Opportunities and challenges for hybrid immunoaffinity LC–MS approach for quantitative analysis of protein biomarkers

Biomarkers are defined as being able to be “objectively measured and evaluated as indicators of normal biological processes, pathogenic processes or pharmacologic responses to therapeutic interventions” [1]. The use of biomarkers represents a competitive advantage in drug discovery and development to improve drug discovery effectiveness, facilitate dose selection, evaluate pharmacodynamic (PD) effect and target engagement, assess safety and select patients for treatment. There are many analytical platforms for biomarker measurements including ligand-binding assays (LBAs), MS, flow cytometry and molecular profiling methodologies such as DNA sequencing and immunohistochemistry. Some of these technologies provide quantitative results while the others are considered semiquantitative...