Therapeutic Drug Monitoring: Performance of a FRET-Based Point-Of-Care Immunoassay for the Quantitation of Infliximab and Adalimumab in Blood

Two fast (<5 min), time-resolved fluorescence resonance energy transfer (FRET)-based immunoassays (Procise IFX™ and Procise ADL™) were developed for the quantitative detection of infliximab (IFX), adalimumab (ADL), and their respective biosimilars for use in therapeutic drug monitoring (TDM) using 20 µL of finger prick whole blood at the point-of-care or whole blood/serum in a central lab. Studies were performed to characterize analytical performance of the Procise IFX and the Procise ADL assays on the ProciseDx™ analyzer. The Procise IFX and Procise ADL assays both showed good analytical performance with respect to sensitivity, specificity, linearity, and precision suitable for routine clinical use as well as excellent correlation to current commercial ELISA IFX and ADL measurement methods. Results indicated that the Procise IFX and Procise ADL assays are sensitive, specific, and precise yielding results in less than 5 minutes from either whole blood or serum. This indicates the Procise IFX and Procise ADL assays are useful for obtaining fast and accurate IFX or ADL quantitation, thus avoiding delays inherent to current methods and enabling immediate drug level dosing decisions to be made during a single patient visit.