This study is looking at the safety and effects of a drug called **ADX-097** for people aged 16 and older with certain kidney diseases: Immunoglobulin A Nephropathy (IgAN), Lupus Nephritis (LN), or Complement Component 3 Glomerulopathy (C3G). **IgAN**, **LN**, and **C3G** are conditions that affect the kidneys and can lead to kidney damage over time. The study involves taking the drug through a shot under the skin. Participants must meet certain requirements to join. They should be aged 16 or older and have specific kidney test results. They should also have had a kidney biopsy to confirm their disease type. Some medications need to be stable for a while before joining the study. **Exclusions** include having fast-progressing kidney disease, other significant renal diseases, or certain medical histories such as organ transplants or splenectomy. **Key Points:** - The study drug is given as a shot. - Participants must have a stable dose of certain medications. - Certain medical conditions or histories may prevent participation. The study aims to help understand how safe this treatment is and how well it works for these kidney conditions.