NCIt definition : An immunoconjugate consisting of the humanized monoclonal antibody huMy9-6 conjugated
to the cytotoxic maytansinoid DM4 with potential antineoplastic activity. The monoclonal
antibody portion of anti-CD33 monoclonal antibody-DM4 conjugate AVE9633 specifically
binds to the cell surface antigen CD33 expressed on myeloid leukemia cells; upon internalization,
the DM4 moiety is released, binds tubulin, and disrupts microtubule assembly/disassembly
dynamics, resulting in the inhibition of cell division and cell growth in myeloid
leukemia cells that express CD33. CD33 is expressed on normal non-pluripotent hematopoietic
stem cells as well as on myeloid leukemia cells.;