How does the calicheamicin component of gemtuzumab ozogamicin (Mylotarg) cause cancer cell death?

Non-clinical data suggest that after Mylotarg (gemtuzumab ozogamicin) binds CD33-expressing cancer cells and is internalised, linker hydrolysis releases its calicheamicin component intracellularly, where activation induces double-stranded DNA breaks, causing cell-cycle arrest and apoptotic cell death.