A recombinant, humanized anti-CD33 monoclonal antibody conjugated with the cytotoxic antitumor antibiotic calicheamicin. Calicheamicin binds to the minor groove of DNA, causing double strand DNA breaks and results in inhibition of DNA synthesis. In this conjugate, the antibody binds to and is internalized by tumor cells expressing CD33 antigen (a sialic acid-dependent glycoprotein commonly found on the surface of leukemic blasts), thereby selectively delivering the attached cytotoxic calicheamicin to CD33-expressing tumor cells. (NCI04)
