Physiological and laboratory makers of drug effect

Abstract

This chapter focuses on physiological and laboratory markers of drug effect. The selection and measurement of relevant drug effects are important parts of clinical pharmacology. The biomarkers have served as surrogate endpoints and have provided the basis for regulatory approval of new drugs. Most of the biomarkers are identified in the studies of pathophysiology and epidemiology that demonstrated an association between the marker and the presence or prognosis of the underlying clinical condition. Laboratory biomarkers are used to establish prognosis and predict or monitor response to therapy or disease progression in patients with cancer. Statistical criteria have played an important role in assessing the predictive utility of biomarkers, but it is always hazardous to equate causation with statistical association. The support for using blood pressure as a surrogate endpoint is provided by the concordance of evidence from a number of clinical trials in which blood pressure lowering with low-dose diuretics and β-blockers was shown to reduce the incidence of stroke, coronary artery disease, and congestive heart failure in hypertensive patients. © 2007 Elsevier Inc. All rights reserved.