Abstract
INTRODUCTION: This study evaluated the effectiveness and safety of an add-on treatment with finerenone as combination therapy in patients with diabetic kidney disease (DKD), an area where real-world data is limited. MATERIALS AND METHODS: We retrospectively evaluated patients with DKD treated with sodium-glucose cotransporter 2 (SGLT-2) inhibitors and add-on finerenone, to assess the effectiveness and safety of the combination therapy (data collected between June 2021 and October 2024). Outcomes included changes in urinary albumin-to-creatinine ratio (UACR), protein-to-creatinine ratio (UPCR), estimated glomerular filtration rate (eGFR), and serum potassium before and after finerenone initiation. RESULTS: Among 23 patients (mean age 72 ± 7; 17 male) on SGLT-2 inhibitors, 21 (91%) also received renin-angiotensin system (RAS) inhibitors and 9 (39%) glucagon-like peptide-1 (GLP-1) receptor agonists. Addition of finerenone significantly reduced UPCR from 0.52 (0.18 - 1.35) to 0.41 (0.16 - 1.78) g/g (p = 0.046), a median decrease of 35% (IQR -53 to -8). UACR showed a reduction trend from 285 (36 - 1,020) to 266 (57 - 1,006) mg/g (p = 0.15), with a median decrease of 36% (IQR -65 to +14). Kidney function remained stable with a small non-significant decline in eGFR (45 ± 22 to 44 ± 21 mL/min/1.73m(2); -4% ± 13%; p = 0.13). Serum potassium increased slightly but significantly (4.3 ± 0.5 to 4.5 ± 0.4 mmol/L; p = 0.045), with 1 mild hyperkalemia case (5.6 mmol/L) and no treatment discontinuations. CONCLUSION: In this real-world cohort, the renoprotective combination therapy with added finerenone was associated with a further reduction in albuminuria and proteinuria. The treatment was well tolerated with a minimal increase in potassium levels and generally stable renal function.