Bioanalytics – Biomolecular
2019 PharmSci 360
Assessment of the suppression of soluble free target is a critical therapeutic response and pharmacodynamic biomarker for biologics and biosimilars. Modeling free target concentrations makes inaccurate assumptions and their assays are highly challenging since dissociation of the drug-target complex can under or overestimate concentrations. Free target biomarker assays will be valuable for personalized medicine as point of care assays in the future could minimize pre-analytical variables affecting drug-target equilibrium.
We will describe how we developed and validated an accurate and sensitive immunoassay for free VEGF in the presence of VEGF inhibitors (bevacizumab, ranibizumab, and aflibercept). Several recent studies have shown commercial ELISAs typically used in clinical sample measurement of free VEGF are inaccurate. To minimize complex dissociation, we reduced incubation time and designed and screened non-competing antibodies. We designed drug-spiked QCs to confirm accuracy. Our case study will provide the bioanalytical community solutions for designing free target biomarker assays.