Simultaneous analysis of multiple monoclonal antibody biotherapeutics by LC-MS/MS method in rat plasma following cassette-dosing.

We have recently developed a general liquid chromatography-tandem mass spectrometric (LC-MS/MS) method using a stable isotope-labeled (SIL) monoclonal antibody (mAb) as an internal standard (IS) for single-analyte quantification of mAb (Li et al. Anal Chem 84(3):1267-1273, 2012). The method offers an advantage over ligand binding assay in reducing the time and resources needed for bioanalytical support in preclinical stages of drug development.