90Y-FAPi-04 is the therapeutic analogue of the PET imaging agent 68Ga-FAPi-04 from the FAPi family developed at the Cancer Research Center of Heidelberg, Germany. It is a DOTA-coupled quinolone analogue radiotherapeutic based on a Fibroblast Activation Protein (FAP)-specific enzyme inhibitor (FAPi). The same molecule has already been labeled with 177Lu.
90Y-FAPi-04 is presently in Phase 0 clinical trial.