This study is testing a medicine called atrasentan for people with a kidney problem called IgA Nephropathy (IgAN). In IgAN, the kidneys don't work well because of a buildup of a protein called IgA. The study will see if atrasentan helps when taken with other usual medicines. Some people will get atrasentan, and others will get a placebo (a dummy pill) to compare results. This study is double-blind, meaning neither you nor the doctors will know which pill you are taking. It will last about a year, and you'll have regular check-ups. You need to be taking medicines called SGLT2 inhibitors and RAS inhibitors for your kidneys already to join the study.

• Study Duration: 1 year with regular visits.
• Participation: Must be on certain kidney medicines already.
• Considerations: No pregnancy or other kidney diseases.