Definition

An antibody-drug conjugate (ADC) consisting of a recombinant humanized anti-epidermal growth factor receptor 2 (HER2) monoclonal antibody conjugated to the maytansinoid DM1 via a nonreducible thioether linkage (MCC), with potential antineoplastic activity. Upon administration of B003, the anti-HER2 monoclonal antibody moiety targets and binds to HER2 on tumor cell surfaces; upon internalization, the DM1 moiety is released and binds to tubulin, thereby disrupting microtubule assembly/disassembly dynamics, inhibiting cell division and the proliferation of cancer cells that overexpress HER2.