B-cell chronic lymphocytic leukemia (B-CLL) is a cancer characterized by a progressive accumulation of functionally incompetent lymphocytes. Despite high morbidity and mortality, the only available potential cure is allogeneic hematopoietic stem cell transplantation (alloHSCST). However, there is less than a 50% chance of finding a matching bone marrow or blood donor for B-CLL patients. Other clinically tested targeted therapies such as rituximab and alemtuzumab target both malignant and normal B cells, resulting in immunosuppression.
Available for licensing are fully human monoclonal antibodies that were selected from the first human post-alloHSCT antibody library. The library was generated from a time point after transplantation at which antibodies to B-CLL cell surface antigens peaked, thus indicating its therapeutic value. Utilizing phage display, the investigators generated a panel of fully human monoclonal antibodies that strongly bind to the same epitope on a B-CLL cell surface antigen. Weaker binding to normal B cells, but not to other lymphocytes, was observed. These fully human monoclonal antibodies provide readily available treatment that selectively targets malignant B cells.