The development of analytical techniques to study therapeutic monoclonal antibodies is expected to be useful for pharmacokinetic analysis and for the development of therapeutic indexes to determine dosage standards. To date, the blood concentration of antibody drugs has been analyzed by the enzyme-linked immunosorbent assay (ELISA). However, with the development of mass spectrometry and microfluidization technologies, the assay implication is drastically changing. We have developed an analytical validation method for many monoclonal antibodies and Fc-fusion proteins using Fab-selective proteolysis nSMOL coupled with liquid chromatography-mass spectrometry (LC-MS/MS). However, the correlation between the analyzed data characterization and the referable value from individual measurement techniques has not been adequately discussed. Therefore, in this study, we discussed in detail the relationship of the bioanalytical data from three different techniques, LC-MS/MS, ELISA, and microfluidic immunoassay, using 245 clinical plasma samples from non-small cell lung cancer patients treated with bevacizumab. The quantified concentration data of bevacizumab in human plasma indicated that the results obtained were almost the same correlation regardless of which technique was used. And the referable value from LC-MS/MS and microfluidic immunoassay were similar and correlated compared with ELISA.
Keywords: ELISA; LC-MS; bevacizumab; bioanalysis; microfluidic immunoassay; nSMOL.