U36

U36 is a murine monoclonal antibody (MAb) that targets the CD44v6 antigen, an isoform of the CD44 protein family. It has been investigated for its tumor-targeting properties in head-and-neck squamous cell carcinoma (HNSCC) xenografts, particularly in the context of radioimmunotherapy (RIT). Studies have shown that U36, even with lower affinity to CD44v6, can exhibit superior tumor localization compared to higher-affinity antibodies. It has been radiolabeled with isotopes such as 186Re for therapeutic efficacy and with 89Zr and 124I for diagnostic imaging (PET scouting) to confirm tumor targeting and estimate radiation doses.