Definition

A radioimmunoconjugate composed of SC16.56, a monoclonal antibody directed against the tumor-associated antigen (TAA) delta-like protein 3 (DLL3; delta like canonical notch ligand 3; drosophila delta homolog 3; delta3; delta-like 3; SCDO1), and linked, via the chelator desferrioxamine (DFO), to the radioisotope zirconium Zr 89 (Zr89), with potential diagnostic properties upon positron emission tomography (PET) imaging. Upon administration of zirconium Zr 89-DFO-SC16.56, the monoclonal antibody moiety specifically targets and binds to DLL3. Upon binding, the radioisotope moiety is detected using PET, thereby allowing the imaging and quantification of DLL3-expressing tumor cells. DLL3, a Notch pathway protein, is overexpressed on a variety of cancer cell types. It plays a key role in embryonic development and in tumor initiation and proliferation.