Radiolabeling of monoclonal antibody B43.13 with rhenium-188 for immunoradiotherapy

In this study we report a novel method for direct radiolabeling of monoclonal antibody B43.13 (MAb-B43.13) with 188Re and have evaluated the productʹs radiochemical, biochemical, immunochemical and selected biological properties. 188Re---MAb---B43.13 was readily prepared by the addition of generator produced perrhenate to a preformulated antibody vial after an optimal amount of supplemental stannous ion, in the form of stannous tartrate, was added. The final radiolabeled product retained its biochemical purity (as determined by size-exclusion HPLC and R/NR-SDS-PAGE), its immunoreactivity (as determined by immunoassay) and presented with a typical stability (in the presence of serum and cysteine) and biodistribution (in tumored mice) profile. The evaluation of the product for immunoradiotherapy of ovarian cancer in a clinical setting requires further studies.