Current treatment of hereditary angioedema: An update on clinical studies.

Hereditary angioedema (HAE) is a rare, potentially life-threatening disease that manifests as recurrent episodes of nonpruritic swelling that may affect the extremities, face, genitalia, gastrointestinal tract, and/or larynx. HAE is the result of a deficiency of functional C1-esterase inhibitor (C1-INH), a key regulator of the complement, coagulation, and kallikrein-kinin cascades. In HAE patients, overactivation of the kallikrein-kinin cascade results in excessive release of bradykinin, the mediator of the pain and swelling that is characteristic of HAE. Historically, treatment options for HAE have been limited, but newly approved and emerging therapies, such as C1-INH replacement products, a plasma kallikrein inhibitor, and a bradykinin B₂-receptor antagonist, appear to provide safe and effective relief for a significant proportion of patients with HAE. Because they may have therapeutic and practical advantages over existing HAE therapies, the new agents have the potential to improve the overall management of patients with HAE. This article reviews the results from recent clinical trials of these drugs and considers their role in clinical practice.