Shorter Peptide Nucleic Acid Probes Improve Affibody-Mediated Peptide Nucleic Acid-Based Pretargeting.

Affibody-mediated PNA-based pretargeting shows promise for HER2-expressing tumor radiotherapy. In our recent study, a 15-mer Z-HP15 affibody-PNA conjugate, in combination with a shorter 9-mer [Lu]Lu-HP16 effector probe, emerged as the most effective pretargeting strategy. It offered a superior tumor-to-kidney uptake ratio and more efficient tumor targeting compared to longer radiolabeled effector probes containing 12 or 15 complementary PNA bases.