Infliximab (IFX) is a chimeric therapeutic monoclonal antibody targeting tumor necrosis factor alpha (TNFα)-mediated inflammatory immune diseases. However, despite of an initial good clinical response, decrease in response to long-term treatment is a common observation.
Recent studies suggest that IFX level in circulation has a correlation with clinical bioavailability. Therefore, the management of IFX dosage for individual manifestation by IFX monitoring may be valuable for the improvement of therapeutic response and outcomes.
In order to develop a broad IFX therapeutic monitoring in human serum, we have developed the validated IFX bioanalysis for RemicadeTM and its biosimilar product using our nano-surface and molecular-orientation limited proteolysis (nSMOL) technology coupled with liquid chromatographytandem mass spectrometry (LC-MS/MS). The nSMOL chemistry has a unique property of Fabselective proteolysis, and makes it possible a global bioanalysis for many monoclonal antibodies.
The quantitation range of IFX in serum was from 0.293 to 300 μg/ml with good linearity. Quantitation verification at the concentrations of 0.293, 0.879, 14.1 and 240 µg/ml was within 1.56- 7.53% of precision and 98.9-111% of accuracy using H-chain signature peptide SINSATHYAESVK. Moreover, cross-verified bioanalysis of Remicade quantitation using biosimilar standard, and its opposite combination, obtained an identical and inter-comparative results.
The nSMOL strategy has the potential as a practical therapeutic monitoring technology in IFX therapeutic applications.