18F-FdCyd + tetrahydrouridine

18F-FdCyd + tetrahydrouridine is a combination of a radiolabeled nucleoside analog and a metabolic inhibitor developed by the National Cancer Institute (NCI). 18F-FdCyd is a fluorine-18 labeled form of 5-fluoro-2'-deoxycytidine, which acts as a DNA methyltransferase (DNMT) inhibitor and is incorporated into DNA. Tetrahydrouridine (THU) is a potent inhibitor of cytidine/deoxycytidine deaminase (CDA), an enzyme that rapidly degrades FdCyd into inactive metabolites like 5-fluorouracil. By co-administering THU, the bioavailability and half-life of 18F-FdCyd are significantly increased, allowing for its use as a PET imaging agent. This combination serves as a companion diagnostic to evaluate the biodistribution, radiation dosimetry, and target engagement of FdCyd therapy in patients with advanced solid tumors, including head and neck, lung, bladder, and breast cancers.

Other names

18FdCydfluorine-18 labeled 5-fluoro-2'-deoxycytidinetetrahydrouridine