Finerenone in diabetic kidney disease: Findings from a single-center retrospective observational study

Abstract

Diabetic kidney disease (DKD) remains associated with substantial residual kidney and cardiovascular risk despite renin–angiotensin system blockade and sodium–glucose cotransporter 2 (SGLT2) inhibitor therapy. Routinely collected data from 16 adults with documented DKD who initiated finerenone 10 mg once daily at a single nephrology center were retrospectively analyzed. The primary outcome was the change in urine albumin-to-creatinine ratio (UACR); estimated glomerular filtration rate (eGFR), serum creatinine, serum potassium, and UACR responder rates were secondary outcomes. Measurements were assessed at baseline, 3 months, and 6 months. The mean age was 68.4 ± 9.6 years; 75.0% were women; the median baseline eGFR was 35.6 (interquartile range [IQR] 29.9–56.7) mL/min/1.73 m 2 ; and the median baseline UACR was 57.0 (IQR 19.8–123.3) mg/g. Background angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker therapy and SGLT2 inhibitor therapy were each present in 93.8% of patients. Six-month data were available for 15 patients. Median UACR decreased to 30.0 mg/g at 3 months and 18.0 mg/g at 6 months (Friedman p < 0.001; Kendall’s W = 0.871). Median relative reductions were 28.4% and 54.1%, respectively. At 6 months, 12/15 patients (80.0%) achieved a ≥30% UACR reduction, and 9/15 (60.0%) achieved a ≥50% reduction. No statistically significant longitudinal change was detected in eGFR ( p = 0.112) or serum potassium ( p = 0.166). A post-baseline potassium value ≥5.5 mmol/L was observed in two patients; no value exceeded 5.5 mmol/L or reached 6.0 mmol/L. In this small uncontrolled cohort, finerenone initiation was associated with a marked reduction in UACR over 6 months. The findings are exploratory and should be interpreted cautiously because of the retrospective design, limited sample size, absence of a comparator, short follow-up, and potential confounding by concomitant therapies.