QUARTET-DKD: Quadruple Therapy for Type 2 Diabetic Nephropathy

Inclusion Criteria: * Age ≥18 years, with a confirmed diagnosis of type 2 diabetes mellitus (T2DM). * Receiving a standard dose of an Angiotensin-Converting Enzyme Inhibitor (ACEI) or Angiotensin Receptor Blocker (ARB) therapy for at least 4 consecutive weeks prior to screening, with the dose expected to remain stable throughout the study period. * Body Mass Index (BMI) ≥ 24.0 kg/m2. * Mean urine albumin-to-creatinine ratio (UACR) ≥ 100 mg/g and \< 5000 mg/g, calculated from first morning void urine samples collected over 3 consecutive days. * Estimated glomerular filtration rate (eGFR) based on the CKD-EPI formula ≥ 30 mL/min/1.73m2 and ≤ 90 mL/min/1.73m2. * Serum potassium level ≤ 4.8 mmol/L. * Glycated hemoglobin (HbA1c) \< 11%. * Voluntarily understood and signed the written Informed Consent Form (ICF). Exclusion Criteria: * Definite diagnosis of non-diabetic kidney disease (e.g., IgA nephropathy, polycystic kidney disease, lupus nephritis, etc). * Personal or family history of medullary thyroid carcinoma (MTC), or a diagnosis of multiple endocrine neoplasia syndrome type 2 (MEN 2). * History of severe acute or chronic pancreatitis. * History of diabetic ketoacidosis (DKA). * Symptomatic hypotension during the screening period, or a resting systolic blood pressure (SBP) \< 110 mmHg. * Refractory hypertension, defined as a resting SBP \> 170 mmHg despite the concurrent use of three antihypertensive medications. * History of severe dehydration, severe diarrhea, or acute volume depletion within 30 days prior to screening. * History of acute kidney injury (AKI) within 30 days prior to screening. * Use of traditional Chinese medicines with potential proteinuria-lowering effects (e.g., Keluoxin capsules, Huangkui capsules, or Shenyan Kangfu tablets) within 30 days prior to screening. * Use of potassium-sparing diuretics (e.g., triamterene or amiloride) or mineralocorticoid receptor antagonists (e.g., spironolactone, eplerenone, or finerenone) within 2 months prior to screening. * Use of GLP-1 receptor agonists, GLP-1/GIP dual receptor agonists, or GLP-1/glucagon (GCG) dual receptor agonists within 6 months prior to screening. * Current use of strong CYP3A4 inhibitors (e.g., itraconazole or clarithromycin) or CYP3A4 inducers that may significantly interfere with finerenone metabolism. * Myocardial infarction, unstable angina, stroke, or hospitalization due to heart failure (NYHA Class III-IV) within 3 months prior to screening. * Active urogenital tract infection, or a history of urogenital tract infection associated with the prior use of SGLT2 inhibitors. * Women who are pregnant, planning to become pregnant, or lactating. * Inability to complete the 6-month follow-up due to general health conditions or geographic relocation. * Any other condition that, in the opinion of the investigator, renders the participant unsuitable for participation in the study.