ABSTRACT
Pharmaceutical companies are increasingly using biomarkers in early clinical drug development (phase I) to enable early proof-of-concept studies and to better predict the dose range for phases II and III. Biomarkers play an important role in decision making during the early phases of clinical drug development. Many biomarkers are used to assess the safety of a drug; others are used to study the pharmacologic effects related to the mechanism of action. Evaluation of a pharmacodynamic (PD) biomarker is a process that starts in drug discovery, when potential drug candidates have been identified, and continues when the PD biomarker is used in clinical studies. A key objective in early clinical drug development is to establish the relationship between dose and the PD effects. The analytical validation of biomarker methods is often performed in an environment that differs from the one in which the methods will be performed during the clinical studies.
