This study is evaluating the long-term safety of avacopan for people with a condition called ANCA-associated vasculitis (AAV). ANCA stands for antineutrophil cytoplasmic antibody, which are proteins that attack healthy cells in the body. Vasculitis means inflammation of blood vessels. The study focuses on people who have specific types of AAV: granulomatosis with polyangiitis or microscopic polyangiitis. To participate, you must be 18 years or older and have a positive test for certain antibodies. You should not have any other autoimmune diseases, recent cancer, or certain infections. Participants must not have had a kidney transplant or required dialysis recently. The study will check if avacopan is safe for long-term use.

• The study involves taking avacopan and regular medical check-ups.
• Participants must not have used certain medications or treatments recently.
• Eligibility requires specific health conditions and tests.