Validation of a flow cytometry-based basophil degranulation assay for use in multi-centric clinical trials

CYTO 2024 -- Basophils are circulating white blood cells that express CD63 marker upon activation of Fc?RI? receptor. Basophil activation/degranulation measurement via CD63 expression, can be used as a pharmacodynamic (PD) biomarker to assess target engagement, inform on drug dose selections and drug efficacy in clinical trials. CD63 Basophil Panel-1 measures induced (anti-Fc?RI?) activation of basophils, by measuring CD63 positivity on CD123+, HLA-DR- or CD123+, HLA-DR-, IgE+ basophil population. The CD63 Basophil Panel-1 aims to improve the measurement of PD effect of (included but not limited to) reversable drugs as basophils are activated with limited volumes of anti-Fc?RI? [and N-Formylmethionine-leucyl-phenylalanine (fMLP)] compared to higher volumes used in other commercially available kits.