This is a humanized IgG4 antibody using the same sequences as the therapeutic antibody garadacimab. It inhibits the kallikrein-kinin pathway at a key initiator, coagulation factor XII alpha (F12a). F12 is a serum glycoprotein. The active factor XIIa participates in the initiation of blood coagulation, fibrinolysis, and the generation of bradykinin and angiotensin. By targeting FXIIa, garadacimab inhibits the hereditary angioedema (HAE) cascade at its origin as compared with other HAE therapies that target downstream mediators. Preclinical in vitro and in vivo studies of garadacimab showed it produced anti-inflammatory effects, prevented the formation of bradykinin as well as effectively reduced edema and blocked proinflammatory cytokine production.