Arzerra is designated as an orphan medicinal product in the European Union (EU) for treatment of chronic lymphocytic leukemia. The Committee for Orphan Medicinal Products (COMP) concluded that chronic lymphocytic leukemia was estimated to be affecting approximately 3.5 in 10,000 persons in the Community at the time the application was made (June 2008) and that the condition is chronically debilitating and life-threatening, in particular due to poor long-term survival in high-risk patients.