Monoclonal antibody based radiopharmaceuticals for imaging and therapy

The concept of personalized medicine has been steadily growing for the past decades. Monoclonal antibodies (mAbs) are undoubtedly playing an important role in the transition away from conventional medical practice to a more tailored approach to deliver the best therapy with the highest safety margin to a specific patient. In certain instances, mAbs and antibody drug conjugates (ADCs) may represent the preferred therapeutic option for several types of cancers due to their high specificity and affinity to the antigen. Monoclonal antibodies can be labeled with specific radionuclides well-suited for PET (Positron Emission Tomography) or gamma camera scintigraphy. The use of radiolabeled mAbs allows the interrogation of specific biomarkers and assessment of tumor heterogeneity in vivo by a single diagnostic imaging scan that includes the whole-body in the field-of-view. Moreover, the same mAb can then be radiolabeled with an analogous radionuclide for the delivery of beta-minus radiation or alpha-particles as part of a radioimmunotherapy (RIT) approach. However, the path to develop, validate, and implement mAb-based radiopharmaceuticals from bench-to-bedside is complex due to the extensive pre-clinical experiments and toxicological studies required, and the necessity of labor-intensive clinical trials that often require multi-time-point imaging and blood draws for internal radiation dosimetry and pharmacokinetics. As more mAb-based radiopharmaceuticals have been developed and evaluated, the opportunities and limitations offered by mAbs have become better defined. Our aim with this manuscript is therefore to provide an overview of the recent advances in the development of mAb-based radiopharmaceuticals and their clinical applications in Oncology.