: IgA-nephropathy is the most common glomerulonephritis with the unfavorable prognosis in patients with persistent albuminuria. Finerenone is a new nonsteroidal mineralocorticoid receptor antagonist that has demonstrated efficacy in reducing albuminuria in patients with CKD and type 2 diabetes in two major trials, FIGARO-DKD and FIDELIO. This finding supported the approval of finerenone by the U.S. Food and Drug Administration (FDA) for the treatment of chronic kidney disease (CKD). A subgroup analysis in the pooled FIDELITY trial demonstrated that in patients with CKD stages 1-4 and type 2 diabetes (T2D), the cardio- and nephroprotective effects of finerenone were independent of concomitant therapy with SGLT-2 inhibitors or GLP-1 receptor agonists. Thus, the role of finerenone in slowing CKD progression in T2D can be considered well-established. Given its albuminuria-reducing effects, finerenone is being investigated in multiple trials, including studies on non-diabetic kidney disease and IgA nephropathy, though no published results are available yet. In this trial finerenone will be used as a nephroprotective agent above standard treatment in terms of assessing adverse events and potential efficacy.

Inclusion Criteria:

• Adults (> 18 years) with the primary IgAN diagnosed by kidney biopsy;
• Treatment with stable doses of iRAS or/and iSGLT2 inhibitors for at least 3 months prior inclusion into the trial;
• Blood pressure < 140/90 mm Hg
• 24-hour urinary albumin excretion > 300 mg

Exclusion Criteria:

• Kidney transplantation in medical history
• Chronic hepatic disease, including hepatitis, malignant tumor, active malignancy;
• Heart failure with ejection fraction <40%;
• Acute myocardial infarction and/or stroke less then 3 months before including in trial;
• Presence ANCA in serum
• Ongoing immunosuppressive treatment
• eGFR < 20 ml/min
• Pregnancy and breastfeeding
• Uncontrolled blood pressure