Is ISR Needed For Biomarker Assays?
Incurred sample reanalysis (ISR) is a well-established measure for the reproducibility of pharmacokinetic (PK) assays and commonly conducted in regulated studies. ISR was established in PK assays to address sources irreproducibility observed in study data that could be attributed to back conversion of unstable metabolites, matrix effects, recovery issues, sample inhomogeneity and undocumented technical errors. In addition, the value of ISR is notably in the fact that validation of PK assays requires the use of spiked samples that are used to characterize the assay, whereas these spiked samples may not adequately mimic study samples (incurred samples) and thus the necessity for establishing in-study ISR.
