PNNL

Abstract

Protein biomarkers in blood have a great deal of promise for facilitating personalized medicine, including detection, diagnosis, prognosis, and monitoring of therapy. Even so, it is widely recognized that these circulating biomarkers are highly variable across individuals, and that it likely will be necessary to identify a panel of biomarkers before blood-based protein detection will be useful for any disease. However, analysis of a panel of biomarkers creates its own problems. In 2005, Anderson [1] estimated that the development of 5 separate protein assays will cost $10-20 million to achieve US Food and Drug Administration approval, and that developing larger sets of biomarkers will be progressively more costly and less worthwhile to diagnostic companies. Because there is much less money from diagnostics (compared to drugs), companies are commonly unwilling to make this type of investment in diagnostic development. Thus, the situation is that it is widely recognized that multiplexed protein assays are needed for diagnostic purposes, but it is financially impractical to get these assays into the clinic where they can benefit patients. Although many analytical approaches have been proposed for multiplexed biomarker analysis, most of these lack the sensitivity to detect the low-abundance proteins that are likely to be useful as biomarkers. For example, in the case of cancer, the goal of early detection is to identify tumors when they are small and not markedly differentiated from the normal tissue.