FIDELIO-DKD

Population

• Patients with CKD and type 2 diabetes on renin-angiotensin system blockade that had been adjusted before randomization to the maximum labeled dose that did not cause unacceptable side effects.
• Either urinary albumin-to-creatinine ratio 30 to less than 300, eGFR 25 to less than 60 ml/min/1.73 m2, and diabetic retinopathy, or urinary albumin-to-creatinine ratio 300 to 5000 and eGFR 25 to less than 75 ml/min/1.73 m2.

Intervention

Finerenone.

Comparator

Placebo.

Key results

• During a median follow-up of 2.6 years, a primary outcome event occurred in 504 of 2833 patients (17.8%) in the finerenone group and 600 of 2841 patients (21.1%) in the placebo group; hazard ratio 0.82 (95% CI 0.73-0.93; P=0.001).
• The key secondary composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure occurred in 367 patients (13.0%) with finerenone and 420 patients (14.8%) with placebo; hazard ratio 0.86 (95% CI 0.75-0.99; P=0.03).
• Overall, the frequency of adverse events was similar in the two groups.

Harms

• The incidence of hyperkalemia-related discontinuation of the trial regimen was higher with finerenone than with placebo (2.3% vs 0.9%).

Practice impact

• Offer finerenone to patients with type 2 diabetes and albuminuric CKD who are already on maximum tolerated RAS blockade.
• Monitor potassium; hyperkalemia-related discontinuation was higher with finerenone (2.3% vs 0.9%).

Applicability

• Most applicable to type 2 diabetes with CKD in the albuminuria and eGFR ranges used for eligibility, including the moderately albuminuric pathway that also required diabetic retinopathy.
• All patients were already on RAS blockade titrated to the maximum labeled dose they could tolerate.

Limitations

• The primary analysis reports 2833 and 2841 patients, fewer than the 5734 who were randomly assigned; the abstract does not explain the difference.
• The cardiovascular composite was a key secondary outcome, not the primary end point.
• The abstract does not report the finerenone dose.

Common misinterpretations

• This is not a trial of finerenone instead of an ACE inhibitor or ARB; it was added to RAS blockade.
• Do not treat the cardiovascular composite as the primary result; the primary end point was the kidney composite.