We have developed a highly sensitive method to detect those low-abundant host cell protein from the drug product using the proteome enrichment beads. This approach help us to find the root cause and the risk associated with the drug product. There are multiple ways to improve the detection limit of HCP analysis, the untargeted method including but not limited to protein A depletion, the limited digestion, the molecular weight cutoff, the immunoprecipitation.
The targeted way to detect the host cell protein, including liquid chromatography, multiple reaction monitoring, and the non-liquid chromatography parallel reaction monitoring. The major challenge associate with these HCP analysis is the significant dynamic range between antibody drug and host cell proteins. So most method aim to reduce the amount of antibody and the enrich HCP before LCMS analysis to decrease the dynamic range between antibody peptides and HCP peptides.
So ProteoMiner technology and the limited digestion protocol significantly improve the detection limit of HCP analysis compared to other methods. It's non-biased compared to immunoprecipitation and can be applied to different drug module compared to protein A depletion method. This protocol is also simple and straightforward.
So ProteoMiner technology and limited digestion protocol help us to identify several HCPs that degrade polysorbate and the fragment antibody drug. In combination with the nano LCMPRM method, the enrichment method can also provide quantitative results to find the biological relevant concentration of problematic host cell proteins.
