Full Validation of Therapeutic Antibody Sequences by Middle-Up Mass Measurements and Middle-Down Protein Sequencing

This application notes reports a novel middle-up LC-ESI-MS subunit analysis and middle-down LC-MALDI in-source decay (ISD) mass spectrometry method applied to cetuximab, panitumumab and natalizumab selected as representative FDA and EMA approved monoclonal antibodies (mAbs). The regulatory agencies require comprehensive primary sequence validation both for innovator and biosimilar monoclonal antibodies (mAbs). Full sequence coverage (SC) is typically obtained by the combination of multiple LC-MS/MS datasets from various protease digests.