Development of a Novel Radiopharmaceutical Kit for Radiolabeling with Lu-177 for Application in Breast Cancer Treatment

Recent developments in cancer treatment have significantly improved cancer patient survival and quality of life. New drugs and treatment strategies are constantly being researched, and targeted cancer therapy is the treatment method with the highest efficacy and negligible side effects compared with other methods. Radioimmunotherapy is a targeted therapy that can potentially increase the effectiveness of conventional monoclonal antibodies. Since trastuzumab is used as a carrier, it is used in lesser amounts than the treatment dose. Thus, both side effects and cost are reduced. Lu-177 is a radionuclide that emits both beta particles and gamma photons. Lu-177 has been reported to be effective at localizing cytotoxic radiation in relatively small areas, with less damage to surrounding normal tissue, and is competent at destroying metastatic lesions and small tumors. This study aimed to develop new theranostic radiopharmaceuticals for breast cancer treatment by radiolabeling the active substance trastuzumab (TRZ), which is used in immunotherapy and targeted to breast cancer tumors, with Lu-177. For this purpose, radionuclide–monoclonal antibody radiolabeling, quality control, in vitro stability studies, cell culture studies, and in vivo imaging studies were carried out.