Targeting primary human Ph B-cell precursor leukemia-engrafted SCID mice using radiolabeled anti-CD19 monoclonal antibodies

Abstract

The Philadelphia chromosome translocation (Ph+) confers a poor prognosis in patients with acute lymphocytic leukemia (ALL). CD19 is highly expressed (CD19+) on ALL cells and is an attractive target for antibody-based therapies. CLB-CD19 is an IgG1κ murine monoclonal antibody (mAb) directed against an epitope on the CD19 antigen. Methods: Radiolabeled CLB-CD19 antibody was evaluated for targeting ALL in a severe combined immunodeficient (SCID) mouse model engrafted with primary human leukemia cells. Lodgment of CD19+ ALL cells in spleen and liver was confirmed using immunohistochemistry analyses. Circulating CD19- ALL cells in blood were also detected by flow cytometry. Results: Antibody was ..