Biological drugs in ANCA-associated vasculitis.

The anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitides granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA) and microscopic polyangiitis (MPA) constitute a wide spectrum of clinical manifestations of systemic vasculitis which may range from limited disease to organ or life-threatening disease. The introduction of biologics for the management of severe ANCA-associated vasculitis and severe, relapsing disease refractory to conventional immunosuppressants, has significantly improved the clinical prognosis of these autoimmune disorders. Rituximab, an anti-CD20 monoclonal antibody is licenced for remission induction in severe GPA and MPA and the management of severe relapsing, refractory GPA and MPA. Belimumab, an anti-B lymphocyte stimulatory monoclonal antibody is in clinical trials for the management of the ANCA-associated vasculitis GPA. Mepolizumab and Omalizumab are biologics which have been reported to be efficacious in refractory asthma associated with EGPA. The role of anti-TNF therapy and T cell targeting drugs in ANCA-associated vasculitis is less clear due to limited study data. This review will summarise the clinical trials and clinical practice use of biologic treatment strategies for the management of ANCA-associated vasculitis.