Development of a CD9-Targeted Radiopharmaceutical for Imaging and Radionuclide Therapy in CD9-Positive Glioma

Area of Science:

• Nuclear Medicine
• Oncology
• Radiopharmaceutical Chemistry

Background:

• High CD9 expression correlates with poor glioma prognosis, necessitating targeted diagnostic and therapeutic agents.
• Peptide-based drugs often face limitations due to rapid metabolism, requiring advanced formulation strategies.

Purpose of the Study:

• To develop an integrated theranostic radiopharmaceutical for in vivo CD9 targeting in glioma.
• To evaluate the diagnostic and therapeutic potential of the synthesized CD9-targeting molecule, DOTA-M-P.

Main Methods:

• Synthesis and radiolabeling of DOTA-M-P with ⁶⁸Ga and ¹⁷⁷Lu.
• In vitro cellular assays and in vivo small animal PET/CT and SPECT/CT imaging.
• DNA damage assays, Western blot analyses, and radioligand therapy studies in a U87-CD9 cell line model.
• Human organ effective dose estimation using OLINDA/EXM software.

Main Results:

• DOTA-M-P demonstrated moderate affinity for CD9 and modest in vivo tumor targeting and retention.
• Biodistribution studies indicated primary metabolism via the kidneys.
• ¹⁷⁷Lu-DOTA-M-P induced DNA damage, activating apoptosis and significantly inhibiting U87-CD9 tumor growth.
• Estimated human organ doses were below regulatory limits, indicating a favorable safety profile.

Conclusions:

• A CD9-targeted peptide precursor, DOTA-M-P, was successfully developed for dual-functional radionuclide imaging and therapy in glioma.
• Human dose estimates support the potential for personalized theranostic regimens in glioma treatment.
• The developed radiopharmaceutical shows promise for clinical translation in glioma management.