Challenges of Imaging as a Biomarker in Drug Research and Drug

Positron emission computed tomography (PET) imaging is a clinically translatable technology with the potential to accelerate drug research and development. Therapy monitoring by non-invasive PET imaging study allows a straightforward translation from preclinical to clinical research. In fact, PET imaging is making a major contribution to drug development today and will continue to grow in value. We hereby demonstrate that PET imaging capabilities and our experiences focused on oncology and central nervous system (CNS) therapeutic areas in drug research and development. PET with labeled anticancer drug may be an ideal biomarker for identification of treatment-responsive populations. Using non-invasive PET imaging with labeled anticancer drug, we investigated whether uptake of anticancer drug in tumors is associated with the efficacy. Brain concentration of CNS drug could be obtained according to the radioactivity of PET-labeled CNS drug in brain measured by PET. Usually, blood-brain barrier (BBB) penetration in non-human primates is a good indication for human BBB penetration and we have performed brain PET study in conscious rhesus macaques using special PET camera for non-human primate. Recently, we have successfully identified 18F-fluorodeoxyglucose (FDG) PET is useful as a tool for the predictive imaging biomarker against CNS drug-induced neuronal degeneration/cell death and available in the clinical trial. Finally, we would like to mention that how imaging biomarkers should be applied to clinical trials including investigational trials beyond preclinical study.