This study is a randomized controlled pilot trial designed to evaluate the effects and safety of a traditional Chinese medicine formula (DKD-1) as an add-on therapy to standard treatment in patients with Diabetic Kidney Disease (DKD). Eligible participants will be randomly assigned to receive either standard care alone or standard care combined with DKD-1 for 12 weeks. Kidney function, glycemic control, proteinuria, quality of life, and traditional Chinese medicine tongue features will be assessed before and after the intervention. The study aims to provide preliminary evidence on whether DKD-1 can improve renal function, glycemic control, and quality of life in this patient population.

This study is a prospective, single-blind (data analyst-blinded), randomized controlled pilot trial evaluating a traditional Chinese medicine formula (DKD-1) as adjunctive therapy in patients with Diabetic Kidney Disease. DKD is a progressive condition with limited treatment options to slow renal deterioration and manage glycemic control. Traditional Chinese medicine is widely used as a complementary approach, but clinical evidence remains limited. After providing informed consent, eligible participants will be screened according to inclusion and exclusion criteria and randomly assigned in a 1:1 ratio to receive either standard therapy alone or standard therapy plus daily oral DKD-1 (14.5 g) for 12 weeks. Baseline and post-intervention assessments include estimated glomerular filtration rate (eGFR), serum creatinine, urine albumin-to-creatinine ratio (UACR), glycated hemoglobin (HbA1c), quality of life (KDQOL-SF™ 1.3), and TCM tongue diagnosis. Adverse events will be monitored throughout the study. This trial is designed to provide preliminary clinical evidence on the potential role of DKD-1 in improving renal function, glycemic control, and quality of life, supporting future larger-scale randomized controlled trials.

Inclusion Criteria:

• Adults aged ≥18 years.
• Patients diagnosed with type 2 diabetes mellitus and stage 3-4 chronic kidney disease (CKD), confirmed by a nephrologist and classified as ICD-10-CM codes E11.21-E11.29 combined with N18.3-N18.4, consistent with diabetic kidney disease (DKD) definitions.
• Ability to understand the study procedures and provide written informed consent.
• Willingness to comply with study procedures and follow-up visits.

Exclusion Criteria:

• Acute kidney injury or major kidney-related surgery within 3 months prior to enrollment.
• Participation in another clinical trial within 3 months that may significantly affect renal function.
• Alanine aminotransferase (ALT) levels greater than 3 times the upper limit of normal.
• Pregnancy or breastfeeding.
• History of malignancy currently receiving chemotherapy, radiotherapy, or other systemic anticancer treatment.
• End-stage disease as defined under palliative care regulations.
• Known allergy to any components of the DKD-1 herbal formula, including Astragalus membranaceus, Salvia miltiorrhiza, Chinese yam, Poria cocos, Moutan cortex, Schisandra chinensis, or Smilax glabra.

The data sharing plan is currently undecided. A final decision regarding the sharing of individual participant data will be made upon the completion of the study and prior to the publication of the primary results.

Although this study is open-label, the data analysts performing statistical analyses and interpreting the results will remain blinded to group allocation throughout the study to minimize analysis and interpretation bias.