The Dual-Integrated Multi-Attribute Method: Simultaneous Evaluation of Post-Translational Modifications and Host Cell Proteins for Unpurified Bulk Harvest of Antibody Therapeutics

The Multi-Attribute Method (MAM) using liquid chromatography/mass spectrometry (LC/MS) is widely applied to evaluate post-translational modifications (PTMs) in antibody therapeutics. This approach allows the monitoring of multiple PTMs within a single method. In this study, we extended the scope of MAM by incorporating host cell proteins (HCPs) as additional targets and developed a dual, integrated PTMs-HCPs MAM platform. This platform enables the simultaneous evaluation of more comprehensive critical quality attributes through a combination of MS1-based PTMs analysis and data-independent acquisition-based HCP quantification. Although proteomics-based characterization of residual HCPs has been extensively reported, prior studies have primarily focused on purified drug substances or products. Here, we demonstrate the application of our integrated platform to unpurified bulk harvest samples, eliminating the need for purification. While conventional PTMs-MAM and HCP-proteomics are typically conducted separately on purified samples, our dual integrated-MAM approach allows the linking of antibody PTMs with their potential HCP influencers within a single LC/MS injection.