The EFfect of FinErenone in Kidney TransplantiOn Recipients: The EFFEKTOR Study

Clinical Trial Inclusion Criteria: * Adult kidney transplant recipients ≥ 18 years * 1 to 10 years post kidney transplantation from a deceased or living donor * Stable kidney allograft function (within 20% baseline eGFR) and based on the clinical judgement of the investigator * Preserved kidney allograft function defined as an eGFR ≥ 25 mL/min/1.73 m * Urine albumin:creatinine ratio (UACR) ≥30 ug/mg * Ability of the participant, or their legally authorized representative, to provide informed consent * Contraceptive requirements: * Women of non-childbearing potential do not need to undergo pregnancy testing or agree to use adequate contraception. Non-childbearing potential is defined as documented hysterectomy, bilateral salpingectomy, oophorectomy or postmenopausal females (amenorrhea for 12 months without an alternative medical cause). A single high follicle stimulating hormone level in the postmenopausal range may be used to confirm a postmenopausal state. * Women of childbearing potential can only be included if a pregnancy test is negative at the screening visit and if they agree to use adequate contraception during the study and until 8 weeks after the last study intervention dose. Adequate contraception is defined as an intrauterine device, implant or combined oral contraceptive with a physical barrier (e,g., condom). Additional Inclusion Criteria for Kidney Biopsy Sub-study: * Willingness to undergo research study biopsies at screening and following the 12 month treatment period * Ability to safely discontinue antiplatelet or anticoagulant treatments * No known intrinsic bleeding diathesis * Hemoglobin \>9.0 g/dL; Platelets \> 100,000; International Normalised Ratio (INR) \<1.4 on the day of kidney biopsy * Body mass index \<40 * Blood pressure controlled on the day of biopsy to \<160/90 Medical Condition Exclusion Criteria: * Documented recurrent lupus nephritis, ANtineutrophilic Cytoplasmic Antibody (ANCA) vasculitis, membranoproliferative glomerulonephritis (including C3 glomerulopathy) * History of solid organ transplantation other than kidney * Acute kidney injury requiring dialysis within 6 months prior to screening * Uncontrolled hypertension with a sitting Systolic Blood Pressure (SBP) ≥180 mmHg or Diastolic Blood Pressure (DBP) ≥100 mmHg * Any indication for treatment with a steroidal MRA * UACR \>3500 mg/g at screening. This may be reassessed if one of the three first morning urine samples is \>3500 mg/g at the screening visit * CV event within 3 months prior to screening (heart failure requiring acute care, myocardial infarction, stroke, transient ischemic attack, pulmonary embolism, elective coronary artery bypass grafting) * Elective percutaneous coronary intervention within 1 month prior to screening * Known hypersensitivity to the study treatment * Addison's disease * Hepatic insufficiency classified as Child-Pugh C * Pregnancy, breast feeding or intention to become pregnant Concomitant Therapies Exclusion Criteria: * Concomitant therapy with spironolactone, eplerenone, sacubitril/valsartan combination, or potassium-sparing diuretic which cannot be discontinued at least 2 weeks prior to screening * Simultaneous use of Angiotensin-Converting Enzyme Inhibitors (ACEI) and Angiotensin Receptor Blockers (ARB), without being able to discontinue one of these at least 2 weeks prior to screening * Use of potent CYP3A4 inhibitors or inducers (to be stopped at least 7 days before randomization). Other Exclusion Criteria: * Participation in the MRI Study is excluded for certain pacemakers, electronic implants, shrapnel of the eye and certain types of aneurysm clips. * Any other history, condition, or therapy which could, in the opinion of the investigator, affect compliance with the study treatment and procedures * Close affiliation with the investigational site, investigators or staff * Simultaneous participation in another interventional trial within 30 days prior to randomization