Anti-HER3/Topoisomerase I Inhibitor Antibody-drug Conjugate IBI133

**Semantic type:** Pharmacologic Substance

**Definition:** An antibody-drug conjugate (ADC) composed of a monoclonal antibody directed against human epidermal growth factor receptor 3 (HER3; ErbB3) conjugated to a topoisomerase I (TopoI) inhibitor-based payload, with potential antineoplastic activity. Upon administration of anti-HER3/TopoI inhibitor ADC IBI133, the anti-HER3 antibody moiety targets and binds to HER3 expressed on tumor cells. Upon cellular uptake, the TopoI inhibitor inhibits DNA topoI activity, thereby inhibiting DNA replication which results in cell cycle arrest and tumor cell apoptosis. This inhibits the proliferation of HER3-expressing tumor cells. HER3, a member of the epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases, is frequently overexpressed in tumors.

**Synonyms:** - Anti-HER3 ADC IBI133 - Anti-HER3 Antibody-drug Conjugate IBI133 - Anti-HER3/TopIi Antibody-drug Conjugate IBI133 - Anti-HER3/TopoI Inhibitor ADC IBI133 - IBI 133 - IBI-133 - IBI133