biostudies-literatureUnknown16(14)Wilford T<b>Aim:</b> Endogenous interferents can cause nonselectivity in ligand binding pharmacokinetic assays, leading to inaccurate quantification of drug concentrations. We describe the development of a Gyrolab immunoassay to quantify a new modality, CB307 and discuss strategies implemented to overcome matrix effects and achieve selectivity at the desired sensitivity.<b>Results:</b> Matrix effects were mitigated using strategies including increasing minimum required dilution (MRD) and lower limit of quantification, optimization of antibody orientation, assay buffer and solid phase.<b>Conclusion:</b> The strategies described resulted in a selective method for CB307 in disease state matrix that met bioanalytical method validation (BMV) guidance and is currently used to support clinical pharmacokinBioanalysis757-769https://www.ebi.ac.uk/biostudies/studies/S-EPMC11389741biostudies-literatureSolving selectivity issues in LBAs: case study using Gyrolab to quantify CB307, a bispecific Humabody in human serum.PMC11389741Wilford TBartlett PDHughes RSchlag APandha HJasaitis LPierce AJfalseSolving selectivity issues in LBAs: case study using Gyrolab to quantify CB307, a bispecific Humabody in human serum.<b>Aim:</b> Endogenous interferents can cause nonselectivity in ligand binding pharmacokinetic assays, leading to inaccurate quantification of drug concentrations. We describe the development of a Gyrolab immunoassay to quantify a new modality, CB307 and discuss strategies implemented to overcome matrix effects and achieve selectivity at the desired sensitivity.<b>Results:</b> Matrix effects were mitigated using strategies including increasing minimum required dilution (MRD) and lower limit of quantification, optimization of antibody orientation, assay buffer and solid phase.<b>Conclusion:</b> The strategies described resulted in a selective method for CB307 in disease state matrix that met bioanalytical method validation (BMV) guidance and is currently used to support clinical pharmacokin2024-01-01T00:00:00Z20242025-04-04T12:09:17.646Z2025-04-04T12:09:17.646ZS-EPMC113897413895792610.1080/17576180.2024.2365545