The age of therapeutic conjugation is upon us! Bioanalysis for support of next generation Antibody Drug Conjugates (ADCs) and Antibody siRNA Conjugates (ARCs) have exploded recently due to the efficacy and safety that these therapies offer for immuno-oncology, rare diseases, vaccines and potentially many other diseases.

Recently, we have seen the role of hybrid LC-MS/MS in the analysis of antibody-drug conjugates (ADC) increase due to the complexity and number of bioanalytical assays needed to support this modality in the drug development process. Antibody drug conjugates tend to consist of a toxic small molecule payload attached via a linker to an antibody. The application of these drugs had mainly been in oncology where their mode of action is for the antibody to attach at the desired target site with subsequent release of the small molecule to combat tumor cells.

Having a therapeutic entity with multiple distinct components means that we need to have analytical methodologies for various components. Recently, we have seen a trend towards the complete ADC analyses being done by LC-MS/MS.

Hybrid LC-MS/MS can easily be used to monitor both the total antibody as well as the ADC conjugate in a variety of species and matrices with performance characteristics that meet industry guidelines/standards. Depending on the type of conjugation and linker used (site-specific vs Cys or Lys conjugation and cleavable vs non-cleavable,) and what reagents are available, hybrid LC-MS/MS offers several strategies or advantages to monitor the various constituent parts of the ADC. In many cases some of these assays can even be multiplexed to allow detection of various components from the same sample. This is most applicable following an affinity capture step with cleavable linkers that can release the payload upon digestion with papain for detection of the ADC while digestion with trypsin produces a surrogate peptide representing the total antibody. The ability to approach the analysis from different angles to gain multiple insights into the analyte can increasingly nudge the decision towards the use of LC-MS/MS. In many preclinical cases, we can even use “generic” methods which make the method development and analysis much quicker and cost effective. At the very least, the availability of hybrid LC-MS/MS as an alternative technology greatly increases your chances of success in the bioanalysis of antibody drug conjugates.

A novel 1.5 plex for support of ADCs/ARCs has a multitude of benefits for support of drug development from solving sample volume issues, sensitivity, impact on critical reagents, time, and quality.

This presentation will give an overview and strategy of ADC bioanalysis as well as a couple case studies that provide a novel PK bioanalytical approach using a 1.5 plex Hybrid LC-MS/MS assay for quantification of total drug (ADC or ARC) and total Ab for support of non-clinical and clinical trials, where multiple assays/components are analyzed from the same sample or extraction thereby ensuring more synergistic data between assays with less variability as well as benefiting from the need for less total sample volume for the bioanalysis.

We would be happy to collect and address your questions about Dawn’s presentation or any other inquiries on how our expertise can support your projects. Please feel free to reach out to us here.