This study tests a new treatment called RO7434656 for people with a kidney problem called Immunoglobulin A (IgA) Nephropathy. This condition is when IgA, a protein that helps fight infections, builds up in the kidneys and can lead to kidney damage. The study aims to see if RO7434656 is safe and works well for people whose kidney disease is getting worse despite usual care.

Participants must have kidney damage confirmed by a test called a biopsy, and must have tried certain medications to help protect the kidneys. The study will not accept people who are pregnant or have other serious health issues.

• The study examines the safety and effectiveness of the new treatment RO7434656.
• Participants will be closely monitored, and certain medications are not allowed during the study.
• There are specific eligibility criteria, such as having high levels of protein in urine and not being pregnant.

This study could help improve treatment for people with serious kidney disease, but it requires careful consideration of whether you meet the criteria and are comfortable with the study's rules.