Given that proteins are the primary working parts of cells, it seems self-evident that proteomics should yield abundant clues to disease mechanisms, as well as numerous clinically useful biomarkers. Biomarkers in readily accessible bodily fluids such as plasma, in particular, offer the potential for rapid advances in patient care through early diagnosis, selection and monitoring of treatment, as well as acceleration of drug development.

It is therefore surprising that the rate at which new protein diagnostics have been approved by FDA over the past 12 years has steadily declined. In fact no protein biomarkers arising from proteomics appear to have entered broad clinical use so far. Why is this?

From the viewpoint of basic biology, biomarker development is probably as difficult as drug development. Both aim at discovery and verification of a disease-related biological invariant across an outbred human population, and they seem to have similar candidate attrition rates. Given the 100:1 revenue advantage of pharma compared to protein diagnostics, one is tempted to imagine that biomarker work should nevertheless be far less expensive and take less time than drug development. This wishful thinking is just that.