Real-world use of finerenone in diabetic kidney disease: eGFR slope analysis with exploratory data on prior MRA use

In the post-SGLT2 inhibitor era, residual renal risk remains a major concern in diabetic kidney disease (DKD). Finerenone, a non-steroidal mineralocorticoid receptor antagonist (MRA), has shown cardiovascular and renal benefits in clinical trials. However, its effectiveness in patients previously treated with other MRAs remains unclear. We retrospectively analyzed 73 patients with DKD who were treated with finerenone at Shimane University Hospital between June 2022 and March 2024. The primary outcome was the change in estimated glomerular filtration rate (eGFR) slope before and after finerenone initiation. The mean eGFR slope significantly improved following finerenone initiation (-7.3 to -0.5 mL/min/1.73 m²/year, P = 0.010). In a sub-analysis of 65 patients with ≥6 months of follow-up, compared to the 1-year pre-treatment period, the decline in eGFR was significantly attenuated (-5.2 to -0.03 mL/min/1.73 m²/year, P = 0.036), accompanied by a significant reduction in the urinary albumin-to-creatinine ratio (UACR). Notably, one-third of patients had switched from other MRAs, most commonly esaxerenone. In this subgroup, a trend toward eGFR preservation was observed, although the reduction in UACR was not observed. In contrast, MRA-naïve patients exhibited significant improvements in both eGFR slope and UACR. No serious cases of hyperkalemic crisis were observed. These findings highlight the favorable renal effects of finerenone, even in high-risk patients previously managed with other MRAs. Finerenone may offer incremental benefit for eGFR preservation and supports its role in comprehensive DKD management.