Mutations in the gene coding for C1-inhibitor (C1-INH) protein result in hereditary angioedema (HAE), whereby insufficient levels of C1-INH or abnormal forms of the protein ultimately result in leakage of fluid from blood vessels into connective tissue, apparent as body swelling. In HAE, various and typically mild triggers such as dental treatment or a cold may bring about painful swelling attacks, but swelling can also occur spontaneously. The face, abdomen, or other body parts may be affected, including swelling of the throat that can lead to a life-threatening constriction of the airways. On-demand therapies for HAE are available from several drug developers, either replacing C1-INH or targeting further downstream factors and have proved to be efficacious for acute swelling attacks. However, HAE patients currently have limited options for routine prophylaxis. A high unmet need remains for efficacious, safe, and easily administered long-term prophylactic therapies.