A generic approach for simultaneous measurements of total antibody and cleavable antibody-conjugated drug by LC/MS/MS.

The current industry practice for antibody-drug conjugate (ADC) bioanalysis includes quantification of total antibody and antibody-conjugated drug. Here, we report a novel 2-in-1 approach for measuring total antibody and protease-cleavable conjugated drug Monomethyl Auristatin E (MMAE) concurrently. This allows for the determination of the DAR (Drug Antibody Ratio) for in vivo samples, with a 3-orders linear range based on total antibody concentration from 0.1 to 100 μg/mL. Our generic, concurrent method has been cross-validated with the previously established methods in an animal study. This novel approach is applicable to all human IgG1 ADCs with papain cleavable conjugated drug in preclinical studies.