This study investigates the effects of a medication called BI 764198 in people with Focal Segmental Glomerulosclerosis, which is a rare kidney disease that damages the small filtering units in the kidneys. The study specifically looks at individuals with primary focal segmental glomerulosclerosis or those with a version of the disease caused by TRPC6 gene mutations, which are changes in the genetic code that affect how the disease behaves. Some participants may also be taking a calcineurin inhibitor, which is a type of medicine used to manage certain immune-related conditions.

The purpose of the study is to determine if BI 764198 is more effective than a placebo at reducing the amount of protein leaked into the urine. During the study, participants will take either the active medication or a placebo in the form of an oral film-coated tablet. The treatment period lasts for 104 weeks, and the process is double-blind, meaning neither the participants nor the researchers know which treatment is being administered during the trial.