In a cohort of 70 adult patients with severe ANCA-RPGN (eGFR: 0–30 ml/min per 1.73 m2 [mean: 12 ± 8]; anti-myeloperoxidase [MPO] antibodies: 76%, relapsing ANCA-associated vasculitis [AAV]: 6%) where a kidney biopsy was available, we compared kidney outcomes at month 6 and 12 according to induction regimen scheme (avacopan- vs. glucocorticoid [GC]-based). This evidence concerns the gene MPO and rapidly progressive glomerulonephritis.