related Kidney Disease: Efficacy Observation and Related Factor Analysis

This is a prospective observational cohort study enrolling patients with type 2 diabetes mellitus (T2DM) complicated with chronic kidney disease (CKD) receiving finerenone therapy. Subjects will be recruited from the Chongqing Diabetes Registry (CDR), endocrine outpatient and inpatient departments of the First Affiliated Hospital of Chongqing Medical University, with a recruitment window from February 2026 to January 2029. A total of 425 eligible participants are planned to be enrolled.

A target sample size of 425 participants is determined using the R pmsampsize package for predictive model development. Key input parameters: C-statistic of 0.80, 10 candidate predictive variables, expected finerenone responder proportion of 53.2% derived from FIDELIO-DKD and FIGARO-DKD trials. The minimum required sample size to satisfy model stability and calibration criteria is 383 participants. A 10% attrition rate is accounted for, leading to the final enrolment target of 425 patients.

Inclusion Criteria:

• Aged 18-75 years, male or female, with full capacity for independent conduct.
• Confirmed type 2 diabetes-associated chronic kidney disease (CKD): Random urine albumin-to-creatinine ratio (UACR) of 100-5000 ug/mg Cr on two non-consecutive days; estimated glomerular filtration rate (eGFR) calculated by the CKD-EPI formula >25 mL/min/1.73m²; Finerenone treatment is indicated per clinical guidelines.
• All concomitant medications have remained stable for 3 months prior to screening, with no planned treatment adjustments throughout the trial. Stable medication is defined as dose adjustments not exceeding ±25% of the screening baseline dose.
• If the glycemic regimen includes sodium-glucose cotransporter 2 inhibitors (SGLT-2i): The daily SGLT-2i dose remains constant for 3 months before screening, and no daily dose changes are planned during the entire trial. If the glycemic regimen excludes SGLT-2i: No SGLT-2i exposure within 4 weeks prior to screening, and no SGLT-2i initiation is planned throughout the trial.
• If the glycemic regimen includes glucagon-like peptide-1 receptor agonists (GLP-1RA): The daily GLP-1RA dose remains constant for 3 months before screening, and no daily dose changes are planned during the entire trial. If the glycemic regimen excludes GLP-1RA: No GLP-1RA exposure within 4 weeks prior to screening, and no GLP-1RA initiation is planned throughout the trial.
• Fully understands the entire trial procedure, voluntarily participates in the study and signs the informed consent form.

Exclusion Criteria:

• Diagnosed or suspected type 1 diabetes, special type diabetes or secondary diabetes.
• Poor glycemic control with glycated hemoglobin (HbA1c) >9.0%.
• Average seated office blood pressure measured over 3 visits with systolic blood pressure >160 mmHg and/or diastolic blood pressure >100 mmHg.
• Serum potassium >5.0 mmol/L without potassium supplementation.
• Diagnosed or suspected chronic kidney disease unrelated to diabetic nephropathy.
• Complicated with liver cirrhosis or moderate-to-severe liver impairment.
• Patients with secondary aldosteronism and primary aldosteronism who have surgery plans within six months.
• Confirmed Addison's disease.
• Complicated with uncontrolled autoimmune diseases.
• Complicated with active malignant tumors.
• Presence or suspicion of depression, bipolar disorder, suicidal tendency, schizophrenia or other severe mental illnesses; or lack of mental capacity or language barrier, unable to fully understand the trial protocol or unwilling to cooperate with study site staff.
• Complicated with other uncontrolled chronic diseases.
• Use of serum potassium-elevating agents (e.g., amiloride, triamterene) or other mineralocorticoid receptor antagonists (MRAs, e.g., spironolactone, eplerenone) within 4 weeks prior to screening.
• Use of strong CYP3A4 inhibitors (itraconazole, ketoconazole, ritonavir, nelfinavir, cobicistat, clarithromycin, telithromycin, nefazodone) or CYP3A4 inducers (carbamazepine, phenytoin, erythromycin, fluvoxamine) within 2 weeks prior to screening.
• Pregnant or breastfeeding women.