To our knowledge, this is the first real-world study to assess the effect of adding finerenone to SGLT2i and GLP-1 RA therapy in adults with T2D and CKD. This addition resulted in a ~51% reduction in UACR over approximately six months, a finding that was consistent across subgroups (including baseline eGFR and UACR). The magnitude of albuminuria lowering aligns with the 52% reduction reported in the finerenone and empagliflozin combination arm of the CONFIDENCE trial [7]. It also mirrors the 51% reduction in UACR observed among the 68 individuals who received finerenone and empagliflozin and were on a GLP-1 RA at baseline in a recent analysis of the CONFIDENCE trial [8].
In contrast to the CONFIDENCE trial, where finerenone and empagliflozin were initiated simultaneously, all individuals in our study had been receiving an SGLT2i (median, 30 months) and a GLP-1 RA (median, 28 months) before finerenone was added. Despite having more advanced kidney disease and higher baseline albuminuria than participants in CONFIDENCE, our cohort showed a robust reduction in albuminuria after finerenone initiation. These findings suggest that finerenone is effective across disease severity and treatment sequences, with its effect on albuminuria-lowering maintained even when added to established SGLT2i and GLP-1 RA therapy.
The adjusted eGFR decline (β3.92 mL/min/1.73 m2) may reflect a hemodynamic dip. This value is close in magnitude to the β5.0 mL/min/1.73 m2 adjusted eGFR decline observed in the combination therapy group of the CONFIDENCE trial at day 180, which largely stabilized thereafter [7]. Importantly, in the CONFIDENCE trial most of the early eGFR decline was reversible after treatment discontinuation, supporting the interpretation that this is a functional, drug-related effect rather than progressive renal impairment. Nevertheless, longer follow-up is needed to determine the full trajectory. Of note, one of the three excluded individuals had acute kidney injury during the first month after initiating finerenone (Figure 1). This uncommon incidence is consistent with the low incidence of acute kidney injury observed in the combination therapy group in the CONFIDENCE trial (~2%) [7]. The modest increase in potassium (+0.34 mmol/L) supports the need for routine monitoring yet suggests acceptable short-term tolerability, with only two individuals >5.5 mmol/L who were managed using potassium binders.
In light of recent evidence, a four-pillar strategy including RAS blockade, SGLT2 inhibition, nonsteroidal MRA, and GLP-1 RA is a well-founded approach for patients with T2D and albuminuric CKD. This approach leverages complementary renoprotective mechanisms. RAS blockade provides favorable hemodynamic effects. Beyond their glucose-lowering properties, SGLT2is may exert pleiotropic effects and provide both hemodynamic and metabolic benefits, thereby enhancing cell survival and function under stress conditions [4,9]; GLP-1 RAs target metabolic and inflammatory drivers; and the nonsteroidal MRA, finerenone, adds hemodynamic, anti-fibrotic, and anti-inflammatory benefits [10]. Renal injury in CKD involves mechanisms in which mineralocorticoid receptor (MR) overactivation, elevated fibroblast growth factor 23 (FGF23), and Klotho insufficiency act together to accelerate kidney damage. MR activation promotes intrarenal inflammation, oxidative stress, and fibrosis, while Klotho deficiency and excess FGF23 further amplify these pathways. By selectively antagonizing MR, finerenone may attenuate both the direct MR-mediated renal injury and the intersecting FGF23/Klotho-related cascades, leading to beneficial renal effects [11]. Furthermore, experimental data indicate that finerenone can even reverse diabetes-related downregulation of renal GLP-1 receptors, providing a strong mechanistic rationale for combining finerenone with GLP-1 RAs [12].
The study has several limitations, including its single-center, uncontrolled design and relatively small sample size. We could not separately analyze the effect of the 10 mg versus 20 mg dose due to the study's design and small sample size. A further limitation is that we did not adjust our models for every individual background antihypertensive drug class. The vast majority of participants (94%) were already receiving RAS inhibitor therapy. We therefore treated its effect as essentially constant across the cohort and focused on the additive effect of finerenone. Other agents such as beta blockers (75%) and calcium channel blockers (63%) were also common, but these classes are not typically associated with albuminuria reductions of the magnitude we observed [13]. Adding all of these medication variables separately to our model would have increased the risk of overfitting and reduced the precision of the main estimate. We assume that any residual confounding from these medications is likely to be small and does not change the conclusion that finerenone provided a substantial additive reduction in UACR. Additionally, due to its observational nature, confounding by unmeasured factors cannot be excluded.