A Study to Learn More About How Well the Study Treatment Finerenone Works, How Safe it is, How it Moves Into, Through, and Out of the Body, and the Effects it Has on the Body When Taken With an ACE Inhibitor or Angiotensin Receptor Blocker in Children With Chronic Kidney Disease and Proteinuria

Primary Outcome Measures

1. Percent change in Urinary protein-to-creatinine ratio (UPCR) reduction from baseline to day 180+/-7
   Percent change from baseline to day 180±7 in UPCR will be calculated.

Secondary Outcome Measures

1. Number participants with treatment emergent adverse events (TEAEs）
   Below sub-categories will be considered: 1. Serious Treatment Emergent Adverse Events (TEAEs) 2. TEAEs and serious TEAEs leading to discontinuation of treatment 3. Study drug related TEAEs and serious TEAEs 4. TEAEs categorized by severity (mild, moderate, severe) 5. TEAEs by maximum intensity 6. Number of participants hospitalized with hyperkalemia, 7. Number of participants discontinuing due to hyperkalemia, 8. Number of participants with hospitalization for worsening of renal function 9. Number of participants discontinuing due to worsening of renal function
2. Change in serum potassium levels from baseline to day 180±7
3. Change in serum creatinine from baseline to day 180±7
4. Change in eGFR from baseline to day 180±7
   Estimated glomerular filtration rate (eGFR)
5. Change in systolic blood pressure from baseline to day 180±7
6. UPCR reduction of at least 30% from baseline to day 180+/-7
   Proportion of participants at day 180+/-7 with a \>=30% reduction in PUCR compared to baseline
7. Change in UACR from baseline to day 180±7
   Urinary albumin-to-creatinine ratio (UACR)
8. Pharmacokinetics (PK) finerenone Cmax, md
   Maximum observed finerenone concentration in plasma after multiple doses.
9. Pharmacokinetics (PK) finerenone AUCτ,md
   Area under the curve for finerenone concentration in plasma after multiple doses.
10. Taste and texture questionnaire of the pediatric formulation