Positron emission tomography and drug discovery: contributions to the understanding of pharmacokinetics, mechanism of action and disease state characterization.

As an imaging modality, positron emission tomography (PET) provides unique quantitative in vivo information of value to drug discovery studies. These non-invasive studies span the pharmacokinetic/pharmacodynamic evaluation of potential drug candidates, receptor occupancy as an important determinant of efficacy, the pharmacological characterization of potential mechanisms of action, and the biological characterization of disease with well-characterized PET ligands. PET techniques are also being applied to the assessment of gene-level activities and the longitudinal evaluation of disease progression and therapeutic intervention. As the availability of PET scanners, cyclotrons, and specific PET ligands grows, the techniques highlighted in this review will become central to target validation, drug candidate selection, pharmacokinetic characterization, and clinical evaluation.