Phase IV Observational Study in Chronic Lymphocytic Leukemia

B-cell chronic lymphocytic leukemia (CLL) is a subtype of mature peripheral B-cell neoplasms, characterized by the accumulation of circulating malignant lymphocytes that typically express cell surface markers CD5, CD20, and CD23. It is the most common type of leukemia in adults in Western Europe and in the US. The median age at diagnosis is 65-70 years, with a male to female ratio of 2:1. Initially, most patients present with asymptomatic lymphocytosis and do not need cytoreductive therapy. Patients with active disease are characterized by a lymphocyte doubling time of less than 6 months, or progressive, even massive lymphadenopathy, hepatosplenomegaly, anemia and thrombocytopenia. Constitutional symptoms such as fever, night sweats, unintended weight loss, and extreme fatigue are common in advanced disease and can significantly impact quality of life. CLL also causes relative immunosuppression that increases the risk of infections that are ultimately the major cause of death in this patient population. Median survival at diagnosis ranges from 5 to 20+ years depending on risk factors, but is only 6 to 14 months for patients with CLL refractory to available therapies. Arzerra (ofatumumab) is a human monoclonal antibody (IgG1) that binds specifically to a distinct epitope encompassing both the small and large extracellular loops of the CD20 molecule. The CD20 molecule is a transmembrane phosphoprotein expressed on B lymphocytes from the pre-B to mature B lymphocyte stage and on B-cell tumors. 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-ri