Inclusion Criteria:  Signed and dated written informed consent in accordance with International Council on Harmonisation - Good Manufacturing Practice (ICH-GCP) and local legislation prior to admission to the trial. Patients with available medical records for data abstraction to meet the objectives of the study. Male or female patients aged ≥ 18 years at time of consent. Body Mass Index (BMI) ≥ 18.5 and < 50 kg/m² at Visit 1. Clinical diagnosis of Chronic Kidney Disease (CKD). Estimated Glomerular Filtration Rate (eGFR) decline of at least 1ml/min/1.73m²/year based on historical data from (electronic) medical records. eGFR (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] formula) 20 - 75 ml/min/1.73m² at Visit 1 calculated from serum creatinine measured by a central laboratory. Patients are expected to be on optimal and stable background treatment (according to local therapy guidelines). At least 4 serum creatinine values in the retrospective phase. The most recent and oldest serum creatinine values should be no less than 2 years apart and no greater than 3 years apart.  Exclusion Criteria:  Changes in CKD or other key background treatments (including dose changes) known to impact eGFR values, over the past 4 weeks for Angiotensin Converting Enzyme inhibitors (ACEis) and Angiotensin Receptor Blockers (ARBs) and 8 weeks for Sodium-Glucose Co-Transporter-2 (SGLT2) inhibitors prior to Screening. Autosomal Dominant Polycystic Kidney Disease (ADPKD), uncontrolled lupus nephritis, in the opinion of investigators. Any iv immune suppression therapy within the last 3 months prior to Visit 1 or anyone currently on >45 mg prednisolone (or equivalent). Acute kidney injury (AKI) according to the Kidney Disease: Improving Global Outcomes (KDIGO) definition in the 30 days prior to Visit 1 until the start of trial assessments. Planned start of chronic renal replacement therapy during the trial or end stage renal disease (i.e < 15 ml/min at 2 measurements 30 days apart) before start of trial assessments. Medical history of cancer or treatment for cancer in the last two years prior to Visit 1 (except appropriately treated basal cell carcinoma of the skin, in situ carcinoma of uterine cervix, and prostatic cancer of low grade [T1 or T2]). Major surgery (investigator's judgement) planned during the trial. Currently enrolled in an investigational device or drug trial, i.e., less than 30 days before Visit 1 since ending an investigational device or drug trial(s) or receiving investigational treatment(s).  Further exclusion criteria apply.