20220159 Avacopan for ANCA-associated Vasculitis

Inclusion Criteria:
*  Participants has provided informed consent before initiation of any study-specific activities/procedures.
*  Newly diagnosed or relapse of granulomatosis with polyangiitis or microscopic polyangiitis, consistent with Chapel-Hill Consensus Conference definitions (Jennette et al, 2013), where treatment with cyclophosphamide or rituximab is needed.
*  Age \>/= 18 years (or \>/= legal age within the country if it is older than 18 years).
*  Positive test for anti-positive antiproteinase 3 or antimyeloperoxidase (current or historic) antibodies.
*  At least 1 Birmingham Vasculitis Activity Score (BVAS) major item, at least 3 BVAS nonmajor items, or at least the 2 renal items of proteinuria and hematuria.
*  eGFR 15 mL/min/1.73 m\^2 (using Chronic Kidney Disease Epidemiology Collaboration equations). Exclusion Criteria
*  Alveolar hemorrhage requiring invasive pulmonary ventilation support anticipated to last beyond the screening period of the study.
*  Any other known multisystem autoimmune disease including eosinophilic granulomatosis with polyangiitis (Churg-Strauss), systemic lupus erythematosus, immunoglobulin A vasculitis (Henoch-Schönlein), rheumatoid vasculitis, Sjogren's syndrome, anti-glomerular basement membrane disease, or cryoglobulinemic vasculitis.
*  Any medical condition requiring or expected to require continued use of immunosuppressive therapies, including corticosteroids that may cause confoundment with study assessments and study conclusions.
*  Received dialysis or plasma exchange within 12 weeks before signing of the informed consent.
*  Have had a kidney transplant.
*  Malignancy except nonmelanoma skin cancers, cervical or breast ductal carcinoma in situ within the last 5 years before signing the informed consent.
*  Acute or chronic, active hepatitis B virus or hepatitis C virus, or human immunodeficiency virus infection during screening.
*  Positive test for active or latent tuberculosis during screening.
*  White blood cell count \< 3500/µL, neutrophil count \< 1500/µL, or lymphocyte count \< 500/µl.
*  Evidence of clinically significant hepatic disease including prior diagnosis of cirrhosis.
*  aspartate aminotransferase, alanine aminotransferase, or alkaline phosphatase \>2.0 times the upper limit of normal (ULN).
*  Total bilirubin \> 1.5 times the ULN. A participant with documented Gilbert's syndrome with total bilirubin \< 2 x ULN may be eligible.
*  Active infection and/or infection requiring oral or intravenous (IV) antimicrobials within 4 weeks before signing of the informed consent.
*  History of any clinically significant cardiovascular disease, such as symptomatic congestive heart failure, unstable angina, myocardial infarction or stroke, within 12 weeks before signing of the informed consent.
*  Received cyclophosphamide (CYC) within 12 weeks before signing the informed consent; if on azathioprine, mycophenolate, or methotrexate at the time of screening, these drugs must be withdrawn before receiving the CYC or rituximab (RTX).
*  Have been taking an oral daily dose of a glucocorticoid of more than 10 mg prednisone equivalent for more than 6 weeks continuously before signing of the informed consent.
*  Received RTX or other B-cell depleting therapies within 52 weeks before signing of the informed consent or within 26 weeks before signing of the informed consent provided CD19 count \> 0.01x10\^9/L, or received any of the following within 12 weeks before signing the informed consent:
*  antitumor necrosis factor treatment
*  abatacept
*  alemtuzumab
*  IV immunoglobulin
*  belimumab
*  tocilizumab.
*  Taking a strong or moderate inducer of the cytochrome P450 3A4 (CYP3A4) enzyme unless the strong or moderate CYP3A4 inducer can be changed to an alternative medicine at least 1 week before Day 1.
*  Received an investigational drug within 30 days or within 5 half-lives (whichever is longer) before signing of the informed consent.
*  Previously received avacopan without clinical benefit per the Investigator's opinion or received avacopan within 60 days before signing of the informed consent.