Phase II study results of a replacement therapy for hereditary angioedema with subcutaneous C1‐inhibitor concentrate

Background Hereditary angioedema (HAE) due to C1 inhibitor deficiency manifests as recurrent swelling attacks that can be disabling and sometimes fatal. Long‐term prophylaxis with twice‐weekly intravenous injections of plasma‐derived C1‐inhibitor (pdC1‐INH) has been established as an effective treatment. Subcutaneous (SC) administration of pdC1‐INH has not been studied in patients with HAE.