A multiplex identification and quantification of monoclonal antibodies

Monoclonal antibodies (mAbs) have emerged as a major class of therapeutics used to treat diseases such as cancer, inflammation or autoimmune diseases. Due to the potential cross-reactivities involved with generic immunoassay-based techniques, LC-MS has gained more and more credit for analysing them even inside complex matrices.

During our collaboration with Pierre Fabre, we developed a proof of concept to specifically detect and quantitate 2 commercial antibodies by LC-MS (pertuzumab and natalizumab) in complex matrix such as rat serum.

After selection of one of several signature peptides for each antibody, we were able to specifically detect and quantitate the different mAbs. The following chart is showing the calibration curves for these antibodies.

Thanks to this kind of study, drug developers could be able to:

• Quickly specifically detect and quantitate mAbs in complex matrices
• Perform Early PK studies and PK triage
• Cross validate immunoassays