Development of a modular click labelling method for producing radioiodine-labelled antibodies.

Direct radioiodination is a simple and convenient method for antibody labelling but suffers from reduced immunoreactivity and metabolic instability. To address these limitations, a modular click radioiodination strategy based on iodo-Azide and ADIBO-antibody conjugates was developed. The resulting [125I]iodo-Azide-Rituximab exhibited approximately 1.6-fold higher immunoreactivity, improved blood retention, and reduced thyroid radiation exposure compared to directly labelled [125I]iodo-Rituximab. This click-based approach minimizes antibody damage and enhances in vivo stability, underscoring its potential for the developing iodine-based radiopharmaceuticals.