Comparison of Bevacizumab Quantification Results in Plasma of Non-small Cell Lung Cancer Patients Using Bioanalytical Techniques Between LC-MS/MS, ELISA, and Microfluidic-based Immunoassay.

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.

Multiplexed monitoring of therapeutic antibodies for inflammatory diseases using Fab-selective proteolysis nSMOL coupled with LC-MS.

Monoclonal antibodies have accelerated the availability of treatment options for many diseases in which the molecular mechanism has been elucidated in detail. Therefore, an assay that can universally analyze antibodies for clinical pharmacokinetics and cross-sectional studies would be indispensable. We have developed a universal antibody bioanalysis with a Fab-selective tryptic reaction, named nano-surface and molecular-orientation limited (nSMOL) proteolysis, that collects the specific antibody signature peptides in biological samples. Using the nSMOL method, we have fully validated the bioanalysis of many antibodies, Fc-fusion proteins, and their biosimilars. Inflammatory immune diseases often require long-term clinical management because of the remission and relapse observed. Accurate antibody monitoring in systemic circulation could contribute to the improvement of clinical outcomes. Because several biopharmaceuticals can be selected as practical treatment options, the assay development that quantitates many antibodies simultaneously would be applicable in many theraprutic monitoring. In this study, we have validated the LC-MS bioanalysis method for seven-mixed antibodies (Infliximab, Adalimumab, Ustekinumab, Golimumab, Eculizumab, Etanercept, and Abatacept) using the nSMOL normal reaction condition and two-mixed antibodies (Tocilizumab and Mepolizumab) using the acidified reduction acceleration condition, as reported in our previous papers. Moreover, this multiplexed assay has been verified using clinical patient samples. The nSMOL approach enables the quantitation of several immunosuppressive antibodies simultaneously in human serum, and nSMOL can potentially be applicable to the drug-drug interaction assays or therapeutic antibody monitoring of several inflammatory immune diseases to optimize administration.

Application of nSMOL coupled with LC-MS bioanalysis for monitoring the Fc-fusion biopharmaceuticals Etanercept and Abatacept in human serum.

The principle of nano-surface and molecular-orientation limited (nSMOL) proteolysis has a unique characteristic Fab-selective proteolysis for antibody bioanalysis that is independent of a variety of monoclonal antibodies by the binding antibody Fc via Protein A/G in a pore with 100 nm diameter and modified trypsin immobilization on the surface of nanoparticles with 200 nm diameter. Since minimizing peptide complexity and protease contamination while maintaining antibody sequence specificity enables a rapid and broad development of optimized methods for liquid chromatography-mass spectrometry (LC-MS) bioanalysis, the application of regulatory LC-MS for monitoring antibody biopharmaceuticals is expected. nSMOL is theoretically anticipated to be applicable for representative Fc-fusion biopharmaceuticals, because Protein A/G-binding site Fc exists on the C-terminus, and its functional domain is available to orient and interact with the reaction solution. In this report, we describe the validated LC-MS bioanalysis for monitoring Ethanercept and Abatacept using nSMOL technology. The quantitation range of Ethanercept in human serum was from 0.195 to 100 µg/mL using the signature peptide VFCTK (aa.43-47), and that of Abatacept was from 0.391 to 100 µg/mL using the signature peptide MHVAQPAVVLASSR (aa.1-14). Both proteins fulfilled the guideline criteria for low-molecular-weight drug compounds. The results indicate that the clinical and therapeutic monitoring for antibody and Fc-fusion biopharmaceuticals are adequately applicable using nSMOL proteolysis coupled with LC-MS bioanalysis.

Verification between Original and Biosimilar Therapeutic Antibody Infliximab Using nSMOL Coupled LC-MS Bioanalysis in Human Serum.

BACKGROUND: 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. OBJECTIVE: 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. METHOD: 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. RESULTS: 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. CONCLUSION: The nSMOL strategy has the potential as a practical therapeutic monitoring technology in IFX therapeutic applications.

Validated LC/MS Bioanalysis of Rituximab CDR Peptides Using Nano-surface and Molecular-Orientation Limited (nSMOL) Proteolysis.

Presently, monoclonal antibodies (mAbs) therapeutics have big global sales and are starting to receive competition from biosimilars. We previously reported that the nano-surface and molecular-orientation limited (nSMOL) proteolysis which is optimal method for bioanalysis of antibody drugs in plasma. The nSMOL is a Fab-selective limited proteolysis, which utilize the difference of protease nanoparticle diameter (200 nm) and antibody resin pore diameter (100 nm). In this report, we have demonstrated that the full validation for chimeric antibody Rituximab bioanalysis in human plasma using nSMOL proteolysis. The immunoglobulin fraction was collected using Protein A resin from plasma, which was then followed by the nSMOL proteolysis using the FG nanoparticle-immobilized trypsin under a nondenaturing condition at 50°C for 6 h. After removal of resin and nanoparticles, Rituximab signature peptides (GLEWIGAIYPGNGDTSYNQK, ASGYTFTSYNMHWVK, and FSGSGSGTSYSLTISR) including complementarity-determining region (CDR) and internal standard P14R were simultaneously quantified by multiple reaction monitoring (MRM). This quantification of Rituximab using nSMOL proteolysis showed lower limit of quantification (LLOQ) of 0.586 µg/mL and linearity of 0.586 to 300 µg/mL. The intra- and inter-assay precision of LLOQ, low quality control (LQC), middle quality control (MQC), and high quality control (HQC) was 5.45-12.9% and 11.8, 5.77-8.84% and 9.22, 2.58-6.39 and 6.48%, and 2.69-7.29 and 4.77%, respectively. These results indicate that nSMOL can be applied to clinical pharmacokinetics study of Rituximab, based on the precise analysis.

Application of nano-surface and molecular-orientation limited proteolysis to LC-MS bioanalysis of cetuximab.

BACKGROUND: We recently reported the principle of nano-surface and molecular-orientation limited (nSMOL) proteolysis, which is useful for LC-MS bioanalysis of antibody drugs. METHODOLOGY: The nSMOL is a Fab-selective limited proteolysis which utilizes the difference of protease-immobilized nanoparticle diameter (200 nm) and antibody collection resin pore (100 nm). We have demonstrated the full validation for chimeric antibody cetuximab bioanalysis in human plasma using nSMOL. Signature peptides (SQVFFK, ASQSIGTNIHWYQQR and YASESISGIPSR) in cetuximab complementarity-determining region were simultaneously quantitated by LC-MS multiple reaction monitoring. CONCLUSION: This nSMOL quantification showed sensitivity of 0.586 µg/ml and linearity of 0.586 to 300 µg/ml. Full validation study archived the guideline criteria of low Mw drug compounds. These results indicate that nSMOL is also significant method for cetuximab bioanalysis.