Zirconium Zr 89-labeled Envafolimab

**Semantic type:** Amino Acid, Peptide, or Protein|Indicator, Reagent, or Diagnostic Aid|Pharmacologic Substance

**Definition:** A radioimmunoconjugate composed of envafolimab, a monoclonal antibody directed against programmed cell death-1 ligand 1 (PD-L1; cluster of differentiation 274; CD274) and labeled with the radioisotope zirconium Zr 89, with potential use for assessing PD-L1 tumor antigen expression using positron emission tomography (PET). Upon administration of zirconium Zr 89-labeled envafolimab, the envafolimab moiety targets and binds to the PD-L1 expressed on certain tumor cells. Upon uptake and PET imaging, the radioisotope moiety can be visualized and the extent of PD-L1 expression can be assessed. This can be used to predict the therapeutic response to envafolimab and other PD-L1-targeting agents.

**Synonyms:** - 89Zr-Envafolimab - 89Zr-KN035 - Zirconium Zr 89-Anti-PD-L1 Monoclonal Antibody KN035 - Zirconium Zr 89-Envafolimab - Zirconium Zr 89-KN035