Development and Evaluation of Copper-67 and Samarium-153 Labeled Conjugates for Tumor Radioimmunotherapy

Copper-67 and samarium-153 are two of the most attractive radionuclides for radioimmunotherapy. Two to three-day halflives, intermediate-energy beta emissions, image-able photons, and suitable chemical characteristics make these radionuclides ideal for this application. Work on the production of high specific activity 67Cu and l53Sm, as well as the development of stable chelates for conjugating these radiometals to tumor-associated monoclonal antibodies is presented. Based on preliminary in vitro and in vivo studies (in nude mice xenografted with human colon carcinoma), both 67Cu and l53Sm appear very promising for tumor radioimmunotherapy and warrant continued investigation.