Micromet Presents Safety, Efficacy Data From Leukaemia, Melanoma Trial
Micromet presented preclinical data of two new human BiTE antibodies targeting CD33 and MCSP, for the treatment of acute myelogenous leukaemia (AML) and melanoma.
BiTE antibodies are designed to direct the body's cytotoxic, or cell-destroying, T cells against tumor cells, and represent a new therapeutic approach to cancer therapy.
Generation of human anti-CD33 and anti-MCSP BiTE antibodies used a novel human BiTE antibody platform that is cross-reactive with non-human primates. In cell-based assays, CD33-specific and MCSP-specific BiTE antibodies were equally potent in eliminating tumor cells expressing the respective target antigens.
While CD33 is present and well accessible on many normal blood cells, MCSP is barely accessible on normal cells, but is exposed and highly expressed on melanoma cells. Consistent with the accessibility of the respective target antigen, the CD33-specific BiTE antibody showed in macaques a dose-dependent depletion of CD33-expressing blood cells, whereas the MCSP-specific BiTE antibody did not show any activity, even at very high doses.
"We are very encouraged by the first in vivo results of these two new BiTE antibodies that continue to expand our novel BiTE antibody pipeline," comments Patrick Baeuerle, chief scientific officer of Micromet. "The data indicate highly target-specific activities of the two BiTE antibodies in primates, and suggest appropriate therapeutic windows for elimination of target cells in vivo."