Kidney Effects of Finerenone Added to Sodium‐Glucose Cotransporter 2 Inhibitors in Patients With Diabetic Kidney Disease

ABSTRACT Background Both finerenone and sodium‐glucose cotransporter 2 inhibitors (SGLT‐2Is) improve kidney outcomes in people with type 2 diabetes (T2D) and chronic kidney disease (CKD), but the real‐world effectiveness of their combination remains unclear. Methods This retrospective, single‐center study recruited people with T2D‐CKD receiving finerenone on SGLT‐2Is or SGLT‐2Is alone in West China Hospital of Sichuan University. Kidney outcomes were compared after 1:4 propensity score matching. The primary outcome was the time from drug initiation to ≥ 30% decline in eGFR. The secondary outcome was the change in chronic eGFR slope. Results The matched cohort included 228 SGLT‐2Is initiators and 69 finerenone initiators on SGLT‐2Is. The baseline mean age was 54.5 years, with eGFR of 68.8 mL/min/1.73 m 2 and eGFR slope of −2.1 mL/min/1.73 m 2 /year. Over a median follow‐up of 18.1 months, people receiving finerenone and SGLT‐2Is were associated with a reduced risk of ≥ 30% eGFR decline (HR: 0.26; 95% CI: 0.11–0.57) compared to those who received SGLT‐2Is only. The between‐group difference in post‐treatment chronic eGFR slope was −0.74 mL/min/1.73 m 2 /year (95% CI: −2.95–1.45). However, of those with rapid pre‐treatment eGFR decline, the finerenone on SGLT‐2Is group experienced significantly greater eGFR decline compared to the SGLT‐2Is group (mean difference: −6.28 mL/min/1.73 m 2 /year; 95% CI: −11.81 to −0.75). Conclusion Finerenone added to SGLT‐2Is was associated with slower eGFR decline in most individuals with T2D‐CKD. However, people with rapid pre‐treatment eGFR decline may experience accelerated deterioration when finerenone is added. These findings are hypothesis‐generating rather than confirmatory, requiring further well‐designed and prospective studies for validation.