Advancing Antibody-Drug Conjugate Development by Simplifying Antibody-Drug Ratio Analysis

Antibody-drug conjugates (ADCs) are an emerging class of therapeutic agents comprising of cytotoxic drugs linked to highly targeted antibodies. Designed by combining a drug and an antibody via a chemical link, their appeal lies in the ability to selectively target cancer cells without delivering the drug to healthy tissues.

To achieve the ideal therapeutic response, these ADCs must carry the desired payload of the drug. Insufficient cytotoxic payload can render the ADC treatment ineffective, while excessive amounts may harm more than help. Analytical labs rely on analyzing the drug-to-antibody ratio (or DAR) of ADCs during the ADC discovery, development and routine manufacturing quality checks. DAR can reveal much about ADCs: it can be used as a data vector to determine the best linker molecule or determine essential pharmacokinetic properties.

With reverse phases or solvent transfers during mass spectrometry (MS) sample preparation, analytical labs may end up with denatured proteins and antibody-drug links, which complicates DAR analysis. Easy and lightweight analytical workflows, such as those with the Phenomenex BioZen 1.8 µm SEC-2 MS columns, can expedite the measurement of average DAR and differentiation between species in samples, even under native conditions (Figure 1). These columns eliminate the need for solvent transfer in LC-MS, reducing workflow complexity and streamlining ADC discovery.

Fig 1. With Phenomenex BioZen 1.8um SEC-2 Column intact ADC DAR analysis and identification under native conditions. Figure courtesy of Phenomenex.

In-depth analytical methods such as DAR measurements are indispensable during the ADC development journey. Besides a sufficiently automated DAR calculation workflow, labs also need powerful analytical tools to assist with data deconvolution and analysis.

Offering a streamlined workflow for ADC analysis, the SCIEX ZenoTOF 7600 system and the Biologics Explorer software can facilitate highly accurate automated DAR calculation as well as allow automated deconvolution. Enabling peak detection and annotation, protein mapping, and data representation, these user-friendly workflows enabled by analytical tools and accompanying analysis software can help deconvolute obtained from DAR analysis.

Optimizing analytical methods such as DAR ratio measurements can help to shorten drug development timelines and get lifesaving therapeutics to patients faster. To streamline existing processes and adopt new, transformative methods, contact an expert at the Life Sciences companies of Danaher today.