Definition

An antibody-drug conjugate (ADC) composed of a humanized immunoglobulin G1 (IgG1) monoclonal antibody against the tyrosine kinase receptor ephrin type-A receptor 5 (EPH receptor A5; EphA5) and conjugated, via a protease-cleavable linker, to the auristatin derivative and microtubule disrupting agent monomethyl auristatin E (MMAE), with potential antineoplastic activity. Upon administration of anti-EphA5/MMAE ADC MBRC-101, the monoclonal antibody moiety targets and binds to EphA5 expressed on tumor cells. Upon binding, internalization, and proteolytic cleavage, MMAE is released. MMAE binds to tubulin and inhibits its polymerization, resulting in G2/M phase arrest and tumor cell apoptosis. This induces cell death in EphA5-expressing cancer cells. EphA5, a member of the ephrin family of receptor tyrosine kinases (RTKs) involved in axonal guidance during embryonic development, is overexpressed by a variety of cancer cell types.