Pretargeting: A Path Forward for Radioimmunotherapy.

Area of Science:

• Nuclear Medicine
• Oncology
• Radiochemistry

Background:

• Pretargeted radioimmunodiagnosis and radioimmunotherapy combine antibodies and radioisotopes for improved tumor imaging and treatment.
• These strategies separate targeting from payload delivery, amplifying tumor uptake and minimizing normal tissue exposure compared to conventional methods.
• Key considerations include contrast, therapeutic index (TI), antibody characteristics, radioisotope availability, and clinical usability.

Purpose of the Study:

• To provide a historical overview of pretargeting strategies in nuclear medicine.
• To highlight major developmental milestones and innovations in pretargeted radioimmunotherapy.
• To identify obstacles and guide the development of next-generation pretargeted theranostics.

Main Methods:

• Review of established protein delivery systems: biotin-streptavidin and hapten-bispecific monoclonal antibodies.
• Discussion of radiohaptens and radioisotopes used in pretargeting.
• Highlighting recent innovations: bioorthogonal chemistry, self-assembling/disassembling proteins, and Affibody molecules.

Main Results:

• Pretargeting approaches demonstrate potential for high-contrast imaging and high therapeutic index (TI) tumor targeting.
• Modular design allows broad applications across tumor types and targets.
• Innovations are expanding the capabilities and efficiency of pretargeted theranostics.

Conclusions:

• Pretargeting offers significant advantages but presents complexities for clinical translation.
• Further development is needed to overcome obstacles to clinical success.
• This approach holds promise for reviving interest in radiotheranostics and advancing cancer treatment.