Eculizumab opens a new era of treatment for paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening and debilitating disorder of hematopoiesis. The only curative treatment is allogeneic stem cell transplantation. Other treatments are generally supportive in nature. Recently, eculizumab, as a targeted, disease-modifying treatment, was approved by the US FDA and the European Commission. Eculizumab is a humanized monoclonal antibody that inhibits complement factor C5. It is the first approved drug that specifically inhibits complement. This article presents the major aspects of PNH that are necessary to understand the mechanism of action of eculizumab. Experience from the pilot study and the Phase III pivotal program of eculizumab in PNH will be summarized and the impact of eculizumab on the future treatment of PNH will be discussed.