Definition

A bispecific antibody targeting both the tumor-associated antigen (TAA) carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5; CEA) and the pro-apoptotic death receptor tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptor 2 (TRAILR2; death receptor 5; DR5), with potential pro-apoptotic and antineoplastic activities. Upon administration, anti-CEA/anti-DR5 bispecific antibody IBI3004 targets and binds to both CEA and DR5 expressed on tumor cells. Receptor clustering and activation of DR5 induces apoptosis in CEA-expressing tumor cells. Activation of DR5 plays a key role in the induction of apoptosis. CEA-dependent clustering of DR5 allows IBI3004 to selectively induce apoptosis in CEA-expressing tumor cells thereby increasing efficacy and decreasing toxicity. CEA is overexpressed by a variety of cancer cell types and plays a key role in cell migration, cell invasion, and cell adhesion.