Clinically important neutralizing anti-drug antibodies detected with an in-house competitive ELISA

Abstract

Therapeutic drug monitoring of TNF-alpha inhibitors is crucial for evaluating patients with inflammatory diseases on a personalized level. It has been clinically observed that many patients receiving TNF-alpha inhibitors, with negative drug and anti-drug antibody results from bridging ELISA (bELISA), lose their drug response over time, despite dose optimization. Our aims were to develop innovative in-house competitive ELISAs (cELISAs) for the detection of neutralizing antibodies against infliximab and adalimumab and compare their results to reporter gene assay (RGA) and in-house bELISA. Furthermore, we aimed to evaluate patient anti-drug antibody results in regard to their clinical records and potential benefits of therapeutic drug monitoring with the novel cELISAs. Sera of patients treated with infliximab (n = 46) or adalimumab (n = 31), having undetectable drug levels, were tested with our in-house cELISA. Briefly, samples were incubated with a fixed amount of drug and the neutralizing capacity of the samples was determined. The cELISA results were compared to RGA and bELISA results using Spearman's correlation coefficient. Additionally, patient clinical data were evaluated in line with the results of cELISA, bELISA, and RGA using the Kaplan-Meier analysis and the Log Rank test. Both anti-infliximab and anti-adalimumab cELISAs showed very good correlation to RGA (r = 0.932, p< 0.0001 and r = 0.947, p < 0.0001, respectively). Furthermore, a positive result in anti-infliximab cELISA can predict treatment failure in 100% of patients with negative bELISA, while a positive result in anti-adalimumab cELISA can predict treatment failure in 80% of patients with negative bELISA. Taken together, we developed innovative cELISAs enabling quantification of functional and neutralizing anti-drug antibodies, comparable to RGA. The association between cELISA results and loss of drug response in patients identified clinically important anti-drug antibodies, as measured by cELISA.

Therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal disease: a systematic literature review informing EULAR points to consider

“…In contrast, drug-tolerant assays detect (sometimes transient) ADAb, even in the presence of circulating biopharmaceuticals, and are therefore less relevant for clinical practice. Five studies compared assays used for the detection of ADAb 24 36 37 43 44. All studies compared ELISA with RGA and, except for one study,24 measurements were comparable (correlation coefficients >0.8); however, absolute levels were not directly comparable between assays.…”

“…All studies compared ELISA with RGA and, except for one study,24 measurements were comparable (correlation coefficients >0.8); however, absolute levels were not directly comparable between assays. ELISAs were additionally compared with enzyme immunoassay, surface plasmon resonance and other ELISA formats, with a high correlation 36 43 44…”

EULAR points to consider for therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases

“…Several assay formats are available and, in accordance with drug concentration measurement, ELISA is the most straightforward method. Test results of other assay formats are comparable to ELISA results24 25 33 34 but a consistent assay type should preferably be used over time, since different assay types might express results with different arbitrary units (eg, ug/L, AU/mL) and have different cut-off values. The radioimmunoassay, an ADAb assay that is mildly drug tolerant and used in some clinical laboratories, was not included in the SLR.…”

Monitoring pharmaceuticals in the aquatic environment using enzyme-linked immunosorbent assay (ELISA)—a practical overview

“…The application of MIPs-based ELISA for the detection of pharmaceuticals in the food [132][133][134] and clinical areas [135][136][137] has been widely developed in the last decade.…”