89Zr-DFO-CD4

89Zr-DFO-CD4 is a zirconium-89 labeled immuno-PET radiotracer designed for the non-invasive visualization and quantification of CD4+ tumor-infiltrating lymphocytes (TILs). The agent is constructed using F(ab)'2 fragments of a rat-anti-mouse CD4 antibody (clone CK 1.5), which are conjugated to a p-SCN-Bn-Desferrioxamine (DFO) chelator and radiolabeled with the positron emitter Zirconium-89. Developed through a collaboration between Minerva Imaging, Rigshospitalet, and Symphogen, this tracer is primarily utilized in preclinical research to phenotype the immune microenvironment of syngeneic mouse tumor models. By assessing the density and location of CD4+ T cells, which orchestrate adaptive and innate immune responses, 89Zr-DFO-CD4 serves as a predictive biomarker for the efficacy of immune checkpoint inhibitors, such as PD-1/PD-L1 blockers. Preclinical studies have demonstrated that the maximum tumor-to-heart ratio of this tracer can stratify responders from non-responders and predict overall survival in immunotherapy regimens.

Other names

89Zr-labeled anti-CD4 F(ab)'289Zr-DFO-anti-CD4Zirconium-89-DFO-CD4Zirconium89-DFO-CD4Zirconium 89-DFO-CD4