High Quality Content by WIKIPEDIA articles! Eculizumab (INN and USAN, trade name Soliris) is a monoclonal antibody directed against the complement protein C5. Eculizumab has been shown to be effective in treating paroxysmal nocturnal hemoglobinuria (PNH), a rare and sometimes life threatening disease of the blood, and was first approved for this indication. It was also approved for atypical hemolytic-uremic syndrome (aHUS), a disease that causes abnormal blood clots to form in the kidneys, near the end of 2011.