Ecallantide (DX-88), a plasma kallikrein inhibitor for the treatment of hereditary angioedema and the prevention of blood loss in on-pump cardiothoracic surgery

Background: Plasma kallikrein plays a major role in the contact (kallikrein–kinin) cascade producing bradykinin. Bradykinin is a vasodilator, which increases vascular permeability, activates inflammation and produces pain. Plasma kallikrein is also crosslinked to the coagulation system and the complement cascade. Objective: Ecallantide (DX-88) is a potent and specific inhibitor of plasma kallikrein. Ecallantide is a recombinantly produced and engineered small protein based on the first Kunitz domain of human tissue factor pathway inhibitor. It was identified through phage display technology. Methods: The search terms ‘ecallantide’, ‘DX-88’ and ‘hereditary angioedema’ were entered into Pubmed/Medline, ClinicalTrials and Google. Results/conclusion: At present, the drug is being studied for two major indications. First, the results for the treatment of hereditary angioedema are promising. Second, a prospective randomised multi-centre trial for the reduction of blood loss during on-pump cardiothoracic surgery will be terminated in October 2008.