Assays and strategies for immunogenicity assessment of biological agents.

Some patients with chronic inflammatory diseases either do not respond to or lose their initial responsiveness to Tumor Necrosis Factor (TNF) inhibitor therapy. In these patients, the clinical response after switching to another anti-TNF drug suggests that lack of response is not related to the therapeutic target itself but immunogenicity. All biologics are potentially immunogenic and can induce the development of antidrug antibodies (ADAs). ADA formation is associated with lower serum drug levels, infusion reactions, and loss of response. Analytical methods for ADA detection include enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), surface plasmon resonance, and electrochemiluminescence. Currently, RIA and ELISA are the preferred methods due to a combination of reproducibility, sensitivity, and cost but have some limitations. There is no single available assay that has all pros and no cons, and therefore the use of more methods for the assessment of samples is a high priority.