Abstract
BACKGROUND: ABP501 is a biosimilar to Reference Adalimumab (HUMIRA®) produced by AMGEN. Adalimumab (ADA) has a marketing authorization for Crohn's disease, ulcerative colitis and other inflammatory or autoimmune diseases. The aim of this study was to evaluate the LISA-TRACKER assays developed by Theradiag (France), for the monitoring of ABP501 and anti-ABP501 antibodies in human serum. RESULTS: 68 ABP501 clinical samples were measured with the LISA TRACKER Duo Adalimumab assay. LISA TRACKER has been validated as suitable for quantification of ABP501 in human serum samples. Accuracy of the LISA-TRACKER was measured using 3 human serum matrices spiked with known levels of biosimilar, 3 levels spanning the dynamic range. Percentages of recovery were ranged from 90 to 120% for biosimilar batch1, and between 93 and 105% for biosimilar batch2. The acceptance criteria (CV < 20%) were met for intra-run (from 3.8 to 16.5%) and inter-run imprecision (from 4.4 to 13.9%) including the two batches. All results were comprised within ± 20% from results, obtained with the kit and sample unexposed in order to evaluate stability of the sample, stability of the kit and consistency of the results. In any case, but two, all percentages of inhibition were > 50% for specificity. Specificity was tested with Biosimilar spiked samples, Biosimilar with Humira® spiked samples, and clinical samples from patients treated with adalimumab biosimilar. All of these samples were spiked with polyclonal antibodies directed against Humira®. Specificity inhibition and specificity detection steps were also part of the validation parameters. Reagents made with ABP501 gave similar results than reagents made with Humira® meeting acceptance criteria. CONCLUSIONS: LISA-TRACKER ADA and anti-ADA assays are reliable for the monitoring of patients treated with ABP501.