Zr-Chloride Can Be Used for Immuno-PET Radiochemistry Without Loss of Antigen Reactivity In Vivo.

Zr immuno-PET continues to be assessed in numerous clinical trials. This report evaluates the use of Zr-chloride in the radiolabeling of monoclonal antibodies conjugated with desferrioxamine B (DFO), describes its effects on radiopharmaceutical reactivity toward antigen, and offers guidance on how to ensure long-term stability and purity. Zr-DFO-trastuzumab and Zr-DFO-cetuximab were prepared using ZrCl The stability of each was evaluated for 7 d in 20 mM histidine/240 mM sucrose buffer, 0.

A comprehensively revised strategy that improves the specific activity and long-term stability of clinically relevant Zr-immuno-PET agents.

Zirconium-89 is currently being used in numerous clinical trials involving monoclonal antibodies and positron emission tomography. This report describes a revised strategy that reduces preparation time while increasing the specific activity of clinically relevant immuno-PET agents. Additionally, it demonstrates that n-acetyl-l-cysteine acts as a superior radioprotective agent that improves long-term stability without compromising antigen affinity in vivo.