MT-103

MEDI-538 is a Bi-Specific T cell Engager (BiTE Ô) molecule being developed with the intent to treat certain types of B-cell lymphomas. In February 2006, the U.S. Food and Drug Administration (FDA) approved an orphan drug designation for MEDI-538 for the treatment of indolent B-cell lymphoma, excluding chronic lymphocytic leukemia and non-hodgkins lymphoma with central nervous system involvement. BiTE molecules are part of a novel class of antibody derivatives that may have the potential to selectively direct and activate an individual’s own immune system to act against cancer cells. This action is believed to occur as a result of the molecule's stimulation of T cells (a very potent type of white blood cell) to target and destroy cancer cells that over-express a specific antigen. MEDI-538 specifically targets the CD19 antigen, which is present on cancerous B cells but not on other types of blood cells or healthy tissues.