The study is using cemdisiran compared to placebo injections to determine the safety and efficay of cemdisiran in treating IgA Nephropathy. The study includes a screening period (up to 90 days), 8 month treating period, and 52 week Open Label extension period. Injections occur monthly during the treatment period. Patients will be randomized 2:1 to the cemdisiran or placebo arms.

This study will use a new investigational study drug called OMS721 in people with Immunoglobulin A (IgA) Nephropathy. OMS721 is an antibody, which is a type of protein that can bind to substances in the body. OMS721 is being studied because it blocks a key enzyme (a protein that causes specific chemical changes in the body) in the blood that may be responsible for causing the damage in IgA Nephropathy.
The study is approximately 23 visits over a period of 3 years. The study drug is administered via a 30-minute intravenous infusion once a week for 12 weeks. You will then be evaluated to determine your response to the drug and followed-up with regularly. Possible re-treatment is determined by the study doctor.