Cancer Imaging and Therapy with Bispecific Antibody Pretargeting

Area of Science:

• Oncology
• Radiochemistry
• Biotechnology

Background:

• Directly-labeled antibodies show limitations in cancer radioimmunodetection and radioimmunotherapy, including poor image quality and insufficient targeted radiation dose.
• Clinical adoption of conventional radioimmunoconjugates has not met expectations due to inherent challenges.

Purpose of the Study:

• To review advances in pretargeting methods for cancer radioimmunodetection and radioimmunotherapy.
• To highlight the use of bispecific antibodies and radiolabeled peptide haptens as a novel pretargeting strategy.
• To emphasize the Dock and Lock (DNL) modular engineering method for creating bispecific trimeric constructs.

Main Methods:

• Review of preclinical and clinical studies on pretargeting strategies.
• Focus on bispecific antibodies for initial tumor targeting.
• Subsequent delivery of radiolabeled peptide haptens for imaging or therapy.

Main Results:

• Pretargeting overcomes limitations of conventional radioimmunodetection and radioimmunotherapy.
• Improved image resolution, contrast, and selective radiation dose delivery to tumors.
• Bispecific antibodies combined with peptide haptens offer a new modality for radionuclide delivery.

Conclusions:

• Pretargeting represents a significant advancement in cancer imaging and therapy.
• The DNL method enables the construction of advanced bispecific constructs for pretargeted radioimmunotherapy.
• This strategy holds promise for more effective and targeted cancer treatment.