FDA expands finerenone use to kidney disease associated with type 1 diabetes

Bayer announced on September 17 that the U.S. Food and Drug Administration had approved an expanded indication for finerenone, marketed as Kerendia, in adults with chronic kidney disease associated with type 1 diabetes. The decision adds a treatment option for a complication that can threaten long-term health and increase the burden of living with diabetes.

The updated U.S. prescribing information defines the indication carefully: reducing urinary albumin-to-creatinine ratio, or UACR, with an expected reduction in the risk of sustained kidney-function decline and end-stage kidney disease. That wording matters because the pivotal type 1 diabetes trial measured a urinary biomarker over six months rather than directly establishing fewer cases of kidney failure.

### What the trial established

FINE-ONE was a randomized, double-blind, placebo-controlled phase 3 trial involving 242 adults with type 1 diabetes and chronic kidney disease. Participants had elevated urinary albumin and an estimated glomerular filtration rate between 25 and less than 90 milliliters per minute per 1.73 square meters. They were already receiving an ACE inhibitor or angiotensin-receptor blocker.

The primary endpoint was the relative change in UACR over six months. The ratio decreased by 34% with finerenone and 12% with placebo. The statistical comparison showed a 25% greater reduction with finerenone, with a treatment-to-placebo ratio of 0.75 and a 95% confidence interval of 0.65 to 0.87.

That 25% figure describes the relative biomarker effect. It cannot be read as a 25% reduction in kidney failure, dialysis, or death.

The results predate this week's regulatory development. They were presented in November 2025 and published online in the New England Journal of Medicine on March 4, 2026. September 17 brings the approval announcement, rather than a newly completed efficacy trial.

### Why the endpoint matters

Albumin appearing in urine is an important sign of kidney damage. UACR measures that protein relative to urinary creatinine, helping account for differences in urine concentration. Lowering it can provide evidence that a treatment is affecting kidney disease, but a biomarker and a patient's eventual clinical outcome remain different measurements.

Bayer said the approval also drew support from the FIDELIO-DKD and FIGARO-DKD studies in chronic kidney disease associated with type 2 diabetes. Those studies contribute evidence about finerenone's kidney benefits in a related population. Applying that evidence to type 1 diabetes requires an inference that the new labeling makes explicit through its description of expected benefit.

For healthspan research, the relevant goal is preserving organ function and reducing future disease burden. FINE-ONE does not establish an increase in lifespan or the number of years lived without disability, and its six-month treatment period limits conclusions about durable clinical benefit.

### Safety remains part of the evidence

Hyperkalemia, or elevated blood potassium, occurred in 10.1% of finerenone recipients and 3.3% of placebo recipients. Two participants stopped finerenone because of hyperkalemia. Kidney filtration estimates also fell more during treatment with finerenone, then approached baseline during the washout period.

The prescribing information warns that potassium risk increases as kidney function decreases and when baseline potassium is higher. It includes laboratory monitoring requirements and restrictions involving certain interacting medicines. These safeguards are part of the approved treatment framework.

The Bayer-funded trial supplies credible human evidence for reducing albuminuria in the population studied. The remaining distinction is consequential: the regulatory expansion provides a new option now, while the magnitude of long-term kidney protection specifically in type 1 diabetes was not directly measured by its primary endpoint.