Adding Finerenone to SGLT2 Inhibitors and Long-Term Kidney Outcomes in Diabetic Kidney Disease

Despite treatment with renin-angiotensin system inhibitors (RASis) and sodium-glucose cotransporter 2 inhibitors (SGLT2is), diabetic kidney disease (DKD) continues to exhibit substantial residual renal risk. The renoprotective effects of adding finerenone to dual therapy remain incompletely characterised.

A total of 255 patients with DKD receiving combined RASi and SGLT2i therapy were analysed by intention-to-treat as triple combination therapy (TCT) with finerenone or dual combination therapy (DCT) alone. The outcomes were longitudinal changes in proteinuria, serum potassium and estimated glomerular filtration rate (eGFR) slope, including total eGFR slope over 24 months and the post-initial dip eGFR slope from 3 to 24 months, evaluated before and after propensity score (PS) matching.

Over a 24-month follow-up period, TCT was associated with a greater and sustained reduction in proteinuria compared with DCT, with significant reductions of 47% at 24 months (p = 0.028). Although the total eGFR slope did not differ significantly between groups, the post-initial dip slope was significantly improved in the TCT group, with an attenuation of annual eGFR decline by approximately 1.31 mL/min/1.73 m²/year (95% CI: 0.25 to 2.36) compared with DCT (p = 0.015). After PS matching, this association remained significant (between-group difference 1.45 mL/min/1.73 m²/year; 95% CI: 0.32-2.58; p = 0.012). Serum potassium increased modestly in the early phase of TCT but stabilised thereafter, with no significant difference between groups at 24 months.

Among patients with DKD receiving RASi and SGLT2i therapy, the addition of finerenone was associated with greater proteinuria reduction and a significant improvement in the post-initial dip eGFR slope, suggesting that TCT may offer an additional renoprotective strategy in DKD.