A Holistic Strategy to Characterize the in-vivo Stability of Novel Modalities using Affinity Capture Coupled to LC-MS or CE-Based Methods

Antibody-derived novel modalities have become a significant portion of the early-stage R&D pipeline in
bio-pharmaceutical companies. Understanding the in vivo stability and degradation propensity of these new
molecular entities is both critical and challenging. Due to the complexity of in vivo sample matrices such as
serum, plasma and tissue homogenate, affinity capture enrichment is often applied prior to LC-MS intact
analysis for the characterization of the stability profile of novel modalities. This approach has been
informative but encountered sensitivity as well as quantitation challenges when analyzing drug candidates
significantly larger than antibodies (e.g. multivalent antibodies with a molecular weight well over 200 kDa).
Here we report a holistic approach to characterize and quantitate the in vivo degradation products of novel
modalities using the combination of intact LC-MS and highly sensitive and robust CE workflows. The
improved sensitivity and the simplified quantitative workflow of CE-based methods provide complementary
information to LC-MS intact analysis, and enables a faster and more reliable data turnaround to trigger indepth
investigation and to gate or rank drug candidates.