Molecular Imaging in Cancer Drug Development

Information that can be extracted using molecular imaging, categorized by population selection, tumor targeting, pharmacokinetics, and pharmacodynamics (7,8). (First panel) Molecular imaging with, for instance, radiolabeled antibodies can potentially identify responders and nonresponders. (Second panel) For tumor targeting, several tumor aspects can be visualized with molecular imaging, such as tumor cell receptors, environmental factors, and immune cells. Example is PET visualization of ⁸⁹Zr-bevacizumab targeting vascular endothelial growth factor A in tumor microenvironment in patient with metastatic renal cell carcinoma (bottom; adapted from (60)). (Third panel) For pharmacokinetics, molecular imaging can provide information about whole-body distribution, normal-tissue accumulation of, for instance, ⁸⁹Zr-bevacizumab (top; adapted from (60)), and penetration of CNS (bottom). Data on normal-tissue uptake might explain drug behavior. (Fourth panel) Pharmacodynamic information can be obtained by performing PET before and after treatment. Example is use of ¹⁸F-FES for tumor uptake per lesion on antiestrogen therapy, resulting in less uptake. By this pharmacodynamic assessment, therapeutic dose with maximal decrease in tracer uptake can support further clinical studies. This figure was prepared using template on Servier medical art website (https://smart.servier.com/).