Personalized medicine: theranostics (therapeutics diagnostics) essential for rational use of tumor necrosis factor-alpha antagonists.

With the discovery of the central pathogenic role of tumor necrosis factor (TNF)-alpha in many immunoinflammatory diseases, specific inhibition of this pleiotropic cytokine has revolutionized the treatment of patients with several non-infectious inflammatory disorders. As a result, genetically engineered anti-TNF-alpha antibody constructs now constitute one of the heaviest medicinal expenditures in many countries. All currently used TNF antagonists may dramatically lower disease activity and, in some patients, induce remission. Unfortunately, however, not all patients respond favorably, and safety can be severely impaired by immunogenicity, i.e., the ability of a drug to induce anti-drug antibodies (ADA). Assessment of ADA is therefore an important component of the evaluation of drug safety in both pre-clinical and clinical studies and in the process of developing less immunogenic and safer biopharmaceuticals. Therapeutics diagnostics, also called theranostics, i.e., monitoring functional drug levels and neutralizing ADA in the circulation, is central to more effective use of biopharmaceuticals. Hence, testing-based strategies rather than empirical dose-escalation may provide more cost-effective use of TNF antagonists as this allows therapies tailored according to individual requirements rather than the current universal approach to diagnosis. The objective of the present review is to discuss the reasons for recommending theranostics to implement an individualized use of TNF antagonists and to highlight some of the methodological obstacles that have obscured cost-effective ways of using these therapies.