Automated radiolabelling of monoclonal antibodies with the Modular Lab system

Automation of radiopharmaceutical preparation represents a way of reducing radiation doses to operators and providing good manufacturing practice-compliant manufacture of radiopharmaceuticals. Although widely adopted for PET radiochemical synthesis, such methods have not widely been used for the preparation of therapeutic radiopharmaceuticals. Here we describe an evaluation of an automated system for the preparation of radiolabelled antibodies. A labelling method based on the Modular Lab system was developed and applied to the radiolabelling of the monoclonal antibody conjugate, YAML568-CHX'A-DTPA, with indium-111. Antibodies were labelled using both manual and automated means and analysed by high-performance liquid chromatography and thin-layer chromatography methods. Radiochemical purities achieved using automation (mean 98%) were slightly lower than those achieved manually (mean 99%); however, the radiochemical purity obtained was reproducible and well within the set specification of greater than 95%. The Modular Lab system can be used to automate the radiolabelling of monoclonal antibody-chelate conjugates with metallic isotopes such as indium for the potential application for therapeutic radionuclide therapy.