Inhibiting Plasma Kallikrein for Hereditary Angioedema Prophylaxis

BackgroundHereditary angioedema with C1 inhibitor deficiency is characterized by recurrent, unpredictable swelling episodes caused by uncontrolled plasma kallikrein generation and excessive bradykinin release resulting from cleavage of high-molecular-weight kininogen. Lanadelumab (DX-2930) is a new kallikrein inhibitor with the potential for prophylactic treatment of hereditary angioedema with C1 inhibitor deficiency. MethodsWe conducted a phase 1b, multicenter, double-blind, placebo-controlled, multiple-ascending-dose trial. Patients with hereditary angioedema with C1 inhibitor deficiency were randomly assigned in a 2:1 ratio to receive either lanadelumab (24 patients) or placebo (13 patients), in two administrations 14 days apart. Patients assigned to lanadelumab were enrolled in sequential dose groups: total dose of 30 mg (4 patients), 100 mg (4 patients), 300 mg (5 patients), or 400 mg (11 patients). The pharmacodynamic profile of lanadelumab was assessed by measurement of plasma levels of cleaved hig...