Monoclonal Antibody Kills Chronic Lymphocytic Leukemia Cells

According to a new study published in the Proceedings of the National Academy of Sciences, a team from the University of California, San Diego, Moores Cancer Center have discovered a humanized monoclonal antibody that targets and kills chronic lymphocytic leukemia.

The discovery could mean a new treatment pathway for patients with chronic lymphocytic leukemia (CLL) one of the most common hematologic cancers in the U.S.

Previous research has determined that CLL cells over-express the cell-surface glycoprotein receptor CD44. Thus San Diego researchers led by principal investigator Thomas Kipps, MD, PhD, Evelyn and Edwin Tasch Chair in Cancer Research, along with their colleagues, uncovered a monoclonal antibody called RG7356, which specifically seeks CD44 on the cell surface.

RG7356 proved to be fatally toxic to the CLL cells while exhibiting little effect on other, healthy cells.

RG7356 also caused cell death in CLL cells that expressed levels of the ZAP-70 protein. This is good news since the disease in about half of all CLL patients express this protein, and this population tends to have a more aggressive and harder-to-treat form of the cancer.

Says Dr. Kipps:

By targeting CD44, it may be possible to kill CLL cells regardless of whether there are sufficient numbers of so-called 'effector cells,' which ordinarily are required by other monoclonal antibodies to kill tumor cells. We plan to initiate clinical trials using this humanized anti-CD44 monoclonal antibody in the not-too-distant future.

Source: PNAS