Characterization of Antibody-Drug Conjugates by SEC with Combined Light Scattering

There has been a significant resurgence in the development of antibody-drug conjugates (ADC) as target-directed therapeutic agents for cancer treatment. The Drug Antibody Ratio (DAR) is a critical factor to the effective design of ADCs as the DAR describes the degree of drug addition which directly impacts both potency and potential toxicity of the therapeutic. Although mass spectrometry is a powerful tool for Mw determination it depends on uniform ionization and recovery between compounds which is not always the case for ADCs. This poster presents a method for DAR determination based on SEC-MALS in conjunction with UV absorption and differential refractive index detection.