Pharmacodynamic Biomarkers can provide information on the pharmacologic effects of a drug on its target. Pharmacodynamic biomarkers studies may provide insights into proof of mechanism (i.e., Does the agent hit its intended target?) and proof of concept (i.e., Does hitting the drug target result in the desired biologic effect?). Pharmacodynamic biomarkers studies may also provide information on the optimal biologic dosing or scheduling of a targeted agent.
A Pharmacodynamic Biomarkers can be used to examine the link between drug regimen, target effect, and biological tumor response. Coupling new drug development with focused PD biomarker measurements provides critical data to make informed, early go/no-go decisions, to select rational combinations of targeted agents, and to optimize schedules of combination drug regimens. Use of PD endpoints also enhances the rationality and hypothesis-testing power throughout drug development, from selection of lead compounds in preclinical models to first-in-human trials. Given these critical roles in delivering targeted therapy, the introduction of validated and reliable clinical PD assays is warranted in drug development.