Background: The bioanalytical strategy for antibody-drug conjugates (ADC) includes multiple integrated measurements of pharmacologically relevant ADC.
Methods & results: Three ligand-binding assays were validated for the measurement of total antibody, active ADC and total ADC. Accuracy and precision demonstrate %bias from -8 to 14%, %CV from 3 to 11% and total error from 3 to 21%, with >98% samples meeting incurred sample reanalysis criteria. Each assay met stability, selectivity, dilutional integrity, carry over and specificity criteria with no interference from associated metabolite/impurity. Given the active ADC assay sensitivity to payload, active ADC was used to assess drug to antibody ratio.
Discussion & conclusion: Implementation of a microfluidic automated platform enabled high throughput sample analysis of multiple analytes with minimal sample processing.
Keywords: antibody–drug conjugate; drug antibody ratio; ligand-binding assays; payload; selectivity; specificity; total antibody.