Complement blockade in the management of antineutrophil cytoplasmic antibodyassociated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are characterized by the presence of ANCA, particularly those directed against proteinase 3 (PR3) or myeloperoxidase (MPO). At present, the most accepted pathogenic pathway is based on the pathogenic nature of ANCA, which stimulate neutrophils with the consequent activation of the alternative complement pathway, leading to the production of C5a, an anaphylatoxin which plays a key role in amplifying the inflammatory process in AAV. Remission induction in patients with AAV continues to depend on the use of glucocorticoids (GC) in combination with rituximab or cyclophosphamide. Indeed, there are very limited treatment options and a clear need for strategies that reduce the use of GC without compromising efficacy. Avacopan is the first drug specifically developed for patients with AAV as its mechanism of action inhibits C5aR1, thus acting on one of the pathophysiological mechanisms of AAV.