Anti-CA19-9 Antibody hu5B1/TCO Immunoconjugate

**Semantic type:** Pharmacologic Substance

**Definition:** An immunoconjugate composed of the recombinant human monoclonal antibody hu5B1, which targets the carbohydrate antigen sialyl Lewis A (carbohydrate antigen 19-9; CA19-9), that is conjugated to trans-cyclooctene (TCO), with potential use in pretargeted radioimmunotherapy (PRIT). Upon intravenous administration of anti-CA19-9 antibody hu5B1/TCO immunoconjugate (hu5B1-TCO), the anti-CA19-9 antibody moiety targets and binds to CA19-9-expressing tumor cells and unbound hu5B1-TCO is readily cleared from the body. Imaging of CA19-9-expressing cells using positron emission tomography (PET) can occur upon administration of copper Cu 64-Tz-SarAr, a tetrazine-based radioligand that binds to the TCO moiety of bound hu5B1-TCO. CA19-9, overexpressed on a number of different tumor cell types, plays a key role in tumor cell survival and metastasis.

**Synonyms:** - Trans-cyclooctene-hu5B1 Immunoconjugate - hu5B1-TCO