On the clinical side, selective C5aR inhibition by avacopan (CCX168, phase III completed, new drug application accepted) has been investigated in patients with vasculitis [118], the monoclonal antibody NNC0215-0384 (not further developed after phase I) in rheumatoid arthritis [119, 120], and anti-C5aR antibody avdoralimab has been lined up against inflammatory responses in the lung [121]. Here, C5AR1 is linked to rheumatoid arthritis.