Development of a Highly Effective Bifunctional Ligand 2E-C-NETA for Targeted Lu-177 Therapy: Synthesis,...

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Chemistry
• Oncology

Background:

• Lutetium-177 (¹⁷⁷Lu) is a key radionuclide in targeted radionuclide therapy (TRT).
• Recent FDA approvals highlight the growing importance of ¹⁷⁷Lu-based radiopharmaceuticals.
• Effective TRT requires bifunctional chelators that stably sequester ¹⁷⁷Lu under mild conditions.

Purpose of the Study:

• Introduce and evaluate a novel bifunctional chelator, 2E-C-NETA, for ¹⁷⁷Lu-based TRT.
• Assess the radiolabeling efficiency, stability, and utility of 2E-C-NETA in antibody-targeted therapy.

Main Methods:

• Synthesized the novel bifunctional chelator 2E-C-NETA.
• Evaluated ¹⁷⁷Lu binding kinetics and serum stability of 2E-C-NETA.
• Conjugated 2E-C-NETA to Herceptin and assessed labeling and stability.
• Performed biodistribution studies in tumor-bearing mice.

Main Results:

• 2E-C-NETA rapidly sequestered ¹⁷⁷Lu at room temperature with excellent serum stability (>2 weeks).
• The 2E-C-NETA-Herceptin conjugate was efficiently labeled with ¹⁷⁷Lu and maintained stability in serum.
• In vivo studies showed favorable biodistribution, with rapid clearance, low normal tissue uptake, and significant tumor accumulation of ¹⁷⁷Lu-2E-C-NETA-Herceptin.

Conclusions:

• 2E-C-NETA is a highly effective bifunctional chelator for ¹⁷⁷Lu radiopharmaceuticals.
• The chelator demonstrates potential for antibody-targeted radionuclide therapy, particularly for metastatic breast cancer.
• Results support the advancement of 2E-C-NETA for developing novel ¹⁷⁷Lu-based TRT agents.