The Rise of Biopharmaceuticals and Immuno-PET: Where Pharmacy and Radiopharmacy Meet

The identification of molecular drivers of disease and the compelling rise of biotherapeutics such as peptides, monoclonal antibodies, antibody fragments and nontraditional binding scaffolds, activatable antibodies, bispecific antibodies, immunocytokines, antibody-drug conjugates, enzymes, polynucleotides, therapeutic cells as well as alternative drug carriers like nanoparticles have impacted clinical care but also came with challenges. Drug development is expensive, attrition rates are high, and efficacy rates are lower than desired. Nowadays, almost all these drugs, which generally have a long residence time in the body, can be stably labeled with 89Zr for whole body PET imaging and quantification. Although not restricted to monoclonal antibodies, this approach is called 89Zr-immuno-PET. This contribution summarizes at a high level the historical background, the technical aspects, and the future perspectives of 89Zr-immuno-PET.