B-343 LC MS/MS Measurement of Infliximab, Adalimumab, Ustekinumab, Vedolizumab and Anti Drug Antibodies Using mAbXmise Kits on Xevo TQ Absolute XR MS for Clinical Research

Abstract

Quantitative measurement of therapeutic monoclonal antibodies and antidrug antibodies is valuable for research on inflammation related biologics. Immunoassay based approaches can be affected by matrix interferences and limited multiplexing, motivating peptide level LC MS/MS methods with internal standards for improved analytical specificity and reproducibility. This clinical research study describes a research use only workflow incorporating standardized sample preparation kits and tandem quadrupole mass spectrometry for the measurement of four monoclonal antibodies and two antidrug antibodies. Serum calibrators, quality controls, and research samples were prepared using mAbXmise™ ITDM2 (Multiplex IFX, ADL, USTE, VDZ, etc.) and mAbXmise IADA1 (multiplex anti-IFX and anti-ADL) kits (Promise Proteomics, France) following the manufacturer’s instructions, including overnight digestion at 37°C with the supplied protease. Ten µL of serum were used for monoclonal antibody measurements and 100 µL for antidrug antibody measurements. Chromatographic separation (8 min) used an ACQUITY™ Premier Peptide CSH™ C18 Column on an ACQUITY Premier System. Detection employed multiple reaction monitoring (MRM) on a Waters Xevo™ TQ Absolute XR Tandem Quadrupole Mass Spectrometer. Calibration ranges: 0.5–100 µg/mL for monoclonal antibodies peptides (ITDM2) and 10–400 ng/mL for antidrug antibodies (IADA1). Analytical performance was assessed using multiple QC levels and seven anonymized research samples previously characterized by immunoassay were analyzed to compare analytical behavior between methods. All monoclonal antibody peptides demonstrated strong linearity across the evaluated concentration range, 0.5–100 µg/mL, with r² > 0.99; all points met = ±15% deviation criteria. QC based precision was = 10 %RSD with accuracy 94.2–114.2% across levels. For antidrug antibodies, four parameter logistic calibration produced stable fits with LOQs in the ng/mL range; QC precision was = 10 %RSD and accuracy 90.5–105.6%. Analysis of research serum samples demonstrated consistent measurement trends between LC MS/MS and previously generated immunoassay results for both monoclonal antibodies and anti drug antibodies. Samples containing detectable anti drug antibodies by immunoassay showed corresponding peptide signals by LC MS/MS. Observed differences were consistent with expected methodological distinctions. This clinical research workflow demonstrates sensitive, specific, and reproducible quantification of monoclonal antibodies and antidrug antibodies using standardized sample preparation and LC-MS/MS detection. The results support its utility for laboratories conducting analytical characterization, method evaluation, and development of mass spectrometry-based approaches for biologic measurement in clinical research settings. For Research Use Only. Not for use in diagnostic procedures.