A Study to Evaluate Avacopan in Participants With ANCA-associated Vasculitis

Inclusion Criteria:

• Participants has provided informed consent before initiation of any study-specificactivities/procedures.

• Newly diagnosed or relapse of granulomatosis with polyangiitis or microscopicpolyangiitis, consistent with Chapel-Hill Consensus Conference definitions (Jennetteet al, 2013), where induction treatment with cyclophosphamide or rituximab isneeded.

• 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 orhistoric) antibodies.

• At least 1 Birmingham Vasculitis Activity Score (BVAS) major item, or at least 3BVAS 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 Collaborationequations).

Exclusion Criteria:

• Alveolar hemorrhage requiring invasive pulmonary ventilation support anticipated tolast beyond the screening period of the study.

• Any other known multisystem autoimmune disease that may confound study assessmentsand study conclusions including but not limited to eosinophilic granulomatosis withpolyangiitis (GPA [Churg-Strauss]), systemic lupus erythematosus, immunoglobulin (Ig) A vasculitis (Henoch-Schönlein), rheumatoid vasculitis, Sjogren's syndrome,anti-glomerular basement membrane disease, or cryoglobulinemic vasculitis.

• Any other medical condition requiring or expected to require continued use ofimmunosuppressive therapies, including corticosteroids that may cause confoundmentwith study assessments and study conclusions.

• Received dialysis or plasma exchange within 16 weeks before Day 1 randomization.

• Have had a kidney transplant.

• Malignancy (except curatively treated nonmelanoma skin cancers, curatively treatedcervical carcinoma in situ, or breast ductal carcinoma in situ) within the last 5years before Day 1 randomization.

• Acute or chronic, active hepatitis B virus or hepatitis C virus, or humanimmunodeficiency virus infection during screening.

• Any known exposure to a case of active tuberculosis (TB) within the last 12 weeksbefore Day 1 randomization.

• Positive test for active or latent TB during screening.

• White blood cell count < 3500/µL, neutrophil count < 1500/µL, or lymphocyte count < 500/µl. Note: Complete Blood Count can be repeated once in the screening period atthe investigator discretion. In such instances, eligibility will be determined basedon the repeat complete blood count.

• Evidence of clinically significant hepatic disease including prior diagnosis ofcirrhosis.

• Aspartate aminotransferase (AST), alanine aminotransferase (ALT), or alkalinephosphatase (ALP) >2.0 times the upper limit of normal (ULN).

• Total bilirubin > 1.5 times the ULN. Note: A participant with documented Gilbert'ssyndrome with total bilirubin < 2 x ULN may be eligible.

• Any of the following within 6 weeks prior to Day 1 randomization: serious infection,infection requiring treatment with intravenous (IV) anti-infective agents, any otherinfection (including active infection, chronic infection, opportunistic infection,or history of recurrent infection) that in the opinion of the investigator wouldpose a risk to participant safety or interfere with the study evaluation,procedures, or completion. Oral or vaginal candidiasis and cutaneous or nail fungalinfections do not constitute an exclusion.

• Any of the following within 12 weeks prior to Day 1 randomization: myocardialinfarction, stroke, unstable angina, symptomatic congestive heart failure requiringprescription medication, any other clinically significant cardiovascular diseasethat in the opinion of the investigator would pose a risk to participant safety orinterfere with the study evaluation, procedures, or completion.

• Received cyclophosphamide (CYC) within 12 weeks before signing the informed consent;if on azathioprine (AZA), mycophenolate, or methotrexate (MTX) at the time ofscreening, these drugs must be withdrawn before receiving CYC. Note: If inductiontherapy with CYC was started within 1 week before signing the informed consent forthe current episode of newly diagnosed or relapse of GPA or microscopic polyangiitis (MPA), the participant may be eligible, provided no CYC was received within 12 weeksbefore the start of the current induction therapy and if on AZA, mycophenolate, orMTX, these were withdrawn prior to receiving the current induction therapy with CYC.

• Have been taking an oral daily dose of a glucocorticoid of more than 10 mgprednisone equivalent for more than 6 weeks continuously before signing of theinformed consent.

• Received RTX or other B-cell depleting therapies within 26 weeks before signing ofthe informed consent; if on AZA, mycophenolate, or MTX at the time of screening,these drugs must be withdrawn before receiving rituximab (RTX). Note: If inductiontherapy with RTX was started within 1 week before signing the informed consent forthe current episode of newly diagnosed or relapse of GPA or MPA, the participant maybe eligible, provided no RTX was received within 26 weeks before the start of thecurrent induction therapy and if on AZA, mycophenolate, or MTX, these were withdrawnprior to receiving the current induction therapy with RTX.

• Received any of the following within 16 weeks before Day 1 randomization:

• antitumor necrosis factor treatment

• abatacept

• alemtuzumab

• IV Ig

• belimumab

• anti interleukin-6 agent (eg, tocilizumab, sarilumab).

• Taking a strong or moderate inducer of the cytochrome P450 3A4 (CYP3A4) enzymeunless the strong or moderate CYP3A4 inducer can be changed to an alternativemedicine at least 1 week before Day 1 randomization.

• Received an investigational drug within 30 days or within 5 half-lives (whichever islonger) before Day 1 randomization.

• Previously received avacopan without clinical benefit per the Investigator's opinionor received avacopan within 60 days before Day 1 randomization.