This is a Randomized, Double-Blind, Placebo-Controlled Study designed to assess safety, tolerability, and efficacy of NM8074 in AAV patients when used in combination with Standard of Care (SOC) cyclophosphamide/azathioprine or rituximab plus corticosteroids.

The proposed study, NM8074-AAV-501, will initially assign six (6) patients per cohort in a 2-cohort trial. In the first cohort, we will evaluate a biweekly dosing regimen with NM8074 and SOC whereas in the second cohort, we will evaluate placebo with SOC. These studies will assess safety, tolerability, and efficacy of NM8074 in AAV patients when used in combination with SOC cyclophosphamide/azathioprine or rituximab plus corticosteroids.

Inclusion Criteria:

• Clinical diagnosis of granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), or renal limited vasculitis.
• Male and female subjects aged at least 18 years, with newly diagnosed or relapsed Associated Vasculitis (AAV) where treatment with cyclophosphamide or rituximab is needed.
• At least 1 major item, or at least 3 non-major items, or at least the 2 renal items of proteinuria and hematuria on Birmingham Vasculitis Activity Score (BVAS).
• Estimated glomerular filtration rate (eGFR) ≥ 20 mL/ minute.
• Positive ANCA Test: indirect immunofluorescence (IIF) test for P-ANCA or C-ANCA, or positive ELISA test for anti-proteinase-3 (PR3) or anti-myeloperoxidase (MPO) at Screening.
• All patients must be vaccinated prior to dosing with MenACWY Menactra® polysaccharide diphtheria toxoid conjugate vaccination against Neisseria meningitidis serogroups A, C, Y, and W-135. Meningitis B (MenB) meningococcal serogroup B vaccine (Bexsero®) will be administered per local guidelines. If the window of vaccination is short, then patients will be prophylactically treated with appropriate antibiotics. Patients will also be required to have confirmation or administration of vaccination against S. pneumoniae and H. influenzae.
• Willing and able to understand and complete informed consent procedures, including signing and dating the informed consent form (ICF), and complying with the study visit schedule.
• Female partners of child-bearing potential (WOCBP), defined as all women physiologically capable of becoming pregnant, must have a negative pregnancy test at screening and must agree to use highly effective methods of contraception during dosing and for at least 8 weeks after stopping the investigational drug, and for at least 6 months after the last cyclophosphamide dose (if receiving cyclophosphamide) and at least 12 months after the last rituximab dose (if receiving rituximab).
• Male patients and partners of child-bearing potential must agree to use contraceptives and male patients must agree to refrain from donating sperm for the duration of the study.

Exclusion Criteria:

• Severe disease as determined by alveolar hemorrhage, hemoptysis, rapid onset mononeuritis multiplex or central nervous system involvement.
• Patients with rapidly progressive glomerulonephritis
• Any other known multi-system autoimmune disease including eosinophilic granulomatosis with polyangiitis (EGPA, Churg Strauss), systemic lupus erythematosus, Immunoglobulin A (lgA) vasculitis (HenochSchönlein purpura), rheumatoid vasculitis, Sjogren's disease, anti
• glomerular basement membrane disease, or cryoglobulinemia.
• Required dialysis or plasma exchange within 12 weeks prior to screening.
• Have a kidney transplant or disease.
• Received cyclophosphamide within 12 weeks prior to screening; if on azathioprine, mycophenolate mofetil or methotrexate at the time of screening, these drugs must be withdrawn prior to receiving the cyclophosphamide or rituximab dose on Day 1.
• Received intravenous glucocorticoids, >3000 mg methylprednisolone equivalent, within 4 weeks prior to screening.
• Have been taking an oral daily dose of a glucocorticoid of more than 10 mg prednisone-equivalent for more than 6 weeks continuously prior to screening.
• Received rituximab or other B-cell antibody within 52 weeks of screening or 26 weeks provided B cell reconstitution has occurred (i.e., Cluster of Differentiation 19 (CD19) count > 0.01x10^9/L); received anti-tumor necrosis factor (TNF) treatment or other complement inhibitor treatment within 12 weeks prior to screening.
• Currently or previously under other complement inhibitor treatments less than 3 months prior to study Day 1.
• Patients who need the initiation of renal replacement therapy within 7 days
• Have any other clinically significant abnormal laboratory value in the opinion of the investigator.
• History of bone marrow, hematopoietic stem cell, or solid organ transplantation.
• History of currently active primary or secondary immunodeficiency.
• Currently active systemic infection or suspicion of active bacterial, viral, or fungal infection within 2 weeks prior to first dose, or history of unexplained, recurrent bacterial infections.
• Pregnant, planning to become pregnant, or nursing female subjects.
• Females who have a positive pregnancy test result at Screening or on Day 1.

This is a double-blind study (subjects and on-site medical/nursing staff at the study site are blinded to study drug/dose assignment). The pharmacy staff preparing the investigational products will not be blinded to NM8074 study drug assignment, but all other site staff, including the Investigator, will be blinded. Unblinding should only be considered for the safety of the subject.