This study is looking at a medicine called iptacopan for treating a kidney disease called IgA nephropathy (IgAN). IgAN is a condition where the immune system damages the kidneys. The study will last for 9 months and involves taking iptacopan pills twice a day. The main aim is to see how the drug affects the kidneys by comparing two biopsies, one at the start and one at the end.

Participants must be adults with confirmed IgAN, have good kidney function, and be on other specific treatments for at least 90 days before the study begins. All participants must receive vaccinations against specific infections like meningitis and pneumonia before starting the study.

• Study duration is 9 months with regular visits and two kidney biopsies.
• Participants will need to take iptacopan twice daily without dose changes.
• Vaccinations are required before starting the treatment.

Participants cannot join if they have other severe health issues, take certain medications, or have had recent infections. Pregnant or breastfeeding women are not allowed to participate, and all women of childbearing potential must use effective contraception.