FIGURE 1.

Personalized treatment strategy at anti-TNF treatment failure. Algorithm based on measurements of anti-TNF drug levels and antidrug antibodies (Abs) for identification of underlying mechanisms for anti-TNF treatment failure with, for example, infliximab (IFX) and corresponding interventions. Initially devised by our group,³ and later tested in clinical trials and observational studies.^4,5,7–10 Adapted from the studies by Bendtzen et al³ and Steenholdt et al.⁷ Reproduced and modified with permission from BMJ Publishing Group Ltd from the study by Steenholdt et al. TNF = tumor necrosis factor.