Evaluation of [⁶⁴Cu]Cu-NOTA-PEG₇-H-Tz for Pretargeted Imaging in LS174T Xenografts—Comparison to [¹¹¹In]In-DOTA-PEG₁₁-BisPy-Tz

• Main Authors: Christian B. M. Poulie, Jesper T. Jørgensen, Vladimir Shalgunov, Georgios Kougioumtzoglou, Troels Elmer Jeppesen, Andreas Kjaer, Matthias M. Herth
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Molecules
• Subjects: tetrazine; pretargeted imaging; radiochemistry; PET; SPECT; cancer
• Online Access: https://www.mdpi.com/1420-3049/26/3/544

Pretargeted nuclear imaging for the diagnosis of various cancers is an emerging and fast developing field. The tetrazine ligation is currently considered the most promising reaction in this respect. Monoclonal antibodies are often the preferred choice as pretargeting vector due to their outstanding targeting properties. In this work, we evaluated the performance of [⁶⁴Cu]Cu-NOTA-PEG₇-H-Tz using a setup we previously used for [¹¹¹In]In-DOTA-PEG₁₁-BisPy-Tz, thereby allowing for comparison of the performance of these two promising pretargeting imaging agents. The evaluation included a comparison of the physicochemical properties of the compounds and their performance in an ex vivo blocking assay. Finally, [⁶⁴Cu]Cu-NOTA-PEG₇-H-Tz was evaluated in a pretargeted imaging study and compared to [¹¹¹In]In-DOTA-PEG₁₁-BisPy-Tz. Despite minor differences, this study indicated that both evaluated tetrazines are equally suited for pretargeted imaging.