| abstract |
The present invention provides processed for preparing a calicheamicin conjugate comprising removing glycosylation of a protein and reacting (i) an activated calicheamicin-hydrolyzable linker derivative and (ii) the deglycosylated protein. In one embodiment, the protein is an antibody, such as an anti-CD33 antibody (e.g., hp67.6), an anti-CD22 antibody (e.g., G544), an anti-Lewis Y antibody (e.g., G193), an anti-5T4 antibody (e.g., H8) or an anti-CD20 antibody (e.g., rituximab). In another embodiment, the calicheamicin derivative is an N-acyl derivative of calicheamicin or a disulfide analog of calicheamicin, such as N-acetyl gamma calicheamicin dimethyl hydrazide (N-acetyl calicheamicin DMH) and the hydrolyzable linker is 4-(4~acetylephenoxy) butanoic acid (AcBut) or (3-Acetylphenyl) acetic acid (AcPAc). Also provided are calicheamicin conjugates produced by such processes. |