Radiolabeled Antibodies for Cancer Radioimmunotherapy

Radioimmunotherapy (RIT) uses monoclonal antibodies (mAb) that are labeled with a particle-emitting radioisotope to deliver damaging radiation to specific antigens on cancer cells. Since its initial development for the treatment of lymphomas, RIT strategies are now being tested in other hematological malignancies and solid tumors. RIT in solid tumors remains a difficult endeavor due to physiological differences imncluding the presence of a dynamic tumor microenvironment. Nevertheless, the interest in RIT is buoyed by the recent clinical success of mAb as cancer therapeutics, the identification of novel cancer-associated proteins, and the development of novel isotope production and radiolabeling methods. The development of new radioimmunoconjugates requires the selection of a suitable target, mAb, and radiolabeling strategies. Many targets have already been validated for RIT, and multiple strategies to improve its therapeutic index have been proposed such as combination treatments, pre-targeting strategies, or imaging with radiolabeled mAb to pre-screen patients that are potential responders.